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   1294篇
  免费   88篇
  国内免费   5篇
耳鼻咽喉   15篇
儿科学   44篇
妇产科学   46篇
基础医学   158篇
口腔科学   33篇
临床医学   115篇
内科学   265篇
皮肤病学   9篇
神经病学   81篇
特种医学   59篇
外科学   198篇
综合类   75篇
一般理论   2篇
预防医学   126篇
眼科学   27篇
药学   64篇
中国医学   9篇
肿瘤学   61篇
  2023年   6篇
  2022年   43篇
  2021年   57篇
  2020年   39篇
  2019年   39篇
  2018年   52篇
  2017年   40篇
  2016年   41篇
  2015年   55篇
  2014年   64篇
  2013年   93篇
  2012年   94篇
  2011年   99篇
  2010年   54篇
  2009年   45篇
  2008年   72篇
  2007年   74篇
  2006年   79篇
  2005年   57篇
  2004年   55篇
  2003年   47篇
  2002年   39篇
  2001年   13篇
  2000年   26篇
  1999年   9篇
  1998年   4篇
  1997年   4篇
  1995年   3篇
  1994年   4篇
  1993年   3篇
  1992年   2篇
  1991年   2篇
  1990年   9篇
  1989年   4篇
  1988年   4篇
  1987年   5篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   5篇
  1979年   2篇
  1977年   2篇
  1976年   2篇
  1975年   2篇
  1973年   3篇
  1972年   3篇
  1968年   6篇
  1967年   4篇
  1965年   5篇
  1923年   1篇
排序方式: 共有1387条查询结果,搜索用时 328 毫秒
131.

Background

The HIV/AIDS epidemic has been accompanied by a severe epidemic of tuberculosis (TB), although the prevalence of coinfection is largely unknown, especially in developing countries, including Nigeria. The aim of this study was to determine the prevalence and predictors of TB coinfection among HIV-seropositive Nigerians.

Methods

The case files of HIV/AIDS patients attending Aminu Kano Teaching Hospital, Nigeria from January to December 2006 were reviewed.

Results

A total of 1320 HIV/AIDS patients had complete records and were reviewed, among which 138 (10.5%) were coinfected with TB (95% CI, 8.9% to 12.2%). Pulmonary TB was diagnosed in 103 (74.6%) patients, among whom only 18 (17.5%) were sputum-positive. Fifty (36.2%) coinfected patients had some type of extrapulmonary TB (EPTB); 15 had both pulmonary TB and EPTB. Among the 35 patients with EPTB only, 20 (57.1%) had abdominal TB, 5 (14.3%) had TB adenitis, 5 (14.3%) had spinal TB, 3 (8.6%) were being monitored for tuberculous meningitis, and 1 (2.9%) each had renal TB and tuberculous adrenalitis. The highest prevalence of TB, 13.7% (n = 28), was seen among patients aged 41–50 years. TB coinfection was significantly associated with marital status, WHO clinical stage, and CD4 count. Marital status (OR, 2.1; 95% CI, 1.28–3.59; P = 0.04), WHO clinical stage at presentation (4.81; 1.42–8.34; P = 0.001), and baseline CD4 count (2.71; 1.51–6.21; P = 0.02) remained significant predictors after adjustment for confounding.

