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   1075篇
  免费   82篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   21篇
妇产科学   16篇
基础医学   190篇
口腔科学   14篇
临床医学   143篇
内科学   253篇
皮肤病学   16篇
神经病学   68篇
特种医学   12篇
外科学   179篇
综合类   21篇
一般理论   1篇
预防医学   85篇
眼科学   6篇
药学   81篇
中国医学   3篇
肿瘤学   44篇
  2023年   12篇
  2022年   2篇
  2021年   40篇
  2020年   26篇
  2019年   29篇
  2018年   39篇
  2017年   26篇
  2016年   16篇
  2015年   26篇
  2014年   42篇
  2013年   53篇
  2012年   73篇
  2011年   84篇
  2010年   34篇
  2009年   23篇
  2008年   70篇
  2007年   71篇
  2006年   62篇
  2005年   54篇
  2004年   61篇
  2003年   38篇
  2002年   45篇
  2001年   17篇
  2000年   25篇
  1999年   20篇
  1998年   17篇
  1997年   12篇
  1996年   11篇
  1995年   7篇
  1994年   6篇
  1993年   6篇
  1992年   10篇
  1991年   11篇
  1990年   8篇
  1989年   10篇
  1988年   10篇
  1987年   13篇
  1986年   5篇
  1985年   10篇
  1984年   3篇
  1983年   3篇
  1982年   2篇
  1981年   4篇
  1979年   2篇
  1976年   3篇
  1974年   4篇
  1971年   2篇
  1955年   2篇
  1935年   2篇
  1927年   1篇
排序方式: 共有1160条查询结果,搜索用时 31 毫秒
1.

Background  

A public hospital in New Mexico required collection of 50% of estimated costs prior to elective surgeries for self-pay patients. This study assesses the impact of this policy on access to elective surgical procedures.  相似文献   
2.
This paper reports the proceedings of the discussion panel assigned to look at clinical aspects of quality in emergency medicine. One of the seven stated objectives of the Academic Emergency Medicine consensus conference on quality in emergency medicine was to educate emergency physicians regarding quality measures and quality improvement as essential aspects of the practice of emergency medicine. Another topic of interest was a discussion of the value of information technology in facilitating quality care in the clinical practice of emergency medicine. It is important to note that this is not intended to be a comprehensive review of this extensive topic, but instead is designed to report the discussion that occurred at this session of the consensus conference.  相似文献   
3.
4.
BACKGROUND: Intrahepatic stones, though common in East Asia, are uncommon in India. There is paucity of data from India regarding the treatment and long-term outcome of patients with intrahepatic stones. METHODS: We retrospectively analyzed medical records of 35 patients with intrahepatic stones who had been treated surgically. Endoscopic biliary drainage had been used in patients who presented with acute cholangitis. Intraoperative stone clearance was confirmed by choledochoscopy and intraoperative cholangiography. Outcome of surgery, frequency and subsequent management of recurrent intrahepatic stones, and factors associated with stone recurrence and cholangitis were analyzed. RESULTS: Twenty-one (60%) patients had bilobar disease. Eight patients underwent hepatectomy and 16 hepatico-jejunostomy with access loop; 12 of these were jejuno-duodenal anastomoses. Postoperative morbidity was observed in 10 patients (29%). Recurrence of stones occurred in 12 patients (34%) and cholangitis in 9 patients (26%). Presence of bilobar disease and associated biliary strictures were associated with recurrent cholangitis (p< 0.05). Two patients (6%) required re-operation for recurrent cholangitis. Complete removal of recurrent stones using conventional endoscope was possible through jejuno-duodenostomy in all 5 cases who had this type of access loop construction. CONCLUSION: Surgical treatment for intrahepatic stones depends on the site of involvement. Construction of a jejuno-duodenal access loop in patients with bilobar disease and intrahepatic strictures is helpful in facilitating postoperative stone clearance. A multidisciplinary approach is beneficial especially when the disease is bilobar and recurrent in type.  相似文献   
5.
Adequate ventilation is required for successful cardiopulmonary resuscitation (CPR). Operator characteristics that influence ventilation performance are not well defined. This study compared ventilation performance and operator characteristics in 74 medical personnel using a self-inflating anesthesia bag. Ventilation device, operator hand size, ventilation technique, average tidal volume, cumulative minute ventilation, and ventilation pressures were recorded during 3 minutes of ventilation. Ventilation volumes and airway pressures were not correlated with hand size or device type. Techniques that used one hand to squeeze the bag resulted in significantly lower average tidal volume than two-handed techniques, with no significant difference in peak or average airway pressure. There was no difference between emergency department and prehospital personnel in average tidal volume delivered. However, prehospital personnel ventilated at significantly higher airway pressures. Emergency department nurses delivered the greatest average tidal volume (923 cc), while emergency department physicians delivered the least (775 cc). Paramedics recorded the highest airway pressures (average, 53 cm H2O; peak, 72 cm H2O), while respiratory therapists recorded the lowest pressures (average, 34 cm H2O; peak, 54 cm H2O). Ventilation during CPR is a complex, learned skill. Large variation exists among different operators. However, appropriate tidal volumes can be delivered using safe airway pressures. Ongoing assessment and retraining of individuals performing ventilation during CPR are essential.  相似文献   
6.
