全文获取类型
收费全文 | 13836篇 |
免费 | 1427篇 |
国内免费 | 334篇 |
专业分类
耳鼻咽喉 | 162篇 |
儿科学 | 379篇 |
妇产科学 | 247篇 |
基础医学 | 843篇 |
口腔科学 | 137篇 |
临床医学 | 1888篇 |
内科学 | 2904篇 |
皮肤病学 | 173篇 |
神经病学 | 648篇 |
特种医学 | 448篇 |
外国民族医学 | 2篇 |
外科学 | 1913篇 |
综合类 | 1693篇 |
现状与发展 | 2篇 |
预防医学 | 1220篇 |
眼科学 | 143篇 |
药学 | 1345篇 |
66篇 | |
中国医学 | 744篇 |
肿瘤学 | 640篇 |
出版年
2024年 | 121篇 |
2023年 | 581篇 |
2022年 | 1004篇 |
2021年 | 1383篇 |
2020年 | 1271篇 |
2019年 | 1033篇 |
2018年 | 976篇 |
2017年 | 797篇 |
2016年 | 669篇 |
2015年 | 597篇 |
2014年 | 1175篇 |
2013年 | 1084篇 |
2012年 | 723篇 |
2011年 | 711篇 |
2010年 | 527篇 |
2009年 | 487篇 |
2008年 | 429篇 |
2007年 | 396篇 |
2006年 | 325篇 |
2005年 | 246篇 |
2004年 | 196篇 |
2003年 | 134篇 |
2002年 | 114篇 |
2001年 | 79篇 |
2000年 | 59篇 |
1999年 | 49篇 |
1998年 | 55篇 |
1997年 | 56篇 |
1996年 | 45篇 |
1995年 | 33篇 |
1994年 | 25篇 |
1993年 | 33篇 |
1992年 | 23篇 |
1991年 | 23篇 |
1990年 | 19篇 |
1989年 | 18篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 17篇 |
1984年 | 15篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Samuels ME Forbey KC Reid JE Abkevich V Bulka K Wardell BR Bowen BR Hopkins PN Hunt SC Ballinger DG Skolnick MH Wagner S 《Clinical genetics》2001,59(2):88-98
Defects in the lipoprotein lipase (LPL) gene are associated with dyslipidemia in the general population. Several rare mutations in the gene, as well as two common coding region polymorphisms, D9N and N291S, exhibit deleterious effects on circulating lipid levels. Using a linkage-based approach, we have identified a large Utah kindred segregating the D9N variant in the LPL gene. The kindred was ascertained for premature coronary heart disease and was expanded based on familial dyslipidemia. A genomic scan identified a region of linkage including LPL, and mutation screening identified the segregating variant. In the kindred, the variant shows high penetrance for a hypoalphalipoproteinemia phenotype, but is also associated with hypertriglyceridemia and elevated insulin levels. The strength of linkage was dependent on the combination of phenotype definition and model parameters, favoring the use of a MOD score approach. Most other studies of LPL have proceeded by mutation screening of randomly chosen individuals or selected affected probands; this is the first example identifying a segregating LPL mutation using direct linkage. 相似文献
72.
帕罗西汀合用心理行为干预治疗老年期抑郁症的疗效 总被引:1,自引:0,他引:1
闫加民 《中国健康心理学杂志》2008,16(8):926-927
目的探讨帕罗西汀合用心理行为治疗对老年期抑郁症的疗效。方法将60例老年期抑郁症随机分成两组,进行为期6周的对照研究,出院后随访1年,分别用心理行为合并帕罗汀治疗(研究组)和帕罗西汀治疗(对照组);采用汉密尔顿抑郁量表(HAMD)和临床疗效总评量表(CGI—SI)进行评定。结果研究组在治疗6周后HAMD评分(9.32±2.28)较对照组(13.17±3.39)有显著性差异(P〈0.01),研究组CGI—SI较对照组有显著性差异(P〈0.01),1年末随访时HAMD评分研究组(9.19±2.33)较对照组(13.98±4.96)有显著性差异(P〈0.01)。且研究组复发率低于对照组(P〈0.05)。结论帕罗西汀合用心理行为治疗对老年期抑郁症的疗效优于帕罗西汀,且复发率低。 相似文献
73.
