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   4822篇
  免费   331篇
  国内免费   133篇
耳鼻咽喉   129篇
儿科学   93篇
妇产科学   41篇
基础医学   574篇
口腔科学   77篇
临床医学   469篇
内科学   908篇
皮肤病学   80篇
神经病学   367篇
特种医学   140篇
外科学   577篇
综合类   498篇
现状与发展   2篇
一般理论   3篇
预防医学   321篇
眼科学   54篇
药学   403篇
中国医学   128篇
肿瘤学   422篇
  2024年   10篇
  2023年   37篇
  2022年   113篇
  2021年   182篇
  2020年   103篇
  2019年   120篇
  2018年   128篇
  2017年   116篇
  2016年   112篇
  2015年   191篇
  2014年   218篇
  2013年   244篇
  2012年   420篇
  2011年   407篇
  2010年   281篇
  2009年   225篇
  2008年   313篇
  2007年   329篇
  2006年   311篇
  2005年   281篇
  2004年   205篇
  2003年   215篇
  2002年   202篇
  2001年   77篇
  2000年   61篇
  1999年   53篇
  1998年   43篇
  1997年   36篇
  1996年   24篇
  1995年   24篇
  1994年   25篇
  1993年   25篇
  1992年   28篇
  1991年   14篇
  1990年   14篇
  1989年   14篇
  1988年   13篇
  1987年   12篇
  1986年   9篇
  1985年   3篇
  1984年   4篇
  1983年   5篇
  1977年   3篇
  1976年   5篇
  1973年   3篇
  1970年   3篇
  1968年   4篇
  1965年   2篇
  1962年   2篇
  1926年   2篇
排序方式: 共有5286条查询结果,搜索用时 16 毫秒
51.
目的 探究妊娠期妇女体质量自我管理特征及人群差异,为制定针对性干预措施提供参考。方法 采用目的抽样法选取15名孕产妇进行半结构式访谈,通过Colaizzi 7步法分析资料;基于自我管理理论,人工抽取妊娠期妇女体质量自我管理特征构建画像,采用词云与表格形式完成画像的可视化。结果 提取5个特征:基本特征、认知特征、行为特征、社会支持特征、心理调适特征;构建4类妊娠期妇女体质量自我管理的典型画像:自主自律型、无能为力型、放任无为型、盲目实践型。结论 妊娠期妇女体质量自我管理存在较大的群体差异性,可根据不同的用户画像群体特征,给予个性化、精准化的管理方案。  相似文献   
52.
Ischemic acute renal failure is characterized by damages to the proximal straight tubule in the outer medulla. Lesions include loss of polarity, shedding into the tubule lumen, and eventually necrotic or apoptotic death of epithelial cells. It was recently shown that peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) increases keratinocyte survival after an inflammatory reaction. Therefore, whether PPARbeta/delta could contribute also to the control of tubular epithelium death after renal ischemia/reperfusion was tested. It was found that PPARbeta/delta+/- and PPARbeta/delta-/- mutant mice exhibited much greater kidney dysfunction and injury than wild-type counterparts after a 30-min renal ischemia followed by a 36-h reperfusion. Conversely, wild-type mice that were given the specific PPARbeta/delta ligand L-165041 before renal ischemia were completely protected against renal dysfunction, as indicated by the lack of rise in serum creatinine and fractional excretion of Na+. This protective effect was accompanied by a significant reduction in medullary necrosis, apoptosis, and inflammation. On the basis of in vitro studies, PPARbeta/delta ligands seem to exert their role by activating the antiapoptotic Akt signaling pathway and, unexpectedly, by increasing the spreading of tubular epithelial cells, thus limiting potentially their shedding and anoikis. These results point to PPARbeta/delta as a remarkable new target for preconditioning strategies.  相似文献   
53.
Novel 2‐phenyl‐4‐quinolone compounds have potent cytotoxic effects on different human cancer cell lines. In this study, we examined anticancer activity and mechanisms of 20‐fluoro‐6,7‐methylenedioxy‐2‐phenyl‐4‐quinolone (CHM‐1) in human osterogenic sarcoma U‐2 OS cells. CHM‐1‐induced apoptosis was determined by flow cytometric analysis, DAPI staining, Comet assay, and caspase inhibitors. CHM‐1‐inhibited cell migration and invasion was assessed by a wound healing assay, gelatin zymography, and a Transwell assay. The mechanisms of CHM‐1 effects on apoptosis and metastasis signaling pathways were studied using Western blotting and gene expression. CHM‐1 induced G2/M arrest and apoptosis at an IC50 (3 µM) in U‐2 OS cells and caspase‐3, ‐8, and ‐9 were activated. Caspase inhibitors increased cell viability after exposure to CHM‐1. CHM‐1‐induced apoptosis was associated with enhanced ROS generation, DNA damage, decreased ΔΨm levels, and promotion of mitochondrial cytochrome c release. CHM‐1 stimulated mRNA expression of caspase‐3, ‐8, and ‐9, AIF, and Endo G. In addition, CHM‐1 inhibited cell metastasis at a low concentration (<3 µM). CHM‐1 inhibited the cell metastasis through the inhibition of MMP‐2, ‐7, and ‐9. CHM‐1 also decreased the levels of MAPK signaling pathways before leading to the inhibition of MMPs. In summary, CHM‐1 is a potent inducer of apoptosis, which plays a role in the anticancer activity of CHM‐1. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1637–1644, 2009  相似文献   
54.
Adjuvant treatment with aromatase inhibitors (AIs) improves outcomes in postmenopausal women with hormone-sensitive early breast cancer compared with tamoxifen. However, AIs should not be used in premenopausal women because they can paradoxically increase estrogen secretion and may therefore stimulate tumor progression. In perimenopausal women undergoing treatment for breast cancer, it can be difficult to determine true menopausal status because adjuvant chemotherapy, tamoxifen, and gonadotropin-releasing hormone analogues can induce transient (or permanent) ovarian suppression. How can one determine whether these women are truly postmenopausal and therefore candidates for AI therapy? A panel of experts in the field of endocrine therapy in breast cancer met in Dubrovnik, Croatia, on October 23, 2006, to discuss this clinical dilemma. This report summarizes the conclusions and recommendations that arose from this discussion.  相似文献   
55.
56.
腔镜辅助与传统开放甲状腺切除术的对比研究   总被引:1,自引:0,他引:1  
目的 探讨腔镜辅助甲状腺手术的安全性、微创性及美容效果.方法 比较我院行腔镜辅助下甲状腺手术230例,传统开放甲状腺手术204例的两种术式手术时间、术后住院时间、切口美容评分、甲状旁腺损伤、神经损伤、切口感染率和复发率.结果 腔镜组平均手术时间(33±29)min、术后平均住院时间(2±1)d,与开放组相比明显缩短(P值分别为0.025、0.000);术中甲状旁腺损伤(1.30%)、一过性神经损伤(1.74%),与开放组相比均明显降低(P值分别为0.021、0.009);术后美容满意度高(P=0.000);切口感染发生率无明显差别(P=0.270).随访6~30个月,两组复发率无差别(P=0.909).结论 腔镜辅助下甲状腺切除术有极佳的美容效果,手术时间短,术后住院时间短,特别是在降低甲状旁腺损伤,一过性神经损伤方面,具有明显的优势,是一种安全、有效的微创手术.  相似文献   
57.
目的探讨腹腔镜腹腔内补片置入术在腹壁切口疝修补中临床应用价值。方法腹腔镜经腹腔内使用膨化聚四氟乙烯双层补片治疗13例腹壁切口疝。结果13例手术均获成功,手术时间45—120min,平均73min,无手术死亡病例及并发症发生,患者术后8~24h后下床活动,1~2d排气,术后疼痛轻,2~3d后完全缓解,3~7d(平均4d)患者顺利康复出院。随访12~24个月无复发。结论腹腔镜腹壁切口疝修补术安全可靠,具有创伤小、术后康复快、并发症少、不增加手术穿刺孔、可完成联合手术等优点,临床应用前景广阔。  相似文献   
58.
目的 评价腹腔镜下修补治疗十二指肠球部前壁溃疡穿孔的临床应用价值。方法 对我院2003年1月~2004年12月收治的42例青年十二指肠溃疡穿孔病例随机分组,20例接受腹腔镜下修补治疗,22例接受传统开腹修补。结果 两组术后胃肠功能恢复情况、术后使用镇痛药、平均住院时间差异均有显著性(P〈0.05),两组术后均无出血、中转开腹、再穿孔等并发症。结论 腹腔镜下修补治疗青年十二指肠球部前壁溃疡穿孔临床安全可行,应该作为首选方法在临床上推广应用。  相似文献   
59.

