首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   186篇
  免费   9篇
  195篇
  2022年   3篇
  2021年   2篇
  2020年   3篇
  2019年   3篇
  2018年   3篇
  2016年   5篇
  2015年   10篇
  2014年   11篇
  2013年   8篇
  2012年   15篇
  2011年   11篇
  2010年   3篇
  2009年   8篇
  2008年   14篇
  2007年   6篇
  2006年   10篇
  2005年   6篇
  2004年   6篇
  2003年   4篇
  2002年   10篇
  2001年   7篇
  2000年   6篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1996年   3篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   5篇
  1990年   2篇
  1989年   3篇
  1988年   1篇
  1987年   4篇
  1986年   4篇
  1985年   3篇
  1975年   4篇
  1974年   1篇
  1972年   1篇
排序方式: 共有195条查询结果,搜索用时 0 毫秒
101.
The gene transduction method is a very powerful tool, not only in basic science but also in clinical medicine. Regenerative medicine is one field that has close connection with both basic and clinical. Recently, it has been reported that induced pluripotent stem (iPS) cells can be produced from somatic cells by a three or four gene transduction. We have also recently reported that lentiviral gene transfer of the tal1/scl gene can efficiently differentiate non-human primate common marmoset ES cells into hematopoietic cells without the support of stromal cells. In this study, we constructed a high-performance human fetal liver-derived lentiviral expression library, which contains a high number of individual clones, in order to develop a very helpful tool for understanding early hematopoiesis and/or hepatocytosis for future regenerative medicine. Our lentiviral cDNA library consisted of more than 8 x 10(7) individual clones, and their average insert size was >2 kb. DNA sequence analysis for each individual inserted cDNAs revealed that >60% contained the full-length protein-coding regions for many genes including cytokine receptors, cytoplasmic proteins, protein inhibitors, and nuclear factors. The transduction efficiency on 293T cells was 100% and the average size of an integrated cDNA was ~1.1 kb. These results suggest that our lentiviral human fetal liver cDNA expression library could be a very helpful tool for accelerating the discovery of novel genes that are involved in early hematopoiesis and hepatopoiesis and to make the use of iPS cells more efficient in the field of regenerative medicine.  相似文献   
102.
In this study, we used genetically modified bone marrow-derived CD11b(+)CD18(+) vehicle cells to deliver IL-1 receptor antagonist (IL-1ra) for treatment of inflamed renal interstitium in an animal model of unilateral ureteral obstruction (UUO). Vehicle cells that expressed the ICAM-1 ligands, CD11b and CD18, were obtained from bone marrow cells of DBA/2j mice and adenovirally transduced with the IL-1ra gene or glucocerebrosidase (GC) gene ex vivo. In kidneys treated to develop UUO, levels of ICAM-1, IL-1 beta, and IL-1R expression increased within 3 days compared with contralateral untreated kidneys in the same mice. Similarly, the macrophage infiltration in the cortical interstitium increased after 3 days in UUO kidneys, but not untreated kidneys. After UUO developed, DBA/2j mice were injected i.v. with either IL-1ra(+) vehicle cells (IL-1ra-treated mice) or GC(+) vehicle cells (GC-treated mice) at 24 h after UUO. Six days after the injection of these vehicle cells, marked increase of CD11b(+) IL-1ra(+) vehicle cells was observed in the ICAM-1-positive interstitium of UUO kidneys from IL-1ra-treated mice. In contrast, no CD11b(+) IL-1ra(+) cells appeared in ICAM-1-negative contralateral kidneys from these mice. Furthermore, the infiltration of macrophages (p < 0.001), expression of ICAM-1 (p < 0.005), and presence of alpha-smooth muscle actin (p = 0.005) in the interstitium of UUO kidneys were significantly decreased in IL-1ra-treated mice compared with GC-treated mice. These findings suggest that IL-1 may contribute to the development of renal interstitial injury and that our method can deliver a functioning gene encoding an antiinflammatory cytokine gene specifically at that site by interacting with local adhesion molecules.  相似文献   
103.
We developed a new technique for culture study that successfully recovers fungi from drug-treated skin tissues, in which tissue specimens were homogenized, dialyzed against water, digested with trypsin, and then washed with PBS, to eliminate the drug that remaining in the skin tissue specimens. With this modified culture method, we reevaluated the efficacy of KP-103, neticonazole, and lanoconazole in a guinea pig interdigital tinea pedis model. Guinea pigs with tinea pedis were topically treated with a 1% solution of KP-103 or a reference drug once a day for 10 consecutive days. Five days after the last treatment, left and right feet were subjected to culture study by the conventional and modified recovery culture methods, respectively. One hundred percent (20/20) of