全文获取类型
收费全文 | 313篇 |
免费 | 25篇 |
国内免费 | 2篇 |
专业分类
儿科学 | 7篇 |
妇产科学 | 3篇 |
基础医学 | 56篇 |
口腔科学 | 2篇 |
临床医学 | 13篇 |
内科学 | 38篇 |
皮肤病学 | 3篇 |
神经病学 | 78篇 |
特种医学 | 7篇 |
外科学 | 50篇 |
综合类 | 6篇 |
预防医学 | 14篇 |
眼科学 | 10篇 |
药学 | 20篇 |
肿瘤学 | 33篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 10篇 |
2011年 | 12篇 |
2010年 | 11篇 |
2009年 | 6篇 |
2008年 | 11篇 |
2007年 | 18篇 |
2006年 | 17篇 |
2005年 | 15篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1969年 | 5篇 |
1968年 | 3篇 |
1967年 | 1篇 |
1966年 | 4篇 |
1960年 | 1篇 |
排序方式: 共有340条查询结果,搜索用时 15 毫秒
1.
First, this study examined genetic and environmental sources of variation in performance on a standardised test of academic achievement, the Queensland Core Skills Test (QCST) (Queensland Studies Authority, 2003a). Second, it assessed the genetic correlation among the QCST score and Verbal and Performance IQ measures using the Multidimensional Aptitude Battery (MAB), [Jackson, D. N. (1984) Multidimensional Aptitude Battery manual. Port Huron, MI:Research Psychologist Press, Inc.]. Participants were 256 monozygotic twin pairs and 326 dizygotic twin pairs aged from 15 to 18 years (mean 17 years ± 0.4 [SD]) when achievement tested, and from 15 to 22 years (mean 16 years ± 0.4 [SD]) when IQ tested. Univariate analysis indicated a heritability for the QCST of 0.72. Adjustment to this estimate due to truncate selection (downward adjustment) and positive phenotypic assortative mating (upward adjustment) suggested a heritability of 0.76 The phenotypic (0.81) and genetic (0.91) correlations between the QCST and Verbal IQ (VIQ) were significantly stronger than the phenotypic (0.57) and genetic (0.64) correlations between the QCST and Performance IQ (PIQ). The findings suggest that individual variation in QCST performance is largely due to genetic factors and that common environmental effects may be substantially accounted for by phenotypic assortative mating. Covariance between academic achievement on the QCST and psychometric IQ (particularly VIQ) is to a large extent due to common genetic influences. 相似文献
2.
Perceptual speed does not cause intelligence, and intelligence does not cause perceptual speed 总被引:2,自引:0,他引:2
Luciano M Posthuma D Wright MJ de Geus EJ Smith GA Geffen GM Boomsma DI Martin NG 《Biological psychology》2005,70(1):1-8
There is ongoing debate whether the efficiency of local cognitive processes leads to global cognitive ability or whether global ability feeds the efficiency of basic processes. A prominent example is the well-replicated association between inspection time (IT), a measure of perceptual discrimination speed, and intelligence (IQ), where it is not known whether increased speed is a cause or consequence of high IQ. We investigated the direction of causation between IT and IQ in 2012 genetically related subjects from Australia and The Netherlands. Models in which the reliable variance of each observed variable was specified as a latent trait showed IT correlations of -0.44 and -0.33 with respective Performance and Verbal IQ; heritabilities were 57% (IT), 83% (PIQ) and 77% (VIQ). Directional causation models provided poor fits to the data, with covariation best explained by pleiotropic genes (influencing variation in both IT and IQ). This finding of a common genetic factor provides a better target for identifying genes involved in cognition than genes which are unique to specific traits. 相似文献
3.
A. Rottenstreich S. Benenson G. Levin G. Kleinstern A.E. Moses S. Amit 《Clinical microbiology and infection》2019,25(2):251.e1-251.e4
Objectives
To investigate the incidence, risk factors, clinical course and outcomes of pregnancy-related group A streptococcus (GAS) infection.Methods
A retrospective 13-year cohort study of culture-proven pregnancy-related GAS infection was performed at two university hospitals serving heterogeneous, multicultural, urban and rural populations.Results
Of 124 women diagnosed with pregnancy-related GAS infection, 115 (93%) were in the puerperium, an incidence of 0.8 cases per 1000 live births (95% confidence interval, 0.7–0.9). A multivariate analysis showed primiparity and cesarean delivery to be independent protective factors against puerperal GAS infection (adjusted odds ratios (95% confidence interval), 0.60 (0.38, 0.97) and 0.44 (0.23, 0.81), respectively). Of the nine remaining patients, eight were diagnosed after first trimester abortions and one had an infected ectopic pregnancy. Among the entire cohort (n = 124), the predominant manifestations were fever and abdominal tenderness. Twenty-eight patients (23%) had severe GAS infections. All were treated with β-lactams, and most (n = 104, 84%) received clindamycin. Only four (3%) required surgical intervention; the rest fully recovered with conservative medical treatment including antibiotics. No recurrences, maternal deaths or neonatal complications were noted.Conclusions
Pregnancy-related GAS infection is not rare; it lacks specific signs and still carries significant morbidity. Primiparity, a presumable surrogate for diminished exposure to children and thus less GAS carriage, and cesarean delivery in which perioperative antibiotic prophylaxis was uniformly provided, appear as protective factors against puerperal GAS infection. This hints to the importance of community-acquired GAS and may support shifting efforts from infection-control–oriented nosocomial investigations to screening and prevention–driven policies. 相似文献4.
