全文获取类型
收费全文 | 23868篇 |
免费 | 1541篇 |
国内免费 | 577篇 |
专业分类
耳鼻咽喉 | 301篇 |
儿科学 | 508篇 |
妇产科学 | 4458篇 |
基础医学 | 2875篇 |
口腔科学 | 494篇 |
临床医学 | 1796篇 |
内科学 | 1035篇 |
皮肤病学 | 194篇 |
神经病学 | 613篇 |
特种医学 | 846篇 |
外国民族医学 | 16篇 |
外科学 | 2444篇 |
综合类 | 4032篇 |
预防医学 | 895篇 |
眼科学 | 160篇 |
药学 | 1208篇 |
13篇 | |
中国医学 | 789篇 |
肿瘤学 | 3309篇 |
出版年
2023年 | 285篇 |
2022年 | 425篇 |
2021年 | 823篇 |
2020年 | 734篇 |
2019年 | 624篇 |
2018年 | 606篇 |
2017年 | 848篇 |
2016年 | 858篇 |
2015年 | 804篇 |
2014年 | 1503篇 |
2013年 | 1635篇 |
2012年 | 1243篇 |
2011年 | 1366篇 |
2010年 | 1195篇 |
2009年 | 1196篇 |
2008年 | 1298篇 |
2007年 | 1295篇 |
2006年 | 1306篇 |
2005年 | 1179篇 |
2004年 | 941篇 |
2003年 | 856篇 |
2002年 | 690篇 |
2001年 | 607篇 |
2000年 | 490篇 |
1999年 | 397篇 |
1998年 | 309篇 |
1997年 | 290篇 |
1996年 | 302篇 |
1995年 | 277篇 |
1994年 | 214篇 |
1993年 | 199篇 |
1992年 | 158篇 |
1991年 | 155篇 |
1990年 | 126篇 |
1989年 | 108篇 |
1988年 | 82篇 |
1987年 | 78篇 |
1986年 | 54篇 |
1985年 | 87篇 |
1984年 | 73篇 |
1983年 | 40篇 |
1982年 | 51篇 |
1981年 | 43篇 |
1980年 | 37篇 |
1979年 | 35篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 10篇 |
1975年 | 5篇 |
1973年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
目的 探讨扩散峰度成像(DKI)对Ⅰ型与Ⅱ型上皮性卵巢癌(EOC)的鉴别诊断价值。 方法 回顾性收集经手术病理证实的45例EOC病人的临床、病理及影像资料,平均年龄(50±13)岁。根据术后病理结果对EOC病人进行分组,分为Ⅰ型组(24例)和Ⅱ型组(21例)。所有病人均于术前行盆腔DKI检查,由2名放射科医师在DKI各参数伪彩图上分别测量平均扩散峰度(MK)、平行扩散峰度(Ka)、垂直扩散峰度(Kr)、平均扩散系数(MD)、平行扩散系数(Da)、垂直扩散系数(Dr)、各向异性分数(FA)、峰度各向异性分数(FAk)。采用Fisher确切概率检验、独立样本t检验或Mann-Whitney U检验比较2组间临床、病理及影像资料的差异,对差异有统计学意义的参数绘制受试者操作特征(ROC)曲线,分析其鉴别诊断效能。 结果 病理表现上,Ⅰ型中交界性肿瘤占比最高(50.0%),Ⅱ型中浆液性癌占比最高(61.9%);Ⅰ型中高分化癌占50%,Ⅱ型多表现为中低分化癌 (76.2%),Ⅰ型EOC的分化程度高于Ⅱ型;Ⅰ型多数处于Ⅰ期(79.2%),Ⅱ型多处于Ⅲ期(57.1%)(均P<0.05)。MRI影像上, Ⅰ型病灶多表现为囊性(41.7%)或囊实性(33.3%),Ⅱ型多表现为实性(52.3%);Ⅱ型(66.7%)腹水发生率高于Ⅰ型(29.2%)(均P<0.05)。Ⅰ型的MK、Ka和Kr值低于Ⅱ型,MD、Da和Dr值高于Ⅱ型(均P<0.05)。ROC曲线分析显示,MK阈值为0.504时,鉴别2组诊断的曲线下面积(AUC,0.817)最大,诊断敏感度(95.2%)、阴性预测值(92.9%)、准确度(78.9%)也最高,Da阈值为2.190时鉴别诊断的AUC(0.770)最小,而特异度(76.2%)、阳性预测值(75.9%)最高。 结论 DKI序列的定量参数MK、Ka、Kr、MD、Da及Dr均有助于鉴别Ⅰ型与Ⅱ型EOC,其中MK值鉴别诊断效能更大。 相似文献
3.
