全文获取类型
收费全文 | 5663篇 |
免费 | 297篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 143篇 |
妇产科学 | 319篇 |
基础医学 | 717篇 |
口腔科学 | 89篇 |
临床医学 | 417篇 |
内科学 | 711篇 |
皮肤病学 | 71篇 |
神经病学 | 400篇 |
特种医学 | 117篇 |
外国民族医学 | 1篇 |
外科学 | 543篇 |
综合类 | 584篇 |
预防医学 | 510篇 |
眼科学 | 24篇 |
药学 | 805篇 |
4篇 | |
中国医学 | 176篇 |
肿瘤学 | 349篇 |
出版年
2023年 | 55篇 |
2022年 | 101篇 |
2021年 | 175篇 |
2020年 | 142篇 |
2019年 | 132篇 |
2018年 | 167篇 |
2017年 | 149篇 |
2016年 | 136篇 |
2015年 | 168篇 |
2014年 | 342篇 |
2013年 | 419篇 |
2012年 | 258篇 |
2011年 | 301篇 |
2010年 | 227篇 |
2009年 | 221篇 |
2008年 | 247篇 |
2007年 | 251篇 |
2006年 | 201篇 |
2005年 | 198篇 |
2004年 | 167篇 |
2003年 | 142篇 |
2002年 | 124篇 |
2001年 | 115篇 |
2000年 | 91篇 |
1999年 | 78篇 |
1998年 | 56篇 |
1997年 | 61篇 |
1996年 | 59篇 |
1995年 | 84篇 |
1994年 | 73篇 |
1993年 | 54篇 |
1992年 | 60篇 |
1991年 | 58篇 |
1990年 | 58篇 |
1989年 | 51篇 |
1988年 | 57篇 |
1987年 | 49篇 |
1986年 | 35篇 |
1985年 | 77篇 |
1984年 | 87篇 |
1983年 | 59篇 |
1982年 | 80篇 |
1981年 | 50篇 |
1980年 | 43篇 |
1979年 | 43篇 |
1978年 | 33篇 |
1977年 | 33篇 |
1976年 | 23篇 |
1975年 | 26篇 |
1974年 | 26篇 |
排序方式: 共有6016条查询结果,搜索用时 15 毫秒
41.
Shanon Patel Risha Patel Federico Foschi Franceso Mannocci 《Journal of endodontics》2019,45(4):406-413
Introduction
The purpose of this study was firstly to compare the impact of radiographs, cone-beam computed tomographic (CBCT) imaging, and 3D Endo software (Dentsply Sirona, Ballaigues, Switzerland) on the assessment of root canal anatomy and radiographic quality of endodontic treatment and secondly to assess stress levels in the same cohort of residents performing endodontic treatment.Methods
Sixty patients requiring primary molar endodontic treatment were allocated randomly into 3 groups: group 1 (n = 20), conventional radiographs (periapical radiography [PR]) only; group 2 (n = 20), PR and CBCT imaging; and group 3 (n = 20), PR, CBCT imaging, and 3D Endo software. All treatment was performed using a standardized protocol. Residents completed a questionnaire to assess their stress levels and usefulness of the imaging modality used. The radiographic quality of completed cases was assessed by 2 experienced endodontists who were not involved in the supervision of the cases being assessed.Results
Groups 2 (CBCT imaging) and 3 (PR, CBCT imaging, and 3D Endo) proved significantly better than group 1 (PR) (P < .001) for assessing the number of root canals and anatomy and estimating the working lengths. Group 3 provided a significantly more accurate determination of the working level (P = .002). There were significantly more cases with obturation short of the apex (<2 mm) and voids in group 1 compared with group 3 (P < .05) and a significantly higher number of cases with voids in group 1 compared with group 3 (P < .01). Clinicians found treatment to be moderately or very stressful in 75%, 5%, and 0% in groups 1, 2, and 3, respectively.Conclusions
3D Endo software followed by CBCT imaging were found to be more desirable for the evaluation of root canal anatomy and working lengths and reducing the residents' stress levels. 相似文献42.
