全文获取类型
收费全文 | 311825篇 |
免费 | 20247篇 |
国内免费 | 8948篇 |
专业分类
耳鼻咽喉 | 3405篇 |
儿科学 | 10596篇 |
妇产科学 | 3623篇 |
基础医学 | 21729篇 |
口腔科学 | 4729篇 |
临床医学 | 41500篇 |
内科学 | 64092篇 |
皮肤病学 | 3533篇 |
神经病学 | 15935篇 |
特种医学 | 15447篇 |
外国民族医学 | 24篇 |
外科学 | 41914篇 |
综合类 | 34879篇 |
现状与发展 | 28篇 |
一般理论 | 1篇 |
预防医学 | 20338篇 |
眼科学 | 5423篇 |
药学 | 31373篇 |
206篇 | |
中国医学 | 9280篇 |
肿瘤学 | 12965篇 |
出版年
2024年 | 770篇 |
2023年 | 3945篇 |
2022年 | 11130篇 |
2021年 | 14465篇 |
2020年 | 9471篇 |
2019年 | 14670篇 |
2018年 | 9106篇 |
2017年 | 8367篇 |
2016年 | 10164篇 |
2015年 | 12818篇 |
2014年 | 23590篇 |
2013年 | 21038篇 |
2012年 | 23268篇 |
2011年 | 20362篇 |
2010年 | 18264篇 |
2009年 | 17592篇 |
2008年 | 16417篇 |
2007年 | 16643篇 |
2006年 | 14294篇 |
2005年 | 10210篇 |
2004年 | 6109篇 |
2003年 | 5378篇 |
2002年 | 4441篇 |
2001年 | 3872篇 |
2000年 | 3307篇 |
1999年 | 2528篇 |
1998年 | 2777篇 |
1997年 | 2610篇 |
1996年 | 2161篇 |
1995年 | 2177篇 |
1994年 | 2050篇 |
1993年 | 1627篇 |
1992年 | 1872篇 |
1991年 | 1640篇 |
1990年 | 1579篇 |
1989年 | 1456篇 |
1988年 | 1365篇 |
1987年 | 1230篇 |
1986年 | 1028篇 |
1985年 | 1933篇 |
1984年 | 2096篇 |
1983年 | 1486篇 |
1982年 | 1595篇 |
1981年 | 1498篇 |
1980年 | 1289篇 |
1979年 | 1116篇 |
1978年 | 883篇 |
1977年 | 819篇 |
1976年 | 731篇 |
1974年 | 488篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
Mani N Pavuluri Megan Marlow O'Connor Erin M Harral Melissa Moss John A Sweeney 《Neuropsychopharmacology》2006,60(9):951-956
BACKGROUND: Previous research has demonstrated that academic and neuropsychological functions are compromised in pediatric bipolar disorder (PBD). Investigation of the degree to which neuropsychological deficits might contribute to those academic problems is needed to aid in the recognition and intervention for school achievement difficulties in PBD. METHODS: A sample of 55 children and adolescents with PBD with and without attention-deficit/hyperactivity disorder (ADHD) (PBD group, n = 28; PBD+ADHD group, n = 27) were tested with a computerized neurocognitive battery and standardized neuropsychological tests. Age range of subjects was 7-17 years, with the mean age of 11.97 (3.18) years. Parents completed a structured questionnaire on school and academic functioning. RESULTS: Logistic regression analyses indicated that executive function, attention, working memory, and verbal memory scores were poorer in those with a history of reading/writing difficulties. A separate logistic regression analysis found that attentional dysfunction predicted math difficulties. These relationships between neuropsychological function and academic difficulties were not different in those with PBD+ADHD than in those with PBD alone. CONCLUSIONS: In PBD neuropsychological deficits in the areas of attention, working memory, and organization/problem solving skills all contribute to academic difficulties. Early identification and intervention for these difficulties might help prevent lower academic achievement in PBD. 相似文献
33.
34.
35.
直肠癌切除前后腹腔冲洗液脱落细胞学对比研究 总被引:1,自引:0,他引:1
目的研究直肠癌术中腹腔多次冲洗,对于降低患者腹腔内脱落癌细胞阳性率的临床意义。方法对63例直肠癌患者术中腹腔冲洗分6次进行,肿瘤切除前3次,切除后3次;将6次腹腔冲洗液行常规病理学涂片细胞学检查结果进行对比。结果肿瘤切除前,全组患者腹腔冲洗液脱落癌细胞均呈阳性表达。肿瘤切除后第1次腹腔冲洗液脱落癌细胞阳性40例,第2次阳性33例,第3次阳性13例。肿瘤切除后第1次冲洗液的脱落癌细胞阳性结果与切除后第2次冲洗液阳性结果比较,P〉0.05,差异无统计学意义;但第3次冲洗液的脱落癌细胞阳性结果与第2次比较,P〈0.01,差异有统计学意义。结论对直肠癌患者进行术中多次腹腔冲洗可降低腹腔内脱落癌细胞的阳性率。 相似文献
36.
Cardiac myxoma has varying clinical presentation, uncertain histogenesis and debatable immunohis- tochemical profile. Glandular epithelial differentiation is a rare phenomenon, but glandular elements are known to be present in cardiac myxoma as an intrinsic component of the tumor. We present a case of cardiac myxoma having focal glandular differentiation, with special reference to the morphologic features and immunohistochemical profiles. 相似文献
37.
