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   2671篇
  免费   150篇
  国内免费   8篇
耳鼻咽喉   21篇
儿科学   235篇
妇产科学   53篇
基础医学   269篇
口腔科学   64篇
临床医学   182篇
内科学   527篇
皮肤病学   118篇
神经病学   117篇
特种医学   84篇
外科学   381篇
综合类   62篇
预防医学   132篇
眼科学   168篇
药学   262篇
中国医学   11篇
肿瘤学   143篇
  2023年   19篇
  2022年   31篇
  2021年   97篇
  2020年   55篇
  2019年   65篇
  2018年   81篇
  2017年   86篇
  2016年   95篇
  2015年   83篇
  2014年   132篇
  2013年   159篇
  2012年   196篇
  2011年   186篇
  2010年   108篇
  2009年   90篇
  2008年   149篇
  2007年   127篇
  2006年   122篇
  2005年   104篇
  2004年   92篇
  2003年   63篇
  2002年   51篇
  2001年   47篇
  2000年   48篇
  1999年   38篇
  1998年   21篇
  1997年   23篇
  1996年   10篇
  1995年   17篇
  1993年   16篇
  1992年   41篇
  1991年   24篇
  1990年   34篇
  1989年   33篇
  1988年   34篇
  1987年   26篇
  1986年   20篇
  1985年   28篇
  1984年   21篇
  1983年   10篇
  1980年   8篇
  1979年   21篇
  1978年   13篇
  1977年   7篇
  1975年   8篇
  1974年   13篇
  1973年   14篇
  1972年   8篇
  1971年   8篇
  1965年   7篇
排序方式: 共有2829条查询结果,搜索用时 373 毫秒
21.
22.
AIMS: The occurrence of human granulocytic ehrlichiosis (HGE) in a patient with chronic myelogenous leukaemia (CML) provided an opportunity to study whether Anaplasma phagocytophilum, the aetiological agent of HGE, infects mature or immature cells, both in vivo and in vitro. METHODS: Diagnosis of HGE was confirmed by culture, polymerase chain reaction (PCR), detection of intragranulocytic inclusions, and serology. The infection rates of different myelogenous stages of granulocytic differentiation were determined by microscopy. Anaplasma phagocytophilum infection of the bone marrow was analysed by PCR, culture, and microscopy. In addition, the in vitro growth of A phagocytophilum in the patient's granulocytes and in HL-60 cells (a promyelocytic leukaemia cell line) was compared. RESULTS: Pretreatment blood smears showed that mature granulocytic cells had a higher infection rate with A phagocytophilum than did immature cells. In the original inoculation of the patient's cells into HL-60 cells to isolate A phagocytophilum, the bacterium grew faster in the patient's leukaemic cells than in HL-60 cells. Anaplasma phagocytophilum inclusions were rarely seen in bone marrow granulocytes and PCR was negative. In vitro, two A phagocytophilum isolates grew faster in the patient's granulocytes than in HL-60 cells. CONCLUSIONS: The superior growth in CML cells compared with HL-60 cells suggests that A phagocytophilum preferentially infects mature granulocytes. The higher infection rate of the patient's mature versus immature granulocytes before treatment and the minimal level of infection of the patient's bone marrow support this. It is possible that the primary site of infection in HGE is the peripheral mature granulocytic population.  相似文献   
23.
Mucormycosis is an uncommon fungal infection, occurring mainly in patients with acidosis, chronic illnesses and malignancies. The most frequent site of involvement in patients of hematological malignancies is the respiratory tract. Isolated subcutaneous localization of mucormycosis in such patients is extremely rare. We report a case of a young patient of non-Hodgkin's lymphoma on chemotherapy who presented with a subcutaneous swelling on the anterior aspect of right thigh. Fine needle aspiration cytology (FNAC) smears from the swelling revealed numerous characteristic broad, irregularly contoured and pleomorphic hyphae of mucormycosis. This fungus seldom grows in culture and confirmation of the diagnosis depends on cytological or histological examination of infected tissues. Our case report documents a rare site of isolated mucormycosis infection and emphasizes the role of FNAC as a simple, rapid, accurate, and useful method of diagnosing fungal infections.  相似文献   
24.
