Статті в журналах з теми "Vapor Mediated Interactions"

Water is ubiquitous in the environment and is present to varying degrees even within dry powder products and most ingredients. Water migration between the environment and a solid, or between different components of a product, may lead to detrimental physical and chemical changes. In efforts to optimize the quality of dry products, as well as the efficiency of production practices, it is crucial to understand the cause–effect relationships of water interactions with different solids. Therefore, this review addresses the basis of moisture migration in dry products, and the modes of water vapor interactions with crystalline and amorphous solids (e.g., adsorption, capillary condensation, deliquescence, crystal hydrate formation, absorption into amorphous solids) and related moisture-induced phase and state changes, and provides examples of how these moisture-induced changes affect the quality of the dry products.

Abstract Two decades of high-resolution satellite observations and climate modeling studies have indicated strong ocean–atmosphere coupled feedback mediated by ocean mesoscale processes, including semipermanent and meandrous SST fronts, mesoscale eddies, and filaments. The air–sea exchanges in latent heat, sensible heat, momentum, and carbon dioxide associated with this so-called mesoscale air–sea interaction are robust near the major western boundary currents, Southern Ocean fronts, and equatorial and coastal upwelling zones, but they are also ubiquitous over the global oceans wherever ocean mesoscale processes are active. Current theories, informed by rapidly advancing observational and modeling capabilities, have established the importance of mesoscale and frontal-scale air–sea interaction processes for understanding large-scale ocean circulation, biogeochemistry, and weather and climate variability. However, numerous challenges remain to accurately diagnose, observe, and simulate mesoscale air–sea interaction to quantify its impacts on large-scale processes. This article provides a comprehensive review of key aspects pertinent to mesoscale air–sea interaction, synthesizes current understanding with remaining gaps and uncertainties, and provides recommendations on theoretical, observational, and modeling strategies for future air–sea interaction research. Significance Statement Recent high-resolution satellite observations and climate models have shown a significant impact of coupled ocean–atmosphere interactions mediated by small-scale (mesoscale) ocean processes, including ocean eddies and fronts, on Earth’s climate. Ocean mesoscale-induced spatial temperature and current variability modulate the air–sea exchanges in heat, momentum, and mass (e.g., gases such as water vapor and carbon dioxide), altering coupled boundary layer processes. Studies suggest that skillful simulations and predictions of ocean circulation, biogeochemistry, and weather events and climate variability depend on accurate representation of the eddy-mediated air–sea interaction. However, numerous challenges remain in accurately diagnosing, observing, and simulating mesoscale air–sea interaction to quantify its large-scale impacts. This article synthesizes the latest understanding of mesoscale air–sea interaction, identifies remaining gaps and uncertainties, and provides recommendations on strategies for future ocean–weather–climate research.

Plasmons associated with zero-dimensional (0D) metal nanoparticles and their synergistic interactions with excitons in two-dimensional (2D) semiconductors offer opportunities for remarkable spectral tunability not otherwise evident in the pristine parent materials. As a result, an in-depth study elucidating the nature of the plasmonic and excitonic interactions, jointly referred to as plexcitons, is critical to understanding the foundational aspects of the light–matter interactions in hybrid 0D–2D systems. In this work, our focal point is to examine the plexcitonic interactions of van der Waals (vdWs) hybrid structures composed of 2D WSe2 and 0D Au nanoparticles (Au-NPs) in their spherical (Au-Sp) and bi-pyramidical (Au-BP) architectures. The geometry-dependent surface plasmon resonance (SPR) peaks in Au-Sp and Au-BP nanoparticles were deciphered using ultraviolet-visible (UV-Vis) optical absorption spectroscopy, while photoluminescence spectroscopy revealed the excitonic behavior in the vapor synthesized monolayer (1L) WSe2 as well as the Au-Sp/WSe2 and Au-BP/WSe2 hybrids. Furthermore, our temperature-dependent and wavelength-dependent optoelectronic transport measurements showed a shift in the spectral response of 1L WSe2 toward the SPR peak locations of Au-Sp and Au-BP, mediated via the plexciton interactions. Models for the plexcitonic interactions are proposed, which provide a framework to explain the photoexcited hot charge carrier injection from AuNPs to WSe2 and their influence on carrier dynamics. Our findings demonstrate that geometry-mediated response of the AuNPs provides another degree of freedom to modulate the carrier photodynamics in WSe2, which can also be useful for tailoring the optoelectronic performance of the broader class of semiconducting 2D materials.

Tobacco is the primary etiologic agent in worsened lung squamous cell carcinoma (LUSC) outcomes. Meanwhile, it has been shown that etiologic agents alter enhancer RNAs (eRNAs) expression. Therefore, we aimed to identify the effects of tobacco and electronic cigarette (e-cigarette) use on eRNA expression in relation to LUSC outcomes. We extracted eRNA counts from RNA-sequencing data of tumor/adjacent normal tissue and before/after e-cigarette tissue from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO), respectively. Tobacco-mediated LUSC eRNAs were correlated to patient survival, clinical variables, and immune-associated elements. eRNA expression was also correlated to mutation rates through the Repeated Evaluation of Variables Conditional Entropy and Redundance (REVEALER) algorithm and methylated sites through methylationArrayAnalysis. Differential expression analysis was then completed for the e-cigarette data to compare with key tobacco-mediated eRNAs. We identified 684 downregulated eRNAs and 819 upregulated eRNAs associated with tobacco-mediated LUSC, specifically, with the cancer pathological stage. We also observed a decrease in immune cell abundance in tobacco-mediated LUSC. Yet, we found an increased association of eRNA expression with immune cell abundance in tobacco-mediated LUSC. We identified 16 key eRNAs with significant correlations to 8 clinical variables, implicating these eRNAs in LUSC malignancy. Furthermore, we observed that these 16 eRNAs were highly associated with chromosomal alterations and reduced CpG site methylation. Finally, we observed large eRNA expression upregulation with e-cigarette use, which corresponded to the upregulation of the 16 key eRNAs. Our findings provide a novel mechanism by which tobacco and e-cigarette smoke influences eRNA interactions to promote LUSC pathogenesis and provide insight regarding disease progression at a molecular level.

A theory for obtaining meniscus forces and profiles for any given liquid-mediated interface is presented that includes the effects of surface interactions, adsorption and evaporation of liquid films. The meniscus force is obtained from the derivative of the total free energy of liquid-mediated interface, which requires the meniscus profile to be known. The meniscus profile is the solution of a second-order differential equation, as derived from Pascal’s law for static incompressible liquids with inclusion of surface interactions. For nonvolatile liquid films, the total liquid amount at the interface is a conserved quantity, whereas for volatile liquids, the liquid films are in thermodynamic equilibrium with their respective vapor phase. Two typical types of initial liquid conditions are considered. Type I represents the case in which one surface is wet and the other is initially dry, having a finite contact angle with the liquid. Type II represents the situation in which both surfaces are wet by either a liquid or by two different liquids before making contact. If two or more types of liquids are involved at the interface, miscibility of the liquids and interactions due to other liquid(s) have to be also considered. For contacts with azimuthal geometry, which is merely a mathematical convenience, such as ellipsoidal/spherical, conical or crater, the theory generates several analytical formulae for calculating meniscus forces without involving meniscus profiles. These formulae can be handily applied to various surface probes techniques such as Scanning Probe Microscopy or Surface Force Apparatus. The proposed theory is also applicable to “meniscus rings” formed around crater geometry, such as encountered in laser-textured magnetic disks. In this case, the outer meniscus ring can be asymmetric to the inner meniscus ring if no liquid passage exists between the inner and outer meniscus ring. Even for the case of spherical contact geometry, the calculated meniscus profile is very nonspherical with a much larger volume than that of the widely assumed spherical meniscus profile for Type I conditions, leading to an under-estimation of the meniscus force in the previous models. It is found that for a spherical or a crater contact geometry, the surface interactions have little effect on the meniscus force provided the lateral meniscus dimension is much smaller than the radius of the sphere or of the crater. However the surface interactions have a large effect on the meniscus force for other contact geometries, such as conical contact geometry. The calculated meniscus forces are compared with the normal component of the stiction force measured at the laser textured surfaces and good agreement is found. The calculated meniscus profiles are also found in good agreement with that measured using light interferometer technique between two cross cylinders. One very interesting finding of our theory is that the meniscus volume grows first and may then shrink, as observed experimentally by others, because the initially dry surface become wetted and the boundary conditions change over from Type I to Type II.

Abstract. Heterogeneous ice nucleation initiated by particles immersed within droplets is likely the main pathway of ice formation in the atmosphere. Theoretical models commonly used to describe this process assume that it mimics ice formation from the vapor, neglecting interactions unique to the liquid phase. This work introduces a new approach that accounts for such interactions by linking the ability of particles to promote ice formation to the modification of the properties of water near the particle–liquid interface. It is shown that the same mechanism that lowers the thermodynamic barrier for ice nucleation also tends to decrease the mobility of water molecules, hence the ice–liquid interfacial flux. Heterogeneous ice nucleation in the liquid phase is thus determined by the competition between thermodynamic and kinetic constraints to the formation and propagation of ice. At the limit, ice nucleation may be mediated by kinetic factors instead of the nucleation work. This new ice nucleation regime is termed spinodal ice nucleation. The comparison of predicted nucleation rates against published data suggests that some materials of atmospheric relevance may nucleate ice in this regime.

