Статті в журналах з теми "TCR particles"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: TCR particles.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 статей у журналах для дослідження на тему "TCR particles".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Poornaiah, B., G. Srinivasa Rao, A. V. Prathap Kumar, and Y. Srinivasa Rao. "Low Frequency Noise and TCR Mechanisms in Polymer Thick Film Resistors." Journal of Microelectronics and Electronic Packaging 7, no. 2 (April 1, 2010): 105–10. http://dx.doi.org/10.4071/1551-4897-7.2.105.
Повний текст джерелаАнотація:
The paper aims to propose a more realistic low frequency noise and TCR mechanisms in polymer thick film resistors. The variation of low frequency noise (also called current noise) and TCR of polymer thick film resistor, namely, PVC-graphite thick film resistor, with parameters such as high volume fraction and grain size has been studied. A model is proposed to explain the observed variations, which assumes that the texture of the polymer thick film resistor consists of densely packed conducting particles with a cavity at the center of the structure. Further, the effect of the cavity diameter of polymer thick film resistor on current noise and TCR is explained using the same model. The current noise of these resistors is controlled mainly by the average relative resistance fluctuations between the conducting particles and the number of contacts each particle has with its neighbors. The TCR of these resistors is controlled mainly by the expansion properties of the insulating medium. The variation of TCR with high voltage is also due to the change in number of contacts and the contact area between the conducting particles.
2
Lo, Ying-Chun, Michael Edidin, and Jonathan Powell. "Selective activation of antigen-specific T cells by nano-particles (144.22)." Journal of Immunology 184, no. 1_Supplement (April 1, 2010): 144.22. http://dx.doi.org/10.4049/jimmunol.184.supp.144.22.
Повний текст джерелаАнотація:
Abstract We hypothesized that the spatial differences of surface TCR between naïve and previously activated cells might be exploited to enable anti-CD3 coated quantum dot (Invitrogen, Qdots) to selectively activate antigen specific cells. CD4+ Rag -/- TCR transgenic T cells specific for Pigeon Cytochrome c were stimulated +/- peptide with or without anti-CD3 Qdots and evaluated for proliferation. Anti-CD3 Qdots markedly enhanced proliferation of T cells previously incubated with low dose peptide, but did not drive proliferation of T cells that were incubated in medium alone, though these cultured T cells responded to soluble anti-CD3. We repeated this experiment using CD4+ 6.5 TCR transgenic T cells, specific for hemagglutinin (HA). These mice are Rag+/+ allowing us to simultaneously evaluate the ability of anti-CD3 Qdots to activate both the 6.5+ and 6.5- T cells. Soluble anti-CD3 resulted in proliferation even in the absence of peptide. When cells were first incubated with low dose HA peptide as expected only the 6.5+ T cells proliferated. Addition of anti-CD3 Qdots to such cultures led to a marked enhancement of proliferation of the 6.5+ T cells but not of the 6.5- T cells in a single culture. In similar experiments using CD8+ TCR transgenic T cells specific for HA, once again, only the HA specific CD8+ T cells responded to the anti-CD3 Qdots. Experiments to exploit these findings in vivo in models of infection and tumor immunity are underway.
3
Shiba, Kota, and Makoto Ogawa. "Precise Synthesis of Well-Defined Inorganic-Organic Hybrid Particles." Chemical Record 18, no. 7-8 (January 10, 2018): 950–68. http://dx.doi.org/10.1002/tcr.201700077.
Повний текст джерела
4
Cao, Zi-Quan, and Guo-Jie Wang. "Multi-Stimuli-Responsive Polymer Materials: Particles, Films, and Bulk Gels." Chemical Record 16, no. 3 (May 6, 2016): 1398–435. http://dx.doi.org/10.1002/tcr.201500281.
Повний текст джерела
5
Mescher, M. F. "Surface contact requirements for activation of cytotoxic T lymphocytes." Journal of Immunology 149, no. 7 (October 1, 1992): 2402–5. http://dx.doi.org/10.4049/jimmunol.149.7.2402.
Повний текст джерелаАнотація:
Abstract Cell activation resulting from binding of receptors on one cell to ligands on another is governed by receptor affinities and by ligand concentrations. Effective ligand concentration is determined by its density on the cell surface, but receptor occupancy level will also be influenced by the area of surface contact between the cells. The present study demonstrates the critical importance of a large, continuous surface contact area for effective CTL activation. Using class I alloantigen immobilized on latex microspheres, particle sizes of 4 to 5 microns were found to provide an optimum stimulus. Below 4 microns, responses decreased rapidly with decreasing particle size, and large numbers of small particles could not compensate for suboptimal size. Comparable size dependence was found for activation of degranulation by cloned CTL and for stimulation of in vitro generation of CTL responses by spleen cells from in vivo primed mice. In the presence of fluid-phase anti-TCR antibody, CD8-dependent binding to non-Ag class I (i.e., class I that is not recognized by the TCR) can provide a costimulatory signal to activate degranulation. This response is also critically dependent upon the class I being presented on a particle of 4 or 5 microns diameter. The results suggest that sufficient receptor occupancy (both TCR and CD8) over a contiguous region of the cell surface, as opposed to total interactions over the entire cell surface, is a critical determinant for activation. The ability of CTL to distinguish between Ag on cell-size vs subcellular fragments is probably necessary for their effective functioning, and may also explain the inability to significantly influence CTL activation in vivo with subcellular or soluble forms of Ag.
6
Choudhuri, Kaushik, Jaime Llodra, Jones Tsai, Eric Roth, Susana Gordo, Kai Wucherpfennig, Lance Kam, David Stokes, and Michael Dustin. "Polarized release and retroviral subversion of TCR-enriched microvesicles at the T cell immunological synapse (P6155)." Journal of Immunology 190, no. 1_Supplement (May 1, 2013): 118.1. http://dx.doi.org/10.4049/jimmunol.190.supp.118.1.
Повний текст джерелаАнотація:
Abstract The recognition events that mediate adaptive cellular immunity depend on intercellular contacts between T cells and antigen presenting cells (APC). T cell signaling is initiated at these specialized junctions between T cells and APCs, known as the immunological synapse (IS), when surface-expressed antigen receptors (TCR) recognize peptide fragments of pathogens (pMHC) on APCs. Using high resolution optical and electron microscopy, optical-EM correlation, and electron-tomography, we show that centrally accumulated TCR at the IS is located on the surface of extracellular microvesicles that bud at the IS center and are recognized by APC bearing cognate antigen. An early endosomal-sorting complex required for transport (ESCRT) sorts TCR for inclusion in microvesicles, while terminal ESCRT components mediate scission of microvesicles from the T cell plasma membrane. The HIV polyprotein GAG co-opts this process by displacing TCR from microvesicles, resulting in release of virus-like particles at the antigen-dependent IS. We conclude that post-signaling TCR accumulates at the IS center and is released in extracellular microvesicles by an ESCRT-dependent mechanism triggered by T cell activation. These microvesicles mediate intercellular communication in immune cell collaboration, and can be co-opted by HIV GAG for viral transmission across antigen-dependent synapses.
7
Choudhuri, Kaushik, Jaime Llodra, Lance Kam, David Stokes, and Micheal Dustin. "Antigen-induced release and retroviral subversion of TCR-enriched microvesicles at the CD4+ T cell immunological synapse (58.5)." Journal of Immunology 188, no. 1_Supplement (May 1, 2012): 58.5. http://dx.doi.org/10.4049/jimmunol.188.supp.58.5.
Повний текст джерелаАнотація:
Abstract The immunological synapse (IS) is a specialized junction that forms between T cells and antigen presenting cells, which is critical for effective T cell antigen recognition and effector functions. Its spatiotemporal evolution results in laterally segregated supramolecular domains composed of a peripheral adhesive ring of the β2 integrin LFA-1 and its ligand ICAM-1, and centrally accumulated T cell receptors (TCR). The molecular and cell biological basis for supramolecular domain organization at the IS remains unclear. Here we show, using novel correlative optical-electron microscopy methods in conjunction with electron tomography, that centrally accumulated TCR is located on the surface of microvesicles that are shed at the IS center. The ESCRT I member TSG101 sorts TCR into microvesicles. TCR-enriched microvesicles (TEMs) are transferred from T cell to B cell during cognate antigen recognition, and B cells initiate intracellular signals in response to TEMs, suggesting their involvement in intercellular communication between immune cells. Expression of the HIV GAG structural polyprotein in human CD4+ T cells, displaces TCR from microvesicles at the IS, resulting in the release of GAG-containing virus-like particles. These findings provide an ultrastructural basis for supramolecular domain organization at the IS, and identify an ESCRT-dependent mechanism for production of stimulatory TEMs, which may be co-opted during infection for the release of enveloped viruses.
8
Yan, Zong-Yao, Jian-Yong Liu, and Jia-Rong Niu. "Research of a Novel Ag Temperature Sensor Based on Fabric Substrate Fabricated by Magnetron Sputtering." Materials 14, no. 20 (October 12, 2021): 6014. http://dx.doi.org/10.3390/ma14206014.
Повний текст джерелаАнотація:
TPU-coated polyester fabric was used as the substrate of a flexible temperature sensor and Ag nanoparticles were deposited on its surface as the temperature sensing layer by the magnetron sputtering method. The effects of sputtering powers and heat treatment on properties of the sensing layers, such as the temperature coefficient of resistance (TCR), linearity, hysteresis, drift, reliability, and bending resistance, were mainly studied. The results showed that the TCR (0.00234 °C−1) was the highest when sputtering power was 90 W and sputtering pressure was 0.8 Pa. The crystallinity of Ag particles would improve, as the TCR was improved to 0.00262 °C−1 under heat treatment condition at 160°. The Ag layer obtained excellent linearity, lower hysteresis and drift value, as well as good reliability and bending resistance when the sputtering power was 90 W. The flexible temperature sensor based on the coated polyester fabric improved the softness and comfortableness of sensor, which can be further applied in intelligent wearable products.
