全文获取类型
收费全文 | 692664篇 |
免费 | 42540篇 |
国内免费 | 1098篇 |
专业分类
耳鼻咽喉 | 9543篇 |
儿科学 | 22250篇 |
妇产科学 | 18014篇 |
基础医学 | 109595篇 |
口腔科学 | 20746篇 |
临床医学 | 56360篇 |
内科学 | 136698篇 |
皮肤病学 | 18003篇 |
神经病学 | 50944篇 |
特种医学 | 22517篇 |
外国民族医学 | 92篇 |
外科学 | 99219篇 |
综合类 | 9466篇 |
一般理论 | 167篇 |
预防医学 | 56140篇 |
眼科学 | 15715篇 |
药学 | 53019篇 |
中国医学 | 1805篇 |
肿瘤学 | 36009篇 |
出版年
2021年 | 7271篇 |
2019年 | 7608篇 |
2018年 | 10840篇 |
2017年 | 7325篇 |
2016年 | 7715篇 |
2015年 | 8465篇 |
2014年 | 11310篇 |
2013年 | 17107篇 |
2012年 | 24922篇 |
2011年 | 26834篇 |
2010年 | 15011篇 |
2009年 | 13244篇 |
2008年 | 23869篇 |
2007年 | 25480篇 |
2006年 | 25052篇 |
2005年 | 24415篇 |
2004年 | 23072篇 |
2003年 | 21896篇 |
2002年 | 21339篇 |
2001年 | 29124篇 |
2000年 | 30531篇 |
1999年 | 24958篇 |
1998年 | 6612篇 |
1997年 | 5560篇 |
1996年 | 5799篇 |
1995年 | 5289篇 |
1992年 | 17682篇 |
1991年 | 18133篇 |
1990年 | 18043篇 |
1989年 | 17203篇 |
1988年 | 15823篇 |
1987年 | 15639篇 |
1986年 | 14729篇 |
1985年 | 13989篇 |
1984年 | 10387篇 |
1983年 | 8896篇 |
1982年 | 4949篇 |
1979年 | 10106篇 |
1978年 | 7323篇 |
1977年 | 6193篇 |
1976年 | 6009篇 |
1975年 | 6902篇 |
1974年 | 8216篇 |
1973年 | 7771篇 |
1972年 | 7505篇 |
1971年 | 7233篇 |
1970年 | 6718篇 |
1969年 | 6414篇 |
1968年 | 6014篇 |
1967年 | 5452篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Megan L. Robbins Robert C. Wright Ana María López Karen Weihs 《Journal of psychosocial oncology》2019,37(2):160-177
AbstractObjectives: This study examined word use as an indicator of interpersonal positive reframing in daily conversations of couples coping with breast cancer and as a predictor of stress.Design: The Electronically Activated Recorder (EAR) and Linguistic Inquiry and Word Count (LIWC) were used to examine naturally occurring word use conceptually linked to positive reframing (positive emotion, negative emotion, and cognitive processing words).Sample: Fifty-two couples coping with breast cancer.Methods: Couples wore the EAR, a device participants wear, that audio-recorded over one weekend (>16,000 sound files), and completed self-reports of positive reframing (COPE) and stress (Perceived Stress Scale). LIWC, a software program, measured word use.Findings: Both partners’ word use (i.e., positive emotion and cognitive processing words) was associated with their own reported positive reframing, and spouses’ word use was also indicative of patients’ positive reframing. Results also revealed that, in general, words indicating positive reframing predicted lower levels of stress.Conclusions: Findings supported the hypothesis that partners—and particularly spouses of breast cancer patients—may assist each other’s coping by positively reframing the cancer experience and other negative experiences in conversation. 相似文献
82.
Martín-Nares Eduardo Zuñiga-Tamayo Diego Hinojosa-Azaola Andrea 《Clinical rheumatology》2019,38(1):97-106
Clinical Rheumatology - We aimed to estimate the frequency of overlap of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) with systemic autoimmune diseases. Retrospective... 相似文献
83.
K. Miura S. Yamaoka K. Arizono S. Ohba T. Koga T. Kawasaki N. Yoshida I. Asahina 《The British journal of oral & maxillofacial surgery》2019,57(6):529-535
Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism. 相似文献
84.