Toward macroscopic applications of graphene, it is desirable to preserve the superior properties of single-layer graphene in bulk scale. However, the AB-stacking structure is thermodynamically favored for multilayer graphene and causes strong interlayer interactions, resulting in property degradation. A promising approach to prevent the strong interlayer interaction is the staking order reduction of graphene, where the graphene layers are rotated in-plane to form a randomly stacking structure. In this study, we propose a strategy to effectively decrease the stacking order of multilayer graphene by incorporating nanospacers, cellulose nanofibers, or nano-diamonds (NDs) in the formation process of porous graphene sponges. We conducted an ultrahigh temperature treatment at 1500 °C with ethanol vapor for the reduction and structural repair of graphene oxide sponges with different concentrations of the nanospacers. Raman spectroscopy indicated an obvious increase in the random-stacking fraction of graphene by adding the nanospacers. The x-ray diffraction (XRD) analysis revealed that a small amount of the nanospacers induced a remarkable decrease in ordered graphene crystalline size in the stacking direction. It was also confirmed that a layer-number increase during the thermal treatment was suppressed by the nanospacers. The increase in the random-stacking fraction is attributed to the efficient formation of randomly rotated graphene through the ethanol-mediated structural restoration of relatively thin layers induced by the nanospacers. This stacking-order-reduced graphene with bulk scale is expected to be used in macroscopic applications, such as electrode materials and wearable devices.

Galactic cosmic rays are considered as one of the external force influencing the Earth’s climate change. The cosmic rays are the main cause of the troposphere ionization. Ions are considered as one of the factors that participates in producing of the aerosol particles and cloud condensation nuclei, when the super saturation level of the water vapor or/and other atmosphere constituents vapor is sufficient. Aerosols are present throughout the atmosphere and affect Earth’s climate directly through backscattering of sunlight and indirectly by altering cloud properties. Both effects are known with considerable uncertainty only, and translate into even bigger uncertainties in future climate predictions. Whereas disputable, the idea is discussed by the scientists that variations in galactic cosmic rays closely correlate with variations in atmospheric cloud cover and therefore constitute a driving force behind aerosol-cloud-climate interactions. A lot of studies were performed to validate or disprove the connection between cosmic ray’s variation (e.g. the Forbush events) and changes of the aerosol content and properties in the atmosphere, cloud cover and properties and other climate parameters, but results are controversial. The enhancement of atmospheric aerosol particle formation by ions generated from cosmic rays was proposed as a physical mechanism explaining this correlation. But the main problem is to find the appropriate physical model which allows to calculate correctly the ion concentrations, nucleation and aerosol particles rate and cosmic rays intensity. Aerosol particle formation occurs in two stages: nucleation to form a critical nucleus and subsequent growth of the critical nucleus to a larger size (>2 – 3 nm) that competes with removal of the freshly nucleated nanoparticles by coagulation with pre-existing aerosols. The most used nucleation and particle growth theories are reviewed and analyzed in the article. The base of the theories is follow. Nucleation is generally defined as creation of molecular embryos or clusters prior to formation of a new phase during the transformation of vapor liquid solid. This process is characterized by a decrease in both enthalpy and entropy of the nucleating system. A free energy barrier is often involved and needs to be surmounted before transformation to the new phase becomes spontaneous. Another limitation in the nucleation and growth of atmospheric nanoparticles lies in significantly elevated equilibrium vapor pressures above small clusters and nanoparticles, also known as the Kelvin (curvature) effect, which considerably restricts growth of freshly nucleated nanoparticles. Ions are capable, under certain conditions, of suppressing or even removing the barrier to nucleation in embryonic molecular clusters of water. But results of the theories are very uncertain so far. Results of the observations of the nucleation and particles formation as well as the special CLOUD experiment results are reviewed and analyzed in the article. The molecular clusters and nuclei can not be observed by remote sensing techniques like sun-photometers, lidars or satellite instruments. The in-situ measurements of the nucleation concentration and particles growth rate are performed in the certain sites only. The observations and experiments revealed the important influence of the trace gases and organic molecules on the nucleation and particle growth rate. Sulphuric acid, ammonia, amines, and oxidised organics play a crucial role in nanoparticle formation in the atmosphere competing with ionmediated mechanism. Saturation pressure of the sulphuric acid and organics vapors at the typical atmospheric conditions is much lower than for water vapor and at typical atmospheric concentration they are capable of suppressing the nucleation barrier. Nucleation with ions started earlier and run faster but the nucleus with sizes ≥ 3 nm more than 90 % of clusters are neutral. Ion-mediated mechanism can dominate when sulphuric asid and organic molecules concentration is low. But more observations in the different atmosphere layers and locations and experiments at different conditions is required to better understanding the ion-mediated nucleation in the atmosphere. Nucleation contribution to the aerosol content and properties in the terrestrial atmosphere is also simulated by the special modules included to the regional and global models of the atmosphere and climate, e.g. GEOS-Chem and CAM5. Comparison of the simulation and observations has showed that in general the averaged model results are in good agreement with observational data at some sites but same biases were revealed at some sites too. It requires the further analysis and models developments. Also ion-mediated mechanism contribution was also estimated by the simulation not more than 10%. Analysis of the observations and models results in the article showed that cosmic rays influencing the aerosol formation also influence the microphysical and optical properties of the particles. First of all particles size distribution is influenced by nucleation mechanism and relative content of the Aitken nuclei increases. Also sulphuric acid can influence the particle refractive index increasing the single-scattering albedo of the aerosols. Modern remote sense technique such as the AERONET sun-photometers can measure the spectral AOD and sky radiance with high accuracy and the reliable size distribution, refractive index and single-scattering albedo averaged over atmosphere column can be determined from that observations, but the AERONET inversion algorithm has to be developed to obtain the particles size finer than 50 nm.

To design a new system of novel TEMPO-oxidized cellulose nanofibrils (TOCNs)/graphene oxide (GO) composite, 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation was utilized. For the better dispersion of GO into the matrix of nanofibrillated cellulose (NFC), a unique process combining high-intensity homogenization and ultrasonication was adopted with varying degrees of oxidation and GO percent loadings (0.4 to 2.0 wt%). Despite the presence of carboxylate groups and GO, the X-ray diffraction test showed that the crystallinity of the bio-nanocomposite was not altered. In contrast, scanning electron microscopy showed a significant morphological difference in their layers. The thermal stability of the TOCN/GO composite shifted to a lower temperature upon oxidation, and dynamic mechanical analysis signified strong intermolecular interactions with the improvement in Young’s storage modulus and tensile strength. Fourier transform infrared spectroscopy was employed to observe the hydrogen bonds between GO and the cellulosic polymer matrix. The oxygen permeability of the TOCN/GO composite decreased, while the water vapor permeability was not significantly affected by the reinforcement with GO. Still, oxidation enhanced the barrier properties. Ultimately, the newly fabricated TOCN/GO composite through high-intensity homogenization and ultrasonification can be utilized in a wide range of life science applications, such as the biomaterial, food, packaging, and medical industries.

Abstract. It has been shown that volcanic ash fertilizes the Fe-limited areas of the surface ocean through releasing soluble iron. As ash iron is mostly insoluble upon the eruption, it is hypothesized that heterogeneous in-plume and in-cloud processing of the ash promote the iron solubilization. Direct evidences concerning such processes are, however, lacking. In this study, a 1-D numerical model is developed to simulate the physicochemical interactions of gas–ash–aerosol in volcanic eruption plumes focusing on the iron mobilization processes at temperatures between 600 and 0 °C. Results show that sulfuric acid and water vapor condense at ~150 and ~50 °C on the ash surface, respectively. This liquid phase then efficiently scavenges the surrounding gases (>95% of HCl, 3–20% of SO2 and 12–62% of HF) forming an extremely acidic coating at the ash surface. The low pH conditions of the aqueous film promote acid-mediated dissolution of the Fe-bearing phases present in the ash material. We estimate that 0.1 to 33% of the total iron available at the ash surface is dissolved in the aqueous phase before the freezing point is reached. The efficiency of dissolution is controlled by the halogen content of the erupted gas as well as the mineralogy of the iron at ash surface: elevated halogen concentrations and presence of Fe2+-carrying phases lead to the highest dissolution efficiency. Findings of this study are in agreement with the data obtained through leaching experiments.

Abstract. It has been shown that volcanic ash fertilizes the Fe-limited areas of the surface ocean through releasing soluble iron. As ash iron is mostly insoluble upon the eruption, it is hypothesized that heterogeneous in-plume and in-cloud processing of the ash promote the iron solubilization. Direct evidences concerning such processes are, however, lacking. In this study, a 1-D numerical model is developed to simulate the physicochemical interactions of the gas–ash–aerosol in volcanic eruption plumes focusing on the iron mobilization processes at temperatures between 600 and 0 °C. Results show that sulfuric acid and water vapor condense at ~ 150 and ~ 50 °C on the ash surface, respectively. This liquid phase then efficiently scavenges the surrounding gases (> 95 % of HCl, 3–20 % of SO2 and 12–62 % of HF) forming an extremely acidic coating at the ash surface. The low pH conditions of the aqueous film promote acid-mediated dissolution of the Fe-bearing phases present in the ash material. We estimate that 0.1–33 % of the total iron available at the ash surface is dissolved in the aqueous phase before the freezing point is reached. The efficiency of dissolution is controlled by the halogen content of the erupted gas as well as the mineralogy of the iron at ash surface: elevated halogen concentrations and presence of Fe2+-carrying phases lead to the highest dissolution efficiency. Findings of this study are in agreement with the data obtained through leaching experiments.

The effects and interactions of water stress and nutrient solution on water relations and concentrations of amino acids, organic acids and sugars in xylem fluid of `Methley' plum (Prunus salicina Lindl.) and `Carolina Beauty' crape myrtle (Lagerstroemia indica L.) during midday were determined. Container-grown plants were irrigated with water or nutrient solution (i.e., osmolarity = 138 mm) for 15 days, then irrigation was either continued or terminated for the next 5 days. The experiments were analyzed as factorial designs for each species separately, with the nutrient solution and irrigation status the last 5 days as the main factors. Xylem fluid tension increased ≈ 2- to 3-fold and leaf conductance to water vapor and transpiration were reduced ≈ 10-fold by withholding irrigation for both species; plant water relations of L. indica were also influenced by the nutrient solution. For both species, the osmolarity of xylem fluid was not altered by withholding irrigation. The predominant organic compounds quantified in both species were amides (i.e., glutamine and asparagine), arginine, and citric and malic acids. Sugars represented a small proportion (i.e., generally ≤ 1%) of total osmolarity. Irrigation altered the chemical profile of amino acids and organic acids to a greater degree than the nutrient solution. Water stress induced a 3-fold increase in total organic acids in xylem fluid of both species. The osmolarity and the concentration of most organic compounds in xylem fluid of P. salicina were not significantly affected by the nutrient solution. Arginine increased markedly in concentration by withholding irrigation or with the application of nutrient solution for L. indica. The concentration of most organic compounds did not vary greatly in response to variations in soil water or nutrient status. In conclusion, soil water-or nutrient-mediated changes in plant water relations exceeded changes in xylem fluid chemistry.

