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排序方式: 共有696条查询结果,搜索用时 15 毫秒
101.
Di Tie Frank Feyerabend Norbert Hort Regine Willumeit Daniel Hoeche 《Advanced Engineering Materials》2010,12(12):B699-B704
Magnesium‐based biomaterials are gaining increasing interest, while in vitro corrosion tests are not standardized yet. Moreover, the effects of different corrosion media on the corrosion products are still not fully understood. To compare and evaluate the three main corrosion media applied in most in vitro studies, an XPS investigation of magnesium surfaces was carried out after exposure of the specimens to Dulbecco's modified eagle medium (DMEM), Hank's buffered salt solution (HBSS), and simulated body fluid (SBF). The effects of rinsing the specimens after immersion were also determined. XPS investigations especially on the Mg 2p state showed that MgO, Mg(OH)2, and MgCO3 species were the dominant corrosion products presenting in all specimens despite of the different corrosion media. However, the ratio of corrosion products depends on the medium composition. It was also shown that rinsing specimens after immersion experiments is a necessary procedure when surface analysis is employed afterward. 相似文献
102.
Microbial quality assessment of household greywater 总被引:1,自引:0,他引:1
O'Toole J Sinclair M Malawaraarachchi M Hamilton A Barker SF Leder K 《Water research》2012,46(13):4301-4313
A monitoring program was undertaken to assess the microbial quality of greywater collected from 93 typical households in Melbourne, Australia. A total of 185 samples, comprising 75 washing machine wash, 74 washing machine rinse and 36 bathroom samples were analysed for the faecal indicator Escherichia coli. Of these, 104 were also analysed for genetic markers of pathogenic E coli and 111 for norovirus (genogroups GI and GII), enterovirus and rotavirus using RT-PCR. Enteric viruses were detected in 20 out of the 111 (18%) samples comprising 16 washing machine wash water and 4 bathroom samples. Eight (7%) samples were positive for enterovirus, twelve (11%) for norovirus genogroup GI, one (1%) for norovirus genogroup GII and another (1%) for rotavirus. Two washing machine samples contained more than one virus. Typical pathogenic E. coli were detected in 3 out of 104 (3%) samples and atypical enteropathogenic E. coli in 11 (11%) of samples. Levels of indicator E. coli were highly variable and the presence of E. coli was not associated with the presence of human enteric viruses in greywater. There was also little correlation between reported gastrointestinal illness in households and detection of pathogens in greywater. 相似文献
103.
Jaiswal MK Mallers TM Larsen B Kwak-Kim J Chaouat G Gilman-Sachs A Beaman KD 《Reproduction (Cambridge, England)》2012,143(5):713-725
Various mechanisms exist to prevent a potentially deleterious maternal immune response that results in compromising survival of semiallogeneic fetus. In pregnancy, there is a necessary early preimplantation inflammatory stage followed by a postimplantation anti-inflammatory stage. Thus, there is a biphasic 'immune response' observed during the course of pregnancy. We provide the evidence that capacitation of sperm induced the expression of a2 isoform of V-ATPase (ATP6V0A2 referred to as a2V), leukemia inhibitory factor (Lif), Il1b, and Tnf in the sperm. Capacitated sperm also released cleaved N-terminal domain of a2V-ATPase (a2NTD), which upregulates the gene expression of Lif, Il1b, Tnf, and monocyte chemotactic protein-1 (Ccl2 (Mcp1)) in the uterus. Unfertilized eggs had low a2V expression, but after fertilization, the expression of a2V increased in zygotes. This increased level of a2V expression was maintained in preimplantation embryos. Seminal plasma was necessary for upregulation of a2V expression in preimplantation embryos, as mating with seminal vesicle-deficient males failed to elicit an increase in a2V expression in preimplantation embryos. The infiltration of macrophages into the uterus was significantly increased after insemination of both sperm and seminal plasma during the preimplantation period of pregnancy. This dynamic infiltration into the uterus corresponded with the uterine a2V expression through the induction of Ccl2 expression. Furthermore, the polarization ratio of M1:M2 (pro-inflammatory/anti-inflammatory) macrophages in the uterus fluctuated from a ratio of 1.60 (day 1) to 1.45 (day 4) when female mice were inseminated with both sperm and seminal plasma. These data provide evidence that exposure to semen may initiate an inflammatory milieu by inducing a2V and cytokine/chemokine expression, which triggers the influx of macrophages into the preimplantation uterus during the onset of pregnancy and ultimately leads to successful pregnancy outcome. 相似文献
104.
