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排序方式: 共有129条查询结果,搜索用时 15 毫秒
1.
Janitha A. Liyanage David M. Taylor David R. Williams 《Chemical Speciation and Bioavailability》2013,25(2):73-75
ABSTRACTA method has been developed for impregnating alginate-based wound dressings with trace elements required for wound healing and for quantifying the transfer from these dressing to wound fluid (for which a substitute—blood serum—was used in these experiments). Under ideal conditions, up to 85% can be carried across from the tow to the wound fluid. 相似文献
2.
Shyamali Mukherjee Mihir Nag Tultul Nayyar Indrani Maitra Parul Chakrabarti Pramod R. Dasgupta 《Journal of biosciences》1986,10(3):311-317
The effect of estradiol-17β and progesterone given separately as well as in combination on the rate of hydrogen peroxide formation
and lipid peroxidation in the uteri of ovariectomized rats was studied. Estradiol in 3μg dose per day per animal elicited maximum stimulatory response and progesterone (100μg), on the other hand, was without any such effect. However, progesterone given along with estradiol completely prevented the
effect due to the latter. In the same way, vitamin E, a well known antioxidant was found to be extremelv effective in protecting
the uterus from the highly peroxidative action of estradiol-17β. 相似文献
3.
Janitha A. Liyanage David M. Taylor David R. Williams 《Chemical Speciation and Bioavailability》2013,25(1-2):45-52
ABSTRACTECCLES computer modelling is used to speciate Ca2+, Zn2+, Cu2+, Mn2+ and Fe3+ in wound fluid samples analysed for total metal content using Potentiometric stripping analysis. Bioavailability of metals, related to lipid soluble net-neutral complexes, was assessed and found to be broadly similar to the speciation in blood plasma. These appear to be benefits worthy of clinical investigation of keeping the wound fluid at pH = 6.4 and of raising the total cysteine concentration levels in wound fluid. 相似文献
4.
Basuroy S Tcheranova D Bhattacharya S Leffler CW Parfenova H 《American journal of physiology. Cell physiology》2011,300(2):C256-C265
We investigated the role of reactive oxygen species (ROS) in promoting cell survival during oxidative stress induced by the inflammatory mediator tumor necrosis factor-α (TNF-α) in cerebral microvascular endothelial cells (CMVEC) from newborn piglets. Nox4 is the major isoform of NADPH oxidase responsible for TNF-α-induced oxidative stress and apoptosis in CMVEC. We present novel data that Nox4 NADPH oxidase-derived ROS also initiate a cell survival mechanism by increasing production of a gaseous antioxidant mediator carbon monoxide (CO) by constitutive heme oxygenase-2 (HO-2). TNF-α rapidly enhanced endogenous CO production in a superoxide- and NADPH oxidase-dependent manner in CMVEC with innate, but not with small interfering RNA (siRNA)-downregulated Nox4 activity. CORM-A1, a CO-releasing compound, inhibited Nox4-mediated ROS production and enhanced cell survival in TNF-α-challenged CMVEC. The ROS-induced CO-mediated survival mechanism requires functional interactions between the protein kinase B/Akt and extracellular signal-related kinase (ERK)/p38 MAPK signaling pathways activated by TNF-α. In Akt siRNA-transfected CMVEC and in cells with pharmacologically inhibited Akt, Erk1/2, and p38 mitogen-activated protein kinase (MAPK) activities, CORM-A1 was no longer capable of blocking Nox4 activation and apoptosis caused by TNF-α. Overall, Nox4 NADPH oxidase-derived ROS initiate both death and survival pathways in TNF-α-challenged CMVEC. The ROS-dependent cell survival pathway is mediated by an endogenous antioxidant CO, which inhibits Nox4 activation via a mechanism that includes Akt, ERK1/2, and p38 MAPK signaling pathways. The ability of CO to inhibit TNF-α-induced ERK1/2 and p38 MAPK activities in an Akt-dependent manner appears to be the key element in ROS-dependent survival of endothelial cells during TNF-α-mediated brain inflammatory disease. 相似文献
5.
Dynamics of T cells and TCR excision circles differ after treatment of acute and chronic HIV infection 总被引:5,自引:0,他引:5
Lewin SR Ribeiro RM Kaufmann GR Smith D Zaunders J Law M Solomon A Cameron PU Cooper D Perelson AS 《Journal of immunology (Baltimore, Md. : 1950)》2002,169(8):4657-4666
We quantified T cell proliferation and thymic function in primary HIV infection (PHI; n = 19) and chronic HIV infection (CHI; n = 14) by measuring Ki67 staining and TCR excision circle (TREC) number. After antiretroviral therapy of PHI there is a profound decrease in the number and percentage of Ki67(+) T cells (<6% Ki67(+)) with no significant increase in TREC per million cells and a transient increase in TREC per milliliter. In contrast, after antiretroviral therapy of CHI there is a reduction in the percentage but little change in the total number of Ki67(+)CD4(+) T cells associated with increases in both TREC per million cells and TREC per milliliter. Using a mathematical model that accounts for proliferation, death, and redistribution of T cells, we find that redistribution is consistent with the TREC changes observed during treatment of PHI and that an increase in thymic output is needed to explain the increase in TREC during treatment of CHI. Consideration of TREC per milliliter shows that changes in proliferation alone cannot explain the changes in TREC. In addition, although increased proliferation of memory cells in HIV infection has been established, we find no difference in TREC per million CD45RA(-) "memory" T cells between healthy and infected individuals (p = 0.154 for CD4(+); p = 0.383 for CD8(+)). Finally, although the number of TREC per million cells is always much lower in memory T cells than in naive T cells, in the setting of HIV infection, given that memory cells make up a larger proportion of total T cells, we find that 50% of TREC per milliliter in CD4(+) T cells is harbored in the CD45RA(-) "memory" subset of our infected subjects. 相似文献
6.