《European journal of surgical oncology》2022,48(12):2525-2530
IntroductionSurgery is the cornerstone of the treatment for advanced ovarian cancer. Reaching complete cytoreduction resulting in no gross residual disease often requires complex surgery. The aim of this study was to assess the impact of increased surgical radicality on the risk of complications in the treatment of advanced ovarian cancer.Materials and methodsAll consecutive patients with advanced ovarian cancer (FIGO Stage IIIB-IVB) who had undergone primary or interval debulking surgery during a six-year study period were identified. In the midst of the study period, a surgical practice change towards maximal surgical effort occurred. Two groups were formed for the analysis: cohort A, that consisted of patients operated before the surgical paradigm shift and cohort B, that consisted of patients operated under the period of increased surgical radicality.Results252 patients were included in the analysis. Complete resection (R0) was achieved in 21.3% of surgeries in cohort A and in 51.2% in cohort B. The total postoperative complication rate was 76.2%. Most of the complications (86.5%) were minor (Clavien-Dindo I-IIIA). The patients in cohort B were at increased risk for complications, OR 2.94 (95%CI 1.58–5.47; p = 0.001). As for the approach to cytoreduction (primary vs. interval debulking), there was no statistically significant association with the occurrence of postoperative complications (p = 0.659).ConclusionIn the present study more extensive surgeries led to better surgical results but increased postoperative morbidity. Postoperative complication rates were similar in both primary and interval debulking surgeries. 相似文献
4.
背景卵巢低反应(POR)患者较差的妊娠结局一直是生殖医学领域难题之一,但目前关于年龄对POR患者辅助生殖技术(ART)治疗后活产率的阈值效应的研究少见。目的分析年龄对POR患者ART治疗后活产率的影响及其阈值效应。方法商丘市第一人民医院妇产科和新疆医科大学第一附属医院生殖助孕中心2014年8月至2018年12月共收治接受常规体外授精/卵胞质内单精子注射-胚胎移植(IVF/ICSI)助孕治疗的女性共19 185例,选取其中诊断为POR者共3 337例为研究对象。所有患者采用控制性促排卵方案,同时采用IVF/ICSI进行胚胎移植并给予黄体支持治疗。分析所有患者活产婴儿情况,年龄对POR患者ART治疗后活产婴儿的影响采用单因素和多因素Logistic回归分析,并建立平滑拟合曲线、进行阈值效应分析。结果3 337例POR患者ART治疗后活产婴儿1 134例,未活产婴儿2 203例,活产率为33.98%(1 134/3 337)。多因素Logistic回归分析结果显示,年龄是POR患者ART治疗后活产婴儿的独立影响因素〔OR=0.920,95%CI(0.902,0.939),P<0.01〕。建立平滑拟合曲线发现,年龄与POR患者ART治疗后活产率呈负相关,但二者之间并非简单的线性关系;阈值效应分析结果显示,POR患者ART治疗后活产率下降的折点为32岁,即年龄≤32岁的POR患者ART治疗后活产率不受年龄影响〔OR=1.000,95%CI(0.998,1.012),P=0.38〕,但年龄>32岁的POR患者ART治疗后活产率随年龄增长而降低〔OR=0.800,95%CI(0.799,0.823),P<0.01〕。结论年龄是POR患者ART治疗后活产婴儿的独立影响因素,年龄>32岁的POR患者ART治疗后活产率随年龄增长而降低。 相似文献
5.
