全文获取类型
收费全文 | 2002篇 |
免费 | 152篇 |
国内免费 | 3篇 |
专业分类
2157篇 |
出版年
2024年 | 2篇 |
2023年 | 26篇 |
2022年 | 28篇 |
2021年 | 60篇 |
2020年 | 30篇 |
2019年 | 47篇 |
2018年 | 66篇 |
2017年 | 51篇 |
2016年 | 81篇 |
2015年 | 87篇 |
2014年 | 112篇 |
2013年 | 163篇 |
2012年 | 175篇 |
2011年 | 155篇 |
2010年 | 102篇 |
2009年 | 91篇 |
2008年 | 125篇 |
2007年 | 122篇 |
2006年 | 105篇 |
2005年 | 72篇 |
2004年 | 69篇 |
2003年 | 70篇 |
2002年 | 64篇 |
2001年 | 30篇 |
2000年 | 31篇 |
1999年 | 29篇 |
1998年 | 14篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1979年 | 4篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1965年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有2157条查询结果,搜索用时 15 毫秒
131.
Kang Su Cho Hae Do Jung Won Sik Ham Doo Yong Chung Yong Jin Kang Won Sik Jang Jong Kyou Kwon Young Deuk Choi Joo Yong Lee 《PloS one》2015,10(12)
Objectives
To investigate whether skin-to-stone distance (SSD), which remains controversial in patients with ureter stones, can be a predicting factor for one session success following extracorporeal shock wave lithotripsy (ESWL) in patients with upper ureter stones.Patients and Methods
We retrospectively reviewed the medical records of 1,519 patients who underwent their first ESWL between January 2005 and December 2013. Among these patients, 492 had upper ureter stones that measured 4–20 mm and were eligible for our analyses. Maximal stone length, mean stone density (HU), and SSD were determined on pretreatment non-contrast computed tomography (NCCT). For subgroup analyses, patients were divided into four groups. Group 1 consisted of patients with SSD<25th percentile, group 2 consisted of patients with SSD in the 25th to 50th percentile, group 3 patients had SSD in the 50th to 75th percentile, and group 4 patients had SSD≥75th percentile.Results
In analyses of group 2 patients versus others, there were no statistical differences in mean age, stone length and density. However, the one session success rate in group 2 was higher than other groups (77.9% vs. 67.0%; P = 0.032). The multivariate logistic regression model revealed that shorter stone length, lower stone density, and the group 2 SSD were positive predictors for successful outcomes in ESWL. Using the Bayesian model-averaging approach, longer stone length, lower stone density, and group 2 SSD can be also positive predictors for successful outcomes following ESWL.Conclusions
Our data indicate that a group 2 SSD of approximately 10 cm is a positive predictor for success following ESWL. 相似文献132.
133.
Seo-Jung Han Jae Eun Jung Do Hee Oh Minsup Kim Jae-Min Kim Kyung-Sook Chung Hee-Soo Han Jeong-Hun Lee Kyung-Tae Lee Hee Jin Jeong In Ho Park Eunkyeong Jeon Jeon-Soo Shin Dongkeun Hwang Art E. Cho Duck-Hyung Lee Taebo Sim 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):1257
Identification of highly selective type II kinase inhibitors is described. Two different chiral peptidomimetic scaffolds were introduced on the tail region of non-selective type II kinase inhibitor GNF-7 to enhance the selectivity. Kinome-wide selectivity profiling analysis showed that type II kinase inhibitor 7a potently inhibited Lck kinase with great selectivity (IC50 of 23.0 nM). It was found that 7a and its derivatives possessed high selectivity for Lck over even structurally conserved all Src family kinases. We also observed that 7a inhibited Lck activation in Jurkat T cells. Moreover, 7a was found to alleviate clinical symptoms in DSS-induced colitis mice. This study provides a novel insight into the design of selective type II kinase inhibitors by adopting chiral peptidomimetic moieties on the tail region. 相似文献
134.
Joseph K. Cheng Amanda M. Lewis Do Soon Kim Timothy Dyess Hal S. Alper 《Biotechnology journal》2016,11(8):1100-1109
Mammalian cell line development requires streamlined methodologies that will reduce both the cost and time to identify candidate cell lines. Improvements in site‐specific genomic editing techniques can result in flexible, predictable, and robust cell line engineering. However, an outstanding question in the field is the specific site of integration. Here, we seek to identify productive loci within the human genome that will result in stable, high expression of heterologous DNA. Using an unbiased, random integration approach and a green fluorescent reporter construct, we identify ten single‐integrant, recombinant human cell lines that exhibit stable, high‐level expression. From these cell lines, eight unique corresponding integration loci were identified. These loci are concentrated in non‐protein coding regions or intronic regions of protein coding genes. Expression mapping of the surrounding genes reveals minimal disruption of endogenous gene expression. Finally, we demonstrate that targeted de novo integration at one of the identified loci, the 12th exon‐intron region of the GRIK1 gene on chromosome 21, results in superior expression and stability compared to the standard, illegitimate integration approach at levels approaching 4‐fold. The information identified here along with recent advances in site‐specific genomic editing techniques can lead to expedited cell line development. 相似文献
135.
