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   4457篇
  免费   152篇
  国内免费   31篇
耳鼻咽喉   20篇
儿科学   62篇
妇产科学   59篇
基础医学   543篇
口腔科学   169篇
临床医学   265篇
内科学   1039篇
皮肤病学   29篇
神经病学   217篇
特种医学   138篇
外科学   1253篇
综合类   11篇
预防医学   60篇
眼科学   58篇
药学   283篇
中国医学   8篇
肿瘤学   426篇
  2023年   21篇
  2022年   54篇
  2021年   86篇
  2020年   30篇
  2019年   55篇
  2018年   80篇
  2017年   63篇
  2016年   79篇
  2015年   84篇
  2014年   120篇
  2013年   155篇
  2012年   243篇
  2011年   266篇
  2010年   172篇
  2009年   128篇
  2008年   256篇
  2007年   237篇
  2006年   246篇
  2005年   247篇
  2004年   267篇
  2003年   271篇
  2002年   243篇
  2001年   99篇
  2000年   96篇
  1999年   95篇
  1998年   55篇
  1997年   41篇
  1996年   57篇
  1995年   46篇
  1994年   39篇
  1993年   25篇
  1992年   45篇
  1991年   57篇
  1990年   57篇
  1989年   49篇
  1988年   52篇
  1987年   70篇
  1986年   34篇
  1985年   44篇
  1984年   37篇
  1983年   34篇
  1982年   24篇
  1981年   13篇
  1979年   18篇
  1978年   13篇
  1974年   16篇
  1973年   11篇
  1972年   19篇
  1971年   12篇
  1968年   12篇
排序方式: 共有4640条查询结果,搜索用时 15 毫秒
1.
We investigated effects of total body hyperthermia (TBH) on endocrine and hemodynamic responses. A total of five treatments were performed in five patients with gastric cancer under neuroleptanesthesia with morphine followed by 0.2 to 0.4% enflurane. TBH was extracorporeally induced with veno-venous shunt incorporating with heat exchanger to keep their temperature between 41.5 degrees C and 42.0 degrees C for three hours. The patients were administered angiotensin to maintain tumor blood flow. Lactated Ringer's solution was administered at the rate of 10 to 15 ml.kg-1.hr-1 for five hours. Plasma cortisol levels decreased significantly to about one third of the control value after heating and the levels recovered to the control value after cooling. Plasma norepinephrine level increased significantly to about 7 to 9 times the control value following TBH, but this hormonal response was insufficient to reveal marked direct hemodynamic effects. The magnitude of fall in SVR was more significant in spite of the administration of angiotensin. Cardiac index increased significantly to about 2.0 to 2.6 fold of control value, but mean arterial blood pressure (MAP) decreased significantly to about two thirds to four fifths of the control value. Morphine relieved the hormonal response in ACTH and cortisol strongly, but morphine suppressed hemodynamics by decreasing SVR. Neither norepinephrine released from sympathetic nerve endings nor even 50 to 200 ng.kg-1.min-1 of angiotensin administered failed to restore SVR or MAP during hyperthermia.  相似文献   
2.
We report anesthetic management of a 20-year-old male patient with cerebral palsy who underwent an operation for retinal detachment of the left eye. Induction and maintenance of anesthesia were smoothly done with inhalation of 1-5% sevoflurane with nitrous oxide and oxygen. Emergence of anesthesia was also smooth except for slight and transient excitement. Anesthetic management of a patient with cerebral palsy was also discussed.  相似文献   
3.
