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41.
Raghavan Krishnaswamy S. Gray David B. Scholz Thomas H. Nemeth Gregory A. Hussain Munir A. 《Pharmaceutical research》1996,13(12):1815-1820
Purpose. The objective was to evaluate the degradation profile of the elastase inhibitor DMP 777 and lay the foundation for formulation development.
Methods. The pKa was determined by potentiometric titration in mixed-aqueous solvents. The degradation kinetics were studied as a function of pH, buffer concentration, ionic strength, methanol concentration and temperature using a stability-indicating HPLC assay. The degradation products were identified by LC-MS, NMR, and by comparison with authentic samples.
Results. The pKa for the protonated piperazine nitrogen was estimated to be 7.04. The pH-rate profile is described by specific acid-, water-, and specific base-catalyzed pathways. The pH of maximum stability is in the range of 4 to 4.5 where water is the principal catalyst in the reaction. Buffer catalysis, primary salt effects and medium effects were observed. The proposed mechanism for acid catalyzed degradation is the rarely observed AAL1 which involves alkyl-nitrogen heterolysis. The driving force for the reaction appears to lie in the stability of the benzylic carbocation. The proposed mechanism for base catalyzed degradation is BAC2 which involves -lactam ring opening. The -lactam ring of DMP 777, a monolactam, appears to be as reactive as that in benzylpenicillin in the k
OH controlled region where a similar mechanism of hydrolysis should be operative. A contributing factor to this increased reactivity may lie in the reduced basicity of the -lactam nitrogen making it a good leaving group.
Conclusions. The degradation profile indicates that development of a solution dosage form of DMP 777 with adequate shelf-life stability at room temperature is feasible. 相似文献
42.
Honn KV Aref A Chen YQ Cher ML Crissman JD Forman JD Gao X Grignon D Hussain M Porter AT Pontes JE Powell I Redman B Sakr W Severson R Tang DG Wood DP 《Pathology oncology research : POR》1996,2(1-2):98-109
Rates of prostate cancer (PCa) have increased so dramatically over the last decade that the age adjusted incidence rate for PCa is now greater than that any other cancer among men in the United States. This review, published as a three part series, provides a state-of-art assessment of the PCa problem in its divergent aspects.Part 1 covers epidemiology, incidence and progression. Several epidemiological studies have demostrated that first degree male relatives of men with PCa are at increased risk of developing the disease. Familial and genetic factors as well as medical, anthropometric, dietary, hormonal and occupational factors involved in PCa are discussed. Postmortem examination of the prostate in men without evidence of PCa documented a high frequency of adenocarcinoma. Latent disease occurred as early as the second decade of life. Although there is no significant difference in incidence between Caucasian and African-American males, high grade prostatic intraepithelial neoplasia (HGPIN) is higher in the latter group. While dietary fat, androgens and certain environmental factors may be determinants for PCa, the exact mechanism of tumorigenesis is still relatively unknown. The current thinking of the role of genomic instability, chromosomal alterations, tumor suppressor genes and the androgen receptor are explored. 相似文献
43.
BACKGROUND: Health professionals should take an active role against smoking, so it is relevant to have information on their smoking habits and their attitudes towards smoking, especially with a view to identifying and offering help to those smokers who wish to stop. Staff in Llandough Hospital were surveyed to determine their smoking habits and attitudes, and the findings were compared with those of a similar survey at Llandough in 1987. METHODS: In October 1991 a questionnaire was sent to each member of staff employed half time or more requesting data on age, sex, department, smoking habit, attitudes to smoking in various areas of the hospital, and attitudes to access to smoking rest rooms for patients, staff, and visitors. Smokers were asked whether they would like to join a "quit smoking" group. Non-responders were sent a reminder four weeks later and all replies returned by 31 December 1991 were analysed. RESULTS: The response rate was 82%; of the respondents, 65% were non-smokers, 15% ex-smokers, and 20% current smokers. The prevalence of current smokers was 5% among doctors, 20% among nurses, 18% among administrative and clerical staff, and 40-42% among domestics, catering, and portering staff. Thirty eight per cent of responders wished smoking to be completely forbidden in all areas of the hospital and 90% in certain areas such as wards, offices, cafeteria, and laboratories. Nearly half wanted smoking to be allowed in rest rooms and over 60% wanted a 24 hour facility for smoking for staff, 56% for patients, and 44% for visitors. Only 39% of smokers wished to join a "quit smoking" support group. In comparison with the 1987 survey, the response rate in this study was higher (82% v 70%), the proportion of non-smokers had increased (65% v 59%), and more smokers wanted help (39% v 26%). Fewer wanted 24 hour access to smoking areas for staff and for visitors. CONCLUSION: This hospital should capitalise on these changes of attitude among staff and proceed more rapidly with the implementation of policies to further reduce smoking among staff, visitors, and patients. As a first step a smoking cessation counsellor has been appointed. 相似文献
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47.
