全文获取类型
收费全文 | 3915篇 |
免费 | 288篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 150篇 |
妇产科学 | 113篇 |
基础医学 | 435篇 |
口腔科学 | 91篇 |
临床医学 | 314篇 |
内科学 | 851篇 |
皮肤病学 | 57篇 |
神经病学 | 340篇 |
特种医学 | 133篇 |
外国民族医学 | 5篇 |
外科学 | 721篇 |
综合类 | 117篇 |
一般理论 | 1篇 |
预防医学 | 251篇 |
眼科学 | 76篇 |
药学 | 273篇 |
中国医学 | 31篇 |
肿瘤学 | 236篇 |
出版年
2023年 | 38篇 |
2022年 | 88篇 |
2021年 | 145篇 |
2020年 | 97篇 |
2019年 | 116篇 |
2018年 | 143篇 |
2017年 | 90篇 |
2016年 | 100篇 |
2015年 | 115篇 |
2014年 | 164篇 |
2013年 | 186篇 |
2012年 | 259篇 |
2011年 | 285篇 |
2010年 | 182篇 |
2009年 | 157篇 |
2008年 | 191篇 |
2007年 | 204篇 |
2006年 | 202篇 |
2005年 | 239篇 |
2004年 | 189篇 |
2003年 | 171篇 |
2002年 | 151篇 |
2001年 | 74篇 |
2000年 | 68篇 |
1999年 | 78篇 |
1998年 | 25篇 |
1997年 | 26篇 |
1996年 | 16篇 |
1995年 | 28篇 |
1994年 | 16篇 |
1993年 | 19篇 |
1992年 | 27篇 |
1991年 | 18篇 |
1990年 | 24篇 |
1989年 | 20篇 |
1988年 | 18篇 |
1987年 | 17篇 |
1986年 | 23篇 |
1985年 | 19篇 |
1984年 | 14篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1979年 | 12篇 |
1978年 | 20篇 |
1976年 | 10篇 |
1973年 | 10篇 |
1972年 | 13篇 |
1969年 | 15篇 |
1966年 | 9篇 |
排序方式: 共有4226条查询结果,搜索用时 15 毫秒
71.
Ayesha Aziz Fazal Ali Khan Geof Wood 《Health research policy and systems / BioMed Central》2015,13(Z1):S56
Background
The maternal, newborn, and child health (MNCH) indicators of Pakistan depict the deplorable state of the poor and rural women and children. Many MNCH programmes stress the need to engage the poor in community spaces. However, caste and class based hierarchies and gendered social norms exclude the lower caste poor women from accessing healthcare. To find pathways for improving the lives of the excluded, this study considers the social system as a whole and describes the mechanisms of exclusion in the externally created formal community spaces and their interaction with the indigenous informal spaces.Methods
The study used a qualitative case study design to identify the formal and informal community spaces in three purposively selected villages of Thatta, Rajanpur, and Ghizer districts. Community perspectives were gathered by conducting 37 focus group discussions, based on participatory rural appraisal tools, with separate groups of women and men. Relevant documents of six MNCH programmes were reviewed and 25 key informant interviews were conducted with programme staff.Results
We found that lower caste poor tenants and nomadic peasants were excluded from formal and informal spaces. The formal community spaces formed by MNCH programmes across Pakistan included fixed, small transitory, large transitory, and emerging institutional spaces. Programme guidelines mandated selection of community notables in groups/committees and used criteria that prevented registration of nomadic groups as eligible clients. The selection criteria and adverse attitude of healthcare workers, along with inadequacy of programmatic resources to sustain outreach activities also contributed to exclusion of the lower caste poor women from formal spaces. The informal community spaces were mostly gender segregated. Infrequently, MNCH information trickled down from the better-off to the lower caste poor women through transitory interactions in the informal domestic sphere.Conclusion
A revision of the purpose and implementation mechanisms for MNCH programmes is mandated to transform formal health spaces into sites of equitable healthcare.72.
Al Dahmani Khaled M Almalki Mussa H. Ekhzaimy Aishah Aziz Faisal Bashier Alaaeldin Mahzari Moeber M. Beshyah Salem A. 《Pituitary》2022,25(4):658-666
Pituitary - Hypogonadism is the most common form of hypopituitarism in men with macroprolactinoma. However, evidence on factors related to hypogonadism recovery is limited. We estimated the... 相似文献
73.
