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   1648篇
  免费   137篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   120篇
妇产科学   37篇
基础医学   211篇
口腔科学   10篇
临床医学   222篇
内科学   294篇
皮肤病学   20篇
神经病学   165篇
特种医学   58篇
外科学   125篇
综合类   59篇
一般理论   2篇
预防医学   236篇
眼科学   36篇
药学   65篇
中国医学   1篇
肿瘤学   120篇
  2023年   14篇
  2022年   17篇
  2021年   50篇
  2020年   25篇
  2019年   31篇
  2018年   46篇
  2017年   36篇
  2016年   28篇
  2015年   44篇
  2014年   57篇
  2013年   82篇
  2012年   105篇
  2011年   99篇
  2010年   63篇
  2009年   67篇
  2008年   84篇
  2007年   88篇
  2006年   67篇
  2005年   91篇
  2004年   79篇
  2003年   68篇
  2002年   79篇
  2001年   31篇
  2000年   25篇
  1999年   35篇
  1998年   33篇
  1997年   16篇
  1996年   16篇
  1995年   7篇
  1994年   13篇
  1993年   23篇
  1992年   17篇
  1991年   23篇
  1990年   12篇
  1989年   11篇
  1988年   17篇
  1987年   8篇
  1986年   13篇
  1985年   23篇
  1984年   7篇
  1983年   14篇
  1982年   11篇
  1981年   8篇
  1980年   17篇
  1979年   8篇
  1974年   6篇
  1973年   5篇
  1972年   6篇
  1971年   5篇
  1967年   5篇
排序方式: 共有1788条查询结果,搜索用时 31 毫秒
51.
INTRODUCTIONOne-third of the world's population is infected with tuberculosis (TB), with intestinal TB representing the sixth most common presentation of extrapulmonary TB. The diagnosis of intestinal TB is a challenge for physicians due to its diverse clinical manifestations that mimic other infectious, autoimmune, and neoplastic disorders, and is thus rarely considered as the causative agent of disease.PRESENTATION OF CASEWe present a 55-year-old male with no relevant familial history, who presented due to a loss of 10 kg of weight in 2 months accompanied by nocturnal diaphoresis and continuous abdominal distension.DISCUSSIONThe incidence and the severity of intestinal TB are increased in immunosuppressed patients and more rapidly progress due to deficient immune response. However, our immunocompetent had severe progression resulting in surgery less than a month after the diagnosis was made.CONCLUSIONWhile the diagnosis of intestinal TB, and specifically colonic TB, is difficult and is almost never the first diagnosis entertained outside the immunocompromised population, we present a rare case in which the disease presents in an immunocompetent patient.  相似文献   
52.
53.
Aim: Circulating immune cell activation is associated with worse outcome in adult and animal models of brain injury. Our aim was to profile the systemic inflammatory response over the first week of life in infants at risk of neonatal encephalopathy (NE) and correlate early neutrophil and monocyte endotoxin and activation responses with outcome.

Methods: Prospective observational study in a tertiary referral university hospital including 22 infants requiring resuscitation at birth who had serial (five time points) neutrophil and monocyte CD11b (marker of cell adhesion), intracellular reactive oxygen intermediates (ROI; cell activation) and Toll-like receptor (TLR; endotoxin recognition) before and after endotoxin stimulation ex vivo compared to neonatal controls.

Results: All neonates requiring resuscitation at delivery (n?=?122 samples) had higher neutrophil and monocyte CD11b and TLR-4 expression compared with adults and neonatal controls. Neonates with abnormal neuroimaging and/or severe NE had increased CD11b, ROI and TLR-4. Increased polymorphonuclear leukocytes TLR-4 expression was associated with increased mortality in infants with NE.

Conclusion: Innate immune dysregulation in the first week of life is associated with severity of outcome in neonatal brain injury in this cohort and may be amenable to immunomodulation.  相似文献   
54.
55.
Pediatric thyroid cancer is rare in children; however, incidence is increasing. Papillary thyroid cancer and follicular thyroid cancer are the most common subtypes, comprising about 90% and 10% of cases, respectively. This paper provides consensus imaging recommendations for evaluation of pediatric patients with thyroid cancer at diagnosis and during follow-up.  相似文献   
56.
Adrenal tumors other than neuroblastoma are uncommon in children. The most frequently encountered are adrenocortical carcinoma and pheochromocytoma. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary adrenal malignancy other than neuroblastoma at diagnosis and during follow-up.  相似文献   
57.

