Littérature scientifique sur le sujet « CHIM/07 »

Abstract. The stratospheric ozone loss during the Arctic winters 2004/05–2009/10 is investigated by using high resolution simulations from the chemical transport model Mimosa-Chim and observations from Microwave Limb Sounder (MLS) on Aura by the passive tracer technique. The winter 2004/05 was the coldest of the series with strongest chlorine activation. The ozone loss diagnosed from both model and measurements inside the polar vortex at 475 K ranges from ~1–0.7 ppmv in the warm winter 2005/06 to 1.7 ppmv in the cold winter 2004/05. Halogenated (chlorine and bromine) catalytic cycles contribute to 75–90% of the accumulated ozone loss at this level. At 675 K the lowest loss of ~0.4 ppmv is computed in 2008/09 from both simulations and observations and, the highest loss is estimated in 2006/07 by the model (1.3 ppmv) and in 2004/05 by MLS (1.5 ppmv). Most of the ozone loss (60–75%) at this level results from cycles catalysed by nitrogen oxides (NO and NO2) rather than halogens. At both 475 and 675 K levels the simulated ozone evolution inside the polar vortex is in reasonably good agreement with the observations. The ozone total column loss deduced from the model calculations at the MLS sampling locations inside the vortex ranges between 40 DU in 2005/06 and 94 DU in 2004/05, while that derived from observations ranges between 37 DU and 111 DU in the same winters. These estimates from both Mimosa-Chim and MLS are in general good agreement with those from the ground-based UV-VIS (ultra violet–visible) ozone loss analyses for the respective winters.