Single crystal of furazolidone (FZL) has been successfully obtained, and its crystal structure has been determined. Common and distinctive features of furazolidone and nitrofurantoin (NFT) crystal packing have been discussed. Combined use of QTAIMC and Hirshfeld surface analysis allowed characterizing the non-covalent interactions in both crystals. Thermophysical characteristics and decomposition of NFT and FZL have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and mass-spectrometry. The saturated vapor pressures of the compounds have been measured using the transpiration method, and the standard thermodynamic functions of sublimation were calculated. It was revealed that the sublimation enthalpy and Gibbs energy of NFT are both higher than those for FZL, but a gain in the crystal lattice energy of NFT is leveled by an entropy increase. The solubility processes of the studied compounds in buffer solutions with pH 2.0, 7.4 and in 1-octanol was investigated at four temperatures from 298.15 to 313.15 K by the saturation shake-flask method. The thermodynamic functions of the dissolution and solvation processes of the studied compounds have been calculated based on the experimental data. Due to the fact that NFT is unstable in buffer solutions and undergoes a solution-mediated transformation from an anhydrate form to monohydrate in the solid state, the thermophysical characteristics and dissolution thermodynamics of the monohydrate were also investigated. It was demonstrated that a combination of experimental and theoretical methods allows performing an in-depth study of the relationships between the molecular and crystal structure and pharmaceutically relevant properties of nitrofuran antibiotics.

We report on the study of the interband pairing interaction in the two-band superconductor MgB2 by tunneling spectroscopy using thin film tunnel junctions. The films were deposited in situ by an approach comprising a conventional planar B sputter gun and a special homemade Mg evaporator providing a high vapor pressure. For the tunneling experiments sandwich-type crossed-strip tunnel junctions with a native MgB2 oxide as the potential barrier and Al, In or Pb counterelectrodes were prepared. Voltage-dependent differential conductance measurements revealed estimates of the barrier thickness and height of 1.5 nm and 1.6 eV, respectively, and allowed us to determine the phonon-induced structures in the tunneling density of states of the phonon-mediated superconductor MgB2. The analysis of the reduced density of states using the standard single-band Eliashberg equations yielded an effective electron-phonon spectral function accounting for the smaller energy gap. A further analysis involving ab-initio LDA calculations and the two-band Eliashberg equations revealed that the dominant feature in the effective spectral function, a strong peak at 58 meV, was mainly due to the interband pairing interaction.

In this study, lychee (Litchi chinensis Sonn.) pericarp powder was added to chitosan (CHS) matrix to develop active packaging films, and their structure, physicochemical, antibacterial, antioxidant, and functional properties were investigated. FT-IR results showed that intermolecular hydrogen bonds were formed between CHS and polyphenols in lychee pericarp powder (LPP), and the intermolecular interaction interfered with the assembly of CHS into semi-crystal structure, which reduced the crystallinity of CHS film. Incorporation of LPP significantly reduced water vapor permeability, water solubility, swelling degree, and elongation at break of CHS film (p < 0.05). However, UV-visible light barrier, tensile strength, and antibacterial and antioxidant properties of CHS films were increased by LPP incorporation. CHS-LPP film remarkably lowered the weight loss, firmness, titratable acidity, and total soluble solids of fresh-cut apple after five days storage. CHS-LPP film packaging effectively inhibited the browning of fresh-cut apple and the reduction of polyphenol content in apple juice caused by polyphenol oxidase (PPO)-mediated oxidation during storage. Therefore, CHS-LPP films have great potential as food packaging material to ensure the quality and extend the shelf life of food products.

Abstract Urokinase-type plasminogen activator (uPA) and its cellular receptor (uPAR) mediate plasminogen activation. The uPA binds to uPAR with high affinity (Kd 0.1–1nM), thus localizing the generation of plasmin from plasminogen on the surface of a variety of cells. uPA-uPAR binding is also involved in other cellular functions and diverse pathophysiological processes such as tissue remodeling during wound healing, atherosclerosis, angiogenesis and tumor metastasis. We have determined the structure of uPAR complexed with the amino terminal fragment (amino acid residues 1–143) of uPA (ATF), which contains the uPAR binding domain, at 1.9 Å resolution by X-ray crystallography. Soluble uPAR (suPAR) and the ATF were expressed separately in stably transfected Drosophila Schneider 2 (S2) cells. The suPAR-ATF complex was crystallized by the sitting-drop vapor diffusion method. However, the diffraction of this crystal was limited to 3.1 Å resolution. Therefore, the Fab fragment of an antibody raised against suPAR, ATN-615, was used to facilitate suPAR-ATF crystallization. Crystals of the suPAR-ATF-ATN615 ternary complex were generated by microdialysis with 4% PEG4K, 5% ethylene glycol, 5% methanol, 0.05% sodium azide, 50 mM cacodylate pH 6.5. A complete data set of the ternary complex to 1.9 Å was collected using synchrotron radiation at the Advanced Photon Source (APS), Argonne National Laboratory. The crystals belong to the monoclinic space group, with unit cell parameters a=51.79 Å, b=86.81 Å, c=124.69 Å and β=94.54°. uPAR is comprised of three consecutive domains (D1, D2 and D3) that form the shape of a thick-walled teacup with a diameter of about 52 Å and a height of 27 Å. At the center of teacup and surrounded by three suPAR domains is a cone shape cavity with a wide opening (25 Å) and large depth (14 Å). ATF consists of a growth factor domain (GFD) and a kringle domain. Both domains pack more tightly in the complex structure compared with their unbound state. The GFD domain of uPA occupies part of the uPAR cavity and is primarily responsible for uPAR binding. The D1 domain of uPAR forms three hydrogen bonds and many hydrophobic interactions with the GFD domain of uPA, thus playing an important role in the binding of uPA. However, D2 and D3 of uPAR also have direct interactions with the GFD domain of uPA. The kringle domain of uPA sits outside the uPAR pocket, but forms some direct contacts with the D1 domain of uPAR. Therefore, the three domains of uPAR and two domains of uPA form a complementary interaction, which describes the structural basis for the high affinity binding of uPA to uPAR. This structure presents the first high resolution view of uPA-uPAR interaction, and may provide a new platform to design de novo uPA-uPAR antagonists.

Arabidopsis thalianaBAG5 (AtBAG5) belongs to the plant BAG (Bcl-2-associated athanogene) family that performs diverse functions ranging from growth and development to abiotic stress and senescence. BAG family members can act as nucleotide-exchange factors for heat-shock protein 70 (Hsp70) through binding of their evolutionarily conserved BAG domains to the Hsp70 ATPase domain, and thus may be involved in the regulation of chaperone-mediated protein folding in plants. AtBAG5 is distinguished from other family members by the presence of a unique IQ motif adjacent to the BAG domain; this motif is specific for calmodulin (CaM) binding, indicating a potential role in the plant calcium signalling pathway. To provide a better understanding of the IQ motif-mediated interaction between AtBAG5 and CaM, the two proteins were expressed and purified separately and then co-crystallized together. Diffraction-quality crystals of the complex were grown using the sitting-drop vapour-diffusion technique from a condition consisting of 0.1 MTris–HCl pH 8.5, 2.5 Mammonium sulfate. The crystals belonged to space groupP212121, with unit-cell parametersa= 64.56,b= 74.89,c= 117.09 Å. X-ray diffraction data were recorded to a resolution of 2.5 Å from a single crystal using synchrotron radiation. Assuming the presence of two molecules in the asymmetric unit, a Matthews coefficient of 2.44 Å3 Da−1was calculated, corresponding to a solvent content of approximately 50%.

Abstract Introduction Haematophages, animals evolved to a bloodsucking lifestyle as their exclusive mode of feeding secrete compounds capable of arresting haemostasis in the host. It is clear that exploitation of host haemostasis is an absolute requirement for the survival of these species. Since the discovery and with the subsequent characterisation and engineering of Hirudin a potent thrombin inhibitor from the European medicinal leech Hirudo medicinalis, attention has been focused on the potential anticoagulant and platelet aggregation inhibitors derived from an array of different species of leech from both the Rhynchobdellid and Arhynchobdellid orders. Haematophagous leeches of the genus Theromyzon sp. of the Rhynchobdellid order, also termed duck leeches, feed directly on the nasal passages, trachea and nictating membranes of migratory birds. We present the novel observation of inhibition of aggregation of human platelets by the salivary secretion extracts of the avian leech Theromyzon tessulatum. Methods Twelve adult leeches of the species T. tessulatum (total weight 2.828g) were anaesthetised with ethanol vapour. The leeches were severed at the anterior end and a homogenate produced containing salivary gland secretions. The posterior two thirds of the leeches were treated identically to serve as control material. Platelet rich plasma (PRP) was prepared from blood from a normal individual (free from known platelet modifying medicines) mixed 9:1 (v:v) with 0.105 M trisodium citrate in siliconised glass vacutainers. Platelet numbers were adjusted with autologous platelet poor plasma (PPP) to obtain concentrations of approximately 300 × 109/L. Leech extracts (anterior or posterior control) were added to PRP at a ratio of 1:4. Aggregation studies were performed using thrombin (10units/ml), collagen 10μg/ml, Ristocetin (1.5mg/ml) and ADP (5μm/ml). Results Data from this study shows that platelet aggregation was completely inhibited when stimulated by thrombin, collagen and ADP and partially inhibited (40%) on the addition of ristocetin. Conclusion Our observations contradict the belief that the anti-thrombocyte properties of this species of haematophagous leech are restricted to duck thrombocytes. We suggest the presence of one or more inhibitory molecules acting by various mechanisms including inhibition of vWF and platelet integrin mediated collagen interactions, inhibition of ristocetin mediated vWF and platelet GPIb receptor binding and salivary secretion derived apyrase inhibition of arachidonic acid mediated platelet aggregation. These findings provide conclusive evidence that this blood sucking bird leech has the ability to overcome thrombocyte function in higher vertebrates.

