首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1152篇
  免费   51篇
  国内免费   20篇
耳鼻咽喉   10篇
儿科学   81篇
妇产科学   34篇
基础医学   123篇
口腔科学   6篇
临床医学   108篇
内科学   272篇
皮肤病学   9篇
神经病学   61篇
特种医学   32篇
外科学   51篇
综合类   192篇
预防医学   82篇
眼科学   2篇
药学   94篇
  2篇
中国医学   36篇
肿瘤学   28篇
  2024年   2篇
  2023年   9篇
  2022年   24篇
  2021年   36篇
  2020年   42篇
  2019年   30篇
  2018年   34篇
  2017年   32篇
  2016年   43篇
  2015年   40篇
  2014年   80篇
  2013年   86篇
  2012年   82篇
  2011年   71篇
  2010年   59篇
  2009年   62篇
  2008年   61篇
  2007年   60篇
  2006年   34篇
  2005年   49篇
  2004年   42篇
  2003年   20篇
  2002年   14篇
  2001年   26篇
  2000年   12篇
  1999年   7篇
  1998年   6篇
  1997年   9篇
  1996年   10篇
  1995年   11篇
  1994年   7篇
  1993年   13篇
  1992年   7篇
  1991年   5篇
  1990年   10篇
  1989年   9篇
  1988年   11篇
  1987年   7篇
  1986年   2篇
  1985年   8篇
  1984年   11篇
  1983年   5篇
  1982年   5篇
  1981年   4篇
  1980年   5篇
  1979年   2篇
  1978年   6篇
  1977年   5篇
  1976年   2篇
  1974年   3篇
排序方式: 共有1223条查询结果,搜索用时 15 毫秒
1.
2.
Thyroid hormone (T3) deficiency impairs the development of the CNS, particularly myelination. We have previously described an increase in the frequency of morphological abnormalities in the central myelin sheath in a hypothyroidism model, which reinforced the hypothesis of a role for T3 in myelin compaction. However, there are no data concerning the cellular distribution of myelin proteins in hypothyroid animals. In the present work, we describe the distribution of 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase), myelin basic protein (MBP) and proteolipid protein (PLP) throughout the central myelin sheath of a hypothyroidism model. We used euthyroid and hypothyroid adult rats at 90 days of age. In order to induce hypothyroid status, animals received 0.02% methimazol from the 19th gestation day onwards. After perfusion with a fixative mixture, small pieces of corpus callosum were obtained, dehydrated and embedded in LR White resin. Ultrathin sections were immunoreacted, using specific antibodies revealed by a secondary antibody coupled to colloidal gold particles of 10 nm. Gold particle density per region of myelin sheath for each one of these proteins was obtained. In normal animals, CNPase, PLP and MBP were identified in sites that had already been described in previous studies. In hypothyroid animals, CNPase was identified in the region corresponding to compact lamellae, which normally does not contain this protein, while, in this same region, PLP and MBP immunolabeling were decreased. These results suggest that thyroid hormone deficiency impairs the distribution of the major oligodendrocyte/myelin markers. This effect may justify the reduction in myelin sheath compaction previously demonstrated in a similar model of hypothyroidism.  相似文献   
3.
简要介绍国内外有关先天愚型患者甲状腺功能减低的发生率、发病机理及处理,并根据近年来儿童先天愚型患者甲低不断增多的趋势,提出应对先天愚型患儿进行定期的甲状腺功能检查,以便早期发现和治疗甲状腺功能减低。  相似文献   
4.
This is a report of a 27-year-old woman with an unusual de novo chromosomal abnormality. Mosaicism was identified in peripheral blood cells examined by standard G-bands by trypsin using Giemsa (GTG) analysis and fluorescence in situ hybridization (FISH) analysis with chromosome-18 region-specific probes, 46,XX,del(18)(pter → q21.33:)[41], 46,XX,r(18)(::p11.21 → q21.33::)[8], and 46,XX,der(18)(pter → q21.33::p11.21 → pter)[1]. On the other hand, the karyotype of periodontal ligament fibroblasts was nonmosaic, 46,XX, der(18)(pter → q21.33::p11.21 → pter)[50]. All cell lines appeared to be missing a portion of 18q (q21.33 → qter). The pattern of the dup(18p)/del(18q) in the rod configuration raises the possibility of an inversion in chromosome 18 in one of the parents. However, no chromosomal anomaly was detected in either parent. The most probable explanation is that de novo rod and ring configurations arose simultaneously from an intrachromosomal exchange. The unique phenotype of this patient, which included primary hypothyroidism and primary hypogonadism, is discussed in relation to her karyotype.  相似文献   
5.
不可逆性甲减患者需要终身服用甲状腺激素,对患者的日常工作和生活造成了很大的不便。随着近年来对自体甲状腺组织与干细胞移植研究的进展,有望解决甲减病人终身服药这一问题。自体甲状腺组织移植的动物实验以及人体试验均表明:甲状腺移植物不但能够存活,而且能够发挥作用。最新的胚胎干细胞(Embryonic stemcell,ESC)研究证明,ESC可以分化为甲状腺滤泡细胞。  相似文献   
6.
Hypothyroidism induced by perinatal administration of propylthiouracil (PTU) had profound effects on growth of the heart, with major organ weight deficits persisting well beyond the termination of drug treatment. These effects were preceded by disruption of the developmental patterns of cardiac ornithine decarboxylase (ODC) and the polyamines, which are thought to be intracellular modulators of cellular maturation. Activity of cardiac ODC was depressed in the PTU-treated group and putrescine and spermidine levels were markedly subnormal. PTU administration also affected brain growth, but much less so than in the heart. The disruption of the brain ODC/polyamine system was also less pronounced, with relatively small degrees of spermidine depletion and a slight elevation of ODC. For both tissues, the biochemical effects of perinatal hypothyroidism were opposite to those found previously for administration of exogenous thyroid hormones. These results support the views that:
1. (1) endogenous thyroid hormones contribute to the maintenance of normal developmental patterns of ODC and the polyamines, and
2. (2) the ODC/polyamine system participates in events modulating subsequent tissue growth.
