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1.
Neutrophils are a type of granulocyte important in the “first line of defense” of the innate immune system. Upon activation, they facilitate the destruction of invading microorganisms by the production of superoxide radicals, as well as the release of the enzymatic contents of their lysozymes. These enzymes include specific serine proteases: cathepsin G, neutrophil elastase, proteinase 3, as well as the recently discovered neutrophil serine protease 4 (NSP4). Under normal conditions, the proteolytic activity of neutrophil proteases is tightly regulated by endogenous serpins; however, this mechanism can be subverted during tissue stress, thereby resulting in the uncontrolled activity of serine proteases, which induce chronic inflammation and subsequent pathology. Herein, we describe the development of low‐molecular‐weight activity‐based probes that specifically target the active sites of neutrophil proteases.  相似文献   
2.
This study directly compared the academic gains of reciprocal peer tutoring, nonreciprocal peer tutoring, and a waiting-list control group. Participants included 59 elementary students from second-, third-, and fourth-grade classrooms who performed below average on curriculum-based measurement (CBM) math probes. Students involved in peer tutoring were trained to tutor basic math facts using a constant time delay procedure. Results indicated that the two types of peer tutoring produced comparable gains in basic math facts. Furthermore, both types of peer tutoring produced substantially larger academic gains than the waiting-list control group, demonstrating at-risk students can successfully tutor each other. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
3.
The process by which metamemory and academic causal attributions relate to recall was examined with hierarchical multiple regression analyses. Several alternative conceptualizations of metamemory were used: general metamemory unrelated to the specific task; task-specific metamemory; memory monitoring; and both general and task-specific attributions. In order to examine the additive benefits of strategy and monitoring instructions, 81 4th graders were assigned to 1 of 4 instructional conditions: Strategy Only, Process Monitoring Only, Strategy Plus Process Monitoring, or Practice-Control group. Regression analyses indicated that the relationships between metamemory and recall depended on how metamemory was assessed and on the timing of the child's engagement with the recall task. Whereas general metamemory was significantly related to recall on the posttest and near-transfer tasks, task-specific metamemory became more relevant for transfer. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
4.
The impacts of large-scale, episodic sediment resuspension on the cycling of polychlorinated biphenyl congeners (PCBs) were examined using a spatially coordinated air and water sampling strategy conducted in southern Lake Michigan in the late winters of 1998, 1999, and 2000. We found no significant temporal changes in gas phase, dissolved phase, or suspended sediment PCB concentrations despite large-scale seasonal storms occurring before and after sampling campaigns. Only gas phase and suspended sediment PCBs varied spatially. Higher total suspended material (TSM) concentrations and fraction organic carbon (foc) were measured at sampling stations located in the near-shore region of southern Lake Michigan than at open-water sampling stations. Gas phase concentrations (ΣPCBg) were higher in the west (0.436 ± 0.200 ng/m3, n = 11) and south (0.408 ± 0.286 ng/m3, n = 5) than the east (0.214 ± 0.082 ng/m3, n = 10) and central (0.253 ± 0.145 ng/m3, n = 8) regions of southern Lake Michigan. Dissolved phase concentrations (ΣPCBd) averaged 0.18 ± 0.024 ng/L (n = 52); suspended sediment concentrations (ΣPCBs) accounted for between 4% and 72% (23 ± 4%, n = 52) of the total ΣPCB concentrations (ΣPCBT = ΣPCBd + ΣPCBs). Despite no consistent temporal variations in both dissolved phase or suspended sediment ΣPCB concentrations, there were temporal and spatial variations in the distribution shift between phases that can be linked to sediment resuspension, not a state of equilibrium. Specifically, our analysis suggests sediment resuspension results in preferential sorption of heavier, more chlorinated PCB congeners.  相似文献   
5.
The enantiomeric enrichment of polychlorinated biphenyl (PCB) atropisomers has been reported in both wildlife and in humans. The biological processes causing this enrichment are only poorly investigated, a fact that limits the use of enantiomeric fractions (EFs) as a tool to study various processes of environmental relevance. To further understand these enantioselective processes, this study investigates the tissue distribution and EFs of some PCB atropisomers after administration of PCB mixtures to immature male Sprague-Dawley rats. The mixtures selected for this study, Aroclor 1254 and an environmental mixture extracted from Chlorofen-contaminated soil, are qualitatively different and are known to induce different groups of hepatic enzymes. Animals were sacrificed 6 days after dosing, PCBs were extracted, and, whenever possible, the EFs of PCBs 84, 91, 95, 149, 174, and 176 were determined by chiral gas chromatography. The EFs of PCB 95 (adipose tissue, liver, and skin) and PCB 149 (adipose tissue, liver, skin, and blood) in tissues from Aroclor 1254-treated animals differed significantly from EFs in the Aroclor standard, while only EFs of PCB 95 (blood) and PCB 174 (adipose tissue) in tissues from soil-extract-treated animals were different from those of the Chlorofen soil extract. PCB 149 in tissues from soil-extract-treated animals underwent no statistically significant enantiomeric enrichment. These differences in the EFs clearly suggest that the enantioselective enrichment of PCB atropisomers may correlate with exposure history, and with the induction of hepatic enzymes, and that EFs may be useful chemical markers of physiologic and biochemical changes following exposure to PCBs.  相似文献   
6.
