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   774篇
  免费   192篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   28篇
妇产科学   62篇
基础医学   63篇
口腔科学   11篇
临床医学   252篇
内科学   174篇
皮肤病学   12篇
神经病学   36篇
特种医学   24篇
外科学   90篇
综合类   5篇
预防医学   86篇
眼科学   17篇
药学   35篇
中国医学   4篇
肿瘤学   63篇
  2024年   3篇
  2023年   31篇
  2022年   23篇
  2021年   37篇
  2020年   29篇
  2019年   18篇
  2018年   47篇
  2017年   50篇
  2016年   50篇
  2015年   52篇
  2014年   66篇
  2013年   66篇
  2012年   45篇
  2011年   43篇
  2010年   34篇
  2009年   56篇
  2008年   32篇
  2007年   31篇
  2006年   36篇
  2005年   16篇
  2004年   26篇
  2003年   15篇
  2002年   17篇
  2001年   12篇
  2000年   6篇
  1999年   13篇
  1998年   17篇
  1997年   21篇
  1996年   13篇
  1995年   8篇
  1994年   4篇
  1993年   3篇
  1992年   4篇
  1991年   5篇
  1990年   4篇
  1989年   2篇
  1988年   2篇
  1986年   5篇
  1985年   2篇
  1980年   3篇
  1978年   2篇
  1977年   2篇
  1976年   3篇
  1975年   2篇
  1972年   2篇
  1971年   1篇
  1970年   1篇
  1968年   2篇
  1966年   1篇
  1958年   1篇
排序方式: 共有969条查询结果,搜索用时 15 毫秒
171.
Little is known about the experience of people with autism in custody. A review of the literature that explored the relationship between autism and criminality and the criminal justice detention system was conducted. Literature suggests that people with autism are potentially overrepresented within the criminal justice system. There is little research that has examined the experiences of people with autism spectrum disorders in custody. There is very little to guide service design to develop autism support services for people in prison.  相似文献   
172.
173.
OBJECTIVE: To investigate the clinical and pharmacoepidemiological determinants of delirium in a psychiatric inpatient population. METHOD: A case-control study design was used. Potential cases and potential controls were identified using hospital discharge data. The clinical record of each subject was reviewed using a validated protocol to confirm case and control status. Subsequently, exposure data were recorded from clinical records. RESULTS: Subjects admitted to hospital with delirium tended to be older, to have pre-existing cognitive deficits, and to have diagnoses of substance use disorders. Subjects who developed delirium after their admission to hospital were older than control subjects, more likely to have a history of cognitive impairment, and were significantly more likely to be treated during the hospitalization with lithium or anticholinergic antiparkinsonian medications. Antipsychotic medication exposures were also associated with delirium, but only at standard or above-standard dosage levels. Antidepressant and sedative-hypnotic medications were not associated with delirium. CONCLUSIONS: These findings indicate that using conservative dosages of antipsychotic medications and minimizing the use of anticholinergic medications for parkinsonian symptoms may help to prevent delirium in psychiatric inpatients. Anticonvulsant mood stabilizers may convey less delirium risk than lithium. Antidepressant medications and sedative-hypnotics were not important determinants of delirium in this population.  相似文献   
174.
175.
The lateral superior olive (LSO), a binaural nucleus involved in sound localization, receives tonotopically organized inhibitory inputs from the medial nucleus of the trapezoid body (MNTB). During development, the tonotopic organization of this glycinergic/GABAergic MNTB-LSO pathway is established by activity-dependent axonal reorganization. However, the underlying mechanisms by which this reorganization takes place have remained largely unknown. As cytosolic calcium is one of the most important second messengers responsible for inducing synaptic plasticity and reorganization, we examined whether and how activity in the MNTB-LSO pathway changes the intracellular calcium concentration ([Ca2+]i) in developing LSO neurons. By applying calcium imaging techniques to Fura-2-labelled slices from neonatal rats and mice, we found that glycine and GABA (gamma-aminobutyric acid) affect [Ca2+]i in LSO neurons in an age-dependent manner; during the first postnatal week, the period at which glycine and GABA are depolarizing in the LSO, glycine and GABA always increased [Ca2+]i. However, in 2-week-old animals, the time around hearing onset when glycine and GABA are hyperpolarizing, glycine and GABA slightly decreased [Ca2+]i. Calcium responses could also be elicited by stimulation of afferent fibres from the MNTB, and these synaptic responses were mediated by glycine and GABA(A) receptors. Furthermore, GABA, which is a neurotransmitter only in the immature MNTB-LSO pathway, played a major role in generating MNTB-elicited Ca2+ responses. The direct link of glycinergic/GABAergic synaptic activity to intracellular calcium signalling during the period of inhibitory synaptic plasticity could be one of the mechanisms by which tonotopic MNTB-LSO connections become established.  相似文献   
176.
