全文获取类型
收费全文 | 5071篇 |
免费 | 408篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 99篇 |
妇产科学 | 150篇 |
基础医学 | 592篇 |
口腔科学 | 80篇 |
临床医学 | 559篇 |
内科学 | 1132篇 |
皮肤病学 | 58篇 |
神经病学 | 316篇 |
特种医学 | 150篇 |
外国民族医学 | 1篇 |
外科学 | 1055篇 |
综合类 | 105篇 |
一般理论 | 2篇 |
预防医学 | 314篇 |
眼科学 | 165篇 |
药学 | 319篇 |
中国医学 | 13篇 |
肿瘤学 | 357篇 |
出版年
2023年 | 38篇 |
2022年 | 92篇 |
2021年 | 203篇 |
2020年 | 102篇 |
2019年 | 170篇 |
2018年 | 186篇 |
2017年 | 160篇 |
2016年 | 150篇 |
2015年 | 170篇 |
2014年 | 235篇 |
2013年 | 265篇 |
2012年 | 436篇 |
2011年 | 418篇 |
2010年 | 212篇 |
2009年 | 188篇 |
2008年 | 282篇 |
2007年 | 268篇 |
2006年 | 275篇 |
2005年 | 263篇 |
2004年 | 220篇 |
2003年 | 233篇 |
2002年 | 189篇 |
2001年 | 70篇 |
2000年 | 61篇 |
1999年 | 55篇 |
1998年 | 37篇 |
1997年 | 22篇 |
1996年 | 20篇 |
1995年 | 21篇 |
1994年 | 14篇 |
1993年 | 14篇 |
1992年 | 32篇 |
1991年 | 29篇 |
1990年 | 25篇 |
1989年 | 23篇 |
1988年 | 16篇 |
1987年 | 15篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1984年 | 16篇 |
1983年 | 16篇 |
1982年 | 16篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1976年 | 16篇 |
1974年 | 12篇 |
1973年 | 19篇 |
1972年 | 23篇 |
1971年 | 27篇 |
1970年 | 14篇 |
排序方式: 共有5499条查询结果,搜索用时 140 毫秒
11.
Karim Serri Philippe Schraub Stephane Lafitte Raymond Roudaut 《European journal of echocardiography》2007,8(1):17-18
A 44-year-old man presented with atypical chest pain and dyspnea. Investigation revealed the presence of a 15-mm rounded, well-vascularized left-ventricular mass. The mass was removed surgically and histopathologic evaluation identified a cardiac hemangioma. 相似文献
12.
Patrick Ambrosetti Karim Francis Dominique Weintraub Jonathan Weintraub 《Journal of gastrointestinal surgery》2007,11(6):767-772
We performed a prospective study to analyze the functional results following elective laparoscopic sigmoidectomy for computed
tomography (CT)-proven diagnosis of acute diverticulitis and review the literature. Forty-three of 45 available patients (96%)
who had laparoscopic sigmoidectomy for CT-proven acute diverticulitis answered, after a mean time of 40 months, a questionnaire
exploring new abdominal symptoms, bowel function, and the patient’s own judgement of the surgical outcome. Surgical technique
aimed at removing all the sigmoid by taking down the splenic flexure and do a colorectal anastomosis. Four patients (9%) complained
of new abdominal pain. Bowel function was reported as better for 24 patients (56%), unchanged for 16 patients (37%), and worse
for 3 (7%). Twenty patients (47%) considered their final result as excellent to good, 17 patients (40%) as satisfying, and
6 patients (13%) as mediocre. Male gender, absence of preoperative history compatible with an irritable bowel syndrome, length
of resected sigmoid and residual acute inflammation on histology are statistically predictive of a better postoperative degree
of satisfaction. After elective laparoscopic sigmoidectomy for CT-proven diverticulitis, a great majority of patients are
very satisfied with their postoperative general comfort. 相似文献
13.
14.
15.
Q Abdool Karim S S Abdool Karim E Preston-Whyte 《Suid-Afrikaanse tydskrif vir geneeskunde》1992,82(5):360-362
This study assessed the ability and preparedness of staff at family planning clinics in Durban to assist in AIDS prevention by promoting condom use among teenagers. Staff at 12 randomly selected clinics were interviewed to assess their attitudes towards teenagers seeking condoms, the information imparted on AIDS and condom use, constraints faced in delivering services, and their perceived role in controlling the spread of AIDS. Despite their awareness of AIDS, those interviewed perceived their role to be that of promoting contraception. Condoms were perceived as a poor choice of contraceptive and their use was discouraged. The pamphlets dispensed along with condoms were thought to provide adequate information about condom use. Information on AIDS was given only if the clinic attender initiated discussion on the subject. Most of the clinic staff were keen to discuss other issues during their consultations, but felt constrained by the large numbers of people they had to attend to and the lack of adequate facilities. If family planning services are to play a role in controlling the spread of AIDS, the first step must be to make this function part of the overall policy. For there to be effective counselling on AIDS prevention, in-service training of current staff is required, as well as more staff and improvements in facilities to ensure greater privacy. 相似文献
16.
