全文获取类型
收费全文 | 519篇 |
免费 | 25篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 20篇 |
妇产科学 | 23篇 |
基础医学 | 46篇 |
口腔科学 | 18篇 |
临床医学 | 52篇 |
内科学 | 74篇 |
皮肤病学 | 40篇 |
神经病学 | 48篇 |
特种医学 | 11篇 |
外国民族医学 | 2篇 |
外科学 | 79篇 |
综合类 | 6篇 |
一般理论 | 1篇 |
预防医学 | 37篇 |
眼科学 | 9篇 |
药学 | 35篇 |
中国医学 | 8篇 |
肿瘤学 | 32篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 25篇 |
2020年 | 23篇 |
2019年 | 24篇 |
2018年 | 29篇 |
2017年 | 24篇 |
2016年 | 18篇 |
2015年 | 12篇 |
2014年 | 18篇 |
2013年 | 33篇 |
2012年 | 47篇 |
2011年 | 43篇 |
2010年 | 22篇 |
2009年 | 12篇 |
2008年 | 19篇 |
2007年 | 22篇 |
2006年 | 25篇 |
2005年 | 24篇 |
2004年 | 13篇 |
2003年 | 15篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有544条查询结果,搜索用时 1 毫秒
1.
Neural origins of the P300 总被引:13,自引:0,他引:13
A review of the literature investigating the neural origins of detection behavior in humans reveals two event-related potential components, P3a and P3b, each with a distinct neural organization and cognitive function.The P3a is involved in automatic novelty detection and characterized by a more anterior cortical distribution, whereas the P3b is concerned with volitional target detection and has a more posterior cortical distribution. Intracranial investigation, studies with patients with focal brain lesions, and functional neuroimaging (fMRI) studies converge with scalp-recorded event-related potential (ERP) data in suggesting that a widespread cortical network gives rise to both automatic and controlled detection behavior. The main regions consistently attributed to generating detection-related brain activation include the temporal-parietal junction, medial temporal complex, and the lateral prefrontal cortex. The extant human and animal literature addressing the neural networks, neuropharmacological underpinnings, and behavioral significance of the P300 potential will be reviewed. 相似文献
2.
Bagher Larijani Mir Reza Bekheirnia Akbar Soltani Alireza Khalili‐Far Hossein Adibi Reza Baradar Jalili 《American journal of human biology》2004,16(2):168-171
The aim of this study was to determine the relationships between bone mineral density (BMD) and blood pressure in 214 men, age 20–76. BMD measurements were done by dual X‐ray absorptiometry using a Lunar DPXMD densitometer at the lumbar spine (L2–L4) and different femoral regions. Systolic (SBP) and diastolic (DBP) blood pressure were measured using an MPC‐350 sphygmomanometer. Physicians gathered demographic data and participants' dietary intake of calcium were determined by using food frequency questionnaires. After adjusting for age, body mass index, dietary calcium, and exercise history, multiple linear regression models showed that DBP was negatively related to femoral neck BMD (β = ?0.145, P = 0.032) and just shy of significant association with femoral neck BMC (β = ?0.114, P = 0.079). SBP was correlated with femoral neck (r = ?0.171, P = 0.012) and Ward's (r = ?0.186, P = 0.006) BMD but not after adjusting for possible confounders. Further studies are needed to determine whether elevated blood pressure is causally related to the development of low bone mass. Am. J. Hum. Biol. 16:168–171, 2004. © 2004 Wiley‐Liss, Inc. 相似文献
3.
4.
Since 1990 and the invention of the very first generation of ordered mesoporous silica materials, several innovative methodologies have been applied to synthesize, characterize, and modify silica/non-silica mesoporous materials. The growth of the mesoporous materials field has generated significant environmental and economic advantages compared to various other industrial developments. According to the literature, there are several key synthesis approaches and parameters that can affect the structural, textural and morphological characteristics of mesoporous materials. To date, huge attempts have been made to maximize the activities and selectivities of these materials through either the in situ or post-synthesis functionalization of the large interior surface areas and internal mesostructured frameworks in the presence of specific organic/inorganic components. However, the main challenge is to provide good control over the incorporation and distribution of multiple guest components within the mesostructured hosts. Mesostructured materials have received great attention for various applications, such as being used in electronics, medicine, photocatalysis, catalyst supports, catalysis, absorbers, sensors, gas separation, etc. In the current paper, several recent developments have been highlighted and reviewed regarding the fabrication and characterization of siliceous/non-siliceous mesoporous materials via various synthetic approaches. Furthermore, the availability of diverse functionalization methods has been reviewed to provide comprehensive approaches for synthesizing new generations of suitably modified mesoporous materials with superior structural, physicochemical, and textural characteristics.Since 1990 and the invention of the very first generation of ordered mesoporous silica materials, several innovative methodologies have been applied to synthesize, characterize, and modify silica/non-silica mesoporous materials. 相似文献
5.
