全文获取类型
收费全文 | 75466篇 |
免费 | 6137篇 |
国内免费 | 3909篇 |
专业分类
耳鼻咽喉 | 2001篇 |
儿科学 | 280篇 |
妇产科学 | 2391篇 |
基础医学 | 3979篇 |
口腔科学 | 533篇 |
临床医学 | 8527篇 |
内科学 | 5368篇 |
皮肤病学 | 349篇 |
神经病学 | 561篇 |
特种医学 | 4806篇 |
外国民族医学 | 52篇 |
外科学 | 15720篇 |
综合类 | 13519篇 |
现状与发展 | 3篇 |
预防医学 | 1925篇 |
眼科学 | 231篇 |
药学 | 3384篇 |
12篇 | |
中国医学 | 212篇 |
肿瘤学 | 21659篇 |
出版年
2025年 | 6篇 |
2024年 | 595篇 |
2023年 | 842篇 |
2022年 | 1614篇 |
2021年 | 2065篇 |
2020年 | 2094篇 |
2019年 | 1746篇 |
2018年 | 1559篇 |
2017年 | 1890篇 |
2016年 | 2490篇 |
2015年 | 2147篇 |
2014年 | 4274篇 |
2013年 | 3706篇 |
2012年 | 4886篇 |
2011年 | 5439篇 |
2010年 | 4751篇 |
2009年 | 4569篇 |
2008年 | 4511篇 |
2007年 | 5008篇 |
2006年 | 4736篇 |
2005年 | 4591篇 |
2004年 | 3584篇 |
2003年 | 3141篇 |
2002年 | 2698篇 |
2001年 | 2580篇 |
2000年 | 2091篇 |
1999年 | 1573篇 |
1998年 | 1350篇 |
1997年 | 1191篇 |
1996年 | 702篇 |
1995年 | 603篇 |
1994年 | 518篇 |
1993年 | 290篇 |
1992年 | 260篇 |
1991年 | 219篇 |
1990年 | 196篇 |
1989年 | 178篇 |
1988年 | 177篇 |
1987年 | 143篇 |
1986年 | 130篇 |
1985年 | 101篇 |
1984年 | 52篇 |
1983年 | 34篇 |
1982年 | 48篇 |
1981年 | 40篇 |
1980年 | 32篇 |
1979年 | 19篇 |
1978年 | 16篇 |
1977年 | 11篇 |
1976年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
PURPOSE: Because human prostatic fluid contributes almost 50% of the volume of seminal plasma and this fluid contains unique prostatic metabolites such as citrate, which are markedly altered during tumorigenesis, we investigated high resolution H nuclear magnetic resonance (NMR) spectroscopy of unprocessed human seminal plasma as a rapid, noninvasive diagnostic tool for prostate adenocarcinoma. MATERIALS AND METHODS: Semen and prostatic massage samples from control and tumor bearing subjects were stored frozen at -20C and thawed prior to water suppressed NMR analysis. We found that freezing produced no significant alterations in the semen NMR spectra. Quantitative NMR spectroscopy was performed by first calibrating the water suppression data acquisition sequence with a series of standard samples containing known amounts of citrate within the physiological range. RESULTS: Well resolved citrate resonances from the seminal plasma of 3 control subjects with prostate specific antigen (PSA) less than 1 ng/ml were integrated to give concentrations of 97 to 178 mM. Semen from a 47-year-old man with benign prostatic hyperplasia and a PSA of 5.5 ng/ml contained 156 mM citrate. In contrast, seminal plasma from 2 patients with prostate cancer, including a 46-year-old man with Gleason grade 8 and PSA 45.2 ng/ml, and a 64-year-old man with grade 6 and PSA 13.0 ng/ml, revealed citrate NMR signals corresponding to a concentration of only 28 and 24 mM, respectively. Spectra from prostatic massage fluid from a normal 23-year-old volunteer showed a citrate of 483 mM, while massage fluid from a 56-year-old patient with Gleason grade 4 cancer showed a citrate of only 1.35 mM. CONCLUSIONS: To our knowledge this study is the first to use high resolution NMR of semen to diagnose prostate cancer. Given the known effects of adenocarcinoma on prostate metabolism, the study indicates that high resolution H NMR can be used to measure citrate in seminal fluid, potentially providing a new, rapid, noninvasive screening method. 相似文献
992.
