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   103029篇
  免费   11360篇
  国内免费   3149篇
耳鼻咽喉   749篇
儿科学   1577篇
妇产科学   1208篇
基础医学   19551篇
口腔科学   2763篇
临床医学   6484篇
内科学   15093篇
皮肤病学   1905篇
神经病学   11144篇
特种医学   2833篇
外国民族医学   27篇
外科学   8262篇
综合类   10280篇
现状与发展   14篇
预防医学   4071篇
眼科学   1059篇
药学   16829篇
  33篇
中国医学   3977篇
肿瘤学   9679篇
  2024年   120篇
  2023年   1774篇
  2022年   2431篇
  2021年   4419篇
  2020年   4142篇
  2019年   4418篇
  2018年   4220篇
  2017年   4186篇
  2016年   3913篇
  2015年   4436篇
  2014年   6433篇
  2013年   6673篇
  2012年   5903篇
  2011年   7034篇
  2010年   5643篇
  2009年   5669篇
  2008年   5590篇
  2007年   4761篇
  2006年   4084篇
  2005年   3769篇
  2004年   3185篇
  2003年   2830篇
  2002年   2106篇
  2001年   1786篇
  2000年   1461篇
  1999年   1302篇
  1998年   1042篇
  1997年   1088篇
  1996年   977篇
  1995年   1105篇
  1994年   1019篇
  1993年   967篇
  1992年   759篇
  1991年   682篇
  1990年   586篇
  1989年   497篇
  1988年   474篇
  1987年   473篇
  1986年   572篇
  1985年   779篇
  1984年   741篇
  1983年   581篇
  1982年   579篇
  1981年   488篇
  1980年   449篇
  1979年   374篇
  1978年   229篇
  1977年   190篇
  1976年   197篇
  1975年   121篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
《Drug discovery today》2022,27(5):1367-1380
The tremendous advances in genomics, recombinant DNA technology, bioengineering and nanotechnology, in conjunction with the development of high-end computations, have been instrumental in the process of rational design of peptide-based vaccines. The use of peptide vaccines was limited owing to their inherent instability when systemically administered; however, advanced formulation techniques have been developed for their systemic delivery, thereby overcoming their degradation, clearance, cellular uptake and off-target effects. With the rise of sophisticated immunological predictors and experimental techniques, several methodological advances have occurred in this field. This review examines contemporary methods to identify and optimize epitopes, engineer their immunogenic properties and develop their safe and efficient delivery into the host.  相似文献   
22.
《Vaccine》2022,40(27):3732-3736
Influenza vaccination is recommended to protect mothers and their infants from influenza. Few studies have evaluated the association between maternal influenza vaccination and child mortality. We aimed to evaluate the association between in utero exposure to seasonal inactivated influenza vaccine (IIV) and mortality among young children. This longitudinal, population-based cohort study included 191,247 maternal-child pairs in Western Australia between April 2012 and December 2017. Maternal vaccine information was obtained from a state-wide antenatal vaccination database. Mortality was defined as a record of a death registration. We used Cox proportional hazard models, weighted by the inverse-probability of treatment (vaccination), to estimate the hazard ratio of child mortality associated with in utero exposure to seasonal IIV. This study found no association between in utero exposure to seasonal IIV and mortality through age five years.  相似文献   
23.
There is a surprising lack of evidence documenting the volumetric symmetry of the bony orbit. This paper establishes reference values for orbital volume (OV) and symmetry in the 25 - 40 year old caucasian population. Secondarily, this paper sets a landmark for the tolerances in OV that can be expected when reconstructing the bony defects which may occur from trauma. A standardised method of quantitative OV measurement was developed using CT sinus examinations acquired for indications unrelated to orbital trauma. Sex, ethnicity, age, right and left OV were recorded. Data for 100 patients was obtained (50 male, 50 female). Mean left OV was 23.1cm3 and mean right OV was 23.3cm3. Left and right OV were strongly positively correlated (correlation coefficient: 0.96). Mean female OV was 21.6cm3 and mean male OV was 24.8cm3. On average, male OV is 3.2cm3 larger than female OV. The mean difference between left and right OV was 0.5cm3 in females and 0.6cm3 in males. The intra-class coefficient score between the two assessors was 0.973 (excellent). There is strong positive correlation between left and right OV in this study population. Previous work suggests that orbital volume loss less than 1cm3 would not lead to significant clinical symptoms of orbital fracture. When orbital reconstruction is undertaken, this study suggests that a volume symmetry difference of <0.5cm3 in females and <0.6cm3 in males would be consistent with the variation seen in the study population of uninjured caucasian 25-40 year olds and is therefore a reasonable goal of surgical management.  相似文献   
24.
