全文获取类型
收费全文 | 506篇 |
免费 | 23篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 24篇 |
妇产科学 | 10篇 |
基础医学 | 42篇 |
口腔科学 | 14篇 |
临床医学 | 63篇 |
内科学 | 122篇 |
皮肤病学 | 11篇 |
神经病学 | 9篇 |
特种医学 | 100篇 |
外科学 | 39篇 |
综合类 | 32篇 |
预防医学 | 20篇 |
眼科学 | 15篇 |
药学 | 11篇 |
中国医学 | 1篇 |
肿瘤学 | 24篇 |
出版年
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 11篇 |
2016年 | 3篇 |
2015年 | 11篇 |
2014年 | 10篇 |
2013年 | 12篇 |
2012年 | 5篇 |
2011年 | 12篇 |
2010年 | 22篇 |
2009年 | 18篇 |
2008年 | 6篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 4篇 |
2004年 | 15篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 10篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 26篇 |
1997年 | 25篇 |
1996年 | 36篇 |
1995年 | 19篇 |
1994年 | 15篇 |
1993年 | 19篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 17篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 10篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 7篇 |
1981年 | 13篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1973年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有539条查询结果,搜索用时 195 毫秒
101.
R E Brolin MD JH Gorman MD RC Gorman MD AJ Petschenik M D LJ Bradley MS RD HA Kenler PhD RP Cody Pb D 《Journal of gastrointestinal surgery》1998,2(5):436-442
Although iron, vltamm B12, and folate deficiency have been well documented after gastric bypass operations performed for morbid obesity, there is surprisingly
little information on either the natural course or the treatment of these deficiencies in Roux-en-Y gastric bypass (RYGB)
patients Durmg a l0-year period, a complete blood count and serum levels of iron, total iron-binding capacity, vltamin B12, and folate were obtained in 348 patients preoperatively and postoperatively at 6-month intervals for the first 2 years,
then annually thereafter The principal objectives of this study were to determine how readily patients who developed metabolic
deficiencies after Roux-en-Y gastric bypass responded to postoperative supplements of the deficient micronutrient and to learn
whether the risk of developmg these deficiencies decreases over time Hemoglobin and hematocrit levels were slgnificantly decreased
at all postoperative intervals in comparison to preoperative values Moreover, at each successive interval through 5 years,
hemoglobin and hematocrit were decreased signifiantly compared to the preceding interval Folate levels were significantly
increased compared to preoperative levels at all time intervals Iron and vltamin B12 levels were lower than preoperative measurements and remained relatively stable postoperatively Half of the low hemoglobin
levels were not associated with iron deficiency Taking multivltamin supplements resulted in a lower incidence of folate deficiency
but did not prevent iron or vitamin B12 deficiency Oral supplementation of iron and vitamin B12 corrected defiaencies in 43% and 81% of cases, respectively Folate deficiency was almost always corrected with multivitamins
alone No patient had symptoms that could be attributed to either vitamin B12 or folate deficiency Conversely, many patients had symptoms of iron deficiency and anenua Lack of symptoms of vitamin B12 and folate deficiency suggests that these deficiencies are not clinically important after RYGB Conversely, iron deficiency
and anemia are potentially serious problems after RYGB, particularly in younger women Hence we recommend prophylactic oral
iron supplements to premenopausal women who undergo RYGB 相似文献
102.
Marcelo A Pinto Marcio F Chedid Leo Sekine re P Schmidt Rodrigo P Capra Carolina Prediger Jo o E Prediger Tomaz JM Grezzana-Filho Cleber RP Kruel 《World journal of gastrointestinal surgery》2019,11(1):11-18
Liver transplant(LT) is the primary treatment for patients with end-stage liver disease. About 25000 LTs are performed annually in the world. The potential for intraoperative bleeding is quite variable. However, massive bleeding is common and requires blood transfusion. Allogeneic blood transfusion has an immunosuppressive effect and an impact on recipient survival, in addition to the risk of transmission of viral infections and transfusion errors, among others.Techniques to prevent excessive bleeding or to use autologous blood have been proposed to minimize the negative effects of allogeneic blood transfusion.Intraoperative reinfusion of autologous blood is possible through previous selfdonation or blood collected during the operation. However, LT does not normally allow autologous transfusion by prior self-donation. Hence, using autologous blood collected intraoperatively is the most feasible option. The use of intraoperative blood salvage autotransfusion(IBSA) minimizes the perioperative use of allogeneic blood, preventing negative transfusion effects without negatively impacting other clinical outcomes. The use of IBSA in patients with cancer is still a matter of debate due to the theoretical risk of reinfusion of tumor cells. However, studies have demonstrated the safety of IBSA in several surgical procedures, including LT for hepatocellular carcinoma. Considering the literature available to date, we can state that IBSA should be routinely used in LT, both in patients with cancer and in patients with benign diseases. 相似文献
103.
