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排序方式: 共有898条查询结果,搜索用时 15 毫秒
821.
Luisa Chocarro Ester Blanco Miren Zuazo Hugo Arasanz Ana Bocanegra Leticia Fernndez-Rubio Pilar Morente Gonzalo Fernndez-Hinojal Miriam Echaide Maider Garnica Pablo Ramos Ruth Vera Grazyna Kochan David Escors 《International journal of molecular sciences》2021,22(10)
Lymphocyte activation gene 3 (LAG-3) is a cell surface inhibitory receptor with multiple biological activities over T cell activation and effector functions. LAG-3 plays a regulatory role in immunity and emerged some time ago as an inhibitory immune checkpoint molecule comparable to PD-1 and CTLA-4 and a potential target for enhancing anti-cancer immune responses. LAG-3 is the third inhibitory receptor to be exploited in human anti-cancer immunotherapies, and it is considered a potential next-generation cancer immunotherapy target in human therapy, right next to PD-1 and CTLA-4. Unlike PD-1 and CTLA-4, the exact mechanisms of action of LAG-3 and its relationship with other immune checkpoint molecules remain poorly understood. This is partly caused by the presence of non-conventional signaling motifs in its intracellular domain that are different from other conventional immunoregulatory signaling motifs but with similar inhibitory activities. Here we summarize the current understanding of LAG-3 signaling and its role in LAG-3 functions, from its mechanisms of action to clinical applications. 相似文献
822.
Jacky Lu Jamisha D. Francis Miriam A. Guevara Rebecca E. Moore Dr. Schuyler A. Chambers Dr. Ryan S. Doster Dr. Alison J. Eastman Lisa M. Rogers Dr. Kristen N. Noble Dr. Shannon D. Manning Dr. Steven M. Damo Dr. David M. Aronoff Dr. Steven D. Townsend Dr. Jennifer A. Gaddy 《Chembiochem : a European journal of chemical biology》2021,22(12):2124-2133
Group B Streptococcus (GBS) is an encapsulated Gram-positive human pathogen that causes invasive infections in pregnant hosts and neonates, as well as immunocompromised individuals. Colonization of the human host requires the ability to adhere to mucosal surfaces and circumnavigate the nutritional challenges and antimicrobial defenses associated with the innate immune response. Biofilm formation is a critical process to facilitate GBS survival and establishment of a replicative niche in the vertebrate host. Previous work has shown that the host responds to GBS infection by producing the innate antimicrobial glycoprotein lactoferrin, which has been implicated in repressing bacterial growth and biofilm formation. Additionally, lactoferrin is highly abundant in human breast milk and could serve a protective role against invasive microbial pathogens. This study demonstrates that human breast milk lactoferrin has antimicrobial and anti-biofilm activity against GBS and inhibits its adherence to human gestational membranes. Together, these results indicate that human milk lactoferrin could be used as a prebiotic chemotherapeutic strategy to limit the impact of bacterial adherence and biofilm formation on GBS-associated disease outcomes. 相似文献
823.
Samantha Salomão Caramori Flaviana Naves de Faria Miriam Pereira Viana Kátia Flávia Fernandes Luiz Bezerra Carvalho 《Materials science & engineering. C, Materials for biological applications》2011,31(2):252-257
Discs of polyvinyl alcohol cross-linked with glutaraldehyde (PVAG) were synthesized and covered with polyaniline activated with glutaraldehyde (PANIG). Trypsin was covalently immobilized on this composite yielding a preparation containing 21.1 units per disc. The FT-IR spectra of the discs showed bands of PVA (3300 cm?1, 2930 cm?1 and 1440 cm?1) and PANI (1594 cm?1 and 1100 cm?1). The best immobilization conditions were: trypsin concentration at 0.2 mg mL?1, pH 7.6 and 60 min of incubation, similar to polyaniline–trypsin systems reported in the literature. The PVAG–PANIG–trypsin derivative showed an optimal pH and an optimal temperature of 7.0 and 35 °C, respectively. Hydrolysis of casein showed variations in the size of the products, revealing differences between the immobilized enzyme and the mechanism catalyzed by the native enzyme. 相似文献
824.
