全文获取类型
收费全文 | 41311篇 |
免费 | 2521篇 |
国内免费 | 223篇 |
专业分类
耳鼻咽喉 | 567篇 |
儿科学 | 894篇 |
妇产科学 | 622篇 |
基础医学 | 4298篇 |
口腔科学 | 7526篇 |
临床医学 | 2528篇 |
内科学 | 9023篇 |
皮肤病学 | 567篇 |
神经病学 | 2930篇 |
特种医学 | 1603篇 |
外科学 | 5886篇 |
综合类 | 132篇 |
一般理论 | 10篇 |
预防医学 | 1538篇 |
眼科学 | 590篇 |
药学 | 2192篇 |
中国医学 | 70篇 |
肿瘤学 | 3079篇 |
出版年
2023年 | 610篇 |
2022年 | 575篇 |
2021年 | 1044篇 |
2020年 | 659篇 |
2019年 | 814篇 |
2018年 | 1260篇 |
2017年 | 993篇 |
2016年 | 1194篇 |
2015年 | 1347篇 |
2014年 | 1672篇 |
2013年 | 1896篇 |
2012年 | 2664篇 |
2011年 | 2650篇 |
2010年 | 1820篇 |
2009年 | 1785篇 |
2008年 | 2352篇 |
2007年 | 2299篇 |
2006年 | 2239篇 |
2005年 | 2161篇 |
2004年 | 1913篇 |
2003年 | 1795篇 |
2002年 | 1778篇 |
2001年 | 651篇 |
2000年 | 570篇 |
1999年 | 610篇 |
1998年 | 556篇 |
1997年 | 461篇 |
1996年 | 446篇 |
1995年 | 397篇 |
1994年 | 363篇 |
1993年 | 306篇 |
1992年 | 416篇 |
1991年 | 312篇 |
1990年 | 350篇 |
1989年 | 282篇 |
1988年 | 308篇 |
1987年 | 270篇 |
1986年 | 225篇 |
1985年 | 212篇 |
1984年 | 218篇 |
1983年 | 176篇 |
1982年 | 154篇 |
1981年 | 121篇 |
1980年 | 85篇 |
1979年 | 112篇 |
1978年 | 104篇 |
1977年 | 69篇 |
1976年 | 75篇 |
1973年 | 65篇 |
1972年 | 75篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
21.
A cross-sectional survey of patients' beliefs about stress and their help-seeking behaviour 下载免费PDF全文
BACKGROUND: Stress has become an increasingly common presentation in general practice. This may relate to an increase in stress in people's lives or a change in the meaning of stress and its conceptualisation as a legitimate problem for the GP. AIM: To explore patients' beliefs about stress, their association with help-seeking behaviour, and to examine differences by ethnic group. DESIGN OF STUDY: Cross-sectional survey of general practice patients attending to see their GP. SETTING: An inner-city London practice. METHOD: Consecutive general practice patients completed a questionnaire, which involved rating a series of symptoms for the extent to which they were associated with stress and describing their help-seeking behaviour. In total, 548 patients completed the questionnaire. Most patients described themselves as black Caribbean (n = 163), black African (n = 48), or white British (n = 187). RESULTS: The symptoms most frequently associated with stress were sleeping problems, feeling depressed, feeling panicky, having high blood pressure and feeling anxious; feeling ashamed, experiencing indigestion, having diarrhoea, feeling hot or cold, and suffering from constipation were least commonly associated to stress. This model of stress did not vary by ethnic group. Ethnic group differences were found for the association between the model of stress and help-seeking behaviour. Although white British patients consistently reported that the more a symptom was seen as indicative of stress, the more likely they would be to visit the doctor for that symptom, this association was not found for either black Caribbean or black African patients. CONCLUSIONS: The belief that stress-related symptoms are a legitimate problem for the GP is not universal and varies according to ethnic group. Stress is used by different patients in different ways and offers a variable pathway to the doctor. 相似文献
22.
