全文获取类型
收费全文 | 1066篇 |
免费 | 75篇 |
国内免费 | 29篇 |
专业分类
儿科学 | 68篇 |
妇产科学 | 14篇 |
基础医学 | 125篇 |
口腔科学 | 49篇 |
临床医学 | 129篇 |
内科学 | 219篇 |
皮肤病学 | 14篇 |
神经病学 | 20篇 |
特种医学 | 255篇 |
外科学 | 81篇 |
综合类 | 19篇 |
预防医学 | 70篇 |
眼科学 | 4篇 |
药学 | 54篇 |
肿瘤学 | 49篇 |
出版年
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 21篇 |
2020年 | 7篇 |
2019年 | 15篇 |
2018年 | 18篇 |
2017年 | 10篇 |
2016年 | 13篇 |
2015年 | 19篇 |
2014年 | 26篇 |
2013年 | 27篇 |
2012年 | 28篇 |
2011年 | 29篇 |
2010年 | 42篇 |
2009年 | 27篇 |
2008年 | 25篇 |
2007年 | 33篇 |
2006年 | 27篇 |
2005年 | 23篇 |
2004年 | 17篇 |
2003年 | 26篇 |
2002年 | 24篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 62篇 |
1997年 | 74篇 |
1996年 | 80篇 |
1995年 | 48篇 |
1994年 | 40篇 |
1993年 | 43篇 |
1992年 | 17篇 |
1991年 | 12篇 |
1990年 | 19篇 |
1989年 | 39篇 |
1988年 | 41篇 |
1987年 | 31篇 |
1986年 | 30篇 |
1985年 | 33篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 12篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1950年 | 1篇 |
排序方式: 共有1170条查询结果,搜索用时 15 毫秒
41.
OBJECTIVE: The ketogenic diet is a high-fat, low-protein, low-carbohydrate diet developed in the 1920s for the treatment of children with difficult to control seizures. Despite advances in both the pharmacotherapy and the surgery of epilepsy, many children continue to have difficult-to-control seizures. This prospective study sought to determine the ketogenic diet's effectiveness and tolerability in children refractory to today's medications. METHODS: One hundred fifty consecutive children, ages 1 to 16 years, virtually all of whom continued to have more than two seizures per week despite adequate therapy with at least two anticonvulsant medications, were prospectively enrolled in this study, treated with the ketogenic diet, and followed for a minimum of 1 year. Seizure frequency was tabulated from patients' daily seizure calendars and seizure reduction calculated as percentage of baseline frequency. Adverse events and reasons for diet discontinuation were recorded. RESULTS: The children (mean age, 5.3 years), averaged 410 seizures per month before the diet, despite an exposure to a mean of 6.2 antiepileptic medications. Three months after diet initiation, 83% of those starting remained on the diet and 34% had >90% decrease in seizures. At 6 months, 71% still remained on the diet and 32% had a >90% decrease in seizures. At 1 year, 55% remained on the diet and 27% had a >90% decrease in seizure frequency. Most of those discontinuing the diet did so because it was either insufficiently effective or too restrictive. Seven percent stopped because of intercurrent illness. CONCLUSIONS: The ketogenic diet should be considered as alternative therapy for children with difficult-to-control seizures. It is more effective than many of the new anticonvulsant medications and is well tolerated by children and families when it is effective. 相似文献
42.
A prospective study of methylenetetrahydrofolate reductase and methionine synthase gene polymorphisms, and risk of colorectal adenoma 总被引:8,自引:2,他引:8
Chen J; Giovannucci E; Hankinson SE; Ma J; Willett WC; Spiegelman D; Kelsey KT; Hunter DJ 《Carcinogenesis》1998,19(12):2129-2132
We examined the relationship between a functional polymorphism (667C--
>T, ala-->val) of the methylenetetrahydrofolate reductase gene
(MTHFR) and the risk of colorectal adenomas in the prospective Nurses'
Health Study. Among 257 incident polyp cases and 713 controls, the MTHFR
val/val polymorphism [relative risk (RR) = 1.35, 95% confidence interval
(CI) 0.84-2.17] was not significantly associated with risk of adenomas.
This lack of association was observed for both small (RR = 1.36, 95% CI
0.76-2.45) and large (RR = 1.32, 95% CI 0.66-2.66) adenomas. Furthermore,
there was no significant interaction between this polymorphism and
consumption of either folate, methionine or alcohol. We also examined the
relationship of a newly identified polymorphism (asp919gly) of the
methionine synthase gene (MS) with the risk of colorectal adenomas in the
same population. The MS gly/gly polymorphism was also not significantly
associated with risk of colorectal adenomas (RR = 0.66, 95% CI 0.26-1.70).