Monitoring intravesical therapy for superficial bladder cancer using fluorescence in situ hybridization 总被引:6,自引:0,他引:6
Kipp BR Karnes RJ Brankley SM Harwood AR Pankratz VS Sebo TJ Blute MM Lieber MM Zincke H Halling KC 《The Journal of urology》2005,173(2):401-404
PURPOSE: We evaluated fluorescence in situ hybridization (FISH) for assessing the response to therapy in patients with superficial bladder cancer receiving bacillus Calmette-Guerin or other intravesical therapies. MATERIALS AND METHODS: A total of 37 patients receiving intravesical therapy for superficial bladder cancer were enrolled in this study. Urine specimens were collected for FISH analysis just prior to the first intravesical therapy in 31 cases and just prior to or within 2 months following the last intravesical therapy in 37. FISH was done using the UroVysion probe set (Abbott Laboratories, Abbott Park, Illinois) with results considered positive if 5 or more cells demonstrated polysomy. Biopsy, cystoscopy and/or cytology results were then compared to FISH results to evaluate the usefulness of the test for monitoring intravesical therapy. RESULTS: Of the patients 25 had a negative and 12 had a positive post-therapy FISH result. All 12 patients with a positive post-therapy FISH result had tumor recurrence, while tumor recurrence was observed in 13 of the 25 with a negative post-therapy FISH result (HR 4.6, 95% CI 1.9 to 11.1, p <0.001). Of the patients with tumor recurrence 7 of 12 with a positive post-therapy FISH result had muscle invasive tumor and 2 of 25 with a negative post-therapy FISH result had muscle invasive tumor (HR 9.4, 95% CI 1.9 to 45.3, p = 0.001). CONCLUSIONS: FISH appears to be useful for monitoring patients with superficial bladder cancer for the response to intravesical therapy. Patients with a positive FISH result at the end of treatment are at high risk for progression to muscle invasive bladder cancer. 相似文献
993.
Pavlovich CP Grubb RL Hurley K Glenn GM Toro J Schmidt LS Torres-Cabala C Merino MJ Zbar B Choyke P Walther MM Linehan WM 《The Journal of urology》2005,173(5):1482-1486
PURPOSE: Herein we describe the evaluation and management of renal tumors in Birt-Hogg-Dubé (BHD), an autosomal dominant disorder predisposing to cutaneous fibrofolliculomas, pulmonary cysts, spontaneous pneumothorax and renal tumors. MATERIALS AND METHODS: A total of 124 affected individuals underwent comprehensive clinical evaluation, including body computerized tomography, to determine cutaneous, pulmonary and renal manifestations of BHD. Of these individuals 14 had their renal tumors managed at our institution. RESULTS: Of the 124 BHD affected individuals 34 (27%) had renal tumors of various histologies, most commonly hybrid oncocytic tumor and chromophobe renal carcinoma. Average age at renal tumor detection was 50.4 years and multiple tumors were found in a majority of patients. Some patients with renal tumors were identified that did not have the characteristic cutaneous hallmarks of BHD. In 4 of the 14 patients treated at our institution small (less than 3 cm) renal tumors were observed, while 10 others underwent a total of 12 renal procedures, including 4 radical and 8 partial nephrectomies. At a median of 38 months of followup 5 of these 10 patients remained free of disease, 3 had small renal tumors and 2 died of metastatic renal cancer. CONCLUSIONS: Patients with BHD are at risk for multiple renal tumors that are often malignant and can metastasize. Individuals at risk or affected by BHD should be radiographically screened for renal tumors at periodic intervals and they are best treated with nephron sparing surgical approaches. Genetic testing for this syndrome is now available. 相似文献
994.
Glasgow SC Yu J Carvalho LP Shannon WD Fleshman JW McLeod HL 《British journal of cancer》2005,92(2):259-264
Patients with mucinous colorectal cancer generally have worse prognoses than those with the nonmucinous variety. The reason for this disparity is unclear, but may result from a differential response to adjuvant chemotherapy. We examined known molecular markers for response to common chemotherapy in these two histological subtypes. In all, 21 patients with mucinous and 30 with nonmucinous Dukes C colorectal cancer were reviewed for demographic data and outcome. Total RNA from the tumours and adjacent normal mucosa was isolated and reverse transcribed. Quantitative expression levels of drug pathway genes were determined using TaqMan RT-PCR (5-fluorouracil (5-FU): TYMS, DPYD, ECGF1; oxaliplatin: GSTP1 (glutathione S-transferase pi), ERCC1 and 2; irinotecan: ABCB1, ABCG2, CYP3A4, UGT1A1, CES2, TOP1). Mucinous tumours significantly overexpressed both TYMS and GSTP1 relative to nonmucinous tumours and patient-matched normal mucosa. No significant differences in expression of the remaining markers were found. Mean follow-up was 20 months; 17 patients had recurrent disease. Among patients receiving 5-FU, those with mucinous tumours experienced shorter disease-free survival (DFS) than those with nonmucinous tumours (median DFS 13.8 vs 46.5 months, P=0.053). Mucinous colorectal cancer overexpresses markers of resistance to 5-FU and oxaliplatin. Likewise, DFS may be decreased in patients with mucinous tumours who receive 5-FU. The presence of mucin should be carefully evaluated in developmental trials of new agents for treating colorectal cancer. 相似文献
995.