We have identified and molecularly characterized a novel deletion in the beta-globin gene cluster that increases fetal hemoglobin (HbF) synthesis in a 24-year-old Laotian man who is heterozygous for this mutation. The patient is asymptomatic with a mild anemia, hypochromia, and microcytosis (Ht = 39%, MCH = 22.8 pg, MCV = 71 fl), normal levels of HbA2 (3.0%) and 11.5% HbF (G gamma A gamma ratio 60 to 40), with heterocellular distribution (52% F cells). Extensive restriction endonuclease mapping defined the 5' breakpoint within the IVS II of the delta-globin gene, between positions 775 to 781 very similar to the 5' breakpoint of the Sicilian delta beta-thalassemia. However, the 3' breakpoint was localized between two Pst I sites 4.7 kb 3' of the beta- globin gene, thus ending about 0.7 kb upstream from the 3' breakpoint of the Sicilian delta beta-thalassemia. This results in a 12.5 kb deletion of DNA. It is of interest that the 5' breakpoint of the deletion residues within an AT-rich region which has been proposed as a specific recognition signal for recombination events, while the 3' breakpoint lies within a cluster of L1 repetitive sequences (formerly known as Kpn I family repeats). The presence of the 3' breakpoints of several other deletions within this region of L1 repeats also suggests that such sequences might serve as hot spots for recombination and eventually lead to thalassemia deletions. The similarity of the 5' and 3' breakpoints of these delta beta-thalassemias underscores the putative regulatory role of the deleted and juxtaposed sequences on the expression of the gamma-globin genes in adult life.  相似文献   
177.
The role of serology in the setting of PCR-based diagnosis of acute respiratory infections (ARIs) is unclear. We found that acute- and convalescent-phase paired-sample serologic testing increased the diagnostic yield of naso/oropharyngeal swabs for influenza virus, respiratory syncytial virus (RSV), human metapneumovirus, adenovirus, and parainfluenza viruses beyond PCR by 0.4% to 10.7%. Although still limited for clinical use, serology, along with PCR, can maximize etiologic diagnosis in epidemiologic studies.  相似文献   
178.
Background: Since pelvic exenteration for the treatment of recurrent gynecologic malignancy first was described, reported rates of morbidity and mortality have declined steadily. However, the factors responsible for this decline have never been clearly delineated. Methods: We reviewed the charts of 154 patients who underwent pelvic exenteration for gynecologic malignancy between 1954 and 1994. Charts were abstracted for details of the surgical procedure, pathologic findings, postoperative management, short- and long-term complications, time to recurrence, and overall survival. Results: Seventy-two patients (47%) experienced 95 identifiable postoperative complications, resulting in death in 22 patients (14%). The rate of infectious complications declined to a statistically significant degree between the first two decades and latter two decades of the study (odds ratio [OR] 0.28, 95% CI 0.11–0.69). The use of routine prophylactic antibiotics was associated with this decline in infectious complications (OR 0.25, 95% CI 0.07–0.83). The use of preoperative subcutaneous heparin was associated with a reduction in thrombotic complications from 5 of 100 patients to 0 of 54 patients (P=.11), as well as a significant reduction in overall risk of complications (OR 0.53, 95% CI 0.33–0.85) and risk of postoperative mortality (OR 0.19, 95% CI 0.05–0.80). There was a significant reduction in overall risk of postoperative complications with both intensive care unit monitoring postoperatively (OR 0.65, 95% CI 0.43–0.99) and routine postoperative monitoring with a pulmonary artery catheter (OR 0.61, 95% CI 0.38–0.98). Conclusions: Routine use of prophylactic antibiotics, prophylactic subcutaneous heparin, and intensive postoperative monitoring appear to have reduced morbidity from pelvic exenteration.  相似文献   
179.
In this white paper, experts from the Digital Pathology Association (DPA) define terminology and concepts in the emerging field of computational pathology, with a focus on its application to histology images analyzed together with their associated patient data to extract information. This review offers a historical perspective and describes the potential clinical benefits from research and applications in this field, as well as significant obstacles to adoption. Best practices for implementing computational pathology workflows are presented. These include infrastructure considerations, acquisition of training data, quality assessments, as well as regulatory, ethical, and cyber-security concerns. Recommendations are provided for regulators, vendors, and computational pathology practitioners in order to facilitate progress in the field. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.  相似文献   
180.

Purpose

There are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists?? Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients.

Principal findings

The document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individual??s type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference.

Conclusions

The document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable.  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