9
Cheng, Ching-Tai, Jiang-Tsair Lin, and Hong-Ching Lin. "Addition of Nb2O5 on the electrical properties of buried resistors in low-temperature cofired ceramics." Journal of Materials Research 18, no. 5 (May 2003): 1211–18. http://dx.doi.org/10.1557/jmr.2003.0166.
Повний текст джерелаАнотація:
Nb2O5 was added to buried resistors for low-temperature cofired ceramics, and the electrical properties of the resultant resistors were examined. Remarkable increases in electrical resistivity and attractive decreases in the temperature coefficient of resistance (TCR) were observed by the addition of Nb2O5, which was attributed to the high solubility of Nb2O5 into the PbO-SiO2-Al2O3 matrix glass. With higher dissolved contents of Nb2O5 into the glass, the resistivity of buried resistors increased by approximately six-fold magnitude, while TCR decreased substantially toward zero. It was indicated that the conductance for these buried resistors was limited by tunneling of charge carriers through the thin glass layer penetrating into the ruthenium-oxide agglomerates. A larger separation observed between RuO2 particles due to high solubility of Nb2O5 in the glass increased the charging energy (E) and lump term (Rbo), which in turn gave rise to a higher resistivity and a lower TCR value.
10
Kolmakov, Andrei, and D. W. Goodman. "In situ scanning tunneling microscopy of oxide-supported metal clusters: Nucleation, growth, and thermal evolution of individual particles." Chemical Record 2, no. 6 (November 2002): 446–57. http://dx.doi.org/10.1002/tcr.10045.
Повний текст джерела
11
Anikeeva, Nadia, Nicholas O. Fischer, Craig D. Blanchette, and Yuri Sykulev. "MHC clustering regulates selectivity and effectiveness of T-cell responses." Journal of Immunology 202, no. 1_Supplement (May 1, 2019): 130.21. http://dx.doi.org/10.4049/jimmunol.202.supp.130.21.
Повний текст джерелаАнотація:
Abstract Although formation of nano-scale MHC clusters on the cell membrane of antigen-presenting cells has been well documented, the essence of MHC clustering and the role in controlling antigen presentation and T-cell responses have been not systematically studied. This is due to the absence of available approaches to evaluate how the clusters’ size, density and composition of MHC clusters influence TCR engagement and triggering of TCR signaling. We exploited nano-scale discoidal membrane mimetics (nanolipoprotein particles, or NLPs) to capture and present pMHC ligands at various densities and examined the binding of these model membrane clusters to the surface of live human CD8+ T cells and the subsequent triggering of intracellular Ca2+ signaling. The data demonstrate that the proximity of pMHC ligands, high association rate of CD8-MHC interactions, and relatively long lifetime of cognate TCR-pMHC complexes emerge as essential parameters explaining the significance of MHC clustering. Rapid rebinding of CD8 to clustered MHC suggests a dual role of CD8 in facilitating the T cells’ hunt for a rare foreign pMHC ligand and the induction of rapid T-cell response. Thus, our findings provide a new understanding of how MHC clustering influences multivalent interactions of pMHC ligands with CD8 and TCR on live T cells that regulate antigen recognition, kinetics of intracellular signaling, and the selectivity and efficiency of T-cell responses.
12
Lo, Ying-Chun, Michael Edidin, and Jonathan Powell. "Selective Activation of Antigen-Specific T Cells by Anti-CD3 Constraining Nano-particles (58.15)." Journal of Immunology 188, no. 1_Supplement (May 1, 2012): 58.15. http://dx.doi.org/10.4049/jimmunol.188.supp.58.15.
Повний текст джерелаАнотація:
Abstract Upon antigen (Ag) recognition, TCRs form nanoscale clusters on the T cell surface. We hypothesized that the spatial differences of surface TCR between naïve and previously activated cells might be exploited by using anti-CD3 coated quantum dots (Qdots) to selectively activate Ag-specific cells. Rag-/- Pigeon Cytochrome c (PCC) specific CD4+ T cells were activated with APC +/- PCC with or without anti-CD3 Qdots. Anti-CD3 Qdots markedly enhanced proliferation of T cells incubated with low dose PCC but did not drive proliferation of T cells incubated with APC alone, though such cells proliferated to soluble anti-CD3. Additionally, anti-CD3 Qdots increased cytokine production of such cells in TH1 and TH2 cultures. We also explored the effect of anti-CD3 Qdots on heterogeneous cultures containing Rag+/+ hemagglutinin peptide (HA) specific 6.5+ CD4+ T cells and bystander 6.5- CD4+ T cells. Soluble anti-CD3 resulted in proliferation of both 6.5+ and 6.5- T cells. Cultures including low dose HA induced only 6.5+ T cells to proliferate, and addition of anti-CD3 Qdots further selectively enhanced proliferation of 6.5+ T cells but not 6.5- T cells in the same culture. This effect was again seen using CD8+ TCR transgenic T cells specific for class I HA. In vivo, anti-CD3 Qdots also increased the recovery of 6.5+ cells in a 6.5 adoptive transfer and HA vaccination model. Thus, constraining anti-CD3 on a nanoparticle confers an Ag-specific “nano boost” to T cell proliferation and function.
13
Lesmana, Hadi, Wahyu Setia Budi, Rasito Rasito, and Pandji Triadyaksa. "MONTE CARLO NEUTRON DOSE MEASUREMENT IN PROTON THERAPY FOR HEALTHCARE WORKER RADIATION SAFETY." Jurnal Kedokteran Diponegoro (Diponegoro Medical Journal) 12, no. 3 (May 22, 2023): 157–66. http://dx.doi.org/10.14710/dmj.v12i3.38660.
Повний текст джерелаАнотація:
Background: Proton therapy is an innovative and highly advanced external radiation therapy modality for cancer treatment that uses positively charged atomic particles. The usage of proton therapy facilities in Asia has been increasing and will be followed by Indonesia in the short-coming years. In line with its significant benefits, the application of proton therapy also requires radiation protection awareness due to its higher energy used by protons produces scattered photon and neutron radiation in proton interactions. Therefore, optimal verification is needed in the commissioning process for designing proton therapy shielding bunkers. Objective: This research aims to examine the effect of concrete density on proton shielding by calculating the equivalent dose H*(10) of neutrons in the treatment control room (TCR) and the door of the compact proton therapy facility (CPTC) using Particle and Heavy Ion Transport code System (PHITS) simulation software. Method: The proton facility modeled for this simulation uses a compact proton therapy type planned to be built at one of the radiotherapy facilities in Indonesia. The proton therapy bunker model consists of a synchrocyclotron accelerator room and an examination room with standard configurations, wall thicknesses, and modeling areas under compact proton therapy standards. The analysis is focused on assessing the suitability of concrete materials and wall thicknesses and determining the neutron exposure dose values in the TCR and CPTC doors. The geometry, radiation source, and type of concrete in the wall are simulated from a conservative assumption to a more realistic model. Result: At the designated points in the TCR and CPTC door, measurements are taken from the simulation, which indicates that the equivalent dose H*(10) value is below one mSv/year. Conclusion: This value indicates that the dose rate passing through the wall does not exceed the dose limit value already set at one mSv/year for the general public.
14
Kueng, Hans J., Victoria M. Leb, Daniela Haiderer, Graça Raposo, Clotilde Thery, Sophia V. Derdak, Klaus G. Schmetterer, et al. "General Strategy for Decoration of Enveloped Viruses with Functionally Active Lipid-Modified Cytokines." Journal of Virology 81, no. 16 (May 30, 2007): 8666–76. http://dx.doi.org/10.1128/jvi.00682-07.
Повний текст джерелаАнотація:
ABSTRACT Viral particles preferentially incorporate extra- and intracellular constituents of host cell lipid rafts, a phenomenon central to pseudotyping. Based on this mechanism, we have developed a system for the predictable decoration of enveloped viruses with functionally active cytokines that circumvents the need to modify viral proteins themselves. Human interleukin-2 (hIL-2), hIL-4, human granulocyte-macrophage colony-stimulating factor (hGM-CSF), and murine IL-2 (mIL-2) were used as model cytokines and fused at their C terminus to the glycosylphosphatidylinositol (GPI) acceptor sequence of human Fcγ receptor III (CD16b). We show here that genetically modified cytokines are all well expressed on 293 producer cells. However, only molecules equipped with GPI anchors but not those linked to transmembrane/intracellular regions of type I membrane proteins are efficiently targeted to lipid rafts and consequently to virus-like particles (VLP) induced by Moloney murine leukemia virus Gag-Pol. hIL-4::GPI and hGM-CSF::GPI coexpressed on VLP were found to differentiate monocytes towards dendritic cells. Apart from myeloid-committed cell types, VLP-bound cytokines also act efficiently on lymphocytes. hIL-2::GPI strongly costimulated T-cell receptor (TCR)/CD3 dependent T-cell activation in vitro and mIL-2::GPI-coactivated antigen-specific T cells in vivo. On a molar basis, the functional activity of VLP-bound hIL-2::GPI was found to be comparable to that of soluble hIL-2. VLP decorated with hIL-2::GPI and coexpressing a TCR/CD3 ligand have an IL-2-specific activity of 5 × 104 units/mg protein. Virus particles decorated with lipid-modified cytokines might help to improve viral strains for vaccination purposes, the propagation of factor-dependent cell types, as well as gene transfer by viral systems in the future.
15
Xiang, Jinhua, James H. McLinden, Qing Chang, Thomas M. Kaufman, Judy A. Streit, and Jack T. Stapleton. "Yellow Fever Virus Vaccine Reduces T Cell Receptor Signaling and the Levels of Phosphatase PTPRE In Vivo." Proceedings 50, no. 1 (June 24, 2020): 97. http://dx.doi.org/10.3390/proceedings2020050097.