Baffone GM Botticelli D Pantani F Cardoso LC Schweikert MT Lang NP 《Clinical oral implants research》2011,22(4):438-444
Aim: To evaluate the influence (i) of various implant platform configurations and (ii) of implant surface characteristics on peri‐implant tissue dimensions in a dog model. Material and methods: Mandibular premolars and first molars were extracted bilaterally in six Labrador dogs. After 3 months of healing, two implants, one with a turned and a second with a moderately rough surface, were installed on each side of the mandible in the premolar region. On the right side of the mandible, implants with a tapered and enlarged platform were used, while standard cylindrical implants were installed in the left side of the mandible. Abutments with the diameter of the cylindrical implants were used resulting in a mismatch of 0.25 mm at the tapered implant sites. The flaps were sutured to allow a non‐submerged healing. After 4 months, the animals were sacrificed and ground sections were obtained for histometric assessment. Results: All implants were completely osseointegrated. A minimal buccal bone resorption was observed for both implant configurations and surface topographies. Considering the animals as the statistical unit, no significant differences were found at the buccal aspect in relation to bone levels and soft tissue dimensions. The surface topographies did not influence the outcomes either. Conclusions: The present study failed to show differences in peri‐implant tissue dimensions when a mismatch of 0.25 mm from a tapered platform to an abutment was applied. The surface topographies influence a neither marginal bone resorption or peri‐implant soft tissue dimension. To cite this article: Baffone GM, Botticelli D, Pantani F, Cardoso LC, Schweikert MT, Lang NP. Influence of various implant platform configurations on peri‐implant tissue dimensions: an experimental study in dog.Clin. Oral Impl. Res. 22 , 2011; 438–444. 相似文献
43.
盐酸米诺四环素软膏对慢性牙周炎龈沟液中硫化物的影响 总被引:2,自引:0,他引:2
目的:分析慢性牙周炎病人局部应用盐酸米诺四环素(minocycline HCl,MINO)后,不同牙周状态下龈沟液(GCF)中硫化物(suleus sulphide level,SUL)浓度变化及其与临床指标的关系。方法:采用金刚牙周探测仪对盐酸米诺四环素治疗前后龈沟液中硫化物浓度及其临床指标进行测定。随机单盲法选择慢性牙周炎病人21例,61个患牙。用药组(T)34个患牙,204个位点,基础治疗后将盐酸米诺四环素软膏置牙周袋内;对照组(C)卯个患牙,162个位点,以单纯基础治疗为主。于基线前两周完成全口龈上洁治、口腔卫生宣教。基线时测定相应位点龈沟液中硫化物浓度,龈沟出血指数(SBI),牙周袋探诊深度(PPD),牙周临床附着丧失水平(CAL);然后行龈下刮治术,用药组龈沟内放药,对照侧不放药。第2周各项指标检查同上。结果:用药组(T)龈沟液中硫化物浓度与其基线时和对照组相比明显下降(P〈0.05),其临床指标用药组(T)与对照组(C)相比改善明显(P〈0.05),龈沟液中硫化物的浓度与临床指标间具有相关性。结论:盐酸米诺四环素软膏(MINO)辅助治疗牙周炎,能有效降低龈沟液中硫化物浓度,改善牙周组织状况;椅旁龈沟液硫化物浓度变化可间接反映对牙周袋内细菌的杀灭、抑制作用。 相似文献
44.