Комплексными методами физико-химического анализа (дифференциально-термический, рентгенофазовый, микроструктурный, измерение микротвердости и определение плотности) изучены фазовые равновесия и построены Т–х фазовые диаграммыв системах Ag8SnS6–Cu2SnS3 и Ag2SnS3–Cu2Sn4S9. Показано, что система Ag8SnS6–Cu2SnS3является квазибинарным сечением квазитройной системы Ag2S-SnS2-Cu2S и относится кпростому эвтектическому типу с ограниченными областями растворимости на основеисходных сульфидов. Координаты эвтектической точки: 50 mol % Ag2SnS3 И Т = 900 К.Растворимость на основе Ag8SnS6 и Cu2SnS3 при эвтектической температуре простираетсядо 20 и 28 mol % соответственно. С уменьшением температуры твердые растворы распадаются и при 300 К составляют 5 и 10 mol %. Установлено, что с увеличением концентрацииAg8SnS6 в твердых растворах (Cu2SnS3)1-х (Ag8SnS6)х параметр кубической решетки увеличивается от а = 0.5445 nm (для чистого Cu2SnS3) до а = 0.725 nm (для состава х = 0.1) т. е. концентрационная зависимость параметра решетки имеет линейный характер.Система Ag2SnS3–Cu2Sn4S9 из-за перитектического плавления Cu2Sn4S9 имеет сложный характер и является частично квазибинарным сечением. Квазибинарность нарушается вобласти концентрации 65-100 mol % Cu2Sn4S9 и выше температуры 900 К. Твердые растворына основе Ag2SnS3 и Cu2Sn4S9 узкие и при 300 К составляют 10; 2.5 mol % соответственно ЛИТЕРАТУРА1. Wang N., Fan A. K. An experimental study of the Ag2S-SnS2 pseudobinary join // Neues Jahrb. Mineral.-Abh, 1989, v. 160, pp. 33–36.2. Wang N. New data for Ag8SnS6 (canfeildite) and Ag8GeS6 (argyrodite) // Neues Jahrb. Mineral. Monatsh.,1978, pp. 269–272.3. Бабанлы М. Б., Юсибов Ю. А., Абишев В. Т. Трехкомпонентные халькогениды на основе медии серебра. Баку: Изд-во БГУ, 1993, 342 с.4. Parasyuk O. V., Chykhrij S. I., Bozhko V. V., Piskach L. V., Bogdanyuk M. S., Olekseyuk I. D.,Bulatetska L. V., Pekhnyo. Phase diagramm of the Ag2S–HgS–SnS2 system and single crystal prepartion,crystal structure and properties of Ag2HgSnS4 // J. Alloys and Compounds, 2005, v. 399, pp. 32–37. DOI: https://doi.org/10.1016/j.jallcom.2005.03.0085. Olekseyuk I. D., Dudchak I. B., Piskach L. V. Phase equilibria in the Cu2S–ZnSe–SnS2 // J. Alloys andCompounds, 2004, v. 368, pp. 135–143. https:doi.org/10.1016/j.jallcom.2003.08.0846. Ollitrault-Fitchet R., Rivet J., Flahaut J., et.al. Description du systeme ternaire Ag–Sn–Se // J. Less-Common. Met., 1988, v. 138(2), pp. 241–261. DOI:https://doi.org/10.1016/0022-5088(88)90113-07. Delgado C. E., Mora A. J., Marcano E. Crystal structure refi nement of the semiconducting compoundCu2SnSe3 from X-ray powder difraction data // Mater. Res. Bull., 2003, v. 38, pp. 1949–1955. DOI: https://doi.org/10.1016/j.materresbull.2003.09.0178. Parasyuk O. V., Olekseyuk I. D., Marchuk O. V. The Cu2Se–HgSe–SnSe2 // J. Alloys and Compounds.,1999, v. 287, pp. 197–205. DOI: https//doi.org/10.1016/S0925-8388(99)00047-X9. Parasyuk O. V., Gulay L. D., Piskach L. V., Kumanska Yu. O. The Ag2Se–HgSe–SnSe2 system and thecrystal structure of the Ag2HgSnSe4 // J. Alloys and Сompounds, 2002, v. 339, pp.1 40–143. DOI: https//doi.org/10.1016/S0925-8388(01)01985-510. Babanly M. B., Yusibov Y. A., Babanly N. B. Electromotive force and measucement in several systema.Ed. by S. Kara, Intechneb. Org., 2011, pp. 57–58.11. Gulay L. D., Olekseyuk I. D., Parasyuk O. V. Crystal structure of b-Ag8SnSe6 // J. Alloys and compounds,2002, v. 339, pp. 113–117. DOI: https//doi.org/10.1016/S0925-8388(01)01970-312. Гусейнов Г. М. Получение соединения Ag8SnS6 в среде диметилформамида // Вестн. Томского гос. ун-та. Химия, 2016, № 1(3), c. 24–34. Режим доступа: fi le:///C:/Users/Lab351/Downloads/sub_%20%20in%20dimethylformamide%20medium.pdf (дата обращения: 19.09.2019)13. Gorchov O. Les composes Ag8MX6 (M = Si, Ge, Sn et X = S, Se, Te) // Bull. Soc. Chim. Fr., 1968, № 6.pp. 2263–2275.14. Kokhan O. P. The Interactions in Ag2X–BIVX2 (BIV – Si, Ge, Sn; X – S, Se) systems and the propertiesof compounds. Doctoral Thesis, Uzhgorod, Uzhgorod State Univ., 1996.15. Onoda U., Chen X. A., Sato A., Wada H. Crystal structure and twinning of monoclinic Cu2SnS3 // Mater.Res. Bull., 2000, v. 35, № 8, pp. 1563–1570. DOI: https//doi.org/10.1016/S0025-5408(00)00347-016. Рзагулиев В. А., Керимли О. Ш., Мамедов Ш. Г. Изучение квазитройной системы Ag2S–SnS2–Cu2S по разрезу Ag8SnS6–Cu2SnS3. Труды Международ. научно–практич. конф., Россия, Белгород,2019, c. 18.17. Рзагулиев В. А., Керимли О. Ш., Маме дов Ш. Г. Исследование квазибинарного разреза Cu2SnS3–Ag2SnS3 в квазитройной системеAg2S–Cu2S–SnS2 . Труды XXI Междун. конф., Санкт-Петербург, 2019,c. 20–21.18. Цигика В. В., Переш Е. Ю., Лазарев В. В. и др. Получение и свойства мнонокристаллов соединений/TlPbJ3, Tl3PbJ5, TlSnJ3, TlSn2J5 and Tl3PbBr5 Изв. АН СССР. Неорган. материалы, 1981, т. 17(6), c. 970–974.

