全文获取类型
收费全文 | 16361篇 |
免费 | 1154篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 180篇 |
儿科学 | 673篇 |
妇产科学 | 553篇 |
基础医学 | 2354篇 |
口腔科学 | 288篇 |
临床医学 | 2218篇 |
内科学 | 2623篇 |
皮肤病学 | 295篇 |
神经病学 | 1819篇 |
特种医学 | 295篇 |
外科学 | 1235篇 |
综合类 | 217篇 |
现状与发展 | 1篇 |
一般理论 | 38篇 |
预防医学 | 2346篇 |
眼科学 | 230篇 |
药学 | 940篇 |
中国医学 | 14篇 |
肿瘤学 | 1233篇 |
出版年
2023年 | 140篇 |
2022年 | 163篇 |
2021年 | 358篇 |
2020年 | 273篇 |
2019年 | 388篇 |
2018年 | 383篇 |
2017年 | 364篇 |
2016年 | 314篇 |
2015年 | 382篇 |
2014年 | 540篇 |
2013年 | 858篇 |
2012年 | 1156篇 |
2011年 | 1200篇 |
2010年 | 624篇 |
2009年 | 584篇 |
2008年 | 1043篇 |
2007年 | 1044篇 |
2006年 | 1064篇 |
2005年 | 1046篇 |
2004年 | 977篇 |
2003年 | 899篇 |
2002年 | 899篇 |
2001年 | 179篇 |
2000年 | 147篇 |
1999年 | 162篇 |
1998年 | 213篇 |
1997年 | 166篇 |
1996年 | 125篇 |
1995年 | 122篇 |
1994年 | 106篇 |
1993年 | 91篇 |
1992年 | 109篇 |
1991年 | 100篇 |
1990年 | 101篇 |
1989年 | 89篇 |
1988年 | 83篇 |
1987年 | 65篇 |
1986年 | 73篇 |
1985年 | 79篇 |
1984年 | 81篇 |
1983年 | 78篇 |
1982年 | 92篇 |
1981年 | 68篇 |
1980年 | 54篇 |
1979年 | 58篇 |
1978年 | 54篇 |
1977年 | 37篇 |
1976年 | 35篇 |
1974年 | 36篇 |
1972年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
991.
Sexual arousal can be viewed as an emotional state generating sex-specific autonomic and general somatic motor system responses that prepare for sexual action. In the present study modulation of spinal tendious (T) reflexes by sexual films of varying intensity was investigated. T reflexes were expected to increase as a function of increased film intensity. Through use of a between-subjects design, participants were exposed to three erotic films of low, moderate, and high intensity or to three films of moderate intensity. Self-report and genital data confirmed the induction of increasing versus stable levels of sexual arousal. Exposure to the films of increasing intensity resulted in increasing T reflexes. The results indicate that T reflex modulation is sensitive to varying levels of sexual arousal and may be of use in research on behavioral mechanisms underlying appetitive motivation. 相似文献
992.
Towbin KE Pradella A Gorrindo T Pine DS Leibenluft E 《Journal of child and adolescent psychopharmacology》2005,15(3):452-464
The autism spectrum disorders (ASDs) can present with symptoms commonly found in mood and anxiety disorders. The Social Communication Questionnaire (SCQ), Children's Communication Checklist (CCC-2), and the Social Reciprocity Scale (SRS) were used to screen children in a mood disorders research clinic setting for symptoms of ASD. Ninety-three patients (mean age, 12.7 +/- 2.8 years; percent male, 63%) completed at least one scale, and 50 children completed all three. The prevalence of those screening positive for a possible ASD on one instrument was 62% and on all three measures was 8%. Fifty-seven percent (n = 21/37; odds ratio, 4.59 [95% confidence interval (CI) = 1.40-15.11]) of those scoring in the "ASD-likely" range on the SRS scored in that range on the CCC-2. Only 16% (n = 6/37; odds ratio, not significant (NS)) of those scoring in the ASD-likely range on the SRS, and 14% (n = 5/37; odds ratio, NS) of those scoring in the ASD-likely range on the CCC-2, scored similarly on the SCQ. These results demonstrate a need to develop valid and reliable instruments to screen for ASDs in children presenting outside of ASD clinics. 相似文献
993.
Easter J McClure EB Monk CS Dhanani M Hodgdon H Leibenluft E Charney DS Pine DS Ernst M 《Journal of child and adolescent psychopharmacology》2005,15(4):563-570
INTRODUCTION: Anxiety disorders in adults involve aberrant processing of emotional information that is hypothesized to reflect perturbations in the amygdala. This study examines the relationship between face-emotion recognition and anxiety in a sample of children and adolescents participating in a brain-imaging study of amygdala structure and function. METHODS: This study recruited 15 children and adolescents with ongoing anxiety disorders and 11 psychiatrically healthy comparisons group-matched on age, gender, and IQ. Face-emotion recognition was assessed using the Diagnostic Analysis of Nonverbal Accuracy Scale (DANVA). RESULTS: Children and adolescents with anxiety disorders exhibited significantly poorer performance on the face-emotion recognition task compared to healthy controls (z = 2.2; p < 0.05). This difference was found only for expressions posed by adults but not children. Discussion: Reduced accuracy on a face-emotion recognition test is consistent with perturbed amygdala function in pediatric anxiety disorders. CONCLUSION: As this study was conducted in a sample undergoing a neuroimaging investigation of amygdala integrity, future analyses will examine associations among amygdala function, clinical anxiety, and face-recognition abilities. 相似文献
994.