Schätzle M Löe H Bürgin W Anerud A Boysen H Lang NP 《Journal of clinical periodontology》2003,30(10):887-901
OBJECTIVES: The purpose of this study was to determine the influence of long-standing gingival inflammation on periodontal attachment loss. On the basis of repeated examinations, the present report describes the influence of gingival inflammation on the initiation of periodontitis from 16 to 59 years of age. MATERIAL AND METHODS: The data originated from a 26-year longitudinal study of Norwegian males, who practiced daily oral home care and received state-of-the-art dental care. The initial examination included 565 individuals. Subsequent examinations took place in 1971, 1973, 1975, 1981, 1988 and 1995. Thus, the study covers the age range of 16-59 years. All tooth sites were divided into four categories according to their history of gingival inflammation over the entire observation period: sites always scoring GI = 0, GI = 1 and GI = 2 sites (GI = gingival index). Sites disclosing various GI scores at different observation periods were not considered. RESULTS: The mean cumulative attachment loss for non-inflamed (GI = 0) sites in individuals approaching 60 years of age was 1.94 mm. Sites always scoring GI = 1 yielded 2.42 mm, and sites that always scored GI = 2 exhibited 3.31 mm of periodontal attachment loss. At interproximal sites of all three groups where gingival trauma was assumed to be minimal or non-existent, only very few sites expressed attachment loss due to gingival recession (2-4%). At interproximal sites always scoring GI = 0, 20% loss of attachment was in the form of pocket formation by 59 years of age. The GI = 1 and the GI = 2 cohorts exhibited attachment loss with pocket formation in 28% and 54%, respectively. CONCLUSION: This study has shown that, as men approach 60 years of age, gingival sites that throughout the 26 years of observation bled on probing had approximately 70% more attachment loss than sites that were consistently non-inflamed (GI = 0). Before 40 years of age, there was a slight increase in periodontal attachment loss due to pocket formation, but after this, the frequency increased significantly. Loss of attachment due to gingival recession was very small in all three groups.The fact that sites with non-inflamed gingiva also exhibited some loss of attachment and pocket formation may be explained by fluctuation in the variations of tissue status during long observation intervals combined with the presence of subclinical inflammation. 相似文献
45.
为探讨男性的正常衰老对内分泌系统的影响,以便对某些老年性疾病进行提前预测、提前治疗,应用电化学发光免疫分析对120名正常男性进行了E2、T、SHBG、DHEA-SO4、LH、FSH、FT3、FT4和TSH的浓度测定,并按年龄类别分为对照组(30名,年龄30~50岁)、低老年组(30名,年龄51~60岁)、中老年组(30名,年龄61~70岁)、高老年组(30名,年龄71~80岁)。结果表明:随着年龄的不断增加,全面了解中老年男性的多种激素的紊乱状况,对提前预测、提前治疗与之相关的疾病有着重要的意义。 相似文献
46.
目的 提高对腺垂体功能减退症的认识。方法 对安徽医科大学第二附属医院内分泌科2015年8月至2020年9月收治的123例腺垂体功能减退症病人的资料进行回顾性分析。结果 男47例(38.2%),女76例(61.8%),年龄范围16~83岁。颅内占位或术后49例(39.9%),希恩综合征39例(31.7%),空泡蝶鞍综合征15例(12.2%),下丘脑-垂体发育不良9例(7.3%),病因不明11例(8.9%)。以消化道症状就诊47例(38.2%,为首要就诊症状),垂体危象23例(18.7%)。性腺轴受损104例(86.7%,为最主要受损腺体),3个腺体(性腺轴、甲状腺轴、肾上腺轴)均受损61例(55.5%)。低钠血症60例(52.2%),血脂异常87例(75%),低血糖21例(18.8%),贫血47例(40.9%)。结论 腺垂体功能减退症临床表现多样,应提高对该病的认识,避免误诊和漏诊,确诊后及时予以激素替代治疗。 相似文献
47.
