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   4423篇
  免费   404篇
  国内免费   134篇
耳鼻咽喉   31篇
儿科学   98篇
妇产科学   155篇
基础医学   539篇
口腔科学   234篇
临床医学   377篇
内科学   632篇
皮肤病学   66篇
神经病学   321篇
特种医学   173篇
外国民族医学   2篇
外科学   338篇
综合类   355篇
现状与发展   1篇
预防医学   530篇
眼科学   72篇
药学   592篇
中国医学   139篇
肿瘤学   306篇
  2024年   10篇
  2023年   113篇
  2022年   174篇
  2021年   245篇
  2020年   211篇
  2019年   220篇
  2018年   199篇
  2017年   201篇
  2016年   177篇
  2015年   193篇
  2014年   273篇
  2013年   398篇
  2012年   236篇
  2011年   242篇
  2010年   204篇
  2009年   200篇
  2008年   205篇
  2007年   224篇
  2006年   178篇
  2005年   163篇
  2004年   133篇
  2003年   94篇
  2002年   96篇
  2001年   68篇
  2000年   53篇
  1999年   48篇
  1998年   44篇
  1997年   42篇
  1996年   32篇
  1995年   24篇
  1994年   23篇
  1993年   25篇
  1992年   24篇
  1991年   25篇
  1990年   17篇
  1989年   22篇
  1988年   19篇
  1987年   13篇
  1986年   11篇
  1985年   12篇
  1984年   14篇
  1983年   12篇
  1982年   11篇
  1981年   6篇
  1980年   5篇
  1979年   6篇
  1977年   4篇
  1976年   7篇
  1974年   1篇
  1973年   2篇
排序方式: 共有4961条查询结果,搜索用时 31 毫秒
1.
Introduction: Dysregulation of histone deacetylase (HDAC) activity is an epigenetic hallmark of multiple myeloma (MM), leading to aberrant gene expression and cellular signaling in myeloma cell growth, survival and resistance to therapy. Hyper-methylation at diagnosis is a frequent observation, which eventually may convert to hypo-methylation during advanced phases.

Areas covered: A literature search on ‘HDAC inhibitors’ and ‘multiple myeloma’ was carried out using PubMed and Google Scholar in the preparation of this overview on clinical efficacy and safety data.

Expert opinion: First-generation non-selective HDAC inhibitors have demonstrated minimal single-agent activity in refractory MM. Subsequently, combination therapy has proven an improvement in progression-free survival (PFS) but not response rates. The main concerns are associated with toxicities. Ongoing studies on new and more selective agents, i.e. Romidepsin or Ricolinostat, are promising in terms of better efficacy and less toxicity.  相似文献   

2.
BackgroundThe optimal management of community acquired pneumonia (CAP) depends on the clinical and microbiological profile in the locality.ObjectivesTo determine the clinical and microbiological profile of patients admitted with CAP in Ilorin, Nigeria.MethodsOne hundred and two consenting consecutively selected patients with clinical and radiologic confirmation of CAP were recruited in 12 months. The socio-demographic, physical examination and laboratory/radiologic parameters were documented in a questionnaire. Microbiological evaluation of their sputum was done and blood samples were taken for complete blood count, culture, serum urea and serological evaluation for atypical bacteria and some viral pathogens.ResultsCAP constituted 5.9% of the total medical admissions during the one-year study period. The mean age of the patients was 49 ± 22 years with the largest frequency in those aged 65 years and above. The commonest symptoms were shortness of breath (96.1%) and cough (94.1%), with a median duration of 3 days from symptom onset to admission. Systemic hypertension was the commonest comorbid illness (25/102; 24.5%). Klebsiella pneumoniae was the predominant pathogen isolated (20/102; 28.1%). The susceptible antibiotics were Imipenem, Ceftazidime and Ceftriaxone. Intra-hospital mortality was 17.6%. CURB – 65 score of ≥ 2 and the presence of complications of CAP were the independent predictors of mortality.ConclusionCAP constitutes a significant disease burden in Ilorin, Nigeria. Typical bacteria accounted for over half of the pathogens isolated from the patients with gram negative agents predominating. This highlights a possible shift in the microbiological profile which could guide empirical treatment.  相似文献   
3.
Objective The present study aims to investigate the concentrations of Hg and its aspects methyl mercury(Me-Hg) and inorganic mercury(I-Hg) in the biological samples(BSs) of fluorescent lamp industries workers(FLIWs).Methodology Different BSs including red blood cells(RBCs),plasma,urine,hair and nails were collected from the workers exposed to Hg and unexposed persons were selected as control group to measure both the T-Hg concentration as well as its species in different biological samples through quantitative analysis.Health data was collected through questionnaire survey.Results The mean concentrations of T-Hg(31.9 μg/L),Me-Hg(27.7 μg/L),and I-Hg(5.36 μg/L) in RBCs were found significantly(P 0.001) higher among the workers(n = 40) as compared to the control group(n = 40).Similarly the mean Hg concentrations in plasma,urine,hair and nails were also significantly higher among the workers than the control group.The statistical relation between Hg concentration and demographic characteristics observed that workers experience and fish consumption has increased the Hg concentration while age,weight and smoking found no significant effect on Hg concentration in the BSs.Conclusion The study observed that the workers were highly exposed to high concentration of Hg and they are at a high health risk.  相似文献   
4.
