全文获取类型
收费全文 | 29147篇 |
免费 | 1242篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 801篇 |
儿科学 | 2312篇 |
妇产科学 | 941篇 |
基础医学 | 2166篇 |
口腔科学 | 1454篇 |
临床医学 | 2184篇 |
内科学 | 5250篇 |
皮肤病学 | 732篇 |
神经病学 | 1975篇 |
特种医学 | 1107篇 |
外科学 | 6660篇 |
综合类 | 334篇 |
一般理论 | 11篇 |
预防医学 | 957篇 |
眼科学 | 916篇 |
药学 | 1607篇 |
1篇 | |
中国医学 | 146篇 |
肿瘤学 | 927篇 |
出版年
2024年 | 32篇 |
2023年 | 306篇 |
2022年 | 360篇 |
2021年 | 655篇 |
2020年 | 451篇 |
2019年 | 561篇 |
2018年 | 862篇 |
2017年 | 716篇 |
2016年 | 828篇 |
2015年 | 712篇 |
2014年 | 1056篇 |
2013年 | 1527篇 |
2012年 | 1845篇 |
2011年 | 2094篇 |
2010年 | 1136篇 |
2009年 | 763篇 |
2008年 | 1658篇 |
2007年 | 1864篇 |
2006年 | 1854篇 |
2005年 | 1873篇 |
2004年 | 1797篇 |
2003年 | 1674篇 |
2002年 | 1569篇 |
2001年 | 874篇 |
2000年 | 984篇 |
1999年 | 617篇 |
1998年 | 222篇 |
1997年 | 176篇 |
1996年 | 160篇 |
1995年 | 113篇 |
1994年 | 97篇 |
1993年 | 64篇 |
1992年 | 105篇 |
1991年 | 101篇 |
1990年 | 76篇 |
1989年 | 79篇 |
1988年 | 58篇 |
1987年 | 50篇 |
1986年 | 46篇 |
1985年 | 47篇 |
1984年 | 33篇 |
1983年 | 29篇 |
1981年 | 33篇 |
1980年 | 24篇 |
1979年 | 29篇 |
1978年 | 24篇 |
1977年 | 22篇 |
1974年 | 21篇 |
1972年 | 20篇 |
1967年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Hasan Sunar Gülara Hüseyinova Suat Canbaz Umit Halici Enver Duran 《Blood coagulation & fibrinolysis》2003,14(8):703-706
Low molecular weight heparins are widely used in the prophylaxis and treatment of thrombotic disorders. The effect of low molecular weight heparins on coagulation was examined ultrastructurally in an animal model. A test and a control group was formed, each consisting of five rabbits. Nadroparine (225 Institute of Chaoy Unit/kg twice daily) was applied to the test group for 10 days. The control group received 1 ml saline solution subcutaneously. Blood and vascular tissue samples collected at the end of the 10th day were evaluated under a JEM 100 B electron microscope. Platelet degranulation and agglutination was observed in the control group. Fibrin materials were detected in the cytoplasms and surroundings of degranulated platelets. Erythrocyte accumulation was remarkable on the vascular endothelium with intact coagulation periods. In the test group, outer membranes of platelets, hyalomere, and granular structures in the granulomeres were detected to be nearly intact. There were rare erythrocytes in the large vascular lumens. The aggregation phase had occurred but no agglutination was detected. Nadroparine seems to preserve consistency of lipoprotein membranes of platelets and granular structures containing enzymes, which contribute to the coagulation mechanisms. 相似文献
4.
Abstract – Traumatic dental injuries often occur to the teeth and their supporting tissues and they are the main reasons for emergency visit to a dental clinic. Management of a fracture depends on its position and the extent of root involvement. Horizontal root fractures are not seen frequently and the treatment consists of reduction and long‐term rigid fixation of the coronal segment. The present case demonstrates the successful management of two horizontally fractured maxillary central incisors with a follow‐up period of 9 months. 相似文献
5.
Melita Kosanovic Mohammad Yousif Hasan Dhanasekhar Subramanian Abdulla Ali Falah Al Ahbabi Omar Ali Awn Al Kathiri Essa Mohammed Ali Abdulla Aleassa Abdu Adem 《Food and chemical toxicology》2007,45(11):2261-2266
We hypothesized that increased ambient concentrations of metals, as a consequence of escalating urbanization and industrialization of the Gulf region will respond in increased contamination of edible fish species. In this study, we report concentrations of chromium, manganese, cobalt, copper, zinc, arsenic, cadmium, mercury and lead in meat and liver of wild Red-spot emperor (Lethrinus lentjan) from three sampling points at the UAE coast. Analysis was performed by the ICP-MS/microwave digestion. Our study has shown that meat and liver metal content was significantly higher in areas with higher industrial activity, although metal values did not exceed permitted levels of fish for human consumption. 相似文献
6.
Mesut Akarsu Murat Meral Sakine Bahceli Dilek Solmaz Hasan Kayahan Mujde Soyturk Hale Akpinar 《Digestive endoscopy》2007,19(1):49-51
Fascioliasis is a worldwide zoonotic infection with fasciola hepatica and fasciola gigantica. The zoonoses are particularly endemic in sheep‐raising countries and are also endemic in Turkey. Clinical features of fascioliasis relate to the stage and intensity of infection. Fasciola hepatica infection comprises two stages: hepatic and biliary, with different signs and symptoms. Cholestatic symptoms may be sudden, but, in some cases, they may be preceded by a long period of fever, eosinophilia and vague gastrointestinal symptoms. We reported a case with fever and upper‐quadrant abdominal pain since 3 months that comes from an area endemic for fasciola hepatica, with suspected imaging about fasciola hepatica in common bile duct on ultrasonography. After that, fasciola hepatica was extracted with endoscopic retrograde cholangiography. 相似文献
7.