Bulimia is a distinct diagnostic eating disorder with its most noted manifestation being the rapid ingestion of large quantities of food followed by its elimination through the mouth. Because of the dental implications of highly acidic stomach contents chronically being regurgitated, the dentist is in a unique position to help identify the patient with bulimia. Dental erosion is not only the most easily noted but also the most destructive of the many oral problems caused by bulimia. This report of case describes a preventive dental prosthesis that can be used by the patient with bulimia to protect those teeth that are most affected by dental erosion. The construction of the prosthesis is easily completed with materials in the dental office and provides a great service to the patient with bulimia. 相似文献
23.
Carlos Alberto Herrero de Morais Norberti Bernardineli Roberto B Garcia Marco A H Duarte Danilo M Z Guerisoli 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,102(3):417-421
OBJECTIVE: The aim of this study was to evaluate the biocompatibility of Portland cement with the addition of iodoform, compared to MTA (ProRoot). STUDY DESIGN: Eighteen Wistar albino rats were divided into 3 groups of 6 animals each. Polyethylene tubes were filled either with freshly mixed MTA or Portland cement mixed with iodoform (20% wt/wt) and implanted subcutaneously. An empty tube served as control. After 7, 30, or 60 days, the implants together with the surrounding tissues were removed in blocks. Sections were evaluated for the presence and thickness of a fibrous capsule, presence of granulation tissue, and the severity of inflammatory response. Data were submitted to nonparametric statistical analysis with individual comparisons between groups at a significance level of P < 0.05. RESULTS: There were no differences between inflammatory responses at 7 and 30 days. After 60 days from surgical removal, there was significantly more tissue reaction to the MTA and Portland cement compared to the control group. CONCLUSION: There were no significant differences regarding inflammatory responses between MTA and Portland cement with iodoform after 7, 30, or 60 days. After 60 days, the fibrous capsule around the Portland cement appeared more organized than tissue surrounding MTA implants. After 60 days, there was still a significantly increased tissue reaction to the 2 cements compared to the empty polyethylene tubes. 相似文献
24.
25.
K Tamazawa H Arima T Kojima Y Isomura M Okada S Fujita T Furuya T Takenaka O Inagaki M Terai 《Journal of medicinal chemistry》1986,29(12):2504-2511
Four enantiomers (3a-d) of the title compound, YM-09730 (3), were synthesized by the reaction of (-)- or (+)-5-(methoxycarbonyl)-2, 6-dimethyl-4-(m-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid (1a or 1b) with (S)- or (R)-1-benzyl-3-pyrrolidinol (2a or 2b). [3H]Nitrendipine binding affinity and coronary vasodilating activity of these compounds were evaluated. The absolute configuration of the most potent enantiomer (3a) with the longest duration was unequivocally determined to be (S)-1,4-dihydropyridine-C4 and (S)-pyrrolidine-C3 (S,S) by X-ray crystallographic study on 3a X HBr as well as 3a X HCl. The configuration of 1a corresponds to R, and the other enantiomers of 3 were respectively determined by chemical correlation. The potency order of the four enantiomers was (S,S)-3a greater than (S,R)-3b greater than (R,R)-3d greater than (R,S)-3c. Latent chiral characters of nifedipine derivatives with the identical ester groups were assigned by comparison of their puckering modes of 1,4-dihydropyridine (DHP) rings with those found in 3a X HCl or 3a X HBr. On the basis of the assignment, it has been revealed that the (S)-DHP nifedipine derivatives possess the synperiplanar carbonyl group at C5. The conformational restriction may be a factor causing stereoselectivity of antagonism. 相似文献
26.
27.
Andrea Salonia MD Alberto Briganti MD Andrea Gallina MD Giuseppe Zanni MD Federico Dehò MD Patrizio Rigatti MD Francesco Montorsi MD 《Current Sexual Health Reports》2007,4(2):85-90
This article assesses the effects of lower urinary tract symptoms (LUTS), not including urinary incontinence, on the overall
sexual health of women, using literature that includes peer-reviewed articles. This article analyzes a number of studies that
provide data on the prevalence and the predictors of sexual function impairment in women with LUTS, such as urinary urgency
and frequency, overactive bladder syndrome, and interstitial cystitis. Because case studies provide substantial heterogeneity
of outcome measures, this article does not apply meta-analytic techniques to the data. Most of the studies showed that LUTS
can have a negative impact on the sexual health of women, sexual pain disorder being the more frequent complaint among patients
with bladder dysfunctions. 相似文献
28.