ObjectiveThe beneficial effects of carnitine supplementation on nonalcoholic fatty liver disease are unclear. We conducted a systematic review and meta-analysis to evaluate the effects of carnitine supplementation on liver function, lipid profile, body mass index, body weight, and homeostasis model assessment of insulin resistance in patients with nonalcoholic fatty liver disease.MethodsA comprehensive search of PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar databases were performed. Only randomized placebo-controlled human studies that examined the effects of carnitine supplementation on liver function, lipid profile, body mass index, body weight, and homeostasis model assessment of insulin resistance up to September 2019 were included. Fixed effects or random-effects models were applied to compute the pooled effect size. Heterogeneity assessments were performed using Cochran’s Q test and I-squared statistics. The quality of the studies was assessed using the Jaded scale.ResultsA total of 5 articles were selected, including 334 individuals (167 in control and 167 in intervention groups). The results demonstrated that carnitine supplementation significantly reduced homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: −0.91; 95 % CI: −1.11, −0.72; p < 0.001, I2 = 0.0 %) and the levels of aspartate aminotransferase (AST) (WMD: −16.62; 95 % CI: −28.11, −5.14; IU/l; p = 0.005, I2 = 93.5 %), alanine aminotransferase (ALT) (WMD: -33.39; 95 % CI: −45.13, −21.66; IU/l; p < 0.001, I2 = 93.4 %), and triglycerides (TG) (WMD: −22.13; 95 % CI: −38.91, −5.34; mg/dl; p = 0.01; I2 = 0.0 %). However, the results of the pooled effect size did not show any significant effect of carnitine supplementation on body mass index (BMI) (WMD: 0.07; 95 % CI: −0.15, 0.29; p = 0.55; I2 = 0.0 %), body weight (WMD: −0.28; 95 % CI: −2.23, 1.68; p = 0.78; I2 = 45.7 %), the levels of gamma-glutamyl transferase (γGT) (WMD: −11.31; 95 % CI: −24.35, 1.73; IU/l; p = 0.09, I2 = 61.1 %), cholesterol (WMD: −13.58; 95 % CI: −46.77, 19.60; mg/dl; p = 0.42; I2 = 94.9 %), high-density lipoprotein-cholesterol (HDL-C) (WMD: 1.36; 95 % CI: −0.96, 3.68; mg/dl; p = 0.25; I2 = 64.7 %), and low density lipoprotein-cholesterol (LDL-C) (WMD: −14.85; 95 % CI: −45.43, 15.73; mg/dl; p = 0.34; I2 = 96.4 %).ConclusionsThis analysis shows that carnitine supplementation for patients with nonalcoholic fatty liver disease demonstrates a reduction in AST, ALT, TG levels and HOMA-IR. However, no significant effect of carnitine supplementation was observed on BMI, body weight, the levels of γGT, TC, HDL-cholesterol and LDL-cholesterol.  相似文献   
5.
6.
《Revue neurologique》2022,178(8):817-825
Current screening batteries for assessing neuropsychological function are not specific for Amyotrophic Lateral Sclerosis (ALS) and are considered as limited tools due to the physical disabilities associated with ALS. The Edinburgh Cognitive and Behavioural ALS screen (ECAS) was developed to detect the specific cognitive and behavioral changes that may occur among ALS patients. This study presents the ECAS developed for Arabic-speaking ALS patients (ECAS-AR) for use by healthcare professionals. ECAS was translated and modified to refined variety of Arabic language. Eighty-five ALS patients were included. Normative data were collected from 200 healthy controls (among them 97 were matched). Subjects were administered the ECAS-AR and two conventional cognitive screening batteries, Frontal Assessment Battery (FAB) and Mini-Mental State Examination (MMSE). ECAS-AR discriminated well between healthy controls and ALS patients. Significant differences were noted in language, executive functions, memory, and visuospatial domains between the two groups. The most prevalent deficit occurred in language and executive functions in ALS-specific functions. Whereas memory was more readily impaired in the lower and middle education groups concerning ALS non-specific functions. Verbal fluency tended to be preserved. Positive correlations were found between ECAS-AR and the standard cognitive tests supporting its full validity. The ECAS-AR version proposed will provide rapid, efficient and sensitive tools for healthcare professional to determine the cognitive-behavioural profile in Arabic-speaking ALS patients.  相似文献   
7.