Повний текст джерелаАнотація:
Background: A Src kinase-activating phosphatase (PTPRE) is targeted by a genome-derived yellow fever virus (YFV) short noncoding RNA (vsRNA) in vitro. The vsRNA reduces PTPRE translation, which leads to reduced TCR signaling. vsRNA point mutations restore PTPRE expression and T cell function. We examined TCR signaling and PTPRE levels in individuals before and after YFV vaccination (YFVax). Methods: Fourteen individuals receiving YFVax (104.7–5.6) IM for travel prophylaxis provided written informed consent for these studies. Blood was obtained once before vaccination and four times after vaccination (days 3 to 28). Serum and PBMCs were purified and YFV was quantified by RNA and infectivity. PBMCs were assessed for activation following anti-CD3 stimulation by measuring phospho-tyrosine-394-Lck and IL-2 release. PBMC PTPRE levels were determined by immunoblot analyses (normalized to actin). A YFV-neutralizing antibody was determined by PRNT. Results: YFVax was administered alone (six out of 14 subjects) or in combination with other vaccines (eight out of 14). All subjects demonstrated reduced resting PBMC PTPRE levels and post-TCR stimulation had reduced IL-2 release between days 4 and 21 compared to pre- and day 28 samples. Phospho-Lck was reduced in all but two subjects on the same days, and both of these subjects also received an influenza vaccine. Low-level viremia was detected in 10/14 subjects, with infectious titers of 100/mL. Viremia was not detected in four out of 14 subjects. All recipients developed neutralizing antibodies by day 21. Conclusion: YFV vaccination regulates PBMC PTPRE levels 4–21 days after infection, despite the low to absent infectious YFV detected in serum, suggesting that enough YFV vsRNA is produced and released from cells to have a functional (and measurable) effect on T cell function. Studies are underway to determine if this is mediated by exosomes or defective particles containing the vsRNA that targets PTPRE. Furthermore, the association between PTPRE and TCR signaling confirms a role for PTPRE in TCR function.
16
Bhattarai, Nirjal, James H. McLinden, Jinhua Xiang, Alan L. Landay, Ernest T. Chivero, and Jack T. Stapleton. "GB Virus C Particles Inhibit T Cell Activation via Envelope E2 Protein-Mediated Inhibition of TCR Signaling." Journal of Immunology 190, no. 12 (May 17, 2013): 6351–59. http://dx.doi.org/10.4049/jimmunol.1300589.
Повний текст джерела
17
Fortin, Jean-François, Réjean Cantin, and Michel J. Tremblay. "T Cells Expressing Activated LFA-1 Are More Susceptible to Infection with Human Immunodeficiency Virus Type 1 Particles Bearing Host-Encoded ICAM-1." Journal of Virology 72, no. 3 (March 1, 1998): 2105–12. http://dx.doi.org/10.1128/jvi.72.3.2105-2112.1998.
Повний текст джерелаАнотація:
ABSTRACT The incorporation of host-derived proteins in nascent human immunodeficiency virus type 1 (HIV-1) particles is a well-established phenomenon. We recently demonstrated that the physical presence of host-encoded ICAM-1 glycoproteins on HIV-1 leads to a significant increase in virus infectivity in an ICAM-1/LFA-1-dependent fashion (J.-F. Fortin, R. Cantin, G. Lamontagne, and M. Tremblay, J. Virol. 71:3588–3596, 1997). We show here that conversion of LFA-1 to high affinity for ICAM-1 with the use of anti-LFA-1 antibodies (clones NKI-L16 and MEM83) markedly enhances the susceptibility of different target T-lymphoid cell lines, as well as of primary peripheral blood mononuclear cells, to infection by ICAM-1-bearing HIV-1 particles (6- to 95-fold). It is known that T-cell receptor (TCR) cross-linking induces a transient increase in LFA-1 affinity for ICAM-1. Treatment of peripheral blood mononuclear cells with anti-TCR antibodies (clone OKT3) resulted in a transient increase in susceptibility to infection by ICAM-1-positive virions that parallels the previously reported kinetics of the LFA-1/ICAM-1 adhesion mechanism. Our results led us to postulate that the strong interaction taking place between virally incorporated ICAM-1 and cell surface-activated LFA-1 markedly enhances the efficiency of virus binding and entry, thus favoring greater infection by ICAM-1-bearing HIV-1 particles. In view of the knowledge that primary HIV-1 isolates harbor host-derived ICAM-1 on their surfaces, these results provide new information about the role of host-derived ICAM-1 in the life cycle of HIV-1 and how it could positively modulate the dynamics of the viral infection, mainly in cellular compartments, such as the lymphoid tissues, where the level of cellular activation is high and where the probability of encountering a T cell expressing the activated LFA-1 form is also elevated.
18
Eskandari, Siawosh K., Ina Sulkaj, Mariane B. Melo, Na Li, Hazim Allos, Juliano B. Alhaddad, Branislav Kollar, et al. "Regulatory T cells engineered with TCR signaling–responsive IL-2 nanogels suppress alloimmunity in sites of antigen encounter." Science Translational Medicine 12, no. 569 (November 11, 2020): eaaw4744. http://dx.doi.org/10.1126/scitranslmed.aaw4744.
Повний текст джерелаАнотація:
Adoptive cell transfer of ex vivo expanded regulatory T cells (Tregs) has shown immense potential in animal models of auto- and alloimmunity. However, the effective translation of such Treg therapies to the clinic has been slow. Because Treg homeostasis is known to require continuous T cell receptor (TCR) ligation and exogenous interleukin-2 (IL-2), some investigators have explored the use of low-dose IL-2 injections to increase endogenous Treg responses. Systemic IL-2 immunotherapy, however, can also lead to the activation of cytotoxic T lymphocytes and natural killer cells, causing adverse therapeutic outcomes. Here, we describe a drug delivery platform, which can be engineered to autostimulate Tregs with IL-2 in response to TCR-dependent activation, and thus activate these cells in sites of antigen encounter. To this end, protein nanogels (NGs) were synthesized with cleavable bis(N-hydroxysuccinimide) cross-linkers and IL-2/Fc fusion (IL-2) proteins to form particles that release IL-2 under reducing conditions, as found at the surface of T cells receiving stimulation through the TCR. Tregs surface-conjugated with IL-2 NGs were found to have preferential, allograft-protective effects relative to unmodified Tregs or Tregs stimulated with systemic IL-2. We demonstrate that murine and human NG–modified Tregs carrying an IL-2 cargo perform better than conventional Tregs in suppressing alloimmunity in murine and humanized mouse allotransplantation models. In all, the technology presented in this study has the potential to improve Treg transfer therapy by enabling the regulated spatiotemporal provision of IL-2 to antigen-primed Tregs.
19
Hermansson, Andreas, Daniel F. J. Ketelhuth, Daniela Strodthoff, Marion Wurm, Emil M. Hansson, Antonino Nicoletti, Gabrielle Paulsson-Berne, and Göran K. Hansson. "Inhibition of T cell response to native low-density lipoprotein reduces atherosclerosis." Journal of Experimental Medicine 207, no. 5 (May 3, 2010): 1081–93. http://dx.doi.org/10.1084/jem.20092243.
Повний текст джерелаАнотація:
Immune responses to oxidized low-density lipoprotein (oxLDL) are proposed to be important in atherosclerosis. To identify the mechanisms of recognition that govern T cell responses to LDL particles, we generated T cell hybridomas from human ApoB100 transgenic (huB100tg) mice that were immunized with human oxLDL. Surprisingly, none of the hybridomas responded to oxidized LDL, only to native LDL and the purified LDL apolipoprotein ApoB100. However, sera from immunized mice contained IgG antibodies to oxLDL, suggesting that T cell responses to native ApoB100 help B cells making antibodies to oxLDL. ApoB100 responding CD4+ T cell hybridomas were MHC class II–restricted and expressed a single T cell receptor (TCR) variable (V) β chain, TRBV31, with different Vα chains. Immunization of huB100tgxLdlr−/− mice with a TRBV31-derived peptide induced anti-TRBV31 antibodies that blocked T cell recognition of ApoB100. This treatment significantly reduced atherosclerosis by 65%, with a concomitant reduction of macrophage infiltration and MHC class II expression in lesions. In conclusion, CD4+ T cells recognize epitopes on native ApoB100 protein, this response is associated with a limited set of clonotypic TCRs, and blocking TCR-dependent antigen recognition by these T cells protects against atherosclerosis.
20
Meyers, S., P. D. Gottlieb, and J. P. Dudley. "Lymphomas with acquired mouse mammary tumor virus proviruses resemble distinct prethymic and intrathymic phenotypes defined in vivo." Journal of Immunology 142, no. 9 (May 1, 1989): 3342–50. http://dx.doi.org/10.4049/jimmunol.142.9.3342.
Повний текст джерелаАнотація:
Abstract A number of murine T cell lymphomas expressing the T cell Ag Thy-1 contain acquired mouse mammary tumor (MMTV) proviruses. These lymphomas all express detectable levels of MMTV RNA, yet the majority of the tumors fail to produce MMTV particles. To determine if the ability of lymphomas to produce MMTV is a reflection of the differentiation state of the tumor, we examined eight lymphomas for expression of surface B and T cell Ag as well as for rearrangements and expression of TCR genes. All tumors could be grouped into three categories observed in vivo, including early lymphoid, nonmature intrathymic T cells, and immature intrathymic T cells. Cell lines corresponding to all three phenotypes produced MMTV particles, suggesting that production of virus is not linked to the differentiation state of lymphoid cells. These studies highlight the potential advantage of studying T cell lymphomas vs mixed primary populations or T cell hybridomas for evaluation of both phenotypic and molecular markers in clonal T cells.
