全文获取类型
收费全文 | 701篇 |
免费 | 38篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 51篇 |
妇产科学 | 8篇 |
基础医学 | 58篇 |
口腔科学 | 16篇 |
临床医学 | 101篇 |
内科学 | 193篇 |
皮肤病学 | 7篇 |
神经病学 | 18篇 |
特种医学 | 162篇 |
外科学 | 39篇 |
综合类 | 12篇 |
预防医学 | 21篇 |
眼科学 | 9篇 |
药学 | 42篇 |
肿瘤学 | 34篇 |
出版年
2024年 | 2篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 13篇 |
2011年 | 15篇 |
2010年 | 37篇 |
2009年 | 38篇 |
2008年 | 17篇 |
2007年 | 30篇 |
2006年 | 13篇 |
2005年 | 20篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 13篇 |
2001年 | 12篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1998年 | 48篇 |
1997年 | 47篇 |
1996年 | 45篇 |
1995年 | 40篇 |
1994年 | 41篇 |
1993年 | 26篇 |
1992年 | 6篇 |
1991年 | 14篇 |
1990年 | 16篇 |
1989年 | 27篇 |
1988年 | 30篇 |
1987年 | 15篇 |
1986年 | 17篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1969年 | 1篇 |
排序方式: 共有775条查询结果,搜索用时 0 毫秒
101.
Stephens RW; Golder JP; Fayle DR; Hume DA; Hapel AJ; Allan W; Fordham CJ; Doe WF 《Blood》1985,66(2):333-337
Adherent monolayer cultures of human blood monocytes, peritoneal macrophages, bone marrow macrophages, and colonic mucosa macrophages were examined for their ability to produce and secrete minactivin, a specific inactivator of urokinase-type plasminogen activator. All except colonic mucosa macrophages produced and secreted appreciable amounts of minactivin, but only blood monocytes were stimulated by muramyl dipeptide (adjuvant peptide) to increase production. The minactivin from each of these populations could be shown to preferentially inhibit urokinase-type plasminogen activator and not trypsin, plasmin, or "tissue"-type plasminogen activator (HPA66). A plasminogen-activating enzyme present in monocyte cultures appeared unaffected by the presence of minactivin and could be shown to be regulated independently by dexamethasone. 相似文献
102.
Pieter?CJ?ter BorgEmail author Durk?Fekkes Jan?Maarten?Vrolijk Henk?R?van Buuren 《BMC gastroenterology》2005,5(1):11
Background
In primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) fatigue is a major clinical problem. Abnormal amino acid (AA) patterns have been implicated in the development of fatigue in several non-hepatological conditions but for PBC and PSC no data are available. This study aimed to identify abnormalities in AA patterns and to define their relation with fatigue. 相似文献103.
The fibrinolytic characteristics of the endothelial hybrid cell line EA.hy 926, established by fusing a human umbilical vein endothelial cell with a human carcinoma cell line, were studied. The hybrid cell line produced large amounts of tissue-type plasminogen activator (t- PA), plasminogen activator inhibitor type 1, and a small amount of urokinase. All plasminogen activator present in conditioned medium was complexed with inhibitor because the cells secreted plasminogen activator inhibitor in excess over plasminogen activator and no activator activity was detectable in conditioned media by direct activity assays. t-PA activator activity was, however, demonstrable in conditioned media after treatment with sodium dodecyl sulfate, in agreement with t-PA antigen determinations. Increased plasminogen activator inhibitor activity could be induced by incubating the cells in the presence of endotoxin or microtubule inhibitors, whereas increased t-PA activity could be induced by microtubule inhibitors. Interleukin-1 had no effect. The fibrinolytic characteristics of the hybrid cell line were stable for at least 30 passages. The perpetual human hybrid cell line EA.hy 926 therefore may be a useful tool for the study of fibrinolysis in cultured endothelial cells. 相似文献
104.
105.