Echocardiographic assessment of left ventricular outflow tract in d-transposition of the great arteries 总被引:2,自引:0,他引:2
The left ventricular outflow tract in 38 patients (aged 0.3 to 13 years) with complete d-transposition of the great arteries, 31 with intraatrial (Mustard) repair, was quantitated with echocardiography, and the findings were correlated with hemodynamic and angiographic data. The left ventricular outflow tract (LVO) was measured on the echocardiogram as an anteroposterior dimension between the closure point on the mitral valve below the pulmonary arterial root (PA) and the left endocardial surface of the interventricular septum. This measurement was expressed as an LVO/PA ratio and on the basis of these measurements three groups were recognized.Group I consisted of 14 patients who had an unobstructed left ventricular outflow tract and no significant pressure differences between the pulmonary artery and left ventricle. In Group II, the 16 patients had evidence of dynamic obstruction and mild to moderate pressure differences between the pulmonary artery and left ventricle, characterized in the echocardiogram by LVO/PA ratios comparable with those of Group I, but with an abnormally prominent early posterior systolic septal bulge in the left ventricular outflow tract, abnormal systolic anterior motion of the mitral valve and coarse fluttering of the pulmonary valve. In Group III the eight patients had anatomically fixed stenosis of the left ventricular outflow tract and severe left ventricular outflow pressure gradients characterized in the echocardiogram by a reduced LVO/PA ratio and fine vibrations of the pulmonary valve. Angiographically discrete or long segmental narrowing of the left ventricular outflow tract correlated well with the echocardiographic data. Echocardiographic measurements of left ventricular posterior wall thickness also correlated well with the severity of left ventricular outflow stenosis in these three groups. The echocardiogram provides clinically useful quantitative and qualitative analysis of the left ventricular outflow tract in patients with complete transposition of the great arteries. 相似文献
74.
Abdel Aziz TA Kumar P Bazargani N Al-Hato E Al Khaja N 《Asian cardiovascular & thoracic annals》2003,11(2):102-106
Twenty-one patients undergoing coronary artery bypass grafting were prospectively evaluated by conventional selective coronary angiography and electron-beam computed tomography. Eighty bypass grafts (60 saphenous vein and 20 left or right internal mammary artery) were evaluated for patency. The sensitivity and specificity of electron-beam computed tomography were 72% and 100%, respectively; positive and negative predictive values were 100% and 92.5%, respectively. Sensitivity and specificity according to coronary region were: left anterior descending artery, 33% and 100%; diagonal artery, 67% and 100%; circumflex artery, 75% and 100%; right coronary artery, 100% and 100%. Electron-beam computed tomography is relatively accurate and a promising tool for noninvasive evaluation of graft patency after coronary artery bypass graft surgery. 相似文献
75.
Evaluation of the FASTPlaqueTB assay for direct detection of Mycobacterium tuberculosis in sputum specimens. 总被引:3,自引:0,他引:3
R Muzaffar S Batool F Aziz A Naqvi A Rizvi 《The international journal of tuberculosis and lung disease》2002,6(7):635-640
SETTING: Sputum samples were collected from suspected tuberculosis patients attending out-patient clinics at the Ojha Institute of Chest Diseases, Karachi, Pakistan. OBJECTIVE: To evaluate the performance of the FASTPlaqueTB assay for rapid diagnosis of pulmonary tuberculosis. DESIGN: A comparative study of 584 sputum samples using acid-fast smear microscopy, Lowenstein-Jensen culture and FASTPlaqueTB. RESULTS: A total of 514 samples yielded complete results. Seventy specimens were lost to analysis due to the overgrowth of contaminants. The addition of antimicrobials inhibited growth of gram-positive contaminants, and reduced the overall contamination rate from 18.2% to 7.2%. Mycobacterium tuberculosis was isolated from 175 smear-positive and 70 smear-negative specimens. FASTPlaqueTB detected M. tuberculosis in 81.6% of specimens, with a specificity of 97.7%. The sensitivity and specificity of the assay for smear-positive specimens were respectively 87.4% and 88.2%. For smear-negative specimens, the sensitivity of the assay was 67.1% and the specificity was 98.4%. The combined sensitivity of smear and FASTPlaqueTB for M. tuberculosis was 90%. Test results were available in 48 hours. CONCLUSION: FASTPlaqueTB is a sensitive and specific test for rapid diagnosis of pulmonary tuberculosis in high prevalence areas. The test is sensitive enough to confirm a large number of clinically suspected smear-negative cases and improve case finding. 相似文献
76.
Sharon Wiener-Ogilvie Hilary Pinnock Guro Huby Aziz Sheikh Martyn R Partridge John Gillies 《Primary care respiratory journal》2007,16(6):369-377
AIMS: Amongst general practices in the NHS Borders region of Scotland, we aimed to determine compliance with the three key recommendations of the British Guideline for the Management of Asthma and to understand the nature of barriers and facilitators to their implementation. METHODS: Using piloted audit tools, a researcher extracted data from computerised and/or paper patient medical records to assess compliance with recommendations for objective diagnosis and stepwise management. Provision of asthma action plans was assessed by patient survey. Clinicians' attitude to guidelines was assessed by postal survey. RESULTS: Fifteen of the 24 practices in the NHS Borders region participated. Audited compliance with the three key recommendations varied markedly amongst and within practices. Whilst 367/547 (67%) of patients were treated appropriately with add-on therapy, only 58/254 (23%) of patients reported having been given an asthma action plan. Barriers to implementation identified by the clinicians' survey (response rate 64/84 - 76%) were theoretical (doubt about the evidence base and relevance to primary care, lack of knowledge and skills, misconceptions) as well as practical (lack of time and resources) and were exacerbated by poor teamwork. Facilitators were good teamwork and appropriate organisation of work within the practice. CONCLUSIONS: Implementation of key recommendations was variable, particularly in the more complex intervention of issuing asthma action plans. An intervention to enhance compliance with these guideline recommendations will need to address both theoretical and practical barriers within the context of improved teamwork. 相似文献
77.
