全文获取类型
收费全文 | 5905篇 |
免费 | 422篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 114篇 |
妇产科学 | 212篇 |
基础医学 | 749篇 |
口腔科学 | 156篇 |
临床医学 | 558篇 |
内科学 | 1140篇 |
皮肤病学 | 94篇 |
神经病学 | 379篇 |
特种医学 | 270篇 |
外科学 | 822篇 |
综合类 | 380篇 |
一般理论 | 2篇 |
预防医学 | 367篇 |
眼科学 | 108篇 |
药学 | 452篇 |
4篇 | |
中国医学 | 122篇 |
肿瘤学 | 447篇 |
出版年
2023年 | 60篇 |
2022年 | 127篇 |
2021年 | 202篇 |
2020年 | 114篇 |
2019年 | 143篇 |
2018年 | 214篇 |
2017年 | 132篇 |
2016年 | 137篇 |
2015年 | 212篇 |
2014年 | 252篇 |
2013年 | 310篇 |
2012年 | 471篇 |
2011年 | 468篇 |
2010年 | 277篇 |
2009年 | 255篇 |
2008年 | 336篇 |
2007年 | 355篇 |
2006年 | 329篇 |
2005年 | 271篇 |
2004年 | 241篇 |
2003年 | 240篇 |
2002年 | 206篇 |
2001年 | 124篇 |
2000年 | 147篇 |
1999年 | 99篇 |
1998年 | 34篇 |
1997年 | 29篇 |
1996年 | 22篇 |
1995年 | 32篇 |
1994年 | 22篇 |
1993年 | 18篇 |
1992年 | 63篇 |
1991年 | 45篇 |
1990年 | 32篇 |
1989年 | 35篇 |
1988年 | 36篇 |
1987年 | 28篇 |
1986年 | 28篇 |
1985年 | 36篇 |
1984年 | 31篇 |
1983年 | 25篇 |
1982年 | 22篇 |
1981年 | 26篇 |
1980年 | 13篇 |
1979年 | 18篇 |
1978年 | 13篇 |
1977年 | 16篇 |
1976年 | 14篇 |
1975年 | 11篇 |
1974年 | 10篇 |
排序方式: 共有6414条查询结果,搜索用时 0 毫秒
1.
Hsien-Chi Liao Jen-Hao Chuang Hsao-Hsun Hsu Ke-Cheng Chen Jin-Shing Chen 《Surgical endoscopy》2020,34(4):1641-1647
Thoracic empyema in uremic patients on maintenance hemodialysis is a challenging situation. The clinical characteristics are rarely reported, and the surgical outcomes remain unclear. We report our experience with video-assisted thoracoscopic surgery in these patients during 10-year period of time. Between 2005 and 2015, we retrospectively reviewed the clinical characteristics, bacteriological studies, and thoracoscopic surgical results of 23 empyema patients undergoing maintenance hemodialysis. The mean patient age was 67.1 ± 12.9 years. All patients had additional preexisting systemic diseases. The mean duration of hemodialysis was 34.7 ± 25.8 months. The infections causing empyema were pneumonia in 11 (47.8%), blood stream infection in 8 (34.8%), and uremic pleuritis in 4 (17.4%). Among the 22 identified microorganisms, the most common pathogen was methicillin-resistant Staphylococcus aureus (31.8%). After thoracoscopic surgery, 8 patients (34.8%) required additional procedures for complications, including 2 patients who required repeated thoracoscopy for hemothorax and 6 (26.1%) patients who required open drainage for residual empyema. The mean hospital stay was 62.4 days, and 6 patients (26.1%) died in the hospital. Univariate and multivariate analyses revealed that maintenance hemodialysis longer than 5 years was a significant factor associated with in-hospital mortality (odds ratio: 14.8, 95% confidence interval 1.5–151.6; p < 0.0001). While surgical management of thoracic empyema in uremic patients undergoing maintenance hemodialysis is associated with high rates of complication and mortality, thoracoscopic surgery is feasible, especially for patients undergoing hemodialysis for less than 5 years. 相似文献
2.
Fu-Wei Wang Yu-Wen Chiu Ming-Shium Tu Ming-Yueh Chou Chao-Ling Wang Hung-Yi Chuang 《International archives of occupational and environmental health》2009,82(7):819-825
Purpose There has been increasing interest in the occupational health of workers in small enterprises, especially in developing countries.