Background

Roux-en-Y gastric bypass (RYGB) surgery is an effective therapy for obstructive sleep apnea (OSA). However, little attention has been paid to the treatment goals systematically stratified by sex. The objective of this study was to assess how sex differences affect obesity indices and metabolic outcomes after RYGB surgery.

Methods

A sleep questionnaire was conducted and medical histories were taken. Full-night polysomnography (PSG), anthropometric variables, and blood samples were collected.

Results

Thirty-five consecutive patients with OSA who underwent laparoscopic RYGB surgery were prospectively examined for at least 6 months were included in the study. Significant improvements (p?<?0.01) in sleep parameters (except for micro-arousal), obesity indices, and metabolic outcomes [except low-density lipoprotein in men and high-density lipoprotein (HDL) in women] were obtained in men and women with OSA. Men had higher baseline triglyceride (TG) (p?<?0.01) and lower HDL levels (p?<?0.01) but a larger neck circumference (NC) (p?=?0.03) at follow-up than did women. However, only TG in men improved more than in women (p?=?0.02).

Conclusions

Sleep parameters, obesity indices, and metabolic outcomes after RYGB surgery were of similar magnitude in women and men with OSA. Alleviating sleep and obesity problems was correlated with metabolic outcomes in men and women.
  相似文献   
60.
目的:探讨梗阻型轻症急性胆源性胰腺炎(MABP)的最佳治疗方案。方法:回顾性分析2008—2014年收治的132例梗阻型MABP患者的临床资料。其中35例行以内镜逆行胆胰管造影为基础的微创治疗(内镜组),43例行腹腔镜下胆囊切除、胆总管探查术(腹腔镜组),54例行开腹手术(开腹组)。比较各组的相关临床指标。结果:内镜组、腹腔镜组、开腹组间的腹痛缓解时间(3.31d vs.3.84d vs.7.65d)、白细胞恢复正常时间(4.20d vs.5.35d vs.8.72d)差异均有统计学意义(均P0.05);内镜组与腹腔镜组的血淀粉酶恢复正常时间(3.26d vs.3.53d)、住院时间(9.49d vs.9.30d)差异无统计学意义(均P0.05),但均短于开腹组(4.35d、9.30d)(均P0.05)。3组的治愈率均为100%,均无死亡病例,并发症发生率差异无统计学意义(P0.05);内镜组术后1年内胰腺炎复发率(42.86%)明显高于腹腔镜组(0.00%)和开腹组(1.85%)(均P0.05),但后两组间差异无统计学意义(P0.05)。结论:对于梗阻型MABP,在大多数情况下,腹腔镜途径是解除胆道梗阻的首选方法。  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