全文获取类型
收费全文 | 655篇 |
免费 | 24篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 10篇 |
妇产科学 | 30篇 |
基础医学 | 124篇 |
口腔科学 | 9篇 |
临床医学 | 42篇 |
内科学 | 156篇 |
皮肤病学 | 7篇 |
神经病学 | 59篇 |
特种医学 | 63篇 |
外科学 | 84篇 |
综合类 | 5篇 |
预防医学 | 19篇 |
眼科学 | 5篇 |
药学 | 34篇 |
肿瘤学 | 29篇 |
出版年
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 10篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 14篇 |
2012年 | 24篇 |
2011年 | 18篇 |
2010年 | 15篇 |
2009年 | 15篇 |
2008年 | 22篇 |
2007年 | 23篇 |
2006年 | 27篇 |
2005年 | 32篇 |
2004年 | 20篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 20篇 |
2000年 | 22篇 |
1999年 | 18篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 20篇 |
1995年 | 13篇 |
1994年 | 22篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 9篇 |
1986年 | 15篇 |
1985年 | 13篇 |
1984年 | 5篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 13篇 |
1979年 | 7篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1972年 | 5篇 |
1970年 | 6篇 |
1967年 | 4篇 |
排序方式: 共有683条查询结果,搜索用时 0 毫秒
61.
Transplantations of peripheral blood progenitor cells (PBPC) are able to assure a complete haematopoietic and immunologic reconstitution. The efficient mobilization of progenitor cells into peripheral blood is the main factor responsible for quality of the graft as well as timing and technique of collections. The aim of the present paper was to find the optimum time for starting PBPC collections and consequently to minimize the number of procedures required. The study was performed in patients with haematological malignancies using an autologous collection regimen. We attempted to determine a relationship between the concentration of CD 34+ cells in peripheral blood at the beginning of the collection and the number of CD 34+ cells in the leukapheresis product prepared in the standard mode processing 2-3 total blood volumes. We assessed the significance of the CD 34+ cells concentration in peripheral blood for the adequate collection of CD 34+ cells. We also evaluated the time of engraftment in patients after autologous PBPC transplantation whenever possible. The study was performed in 70 patients. Two groups were defined: Group I patients were well mobilized, whereas Group II patients were weakly mobilized. CD 34+ counts, using flow cytometry were found to be useful in predicting the optimal time for collections. 相似文献
62.
Objective
The aim of this study was to assess the role of sonographic evaluation of Talar dysplasia in predicting the outcome of standard Ponseti method in the treatment of clubfoot deformity.Methods
A total 23 children (15 boys and 8 girls; mean age: 18.2 ± 5.4 days (8–32)) who underwent Ponseti treatment were included in the study. Before the treatment, maximal talus length of affected and non-affected feet were measured by US and relative talar dysplasia ratio (RTDR) was calculated. The patients were categorized 2 groups according to RTDR: group A – mild and group B – severe deformity. Pirani score was used for clinical evaluation. The groups were compared in terms of number of the applied casts, need of percutaneous tenotomy of Achilles tendon (AchT) and frequency of deformity recurrence.Results
Pirani score was 4.46 for population (4.33 for group A; 4.54 for group B). Number of casts significantly differed between groups (p < 0.001) and positive correlation was found (r = 0.851, p < 0.001). AchT was performed in 56% cases for group A and in 86% cases for group B; no statistically significant difference was obtained (p = 0.162). Recurrence occurred in 2 patients belonging to group B without significant difference compared to group A (p = 0.502).Conclusion
Talar dysplasia assessment appeared as a promising prognostic factor for predicting the outcome of the Ponseti technique in treatment of clubfoot deformity.Level of evidence
Level IV, diagnostic study. 相似文献63.