The sp2 carbon-based allotropes have been extensively exploited for the realization of gas sensors in the recent years because of their high conductivity and large specific surface area. A study on graphene that was synthetized by means of a novel transfer-free fabrication approach and is employed as sensing material is herein presented. Multilayer graphene was deposited by chemical vapour deposition (CVD) mediated by CMOS-compatible Mo. The utilized technique takes advantage of the absence of damage or contamination of the synthesized graphene, because there is no need for the transfer onto a substrate. Moreover, a proper pre-patterning of the Mo catalyst allows one to obtain graphene films with different shapes and dimensions. The sensing properties of the material have been investigated by exposing the devices to NO2, NH3 and CO, which have been selected because they are well-known hazardous substances. The concentration ranges have been chosen according to the conventional monitoring of these gases. The measurements have been carried out in humid N2 environment, setting the flow rate at 500 sccm, the temperature at 25 °C and the relative humidity (RH) at 50%. An increase of the conductance response has been recorded upon exposure towards NO2, whereas a decrease of the signal has been detected towards NH3. The material appears totally insensitive towards CO. Finally, the sensing selectivity has been proven by evaluating and comparing the degree of adsorption and the interaction energies for NO2 and NH3 on graphene. The direct-growth approach for the synthesis of graphene opens a promising path towards diverse applicative scenarios, including the straightforward integration in electronic devices.

Increasing costs of housing and processes of gentrification are excluding poorer people from convenient areas of cities where they have traditionally lived. This paper responds to the loss of diversity being experienced in part of inner western of Sydney which has been a first home for successive waves of immigrants. It considers claims to various rights and forms of capital as a possible foundation of resistance to gentrification and the commodification of housing, and for their potential to promote egalitarian participation in urban life more generally. It asks whether there is any sense in which residents of a neighbourhood can assert a right to place. In conclusion, the interaction between rights and forms of capital is seen to be mediated by exchange and contestation. These concepts will be used to examine some of the social, political and economic means for promoting claims to cultural rights and the primacy of housing’s use value. Los costes crecientes de la vivienda y los procesos de gentrificación están excluyendo a personas más pobres de vecindarios cómodos donde siempre habían residido. Este artículo responde a la pérdida de la diversidad que se ha experimentado en la parte occidental interior de Sydney, que ha sido una primera residencia para varias generaciones de inmigrantes. Se toman en consideración reclamaciones de derechos y formas de capital como posible base de la resistencia a la gentrificación y la mercantilización de la vivienda, y para su potencial para promover una participación generalizada más igualitaria; además, plantea si hay algún sentido en las proclamaciones de un derecho territorial. La conclusión es que la interacción entre derechos y formas de capital está mediatizada por el intercambio y la contestación. Estos conceptos se utilizarán para examinar algunas de las formas sociales, políticas y económicas para promover reclamaciones de derechos culturales y la primacía del valor de uso de la vivienda.

This article focuses on the analysis of strategies and tactics variation within the modern network communication, which is a result of the dynamic implementation of a new “crisis-based” concept & valor space under the stimulus-reactive process of contrastive features explication in different types of discourse practices in a single consituative interpretation. Such indirect interaction, while complicated by a “dead” public space features a wide variety of encoding types and methods based on non-converging codes. The author employs critical discourse analysis to investigate the specific and most effective tactics that can be used to manipulate the collective mind of the topically and situational labeled pandemic discourse, and which implement a special type of understanding and description of respective phenomena in relation to various texts determined by the pandemic-bound reality. The focus is on complex, hierarchically arranged cognitive-cultural structures of generalized strategies, which are saccadic selected in various code systems (verbal, visual, auditory, symbolic, etc.). The primary tactics used within the strategy of creating psychological tension include “severe prognostics” and “illustration”, within the irony strategy the most effective in terms of shaping a new axiological space are the tactics of increasing voluntative potential: explication of expectations, game forms and oneiric perception. Thus, a kind of universal model of dominant strategies in crisis network communication is being built. Despite the contrastive basis of imprinting when employing these dominant strategies, the tactics that fill them will mix constantly and complement one another, which can be explained by the polydiscourse and polycode specifics of filling the “dead” communication space with mediated variable coding. This study offers a view at the first attempt at strategic modelling of complicated discourse practices not as a special way to contaminate ideological and worldview components, which was to be observed in some works, yet as an instrumental space for shaping these components based on the code convergence as well as communication registers, i.e. shaping a global axiosphere as an unequal sum of perception of criteria pertaining to the objective reality.

Temperate rainforests and eucalypt forests of coastal south-eastern Australia are distributed differentially with aspect. Rainforests, in which Ceratopetalum apetalum D.Don and Doryphora sassafras Endl. are the dominant tree species, occur on slopes of southerly aspect and along gully bottoms, whereas eucalypt forests, dominated by Eucalyptus maculata Hook., occur on upper slopes of northerly aspect and on ridge tops. Whether transpiration rates of trees differed across the rainforest-eucalypt forest boundary on north and south facing aspects was tested by measuring stem sap flow in trees in a single catchment during winter, summer and autumn. Differences in transpiration rate by trees in these stands were due to various combinations of biological and physical factors. Firstly, mean maximum transpiration rate per tree (crown area basis) was greater in rainforest on the gully bottom where deep soil water from down-slope drainage was greater than in eucalypt forest located upslope on the northern aspect. By contrast, there was no difference between maximum transpiration rates in rainforest and eucalypt forest on the southern aspect. Variation in transpiration rate between seasons was not related to variation in surface soil moisture content (< 0.35 m depth). Secondly, transpiration rates per unit crown area in rainforest at the gully bottom were associated with higher leaf area indices than upslope on the northern aspect. However, in rainforest upslope on the southern aspect, higher transpiration rates were not associated with higher leaf area indices. Thirdly, trees in eucalypt forest maintained similar sapwood moisture contents in summer as in winter and autumn, whereas sapwood moisture contents declined in rainforest trees in summer, suggesting that eucalypts had access to water from deep within the soil profile which was unavailable to more shallow rooting rainforest trees. Fourthly, higher modal and maximal sap velocities in eucalypt trees were partly due to wider xylem vessels and resulted in faster maximum sap flow and greater daily total water use in all seasons on both aspects than in rainforest species. Finally, as atmospheric demand for water increased from winter to summer, transpiration rates were mediated by stomata1 closure as indicated by lower average midday shoot conductance to water vapour during summer than other seasons. The interaction between microenvironment, which deteimines water availability, and physiological attsibutes, which determine tree water acquisition and use, may contribute to the differential distribution of rainforest and eucalypt forest with aspect in south-eastern Australia.

Abstract Introduction Skin damage as a result of injury, be it acute or chronic, can adversely impact the quality of life of affected individuals, with serious wounds being life-threatening in certain cases, leading to a high clinical demand for effective wound dressing materials. Effective wound dressings are those which maintain moisture in the wound site, maintaining hemostasis while preventing the development of any infections, thereby allowing air and water to more effectively facilitate epithelization. At present the bioactivity of most wound dressings is relatively poor, with more effective dressings being very costly and difficult to produce, necessitating the development of novel wound healing materials. Recent research has highlighted the potential of electrospun fibrous membranes as a material for use in wound dressing design. Membranes designed using electrospinning technology have desirable features including a pore size that is readily tunable, as well as substantial air permeability and a high surface-to-volume ratio. These membranes also have a 3D structure that is similar to the structure of the extracellular matrix (ECM), which is essential for mediating effective cellular adhesion and proliferation. These advantageous properties make such electrospun fibers potentially ideal for use in wound dressings. Studies have further sought to functionalize these fibers so as to enhance their ability to promote wound healing via imbuing them with growth factors, antibacterial compounds, or other bioactive materials. Current ongoing efforts have to functionalize electrospun fibers offer great potential for efforts to regulate wound healing. Given their safety and relatively low cost, bioactive plant extracts have been the subject of particular interest in the context of wound healing. One such extract is bromelain, which is a crude extract isolated from the pineapple fruit that contains a number of therapeutically valuable proteolytic enzymes. Previous work has shown bromelain to be capable of mediating anti-inflammatory and anti-edematous properties in many contexts including sinusitis, thrombophlebitis, angina pectoris, bronchitis, surgical trauma, and pyelonephritis. Bromelain is also known to be capable of hydrolyzing devitalized tissues so as to enhance rates of wound healing. Efforts to maintain the stability of bromelain are essential for its therapeutic utilization, with previous groups having demonstrated that bromelain can be effectively incorporated into electrospun or other polymer matrices. For example, Bayat et al. were able to use a blending electrospinning process to generate chitosan nanofibers loaded with bromelain, while Korrapati et al. used coaxial electrospinning in order to incorporate bromelain into electrospun fibers. In addition to direct incorporation, bromelain can also be immobilized directly onto the surface of electrospun fibers, allowing for more direct interaction between bromelain and wound tissue. Unfortunately, electrospun fibers tend to interact poorly with enzymes, resulting in relatively poor enzymatic activity and stability. Therefore there is a need to develop better techniques for immobilizing bromelain onto electrospun fibers. Previous studies have highlighted the potential of mussel-inspired polydopamine (PDA), which is produced via oxidatively polymerizing dopamine, as a substrate with the potential for utilization in the development of advanced biomaterials. PDA is readily deposited onto a wide range of surfaces without the need of expensive or complex instruments and procedures in order to achieve this deposition. Importantly, PDA is highly versatile owing to the abundance of available functional groups, allowing it to be developed into a platform well-suited to use in myriad applications. PDA has been shown to ameliorate enzymatic immobilization via both Schiff base reactions and Michael-type addition. However, at present there are no reports regarding the potential for PDA to facilitate bromelain immobilization. In the present report we describe the successful use of PDA to mediate bromelain immobilization on electrospun fibers, with the resultant fibers being effective when used for dressing wounds. The synthetic polymer poly(e-caprolactone) (PCL), which exhibits good biocompatibility, was selected for use as a matrix that was used to generate a fibrous membrane onto which bromelain could be immobilized. The FDA has approved the biomedical use of PCL, and it has previously been shown to exhibit both a high degree of mechanical stability while also remaining biodegradable. In this report, we first immobilized bromelain onto electrospun PCL fibers via use of PDA and then explored the physical and chemical properties of the resultant membranes and of the bromelain deposited thereupon. We additionally assessed the utility of these membranes as mediators of cellular adhesion, cell proliferation, and antibacterial activity in vitro, and as drivers of enhanced wound healing in vivo. Together our findings highlight these bromelain-immobilized electrospun PCL fiber membranes as having great promise for use in wound healing applications. Methods PCL fiber were prepared via electrospinning, then bromelain-immobilized PCL fiber were generated. The surface morphology of fibers was obtained by scanning electron microscopy. Swelling test, water vapor transmission rates (WVTR), in vitro bromelain release and loading, enzyme activity and stability were tested to demonstrate the fiber scaffold characteristic. The prepared composite scaffolds had satisfactory antibacterial activity via Kirby–Bauer (K-B) disc method. The cell studies were performed to reveal that the scaffolds were biocompatible and safe for cell attachment. Histological and immunohistochemical examinations were performed in rats. In Vivo wound healing model were chosen to verify the PCL functionalization using PDA and bromelain can accelerate the wound healing process. Results We found that bromelain activity could be better stabilized when via its immobilization on electrospun fibers. The resultant BrPDA-PCL fibers exhibited promising properties including optimal mechanical stability, wettability, and rates of water vapor transmission. In addition, these BrPDA-PCL fibers were biocompatible, allowing for effective cellular adhesion and proliferation. The results of zone of inhibition testing further confirmed that these fibers achieved effective antibacterial activity against Escherichia coli and Staphylococcus aureus. When used in vivo, as compared with PCL fibers or control animals the BrPDA-PCL fibers enhanced wound healing rates while reducing associated inflammation. Conclusions Herein we found that using PDA to immobilize bromelain onto electrospun PCL fibers resulted in the production of membranes that were highly effective wound dressings. Bromelain activity was markedly stabilized via the immobilization process, and the resultant BrPDA-PCL fibers were capable of supporting both cellular adhesion and proliferation. Given the observed synergy between PDA and bromelain, these BrPDA-PCL fibers also exhibited antibacterial activity. When utilized in a rat model of wound healing, inflammation was reduced and healing rates were improved in rats treated using BrPDA-PCL fibers relative to untreated controls. We therefore propose that future studies further examine the value of bromelain-immobilized electrospun PCL fibers as a means of enhancing epithelial regeneration. Applicability of Research to Practice The electrospun BrPDA-PCL fibers were capable of loading and delivering drugs, and could be potentially used as novel antibacterial burn wound dressings. These scaffolds have promising potential applications in infection control at the early phase of burn injury and accelerate wound healing process.

