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   3551篇
  免费   206篇
  国内免费   33篇
耳鼻咽喉   29篇
儿科学   169篇
妇产科学   127篇
基础医学   390篇
口腔科学   157篇
临床医学   329篇
内科学   768篇
皮肤病学   36篇
神经病学   115篇
特种医学   80篇
外科学   765篇
综合类   76篇
一般理论   2篇
预防医学   179篇
眼科学   86篇
药学   255篇
中国医学   30篇
肿瘤学   197篇
  2024年   3篇
  2023年   35篇
  2022年   95篇
  2021年   125篇
  2020年   95篇
  2019年   116篇
  2018年   137篇
  2017年   92篇
  2016年   114篇
  2015年   123篇
  2014年   157篇
  2013年   201篇
  2012年   284篇
  2011年   297篇
  2010年   149篇
  2009年   134篇
  2008年   222篇
  2007年   202篇
  2006年   191篇
  2005年   195篇
  2004年   177篇
  2003年   144篇
  2002年   130篇
  2001年   48篇
  2000年   42篇
  1999年   39篇
  1998年   24篇
  1997年   23篇
  1996年   17篇
  1995年   15篇
  1994年   14篇
  1993年   10篇
  1992年   11篇
  1991年   8篇
  1990年   12篇
  1989年   10篇
  1988年   9篇
  1987年   6篇
  1986年   13篇
  1985年   11篇
  1984年   6篇
  1983年   6篇
  1982年   7篇
  1981年   6篇
  1980年   3篇
  1978年   8篇
  1977年   3篇
  1976年   5篇
  1974年   3篇
  1969年   3篇
排序方式: 共有3790条查询结果,搜索用时 0 毫秒
31.
Our patient is a 3‐week‐old female neonate, presented with complaints of low‐grade fever and a congested nose for one day. Eventually, she developed progressive desaturation, hypotension, and poor perfusion due to severe pulmonary hemorrhage. Then, she developed cardiac arrest and was declared dead.  相似文献   
32.
33.
Swyer syndrome is a 46, XY karyotype, with pure gonadal dysgenesis and primary amenorrhea. These females have primordial Mullerian structures and seek medical attention as they experience primary amenorrhea. Here, we report a 15‐year‐old girl, diagnosed as Swyer syndrome associated with left ovarian dysgerminoma.  相似文献   
34.
Nanoparticles (NPs) are increasingly being commercialized for use in biomedicine. NP toxicity following acute or chronic exposure has been described, but mechanistic insight into this process remains incomplete. Recent evidence from in vitro studies suggested a role for NLRP3 in NP cytotoxicity. In this study, we investigated the effect of systemic administration of composite inorganic NP, consisting of Ag:Cu:B (dose range 1–20?mg/kg), on the early acute (4–24?h post-exposure) and late phase response (96?h post-exposure) in normal and NLRP3-deficient mice. Our findings indicate that systemic exposure (≥2?mg/kg) was associated with acute liver injury due to preferential accumulation of NP in this organ and resulted in elevated AST, ALT and LDH levels. Moreover, within 24?h of NP administration, there was a dose-dependent increase in intraperitoneal neutrophil recruitment and upregulation in gene expression of several proinflammatory mediators, including TNF-α, IL-1β and S100A9. Histological analysis of liver tissue revealed evidence of dose-dependent hepatocyte necrosis, increase in sinusoidal Kupffer cells, lobular granulomas and foci of abscess formation which were most pronounced at 24?h following NP administration. NP deposition in the liver led to a significant upregulation in gene expression of S100A9, an endogenous danger signal recognition molecule of phagocytes, IL-1β and IL-6. The extent of proinflammatory cytokine activation and hepatotoxicity was significantly attenuated in mice deficient in the NLRP3 inflammasome, demonstrating the critical role of this innate immune system recognition receptor in the response to NP.  相似文献   
35.
IntroductionThe glans penis is prone to mutilation in a handful of conditions, some accidental and others iatrogenic. Deformed functioning remnants of the glans challenge the surgeon's decision. Neither is the glans totally amputated, justifying a neoglansplasty, nor are the remnants cosmetically acceptable, though retaining sensibility and engorgement.AimIn this work, we described the “reconfiguration of the glans penis” whereby deformed glanular tissue remnants can be made into a functional and cosmetically acceptable glans.MethodsFive patients with separate mutilated lumps of functioning glanular tissue were operated upon. The lumps were mobilized and flattened into sheets and configured to redrape the summit of the penis, minding their vascular and nerve supply.Main Outcome MeasuresCosmetic and functional outcome.ResultsThe outcome was cosmetically acceptable for all patients in comparison to the preoperative state.ConclusionGlans reconfiguration may possibly confer an acceptable cosmetic outlook to a mutilated glans without compromising valuable functional characteristics. Shaeer O, El-Sebaie A, Sherif A, El-Sadat A, and Shaeer A. Glans reconfiguration for management of glanular mutilation.  相似文献   
36.
