全文获取类型
收费全文 | 626篇 |
免费 | 62篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 3篇 |
妇产科学 | 1篇 |
基础医学 | 62篇 |
口腔科学 | 36篇 |
临床医学 | 70篇 |
内科学 | 124篇 |
皮肤病学 | 18篇 |
神经病学 | 85篇 |
特种医学 | 22篇 |
外科学 | 54篇 |
综合类 | 85篇 |
预防医学 | 28篇 |
眼科学 | 2篇 |
药学 | 52篇 |
2篇 | |
中国医学 | 20篇 |
肿瘤学 | 38篇 |
出版年
2024年 | 7篇 |
2023年 | 27篇 |
2022年 | 54篇 |
2021年 | 61篇 |
2020年 | 38篇 |
2019年 | 27篇 |
2018年 | 27篇 |
2017年 | 20篇 |
2016年 | 30篇 |
2015年 | 22篇 |
2014年 | 35篇 |
2013年 | 33篇 |
2012年 | 27篇 |
2011年 | 45篇 |
2010年 | 18篇 |
2009年 | 10篇 |
2008年 | 28篇 |
2007年 | 29篇 |
2006年 | 24篇 |
2005年 | 25篇 |
2004年 | 15篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 13篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有709条查询结果,搜索用时 15 毫秒
91.
目的:评价乳腺B超、乳腺X线及两者结合的方法在城市高危人群乳腺癌筛查中的诊断价值。方法:通过防癌风险评估问卷调查筛选出乳腺癌高风险人群,乳腺B超和X线检查进行乳腺癌筛查,利用ROC曲线分析法评价不同筛查方案的应用价值。结果:在3 275例高危人群中,共检出乳腺癌12例,检出率为366.41/10万。单独乳腺B超检查、单独乳腺X线检查、B超+X线、B超-X线筛查模式的灵敏度分别为53.85%、84.62%、92.31%和53.85%,ROC曲线下面积分别为0.802、0.959、0.964和0.805,Z检验结果显示B超+X线筛查模式具有较高的诊断能力(P<0.05)。结论:乳腺B超、乳腺X线均是乳腺癌筛查的有效方法,各有优缺点。两者综合可以相互弥补,提高早期乳腺癌的检出率。 相似文献
92.
Cheng X Li T Wang H Zhu D Ma C Ma B Wang Y Zhang J Guo L Wang L Yun L Chen S Jiang Z He L Zhu C Xing Q 《Journal of human genetics》2011,56(1):17-21
Genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) have been suggested as being associated with cerebral palsy (CP) but the evidence is uncertain. The purpose of this study was to investigate whether MTHFR gene polymorphisms contribute to the development of CP in Chinese infants. For this study, 169 health controls and 159 infants with CP including 43 cases also suffering from mental retardation (MR) were recruited. Genomic DNA was prepared from venous blood and all five single nucleotide polymorphisms in MTHFR (rs4846049, rs1476413, rs1801131, rs1801133 and rs9651118) were genotyped using TaqMan technology. There were no significant differences in allele or genotype frequencies between the CP patients and controls at any of the five genetic polymorphisms. Subgroup analysis found statistically significant difference in allele and genotype frequencies between cases with both CP and MR (CP + MR) compared with both CP-only cases and controls at rs4846049, rs1476413 and rs1801131. The frequencies of the T alleles of rs4846049, rs1476413 and the G allele of rs1801131 were greater in the CP + MR patients than in the CP-only patients and controls. This study provides the first evidence pointing to a MTHFR gene polymorphism as a potential risk factor for CP combined with MR. 相似文献
93.
Heart murmurs are pathological sounds produced by turbulent blood flow due to certain cardiac defects such as valves disorders. Detection of murmurs via auscultation is a task that depends on the proficiency of physician. There are many cases in which the accuracy of detection is questionable. The purpose of this study is development of a new mathematical model of systolic murmurs to extract their crucial features for identifying the heart diseases. A high resolution algorithm, multivariate matching pursuit, was used to model the murmurs by decomposing them into a series of parametric time–frequency atoms. Then, a novel model-based feature extraction method which uses the model parameters was performed to identify the cardiac sound signals. The proposed framework was applied to a database of 70 heart sound signals containing 35 normal and 35 abnormal samples. We achieved 92.5% accuracy in distinguishing subjects with valvular diseases using a MLP classifier, as compared to the matching pursuit-based features with an accuracy of 77.5%. 相似文献
94.
基于香港大学等机构科学家对针灸机理的研究,提出如下假说:穴位的本质就是针灸针的机械运动(或艾灸的热效应等)转化为细胞信号并激活细胞产生效应的敏感点(或者特定点、特异点等);经络的本质就是这些有密切关系的(效应相关的)细胞(以及其它相关的组织结构等或效应传导通路等)的空间分布。 相似文献
95.
96.
Objective Poisoning does the most serious damages in pediatrics. In the northeast of Iran (Golestan province), opium is used widely
for symptomatic therapy of routine illnesses in young children by parents. In the present study, opium toxicity was assessed
in young children referred to pediatric centers in our area.