Cronenberg AM van Geffen CE Dorrestein J Vermeulen AN Sondermeijer PJ 《Acta virologica》1999,43(2-3):192-197
The sequence encoding part of the 100 kDa refractile body protein (Ea1A) from Eimeria acervulina was cloned into the US10 locus of herpesvirus of turkeys (HVT) downstream of LTR promoter. Expression of the fusion protein was shown in vitro. Recombinant HVT showed a delayed and slightly reduced level of viremia compared to the parent strain in SPF chickens as well as in broilers. Effect on the performance of broilers vaccinated with recombinant or parent HVT was measured by challenge at day 24 with a high dose of E. acervulina and E. maxima oocysts. A significant improvement in weight of animals vaccinated with the recombinant HVT was detected at the end of the challenge period. 相似文献
5.
Geffen T 《Health trends》1990,22(2):87-89
Between October 1981, when the Health Services Complaints' Procedure was introduced, and June 1989, the Regional Medical Officer of the North West Thames Regional Health Authority received 171 complaints with a request for an independent professional review. This was granted in 75 cases, and this paper describes the procedure and the results of the analysis. 相似文献
6.
7.
Hiba Zaaroura Yuval Geffen Reuven Bergman Emily Avitan‐Hersh 《The Journal of dermatology》2018,45(8):994-999
Staphylococcus lugdunensis is an emerging pathogen in skin and soft tissue infections that was previously considered a commensal. The aim of this study was to elucidate the characteristics of skin infections by S. lugdunensis and its appropriate management, in a tertiary referral medical center. The clinical files, bacterial cultures and histopathology reports of all S. lugdunensis isolates from skin infections over a period of 8 years (September 2009–September 2017) were reviewed. S. lugdunensis was isolated from 29 patients with skin infections, aged 7–89 years (mean 33.3 years). A state of immune suppression (drug‐induced, malignancy or diabetes) was present in five patients (17%). Folliculitis and cutaneous pustulosis were the most common presentations (16 cases, 55%), followed by secondary infection of hidradenitis suppurativa (five cases, 17%). Other sources of isolation were infected molluscum contagiosum (two cases), folliculitis decalvans (one case), dissecting cellulitis (one case), abscess (one case), cyst (one case), impetigo (one case) and granuloma after trauma (one case). The in vitro antibiotic sensitivity tests showed susceptibility to most tested antibiotics, although a few isolates were resistant to gentamycin, penicillin and oxacillin. In 19 of 20 patients for whom follow ups were available, cutaneous manifestations improved or resolved with proper local and/or oral antibiotic therapy. S. lugdunensis may play a role as a primary or secondary pathogen in various skin infections, most commonly folliculitis and pustulosis. Proper antibiotic therapy may lead to improvement or resolution. 相似文献
8.
This study provides Auditory Verbal Learning Test (AVLT) data for 10 boys and 10 girls in each offour age groups, 7-to 8-years, 9-to 10-years, 11-to 12-years and 14-to 15-years. Gender was not a significant factor in any of the measures in this study. Superior performance by older children was found for acquisition, retention, word span, and retrieval efficiency. Age did not affect acquisition rate, the shape of the serial position curve, memory for the source of items, or the proportion of items recalled after a 20-min delay. The stability of these measures across the wide age range of normal children is indicative of their potential diagnostic significance. 相似文献
9.
Rein Ketelaars Christian Beekers Geert-Jan Van Geffen Gert Jan Scheffer Nico Hoogerwerf 《Prehospital emergency care》2018,22(4):406-413
Background: Patients in cardiac arrest must receive algorithm-based management such as basic life support and advanced (cardiac) life support. International guidelines dictate diagnosing and treating any factor that may have caused the arrest or may be complicating the resuscitation. Ultrasound may be of potential value in this process and can be used in a prehospital setting. The objective is to evaluate the use of prehospital ultrasound during traumatic and non-traumatic CPR and determine its impact on prehospital treatment decisions in a Dutch helicopter emergency medical service (HEMS). Methods: We conducted an observational study in cardiac arrest patients, of any cause, in whom the Nijmegen HEMS performed CPR with concurrent echocardiography. The participating physicians had to adhere to Advanced Life Support protocols as per standard operating procedure. Simultaneous with the interruptions of chest compressions to allow for heart rhythm analysis, ultrasound-trained HEMS physicians performed echocardiography according to study protocol. The HEMS nurse and physician recorded patient data and data on impacted (supported or altered) patient treatment decisions. Results: From February 2014 through November 2016, we included 56 patients who underwent 102 ultrasound examinations. Sixty-two (61%) ultrasound examinations impacted 78 treatment decisions in 49 patients (88%). The impacted treatment was related to termination of CPR in 32 (57%), fluid management (14%), drugs selection and doses (14%), and choice of destination hospital (5%). Causes of cardiac arrest included trauma (48%), cardiac (21%), medical (14%), asphyxia (9%), and other (7%). Conclusion: Prehospital echocardiography has an impact on patient treatment and may be a useful tool to support decision-making during CPR in a Dutch HEMS. 相似文献
10.
Dabaja-Younis Halima Geller Dan Geffen Yuval Almog Ronit Kassis Imad 《European journal of clinical microbiology & infectious diseases》2021,40(7):1433-1439
European Journal of Clinical Microbiology & Infectious Diseases - The purpose of this study was to estimate the impact of pneumococcal conjugate vaccine-13 (PCV-13) introduction into the... 相似文献