These results, which need to be confirmed in other studies, suggest that
the MTHFR val/val polymorphism, which has been previously inversely
associated with risk of colorectal cancer, plays a role only in a late
stage (adenoma-- >carcinoma) of colorectal tumorigenesis, and/or may
protect against malignant transformation in the subset of benign adenomas,
which may progress to malignancy.
相似文献
43.
44.
A. M. Getachew G. Innocent C. J. Proudman A. Trawford G. Feseha S. W. J. Reid B. Faith S. Love 《Parasitology research》2013,112(1):141-146
The efficacy of an oral formulation of praziquantel (Equitape, Horse paste, Fort Dodge) in the reduction of cestode egg counts and serum antibody level against Anoplocephala perfoliata was assessed in 44 donkeys under field conditions. The donkeys were confirmed both by faecal examination and serum antibody assessed by an enzyme-linked immunosorbent assay to have natural infection with tapeworms. The donkeys were randomly allocated into treatment (n?=?22) and control (n?=?22) groups. The treatment group was treated with both praziquantel and ivermectin (Ivomec, Merial) at a dose rate of 1 mg/kg and 200 μg/kg, respectively while the control group was treated only with ivermectin. Faecal samples were collected before treatment (day-0) and 2, 6, 8, 12, and 16 weeks post-treatment while blood samples were collected before treatment and 8 and 16 weeks after treatment and analysed. The results of the study demonstrated that praziquantel paste was highly effective in reducing cestode eggs in donkeys and had an efficacy of more than 99 % until week 16 (day?112). No cestode egg reappearance by 16 weeks post-treatment in any animal in the treatment group was observed while donkeys in the control group continued shedding cestode eggs. The immunological assay also showed a significant reduction in serum antibody level against A. perfoliata in treated donkeys compared to the control group (p?=?0.0001). This marked decrease in serum antibody level indicates reduced risk of cestode-associated colic and other gastrointestinal disorders and clinical diseases. No adverse reactions or clinical effects were encountered in any animal within either group throughout the trial period. 相似文献
45.
Frank Zongo Christophe Ribuot Ahcène Boumendjel Innocent Guissou 《Fundamental & clinical pharmacology》2014,28(3):323-330
Waltheria indica is used in traditional pharmacopeia in Burkina Faso for the treatment of asthma and conditions of inflammation. To evaluate its pharmacological properties and isolate the active compounds, a study through a bioguided phytochemical approach was conducted. This search was guided by a two‐level investigation. First, we evaluated the impact of various fractions on the activity of enzymes involved in smooth muscle contraction (PDE4A1α) and inflammatory processes (PLA2, 5‐LOX). Second, we investigated the inhibitory effect of fractions on isolated rat trachea. The initial hydroalcoholic extract from roots of W. indica (HA), n‐hexane fraction (F1), dichloromethane fraction (F2), ethyl acetate fraction (F3), residuary fraction (F4) reduced enzyme activity of PDE4A1α (inhibition of 22–42% at 50 μg/mL), 5‐LOX (60–80% at 10 μg/mL), and PLA2 (42–94% at 100 μg/mL). On isolated rat trachea, only HA, F3, and fractions obtained from F3 by chromatography on silica gel column, using dichloromethane/methanol, dose dependently inhibited contraction induced by acetylcholine. IC50 was 1051 μg/mL for HA and comprised between 181 and 477 μg/mL for F3 and its fractions. The most active fractions were purified and led to the identification of (‐)‐epicatechin. (‐)‐epicatechin from W. indica dose dependently inhibited PLA2 (IC50 = 154.7 μm ) and 5‐LOX (IC50 = 15.8 μm ). In conclusion, both inhibition of PDE4A1α, 5‐LOX, and PLA2 activities and rat trachea relaxation by W. indica validate its use in traditional management of asthma and other conditions of inflammation. These effects should be, at least in part, attributed to the presence of (‐)‐epicatechin in roots of W. indica. 相似文献
46.