《Neuro-Chirurgie》2023,69(5):101478
ObjectivePituitary abscess is an often misdiagnosed, rare clinical disorder. To improve diagnostic accuracy and the efficacy of surgical and antibiotic therapy for patients with pituitary abscess, herein, we retrospectively reviewed 15 patients who presented with pituitary abscesses from 2005 to 2022.DesignRetrospective study.PatientsFifteen patients underwent transsphenoidal surgery and received antibiotic treatment.MeasurementsComplete details regarding medical history, clinical manifestations, laboratory examinations, imaging studies, and treatment strategies were obtained for all patients.ResultsMost patients presented with hypopituitarism and headaches, while some presented with fever, visual disturbances, and diabetes insipidus (DI). Abscesses showed significant annular enhancement post gadolinium injection. In most patients, pituitary abscess can be cured via microscopic or endoscopic drainage of the abscess followed by antibiotic treatment. Complete cure of pituitary abscess was observed in nine patients, with six cases of prolonged hypopituitarism and only one case of recurrence. Long-term hormone replacement therapy was effective in the postoperative management of hypopituitarism.ConclusionsThe typical manifestations of pituitary abscess include hypopituitarism and headaches; the presence of an enhanced ring at the edge of the mass on contrast-enhanced magnetic resonance images (MRI) is highly suggestive of pituitary abscess. We recommend antibiotic treatment for 4–6 weeks postoperatively, based on the results of bacterial cultures or metagenomic next-generation sequencing (mNGS).  相似文献   
25.
This project aimed to enhance clinical education preparation in a family nurse practitioner graduate program in rural central Appalachian by providing a psychomotor skills-based simulation with the use of the defusing, discovering, and deepening (3D) debriefing method. The students were surveyed after graduation to determine effectiveness. Program outcomes to measure readiness to practice were graduation, employment, and certification rates. The postgraduation surveys indicated the simulation contributed to an increase in psychomotor skill performance, practicing safe patient care, and making independent decisions in practice. Common themes emerged of feeling “prepared for practice” and being “more marketable” with the procedural skills learned in the simulation.  相似文献   
26.
目的探讨ω-3多不饱和脂肪酸(ω-3 poly unsaturated fatty acids,ω-3 PUFAs)对慢性移植物抗宿主病(chronic graft versus host disease,cGVH)狼疮模型小鼠的免疫调节功能影响。方法单次腹腔注射bm12小鼠淋巴细胞建立cGVH小鼠模型,造模当天分别给予90%ω-3 PUFAs和97%EPA灌胃治疗,持续14 d。通过流式细胞术检测小鼠脾脏淋巴细胞中各免疫指标,ELISA检测小鼠血清中总IgG水平。结果与正常对照组相比,cGVH组明显下调Treg亚群,明显上调TFH细胞、生发中心B细胞和浆细胞亚群;与模型对照组相比,90%ω-3和97%EPA均明显上调Treg亚群,并明显下调TFH细胞、生发中心B细胞和浆细胞亚群;且97%EPA组小鼠血清中总IgG水平明显下降。结论在cGVH狼疮小鼠模型中,ω-3 PUFAs通过增加Treg细胞,减少TFH细胞、生发中心B细胞和浆细胞,抑制IgG的分泌,从而发挥免疫抑制作用,且其免疫抑制作用可能与ω-3 PUFAs含量相关。  相似文献   
27.
