全文获取类型
收费全文 | 872篇 |
免费 | 46篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 34篇 |
妇产科学 | 19篇 |
基础医学 | 131篇 |
口腔科学 | 24篇 |
临床医学 | 107篇 |
内科学 | 151篇 |
皮肤病学 | 4篇 |
神经病学 | 97篇 |
特种医学 | 70篇 |
外科学 | 63篇 |
综合类 | 27篇 |
预防医学 | 93篇 |
眼科学 | 16篇 |
药学 | 49篇 |
中国医学 | 1篇 |
肿瘤学 | 34篇 |
出版年
2023年 | 7篇 |
2022年 | 34篇 |
2021年 | 44篇 |
2020年 | 17篇 |
2019年 | 26篇 |
2018年 | 27篇 |
2017年 | 25篇 |
2016年 | 17篇 |
2015年 | 22篇 |
2014年 | 28篇 |
2013年 | 36篇 |
2012年 | 55篇 |
2011年 | 66篇 |
2010年 | 29篇 |
2009年 | 22篇 |
2008年 | 49篇 |
2007年 | 46篇 |
2006年 | 42篇 |
2005年 | 32篇 |
2004年 | 46篇 |
2003年 | 40篇 |
2002年 | 61篇 |
2001年 | 13篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 16篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有922条查询结果,搜索用时 15 毫秒
61.
Randomized controlled trial of the effect of zinc supplementation on the mental development of Bangladeshi infants 总被引:2,自引:0,他引:2
Hamadani JD Fuchs GJ Osendarp SJ Khatun F Huda SN Grantham-McGregor SM 《The American journal of clinical nutrition》2001,74(3):381-386
BACKGROUND: Zinc deficiency is thought to be common in young children in developing countries and some data suggest that it may detrimentally affect children's development. OBJECTIVE: Our goal was to assess the effect of zinc supplementation on the developmental levels and behavior of Bangladeshi infants. DESIGN: This was a randomized, double-blind, controlled trial conducted in Dhaka, Bangladesh. Three hundred one infants aged 1 mo were randomly assigned to receive either 5 mg elemental Zn or placebo daily for 5 mo, and subsequent growth and morbidity were observed. For the present study, developmental levels were assessed in a subsample of 212 infants at 7 and 13 mo of age with use of the Bayley Scales of Infant Development, and the infants' behavior during the tests was observed. The children's social backgrounds, weights, and lengths were also recorded. RESULTS: The children's nutritional status was generally poor. The zinc-treated group had slightly lower scores on the mental development index of the Bayley Scales than did the placebo group (beta = 3.7, SE = 1.3, P < 0.005). This effect remained significant when nutritional status and social background were controlled for. No other significant differences between groups were noted. CONCLUSIONS: The mental development index scores of the zinc-treated group were slightly but significantly lower than those of the placebo group. This finding may have been due to micronutrient imbalance. Caution should be exercised when supplementing undernourished infants with a single micronutrient. 相似文献
62.
From August till November 1998, the Paediatric and Anaesthetic Units of Hospital Kuala Terengganu managed three patients from Kuala Terengganu District who were ventilated for respiratory diphtheria. Their ages were 5, 4 and 7 years old and their immunisation for diphtheria were not complete. All three patients presented with respiratory distress and were ventilated for upper airway obstruction. Their treatment included intravenous penicillin and diphtheria antitoxin. One patient died of cardiogenic shock with secondary pneumonia. Pharyngeal and tonsillar swabs of all three patients grew toxigenic Corynebacterium diphtheriae biotype mitis. There were 765 throat cultures taken from contacts. The confirmed positive cultures grew 2 toxigenic and 3 non-toxigenic Corynebacterium diphtheriae biotype mitis and surprisingly, 10 non-toxigenic biotype gravis. A prevalence study is needed to document the endemicity of diphtheria in Kuala Terengganu and to determine the carrier rate of both biotypes. Steps have been taken to increase the immunisation coverage in children. The giving of regular booster doses of diphtheria toxoid to the adult population should be considered. 相似文献
63.
Walter Huda PhD Associate Professor Lynn N Rill MSc Graduate Student Douglas K Benn BDS PhD Associate Professor James C Pettigrew DMD Associate Professor 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》1997,83(6):725-731
This study compared the imaging performance of a photostimulable phosphor system with E speed film for dental radiography. The response of each imaging system was measured as a function of radiation exposure. Measurements were also made of imaging performance in terms of the limiting spatial resolution and low contrast detectability. Photostimulable phosphors had a wider dynamic range in comparison with film. The limiting spatial resolution of the photostimulable phosphor was approximately 6.5 lp/mm and independent of image magnification. For film, the limiting spatial resolution was in the range 11 to 20 lp/mm depending on image magnification. At the same radiation exposure, low contrast detectability of the photostimulable phosphor was superior to that of film. Major benefits of photostimulable phosphor systems include the elimination of chemical processing and an improved low contrast detectability performance. 相似文献
64.