Celestine Chidi Ogbonna Geme Urge Dori Emeka Innocent Nweze Gilbert Muoneke Innocent Ejike Nwankwo Nkiru Akputa 《Asian Pacific journal of tropical medicine》2012,5(10):796-802
ObjectiveTo determine the prevalence, sex-age related intensity of urinary schistosomiasis and to compare such parameters among rural school children and rural farmers in selected communities in Obollo-Eke located in Southeast, Nigeria.MethodsA cross-sectional survey involving 1 337 school children and farmers was conducted in Obollo-Eke community between September 2006 and July 2007. Demographic data of subjects was collected using a questionnaire prepared for this purpose. Urine samples were collected and examined for haematuria and ova of Schistosoma haematobium (S. haematobium) using Medi-test Combi 9 and sedimentation technique respectively.ResultsThe prevalence of urinary schistosomiasis based on microscopic examination of the urine sediment for the ova of S. haematobium was 17.5% while the prevalence of haematuria was 15.6%. Infection intensity varied from light to heavy. In general, the prevalence was higher among males (20.8%) than females (14.6%; P>0.05) and was slightly higher among primary school children (18.0%; n=762) than farmers (16.9%; n=575; P>0.05). The age-specific prevalence of schistosomiasis among the study subjects ranged from 8.3% to 21.2% in 0-5 years and 11-15 years age groups respectively.ConclusionsHaematuria and mean egg/10 mL urine (r = 0.95; P<0.01) showed that both procedures are reliable for the diagnosis of the disease and can be used to ascertain the prevalence of the disease in any community. The comparative analysis of urinary bilharziasis among primary school children and rural farmers demonstrated that the infection is moderately high in these two risk population groups at Obollo-Eke. A robust intervention strategy is clearly needed. 相似文献
47.
Barennes H Nagot N Valea I Koussoubé-Balima T Ouedraogo A Sanou T Yé S 《Tropical medicine & international health : TM & IH》2004,9(4):438-444
Combining artesunate (AR) with existing antimalarial drugs may improve cure rates, delay emergence of resistance and reduce parasite clearance time. In order to investigate the latter, we conducted a randomized clinical trial testing the AR plus amodiaquine (AQ) combination for the treatment of uncomplicated Plasmodium falciparum malaria in Burkina Faso. Children aged 1-15 years were randomly assigned to either AQ (10 mg/kg) or AR (4 mg/kg first day then half dose) or AQ + AR (AQAR) as a single daily dose under supervision for three consecutive days for all groups. Follow-up lasted 28 days. Primary endpoints were parasite and fever clearance time. Eighty-seven children were evaluated: 27 received AQ, 27 AR and 33 AQAR. Using an intention to treat analysis, fever clearance time was similar in the three groups. However, it was significantly faster in the AR (1.21 days; P = 0.02) and AQAR groups (1.19 days; P < 0.01) than in the AQ group (1.46 days) when excluding other concomitant causes of fever. Parasite clearance time was faster in AR (1.13 days; P = 0.008) and AQAR groups (1.13 days; P < 0.01) than in the AQ group (1.6 days). All children cleared their parasites by day 14, including the child with Late Parasitological Failure (LPF) at day 7 after rescue treatment. Only one child (4%) from the AR group and one (4%) from the AQ group presented with asymptomatic parasitaemia at day 7 and day 21, respectively (LPF). Gametocyte carriage was not detectable in any group during follow-up nor was any adverse reaction observed. While resistance to first-line treatment (chloroquine) is already established in the country, AQ and AR used alone or in combination therapy proved highly efficacious in our study. Burkina Faso stands in a very good situation for an internationally recommended switch to AR-containing combination as first-line treatment for uncomplicated malaria. Including AQ in this regimen seems the best option. 相似文献
48.
49.
Interleukin-1 alpha (IL-1 alpha) is a macrophage-derived, multifunctional cytokine that broadly potentiates myelopoiesis and induces the synthesis of hematopoietic colony-stimulating factors (CSF) in vitro and in vivo. To evaluate the possibility for use of IL-1 alpha in ameliorating in vivo bone marrow suppression induced by drugs or radiation, we examined the in vivo effects of the cytokine on erythropoietic and other hematopoietic progenitor cells. Normal mice were treated with a single intraperitoneal (IP) injection of recombinant human IL-1 alpha at varying doses and were assayed at various times post-treatment. By six hours postinjection, a significant suppression of mature erythroid progenitors (CFU-E) was observed in animals treated with IL-1 alpha (0.5 micrograms/mouse), with maximum suppression of CFU-E and peripheral blood reticulocyte counts occurring at 24 hours. Decreases in peripheral blood hematocrit did not occur after a single IL-1 alpha injection but were observed after multiple injections of the cytokine. The suppressive effects of IL-1 alpha on late-stage erythropoiesis were abrogated by simultaneous administration of erythropoietin (EPO). At 48 hours post-treatment, a marked stimulation was observed in the numbers of spleen and marrow immature erythroid (BFU-E), macrophage (CFU-M), granulocyte (CFU-G), granulocyte- macrophage (CFU-GM), and megakaryocyte (CFU-meg) progenitor cells. These results demonstrate the potential use of IL-1 alpha as a generalized stimulator of hematopoiesis and show that the cytokine- induced suppression of late-stage erythropoiesis can be prevented by EPO. 相似文献
50.
EH Gemmill DJ Humes JA Catton 《Annals of the Royal College of Surgeons of England》2015,97(3):173-179