Hasan F Batirel Saime Batirel Richard N Mitchell Scott J Swanson 《The Journal of heart and lung transplantation》2005,24(6):658-664
BACKGROUND: Interferon-gamma, produced by T-helper cells, activates macrophages and increases expression of major histocompatibility complex (MHC) products in acute and chronic rejection. We investigated the role of interferon-gamma in murine heterotopic tracheal allografts. METHODS: Tracheas from BALB/c mice were heterotopically transplanted to BALB/c (12 isografts: 2 weeks [n = 6] and 4 weeks [n = 6], C57BL/6 (12 allografts: 2 weeks [n = 6] and 4 weeks [n = 6]) and C57BL/6 interferon-gamma knockout mice (12 interferon-gamma knockout allografts: 2 weeks [n = 4] and 4 weeks [n = 8]). BALB/c interferon-gamma knockout tracheas were transplanted to C57BL/6 mice (reverse knockout: 4 weeks [n = 6]) and BALB/c interferon-gamma knockout mice (4 weeks [n = 2]). C57BL/6 tracheas were transplanted to Bm12 mice (MHC Class II mismatch allografts: 4 weeks [n = 6]). Conventional histology and immunohistochemistry for CD4, CD8 and CD11b were performed. RESULTS: Minimal (<20%) obliteration was seen at 2 weeks in the allograft groups. No obliteration was seen in the isograft groups. However, all allografts were completely obliterated at 4 weeks. Interferon-gamma knockout allograft combinations displayed severe rejection characterized by intense intra- and extraluminal infiltration by CD4-, CD8- and CD11b-labeled cells. The MHC Class II mismatch allograft group showed normal epithelium and mild sub-epithelial infiltration by CD4+ cells at 4 weeks (CD8-, CD11b-). CONCLUSIONS: Absence of interferon-gamma does not protect the allograft from obliteration. Epithelial destruction by cytotoxic T cells appears to be an important mechanism in the development of obliteration in murine heterotopic tracheal allografts. 相似文献
8.
Hasan Yüksel Ali Riza Odaba?i Selda Demircan Aslihan Karul Leyla Didem Kozaci Kutsi K?seo?lu Kadir Kizilkaya Okay Ba?ak 《Gynecological endocrinology》2006,22(7):381-387
AIM: To evaluate the effects of oral continuous 17beta-estradiol plus norethisterone acetate (E2/NETA) replacement therapy on abdominal subcutaneous fat, serum leptin level (SLL) and body composition in postmenopausal women. MATERIALS AND METHODS: A 6-month, prospective, randomized, double-blind and placebo-controlled study was conducted. Forty-three healthy naturally postmenopausal women aged 43-65 years were randomly assigned to receive E2/NETA (2 mg E2 plus 1 mg NETA, n = 22) or placebo (n = 21). Fasting SLL by enzyme-linked immunosorbent assay, subcutaneous abdominal fat thickness (STh) by ultrasound and the anthropometric indices of body weight (BW), body mass index (BMI), waist and hip circumference (WC, HC) and waist-to-hip ratio (WHR) were recorded at the beginning and the end of the study. RESULTS: After 6 months of therapy, BW and SLL increased in the placebo group (p = 0.043 and 0.033, respectively). WC, HC and STh decreased significantly in the E2/NETA group (p = 0.002, 0.006 and 0.000, respectively) and they were also significantly lower in women receiving E2/NETA than in women taking placebo (p = 0.000, 0.034 and 0.000, respectively). At baseline, SLL and STh were positively correlated with all anthropometric indices except WHR. CONCLUSION: Oral continuous combined regimen of E2/NETA significantly reduced central fat accumulation as assessed by WC and STh, and attenuated the increase in SLL. The observed changes in SLL were highly and positively related to changes in STh. The oral continuous combined E2/NETA regimen appears to have protective effects on cardiovascular function and probably on metabolic diseases by its slimming effect upon WC in postmenopausal women. 相似文献
9.
Uur Koçer MD Nilgün Atakan MD Hasan Mete Aksoy MD Yigit Özer Tiftikcioglu MD Berna Aksoy MD Müzeyyen Astarci MD 《Dermatologic surgery》2003,29(3):291-293
BACKGROUND: Superficial lymphatic malformations are predominantly developmental malformations of infancy, but they may arise at any age. OBJECTIVE: To describe a patient with a late-onset superficial lymphatic malformation. METHODS: Case report and literature review. RESULTS: A 53-year-old woman was evaluated for a colored lesion that developed spontaneously on the anterior abdominal wall. The lesion was treated by surgical excision. Findings on histopathologic examination of the specimen were consistent with superficial lymphatic malformation. There was no recurrence of the lesion at 4 months after the operation. CONCLUSION: Superficial lymphatic malformations can develop in adults spontaneously without the presence of any predisposing condition. Because the majority of such late-onset malformations reported in the literature are localized lesions similar to the one in our patient, surgical removal with inclusion of subcutaneous tissue usually results in cure without recurrence. 相似文献
10.
T. Aköz B. Erdoğan M. Görgü M. R. Kapucu O. Girgin 《European journal of plastic surgery》1998,21(6):308-310
Camptodactyly is a flexion deformity of the proximal interphalangeal joint. Because of unsatisfactory results, treatment is
not recommended for mild deformities, and in severe deformities surgery has been disappointing. A specially designed external
fixator providing gradual distraction was used in a severe case. With this mildly aggressive method, an acceptable result
was obtained.
Received: 5 June 1997/Accepted: 2 February 1998 相似文献