首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1508篇
  免费   73篇
  国内免费   15篇
耳鼻咽喉   11篇
儿科学   32篇
妇产科学   7篇
基础医学   234篇
口腔科学   13篇
临床医学   75篇
内科学   413篇
皮肤病学   13篇
神经病学   141篇
特种医学   53篇
外科学   335篇
综合类   2篇
预防医学   27篇
眼科学   16篇
药学   67篇
中国医学   7篇
肿瘤学   150篇
  2023年   9篇
  2022年   22篇
  2021年   29篇
  2020年   15篇
  2019年   26篇
  2018年   33篇
  2017年   24篇
  2016年   26篇
  2015年   30篇
  2014年   39篇
  2013年   53篇
  2012年   80篇
  2011年   123篇
  2010年   67篇
  2009年   54篇
  2008年   110篇
  2007年   109篇
  2006年   113篇
  2005年   100篇
  2004年   116篇
  2003年   107篇
  2002年   97篇
  2001年   25篇
  2000年   24篇
  1999年   18篇
  1998年   28篇
  1997年   10篇
  1996年   16篇
  1995年   9篇
  1994年   6篇
  1993年   7篇
  1992年   10篇
  1991年   3篇
  1989年   3篇
  1988年   6篇
  1987年   3篇
  1986年   3篇
  1985年   4篇
  1983年   5篇
  1982年   4篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1978年   3篇
  1977年   2篇
  1976年   2篇
  1974年   2篇
  1973年   2篇
  1962年   2篇
  1961年   2篇
排序方式: 共有1596条查询结果,搜索用时 31 毫秒
71.
The prognosis for patients with decompensated hepatitis B virus (HBV) related liver cirrhosis (LC-B), especially for those with LC-B complicated with hepatocellular carcinoma (HCC), is poor. We investigated the effects of lamivudine in patients with decompensated LC-B, with and without HCC. Decompensated LC-B patients (n=55) with Child-Pugh classification scores (CPS) >7 points were enrolled. All were admitted to the hospitals of the authors between January 1997 and December 2004. Decompensated cases due to a severe exacerbation of hepatitis with CH-B and patients with HCC showing an extra hepatic metastasis or portal vein tumor thrombus were excluded. Some 19 cases (including 5 cases complicated with HCC at the start of therapy) were treated with lamivudine at 100 mg/day (L group), and 36 (including 7 cases with HCC at time of admittance) were treated without lamivudine (non-L group). The median of CPS points in the L group was higher than that of non-L group (11 points versus 9 points, p<0.02). Prothrombin time (%), albumin, ascites, CPS, and HBV-DNA quantity were each significantly improved after 6 months in the L group (p<0.05). A mutation in the YMDD motif was observed in 5 patients in the L group, however liver function did not deteriorate. Further, the survival rate was significantly higher in the L group (p<0.05). HCC was found in 3 L group and 4 non-L group patients during the study. In the L group, all patients complicated with HCC were treated repeatedly or until cured, whereas 91% of those in the non-L group could not be treated (p<0.01). Our results suggest that lamivudine is a useful and important therapy for patients with decompensated LC-B with and without HCC, as well as those who are restricted from having liver transplantation.  相似文献   
72.
BACKGROUND: Metastasis to regional lymph nodes from colon cancer is an important prognostic factor. In the TNM classification, node metastases are classified into three grades based on the number of metastatic nodes. In the Japanese General Rules for Clinical and Pathologic Studies on Cancer of the Colon, Rectum, and Anus (JGR), node metastases are classified into four grades based on the distribution of metastatic nodes. STUDY DESIGN: Based on the findings of node metastases in 164 patients with colon cancer obtained by the clearing method, node classifications by the JGR and TNM classifications were compared. RESULTS: The case distribution by the JGR grading was 41.5% in n (-), 29.3% in n1 (+), 18.3% in n2 (+), and 11.0% in n3 (+) disease. In the TNM classification, the distribution was 23.8% in pN1 and 34.8% in pN2 disease. The 5-year survival rate by the JGR was 98.4% in n (-), 74.3% in n1 (+), 51.2% in n2 (+), and 30.0% in n3 (+) disease; in TNM classification, this rate was 76.0% in pN1 and 45.0% in pN2 disease. CONCLUSIONS: In the classification of regional node metastases from colon cancer, the JGR classification showed a wider range in distribution and 5-year survival rate compared with the TNM system.  相似文献   
73.
A 6-year-old girl, who had received a ventriculoperitoneal (VP) shunt using the Codman-Hakim programmable valve system at age 3 months, presented with intractable seizures. Neuroimaging studies showed migration of the proximal part of the system, including the prechamber, into the cranium through the right frontal burr hole. Electroencephalography showed spike-and-wave complexes in the right hemisphere including the site of the migration. The ictus was resolved following revision surgery. The clinical findings suggested the seizures were due to irritation of the brain parenchyma by the migrated system. Proximal migration of a VP shunt may cause both shunt failure and additional focal symptoms.  相似文献   
74.
A 48-year-old woman was admitted to our institution complaining of headache and a 2-month history of blurred vision and increased urinary volume. T(1)-weighted magnetic resonance (MR) imaging with gadolinium showed a ring-enhanced mass lesion in the pituitary. Fluid-attenuated inversion recovery MR imaging showed high-intensity lesions in the optic nerves, hypothalamus, and thalamus. The histological diagnosis was pituitary abscess. The blurred vision was caused by inflammation, but not compression, of the optic nerves due to the pituitary abscess outside the hypophysis.  相似文献   
75.
