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   8359篇
  免费   580篇
  国内免费   329篇
耳鼻咽喉   23篇
儿科学   104篇
妇产科学   75篇
基础医学   303篇
口腔科学   34篇
临床医学   584篇
内科学   1559篇
皮肤病学   47篇
神经病学   27篇
特种医学   280篇
外国民族医学   3篇
外科学   2755篇
综合类   783篇
预防医学   241篇
眼科学   2篇
药学   424篇
  4篇
中国医学   82篇
肿瘤学   1938篇
  2024年   17篇
  2023年   127篇
  2022年   297篇
  2021年   341篇
  2020年   335篇
  2019年   286篇
  2018年   293篇
  2017年   247篇
  2016年   293篇
  2015年   292篇
  2014年   605篇
  2013年   483篇
  2012年   467篇
  2011年   523篇
  2010年   451篇
  2009年   496篇
  2008年   465篇
  2007年   500篇
  2006年   439篇
  2005年   342篇
  2004年   253篇
  2003年   223篇
  2002年   170篇
  2001年   164篇
  2000年   139篇
  1999年   133篇
  1998年   107篇
  1997年   89篇
  1996年   92篇
  1995年   74篇
  1994年   57篇
  1993年   42篇
  1992年   53篇
  1991年   43篇
  1990年   38篇
  1989年   41篇
  1988年   21篇
  1987年   30篇
  1986年   26篇
  1985年   41篇
  1984年   29篇
  1983年   19篇
  1982年   18篇
  1981年   12篇
  1980年   12篇
  1979年   10篇
  1978年   8篇
  1976年   5篇
  1975年   6篇
  1973年   5篇
排序方式: 共有9268条查询结果,搜索用时 31 毫秒
1.
Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy.  相似文献   
2.
目的采用图像融合技术获得T2WI与T2WI-FS的融合图像,评估其在肛瘘及肛周结构显示中的优势。 方法2016年6月至2018年6月,前瞻性选择中山大学附属第一医院29例肛瘘患者进行肛管磁共振(MR)检查,采用图像融合技术获取T2WI与T2WI-FS的融合图像T2WI-Fusion,利用Fisher score算法计算瘘管及肛门括约肌的组织间分辨力Fisher值、脂肪与肛门括约肌间的Fisher值,评估融合图像中瘘管及肛周结构的显示情况。采用改进的双刺激连续质量量表(DSCQS)对T2WI-FS、T2WI、增强3D-VIBE和T2WI-Fusion序列图像进行主观图像质量评价。 结果29例患者均成功获得T2WI与T2WI-FS的融合图像T2WI-Fusion。T2WI-Fusion、T2WI瘘管与括约肌间Fisher均值分别为6.46、3.31,T2WI-Fusion图像对瘘管的显示优于T2WI序列图像(P<0.001)。T2WI-Fusion、T2WI-FS脂肪与括约肌间Fisher均值分别为10.61、2.45,T2WI-Fusion图像对括约肌的显示优于T2WI-FS序列图像(P<0.001)。T2WI-Fusion对瘘管与括约肌的图像质量评价总评分均高于T2WI-FS、T2WI、增强3D-VIBE序列(P<0.001)。 结论MRI图像融合技术同时具备T2WI及T2WI-FS的优势,无需增加扫描序列及扫描时间,且操作简单,花费时间短,显著提高病变及肛周解剖结构的对比度和图像质量。  相似文献   
3.
4.
目的应用免疫组织化学染色的方法检测硒蛋白P在直肠癌组织中的表达,以探讨其与直肠癌发生的关系及临床意义。方法收集山西大医院2013年6月至2014年5月间行手术治疗并经病理证实的60例直肠癌组织、40例直肠腺瘤组织、40例正常直肠组织,应用SABC法检测上述组织中硒蛋白P的表达情况,结果依据阳性细胞百分率和染色强度进行评价,三组间样本率的比较采用无序行×列表?2检验(α=0.05),两组间样本率的比较采用独立样本?2检验(α=0.016 7),硒蛋白的表达与直肠癌临床病理参数的关系采用四格表?2检验(α=0.05)进行分析。结果硒蛋白P在正常直肠组织、直肠腺瘤组织、直肠癌组织中的表达阳性率分别为82.5%(33/40)、70.0%(28/40)、45.0%(27/60),组间差异有统计学意义(?2=15.680,P<0.001),癌组织与正常组织、腺瘤组织间差异显著(?2=14.063,P<0.001;?2=6.061,P=0.015);硒蛋白的表达与肿瘤大小、是否浸润浆膜有关(P<0.05),与性别、年龄、淋巴结有无转移、肿瘤细胞分化程度、TNM分期无关(P>0.05)。结论硒蛋白在直肠癌中低表达,对直肠癌的发生发展具有重要作用,有望为直肠癌的治疗提供新思路。  相似文献   
5.