Saeed K Gater R Hussain A Mubbashar M 《Social psychiatry and psychiatric epidemiology》2000,35(10):480-485
Background: Although native faith healers are found in all parts of Pakistan, where they practice in harmony with the cultural value
system, their practice is poorly understood. This study investigated the prevalence, classification and treatment of mental
disorders among attenders at faith healers. Method: The work of faith healers with 139 attenders was observed and recorded. The mental status of attenders was assessed using
a two-stage design: screening using the General Health Questionnaire followed by diagnostic interview using the Psychiatric
Assessment Schedule. Results: The classification used by faith healers is based on the mystic cause of disorders: saya (27%), jinn possession (16%) or
churail (14%). Sixty-one percent of attenders were given a research diagnosis of mental disorder: major depressive episode
(24%), generalized anxiety disorder (15%) or epilepsy (9%). There was little agreement between the faith healers' classification
and DSM-IIIR diagnosis. Faith healers use powerful techniques of suggestion and cultural psychotherapeutic procedures. Conclusions: Faith healers are a major source of care for people with mental health problems in Pakistan, particularly for women and
those with little education. Further research should assess methods of collaboration that will permit people with mental health
problems to access effective and culturally appropriate treatment.
Accepted: 9 June 2000 相似文献
48.
49.
Muhammad Irfan Irshad Ahmad Shazia Shukrullah Humaira Hussain Muhammad Atif Stanislaw Legutko Jana Petru Michal Hatala Muhammad Yasin Naz Saifur Rahman 《Materials》2022,15(13)
The development of cost-effective co-catalysts of high photocatalytic activity and recyclability is still a challenge in the energy transformation domain. In this study, 0D/2D Schottky heterojunctions, consisting of 0D ZnO and 2D Ti3C2, were successfully synthesized by the electrostatic self-assembling of ZnO nanoparticles on Ti3C2 nanosheets. In constructing these heterojunctions, Ti3C2 nanosheets acted as a co-catalyst for enhancing the transfer of excitons and their separation to support the photocatalytic response of ZnO. The as-prepared ZnO/Ti3C2 composites demonstrate an abbreviated charge transit channel, a huge interfacial contact area and the interfacial electrons’ transport potential. The extended optical response and large reactive area of the ZnO/Ti3C2 composite promoted the formation of excitons and reactive sites on the photocatalyst’s surface. The ZnO/Ti3C2 Schottky heterojunction showed significantly high photocatalytic activity for hydrogen production from a water–ethanol solution under the light illumination in the visible region. The hydrogen evolution overoptimized the ZnO/Ti3C2 composition with 30 wt.% of Ti3C2, which was eight times higher than the pristine ZnO. These findings can be helpful in developing 0D/2D heterojunction systems for photocatalytic applications by utilizing Ti3C2 as a low-cost co-catalyst. 相似文献
50.
Ikram Hussain Saba Ishrat Veeraraghavan Meyyur Aravamudan Shahab R. Khan Babu P. Mohan Rahul Lohan Muhammad Bilal Abid Tiing Leong Ang 《Medicine》2022,101(17)
Background:Mesenteric panniculitis (MP) is a non-specific, localized inflammation at the mesentery of small intestines which often gets detected on computed tomography. An association with malignant neoplasms remains unclear. We performed a systematic review and meta-analysis to examine the association of malignancy with MP.Methods:MEDLINE, EMBASE, Web of Science, and Cochrane databases were searched for articles published from inception to 2020 that evaluated the association of malignant neoplasms with MP in comparison with control groups. Using random-effects method, a summary odds ratio (OR) estimate with 95% confidence intervals for malignant neoplasms in MP was estimated.Results:Four case-control studies reporting data on 415 MP patients against 1132 matched-controls met inclusion criteria and were analyzed. The pooled OR for finding a malignant neoplasm in patients with MP was 0.907 (95% CI: 0.688–1.196; P = .489). The heterogeneity was mild and non-significant. Also, there was no heightened risk of any specific type of malignancy with MP. Three more case-series with unmatched-control groups (MP: 282, unmatched-controls: 17,691) were included in a separate analysis where the pooled OR of finding a malignant neoplasm was 2.963 (95% CI: 1.434–6.121; P = .003). There was substantial heterogeneity in this group.Conclusion:This meta-analysis of matched controlled studies proves absence of any significant association of malignant neoplasms with MP. Our study also demonstrates that the putative association of malignancy with MP is mainly driven by uncontrolled studies or case-series. 相似文献