全文获取类型
收费全文 | 2225篇 |
免费 | 116篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 93篇 |
妇产科学 | 32篇 |
基础医学 | 266篇 |
口腔科学 | 97篇 |
临床医学 | 199篇 |
内科学 | 504篇 |
皮肤病学 | 55篇 |
神经病学 | 141篇 |
特种医学 | 84篇 |
外科学 | 326篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 114篇 |
眼科学 | 44篇 |
药学 | 220篇 |
中国医学 | 7篇 |
肿瘤学 | 141篇 |
出版年
2023年 | 18篇 |
2022年 | 35篇 |
2021年 | 40篇 |
2020年 | 34篇 |
2019年 | 38篇 |
2018年 | 47篇 |
2017年 | 47篇 |
2016年 | 44篇 |
2015年 | 54篇 |
2014年 | 64篇 |
2013年 | 81篇 |
2012年 | 148篇 |
2011年 | 136篇 |
2010年 | 84篇 |
2009年 | 54篇 |
2008年 | 133篇 |
2007年 | 130篇 |
2006年 | 127篇 |
2005年 | 118篇 |
2004年 | 123篇 |
2003年 | 119篇 |
2002年 | 135篇 |
2001年 | 55篇 |
2000年 | 52篇 |
1999年 | 56篇 |
1998年 | 21篇 |
1997年 | 17篇 |
1996年 | 20篇 |
1995年 | 16篇 |
1994年 | 12篇 |
1993年 | 5篇 |
1992年 | 35篇 |
1991年 | 29篇 |
1990年 | 16篇 |
1989年 | 16篇 |
1988年 | 27篇 |
1987年 | 20篇 |
1986年 | 20篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 13篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1972年 | 4篇 |
排序方式: 共有2345条查询结果,搜索用时 15 毫秒
41.
42.
Miyatake N Takahashi K Wada J Nishikawa H Morishita A Suzuki H Kunitomi M Makino H Kira S Fujii M 《Diabetes research and clinical practice》2003,62(3):149-157
OBJECTIVE: To investigate the link between a reduction in blood pressure (BP) and daily exercise. DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education. SUBJECTS: 43 overweight Japanese men aged 32-59 years (BMI, 29.0+/-2.3 kg/m2) at baseline. Among the participants, a randomly selected 23 overweight men (BMI, 28.5+/-1.7) were further enrolled into the 10 months exercise program. MEASUREMENTS: BP was measured every week and steps per day were also recorded every day throughout the observation period. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical level, at before, 5 months and after intervention. Anthropometric parameters were also measured at same point. Aerobic exercise level, muscle strength, flexibility and calorie intake and insulin resistance (HOMA index) were investigated at before and after the study. RESULTS: In a cross sectional analysis, systolic BP (SBP) and diastolic BP (DBP) were significantly correlated with body composition. In a second longitudinal analysis, SBP was significantly reduced at 2 months and DBP was also reduced at 3 months, and almost maintained until the end of the observation period. Increasing daily walking was observed in 3 months and maintained until 10 months. Body composition, aerobic exercise level, muscle strength, flexibility and insulin resistance were significantly improved. There was positive correlation between DeltaDBP and Deltavisceral fat area (1-5, 5-10, 1-10 months). By stepwise multiple regression analysis, only Deltavisceral fat area was independently related to DeltaDBP at a significant level (1-10 months: DeltaDBP=-0.608+0.105Deltavisceral fat area, r2=0.227, P=0.0334). CONCLUSION: The present study indicated daily exercise lowers BP and visceral fat area is the critical factor for BP change. 相似文献
43.
44.
45.