Fever therapy revisited 总被引:2,自引:0,他引:2
Hobohm U 《British journal of cancer》2005,92(3):421-425
The phenomenon of spontaneous regression and remission from cancer has been observed by many physicians and was described in hundreds of publications. However, suggestive clues on cause or trigger are sparse and not substantiated by much experimental evidence. In this review, literature is surveyed and summarised and possible causes are discussed. At least in a larger fraction of cases a hefty feverish infection is linked with spontaneous regression in time and is investigated as putative trigger. Epidemiological and immunological evidence is put into perspective. An online forum to discuss the possible application of fever therapy in the future can be accessed at http://bioinfo.tg.fh-giessen.de/fever-and-cancer. 相似文献
996.
EB病毒编码潜伏膜蛋白1通过转录因子c-Jun和Ets1间信息交流调控鼻咽癌中基质金属蛋白酶9的表达 总被引:5,自引:0,他引:5
目的 探讨在EBV -LMP1作用下,基质金属蛋白酶9(MMP 9)启动子区相邻的AP 1( 5 33)和Ets( 5 4 0 )结合位点对其转录活化的影响,并确定LMP1可通过c -Jun和Ets1间信息交流(cross -talk)调控鼻咽癌细胞中MMP 9的表达。方法 应用定点突变技术,在野生型MMP- 9 -CAT质粒的基础上,建立MMP- 9启动子区相邻Ets( 5 4 0 )结合位点和AP- 1 (- 5 33)结合位点单独突变体和共同突变体;在四环素调控表达LMP1的鼻咽癌细胞系L7中,比较LMP1对这些突变体报道基因活性的影响。通过针对c- Jun、Ets1的硫代反义寡核苷酸进行阻断,采用GelatinZymography观察c -Jun、Ets1及其cross- talk对LMP1介导的MMP 9表达的影响。结果 与野生型MMP -9 -CAT质粒比较,突变体的报道基因活性均降低(P <0 .0 1 ) ,以MMP- 9 -CATAP -1 ( 5 33) /Ets( 5 4 0 )mt降低最为显著;在c Jun和Ets1反义寡核苷酸单独或共同阻断后,LMP1介导的MMP -9活性均降低,以共同阻断的作用最为明显。结论 EBV -LMP1可以通过转录因子c -Jun和Ets1间cross talk调控鼻咽癌细胞中MMP 9的表达。 相似文献
997.
奥沙利铂联合5-氟尿嘧啶和醛氢叶酸钙时辰治疗晚期胃癌的初步临床研究 总被引:16,自引:0,他引:16
目的观察奥沙利铂(L-OHP)联合5-氟尿嘧啶(5-Fu)、醛氢叶酸钙(FA)方案(FFL方案)时辰输注法治疗晚期胃癌的疗效和不良反应。方法FFL方案时辰输注法治疗26例晚期胃癌患者,L-OHP 25 mg.m-2.d-1,5-Fu 600 mg.m-2.d-1,FA 300 mg.m-2.d-1,多通道程控时辰输液泵连续给药4 d,每14 d为1个周期,至少用2个周期。结果26例晚期胃癌患者中,完全缓解(CR)2例(7.7%),部分缓解(PR)13例(50.0%),稳定(SD)6例(23.1%),进展(PD)5例(19.2%),总有效率为57.7%。在共80个周期的化疗中,最常见的不良反应为血液学毒性、胃肠道毒性、外周神经毒性,但均以Ⅰ度为主,Ⅲ度中性粒细胞减少发生2例次,血小板减少、呕吐和口腔黏膜炎分别发生1例次,未出现Ⅳ度不良反应。中位缓解时间为3.5个月,中位肿瘤进展时间为4.5个月,全组患者中位生存期为8个月。结论FFL方案时辰输注法是治疗晚期胃癌安全有效的化疗方案。 相似文献
998.
