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91.
92.
The volume-activated chloride current in human endothelial cells depends on intracellular ATP 总被引:6,自引:0,他引:6
Masahiro Oike Guy Droogmans Bernd Nilius 《Pflügers Archiv : European journal of physiology》1994,427(1-2):184-186
We have studied the effect of intracellular ATP on volume-activated Cl–-currents in endothelial cells from human umbilical veins by means of the whole-cell patch clamp technique. The run-down of this current in ruptured patches during repetitive applications of hypotonic solutions (HTS) could be significantly reduced if the cells were internally perfused with a pipette solution that contained 4 mmol/l ATP. This run-down was much less pronounced if currents were recorded using nystatin-perforated patches. The amplitude of the current was drastically reduced and its activation became slower if the cells were superfused with a glucose-free medium with 1 mmol/l KCN. Adding 4 mmol/l ATPS, a poorly hydrolyzable ATP-analogue, to the patch pipette prevented run-down of the current during repetitive activations by HTS, even if the cells were superfused with glucose-free solution with 1 mmol/l KCN. It is concluded that activation of the mechanosensitive Cl– conductance in human endothelial cells requires the presence of intracellular ATP, but not its hydrolysis. 相似文献
93.
Natural killer (NK) cells and cytotoxic T lymphocytes (CTL), the functional coordination of which are governed by various signal substances, are crucial in the body’s defense of tumor and virus-infected cells. We investigated the role of various neurotransmitters and hormones on the regulation of functional parameters, including NK cell cytotoxicity, and the migration of NK cells and CTL within a three-dimensional collagen lattice. Using peripheral blood CTL and NK cells, we show that the neurotransmitters endorphin, histamine and substance P increase NK cell cytotoxicity, while norepinephrine inhibits cytotoxicity. Moreover, substance P reduces migratory activity, while norepinephrine increases NK cell and CTL migration. Furthermore, all three steroid hormones which were investigated, namely cortisone, testosterone, and estradiol, had regulatory influence on both cytotoxicity and migration of NK cells. These results further specify the functional basis of the complex interconnection between the immune and neuro-endocrine systems. 相似文献
94.
(Patho)physiological implications of the novel epithelial Ca2+ channels TRPV5 and TRPV6 总被引:1,自引:0,他引:1
Nijenhuis T Hoenderop JG Nilius B Bindels RJ 《Pflügers Archiv : European journal of physiology》2003,446(4):401-409
The epithelial Ca(2+) channels TRPV5 and TRPV6 constitute the apical Ca(2+) entry mechanism in active Ca(2+) (re)absorption. These two members of the superfamily of transient receptor potential (TRP) channels were cloned from the vitamin-D-responsive epithelia of kidney and small intestine and subsequently identified in other tissues such as bone, pancreas and prostate. These channels are regulated by vitamin D as exemplified in animal models of vitamin-D-deficiency rickets. In addition, the epithelial Ca(2+) channels might be involved in the multifactorial pathogenesis of disorders ranging from idiopathic hypercalciuria, stone disease and postmenopausal osteoporosis. This review highlights the emerging (patho)physiological implications of these epithelial Ca(2+) channels. 相似文献
95.
Hoenderop JG Nilius B Bindels RJ 《Pflügers Archiv : European journal of physiology》2003,446(3):304-308
The epithelial calcium channels TRPV5 and TRPV6 have been studied extensively in the epithelial tissues controlling Ca(2+) homeostasis and exhibit a range of distinctive properties that distinguish them from other transient receptor potential (TRP) channels. These two novel members of the superfamily of TRP channels were cloned from vitamin D-responsive epithelia: kidney, small intestine and placenta, and identified subsequently in tissues like pancreas, bone and prostate. This review addresses the unique properties of these highly Ca(2+)-selective channels and highlights their implications for the process of transepithelial Ca(2+) transport. 相似文献
96.
Seiler Petra; Fischer Bernd; Lindenau Antje; Beier Henning M. 《Human reproduction (Oxford, England)》1994,9(10):1920-1926
The commercial polychlorinated biphenyl (PCB) formulation Aroclor1260 (4 mg/kg body weight), technical grade dichlorodiphenyltrichloroethane(DDT; 3 mg) and Lindane (-hexachlorocyclohexane; 0.8 mg) wereadministered orally, either separately or in combination, tosexually mature female rabbits three times per week for 1215weeks. Oviductal and uterine luminal fluid, cleavage stage embryos(day 1 post coitum), blastocysts (day 6), fetuses, exocoelicfluid and placentae (day 11) were analysed, firstly for chlorinatedhydrocarbon residues, and secondly for embryonic and fetal development.The doses applied were well tolerated by the treated animals.PCB and DDT accumulated in uterine secretions (day 6) but notin oviductal luminal fluid (day 1). Both chlorinated hydrocarbonswere found in preimplantation blastocysts. Residues in day 11fetuses were 16- (DDT) or 18-fold (PCB) higher than in day 6blastocysts. Significant amounts were also detected in placentaltissue and in exocoelic fluid. A specific accumulation of thehighly chlorinated biphenyl congener no. 180 was noted in fetuses,placentae and exocoelic fluid. The clear accumulation of thechlorinated hydrocarbon compounds in luminal fluid and embryonictissue is contrasted by rather weak effects on fertility. Nostatistically significant differences between treated animalsand controls were observed for fertilization rate and pre- andpost-implantation (up to day 11 post coitum) losses. However,in females exposed to PCB, a 20% higher loss of blastocystswas noticed, as compared with controls (P > 0.05). This effectwas shown on day 6 of embryonic development and may be due tothe embryotoxic activities of PCB. 相似文献
97.