Keywords: Hypothyroidism; Polyamines; Ornithine decarboxylase; Propylthiouracil  相似文献   
7.
目的:了解湖南省新生儿先天性甲状功能减低症(CH)和苯丙酮尿症(PKU)的发病情况,早期诊断和治疗。方法:采用时间分辨荧光免疫法(DELFIA)测定促甲状腺素(TSH)浓度,使用盖塞利细菌抑制法或荧光法测定血苯丙氨酸(Phe)浓度。对TSH≥20μU/L或Phe≥0.26mmol/L(2mg/dl)者,进行确诊检查,确诊后给予治疗并随访。结果:湖南省部分地区46323例新生儿,确诊为CH28例(包括3例TSH延期上升型CH),PKU患儿1例。经治疗随访患者智能体格发育正常。结论:新生儿筛查能早期发现PKU和CH患儿,及时诊断、治疗和预防智力低下发生,值得大力推广。  相似文献   
8.
BackgroundMany health benefits of bariatric surgery are known and well-studied, but there is scarce data on the benefits of bariatric surgery on the thyroid function.ObjectiveWe aimed to make a meta-analysis regarding the impact of bariatric surgery on thyroid-stimulating hormone (TSH) levels, levothyroxine dose, and the status of subclinical hypothyroidism.SettingSystematic review and meta-analysis.MethodsPubMed, EMBASE, and Cochrane Library were searched up to December 2020 for relevant clinical studies. Random-effects model was used to pool results. Network meta-analysis was performed, incorporating direct and indirect comparisons among different types of bariatric surgery. Meta-regression analysis was performed to evaluate the impact of moderator variables on TSH levels and required levothyroxine dose after surgery. We followed the PRISMA guidelines for data selection and extraction. PROSPERO registry number: CRD42018105739.ResultsA total of 28 studies involving 1284 patients were included. There was a statistically significant decrease in TSH levels after bariatric surgery (mean difference = ?1.66 mU/L, 95%CI [?2.29, ?1.03], P < .0001). In meta-regression analysis, we found that the following moderator variables: length of follow-up, mean age, baseline TSH, and preoperative thyroid function, could explain 1%, 43%, 68%, and 88% of the between-study variance, respectively. Furthermore, subclinical hypothyroidism was completely resolved in 87% of patients following bariatric surgery. In addition, there was a statistically significant decrease of levothyroxine dose in frank hypothyroid patients following bariatric surgery (mean difference = ?13.20 mcg/d, 95%CI [?19.69, ?6.71]). In network meta-analysis, we found that discontinuing or decreasing levothyroxine dose was significant following Roux-en-Y gastric bypass, 1 anastomosis gastric bypass, and sleeve gastrectomy, (OR = 31.02, 95%CI [10.34, 93.08]), (OR = 41.73, 95%CI [2.04, 854.69]), (OR = 104.03, 95%CI [35.79, 302.38]), respectively.ConclusionsBased on our meta-analysis, bariatric surgery is associated with the resolution of subclinical hypothyroidism, a decrease in TSH levels, and a decrease in levothyroxine dose.  相似文献   
9.
目的:探究妊娠期甲状腺功能减退症孕妇不同时期治疗效果及血清促甲状腺激素(TSH)、游离甲状腺激素(FT4)、甲状腺过氧化物酶抗体(TPOAb)水平和妊娠结局。方法:2017年6月30日-2018年5月30日本院产前检查孕妇中筛选患有甲状腺功能减退症者120例,选择60例为一般给药组,在孕8周前行L-T4替代治疗;60例为推迟给药组,在孕8周后行L-T4替代治疗;另选同期产前健康健康孕妇60例为对照组。检测不同妊娠期TSH、FT4、TT4及TPOAb水平。统计围生期结局。结果:治疗前,一般给药组与推迟给药组血清TSH、FT4、TT4及TPOAb水平与对照组存在差异(P<0.05),治疗后在孕30周时两给药组血清上述指标与对照组无差异(P>0.05)。一般给药组自然流产、妊娠期糖尿病、胎盘早剥比例低于延迟给药组(P<0.05),但与对照组没有差异(P>0.05);妊娠期高血压、低出生体重儿两给药组及与对照组均无差异(P>0.05);一般给药组子代6月龄、12月龄时Gesell量表评分高于推迟给药组(P<0.05),与对照组无差异(P>0.05)。结论:对甲状腺功能减退症孕妇妊娠早期及早干预,可有效降低围产期不良结局发生几率,保证新生儿的早期发育。  相似文献   
10.
目的探讨131I治疗甲状腺功能亢进症(甲亢)后413例继发甲状腺功能减退症(甲减)发生的影响因素。方法1236例甲亢患者行131I治疗,每克甲状腺组织131I给予剂量为1.85~3.70MBq,并实行剂量个体化。结果1236例甲亢患者继发甲减413例(33.4%),其中94.0%患者发生于第1年,性别与甲减发生率无明显关系,而年龄、甲状腺大小、有无突眼、病程、131I剂量及治疗次数都与甲减发生有明显相关性。结论131I治疗甲亢后甲减发生的影响因素较多,因此临床用药应根据患者病情采取个体化治疗方案。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号