Jafar Soltani Bahram Nikkhoo Jabar Khormehr Pedram Ataee Mohammad-Saeid Hakhamaneshi Fardin Gharibi 《Iranian journal of pediatrics.》2014,24(6):745-752
Objective:
Helicobacter pylori (H. pylori) is the most common chronic bacterial infection in humans. Chronic colonization increases the risk of duodenal ulcer and gastric cancer. The risk factors for acquiring the infection have been extensively studied. However, there are conflicting results on the role of breastfeeding in the prevention of H. pylori infection. We conducted a study to evaluate the effects of breastfeeding on the H. Pylori infection in Kurdish children in Sanandaj, IR Iran.Methods:
A historical cohort study was carried out from January 2011 through December 2012. Totally 221 children who were going to attain 2 years old during the study period were randomly enrolled. They were divided into two groups, i.e. breastfed and non-breastfed. We used H. pylori stool antigen test to detect infection in the selected group of children after age of 2 years and cessation of breastfeeding. Each group was subdivided into two subgroups, infected and non-infected. The associations of breastfeeding with H. pylori infection was assessed using statistical software.Findings:
We found no difference in the odds of infection between breastfed and non-breastfed groups (OR=0.809, 95% CI [0.453–1.444]). An association between age and the prevalence of infection was found (P=0.008). There was an increase in the odds of infection as the family size grew (OR=1.93, 95% CI [1.04–3.6]) as well as increasing housing density (OR=2.12, 95% CI [1.10–4.10]).Conclusion:
The data suggests that breastfeeding in infancy does not protect against H. pylori infection for long duration among studied children in Iran. The protective effects of breastfeeding, if any, are at most transient. 相似文献6.
Hasani-Ranjbar S Amoli MM Ebrahim-Habibi A Dehghan E Soltani A Amiri P Larijani B 《Journal of clinical research in pediatric endocrinology》2012,4(2):89-93
Objective: Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is an autosomal recessive form of hypophosphatemia with hyperphosphaturia, hypercalciuria, and hypercalcemia. In two reports on six affected kindreds with HHRH, the disease was mapped to chromosome 9q34, which contains the SLC34A3 gene that encodes the renal type 2c sodium-phosphate cotransporter. Our objective was to define the clinical course of these cases in a family with HHRH and to screen for SLC34A3 gene in order to determine whether these mutations are responsible for HHRH.Methods: After clinical and biochemical evaluations, the entire SLC34A3 gene was screened using PCR amplification followed by direct sequencing technique. In this paper, we describe a new kindred with HHRH and a case of progressive and complicated HHRH presenting at age 27 years.Results: We found 101-bp deletion in intron 9 of the SLC34A3 gene. The index patient was homozygous for this mutation which has been previously reported in a Caucasian population. This is the first report for presence of SLC34A3 intron 9 deletion in an Iranian population.Conclusions: These data showed that HHRH can be easily missed or underdiagnosed. Genetic evaluation of patients with familial hypercalciuria, hypophosphatemia and nephrolithiasis is needed for further information on the prevalence and management of this rare disorder. Conflict of interest:None declared. 相似文献
7.
8.
