全文获取类型
收费全文 | 1215篇 |
免费 | 72篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 64篇 |
妇产科学 | 14篇 |
基础医学 | 155篇 |
口腔科学 | 13篇 |
临床医学 | 151篇 |
内科学 | 385篇 |
皮肤病学 | 15篇 |
神经病学 | 62篇 |
特种医学 | 65篇 |
外科学 | 109篇 |
综合类 | 41篇 |
预防医学 | 42篇 |
眼科学 | 30篇 |
药学 | 107篇 |
中国医学 | 8篇 |
肿瘤学 | 46篇 |
出版年
2022年 | 8篇 |
2021年 | 24篇 |
2020年 | 12篇 |
2019年 | 9篇 |
2018年 | 23篇 |
2017年 | 11篇 |
2016年 | 17篇 |
2015年 | 21篇 |
2014年 | 45篇 |
2013年 | 48篇 |
2012年 | 53篇 |
2011年 | 53篇 |
2010年 | 48篇 |
2009年 | 38篇 |
2008年 | 51篇 |
2007年 | 68篇 |
2006年 | 51篇 |
2005年 | 48篇 |
2004年 | 36篇 |
2003年 | 33篇 |
2002年 | 35篇 |
2001年 | 17篇 |
2000年 | 22篇 |
1999年 | 34篇 |
1998年 | 34篇 |
1997年 | 22篇 |
1996年 | 30篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 16篇 |
1991年 | 23篇 |
1990年 | 14篇 |
1989年 | 21篇 |
1988年 | 22篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 15篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1980年 | 11篇 |
1978年 | 8篇 |
1975年 | 9篇 |
1973年 | 9篇 |
1959年 | 15篇 |
1958年 | 16篇 |
1957年 | 14篇 |
1956年 | 10篇 |
1955年 | 15篇 |
1954年 | 19篇 |
排序方式: 共有1311条查询结果,搜索用时 31 毫秒
61.
In the early 1960s, peritoneal dialysis (PD) was introduced as a form of long-term maintenance therapy in patients with end-stage renal disease (ESRD). We have come a long way since. Increasing understanding of peritoneal kinetic behavior, its innovative manipulation to meet patient needs, critical monitoring of clinical outcomes, and parallel development in technology have all contributed to the worldwide success of the therapy over the past four decades. In this article we review the evolution of the various PD modalities in the context of these factors. 相似文献
62.
A column trapping system has been incorporated into high performance liquid chromatography-nuclear magnetic resonance-mass spectrometry (HPLC-NMR-MS) to reduce data acquisition time of NMR experiments. The system uses a trapping column to capture analytes after the HPLC column and back flush trapped analyte to the flow cell of the NMR probe for detection. A dilution solvent is mixed with eluent from HPLC column to reduce the influence of the organic content in the mobile phase before column trapping. The trapping column is also coupled with a mass spectrometer (MS) to get complementary MS data on the same peak. Studies on 1-hydroxylated 9-amino-1,2,3,4-tetrahydro-acridine (1-OH tacrine), indomethacin and testosterone with the column trapping system showed good recovery of analytes and over 3-fold mean increase in UV-VIS signal intensity. The time saving on NMR experiments with the column trapping system was demonstrated by the analysis of dog microsomal incubate with tacrine. 相似文献
63.
The authors report six patients with tick paralysis seen over 5 years. Clinical and electrodiagnostic findings failed to adequately distinguish tick paralysis from Guillain-Barré syndrome in these patients. Finding a tick attached to the scalp or the nape of the neck and removing it resulted in rapid clinical improvement. 相似文献
64.
