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   590篇
  免费   27篇
耳鼻咽喉   6篇
儿科学   24篇
妇产科学   18篇
基础医学   89篇
口腔科学   8篇
临床医学   41篇
内科学   100篇
皮肤病学   16篇
神经病学   48篇
特种医学   59篇
外科学   82篇
预防医学   40篇
眼科学   4篇
药学   17篇
中国医学   6篇
肿瘤学   59篇
  2024年   5篇
  2023年   11篇
  2022年   16篇
  2021年   24篇
  2020年   14篇
  2019年   17篇
  2018年   20篇
  2017年   14篇
  2016年   16篇
  2015年   23篇
  2014年   28篇
  2013年   30篇
  2012年   44篇
  2011年   49篇
  2010年   22篇
  2009年   18篇
  2008年   32篇
  2007年   20篇
  2006年   38篇
  2005年   34篇
  2004年   16篇
  2003年   22篇
  2002年   17篇
  1997年   5篇
  1996年   3篇
  1995年   3篇
  1994年   4篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1989年   5篇
  1988年   1篇
  1987年   3篇
  1986年   8篇
  1985年   3篇
  1984年   5篇
  1983年   5篇
  1982年   2篇
  1981年   2篇
  1979年   5篇
  1978年   2篇
  1977年   3篇
  1976年   1篇
  1975年   3篇
  1974年   5篇
  1973年   1篇
  1972年   3篇
  1971年   3篇
  1970年   3篇
  1969年   2篇
排序方式: 共有617条查询结果,搜索用时 15 毫秒
21.
OBJECTIVE: We assessed a new estradiol (E2) immunoassay on the Architect-i2000 (Abbott Laboratories) for monitoring ovulation stimulation for IVF-ET and re-establishing clinical cut-off points. The method has been modified to improve E2 measurements especially at normal and low concentrations. DESIGN AND METHOD: E2 was determined for 552 samples, from 83 women, presenting normal follicular status and undergoing 100 cycles of IVF treatment. We assessed the value of this assay for down-regulation of E2 concentration limit using gonadoliberin-releasing hormone agonist (GnRHa), and monitoring of the ovarian hyperstimulation, expected range of E2 per mature follicle prior to the administration of exogenous hCG and day 3 concentration limit. We compared results with our routine method (E2-6II Advia-Centaur; Siemens-Diagnostics) for which decision-making values were known. RESULTS: Considering E2 concentrations obtained with the new Architect-i2000 assay for patients treated with GnRHa for 2 weeks, the cutoff-point for ovarian down-regulation should be set down at 110 pmol/L to maintain 100% of sensitivity. Considering day 3 concentration limit determination, results were not significantly different from those obtained with our routine method. The mean E2 values per mature follicle fell into the range generally expected. CONCLUSION: E2 determination with the new E2 Architect-i2000 assay could be used to monitor ovulation, in patients undergoing IVF-ET, in combination with transvaginal ultrasound.  相似文献   
22.
23.

Background

Patients with stage IV colorectal cancer and peritoneal carcinomatosis are increasingly treated with curative intent and perioperative systemic chemotherapy combined with targeted therapy. The aim of this study was to analyze the potential impact of bevacizumab on early morbidity after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with peritoneal carcinomatosis of colorectal origin.

Methods

From 2004 to 2010, in three referral centers, 182 patients with colorectal carcinomatosis were treated with complete cytoreduction followed by HIPEC after either preoperative systemic chemotherapy alone or in combination with bevacizumab. Because there was no control on treatment allocation, propensity score methods were used to control for this bias.

Results

The median time from discontinuation of bevacizumab to HIPEC was 7 weeks (range 6–10 weeks). Major morbidity was greater in the bevacizumab group (34 vs. 19 %, p = 0.020). Nine patients died postoperatively, 5 (6.2 %) in the bevacizumab group (n = 80) and 4 (3.9 %) in the group treated with chemotherapy alone (n = 102) (p = 0.130). The rate of digestive fistulas was greater in the bevacizumab group, although not statistically significant (18 vs. 10 %, p = 0.300). The effect of bevacizumab on major morbidity (including death) was found to be statistically significant (odds ratio 2.28, 95 % confidence interval 1.05–4.95) (p = 0.04).