Fish oil addition to infant formulas has raised concern on whether increased intake of n-3 long-chain polyunsaturated fatty acid (n-3LCPUFA) affects infant growth. The objective of this study was to determine whether maternal fish oil supplementation during 0-4 mo of lactation influences growth in infancy and early childhood. In a randomized, blinded intervention trial, lactating Danish mothers with a fish intake below the population median were randomized to 4.5 g/d fish oil or olive oil. A reference group of 53 mothers with a fish intake in the highest quartile of the population and their infants were included in the study. Head circumference, weight, length, skinfold thickness, and waist circumference of children were measured at 2, 4, and 9 mo and at 2.5 y. One hundred children completed the intervention trial, and 72 were followed up at 2.5 y together with 29 from the reference group. Growth in weight, length, and head circumference did not differ between the randomized groups up to 9 mo, but at 2.5 y, body composition differed significantly. Children in the fish oil group had larger waist circumference body mass index (BMI; 0.6 kg/m(2); p = 0.022), and head circumference compared with those in the olive oil group. Adjusted for sex, ponderal index at birth and current energy intake, BMI at 2.5 y was associated with docosahexaenoic acid in maternal erythrocytes after the intervention. In conclusion, the n-3LCPUFA intake of lactating mothers may be important for growth of young children. The long-term effect on weight and BMI remains to be investigated. 相似文献
995.
996.
997.
Hazra R Gafni RI Maldarelli F Balis FM Tullio AN DeCarlo E Worrell CJ Steinberg SM Flaherty J Yale K Kearney BP Zeichner SL 《Pediatrics》2005,116(6):e846-e854
998.
Benya EC 《Pediatric annals》2005,34(3):172, 175
999.
Louthan MV Theriot JA Zimmerman E Stutts JT McClain CJ 《Journal of pediatric gastroenterology and nutrition》2005,41(4):426-429
OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is a common cause of pediatric liver disease. Studies suggest decreased prevalence in blacks, females, and younger children. However, the proportion of black subjects in these studies was small, and children under 12 were not included. We propose that abnormal alanine aminotransferase (ALT) is more common in whites than blacks, males than females, and children over 12 compared with younger children in a prospective study. METHODS: We enrolled 181 consecutive asymptomatic obese children attending general pediatric clinics who denied recent fever or known liver disease. Obesity was defined as body mass index (BMI) z score of greater than 1.64 (95th percentile for age and sex). Elevated ALT was defined as greater than 40 U/L. BMI z score, race, sex, age, and parental obesity were compared using the chi-square test and Fisher's exact test. RESULTS: The population included 81 males and 100 females, 147 non-Hispanic black, 33 non-Hispanic white, and 1 Hispanic white. Elevated ALT occurred in 14 (8%) subjects. White children were significantly more likely to have abnormal ALT (odds ratio [OR] = 4.0, P < .02). Very obese children (BMI z score >2.3) were more likely to have abnormal ALT compared with mildly obese children (OR = 4.0, P < 0.05). Sex, age, hepatomegaly, acanthosis nigricans, and parental obesity did not significantly predict elevated ALT. CONCLUSION: Eight percent of asymptomatic, obese children had an elevated ALT suggestive of NAFLD. White and very obese children are more likely to be affected. Sex and age are not good clinical predictors of NAFLD. We suggest that all obese children be screened for NAFLD. 相似文献
1000.
Roll EB 《Acta paediatrica (Oslo, Norway : 1992)》2005,94(10):1437-1442
AIM: To compare continuous and intermittent light exposure in the presence of bilirubin with respect to cellular damage. Furthermore, it was of interest to characterize the nature of cellular toxicity of bilirubin in the dark. METHOD: A murine lymphoma cell line, L5178Y-R (LY-R), was exposed to solutions of bilirubin (160 microM) supplemented with human serum albumin (200 microM) and irradiated with phototherapy light (Philips 20W/52) at a constant total dose of approximately 500 kJ/m2. The irradiation was given either as intermittent or continuous treatment with light of variable irradiance. The three lower irradiance levels were clinically relevant. Cells treated with bilirubin were also kept in the dark for various periods of time. Cell toxicity was determined by measuring apoptosis and necrosis. Apoptosis was measured by terminal deoxynucleotide transferase and propidium iodide staining assay, while trypan blue assay was used for detection of necrosis. RESULTS: There was no difference (n = 6, p > 0.05) between continuous and intermittent irradiation in the induction of early and late apoptotic cell death. Necrosis was more pronounced after intermittent treatment. Bilirubin dark toxicity was observed and classified as both apoptotic and necrotic. CONCLUSION: Continuous and intermittent light exposure caused the same degree of apoptotic cell death, while the cells underwent more necrotic death after intermittent exposure. Bilirubin was cytotoxic in the dark by both cell death mechanisms. 相似文献