21
Mazhukin, Vladimir Ivanovich, Olga Nikolaevna Koroleva, Mikhail Mikhailovich Demin, and Anna Andreevna Aleksashkina. "Atomistic modeling of the parameters of the critical region of gold using the liquid-vapor coexistence curve." Keldysh Institute Preprints, no. 83 (2021): 1–16. http://dx.doi.org/10.20948/prepr-2021-83.
Повний текст джерелаАнотація:
The liquid-vapor coexistence curve for gold was obtained by molecular dynamics (MD) modeling and the critical parameters were determined: temperature, density and pressure. The interaction potential of particles of the “embedded atom” family EAM is used. The critical temperature Tcr was determined from the results of MD simulation using the method of the average cluster size in the critical region. To clarify the value of the critical density, the empirical rule of the rectilinear diameter was used. The comparison of the simulation results of this work with the results of the assessment of the critical parameters of gold by other authors using different approaches.
22
Szomolanyi-Tsuda, Eva, Quang P. Le, Robert L. Garcea, and Raymond M. Welsh. "T-Cell-Independent Immunoglobulin G Responses In Vivo Are Elicited by Live-Virus Infection but Not by Immunization with Viral Proteins or Virus-Like Particles." Journal of Virology 72, no. 8 (August 1, 1998): 6665–70. http://dx.doi.org/10.1128/jvi.72.8.6665-6670.1998.
Повний текст джерелаАнотація:
ABSTRACT Immunoglobulin G (IgG) responses to viruses are generally assumed to be T-cell dependent (TD). Recently, however, polyomavirus (PyV) infection of T-cell-deficient (T-cell receptor β chain [TCR-β] −/− or TCR-β×δ −/−) mice was shown to elicit a protective, T-cell-independent (TI) antiviral IgM and IgG response. A repetitive, highly organized antigenic structure common to many TI antigens is postulated to be important in the induction of antibody responses in the absence of helper T cells. To test whether the repetitive structure of viral antigens is essential and/or sufficient for the induction of TI antibodies, we compared the abilities of three forms of PyV antigens to induce IgM and IgG responses in T-cell-deficient mice: soluble capsid antigens (VP1), repetitive virus-like particles (VLPs), and live PyV. Immunization with each of the viral antigens resulted in IgM production. VLPs and PyV elicited 10-fold-higher IgM titers than VP1, indicating that the highly organized, repetitive antigens are more efficient in IgM induction. Antigen-specific TI IgG responses, however, were detected only in mice infected with live PyV, not in VP1- or VLP-immunized mice. These results suggest that the highly organized, repetitive nature of the viral antigens is insufficient to account for their ability to elicit TI IgG response and that signals generated by live-virus infection may be essential for the switch to IgG production in the absence of T cells. Germinal centers were not observed in T-cell-deficient PyV-infected mice, indicating that the germinal center pathway of B-cell differentiation is TD even in the context of a virus infection.
23
Liu, Hongrui, Yongchun Li, Weiji Xie, Xinyi Zhou, Jishuang Hong, Junfeng Liang, Yanghui Liu, Wei Li, and Hong Wang. "Fabrication of Temperature Sensors with High-Performance Uniformity through Thermal Annealing." Materials 16, no. 4 (February 10, 2023): 1491. http://dx.doi.org/10.3390/ma16041491.
Повний текст джерелаАнотація:
It is considered to be of great significance to monitor human health and track the effect of drugs by measuring human temperature mapping through flexible temperature sensors. In this work, we found that the thermal annealing of flexible temperature sensors based on graphite–acrylate copolymer composites can not only improve the temperature coefficient of resistance (TCR) values of the devices, but also greatly improve the uniformity of the performance of the devices prepared in parallel. The best results were obtained when the devices were annealed at 100 °C, which is believed to be due to the rearrangement of graphite particles to generate more uniform and numerous conductive channels within the conductive composite. We believe this finding might promote the practical development of flexible temperature sensors in body temperature sensing for health maintenance and medical applications.
24
McLain, L., and N. J. Dimmock. "A monoclonal antibody produced during infection which recognizes an epitope of influenza hemagglutinin only in the context of H-2k MHC class I antigen." Journal of Immunology 150, no. 8 (April 15, 1993): 3421–26. http://dx.doi.org/10.4049/jimmunol.150.8.3421.
Повний текст джерелаАнотація:
Abstract A hybridoma prepared from cells isolated from the lungs of H-2k mice infected with influenza virus (A/WSN) produces a monoclonal IgM (LM41) which recognizes an epitope of the A/WSN hemagglutinin (HA) Ag only when it is expressed in H-2k cells, as shown by Ag binding and complement-mediated lysis. However, it did not bind to the native HA of virus particles or any form of HA protein present on A/WSN-infected H-2d cells. LM41 inhibited Ag-specific, MHC class I-restricted lysis of H-2k target cells infected with a vaccinia recombinant virus expressing the HA of A/WSN by CTL from A/WSN virus-infected H-2k mice. We conclude that LM41 has a similar Ag specificity to the HA-specific TCR.
25
Jun, Chang-Duk, Jeong-Su Park, Jun-Hyeong Kim, Won-Chang Soh, Na-Young Kim, Kyung-Sik Lee, Chang-Hyun Kim, Ik-Joo Chung, Sunjae Lee, and Hye-Ran Kim. "Trogocytic-molting of T-cell microvilli controls T-cell clonal expansion." Journal of Immunology 210, no. 1_Supplement (May 1, 2023): 168.01. http://dx.doi.org/10.4049/jimmunol.210.supp.168.01.
Повний текст джерелаАнотація:
Abstract Internalization of the T-cell antigen receptor (TCR) is intimately linked to T-cell activation: a phenomenon thought to be related to the “exhaustion” of T-cell responses. To date, however, no report has considered that during physical interaction with cognate antigen-presenting cells, T cells release many TCRs via T-cell microvilli particles, which are derived from finger-like membrane structures (microvilli) in a combined process of trogocytosis and enzymatic vesiculation and correspond with the loss of membrane TCRs and many external membrane components. Surprisingly, in contrast to TCR internalization, this event leads to rapid upregulation of surface TCRs and remarkable metabolic reprogramming of cholesterol and fatty acids synthesis to meet the demands of clonal expansion, which drives multiple rounds of division and cell survival. We called this event “trogocytic-molting,” which represents an intrinsic molecular basis of T-cell clonal expansion by which T cells gain increased sensitivity to low antigen concentrations. This work was supported by the Creative Research Initiative Program (2015R1A3A2066253); Bio-Synergy Research Project (2021M3A9C4000991); Bio & Medical Technology Development Program [2020M3A9G3080281] through National Research Foundation (NRF) grants funded by the Ministry of Science and ICT (MSIT), the Basic Science Program (2019R1C1C1009570 & 2022R1A2C4002627) through National Research Foundation (NRF) grants funded by the Ministry of Education (MOE), and supported by Global University Project (GUP), GIST Research Institute (GRI) IBBR grant funded by the GIST (in 2021-2022), and the Joint Research Project of Institutes of Science and Technology (2021–2022), Korea.
26
Elia, Angela Rita, Giorgio Inghirami, Paola Circosta, Flavio Cristofani, Nathalie Santoro, Dario Sangiolo, Corrado Tarella, and Alessandro Cignetti. "Retargeting of Citokine-Induced Killer (CIK) Cells with Molecularly Engrafted T-Cell Receptors (TCR): A Preclinical in Vitro and In Vivo Study." Blood 118, no. 21 (November 18, 2011): 1917. http://dx.doi.org/10.1182/blood.v118.21.1917.1917.
Повний текст джерелаАнотація:
Abstract Abstract 1917 Cytokine Induced Killer (CIK) cells are a heterogeneous population of T lymphocytes sharing NK phenotype and functional properties: they are CD3+/CD56+ and have a potent MHC-unrestricted antitumor activity. We hypothesized that the therapeutic potential of CIK cells might be increased if they acquired the ability to recognize MHC-restricted tumor associated antigens. To this end, we transduced CIK cells with an HLA-A2 restricted T-Cell Receptor (TCR) directed against the melanocyte associated antigen Mart-1. PBMC were incubated with IFN-γ on day 0 and supplemented with anti-CD3 and IL-2 on day +1 to generate CIK cells. Cultures were transduced at day 4 with concentrated lentiviral particles and successfully expanded over a 4 week period. This allowed to generate CIK cells that contained 11±9% Mart-1 TCR positive cells, as detected by staining with a Mart-1 specific tetramer. Transduced CIK cultures contained 61±19% CD3+/CD56+ cells. Tetramer positive cells were both CD3+/CD56- and CD3+/CD56+ (31±8% and 59±9%, respectively), indicating that both MHC-restricted T-cells and MHC-unrestricted CIK cells could be targeted by lentiviral transduction. TCR-transduced CIK cells specifically recognized tumor cells presenting the relevant peptide and maintained their MHC-unrestricted tumor activity at the same time. The cytotoxic activity of Mart-1 redirected CIK against HLA-A2+ melanoma cell lines was 2.8 fold higher than the untransduced counterparts (62%±9 vs 22±6% lysis at an effector/target ratio of 20:1), while the cytotoxic activity against a Mart-1+/HLA-A2- melanoma cell line was similar in transduced and untransduced CIK cells (24%±8 vs 22±6% lysis), indicating that the increased activity was due to HLA-restricted recognition. This was confirmed by blocking experiments with an HLA-Class I antibody. At the end of the culture, the majority of both unmodified and transduced CIK cells expressed an effector memory phenotype, with few residual central memory cells. In TCR redirected cells there was a slight increase of cells with a naive phenotype compared to unmodified cells (19±5% vs 9±4%). These data suggest that the naive and central memory pool of redirected CIK cells might efficiently expand in vivo and support a long lived memory response, whereas the terminally differentiated pool might mediate short lived but potent MHC-restricted and unrestricted activity. To demonstrate that TCR transduced CIK cells display an increased antitumor activity also in vivo, we have conducted preparative experiments in humanized immunocompromised mice (NOD/scid/γ(c)(−/−), NSG). Results obtained so far have shown that: i) When 5×106 or 10×106 CIK cells (both TCR-transduced and unmodified) were injected intravenously, they stably engrafted NSG mice, homing predominantly to spleen and liver and also, to a lesser extent, to bone marrow and kidney (36±9%, 39±12%, 4±3%, 1.6±3% of human CD3+/CD45+ cells at 3 months in the spleen, liver, bone marrow and kidney, respectively); circulating cells were also detected in the peripheral blood. Engrafted CIK cells maintained high expression of CD8 but progressively downregulated and finally lost CD56 expression. When 10×106 CFSE-marked CIK cells where injected intravenously, they similarly engrafted and proliferated in NSG mice, reaching a peak of proliferation 2–3 weeks after injection; at 4 weeks, the CFSE dye was already completely diluted out. ii) Differently from normal PBMC, CIK cells did not induce any appreciable clinical sign of acute or chronic Graft versus Host Disease (GVHD), as determined by the general appearance of the fur, mobility and weight loss. Mice were observed up to 5 months, and both unmodified and TCR transduced CIK cells displayed the same behavior. iii) NSG accepted the graft of as few as 50.000 matrigel-resuspended melanoma cells that were injected subcutaneously, with the appearance of a measurable mass (>3mm) ten days after inoculation. From these in vivo experiments we conclude that: i) human CIK cells engraft and proliferate in NSG mice; ii) CIK cells do not cause GVHD; iii) the human melanoma cell lines used in vitro can grow in NSG mice. We are now testing whether TCR transduced CIK cells have superior antitumor activity than unmodified CIK in the NSG mice model. Taken together, our data suggest that TCR transfer into CIK cells is feasible and greatly improves their antitumor potential in vitro and possibly in vivo. Disclosures: No relevant conflicts of interest to declare.
