全文获取类型
收费全文 | 931875篇 |
免费 | 66347篇 |
国内免费 | 1342篇 |
专业分类
耳鼻咽喉 | 12957篇 |
儿科学 | 24365篇 |
妇产科学 | 23232篇 |
基础医学 | 132902篇 |
口腔科学 | 28247篇 |
临床医学 | 80534篇 |
内科学 | 183260篇 |
皮肤病学 | 19233篇 |
神经病学 | 72177篇 |
特种医学 | 36798篇 |
外国民族医学 | 79篇 |
外科学 | 152105篇 |
综合类 | 18042篇 |
现状与发展 | 1篇 |
一般理论 | 234篇 |
预防医学 | 61745篇 |
眼科学 | 21309篇 |
药学 | 72539篇 |
3篇 | |
中国医学 | 2162篇 |
肿瘤学 | 57640篇 |
出版年
2018年 | 8966篇 |
2017年 | 7029篇 |
2016年 | 7762篇 |
2015年 | 8860篇 |
2014年 | 11982篇 |
2013年 | 17494篇 |
2012年 | 24080篇 |
2011年 | 25038篇 |
2010年 | 14802篇 |
2009年 | 14266篇 |
2008年 | 24599篇 |
2007年 | 25682篇 |
2006年 | 26480篇 |
2005年 | 25430篇 |
2004年 | 24562篇 |
2003年 | 23606篇 |
2002年 | 23158篇 |
2001年 | 54731篇 |
2000年 | 56546篇 |
1999年 | 46948篇 |
1998年 | 10731篇 |
1997年 | 9465篇 |
1996年 | 9594篇 |
1995年 | 8927篇 |
1994年 | 8279篇 |
1993年 | 7593篇 |
1992年 | 35494篇 |
1991年 | 33915篇 |
1990年 | 32741篇 |
1989年 | 31875篇 |
1988年 | 28994篇 |
1987年 | 28250篇 |
1986年 | 26288篇 |
1985年 | 25146篇 |
1984年 | 17833篇 |
1983年 | 15141篇 |
1982年 | 7795篇 |
1981年 | 6771篇 |
1979年 | 15782篇 |
1978年 | 10599篇 |
1977年 | 9052篇 |
1976年 | 7871篇 |
1975年 | 8628篇 |
1974年 | 10466篇 |
1973年 | 9858篇 |
1972年 | 9357篇 |
1971年 | 8852篇 |
1970年 | 8426篇 |
1969年 | 7923篇 |
1968年 | 7200篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
T. Scholz Ø. Mathisen A. Bergan S. Osnes R. Innes T. Pedersen A. O. Aasen O. Søreide 《Transplant international》1997,10(3):180-184
We have introduced and evaluated several modifications of the conventional venovenous bypass (VVBP) in 29 adult patients
undergoing liver transplantation (OLT). A percutaneous technique for insertion of a jugular venous return cannula and a femoral
vein cannula was applied. The inferior mesenteric vein (IMV) was used for splanchnic decompression, which facilitated dissection
of the recipient liver and allowed portal anastomosis to be performed without disconnecting the portal bypass. A heat exchanger
was introduced into the bypass circuit to prevent heat loss. The percutaneous technique prevented complications related to
dissection in the axilla and groin. Hemodynamic characteristics corresponded to those found using the traditional technique.
Complications related to the VVBP were seen in only one patient in whom the femoral catheter was accidentally introduced into
the femoral artery. We conclude that percutaneous cannulas, use of the IMV for splanchnic decompression and the introduction
of a heat exchanger offer significant benefits and that they are safe and reliable.
Received: 23 August 1996 Received after revision: 14 January 1997 Accepted: 27 January 1997 相似文献
992.
Knife injuries can be classified into stabbing injuries and multiple laceration or multiple chops, the latter being much more common in Chinese communities. It is the mark of criminal gang attacks with their tendency to use long knives and choppers rather than guns. The intention is often to wound rather than kill. A survey of 89 cases revealed that 90% of the victims are men, with a mean age of 27 years; 75% was admitted to the hospital at night, and in 78% of the cases the assailants were persons unknown, or so we were told by the victims. The reasons for the attacks were also not given. Most of the women victims were assaulted by their spouse. Some 74% of the patients suffered three to six lacerations; 62% of the injuries were on the extensor surfaces of the upper limbs, while the hand and the back of the trunk were also common sites. The type of management differs from that for stabbing injuries. There were no fatalities, and less than half of the patients required blood transfusion. The average hospital stay was 6.2 days. The morbidity of these injuries involves damaged tendons and nerves. 相似文献
993.