BACKGROUND: Chlorofluorocarbons (CFCs) have historically served as the propellants of choice in pressurised metered-dose asthma inhalers, but concern has been raised in recent decades regarding their damaging effect on the ozone layer. Among the alternative propellants being considered is alcohol, which can be used as a co-solvent in asthma inhalers. Healthcare professionals need to be aware of alcohol-containing inhalers, since certain populations may have religious and/or cultural concerns regarding the use of such preparations. OBJECTIVES: To identify pressurised metered-dose asthma inhalers which contain alcohol-based propellants. METHODS: We searched the British National Formulary to identify companies that manufacture asthma treatments and wrote to them to enquire about which of their products contained alcohol and if so in what percentage. These direct contacts were supplemented by searching medical databases and the Internet for additional information. RESULTS: We identified 11 manufacturers of asthma inhalers, seven of which produced pressurised metered-dose inhalers; of these, six were willing to disclose the requested information, and information on the seventh product was obtained from an alternative valid source of information. Most CFC preparations contain alcohol, but CFC- and alcohol-free preparations do exist. CONCLUSIONS: Clinicians need to be aware that the majority of CFC-free inhalers contain alcohol. Alcohol-free, and CFC- and alcohol-free, preparations are available for the delivery of both rescue and preventative treatment and these should be considered for use in those patients who may have concern about alcohol-based treatments. 相似文献
78.
79.
GOALS: To report the use of pH-impedance testing in evaluating patients with suspected gastroesophageal reflux disease (GERD) with atypical symptoms. BACKGROUND: Although the role of acid reflux in causing atypical GERD symptoms is generally accepted, the role, if any, of nonacid reflux is controversial, largely because until recently it has not been possible to detect nonacid reflux. The advent of intraluminal combined pH impedance testing (MII-pH), to detect nonacid reflux has heightened interest in its possible contribution to atypical symptoms. STUDY: Fifty consecutive patients referred for MII-pH testing to evaluate the cause of atypical symptoms presumed due to GERD were evaluated. The symptoms were either refractory to acid inhibition therapy or so atypical that further work up was desired by the referring physician. Patients underwent MII-pH testing to determine whether reflux was present, and, if so, if it was due to acid, nonacid, or gas. RESULTS: Only 16%, 22%, and 2% patients were found to have symptoms due to acid reflux, nonacid reflux, or both, respectively. Ten percent of these patients had gas reflux. MII-pH testing was useful in redirecting the management of patients who did not have reflux as the cause of their symptoms. CONCLUSIONS: MII-pH testing is useful in determining whether gastroesophageal reflux is present in patients with atypical symptoms that have not responded to proton pump inhibitor therapy. It also distinguishes between reflux due to acid, nonacid, and gas, with consequences for management. 相似文献
80.
Isabelle Le Huerou PhD Paul Guilloteau PhD Catherine Wicker PhD Aziz Mouats PhD Jean-Alain Chayvialle PhD Christine Bernard PhD John Burton PhD Rene Toullec PhD Antoine Puigserver PhD 《Digestive diseases and sciences》1992,37(1):40-46
Ten groups of calves were used to study the changes in activity levels and distribution of seven hydrolases in the intestinal mucosa during development and weaning. The calves in the first group were sacrificed at birth while those in the remaining nine groups were either milk-fed until slaughter on days 2, 7, 28, 56, 70, and 119; or weaned between days 28 and 56 and then slaughtered on days 56, 70, and 119, respectively. The small intestine was immediately cut off and divided into five segments, ie, duodenum, proximal jejunum, median jejunum, distal jejunum, and ileum. In the milk-fed animals, the activity levels of aminopeptidases A and N, alkaline phosphatase, lactase, and isomaltase were maximum at 2 days of age, and then declined sharply between days 2 and 7 but did not change significantly thereafter. By contrast, the maltase activity increased between days 7 and 119, while no sucrase activity was detected. Weaning resulted in a decrease in the activity of lactase and an increase in that of aminopeptidase N, maltase, and isomaltase. The distribution of all these enzymes along the small intestine was slightly influenced by age but not at all by weaning. 相似文献