全文获取类型
收费全文 | 23827篇 |
免费 | 1909篇 |
国内免费 | 476篇 |
专业分类
耳鼻咽喉 | 834篇 |
儿科学 | 305篇 |
妇产科学 | 448篇 |
基础医学 | 2207篇 |
口腔科学 | 248篇 |
临床医学 | 2430篇 |
内科学 | 2771篇 |
皮肤病学 | 330篇 |
神经病学 | 318篇 |
特种医学 | 1281篇 |
外国民族医学 | 7篇 |
外科学 | 4841篇 |
综合类 | 3318篇 |
现状与发展 | 2篇 |
预防医学 | 747篇 |
眼科学 | 91篇 |
药学 | 1293篇 |
14篇 | |
中国医学 | 200篇 |
肿瘤学 | 4527篇 |
出版年
2024年 | 28篇 |
2023年 | 363篇 |
2022年 | 640篇 |
2021年 | 980篇 |
2020年 | 923篇 |
2019年 | 808篇 |
2018年 | 846篇 |
2017年 | 818篇 |
2016年 | 918篇 |
2015年 | 920篇 |
2014年 | 1668篇 |
2013年 | 1458篇 |
2012年 | 1419篇 |
2011年 | 1506篇 |
2010年 | 1294篇 |
2009年 | 1180篇 |
2008年 | 1279篇 |
2007年 | 1242篇 |
2006年 | 1103篇 |
2005年 | 957篇 |
2004年 | 826篇 |
2003年 | 701篇 |
2002年 | 570篇 |
2001年 | 501篇 |
2000年 | 409篇 |
1999年 | 366篇 |
1998年 | 301篇 |
1997年 | 247篇 |
1996年 | 193篇 |
1995年 | 182篇 |
1994年 | 198篇 |
1993年 | 140篇 |
1992年 | 111篇 |
1991年 | 151篇 |
1990年 | 112篇 |
1989年 | 92篇 |
1988年 | 90篇 |
1987年 | 99篇 |
1986年 | 84篇 |
1985年 | 87篇 |
1984年 | 81篇 |
1983年 | 45篇 |
1982年 | 61篇 |
1981年 | 42篇 |
1980年 | 36篇 |
1979年 | 32篇 |
1978年 | 30篇 |
1977年 | 24篇 |
1976年 | 12篇 |
1975年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
目的:分析超声内镜引导下经支气管针吸活检(endobronchial ultrasound-guided transbronchial needle aspiration,EBUS-TBNA)术中肿大纵隔淋巴结的超声图像特点,探讨EBUS-TBNA超声内镜对纵隔淋巴结良恶性的鉴别诊断价值,以期提高EBUS-TBNA对纵隔淋巴结恶性病变的活检率。方法:回顾性分析2014年10月至2018年11月行EBUS-TBNA患者的超声内镜图像。我们使用以下EBUS超声内镜特征来预测淋巴结的良恶:回声,长轴长度,短轴长度,纵横比,形态,边界,淋巴门有无,淋巴结内血流信号分级。将超声检查结果与最终病理结果或临床随访结果进行比较。采用SPSS 20.0软件进行统计学分析,采用logistic回归分析评价肿大淋巴结EBUS-TBNA超声内镜下的特征与良恶性的相关性,以 P<0.05 为标准判定差异有统计学意义。结果:对130例纵隔淋巴结肿大患者的227个淋巴结进行回顾性分析,67.4%的肿大淋巴结被证实为恶性转移。Logistic回归分析显示回声、长轴及短轴的长度、正常淋巴门结构的消失是诊断恶性淋巴结的独立预测因素。结论:纵隔恶性淋巴结具有一定的超声特征,可以通过这些超声特征提高EBUS-TBNA对纵隔恶性淋巴结的检出率。 相似文献
12.
R.D. Olmos R.C. de Figueiredo E.M. Aquino P.A. Lotufo I.M. Bensenor 《Brazilian journal of medical and biological research》2015,48(8):751-758
Thyroid diseases are common, and use of levothyroxine is increasing worldwide. We
investigated the influence of gender, race and socioeconomic status on the diagnosis
and treatment of thyroid disorders using data from the Brazilian Longitudinal Study
of Adult Health (ELSA-Brasil), a multicenter cohort study of civil servants (35-74
years of age) from six Brazilian cities. Diagnosis of thyroid dysfunction was by
thyrotropin (TSH), and free thyroxine (FT4) if TSH was altered, and the use of
specific medications. Multivariate logistic regression models were constructed using
overt hyperthyroidism/hypothyroidism and levothyroxine use as dependent variables and
sociodemographic characteristics as independent variables. The frequencies of overt
hyper- and hypothyroidism were 0.7 and 7.4%, respectively. Using whites as the
reference ethnicity, brown, and black race were protective for overt hypothyroidism
(OR=0.76, 95%CI=0.64-0.89, and OR=0.53, 95%CI=0.43-0.67, respectively, and black race
was associated with overt hyperthyroidism (OR=1.82, 95%CI=1.06-3.11). Frequency of
hypothyroidism treatment was higher in women, browns, highly educated participants
and those with high net family incomes. After multivariate adjustment, levothyroxine
use was associated with female gender (OR=6.06, 95%CI=3.19-11.49) and high net family
income (OR=3.23, 95%CI=1.02-10.23). Frequency of hyperthyroidism treatment was higher
in older than in younger individuals. Sociodemographic factors strongly influenced
the diagnosis and treatment of thyroid disorders, including the use of
levothyroxine. 相似文献
13.
