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   4347667篇
  免费   350849篇
  国内免费   14644篇
耳鼻咽喉   60564篇
儿科学   139897篇
妇产科学   114638篇
基础医学   666949篇
口腔科学   118178篇
临床医学   397051篇
内科学   786788篇
皮肤病学   107903篇
神经病学   369450篇
特种医学   170130篇
外国民族医学   753篇
外科学   658101篇
综合类   121666篇
现状与发展   24篇
一般理论   2636篇
预防医学   357667篇
眼科学   100909篇
药学   308809篇
  21篇
中国医学   11970篇
肿瘤学   219056篇
  2021年   56361篇
  2020年   36017篇
  2019年   59104篇
  2018年   74830篇
  2017年   56960篇
  2016年   63141篇
  2015年   76061篇
  2014年   110452篇
  2013年   176160篇
  2012年   126526篇
  2011年   131382篇
  2010年   126767篇
  2009年   128309篇
  2008年   117236篇
  2007年   124678篇
  2006年   133348篇
  2005年   127472篇
  2004年   128532篇
  2003年   118707篇
  2002年   107844篇
  2001年   167115篇
  2000年   162149篇
  1999年   148802篇
  1998年   71832篇
  1997年   67740篇
  1996年   65734篇
  1995年   61151篇
  1994年   55065篇
  1993年   51112篇
  1992年   106300篇
  1991年   101361篇
  1990年   97157篇
  1989年   94693篇
  1988年   86949篇
  1987年   85191篇
  1986年   80062篇
  1985年   78230篇
  1984年   65130篇
  1983年   57814篇
  1982年   46766篇
  1981年   43454篇
  1980年   40636篇
  1979年   54769篇
  1978年   44438篇
  1977年   39556篇
  1976年   36482篇
  1975年   36507篇
  1974年   39385篇
  1973年   37578篇
  1972年   35278篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Background: Traumatic brain injury (TBI) results in verbal recall deficits and impaired processing of emotion encoded in facial appearance, prosody and the linguistic content of messages. Emotion facilitates memory (emotional memory advantage) for non-brain injured (NBI) individuals but the impact of emotion on verbal recall for linguistically encoded stimuli in TBI has not been explored.

Aims: The purpose of this study was to determine the effects of stimulus emotional content on verbal recall of words and paragraphs in TBI compared to NBI individuals.

Methods and procedures: Six 10-item lists, each with five emotional and five neutral words, and six paragraphs (three emotional, three neutral) were counterbalanced and presented in random order to 20 individuals with TBI and 44 NBI. The number of words from lists and the number of content units from paragraphs were compared for the two groups.

Outcomes and results: The NBI participants recalled more words from the lists and content units from the paragraphs than the individuals with TBI. Both groups recalled significantly more emotional than neutral words. NBI but not TBI participants had significantly greater recall for information in paragraphs with emotional content.

Conclusions: Participants with TBI showed impaired recall of words and paragraph content. Emotion facilitated word and paragraph content recall for neurotypical individuals but emotional memory advantage was limited to words for the TBI participants.  相似文献   

132.

Objectives

To determine: (i) the behaviour change techniques used by a sample of Australian physiotherapists to promote non-treatment physical activity; and (ii) whether those behaviour change techniques are different to the techniques used to encourage adherence to rehabilitation exercises.

Design

Cross-sectional survey.

Method

An online self-report survey was advertised to private practice and outpatient physiotherapists treating patients with musculoskeletal conditions. The use of 50 behaviour change techniques were measured using five-point Likert-type scale questions.

Results

Four-hundred and eighty-six physiotherapists responded to the survey, with 216 surveys fully completed. Most respondents (85.1%) promoted non-treatment physical activity often or all of the time. Respondents frequently used 29 behaviour change techniques to promote non-treatment physical activity or encourage adherence to rehabilitation exercises. A similar number of behaviour change techniques was frequently used to encourage adherence to rehabilitation exercises (n = 28) and promote non-treatment physical activity (n = 26). Half of the behaviour change techniques included in the survey were frequently used for both promoting non-treatment physical activity and encouraging adherence to rehabilitation exercises (n = 25). Graded tasks was the most, and punishment was the least, frequently reported technique used to promote non-treatment physical activity and encourage adherence to rehabilitation exercises.

Conclusions

Respondents reported using similar behaviour change techniques to promote non-treatment physical activity and encourage adherence to rehabilitation exercises. The variability in behaviour change technique use suggests the behaviour the physiotherapist is promoting influences their behaviour change technique choice. Including the frequently-used behaviour change techniques in non-treatment physical activity promotion interventions might improve their efficacy.  相似文献   
133.
G. Berlin  M. Hammar  L. Tapper 《Platelets》2019,30(4):473-479
Platelets are needed to prevent or arrest bleeding and aggregate at the site of injury upon vascular damage. Platelets express receptors for estrogens which might affect the function of the platelets and their hemostatic ability. The aim was to identify possible differences in platelet function related to age, gender, and phases of the menstrual cycle by use of impedance aggregometry with Multiplate. In the first part of the study, platelet function was assessed in 60 healthy individuals (30 men and 30 women) in each of three age groups (20–25, 40–45, and 60–65 years). In the second part of the study, the platelet function was analyzed on four occasions during the menstrual cycle in women without oral contraceptives (OCs) (n = 17) and compared to 19 women on OCs and 18 men of similar age (20–40 years). For the women on OCs, aggregation was analyzed once during the tablet-free week and once late during the period with OCs. The men were sampled once. Women of younger age (<45 years) had significantly higher agonist-induced aggregation response than both men and post-menopausal women (60–65 years). The agonist-induced aggregation response did not differ between phases of the menstrual cycle or OC use. The results suggest that estradiol and/or progesterone affect spontaneous aggregation since it was found to be lowest in the mid-luteal phase. Spontaneous aggregation was significantly lower in women on OCs than in both men and women without OCs. Our findings indicate that fertile age is associated with higher aggregation response capacity of the platelets, possibly to prevent excessive bleeding during menstruation, but this response capacity is not altered during the menstrual cycle or by use of OCs.  相似文献   
134.
135.
Introduction: In men, lower urinary tract symptoms (LUTS) are primarily attributed to benign prostatic hyperplasia (BPH). Therapeutic options are targeted to relax prostate smooth muscle and/or reduce prostate enlargement.

