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   12119篇
  免费   768篇
  国内免费   38篇
耳鼻咽喉   113篇
儿科学   276篇
妇产科学   247篇
基础医学   1668篇
口腔科学   1644篇
临床医学   854篇
内科学   2563篇
皮肤病学   303篇
神经病学   1008篇
特种医学   290篇
外科学   1266篇
综合类   63篇
预防医学   1282篇
眼科学   156篇
药学   763篇
中国医学   111篇
肿瘤学   318篇
  2023年   117篇
  2022年   242篇
  2021年   454篇
  2020年   317篇
  2019年   454篇
  2018年   525篇
  2017年   345篇
  2016年   375篇
  2015年   431篇
  2014年   547篇
  2013年   662篇
  2012年   1025篇
  2011年   1106篇
  2010年   544篇
  2009年   450篇
  2008年   728篇
  2007年   754篇
  2006年   599篇
  2005年   509篇
  2004年   359篇
  2003年   314篇
  2002年   310篇
  2001年   225篇
  2000年   207篇
  1999年   166篇
  1998年   45篇
  1997年   35篇
  1996年   25篇
  1995年   25篇
  1994年   37篇
  1993年   25篇
  1992年   75篇
  1991年   77篇
  1990年   52篇
  1989年   69篇
  1988年   62篇
  1987年   59篇
  1986年   58篇
  1985年   56篇
  1984年   47篇
  1983年   32篇
  1982年   28篇
  1979年   32篇
  1977年   26篇
  1976年   23篇
  1975年   25篇
  1971年   21篇
  1970年   33篇
  1969年   26篇
  1968年   29篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
Transplantation of any organ has some inherent risk of disease transmission, such as infection and malignancy. The present study aims to describe 2 cases of choriocarcinoma transmission after kidney and liver transplantation originating from the same patient. The donor was a 17-year-old woman who died of cerebral hemorrhage. Both organ recipients died of metastatic choriocarcinoma few months after the transplantation, within days after starting chemotherapy. Retrospective hCG (human chorionic gonadotropin hormone) analysis in donor's blood stored at the time of donation had a result of 9324 mIU/mL. Despite its rarity, clinicians should be aware of the risk of transplant-related choriocarcinoma from female donors in childbearing age. In some cases, hCG dosage should be performed before donation.  相似文献   
102.
BackgroundVascular injury after hallux valgus surgery is a rare condition but serious complications can ensue.MethodsWe performed an anatomical study using 26 cadaveric lower extremities. We enhanced first metatarsal bone’s (FMB) vascularization by injecting latex. Each specimen was classified according to the severity of hallux valgus deformity (HVD). Then we measured two distances: one between the first tarsometatarsal joint (FTMJ) to the first dorsal branch’s origin, the other between the first metatarsophalangeal joint (MTP) to the dorsal plexus’s origin.ResultsThe distance between the FTMJ and the first dorsal branch to the FMB ranges from 10 mm in normal feet to 15 mm in severe deformed feet. The distance between the MTP and the dorsal plexus’ origin ranges from 20 mm in normal feet to 25 mm in severe deformed feet.ConclusionsUnderstanding the foot’s vascular anatomy has allowed us to adapt surgical landmarks to the severity of the HVD and to avoid post-operative complications.  相似文献   
103.
IntroductionWith the emergence of blunt-tipped microcannulas, there is a hypothesis that these could cause less damage and reduce pain as compared to conventional sharp needles in eyelid surgery. The purpose is to determine whether an 18G blunt-tipped cannula can be better than a 26G needle.MethodsThis prospective, observer-blinded, randomized clinical trial was conducted from June 2017 to December 2018. Sixty-eight patients were randomized to receive local anesthesia injections for upper blepharoplasty. Infiltration was performed by using a 26-gauge sharp needle on one side and on the other side, infiltration was performed by using an 18-gauge stainless-steel blunt-tipped microcannula. A numeric rating scale (NRS) from 0 to 10 was used to blindly assess pain in patients receiving anesthesia injections with both needle types. Photographs of the eyelids of each patient were taken in five different periods and used by three blinded observers to identify bruise or ecchymoses.ResultsA total of 136 eyelid operations were performed. There was no statistically significant difference when both groups were compared; however, the average score of pain was higher in patients taking the infiltration through the needle (2.85 versus 2.50). Regarding the evaluation of bruising and ecchymoses, the results showed that, in the five periods evaluated, there was no statistical difference in bruising and ecchymosis in the eyelids when taking the infiltration through a sharp needle when compared with that of the eyelids taking infiltration through a (blunt-tipped) microcannula.ConclusionThe evaluation of the blunt-tipped microcannula showed a lower pain score mean than that obtained for the sharp needle (2.5 versus 2.85) (p > 0.05). There was no statistically significant difference in the bruising and ecchymosis courses.  相似文献   
104.
105.