Abstract Background Influenza vaccines require yearly updates due to constant antigenic drift. Improvement of current vaccines requires a deep understanding of the pathogen as well as immunity to the virus. Controlled Human Infection Models (CHIM) provide opportunities to i) test new vaccine approaches in a controlled environment and, ii) better understand host immunity. The University of Maryland School of Medicine (UMSOM) was one of four clinical sites to conduct an H1N1 influenza A virus (IAV) (A/California/07/2009-pdm-like) challenge in 2019. Methods Healthy adult volunteers were intranasally challenged with IAV (2 mL of ∼5x10e6 TCID50/mL). After challenge (Day 1), volunteers were assessed for the development of clinical symptoms, virus shedding, development of anti-influenza antibodies (reported elsewhere). Blood specimens were collected at Days -2, 4, 6, 8, 15 and 61 to assess changes in cellular immunity (flow cytometry and ELISpot). Our sub-study included subjects (n=20) from the UMSOM cohort only. Results B cell compartment, ASC (plasmablast) responses to homologous hemagglutinin (HA) and neuraminidase (NA) peaked at Day 8. Anti-HA IgG and IgA ASC responses were present in 95% and 75% participants, respectively. NA IgG and IgA ASC responses were present in 60% and 50% of participants, respectively. In the innate compartment, plasmocytoid dendritic cells (pDCs) as well as Classical (CM), intermediate (IM) and non-classical (NCM) monocytes increased in frequency at various timepoints post-challenge. Myeloid DC (mDC), pDC, CM and IM also upregulated expression of CD38 and/or HLA-DR at specific timepoints. The frequency of the CD16+CD56+ natural killer (NK) cell subset and NKT cells were also increased post-challenge. Among T cells, CD4 and CD8 T effector memory (TEM) and TEM CD45RA+ (TEMRA) were activated (CD38+ HLA-DR+) after challenge (Figure 1). CD4 T follicular helper cells (TFH)-17, TFH-1 and TFH-2 were activated (CD38+ ICOS+) at various timepoints post-challenge. Figure 1.Overview of cellular responses to Influenza CHIM. The heat maps show changes in population frequency and/or expression of activation markers in innate (DC and monocytes) and T cells after challenge (D-2 pre-challenge). Each square displays the mean (n=20) of the population/marker. The color scale indicates the degree of change. Conclusion After influenza CHIM, all cell populations assessed showed signs of activation at diverse time-points. The relationship between the presence of pre-existing protective immunity (HAI >40) and degree of immune activation is still under analysis. Disclosures Catherine J. Luke, Ph.D., GSK: Spouse is an employee of GSK Justin Ortiz, MD, Moderna: Advisor/Consultant|Pfizer: Advisor/Consultant.

Biodegradable polymers for short time applications have attracted much interest all over the world. The reason behind this growing interest is the incompatibility of the polymeric wastes with the environment where they are disposed after usage. Synthetic aliphatic polyesters represent one of the most economically competitive biodegradable polymers. In addition, they gained considerable attention as they combine biodegradability and biocompatibility with interesting physical and chemical properties. In this framework, the present research work focused on the modification by reactive blending and polycondensation of two different aliphatic polyesters, namely poly(butylene succinate) (PBS) and poly(butylene 1,4-cyclohexanedicarboxylate) (PBCE). Both are characterized by good thermal properties, but their mechanical characteristics do not fit the requirements for applications in which high flexibility is requested and, moreover, both show slow biodegradation rate. With the aim of developing new materials with improved characteristics with respect to the parent homopolymers, novel etheroatom containing PBS and PBCE-based fully aliphatic polyesters and copolyesters have been therefore synthesized and carefully characterized. The introduction of oxygen or sulphur atoms along the polymer chains, by acting on chemical composition or molecular architecture, tailored solid-state properties and biodegradation rate: type and amount of comonomeric units and sequence distribution deeply affected the material final properties owing, among all, to the hydrophobic/hydrophilic ratio and to the different ability of the polymer to crystallize. The versatility of the synthesized copolymers has been well proved: as a matter of fact these polymers can be exploited both for biomedical and ecological applications. Feasibility of 3D electrospun scaffolds has been investigated, biocompatibility studies and controlled release of a model molecule showed good responses. As regards ecological applications, barrier properties and eco-toxicological assessments have been conducted with outstanding results. Finally, the ability of the novel polyesters to undergo both hydrolytic and enzymatic degradation has been demonstrated under physiological and environmental conditions.

Biodegradable polymers for short time applications have attracted much interest all over the world. The reason behind this growing interest is the incompatibility of the polymeric wastes with the environment where they are disposed after usage. Synthetic aliphatic polyesters represent one of the most economically competitive biodegradable polymers. In addition, they gained considerable attention as they combine biodegradability and biocompatibility with interesting physical and chemical properties. In this framework, the present research work focused on the modification by reactive blending and polycondensation of two different aliphatic polyesters, namely poly(butylene succinate) (PBS) and poly(butylene 1,4-cyclohexanedicarboxylate) (PBCE). Both are characterized by good thermal properties, but their mechanical characteristics do not fit the requirements for applications in which high flexibility is requested and, moreover, both show slow biodegradation rate. With the aim of developing new materials with improved characteristics with respect to the parent homopolymers, novel etheroatom containing PBS and PBCE-based fully aliphatic polyesters and copolyesters have been therefore synthesized and carefully characterized. The introduction of oxygen or sulphur atoms along the polymer chains, by acting on chemical composition or molecular architecture, tailored solid-state properties and biodegradation rate: type and amount of comonomeric units and sequence distribution deeply affected the material final properties owing, among all, to the hydrophobic/hydrophilic ratio and to the different ability of the polymer to crystallize. The versatility of the synthesized copolymers has been well proved: as a matter of fact these polymers can be exploited both for biomedical and ecological applications. Feasibility of 3D electrospun scaffolds has been investigated, biocompatibility studies and controlled release of a model molecule showed good responses. As regards ecological applications, barrier properties and eco-toxicological assessments have been conducted with outstanding results. Finally, the ability of the novel polyesters to undergo both hydrolytic and enzymatic degradation has been demonstrated under physiological and environmental conditions.