Morphological evaluation of human embryos and derivation of an embryo quality scoring system specific for day 3 embryos: a preliminary study 总被引:16,自引:0,他引:16
Desai NN Goldstein J Rowland DY Goldfarb JM 《Human reproduction (Oxford, England)》2000,15(10):2190-2196
A scoring system specific for day 3 embryos has not been extensively explored. Most IVF laboratories continue to grade embryos solely on the basis of cell number and percentage fragmentation as was traditionally done for day 2 embryos. Additional morphological features, some unique to day 3 embryos, may be useful in selecting embryos most likely to blastulate and implant. The objective of this study was to derive an embryo scoring system for day 3 transfers which is predictive of positive pregnancy outcomes. A total of 316 transferred embryos from 93 patients was recorded on videotape and evaluated. The following parameters were used to grade the embryos: cell number, fragmentation pattern (FP), cytoplasmic pitting, compaction, equal sized blastomeres, blastomere expansion and absence of vacuoles. The clinical pregnancy rate was 41.9%, with an implantation rate of 18% per embryo transferred. The mean number of embryos transferred per patient was 3.4. Three formulae were derived to score embryo quality in each transfer based on the average score of individual embryos transferred. In the first scoring system, cell number alone was used to predict pregnancy outcome. The second scoring system was based on blastomere number and the observed FP. The third scoring system utilized both blastomere number and FP but also combined this with five morphological criteria to yield a final day 3 embryo quality (D3EQ) score. We found the D3EQ score to be prognostic of pregnancy outcome. This study suggests that although cell number and FP are certainly predictors of positive pregnancy outcomes, additional parameters specific to day 3 embryos should be used to stratify a cohort of embryos further. 相似文献
74.
AIMS: Apoptosis is mediated by apoptosis-specific genes, certain oncogenes and tumour suppressor genes. Caspase-3, a group of cystein proteases, is involved in the induction of apoptosis and has been considered to correlate with apoptosis. The aim of this study was to determine whether caspase-3 is expressed in prostatic carcinoma and benign prostatic hyperplasia, and correlated with the apoptosis. METHODS AND RESULTS: We studied the apoptotic index and caspase-3 immunoreactivity in 40 cases of benign nodular hyperplasia (BPH) and 40 cases of prostate carcinoma (PCA) by in-situ labelling and immunohistochemistry. The mean number of apoptotic bodies in cases with BPH was not significantly different from cases with PCA I (Gleason score 2-4), but samples from patients with PCA II (Gleason score 5-7) and PCA III (Gleason score 8-10) showed a significantly higher apoptotic number than cases with BPH. Positive staining for caspase-3 was seen in 42.5% (17/40) of the BPH, and 27.5% (11/40) of the PCA: PCA I was 41.7% (5/12), PCA II 14.3% (2/14) and PCA III was 28.6% (4/14). CONCLUSIONS: Based on our results, the number of apoptotic bodies was not correlated with the caspase-3 expression and there was no relationship between caspase-3 expression and Gleason score. However, the number of apoptotic bodies was significantly higher in cases with intermediate (Gleason score 5-7) and high-grade (Gleason score 8-10) PCAs than cases with BPH and low-grade PCAs (Gleason score 2-4). 相似文献
75.