Frontal white matter biochemical abnormalities in late-life major depression detected with proton magnetic resonance spectroscopy 总被引:13,自引:0,他引:13
Kumar A Thomas A Lavretsky H Yue K Huda A Curran J Venkatraman T Estanol L Mintz J Mega M Toga A 《The American journal of psychiatry》2002,159(4):630-636
OBJECTIVE: Neuroanatomical abnormalities have been identified in patients with late-life mood disorders by using magnetic resonance imaging. This study examined the biochemical correlates of late-life major depression in the frontal gray and white matter by using single-voxel proton spectroscopy. METHOD: Twenty elderly patients with major depression and 18 comparison subjects similar in age and gender to the patients were scanned on a 1.5-T magnetic resonance scanner with head coil. Voxels were placed in the left dorsolateral white matter and bilaterally in the anterior cingulate gray matter. Absolute levels of N-acetylaspartate, choline, myo-inositol, and creatine were estimated with the LC-Model algorithm. Ratios of metabolite to creatine levels were computed from the absolute values. RESULTS: myo-Inositol/creatine and choline/creatine ratios were significantly higher in the frontal white matter in the major depression group than in the comparison group. The groups had no significant differences in the metabolite ratios in the gray matter. CONCLUSIONS: Biochemical changes in the white matter may provide some of the neurobiological substrates to late-life major depression. 相似文献
65.
66.
Amin N. Olaimat Islam K. Alshami Huda Al Hourani Wafaa Sarhan Murad Al-Holy Mahmoud Abughoush Narmeen Jamal Al-Awwad Maha Hoteit Ayoub Al-Jawaldeh 《Nutrients》2022,14(11)
The 2019 coronavirus disease (COVID-19) is an emerging respiratory infection with severe impacts on the nutritional status of the worldwide population. This cross-sectional study was conducted to assess the food insecurity, dietary diversity, and food-related coping strategies in Jordan during the pandemic using an online, self-administered questionnaire. Among the 740 adults who completed the survey, the prevalence of food security was 84.1%, whereas 2% and 13.9% were moderately and severely food-insecure, respectively. The determinants of food insecurity were educational level, monthly income, marital status, availability of health insurance, and type of residence. In addition, food insecurity was significantly higher among the participants who consumed two or fewer meals per day (p = 0.015). Moreover, an acceptable food consumption score was shown among 76.2% of the participants, and the remaining participants were at borderline (14.1%) or had poor scores (9.7%), with a significant association between food insecurity and food consumption scores (p < 0.001). The food-related coping strategies studied were significantly associated with food insecurity at both levels (p < 0.001) and were more evident in the severely food-insecure group. These findings highlight the adverse effects of COVID-19 restrictions on nutritional status, especially among food-insecure households, which might reduce food accessibility due to economic difficulties. 相似文献
67.
The prevalence and determinants of health care-seeking behavior for fecal incontinence in multiparous United Arab Emirates females 总被引:1,自引:1,他引:0
Dr. Diaa E. E. Rizk M.D. Mohammed Y. Hassan Ph.D. Huda Shaheen M.Sc. John V. Cherian B.Sc. Rosetta Micallef M.D. Earl Dunn M.D. 《Diseases of the colon and rectum》2001,44(12):1850-1856
PURPOSE: This study was designed to determine the prevalence and sociodemographics of fecal incontinence in United Arab Emirates females. METHODS: A representative sample of multiparous United Arab Emirates females aged 20 years or older (N=450) were randomly selected from the community (n=225) and health care centers (n=225). Patients were interviewed about inappropriate stool loss in the past year using a structured and pretested questionnaire. RESULTS: Fifty-one participants (11.3 percent) admitted fecal incontinence; 26 (5.8 percent) were incontinent to liquid stool and 25 (5.5 percent) to solid stool. Thirty-eight patients (8.4 percent) had double (urinary and fecal) incontinence. Sixty-five patients (14.4 percent) were incontinent to flatus only but not to stools. The association between having fecal incontinence and chronic constipation was significant (P<0.0001), but there was no significant association with other known risk factors such as age, parity, and previous instrumental delivery, episiotomy, perineal tears, or anorectal operations. Only 21 incontinent patients (41 percent) had sought medical advice. Patients did not seek medical advice because they were embarrassed to consult their physician (64.7 percent), they preferred to discuss the difficulty with friends, assuming that fecal incontinence would resolve spontaneously (47.1 percent) or was normal (31.3 percent), and they chose self-treatment as a result of low expectations for medical care (23.5 percent). Sufferers were bothered by the inability to pray (92.2 percent) and to have sexual intercourse (43.1 percent). Perceived causes of fecal incontinence were paralysis (90.2 percent), old age (80.4 percent), childbirth (23.5 percent), or menopause (19.6 percent). CONCLUSIONS: Fecal incontinence is common yet underreported by multiparous United Arab Emirates females because of cultural attitudes and inadequate public knowledge.Poster presentation accepted at the XIX Biennial Congress of the International Society of University Colon and Rectal Surgeons, Osaka, Japan, April 14–18, 2002. 相似文献
68.