Surgery in tropical pancreatitis: analysis of risk factors.   总被引:2,自引:0,他引:2  
Over a 7-year period, 91 patients with tropical pancreatitis underwent operation for intractable pain. Univariate and multivariate analyses were performed to identify factors correlating with mortality, major complications, poor pain relief and associated malignancy. Patients with benign disease (group 1, n = 72) had longer survival than those with superimposed malignancy (group 2, n = 19). Pain relief was better in group 1 (59 patients compared with none, P less than 0.01). Age above 40 years, short duration of symptoms, mass lesions on ultrasonography and main pancreatic duct obstruction on endoscopic retrograde pancreatography were associated with a high risk of cancer. After reoperation major complications (four of ten) or death (three of ten) occurred more commonly than after primary procedures (seven of 81, P = 0.019 and five of 81, P less than 0.05, respectively). Poor pain relief in group 1 patients was more common after incomplete clearance of main duct stones (four of 13 versus three of 53, P less than 0.01) and after short length ductotomy (three of eight versus four of 58, P less than 0.01). Tropical pancreatitis has a high association with pancreatic adenocarcinoma. Wide ductotomy, stone clearance and drainage gave good symptomatic results in patients with benign disease. Overall results were poor in patients with cancer.  相似文献   
7.
Lyme disease is a systemic illness caused by the spirochete Borrelia burgdorferi and transmitted by the bite of a tick in the Iocodes ricinus complex. While the illness is often associated with a characteristic rash, erythema migrans, patients may also present with a variety of complaints in the absence of the rash. The otolaryngologist may be called upon to see both groups of patients, with any number of signs and symptoms referable to the head and neck, including headache, neck pain, odynophagia, cranial nerve palsy, head and neck dysesthesia, otalgia, tinnitus, hearing loss, vertigo, temporomandibular pain, lymphad-enopathy, and dysgeusia. We review our institutional experience with 266 patients with Lyme disease, 75% of whom experienced head and neck symptoms. We also summarize the diagnostic and treatment modalities for this illness.  相似文献   
8.
In previous studies, we reported that fibronectin (FN) markedly enhances phagocytic uptake of antibody-coated group B streptococci (GBS) by human polymorphonuclear leukocytes. Furthermore, administration of FN along with a GBS type-specific monoclonal or polyclonal antibody to infected neonatal rats significantly enhances survival. In this study, we have examined the molecular mechanism of this enhancement through phagocyte receptors which recognize the Arg-Gly-Asp (RGD) peptide sequences contained within the FN molecule. Incubation of human polymorphonuclear leukocytes or culture-derived macrophages on coverslips coated with GRGDSP but not GRGESP markedly enhanced uptake of immunoglobulin G-coated GBS. The enhancing effect of the RGD-containing peptides was blocked by monoclonal antibodies B6H12 (directed against the integrin-associated protein) and 7G2 (directed against the beta 3-integrin receptor for RGD). These data suggest that FN enhancement of antibody-coated GBS uptake is mediated by the critical RGD sequence. Furthermore, this active peptide sequence may have an important role in immunotherapy of bacterial infections, especially in patients with decreased plasma FN concentrations.  相似文献   
9.
Transmission electron microscopy was used to study the in vitro development ofEimeria tenella in a novel established avian-derived cell line (designated CEV-1/F7) used for antigen production in chicken immunization studies. Sporozoites ofE. tenella were inoculated onto cell monolayers and the cells were fixed at 24-h intervals. Large numbers of intracellular sporozoites were seen at 24 h postinoculation (p.i.), and trophozoites were identified at 24–48 h p.i. Immature schizonts, some with budding merozoites, were seen by 48 h p.i. At 72–96 h p.i., immature and mature schizonts and extracellular merozoites were observed. No merozoite invasion occurred, but immature second-generation schizogony was seen in parasitophorous vacuoles of first-generation schizonts. No further development occurred and degeneration of most schizonts was seen by 120–144 h p.i. The results confirmed synchronous development ofE. tenella until 48 h p.i., followed by asynchronous development and ultrastructural degeneration with increased incubation time.  相似文献   
10.
Previous studies have suggested a neuroinvasive and neuropersistent potential of human herpesvirus 7 (HHV-7). In this report, a case of fatal encephalitis is described and its association with HHV-7 infection is discussed. An 8-year-old girl received a peripheral blood stem cell transplant for relapsed acute lymphoblastic leukaemia. The post-transplant period was uneventful and a course of intrathecal chemotherapy was given on Day-30. On Day-41, she developed acute encephalopathy with diplopia and nystagmus. She ran a rapid downhill course and succumbed despite antiviral treatment. The only positive pathological finding was the multiple microscopic foci of haemorrhage associated with neuronal degeneration detected in the brain stem. All microbiological investigations were negative, except for the presence of HHV-7 DNA in cerebrospinal fluid and brain stem tissue samples.  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