Holly L Valentine Kalyani Amarnath Venkataraman Amarnath William M Valentine 《Toxicological sciences》2006,89(2):485-494
The neurotoxic hazard of a dithiocarbamate is influenced by route of exposure and acid stability of the dithiocarbamate. As an example, oral administration of the acid labile dithiocarbamate N,N-diethyldithiocarbamate (DEDC) causes a central-peripheral axonopathy thought to result from acid-promoted decomposition to CS2 in the stomach. In contrast, parenteral administration of DEDC, which bypasses the acidic environment of the stomach, causes a primary demyelination that is thought to be mediated through the intact parent dithiocarbamate. The relative acid stability of pyrrolidine dithiocarbamate (PDTC) suggests that a significant portion of a dose can be absorbed intact following oral exposure with the potential to produce a primary myelin injury. The present study was performed to characterize the neurotoxicity of PDTC and evaluate the possible role of copper in dithiocarbamate-mediated demyelination. Male Sprague Dawley rats were administered PDTC in drinking water and given either a normal- or high-copper diet for 18, 47, or 58 weeks. Examination of peripheral nerve by light microscopy and electron microscopy at the end of exposures revealed primary myelin lesions and axonal degeneration in the PDTC groups, with a significant increase in the severity of several lesions observed for the PDTC, high-copper group relative to the PDTC normal-copper diet. ICP-AES metal analysis determined that the PDTC groups had significantly increased brain copper, and at 58 weeks a significant increase in copper was seen in the sciatic nerve of PDTC high-copper animals relative to PDTC normal-copper diet animals. Although RP-HPLC analysis could not detect globin alkylaminocarbonyl cysteine modifications analogous to those seen with parenteral DEDC, LC/MS/MS identified (pyrrolidin-1-yl carbonyl)cysteine adducts on PDTC-exposed rat globin. These findings are consistent with previous studies supporting the ability of acid-stable dithiocarbamates to mediate myelin injury following oral exposure. The greater severity of lesions associated with dietary copper supplementation and elevated copper levels in nerve also suggests that perturbation of copper homeostasis may contribute to the development of myelin lesions. 相似文献
65.
F Haque ST Fazal SA Ahmad SZ Abbas S Naseem 《Journal of Medical Imaging and Radiation Oncology》2006,50(1):63-65
Primary osteogenic sarcoma of the skull is an exceedingly rare condition. An adult male patient is described, who had a painless swelling in the right forehead that had rapidly enlarged in the previous 6 months. Radiological investigations showed a large destructive mass lesion involving the right side of the frontal bone with extension into the frontal sinus, causing marked extradural compression of brain parenchyma. Histopathological examination confirmed the lesion to be primary osteogenic sarcoma. 相似文献
66.
Expression of differential nitric oxide synthase isoforms in human normal gastric mucosa and gastric cancer tissue 总被引:10,自引:2,他引:10
The present study investigated the expression and distribution of three
isoforms of nitric oxide synthase (NOS) in different anatomical regions of
the human stomach and in gastric neoplastic tissues by immunohistochemistry
using specific antibodies. Intracellular localization of individual
isoenzymes of NOS was detected in normal gastric mucosa. Gastric cancer
tissues had a marked reduction of all three NOS isoforms expression. The
expression of the endothelial NOS, neuronal NOS and inducible NOS in the
tumor tissue was significantly lower than in normal gastric mucosa (P =
0.01, P = 0.02, P < 0.01, respectively). In the tumor tissue the
expression of inducible NOS was significantly lower than the expression of
both constitutive forms of NOS (P < 0.01). There was a tendency to
higher expression of both constitutive forms of NOS in earlier stages T2 of
the tumor compared to advanced T4 tumor. In contrast, the expression of
inducible NOS was higher than in the advanced T4 tumor than in the earlier
stages T2 of the tumor. The mapping of the expression of endothelial NOS,
neuronal NOS and inducible NOS in human stomach showed higher expression of
NOS isoforms in the distal third than in the proximal third of the stomach
(P = 0.03, P = 0.04, P = 0.01, respectively). We conclude that there is
greater expression of NOS in the stomach corpus and in antrum than in the
proximal third of the normal human stomach mirroring the anatomical
predilection of common pathological changes in this part of the human
stomach. Furthermore, there was loss of the expression of individual
isoenzymes in gastric neoplasms.
相似文献
67.
68.
Venkataraman S George V Jesudason M Ganesh A 《The Journal of the Association of Physicians of India》1999,47(10):1020-1021
A case of acinetobacter meningitis following head injury in a patient who developed cerebrospinal fluid otorrhea, and did not have any neurosurgical procedure, is presented. Previously reported cases are cited, with a review of the literature. Pefloxacin monotherapy is associated with a poor clinical response. 相似文献
69.
Kalyanasundaram Venkataraman Robert Siegel Sun June Kim John W. Allen 《The American journal of cardiology》1978,41(5):952-955
Five patients with musical murmurs were studied noninvasively with simultaneous echocardiography and phonocardiography. Three patients had aortic regurgitation, one mitral regurgitation and one tricuspid regurgitation. The frequency of the musical murmurs ranged from 40 to 158 cycles/sec. The patient with tricuspid regurgitation manifested an inspiratory honk. Simultaneous echo-phonocardiography revealed regular valve leaflet flutter (aortic, mitral or tricuspid) at a frequency identical to that of the simultaneously recorded musical murmur. This study demonstrates that echocardiography is a useful noninvasive tool in identifying the site of origin of musical murmurs. 相似文献
70.