Sahiti Myneni Kayo Fujimoto Nathan Cobb Trevor Cohen 《American journal of public health》2015,105(6):1206-1212
Objectives. We identified content-specific patterns of network diffusion underlying smoking cessation in the context of online platforms, with the aim of generating targeted intervention strategies.Methods. QuitNet is an online social network for smoking cessation. We analyzed 16 492 de-identified peer-to-peer messages from 1423 members, posted between March 1 and April 30, 2007. Our mixed-methods approach comprised qualitative coding, automated text analysis, and affiliation network analysis to identify, visualize, and analyze content-specific communication patterns underlying smoking behavior.Results. Themes we identified in QuitNet messages included relapse, QuitNet-specific traditions, and cravings. QuitNet members who were exposed to other abstinent members by exchanging content related to interpersonal themes (e.g., social support, traditions, progress) tended to abstain. Themes found in other types of content did not show significant correlation with abstinence.Conclusions. Modeling health-related affiliation networks through content-driven methods can enable the identification of specific content related to higher abstinence rates, which facilitates targeted health promotion.Epidemiological evidence indicates that modifiable risky health behaviors place a substantial socioeconomic burden on human health and wellness.1 Understanding human behavior in real-time settings is essential to improving health outcomes related to these behaviors.2,3 Technological advances in connectivity offer the means to obtain potentially valuable data sets in the form of electronic traces of the activities of online social communities. These data may help us to understand the intra- and interindividual intricacies of health-related behaviors. Studies of online and offline social networks provide valuable insight into social influence, information spread, and behavioral diffusion.4–6 Most of these analyses have paid more attention to the frequency of communication between members than to its content. The content, however, is relevant to behavior change theories, which address the use of specialized content to stimulate and support individuals to achieve a desired change.7,8 Contemporary work on social media data rarely addresses this fundamental concern of behavior change theorists.Outside the context of online networks, several theories have been formulated to explain behavior change. Some, such as the Transtheoretical Model,9 belong to the intrapersonal category; others, such as Social Cognitive Theory10 and social network and support models,11 are classified as interpersonal. (Appendix A, available as a supplement to the online version of this article at http://www.ajph.org, provides an overview of the theoretical constructs.) Empirical research on the applicability of these models to behavior change of health consumers in the digital era is minimal.12 Recent research showed that participation in health issue–specific social networking sites significantly influenced social factors such as identification, perceived subjective norms, and social support, which in turn resulted in greater smoking cessation self-efficacy.13 Content inclusion in analytical models of social networks can enable us to examine the content-specific patterns of social factors underlying behavior change. Through mapping of the specific content to theories, such content inclusion can facilitate the development of network interventions for health behavior changes by harnessing the power of social relationships.Studies of QuitNet, an online social network for smoking cessation, have examined the structure of peer-to-peer communication patterns and provided insights into social integrators and opinion leaders.5,14 Previous work showed the applicability of affiliation networks to real-world diffusion networks, enriching our understanding of the affiliation-based sources of influence on individuals’ behavior. Examples include the diffusion of (1) ratification of the World Health Organization Framework Convention on Tobacco Control by comembership with an online forum among countries15; (2) gunshot victimization by co-offending with victims among Chicago, Illinois, gangsters16; (3) substance use by coparticipating in school-sponsored sports or co-identifying with the same crowd types17,18; and (4) sexual behavior by coaffiliating with venues among male sex workers.19We used affiliation networks to analyze messages for content-specific patterns of network diffusion. We took an interdisciplinary approach, integrating methods from sociobehavioral sciences, social network analytics, and biomedical informatics. We employed qualitative techniques derived from grounded theory, automated text analysis, and affiliation network analysis to investigate the communication patterns underlying human behavior in online environments. Our study had 3 major components: (1) a qualitative study of human communication within user-generated data in QuitNet, (2) computational text analysis to further extend this analysis, and (3) identification of communication patterns pertinent to behavior change in affiliation networks. We anticipate that the insights gained from this research will enhance our understanding of behavior change and will have implications for the design of sociobehavioral interventions that draw upon social influence. 相似文献
46.
Kayo Shimizu Akio Oishi Maho Oishi Ken Ogino Satoshi Morooka Masako Sugahara Norimoto Gotoh Nagahisa Yoshimura 《Case reports in ophthalmology》2015,6(2):246-250
We screened patients with choroideremia using next-generation sequencing (NGS) and identified a novel mutation and a known mutation in the CHM gene. One patient presented an atypical fundus appearance for choroideremia. Another patient presented macular hole retinal detachment in the left eye. The present case series shows the utility of NGS-based screening in patients with choroideremia. In addition, the presence of macular hole in 1 of the 2 patients, together with a previous report, indicated the susceptibility of patients with choroideremia to macular hole.Key Words: Choroideremia, Next-generation sequencing, Diagnosis, Utility 相似文献
47.
Shingo Nasu Kunimitsu Kawahara Yuki Han Norio Okamoto Yoshitaka Tamura Hidekazu Suzuki Takayuki Shiroyama Yumiko Samejima Tomohiro Kanai Yoshimi Noda Ayako Tanaka Naoko Morishita Kayo Ueda Shoji Hashimoto Tomonori Hirashima Takayuki Nagai 《Internal medicine (Tokyo, Japan)》2021,60(3):445
Miliary tuberculosis is a potentially lethal type of tuberculosis that results from the hematogenous dissemination of Mycobacterium tuberculosis bacilli. We herein describe the case of a 34-year-old man that presented with a one-month history of cough and fever, while his sputum smear results were negative. Chest computed tomography revealed bilateral centrilobular ground-glass opacification (GGO), suggestive of hypersensitivity pneumonitis; thus, bronchoscopy was performed. Cryobiopsy specimens revealed necrotic granulomas. A re-examination of sputum after bronchoscopy identified Mycobacterium tuberculosis, and miliary tuberculosis was diagnosed. A cryobiopsy might be useful for diagnosing miliary tuberculosis pathologically, particularly when miliary nodules may be masked by GGO. 相似文献
48.
