全文获取类型
收费全文 | 1597篇 |
免费 | 143篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 25篇 |
妇产科学 | 35篇 |
基础医学 | 172篇 |
口腔科学 | 135篇 |
临床医学 | 138篇 |
内科学 | 169篇 |
皮肤病学 | 42篇 |
神经病学 | 85篇 |
特种医学 | 73篇 |
外科学 | 311篇 |
综合类 | 221篇 |
预防医学 | 27篇 |
眼科学 | 35篇 |
药学 | 90篇 |
2篇 | |
中国医学 | 35篇 |
肿瘤学 | 186篇 |
出版年
2024年 | 6篇 |
2023年 | 73篇 |
2022年 | 85篇 |
2021年 | 123篇 |
2020年 | 88篇 |
2019年 | 67篇 |
2018年 | 59篇 |
2017年 | 64篇 |
2016年 | 47篇 |
2015年 | 59篇 |
2014年 | 98篇 |
2013年 | 104篇 |
2012年 | 67篇 |
2011年 | 73篇 |
2010年 | 61篇 |
2009年 | 61篇 |
2008年 | 66篇 |
2007年 | 85篇 |
2006年 | 49篇 |
2005年 | 62篇 |
2004年 | 57篇 |
2003年 | 47篇 |
2002年 | 33篇 |
2001年 | 32篇 |
2000年 | 32篇 |
1999年 | 22篇 |
1998年 | 23篇 |
1997年 | 15篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 13篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 10篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 4篇 |
1972年 | 3篇 |
1970年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有1807条查询结果,搜索用时 15 毫秒
1.
BackgroundTumor mutation burden (TMB) as a prognostic marker for immunotherapy has shown prognostic value in many cancers. However, there is no systematic investigation on TMB in papillary thyroid carcinoma (PTC).MethodsBased on the somatic mutation data of 487 PTC patients from The Cancer Genome Atlas (TCGA), TMB was calculated, and we classified the samples into high-TMB (H-TMB) and low-TMB (L-TMB) groups. Bioinformatics methods were used to explore the characteristics and potential mechanism of TMB in PTC.ResultsHigh TMB predicts shorter progression-free survival (PFS) (P < 0.001). TMB was positively correlated with age, stage, tumor size, metastasis, the male sex and tall cell PTC. Compared to the L-TMB group, the H-TMB group presented with lower immune cell infiltration, a higher proportion of tumor-promoting immune cells (M0 macrophages, activated dendritic cells and monocytes) and a lower proportion of antitumor immune cells (M1 macrophages, CD8+ T cells and B cells). Additionally, the characteristics displayed by different TMB groups were not driven by critical driver mutations such as BRAF and RAS.ConclusionsPTC patients with high TMB have a worse prognosis. By stratifying PTC patients according to their TMB, advanced PTC patients who are candidates for immunotherapy could be selected. 相似文献
2.
Objectives:To reassess the long-term camouflage effects of resin infiltration (Icon, DMG, Hamburg, Germany) of white spot lesions (WSL) and sound adjacent enamel (SAE) achieved in a previous trial. The null hypothesis was tested that there were no significantly different CIE-L*a*b*-ΔE-values between WSL and SAE areas of assessment after at least 24 months (T24) compared to those at baseline (T0).Materials and Methods:Of twenty subjects who received previous resin infiltration treatment of nteeth = 111 nonrestored, noncavitated postorthodontic WSL after multibracket treatment during a randomized controlled trial and were contacted 20 months after baseline, eight subjects (trial teeth nteeth = 40; m/f ratio 1/7; age range (mean; SD) 12–17 [15.25; 2.12] years); response rate: 40%) were available for follow-up after at least 24 months (T24). CIE-L*a*b* differences between summarized color and lightness values (ΔEWSL/SAE) of WSL and SAE were assessed using a spectrophotometer and compared to baseline data assessed prior to infiltration (T0), and those after 6 (T6), and 12 (T12) months using paired t tests at a significance level of α = 5%.Results:T24 assessments were performed after a mean 33.86 (SD: 8.64; Min: 24; Max: 45) months following T0. Mean (SD) ΔEWSL/SAE units of available teeth were 8.76 (5.33) at baseline; 5.5 (2.75) at T6; 5.2 (2.41) at T12; and 5.57 (2.6) at T24. Comparisons of T6, T12, and T24 with T0 yielded highly significant differences, whereas T6–T24 and T12–T24 differences were found to be not significant.Conclusions:Assimilation of infiltrated WSL to the color of adjacent enamel by resin infiltration is considered to be suitable for the long-term improvement in the esthetic appearance of postorthodontic WSL. 相似文献
3.