中国医师协会妇产科医师分会妇科肿瘤学组 《中国实用妇科与产科杂志》2022,38(8):814-819
卵巢囊肿(ovarian cyst)是妇科常见疾病,可发生于任何年龄段,以育龄期最为多见。卵巢囊肿多为良性,除个别因扭转、破裂等表现为急腹症外,一般无特异性症状。部分功能性卵巢囊肿可伴有月经紊乱、腹部不适等症状,多数随着囊肿的消退而逐渐消失。 相似文献
6.
目的探讨PCOS患者血清中血小板反应蛋白-1(TSP-1)表达水平与卵巢间质血供之间的关系,以及TSP-1对体外培养的人卵巢微血管内皮细胞(HOMEC)增殖能力的影响。方法选取2018年10月至2019年10月在我院生殖中心就诊的女性,50例诊断为PCOS的患者纳入PCOS组,50例因男方因素不孕的健康女性纳入对照组。ELISA法用于测定所有入组患者血清中的TSP-1水平。在患者处于卵泡早期时,经阴道超声测量双卵巢间质血供,计算血流动力学参数搏动指数(PI)和阻力指数(RI)。体外培养HOMEC,在不同浓度TSP-1(10-9 mmol/L、10-10 mmol/L和10-11 mmol/L)处理细胞12 h、24 h、48 h后,用CCK-8检测细胞增殖情况。结果PCOS组血清LH、T水平及LH/FSH均显著高于对照组(P<0.05)。与对照组比较,PCOS组血清TSP-1水平显著降低(P<0.05),卵巢间质血流动力学参数RI、PI值均显著降低(P<0.05)。Pearson相关性分析发现血清TSP-1水平与卵巢间质血流RI、PI均呈显著正相关(分别为r=0.83,P<0.05;r=0.85,P<0.05)。CCK-8实验显示,与对照组比较,不同浓度(10-11 mmol/L、10-10 mmol/L、10-9 mmol/L)TSP-1作用12 h、24 h、48 h后,对HOMEC增殖的抑制率均显著升高(P<0.05)。在TSP-1各浓度组,TSP-1作用24 h、48 h对HOMEC的抑制率均较作用12 h显著升高(P<0.05),且24 h时达到峰值。结论PCOS患者血清中TSP-1表达降低,卵巢间质血流动力学参数RI、PI值显著降低,卵巢间质血流量丰富,且TSP-1与RI、PI值呈正相关。TSP-1抑制HOMEC增殖,可能参与负调控血管生成。 相似文献
7.
8.
Cynthia S. E. Hendrikse MD Phyllis van der Ploeg MD PhD Nienke M. A. van de Kruis MD Jody H. C. Wilting MD Floor Oosterkamp BSc Pauline M. M. Theelen MSc Christianne A. R. Lok MD PhD Joanne A. de Hullu MD PhD Huberdina P. M. Smedts MD PhD M. Caroline Vos MD PhD Brenda M. Pijlman MD Loes F. S. Kooreman MD Johan Bulten MD PhD Marjolein H. F. M. Lentjes-Beer MD PhD Steven L. Bosch MD PhD Anja van de Stolpe MD PhD Sandrina Lambrechts MD PhD Ruud L. M. Bekkers MD PhD Jurgen M. J. Piek MD PhD 《Cancer》2023,129(9):1361-1371
Background
Advanced low-grade ovarian carcinoma (LGOC) is difficult to treat. In several studies, high estrogen receptor (ER) protein expression was observed in patients with LGOC, which suggests that antihormonal therapy (AHT) is a treatment option. However, only a subgroup of patients respond to AHT, and this response cannot be adequately predicted by currently used immunohistochemistry (IHC). A possible explanation is that IHC only takes the ligand, but not the activity, of the whole signal transduction pathway (STP) into account. Therefore, in this study, the authors assessed whether functional STP activity can be an alternative tool to predict response to AHT in LGOC.Methods
Tumor tissue samples were obtained from patients with primary or recurrent LGOC who subsequently received AHT. Histoscores of ER and progesterone receptor (PR) were determined. In addition, STP activity of the ER STP and of six other STPs known to play a role in ovarian cancer was assessed and compared with the STP activity of healthy postmenopausal fallopian tube epithelium.Results
Patients who had normal ER STP activity had a progression-free survival (PFS) of 16.1 months. This was significantly shorter in patients who had low and very high ER STP activity, with a median PFS of 6.0 and 2.1 months, respectively (p < .001). Unlike ER histoscores, PR histoscores were strongly correlated to the ER STP activity and thus to PFS.Conclusions
Aberrant low and very high functional ER STP activity and low PR histoscores in patients with LGOC indicate decreased response to AHT. ER IHC is not representative of functional ER STP activity and is not related to PFS. 相似文献9.
