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   2177篇
  免费   116篇
  国内免费   5篇
耳鼻咽喉   6篇
儿科学   99篇
妇产科学   73篇
基础医学   177篇
口腔科学   192篇
临床医学   132篇
内科学   726篇
皮肤病学   113篇
神经病学   146篇
特种医学   49篇
外科学   247篇
综合类   45篇
一般理论   2篇
预防医学   69篇
眼科学   28篇
药学   93篇
中国医学   7篇
肿瘤学   94篇
  2023年   12篇
  2022年   31篇
  2021年   43篇
  2020年   26篇
  2019年   33篇
  2018年   35篇
  2017年   38篇
  2016年   42篇
  2015年   66篇
  2014年   82篇
  2013年   103篇
  2012年   137篇
  2011年   149篇
  2010年   101篇
  2009年   73篇
  2008年   94篇
  2007年   99篇
  2006年   103篇
  2005年   103篇
  2004年   118篇
  2003年   89篇
  2002年   63篇
  2001年   51篇
  2000年   67篇
  1999年   50篇
  1998年   20篇
  1997年   14篇
  1996年   13篇
  1995年   9篇
  1994年   16篇
  1993年   6篇
  1992年   35篇
  1991年   32篇
  1990年   48篇
  1989年   28篇
  1988年   26篇
  1987年   29篇
  1986年   21篇
  1985年   19篇
  1984年   18篇
  1983年   11篇
  1982年   19篇
  1981年   7篇
  1979年   15篇
  1978年   12篇
  1977年   13篇
  1975年   11篇
  1973年   9篇
  1972年   8篇
  1969年   18篇
排序方式: 共有2298条查询结果,搜索用时 15 毫秒
11.
Cardiomyopathy refers to a set of diseases that are characterized by myocardial dysfunction. Classically, two-dimensional echocardiography has been used in the diagnosis of these disorders and to help guide their management. Three-dimensional transthoracic echocardiography is now increasingly being used in the diagnosis, management, and prognostication of intrinsic cardiomyopathies. In this article, we summarize the available data on the use of three-dimensional transthoracic echocardiography in various forms of intrinsic cardiomyopathy as well as some of its advantages over traditional two-dimensional transthoracic echocardiography. (Echocardiography 2012;29:76-87)  相似文献   
12.
13.
Erosion of a retained surgical sponge into the intestine is an unusual occurrence and may make its appearance months or years later. The demonstration of a distended bowel by the barium-impregnated mass with multiple polypoidal filling defects in a patient who has undergone previous laparotomy should lead the physician to suspect a retained surgical sponge. Surgical intervention is rewarding.  相似文献   
14.
15.
The role of in situ decompression in patients with severe ulnar nerve compression is still controversial. Thirty patients with severe ulnar nerve compression confirmed clinically and electrophysiologically underwent simple decompression. The mean age of the patients was 58 (range 26-87) years. Through incisions ≤4?cm the nerves were fully visualized and decompressed. Outcome was measured prospectively using Modified Bishop's score (BS), grip and pinch strengths and two-point discrimination (2PD). Significant improvement in power (p?=?0.01) and pinch grip (p?=?0.001) was noted at 1 year. The grip strength continued to improve up to 1 year. According to the BS, 24 patients (80%) had good to excellent results at 1 year. Minimally invasive in situ decompression is technically simple, safe and gives good results in patients with severe nerve compression. The BS and 2PD were more reliable than grip strength in assessing these patients at follow-up.  相似文献   
16.
We retrospectively analysed 25 patients (27 hands) who had both clinical and electrophysiological confirmation of true recurrent carpal tunnel syndrome from January 2004 to December 2009. In all the patients, after releasing the nerve a vascularised fat pad flap was mobilised from the hypothenar region and sutured to the lateral cut end of flexor retinaculum. The patient characteristics, co-morbidities, duration of symptom, interval between first release and revision surgery and intra-operative findings were assessed against post-operative relief of pain, recovery of sensory and motor dysfunction. The average age of the patients was 58?years (43?C81) and the dominant hand was involved in 22 patients. Intra-operatively the nerve was compressed by scar tissue connecting the previously divided ends of the retinaculum in 18 and nine had scar tissue and fibrosis around the nerve. Following surgery 16 patients had complete recovery (asymptomatic at the first follow-up), eight had delayed recovery (partial recovery of symptoms at final follow-up) and three had a poorer outcome (persistence of preoperative symptoms at the final follow-up). The patients with delayed recovery/poorer outcome had a) Early recurrence; b) Diabetes mellitus; c) Obesity; d) Cervical spine problems; e) Involvement of non-dominant hand; and f) Intraoperative scar tissue and fibrosis. The hypothenar fat pad transposition flap provides a reliable source of vascularised local tissue that can be used in patients with recurrent carpal tunnel syndrome. The factors that were associated with poorer/delayed recovery were involvement of non-dominant hand, recurrence within a year from the previous surgery, intra-operatively scar tissue in the carpal tunnel and associated co-morbidities, like obesity diabetes mellitus and cervical spine problems.  相似文献   
17.