William P Howlett Sarah J Urasa Venance P Maro Richard W Walker Kajiru G Kilonzo Patrick J Howlett Marieke CJ Dekker 《African health sciences》2022,22(1):269
BackgroundThe burden of neurological disorders is large and altered by the HIV epidemic.ObjectivesWe describe the pattern of neurological disorders and their association with HIV infection in adult patients attending a consultant hospital in Northern Tanzania.MethodsIn this prospective cross-sectional study, we collected data on adult neurological referrals over a 6-year period between 2007–13. The odds of HIV infection, across neurological categories adjusted for age and sex, was calculated.ResultsOf 2037 participants, 54.8% were male and 45.2% were female. The median age of participants was 43 years. The results for HIV screening were available for 992/2037 (48.7%) patients, of whom 306 (30.8%) were seropositive. The most frequent neurological disorders were cerebrovascular disease (19.9%), paraplegia (13.6%), and peripheral neuropathies (8%). Taken together CNS infection accounted for 278/2037 (13.6%). The adjusted odds (aOR) of HIV infection was highest amongst infections; brain abscesses (aOR 107, 95% CI 35.1–470.4) and meningitis/encephalitis (aOR 40.1, 95% CI 13.6–172.9), but also raised in cerebrovascular disease, paraplegia, peripheral neuropathies, cranial nerve palsies, seizures, cerebllar disorders, movement disorders, motor neuron disease and headache.ConclusionThe main pattern of neurological disorders in Northern Tanzania is presented. The odds of HIV infection was highest in CNS infections and in a wide range of non-communicable neurological disorders. 相似文献
106.
107.
108.
The aim of the study was to conduct a structured review of theliterature published on the use of normal sperm morphology,as an indicator of male fertility potential in the in-vitrofertilization (IVF) situation, and to establish the universalpredictive value of this semen parameter. Published literaturein which normal sperm morphology was used to predict fertilizationand pregnancy, during the period 1978-1996, was reviewed. Atotal of 216 articles were identified by the sourcing methodology,but only 49 provided data that could be tabulated and analysed.Of these, only 18 provided sufficient data for statistical analysis.Fifteen studies used the strict criteria to evaluate sperm morphology,two used World Health Organization (WHO) guidelines and oneused both the strict criteria and the WHO guidelines. All thestudies (n=10) using the 5 and 14% normal sperm morphology thresholds(strict criteria) produced positive predictive values for IVFsuccess. In the prediction of pregnancy, 82% (9/11) and 75%(6/8) of the studies produced positive predictive values whenusing the 5% and 14% thresholds respectively. Aggregating thedata produced around the 5% normal sperm morphology threshold(strict criteria), the overall fertilization rates were 59.3%(1979/3337; per oocyte) for the 4% group and 77.6% (10345/13327;per oocyte) for the >4% group, and the overall pregnancyrates were 15.2% (60/395; per cycle) and 26.0% (355/1368; percycle) respectively. The no-transfer rates across the 5% thresholdwere 24.0% (86/359; per cycle) in the 4% group compared to 7.4%(80/1088; per cycle) in the >4% group. The inclusion of anaccurately evaluated normal sperm morphology count as an integralpart of the standard semen analysis makes this analysis stillthe most cost-effective means of evaluating the male factor. 相似文献
109.
LR Caplan C-S Chung RJ Wityk TA Glass J Tapia L Pazdera H-M Chang JF Dashe CJ Chaves K Vemmos M Leary LD Dewitt MS Pessin 《JOURNAL OF CLINICAL NEUROLOGY》2005,1(1):14-30
Among 407 New England Medical Center Posterior Circulation Registry (NEMC-PCR) patients, 59% had strokes without transient ischemic attacks (TIAs), 24% had TIAs before strokes, and 16% had only posterior circulation TIAs. Embolism was the commonest stroke mechanism accounting for 40% of cases (24% cardiac origin, 14% arterial origin, 2% had potential cardiac and arterial sources). In 32%, large artery occlusive lesions caused hemodynamic brain infarction. Stroke mechanisms in the posterior and anterior circulation are very similar. Infarcts most often included the distal posterior circulation territory (rostral brainstem, superior cerebellum and occipital and temporal lobes), while the proximal (medulla and posterior inferior cerebellum) and middle (pons and anterior inferior cerebellum) territories were equally involved. Infarcts that included the distal territory were twice as common as those that included the proximal or middle territories. Most distal territory infarcts were attributable to embolism. Thirty day mortality was low (3.6%). Embolic stroke mechanism, distal territory location, and basilar artery occlusive disease conveyed the worst prognosis. 相似文献
110.