Areas covered: This article reviews the major preclinical and clinical data on PDE5 inhibitors with a specific focus on tadalafil. It includes details of the role of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) – PDE5 pathway in the LUT organs (bladder and prostate) in addition to the available data on tadalafil in patients with LUTS secondary to BPH with or without erectile dysfunction (ED).

Expert opinion: Preclinical and clinical data have clearly demonstrated that PDE5 inhibitors induce bladder and prostate relaxation, which contributes to the improvement seen in storage symptoms in both animal models of bladder and prostate hypercontractility. Tadalafil is effective both as a monotherapy and add-on therapy in patients with LUTS secondary to BPH. Furthermore, as LUTS-BPH and ED are urological disorders that commonly coexist in aging men, tadalafil is more advantageous than α1-adrenoceptors and should be used as the first option. Tadalafil is a safe and tolerable therapy and unlike α1- adrenoceptors and 5-alpha reductase inhibitors, which can cause sexual dysfunctions, tadalafil improves sexual function.  相似文献   

136.
137.
138.
139.
Now is an exciting era of development in immunotherapy checkpoint inhibitors and their effect on the treatment of NPC. While the general prognosis of R/M disease is poor, immunotherapy offers some promise in a malignancy associated with EBV and characterized by a peritumoural immune infiltrate. Our study aims to review past and on-going clinical trials of monoclonal antibody therapies against the checkpoint inhibitors (e.g. PD1 and CTLA-4), in R/M NPC. All randomized and nonrandomized controlled trials involving immune checkpoint inhibitor interventions for treatment of NPC were included in the study. We utilized a validated “risk of bias” tool to assess study quality. Four separate Phase I–II trials report the potential of PD1 inhibitor treatment for patients with NPC. Within the observed groups, camrelizumab combined with chemotherapy achieved an objective response in 91% of patients as first-line treatment for metastatic NPC (PFS 68% at 1-year) but this was associated with a high rate of grade >3 adverse events (87%; CTCAE version 4.03). The remaining three studies focused on recurrent NPC disease in patients who had received at least one line of prior chemotherapy. Within this group, camrelizumab monotherapy achieved an objective response in 34% of patients (PFS 27% at 1-year; range across all three studies 20.5–34%). No NPC trial has yet reported on specific outcomes for non-PD1 checkpoint inhibitors but 11 on-going studies include alternative targets (e.g. PD-L1/CTLA-4) as combination or monotherapy treatments. In considering checkpoint immunotherapies for NPC, initial results show promise for anti-PD1 interventions. Further phase I–III trials are in progress to clarify clinical outcomes, fully determine safety profiles, and optimize drug combinations and administration schedules.  相似文献   
140.
Dietary assessment in infants is challenging but necessary to understand the relationship between nutrition and growth and development. Currently no simple, validated methods exist to assess nutrient intake in New Zealand (NZ) infants. Therefore, this study aimed to assess the relative validity and reproducibility of a Complementary Food Frequency Questionnaire (CFFQ) to determine nutrient intakes of NZ infants. Ninety‐five parent–infant pairs (infant age 10 ± 1 months) completed the CFFQ twice (CFFQ‐1 and CFFQ‐2), 4 weeks apart (to assess reproducibility). A 4‐day weighed food record (4dWFR) was collected between CFFQ administrations (to assess validity). Validity and reproducibility were assessed for intakes of energy and 18 nutrients using Bland–Altman analysis, Pearson's correlation coefficients, cross‐classification, and weighted Kappa (κ). The CFFQ showed acceptable validity: Nutrients from the CFFQ were comparable with the 4dWFR (bias, 9–28%), correlation between methods ranged from r = .18 (saturated fat) to r = .81 (iron; mean r = .52), 54% (mean) of participants were correctly classified (range 39% to 67%), and 7.1% (mean) misclassified into opposite tertiles (range 2.1% to 14.7%). There was acceptable agreement between the CFFQ and 4dWFR (κ = 0.20–0.60). The CFFQ showed good reproducibility: Correlations ranged from r = .34 (folate) to r = .80 (zinc); for 16 nutrients, >50% of participants were correctly classified, and for all nutrients, <10% of participants were grossly misclassified. All nutrients showed acceptable to good agreement (κ > 0.20). The CFFQ has acceptable relative validity and good reproducibility for assessing nutrient intake in NZ infants aged 9–12 months, making it a useful tool for use in future research.  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