27
Ade, Brian J., Benjamin R. Betzler, Aaron J. Wysocki, Michael S. Greenwood, Phillip C. Chesser, Kurt A. Terrani, Prashant K. Jain, et al. "Candidate Core Designs for the Transformational Challenge Reactor." Journal of Nuclear Engineering 2, no. 1 (March 19, 2021): 74–85. http://dx.doi.org/10.3390/jne2010008.
Повний текст джерелаАнотація:
Early cycle activities under the Transformational Challenge Reactor (TCR) program focused on analyzing and maturing four reactor core design concepts: two fast-spectrum systems and two thermal-spectrum systems. A rapid, iterative approach has been implemented through which designs can be modified and analyzed and subcomponents can be manufactured in parallel over time frames of weeks rather than months or years. To meet key program initiatives (e.g., timeline, material use), several constraints—including fissile material availability (less than 250 kg of HALEU), component availabilities, materials compatibility, and additive manufacturing capabilities—were factored into the design effort, yielding small (less than one cubic meter in volume) cores with near-term viability. The fast-spectrum designs did not meet the fissile material constraint, so the thermal-spectrum systems became the primary design focus. Since significant progress has been made on advanced moderator materials (YHx) under the TCR program, gas-cooled thermal-spectrum systems using less than 250 kg of HALEU that occupy less than 1 m3 are now feasible. The designs for two of these systems have been evolved and matured. In both thermal-spectrum design concepts, bidirectional coolant flow is used. Coolant flows down through YHx moderator elements and is reversed in a bottom manifold and core support structure, and then flows up though or around the fuel elements. The main difference between the two thermal-spectrum design concepts is the fuel elements—one uses traditional UO2 ceramic fuel, and the other uses UN-bearing TRISO fuel particles embedded inside a SiC matrix. Core neutronics and thermal performance for these systems are assessed and summarized herein.
28
Dunkle, Alexis, Craig Blanchette, Tyler Boone, Michele Corzett, Mona Hwang, Nicholas Fischer, Doerte Lehmann, et al. "Use of biologic nanolipoprotein particles containing monophosphoryl lipid A as a novel vaccine platform against inhalational pathogens (VAC7P.956)." Journal of Immunology 192, no. 1_Supplement (May 1, 2014): 141.1. http://dx.doi.org/10.4049/jimmunol.192.supp.141.1.
Повний текст джерелаАнотація:
Abstract Subunit vaccines are theoretically safe and easy to manufacture but require effective adjuvants and delivery systems to yield protective immunity, particularly at critical mucosal sites such as the lung. We investigated nanolipoprotein particles (NLPs) containing the Toll-like receptor 4 agonist monophosphoryl lipid A (MPLA) as a platform for intranasal vaccination against Bacillus anthracis. Modified lipids enabled attachment of disparate spore and toxin protein antigens. Intranasal vaccination of mice with B. anthracis antigen-MPLA-NLP constructs vs. delivery with free MPLA induced robust IgG and IgA responses in serum and in bronchoalveolar and nasal lavage. Typically, a single dose sufficed to induce sustained antibody titers over time. When multiple immunizations were required, specific antibodies were detected earlier in the boost schedule with MPLA-NLP-mediated delivery than with free MPLA. Administering combinations of constructs induced responses to multiple antigens, indicating potential for a multivalent vaccine preparation. No off-target responses to the species-matched NLP scaffold protein were detected. Using the ovalbumin/TCR transgenic model, MPLA-NLPs enhanced antigen-specific T cell expansion in lung-draining lymph nodes. In summary, the NLP platform enhances cellular, humoral, and mucosal responses to intranasal immunization, indicating promise for NLPs as a flexible, robust vaccine platform against B. anthracis and potentially other inhalational pathogens.
29
Ichise, Hiroshi, Jyh Liang Hor, Armando J. Arroyo-Mejías, Yasmine Belkaid, and Ronald N. Germain. "Deciphering the functional role of commensal-induced T-DC clustering along sensory nerves in the lung." Journal of Immunology 210, no. 1_Supplement (May 1, 2023): 156.08. http://dx.doi.org/10.4049/jimmunol.210.supp.156.08.
Повний текст джерелаАнотація:
Abstract The airway mucosa is a primary site of the immune response to inhaled antigens. However, how immune homeostasis is maintained in this organ during continuous exposure to airborne particles and microbial antigens is not known. Previous studies have shown that the spatial organization of immune components in relationship to each other and to non-hematopoietic components in tissues is critical to their proper function, as is communication with commensal microbes. To interrogate such relationships in the lung, especially the possible connections between immune cells and the densely innervated pulmonary airway, 3D information is required. However, current methods for 3D imaging of optically cleared tissue do not provide the marker depth afforded by high-content 2D imaging. To overcome this constraint, we combined a fast hydrophilic tissue clearing technique, Ce3D, with the recently developed IBEX technique, and created Ce3D-IBEX. To date, up to 20 markers have been visualized in a single sample. Using Ce3D-IBEX, we identified a previously uncharacterized clustering of T cells and dendritic cells in proximity to the pulmonary sensory nerves in naïve mice. Agonistic denervation of the sensory nerves with resiniferatoxin reduced the number of clusters, and the cluster formation was disrupted in germ-free mice as well as OT-I and OT-II TCR-Tg mice. These findings indicate that the clustering requires sensory nerve-derived signals and TCR-mediated recognition of bacterial antigens. Future studies will be aimed at elucidating the functional role of the clusters in homeostasis and disease conditions and determining the molecular basis for neuro-immune communication that regulates cluster formation and activity. All studies were done with approval from the ICUC of the NIH/NIAID. This work was supported by the Intramural Research Program of NIAID, NIH.
30
Hong, Xinghua, Wei Sun, Tao Peng, Junnan Qian, Zhaofa Zhang, Chengyan Zhu, and Guangmin Cai. "Manganese waste liquid derived MnFe2O4/RGO fabric for microwave blocking, high stable strain and temperature sensing." Journal of Industrial Textiles 52 (August 2022): 152808372211219. http://dx.doi.org/10.1177/15280837221121969.
Повний текст джерелаАнотація:
Herein, a MnFe2O4/RGO knitted fabric derived from manganese waste was constructed by a simple in-situ assembled coating method, involving the incorporation of Graphene Oxide (GO) and manganese ferrite nanoparticles on polyester fabric, followed reducing by hydrazine hydrate. The reuse of manganese waste from the preparation of GO can reduce chemical waste emissions and endow the absorption performance. The coated particles possess certain magnetism can be attracted and securely collected in seconds, which is convenient for recycling. This fabric gives well microwave absorption with the maximum reflection loss (RL) of −58.6 dB at 9.1 GHz by a thickness of 1.9 mm. In addition, this fabric presents high stable strain sensing under 1000 stretching and bending cycles. Meanwhile, the resistance-deformation-velocity relationship is provided based on the structure, for the analysis of electromechanical behaviors. Moreover, the fabric has the capability for temperature sensing (TCR=−0.738%/°C), and fire alarm. As such, this fabric can be promising alternatives for a wide application on motion and temperature sensing, microwave blocking.
31
Malyshev, V. P., and A. M. Makasheva. "Description of dynamic viscosity depending on the alloys composition and temperature using state diagrams." Izvestiya Visshikh Uchebnykh Zavedenii. Chernaya Metallurgiya = Izvestiya. Ferrous Metallurgy 61, no. 9 (October 21, 2018): 743–49. http://dx.doi.org/10.17073/0368-0797-2019-9-743-749.