Decompression illness (DCI) is a general term encompassing all pathological changes secondary to reduction of environmental pressure. This condition has two forms: decompression sickness (DCS) and arterial gas embolism (AGE) secondary to pulmonary barotrauma. Moreover, DCS is categorized as minor, such as limb and/or joint pains or skin rash (Type I), and serious, as in cardiopulmonary and/or central nervous system involvements (Type II). Cerebral and spinal injuries have been symptomatically classified into AGE and DCS. Brain scans of patients with AGE or DCS showed multiple cerebral infarctions in the terminal and/or border zones of the cerebral arteries. Brain involvements of patients in both AGE and DCS show no differences in neurological or neuro-radiological findings. From the neurological and radiological standpoint, it is therefore impossible to distinguish these two conditions. Despite established treatments for neurological DCI (both AGE and DCS), it is unclear whether US Navy treatment Table 6 is preferable to standard hyperbaric oxygen therapy such as 2.4 atmospheres pressure for 90 minutes. Japanese laws and regulations have peculiarities that permit air diving to 90 meters depth, but with explicit prohibition of the use of oxygen for decompression, albeit a limited use of mixed gas is permissible. Moreover, currently the health screening for hyperbaric workers does not include detailed examination of the cardiopulmonary or the central nervous system.  相似文献   
76.
OBJECT: Revascularization is an important component of treatment for complex aneurysms that require parent vessel occlusion, skull base tumors that involve major vessels, and certain ischemic diseases. In this study, the authors examined the microsurgical anatomy of cerebral revascularization in the anterior circulation by demonstrating various procedures for bypass surgery. METHODS: Twenty-five adult cadaveric specimens were studied, using 3 to 40 magnification, after the arteries and veins had been perfused with colored silicone. The microsurgical anatomy of cerebral revascularization in the anterior circulation was examined with the focus on the donor, recipient, and graft vessels. The techniques discussed in this paper include the superficial temporal artery (STA)-middle cerebral artery (MCA), middle meningeal artery (MMA)-MCA, and side-to-side anastomoses; short arterial and venous interposition grafting; and external carotid artery/internal carotid artery (ICA)-M2 and ICA-ICA bypasses. Bypass procedures for cerebral revascularization are divided into two categories depending on their flow volume: low-flow and high-flow bypasses. A low-flow bypass, such as the STA-MCA anastomosis, is used to cover a relatively small area, whereas a high-flow bypass, such as the ICA-ICA anastomosis, is used for larger areas. Cerebral revascularization techniques are also divided into two types depending on the graft materials: pedicled arterial grafts, such as STA and occipital artery grafts, and free venous or arterial grafts, which are usually saphenous vein and radial artery grafts. Pedicled arterial grafts are mainly used for low-flow bypasses, whereas venous or arterial grafts are used for high-flow bypasses. CONCLUSIONS: It is important to understand the methods of bypass procedures and to consider indications in which cerebral revascularization is needed.  相似文献   
77.
The PediPump is a new rotary dynamic ventricular assist device designed specifically for pediatric applications. Although it is capable of providing support for adults, the small size of the PediPump makes it suitable for newborn circulatory support while retaining excellent hemodynamics. Current and future development plans include: (1) determination of the basic engineering requirements for hardware and control logic, including design analysis for system sizing, evaluation of control concepts and bench testing of prototypes; (2) performance of preclinical anatomical fitting studies using computed tomography-based three-dimensional modeling; and, (3) evaluation with animal studies to provide characterization and reliability testing of the device.  相似文献   
78.
BACKGROUND: Acute blood pressure (BP) elevation and cardiac abnormalities are known to follow ischemic stroke. Brain natriuretic peptide (BNP), which is produced in response to such cardiovascular alterations, is expected to play a hemodynamic role. We measured plasma BNP concentrations in patients with cerebral infarction (CI) to determine the implications of BNP in acute ischemic stroke. METHODS: Eighty-eight patients with CI, 59 with essential hypertension, 44 with spontaneous intracerebral hemorrhage, 22 with asymptomatic atrial fibrillation (Af), and 20 age- and sex-matched healthy volunteers were recruited in the study. CI patients were divided into 2 subgroups either having Af (27 patients) or not (61 patients). BNP levels were repeatedly measured in 58 patients with CI. BNP levels were compared between ischemic subgroups categorized by size of infarction. Correlation was investigated between BNP levels and hemodynamic parameters. RESULTS: BNP levels in CI patients were significantly higher, but they decreased in the subacute period. BNP levels in CI patients without Af were correlated with mean arterial blood pressure (MAP) on admission or the degree of reduction in MAP at day 1, while in CI patients with Af BNP levels showed negative correlation with MAP on admission. Follow-up serum sodium levels in CI patients with Af were negatively correlated with BNP levels on admission. CONCLUSIONS: This study suggests the hemodynamic implications of BNP in acute ischemic patients.  相似文献   
79.
80.
This report details clinical and experimental studies of focal cortical dysplasia. The first part deals with 14 surgical cases of children with intractable epilepsy. At surgery, intraoperative electrocorticography was performed to localize the epileptic foci under neuroleptanalgesia. Thirteen patients showed epileptiform discharges on this preresection electrocorticography. All foci in noneloquent areas were resected. Patients who had undergone total lesionectomy with complete focus resection showed the most favorable postoperative results. However, the positive correlation between the intraoperative electrocorticographic findings and the pathologic classification of cortical dysplasia was not found in the present study. Nine patients have been seizure free with reduced medication and two patients have achieved worthwhile improvement. We conclude that intraoperative electrocorticography can improve the surgical outcome for intractable epilepsy by localizing epileptic foci for resection. The second part describes a kainic acid-induced experimental model of focal cortical dysplasia, which demonstrated not only the epileptic properties of the dysplasia but also the perilesional epileptogenicity. The findings supported the surgical results for the patients with focal cortical dysplasia.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号