OBJECTIVE: To describe a case of left vagal nerve stimulation (VNS) resulting in immediate cessation of status epilepticus (SE) with good neurological outcome. CASE DESCRIPTION: A 30-year-old man with medically intractable seizures including episodes of SE was successfully treated using left VNS. After requiring discontinuation of phenytoin, valproic acid, carbamazepine, and topiramate because of severe allergic reactions resembling Stevens-Johnson syndrome, the patient required pentobarbital coma along with phenobarbital, tiagabine, and levetiracetam for seizure frequency reduction. He underwent left vagal nerve stimulator placement after nearly 9 days of barbiturate-induced coma, with stimulation initiated in the operating room. On the following day, electroencephalography revealed resolution of previously observed periodic lateral epileptiform discharges and the patient was free of seizures. Prestimulation seizure frequency was recorded at 59 times a day, with some seizures enduring 45 minutes despite barbiturate coma. Poststimulation, the patient has been free of seizures for 19 days and is presently taking only levetiracetam and phenobarbital, from which he continues to be successfully weaned without seizures. He is awake, alert, and can recall events leading up to his seizures, with good long-term memory and residual left upper extremity and lower extremity weakness. CONCLUSION: This case illustrates the role of left vagal stimulation in the treatment of SE and otherwise medically intractable seizures caused by allergic reactions. To our knowledge, this is the first case in the world literature for adults reporting cessation of SE after VNS. Another case with a similar improvement has been reported in the pediatric population.  相似文献   
18.
Nanda A  Vannemreddy P 《Surgical neurology》2002,58(1):13-9; discussion 19-20
BACKGROUND: The treatment of unruptured aneurysms (UA) remains controversial. Therefore, it has become necessary to define various prognostic indicators in the surgical treatment of unruptured aneurysms not associated with previously ruptured aneurysms. METHODS: During a 6-year period, 78 unruptured aneurysms were managed. The results of management were retrospectively reviewed to define the prognostic indicators. RESULTS: There were 104 patients with unruptured aneurysms who underwent surgical treatment. Seventy-five patients without previous subarachnoid hemorrhage (SAH) were selected for data analysis. Eighty-seven percent of the aneurysms were on the anterior circulation. The most common location was the middle cerebral artery (MCA) followed by the posterior communicating artery (PCom), ophthalmic artery, and anterior communicating artery (ACom). Six percent were found on the basilar artery. The mean size of aneurysms was 12.5 mm (range = 3-30 mm, SD = 7.4). At surgery, rupture of the aneurysm was encountered in eight cases with temporary control of the parent vessel being required in 31 procedures. In four cases, intraoperative angiography warranted clip reapplication. The Glasgow Outcome Scale (GOS) was used as an outcome measure. Surgical treatment resulted in good outcome (GOS 1) in 87% and 10.7% had fair outcome; 2.3% were in GOS 3 (severe disability) at 6 month follow-up. There was no mortality. Logistic regression identified significant relationships between GOS and intraoperative rupture (p < 0.0002), rupture and size (p < 0.003), and size and age (p < 0.01). CONCLUSIONS: Large size aneurysms were associated with intraoperative rupture, which had a strong correlation with poor outcome. Increased age showed a linear relationship with the size of the aneurysm. Overall results of treatment for UA are gratifying. There was no mortality. Early diagnosis and surgical extirpation of UA may reduce both intraoperative difficulties as well as poor outcome probability.  相似文献   
19.
BACKGROUND: The changes in microvascular permeability characteristic of postinjury inflammation and sepsis may involve dysfunctional regulatory mechanisms at the capillary level. Pericytes, positioned abluminal to microvascular endothelium may, by their contractility, contribute to this regulation. Reactive oxygen metabolites (ROMs), well-known participants in lung inflammation, may exert an effect on pericytes, leading to changes in permeability and adult respiratory distress syndrome. This study investigates the effect of ROMs and antioxidants in an established in vitro assay of pericyte contractility. METHODS: Rat lung pericytes were cultured on collagen gel matrices. After exposure to the ROMs, the surface area of the collagen disks was digitally quantified (an integrated measure of cellular contraction) at 10 and 30 minutes. The cells were exposed to hydrogen peroxide and pyrogallol at 10, 100, and 1,000 micromol/L. Antioxidant effects of catalase (100 micromol/L), superoxide dismutase (100 micromol/L), and pretreatment with vitamin E (1 mmol/L) were quantified. RESULTS: Hydrogen peroxide and pyrogallol induced concentration-dependent relaxation at 10 minutes. Conversely, concentration-dependent contraction was seen at 30 minutes. Catalase completely attenuated both responses, whereas superoxide dismutase had no effect. Vitamin E had no effect at 10 minutes but partially attenuated the contraction seen at 30 minutes. CONCLUSION: ROMs are capable of producing early relaxation and late contraction in cultured lung pericytes. Whereas catalase attenuates both responses, membrane-bound vitamin E only partially attenuates late contraction. This suggests two separate mechanisms: early physiologic relaxation through signaling pathways affecting actin/myosin tone, and late membrane damage causing contraction. Either pathway may cause dysfunction in pulmonary capillary fluid regulation.  相似文献   
20.
BACKGROUND: Osteoblastic metastases are commonly induced by prostate cancer. A canine prostate carcinoma xenograft (Ace-1) was developed and used to evaluate neoplastic prostate cell growth, metastasis, and effects on bone formation in nude mice. METHODS: Characteristics of the Ace-1 cells were evaluated with histopathology, radiography, and bioluminescent imaging (BLI). Immunohistochemistry and quantitative RT-PCR were used to evaluate the expression of factors important in the development of osteoblastic metastases. RESULTS: The Ace-1 cells were invasive and induced bone formation and destruction. Radiographs demonstrated a mixed osteoblastic/osteolytic reaction. Lung and lymph node metastases occurred in 30% of mice. The tumor cells expressed parathyroid hormone-related protein (PTHrP-141 isoform), cathepsin K, keratins 8/18, and vimentin, but not keratins 5/14, and were androgen receptor negative. Intracardiac (IC) injections resulted in metastases in vertebrae and long bones. CONCLUSIONS: The Ace-1 xenograft is a useful model for investigating the pathogenesis of prostate cancer invasion and mixed osteoblastic/osteolytic bone metastases.  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