Phillip F. Chance 《Neuromolecular medicine》2006,8(1-2):159-173
Hereditary neuropathy with liability to pressure palsies (HNPP; also called tomaculous neuropathy) is an autosomal-dominant
disorder that produces a painless episodic, recurrent, focal demyelinating neuropathy. HNPP generally develops during adolescence,
and may cause attacks of numbness, muscular weakness, and atrophy. Peroneal palsies, carpal tunnel syndrome, and other entrapment
neuropathies may be frequent manifestations of HNPP. Motor and sensory nerve conduction velocities may be reduced in clinically
affected patients, as well as in asymptomatic gene carriers. The histopathological changes observed in peripheral nerves of
HNPP patients include segmental demyelination and tomaculous or “sausage-like” formations. Mild overlap of clinical features
with Charcot-Marie-Tooth (CMT) disease type 1 (CMT1) may lead patients with HNPP to be misdiagnosed as having CMT1. HNPP and
CMT1 are both demyelinating neuropathies, however, their clinical, pathological, and electrophysiological features are quite
distinct. HNPP is most frequently associated with a 1.4-Mb pair deletion on chromosome 17p12. A duplication of the identical
region leads to CMT1A. Both HNPP and CMT1A result from a dosage effect of the PMP22 gene, which is contained within the deleted/duplicated region. This is reflected in reduced mRNA and protein levels in sural
nerve biopsy samples from HNPP patients. Treatment for HNPP consists of preventative and symptom-easing measures. Hereditary
neuralgic amyotrophy (HNA; also called familial brachial plexus neuropathy) is an autosomal-dominant disorder causing episodes
of paralysis and muscle weakness initiated by severe pain. Individuals with HNA may suffer repeated episodes of intense pain,
paralysis, and sensory disturbances in an affected limb. The onset of HNA is at birth or later in childhood with prognosis
for recovery usually favorable; however, persons with HNA may have permanent residual neurological dysfunction following attack(s).
Episodes are often triggered by infections, immunizations, the puerperium, and stress. Electrophysiological studies show normal
or mildly prolonged motor nerve conduction velocities distal to the affected brachial plexus. Pathological studies have found
axonal degeneration in nerves examined distal to the plexus abnormality. In some HNA pedigrees there are characteristic facial
features, including hypotelorism. The prognosis for recovery of normal function of affected limbs in HNA is good, although
recurrent episodes may cause residual deficits. HNA is genetically linked to chromosome 17q25, where mutations in the septin-9 (SEPT9) gene have been found. 相似文献
38.
Gerald T Voelbel Marsha E Bates Jennifer F Buckman Gahan Pandina Robert L Hendren 《Neuropsychopharmacology》2006,60(9):942-950
BACKGROUND: Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability. METHODS: Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed. RESULTS: The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups. CONCLUSIONS: Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group. 相似文献
39.
三磷酸腺苷结合盒运转体A1与颈动脉粥样硬化斑块的关系 总被引:4,自引:0,他引:4
目的 探讨三磷酸腺苷结合盒运转体A1(ATP binding cassette transporter A1,ABCA1)在人颈动脉粥样硬化斑块中的表达变化及作用机制.方法 收集24例人颈动脉粥样硬化斑块标本和10例肠系膜动脉标本(对照组),采用RT-PCR测定ABCA1 mRNA和视黄酸X受体α(RXRα)mRNA表达水平,并采用Western Blot检测ABCA1及RXRα的蛋白表达水平.24例人颈动脉粥样硬化斑块标本按病理分级,比较病理组织为Ⅲ级和Ⅰ级动脉粥样硬化组织间ABCA1 mRNA、RXRαmRNA表达水平及蛋白表达水平.结果 颈动脉粥样硬化斑块组的ABCA1 mRNA(0.79±0.04)和RXRα mRNA(0.73±0.04)表达与对照组相比上调,差异有统计学意义(P<0.05);ABCA1 mRNA与RXRα mRNA增加水平相关(P<0.05);颈动脉粥样硬化斑块的ABCA1蛋白表达(0.22±0.03)下调水平与对照组(0.53±0.03)相比差异有统计学意义(P<0.05);Ⅲ级和Ⅰ级动脉硬化斑块ABCA1mRNA、RXRα mRNA及蛋白表达水平差异有统计学意义(P<0.05).结论 ABCA1及RXRα蛋白表达水平下调可能是进展性动脉粥样硬化损害的关键因素. 相似文献
40.
直肠癌术中保留盆腔自主神经对男性排尿及性功能的影响 总被引:5,自引:0,他引:5
目的探讨直肠癌根治术中保留盆腔自主神经(PANP)对男性排尿及性功能的影响。方法以问卷彤式调查48例直肠癌患者PANP手术和24例非PANP手术前、后的排尿功能和性功能,比较分析行直肠癌根治术的PANP组和非PANP组患者术后排尿和性功能指标及直肠癌的局部复发率。结果PANP组患者术后排尿及性功能部分指标优于对照组(P〈0.05),两组术后局部癌肿复发率比较尤显著性差异(P〉0.05)。结论直肠癌患者根治术中实施PANP,既不增加局部癌肿复发率,还可以改善患者的排尿和性功能,提高患者的生存质量。 相似文献