We developed a semiautomatic method termed “cortical circumferential profiling” for objective analysis of cerebral cortex function in emission tomographic neuroimaging studies. This method treats cortex as a continuous ring near the outer brain edge. A computer algorithm samples the cortex at 60 contiguous, equiangular locations, using 1-cm2 samples. These values are plotted as a function of cortical angle to produce the cortical circumferential profile. This method was used in a study of regional cerebral perfusion in 15 patients with Alzheimer's disease and 8 elderly control subjects using N-isopropyl [I-123]-iodoamphetamine. Cortical circumferential profiling decreases variability, examines the entire cortex within slices at preselected levels above the orbital-meatal line, and facilitates intrasubject and intersubject comparisons.  相似文献   
8.
Recently, Korean people are consuming seaweeds almost 3.5 times more now than three decades ago. It is well known that seaweeds contain lots of soluble dietary fiber in addition to micronutrients such as β-carotene, iodine and some bioactive components. Seaweeds are considered to be effective for preventing chronic diseases including obesity, diabetes mellitus, atherosclerosis, cancer or constipation. This study was conducted to investigate the effect of seamustard intake on body weight gain, blood glucose level and lipid profiles in rats fed diets with different energy nutrient composition. Male Sprague-Dawley rats (average initial weight 103.7 g) were divided into groups for two experiments as follows; Control, M2.5 & M5 groups (Exp. I) and M5, M10, HCM5, HCM10, HFM5 & HFM10 groups (Exp. II). The rats were fed diet and water ad libitum for 4 weeks. In general, there was no significant difference in blood glucose and triglyceride concentration among groups. In Exp. I, serum LDL-cholesterol level of rats fed diet with 5% seamustard powder (M5) was significantly lower than that of control group, while HDL-cholesterol level, TC/LDL ratio and weight of adrenal gland were higher. In Exp. II, food intake, body weight gain and EER of high fat diet with 10% seamustard group (HFM10) were the lowest among groups. Except gastrocnemius muscle, all organ weights of HFM10 group were the lowest. Fecal cholesterol excretion and serum LDL-cholesterol concentration of HFM10 group were the highest, while serum HDL-cholesterol level was the lowest among groups. Interestingly, HDL-cholesterol concentration was the highest in HCM5 group among groups. From these results, it was suggested that seamustard intake might be more effective for body weight control, but not for improving blood lipid profiles in high fat diet than in high carbohydrate diet.  相似文献   
9.
An efficient shim system and an optimized localization sequence were used to measure in vivo 1H NMR spectra from cerebral cortex, hippocampus, striatum, and cerebellum of C57BL/6 mice at 9.4 T. The combination of automatic first- and second-order shimming (FASTMAP) with strong custom-designed second-order shim coils (shim strength up to 0.04 mT/cm2) was crucial to achieve high spectral resolution (water line width of 11-14 Hz). Requirements for second-order shim strengths to compensate field inhomogeneities in the mouse brain at 9.4 T were assessed. The achieved spectral quality (resolution, S/N, water suppression, localization performance) allowed reliable quantification of 16 brain metabolites (LCModel analysis) from 5-10-microL brain volumes. Significant regional differences (up to 2-fold, P < 0.05) were found for all quantified metabolites but Asp, Glc, and Gln. In contrast, 1H NMR spectra measured from the striatum of C57BL/6, CBA, and CBA/BL6 mice revealed only small (<13%, P < 0.05) interstrain differences in Gln, Glu, Ins, Lac, NAAG, and PE. It is concluded that 1H NMR spectroscopy at 9.4 T can provide precise biochemical information from distinct regions of the mouse brain noninvasively that can be used for monitoring of disease progression and treatment as well as phenotyping in transgenic mice models.  相似文献   
10.
目的 探讨东北地区2000~2005年住院军事飞行人员疾病的发生、发展与分布规律,为完善新时期飞行人员疾病预防、诊治和医学鉴定提供客观依据. 方法 采用流行病学回顾性调查方法 ,统计分析东北地区2000~2005年2223人次住院军事飞行人员的病例资料,并按国际疾病分类法第9版(ICD-9)编制"东北地区2000~2005年军事飞行人员疾病构成"和"东北地区2000~2005年军事飞行人员常见病疾病谱".应用SPSS 10.0统计软件进行统计分析. 结果 疾病构成显示,军事飞行人员肌肉骨骼系统疾病多年居首位,构成比是居第2位的消化系统疾病的2~3倍.与1995年比较,肌肉骨骼系统、感觉器官及泌尿生殖系统疾病的构成比上升显著;疾病谱显示腰椎间盘突出症、颈椎病、头痛、神经性耳聋和心律失常居前5位. 结论 21世纪前6年东北地区军事飞行人员常见病是腰椎间盘突出症、颈椎病、头痛、神经性耳聋和心律失常.提示转氨酶增高、半月板损伤和颈椎间盘突出症增加迅速,应引起关注.  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