Gláucia S. Vieira Leila M. Pereira Miriam D. Hubinger 《International Journal of Food Science & Technology》2012,47(1):132-140
Response surface methodology was used to assess the effects of osmotic solution concentration (40–60°Brix), process temperature (20–40 °C) and vacuum pulse application time (0–20 min) at 100 mbar on water loss (WL), weight reduction (WR), solid gain (SG), water activity (aw), colour parameters and mechanical properties of guava slices. Optimal process conditions were determined through the desirability function approach and quality characteristics of osmotically dehydrated guavas were analysed. Only models obtained for WL, WR and aw were suitable to describe the experimental data. The desirability function showed that optimal conditions for osmotic dehydration of guavas were: osmotic solution concentration at 60°Brix, process temperature at 32 °C and 20 min of vacuum pulse application. Under optimal conditions, colour and mechanical properties of treated guavas were similar to fresh fruit, presenting WL of 29.01 g/100 g, WR of 25.91 g/100 g, SG of 3.10 g/100 g and aw of 0.979. 相似文献
825.
Javier R. Arballo Ruth R. Bambicha Laura A. Campañone Miriam E. Agnelli Rodolfo H. Mascheroni 《International Journal of Food Science & Technology》2012,47(2):306-314
Mass transfer kinetics and optimisation of osmotic dehydration (OD) of fruits and vegetables with diverse structures were studied. Different concentrations of sucrose (20–60 °Brix) and process times (0–24 h) were used. Magee’s model was appropriate for predicting water loss (WL), while Azuara’s model fitted well solids gain (SG) data and represented more accurately the evolution of the complete process close to equilibrium. Polynomial equations for each kinetic variable [WL, SG and weight reduction (WR) – for pumpkin, kiwi and pear] using multiple linear regression were fitted for a selected range of experimental data (30–240 min, 20–60 °Brix). A complete solution algorithm for desirability function was coded in Matlab® 7.2 (Mathworks, Natick, MA, USA) with the aim to optimise osmotic dehydration process in terms of WL, SG and WR; optimal conditions were found for each fruit. Besides, an optimal common zone was identified for OD corresponding to process time from 114 to 240 min and sucrose concentration from 54 to 60 °Brix. 相似文献
826.
Ana Clarissa dos Santos Pires Nilda de Fátima Ferreira Soares Luis Henrique Mendes da Silva Nélio José de Andrade Miriam Fontes Araujo Silveira Antônio Fernandes de Carvalho 《Food and Bioprocess Technology》2010,3(2):172-181
Biosensors offer the potential for real-time pathogen detection. Polydiacetylene (PDA) is an ideal choice for use as a sensor
due to its unique optical properties. PDA molecules can form thin films or vesicles that change color from deep blue to red
in response to different stimuli, like temperature, pH, and the presence of biological molecules. PDA films and vesicles have
been proven to be promising devices for the detection of bacteria and bacterial toxins. Langmuir troughs (for films) and microcalorimetry
(for vesicles) are among the many techniques used to characterize PDA films and vesicles. In order to enable more applications
of PDA films, it is imperative to elucidate and gain a deeper understanding of the molecular interactions associated with
their color change. In addition, it is necessary to transfer the PDA film onto a solid support like plastic in order to incorporate
PDA biosensors into an intelligent packaging system. Through the use of such a system, consumers can monitor food quality,
thereby preventing foodborne outbreaks. In this review, we discuss the formation of PDA films and vesicles, their characteristics,
and their potential applications as biosensors. The possibility to incorporate PDA biosensors into an intelligent packaging
system to be used in the food industry is also explored. 相似文献
827.
Miriam Cerro-Alarcn Avelino Corma Sara Iborra Juan Pedro Gmez 《Applied Catalysis A: General》2008,346(1-2):52-57
Non-ionic triamino(imino)phosphoranes (phosphazenes) give excellent results as base catalysts for the water-free alcoholysis of vegetable fatty esters. Two phosphazene catalysts, with different intrinsic basicities, P1-t-Bu and P4-t-Bu, together with reaction parameters, such as temperature, alcohol/oil molar ratio, or catalyst concentration, have been studied. It was found that activity can be directly correlated to the basicity of the catalyst. Very high biodiesel yields (93–95% mol) were achieved under mild reaction conditions with methanol and ethanol. The catalyst can be recovered and recycled. 相似文献
828.