lanoconazole-treated feet were judged as culture-negative by the conventional culture method, but 85% (17/20) of the feet were shown to be culture-positive when the modified recovery culture method was used. On the other hand, KP-103 achieved high rates of culture-negative rates, 95% (19/20) and 85% (17/20), in both conventional and modified culture methods, respectively. Furthermore, on day-30 posttreatment, KP-103 sterilized 14 of the 20 infected feet, whereas neticonazole and lanoconazole were not effective even in reducing fungal burden. KP-103 proved to be highly effective in achieving mycological cure and preventing relapse against tinea pedis presumably because of its good bioavailability in the skin based on its low keratin-affinity, along with its potent antifungal activity.  相似文献   
104.
To search for negative regulatory components of the NF-kappaB activation pathways, we mutagenized Rat-1 fibroblasts and established a stable mutant cell line with a constitutive NF-kappaB activity. This mutant cell line, designated as TK26, showed permanently elevated I kappa B kinase (IKK) activity and a genetically recessive phenotype revealed by somatic cell hybridization between TK26 and Rat-1. Our results suggested that lack of a negative regulation of IKK could lead to permanent NF-kappaB activation. The TK26 cell line will be useful to genetically identify a component necessary for keeping the IKK complex under an inactive form in resting cells.  相似文献   
105.
Taurine is not only present in foods, tonics and nutrient drinks but is also used as a medicinal agent mainly for treatment of chronic heart failure and liver disease. However, little is known about its influence on drug-metabolizing enzymes, especially cytochrome P450 (CYP), in human. We examined whether taurine could affect the expression of CYP3A4 mRNA in the presence or absence of rifampicin (RFP), which is a potent inducer of CYPs, with HepG2 cells. Taurine enhanced twice the induction of CYP3A4 mRNA by RFP, but did not affect the expression by itself. This effect was both concentration- and time-dependent. On the other hand, taurine did not affect the induction by phenobarbital. Taurine did not increase intracellular uptake of RFP. Therefore, we conclude that taurine is an enhancer for the induction of CYP3A4 by RFP.  相似文献   
106.
Identification of the novel splicing variants for the hPXR in human livers   总被引:2,自引:0,他引:2  
Chronic anthracycline administration to rabbits causes impairment of cardiac contractility and decreased gene expression of the calcium-induced calcium release channel of sarcoplasmic reticulum (SR), the ryanodine receptor (RYR2). The C-13 hydroxy metabolite (doxorubicinol), formed in the heart, has been hypothesized to contribute to anthracycline cardiotoxicity. C-13 deoxydoxorubicin is an analog unable to form the C-13 hydroxy metabolite. Therefore, doxorubicin, C-13 deoxydoxorubicin, or saline was administered to rabbits (1 mg/kg iv twice weekly for 8 weeks). Left ventricular fractional shortening (LVFS) was decreased by chronic treatment with doxorubicin (28 +/- 2%; P < 0.05), but not C-13 deoxydoxorubicin (33 +/- 2%) compared to age-matched pair-fed controls. Doxorubicin, but not C-13 deoxydoxorubicin, caused a significant reduction (P < 0.02) in the ratio of RYR2/Ca-Mg ATPase (SERCA2) mRNA levels (0.57 +/- 0.1 vs 1.22 +/- 0.2, respectively) in the left ventricle. This suggests that doxorubicinol may contribute to the downregulation of cardiac RYR2 expression in chronic doxorubicin cardiotoxicity.  相似文献   
107.
We studied the effect of peroxisome proliferator-activated receptor gamma (PPARgamma) activation on thromboxane A(2)(TXA(2)) and prostaglandin E(2)(PGE(2)) production in monocyte/macrophage cell lines. In present experiment, we used human peripheral blood monocyte (PBMC), monocyte-cell line THP-1 and mouse macrophage-like cell line RAW264.7. The expression of PPARgamma is reported in PBMC and THP-1. Synthetic PPARgamma ligands (troglitazone or BRL49653) inhibited TXA(2) production and enhanced PGE(2) production of PBMC and THP-1. When treated with 0.5-10 microM of troglitazone, there were no significant changes of TXA(2) and PGE(2) production of RAW264.7 cells, which express very low levels of PPARgamma. When RAW264.7 cells was transfected with PPARgamma expression plasmid and treated with troglitazone, PPARgamma was activated in a dose-dependent manner. In PPARgamma-transfected RAW264.7, TXA(2) production was decreased and PGE(2) production was increased by troglitazone treatment. But it needs high concentration of troglitazone (10 microM) for increasing PGE(2) production. These results suggest that PPARgamma may have negative effect on TXA(2) production, and also have slightly positive effect on PGE(2) production of macrophage.  相似文献   
108.
109.