Methods This survey was done as a prospective cross-sectional study. At first, a pilot study was undertaken to estimate the condition
of opium intoxicated children and evaluate the validity of questionnaire. We collected data in collaboration with committee
of Adverse Drug Reactions (ADR) in Golestan Province. All members of ADR committee in pediatric centers were trained to complete
questionnaires in referred or admitted children under-5-year. Data was entered into computer and analyzed by Chi-square and
Fisher exact test.
Results In this survey, 67 opium-intoxicated children were recruited. Minimum age of the cases was 6 days and maximum 5-year. Uneducated
mothers, in most cases, gave opium to the child. Most of them were from the low socio-economic level. Ethnic was disparity
was observed. Four deaths occurred.
Conclusion As the results showed, opioids are dangerous in pediatric population, especially under 5-year. Respiratory depression, bradypnea,
coma and death are the serious outcomes of opium toxicity in pediatrics. Such a practice of unrestricted use of opium contributes
to children mortality and so it is essential to launch educational programs. 相似文献
97.
目的研究促红细胞生成素(EPO)对人牙髓细胞(hDPC)迁移能力的影响,并初步探讨相关分子机制。
方法实时荧光定量聚合链反应(PCR)检测EPO对hDPC表达趋化因子mRNA的影响;Transwell实验观察不同浓度的EPO对hDPC迁移能力的影响;Western blot检测不同时间点hDPC中p38、ERK1/2、JNK磷酸化水平的变化;细胞划痕实验观察丝裂原活化蛋白激酶(MAPK)信号通路抑制剂对EPO诱导hDPC迁移的影响。
结果EPO上调趋化因子CXCR4、SDF-1 mRNA的表达(tCXCR4= 5.727,PCXCR4= 0.005;tSDF-1= 3.412,PSDF-1= 0.027);与对照组相比,EPO显著促进hDPC的迁移能力(F= 207.775,P10 U/ml= 0.000,P20 U/ml= 0.000,P40 U/ml= 0.000);EPO可升高MAPK信号通路中关键蛋白ERK1/2(t15 min= 6.554,P15 min= 0.000;t30 min= 17.305,P30 min= 0.000;t60 min= 8.913,P60 min= 0.000;t120 min=-5.896,P120 min= 0.934)和p38的磷酸化程度(t15 min= 4.396,P15 min= 0.004;t30 min= 6.447,P30 min= 0.000;t60 min= 34.676,P60 min= 0.000;t120 min= 4.689,P120 min= 0.003);MAPK信号通路抑制剂U0126、SB203580可抑制EPO诱导的hDPC迁移(tEPO-U0126= 2.422,PEPO- U0126= 0.025;tEPO-SB203580= 3.837,PEPO-SB203580= 0.001)。
结论EPO上调趋化因子CXCR4和SDF-1 mRNA的表达,通过激活MAPK信号通路,促进hDPC迁移。 相似文献
98.
Mehdi Bakhshaee Mohammad Fereidouni Morteza Nourollahian Mohajer Mohammad Reza Majidi Farahzad Jabbari Azad Toktam Moghiman 《European archives of oto-rhino-laryngology》2013,270(12):3095-3098
Allergic fungal sinusitis (AFS) is a noninvasive form of fungal rhinosinusitis with a prevalence of 6–9 % among all rhinosinusitis cases requiring surgery. The fungi causing AFRS have a great diversity and regional variation in the incidence of AFS has been reported worldwide. The aim of this study was to evaluate the prevalence of AFS among rhinosinusitis patients in the north east of Iran. In a prospective cross-sectional study 127 patients with sinonasal polyposis who were candidates for surgery were recruited. All cases were evaluated by sinonasal CT scan, Prick test for common regional allergens, total serum immunoglobulin E (IgE) level, and allergic mucin culture for fungi in suspected cases. Data analyses were done using SPSS version 13.0. Their mean age was 37.4 ± 11.6 years, the male-to-female ratio was 69/58. Eleven patients (9.45 %) met the AFS criteria. Nine cases had a positive culture for Aspergillus specimen and three for Alternaria. Prick test was positive for at least one allergen in 28 cases (22.05 %). The most common allergen was weed. The total IgE level was significantly higher in AFS patients. This study showed the prevalence of AFS among patients with nasal polyposis to be 9.45 %. 相似文献
99.
Cancer patients who undergo surgery or radiation can develop persistent focal pain at the site of radiation or surgery. Twelve patients who had surgery or radiation for local cancer and failed at least two analgesic medications for pain control were prospectively enrolled in a research protocol. Patients were injected up to 100 units of incobotulinum toxin A (IncoA) intramuscularly or subcutaneously depending on the type and location of pain (muscle cramp or neuropathic pain). Two patients passed away, one dropped out due to a skin reaction and another patient could not return for the follow up due to his poor general condition. All remaining 8 subjects (Age 31–70, 4 female) demonstrated significant improvement of Visual Analog Scale (VAS) (3 to 9 degrees, average 3.9 degrees) and reported significant satisfaction in Patients’ Global Impression of Change scale (PGIC) (7 out of 8 reported the pain as much improved). Three of the 8 patients reported significant improvement of quality of life. 相似文献