Y. Mikawa R. Watanabe Y. Nakashima T. Hayashida 《Archives of orthopaedic and trauma surgery》1997,116(1-2):112-115
Spinal cord compression is an extremely serious complication of hereditary multiple exostoses (HME). A case of HME with compression of the cervical spinal cord is reported. Complete recovery following surgery was achieved. A review of the relevant literature revealed 51 previous cases of HME with cord/cauda equina compression. Most patients were under 30 years of age with more men affected than women. The family history was positive in 60%. The cervical and thoracic areas were predominantly affected, with the symptoms usually developing slowly. Recovery following surgery is to be expected in the majority of cases. In patients with HME and suffering from neurological symptoms, the possibility of spinal cord compression should be considered. Prompt diagnosis and surgical excision provide the best prognosis. 相似文献
994.
T. Viljakka 《Archives of orthopaedic and trauma surgery》1997,116(1-2):6-9
Distortion of the knee joint is a considerable trauma even when the knee is primarily stable. Of 50 patients 30% displayed symptoms or signs 2 months after the injury and 36% on subsequent examination an average of 5.6 years later. In a repeat clinical examination one anterior cruciate ligament rupture was not confirmed at the primary stage (2%). For assessment of stability and extent of injury, the repeat clinical examination proved reliable. Ruptures of the meniscus were noted in 18% of the patients in connection with the primary injury. Of those who underwent a meniscus operation, 27% had further operations and, four patients of 50 had another operation as a result of a new trauma. Thus, a total of 25% of the patients required surgery. The material is biased as I sought to exclude ligament ruptures in the first instance. No patient was permanently incapacitated from work. A large portion of the later symptoms were connected with the patellofemoral joint or with the postoperative condition. Bandaging did not affect the resulting recovery rate. Regular exercise of the thigh muscles prevented the onset of quadriceps atrophy, but there was a clear deterioration in the condition of the muscles in the early stages. 相似文献
995.
Staging of esophageal carcinoma in vitro with 4.7-T MR imaging 总被引:4,自引:0,他引:4
996.
997.
Definition of Mycobacterium tuberculosis culture filtrate proteins by two-dimensional polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and electrospray mass spectrometry. 总被引:9,自引:0,他引:9 下载免费PDF全文
A number of the culture filtrate proteins secreted by Mycobacterium tuberculosis are known to contribute to the immunology of tuberculosis and to possess enzymatic activities associated with pathogenicity. However, a complete analysis of the protein composition of this fraction has been lacking. By using two-dimensional polyacrylamide gel electrophoresis, detailed maps of the culture filtrate proteins of M. tuberculosis H37Rv were generated. In total, 205 protein spots were observed. The coupling of this electrophoretic technique with Western blot analysis allowed the identification and mapping of 32 proteins. Further molecular characterization of abundant proteins within this fraction was achieved by N-terminal amino acid sequencing and liquid chromatography-mass spectrometry. Eighteen proteins were subjected to N-group analysis; of these, only 10 could be sequenced by Edman degradation. Among the most interesting were a novel 52-kDa protein demonstrating significant homology to an alpha-hydroxysteroid dehydrogenase of Eubacterium sp. strain VPI 12708, a 25-kDa protein corresponding to open reading frame 28 of the M. tuberculosis cosmid MTCY1A11, and a 31-kDa protein exhibiting an amino acid sequence identical to that of antigen 85A and 85B. This latter product migrated with an isoelectric point between those of antigen 85A and 85C but did not react with the antibody specific for this complex, suggesting that there is a fourth member of the antigen 85 complex. Novel N-terminal amino acid sequences were obtained for three additional culture filtrate proteins; however, these did not yield significant homology to known protein sequences. A protein cluster of 85 to 88 kDa, recognized by the monoclonal antibodies IT-57 and IT-42 and known to react with sera from a large proportion of tuberculosis patients, was refractory to N-group analysis. Nevertheless, mass spectrometry of peptides obtained from one member of this complex identified it as the M. tuberculosis KatG catalase/peroxidase. Thus, the detailed mapping of M. tuberculosis proteins, combined with state-of-the-art analytical techniques such as mass spectrometry, provides a basis for further analysis and rapid identification of biologically relevant molecules. 相似文献
998.