Conclusions

The moderately high prevalence of TB among HIV-seropositive patients underscores the urgent need for strategies that lead to rapid identification and treatment of coinfection with active or latent TB.Key words: tuberculosis, HIV, coinfection, prevalence, Kano, Nigeria  相似文献   
132.
Axillary neuropathy due to entrapment of the nerve in the quadrilateral space is seen rarely. Here, we describe a 24-year-old patient diagnosed with isolated axillary neuropathy that mimicked quadrilateral space syndrome. Quadrilateral or quadrangular space syndrome (QSS), first described by Cahill and Palmer in 1983, was defined as the entrapment of the distal branch of the axillary nerve and the posterior humeral circumflex artery (PHCA) in the quadrangular shaped anatomic space. We tracked the follow up of the patient for one year both clinically and electrophysiologically. Our aim in reporting this case is to stress the point that cases of such a nature usually represent situations of diagnostic and treatment challenges, where multidisciplinary approaches are required.  相似文献   
133.
HBV entry to the host cells and its successful infection depends on its ability to modulate the host restriction factors. DEAD box RNA helicase, DDX3, is shown to inhibit HBV replication. However, the exact mechanism of inhibition still remains unclear. DDX3 is involved in multitude or RNA metabolism processes including biogenesis of miRNAs. In this study, we sought to determine the mechanism involved in DDX3-mediated HBV inhibition. First, we observed that HBx protein of HBV downregulated DDX3 expression in HBV-infected cells. Overexpression of DDX3 inhibited HBx, HBsAg and total viral load, while its knockdown reversed the result in Hep G2.2.15 cells. Expression of miR-34 was downregulated in HBV-infected cells. Overexpression of pHBV1.3 further confirmed that HBV downregulates miR-34 expression. Consistent with the previous finding that DDX3 is involved in miRNA biogenesis, we observed that expression of miR-34 positively corelated with DDX3 expression. miRNA target prediction tools showed that miR-34 can target autophagy pathway which is hijacked by HBV for the benefit of its own replication. Indeed, transfection with miR-34 oligos downregulated the expression of autophagy marker proteins in HBV-expressing cells. Overexpression of DDX3 in HBV-expressing cells, downregulated expression of autophagy proteins while silencing of DDX3 reversed the results. These results led us to conclude that DDX3 upregulates miR-34 expression and thus inhibits autophagy in HBV-expressing cells while HBx helps HBV evade DDX3-mediated inhibition by downregulating DDX3 expression in HBV-infected cells.  相似文献   
134.
Transforming growth factor-beta1 (TGF-beta1) stimulates the expression of collagen mRNA in cultured human peritoneal mesangial cells, which may predispose them to developing peritoneal fibrosis. Polymorphisms in the signal sequence genetically may be responsible for increased TGF-beta1 production (i.e., a substitution at amino acid position 10 and 25, +869 Leu(10)-Pro and +915 Arg(25)-Pro, respectively). The aim of this study was to find out whether there is any relation between peritoneal equilibration test (PET) results and TGF-beta1 gene polymorphism. Thirty-two CAPD patients and 72 healthy subjects were included into the study. Each CAPD patient had undergone two PET with a two-year interval. The patients were classified according to the results of a baseline PET as high (high-high average) and low (low-low average) transporters. In high transporters group (n = 20), the genotype frequencies were found as 45% Leu/Leu, 55% Leu/Pro for codon 10; and 85% Arg/Arg, 15% Arg/Pro for codon 25. In low transporters group (n = 12), the genotype frequencies were detected as 66.7% Leu/Leu and 33.3% Leu/Pro for codon 10; and 83.3% Arg/Arg, 16.7% Arg/Pro for codon 25. The distribution of the TGF-beta1 genotypes in our control population was compatible with a Hardy-Weinberg equilibrium. We found no relation between TGF-beta1 genotypes and peritoneal transport group (chi(2) test, p > 0.5). There was no relation between TGF-beta1 genotype and longitudinal change in peritoneal transport. This study is the first study analyzing the possible link between TGF-betal gene polymorphisms and the characteristics of peritoneal transport and longitudinal change of peritoneal transport characteristics in CAPD patients. Further work is needed to clarify the functional importance of these two polymorphisms in TGF-beta1 production and in the development of peritoneal fibrosis.  相似文献   
135.
A survey was conducted among Hausa and Fulani, two major tribes of Northern Nigeria to identify plants and methods used traditionally in the treatment of cancers and inflammatory diseases. The ecological zones that were considered include Zaria, Kaduna and Kano in the Northern part of Nigeria. The survey involves traditional healers, hunters, farmers and Fulani nomads. This survey has identified plants useful in the treatment of cancers. The plants were identified via taxonomic means and classified according to their habitats, families, genera. Evidently the plants span families and genera, the knowledge and values of the plants was evaluated with the aim of understanding the scientific basis for the use of the plants. The inventory provides the unique opportunity of capturing plants of common uses across the communities.  相似文献   
