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   40290篇
  免费   2142篇
  国内免费   121篇
耳鼻咽喉   469篇
儿科学   2387篇
妇产科学   757篇
基础医学   4989篇
口腔科学   1039篇
临床医学   2858篇
内科学   8165篇
皮肤病学   990篇
神经病学   2262篇
特种医学   979篇
外科学   5638篇
综合类   1401篇
一般理论   16篇
预防医学   2290篇
眼科学   1657篇
药学   3812篇
中国医学   298篇
肿瘤学   2546篇
  2023年   268篇
  2022年   730篇
  2021年   1313篇
  2020年   713篇
  2019年   981篇
  2018年   1177篇
  2017年   846篇
  2016年   1087篇
  2015年   1149篇
  2014年   1568篇
  2013年   2018篇
  2012年   2821篇
  2011年   2872篇
  2010年   1603篇
  2009年   1430篇
  2008年   2040篇
  2007年   2020篇
  2006年   1980篇
  2005年   1631篇
  2004年   1608篇
  2003年   1349篇
  2002年   1151篇
  2001年   843篇
  2000年   879篇
  1999年   758篇
  1998年   338篇
  1997年   235篇
  1996年   237篇
  1995年   230篇
  1994年   190篇
  1993年   162篇
  1992年   506篇
  1991年   413篇
  1990年   435篇
  1989年   401篇
  1988年   362篇
  1987年   363篇
  1986年   353篇
  1985年   328篇
  1984年   265篇
  1983年   221篇
  1979年   235篇
  1978年   157篇
  1977年   184篇
  1976年   144篇
  1975年   174篇
  1974年   182篇
  1973年   184篇
  1972年   173篇
  1971年   161篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.

INTRODUCTION

Accidental and unnoticed ingestion of foreign bodies are not very uncommon. Most of such foreign bodies pass through gastrointestinal tract uneventfully and only on rare instances cause obstruction and/or perforation.

PRESENTATION OF CASE

We are reporting a case in which a 45 yr old male presented to accident and emergency department of our institute with complaints of pain abdomen, greenish vomiting, abdominal distension, fever and non passage of flatus and stool following alcoholic binge 15 days back. On presentation tachycardia, hypotension, generalised abdominal tenderness and guarding were present. After initial resuscitation and investigation diagnosis of perforation peritonitis was made and emergency exploratory lapratomy was done and a single perforation with plastic foreign body protruding through it was found in jejunum 5 cm distal to duodeno-jejunal junction.

DISCUSSION

The majority of ingested FBs that reach the stomach pass uneventfully through the gastrointestinal tract. The majority of cases occur in children. Only 1% of patient of patients requires surgical intervention depending upon nature, size and shape of the foreign body.

CONCLUSION

Present case report intends to draw the attention towards possibility of intestinal obstruction and perforation by a single plastic foreign body. High index of suspicion is needed as this foreign body is not even radio-opaque and cannot be picked up in X-ray investigations. Also with increasing use of such plastic materials there are increased chances of such incidents.  相似文献   
993.

INTRODUCTION

Thrombosis of the inferior vena cava (IVC) is governed by Virchow''s triad of stasis of blood flow, endothelial damage and hypercoagulability. Causes may be secondary to malignancy, congenital anomalies or other infrequent events such as external compression. We present a case of external compression of the IVC leading to extensive thrombus burden secondary to a benign hepatic cyst.

PRESENTATION OF CASE

A 72 year old African American female presented to the emergency department with new onset shortness of breath, right lower extremity weakness and swelling. CT imaging demonstrated multiple hepatic cysts compressing the IVC, leading to extensive clot burden. Treatment with heparin drip was initiated without resolution of her symptoms. Transcatheter mechanical thrombectomy and tPA infusion was performed. After 24 h, swelling and weakness were nearly resolved. The patient was bridged to therapeutic low molecular weight heparin in preparation for surgery.

DISCUSSION

Management of IVC thrombosis has typically been with a heparin drip and transition to oral anticoagulants. Thrombolysis has been shown to promote complete clot lysis more often than compared to standard anticoagulant therapy. In addition, venous patency was better maintained.