Background

Diagnostic mIBG (meta-iodobenzylguanidine) scans are an integral component of response assessment in children with high-risk neuroblastoma. The role of end-of-induction (EOI) Curie scores (CS) was previously described in patients undergoing a single course of high-dose chemotherapy (HDC) and autologous hematopoietic cell transplant (AHCT) as consolidation therapy.

Objective

We now examine the prognostic significance of CS in patients randomized to tandem HDC and AHCT on the Children's Oncology Group (COG) trial ANBL0532.

Study design

A retrospective analysis of mIBG scans obtained from patients enrolled in COG ANBL0532 was performed. Evaluable patients had mIBG-avid, International Neuroblastoma Staging System (INSS) stage 4 disease, did not progress during induction therapy, consented to consolidation randomization, and received either single or tandem HDC (n = 80). Optimal CS cut points maximized the outcome difference (≤CS vs. >CS cut-off) according to the Youden index.

Results

For recipients of tandem HDC, the optimal cut point at diagnosis was CS = 12, with superior event-free survival (EFS) from study enrollment for patients with CS ≤ 12 (3-year EFS 74.2% ± 7.9%) versus CS > 12 (59.2% ± 7.1%) (p = .002). At EOI, the optimal cut point was CS = 0, with superior EOI EFS for patients with CS = 0 (72.9% ± 6.4%) versus CS > 0 (46.5% ± 9.1%) (p = .002).

Conclusion

In the setting of tandem transplantation for children with high-risk neuroblastoma, CS at diagnosis and EOI may identify a more favorable patient group. Patients treated with tandem HDC who exhibited a CS ≤ 12 at diagnosis or CS = 0 at EOI had superior EFS compared to those with CS above these cut points.  相似文献   
58.
Hypertrophy is an adaptive response of the heart to myocardial injury or hemodynamic overload that may progress and contribute to cardiac decompensation and eventually to heart failure. The signaling pathways controlling this response in the cardiac myocyte are poorly understood. A data mining effort of a human failed heart cDNA library was undertaken in an effort to identify novel signaling molecules involved in cardiac hypertrophy. This effort identified a novel kinase (MLK7) homologous to the mixed lineage kinase family of proteins. The mixed lineage kinases are mitogen-activated protein kinase kinase kinases (MAPKKKs) which activate stress activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) and p38 kinase pathways. They contain a catalytic domain with homology to both serine/threonine and tyrosine-specific kinases and a dual leucine zipper. MLK7 is identical to leucine zipper and sterile-alpha motif protein kinase (ZAK) through the leucine zipper domain but has a completely divergent COOH-terminus and shares approximately 40% homology with the other MLKs overall. Expression of MLK7 mRNA is most abundant in skeletal muscle and heart, with expression restricted to the cardiac myocyte. The recombinant histidine tagged MLK7 expressed and purified from insect cells exhibited serine/threonine kinase activity in vitro with myelin basic protein as substrate. When expressed in cardiac myocytes, MLK7 activated SAPK/JNK1, and ERK and p38 to a lesser extent. Additionally, MLK7 altered fetal gene expression and increased protein synthesis in cardiac myocytes. These data suggest that MLK7 is a new member of the mixed lineage kinase family that modulates cardiac SAPK/JNK pathway and may play a role in cardiac hypertrophy and progression to heart failure.  相似文献   
59.
Explanations for biogeographic disjunctions involving South America and Africa typically invoke vicariance of western Gondwanan biotas or long distance dispersal. These hypotheses are problematical because many groups originated and diversified well after the last known connection between Africa and South America (approximately 105 million years ago), and it is unlikely that "sweepstakes" dispersal accounts for many of these disjunctions. Phylogenetic analyses of the angiosperm clade Malpighiaceae, combined with fossil evidence and molecular divergence-time estimates, suggest an alternative hypothesis to account for such distributions. We propose that Malpighiaceae originated in northern South America, and that members of several clades repeatedly migrated into North America and subsequently moved via North Atlantic land connections into the Old World during episodes starting in the Eocene, when climates supported tropical forests. This Laurasian migration route may explain many other extant lineages that exhibit western Gondwanan distributions.  相似文献   
60.
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