中国人口老龄化日益严重,骨质疏松症的发生率愈来愈高,其防治费用给患者家庭和社会经济造成了沉重的负担。随着国家分级诊疗制度建设的深入,各级医疗机构就诊人数越来越多,其中大部分对于骨质疏松症的认识程度较低。在此背景下,骨质疏松症初筛工具的应用显得尤为重要。亚洲人骨质疏松自我筛查工具(osteoporosis self-assessment tool for Asians,OSTA)是针对亚洲绝经后女性制定的一套工具,只参考年龄和体重两个因素。虽然在使用过程中仍存在一定的局限性,但具有操作简单方便,灵敏度相对较高的特点,特别是在缺乏检测手段的基层医疗机构中进行骨质疏松筛查应用方面前景广阔。本文将近年来利用OSTA在中国各级医疗机构进行骨质疏松筛查的相关研究进行综述,旨在探讨OSTA在此方面的适用性,以期为骨质疏松症的初筛、管理、分级诊疗等方面提供新视角。 相似文献
48.
《Surgery for obesity and related diseases》2020,16(2):288-295
BackgroundDespite a known negative association between serum uric acid level (SUA) and renal function, this correlation in patients after bariatric surgery remains unknown.ObjectiveTo assess correlation between postoperative SUA and estimated glomerular filtration rate (eGFR) at 12 months after bariatric surgery.SettingA single tertiary referral center.MethodsA total of 252 patients (age = 40.5 ± 11.2; body mass index = 39.0 ± 5.5 kg/m2) undergoing bariatric surgery divided into 2 groups (i.e., normal renal function [90 ≤ eGFR < 125 mL/min/1.73 m2, n = 176] versus renal function impairment [eGFR < 90 mL/min/1.73 m2, n = 76]) were assessed for relationships between SUA and eGFR in both groups (primary endpoint) and associations of percentage weight loss with changes in SUA (△SUA) and eGFR (△eGFR) for all patients (secondary endpoint) at 12 months.ResultsOverall, prevalence of hyperuricemia was 40.4% and 22.2% (baseline and postoperative 12 mo, respectively). Reverse relationship was observed between SUA and eGFR (r = −.152, P = .007) for all patients with no association noted between baseline SUA and eGFR in each group as well as between SUA and eGFR at 12 months in the normal group (r = −.076, P = .437). The reverse relationship was found (r = −.417, P = .005) in renal function impairment group for whom SUA was identified as a predictor of eGFR at 12 months. There was no association of percentage weight loss with △SUA (r = .089, P = .601) and △eGFR (r = −.046, P = .785).ConclusionThe results demonstrated a negative relationship between postoperative SUA and renal function in patients with preexisting renal dysfunction undergoing bariatric surgery. Clinical significance of our findings warrants further investigation. 相似文献
49.
Subjective insomnia symptoms and sleep duration are not related to hypothalamic–pituitary–adrenal axis activity in older adults 下载免费PDF全文
Rian J. G. Peters van Neijenhof Erik van Duijn Julia F. Van Den Berg Margot W. M. de Waal Roos C. van der Mast Hannie C. Comijs 《Journal of sleep research》2018,27(1):40-46
Insomnia symptoms are highly prevalent in depressed older adults. This study investigates the association between hypothalamic–pituitary–adrenal (HPA) axis activity and symptoms of insomnia, respectively, sleep duration among 294 depressed and 123 non‐depressed older adults of the Netherlands Study of Depression in Older people (NESDO) study. Insomnia symptoms were defined as clinically relevant when having a score ≥ 10 points on the Women's Health Initiative Insomnia Rating Scale (WHIIRS). Sleep duration was categorized in short (≤ 6 h per night), normal (7–8 h per night) and long (≥ 9 h per night) duration. Salivary cortisol levels were used to assess the following cortisol parameters for HPA axis activity: area under the curve with respect to the increase (AUCi) and to the ground (AUCg), diurnal slope, evening cortisol level and dexamethasone suppression ratio. Clinically relevant insomnia symptoms were present in 46% of the participants. Thirty‐two per cent of the participants were short sleepers, whereas 16% were long sleepers. However, univariate analyses showed no differences in any of the HPA axis parameters between people with and without insomnia symptoms or between the three groups with different sleep duration. In addition, no significant interaction was found between a diagnosis of depression or the severity of depressive symptoms and any of the cortisol parameters in relation to insomnia symptoms or sleep duration. 相似文献
50.