CONCLUSION

We feel that the added benefit of short term effects of improved venous patency and long term benefits of less post thrombotic syndrome, catheter based tPA administration and mechanical thrombectomy for thrombus offers an adjuvant treatment in the setting of large clot burden refractory to standard treatment.  相似文献   
994.
Effective control and eventual eradication of malaria drives the imperative need for clinical development of a malaria vaccine. Asexual parasite forms are responsible for clinical disease and death while apathogenic gametocytes are responsible for transmission from man to mosquito. Vaccines that combine antigens from both stages may provide direct protection and indirect benefit by reducing the force of infection. We constructed a chimeric antigen composed of a fragment of the Plasmodium falciparum (Pf) glutamate-rich protein fused in frame to a correctly folded fragment of Pfs48/45. The chimera was produced in Lactococcus lactis and induced robust antibody responses in rodents to the individual components. Specific antibodies showed strong transmission blocking activity against multiple Pf-strains in the standard membrane feeding assay and functional activity against asexual stages in the antibody dependent cellular inhibition assay. The combined data provide a strong rationale for entering the next phase of clinical grade production and testing.  相似文献   
995.
Antipsychotic medications are the gold-standard treatment for schizophrenia, and are often prescribed for other mental conditions. However, the efficacy and side-effect profiles of these drugs are heterogeneous, with large interindividual variability. As a result, treatment selection remains a largely trial-and-error process, with many failed treatment regimens endured before finding a tolerable balance between symptom management and side effects. Much of the interindividual variability in response and side effects is due to genetic factors (heritability, h2~ 0.60-0.80). Pharmacogenetics is an emerging field that holds the potential to facilitate the selection of the best medication for a particular patient, based on his or her genetic information. In this review we discuss the most promising genetic markers of antipsychotic treatment outcomes, and present current translational research efforts that aim to bring these pharmacogenetic findings to the clinic in the near future.  相似文献   
996.
997.
998.
Introduction: Patients with hereditary neuropathy with liability to pressure palsies (HNPP) manifest with episodes of focal paresis when exposed to mechanical stress, although the basis for vulnerability to conduction block remains relatively unexplained. Methods: Axonal excitability techniques were utilized to provide insights into pathophysiological mechanisms in 13 HNPP patients, stimulating median motor and sensory axons at the wrist. Results: In HNPP, distal latencies were prolonged, and motor and sensory amplitudes were reduced. Threshold was increased. Depolarizing and hyperpolarizing electrotonus was greater, and resting current–threshold slope was reduced. There were greater threshold changes in superexcitability, and refractoriness was decreased. Conclusions: Taken together, excitability testing in patients with HNPP established axonal hyperpolarization in both motor and sensory axons that may be attributable to changes in nerve architecture. In turn, the hyperpolarized resting membrane potential in HNPP may be a major predisposing factor for development of conduction block with mechanical stresses. Muscle Nerve 49 : 858–865, 2014  相似文献   
999.

Purpose

Intracranial aneurysms in children are not as common as in adults and there are many differences in the etiology, demographic variables, aneurysm location, aneurysm morphological characteristics, clinical presentation, and outcome in pediatric and adult intracranial aneurysms.

Methods

All children (≤18 years) suffering from intracranial aneurysm managed at our center from July 2001 through June 2013 were included in the study, and the details of these patients were retrieved from the computerized database of our hospital.

Observations

A total of 62 pediatric patients were treated for 74 aneurysms during the study period and constituted 2.3 % of all intracranial aneurysms treated during the same period. The mean age at presentation was 13.5 years. Headache (82 %) was the commonest presenting feature; other symptoms included seizures (21 %), ictal loss of consciousness (27 %), and motor/cranial nerve deficits (22.6 %). Computed tomogram revealed subarachnoid hemorrhage in 58 % of patients. Eighty-two percent of aneurysms were in anterior circulation. Sixty-seven percent of aneurysms were complex aneurysms. Fifty-eight percent of patients underwent surgical intervention while 30 % underwent endovascular procedures. Twenty-one percent of the patients developed vasospasm. There was no postoperative mortality. Favorable outcome was seen in 72 % of the patients.

Conclusions

Pediatric intracranial aneurysms are uncommon as compared to in adult patients. Seizures and cranial nerve involvement are seen more often as the presenting features in children. Posterior circulation aneurysms are more common in children, as are the internal carotid artery bifurcation aneurysms. There is high incidence of giant, posttraumatic, and mycotic aneurysms in children.  相似文献   
1000.
Primary intra osseous venous malformation with involvement of nasal bone is a rare phenomenon. Nasal bone intraosseous venous malformation on a back ground of port wine stain of face has not been reported in the available literature. We report the very rare case of intraosseous venous malformation of left nasal bone developing on a background of port wine stain of face, its diagnosis, pathology, management and review of literature.KEY WORDS: Intraosseous venous malformation, nasal bone, port wine stain, sun burst appearance  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