全文获取类型
收费全文 | 4407篇 |
免费 | 237篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 75篇 |
儿科学 | 153篇 |
妇产科学 | 146篇 |
基础医学 | 464篇 |
口腔科学 | 111篇 |
临床医学 | 317篇 |
内科学 | 945篇 |
皮肤病学 | 87篇 |
神经病学 | 187篇 |
特种医学 | 186篇 |
外科学 | 819篇 |
综合类 | 211篇 |
一般理论 | 2篇 |
预防医学 | 300篇 |
眼科学 | 106篇 |
药学 | 342篇 |
中国医学 | 22篇 |
肿瘤学 | 201篇 |
出版年
2023年 | 51篇 |
2022年 | 117篇 |
2021年 | 171篇 |
2020年 | 106篇 |
2019年 | 135篇 |
2018年 | 169篇 |
2017年 | 109篇 |
2016年 | 134篇 |
2015年 | 151篇 |
2014年 | 165篇 |
2013年 | 213篇 |
2012年 | 352篇 |
2011年 | 334篇 |
2010年 | 194篇 |
2009年 | 151篇 |
2008年 | 221篇 |
2007年 | 216篇 |
2006年 | 198篇 |
2005年 | 204篇 |
2004年 | 165篇 |
2003年 | 157篇 |
2002年 | 142篇 |
2001年 | 52篇 |
2000年 | 40篇 |
1999年 | 52篇 |
1998年 | 74篇 |
1997年 | 58篇 |
1996年 | 40篇 |
1995年 | 36篇 |
1994年 | 36篇 |
1993年 | 35篇 |
1992年 | 16篇 |
1991年 | 21篇 |
1990年 | 16篇 |
1989年 | 31篇 |
1988年 | 28篇 |
1987年 | 37篇 |
1986年 | 21篇 |
1985年 | 20篇 |
1984年 | 17篇 |
1983年 | 21篇 |
1982年 | 21篇 |
1981年 | 22篇 |
1980年 | 18篇 |
1979年 | 6篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1976年 | 18篇 |
1975年 | 8篇 |
1972年 | 6篇 |
排序方式: 共有4674条查询结果,搜索用时 15 毫秒
31.
Abdel Gawwad E Ahmed MH Kamal MM 《The Journal of the Egyptian Public Health Association》1999,74(1-2):139-173
The purpose of this study is to develop and test the reliability and validity of an Egyptian version of the Children's Health Locus of Control scale. A cross sectional study design was applied using a stratified random sample of 930 students from the final two grades of primary and all grades of the preparatory schools. A further convenience sample of 120 students was selected to examine test-retest reliability of the scale. A preliminary instrument was developed and consisted of 40 statements having one of two response forms; a Yes/No format and a 4-point Likert scale format From data analysis the later format showed higher validity and reliability than the former one. Construct validity of the scale is evidenced by the factor analysis which revealed five factors (Internal, Chance, Powerful Others, Fate and Self blame) consistent with the previous theoretical model of HLC. As indicated by eta coefficient the scale and the subscales showed strong discriminating power between subjects. The known group comparison indicated a good criterion validity of the scale and the subscales. The scale showed a considerable reliability as alpha coefficient was 0.73 with test-retest reliability of 0.65. Comparison of different groups of students indicated that the scale could be used with confidence for all age groups, though it was more reliable for the preparatory phase, for private and governmental schools for males and females and for different social strata. Further testing of the developed scale is indicated among Egyptian children in different cultures. 相似文献
32.
The prevalence of microalbuminuria was assessed in 50 patients of non-insulin dependent diabetes mellitus. The mean age of patients was 52.1 ± 11.6 years and the duration of diabetes was 8.3 ± 6.8 years. Twenty (40%) patients had microalbuminuria. Microalbuminuria was more common in patients with a longer duration of diabetes (more than 5 years), a poor glycaemic control, and higher systolic blood pressure.KEY WORDS: Microalbuminuria, Diabetes mellitus, Diabetic nephropathy, Chronic renal failure 相似文献
33.
AS Harvey 《Journal of paediatrics and child health》2003,39(8):640-640
34.
35.
WF Paterson E McNeill S Reid AS Hollman MD Donaldson 《Archives of disease in childhood》1998,79(4):323-327
OBJECTIVE: To assess the efficacy of a longer acting preparation of the gonadotrophin releasing hormone (GnRH) analogue goserelin (Zoladex LA, 10.8 mg) in 12 girls with central precocious or early puberty. METHODS: Two girls started treatment de novo; the remainder had been on suppressive treatment for a median duration of 1.5 (range, 0.2-5.6) years. Assessment comprising auxology, pubertal staging, and pelvic ultrasound examination was carried out at weeks 0, 4, 8, 10, and 12 (first cycle) and weeks 8, 10, and 12 (second cycle) to evaluate the required injection frequency. Thereafter, assessment was performed on the day of injection. Zoladex LA was given every 12 weeks unless pubertal progression occurred. RESULTS: Satisfactory control was achieved in eight patients using this regimen, and three patients required more frequent injections. One girl was removed from the study because of clinical progression and extreme mood swings. No serious adverse effects occurred. Mean height velocity during the study period was 4.5 cm/year (range, 3.1-6.6) compared with 6.5 cm/year (range, 3.8-9.6) before treatment in nine patients for whom data were available. CONCLUSIONS: Zoladex LA was effective in controlling precocious puberty in girls when given at intervals of 9-12 weeks and it is recommended that an initial assessment is made eight weeks after beginning treatment. 相似文献
36.
Peri-catheter calcification is an unusual and previously unreported complication of central venous (CV) catheterization in
infants. A 1.9 Fr Silastic CV catheter was placed in a term infant for administration of total parenteral nutrition and antibiotics
following intra-abdominal sepsis. The catheter was removed, without complication, at a later date after another septic episode.