We determine the three-dimensional shape, to within 1 nm resolution, of single-crystal gold nanorods grown in the presence of silver ions using electron tomography and thickness profile measurements. We find that, contrary to the current literature, the octagonal side-facets are sparsely packed atomic planes all belonging to the same symmetry-equivalent family, {0 5 12}. Furthermore, the rod ends terminate in a pyramid with slightly different facets, and each pyramid is connected to the sides by four small {0 5 12} "bridging" facets. 相似文献
105.
Dickson Joanne M.; Moberly Nicholas J.; Kinderman Peter 《Canadian Metallurgical Quarterly》2011,120(4):975
Despite its theoretical importance, personal goal motivation has rarely been examined in clinical depression. Here we investigate whether clinically depressed persons (n = 23) differ from never-depressed persons (n = 26) on number of freely generated approach and avoidance goals, appraisals of these goals, and reasons why these goals would and would not be achieved. Participants listed approach and avoidance goals separately and generated explanations for why they would (pro) and would not (con) achieve their most important approach and avoidance goals, before rating the importance, likelihood, and perceived control of goal outcomes. Counter to hypothesis, depressed persons did not differ from never-depressed controls on number of approach or avoidance goals, or on the perceived importance of these goals. However, compared to never-depressed controls, depressed individuals gave lower likelihood judgments for desirable approach goal outcomes, tended to give higher likelihood judgments for undesirable to-be-avoided goal outcomes, and gave lower ratings of their control over goal outcomes. Furthermore, although controls generated significantly more pro than con reasons for goal achievement, depressed participants did not. These results suggest that depressed persons do not lack valued goals but are more pessimistic about their likelihood, controllability, and reasons for successful goal attainment. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
106.
Nicole Berndt Claudia C. Bippes Irene Michalk Tabea Bartsch Claudia Arndt Edinson Puentes-Cala Javier Andrs Soto Liliana R. Loureiro Alexandra Kegler Dominik Bachmann Joanne K. Gross Tim Gross Biji T. Kurien R. Hal Scofield A. Darise Farris Judith A. James Ralf Bergmann Marc Schmitz Anja Feldmann Michael P. Bachmann 《International journal of molecular sciences》2021,22(18)
Decades ago, we and many other groups showed a nucleo-cytoplasmic translocation of La protein in cultured cells. This shuttling of La protein was seen after UV irradiation, virus infections, hydrogen peroxide exposure and the Fenton reaction based on iron or copper ions. All of these conditions are somehow related to oxidative stress. Unfortunately, these harsh conditions could also cause an artificial release of La protein. Even until today, the shuttling and the cytoplasmic function of La/SS-B is controversially discussed. Moreover, the driving mechanism for the shuttling of La protein remains unclear. Recently, we showed that La protein undergoes redox-dependent conformational changes. Moreover, we developed anti-La monoclonal antibodies (anti-La mAbs), which are specific for either the reduced form of La protein or the oxidized form. Using these tools, here we show that redox-dependent conformational changes are the driving force for the shuttling of La protein. Moreover, we show that translocation of La protein to the cytoplasm can be triggered in a ligand/receptor-dependent manner under physiological conditions. We show that ligands of toll-like receptors lead to a redox-dependent shuttling of La protein. The shuttling of La protein depends on the redox status of the respective cell type. Endothelial cells are usually resistant to the shuttling of La protein, while dendritic cells are highly sensitive. However, the deprivation of intracellular reducing agents in endothelial cells makes endothelial cells sensitive to a redox-dependent shuttling of La protein. 相似文献
107.
108.
Charles E. Carraher Jr. Theodore S. Sabir Michael R. Roner Kimberely Shahi Robert E. Bleicher Joanne L. Roehr Kelly D. Bassett 《Journal of Inorganic and Organometallic Polymers and Materials》2006,16(3):249-257
Organotin polyamine ethers containing acyclovir in their backbone were synthesized in moderate to high yield employing the aqueous interfacial polycondensation system. The products are high molecular weight polymers. Infrared spectroscopy of the products shows new bands characteristic of the formation of Sn–N and Sn–O bonds consistent with the proposed structure. MALDI-TOF MS below 2000 Da shows the presence of organotin and acyclovir units containing these two moieties. The products show moderate inhibition of a number of cancer cell lines and exhibit the ability to inhibit a number of viruses, particularly the herpes simplex virus-1 and varicella zoster virus that are responsible for herpes, chicken pox and shingles. 相似文献
109.