Inhibition of allergic airways inflammation and airway hyperresponsiveness in mice by dexamethasone: role of eosinophils,IL-5, eotaxin,and IL-13 总被引:4,自引:0,他引:4
Eum SY Maghni K Hamid Q Eidelman DH Campbell H Isogai S Martin JG 《The Journal of allergy and clinical immunology》2003,111(5):1049-1061
BACKGROUND: Glucocorticoids inhibit allergen-induced airway eosinophilia and airway hyperresponsiveness (AHR). Whether glucocorticoids mediate their effects on AHR by inhibiting eotaxin and IL-5, 2 of the principal mediators of eosinophilia, or through IL-13, an important mediator of AHR, has not been established. OBJECTIVE: We sought to investigate the effects of glucocorticoids on airway eosinophilia and the expression of IL-5, eotaxin, and IL-13 in relation to the induction of AHR in a murine model of allergic asthma. METHODS: Dexamethasone (4 mg/kg) and mAbs against eotaxin (80 micro g/kg) and IL-5 (100 micro g/kg) singly and in combination were administered to immunized mice before antigen challenge. Airway responsiveness to methacholine was measured in anesthetized and mechanically ventilated animals. Eotaxin, IL-5, and IL-13 in bronchoalveolar lavage fluid (BALF), lung homogenates, or both were measured by means of ELISA. RESULTS: A single antigen challenge induced AHR that lasted at least 10 days. Eotaxin protein and mRNA levels increased in lung tissue but not in BALF after challenge. IL-5 protein and mRNA levels increased both in BALF and in lung tissue. Dexamethasone reduced airway eosinophilia, AHR, and protein and mRNA for eotaxin and IL-5. Anti-murine eotaxin and anti-IL-5 antibodies alone and in combination reduced the ovalbumin-induced airway eosinophilia significantly but failed to inhibit AHR. Both dexa-methasone and anti-IL-5/anti-eotaxin inhibited the increases in lung IL-13 levels after ovalbumin challenge to a similar extent. CONCLUSION: These findings suggest that the inhibition of AHR by the glucocorticoid dexamethasone does not appear to be explained by effects on eosinophilia, eotaxin, IL-5, or IL-13. 相似文献
17.
18.
Variations in Helicobacter pylori lipopolysaccharide to evade the innate immune component surfactant protein D 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Khamri W Moran AP Worku ML Karim QN Walker MM Annuk H Ferris JA Appelmelk BJ Eggleton P Reid KB Thursz MR 《Infection and immunity》2005,73(11):7677-7686
Helicobacter pylori is a common and persistent human pathogen of the gastric mucosa. Surfactant protein D (SP-D), a component of innate immunity, is expressed in the human gastric mucosa and is capable of aggregating H. pylori. Wide variation in the SP-D binding affinity to H. pylori has been observed in clinical isolates and laboratory-adapted strains. The aim of this study was to reveal potential mechanisms responsible for evading SP-D binding and establishing persistent infection. An escape variant, J178V, was generated in vitro, and the lipopolysaccharide (LPS) structure of the variant was compared to that of the parental strain, J178. The genetic basis for structural variation was explored by sequencing LPS biosynthesis genes. SP-D binding to clinical isolates was demonstrated by fluorescence-activated cell sorter analyses. Here, we show that H. pylori evades SP-D binding through phase variation in lipopolysaccharide. This phenomenon is linked to changes in the fucosylation of the O chain, which was concomitant with slipped-strand mispairing in a poly(C) tract of the fucosyltransferase A (fucT1) gene. SP-D binding organisms are predominant in mucus in vivo (P = 0.02), suggesting that SP-D facilitates physical elimination. Phase variation to evade SP-D contributes to the persistence of this common gastric pathogen. 相似文献
19.
20.
Evaluation of cleaving agents other than trypsin in direct agglutination test for further improving diagnosis of visceral leishmaniasis. 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A el Harith S Chowdhury A al-Masum S Semio-Santos E Karim S el-Safi I Haque 《Journal of clinical microbiology》1995,33(8):1984-1988
Trypsin treatment of Leishmania promastigote antigen has proved to be indispensible in the direct agglutination test (DAT) for the diagnosis of visceral leishmaniasis (VL) and canine visceral leishmaniasis (CVL). In the present study four antigen batches were prepared with pronase (400 micrograms/ml), lipase (0.45% [wt/vol]), pancreatin (0.3% [wt/vol]), or 2-mercaptoethanol (2-ME) (1.2% [vol/vol]) at a ratio of 20:1 versus promastigote packed cell volume or a density of 10(8)/ml. Batches prepared in this way performed satisfactorily when compared with the performance of the initial trypsinated antigen. Even higher was the sensitivity and specificity of the 2-ME-processed antigen, scoring a minimum DAT titer of 1:102,400 in the VL and CVL group and a maximum of 1:400 in the negative control group. Corresponding titers ranging from 1:6,400 to 1:12,800 and 1:800 to 1:1,600 were obtained with the antigen variants processed with pronase, lipase, pancreatin, or trypsin. By combining the use of indigenous Leishmania donovani subspecies from Sudan, Bangladesh, or Morocco and incorporating 2-ME instead of trypsin in the antigen processing step, a threefold increase in titer was attained in sera from the respective areas where VL is endemic. 2-ME-processed antigen suspensions maintained stability at 4 degrees C for up to 9 months, as evidenced by the absence of autoagglutination and the reproducibility of DAT readings with standard sera. The specificity of DAT was further improved by supplementation of the sample diluent with 0.03 M urea and incubation of the test plates at 37 degrees C for 1 h.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献