Yano M Yasuda T Miyata H Fujiwara Y Takiguchi S Monden M 《Journal of surgical oncology》2005,89(4):244-50; discussion 250
BACKGROUND AND OBJECTIVES: Although the histological effectiveness of preoperative chemoradiotherapy against the main tumor is reported to be the strongest prognostic factor for patients with esophageal cancer, it remains unknown whether such chemoradiotherapy is equally effective against metastatic lymph nodes. METHODS: We studied 103 consecutive patients with esophageal cancer, who were given preoperative chemoradiotherapy followed by surgery. The histological effectiveness against the main tumor of the chemoradiotherapy was correlated with lymph mode metastasis and other clinico-pathological factors. RESULTS: The histological effectiveness against the main tumor was grade 3 in 26 patients, grade 2 in 49 and grade 1 in 28. The number of pathological node-negative patients was 21 (80.8%), 19 (38.8%), and 7 (25.0%) in those having grade 3, 2, and 1 responses of their main tumors, respectively. The average number of pathological metastatic lymph nodes was 0.19, 1.4, and 4.4 in patients with grade 3, 2, and 1 responses, respectively. Endoscopic biopsy after the chemoradiotherapy could not accurately diagnose the pathological complete response (CR) of the main tumors, with a high false negative rate (60.9%). CONCLUSIONS: The effects of chemoradiotherapy against main tumors significantly correlated with nodal status. Most patients with main tumors of pathological CR are node-negative. Patients with a grade 2 response have at most a few positive nodes. Surgery would be most beneficial for such patients. 相似文献
999.
Radiotherapy for uterine cervical cancer: results of the 1995-1997 patterns of care process survey in Japan 总被引:1,自引:0,他引:1
Toita T Nakamura K Uno T Kodaira T Shinoda A Ogawa K Mitsuhashi N Maebayashi K Kawaguchi A Inoue T Teshima T 《Japanese journal of clinical oncology》2005,35(3):139-148
OBJECTIVE: The aim of this study is to establish Japanese national practice patterns for uterine cervical cancer patients who received radiotherapy without surgery. METHODS: The Japanese Patterns of Care Study (JPCS) conducted a national survey of 73 institutions using two-stage cluster sampling, and collected specific information on 591 patients with uterine cervical cancer treated by radiotherapy without planned surgery between 1995 and 1997. RESULTS: The median age of the patients was 70 years. Karnofsky performance status (KPS) was >/=90 for 37%. Most patients (95%) had histology of squamous cell carcinoma. Ten percent were stage I, 29% stage II, 48% stage III and 13% stage IVA. Photon beams of 10-14 MV were the most used for external beam radiotherapy (EBRT). The beam energy utilized varied significantly by institution strata. Midline block was used in approximately 70% of institutions. Intracavitary brachytherapy (ICBT) was performed in 77%. Institution strata correlated significantly with the ICBT application. The majority of patients (89%) were treated with high-dose-rate (HDR) ICBT. The median single point A dose of HDR-ICBT was 600 cGy. The median summated point A dose from EBRT and HDR-ICBT was 5800 cGy (range: 1196-8600). The median overall treatment time including ICBT was 49 days. Twenty-four percent of the patients received chemotherapy. Concurrent chemoradiation was performed in 5%. CONCLUSIONS: The JPCS established the Japanese national practice patterns of care for uterine cervical cancer patients treated with radiotherapy without planned surgery between 1995 and 1997. This survey demonstrated that the institutional strata significantly affected several practice patterns. 相似文献
1000.
背景与目的:树突细胞(dendriticcell,DC)是最重要的抗原呈递细胞(antigenpresentingcell,APC),而CD1a作为未成熟DC的标记物,在肿瘤的发生及发展过程中有一定的影响。本文旨在探讨CD1a DC与声门型喉癌病理分级、T分期及局部复发的关系,从而间接了解它与预后的关系。方法:收集111例有完整病理资料及临床随诊资料的声门型喉鳞癌病例,并取17例非肿瘤组织做对照。用免疫组化技术检测CD1a DC在癌组织中的表达,分析癌组织中CD1a DC在不同病理分级、T分期及局部复发组织中的表达,间接了解其与声门型喉鳞癌预后的关系。结果:111例声门型喉鳞癌病例中,CD1a阳性率为59.46%(66/111);高分化组阳性率为71.43%(55/77),中低分化组阳性率为28.57%(11/34);T1 T2组阳性率为67.16%(45/67),T3 T4组阳性率为47.73%(21/44)。局部复发组阳性率为42.86%(12/28),局部无复发组阳性率为65.06%(54/83)。17例非肿瘤组织中CD1a均为阴性。结论:声门型喉鳞癌中,肿瘤细胞分化越差,T分期越高,则CD1a标记树突细胞阳性率越低。局部复发者CD1a DC阳性率低。CD1a可作为预测声门型喉鳞癌预后的参考指标之一。 相似文献