Agriculture production is directly dependent on climate change and weather. Possible changes in temperature, precipitation and CO2 concentration are expected to significantly impact crop growth and ultimately we lose our crop productivity and indirectly affect the sustainable food availability issue. The overall impact of climate change on worldwide food production is considered to be low to moderate with successful adaptation and adequate irrigation. Climate change has a serious impact on the availability of various resources on the earth especially water, which sustains life on this planet. The global food security situation and outlook remains delicately imbalanced amid surplus food production and the prevalence of hunger, due to the complex interplay of social, economic, and ecological factors that mediate food security outcomes at various human and institutional scales. Weather aberration poses complex challenges in terms of increased variability and risk for food producers and the energy and water sectors. Changes in the biosphere, biodiversity and natural resources are adversely affecting human health and quality of life. Throughout the 21st century, India is projected to experience warming above global level. India will also begin to experience more seasonal variation in temperature with more warming in the winters than summers. Longevity of heat waves across India has extended in recent years with warmer night temperatures and hotter days, and this trend is expected to continue. Strategic research priorities are outlined for a range of sectors that underpin global food security, including: agriculture, ecosystem services from agriculture, climate change, international trade, water management solutions, the water-energy-food security nexus, service delivery to smallholders and women farmers, and better governance models and regional priority setting. There is a need to look beyond agriculture and invest in affordable and suitable farm technologies if the problem of food insecurity is to be addressed in a sustainable manner. Introduction Globally, agriculture is one of the most vulnerable sectors to climate change. This vulnerability is relatively higher in India in view of the large population depending on agriculture and poor coping capabilities of small and marginal farmers. Impacts of climate change pose a serious threat to food security. “Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life” (World Food Summit, 1996). This definition gives rise to four dimensions of food security: availability of food, accessibility (economically and physically), utilization (the way it is used and assimilated by the human body) and stability of these three dimensions. According to the United Nations, in 2015, there are still 836 million people in the world living in extreme poverty (less than USD1.25/day) (UN, 2015). And according to the International Fund for Agricultural Development (IFAD), at least 70 percent of the very poor live in rural areas, most of them depending partly (or completely) on agriculture for their livelihoods. It is estimated that 500 million smallholder farms in the developing world are supporting almost 2 billion people, and in Asia and sub-Saharan Africa these small farms produce about 80 percent of the food consumed. Climate change threatens to reverse the progress made so far in the fight against hunger and malnutrition. As highlighted by the assessment report of the Intergovernmental Panel on Climate change (IPCC), climate change augments and intensifies risks to food security for the most vulnerable countries and populations. Few of the major risks induced by climate change, as identified by IPCC have direct consequences for food security (IPCC, 2007). These are mainly to loss of rural livelihoods and income, loss of marine and coastal ecosystems, livelihoods loss of terrestrial and inland water ecosystems and food insecurity (breakdown of food systems). Rural farmers, whose livelihood depends on the use of natural resources, are likely to bear the brunt of adverse impacts. Most of the crop simulation model runs and experiments under elevated temperature and carbon dioxide indicate that by 2030, a 3-7% decline in the yield of principal cereal crops like rice and wheat is likely in India by adoption of current production technologies. Global warming impacts growth, reproduction and yields of food and horticulture crops, increases crop water requirement, causes more soil erosion, increases thermal stress on animals leading to decreased milk yields and change the distribution and breeding season of fisheries. Fast changing climatic conditions, shrinking land, water and other natural resources with rapid growing population around the globe has put many challenges before us (Mukherjee, 2014). Food is going to be second most challenging issue for mankind in time to come. India will also begin to experience more seasonal variation in temperature with more warming in the winters than summers (Christensen et al., 2007). Climate change is posing a great threat to agriculture and food security in India and it's subcontinent. Water is the most critical agricultural input in India, as 55% of the total cultivated areas do not have irrigation facilities. Currently we are able to secure food supplies under these varying conditions. Under the threat of climate variability, our food grain production system becomes quite comfortable and easily accessible for local people. India's food grain production is estimated to rise 2 per cent in 2020-21 crop years to an all-time high of 303.34 million tonnes on better output of rice, wheat, pulse and coarse cereals amid good monsoon rains last year. In the 2019-20 crop year, the country's food grain output (comprising wheat, rice, pulses and coarse cereals) stood at a record 297.5 million tonnes (MT). Releasing the second advance estimates for 2020-21 crop year, the agriculture ministry said foodgrain production is projected at a record 303.34 MT. As per the data, rice production is pegged at record 120.32 MT as against 118.87 MT in the previous year. Wheat production is estimated to rise to a record 109.24 MT in 2020-21 from 107.86 MT in the previous year, while output of coarse cereals is likely to increase to 49.36 MT from 47.75 MT. Pulses output is seen at 24.42 MT, up from 23.03 MT in 2019-20 crop year. In the non-foodgrain category, the production of oilseeds is estimated at 37.31 MT in 2020-21 as against 33.22 MT in the previous year. Sugarcane production is pegged at 397.66 MT from 370.50 MT in the previous year, while cotton output is expected to be higher at 36.54 million bales (170 kg each) from 36.07. This production figure seem to be sufficient for current population, but we need to improve more and more with vertical farming and advance agronomic and crop improvement tools for future burgeoning population figure under the milieu of climate change issue. Our rural mass and tribal people have very limited resources and they sometime complete depend on forest microhabitat. To order to ensure food and nutritional security for growing population, a new strategy needs to be initiated for growing of crops in changing climatic condition. The country has a large pool of underutilized or underexploited fruit or cereals crops which have enormous potential for contributing to food security, nutrition, health, ecosystem sustainability under the changing climatic conditions, since they require little input, as they have inherent capabilities to withstand biotic and abiotic stress. Apart from the impacts on agronomic conditions of crop productions, climate change also affects the economy, food systems and wellbeing of the consumers (Abbade, 2017). Crop nutritional quality become very challenging, as we noticed that, zinc and iron deficiency is a serious global health problem in humans depending on cereal-diet and is largely prevalent in low-income countries like Sub-Saharan Africa, and South and South-east Asia. We report inefficiency of modern-bred cultivars of rice and wheat to sequester those essential nutrients in grains as the reason for such deficiency and prevalence (Debnath et al., 2021). Keeping in mind the crop yield and nutritional quality become very daunting task to our food security issue and this can overcome with the proper and time bound research in cognizance with the environment. Threat and challenges In recent years, climate change has become a debatable issue worldwide. South Asia will be one of the most adversely affected regions in terms of impacts of climate change on agricultural yield, economic activity and trading policies. Addressing climate change is central for global future food security and poverty alleviation. The approach would need to implement strategies linked with developmental plans to enhance its adaptive capacity in terms of climate resilience and mitigation. Over time, there has been a visible shift in the global climate change initiative towards adaptation. Adaptation can complement mitigation as a cost-effective strategy to reduce climate change risks. The impact of climate change is projected to have different effects across societies and countries. Mitigation and adaptation actions can, if appropriately designed, advance sustainable development and equity both within and across countries and between generations. One approach to balancing the attention on adaptation and mitigation strategies is to compare the costs and benefits of both the strategies. The most imminent change is the increase in the atmospheric temperatures due to increase levels of GHGs (Green House Gases) i.e. carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and chlorofluorocarbons (CFCs) etc into the atmosphere. The global mean annual temperatures at the end of the 20th century were almost 0.7 degree centigrade above than those recorded at the end of the 19th century and likely to increase further by 1.8- 6.4ºC by 2100 AD. The quantity of rainfall and its distribution will be affected to a great extent resulting in more flooding. The changes in soil properties such as loss of organic matter, leaching of soil nutrients, salinization and erosion are a likely outcome of climate change in many cases. Water crisis can be a serious problem with the anticipated global warming and climate change. With increasing exploitation of natural resources and environmental pollution, the atmospheric temperature is expected to rise by 3-5 0C in next 75-100 years (www.ipcc.ch/sr15/chapter/chapter-1). If it happens most of the rivers originating from the Himalayas may dry up and cause severe shortage of water for irrigation, suppressing agriculture production by 40-50%. There has been considerable concern in recent years about climatic changes caused by human activities and their effects on