全文获取类型
收费全文 | 3469篇 |
免费 | 179篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 165篇 |
妇产科学 | 133篇 |
基础医学 | 234篇 |
口腔科学 | 132篇 |
临床医学 | 328篇 |
内科学 | 840篇 |
皮肤病学 | 151篇 |
神经病学 | 214篇 |
特种医学 | 130篇 |
外科学 | 763篇 |
综合类 | 44篇 |
预防医学 | 73篇 |
眼科学 | 99篇 |
药学 | 121篇 |
中国医学 | 7篇 |
肿瘤学 | 156篇 |
出版年
2023年 | 35篇 |
2022年 | 59篇 |
2021年 | 89篇 |
2020年 | 71篇 |
2019年 | 74篇 |
2018年 | 113篇 |
2017年 | 83篇 |
2016年 | 134篇 |
2015年 | 127篇 |
2014年 | 140篇 |
2013年 | 211篇 |
2012年 | 258篇 |
2011年 | 257篇 |
2010年 | 149篇 |
2009年 | 114篇 |
2008年 | 249篇 |
2007年 | 252篇 |
2006年 | 226篇 |
2005年 | 218篇 |
2004年 | 176篇 |
2003年 | 161篇 |
2002年 | 136篇 |
2001年 | 75篇 |
2000年 | 44篇 |
1999年 | 43篇 |
1998年 | 17篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1967年 | 6篇 |
1966年 | 3篇 |
1909年 | 2篇 |
排序方式: 共有3669条查询结果,搜索用时 15 毫秒
21.
22.
23.
BACKGROUND: Intrathecal neostigmine produces analgesia but also nausea, limiting its utility. In contrast, epidural administration of neostigmine has been suggested to produce postoperative analgesia without nausea in nonpregnant patients. The purpose of this study was to examine the dose range for efficacy and side effects of epidural neostigmine in women at cesarean delivery receiving combined spinal-epidural anesthesia. METHODS: After institutional approval and informed consent, 80 patients for elective cesarean delivery were given combined spinal-epidural anesthesia with 8 mg hyperbaric bupivacaine plus 10 microg fentanyl. Patients were randomized to receive either saline or 75, 150, or 300 microg neostigmine (n = 20 per group) in 10 ml saline after cord clamping. Pain, morphine consumption, and side effects were monitored for 24 h. RESULTS: Global pain assessment for the first 24 h was reduced from 5.4 +/- 0.2 in the saline group to 3.0-3.5 +/- 0.3 in the neostigmine groups, dose independently. Correspondingly, global satisfaction with neostigmine was also improved (P < 0.05). Nausea and morphine consumption were similar among groups. Intraoperative shivering and sedation were increased in the 300-microg neostigmine group only (P < 0.05), and postoperative sedation was increased by neostigmine in a dose-independent fashion (P < 0.05). CONCLUSIONS: Epidural neostigmine produced modest analgesia in women after cesarean delivery. In contrast with previous reports, which focused primarily on nausea, these data suggest that epidural neostigmine can also produce mild sedation for several hours. These data suggest a limited role for single bolus-administration epidural neostigmine for analgesia after cesarean delivery. They also support future study of epidural neostigmine for obstetric analgesia. 相似文献
24.
Computed tomography features in malignant pleural mesothelioma and other commonly seen pleural diseases. 总被引:4,自引:0,他引:4
Muzaffer Metintas Irfan Ucgun Osman Elbek Sinan Erginel Selma Metintas Mustafa Kolsuz Emel Harmanci Fusun Alatas Gunnar Hillerdal Ragip Ozkan Tamer Kaya 《European journal of radiology》2002,41(1):1-9
OBJECTIVE: To investigate the computed tomography (CT) features of malignant pleural mesothelioma (MPM) cases, comparing them to those in other malignant and benign pleural diseases. MATERIALS AND METHODS: We reviewed the CT findings of 215 patients; 99 with MPM, 39 with metastatic pleural disease (MPD), and 77 with benign pleural disease. The findings were evaluated in univariate and multivariate analysis for differentiation of pleural diseases. RESULTS: In patients with MPM, the most common CT features were circumferential lung encasement by multiple nodules (28%); pleural thickening with irregular pleuropulmonary margins (26%); and pleural thickening with superimposed nodules (20%). In the majority (70%) of cases, there was rind-like extension of tumor on the pleural surfaces. In multivariate analysis, the CT findings of "rind-like pleural involvement", "mediastinal pleural involvement", and "pleural thickness more than 1 cm" were independent findings in differentiating MPM from MPD with the sensitivity/specificity values of 70/85, 85/67, and 59/82, respectively. "Rind-like pleural involvement", "mediastinal pleural involvement", "pleural nodularity" and "pleural thickness more than 1 cm" were independent findings for differentiation of malignant pleural diseases (MPM+MPD) from benign pleural disease with the sensitivity/specificity values of 54/95, 70/83, 38/96, and 47/64, respectively. Invasion of thoracic structures such as pericardium, chest wall, diaphragm, mediastinum, with pleural disease and nodular involvement of fissures, was detected infrequently; however, since these invasions were not seen in benign pleural diseases, it was concluded these invasions, if detected on a CT scan, directly suggested malignancy. CONCLUSION: A patient has extremely high probability of malignant pleural disease if one or more of these CT findings are found and the possibility of MPM is high. These findings may be important for patients in bad state or patients who do not want any invasive biopsy procedures. It is also possible to identify cases with a low probability of malignant disease. 相似文献
25.