AIM: To establish the association between lymph node involvement and the response to neoadjuvant therapy in locally advanced rectal cancer.METHODS: Data of 130 patients with mid and low locally advanced rectal adenocarcinoma treated with neoadjuvant chemoradiation followed by radical surgery over a 5-year period were reviewed. Tumor staging was done by endorectal ultrasound and/or magnetic resonance imaging. Tumor response to neoadjuvant therapy was determined by T-downstaging and tumor regression grading (TRG). Pathologic complete response (pCR) is defined as the absence of tumor cells in the surgical specimen (ypT0N0). The varying degrees TRG were classified according to Mandard’s scoring system. The evaluation of the response is based on the comparison between previous clinico-radiological staging and the results of pathological evaluation. χ2 and Spearman’s correlation tests were used for the comparison of variables.RESULTS: Pathologic complete response (pCR, ypT0N0, TRG1) was observed in 19 cases (14.6%), and other 18 (13.8%) had only very few residual malignant cells in the rectal wall (TRG2). T-downstaging was found in 63 (48.5%). Mean lymph node retrieval was 9.4 (range 0-38). In 37 cases (28.5%) more than 12 nodes were identified in the surgical specimen. Preoperative lymph node involvement was seen in 77 patients (59.2%), 71 N1 and 6 N2. Postoperative lymph node involvement was observed in 41 patients (31.5%), 29 N1 and 12 N2, while the remaining 89 were N0 (68.5%). In relation to ypT stage, we found nodal involvement of 9.4% in ypT0-1, 22.2% in ypT2 and 43.7% in ypT3-4. Of the 37 patients considered “responders” to neoadjuvant therapy (TRG1 and 2), there were only 4 N+ (10.8%) and the remainder N0 (89.2%). In the “non responders” group (TRG 3, 4 and 5), 37 cases were N+ (39.8%) and 56 (60.2%) were N0 (P < 0.001).CONCLUSION: Response to neoadjuvant chemoradiation in rectal cancer is associated with lymph node involvement.  相似文献   
6.
BackgroundThe association of treatment volume and oncological outcome of rectal cancer patients undergoing multidisciplinary treatment is subject of an ongoing debate. Prospective data on long-term local control and overall survival (OS) are not available so far. This study investigated the long-term influence of hospital and surgeon volume on local recurrence (LR) and OS in patients with locally advanced rectal cancers.MethodsIn a post-hoc analysis of the randomized phase III CAO/ARO/AIO-94 trial after a follow-up of more than 10 years, 799 patients with stage II/III rectal cancers were evaluated. LR-rates and OS were stratified by hospital recruitment volume (≤20 vs. 21–90 vs. >90 patients) and by surgeon volume (≤10 vs. 11–50 vs. >50 procedures).ResultsPatients treated in high-volume hospitals had a longer OS than those treated in hospitals with medium or low treatment volume (p = 0.03). The surgeon volume was adversely associated with LR (p = 0.01) but had no influence on overall survival. The positive effect of neoadjuvant chemoradiation (CRT) on local control was the strongest in patients being operated by medium-volume surgeons, less in patients being operated by high-volume surgeons and missing in those being operated by low-volume surgeons.ConclusionsPatients with locally advanced rectal cancers might benefit from treatment in specialized high-volume hospitals. In particular, the surgeon volume had significant influence on long-term local tumour control. The effect of neoadjuvant CRT on local tumour control may likewise depend on the surgeon volume.  相似文献   
7.
目的介绍腹腔镜下经腹部和后矢状路联合手术治疗直肠肛门手术后复发性直肠尿道瘘和直肠阴道瘘。方法5例术后多次复发性直肠尿道瘘或直肠阴道瘘患儿,男3例,女2例,年龄3~13岁。腹部在腹腔镜下游离结肠,远端尽可能从骶前向盆腔分离肠管,近端肠管游离保证正常结肠能无张力拖至肛门处吻合。低位盆腔肠管分离通过后矢状位切口(肛缘后上1cm),正中切开直肠后壁,直肠内剥离黏膜至齿状线,直视下修补瘘口,近端切断结肠,将正常结肠拖出与肛门吻合。结果所有患儿排便功能良好,仅1例有轻度污粪,未见瘘管复发。结论腹腔镜下经腹部和后矢状路游离结肠、直肠,创伤小,视野清晰,避开了粘连紧密的瘘管分离,完整结肠拖出避免了瘘管的复发,后矢状路直肠切开能直视下显示并修补瘘管。  相似文献   
8.
手术前后提肛运动对直肠癌保肛术后大便失禁的影响   总被引:1,自引:0,他引:1  
  相似文献   
9.
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   
10.
低位直肠癌保留神经的腹膜外侧方扩大清扫的效果分析   总被引:1,自引:1,他引:0  
目的 探讨低位直肠癌保留神经的腹膜外侧方扩大清扫对患者术后生存率、排尿功能和性功能的影响。方法 回顾性分析我院1996年1月至2000年6月期间收治的392例进展期低位直肠癌实施保留神经的根治性切除术患者的临床资料,其中行腹腔内清扫173例,腹腔内加腹膜外侧方清扫219例,2组患者在年龄、性别、浸润肠壁深度及肿瘤病理组织学类型方面差异无统计学意义。结果 腹腔内加腹膜外侧方清扫组侧方淋巴结转移率为17.8%(39/219),侧方盆壁非连续性癌灶转移率为5,9%(13/219)。术后发生排尿功能障碍:腹腔内清扫组7例(4.0%),腹腔内加腹膜外侧方清扫组113例(51.6%),2组比较差异有统计学意义(P〈0.01);性功能障碍:腹腔内清扫组93例男性患者中有12例(12.9%),腹腔内加腹膜外侧方清扫组119例男性患者中有62例(52.1%),2组比较差异有统计学意义(P〈0.01);局部复发率:腹腔内清扫组为16.2%(28/173),腹腔内加腹膜外侧方清扫组为9.6%(21/219),2组比较差异有统计学意义(P〈0.05);5年生存率:腹腔内清扫组为49.1%(85/173),腹腔内加腹膜外侧方清扫组为59.4%(130/219),2组比较差异有统计学意义(P〈0.05)。结论 低位直肠癌保留神经的腹膜外侧方扩大清扫,可以减少局部复发,提高患者5年生存率,但也会影响患者术后排尿和男性性机能。  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