Yussra Ata Yaseen Abdulqader Hala Salah Abdel Kawy Huda Mohammed Alkreathy Nisreen Abdullah Rajeh 《Saudi Pharmaceutical Journal》2021,29(5):418-426
ObjectivesEpilepsy is a neurological disease characterized by sudden, abnormal, and hyper- discharges in the central nervous system (CNS). Valproic acid (VPA) is commonly used as a broad-spectrum antiepileptic therapeutic. However, in many cases, patients develop resistance to VPA treatment due to overwhelming oxidative stress, which in turn might be a major catalyst for disease progression. Therefore, antioxidants can potentially become therapeutic agents by counteracting reactive oxygen species (ROS)-mediated damage. The present study is aimed to evaluate the potential antiepileptic effect of astaxanthin (ASTA) in pentylenetetrazol (PTZ) induced epileptic model rats that are chronically treated with VPA for 8 weeks.MethodFifty-male Wistar rats were randomly divided into five groups: Non-PTZ group, PTZ, PTZ/VPA, PTZ/ASTA, and PTZ/VPA/ASTA treated groups.ResultsPTZ/VPA treated group showed a neuroprotective effect with improvement in antioxidant levels, behavioral test, and histopathological changes induced by PTZ. VPA also exhibited an anti-inflammatory effect as its treatment resulted in the reduction of tumor necrosis factor-α (TNF-α). ASTA exhibited an anticonvulsant effect and enhanced anti-inflammatory effect as compared to VPA. During the combined therapy, ASTA potentiated the antiepileptic effect of the VPA by reducing the oxidative stress and TNF-α as well as increased the glutathione (GSH) levels. Also, there were substantial improvements in the behavioral and histopathological changes in the VPA/ASTA treated group as compared to the VPA treated group.ConclusionASTA could have an antiepileptic and anti-inflammatory effect by reducing ROS generation. Therefore, co-administration of both the therapeutics (VPA/ASTA) has a synergistic effect in treating epilepsy and could potentially minimize recurrence and/or exacerbation of seizures. 相似文献
69.
70.
EfrAB, an ABC multidrug efflux pump in Enterococcus faecalis 总被引:3,自引:0,他引:3
Lee EW Huda MN Kuroda T Mizushima T Tsuchiya T 《Antimicrobial agents and chemotherapy》2003,47(12):3733-3738
A DNA fragment responsible for resistance to antimicrobial agents was cloned from the chromosomal DNA of Enterococcus faecalis ATCC 29212 by using drug-hypersensitive mutant Escherichia coli KAM32 as a host cell. Cells of E. coli KAM32 harboring a recombinant plasmid (pAEF82) carrying the DNA fragment became resistant to many structurally unrelated antimicrobial agents, such as norfloxacin, ciprofloxacin, doxycycline, acriflavine, 4',6-diamidino-2-phenylindole, tetraphenylphosphonium chloride, daunorubicin, and doxorubicin. Since the sequence of the whole genome of E. faecalis is known, we sequenced several portions of the DNA insert in plasmid pAEF82 and identified two open reading frames within the insert. We designated the genes efrA and efrB. A search of the deduced amino acid sequences of EfrA and EfrB revealed that they are similar to each other and that they belong to the ATP-binding cassette (ABC) family of multidrug efflux transporters. Transformed E. coli KAM32 cells harboring efrAB showed energy-dependent efflux of acriflavine. The efflux activity was inhibited by reserpine, verapamil, and sodium-o-vanadate, known inhibitors of ABC efflux pumps. 相似文献