Повний текст джерелаАнотація:
The equilibrium nature of viscosity and fluidity is discovered on the basis of the Boltzmann distribution within the framework of the concept of randomized particles as a result of the virtual presence of crystal-mobile, liquid-mobile and vapor-mobile particles. It allows one to consider the viscosity and fluidity of solutions, in particular, melts of metal alloys, from the point of view of the equilibrium partial contributions of each component in the total viscosity and fluidity, despite the kinetic interpretation of natural expressions for these properties of the liquid. A linearly additive partial expression of viscosity is possible only for perfect solutions, in this case, for alloys with unrestricted mutual solubility of the components. Alloys with eutectics, chemical compounds and other features of the state diagram are characterized by viscosity dependencies that repeat the shape of liquidus curve over entire range of the alloy composition at different temperatures, with an increase in smoothness and convergence of these curves at increasing temperature. It was established that these features of viscosity temperature dependence are completely revealed within the framework of the concept of randomized particles and the virtual cluster model of viscosity in calculating the fraction of clusters determining the viscosity of the alloy. That viscosity of the alloy is found by the formula in which thermal energy RTcr at liquidus temperature is the thermal barrier of chaotization, characterizing the crystallization temperature of the melt Tcr, as well as the melting point of pure substances. On this basis, a method is proposed for calculating the alloys viscosity by phase diagrams using the temperature dependences of pure components viscosity to change the alloy’s viscosity in proportion to ratio of the clusters fractions at any temperature above liquidus line and for the pure component, taking into account the mole fraction of each component. As a result, a three-factor model of the liquid alloy viscosity has been obtained in which the thermal barrier of chaotization RTcr is used as variable for the first time. It determines the fraction of clusters for both pure substances (at RTcr = RTm ) and for alloys. This thermal barrier reflects the essence of the virtual cluster theory of liquid and adequacy of the concept of randomized particles.
32
Pagar*, Ujwala M., and U. P. Shinde. "Annealing Effect on Structural, Morphological and Electrical Properties by Screen Printed Bunsenite NiO Thick Films." International Journal of Innovative Technology and Exploring Engineering 10, no. 6 (April 30, 2021): 80–85. http://dx.doi.org/10.35940/ijitee.f8826.0410621.
Повний текст джерелаАнотація:
Thick films of NiO deposited on glass substrate by screen printing technique. The nano powder of AR grade NiO was used for the preparation of thick films. The X-ray diffraction (XRD), Scanning Electron Microscopy and Electrical Characterization was carried out for unannealed and annealed films. The annealed films were at 250 0 C-400 0 C in a muffle furnace. Using characterisation techniques, the success of the synthesised nanoparticles was confirmed. The x-ray diffraction was used for structural characterization which confirms the polycrystalline nature of the films with cubic structure. From the SEM analysis the films show uniformity, roughness, large crystals and agglomeration of particles. The SEM-EDS analysed morphology and chemical compositions. The correlations between structural and morphological properties are reported. The D.C. resistance of the films was measured by half bridge method in air atmosphere at 30OC to 350OC. From the electrical parameters the NiO films shows semiconducting nature. The TCR, activation energy and sheet resistivity, specific surface area were calculated at different annealing temperatures. The electrical conductivity at room temperature was calculated as 4.56 × 𝟏𝟎 −𝟒 (𝜴 ∙ 𝒎) −𝟏
33
Zhang, Qiuli, Xiangrong Hui, Long Yan, Min Luo, Wenru Feng, Jun Zhou, and Xinzhe Lan. "Numerical Simulation of the Tar Mist and Dust Movement Process in a Low-Temperature Dry Distillation Furnace." Journal of Chemistry 2020 (March 2, 2020): 1–16. http://dx.doi.org/10.1155/2020/2356038.
Повний текст джерелаАнотація:
In the low-temperature dry distillation of low-rank coal, the important liquid product of coal tar is produced, but its quality and utilization rate are degraded by entrained dust. The movement of coal tar and dust in the furnace is a key factor in causing particles such as dust to mix with coal tar. Therefore, the Euler–Lagrangian method is used to simulate the two-phase motion process of gas, tar, and dust in a furnace. By considering the effects of tar particle size, dust particle size, gas velocity, tar density, and dust density, the motion process mechanism is revealed, enabling the dust content in coal tar to be reduced and the quality improved. The results indicate that tar particles with sizes less than 0.20 mm can be removed from the furnace by gas, and the smaller the particle size is, the shorter the time required for removal. Dust particles greater than 0.18 mm in size cannot be completely removed from the furnace. As the gas velocity increases, the time required for complete removal of the tar mist and dust gradually decreases. When the speed is 0.70 m/s, all tar mist is removed, although some particles remain. Tar mist with a density of more than 900 kg/m3 can be extensively removed, but dust with a density of more than 1400 kg/m3 is difficult to remove and remains in the furnace. Finally, particle size distribution experiments in the product were conducted to verify the accuracy of the numerical simulation.
34
Tan, Xiao. "Gag-derived VLPs and the delivery of CRISPR-Cas9 system in Gene and Cell Therapies." Highlights in Science, Engineering and Technology 36 (March 21, 2023): 1511–16. http://dx.doi.org/10.54097/hset.v36i.6278.
Повний текст джерелаАнотація:
Cancer had been an unsolved problem for decades that accounts for 375,400 cases in UK each year, with only a 50% survival rate of 10 or more years. With more recent advances in gene editing techniques like CRISPR-Cas9, immunotherapy was able to advance to better engineer T cells for adoptive T cell transfer therapies such as T cell receptor (TCR) therapy and chimeric antigen receptor T cell (CAR-T) therapy. For more efficient delivery of CRISPR-Cas9 system, several human immunodeficiency virus type 1 (HIV-1) as well as murine leukaemia virus (MLV) group-specific antigen (Gag)-based virus like particles (VLP)s were designed by either directly fusing the Cas9 mRNA, Cas9 protein, or sgRNA to either the N- or C-terminus of the Gag polyprotein or by inserting or replacing a part of the Gag polyprotein. The Gag polyproteins can then self-assemble, carrying their cargo and packaging them inside the VLP. All designs demonstrated a significant increase in cargo capacity and successful delivery of both Cas9 mRNA and Cas9 proteins or nucleases for T cell engineering, and this provides great potential for additional gene modifications in order to target specifically solid tumour due to their high efficiency and multiplexed editing nature.
35
Huan, Haixiang, Chilei Zhu, Biao Zhao, Wenqiang Xu, and Ke Zhang. "Simulation and Experimental Analysis of Surface Defects in Turning of TiCp/TC4 Composites." Micromachines 14, no. 1 (December 27, 2022): 69. http://dx.doi.org/10.3390/mi14010069.
Повний текст джерелаАнотація:
Processing TiCp/TC4 composites has always been difficult due to the mismatch between the mechanical and thermal properties of the matrix and the reinforced particles, which results in a variety of machined surface defects. To expose the mechanism of defect generated on the cutting surface of TiCp/TC4 composites and improve their cutting surface quality, a 3D finite element orthogonal turning simulation model of TiCp/TC4 composites is developed. The failure at the matrix-particle interface and the fracture and removal mechanism of the reinforcing phase particles are analyzed from a microscopic perspective using a single particle cutting simulation model. In addition, a three-dimensional cutting simulation model with randomly dispersed TiC particles and a volume fraction of 5% is developed, and various forms of cutting surface defects of TiCp/TC4 composites are examined. To verify the validity of the finite element simulation model, TiCp/TC4 composites with a volume fraction of 5% are selected for turning tests. For various cutting tools and particle relative positions, the simulation and test results show that the removal of particles takes the following forms: debonding, crushing, brittle fracture, and slight fracture at the top, leading to a shallow cavity, microcracks, residual TiC particles embedded in the cavity, and surface defects with severe plastic deformation of the matrix surrounding the cavity on the machined surface.
36
Kairytė, Agnė, Saulius Vaitkus, and Sigitas Vėjelis. "Titanate-Based Surface Modification of Paper Waste Particles and its Impact on Rigid Polyurethane Foam Properties." Key Engineering Materials 721 (December 2016): 58–62. http://dx.doi.org/10.4028/www.scientific.net/kem.721.58.
Повний текст джерелаАнотація:
Producing particulate filled polymer composites, even dispersion and sufficient adhesion between filler and polymer matrix is of great importance. In order to solve these issues, methodologies, such as ultrasonic dispersing and coupling agents, are proposed. The impact of particle surface modification with three different titanate coupling agents having the tradenames of TCA L44, TCA L38 and TCA K44 on paper waste sludge particles surface, polyurethane foam composite density, compressive and tensile strengths as well as water absorption and water vapour permeability is evaluated. Apparently, titanates form layer on the particle surface, thus increasing the interfacial adhesion between particles and polymer matrix. Basing on the obtained results, the optimal amount and type of titanate is 1 wt.% of TCA K44.
37
Jun, Chang-Duk, and Hye-Ran Kim. "T-cell microvilli constitute immunological synaptosomes that are specialized for intercellular communications." Journal of Immunology 202, no. 1_Supplement (May 1, 2019): 56.5. http://dx.doi.org/10.4049/jimmunol.202.supp.56.5.
Повний текст джерелаАнотація:
Abstract Lymphocytes contain abundant flexible projections termed microvilli, the inside of which contain many parallel bundles of actin filaments that extend the cell membrane in the form of a finger. Previous reports demonstrated microvilli on T cells have been proposed to survey surfaces of antigen-presenting cells (APC) or facilitate adhesion under flow. However, in addition to their key role in antigen sensing on APCs, whether they serve essential functions during T cell activation remains largely unclear. In this study, we observed that single T cell contacts with APCs occur through microvillar extensions, which appear to serve as locations for sequestration of immunologically important molecules, including TCR complexes, costimulatory and adhesion molecules, and various cytokines. Strikingly, we found that microvilli were separated from the T cell body by the combined action of two independent mechanisms (trogocytosis and membrane budding) and are deposited at the surface of cognate APCs, thereby potentially acting as the most efficient and effective means of delivering T cell messages to cognate APCs. Consistent with this potential role, these T cell microvilli-derived particles (TMPs) were independently capable of activating cognate dendritic cells (DCs). Therefore, our findings suggest that T cell microvilli might serve as ‘immunological synaptosomes’ with TMPs as a novel class of membrane vesicles serving as conveyors of T cell messages or traits to cognate APCs.
