全文获取类型
收费全文 | 91112篇 |
免费 | 8367篇 |
国内免费 | 6187篇 |
专业分类
耳鼻咽喉 | 875篇 |
儿科学 | 1137篇 |
妇产科学 | 732篇 |
基础医学 | 9397篇 |
口腔科学 | 1588篇 |
临床医学 | 11843篇 |
内科学 | 11967篇 |
皮肤病学 | 961篇 |
神经病学 | 3989篇 |
特种医学 | 3340篇 |
外国民族医学 | 34篇 |
外科学 | 8772篇 |
综合类 | 18554篇 |
现状与发展 | 19篇 |
一般理论 | 1篇 |
预防医学 | 7571篇 |
眼科学 | 2203篇 |
药学 | 10208篇 |
89篇 | |
中国医学 | 5668篇 |
肿瘤学 | 6718篇 |
出版年
2024年 | 329篇 |
2023年 | 1341篇 |
2022年 | 3479篇 |
2021年 | 4339篇 |
2020年 | 3343篇 |
2019年 | 2625篇 |
2018年 | 2763篇 |
2017年 | 2700篇 |
2016年 | 2431篇 |
2015年 | 4052篇 |
2014年 | 5086篇 |
2013年 | 4823篇 |
2012年 | 7355篇 |
2011年 | 7992篇 |
2010年 | 5820篇 |
2009年 | 4726篇 |
2008年 | 5432篇 |
2007年 | 5496篇 |
2006年 | 5211篇 |
2005年 | 4857篇 |
2004年 | 3174篇 |
2003年 | 2889篇 |
2002年 | 2380篇 |
2001年 | 1947篇 |
2000年 | 1967篇 |
1999年 | 1747篇 |
1998年 | 1109篇 |
1997年 | 1023篇 |
1996年 | 785篇 |
1995年 | 729篇 |
1994年 | 690篇 |
1993年 | 400篇 |
1992年 | 484篇 |
1991年 | 431篇 |
1990年 | 366篇 |
1989年 | 317篇 |
1988年 | 233篇 |
1987年 | 235篇 |
1986年 | 174篇 |
1985年 | 118篇 |
1984年 | 69篇 |
1983年 | 63篇 |
1982年 | 44篇 |
1981年 | 31篇 |
1980年 | 14篇 |
1979年 | 23篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1975年 | 4篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
本文介绍17例(34髋)特发性股骨头坏死、4例(4髋)正常人骨髓腔静脉造影所见。发现25髋有异常改变,并经病理证实。作者认为:①骨干返流;②2支或2支以上静脉不显影;③多条静脉明显变细;④干骺端瘀积是股骨头坏死的造影表现,前二者是可靠的诊断依据。造影结果提示髓腔静脉造影是一种安全而敏感的诊断技术。 相似文献
42.
本文报导181例外伤性脾破裂,其中包括21例延迟性脾破裂的诊断和治疗。术中脾损伤的临床分度有助于治疗方法的选择。及时.有效的止血和治疗以及重视对合并伤的防治是降低死亡率的关键。 相似文献
43.
在耳鼻咽喉科手术中应用颈外动脉栓塞法10例,形成栓塞组,并把单纯颈外动脉结扎10例作为对照组。结果表明:栓塞组较对照组术中出血量显著减少,有利于病灶彻底清除,因而有提高治愈率减少复发率的作用。掌握栓塞位置、栓塞剂用量和注射速度是防止并发症的关键。 相似文献
44.
Jun Gu Yang O Huh Feng Jiang Nancy P Caraway Jorge E Romaguera Tanweer M Zaidi Ricardo L Fernandez Huazhong Zhang Issa F Khouri Ruth L Katz 《Modern pathology》2004,17(5):553-560
Mantle cell lymphoma is non-Hodgkin's B-cell lymphoma characterized by the t(11;14)(q13;q32) translocation. Peripheral blood involvement of mantle cell lymphoma is usually associated with a poor prognosis and therefore, its identification is clinically important. In this study, we performed cyclin D1/IgH-probe fusion fluorescence in situ hybridization analysis on 223 peripheral blood samples: 185 from 125 mantle cell lymphoma patients, and 38 normal controls. The cutoff values for the test were established using normal controls. Flow cytometry on peripheral blood and corresponding bone marrow samples was used to evaluate this test. In all, 26% of the 185 peripheral blood samples and 27% of the 161 corresponding bone marrow samples were flow cytometry positive for mantle cell lymphoma. The mean numbers of single and- double-fusion signals and the mean number of CD5/CD19-positive cells, absolute blood lymphocyte count, and white blood cell count were significantly higher in peripheral blood and corresponding bone marrow samples with mantle cell lymphoma-positive flow cytometry. Double-fusion signals were more specific than single-fusion ones. Fluorescence in situ hybridization was far more likely to be positive for mantle cell lymphoma when the peripheral blood and the corresponding bone marrow samples had positive flow cytometry results or morphology (P<0.01). Our study indicates that cyclin D1/IgH-fusion fluorescence in situ hybridization analysis could be used to determine the presence and character of circulating mantle cell lymphoma cells in peripheral blood, thus enhancing our ability to evaluate leukemic mantle cell lymphoma and minimum residual disease. 相似文献
45.