Organic printed electronics is attracting an ever-growing interest in the last decades because of its impressive breakthroughs concerning the chemical design of π-conjugated materials and their processing. This has an impact on novel applications, such as flexible-large-area displays, low- cost printable circuits, plastic solar cells and lab-on-a-chip devices. The organic field-effect transistor (OFET) relies on a thin film of organic semiconductor that bridges source and drain electrodes. Since its first discovery in the 80s, intensive research activities were deployed in order to control the chemico-physical properties of these electronic devices and consequently their charge. Self-assembled monolayers (SAMs) are a versatile tool for tuning the properties of metallic, semi-conducting, and insulating surfaces. Within this context, OFETs represent reliable instruments for measuring the electrical properties of the SAMs in a Metal/SAM/OS junction. Our experimental approach, named Charge Injection Organic-Gauge (CIOG), uses OTFT in a charge-injection controlled regime. The CIOG sensitivity has been extensively demonstrated on different homologous self-assembling molecules that differ in either chain length or in anchor/terminal group. One of the latest applications of organic electronics is the so-called “bio-electronics” that makes use of electronic devices to encompass interests of the medical science, such as biosensors, biotransducers etc… As a result, thee second part of this thesis deals with the realization of an electronic transducer based on an Organic Field-Effect Transistor operating in aqueous media. Here, the conventional bottom gate/bottom contact configuration is replaced by top gate architecture with the electrolyte that ensures electrical contact between the top gold electrode and the semiconductor layer. This configuration is named Electrolyte-Gated Field-Effect Transistor (EGOFET). The functionalization of the top electrode is the sensing core of the device allowing the detection of dopamine as well as of protein biomarkers with ultra-low sensitivity.

Organic printed electronics is attracting an ever-growing interest in the last decades because of its impressive breakthroughs concerning the chemical design of π-conjugated materials and their processing. This has an impact on novel applications, such as flexible-large-area displays, low- cost printable circuits, plastic solar cells and lab-on-a-chip devices. The organic field-effect transistor (OFET) relies on a thin film of organic semiconductor that bridges source and drain electrodes. Since its first discovery in the 80s, intensive research activities were deployed in order to control the chemico-physical properties of these electronic devices and consequently their charge. Self-assembled monolayers (SAMs) are a versatile tool for tuning the properties of metallic, semi-conducting, and insulating surfaces. Within this context, OFETs represent reliable instruments for measuring the electrical properties of the SAMs in a Metal/SAM/OS junction. Our experimental approach, named Charge Injection Organic-Gauge (CIOG), uses OTFT in a charge-injection controlled regime. The CIOG sensitivity has been extensively demonstrated on different homologous self-assembling molecules that differ in either chain length or in anchor/terminal group. One of the latest applications of organic electronics is the so-called “bio-electronics” that makes use of electronic devices to encompass interests of the medical science, such as biosensors, biotransducers etc… As a result, thee second part of this thesis deals with the realization of an electronic transducer based on an Organic Field-Effect Transistor operating in aqueous media. Here, the conventional bottom gate/bottom contact configuration is replaced by top gate architecture with the electrolyte that ensures electrical contact between the top gold electrode and the semiconductor layer. This configuration is named Electrolyte-Gated Field-Effect Transistor (EGOFET). The functionalization of the top electrode is the sensing core of the device allowing the detection of dopamine as well as of protein biomarkers with ultra-low sensitivity.

Regenerative medicine and tissue engineering attempt to repair or improve the biological functions of tissues that have been damaged or have ceased to perform their role through three main components: a biocompatible scaffold, cellular component and bioactive molecules. Nanotechnology provide a toolbox of innovative scaffold fabrication procedures in regenerative medicine. In fact, nanotechnology, using manufacturing techniques such as conventional and unconventional lithography, allows fabricating supports with different geometries and sizes as well as displaying physical chemical properties tunable over different length scales. Soft lithography techniques allow to functionalize the support by specific molecules that promote adhesion and control the growth of cells. Understanding cell response to scaffold, and viceversa, is a key issue; here we show our investigation of the essential features required for improving the cell-surface interaction over different scale lengths. The main goal of this thesis has been to devise a nanotechnology-based strategy for the fabrication of scaffolds for tissue regeneration. We made four types of scaffolds, which are able to accurately control cell adhesion and proliferation. For each scaffold, we chose properly designed materials, fabrication and characterization techniques.