Discovery of 5′′‐Chloro‐N‐[(5,6‐dimethoxypyridin‐2‐yl)methyl]‐2,2′:5′,3′′‐terpyridine‐3′‐carboxamide (MK‐1064): A Selective Orexin 2 Receptor Antagonist (2‐SORA) for the Treatment of Insomnia 下载免费PDF全文
Dr. Anthony J. Roecker Swati P. Mercer John D. Schreier Dr. Christopher D. Cox Dr. Mark E. Fraley Justin T. Steen Wei Lemaire Joseph G. Bruno C. Meacham Harrell Susan L. Garson Dr. Anthony L. Gotter Steven V. Fox Joanne Stevens Dr. Pamela L. Tannenbaum Dr. Thomayant Prueksaritanont Dr. Tamara D. Cabalu Dr. Donghui Cui Joyce Stellabott Dr. George D. Hartman Dr. Steven D. Young Dr. Christopher J. Winrow Dr. John J. Renger Dr. Paul J. Coleman 《ChemMedChem》2014,9(2):311-322
The field of small‐molecule orexin antagonist research has evolved rapidly in the last 15 years from the discovery of the orexin peptides to clinical proof‐of‐concept for the treatment of insomnia. Clinical programs have focused on the development of antagonists that reversibly block the action of endogenous peptides at both the orexin 1 and orexin 2 receptors (OX1R and OX2R), termed dual orexin receptor antagonists (DORAs), affording late‐stage development candidates including Merck’s suvorexant (new drug application filed 2012). Full characterization of the pharmacology associated with antagonism of either OX1R or OX2R alone has been hampered by the dearth of suitable subtype‐selective, orally bioavailable ligands. Herein, we report the development of a selective orexin 2 antagonist (2‐SORA) series to afford a potent, orally bioavailable 2‐SORA ligand. Several challenging medicinal chemistry issues were identified and overcome during the development of these 2,5‐disubstituted nicotinamides, including reversible CYP inhibition, physiochemical properties, P‐glycoprotein efflux and bioactivation. This article highlights structural modifications the team utilized to drive compound design, as well as in vivo characterization of our 2‐SORA clinical candidate, 5′′‐chloro‐N‐[(5,6‐dimethoxypyridin‐2‐yl)methyl]‐2,2′:5′,3′′‐terpyridine‐3′‐carboxamide (MK‐1064), in mouse, rat, dog, and rhesus sleep models. 相似文献
110.
Mathias Uller Rothmann Wei Li Ye Zhu Amelia Liu Zhiliang Ku Udo Bach Joanne Etheridge Yi‐Bing Cheng 《Advanced materials (Deerfield Beach, Fla.)》2018,30(25)
Organic–inorganic hybrid perovskites, such as CH3NH3PbI3, have shown highly promising photovoltaic performance. Electron microscopy (EM) is a powerful tool for studying the crystallography, morphology, interfaces, lattice defects, composition, and charge carrier collection and recombination properties at the nanoscale. Here, the sensitivity of CH3NH3PbI3 to electron beam irradiation is examined. CH3NH3PbI3 undergoes continuous structural and compositional changes with increasing electron dose, with the total dose, rather than dose rate, being the key operative parameter. Importantly, the first structural change is subtle and easily missed and occurs after an electron dose significantly smaller than that typically applied in conventional EM techniques. The electron dose conditions under which these structural changes occur are identified. With appropriate dose‐minimization techniques, electron diffraction patterns can be obtained from pristine material consistent with the tetragonal CH3NH3PbI3 phases determined by X‐ray diffraction. Radiation damage incurred at liquid nitrogen temperatures and using Ga+ irradiation in a focused ion beam instrument are also examined. Finally, some simple guidelines for how to minimize electron‐beam‐induced artifacts when using EM to study hybrid perovskite materials are provided. 相似文献