Enhanced amylin-mediated body weight loss in estradiol-deficient diet-induced obese rats 总被引:1,自引:0,他引:1
Trevaskis JL Turek VF Wittmer C Griffin PS Wilson JK Reynolds JM Zhao Y Mack CM Parkes DG Roth JD 《Endocrinology》2010,151(12):5657-5668
In rodents, ovariectomy (OVX) elicits weight gain and diminished responsiveness to homeostatic signals. Here we characterized the response of obese OVX rats to peripheral amylin. Rats received sham surgery (SHAM), OVX, or OVX with hormonal replacement (17β-estradiol, 2 μg per 4 d; OVX+E) and were infused with vehicle or amylin (50 μg/kg · d) for 28 d. Amylin reduced body weight (5.1 ± 1.1%) and food intake (10.9 ± 3.4%) in SHAM rats but was twice as efficacious in OVX rats in reducing weight (11.2 ± 1.9%) and food intake (23.0 ± 2.0%). There were no differences between amylin-treated SHAM and OVX+E rats. OVX decreased metabolic rate (~24%) and increased respiratory exchange ratio relative to SHAM. Amylin partially normalized metabolic rate (13% increase) in OVX rats and decreased respiratory exchange ratio in OVX and SHAM rats. Regarding central mechanisms, amylin infusion corrected the OVX-induced decrease in hippocampal neurogenesis and increased immobility in the forced swim test. Additionally, amylin increased neurogenesis (~2-fold) within the area postrema of OVX rats. To assess the contribution of endogenous leptin to amylin-mediated weight loss in OVX rats, amylin was administered to SHAM or OVX Zucker diabetic fatty rats. In SHAM rats, amylin infusion reduced food intake but not body weight, whereas in OVX Zucker diabetic fatty rats, food intake, body weight, and insulin were reduced. Overall, amylin induced greater body weight loss in the absence of estradiol via central and peripheral actions that did not require leptin. These findings support the clinical investigation of amylin in low estradiol (e.g. postmenopausal) states. 相似文献
64.
BACKGROUND: Understanding anti-non-gal antibody response is of significance for success in xenotransplantation. Long-term anti-non-gal response in humans was studied in patients transplanted with porcine patellar tendon (PT) lacking alpha-gal epitopes, for replacing ruptured anterior cruciate ligament (ACL). METHODS: Porcine PTs were treated with recombinant alpha-galactosidase to eliminate alpha-gal epitopes and with glutaraldehyde for moderate cross-linking of collagen fibers. The processed pig PTs were implanted to replace ruptured ACL in patients. RESULTS: In five of six evaluable subjects, the xenografts have continued to function for over two years and passed all functional stability assessments. Thus, processed porcine PT seems to be appropriate for replacing ruptured human ACL. Enzyme-linked immunosorbent assay and Western blot studies indicated that all subjects produced anti-non-gal antibodies against multiple pig xenoproteins, but not against human ligament proteins. Production of anti-non-gal antibodies peaked two to six months posttransplantation and disappeared after two years. CONCLUSIONS: These antibodies contribute to a low-level inflammatory process that aids in gradual xenograft replacement by infiltrating host fibroblasts that align with the pig collagen "scaffold" and secrete collagen matrix. The assays monitoring anti-non-gal antibodies will help to determine whether long-term survival of live organ xenografts requires complete suppression of this antibody response. 相似文献
65.
66.
Liquid column chromatography, planar chromatography (TLC) on modified and unmodified silica layers, reversed-phase high-pressure liquid chromatography (HPLC), as well as ESI-TOF MS and 1H-NMR have been used for separation, purification and identification of phenolic acids in the barks of Sambucus nigra and Viburnum opulus (Caprifoliaceae). By the use of these procedures three cinnamic acid derivatives: caffeic acid, p-coumaric, and ferulic acid, four benzoic acid derivatives: gallic acid, protocatechuic acid, syringic acid, 3,4,5-trimethoxybenzoic acid, two phenylacetic acid derivatives: 3,4-dihydroxyphenylacetic acid, homogentisic acid, and two depsides: chlorogenic acid and ellagic acid were detected and identified in the bark of Viburnum opulus. Caffeic acid, p-coumaric acid, ferulic acid, gallic acid, syringic acid, 3,4,5-trimethoxybenzoic acid and chlorogenic acid were also detected and identified in the bark of Sambucus nigra. Except for chlorogenic acid, this is the first time these phenolic acids have been isolated, detected, and identified in the bark of V. opulus and S. nigra. 相似文献
67.