136.
Abnormalities in the metabolism of essential fatty acids and the results of increased oxidative stress have been implicated in cardiovascular disorders observed in diabetes mellitus. This study, therefore, aimed to investigate the effects of cod liver oil (CLO, Lysi Ltd, Iceland), which comprises mainly an antioxidant vitamin A, n:3 polyunsaturated fatty acids (n:3 PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on cardiovascular abnormalities in streptozotocin (STZ)-diabetic rats. Two days after single STZ (55 mg kg(-1), i.p.) or vehicle injection, diabetes was verified by increased blood glucose, and non-diabetic and diabetic rats were left untreated or treated with CLO (0.5 mL kg(-1) daily, by intragastric probing) for 12 weeks. Plasma glucose, triacylglycerol and cholesterol concentrations were significantly elevated in 12-week untreated-diabetic rats; CLO provided better weight gain, entirely prevented the plasma lipid abnormalities, but partially controlled the glycaemia in diabetic rats. In isolated aorta rings, diabetes resulted in increased phenylephrine-induced vasoconstriction and isoprenaline-induced vasorelaxation, impaired endothelium-dependent vasodilatation and unchanged responsiveness to sodium nitroprusside. CLO treatment completely prevented endothelial deficiency, partly corrected the phenylephrine-induced vasoconstriction and did not affect the responses to isoprenaline and sodium nitroprusside in diabetic aorta. Diabetes also produced a marked decrease in the rate of spontaneously beating right atria and a significant increase in basal contractile force of left ventricular papillary muscle. The responsiveness of right atria to the positive chronotropic effect of isoprenaline was significantly decreased in diabetic rats, and was increased in CLO-treated diabetic rats. The positive chronotropic effect of noradrenaline was markedly increased in diabetic atria, but prevented by CLO treatment. Diabetes also resulted in an increased positive inotropic response of papillary muscle to both noradrenaline and isoprenaline, which were prevented by CLO treatment. CLO treatment also resulted in lower tissue sensitivity (pD(2)) to these agonists in diabetic papillary muscle. Ventricular hydroxyproline content was found to be unchanged among the experimental groups. The ultrastructure of diabetic myocardium displayed various degenerations (i.e. intracellular oedema, myofibrillar fragmentation, condensed pleomorphic mitochondria, thick capillary irregular basement membrane, swollen endothelial cells), which were partially prevented by CLO treatment. We conclude that the supplementation with CLO is effective in preventing cardiovascular disorders observed in experimental diabetes.  相似文献   
137.
138.
Bone marrow transplant (BMT) recipients are prone to bacterial, viral and fungal infections. Mycobacterium tuberculosis infection can occur in these patients, but the incidence is lower than that of other infections. This report describes four patients with Mycobacterium tuberculosis infection identified from 641 adult patients who received a BMT over a 12-year period (prevalence 0.6%). The pre-transplant diagnosis was AML in two patients and CML in the other two. Pre-transplant conditioning consisted of BU/CY in three patients and CY/TBI in one. Graft-versus-host disease (GVHD) prophylaxis was MTX/CsA in three patients and T cell depletion of the graft in one patient. Sites of infection were lung (two), spine (one) and central nervous system (one). Onset of infection ranged from 120 days to 20 months post BMT. Two patients had co-existing CMV infection. One patient had graft failure. The two patients who received anti-tuberculous (TB) therapy recovered from the infection. Although the incidence of tuberculosis in BMT patients is not as high as in patients with solid organ transplants, late diagnosis due to the slow growth of the bacterium can lead to delay in instituting anti-TB therapy. A high index of suspicion should be maintained, particularly in endemic areas.  相似文献   
139.
We have reconstructed soft tissue defects in 121 hands with radial forearm flaps. So that the flap perfectly fitted the defect, and to minimise the size of the donor site, we divided the flap into two or three components in each case. We call this the shape-modified radial forearm flap. Of the 118 patients, 113 had complete survival of the flap. The follow-up time was 1 to 15 years. The donor sites were closed primarily in all patients, giving good aesthetic results. The shape-modified radial forearm flap seems to be reliable, and makes it possible to adjust the flap according to the defect. The donor area can be closed primarily in all cases.  相似文献   
140.
Intravesical bacillus Calmette-Guerin (BCG) is used in patients with urinary bladder carcinoma. Although it is generally well tolerated, granulomatous hepatitis is a rare but serious complication. We report a 42-year-old man and a 56-year-old man who developed granulomatous hepatitis following intravesical BCG. One of them was treated successfully with antitubercular therapy; the other died because of BCG sepsis and multi-organ failure.  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