98.
Bernd Kupfer Torsten Ruf Bertfried Matz Jacob Nattermann Ulrich Spengler Jürgen K Rockstroh Hans H Brackmann Johannes Blümel Michael Tacke Rolf Kaiser 《Journal of clinical virology》2005,34(1):42-47
BACKGROUND: Until the mandatory introduction of viral inactivation techniques of blood plasma products in the early 1980s many recipients of these products were infected with various viral pathogens. OBJECTIVES: To determine the rate of transmission of GB virus C/hepatitis G virus (GBV-C/HGV) HCV, and HIV through non-virus-inactivated clotting factor concentrates in hemophiliacs, as well as the relation between amount of administered clotting factor and risk for GBV-C/HGV infection. STUDY DESIGN: In this cross-sectional study, we determined retrospectively the rates of infection markers for GBV-C/HGV, HCV, and HIV in a German cohort of hemophiliacs treated with documented amounts of non-virus-inactivated clotting factor concentrates (group A) and in a second group of hemophiliacs who were treated exclusively with virus-inactivated clotting factor (group B). The presence of anti-virus antibodies was determined by ELISA. Viral RNA was detected by RT-PCR. Markers for viral infections were compared to amounts of administered non-virus-inactivated clotting factor. RESULTS: Among hemophiliacs treated with documented amounts of non-virus-inactivated clotting factor the prevalence for GBV-C/HGV, HCV, and HIV was 40.3%, 98.6%, and 56.3%, respectively. In contrast to HIV, the rate of GBV-C/HGV infections did not increase with increasing amounts of consumed non-inactivated clotting factor. Even in the subgroup of heavily treated hemophiliacs the rate of GBV-C/HGV infection markers did not exceed 45%. CONCLUSIONS: The amount of non-virus-inactivated clotting factor is not predictive for the risk of GBV-C/HGV infection in hemophiliacs. Despite repeated parenteral exposure more than 55% of hemophiliacs were not infected with GBV-C/HGV. Our findings indicate a high frequency of host factors preventing parenteral transmission of GBV-C/HGV. 相似文献
99.
Prognostic value of MMP-2, -9 and TIMP-1,-2 immunoreactive protein at the invasive front in advanced head and neck squamous cell carcinomas 总被引:10,自引:0,他引:10
Ondruschka C Buhtz P Motsch C Freigang B Schneider-Stock R Roessner A Boltze C 《Pathology, research and practice》2002,198(8):509-515
In head and neck cancer as well as in other carcinomas, tumor expansion and spread to distant sites require the secretion of destructive enzymes that degrade the extracellular matrix. A variety of proteases contribute to matrix destruction. Characteristics of the invasive tumor front may reflect tumor prognosis better than do other parts of the tumor. Therefore, it was the aim of the present study to (i) compare central and peripheral tumor zones for differences in the expression of matrix-metalloproteinases (MMP) -2 and -9 and their naturally occurring inhibitors (tissue inhibitor of matrix-metalloproteinases (TIMP) -1 and -2), (ii) examine the morphological potential of malignancy, and (iii) correlate these findings with clinicopathological parameters. The study population consisted of 106 surgical specimens of advanced head and neck squamous cell carcinomas. The invasive front was graded for malignancy, and immunohistochemical staining with MMP-2, MMP-9, TIMP-1 and TIMP-2 antibodies was performed. Both MMP-2 and MMP-9 were found to be significantly overexpressed at the tumor front. The MMP-2-positive invasive front exhibited diminished overall survival times. In multivariate analysis, MMP-2 expression retained its correlation with overall survival in addition to nodal status and total malignancy score. Expression of TIMP-2 correlated with local tumor invasion. We conclude that the expression of MMP-2 at the invasive front is a marker of poor survival and appears to be associated with early recurrence in initially lymph node-negative patients. 相似文献
100.
van der Loo B Oechslin E Jenni R 《The New England journal of medicine》2002,347(12):949; author reply 949