S. Suominen I. Antti-Poika K. Tallroth S. Santavirta P. Voutilainen T. S. Lindholm 《Archives of orthopaedic and trauma surgery》1996,115(5):276-279
A total of 113 patients underwent a cemented total hip replacement (THR) operation involving femoral component fixation either without the use of a distal intramedullary plug (n = 57, group 1) or with the plug (n =56, group 2). We studied the femoral component fixation radiographically at on average 6 years after THR. The cement coating was assessed as technically good in 86% and 95% of groups 1 and 2, respectively. There was radiographically diagnosable loosening of the femoral component at the follow-up in 25 cases in which stems were inserted without the intramedullary plug, and in 6 cases in those with the plug (P < 0.0008), and the mean subsidence of the femoral component was 5 mm in group 1 and 1.5 mm (P < 0.0003) in group 2, respectively. Osteolytic changes around the femoral component were noticed in both groups in equal numbers and with no statistical difference. The use of a distal intramedullary plug in the cementation of the femoral stem results in a better cement coating, reduces femoral component subsidence and ameliorates the loosening rates. 相似文献
999.
Use of omeprazole in Zollinger-Ellison syndrome: a prospective nine-year study of efficacy and safety 总被引:1,自引:1,他引:0
D. C. METZ D. B. STRADER M. ORBUCH P. D. KOVIACK K. M. FEIGENBAUM R. T. JENSEN 《Alimentary pharmacology & therapeutics》1993,7(6):597-610
H+, K+-ATPase inhibitors such as omeprazole are the antisecretory agents of choice for the management of gastric acid hypersecretory states, including the Zollinger-Ellison syndrome. However, long-term follow-up data on the overall efficacy and safety of these agents in large numbers of patients are lacking. In the current study we examined the long-term efficacy and safety of omeprazole in 116 patients with Zollinger-Ellison syndrome treated with oral omeprazole at a single centre for up to 114 months (mean ± S.E.M. = 38 ± 3 months). The initial omeprazole maintenance dose was established according to the acute upward dose titration method in 89/116 patients (77%). Gastric acid output was effectively controlled using 60 mg of omeprazole once daily in 41/89 patients (46%) and 22/89 patients (25 %) required twice daily omeprazole therapy. The mean ranitidine equivalent dose for patients who required 60 mg omeprazole once daily (2.5 ± 0.2 g/day) was significantly lower than the mean ranitidine equivalent dose for patients who required more than 60 mg omeprazole once daily (4.3 ± 0.3 g/day). Long-term omeprazole maintenance therapy was discontinued in 36/116 patients (31%) but in no cases was discontinuation due either to drug-induced side-effects or uncontrolled gastric acid output. Fasting serum gastrin levels were significantly elevated above pre-treatment levels at only one time point during follow-up and were likely due to tumour growth rather than a drug effect. The final long-term omeprazole maintenance doses were lower than the initial doses but correlated closely with the preomeprazole basal acid output (r= 0.41, P < 0.001) and ranitidine equivalent dose requirements (r= 0.49, P < 0.001). We conclude that omeprazole effectively and safely controls gastric acid hypersecretion in all patients with Zollinger-Ellison syndrome for up to nine years without evidence by tachyphylaxis. 相似文献
1000.
M Ohsugi Y Imanishi T Teraoka K Nishimura S Nakao 《Journal of nutritional science and vitaminology》1990,36(5):447-456
The biosynthesis of biotin-vitamers from various carbon sources by the members of the Enterobacteriaceae as one of the groups of intestinal bacteria was investigated. The biotin-vitamers synthesized in each case included one or more of dethiobiotin (main product), 7-keto-8-aminopelargonic acid, and biotin. True biotin was shown to be synthesized under aerobic conditions but not under anaerobic conditions by each of several strains belonging to one of the genera, Erwinia, Escherichia, Proteus, and Serratia, and using culture media containing one of galactose, peptone, Polypepton, or casamino acid. In addition, a biotin precursor, pimelic acid, was also synthesized by several bacteria utilizing carbon sources such as maltose, mannose, galactose, peptone, or casamino acid. 相似文献