The atopy patch test -- reproducibility and comparison of different evaluation methods 总被引:2,自引:0,他引:2
Heinemann C Schliemann-Willers S Kelterer D Metzner U Kluge K Wigger-Alberti W Elsner P 《Allergy》2002,57(7):641-645
BACKGROUND: There is still a lack of standardization of the atopy patch test (APT) in test procedures and evaluation methods. Our aim was to examine the reproducibility of APT results and to compare visual evaluation to chromametry and laser Doppler imaging. METHODS: Fifty-two volunteers with atopic eczema/dermatitis syndrome (AEDS) were included. The APT was performed on tape-stripped and unstripped test fields on their backs using cat dander, house dust mite and grass pollen allergens from two different suppliers. Responders were re-tested 4-12 weeks later with the same allergens on their forearms. RESULTS: Using Allergopharma allergens, 14 (26.9%) volunteers showed one or more positive reactions. The reproducibility rate was 56.3%. The Erlangen atopy score in APT-positive and negative volunteers was 19 +/- 6 vs 15 +/- 6. The test agreement in volunteers tested with both allergens, from Allergopharma and Stallergènes, was poor. Correlation of the results between the three evaluation methods was significant (P < or = 0.001). CONCLUSIONS: The low reproducibility rate of APT results and the poor inter-test-agreement using allergens from different suppliers show that much work remains to make the APT a reliable tool in identifying relevant aeroallergens that lead to flare ups of AEDS. Compared to chromametry and laser Doppler imaging, visual scoring was superior in differentiation between irritative and allergic reactions. 相似文献
76.
The use of a pretherapeutic, predictive score to determine inclusion criteria for the non-surgical treatment of ectopic pregnancy. 总被引:6,自引:1,他引:6
H Fernandez C Lelaidier V Thouvenez R Frydman 《Human reproduction (Oxford, England)》1991,6(7):995-998
Non-surgical management of ectopic pregnancy has recently become an alternative to surgery. We have investigated a pretherapeutic score to define the indication for non-surgical and surgical treatment in 61 patients with ectopic pregnancy. The score was performed before the patients' inclusion in a nonsurgical management scheme. The score used six criteria which were evaluated on a scale from 1 to 3: gestational age, human chorionic gonadotrophin (HCG) level, progesterone level, abdominal pain, haemoperitoneum volume and haematosalpinx diameter (estimated by laparoscopy or transvaginal ultrasound). Three scores, 10, 11 and 12, were studied in order to define a threshold beyond which surgical treatment should be performed. For each one, sensitivity, specificity and positive and negative predictive values were analysed. The success rate of non-surgical treatment was 75% (46/61). For patients undergoing medical treatment with a score less than or equal to 12, the success rate was significantly higher compared with a success rate of 50% when the score was greater than 12. We conclude that a score less than or equal to 12 permits non-surgical management with a success rate of 82%. A score greater than 12 indicates that laparoscopic surgery may be more suitable. The choice between different non-surgical approaches, did not influence the success rate. When ultrasound reveals embryo heart activity, medical treatment is always possible if the score is less than or equal to 12. 相似文献
77.
目的:回顾性分析急性胰腺炎(AP)患者空腹高血糖发生率及其危险因素。方法:收集2018-01—2018-12武汉大学人民医院胰腺外科133例AP且无糖尿病(DM)病史的住院患者病历资料,按照不同性别、年龄、AP临床分型、病因、CT指数评分(CISI)等分组,χ2检验分析各组临床因素与空腹高血糖(FPG≥6.1mmol/L)发生率的关系,多因素二元logistic回归分析空腹高血糖独立危险因素。结果:AP临床分型(χ2=5.494,P=0.019)和CTSI(χ2=6.236,P=0.013)与AP患者空腹高血糖相关(P<0.05)。CTSI≥6分(P=0.015,OR=2.920,95%Cl=1.234—6.905)为AP患者空腹高血糖的独立危险因素(P<0.05)。结论:临床分型中重症+重症及CTSI≥6分的AP患者易发生空腹高血糖,尤其CTSI≥6分是AP后空腹高血糖的独立危险因素,临床应高度关注。 相似文献
78.