PURPOSE: The aim of this study was to evaluate the changes in salivary gland function in patients with chronic renal failure (CRF) undergoing hemodialysis. METHODS: The group consisted of 23 patients with CRF (13 female, 10 male; mean age: 40 +/- 13 yr) and 14 healthy control subjects (mean age: 40 +/- 13 yr). All underwent dynamic salivary gland scintigraphy with gustatory stimulation. After intravenous administration of 99mTc pertechnetate, first, perfusion images at 2 seconds per frame were acquired for 1 minute, then dynamic images at 1 minute per frame were acquired for 45 minutes. At 30 minutes after injection, 10 ml lemon juice was given for 15 minutes as a gustatory stimulus. We obtained time-activity curves derived from regions of interest centered over the four major salivary glands. The following functional indices were calculated for each gland: the time of maximum radioactivity (Tmax) for the prestimulated period, the time of minimum radioactivity (Tmin), as an indicator of velocity of secretion after stimulation, and the Lem E5% value as an indicator of the secretion function. RESULTS: When the patients with CRF undergoing hemodialysis were compared to the controls, there were statistically significant differences in Tmax, Tmin and Lem E5% values for bilateral parotid glands, and Tmin values for bilateral submandibular glands (p < 0.05), there were no statistically significant differences in Tmax and Lem E5% values for bilateral submandibular glands. There were also significant differences in Tmax and Lem E5% values for bilateral parotid glands between mild oral problems and severe oral problems in patients with CRF (undergoing hemodialysis). CONCLUSION: In this study, prolonged Tmax and Tmin values, and decreased Lem E5% values for parotid glands and prolonged Tmin values for submandibular glands on salivary scintigraphy pointed out decreased parenchymatous and excretory function in patients with CRF undergoing hemodialysis. 相似文献
26.
PURPOSE: In this prospective study we aimed to describe our new technique; dehydrated human dura mater as an interposition graft in patients undergoing benign vesicovaginal fistula repair (VVF). PATIENTS AND METHODS: Eleven patients with benign VVFs aged 38-73 years were operated with dura mater interposition technique at our institution between July 1996 and February 2002. In all patients fistula were secondary to abdominal hysterectomies with benign diseases and two had undergone previous transvaginal surgery. Patients were operated 8-15 (mean 12) weeks after previous surgery. A suprapubic cystotomy was performed and the fistula was not excised. The bladder wall is widely dissected from underlying vagina. Dura-mater was placed over the vaginal suture line to close the fistulous tract, cytostomy was inserted and the bladder was closed. An 18 F Foley catheter was left in the bladder for 5 days. A successful repair is defined as no leakage by cystogram at 14 days postoperatively and completely dry by patient report. RESULTS: An overall success rate of 100% was achieved in all patients. All patients remain dry at the follow-up which ranges from 7 to 60 (mean 26) mounts. Patients were discharged at 14 to 26 (mean 16) days postoperatively. No major complications or side effects were observed during the follow-up period. CONCLUSIONS: The use of human dura mater as an interposition graft in the treatment of vesicovaginal fistula is an alternative for VVF repairs because of its excellent tissue compability, stability, good elasticity and absorbability. 相似文献
27.
