全文获取类型
收费全文 | 1445897篇 |
免费 | 141731篇 |
国内免费 | 4489篇 |
专业分类
耳鼻咽喉 | 18753篇 |
儿科学 | 48640篇 |
妇产科学 | 37886篇 |
基础医学 | 216922篇 |
口腔科学 | 41084篇 |
临床医学 | 145460篇 |
内科学 | 287465篇 |
皮肤病学 | 33363篇 |
神经病学 | 128014篇 |
特种医学 | 52093篇 |
外国民族医学 | 368篇 |
外科学 | 204058篇 |
综合类 | 29132篇 |
现状与发展 | 1篇 |
一般理论 | 525篇 |
预防医学 | 121128篇 |
眼科学 | 30739篇 |
药学 | 106592篇 |
6篇 | |
中国医学 | 4217篇 |
肿瘤学 | 85671篇 |
出版年
2021年 | 13121篇 |
2020年 | 12018篇 |
2019年 | 22378篇 |
2018年 | 25894篇 |
2017年 | 22637篇 |
2016年 | 24227篇 |
2015年 | 26361篇 |
2014年 | 32550篇 |
2013年 | 44978篇 |
2012年 | 51373篇 |
2011年 | 54257篇 |
2010年 | 36853篇 |
2009年 | 31666篇 |
2008年 | 47970篇 |
2007年 | 49617篇 |
2006年 | 49530篇 |
2005年 | 47743篇 |
2004年 | 45455篇 |
2003年 | 43305篇 |
2002年 | 42132篇 |
2001年 | 61960篇 |
2000年 | 63454篇 |
1999年 | 52948篇 |
1998年 | 15281篇 |
1997年 | 13874篇 |
1996年 | 13575篇 |
1995年 | 12950篇 |
1994年 | 12028篇 |
1993年 | 11287篇 |
1992年 | 41710篇 |
1991年 | 41004篇 |
1990年 | 39630篇 |
1989年 | 37496篇 |
1988年 | 34721篇 |
1987年 | 33851篇 |
1986年 | 32296篇 |
1985年 | 30803篇 |
1984年 | 23203篇 |
1983年 | 19703篇 |
1982年 | 11925篇 |
1979年 | 20886篇 |
1978年 | 14896篇 |
1977年 | 12122篇 |
1976年 | 11907篇 |
1975年 | 12160篇 |
1974年 | 14843篇 |
1973年 | 14526篇 |
1972年 | 13427篇 |
1971年 | 12453篇 |
1970年 | 11516篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
41.
42.
43.
Julie Despres Yasmina Ramdani Marine di Giovanni Magalie Bnard Abderrakib Zahid Mait Montero‐Hadjadje Florent Yvergnaux Thibaut Saguet Azeddine Driouich Marie‐Laure Follet‐Gueye 《Experimental dermatology》2019,28(8):922-932
It is well recognized that the world population is ageing rapidly. Therefore, it is important to understand ageing processes at the cellular and molecular levels to predict the onset of age‐related diseases and prevent them. Recent research has focused on the identification of ageing biomarkers, including those associated with the properties of the Golgi apparatus. In this context, Golgi‐mediated glycosylation of proteins has been well characterized. Additionally, other studies show that the secretion of many compounds, including pro‐inflammatory cytokines and extracellular matrix–degrading enzymes, is modified during ageing, resulting in physical and functional skin degradation. Since the Golgi apparatus is a central organelle of the secretory pathway, we investigated its structural organization in senescent primary human dermal fibroblasts using confocal and electron microscopy. In addition, we monitored the expression of Golgi‐related genes in the same cells. Our data showed a marked alteration in the Golgi morphology during replicative senescence. In contrast to its small and compact structure in non‐senescent cells, the Golgi apparatus exhibited a large and expanded morphology in senescent fibroblasts. Our data also demonstrated that the expression of many genes related to Golgi structural integrity and function was significantly modified in senescent cells, suggesting a relationship between Golgi apparatus function and ageing. 相似文献
44.
Jakub Pazdrowski Aleksandra Daczak‐Pazdrowska Adriana Polaska Joanna Ka
mierska Wojciech Barczak Mateusz Szewczyk Pawe Golusiski Zygmunt Adamski Ryszard aba Wojciech Golusiski 《Skin research and technology》2019,25(6):857-861
Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy. 相似文献
45.
Breanne E. Kunstler Jill L. Cook Joanne L. Kemp Paul D. O’Halloran Caroline F. Finch 《Journal of Science and Medicine in Sport》2019,22(1):2-10
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46.
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
47.
Jean‐Franois Etter 《Addiction (Abingdon, England)》2019,114(12):2252-2256
48.
49.
Liam Masterson James Howard Jazmina Gonzalez-Cruz Christopher Jackson Catherine Barnett Lewis Overton Howard Liu Rahul Ladwa Fiona Simpson Margie McGrath Ben Wallwork Terry Jones Christian Ottensmeier Melvin L.K. Chua Chris Perry Rajiv Khanna Benedict Panizza Sandro Porceddu Matt Lechner 《International journal of cancer. Journal international du cancer》2020,146(8):2305-2314
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
50.
Amy L. Judd Kathryn L. Beck Christopher McKinlay Ashleigh Jackson Cathryn A. Conlon 《Maternal & child nutrition》2020,16(1)
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