38
Tabatabaei-Zavareh, Nooshin, Tim Le Fevre, Terry Thomas, and Maureen Fairhurst. "A fast and simple method for the isolation of untouched human gamma-delta T cells from PBMC (45.7)." Journal of Immunology 188, no. 1_Supplement (May 1, 2012): 45.7. http://dx.doi.org/10.4049/jimmunol.188.supp.45.7.
Повний текст джерелаАнотація:
Abstract T cells expressing the γδT cell receptor (γδTCR) comprise a minor subset of human circulating T cells (1-10%). γδT cells are distinct from αβT cells in that they exhibit limited combinatorial diversity of the TCR and recognize non-peptide antigens independent of HLA molecules. γδT cells exert innate effector functions including rapid release of cytokines and killing of target cells. Adaptive immune responses such as memory functions have also been attributed to γδT cells. Typically, elaborate purification protocols such as FACS-based cell sorting or expansion in culture are needed to obtain enough γδT cells for subsequent studies. Here, we describe a negative selection method to isolate untouched γδT cells from fresh or previously frozen peripheral blood mononuclear cells (PBMC). This method uses immunomagnetic, column-free cell separation technology (EasySepTM). Briefly, bispecific antibody complexes are used to cross-link non-γδT cells to dextran-coated magnetic particles. The unwanted cells are then removed using an EasySepTM magnet. Starting with 3±0.9% γδTCR+ T cells in PBMC, purities of 90±2% (n=7) are achieved. The isolated γδT cells produce IFN-γ when activated with non-peptide antigens. γδT cells have potential therapeutic applications in cancer and infectious diseases. This rapid method for the isolation of γδT cells will assist in the study of γδT cell biology and the development of γδT cell-based immunotherapies.
39
Bayani, Siavash, Hamid R. Taghiyari, and Antonios N. Papadopoulos. "Physical and Mechanical Properties of Thermally-Modified Beech Wood Impregnated with Silver Nano-Suspension and Their Relationship with the Crystallinity of Cellulose." Polymers 11, no. 10 (September 20, 2019): 1538. http://dx.doi.org/10.3390/polym11101538.
Повний текст джерелаАнотація:
The aim of this study was to investigate the physical and mechanical properties of thermally modified beech wood impregnated with silver nano-suspension and to examine their relationship with the crystallinity of cellulose. Specimens were impregnated with a 400 ppm nanosilver suspension (NS); at least, 90% of silver nano-particles ranged between 20 and 100 nano-meters. Heat treatment took place in a laboratory oven at three temperatures, namely 145, 165, and 185 °C. Physical properties and mechanical properties of treated wood demonstrated statistically insignificant fluctuations at low temperatures compared to control specimens. On the other hand, an increase of temperature to 185 °C had a significant effect on all properties. Physical properties (volumetric swelling and water absorption) and mechanical properties (MOR and MOE) of treated wood demonstrated statistically insignificant fluctuations at low temperatures compared to control specimens. This degradation ultimately resulted in significant decrease in MOR, impact strength, and physical properties. However, thermal modification at 185 °C did not seem to cause significant fluctuations in MOE and compression strength parallel to grain. As a consequence of the thermal modification, part of amorphous cellulose was changed to crystalline cellulose. At low temperatures an increased crystallinity caused some of the properties to be improved. Crystallinity also demonstrated a decrease in NS-HT185 in comparison to HT185 treatment. TCr indices in specimens thermally treated at 145 °C revealed a significant increase as a result of impregnation with nanosilver suspension. This improvement in TCr index resulted in a noticeable increase in MOR and MOE values. Other properties did not show significant fluctuations, suggesting that the effect of the increased crystallinity and cross-linking in lignin was more than the negative effect of the low cell-wall polymer degradation caused by thermal modification. Change of amorphous cellulose to crystalline cellulose, as well as cross-linking in lignin, partially ameliorated the negative effects of thermal degradation at higher temperatures and therefore, compression parallel to grain and modulus of elasticity did not decrease significantly. Overall, it can be concluded that increased crystallinity and cross-linking in lignin can compensate for some decreased properties caused by thermal modification, but it would be significantly dependent on the temperature under which modification is carried out. Impregnating specimens with silver nano-suspension prior to thermal modification enhanced the effects of thermal modification as a result of improved thermal conductivity.
40
Corbin, Joel C., and Martin Gysel-Beer. "Detection of tar brown carbon with a single particle soot photometer (SP2)." Atmospheric Chemistry and Physics 19, no. 24 (December 20, 2019): 15673–90. http://dx.doi.org/10.5194/acp-19-15673-2019.
Повний текст джерелаАнотація:
Abstract. We investigate the possibility that the refractory, infrared-light-absorbing carbon particulate material known as “tarballs” or tar brown carbon (tar brC) generates a unique signal in the scattering and incandescent detectors of a single particle soot photometer (SP2). As recent studies have defined tar brC in different ways, we begin by reviewing the literature and proposing a material-based definition of tar. We then show that tar brC results in unique SP2 signals due to a combination of complete or partial evaporation, with no or very little incandescence. Only a subset of tar brC particles exhibited detectable incandescence (70 % by number); for these particles the ratio of incandescence to light scattering was much lower than that of soot black carbon (BC). At the time of incandescence the ratio of light scattering to incandescence from these particles was up to 2-fold greater than from soot (BC). In our sample, where the mass of tar was 3-fold greater than the mass of soot, this led to a bias of <5 % in SP2-measured soot mass, which is negligible relative to calibration uncertainties. The enhanced light scattering of tar is interpreted as being caused by tar being more amorphous and less graphitic than soot BC. The fraction of the tar particle which does incandesce was likely formed by thermal annealing during laser heating. These results indicate that laser-induced incandescence, as implemented in the SP2, is the only BC measurement technique which can quantify soot BC concentrations separately from tar while also potentially providing real-time evidence for the presence of tar. In contrast, BC measurement techniques based on thermal–optical (EC: elemental carbon) and absorption (eBC: equivalent BC) measurements cannot provide such distinctions. The optical properties of our tar particles indicate a material similarity to the tar particles previously reported in the literature. However, more- and less-graphitized tar samples have also been reported, which may show stronger and weaker SP2 responses, respectively.
41
Manco, Roberta, Luciana D’Apice, Maria Trovato, Lucia Lione, Erika Salvatori, Eleonora Pinto, Mirco Compagnone, Luigi Aurisicchio, Piergiuseppe De Berardinis, and Rossella Sartorius. "Co-Delivery of the Human NY-ESO-1 Tumor-Associated Antigen and Alpha-GalactosylCeramide by Filamentous Bacteriophages Strongly Enhances the Expansion of Tumor-Specific CD8+ T Cells." Viruses 15, no. 3 (March 2, 2023): 672. http://dx.doi.org/10.3390/v15030672.
Повний текст джерелаАнотація:
Tumor-associated antigens (TAAs) represent attractive targets in the development of anti-cancer vaccines. The filamentous bacteriophage is a safe and versatile delivery nanosystem, and recombinant bacteriophages expressing TAA-derived peptides at a high density on the viral coat proteins improve TAA immunogenicity, triggering effective in vivo anti-tumor responses. To enhance the efficacy of the bacteriophage as an anti-tumor vaccine, we designed and generated phage particles expressing a CD8+ peptide derived from the human cancer germline antigen NY-ESO-1 decorated with the immunologically active lipid alpha-GalactosylCeramide (α-GalCer), a potent activator of invariant natural killer T (iNKT) cells. The immune response to phage expressing the human TAA NY-ESO-1 and delivering α-GalCer, namely fdNY-ESO-1/α-GalCer, was analyzed either in vitro or in vivo, using an HLA-A2 transgenic mouse model (HHK). By using NY-ESO-1-specific TCR-engineered T cells and iNKT hybridoma cells, we observed the efficacy of the fdNY-ESO-1/α-GalCer co-delivery strategy at inducing activation of both the cell subsets. Moreover, in vivo administration of fdNY-ESO-1 decorated with α-GalCer lipid in the absence of adjuvants strongly enhances the expansion of NY-ESO-1-specific CD8+ T cells in HHK mice. In conclusion, the filamentous bacteriophage delivering TAA-derived peptides and the α-GalCer lipid may represent a novel and promising anti-tumor vaccination strategy.
42
Sedlacek III, Arthur J., Peter R. Buseck, Kouji Adachi, Timothy B. Onasch, Stephen R. Springston, and Lawrence Kleinman. "Formation and evolution of tar balls from northwestern US wildfires." Atmospheric Chemistry and Physics 18, no. 15 (August 13, 2018): 11289–301. http://dx.doi.org/10.5194/acp-18-11289-2018.
Повний текст джерелаАнотація:
Abstract. Biomass burning is a major source of light-absorbing black and brown carbonaceous particles. Tar balls (TBs) are a type of brown carbonaceous particle apparently unique to biomass burning. Here we describe the first atmospheric observations of the formation and evolution of TBs from forest fires. Aerosol particles were collected on transmission electron microscopy (TEM) grids during aircraft transects at various downwind distances from the Colockum Tarps wildland fire. TB mass fractions, derived from TEM and in situ measurements, increased from <1 % near the fire to 31–45 % downwind, with little change in TB diameter. Given the observed evolution of TBs, it is recommended that these particles be labeled as processed primary particles, thereby distinguishing TB formation–evolution from secondary organic aerosols. Single-scattering albedo determined from scattering and absorption measurements increased slightly with downwind distance. Similar TEM and single-scattering albedo results were observed sampling multiple wildfires. Mie calculations are consistent with weak light absorbance by TBs (i.e., m similar to the literature values 1.56−0.02i or 1.80−0.007i) but not consistent with absorption 1 order of magnitude stronger observed in different settings. The field-derived TB mass fractions reported here indicate that this particle type should be accounted for in biomass burning emission inventories.