Purpose

To evaluate the dose-response relationship for development of acute radiation mucositis (ARM) using an oral mucosal dose surface model (OMDS-model) in carbon ion radiotherapy (C-ion RT) for head and neck tumors.

Methods

Thirty-nine patients receiving C-ion RT for head and neck cancer were evaluated for ARM (once per week for 6 weeks) according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0, and the Radiation Therapy Oncology Group (RTOG) scoring systems. The irradiation schedule typically used was 64 Gy [relative biological effectiveness (RBE)] in 16 fractions for 4 weeks. Maximum point doses in the palate and tongue were compared with ARM in each patient.

Results

The location of the ARM coincided with the high-dose area in the OMDS-model. There was a clear dose-response relationship between maximum point dose and ARM grade assessed using the RTOG criteria but not the CTCAE. The threshold doses for grade 2–3 ARM in the palate and tongue were 43.0 Gy(RBE) and 54.3 Gy(RBE), respectively.

Conclusions

The OMDS-model was useful for predicting the location and severity of ARM. Maximum point doses in the model correlated well with grade 2–3 ARM.  相似文献   
110.
The value of no-take marine reserves as fisheries-management tools is controversial, particularly in high-poverty areas where human populations depend heavily on fish as a source of protein. Spillover, the net export of adult fish, is one mechanism by which no-take marine reserves may have a positive influence on adjacent fisheries. Spillover can contribute to poverty alleviation, although its effect is modulated by the number of fishermen and fishing intensity. In this study, we quantify the effects of a community-managed marine reserve in a high poverty area of Northern Mozambique. For this purpose, underwater visual censuses of reef fish were undertaken at three different times: 3 years before (2003), at the time of establishment (2006) and 6 years after the marine reserve establishment (2012). The survey locations were chosen inside, outside and on the border of the marine reserve. Benthic cover composition was quantified at the same sites in 2006 and 2012. After the reserve establishment, fish sizes were also estimated. Regression tree models show that the distance from the border and the time after reserve establishment were the variables with the strongest effect on fish abundance. The extent and direction of the spillover depends on trophic group and fish size. Poisson Generalized Linear Models show that, prior to the reserve establishment, the survey sites did not differ but, after 6 years, the abundance of all fish inside the reserve has increased and caused spillover of herbivorous fish. Spillover was detected 1km beyond the limit of the reserve for small herbivorous fishes. Six years after the establishment of a community-managed reserve, the fish assemblages have changed dramatically inside the reserve, and spillover is benefitting fish assemblages outside the reserve.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号