AIMS--To determine whether the routine measurement of lymphocyte transformation responses to mitogenic stimuli provide any information additional to that available from routine T cell CD4 and CD8 analysis in patients with HIV infection. METHODS--The case records of 197 immunologically investigated HIV seropositive patients were reviewed. The influence of disease stage on T lymphocyte subsets and lymphocyte transformation responses (LyTR) to phytohaemagglutinin (PHA) and Pokeweed mitogen was assessed. RESULTS--The median CD3 and CD4 counts and LyTR to PHA and Pokeweed mitogen were highest in patients with persistent generalised lymphadenopathy (PGL) and decreased progressively in the order: asymptomatic patients, those with ARC, those with AIDS. LyTR to PHA was preserved in over 70% of all patients, but the response to Pokeweed mitogen was depressed in 8% of patients with PGL, 34% of asymptomatic patients, 68% of those with ARC and 78% of those with AIDS. Subnormal values of both CD4 + T cells and LyTR to Pokeweed mitogen were more common in patients with ARC and AIDS (68%) than in those who were asymptomatic or had PGL (20%). CONCLUSIONS--CD4 T cell analysis and LyTR to Pokeweed mitogen, but not to PHA, both correlate with disease states in patients with HIV infection.  相似文献   
25.
Effects of ß-naphthonflavoe (ßNF) on theactivity of hepatic microsomal aflatoxin B1 (AFB1)-4-hydroxylase- the cytochrome P-450-dependent enzyme system which catalyzesthe metabolism of AFB1 to AFM1 - and on AFB1 induced in vivohepatocarcinogenesis were investigated in weanling male Fischerrats. A single i.p. injection of ßNF in doses of 20mg/kg and 150 mg/kg induced AFB1 -4-hydroxylase 3- and 4-fold,respectively, 48 h post injection. Feeding of diet containing0.01% ßNF for a period of 9-weeks induced AFB1 2-fold.AFB1, given by intubatlon in a dose of 25 µg five times/weekfor 8 weeks, produced 42 weeks later a 100% incidence of liverlesions (neoplastic foci, nodules or tumors), but feeding ßNFin diet at a con centration of 0.015% for one week prior toand during the 8 weeks of AFB treatment inhibited AFB1 hepatocarcinogenesis by -7%. These results are in accord with the suggestionthat AFB1 induction may be associated with the inhibition ofAFB1 carcinogenesis, possibly occurring as a consequence ofaccelerated detoxi-fication of AFB1 via its conversion to AFM1  相似文献   
26.
Summary Floating knee is the term used to describe simultaneous fractures of the femur and tibia in the same limb. Thirty nine patients, with 40 such injuries, are presented with a follow up interval of six months to five years. The final functional result was poor if the femoral fracture was situated in the condylar flare and the results were comparatively better in those cases treated by cast bracing or when the fracture of the femur was stabilised internally. In all cases the fracture of the tibia was treated conservatively.
Résumé Sous le terme de «genou flottant» les auteurs décrivent les fractures simultanées du fémur et du tibia au niveau du même membre. Ils présentent 40 lésions de ce type, chez 39 sujets, avec un recul compris entre six mois et cinq ans. Le résultat fonctionnel est médiocre lorsque le siège de la fracture du fémur est juxta-articulaire. Comparativement, les résultats sont meilleurs lorsque la fracture du fémur a été immobilisée dans une attelle plâtrée ou stabilisée par ostéosynthèse. Toutes les fractures du tibia ont été traitées orthopédiquement.
  相似文献   
27.
Journal of Public Health - Few studies have been performed to investigate multiorgan failure occurring with extrapulmonary symptoms like diarrhea, anorexia, and vomiting. There has been no attempt...  相似文献   
28.
29.
30.
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