Conclusions

Administration of bevacizumab before surgery with complete cytoreduction followed by HIPEC for colorectal carcinomatosis is associated with twofold increased morbidity. The oncologic benefit of bevacizumab before HIPEC remains to be evaluated.  相似文献   
24.
Background: Development of the epidermal permeability barrier (EPB) is essential for neonatal life. Defects in this barrier are found in many skin diseases such as atopic dermatitis.Objective: We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development and function of the EPB.Methods: Timed-pregnant C57BL/6J mice were gavaged with corn oil or TCDD (10 μg/kg body weight) on gestation day 12. Embryos were harvested on embryonic day (E) 15, E16, E17, and postnatal day (PND) 1.Results: A skin permeability assay showed that TCDD accelerated the development of the EPB, beginning at E15. This was accompanied by a significant decrease in transepidermal water loss (TEWL), enhanced stratification, and formation of the stratum corneum (SC). The levels of several ceramides were significantly increased at E15 and E16. PND1 histology revealed TCDD-induced acanthosis and epidermal hyperkeratosis. This was accompanied by disrupted epidermal tight junction (TJ) function, with increased dye leakage at the terminal claudin-1–staining TJs of the stratum granulosum. Because the animals did not have enhanced rates of TEWL, a commonly observed phenotype in animals with TJ defects, we performed tape-stripping. Removal of most of the SC resulted in a significant increase in TEWL in TCDD-exposed PND1 pups compared with their control group.Conclusions: These findings demonstrate that in utero exposure to TCDD accelerates the formation of an abnormal EPB with leaky TJs, warranting further study of environmental exposures, epithelial TJ integrity, and atopic disease.Citation: Muenyi CS, Leon Carrion S, Jones LA, Kennedy LH, Slominski AT, Sutter CH, Sutter TR. 2014. Effects of in utero exposure of C57BL/6J mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin on epidermal permeability barrier development and function. Environ Health Perspect 122:1052–1058; http://dx.doi.org/10.1289/ehp.1308045  相似文献   
25.
Background: Chronotype, phase preference to perform activities during a 24-hour day, represents distinct circadian temporal organization of living organisms. Morning and evening types can be identified by questionnaires such as Horne and Östberg (HO) and Munich Chronotype Questionnaire (MCTQ). Environmental factors, such as different light–dark cycles experienced at different latitudes, interact with the organisms’ circadian timekeeping system. Therefore, chronotype is expected to vary as a result of different geographical locations.

Aim: To identify differences in chronotype distribution in populations of two Brazilian cities, Natal and Sao Paulo, located at different latitudes.

Subjects and methods: Two specific questionnaires, the Horne and Östberg Questionnaire (HO) and the Munich Chronotype Questionnaire (MCTQ), were used to identify chronotypes of undergraduate students from São Paulo and Natal.

Results: The comparison of the curve distributions of HO and MCTQ scores between both cities allowed one to observe that, while HO curves of São Paulo and Natal overlapped, MCTQ curves showed a clear shift towards eveningness in São Paulo.

Conclusion: This experiment confirmed results from previous studies that the farther away from the equator, the longer the delay of the sleep phase. It was also concluded that MCTQ is better at detecting this phenomenon.  相似文献   