agriculture. Surface climate is always changing, but at the beginning of industrial revolution these changes have been more noticeable due to interference of human beings activity. Studies of climate change impacts on agriculture initially focused on increasing temperature. Many researchers, including reported that changes in temperature, radiation and precipitation need to be studied in order to evaluate the impact of climate change. Temperature changes can affect crop productivity. Higher temperatures may increase plant carboxilation and stimulate higher photosynthesis, respiration, and transpiration rates. Meanwhile, flowering may also be partially triggered by higher temperatures, while low temperatures may reduce energy use and increased sugar storage. Changes in temperature can also affect air vapor pressure deficits, thus impacting the water use in agricultural landscapes. This coupling affects transpiration and can cause significant shifts in temperature and water loss (Mukherjee, 2017). In chickpea and other pulse crop this increase in temperature due to climate change affects to a greater extent flower numbers, pod production, pollen viability, and pistilfunction are reduced and flower and pod abortion increased under terminal heat stress which ultimately leads to hamper its productivity on large scale. There is probability of 10-40% loss in crop production in India with the expected temperature increase by 2080-2100. Rice yields in northern India during last three decades are showing a decreasing trend (Aggarwal et al., 2000). Further, the IPCC (2007) report also projected that cereal yields in seasonally dry and tropical regions like India are likely to decrease for even small local temperature increases. wheat production will be reduced by 4-5 million tonnes with the rise of every 10C temperature throughout the growing period that coincides in India with 2020-30. However, grain yield of rice declined by 10% for each 1ºC increase in growing season. A 1ºC increase in temperature may reduce rapeseed mustard yield by 3-7%. Thus a productivity of 2050-2562 kg/ha for rapeseed mustard would have to be achieved by 2030 under the changing scenario of climate, decreasing and degrading land and water resources, costly inputs, government priority of food crops and other policy imperatives from the present level of nearly 1200 kg/ha. Diseases and pest infestation In future, plant protection will assume even more significance given the daunting task before us to feed the growing population under the era of shifting climate pattern, as it directly influence pest life cycle in crop calendar (Mukherjee, 2019). Every year, about USD 8.5 billion worth of crops are lost in India because of disease and insects pests and another 2.5 billion worth of food grains in storages. In the scenario of climate change, experts believe that these losses could rise as high as four folds. Global warming and climate change would lead to emergence of more aggressive pests and diseases which can cause epidemics resulting in heavy losses (Mesterhazy et al., 2020). The range of many insects will change or expand and new combinations of diseases and pests may emerge. The well-known interaction between host × pathogen × environment for plant disease epidemic development and weather based disease management strategies have been routinely exploited by plant pathologists. However, the impact of inter annual climatic variation resulting in the abundance of pathogen populations and realistic assessment of climatic change impacts on host-pathogen interactions are still scarce and there are only handful of studies. Further emerging of new disease with climate alteration in grain crop such as wheat blast, become challenging for growers and hamper food chain availability (Mukherjee et al., 2019). Temperature increase associated with climatic changes could result in following changes in plant diseases: Extension of geographical range of pathogens Changes in population growth rates of pathogens Changes in relative abundance and effectiveness of bio control agents Changes in pathogen × host × environment interactions Loss of resistance in cultivars containing temperature-sensitive genes Emergence of new diseases/and pathogen forms Increased risk of invasion by migrant diseases Reduced efficacy of integrated disease management practices These changes will have major implications for food and nutritional security, particularly in the developing countries of the dry-tropics, where the need to increase and sustain food production is most urgent. The current knowledge on the main potential effects of climate change on plant patho systems has been recently summarized by Pautasso et al. (2012). Their overview suggests that maintaining plant health across diversified environments is a key requirement for climate change mitigation as well as the conservation of biodiversity and provisions of ecosystem services under global change. Changing in weed flora pattern under different cropping system become very challenging to the food growers, and threat to our food security issue. It has been estimated that the potential losses due to weeds in different field crops would be around 180 million tonnes valued Rs 1,05,000 crores annually. In addition to the direct effect on crop yield, weeds result in considerable reduction in the efficiency of inputs used and food quality. Increasing atmospheric CO2 and temperature have the potential to directly affect weed physiology and crop-weed interactions vis-à-vis their response to weed control methods. Many of the world’s major weeds are C4 plants and major crops are C3 plants (Mandal and Mukherjee, 2018). The differential effects of CO2 on C3 and C4 plants may have implications on crop-weed interactions. Weed species have a greater genetic diversity than most crops and therefore, under the changing scenario of resources (eg., light, moisture, nutrients, CO2), weeds will have the greater capacity for growth and reproductive response than most crops. Differential response to seed emergence with temperature could also influence species establishment and subsequent weed-crop competition. Increasing temperature might allow some sleeper weeds to become invasive (Mukherjeee, 2020; Science Daily, 2009). Studies suggest that proper weed management techniques if adopted can result in an additional production of 103 million tonnes of food grains, 15 million tonnes of pulses,10 million tonnes of oilseeds, and 52 million tonnes of commercial crops per annum, which in few cases are even equivalent to the existing annual production (Rao and Chauhan, 2015). There is tremendous scope to increase agricultural productivity by adopting improved weed management technologies that have been developed in the country. Conclusion The greatest challenge before us is to enhance the production of required amount of food items viz., cereals, pulses, oilseeds, vegetable, underutilized fruit etc to keep pace with population growth through employing suitable crop cultivars, biotechnological approaches, conserving natural resources and protecting crops from weeds, insects pests and diseases eco-friendly with climate change. Research is a continuous process that has to be pursued vigorously and incessantly in the critical areas viz., evolvement of new genotype, land development and reclamation, soil and moisture conservation, soil health care, seeds and planting material, enhancing fertilizer and water use efficiencies, conservation agriculture, eco-friendly plant protection measures etc. Due to complexity of crop environment interaction under different climate situation, a multidisciplinary approach to the problem is required in which plant breeders, agronomists, crop physiologists and agrometeorologists need to interact for finding long term solutions in sustaining crop production. References: Abbade, E. B. 2017. Availability, access and utilization: Identifying the main fragilities for promoting food security in developing countries. World Journal of Science, Technology and Sustainable Development, 14(4): 322–335. doi:10.1108/WJSTSD-05-2016-0033 Aggrawal, P.K., Bandyopadhyay, S. and Pathak, S. 2020. Analysis of yield trends of the Rice-Wheat system in north-western India. Outlook on Agriculture, 29(4):259-268. Christensen, J.H., Hewitson, B., Busuioc, A., Chen, A. and Gao, X, 2007. Regional Climate Projections. In: Climate Change 2007: The Physical Science Basis. Cambridge University Press. Cambridge, United Kingdom. Debnath, S., Mandal, B., Saha, S., Sarkar, D., Batabyal, K., Murmu, S., Patra, B.C., Mukherjee, and Biswas, T. 2021. Are the modern-bred rice and wheat cultivars in India inefficient in zinc and iron sequestration?. Environmental and Experimental Botany,189:1-7. (https://doi.org/10.1016/j.envexpbot.2021.104535) 2007. Climate Change 2007- Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 976pp. Mandal, B and Mukherjee, D. 2018. Influenced of different weed management Practices for Higher Productivity of Jute (Corchorus olitorius) in West Bengal. International Journal of Bioresource Science, 5 (1): 21-26. Mesterhazy, A., Olah, J. and Popp, J. 2020. Losses in the grain supply chain: causes and solutions. Sustainability, 12, 2342; doi:10.3390/su12062342. Mukherjee D. 2019. Effect of various crop establishment methods and weed management practices on growth and yield of rice. Journal of Cereal Research, 11(3): 300-303. http://doi.org/10.25174/2249-4065/2019/95811. Mukherjee, D. 2014. Climate change and its impact on Indian agriculture. In : Plant Disease Management and Microbes (eds. Nehra, S.). Aavishkar Publishers, Jaipur, India. Pp 193-206. Mukherjee, D. 2017. Rising weed problems and their effects on production potential of various crops under changing climate situation of hill. Indian Horticulture Journal, 7(1): 85-89. Mukherjee, D., Mahapatra, S., Singh, D.P., Kumar, S., Kashyap , P.L. and Singh, G.P. 2019. Threat assessment of wheat blast like disease in the West Bengal". 4th International Group Meeting on Wheat production enhancement through climate smart practices. at CSK HPKV, Palampur, HP, India, February, 14-16, 2019. Organized by CSK HPKV, Palampur and Society of Advancement of Wheat and Barley Research (SAWBAR). Journal of Cereal Research, 11 (1): 78. Mukherjee, D. 2020. Herbicide combinations effect on weeds and yield of wheat in North-Eastern plain. Indian Journal of Weed Science, 52 (2): 116–122. Pautasso, M. 2012. Observed impacts of climate change on terrestrial birds in Europe: an overview. Italian Journal of Zoology, 38:56-74. .Doi:10.1080/11250003.2011.627381 Rao, A.N. and Chauhan, B.S. 2015. Weeds and weed management in India -A Review. 25 Asian Pacific Weed Science Society Conference, at Hyderabad, India, Volume: 1 (A.N. Rao and N.T. Yaduraju (eds.). pp 87-118.

