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   631篇
  免费   31篇
  国内免费   18篇
儿科学   18篇
妇产科学   18篇
基础医学   32篇
口腔科学   1篇
临床医学   76篇
内科学   94篇
皮肤病学   20篇
神经病学   49篇
特种医学   86篇
外科学   43篇
综合类   12篇
预防医学   43篇
眼科学   1篇
药学   144篇
  1篇
肿瘤学   42篇
  2022年   2篇
  2021年   7篇
  2020年   4篇
  2019年   4篇
  2018年   10篇
  2017年   2篇
  2016年   9篇
  2015年   11篇
  2014年   20篇
  2013年   27篇
  2012年   29篇
  2011年   31篇
  2010年   25篇
  2009年   24篇
  2008年   46篇
  2007年   44篇
  2006年   41篇
  2005年   28篇
  2004年   26篇
  2003年   26篇
  2002年   31篇
  2001年   19篇
  2000年   34篇
  1999年   17篇
  1998年   18篇
  1997年   13篇
  1996年   7篇
  1995年   8篇
  1994年   7篇
  1993年   6篇
  1992年   9篇
  1991年   3篇
  1990年   4篇
  1989年   9篇
  1988年   12篇
  1987年   10篇
  1986年   11篇
  1985年   9篇
  1984年   8篇
  1983年   7篇
  1982年   5篇
  1981年   3篇
  1980年   5篇
  1978年   2篇
  1977年   1篇
  1976年   1篇
  1975年   4篇
  1973年   1篇
排序方式: 共有680条查询结果,搜索用时 15 毫秒
1.
In patients with Type 2 diabetes, the appropriate intensity of glucose control is determined by age, life expectancy, and the presence of concomitant disease. Geriatric patients are especially susceptible to hypoglycaemia and therefore particular care should be taken in this group characterized by polypharmacy, renal or hepatic dysfunction, cardiovascular multimorbidity and malnutrition. As hypoglycaemia is a significant cause of morbidity and mortality, treatment regimens for diabetes should minimize the occurrence of hypoglycaemic episodes and be tailored to the patient's individual needs. The pharmacological options for treating Type 2 diabetes have increased considerably and the risk of hypoglycaemia of the currently available drugs varies considerably. Metformin, thiazolidinediones, and acarbose, oral antidiabetic drugs that decrease insulin resistance or postprandial glucose absorption, are associated with a low risk of hypoglycaemia. These drugs can also be used effectively in various combination regimens; however, by improving insulin sensitivity, combinations of metformin and thiolidinediones with sulphonylureas or meglitinides may considerably increase the risk of hypoglycaemia. On account of its complex pharmacoprofile glibenclamide is a problematic substance carrying a high risk of hypoglycaemia. There are limited preliminary data indicating that, under routine conditions, glimepiride may be associated with a lower risk of hypoglycaemia than glibenclamide and is no more likely to cause hypoglycaemia than other shorter-acting agents such as gliclazide and glipizide. Nateglinide and repaglinide as short-acting insulin secretagogues may be associated with a reduced risk of hypoglycaemia compared with glibenclamide, in particular when dosed flexibly. Repaglinide might be beneficial in individuals with renal impairment.  相似文献   
2.
3.
BACKGROUND: Malignant peripheral epineurial tumours are a group of tumours that derive histomorphologically from peripheral nerve sheaths. They occur sporadically, with an incidence of approximately 0.001%, and very rarely require emergency operation. PATIENT AND PROCEDURE: An athletic 19-year-old man presented to an orthopaedic outpatient clinic with lumboischialgia and weakness of the third and fourth left toes. A 12 x 10 x 8-cm paravertebral/retroperitoneal tumour was diagnosed by CT, and the patient was referred to our clinic. For classification, CT-assisted puncture of the tumour was carried out. A haemorrhage into the tumour resulted from the puncture, with consequently lower Hb level and progressive peripheral sensomotoric deficits demanding emergency surgery on a weekend. On this occasion, the tumour was resected together with the L5 and S1 nerve roots through cooperation between the general surgical and neurosurgical departments and was classified as a malignant peripheral epineurial tumour in the rapid stage. Due to the spinal R2 resection, after-loading probes were inserted and the tumour bed was clip-marked. Percutaneous radiotherapy and brachytherapy followed postoperatively. Shortly afterwards, relaparotomy had to be performed due to an adhesive ileus, from which the patient recovered quickly. Chemotherapy was carried out due to a G2 tumour classification. The patient is currently undergoing rehabilitation, during which the peripheral neurological deficits are improving gradually. CONCLUSION: This rare case of a malignant peripheral epineurial tumour with acute symptoms demonstrates the ability of hospitals with maximum care facilities to maintain services even in times of financial cuts in health care services.  相似文献   
4.
