全文获取类型
收费全文 | 16198篇 |
免费 | 805篇 |
国内免费 | 126篇 |
专业分类
耳鼻咽喉 | 151篇 |
儿科学 | 319篇 |
妇产科学 | 351篇 |
基础医学 | 1890篇 |
口腔科学 | 394篇 |
临床医学 | 1221篇 |
内科学 | 5051篇 |
皮肤病学 | 413篇 |
神经病学 | 1287篇 |
特种医学 | 290篇 |
外科学 | 2236篇 |
综合类 | 96篇 |
一般理论 | 8篇 |
预防医学 | 1059篇 |
眼科学 | 302篇 |
药学 | 898篇 |
中国医学 | 37篇 |
肿瘤学 | 1126篇 |
出版年
2024年 | 13篇 |
2023年 | 138篇 |
2022年 | 308篇 |
2021年 | 697篇 |
2020年 | 310篇 |
2019年 | 622篇 |
2018年 | 683篇 |
2017年 | 404篇 |
2016年 | 418篇 |
2015年 | 452篇 |
2014年 | 736篇 |
2013年 | 803篇 |
2012年 | 1479篇 |
2011年 | 1483篇 |
2010年 | 767篇 |
2009年 | 690篇 |
2008年 | 1109篇 |
2007年 | 1106篇 |
2006年 | 953篇 |
2005年 | 913篇 |
2004年 | 835篇 |
2003年 | 674篇 |
2002年 | 687篇 |
2001年 | 72篇 |
2000年 | 56篇 |
1999年 | 82篇 |
1998年 | 103篇 |
1997年 | 96篇 |
1996年 | 66篇 |
1995年 | 44篇 |
1994年 | 46篇 |
1993年 | 38篇 |
1992年 | 24篇 |
1991年 | 19篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 13篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 15篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 14篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1975年 | 11篇 |
1971年 | 9篇 |
1970年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A small health center is located in Velingara,Senegal.It is approximately 7 o'clock in the morning.In the old,dusty room that constitutes the operating room,a s... 相似文献
82.
Recio-Vega R Ocampo-Gómez G Borja-Aburto VH Moran-Martínez J Cebrian-Garcia ME 《Journal of applied toxicology : JAT》2008,28(5):674-680
Several studies have suggested that human semen quality has declined over the past decades and some of them have associated it with occupational exposure to pesticides. However, most of these studies have not been associated with a reliable exposure level and have been designed mostly as cross-sectional studies. The present work evaluates, in a longitudinal follow-up study, the effect of organophosphate pesticides (OP) at three occupational exposure levels on semen quality. In addition, the study examined the association between OP urinary levels and sperm parameters in exposed and unexposed workers. A total of 139 semen samples from 52 volunteers were assessed. Urinary OP levels were measured by gas-liquid chromatography.The results revealed that the poorest semen quality was found among the subjects with the highest OP exposure and the highest urinary OP levels. Seasonal variations in sperm concentration and sperm count were registered.The results showed a significant decrease in total sperm count among subjects with the highest exposure to OP. Further studies assessing the effects of OP on male reproductive health should be controlled by the variability in human sperm parameters, sperm seasonality, spermatogenesis time and the changing OP exposure level in men highly exposed to OP. 相似文献
83.
目的:报道经玻璃体腔内注射高剂量曲安奈德(triamcinolone acetonide,TA)联合光动力学疗法(photodynamic therapy,PDT)治疗老年性黄斑变性( age related macular degeneration, AMD)的脉络膜新生血管(choroidal neovascularization,CNV)后发生的脉络膜毛细血管萎缩。方法:我们采用非随机回顾性干涉治疗病例。在阿利坎特学院眼科,连续观察51眼(实验组)玻璃体腔内的注射(19.4±2.1)mg/0.1mL TA联合PDT治疗AMD的全部中心凹下型CNV患者,经过2a的随访,检查黄斑部脉络膜毛细血管和视网膜色素上皮细胞(RPE)萎缩情况。同时,采用单独PDT治疗的连续30眼患者作为对照组,其年龄,性别和AMD的CNV类型及大小与实验组相匹配。结果:随访24mo后,在治疗区域21/47眼(45%,实验组)和7/30眼(23%,对照组)发展成黄斑部RPE和脉络膜毛细血管萎缩(P=0.04,卡方检验)。实验组平均最大萎缩区域的直径为(5044±1666)μm,而对照组为(4345±1550)μm。在实验组中,RPE萎缩患者的平均最佳矫正视力为(0.87±0.33),而非RPE萎缩患者的平均最佳矫正视力为(0.66±0.26) (P=0.11,秩和U检验)。结论:玻璃体腔内注射大剂量TA联合PDT治疗可能会增加RPE和脉络膜毛细血管萎缩的风险。 相似文献
84.
85.