STUDY OBJECTIVE: The presence of fimbrial pathology in advanced endometriosis is clearly understood. However, little is known about the prevalence of fimbrial pathology in early stages of endometriosis. The purpose of this study is to determine the prevalence of fimbrial pathology in patients with infertility with early stages of endometriosis. DESIGN: Historical cohort study (Canadian Task Force classification II/III). SETTING: Tertiary referral center. PATIENTS: The study group (Group 1) consisted of 315 infertile women who were found to have stage I or stage II endometriosis, and the control group (Group 2) consisted of 152 infertile women without endometriosis (Group 2). INTERVENTION: Laparoscopic evaluation for the presence and type of fimbrial pathology. MEASUREMENTS AND MAIN RESULTS: The prevalence of fimbrial pathology was significantly higher in infertile patients with early stages of endometriosis (50.2%) compared with infertile patients with no endometriosis (17.8%, p <.0001). CONCLUSION: These preliminary data suggest the presence of fimbrial pathology in many patients with early stages of endometriosis. Such pathology may act as a mechanical factor interfering with the ovum pick-up mechanism.  相似文献   
37.
The cytochemical distribution of Na-K-ATPase was demonstrated in the guinea-pig myocardium. The hearts were fixed with paraformaldehyde glutaraldehyde mixture, sections were incubated at room temperature in modified Ernst medium employing p-nitrophenyl phosphate as substrate and the tissue was processed for electron microscopy. The ATPase activity was localized in the subsarcolemmal cisterns, inner side of plasma membrane, T-tubules, free and junctional sarcoplasmic reticulum and capillary endothelium. The reaction product on the plasma membrane and T-tubules was inhibited by ouabain or by potassium deletion. However, the amount of precipitation in mitochondria, sarcoplasmic reticulum (free and junctional) and subsarcolemmal cisterns remained unaffected by ouabain or by potassium deletion. The enzyme reaction in the myocardium represents ouabain-sensitive, potassium-dependent ATPase.  相似文献   
38.
39.
Exclusive breastfeeding (EBF) for the first 6 months has established benefits, yet had slow improvements globally. Little is known about electronic job aid‐assisted counselling to support EBF. As a secondary outcome of a cluster randomized controlled trial in Bangladesh, we assessed the effect of electronic job aid‐supported nutrition counselling and practical demonstration on EBF. We randomized pregnant women to one of five study arms in the trial and followed mother–child dyads until 2 years of age. Community health workers (CHWs) provided breastfeeding counselling with or without prenatal and complementary nutrient supplements in all four intervention arms. The comparison arm continued with the usual practice where mothers could receive nutrition counselling at routine antenatal and postnatal care, and during careseeking for childhood illnesses. We assessed breastfeeding indicators at birth and monthly until the child was 6 months old, in both intervention and comparison arms. To evaluate the effect of nutrition counselling on breastfeeding, we combined all four intervention arms and compared them with the comparison arm. Intervention newborns had half the risk (relative risk [RR]: 0.54, 95% confidence interval [CI]: 0.39, 0.76) of receiving prelacteal feeds than those in the comparison arm. EBF declined steeply in the comparison arm after 3 months of age. EBF was 16% higher in the intervention than the comparison arm at 4 months (RR: 1.16, 95% CI: 1.08, 1.23) and 22% higher at 5 months of age (RR: 1.22, 95% CI: 1.12, 1.33). Maternal background and household characteristics did not modify the intervention effect, and we observed no difference in EBF among caesarean versus vaginal births. Breastfeeding counselling and practical demonstration using an electronic job aid by CHWs are promising interventions to improve EBF and are scalable into existing community‐based programmes.  相似文献   
40.
The present study aimed to design and optimize, a nanoconjugate of gabapentin (GPN)-melittin (MLT) and to evaluate its healing activity in rat diabetic wounds. To explore the wound healing potency of GPN-MLT nanoconjugate, an in vivo study was carried out. Diabetic rats were subjected to excision wounds and received daily topical treatment with conventional formulations of GPN, MLT, GPN-MLT nanoconjugate and a marketed formula. The outcome of the in vivo study showed an expedited wound contraction in GPN-MLT-treated animals. This was confirmed histologically. The nanoconjugate formula exhibited antioxidant activities as evidenced by preventing malondialdehyde (MDA) accumulation and superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic exhaustion. Further, the nanoconjugate showed superior anti-inflammatory activity as it inhibited the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). This is in addition to enhancement of proliferation as indicated by increased expression of transforming growth factor-β (TGF- β), vascular endothelial growth factor-A (VEGF-A) and platelet-derived growth factor receptor-β (PDGFRB). Also, nanoconjugate enhanced hydroxyproline concentration and mRNA expression of collagen type 1 alpha 1 (Col 1A1). In conclusion, a GPN-MLT nanoconjugate was optimized with respect to particle size. Analysis of pharmacokinetic attributes showed the mean particle size of optimized nanoconjugate as 156.9 nm. The nanoconjugate exhibited potent wound healing activities in diabetic rats. This, at least partly, involve enhanced antioxidant, anti-inflammatory, proliferative and pro-collagen activities. This may help to develop novel formulae that could accelerate wound healing in diabetes.  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