Lack of PTEN expression in endometrial intraepithelial neoplasia is correlated with cancer progression 总被引:6,自引:0,他引:6
Baak JP Van Diermen B Steinbakk A Janssen E Skaland I Mutter GL Fiane B Løvslett K 《Human pathology》2005,36(5):555-561
We tested the hypothesis that PTEN inactivation may stratify cancer progression risk among putative endometrial hyperplasias, classified prognostically by means of the morphometric D score (DS). The DS, calculated from 3 morphometric variables measured in routine hematoxylin-eosin-stained endometrial biopsy slides, is the most sensitive and specific method of endometrial cancer risk prediction currently available. Clinical outcomes of 103 women with endometrial hyperplasia on biopsy were tallied according to the DS. Seven (7/103; 7%) patients with carcinoma during follow-up were all distributed within the high-risk prognostic group (ie, DS <1 = endometrial intraepithelial neoplasia [EIN]) (7/21; 33% progression). None of the 82 cases with a DS higher than 1 progressed. All cases that progressed were PTEN null, indicating that this genotype is capable of further stratifying cancer progression risk in hyperplasias irrespective of histological categorization. However, only 16% of the PTEN-null cases progressed. When PTEN expression pattern was combined with EIN, the prognostic power was greatly increased (specificity from 63% for PTEN and 85% for EIN to 93% when combined; positive predictive value from 16% and 33% to 50%). We conclude that loss of PTEN expression is the first biomarker in EIN that increases the accuracy of the prognostic DS to predict cancer progression risk. Unless endometrial hyperplasias are stratified by histological morphometric D-Score, PTEN has a low positive predictive value. 相似文献
79.
动态脑电图对缺血缺氧性昏迷病人的预后评估 总被引:4,自引:0,他引:4
目的:观察动态脑电图和临床检测指标对缺血缺氧性昏迷病人预后的评估价值。方法:在45例缺血缺氧性昏迷病人急性期进行动态脑电图检测和Glasgow评分、瞳孔对光反应、脑干反应检查,随访3个月时病人的预后,将动态脑电图检测和各项临床检查结果与病人的预后结果进行相关分析。结果:动态脑电图对昏迷病人预后的评估在敏感性(83.3%)、特异性(100%)和对预后评估的准确率(91.7%)方面均比临床检测结果高,临床指标Glasgow评分、瞳孔对光反射、脑干反射的敏感性、特异性及准确率分别为73.1%、84.2%及77.9%;76.9%、73.7%及75.6%;76.0%、68.4%及68.9%。结论:动态脑电图检测对急性缺血缺氧性昏迷病人预后的评估有确定的价值。 相似文献
80.
Evolution of sleep and sleep EEG after hemispheric stroke 总被引:3,自引:0,他引:3
Vock J Achermann P Bischof M Milanova M Müller C Nirkko A Roth C Bassetti CL 《Journal of sleep research》2002,11(4):331-338
The evolution of subjective sleep and sleep electroencephalogram (EEG) after hemispheric stroke have been rarely studied and the relationship of sleep variables to stroke outcome is essentially unknown. We studied 27 patients with first hemispheric ischaemic stroke and no sleep apnoea in the acute (1-8 days), subacute (9-35 days), and chronic phase (5-24 months) after stroke. Clinical assessment included estimated sleep time per 24 h (EST) and Epworth sleepiness score (ESS) before stroke, as well as EST, ESS and clinical outcome after stroke. Sleep EEG data from stroke patients were compared with data from 11 hospitalized controls and published norms. Changes in EST (>2 h, 38% of patients) and ESS (>3 points, 26%) were frequent but correlated poorly with sleep EEG changes. In the chronic phase no significant differences in sleep EEG between controls and patients were found. High sleep efficiency and low wakefulness after sleep onset in the acute phase were associated with a good long-term outcome. These two sleep EEG variables improved significantly from the acute to the subacute and chronic phase. In conclusion, hemispheric strokes can cause insomnia, hypersomnia or changes in sleep needs but only rarely persisting sleep EEG abnormalities. High sleep EEG continuity in the acute phase of stroke heralds a good clinical outcome. 相似文献