Imaging studies performed in the investigation of a possible intra-abdominal abscess revealed a cylindrical density within
a clot in the inferior vena cava (IVC). The density was presumed to be a retained catheter fragment. Further investigation
indicated total occlusion of the IVC. Surgical exploration of the IVC revealed only a calcified thrombus. This case represents
a rare and previously unreported complication of CV catheterization in infants. Diagnosing this condition on radiographic
evidence alone can be difficult. It is hoped that awareness of the potential for this complication will avoid unnecessary
invasive procedures in the future. We also suggest a high level of clinical suspicion and routine Doppler ultrasound investigations
to detect IVC thrombosis when indwelling CV catheters are used in infants.
Accepted: 15 July 1997 相似文献
37.
Mutation of the p53 tumor suppressor gene in spontaneously occurring osteosarcomas of the dog 总被引:8,自引:0,他引:8
Inactivation of the p53 tumor suppressor gene has been implicated in the
pathogenesis of numerous human cancers, including osteosarcomas.
Appendicular osteosarcomas of the dog appear to be a good model for their
human equivalent with regard to biologic behavior, epidemiology and
histopathology. We individually screened exons 5-8 of the p53 gene for
mutations in 15 canine appendicular osteosarcomas using 'Cold' SSCP to
compare the role of this gene in human and canine osteosarcoma
tumorigenesis. Seven of the tumors (47%) exhibited point mutations, with
one tumor possessing two mutations within different exons. Of these, seven
were missense mutations and the eighth was a 'silent' mutation potentially
affecting the exon 6-7 splicing region. Five of the missense mutations were
located in highly conserved regions IV and V, while another corresponded
with the highly conserved codon 220 mutational hotspot located outside the
conserved domains. The locations and types of mutations were nearly
identical to those reported in human cancer. These findings provide strong
evidence of the involvement of p53 mutations in the development of canine
appendicular osteosarcomas. Canine osteosarcomas appear to be a promising
model for their human equivalent on a clinical, pathologic, and molecular
level.
相似文献
38.
One hundred patients of Diabetes Mellitus (70 with and 30 without clinical somatic neuropathy) were studied to correlate clinical severity with the magnitude of nerve conduction abnormalities. Age range was 10-79 years (mean 49) with equal number of males and females. Incidence of neuropathy was more in patients over 40 years of age (60 out of 70 patients) with duration of disease over two years (78.33%). The grades of severity were mild in 22 (31.33%), moderate in 25 (35.71%) and severe in 23 (32.86%) patients. Nerve conduction studies were carried out in 48 (27 with and 21 without clinical neuropathy) patients, using the apparatus Dantec (Cantata TM). The nerves (median, peroneal and sural) were stimulated at two points and the recording of latency; amplitude (micro V) and motor and sensory nerve conduction velocities (m/s) were done under identical environmental conditions. Sensory nerve conduction velocity was more affected than motor velocity. In the 21 patients without clinical neuropathy, 14 showed abnormalities indicating early involvement of peripheral nerves. Reduction of motor nerve conduction velocity was more in patients with moderate and severe grades. The reduction was more in lower than in upper limbs. Nerve conduction abnormality helps in diagnosis in diabetic neuropathy even in preclinical state and correlates with severity, in clinical neuropathy.KEY WORDS: Diabetic neuropathy, Nerve conduction abnormality, Peripheral neuropathy 相似文献
39.
40.
Kiramat Ali Shah Binbin Gao Robia Kamal Anam Razzaq Sun Qi Qiu-Ning Zhu Song Lina Linyu Huang Grainne Cremin Haroon Iqbal Farid Menaa Jing-Hao Cui 《Materials》2022,15(10)
Migraine is a neurological disorder characterized by severe headaches, visual aversions, auditory, and olfactory disorders, accompanied by nausea and vomiting. Zolmitriptan (ZMT®) is a potent 5HT1B/1D serotonin receptor agonist frequently used for the treatment of migraine. It has erratic absorption from the gastrointestinal tract (GIT), but its oral bioavailability is low (40–45%) due to the hepatic metabolism. This makes it an ideal candidate for oral fast dissolving formulations. Hence, the current study was undertaken to design and develop oral fast-dissolving films (OFDFs) containing ZMT for migraine treatment. The OFDFs were formulated by the solvent casting method (SCM) using Pullulan (PU) and maltodextrin (MDX) as film-forming agents and propylene glycol (PG) as a plasticizer. The strategy was designed using Box–Behnken experimental design considering the proportion of PU:MDX and percentage of PG as independent variables. The effectiveness of the OFDF’s was measured based on the following responses: drug release at five min, disintegration time (D-time), and tensile strength (TS). The influence of formulation factors, including percent elongation (%E), thickness, water content, moisture absorption, and folding endurance on ZMT-OFDFs, were also studied. The results showed a successful fabrication of stable ZMT-OFDFs, with surface uniformity and amorphous shape of ZMT in fabricated films. The optimized formulation showed a remarkable rapid dissolution, over 90% within the first 5 min, a fast D-time of 18 s, and excellent mechanical characteristics. Improved maximum plasma concentration (C max) and area under the curve (AUC 0–t) in animals (rats) treated with ZMT-OFDFs compared to those treated with an intra-gastric (i-g) suspension of ZMT were also observed. Copolymer OFDFs with ZMT is an exciting proposition with great potential for the treatment of migraine headache. This study offers a promising strategy for developing ZMT-OFDFs using SCM. ZMT-OFDFs showed remarkable rapid dissolution and fast D-time, which might endeavor ZMT-OFDFs as an auspicious alternative approach to improve patient compliance and shorten the onset time of ZMT in migraine treatment. 相似文献