85.
M. D. Wiles A. El-Nayal G. Elton M. Malaj J. Winterbottom C. Gillies I. K. Moppett K. Bauchmuller 《Anaesthesia》2022,77(2):143-152
Pulse oximetry is used widely to titrate oxygen therapy and for triage in patients who are critically ill. However, there are concerns regarding the accuracy of pulse oximetry in patients with COVID-19 pneumonitis and in patients who have a greater degree of skin pigmentation. We aimed to determine the impact of patient ethnicity on the accuracy of peripheral pulse oximetry in patients who were critically ill with COVID-19 pneumonitis by conducting a retrospective observational study comparing paired measurements of arterial oxygen saturation measured by co-oximetry on arterial blood gas analysis (SaO2) and the corresponding peripheral oxygenation saturation measured by pulse oximetry (SpO2). Bias was calculated as the mean difference between SaO2 and SpO2 measurements and limits of agreement were calculated as bias ±1.96 SD. Data from 194 patients (135 White ethnic origin, 34 Asian ethnic origin, 19 Black ethnic origin and 6 other ethnic origin) were analysed consisting of 6216 paired SaO2 and SpO2 measurements. Bias (limits of agreement) between SaO2 and SpO2 measurements was 0.05% (−2.21–2.30). Patient ethnicity did not alter this to a clinically significant degree: 0.28% (1.79–2.35), −0.33% (−2.47–2.35) and −0.75% (−3.47–1.97) for patients of White, Asian and Black ethnic origin, respectively. In patients with COVID-19 pneumonitis, SpO2 measurements showed a level of agreement with SaO2 values that was in line with previous work, and this was not affected by patient ethnicity. 相似文献
86.
Tormo Nuria Giménez Estela Martínez-Navarro María Albert Eliseo Navalpotro David Torres Ignacio Gimeno Concepción Navarro David 《European journal of clinical microbiology & infectious diseases》2022,41(4):657-662
European Journal of Clinical Microbiology & Infectious Diseases - We compared the performance of an in-house-developed flow cytometry assay for intracellular cytokine staining (FC-ICS) and a... 相似文献
87.
Jenny U. Johansson Nathaniel S. Woodling Qian Wang Maharshi Panchal Xibin Liang Angel Trueba-Saiz Holden D. Brown Siddhita D. Mhatre Taylor Loui Katrin I. Andreasson 《The Journal of clinical investigation》2015,125(1):350-364
Microglia, the innate immune cells of the CNS, perform critical inflammatory and noninflammatory functions that maintain normal neural function. For example, microglia clear misfolded proteins, elaborate trophic factors, and regulate and terminate toxic inflammation. In Alzheimer’s disease (AD), however, beneficial microglial functions become impaired, accelerating synaptic and neuronal loss. Better understanding of the molecular mechanisms that contribute to microglial dysfunction is an important objective for identifying potential strategies to delay progression to AD. The inflammatory cyclooxygenase/prostaglandin E2 (COX/PGE2) pathway has been implicated in preclinical AD development, both in human epidemiology studies and in transgenic rodent models of AD. Here, we evaluated murine models that recapitulate microglial responses to Aβ peptides and determined that microglia-specific deletion of the gene encoding the PGE2 receptor EP2 restores microglial chemotaxis and Aβ clearance, suppresses toxic inflammation, increases cytoprotective insulin-like growth factor 1 (IGF1) signaling, and prevents synaptic injury and memory deficits. Our findings indicate that EP2 signaling suppresses beneficial microglia functions that falter during AD development and suggest that inhibition of the COX/PGE2/EP2 immune pathway has potential as a strategy to restore healthy microglial function and prevent progression to AD. 相似文献
88.
Talita da Silva Mendes de Farias Ariclécio Cunha de Oliveira Sandra Andreotti Fernanda Gaspar do Amaral Patrícia Chimin André Ricardo Alves de Proença Francisco Leonardo Torres Leal Rogério Antonio Laurato Sertié Amanda Baron Campana Andressa Bolsoni Lopes Arnaldo Henrique de Souza José Cipolla‐Neto Fabio Bessa Lima 《Journal of pineal research》2015,58(3):251-261
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals. 相似文献
89.