Jann-Tay Wang Sheng-Fong Lin Hsu-Ling Chiu Li-Chen Wang Hui-Ming Tai Chaw-Fung Jiang Shan-Chwen Chang Shu-Hsun Chu 《台湾医志》2004,103(1):32-36
BACKGROUND AND PURPOSE: Nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection is difficult to control. Due to a dramatic increase in the nosocomial MRSA infection rate at our hospital from 2000 to 2001, this study was conducted to identify the source of these infections and the effectiveness of control measures. METHODS: 179 healthcare workers (HCWs) were screened for carriage of MRSA. Starting in April 2001, all patients with MRSA infection or colonization were put in strict contact and cohort isolation. The bacterial isolates of HCW carriers and patients with MRSA infection from April 2001 to September 2001 were subjected to antimicrobial susceptibility testing by disk-diffusion method and molecular typing by pulsed-field gel electrophoresis (PFGE). RESULTS: Fifteen HCWs were found to be carriers of MRSA. They were all given topical mupirocin treatment. After these interventions, the nosocomial MRSA infection rate decreased from 1.23 to 0.53 per 1000 patient-days. All 61 MRSA isolates available for antimicrobial susceptibility testing and molecular typing were multidrug resistant. PFGE study revealed 2 predominant types, type C and type Y, comprising 36 and 12 isolates, respectively. CONCLUSIONS: The current study demonstrates the importance of measures to control nosocomial MRSA infections in hospitals that already have a high incidence of endemic MRSA infection. Elimination of carriage by healthcare workers, and strict contact and cohort isolation are the main effective measures. 相似文献
46.
乳腺导管瘘的诊断和治疗:附40例报告 总被引:1,自引:0,他引:1
为探讨乳腺导管瘘的诊断和治疗方法,笔者回顾分析2年间收治的40例乳腺导管瘘患者的临床资料。诊断主要依据病史、体征和病理检查。治疗采用完整切除瘘管和受累乳导管,去除炎性组织,并充分引流的方法,通过肉芽组织生长使乳管瘘痊愈。结果显示,全部病例均治愈,随访其中37例住院治疗的患者2.5年,无1例复发。提示:在治疗上完整切除瘘管和受累乳导管,修复乳头畸形,是防止导管瘘复发的关键。 相似文献
47.
Foreign bodies in the heart are a rare but serious form of cardiac injury. The objects usually are sharp pointed. Such as acupuncture needles,sewing needles, coat hangers, fragments of Kirschner wires, pins, etc. 1 We report a patient with a metallic pellet lodged in the heart, which was accurately diagnosed and successfully removed. 相似文献
48.
Objective: To investigate the anti-inflammatory effect of erythropoietin (EPO) pretreatment on cardiomyocytes exposed to hypoxialreoxygenation injury (H/R) and explore the possible mechanism.
Methods: The cultured neonatal rats' ventricular cardiomyocytes were divided randomly into 4 groups, control group (C group), EPO pretreatment group (E group), EPO and pyrrolidine dithiocarbamate (PDTC) pretreatment group (EP group) and PDTC pretreatment group (P group). After 24 hours' pretreatment, the cardiomyocytes were exposed to H/R. After pretreatment and H/R, the expression of tumor necrosis factor- α (TNF- α ) gene in all the groups was detected by RT-PCR and Western blot. The nuclear factor- κ B (NF- κB) activity was detected by electrophoretic mobility shift assay (EMSA) and the inhibitor- κB α (Ⅰ- κB α) protein level was detected by Western blot.
Results: The decrement of Ⅰ- κB a protein and the increasing NF- KB activity were found in cardiomyocytes pretreated with EPO before H/R compared to other groups (t=3.321, 4.183, P〈0.01). However, after H/R, NF- κB activity and expression of TNF- α gene were significantly reduced, Ⅰ- κB a protein expression was increased in cardiomyocytes of E group compared to other groups (t=-3.425, 3.687, 3.454, P〈0.01). All theses changes caused by EPO pretreatment were eliminated by the intervention of PDTC (an antagonist to NF- κB) during pretreatment.