VS Gurunadh A Banarji S Patyal AK Upadhyay TS Ahluwalia RP Gupta M Bhaduria 《Medical Journal Armed Forces India》2010,66(2):125-128
Background
Vitreous substitutes presently in use for intraoperative tamponade are perfluorocarbon liquids (PFCL) and for post operative tamponade are silicon oil (SO), sulphur hexafluoride (SF6) and perfluorocarbon gas (PFC). Several factors are important for a thorough understanding of each of these vitreous substitutes. The absorption or necessity for removal, indications for use (including clinical studies and special surgical methods), additives and complications of use have to be considered.Methods
Three port standard pars plana vitrectomy was performed in 60 consecutive cases requiring intra-vitreal intervention. PFCL was used intra-operatively in 30 cases (PFCL group and X group). The eyes were implanted with SO (silicon oil subgroup), PFC (C3F8 sub-group) and SF6 (SF6 sub-group) in twenty cases each. Apart from best corrected visual acuity (BCVA), the retinal status and the longevity of gas when used, changes and reaction in both the anterior and posterior segments were noted.Result
The difference of postoperative BCVA in the PFCL and non-PFCL groups was statistically significant with p < 0.001. In both the PFCL and non-PFCL groups the difference between preoperative and postoperative BCVA was statistically significant with p < 0.0001. All three vitreous substitutes studied are effective given the case where they had been utilised.Conclusion
PFCL is invaluable in the management of complicated retinal detachment (RD). Where a vitreous microsurgery is indicated, the visual outcome is good. SF6 is useful for short-term tamponade. Silicon oil and C3F8 are useful for longer tamponade.Key Words: Tamponade, Perfluorocarbon liquids, Silicon oil, Sulphur hexafluoride, Perfluorocarbon gas, Retinal detachment 相似文献104.
105.
R. Mahanta A. Gogoi P. N. B. Chaudhury S. Roy I. K. Bhattacharyya P. Sharma 《Journal of obstetrics and gynaecology of India》2012,62(5):546-550
Introduction
Oxidative stress is a common pathology seen in approximately half of all infertile men. In a normal situation, the seminal plasma contains antioxidant mechanisms which are likely to quench these reactive oxygen species. However, during infertility complications these antioxidant mechanisms may downplay and create a situation which is called oxidative stress.Objective
The aim of the present study was to assess the levels of lipid peroxide (LPO), protein peroxide (PPO) and activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPX) in blood and semen samples of an infertile male population from North-East India.Method
We measured LPO, PPO, SOD and GPX in a total of 50 infertile individuals. For the study 20 fertile donors served as the control group.Result
Patients with male factor infertility had significantly higher LPO and PPO levels (60.84 ± 3.55 and 72.84 ± 3.66; P < 0.001) compared with controls (40.20 ± 4.33 and 59.93 ± 5.24) in blood. In semen also, the same trend was found with significantly higher LPO and PPO levels (200.27 ± 6.25 and 149.80 ± 11.47; P < 0.001) compared with controls (116.51 ± 5.49 and 59.10 ± 4.62). The SOD and GPX enzymes in blood (3.40 ± 1.06 and 0.16 ± 0.01; P < 0.001) and in semen (2.42 ± 1.32 and 0.24 ± 0.015; P < 0.001) showed a significantly lower activity when compared with their respective controls (4.85 ± 0.78; 0.36 ± 0.05 and 4.24 ± 0.89; 0.65 ± 0.03). The SOD and GPX activity when compared with the LPO and PPO values, showed a positive correlation.Conclusion
We conclude that oxidative stress is associated with male factor infertility. This assessment may help in the treatment of this male infertility by suitable antioxidants. 相似文献106.
107.