Regenerative medicine and tissue engineering attempt to repair or improve the biological functions of tissues that have been damaged or have ceased to perform their role through three main components: a biocompatible scaffold, cellular component and bioactive molecules. Nanotechnology provide a toolbox of innovative scaffold fabrication procedures in regenerative medicine. In fact, nanotechnology, using manufacturing techniques such as conventional and unconventional lithography, allows fabricating supports with different geometries and sizes as well as displaying physical chemical properties tunable over different length scales. Soft lithography techniques allow to functionalize the support by specific molecules that promote adhesion and control the growth of cells. Understanding cell response to scaffold, and viceversa, is a key issue; here we show our investigation of the essential features required for improving the cell-surface interaction over different scale lengths. The main goal of this thesis has been to devise a nanotechnology-based strategy for the fabrication of scaffolds for tissue regeneration. We made four types of scaffolds, which are able to accurately control cell adhesion and proliferation. For each scaffold, we chose properly designed materials, fabrication and characterization techniques.

In Chapter 1 I will present a brief introduction on the state of art of nanotechnologies, nanofabrication techniques and unconventional lithography as a technique to fabricate the novel electronic device as resistive switch so-called memristor is shown. In Chapter 2 a detailed description of the main fabrication and characterization techniques employed in this work is reported. Chapter 3 parallel local oxidation lithography (pLOx) describes as a main technique to obtain accurate patterning process. All the effective parameters has been studied and the optimized condition observed to highly reproducible with excellent patterned nanostructures. The effect of negative bias, calls local reduction (LR) studied. Moreover, the use of AC bias shows faster patterning process respect to DC bias. In Chapter 4 (metal/ e-SiO2/ Si nanojunction) it is shown how the electrochemical oxide nanostructures by using pLOx can be used in the fabrication of novel devices call memristor. We demonstrate a new concept, based on conventional materials, where the lifetime problem is resolved by introducing a “regeneration” step, which restores the nano-memristor to its pristine condition by applying an appropriate voltage cycle. In Chapter 5 (Graphene/ e-SiO2/ Si), Graphene as a building block material is used as an electrode to selectively oxidize the silicon substrate by pLOx set up for the fabrication of novel resistive switch device. In Chapter 6 (surface architecture) I will show another application of pLOx in biotechnology is shown. So the surface functionalization combine with nano-patterning by pLOx used to design a new surface to accurately bind biomolecules with the possibility of studying those properties and more application in nano-bio device fabrication. So, in order to obtain biochips, electronic and optical/photonics devices Nano patterning of DNA used as scaffolds to fabricate small functional nano-components.

In Chapter 1 I will present a brief introduction on the state of art of nanotechnologies, nanofabrication techniques and unconventional lithography as a technique to fabricate the novel electronic device as resistive switch so-called memristor is shown. In Chapter 2 a detailed description of the main fabrication and characterization techniques employed in this work is reported. Chapter 3 parallel local oxidation lithography (pLOx) describes as a main technique to obtain accurate patterning process. All the effective parameters has been studied and the optimized condition observed to highly reproducible with excellent patterned nanostructures. The effect of negative bias, calls local reduction (LR) studied. Moreover, the use of AC bias shows faster patterning process respect to DC bias. In Chapter 4 (metal/ e-SiO2/ Si nanojunction) it is shown how the electrochemical oxide nanostructures by using pLOx can be used in the fabrication of novel devices call memristor. We demonstrate a new concept, based on conventional materials, where the lifetime problem is resolved by introducing a “regeneration” step, which restores the nano-memristor to its pristine condition by applying an appropriate voltage cycle. In Chapter 5 (Graphene/ e-SiO2/ Si), Graphene as a building block material is used as an electrode to selectively oxidize the silicon substrate by pLOx set up for the fabrication of novel resistive switch device. In Chapter 6 (surface architecture) I will show another application of pLOx in biotechnology is shown. So the surface functionalization combine with nano-patterning by pLOx used to design a new surface to accurately bind biomolecules with the possibility of studying those properties and more application in nano-bio device fabrication. So, in order to obtain biochips, electronic and optical/photonics devices Nano patterning of DNA used as scaffolds to fabricate small functional nano-components.