Conclusions: EPO pretreatment can inhibit the activation of NF- κB and upregulation of TNF- α gene in cardiomyocytes exposed to H/R through a negative feedback of NF- κB signaling pathway, and thus produces the anti-inflammatory effect. This might be one of the ways EPO produces the anti-inflammatory effect. 相似文献
Methods: The cultured neonatal rats' ventricular cardiomyocytes were divided randomly into 4 groups, control group (C group), EPO pretreatment group (E group), EPO and pyrrolidine dithiocarbamate (PDTC) pretreatment group (EP group) and PDTC pretreatment group (P group). After 24 hours' pretreatment, the cardiomyocytes were exposed to H/R. After pretreatment and H/R, the expression of tumor necrosis factor- α (TNF- α ) gene in all the groups was detected by RT-PCR and Western blot. The nuclear factor- κ B (NF- κB) activity was detected by electrophoretic mobility shift assay (EMSA) and the inhibitor- κB α (Ⅰ- κB α) protein level was detected by Western blot.
Results: The decrement of Ⅰ- κB a protein and the increasing NF- KB activity were found in cardiomyocytes pretreated with EPO before H/R compared to other groups (t=3.321, 4.183, P〈0.01). However, after H/R, NF- κB activity and expression of TNF- α gene were significantly reduced, Ⅰ- κB a protein expression was increased in cardiomyocytes of E group compared to other groups (t=-3.425, 3.687, 3.454, P〈0.01). All theses changes caused by EPO pretreatment were eliminated by the intervention of PDTC (an antagonist to NF- κB) during pretreatment.
Conclusions: EPO pretreatment can inhibit the activation of NF- κB and upregulation of TNF- α gene in cardiomyocytes exposed to H/R through a negative feedback of NF- κB signaling pathway, and thus produces the anti-inflammatory effect. This might be one of the ways EPO produces the anti-inflammatory effect. 相似文献
49.
Reinaldo Figueroa MD Edilberto Martinez MD Raisa P. Fayngersh MD Hong Jiang MD Hatim A. Omar MD Nergesh Tejani MD Michael S. Wolin PhD 《American journal of obstetrics and gynecology》1995,173(6):1800-1806
OBJECTIVE: Our objective was to determine whether the observed relaxation to lactate and other agents in placental vessels of normal pregnancies is altered in severe preeclampsia.STUDY DESIGN: Isolated placental arteries and veins from women with severe preeclampsia and uncomplicated term pregnancies were precontracted with prostaglandin F2α under 5% oxygen and 5% carbon dioxide with the balance nitrogen (Po2 35 to 38 torr) and then exposed to lactate (1 to 10 mmol/L, pH 7.4, n = 8 to 15), arachidonic acid (0.01 to 10 μmol/L, n = 6 to 13), nitroglycerin (1 nmol to 1 μmol/L, n = 4 to 12), or forskolin (0.01 to 10 μmol/L, n = 6 to 9). The response to lactate was also examined in placental vessels from appropriate-for-gestational-age preterm deliveries (n = 8) for comparison with a similar group with severe preeclampsia (n = 8). The t test and analysis of variance statistics were used.RESULTS: Relaxation to lactate was markedly inhibited in both placental arteries and veins of women with severe preeclampsia compared with vessels from uncomplicated term or preterm pregnancies. Responses to the other relaxing agents were not altered in the severely preeclampsia vessels.CONCLUSIONS: In severe preeclampsia absence of lactate-induced dilatation of placental vessels may contribute to the fetal complications associated with impaired blood flow and vasospasm. 相似文献
50.
Toshiaki Nakashima Fuminori Goda Jinge Jiang Toshihide Shima Harold M. Swartz 《Magnetic resonance in medicine》1995,34(6):888-892
The partial pressure of oxygen (pO2) of the liver in vivo in unanesthetized mice was determined using electron paramagnetic resonance (EPR) oximetry with India ink. The EPR spectra were obtained using a low-frequency (1.2 GHz) EPR spectrometer with a loop gap cavity resonator. The line width of the India ink used in this experiment was reversibly broadened by oxygen and was particularly sensitive to pO2 below 30 torr. After the administration of India ink into the tail vein, the India ink particles were taken up mainly by Kupffer cells in the liver and in part by phagocytes in the spleen. The pO2 measured in the normal liver was about 14 torr and was constant for the 2-week experimental period. The pO2 decreased when measured at 1, 2, and 6 days after treatment with a hepatotoxin (carbon tetrachloride (CCI4)); within 2 weeks, it returned almost to the initial level. Measurements by EPR at sacrifice of controls and CCI4-treated mice indicated that more than 90% of the India ink went to the liver; the spleen contained 4.7% of total amount in control mice and 8.8% in CCI4-treated mice when measured 2 weeks after the treatment. These data indicate the usefulness of India ink for measuring the pO2 of the liver in vivo and that the pO2 in the Kupffer cells is decreased when the liver is damaged by CCI4. 相似文献