Ion channels-related diseases 总被引:4,自引:0,他引:4
There are many diseases related to ion channels. Mutations in muscle voltage-gated sodium, potassium, calcium and chloride channels, and acetylcholine-gated channel may lead to such physiological disorders as hyper- and hypokalemic periodic paralysis, myotonias, long QT syndrome, Brugada syndrome, malignant hyperthermia and myasthenia. Neuronal disorders, e.g., epilepsy, episodic ataxia, familial hemiplegic migraine, Lambert-Eaton myasthenic syndrome, Alzheimer's disease, Parkinson's disease, schizophrenia, hyperekplexia may result from dysfunction of voltage-gated sodium, potassium and calcium channels, or acetylcholine- and glycine-gated channels. Some kidney disorders, e.g., Bartter's syndrome, policystic kidney disease and Dent's disease, secretion disorders, e.g., hyperinsulinemic hypoglycemia of infancy and cystic fibrosis, vision disorders, e.g., congenital stationary night blindness and total colour-blindness may also be linked to mutations in ion channels. 相似文献
136.
Jutabha P Kanai Y Hosoyamada M Chairoungdua A Kim DK Iribe Y Babu E Kim JY Anzai N Chatsudthipong V Endou H 《The Journal of biological chemistry》2003,278(30):27930-27938
A novel transport protein with the properties of voltage-driven organic anion transport was isolated from pig kidney cortex by expression cloning in Xenopus laevis oocytes. A cDNA library was constructed from size-fractionated poly(A)+ RNA and screened for p-aminohippurate (PAH) transport in high potassium medium. A 1856-base pair cDNA encoding a 467-amino acid peptide designated as OATV1 (voltage-driven organic anion transporter 1) was isolated. The predicted amino acid sequence of OATV1 exhibited 60-65% identity to those of human, rat, rabbit, and mouse sodium-dependent phosphate cotransporter type 1 (NPT1), although OATV1 did not transport phosphate. The homology of this transporter to known members of the organic anion transporter family (OAT family) was about 25-30%. OATV1-mediated PAH transport was affected by the changes in membrane potential. The transport was Na+-independent and enhanced at high concentrations of extracellular potassium and low concentrations of extracellular chloride. Under the voltage clamp condition, extracellularly applied PAH induced outward currents in oocytes expressing OATV1. The current showed steep voltage dependence, consistent with the voltage-driven transport of PAH by OATV1. The PAH transport was inhibited by various organic anions but not by organic cations, indicating the multispecific nature of OATV1 for anionic compounds. This transport protein is localized at the apical membrane of renal proximal tubule, consistent with the proposed localization of a voltage-driven organic anion transporter. Therefore, it is proposed that OATV1 plays an important role to excrete drugs, xenobiotics, and their metabolites driven by membrane voltage through the apical membrane of the tubular epithelial cells into the urine. 相似文献
137.
Theresa Ohlig Do Viet Le Andreas Gardemann Carmen Wolke Sarah Gürtler Daniela Peter Lorenz Schild Uwe Lendeckel 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2018,1863(4):379-387
The mitochondrial phospholipid cardiolipin (CL) has been implicated with mitochondrial morphology, function, and cell proliferation. Changes in CL are often paralleled by changes in the lipid environment of mitochondria that may contribute to mitochondrial function and proliferation. This study aimed to separate the effects of CL content and CL composition from cellular free fatty acid distribution on bioenergetics and proliferation in C6 glioma cells. To this end, cardiolipin synthase and the CL remodelling enzyme, tafazzin, were knocked-down by siRNA in C6 cells. After 72?h of cultivation, we analysed CL composition by means of LC/MS/MS, distribution of cellular fatty acids by means of gas chromatography, and determined oxygen consumption and proliferation. Knock-down of cardiolipin synthase affected the cellular CL content in the presence of linoleic acid (LA) in the culture medium. Knock-down of tafazzin had no consequence with respect to the pattern of cellular fatty acids but caused a decrease in cell proliferation. It significantly changed the distribution of molecular CL species, increased CL content, decreased oxygen consumption, and decreased cell proliferation when cultured in the presence of linoleic acid (LA). The addition of linoleic acid to the culture medium caused significant changes in the pattern of cellular fatty acids and the composition of molecular CL species. These data suggest that tafazzin is required for efficient bioenergetics and for proliferation of glioma cells. Supplementation of fatty acids can be a powerful tool to direct specific changes in these parameters. 相似文献
138.