26.
HHV-6 is the etiological agent of Exanthem subitum which is considered the sixth most frequent disease in infancy. In immuno-compromised hosts, reactivation of latent HHV-6 infection may cause severe acute disease. We developed a Sybr Green Real Time PCR for HHV-6 and compared the results with nested conventional PCR. A 214 pb PCR derived fragment was cloned using pGEM-T easy from Promega system. Subsequently, serial dilutions were made in a pool of negative leucocytes from 10-6 ng/microL (equivalent to 2465.8 molecules/microL) to 10-9 (equivalent to 2.46 molecules/microL). Dilutions of the plasmid were amplified by Sybr Green Real Time PCR, using primers HHV3 (5' TTG TGC GGG TCC GTT CCC ATC ATA 3)'and HHV4 (5' TCG GGA TAG AAA AAC CTA ATC CCT 3') and by conventional nested PCR using primers HHV1 (outer): 5'CAA TGC TTT TCT AGC CGC CTC TTC 3'; HHV2 (outer): 5' ACA TCT ATA ATT TTA GAC GAT CCC 3'; HHV3 (inner) and HHV4 (inner) 3'. The detection threshold was determined by plasmid serial dilutions. Threshold for Sybr Green real time PCR was 24.6 molecules/microL and for the nested PCR was 2.46 molecules/microL. We chose the Real Time PCR for diagnosing and quantifying HHV-6 DNA from samples using the new Sybr Green chemistry due to its sensitivity and lower risk of contamination.  相似文献   
27.
TCD8+ cells may be divided into subsets with different phenotypes and functions: naive, central memory, effector memory and effector. Aiming to better understand the differences in early reconstitution of these TCD8+ cell subsets and their relationship with post-transplant anti-cytomegalovirus (CMV) immune responses recovery, we prospectively analyzed the transfer and expansion of these subsets in different transplant types. We found that graft cells from donor's peripheral blood, either allogeneic or autologous, were enriched for central memory, effector memory and effector phenotypes compared to allogeneic bone marrow grafts, as assessed by surface markers phenotyping and granzyme B expression. However, post-transplant, these subsets expanded in autologous recipients only, reaching numbers much greater than in allo-recipients at days +29 and +96. At the same time, autologous recipients presented less CMV reactivation and more vigorous CMV-induced interferon-gamma and lymphoproliferative responses. The marked loss of allo-transferred memory TCD8+ cells was probably due to the fact that they were more activated and more prone to apoptosis than auto-transferred TCD8+ cells as assessed by CD69 and active caspase 3 expression. Thus, transfer of peripheral blood stem cells in the allogeneic but not autologous setting is associated with poor expansion of memory TCD8+ cells, probably delaying antiviral immune reconstitution. These data may have important implications for the design of better strategies to immunoprotect this population against infectious challenges since different transplant types have different potentials for memory TCD8+ cells transfer and expansion.  相似文献   
28.
Mandibulofacial dysostosis, Guion‐Almeida type (MFDGA) is a recently delineated multiple congenital anomalies/mental retardation syndrome characterized by the association of mandibulofacial dysostosis (MFD) with external ear malformations, hearing loss, cleft palate, choanal atresia, microcephaly, intellectual disability, oesophageal atresia (OA), congenital heart defects (CHDs), and radial ray defects. MFDGA emerges as a clinically recognizable entity, long underdiagnosed due to highly variable presentations. The main differential diagnoses are CHARGE and Feingold syndromes, oculoauriculovertebral spectrum, and other MFDs. EFTUD2, located on 17q21.31, encodes a component of the major spliceosome and is disease causing in MFDGA, due to heterozygous loss‐of‐function (LoF) mutations. Here, we describe a series of 36 cases of MFDGA, including 24 previously unreported cases, and we review the literature in order to delineate the clinical spectrum ascribed to EFTUD2 LoF. MFD, external ear anomalies, and intellectual deficiency occur at a higher frequency than microcephaly. We characterize the evolution of the facial gestalt at different ages and describe novel renal and cerebral malformations. The most frequent extracranial malformation in this series is OA, followed by CHDs and skeletal abnormalities. MFDGA is probably more frequent than other syndromic MFDs such as Nager or Miller syndromes. Although the wide spectrum of malformations complicates diagnosis, characteristic facial features provide a useful handle.  相似文献   
29.
Aniridia, Wilms tumor, genitourinary abnormalities, growth and mental retardation are the cardinal features of the WAGR 11p13 deletion syndrome. The Potocki-Schaffer syndrome or proximal 11p deletion syndrome (previously DEFECT11 syndrome) is a contiguous gene syndrome associated with deletions in 11p11.2, principal features of which are multiple exostoses and enlarged parietal foramina. Mental handicap, facial dysmorphism and craniosynostosis may also be associated. We report a patient with combined WAGR and Potocki-Shaffer syndromes, and obesity. She presented with aniridia, cataract, nystagmus, corneal ulcers and bilateral congenital ptosis. A left nephroblastoma was detected at 15 months. Other features included moderate developmental delay, growth deficiency, facial dysmorphism, multiple exostoses and cranial lacunae. High-resolution and molecular cytogenetics confirmed a del(11)(p11.2p14.1) deletion with a proximal breakpoint between the cosmid DO8153 and the BAC RP11-104M24 to a distal breakpoint between cosmids CO8160 (D11S151) and F1238 (D11S1446). The deletion therefore includes EXT2, ALX4, WT1 and PAX6. This case appears to be the second patient reported with this combined deletion syndrome and confirms the association of obesity in the WAGR spectrum, a feature previously reported in four cases, and for which the acronym WAGRO has been suggested. Molecular and follow-up data on the original WAGRO case are briefly presented.  相似文献   
30.
Hematopoietic stem cell transplant recipients lose immune memory of exposure to infectious agents and vaccines accumulated through a lifetime, and therefore need to be revaccinated. Reimmunization protocols vary greatly among hematopoietic stem cell transplant centers. Diphtheria and tetanus toxoids, pertussis vaccine, Haemophilus influenza type B conjugate, 23-valent pneumococcal polysaccharide, inactivated influenza and polio vaccine and live attenuated measles-mumps-rubella vaccine are the currently recommended vaccines to be included in a vaccination program after hematopoietic stem cell transplant. Other variables, such as stem cell source, new adjuvants, T-cell depleted transplants, nonmyeloablative conditioning and donor immunization have recently been introduced and a constant update of current recommendations are needed. Studies recently published, the use of other vaccines and the perspectives for different vaccination protocols are discussed in this review.  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