Safdarian L Mohammadi FS Alleyassin A Aghahosseini M Meysamie A Rahimi E 《Human reproduction (Oxford, England)》2007,22(9):2449-2454
BACKGROUND: Traditional doses of depot GnRH agonist may be excessive for ovarian stimulation. We compared half-dose depot triptorelin (Group I) with reduced-dose daily buserelin (Group II) in a long protocol ICSI/embryo transfer through a double-blind randomized clinical trial. METHODS: Controlled ovarian stimulation (COS) was started by a pretreatment with oral contraceptives for 21 days. Then, 182 patients were randomized into two groups of 91. Group I received 1.87 mg triptorelin depot i.m. followed by daily s.c. injections of saline. Group II (reduced-dose protocol) received a bolus injection of i.m. saline followed by daily s.c. injections of 0.5 mg buserelin, which was then reduced to 0.25 mg at the start of human menopausal gonadotrophin stimulation. When transvaginal ultrasound showed at least two follicles of 16-20 mm diameter, HCG was given and ICSI was performed 40-42 h later. RESULTS: No significant differences were seen in the mean (SD) number of follicles at HCG administration, as our primary outcome [10.3 (4.4) in Group I versus 11.1 (4.2) in Group II, P = 0.180, mean difference = 0.86, 95% confidence interval 0.39-2.11]. The other early results of COS, clinical and ongoing pregnancy rates, or early pregnancy loss were also not significantly different between the groups. Group I endured longer stimulation period [11.2 (1.8) days versus 10.6 (1.9), P = 0.030]. CONCLUSIONS: Clinical outcomes were not significantly different between Group I and Group II. 相似文献
9.
Mohammad Navid Soltani Rad Somayeh Behrouz Elham Zarenezhad Mohammad Hossein Moslemin Ali Zarenezhad Mehdi Mardkhoshnood Marzieh Behrouz Saeid Rostami 《Medicinal chemistry research》2014,23(8):3810-3822
The syntheses and biological studies of O-oxime ethers having α-amino acid residues as new analogs of IPS-339 have been described. In this synthesis, the reaction of fluorene and/or benzophenone O-oxime with epichlorohydrin or epibromohydrin afforded the corresponding O-oxime ether adducts. The N-alkylation of amino acid with O-oxime ether adducts led to synthesis of new analogs of IPS-339. The products were examined for their cardiovascular property. It was demonstrated that 2-(3-(9H-fluoren-9-ylideneaminooxy)-2-hydroxypropylamino)-3-methyl-butanoic acid as the most potent compound substantially reduces the heart rate of dogs. Compounds were also evaluated for their in vitro antibacterial activity against some Gram-negative and Gram-positive bacteria. The antibacterial screening proved the considerable antibacterial activity against both groups of bacteria. The docking analysis demonstrated the appropriate fitting of 2-(3-(9H-fluoren-9-ylideneaminooxy)-2-hydroxy-propylamino)-3-methyl-butanoic acid in human β2-adrenergic receptor active site. Potential drug toxicity for some active compounds has also been predicted. 相似文献
10.
Masoud Mirzaei Mohammadhossien Soltani Mahdieh Namayandeh Neda GharahiGhehi 《Journal of health, population, and nutrition》2014,32(1):111-117
To assess the daily salt intake of people aged 20-74 years based on the 24-hour urinary sodium excretion in urban population of Yazd, a population-based cross-sectional study was conducted. This is a substudy of Yazd Healthy Heart Project in Iran. From 2004 to 2005, two thousand people of the urban population of Yazd city, aged 20-74 years, were enrolled in the main study. Overall, 219 volunteer participants of 20-70 years were enrolled in this substudy. Sample frame was the household numbers according to the database of Yazd City Health Services. Calcium, phosphorus, sodium, potassium, and creatinine were measured in the urine samples collected from the participants over a 24-hour period. Sodium content in urine over 24 hours was 171.7±82.9 mmol/day in males and 127.8±56.1 mmol/day in females (p<0.0001) while potassium content was 49.4±23.2 mmol/day in males and 41.5±25.1 mmol/day in females (p=0.2). Estimated average daily salt (NaCl) intake was 10.0±4.8 g/day in males and 7.5±3.3 g/day in females (p<0.0001). Only one participant had the ideal Na/K ratio of less than one. Na/K ratios greater than one and less than two were seen in 11.3% (n=24), and a ratio equal to or greater than 2 was observed in 82.3% (n=118) of the participants. The average Na/K ratio was 3.69±1.58. Unlike many developed countries where sodium intake declined over the past few decades, the daily sodium intake in Yazd is high, and daily potassium intake is low. This is similar to what was observed four decades ago in an area not far from Yazd. Efforts must be directed towards health promotion interventions to increase public awareness to reduce sodium intake and increase potassium intake.Key words: 24-hour urine, Blood pressure, Cardiovascular disease, Hypertension, Policy, Potassium, Prevention, Salt, Sodium, Iran 相似文献