Sentinel lymph node biopsy for 102 patients with primary cutaneous melanoma at a single Japanese institute 下载免费PDF全文
Masaki Otsuka Osamu Yamasaki Tatsuya Kaji Keiji Iwatsuki Kenji Asagoe 《The Journal of dermatology》2015,42(10):954-961
Sentinel lymph node biopsy (SLNB) is a widely accepted standard procedure for patients with clinically localized melanoma. Melanoma prevalence and Clark's subtype differ between Asians and Caucasians. Here, we evaluated our experience on SLNB for cutaneous melanoma in a Japanese population. SLNB was performed for patients with melanoma between July 2000 and June 2014. We retrospectively analyzed 102 patients regarding association of clinicopathological features with sentinel lymph node (SLN) status, melanoma‐specific survival (MSS) and disease‐free survival (DFS). A positive SLN was significantly associated with primary Breslow thickness. Compared with 43 patients with negative SLN, 59 patients with positive SLN had significantly shorter MSS (5‐year survival rate, 94.3% vs 63.2%; P = 0.0002) and DFS (5‐year survival rate, 92.7% vs 63.4%; P = 0.0004). According to our subgroup analyses, nine patients with positive non‐SLN had significantly shorter MSS compared with 32 patients with negative non‐SLN (5‐year survival rate, 32.4% vs 68.5%; P = 0.0273). The survival of 51 Japanese patients with acral lentiginous melanoma (ALM) was not inferior to the survival of patients with other Clark's subtype. Breslow thickness is an important factor for both MSS and DFS, and the status of SLN is the most predictive prognostic factor in Japanese patients with clinically localized melanomas, as in case of Caucasians. Features of ALM may be different between Asians and Caucasians. 相似文献
14.
目的 对促甲状腺素(TSH) 抑制治疗期间的分化型甲状腺癌(DTC)患者进行膳食调查,为对患者进行个性化膳食指导及营养干预研究提供参考依据。方法 从湖南省肿瘤医院甲状腺内科的门诊患者中收集行TSH抑制治疗的DTC患者,根据抑制治疗副作用危险分层标准,收集低、中、高危患者各200例,共600例患者作为研究对象。对所有入选病例进行膳食调查:一年食物摄入频率和3天24小时回顾法膳食调查。结果 TSH抑制治疗的DTC患者整体人群膳食摄入不足且膳食结构不合理;整体人群畜肉类摄入过多,鱼类及水产品、蛋、奶、豆、蔬菜、水果则摄入过少;整体人群脂类、碳水化合物、维生素E摄入量基本达到要求;蛋白质、膳食纤维、钙、铁、锌、硒、维生素A、维生素B1、维生素B2、维生素C、烟酸摄入明显不足;碘摄入基本符合要求;低、中、高危组膳食摄入不足率分别是21.0%、8.0%、11.5%;中危组畜肉类摄入最多,碘摄入有0.5%的患者超标;高危组牛奶摄入最少。结论 TSH抑制治疗的DTC患者膳食结构不合理及多种营养素摄入不足,在临床工作中应加强对整体人群的营养教育及针对性的干预,以降低TSH抑制治疗对心血管系统及影响骨代谢的风险。 相似文献
15.
目的 探究原发灶定位与甲状腺乳头状微小癌(PTMC)颈侧区淋巴结转移的关系,评估超声检查预测颈侧区淋巴结转移的准确率。方法 回顾性分析2014年1月至2015年12月天津医科大学肿瘤医院收治的134例PTMC病人的临床资料,均行中央区淋巴结清扫+改良颈侧区淋巴结清扫。依据超声定位分组,分析癌灶位置与颈侧区淋巴结转移的关系。结果 颈侧各分区淋巴结转移发生率分别为:Ⅱ区30.6%、Ⅲ区50.7%、Ⅳ区57.5%、Ⅴ区11.3%。癌灶位于中上极者颈侧区淋巴结转移发生率高于癌灶位于下极者(89.7% vs. 75.7%,P=0.038),靠近外侧者较内侧者更易出现颈侧区淋巴结转移(93.7% vs. 81.4%,P=0.049)。超声检查判定Ⅱ、Ⅲ、Ⅳ、Ⅴ区淋巴结转移的敏感度分别为43.9%、85.3%、85.7%、14.3%;特异度为91.4%、57.6%、35.1%、99.1%。超声预测Ⅲ、Ⅳ区淋巴结转移敏感度较高,Ⅱ、Ⅴ区淋巴结转移特异度较高。结论 癌灶位置与甲状腺微小癌颈侧区淋巴结转移密切相关,超声可为临床确定颈侧区淋巴结的清扫范围提供依据。 相似文献
16.