Miriam Linnert Claudia Fritz Christian Jger Dagmar Schlenzig Daniel Ramsbeck Martin Kleinschmidt Michael Wermann Hans-Ulrich Demuth Christoph Parthier Stephan Schilling 《International journal of molecular sciences》2021,22(11)
The astacin protease Meprin β represents an emerging target for drug development due to its potential involvement in disorders such as acute and chronic kidney injury and fibrosis. Here, we elaborate on the structural basis of inhibition by a specific Meprin β inhibitor. Our analysis of the crystal structure suggests different binding modes of the inhibitor to the active site. This flexibility is caused, at least in part, by movement of the C-terminal region of the protease domain (CTD). The CTD movement narrows the active site cleft upon inhibitor binding. Compared with other astacin proteases, among these the highly homologous isoenzyme Meprin α, differences in the subsites account for the unique selectivity of the inhibitor. Although the inhibitor shows substantial flexibility in orientation within the active site, the structural data as well as binding analyses, including molecular dynamics simulations, support a contribution of electrostatic interactions, presumably by arginine residues, to binding and specificity. Collectively, the results presented here and previously support an induced fit and substantial movement of the CTD upon ligand binding and, possibly, during catalysis. To the best of our knowledge, we here present the first structure of a Meprin β holoenzyme containing a zinc ion and a specific inhibitor bound to the active site. The structural data will guide rational drug design and the discovery of highly potent Meprin inhibitors. 相似文献
829.
Frey Karin S.; Hirschstein Miriam K.; Edstrom Leihua V.; Snell Jennie L. 《Canadian Metallurgical Quarterly》2009,101(2):466
This study was a longitudinal extension of a random control trial of the Steps to Respect antibullying program. Students in Grades 3–5 were surveyed (n = 624) and observed on the playground (n = 360). Growth curve models of intervention students showed 2-year declines in playground bullying, victimization, nonbullying aggression, destructive bystander, and argumentative behavior. Grade-equivalent contrasts indicated group differences in all problem behaviors. Problem behaviors in the control group increased or remained stable across grade. Intervention group students reported less difficulty responding assertively to bullying compared with control students. Within both groups, older students perceived themselves to be more aggressive and less frequently victimized than younger students. Methodological issues posed by inconsistencies between self-reported and observed behavior are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
830.
Miriam F. Beristain Emilio Bucio Guillermina Burillo Eduardo Muñoz Takeshi Ogawa 《Polymer Bulletin》1999,43(4-5):357-364
In order to study the nature of interaction of arylbutadiynes with transient free radicals, polymerization and copolymerization
of some vinyl monomers such as methyl methacrylate (MMA), styrene (ST), methacrylonitrile (MAN), vinylidene chloride (VCl2), ethyl acrylate (EA) and acrylonitrile (AN), were carried out in the presence of diphenylbutadiyne (DPB), 4,4'-butadiynylene-N,N,N',N'-tetra-n-butyl-dibenzamide (BBA), and 4,4'-dibromodiphenylbutadiyne (BPB). MMA gave an intense ESR signal at the polymerization temperature
when the polymerization system became viscous, and the number of radicals increased with polymerization time. Strong signals
of polyEA and polyMAN radicals were also observed in the presence of DPB when the polymerization system became almost solid.
This is a unique case where active transient propagating radicals such as that of polyEA can be detected at polymerization
temperature. The rates of polymerization decreased by the presence of the diacetylenes, but the molecular weights did not
change with the diacetylene concentrations. UV spectroscopy revealed that there was no diacetylene unit bonded to the obtained
polymers, indicating that degradative chain transfer is not the case. The monomer reactivity ratios for MMA-ST and MMA-AN
systems did not vary significantly in the presence of the diacetylenes, although some difference was observed. It seems that
some arylbutadiynes interact with free radicals but do not form bonds.
Received: 4 June 1999/Revised version: 29 September 1999/Accepted: 29 September 1999 相似文献