O Al‐Saeed M Ismail RP Athyal M Rudwan S Khafajee 《Journal of Medical Imaging and Radiation Oncology》2009,53(4):366-372
T1‐weighted fluid‐attenuated inversion recovery (FLAIR) sequence is a relatively new pulse sequence for intracranial MR imaging. This study was performed to compare the image quality of T1‐weighted FLAIR with the T1‐weighted FSE sequence. Twenty patients with brain lesions underwent T1‐weighted fast spin‐echo (FSE) and T1‐weighted FLAIR during the same imaging session. Four quantitative and three qualitative criteria were used to compare the two sequences after contrast. Two of four quantitative criteria pertained to lesion characteristics: lesion to white matter (WM) contrast‐to‐noise ratio (CNR) and lesion to cerebrospinal fluid (CSF) CNR, and two related to signals from normal tissue: grey matter to WM CNR and WM to CSF CNR. The three qualitative criteria were conspicuousness of the lesion, the presence of image artefacts and the overall image contrast. Both T1‐weighted FSE and FLAIR images were effective in demonstrating lesions. Image contrast was superior in T1‐weighted FLAIR images with significantly improved grey matter‐WM CNRs and CSF‐WM CNRs. The overall image contrast was judged to be superior on T1‐weighted FLAIR images compared with T1‐weighted FSE images by all neuroradiologists. Two of three reviewers considered that the FLAIR images had slightly increased imaging artefacts that, however, did not interfere with image interpretation. T1‐weighted FLAIR imaging provides improved lesion‐to‐background and grey to WM contrast‐to‐noise ratios. Superior conspicuity of lesions and overall image contrast is obtained in comparable acquisition times. These indicate an important role for T1‐weighted FLAIR in intracranial imaging and highlight its advantage over the more widely practiced T1‐weighted FSE sequence. 相似文献
108.
敏定偶用于35岁以上妇女的疗效、安全性和周期控制 总被引:11,自引:0,他引:11
<正> 口服避孕药在投放市场之初,应用于各种年龄段的妇女。然而资料显示早期使用的高剂量口服避孕药会增加心肌梗塞的发病率;在1975年,美国食品药物管理局(FDA)不建议40岁以上的妇女服用避孕药,对30岁以上的吸烟妇女建议她们要么停止吸烟要么改换避孕方式。随着研究的进一步深入及低剂量口服避孕药的问市,已证实任何年龄的非吸烟 相似文献
109.
Biliary decompression: an institutional comparison of percutaneous and endoscopic methods 总被引:1,自引:0,他引:1
Endoscopically performed biliary drainage (EPBD) is now an alternative to percutaneous biliary drainage. The morbidity, mortality, and survival statistics of 97 patients with obstructive jaundice who had undergone percutaneous transhepatic biliary drainage (PTBD) and surgery, PTBD alone, EPBD and surgery, or EPBD alone were compared. Overall, the EPBD group had fewer complications and lower mortality than the other groups. When palliative treatment of patients with malignancies was compared, the complication rates associated with EPBD and PTBD were similar; however, mortality was lower with EPBD. No negative effect on survival was found with EPBD. In addition, EPBD offered several additional advantages over PTBD, including fewer bleeding complications, better patient acceptance, and avoidance of external catheter care. EPBD should be considered as a viable alternative to PTBD. Additional studies are needed to determine whether it is to be considered the initial drainage procedure of choice in patients with obstructive jaundice. 相似文献
110.
R Baveja L K Bichille K J Coyaji A D Engineer M P Gogoi M N Hazra M Kochhar B C Lahiri M Manuel U K Nanda 《Contraception》1989,39(1):37-52
A total of 1905 subjects were randomly allocated to four types of intrauterine devices (IUDs) and were observed for 45,683 woman-months of use. While no method failure was observed with levonorgestrel (LNG) IUD, 11 women became pregnant with other devices; 4 with Copper T 380Ag, 1 with Copper T 220C, and 6 while using Copper T 200B, indicating method failure rates of 1.0, 0.3 and 1.6, respectively, at 36 months of use. These rates were within acceptable range. Continuation rates were significantly lower with LNG IUD (74.5, 58.7, 38.8 at 1 year, 2 years and 3 years, respectively) as compared to other copper devices, which ranged between 82.4 to 84.4 at 1 year, 66.6 to 69.9 at 2 years and 45.4 to 50.4 at 3 years. The difference in continuation rates was mainly due to menstrual disturbances (e.g. amenorrhoea, irregular bleeding) which were higher with LNG IUD (27.9 per 100 users) as compared to the copper devices (13.4-15.4 per 100 users) at 36 months of use. The risk of expulsion ranged between 8.3 to 10.6 per 100 users and was comparable for all the devices. The observations from the present study based on 36 months of experience with different intrauterine devices do not indicate the need to replace CuT 200, the device currently in use in the National Programme. 相似文献