Kenji Sakurai Takeshi Saito Fumi Yamauchi Daiki Asahi Hiromi Hosoya 《Journal of artificial organs》2013,16(3):316-321
Numerous studies have been carried out to investigate the solute removal efficiency of hemodiafiltration (HDF). However, the effect of the dilution mode on blood cell damage during HDF has not yet been examined in detail. Here, we compared predilution and postdilution HDF with respect to their effects on blood cells. Five patients were allocated to one session each of predilution HDF and postdilution HDF. Concentrations of interleukin (IL)-6, intercellular adhesion molecule (ICAM)-1, and platelet-derived microparticles (PDMP), and the phagocytotic and sterilizing functions of neutrophils before and after the HDF sessions were evaluated. Lymphocyte blastoid transformation induced by mitogens was also evaluated by measurement of the [3H]-thymidine uptake. The IL-6 and ICAM-1 concentrations decreased after predilution HDF, and increased after postdilution HDF. Lymphocyte blastoid transformation was more pronounced after predilution HDF than after postdilution HDF. There was no significant difference in PDMP between the dilution modes. We conclude that predilution HDF could be more favorable for dialysis patients than postdilution HDF from the point of view of the effects on the blood cells, especially neutrophils and lymphocytes. 相似文献
49.
Reo Kanda Chieko Hamada Kayo Kaneko Takanori Nakano Keiichi Wakabayashi Hiroaki Io Satoshi Horikoshi Yasuhiko Tomino 《Journal of artificial organs》2013,16(1):66-73
It is well known that bioincompatible peritoneal dialysate plays a central role in the development of peritoneal fibrosis. Peritoneal inflammation continues even after the cessation of peritoneal dialysate stimulation. It is important to establish the definition of persistent inflammation in the peritoneal cavity at the cessation of peritoneal dialysis (PD). The objective of the present study was to determine whether pentraxin 3 (PTX3) in peritoneal effluent (PE) may be a new biomarker in PD patients. Serum, PE, and peritoneal specimens were obtained from 50 patients with end-stage kidney disease at Juntendo University Hospital. Samples of 19 patients were obtained at the initiation of PD and those of 31 patients at the cessation of PD. PTX3, high-sensitivity CRP, and MMP-2 and IL-6 were analyzed. An immunohistological examination using an anti-PTX3 antibody was performed. Expressions of PTX3 were observed in endothelial cells, fibroblasts, and mesothelial cells in the peritoneum. The PTX3 level in PE at the cessation of PD was significantly higher than that at the initiation of PD. Effluent PTX3 levels in patients with a history of peritonitis or a PD duration of more than 8 years were significantly higher than those in patients without peritonitis or patients with a PD duration of <8 years. The PTX3 level was significantly correlated with MMP-2 and IL-6 levels in PE, as well as the thickness of the submesothelial compact zone and the vasculopathy. It appears that PTX3 may be a new biomarker of peritoneal inflammation and progressive fibrosis. 相似文献
50.
Mitsuaki Morimoto Yoshikazu Nakamura Yoshikazu Yasuda Alan T. Lefor Takashi Nagaie Naohiro Sata Yoshinori Hosoya Hisanaga Horie Koji Koinuma 《The Indian journal of surgery》2015,77(4):283-289
It has been suggested that total cholesterol levels and the use of statin medications are associated with the incidence of complications after gastrointestinal surgery. The aim of this study was to determine if preoperative total cholesterol levels are associated with a higher risk of postoperative infections and mortality. A total of 2211 patients undergoing general surgical procedures between December 2006 and November 2008 at Iizuka Hospital and between January 2010 and March 2012 at Jichi Medical University Hospital were reviewed. Multiple logistic regression models were used to evaluate serum total cholesterol and other variables as predictors of postoperative nosocomial infections. Serum total cholesterol concentrations lower than 160 mg/dl were associated with an increased incidence of superficial and deep incisional surgical site infections. Serum total cholesterol levels showed a reverse J-shaped relationship with the development of organ space surgical site infection and pneumonia. There was no discernible effect of serum cholesterol levels on the postoperative mortality observed in this cohort of patients. Decreased serum albumin was one of the strongest risk factors for the development of nosocomial infection after surgery. Postoperative pneumonia was not observed in patients taking statin medications whose cholesterol levels were <200 mg/dl. Serum total cholesterol may be a valid predictor of surgical outcome. Preoperative statin use may affect the development of postoperative pneumonia in patients with total cholesterol levels below 200 mg/dl. 相似文献