Gomes Helga Do R.; Goes Joaquim I.; Parulekar A.H. 《Journal of plankton research》1992,14(9):1307-1329
This study examines the spatial distribution and size structureof phytoplankton biomass and productivity in relation to thevertical structrure of the Andaman Sea (northeastern IndianOcean). This region was characterized by low concentrationsof nutrients and high levels of insolation. Nitrogen availabilityappeared to control overall productivity with nitrate-basednew production accounting for 824% of thetotal primary production. Euphotic column chlorophyll (chl a)averaged 52.5 mg m2 of which a major portion was locatedas a subsurface chl a maximum (SCM) at 相似文献
139.
Monica Daniela Doşa Laurentiu-Tony Hangan Eduard Crauciuc Cristina Galeş Mihai Nechifor 《Biological trace element research》2011,142(1):36-46
Research was performed on a group of 30 patients with non-insulin-dependent diabetes mellitus (NIDDM), who never received
antidiabetic medication before, and on a group of 17 healthy adults. The patients were administered treatment with metformin,
1,000 mg/day. Plasmatic and urinary concentration of magnesium have been measured, copper and zinc along with the concentrations
of glucose, HDL, LDL, cholesterol, tryglicerides, HbA1c, and total erythrocyte magnesium, in advance and after 3 months of
treatment. Data showed significant differences in the NIDDM group vs the control group: for plasma magnesium—1.95 ± 0.19 vs
2.20 ± 0.18 mg/dl, p < 0.001; urine magnesium—237.28 ± 34.51 vs 126.25 ± 38.22 mg/24 h, p < 0.001; erythrocyte magnesium—5.09 ± 0.63 vs 6.38 ± 0.75 mg/dl, p < 0.001; plasma zinc—67.56 ± 6.21 vs 98.41 ± 20.47 μg/dl, p < 0.001; urine zinc—1,347.54 ± 158.24 vs 851.65 ± 209.75 μg/24 h, p < 0.001; plasma copper—111.91 ± 20.98 vs 96.33 ± 8.56 μg/dl, p < 0.001; and urine copper—51.70 ± 23.79 vs 36.00 ± 11.70 μg/24 h, p < 0.05. Treatment with metformin for 3 months modified significant erythrocyte magnesium—5.75 ± 0.61 vs 5.09 ± 0.63 mg/dl,
p < 0.001 and urine magnesium—198.27 ± 27.07 vs 237.28 ± 34.51 mg/24 h, p < 0.001, whereas it did not modify significant the plasmatic and urinary concentration of the other cations. The erythrocyte
magnesium concentration was inversely correlated with HbA1c (r = −0.438, p = 0.015). The plasma level of copper was positively correlated with HbA1c (r = 0.517, p < 0.003), tryglicerides (r = 0.534, p < 0.003), and cholesterol (r = 0.440, p < 0.05), and the plasma level of zinc was inversely correlated with glycemia (r = −0.399, p = 0.029). Our data show a significant action of metformin therapy, by increasing the total intraerythrocyte magnesium concentration
and decreasing the urinary magnesium elimination, positively correlated with the decrease of glycemia and HbA1c in NIDDM patients. 相似文献
140.
Hepatitis C virus core and nonstructural protein 3 proteins induce pro- and anti-inflammatory cytokines and inhibit dendritic cell differentiation 总被引:18,自引:0,他引:18
Dolganiuc A Kodys K Kopasz A Marshall C Do T Romics L Mandrekar P Zapp M Szabo G 《Journal of immunology (Baltimore, Md. : 1950)》2003,170(11):5615-5624
Antiviral immunity requires recognition of viral pathogens and activation of cytotoxic and Th cells by innate immune cells. In this study, we demonstrate that hepatitis C virus (HCV) core and nonstructural protein 3 (NS3), but not envelope 2 proteins (E2), activate monocytes and myeloid dendritic cells (DCs) and partially reproduce abnormalities found in chronic HCV infection. HCV core or NS3 (not E2) triggered inflammatory cytokine mRNA and TNF-alpha production in monocytes. Degradation of I-kappa B alpha suggested involvement of NF-kappa B activation. HCV core and NS3 induced production of the anti-inflammatory cytokine, IL-10. Both monocyte TNF-alpha and IL-10 levels were higher upon HCV core and NS3 protein stimulation in HCV-infected patients than in normals. HCV core and NS3 (not E2) inhibited differentiation and allostimulatory capacity of immature DCs similar to defects in HCV infection. This was associated with elevated IL-10 and decreased IL-2 levels during T cell proliferation. Increased IL-10 was produced by HCV patients' DCs and by core- or NS3-treated normal DCs, while IL-12 was decreased only in HCV DCs. Addition of anti-IL-10 Ab, not IL-12, ameliorated T cell proliferation with HCV core- or NS3-treated DCs. Reduced allostimulatory capacity in HCV core- and NS3-treated immature DCs, but not in DCs of HCV patients, was reversed by LPS maturation, suggesting more complex DC defects in vivo than those mediated by core or NS3 proteins. Our results reveal that HCV core and NS3 proteins activate monocytes and inhibit DC differentiation in the absence of the intact virus and mediate some of the immunoinhibitory effects of HCV via IL-10 induction. 相似文献