The field of games aimed at social change is young and ripe with opportunity, and several recent announcements of corporate/public-sector partnerships to develop such games are further fueling hopes for its success. These games raise awareness of important social issues in two ways: through "engaging and meaningful game play" and innovative, successful, and often large-scale distribution techniques. Such games are typically low-budget, grassroots creations distributed virally. The focus is on reaching new audiences, exploring innovative distribution options, and drawing attention to an issue.  相似文献   
7.
Examines, from a therapeutic jurisprudence (TJ) perspective, the rights of institutionalized mentally disabled persons to determine whether TJ is compatible with positions advancing civil rights and liberties, and whether lawyers for such individuals should look more closely to TJ as a source of rights. It concludes (1) that despite harsh criticisms of mental disability law reform, most of the important decisions in the areas of involuntary civil commitment, right to treatment, and right to refuse treatment law have a strong TJ component and (2) that TJ analyses may be the appropriate tool to reinvigorate this area of mental disability law. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
Existing models for isolation bearings neglect certain aspects of their response behavior. For instance, rubber bearings have been observed to decrease in stiffness with increasing axial load, and soften in the vertical direction at large lateral deformations. The yield strength of lead–rubber bearings has also been observed to vary with axial load, such that a lightly loaded bearing may not achieve its theoretical strength. Models that include these axial-load effects in lead–rubber bearings are developed by extending an existing linear two-spring model to include nonlinear behavior. The nonlinearity includes an empirical equation for the experimentally observed variation of yield strength. For numerical implementation, the bearing forces are found by solving the nonlinear equilibrium and kinematic equations using Newton’s method, and the instantaneous bearing stiffness matrix is formed from the differentials of these equations. The response behavior of the models is confirmed by comparison with experimental data.  相似文献   
9.
An 800-kV metal oxide transmission line surge arrester (TLA) has been developed, installed and tested on the AEP 765-kV Marysville-Kammer transmission line. The purpose of this TLA is to pave the way for the development, construction and application of an 800-kV SF/sub 6/ dead tank circuit breaker without closing resistors and free standing current transformers at American Electric Power's (AEP) 800-kV Orange station. Eight hundred kilovolts is the maximum design operating voltage, and 765 kV is the nominal operating voltage. Successful field test results of the TLAs ability to limit switching overvoltages emanating from circuit breaker operation to below the transmission line switching withstand are given. In addition, successful test results of the 800-kV dead tank circuit breaker design dielectric test are given in this paper.  相似文献   
10.
We report the first example of a Ni(II) complex that demonstrates sensitiser function in a Dye-Sensitised Solar Cell (DSSC). Complexes [Ni(dcbpy)(qdt)] (1), [Ni(decbpy)(qdt)] (2) and [Ni(decbpy)Cl2] (3) (where dcbpy = 4,4′-dicarboxy-2,2′-bipyridine; decbpy = 4,4′-di(CO2Et)-2,2′-bipyridine; and qdt = quinoxaline-2,3-dithiolate) have been prepared. Characterisation was carried out using electrochemical, spectroscopic and computational techniques. Intensive visible transitions of 1 and 2 have been assigned predominantly to Ligand-to-Ligand Charge Transfer (LLCT) from the qdt to the diimine ligand, suggesting appropriate charge separation for application in a photoelectrochemical device. TiO2 sensitised with 2, following charge injection, processes a recombination time significantly long for photovoltaic function. In a DSSC, using redox electrolyte, photocurrents and photovoltages of 0.293 mA and 521 mV were observed, with optimum values requiring TiCl4 post-treatment of TiO2 and co-adsorption of Chenodeoxycholic acid (Cheno). Although photovoltaic function was observed, the low photocurrent is attributed to a short-lived excited state lifetime resulting in poor charge injection from the Ni(II) sensitiser.  相似文献   
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