Marcela Parra Xia Liu Steven C. Derrick Amy Yang Alvaro Molina-Cruz Carolina Barillas-Mury Hong Zheng Phuong Thao Pham Martha Sedegah Arnel Belmonte Dianne D. Litilit Thomas A. Waldmann Sanjai Kumar Sheldon L. Morris Liyanage P. Perera 《PloS one》2015,10(10)
Malaria remains a major global public health problem with an estimated 200 million cases detected in 2012. Although the most advanced candidate malaria vaccine (RTS,S) has shown promise in clinical trials, its modest efficacy and durability have created uncertainty about the impact of RTS,S immunization (when used alone) on global malaria transmission. Here we describe the development and characterization of a novel modified vaccinia virus Ankara (MVA)–based malaria vaccine which co-expresses the Plasmodium yoelii circumsporozoite protein (CSP) and IL-15. Vaccination/challenge studies showed that C57BL/6 mice immunized with the MVA-CSP/IL15 vaccine were protected significantly better against a P. yoelii 17XNL sporozoite challenge than either mice immunized with an MVA vaccine expressing only CSP or naïve controls. Importantly, the levels of total anti-CSP IgG were elevated about 100-fold for the MVA-CSP/IL15 immunized group compared to mice immunized with the MVA-CSP construct that does not express IL-15. Among the IgG subtypes, the IL-15 expressing MVA-CSP vaccine induced levels of IgG1 (8 fold) and IgG2b (80 fold) higher than the MVA-CSP construct. The significantly enhanced humoral responses and protection detected after immunization with the MVA-CSP/IL15 vaccine suggest that this IL-15 expressing MVA construct could be considered in the development of future malaria immunization strategies. 相似文献
7.
8.
Helgason A Pálsson S Lalueza-Fox C Ghosh S Sigurdardóttir S Baker A Hrafnkelsson B Arnadóttir L Thorsteinsdóttir U Stefánsson K 《Journal of molecular evolution》2007,65(1):92-102
One of the key problems in the study of ancient DNA is that of authenticating sequences obtained from PCR amplifications of
highly degraded samples. Contamination of ancient samples and postmortem damage to endogenous DNA templates are the major
obstacles facing researchers in this task. In particular, the authentication of sequences obtained from ancient human remains
is thought by many to be rather challenging. We propose a novel approach, based on the c statistic, that can be employed to help identify the sequence motif of an endogenous template, based on a sample of sequences
that reflect the nucleotide composition of individual template molecules obtained from ancient tissues (such as cloned products
from a PCR amplification). The c statistic exploits as information the most common form of postmortem damage observed among clone sequences in ancient DNA
studies, namely, lesion-induced substitutions caused by cytosine deamination events. Analyses of simulated sets of templates
with miscoding lesions and real sets of clone sequences from the literature indicate that the c-based approach is highly effective in identifying endogenous sequence motifs, even when they are not present among the sampled
clones. The proposed approach is likely to be of general use to researchers working with DNA from ancient tissues, particularly
from human remains, where authentication of results has been most challenging.
[Reviewing
Editor: Dr. Magnus Nordborg] 相似文献
9.
Ellery PJ Tippett E Chiu YL Paukovics G Cameron PU Solomon A Lewin SR Gorry PR Jaworowski A Greene WC Sonza S Crowe SM 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(10):6581-6589
HIV-1 persists in peripheral blood monocytes in individuals receiving highly active antiretroviral therapy (HAART) with viral suppression, despite these cells being poorly susceptible to infection in vitro. Because very few monocytes harbor HIV-1 in vivo, we considered whether a subset of monocytes might be more permissive to infection. We show that a minor CD16+ monocyte subset preferentially harbors HIV-1 in infected individuals on HAART when compared with the majority of monocytes (CD14highCD16-). We confirmed this by in vitro experiments showing that CD16+ monocytes were more susceptible to CCR5-using strains of HIV-1, a finding that is associated with higher CCR5 expression on these cells. CD16+ monocytes were also more permissive to infection with a vesicular stomatitis virus G protein-pseudotyped reporter strain of HIV-1 than the majority of monocytes, suggesting that they are better able to support HIV-1 replication after entry. Consistent with this observation, high molecular mass complexes of apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G (APOBEC3G) were observed in CD16+ monocytes that were similar to those observed in highly permissive T cells. In contrast, CD14highCD16- monocytes contained low molecular mass active APOBEC3G, suggesting this is a mechanism of resistance to HIV-1 infection in these cells. Collectively, these data show that CD16+ monocytes are preferentially susceptible to HIV-1 entry, more permissive for replication, and constitute a continuing source of viral persistence during HAART. 相似文献
10.
Malavige GN Rostron T Rohanachandra LT Jayaratne SD Fernando N De Silva AD Liyanage M Ogg G 《PloS one》2011,6(6):e20581