Y Matsuki  K Suzuki  M Hara  A Kitani  T Hirose  M Harigai  M Kawakami  N Tanaka  M Kawagoe  H Nakamura 《Ryūmachi》1992,32(2):154-9; discussion 159-62
Arterial thrombosis is one of the major symptoms of antiphospholipid syndrome (APS). However, thrombosis in a primary branch of the aorta has rarely been reported in APS. We report here a case of APS complicated by thromboses in both the left subclavian artery and the left external iliac vein. A 32-year-old woman was admitted in May, 1990 complaining of no pulse in the left superficial arteries (e.g., left radial artery) for the past 5 years and acute swelling of the left lower extremity. A left ascending phlebography showed an occlusion of the external iliac vein and arteriography revealed obstruction in the left subclavian artery. Collateral circulations were developed at the site of each thrombus. Clotting and immunological studies revealed a prolonged APTT, a high titer of anticardiolipin antibody and lupus anticoagulant positive. We ruled out various diseases and clinical risk factors predisposing to both arterial and venous thromboses. Accordingly, we concluded that both thromboses were based on APS. Following treatment with anticoagulants, aspirin and corticosteroid, the swelling of her left thigh was diminished and the antibody titer was decreased within 3 months.  相似文献   
4.
Magnetic resonance cholangiopancreatography (MRCP) was performed in 35 patients to evaluate the feasibility of its use as a postsurgical imaging technique after resection of the pancreas. The surgical procedures performed were: pancreatoduodenectomy in 22 patients, segmental pancreatectomy in 1, distal pancreatectomy in 7, and pyroluspreserving pancreatoduodenectomy in 5. The pancreatic duct was shown in its entirety in 24 of the 35 patients (68.6%) and was partially visualized in 8 patients (22.9%), but the intrahepatic and extrahepatic bile ducts were visualized completely in all patients. Furthermore, MRCP was able to demonstrate lesions in 3 of 6 patients who had shown clinical evidence of recurrence. The visualization of the pancreatic and bile duct system was satisfactory despite anatomical changes brought about by resection of the pancreas. Thus, we conclude that MRCP is an appropriate follow-up screening test for patients with suspected abnormalities of the biliary and pancreatic duct system.  相似文献   
5.
Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were measured in a mild case of dyssegmental dysplasia. X-ray pictures of a female baby born vaginally at 39 weeks of gestation showed short, bent, dumbbell-shaped long bones of the limbs and profound dyssegmental ossification in the spine, findings characteristic of dyssegmental dysplasia. When the levels of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured, the levels of MMP-2 and TIMP-1 were significantly reduced. This case might provide a clue to disclose the etiology of dyssegmental dysplasia.  相似文献   
6.
In order to investigate the influence of respiratory frequency in the measurement of specific airway conductance (sGaw) during non-panting breathing, we examined specific airway conductance using a body plethysmograph (BX-82, Minato) in 20 stable pulmonary emphysema patients and 19 normal control subjects. Our body plethysmograph device can measure sGaw automatically without panting by making various corrections using a 16-bit microcomputer. We measured sGaw first at a flow of 0.5 L/sec during both inspiratory and expiratory ventilatory phases, then the respiratory frequency was changed from 0.5 to 1.0, 1.5 and 2.0 Hz. In normal control subjects sGaw, tidal volume and mouth flow significantly changed by increasing respiratory frequency, and there was a significant correlation between sGaw and mouth flow. In pulmonary emphysema patients, tidal volume decreased significantly by increasing respiratory frequency, and there was a significant correlation between sGaw and tidal volume, but sGaw and mouth flow did not change significantly by increasing respiratory frequency. These results suggest that specific airway conductance is influenced by respiratory frequency, possibly due to the change in tidal volume and mouth flow. It is necessary to standardize respiratory frequencies and mouth flows in the measurement of specific airway conductance during non-panting breathing.  相似文献   
7.