Javier Gomez-Pilar Víctor Martínez-Cagigal David García-Azorín Carlos Gmez ngel Guerrero Roberto Hornero 《The journal of headache and pain》2022,23(1)
BackgroundThe diagnosis of migraine is mainly clinical and self-reported, which makes additional examinations unnecessary in most cases. Migraine can be subtyped into chronic (CM) and episodic (EM). Despite the very high prevalence of migraine, there are no evidence-based guidelines for differentiating between these subtypes other than the number of days of migraine headache per month. Thus, we consider it timely to perform a systematic review to search for physiological evidence from functional activity (as opposed to anatomical structure) for the differentiation between CM and EM, as well as potential functional biomarkers. For this purpose, Web of Science (WoS), Scopus, and PubMed databases were screened.FindingsAmong the 24 studies included in this review, most of them (22) reported statistically significant differences between the groups of CM and EM. This finding is consistent regardless of brain activity acquisition modality, ictal stage, and recording condition for a wide variety of analyses. That speaks for a supramodal and domain-general differences between CM and EM that goes beyond a differentiation based on the days of migraine per month. Together, the reviewed studies demonstrates that electro- and magneto-physiological brain activity (M/EEG), as well as neurovascular and metabolic recordings from functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), show characteristic patterns that allow to differentiate between CM and EM groups.ConclusionsAlthough a clear brain activity-based biomarker has not yet been identified to distinguish these subtypes of migraine, research is approaching headache specialists to a migraine diagnosis based not only on symptoms and signs reported by patients. Future studies based on M/EEG should pay special attention to the brain activity in medium and fast frequency bands, mainly the beta band. On the other hand, fMRI and PET studies should focus on neural circuits and regions related to pain and emotional processing. 相似文献
86.
Objectives
To analyze the results of laparoscopic colposacropexy and to achieve a long-lasting support system without recurrences.Material and methods
From March 2001 to March 2007, we performed laparoscopic colposacropexy in 42 patients. The mean age was 56 years (42-70 years).Patients with prior hysterectomy showed complex vaginal vault prolapse while those without hysterectomy showed prolapse affecting more than one compartment. The 28 women with pelvic uterine prolapse underwent hysterectomy (supracervical hysterectomy in 15 and total hysterectomy in 13). The transperitoneal Burch procedure was carried out in eight patients with stress urinary incontinence.Results
The mean length of follow-up was 3.5 years (range: 1-6). Surgery was successful in 39 patients (92.8%). Anterior compartment recurrence was observed in one patient and severe lumbar pain associated with postoperative spondylodiscitis in another patient. A third patient required posterior trachelectomy. The mean operating time was 180 min (range: 120-240). The mean length of hospital stay was 2.5 days (range: 2-3).Conclusions
Laparoscopic colposacropexy is a safe and constantly evolving procedure with longterm durability. This procedure provides similar results to laparotomy but produces fewer vaginal complications. 相似文献87.
Javier Agüera Ortiz M. del Mar Mas MoreyAndrés Calvo Pérez 《Progresos de Obstetricia y Ginecología》2008
Objective
To alert clinicians to the possibility of synchronous tumors in patients with gynecological cancer. An important tool in diagnosis is the family history. We describe several familial syndromes involving the development of synchronous gynecological tumors.Subjects and methods
We studied all cases of synchronous gynecological tumors in the Manacor Hospital from 1997 to 2006.Results
Synchronous gynecologic tumors represented 0.83% of all gynecological neoplasms treated in our center in the period studied.Conclusions
This kind of tumor is uncommon but should be considered by clinicians, especially in women with a familial history of cancer or in those with certain genetic syndromes. Examination aimed at excluding the presence of synchronous tumors is recommended. 相似文献88.
89.
ABSTRACT: BACKGROUND: Records kept as a result of the implementation of Integrated Pollution Prevention and Control (IPPC) and the European Pollutant Release and Transfer Register (E-PRTR) constitute a public inventory of industries, created by the European Commission, which is a valuable resource for monitoring industrial pollution. Our objective is to ascertain whether there might be excess colorectal cancer mortality among populations residing in the vicinity of Spanish industrial installations that are governed by the IPPC Directive and E-PRTR Regulation and report their emissions to air. METHODS: An ecological study was designed to examine colorectal cancer mortality at a municipal level (8098 Spanish towns), over the period 1997-2006. We conducted an exploratory "near vs. far" analysis to estimate the relative risks (RR) of towns situated at a distance of less than 2 km from industrial installations. The analysis was repeated for each of the 24 industrial groups. RR and their 95 % credible/confidence intervals (95%CI) were estimated on the basis of Poisson regression models, using two types of modelling: a) the conditional autoregressive Bayesian model proposed by Besag, York and Mollie, with explanatory variables; and b) a mixed regression model. Integrated nested Laplace approximations were used as a Bayesian inference tool. RESULTS: Statistically significant RRs were detected in the vicinity of mining industry (RR 1.258; 95%CI 1.082 - 1.463), paper and wood production (RR 1.071; 95%CI 1.007 - 1.140), food and beverage sector (RR 1.069; 95%CI 1.029 - 1.111), metal production and processing installations (RR 1.065; 95 % CI 1.011 - 1.123) and ceramics (RR 1.050 ; 95%CI 1.004 - 1.099). CONCLUSIONS: Given the exploratory nature of this study, it would seem advisable to check in other countries or with other designs, if the proximity of industries that emit pollutants into the air could be an added risk factor for colorectal cancer mortality. Nevertheless, some of the differences between men and women observed in the analyses of the industrial groups suggest that there may be a component of occupational exposure, little-studied in the case of cancers of the digestive system. 相似文献
90.
Nerea Becerra-Tomás Andrés Díaz-López Núria Rosique-Esteban Emilio Ros Pilar Buil-Cosiales Dolores Corella Ramon Estruch Montserrat Fitó Lluís Serra-Majem Fernando Arós Rosa Maria Lamuela-Raventós Miquel Fiol José Manuel Santos-Lozano Javier Díez-Espino Olga Portoles Jordi Salas-Salvadó 《Clinical nutrition (Edinburgh, Scotland)》2018,37(3):906-913