This study examines the association between psychosocial job characteristics and fatigue, and attempts to identify risk factors
for fatigue among workers of small enterprises in southern Taiwan.
Methods A structured questionnaire was administered to workers receiving regular health examinations between August 2005 and January
2006. The questionnaire collected demographic information and data on working conditions, personal health status and life
styles. It also collected information on psychosocial job characteristics, fatigue and psychological distress using three
instruments.
Results A total of 647 workers with mean age of 43.7 were completed. Probable fatigue was found in 34.6% of the sample. Fatigue was
found by multiple logistic regressions to be associated with the lack of exercise, working in shifts, depression score and
lack of social support at workplace.
Conclusions This study found associations between life style, psychosocial job characteristics and fatigue. Because the high prevalence
of probable fatigue was found in such small enterprises, the authors suggest that a short interview with some quick questionnaires
in health checkup for these small enterprise workers are helpful to early detect psychosocial and fatigue problems. 相似文献
3.
4.
Guo-Lin Wei Juri Melnik Jing-Li Luo Alan R. Sanger Karl T. Chuang 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》2005,575(2):183-193
The performances of three widely different cathode materials (Pt, strontium-doped lanthanum manganite (LSM), and NiO) have been compared for use with proton conducting Li2SO4–Al2O3 composite electrolyte, using H2S–air and H2–air fuel cells operating at 600 °C. Surface analysis and electrochemical techniques were used to characterize fresh and used electrode materials. Pt or LSM cathodes each became covered with Li2SO4 and Al2O3 and, as a consequence, the fuel cells showed poor performance. In contrast, the NiO cathode catalyst did not become covered with Li2SO4 and good fuel cell performance was achieved. Exceptionally good current densities of over 100 mA/cm2 and power densities of over 30 mW/cm2 were obtained for H2S–air fuel cells having Mo–Ni–S anode catalysts. Slight agglomeration of NiO particles during fuel cell operation had only a minor effect on performance. 相似文献
5.
6.
Oral and dental manifestations in diabetic and nondiabetic uremic patients receiving hemodialysis. 总被引:2,自引:0,他引:2
Shu-Fen Chuang Junne-Ming Sung Shih-Chen Kuo Jeng-Jong Huang Su-Yuan Lee 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2005,99(6):689-695
OBJECTIVE: The aim of this study was to examine the dental condition and oral manifestations in diabetic and nondiabetic uremic patients undergoing hemodialysis. STUDY DESIGN: A total of 128 patients undergoing hemodialysis therapy were classified into the diabetic and nondiabetic groups and examined for uremic oral manifestations, dental caries, and the periodontal status. All the patients received predialytic salivary pH examination. In the diabetic group, the correlation between oral findings and glycemic controlled levels, which was collected based on Hb A1C values, were further studied. RESULTS: The diabetic group exhibited significantly higher prevalence of caries and more severe dry mouth, taste change, and mucosa pain than the nondiabetic group. The diabetic group tended to have lower predialytic salivary pH, and patients with poor glycemic control (ie, Hb A1C > 9%) showed higher incidence of dry mouth, mucosal pain, and tongue coating. However, the DMFT and CPI index were not associated with glycemic control in the diabetic group. CONCLUSIONS: This study reveals that diabetic uremic patients undergoing maintained hemodialysis exhibited a potentially higher risk for dental decay and xerostomia. Lower salivary pH and poor glycemic control may affect oral manifestations. Further research is needed to clarify the combined influence of diabetic nephropathy on oral health. 相似文献
7.
A case of duodenojejunal intussusception secondary to a large hamartomatous polyp of Brunner's glands was reported in a 15-year-old girl. Despite a great preponderance of ileocolic intussusception in childhood, this is the first reported case of duodenojejunal intussusception occurring in that age group. The diagnosis was not made by clinical examination; complete duodenal obstruction was shown in upper gastrointestinal series and by endoscopy. The intussusception was reduced manually at laparotomy, and the polyp was excised. Pathological examination revealed a preponderance of normal-appearing Brunner's glands in the tumor, consistent with the diagnosis of Brunner's gland hamartoma. 相似文献
8.