Salwa AlDahlawi BDS MSc ; Ameneh Eslami MD ; Lari Häkkinen DDS PhD ; Hannu S. Larjava DDS PhD 《Wound repair and regeneration》2006,14(3):289-297
The alphavbeta6 integrin is an exclusively epithelial integrin that is highly expressed during fetal development. In adult tissue, alphavbeta6 integrin is expressed during inflammation, carcinogenesis, and in wound healing. We previously reported that alphavbeta6 integrin is highly expressed in poorly healing human wounds and its over-expression is associated with chronic wounds in a mouse model. The objective of this study was to investigate the role of alphavbeta6 integrin in compromised wound healing induced by hydrocortisone treatment or aging by using young and old mice deficient in or overexpressing the beta6 integrin subunit in the epidermis. Untreated aged beta6 integrin-deficient (beta6-/-) animals showed a significant delay in wound healing when compared to their age-matched controls or younger beta6-/- mice. The most significant delay was observed at the stages where granulation tissue deposition was occurring. Hydrocortisone treatment significantly delayed wound healing in wild-type and beta6 integrin-deficient mice in comparison with the untreated controls. However, hydrocortisone treatment in beta6 integrin overexpressing animals did not cause a significant delay in wound healing. The results of this study suggest that alphavbeta6 integrin plays an important role in wound healing in animals compromised by either age or stress mimicked by hydrocortisone. 相似文献
29.
Eric T. Stoopler DMD res Pinto DMD Faizan Alawi DDS Sree Raghavendra DMD Ricardo Boyce Jr. DDS David Porter MD Thomas P. Sollecito DMD 《Special care in dentistry》2004,24(2):65-69
Acute myelogenous leukemia (AMU is a hematologic disorder that is characterized by an abnormal proliferation of immature myeloid cells. Granulocytic sarcomas are clusters of leukemic myeloid cells that may develop as a result of AML. Oral manifestations of AML are common and often involve enlargements of the gingiva and/or mucosal tissue from direct leukemia cell infiltration. We describe the case history of a 50-year-old man who had an ulcera-tive lesion of the oral mucosa that was determined to be a granulocytic sarcoma of AML-M0 subtype. The combination of both the subtype and clinical presentation of the leukemia makes this presentation unusual, and to the best of our knowledge, of a type that has not been previously reported in the literature. 相似文献
30.
目的:分析胃癌大肠转移的X线钡灌肠表现。方法:104例胃癌入院术前检查发现结肠转移或胃癌术后转移入院治疗的病例。分析钡灌肠初次发现大肠转移征象的年龄、发现胃癌原发病变距初次发现大肠转移的间隔时间、转移病变的发生部位和病变造成的X线钡灌肠图像上的肠管变形和粘膜面的改变。结果:104例胃癌结肠转移,男67例,女37例。胃癌术前检查中发现结肠转移者32例,术后发现的大肠转移中,多数转移发生在手术后3年内(占91.3%)。胃癌原发灶的肉眼形态BorrmannⅢ型(28例)和BorrmannⅣ型(65例)者占89.4%,组织学中以低分化腺癌和印戒细胞癌为主要成分者占91.3%。X线钡灌肠检查显示大肠转移的好发部位为横结肠(80),其次为直肠(50)。转移灶可累及多节段肠管,其中横结肠中1/3段(47),横结肠左1/3(44),横结肠右1/3(39)和直肠腹膜返折之上(39)。X线显示肠管单侧变形者227处,双侧变形者96处。黏膜面表现为梳齿状黏膜纹聚集改变253处,颗粒结节状改变23处,外压性改变20处,弥漫性改变62处。结论:胃癌大肠转移的好发部位为横结肠和直肠,结肠黏膜面的梳齿状黏膜纹聚集为胃癌大肠转移的主要X线钡剂灌肠表现。 相似文献