目的观察两种方法分离的人卵巢颗粒细胞(GCs)体外培养后的连续传代情况。方法选取行辅助生殖技术治疗的不孕患者,收集促排卵后穿刺取卵获得的卵泡液(FF),分别用密度梯度离心法和红细胞裂解法分离人GCs,进行体外培养、扩增及连续传代,并用免疫荧光法对原代及传代后GCs进行鉴定。结果红细胞裂解法获得的GCs数量较密度梯度离心法显著增多(P<0.05),密度梯度离心法分离的GCs的24 h贴壁率显著高于红细胞裂解法(P<0.05)。两种方法分离的GCs均在7 d出现短梭形改变,10 d左右开始退化。两种方法分离的原代GCs在第3~5天为快速增殖期,第7天细胞增殖达到顶峰,第10天左右细胞量下降,每个时间点密度梯度离心法处理的细胞量均显著高于红细胞裂解法(P<0.05);传代后细胞1~5 d为快速增殖期,7 d左右达顶峰,10 d左右下降,各时间点两种分离方法所获GCs传代培养的细胞量均无统计学差异(P>0.05)。两种方法分离的GCs均可进行连续传代,细胞形态无明显差异,且连续传代后的GCs仍表达卵泡刺激素受体(FSHR)。结论密度梯度离心法较红细胞裂解法可获得生长情况更为良好的原代GCs;两种分离方法所获GCs均可体外连续传代。 相似文献
10.
《Neuro-Chirurgie》2023,69(4):101455
ObjectiveSpinal arachnoid web (SAW) is a rare condition of the spine with limited long-term follow-up data in the literature. The longest reported follow-up period was an average 3.2 years. The objective of this study is to report our long-term results of patients who underwent surgical treatment for symptomatic idiopathic SAW.MethodsWe conducted a retrospective review of cases of idiopathic SAW that were operated between 2005–2020. We collected preoperative and last follow-up (LFU) data on motor force, sensory loss, pain, upper motor neuron (UMN) sign, gait disorder, sphincter dysfunction, syringomyelia, hyperintensity on T2-MRI, appearance of newer symptoms and number of reoperations.ResultsOur study included 9 patients with a mean follow-up period of 3.6 years (range 2–9.1 years). The surgical intervention involved a standard centered laminectomy, durotomy and arachnoid lysis. At presentation, motor weakness was present in 77.8% of patients, sensory loss in 66.7%, pain in 88.9%, sphincter dysfunction in 33.3%, UMN sign in 22%, gait disorder 55.6%, syringomyelia in 55.6% and MRI T2 hyperintensity in 55.6% of patients. At LFU, there was an improvement in all symptoms and signs to varying degrees. No new neurological symptoms appeared postoperatively, and there was no recurrence during the follow-up period.ConclusionOur results demonstrate that the reported immediate and short-term favorable outcomes following arachnoid lysis for symptomatic SAW persist over a long-term period and the risk of readhesion-correlated neurological deterioration following conventional surgical intervention is low. 相似文献