P Y Chang K C Lin C Y Chuang C R Wang M Y Chen W C Hsieh G R Wang D L Cheng K S Chang Y C Ko 《Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand》1992,10(1):65-68
From May 1, 1985 to December 31, 1991, a total of 4,962,707 serum samples from 8 population groups in Taiwan were tested for anti-human immunodeficiency virus type 1 (anti-HIV-1). In total, 256 samples were seropositive; of these individuals, 43 developed acquired immunodeficiency syndrome (AIDS): 29 were homosexuals; 5 were hemophiliacs; 8 were heterosexuals and 1 was of unknown risk. Although the prevalence of HIV-1 infection and AIDS remains low compared with other countries, since 1988 the increase has been rapid. Before 1977 the majority were homosexuals and hemophiliacs; thereafter the risk groups diversified, with a trend away from homosexuals and hemophiliacs towards heterosexuals and intravenous drug abusers (IVDAs). A few patients have caused serious social problems for the public, health care workers and families. Active community efforts are needed to achieve future success in the control of HIV-1 infection and AIDS in Taiwan. 相似文献
9.
Exposure of cultured cerebellar granule cells to glutamate results in a concentration-dependent (EC50 = 22.7 +/- 0.4 microM) and delayed (24-72 hr) neurotoxicity, which is blocked by the specific N-methyl-D-aspartate (NMDA) receptor antagonists 2-amino-5-phosphovalerate and MK-801 but is unaffected by the non-NMDA receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione and 6,7-dinitroquinoxaline-2,3-dione. Although glutamate toxicity in these cells is mediated by the NMDA subtype of glutamate receptor, pretreatment of cerebellar granule cells with subtoxic concentrations of NMDA markedly antagonizes the neurotoxic actions of glutamate, with an IC50 of 55 +/- 4 microM. The neuroprotective effect of NMDA requires a preincubation time of approximately 120 min to be fully manifested and does not require the presence of NMDA during glutamate exposure. These data demonstrate that NMDA receptors mediate both neurotoxicity and neuroprotection in cerebellar granule cells. Among four glutamate receptor agonists tested (NMDA, quisqualate, ibotenate, and kainate), only NMDA was able to provide a robust neuroprotection against glutamate toxicity. Quisqualate was neither neurotoxic nor neuroprotective, whereas ibotenate, which was nontoxic by itself, induced a small degree of neuroprotection. In contrast, kainate, which was neurotoxic to cerebellar granule cells, also provided considerable neuroprotection against glutamate toxicity. Because preincubation of cerebellar granule cells with NMDA fails to alter NMDA receptor-mediated phosphoinositide hydrolysis or the specific binding of [3H]MK-801 to NMDA receptors, it appears that the neuroprotective effects of NMDA are not due to NMDA receptor desensitization. 相似文献
10.
Further evidence supporting a cause and effect relationship between blood transfusion and earlier cancer recurrence. 总被引:12,自引:0,他引:12
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Studies of associations between perioperative blood transfusions and later recurrence of solid tumors have yielded conflicting results. A previous analysis of transfused patients suggested that recurrence was associated with transfusion of whole blood as opposed to red blood cell concentrates. Additional analyses were performed on patients with cancers of the colon, rectum, cervix, and prostate to determine if patients receiving whole blood, red blood cells only, or no transfusions had differing outcomes. Patients receiving 1 unit or more of whole blood had uniformly poor outcomes compared with nontransfused patients (p less than 0.001). In contrast, patients receiving only red blood cells had progressively worse recurrence and death rates with increasing numbers of transfusion, suggesting the presence of a dose-effect relationship. Employing multivariate techniques, blood transfusion of less than or equal to 3 units that included any whole blood were independently and significantly associated with earlier recurrence (p = 0.003) and death due to cancer (p = 0.02). Transfusions of less than or equal to 3 units of blood comprised solely of red blood cell concentrates were associated with no greater risk of recurrence than that seen in patients receiving no transfusion (p = 0.50). These results provide a potential explanation for the disparate results reported in studies of blood transfusion and cancer outcome. The marked difference in outcome seen between patients receiving a few units of red blood cells and comparable patients receiving even one unit of whole blood are consistent with the hypothesis that transfusion of stored blood plasma causes earlier tumor recurrence in some instances. Strategies for reducing these risks might include avoidance of whole blood transfusions when only 1-3 units are required, more conservative transfusion practice, use of autologous blood transfusions, and perhaps, use of red blood cells washed free of plasma and white cell debris. Clinical trials to test these hypotheses are urgently needed. 相似文献