《European journal of surgical oncology》2022,48(2):326-332
BackgroundIn patients with melanoma, sentinel lymph node (SLN) status is pivotal for treatment decisions. Current routine for SLN detection combines Technetium99m (Tc99) lymphoscintigraphy and blue dye (BD). The primary aim of this study was to examine the feasibility of using a low dose of superparamagnetic iron oxide (SPIO) injected intracutaneously to detect and identify the SLN, and the secondary aim was to investigate if a low dose of SPIO would enable a preoperative MRI-evaluation of SLN status.MethodsPatients with melanoma of the extremities were eligible. Before surgery, a baseline MRI of the nodal basin was followed by an injection of a low dose (0.02–0.5 mL) of SPIO and then a second MRI (SPIO-MRI). Tc99 and BD was used in parallel and all nodes with a superparamagnetic and/or radioactive signal were harvested and analyzed.ResultsFifteen patients were included and the SLNB procedure was successful in all patients (27 SLNs removed). All superparamagnetic SLNs were visualized by MRI corresponding to the same nodes on scintigraphy. Micrometastatic deposits were identified in four SLNs taken from three patients, and SPIO-MRI correctly predicted two of the metastases. There was an association between MRI artefacts in the lymph node and the dose SPIO given.DiscussionIt is feasible to detect SLN in patients with melanoma using a low dose of SPIO injected intracutaneously compared with the standard dual technique. A low dose of SPIO reduces the lymph node MRI artefacts, opening up for a non-invasive assessment of SLN status in patients with cancer. 相似文献
17.
《European journal of surgical oncology》2022,48(4):783-788
BackgroundInvestigation of lymph node micrometastasis (mN) of gastric cancer has been focused on either T1 disease or T1-4N0 disease. Yet, it is unclear whether standard management algorithm toward poorly differentiated gastric cancer (PDGC) is more vulnerable to existence of mN, given its inherently biological aggressiveness, as compared with other histological types.Patients and methodsA surgical series (n = 3456) of gastric cancer categorized by histological differentiation was enrolled to analyze survival stratification. Of them, a cohort of T1-T4 N0 PDGC (n = 100) were subjected to cytokeratin immunohistochemistry, a surrogate of mN.ResultsCancer-specific survival by AJCC8 staging system could be nicely differentiated in both well-/moderately differentiated and signet ring cell types, while those between stage IA versus IB (p = 0.105), and stage IB versus IIA (p = 0.141) in PDGC could not. Thirteen (13%) out of 100 node-negative PDGC cases exhibited mN, with 5, 2, 5 and 1 cases occurring in T1, T2, T3, and T4 stage, respectively, without identifiable contributing factors. Prognostic performance of AJCC8 working upon PDGC became more discriminative by incorporating mN, as hazard ratio of stage IIIC referenced to stage IA increased from 43 to 78.ConclusionDefective discriminative survival of PDGC by standard staging algorithm prompted us to survey mN occurring in T1-T4N0 PDGC. The prognostic performance of AJCC8 working upon PDGC was enhanced by incorporating mN. As so, we recommend documentation of mN exclusively on node-negative PDGC that helps unveil stage migration phenomenon and switch to appropriate adjuvant therapy in need. 相似文献
18.
目的 探讨甲状腺功能减退与子宫内膜癌(EC)的关系及EC患者癌组织分化程度和雌激素受体(ER)、孕激素受体(PR)的表达与甲状腺功能之间的关系。方法 选取2015年1月—2018年7月我院收治的EC患者113例,同时随机选取年龄与EC组相匹配的此段时间内我院健康体检的妇女156例作为对照组,检测血清促甲状腺激素(TSH)、甲状腺激素(FT4)。比较两组间甲状腺功能减退的患病率,并利用免疫组织化学法测定EC患者手术切除标本的癌组织中ER、PR的表达,分析EC患者癌组织分化程度及癌组织中ER、PR的表达与甲状腺功能之间的相关性。结果 EC组甲状腺功能减退的患病率较对照组高(P<0.000)。低分化EC患者的TSH高于中分化EC患者(P=0.025)。EC手术切除标本的癌组织中ER、PR阳性与阴性患者的TSH、FT4差异无统计学意义(P>0.05)。结论 甲状腺功能减退与EC具有相关性。 相似文献
19.
20.