Gumus E Erdamar S Demirel G Horasanli K Ozmen G Miroglu C 《Urologia internationalis》2004,73(3):219-225
INTRODUCTION: Etiology of serum anti-p53 antibodies in bladder cancer patients is still unknown. In this study we evaluated the relationship between serum anti-p53 antibodies and microvessel density in bladder cancer patients. MATERIALS AND METHODS: Seventy-six patients with transitional cell carcinoma of the urinary bladder were assessed prospectively (18 Ta, 30 T1, 28 T2>or =). Serum anti-p53 antibodies were detected by enzyme-linked immunosorbent assay. Tumor p53 overexpression was assessed by immunohistochemical staining. Vessels were stained immunohistochemically using an antibody against platelet endothelial cell-adhesion molecule CD31. Spearman correlation test and t test were used for statistical analysis. RESULTS: Serum anti-p53 antibodies were positive in 25 (60%) of 41 tumor p53-positive patients. While the mean (SD, range) microvessel density was found to be 43 (7.59, 8-99) in patients who had positive serum anti-p53 antibodies, it was found to be 23 (4.53, 6-98) in patients who had negative serum anti-p53 antibodies. There was a good correlation between serum anti-p53 antibodies and microvessel density (p<0.05). No correlation was found between tumor p53 expression and microvessel density (p>0.05). CONCLUSIONS: We found that there is a significant correlation between the microvessel density and serum anti-p53 antibodies. This result may show the role of angiogenesis in the etiology of serum anti-p53 antibodies in bladder cancer patients. 相似文献
28.
N-acetylcysteine reduces lung reperfusion injury after deep hypothermia and total circulatory arrest 总被引:3,自引:0,他引:3
OBJECTIVE: We hypothesized that the use of N-acetylcysteine would ameliorate the lung reperfusion injury observed after deep hypothermia and total circulatory arrest (DHTSA). METHODS: Experiments were carried out on 12 adult mongrel dogs of either sex weighing 25 to 30 kg. The animals were randomly divided into two groups of six animals each. All animals were cooled to an esophageal temperature of 15 degrees C during 30 minutes and underwent 60 minutes of DHTSA, followed by the reinstitution of cardiopulmonary bypass (CPB) and rewarming. Before rewarming, while 100 mL physiologic saline solution was added into the pump in group I, 50 mg/kg N-acetylcysteine(NAC) was given in group II. Heart rate, mean arterial pressure, pulmonary arterial pressure, left atrial pressure, central venous pressure, and cardiac output were recorded. To measure lung tissue malondialdehyde (MDA), water content and polymorphonuclear leukocytes (PMNs) count, lung tissue samples were taken before CPB and after weaning CPB. In addition, alveolar-arterial oxygen difference (AaDO(2))()for tissue oxygenation was calculated by obtaining arterial blood gas samples. Dynamic lung compliance (DLC) was measured before CPB and after CPB. RESULTS: MDA levels before CPB of 44.2 +/- 3.9 nmol/g tissue rose to 76.6 +/- 5.6 nmol/g tissue after weaning CPB in group I (p = 0.004). In group II also, the MDA levels increased from 43.5 +/- 4.2 to 57.4 +/- 5.6 nmol MDA/g tissue after weaning CPB (p = 0.006). The MDA increase in group II after CPB was found to be significantly lower than in group I (p = 0.006). The wet-to-dry lung weight ratio in the NAC group was 5.1 +/- 0.2, significantly less than in the control group (5.9 +/- 0.3), (p = 0.004). AaDO(2) significantly increased in the group I and II (p = 0.002 and p = 0.002, respectively); this elevation in group I was significant than in group II (p = 0.044). In histopathological examination, it was observed that neutrophil counts in the lung parenchyma rose significantly after CPB in both groups (p < 0.001). The increase in group I was significantly larger than group II (p < 0.001). CONCLUSIONS: Results represented in our study indicate that addition of NAC into the pump after DHTSA can reduce lung reperfusion injury. 相似文献
29.
30.
Transcaval extension of the thymoma to the right atrium has very rarely been reported, and cardiopulmonary bypass is recommended for successful resection. An invasive thymoma with intravascular invasion of the superior vena cava, and the left innominate vein extending into the right atrium was presented. Intra-atrial extension was resected through a transient external shunt from the inferior vena cava to the main pulmonary artery. We discussed the feasibility of this surgical technique and possible advantages of cardiopulmonary bypass avoidance. 相似文献