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   3788篇
  免费   757篇
  国内免费   45篇
耳鼻咽喉   100篇
儿科学   201篇
妇产科学   36篇
基础医学   315篇
口腔科学   88篇
临床医学   450篇
内科学   924篇
皮肤病学   95篇
神经病学   358篇
特种医学   142篇
外科学   903篇
综合类   25篇
一般理论   2篇
预防医学   209篇
眼科学   232篇
药学   221篇
中国医学   6篇
肿瘤学   283篇
  2024年   18篇
  2023年   215篇
  2022年   65篇
  2021年   147篇
  2020年   136篇
  2019年   92篇
  2018年   227篇
  2017年   216篇
  2016年   217篇
  2015年   202篇
  2014年   287篇
  2013年   284篇
  2012年   212篇
  2011年   184篇
  2010年   219篇
  2009年   246篇
  2008年   172篇
  2007年   132篇
  2006年   151篇
  2005年   116篇
  2004年   97篇
  2003年   62篇
  2002年   80篇
  2001年   62篇
  2000年   66篇
  1999年   57篇
  1998年   41篇
  1997年   37篇
  1996年   42篇
  1995年   40篇
  1994年   20篇
  1993年   24篇
  1992年   47篇
  1991年   38篇
  1990年   28篇
  1989年   34篇
  1988年   26篇
  1987年   31篇
  1986年   27篇
  1985年   23篇
  1984年   17篇
  1983年   13篇
  1982年   19篇
  1981年   12篇
  1980年   13篇
  1977年   9篇
  1976年   10篇
  1974年   9篇
  1972年   12篇
  1970年   9篇
排序方式: 共有4590条查询结果,搜索用时 15 毫秒
971.
Nitrous oxide is one of the most commonly used inhalational anesthetic agents used in practice. It is a cost-effective, pleasant, safe, and versatile anesthetic agent with many desirable properties like good quality analgesia, decreased awareness, accelerated induction and recovery from anesthesia, and reduced utilization of other expensive inhalational agents with potential cost savings. The use of nitrous oxide has been questioned by a lot of studies and case reports perceiving its adverse systemic, hematological, immune, and neurologic adverse effects. However, the literature in the recent past has tried to resolve the controversies related to its use. The concerns over an increase in cardiovascular complications and mortality following nitrous oxide use have been negated by recent data. However, its use in certain vulnerable populations like children with cobalamin and folate deficiency or defects in their metabolic pathways remains a cause of concern for its toxic effects. In this narrative review, we aim to discuss the pharmacological properties of nitrous oxide, the potential advantages and drawbacks of the use of nitrous oxide in children, address the neurodevelopmental and other systemic effects, and throw light on the evidence regarding the safety of nitrous oxide use and its current role in pediatric procedural sedation and anesthesia practice. The literature related to its use in the pediatric population for painful procedures and surgeries has been summarized.  相似文献   
972.
The characteristics of a concrete mix are purely dependent on the hydration of cement that is carried forward by using the water quality used in the mix. Several researchers have focused on incorporating pozzolanic or nanomaterials to improve the hydration mechanisms and impart high strength to concrete. A new technology has been introduced to improve the properties of concrete by magnetic-field-treated water (MFTW). Due to magnetization, water particles become charged and the molecules inside the water cluster decrease from 13 to 5 or 6, which eventually decreases the hardness of water, thus improving the strength of concrete when compared to the use of normal water (NW). In advanced construction techniques and practices, the application of Magnetic Water (MW) plays an important role in boosting physicochemical properties. This research work focused on evaluating the standards of water quality through physiochemical analysis, such as Electrical Conductivity (EC), Viscosity, pH, and Total Dissolved Solids (TDS) with the MW at different exposure periods (60 min (MW60), 45 min (MW45), 30 min (MW30), 15 min (MW15), and instant exposure (MWI)). Experiments were carried out to evaluate the fresh, hardened, and microstructural behavior of concrete made with magnetic water (MW) using a permanent magnet of PERMAG (N407) under a field intensity of 0.9 Tesla. In addition, optical properties such as X-ray Diffraction (XRD) and Ultraviolet (UV) absorption were considered for the MW60 mix to ensure water magnetization. Characterization methods such as Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) were employed for NWC and MWC to quantify the hydrated products. From the results, it was observed that the magnetic effect on water characteristics showed significant improvement in the concrete properties with the increase in exposure duration. There were increments of 25.6% and 24.1% in workability and compressive strength, respectively, for the MW60 mix compared to normal water concrete (NWC).  相似文献   
973.
974.
975.
976.
The purpose of the study was to review the current evidence and design a diabetic macular edema (DME) management guideline specific for India. The published DME guidelines from different organizations and publications were weighed against the practice trends in India. This included the recently approved drugs. DME management consisted of control of diabetes and other associated systemic conditions, such as hypertension and hyperlipidemia, and specific therapy to reduce macular edema. Quantification of macular edema is precisely made with the optical coherence tomography and treatment options include retinal laser, intravitreal anti-vascular endothelial growth factors (VEGF), and implantable dexamethasone. Specific use of these modalities depends on the presenting vision and extent of macular involvement. Invariable eyes with center-involving macular edema benefit from intravitreal anti-VEGF or dexamethasone implant therapy, and eyes with macular edema not involving the macula center benefit from retinal laser. The results are illustrated with adequate case studies and frequently asked questions. This guideline prepared on the current published evidence is meant as a guideline for the treating physicians.  相似文献   
977.
This study aims to assess the association between microbial composition, biofilm formation and chronic otorhinolaryngologic disorders in Malaysia. A total of 45 patients with chronic rhinosinusitis, chronic tonsillitis and chronic suppurative otitis media and 15 asymptomatic control patients were studied. Swab samples were obtained from these subjects. Samples were studied by conventional microbiological culturing, PCR-based microbial detection and Confocal Laser Scanning Microscopy (CLSM). Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, coagulase-negative staphylococci (CoNS) and other Streptococcus species were detected in subjects of both patient and control groups. Biofilm was observed in approximately half of the smear prepared from swab samples obtained from subjects of the patient group. Most of these were polymicrobial biofilms. S. aureus biofilm was most prevalent among nasal samples while H. influenzae biofilm was more common among ear and throat samples. Results from this study supported the hypothesis that chronic otorhinolaryngologic diseases may be biofilm related. Due to the presence of unculturable bacteria in biofilms present in specimens from ear, nose and throat, the use of molecular methods in combination with conventional microbiological culturing has demonstrated an improvement in the detection of bacteria from such specimens in this study.  相似文献   
978.
979.
Contemporary protocols for the treatment of malignant brain tumors such as medulloblastoma (MB) in children, often involve craniospinal irradiation (CSI) at diagnosis followed by serial courses of high dose chemotherapy and autologous hematopoietic stem cell support. Patients often require several pheresis procedures in order to collect sufficient stem cells for this type of treatment, particularly if they have already had CSI. We describe the successful mobilization, collection and subsequent transplant of a 7‐year‐old female with medulloblastoma after recent CSI using granulocyte colony stimulating factor (G‐CSF) and the CXCR4 antagonist AMD3100 after a failed previous mobilization attempt using G‐CSF alone. Pediatr Blood Cancer 2010;54:613–615. © 2009 Wiley‐Liss, Inc.  相似文献   
980.
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