Vaccine adjuvants are compounds that enhance/prolong the immune response to a co-administered antigen. Saponins have been widely used as adjuvants for many years in several vaccines – especially for intracellular pathogens – including the recent and somewhat revolutionary malaria and shingles vaccines. In view of the immunoadjuvant potential of Q. brasiliensis saponins, the present study aimed to characterize the QB-80 saponin-rich fraction and a nanoadjuvant prepared with QB-80 and lipids (IMXQB-80). In addition, the performance of such adjuvants was examined in experimental inactivated vaccines against Zika virus (ZIKV). Analysis of QB-80 by DI-ESI-ToF by negative ion electrospray revealed over 29 saponins that could be assigned to known structures existing in their congener Q. saponaria, including the well-studied QS-21 and QS-7. The QB-80 saponins were a micrOTOF able to self-assembly with lipids in ISCOM-like nanoparticles with diameters of approximately 43 nm, here named IMXQB-80. Toxicity assays revealed that QB-80 saponins did present some haemolytical and cytotoxic potentials; however, these were abrogated in IMXQB-80 nanoparticles. Regarding the adjuvant activity, QB-80 and IMXQB-80 significantly enhanced serum levels of anti-Zika virus IgG and subtypes (IgG1, IgG2b, IgG2c) as well as neutralized antibodies when compared to an unadjuvanted vaccine. Furthermore, the nanoadjuvant IMXQB-80 was as effective as QB-80 in stimulating immune responses, yet requiring fourfold less saponins to induce the equivalent stimuli, and with less toxicity. These findings reveal that the saponin fraction QB-80, and particularly the IMXQB-80 nanoadjuvant, are safe and capable of potentializing immune responses when used as adjuvants in experimental ZIKV vaccines.  相似文献   
106.
Quality of Life Research - As people around the world are facing the Covid-19 outbreak, their perception of oral health problems could be changed. This study aimed to evaluate the immediate effects...  相似文献   
107.
Summary Therapeutic success in dysplasia and congenital dislocation of the hip depends on an early diagnosis. The physiopathology remains very debatable and several concepts are propounded. For a better physiopathologic understanding, the authors have carried out a study of the morphology and development of 22 pre- and neonatal hips. At first, the acetabulum is cartilaginous and distorted by the moving femoral head; this acetabulum is histologicaly affected by the femoral pressure.The pathologic hip is characterized by defective posterior bony coverage of the femoral head by the acetabulum. The acetabulum ossifies during the 3 months following birth, forming a cup-like cavity under the pressure of the femoral head. Therefore, neonatal screening tests such as sonography must take place in the first weeks of life.
Étude anatomique de la hanche antéet néonatale. Réflexions sur la physiopathologie des dysplasies et luxations congénitales de la hanche
Résumé Le succès du traitement des dysplasies et luxations congénitales de hanche est lié à la précocité du diagnostic. La physiopathologie de ces affections reste discutée et plusieurs conceptions ont pu être proposées. Les auteurs ont réalisé une étude structurale et évolutive de 22 hanches anté et néonatales afin de mieux comprendre cette physiopathologie. Dans les périodes anté- et néonatale, l'acétabulum est cartilagineux, déformable sous l'action d'une tête fémorale en mouvement et il est le siège de remainements histologiques dépendant de la pression exercée par l'épiphyse fémorale. L'ossification de l'acétabulum s'effectue lors du ler trimestre postnatal, construisant la cavité articulaire sous l'effet de la pression de la tête du fémur. Dysplasies et luxations apparaissent comme un défaut de couverture postéro-supérieure de l'épiphyse fémorale par l'acétabulum. Le dépistage d'anomalies, notamment par l'échographie, devra donc être réalisé dans les premières semaines de la vie.
  相似文献   
108.
A novel methodology for characterization of animal sperm shape involving the use of a spectral approach to multiscale curvature estimation is proposed. By using the derivative property of the Fourier transform, allied to Gaussian smoothing, accurate estimates of the curvature along the sperm contour can be obtained in such a way that the curvature peaks corresponding to the sperm head vertices can be effectively identified. The measurements derived from such a processing, namely the width of the basal region of the head, the centralization of tail implantation, and the multiscale bending energy, provide valuable resources for fertility and phylogenetic studies.  相似文献   
109.
110.
To further understand the role of NS1-specific antibodies (Abs) in disease pathogenesis, we compared neutralizing antibody levels (Nabs), NS1-Ab levels, IgG antibody subclass profiles and NS1-specific memory B-cell responses (Bmems) in individuals, with varying severity of past dengue. Nabs (Neut50 titres) were assessed using the Foci Reduction Neutralization Test (FRNT) and in-house ELISAs were used to assess NS1-Abs and NS1-Ab subclasses for all four DENV serotypes in individuals with past DF (n = 22), those with past DHF (n = 14) and seronegative (SN) individuals (n = 7). B-cell ELISpot assays were used to assess NS1-specific Bmem responses. 15/22 (68.18%) individuals with past DF and 9/14 (64.29%) individuals with past DHF had heterotypic infections. Neut50 titres were found to be significantly higher for DENV1 than DENV2 (p = 0.0006) and DENV4 (p = 0.0127), in those with past DHF, whereas there was no significant difference seen in titres for different DENV serotypes in those with past DF. Overall NS1-Ab to all serotypes and NS1-specific IgG1 responses for DENV1, 2 and 4 serotypes were significantly higher in those with past DHF than individuals with past DF. Those with past DHF also had higher IgG1 than IgG3 for DENV1 and DENV3, whereas no differences were seen in those with past DF. Over 50% of those with past DF or DHF had NS1-specific Bmem responses to >2 DENV serotypes. There was no difference in the frequency of Bmem responses to any of the DENV serotypes between individuals with past DF and DHF. Although the frequency of Bmem responses to DENV1 correlated with DENV1-specific NS1-Abs levels (Spearman r = 0.35, p = 0.02), there was no correlation with other DENV serotypes. We found that those with past DF had broadly cross-reactive Nabs, while those with past DHF had higher NS1-Ab responses possibly with a different functionality profile than those with past DF. Therefore, it would be important to further evaluate the functionality of NS1-specific antibody and Bmem responses to find out the type of antibody repertoire that is associated with protection against severe disease.  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