Spectrum of pulmonary nontuberculous mycobacterial infection   总被引:5,自引:0,他引:5  
Miller  WT  Jr 《Radiology》1994,191(2):343
  相似文献   
5.
6.
7.
Localization of a gene for otosclerosis to chromosome 15q25-q26   总被引:5,自引:0,他引:5  
Among white adults otosclerosis is the single most common cause of hearing impairment. Although the genetics of this disease are controversial, the majority of studies indicate autosomal dominant inheritance with reduced penetrance. We studied a large multi- generational family in which otosclerosis has been inherited in an autosomal dominant pattern. Five of16 affected persons have surgically confirmed otosclerosis; the remaining nine have a conductive hearing loss but have not undergone corrective surgery. To locate the disease- causing gene we completed genetic linkage analysis using short tandem repeat polymorphisms (STRPs) distributed over the entire genome. Multipoint linkage analysis showed that only one genomic region, on chromosome 15q, generated a lod score >2.0. Additional STRPs were typed in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis gene.   相似文献   
8.
9.
In the context of studies on the expression of MhcCyca-Z sequences of the common carp, PCR amplifications of exon 4 were performed on cDNA obtained from pooled thymi of 20 carp F1 individuals. Five recombinant clones (Cyca-TC3, -TC13, -TC15, -TC17 and -TC18) were found to be 96% similar to the exon 4 region of Cyca-ZA1. Each of the five sequences was unique, and differed in a few positions in both the nucleotide and the derived amino acid sequences from any of the Cyca-Z sequences known to date. These data suggest that multiple Z genes per locus are present in the carp, which are transcribed in the thymus. In the course of analysing the amplified Cyca-Z sequences, serendipity yielded a clone, Cyca-TC16, containing a class I-like sequence substantially different from any other carp class I sequence. The predicted amino acid sequence of Cyca-TC16 was most similar to the class I genes (Lach-U) from the coelacanth (42–46% amino acid identity). Cyca-TC16 contains three conserved β2-microglobulin contact residues, and the secondary structure was predicted by computer algorithms to be similar to that of the α3 domain of HLA-A2. Phylogenetic analysis shows that carp class I sequences reside in four distinct clusters: (i) Cyca-Z, Cyca-TC3, -TC13, -TC15, -TC17 and -TC18 together with Caau-Z from ginbuna crucian carp, (ii) Cyca-U with Bree-U (zebrafish) and Sasa-p30 (Atlantic salmon), (iii) Cyca-TC16 with Lach-U (coelacanth), and (iv) Cyca-C4.  相似文献   
10.
目的:研究L-门冬酰胺酶(L-Asparaginase,L-A)前体脂质体(Proliposome,PL)[L-APL]iv对小鼠的毒性及对荷瘤小鼠的抗肿瘤活性。方法:以小鼠的急性毒性和外周血中白细胞数及血小板数为指标观察药物对小鼠的毒性及以荷瘤小鼠的瘤重和生命延和工率观察药物的抗肿瘤活性;结果:L-APL iV对小鼠的急性毒性与L-A相比明显降低,L-APL对正常小鼠外周血中白细胞数,血小板数无明显影响,而相同剂量L-A对小鼠外周血中白细胞数,血小板数明显降低。与对照组相比,L-APL和L-Aip可明显延长腹水型小鼠移瘤L1210,P388的存活天数,与同剂量L-A相比,L-APL高剂量有明显延长腹水型小鼠移植瘤的存活天数作用。L-APL及L-A ip对小鼠移植瘤Heps,EC实体型的肿瘤生长具有明显的抑制作用,两者抑瘤作用相近。结论:L-APL对小鼠的毒性明显小于相同剂量的L-A,L-APL不仅保持了L-A的抗肿瘤活性,而且有明显的增效作用。  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