Pyeon D Newton MA Lambert PF den Boon JA Sengupta S Marsit CJ Woodworth CD Connor JP Haugen TH Smith EM Kelsey KT Turek LP Ahlquist P 《Cancer research》2007,67(10):4605-4619
Human papillomaviruses (HPV) are associated with nearly all cervical cancers, 20% to 30% of head and neck cancers (HNC), and other cancers. Because HNCs also arise in HPV-negative patients, this type of cancer provides unique opportunities to define similarities and differences of HPV-positive versus HPV-negative cancers arising in the same tissue. Here, we describe genome-wide expression profiling of 84 HNCs, cervical cancers, and site-matched normal epithelial samples in which we used laser capture microdissection to enrich samples for tumor-derived versus normal epithelial cells. This analysis revealed that HPV(+) HNCs and cervical cancers differed in their patterns of gene expression yet shared many changes compared with HPV(-) HNCs. Some of these shared changes were predicted, but many others were not. Notably, HPV(+) HNCs and cervical cancers were found to be up-regulated in their expression of a distinct and larger subset of cell cycle genes than that observed in HPV(-) HNC. Moreover, HPV(+) cancers overexpressed testis-specific genes that are normally expressed only in meiotic cells. Many, although not all, of the hallmark differences between HPV(+) HNC and HPV(-) HNC were a direct consequence of HPV and in particular the viral E6 and E7 oncogenes. This included a novel association of HPV oncogenes with testis-specific gene expression. These findings in primary human tumors provide novel biomarkers for early detection of HPV(+) and HPV(-) cancers, and emphasize the potential value of targeting E6 and E7 function, alone or combined with radiation and/or traditional chemotherapy, in the treatment of HPV(+) cancers. 相似文献
68.
69.
STUDY OBJECTIVES: Sex is an important determinant of the pathophysiology of several disorders that influence and/or impair sleep-wake regulation. To date, few studies have examined either the role of sex or the gonadal hormones on sleep and wakefulness. The difficulty in performing well-controlled clinical experiments on sex and sleep underscores the need for effective animal models to investigate the influence of the gonadal hormones on sleep-wake states. This study describes the influence of sex on sleep and wakefulness in mice, the primary mammalian genetic model for sleep analysis, and tests the hypothesis that gonadal function drives sex differences in sleep-wake states. DESIGN: Electroencephalogram/electromyogram sleep-wake patterns were recorded in intact and gonadectomized male and female C57BL/6J mice maintained on a 14-hour light:10-hour dark schedule. Following a 24-hour baseline recording, mice were sleep deprived during the light phase by gentle handling and given a 10-hour recovery opportunity during the immediate dark phase. MEASUREMENTS AND RESULTS: Intact female mice spent more time awake than intact males during 24 hours of baseline recording at the expense of non-rapid eye movement (NREM) sleep. Though the recovery response of NREM sleep was similar between males and females, when examined in reference to baseline levels, females exhibited a more robust recovery response. Gonadectomy in males and females reduced or eliminated the majority of sex differences in sleep architecture and homeostasis. CONCLUSIONS: These data demonstrate that the gonadal hormones influence the amount, distribution, and intensity of sleep but do not account for all sex differences in the sleep-wake cycle. 相似文献
70.
Prevalence of human papillomavirus in the oral cavity/oropharynx in a large population of children and adolescents 总被引:1,自引:0,他引:1
Smith EM Swarnavel S Ritchie JM Wang D Haugen TH Turek LP 《The Pediatric infectious disease journal》2007,26(9):836-840
OBJECTIVE: Human papillomavirus (HPV) in the oral cavity or oropharynx is associated with an increased risk of laryngeal papillomatosis, head and neck cancer, and cervical and other genital cancers. We evaluated the prevalence of HPV DNA in the oral cavity/oropharynx in a cross section of children aged 2 weeks to 20 years. METHODS: A risk factor questionnaire and oral exfoliated cells were collected from children (N = 1235). HPV DNA was detected using PCR, dot blot hybridization, and DNA sequencing. RESULTS: The HPV prevalence was 1.9% in the oral cavity/oropharynx of children. A bimodal age distribution was observed with the highest HPV prevalence in the youngest and oldest groups: 2.5% aged <1 year, 0.8% aged 1 to 4 years, 1.2% aged 5 to 11 years, 1.5% in aged 12 to 15 years, and 3.3% in aged 16 to 20 years. The prevalence of the HPV quadrivalent vaccine types (HPV-6, 11, 16, 18) reached 0.9% in the 16- to 20-year age group. In this age group, female gender [odds ratio (OR): 6.9, P = 0.04], genital warts (OR: 19.3, P < 0.01), and current smoker (OR: 6.5, P = 0.01) were associated with a higher risk of being detected with an oral HPV infection. No risk factors in parents were identified with transmission of HPV to infants. CONCLUSIONS: The age-specific prevalence rates of HPV in this large cross section of children and adolescents demonstrate that HPV infection is acquired gradually in childhood. These data support a target age for HPV vaccination before puberty to prevent serious HPV-related genital and oral diseases. 相似文献