OBJECTIVE: Many phase II trials have shown that preoperative chemotherapy for lung cancer is feasible but associated with postoperative morbidity and mortality. However, little is known about the effect of preoperative chemotherapy on surgical stress and postoperative complications associated with surgical intervention. We evaluated the effect of preoperative chemotherapy on perioperative inflammatory cytokine production as a surgical stress marker. METHODS: The study group comprised 38 patients undergoing anatomical lung resection and mediastinal nodal dissection for clinical stage IB/II non-small cell lung cancer during the period October 2001-December 2003. Nineteen patients received a single cycle of cisplatin (80 mg/m(2)) and docetaxel (60 mg/m(2)) chemotherapy prior to surgery (neoadjuvant group), and 19 patients underwent surgery without any previous chemotherapy (control group). White blood cell and neutrophil counts and serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), and granulocyte colony-stimulating factor (GCSF) were determined before surgery and on postoperative days 1 and 3. Postoperative complications were reviewed. Differences were assessed by repeated analysis of variance. RESULTS: Serum concentrations of IL-6 and GCSF rose significantly on postoperative days 1 and 3 in the neoadjuvant group in comparison to concentrations in the control group, but white blood cell count, neutrophil count, and CRP did not differ between the groups. No major complication occurred in either group. CONCLUSIONS: A single cycle of cisplatin and docetaxel chemotherapy followed by surgery can exacerbate overproduction of inflammatory cytokines during the perioperative period in lung cancer patients.  相似文献   
8.
BACKGROUND: A new electronic mesh nebulizer, eMotion is known to have higher performance compared to conventional nebulizers. However, there are some concerns about whether too much delivered dose might cause side effects with higher frequency. METHODS: To evaluate the safety and usefulness of the nebulizer, we measured changes in heart rates and lung functions of 73 asthmatic children when they inhaled 1 microg/kg of procaterol with eMotion or a conventional nebulizer, Junior BOY. RESULTS: In 34 children with mild asthma exacerbation, physical findings, lung function and transcutaneous oxygen saturation levels were improved after inhalation using both nebulizers. No adverse effects including significant increase of heart rate were found. Improvements in the rates of the parameters were comparable. When response to beta2-agonist inhalation was checked in 39 children in stable condition, similar degrees of improvement in lung function were observed, and heart rates did not change after inhalation with either nebulizers. CONCLUSIONS: Safety and efficacy was comparable between eMotion and a conventional nebulizer when it was used to administer beta2-agonists in asthmatic children. However, from the fact that eMotion needs only 3-4 minutes to inhale 2 mL solution, eMotion could be more useful for most children who usually do not prefer longer inhalation time with conventional compressor nebulizers.  相似文献   
9.
Endobronchial aspergillosis or actinomycosis associated with broncholithiasis is extremely rare. Here, we describe two cases of endobronchial aspergillosis and actinomycosis associated with broncholithiasis. The patients underwent pulmonary resection due to massive hemoptysis. These cases reveal that a bronchiolith can potentially induce endobronchial fungal or bacterial infection, even in immunocompetent patients.  相似文献   
10.
The purpose of this study is to evaluate the relationship between the magnitude of knee laxity and posterior instability at different knee flexion angles and clinical disability in isolated posterior cruciate ligament (PCL) deficient patients. Knee laxity at 20° and 70° of knee flexion were evaluated using KT-2000 arthrometer, and the posterior instability at 20°, 45° and 90° of flexion were evaluated using stress radiography. We assessed the differences in the knee laxity and the tibial translation between isolated PCL deficient knees and normal knees, and between the patients with giving-way during activities of daily living (ADL) and without giving-way. There were statistical differences in the knee laxity and the tibial translation at all knee flexion angles between the PCL deficient knees and normal knees. The magnitude of the knee laxity at 20° of flexion measured with KT-2000 arthrometer was significantly larger in the patients with giving-way than those in the patients without giving-way although there was no significant difference in the tibial translation at 70° between the two groups. The tibial translation in both medial and lateral compartments at 20° and 45° measured with stress radiography were significantly larger in the patients with giving-way than those in the patients without giving-way although there was not significant difference at 90° between the two groups. These results suggested that the magnitude of the knee laxity and the posterior tibial translation at shallow knee flexion angles would be related to giving-way during ADL in isolated PCL deficient patients.  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