ObjectivesThe study aimed to analyse the association between Sports-Related Concussion (SRC) and Subsequent Musculoskeletal Injury (MSK) in United Kingdom university-aged rugby union players whilst considering the effects of sex, athlete playing position and injury location.DesignRetrospective cohort study. A period of 365 days with 0–90, 91–180 and 181–365 days sub-periods was analysed for the following variables; MSK injury incidence, occurrence, severity, injury location, playing position and sex.SettingInjury data was collected from the Sports Development Centre database at Loughborough University.ParticipantsA total of 408 injuries in 181 athletes (55 females and 126 males) were included.ResultsThe MSK injury incidence of SRC group was significantly higher than control and higher post-SRC than pre-SRC period over a 365-day period (p=0.012 and p=0.034, respectively). The odds ratios of MSK injury incidence between groups and between periods were 1.62 (95% CI, 1.10–2.25) and 1.57 (95% CI ,1.08–2.29). A SRC was not associated with a greater time loss from a subsequent MSK injury or a specific MSK injury location.ConclusionsAthletes with a second recorded injury were more likely to sustain a MSK injury if they had experienced SRC, however, there was no indication a SRC resulted in greater time loss from a MSK injury.  相似文献   
28.
ObjectiveTo analyze the efficacy and safety of photodynamic therapy (PDT) on postmenopausal women with persistent human papillomavirus (HPV) infection with or without low-grade cervical and vaginal intraepithelial neoplasia (CIN1 and VaIN1).Materials and methodsThe clinicopathological and follow-up data of 86 postmenopausal women with HPV infection (35 cases with chronic cervicitis and 51 cases with CIN1/VaIN1) were collected. All the women in this group met these criteria: menopausal time ≥ 1 year, HPV infection time ≥ 2 years, colposcopy and pathological diagnosis of biopsy ≤ CIN1/VaIN1 before PDT treatment, and 5-aminolaevulinic acid (5-ALA) as photosensitizer treating for 6 times with a week interval. The above patients were followed up 6 months and 12 months after PDT treatment, and the follow-up contents included HPV typing, cytology, colposcopy and pathological examinations. HPV negative conversion rate and lesion remission rate are the evaluation indicators of treatment efficacy. In addition, we also assessed the safety of PDT treatment.ResultsAt 12-month follow-up, the overall HPV clearance rate was 60% (45/75), of which the negative conversion rate of 16/18 HPV was 41.38% (12/29), and non-16/18 HPV was 71.74% (33/46) (p = 0.009). In patients without lesions, the HPV clearance rate was 51.72% (15/29), while in patients with CIN1/VaIN1 (n = 46), the HPV complete remission rate and lesion regression rate were 65.22% (30/46) and 89.13% (41/46), respectively. In addition, the clearance rate of HPV in lesion regression group was significantly higher than that in lesion persistence/progression group (0.00% vs. 73.17%, p = 0.003). The adverse reactions after PDT treatment were mild, mainly manifested as increased vaginal secretions or burning/tingling.ConclusionsPhotodynamic therapy can significantly enhance the elimination rate of persistent HPV infection in postmenopausal women and reduce the progression of CIN1/VaIN1. It could be an effective conservative treatment for persistent HPV infection and CIN1/VaIN1 in postmenopausal women.  相似文献   
29.
BackgroundConsiderable progress has been made in therapeutic options for multiple myeloma (MM). Understanding the current landscape of MM treatment options and associated outcomes in the real world is important in providing key insights into clinical and knowledge gaps which could be targeted for further optimization.MethodsThe Canadian Myeloma Research Group Database (CMRG-DB) is a prospectively maintained disease-specific database with >7000 patients. The objective of this study was to describe the trends in the treatment landscape and outcomes including early mortality, time to next treatment, and overall survival (OS) in each line of treatment stratified by autologous stem cell transplant (ASCT) receipt among newly-diagnosed MM patients in Canada between 2007 and 2018.ResultsA total of 5154 patients were identified among which 3030 patients (58.8%) received an upfront ASCT and 2124 (41.2%) did not. At diagnosis, the median age was 64 years and 58.6% were males. Bortezomib and lenalidomide were most frequently used (>50%) in first and second-line treatment respectively among both the ASCT and non-ASCT cohort. The median OS was 122.0 months (95% Cl 115.0-135.0 months) and 54.3 months (95% CI 50.8-58.8 months) for the ASCT and non-ASCT cohort respectively with an incremental decrease in OS in each subsequent line of treatment.ConclusionWe present the largest study to date in the Canadian landscape showing the characteristics, therapy usage, and outcomes among MM patients. This information will be critical in benchmarking current outcomes and provide key insight into areas of unmet needs and gaps for improvement of MM patients nationally.  相似文献   
30.
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