ABSTRACTWe have investigated the formation of thin layers of carbides and nitrides by irradiating silicon (100) single crystal immersed in clear organic solvents or liquid ammonia. The liquids were transparent to the excimer laser (λ=308 nm, τ45 ns) used, at energy densities from 0.5 to 3.0 Jcm−2. Most of the laser energy was absorbed by the silicon specimens above a certain threshold to cause melting of the surface to a depth of approximately 250 nm. The pool of liquid silicon reacts with the solvents or ammonia in a saturated high pressure vapor phase for a duration of approximately 200 ns per pulse. The specimens were irradiated with a number of pulses ranging from 1 to 50. The films were then analyzed for structure and composition using TEM, AES, and IR spectroscopy. We report here calculations of laser-solid interactions, microstructure, and properties of the resulting thin films.

Stable glasses (SGs) are formed through surface-mediated equilibration (SME) during physical vapor deposition (PVD). Unlike intermolecular interactions, the role of intramolecular degrees of freedom in this process remain unexplored. Here, using experiments and coarse-grained molecular dynamics simulations, we demonstrate that varying dihedral rotation barriers of even a single bond, in otherwise isomeric molecules, can strongly influence the structure and stability of PVD glasses. These effects arise from variations in the degree of surface mobility, mobility gradients, and mobility anisotropy, at a given deposition temperature (Tdep) At high Tdep, flexible molecules have access to more configurations, which enhances the rate of SME, forming isotropic SGs. At low Tdep, stability is achieved by out of equilibrium aging of the surface layer. Here, the poor packing of rigid molecules enhances the rate of surface-mediated aging (SMA), producing stable glasses with layered structures in a broad range of Tdep. In contrast, the dynamics of flexible molecules couple more efficiently to the glass layers underneath, resulting in reduced mobility and weaker mobility gradients, producing unstable glasses. Independent of stability, the flattened shape of flexible molecules can also promote in-plane orientation orderat low Tdep. These results indicate that small changes in intramolecular relaxation barriers can be used as an approach to independently tune the structure and mobility profiles of the surface layer and thus the stability and structure of PVD glasses.

ABSTRACTA new strategy for stabilizing inorganic nanoparticles in nonpolar solutions is described. Resorcinarenes 1-3 were synthesized and evaluated as surfactants because of their large concave headgroups with multiple contact sites. Au nanoparticles ranging from 3-20 nm in diameter were generated in the vapor phase and dispersed into dilute hydrocarbon solutions of 1-3, where they were stabilized for up to several months. Chemisorption is most likely mediated by multiple Au-O interactions, as indicated by several control experiments and by surface-enhanced Raman spectroscopy. The resorcinarenes were readily displaced by dodecanethiol, which resulted in the precipitation of particles >5 nm as determined by absorption spectroscopy and transmission electron microscopy. This suggests that the mobility of the resorcinarene tailgroups are important for maintaining the larger nanoparticles in a dispersed state. Resorcinarene surfactants with stronger chemisorptive properties are currently being explored.

In humans, elevated body temperatures can markedly increase the ventilatory response to exercise. However, the impact of changing the effective body surface area for sweat evaporation on such responses is unclear. Ten healthy adults (9 Male, 1 Female) performed eight exercise trials cycling at 6 W/kg of metabolic heat production for 60 minutes. Four conditions were used where the effective body surface area for sweat evaporation (BSAeff) corresponded to 100, 80, 60, and 40% of BSA using vapor impermeable material. Four trials (one at each BSAeff) were performed at 25°C air temperature, and four trials (one at each BSAeff) at 40°C air temperature, each with 20% humidity. The slope of the relation between minute ventilation and carbon dioxide elimination (V̇E/V̇CO2 slope) assessed the ventilatory response. At 25°C, the V̇E/V̇CO2 slope was elevated by 1.9 and 2.6 units when decreasing BSAeff from 100 to 80 and to 40% (ps = 0.033 and 0.004, respectively). At 40°C, V̇E/V̇CO2 slope was` elevated by 3.3 and 4.7 units, when decreasing BSAeff from 100 to 60 and to 40% (ps = 0.016 and < 0.001, respectively). Linear regression analyses using group average data from each condition demonstrated that end-exercise mean body temperature (integration of core and mean skin temperatures) was better associated with the end-exercise ventilatory response, compared with core temperature alone. Overall, we show that impeding regional sweat evaporation increases the ventilatory response to exercise in temperate and hot environmental conditions, and the effect is mediated primarily by increases in mean body temperature.

Abstract Background Microorganisms synthesize and release a large diversity of small molecules like volatile compounds, which allow them to relate and interact with their environment. Volatile organic compounds (VOCs) are carbon-based compounds with low molecular weight and generally, high vapor pressure; because of their nature, they spread easily in the environment. Little is known about the role of VOCs in the interaction processes, and less is known about VOCs produced by Malassezia, a genus of yeasts that belongs to the human skin mycobiota. These yeasts have been associated with several dermatological diseases and currently, they are considered as emerging opportunistic yeasts. Research about secondary metabolites of these yeasts is limited. The pathogenic role and the molecular mechanisms involved in the infection processes of this genus are yet to be clarified. VOCs produced by Malassezia yeasts could play an important function in their metabolism; in addition, they might be involved in either beneficial or pathogenic host-interaction processes. Since these yeasts present differences in their nutritional requirements, like lipids to grow, it is possible that these variations of growth requirements also define differences in the volatile organic compounds produced in Malassezia species. Aim of review We present a mini review about VOCs produced by microorganisms and Malassezia species, and hypothesize about their role in its metabolism, which would reveal clues about host-pathogen interaction. Key scientific concepts of review Since living organisms inhabit a similar environment, the interaction processes occur naturally; as a result, a signal and a response from participants of these processes become important in understanding several biological behaviors. The efforts to elucidate how living organisms interact has been studied from several perspectives. An important issue is that VOCs released by the microbiota plays a key role in the setup of relationships between living micro and macro organisms. The challenge is to determine what is the role of these VOCs produced by human microbiota in commensal/pathogenic scenarios, and how these allow understanding the species metabolism. Malassezia is part of the human mycobiota, and it is implicated in commensal and pathogenic processes. It is possible that their VOCs are involved in these behavioral changes, but the knowledge about this remains overlocked. For this reason, VOCs produced by microorganisms and Malassezia spp. and their role in several biological processes are the main topic in this review.

IntroductionCartilaginous fishes are the most evolutionary-distant vertebrates from mammals and possess an immunoglobulin (Ig)- and T cell-mediated adaptive immunity. CD8 is the hallmark receptor of cytotoxic T cells and is required for the formation of T cell receptor-major histocompatibility complex (TCR-MHC) class I complexes.MethodsRACE PCR was used to obtain gene sequences. Direct dilution was applied for the refolding of denatured recombinant CD8 protein. Hanging-drop vapor diffusion method was performed for protein crystallization.ResultsIn this study, CD8α and CD8β orthologues (termed ScCD8α and ScCD8β) were identified in small-spotted catshark (Scyliorhinus canicula). Both ScCD8α and ScCD8β possess an extracellular immunoglobulin superfamily (IgSF) V domain as in previously identified CD8 proteins. The genes encoding CD8α and CD8β are tandemly linked in the genomes of all jawed vertebrates studied, suggesting that they were duplicated from a common ancestral gene before the divergence of cartilaginous fishes and other vertebrates. We determined the crystal structure of the ScCD8α ectodomain homodimer at a resolution of 1.35 Å and show that it exhibits the typical topological structure of CD8α from endotherms. As in mammals, the homodimer formation of ScCD8αα relies upon interactions within a hydrophobic core although this differs in position and amino acid composition. Importantly, ScCD8αα shares the canonical cavity required for interaction with peptide-loaded MHC I in mammals. Furthermore, it was found that ScCD8α can co-immunoprecipitate with ScCD8β, indicating that it can form both homodimeric and heterodimeric complexes.ConclusionOur results expand the current knowledge of vertebrate CD8 dimerization and the interaction between CD8α with p/MHC I from an evolutionary perspective.

The evaporation of droplets in an array is hindered by adjacent droplets because of vapor-mediated interactions. Existing theoretical models for predicting the evaporation rate of droplets in the array neglect the important factor of surface wettability. In this work, we developed a model involving a contact angle function to accurately predict the evaporation rate of droplets with an arbitrary contact angle in the array. Fick's first and second laws were solved for evaporating droplets in the array by using steady-state three-dimensional numerical simulations, to derive the contact angle function. The proposed model was experimentally validated for arrayed droplets evaporating on flat hydrophilic and hydrophobic surfaces. We show that the contact angle function approaches unity on hydrophilic surfaces, which implies that the proposed model coincides with Wray et al.'s model. On the other hand, the contact angle function is much lower than unity on hydrophobic surfaces, indicating a low evaporation rate of droplets in the array. The findings of this study are expected to advance our understanding of droplet evaporation in arrays in a wide range of scientific and engineering applications.

Ecological processes are complex, often exhibiting non-linear, interactive, or hierarchical relationships. Furthermore, models identifying drivers of phenology are constrained by uncertainty regarding predictors, interactions across scales, and legacy impacts of prior climate conditions. Nonetheless, measuring and modeling ecosystem processes such as phenology remains critical for management of ecological systems and the social systems they support. We used random forest models to assess which combination of climate, location, edaphic, vegetation composition, and disturbance variables best predict several phenological responses in three dominant land cover types in the U.S. Northwestern Great Plains (NWP). We derived phenological measures from the 25-year series of AVHRR satellite data and characterized climatic predictors (i.e., multiple moisture and/or temperature based variables) over seasonal and annual timeframes within the current year and up to 4 years prior. We found that antecedent conditions, from seasons to years before the current, were strongly associated with phenological measures, apparently mediating the responses of communities to current-year conditions. For example, at least one measure of antecedent-moisture availability [precipitation or vapor pressure deficit (VPD)] over multiple years was a key predictor of all productivity measures. Variables including longer-term lags or prior year sums, such as multi-year-cumulative moisture conditions of maximum VPD, were top predictors for start of season. Productivity measures were also associated with contextual variables such as soil characteristics and vegetation composition. Phenology is a key process that profoundly affects organism-environment relationships, spatio-temporal patterns in ecosystem structure and function, and other ecosystem dynamics. Phenology, however, is complex, and is mediated by lagged effects, interactions, and a diversity of potential drivers; nonetheless, the incorporation of antecedent conditions and contextual variables can improve models of phenology.