43
Podojil, Joseph R., Andrew Cogswell, Ming-Yi Chiang, Tobias Neef, Tushar Murthy, Michael Boyne, Adam Elhofy, and Stephen D. Miller. "Antigen-specific nanoparticle tolerance treatment actively induces both FoxP3- and IL-10-dependent regulatory mechanisms." Journal of Immunology 208, no. 1_Supplement (May 1, 2022): 60.08. http://dx.doi.org/10.4049/jimmunol.208.supp.60.08.
Повний текст джерелаАнотація:
Abstract There are many autoimmune diseases where pathologic self T cells are the underlying cause of disease symptoms and progression. T cells are found at the site of tissue destruction, resulting not only in the exacerbation of disease, but also the release of self-epitopes in the context of inflammation resulting in the activation of additional T cell populations perpetuating disease. Published data have shown treatment with antigen-containing biodegradablepoly(lactide-co-glycolide) (PLGA) nanoparticles, i.e. tolerogenic immune-modifying particles (TIMP), is both safe and induces antigen-specific tolerance in mouse models of autoimmunity and allergy, as well as in a celiac disease Phase I/IIa clinical trial. This study further investigated the role and mechanism of TIMP-induced tolerance. The present data show that TIMP treatment modulated T cells specific for spread epitopes associated with disease progression, but not encapsulated within the TIMP, i.e. tissue-specific bystander suppression. The PLP139–151 TCR transgenic model systems was utilized to determine the cellular and molecular mechanisms driving antigen specific tolerance mediated by tolerogenic nanoparticle treatment. These data show antigen-specific TIMP treatment induced both FoxP3+ iTregs and IL-10+ Tr1 regulatory phenotypes within the antigen-specific T cell populations in both naïve mice and mice pre-primed with antigen/CFA. Additionally, both functional Tregs and IL-10 are required for TIMP-induced tolerance. Treatment thus activates various antigen-specific Treg subsets capable of regulating responses to disease-relevant autoepitopes not encapsulated within the TIMP via release of immunoregulatory cytokines within the inflammatory site. Supported by funding provided by Cour Pharmaceuticals Development, Inc.
44
Emerson, L. F., and A. W. Rempel. "Thresholds in the sliding resistance of simulated basal ice." Cryosphere Discussions 1, no. 1 (June 29, 2007): 99–122. http://dx.doi.org/10.5194/tcd-1-99-2007.
Повний текст джерелаАнотація:
Abstract. We report on laboratory determinations of the shear resistance to sliding melting ice with entrained particles over a hard, impermeable surface. With higher particle concentrations and larger particle sizes, Coulomb friction at particle-bed contacts dominates and the shear stress increases linearly with normal load. We term this the sandy regime. When either particle concentration or particle size is reduced below a threshold, the dependence of shear resistance on normal load is no longer statistically significant. We term this regime slippery. We use force and mass balance considerations to examine the flow of melt water beneath the simulated basal ice. At high particle concentrations, the transition from sandy to slippery behavior occurs when the particle size is comparable to the thickness of the melt film that separates the sliding ice from its bed. For larger particle sizes, a transition from sandy to slippery behavior occurs when the particle concentration drops sufficiently that the normal load is no longer transferred completely to the particle–bed contacts. We estimate that the melt films separating the particles from the ice are approximately 0.1 μm thick at this transition. Our laboratory results suggest the potential for abrupt transitions in the shear resistance beneath hard-bedded glaciers with changes in either the thickness of melt layers or the particle loading.
45
Hoffer, A., A. Tóth, I. Nyirő-Kósa, M. Pósfai, and A. Gelencsér. "Light absorption properties of laboratory generated tar ball particles." Atmospheric Chemistry and Physics Discussions 15, no. 12 (June 16, 2015): 16215–34. http://dx.doi.org/10.5194/acpd-15-16215-2015.
Повний текст джерелаАнотація:
Abstract. Tar balls (TBs) are a specific particle type which is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC) which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g. organic particles with inorganic inclusions and soot, the latter is emitted mainly during flaming conditions) from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study we have installed on-line instruments to our laboratory set-up generating pure TB particles to measure the absorption and scattering, as well as size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM) and total carbon (TC) analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory generated TBs were found to be in the range of 0.8–3.0 m2 g−1 at 550 nm, with absorption Ångström exponents (AAE) between 2.7 and 3.4 (average 2.9) in the wavelength range 467–652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84–0.21i at 550 nm. In the brown carbon continuum these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS). Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning emissions, these findings may have substantial influence on the understanding of global radiative energy fluxes.
46
Hoffer, A., A. Tóth, I. Nyirő-Kósa, M. Pósfai, and A. Gelencsér. "Light absorption properties of laboratory-generated tar ball particles." Atmospheric Chemistry and Physics 16, no. 1 (January 18, 2016): 239–46. http://dx.doi.org/10.5194/acp-16-239-2016.
Повний текст джерелаАнотація:
Abstract. Tar balls (TBs) are a specific particle type that is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC), which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g., organic particles with inorganic inclusions and soot, the latter emitted mainly during flaming conditions) from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study, we have installed on-line instruments to our laboratory set-up, which generate pure TB particles to measure the absorption and scattering, as well as the size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM) and total carbon (TC) analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory-generated TBs were found to be in the range of 0.8–3.0 m2 g−1 at 550 nm, with absorption Ångström exponents (AAE) between 2.7 and 3.4 (average 2.9) in the wavelength range 467–652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84 − 0.21i at 550 nm. In the brown carbon continuum, these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS). Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning emissions, these findings may have substantial influence on the understanding of global radiative energy fluxes.
47
Huang, N., and Z. Wang. "A 3-D simulation of drifting snow in the turbulent boundary layer." Cryosphere Discussions 9, no. 1 (January 15, 2015): 301–31. http://dx.doi.org/10.5194/tcd-9-301-2015.
Повний текст джерелаАнотація:
Abstract. The drifting snow is one of the most important factors that affect the global ice mass balance and hydrological balance. Current models of drifting snow are usually one- or two-dimensional, focusing on the macroscopic quantities of drifting snow under temporal average flow. In this paper, we take the coupling effects between wind and snow particles into account and present a 3-D model of drifting snow with mixed grain size in the turbulent boundary layer. The Large Eddy Simulation (LES) method is used for simulating the turbulent boundary layer of the wind field and the 3-D trajectory of every motion snow particle is calculated through Lagrangian Particle Tracking method. The results indicated that the drifting snow in the turbulent boundary layer has apparent 3-D structure and snow streamers, which lead to an intermittent transport of the snow particles and spatial inhomogeneity, and the motion trajectories of snow particles, especially the small snow particles, are obviously affected by the turbulent fluctuation. The macro statistics of drifting snow indicates that the spanwise velocity of snow particles increases with height and is one order smaller than that of streamwise velocity. Furthermore, the diameter distribution of snow particles in the air along the height shows a stratification structure.
48
Chorshanbiev, Umar, Ahmadjon Ibadullaev, Asqar Babaev, and Baxadir Kaxarov. "Study of the motion of modified solid particles in hydratransport systems." E3S Web of Conferences 401 (2023): 03027. http://dx.doi.org/10.1051/e3sconf/202340103027.
Повний текст джерелаАнотація:
The article examines the movement of solid particles, the hydraulic calculations of pipes in the process of movement, the classification of reducing the impact of solid particles on hydrotransport systems. The effect of solid particle magnification on flow rate, pressure loss, speed reduction as a result of the effect of internal friction forces of solid particles, friction in the flow of solid particle hydroarations, pressure loss as a result of the impact of Resistance Forces, internal corrosion process observed in the pipe, increased energy consumption were analyzed using the example of hydrotransport systems Recommendations have been made to solve the problems of speed reduction and pressure loss due to the movement of solid particles in the hydroaration flow through the modification method. The prior and subsequent movement of solid particles in a pipe modification is shown through comparison graphs. Information about the gossipol Tar selected as a modifier is provided.
49
Peng, Xu Hui, Yuan Le, Shu Guang Bian, Wo Yuan Li, Kuang Yang, and Jian Feng Chen. "Dispersibility and Charge Property of Different Surface Modified Titanium Dioxide as Electrophoretic Particles." Advanced Materials Research 11-12 (February 2006): 563–66. http://dx.doi.org/10.4028/www.scientific.net/amr.11-12.563.
Повний текст джерелаАнотація:
To prepare stable electrophoretic ink (E Ink) contains titanium dioxide particles, oil soluble red, dispersant and tetrachloroethylene (TCE), the modification of organic and inorganic material onto the particle surface was investigated. Modified particles were characterized by measurement of X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) to confirm the composites and structures. The electrophoretic properties of sample in TCE were investigated by static sedimentation experiment and electrophoresis instrument. The type of inorganic and organic materials used for the surface modification influence dispersibility and charge property of particles. On the whole, organic modified particles especially modified by anionic surfactant show better properties. The process conditions were investigated in detail using SDBS as the modifier. The dispersibility and charge property have significantly improved in optimized modifying condition that the proportion of surfactant is 15%, pH is 6 and reaction time is 1 hour which means SDBS modified TiO2 is suitable for electrophoretic particles.
50
Li, Zhe, JieChen Xian, Fei Wu, Xiao Lin, Lan Shen, and Yi Feng. "Development of TCM-based composite particles for direct compaction by particle design." Powder Technology 338 (October 2018): 481–92. http://dx.doi.org/10.1016/j.powtec.2018.07.014.
Повний текст джерела