Evaporation of droplets over a hot oil surface is a natural phenomenon. However, most existing studies focus on a single droplet, and the evaporation of multiple droplets is insufficiently understood. Here, we explore the Leidenfrost evaporation of two identical FC-72 droplets over a hot oil bath. The oil temperature covers 73.6~126.6 ^°C, and the evaporation of droplets with an initial diameter of 1.5 mm was recorded by an infrared thermographer and a high-speed camera. The shallow oil depth keeps a relatively uniform oil temperature in the slot compared to the deep liquid pool, due to the larger ratio of the surface area for copper-oil contact to the slot volume. We found that neighboring droplets evaporate in three stages: non-coalescence, bouncing and separation. The radius of neighboring Leidenfrost droplets follows the power law <em>R</em>(<em>t</em>)~(1−<em>t</em>/<em>τ</em>)<em>ⁿ</em>, where <em>τ</em> is the characteristic droplet lifetime and <em>n</em> is an exponent factor. Moreover, the diffusion-mediated interactions between the neighboring droplets slow down the evaporation process compared to isolated Leidenfrost droplets and lead to an asymmetric temperature field on the droplet surface, which breaking the balance of the forces acting on the droplets. A simple dual-droplet evaporation model is developed which considers four forces acting horizontally on the droplet, including the Marangoni force resulting from the non-uniform droplet temperature, the gravity component, the lubrication-propulsion force, and the viscous drag force. Scale analysis shows that the Marangoni force and gravity component dominate dual-droplet evaporation dynamics. In the non-coalescence stage, the gravity component induces the droplets to attract each other, while the vapor film trapped between droplets avoids their direct touch. When the droplets get smaller, the gravity component is insufficient to overcome the Marangoni force. Hence, the droplets separate in the final evaporation stage. Finally, we identify the competition between Marangoni force and gravitational force as the origin of the bounce evaporation by comparing the theoretical and experimental transition times at distinct stages. This study contributes to explaining the complex Leidenfrost droplet dynamics and evaporation mechanism.

Abstract In this article, we experimentally probe the vapor-mediated interaction behavior of evaporating sessile and pendant droplets in an interacting droplet system. For this purpose, a pendant droplet was introduced in the vapor diffusion domain of a sessile droplet and both were allowed to evaporate simultaneously. The evaporation dynamics were monitored using optical imaging technique for varied separation (both horizontal and vertical) distances between them. Our observations reveal curtailed mass transfer rate from both the droplets although the evolution of droplet morphology (such as pendant droplet radius, contact radius and contact angle of sessile droplet) at different stages of evaporation remain similar. The evaporative fluxes from these two droplets interact with one another and thereby reduces the diffusive mobility of vapor molecules in the liquid-vapor interface of both. This condition suppresses the diffusion mechanism and thereby impedes the evaporation rate. We show that the evaporation behavior for two droplets in an interacting droplet system is solely dictated by an effective external vapor concentration depending on the problem geometry. Therefore, to characterize the vapor diffusion domain we hypothesize a vapor front enfolding both the droplets and proffer a theoretical model by applying conservation of mass across it. We also propose a relationship to show the variation of the effective external vapor concentration with the relative separation distance between the droplets. The predictions from theoretical models are found to be in good agreement with our detailed experimental observations.

AbstractMorphology-controlled strontianite nanostructures have attracted interest in various fields, such as electrocatalyst and photocatalysts. Basic additives in aqueous strontium solutions is commonly used in controlling strontianite nanostructures. Here, we show that trace water also serves an important role in forming and structuring vertically oriented strontianite nanorod arrays on strontium compounds. Using in situ Raman spectroscopy, we monitored the structural evolution from hydrated strontium to strontianite nanorods, demonstrating the epitaxial growth by vapor–liquid–solid mechanism. Water molecules cause not only the exsolution of Sr liquid droplets on the surface but also the uptake of airborne CO2 followed by its ionization to CO32−. The existence of intermediate SrHO+–OCO22− phase indicates the interaction of CO32− with SrOH+ in Sr(OH)x(H2O)y cluster to orient strontianite crystals. X-ray diffraction simulation and transmission electron microscopy identify the preferred-orientation plane of the 1D nanostructures as the (002) plane, i.e., the growth along the c-axis. The anisotropic growth habit is found to be affected by the kinetics of carbonation. This study paves the way for designing and developing 1D architecture of alkaline earth metal carbonates by a simple method without external additives at room temperature.

Despite the various strategies for achieving metal–nitrogen–carbon (M–N–C) single-atom catalysts (SACs) with different microenvironments for electrochemical carbon dioxide reduction reaction (CO 2 RR), the synthesis–structure–performance correlation remains elusive due to the lack of well-controlled synthetic approaches. Here, we employed Ni nanoparticles as starting materials for the direct synthesis of nickel (Ni) SACs in one spot through harvesting the interaction between metallic Ni and N atoms in the precursor during the chemical vapor deposition growth of hierarchical N-doped graphene fibers. By combining with first-principle calculations, we found that the Ni-N configuration is closely correlated to the N contents in the precursor, in which the acetonitrile with a high N/C ratio favors the formation of Ni-N 3 , while the pyridine with a low N/C ratio is more likely to promote the evolution of Ni-N 2 . Moreover, we revealed that the presence of N favors the formation of H-terminated edge of sp 2 carbon and consequently leads to the formation of graphene fibers consisting of vertically stacked graphene flakes, instead of the traditional growth of carbon nanotubes on Ni nanoparticles. With a high capability in balancing the *COOH formation and *CO desorption, the as-prepared hierarchical N-doped graphene nanofibers with Ni-N 3 sites exhibit a superior CO 2 RR performance compared to that with Ni-N 2 and Ni-N 4 ones.

AbstractIn this paper, we describe nanostructured substrates as suitable and functional platforms for neuron scaffolding. Neurons are electrically excitable mammalian cells that on network formation serve as conduits for information transfer. A vast amount of information is transferred through the cells in the spinal cord via synaptic and gap junctions in the electro-ionic fashion mediated by neutrotransmitters. Carbon nanotubes (CNT) are strong, flexible, conduct electrical current and they are biocompatible and non-biodegradable. They can be functionalized with different biomolecules like neuron growth factors and adhesion agents, properties that come useful in formation of neuron hybrids. These properties of the nanotubes make them potentially successful candidates to form prosthetic substrates to guide neurite outgrowth. A combination of microlithography and chemical vapor deposition is used to engineer patterned vertical multiwalled carbon nanotube substrates. These substrates function as scaffolds and are used to demonstrate the formation of directed neuronal networks. Multiple substrate geometries and nanotube heights are fabricated to determine the most suitable combination for understand the cell morphological changes. Changes in the interaction between the cell membrane and the nanotube substrate are visually characterized. Cell viability is determined via calcium staining and different types of nano-structure substrates are also tested for further studies.

ABSTRACTIn-situ wafer curvature measurements were used to study the effect of Si doping on intrinsic growth stress during the metalorganic chemical vapor deposition (MOCVD) growth of AlxGa1-xN (x=0-0.62) layers on SiC substrates. Post-growth transmission electron microscopy (TEM) characterization was used to correlate measured changes in stress with changes in film microstructure. Si doping was found to result in the inclination of edge-type threading dislocations (TDs) in AlxGa1-xN which resulted in a relaxation of compressive stress and generation of tensile stress. The experimentally measured stress gradient was similar to that predicted by an effective climb model. Dislocation inclination resulted in a reduction in the TD density for Si-doped layers compared to undoped AlxGa1-xN likely due to increased opportunities for dislocation interaction and annihilation. The TD density, which increased with increasing Al-fraction, was found to significantly alter the stress gradients in the films. Film stress was also observed to play a role in TD inclination. In undoped AlxGa1-xN, TD inclination was observed only when the film grew under a compressive stress while in Si-doped AlxGa1-xN, TD inclination was observed independent of the sign or magnitude of the film stress. Si dopants are believed to alter the concentration of surface vacancies which gives rise to dislocation jog via a surface-mediated climb mechanism.

AbstractStomata are central players in the hydrological and carbon cycles, regulating the uptake of carbon dioxide (CO2) for photosynthesis and transpirative loss of water (H2O) between plants and the atmosphere. The necessity to balance water-loss and CO2-uptake has played a key role in the evolution of plants, and is increasingly important in a hotter and drier world. The conductance of CO2 and water vapour across the leaf surface is determined by epidermal and stomatal morphology (the number, size, and spacing of stomatal pores) and stomatal physiology (the regulation of stomatal pore aperture in response to environmental conditions). The proportion of the epidermis allocated to stomata and the evolution of amphistomaty are linked to the physiological function of stomata. Moreover, the relationship between stomatal density and [CO2] is mediated by physiological stomatal behaviour; species with less responsive stomata to light and [CO2] are most likely to adjust stomatal initiation. These differences in the sensitivity of the stomatal density—[CO2] relationship between species influence the efficacy of the ‘stomatal method’ that is widely used to infer the palaeo-atmospheric [CO2] in which fossil leaves developed. Many studies have investigated stomatal physiology or morphology in isolation, which may result in the loss of the ‘overall picture’ as these traits operate in a coordinated manner to produce distinct mechanisms for stomatal control. Consideration of the interaction between stomatal morphology and physiology is critical to our understanding of plant evolutionary history, plant responses to on-going climate change and the production of more efficient and climate-resilient food and bio-fuel crops.