《The Journal of arthroplasty》2022,37(7):1338-1347
BackgroundMultimodal pain therapy combining analgesics, local infiltration analgesia (LIA) and peripheral nerve blocks, such as fascia iliaca compartment block (FICB), can improve postoperative pain, nausea and vomiting (PONV) and ambulation in patients undergoing total hip arthroplasty (THA). We hypothesized that addition of FICB would decrease opioid requirements and length of stay (LOS) but could create a motor block.MethodsThis is a single center, prospective, blinded randomized controlled study of 152 patients undergoing elective THA via direct anterior approach from October 2019 till August 2021. Three patient groups were defined: patients receiving only spinal anesthesia (control group, n = 53); spinal anesthesia with LIA perioperatively (n = 50); and spinal anesthesia with FICB on the recovery unit (n = 49). Outcome measures consisted of postoperative pain scores, PONV, length of hospital stay, opioid requirements and mobility.ResultsOverall pain scores were low for all patient groups, with a lower pain score for LIA in comparison to the control group until 4 hours postoperatively (P < .05). Length of hospital stay, postoperative pain, nausea and vomiting (PONV) scores and quadriceps muscle strength did not differ significantly between groups. The control group showed higher scores at 12 hours postoperatively in comparison to FICB regarding rehabilitation potential, use of walking aids and activities of daily living (P < .05), but all groups reached the same endpoint 48 hours postoperatively. The LIA and FICB groups required less opioids until 24 hours postoperatively.ConclusionLIA is a beneficial adjuvant therapy to spinal anesthesia in THA patients as it may decrease pain scores and the need for opioid consumption. Adjuvant FICB only provided lower opioid requirements. 相似文献
4.
5.
L. Rosenberg M.D. I. T. Jackson D. Sharpe J. Weiss 《European journal of plastic surgery》1987,9(4):158-159
Summary A system which can be used for injection or infiltration of large volumes of fluid is described. This consists of a syringe which fills automatically from a reservoir through an inlet/outlet valve. 相似文献
6.
局部浸润麻醉在隆乳术中的应用 总被引:1,自引:0,他引:1
目的 探讨局部浸润麻醉方法在隆乳术中的应用效果。方法 将2%利多卡因20ml加0.5%布匹卡因5ml配制成120ml局部麻醉液,采用局部浸润麻醉方法为568例受术者行隆乳手术,根据胸部神经、肌肉的解剖特点,行合理的分布药量和准确有效的注射。结果 568例隆乳术者,局部浸润麻醉方法均有效,且麻醉效果良好。无一例受术者因分离腔穴时产生疼痛而影响手术操作或停止手术。结论 局部麻醉效果理想可靠,方法简单易行,适用于任何术式的隆乳术。而在分离腔穴时产生的疼痛主要是因注射层次不当和药量分布不均所致。与麻醉方法无关;其麻醉效果与假体置入层次或乳腺胸大肌是否发达无因果关系。 相似文献
7.
CHENG Yu-tong YANG Yue-jin ZHANG Hai-tao QIAN Hai-yan ZHAO Jing-lin MENG Xian-min LUO Fu-liang WU Yi-ling 《中华医学杂志(英文版)》2005,122(1):1529-1538
Background The traditional Chinese medicine Tongxinluo can protect myocardium against ischaemia/reperfusion injury, but the mechanism of its action is not well documented. We examined the involvement of nitric oxide in the protective role of Tongxinluo. Methods Miniswine were randomized to four groups of seven: sham, control, Tongxinluo and Tongxinluo coadministration with a nitric oxide synthase inhibitor Nω-nitro-L-arginine (L-NNA, 10 mg/kg i.v.). Three hours after administration of Tongxinluo, the animals were anaesthetised and the left anterior descending coronary artery ligated and maintained in situ for 90 minutes followed by 3 hours of reperfusion before death. Area of no reflow and necrosis and risk region were determined pathologically by planimetry. The degree of neutrophil accumulation in myocardium was obtained by measuring myeloperoxidase activity and histological analysis. Myocardial endothelial nitric oxide synthase activity and vascular endothelial cadherin content were measured by colorimetric method and immunoblotting analysis respectively.Results Tongxinluo significantly increased the local blood flow and limited the infarct and size of no reflow. Tongxinluo also attenuated myeloperoxidase activity and neutrophil accumulation in histological sections and maintained the level of vascular endothelial cadherin and endothelial nitric oxide synthase activity in the reflow region when compared with control group. The protection of Tongxinluo was counteracted by coadministration with L-NNA. Conclusions Tongxinluo may limit myocardial ischaemia and protect the heart against reperfusion injury. Tongxinluo regulates synthesis of nitric oxide by altering activity of endothelial nitric oxide synthase. 相似文献
8.
观察126例人类转移癌,分析比较淋巴样细胞浸润(LI)程度与患者年龄、病理类型、组织分化和核异型程度的关系。结果表明:患者年龄及病理类型与LI程度无关;组织分化程度在LI上虽有差别,但无对应性关系;而核异型程度与LI关系密切。核异型性愈明显,LI程度愈高,反之亦然。这说明核分级不仅可以反映宿主免疫反应的高低,也可提示转移癌抗原性的强弱。 相似文献
9.
MRI gadolinium enhancement of bone marrow: age-related changes in normals and in diffuse neoplastic infiltration 总被引:5,自引:0,他引:5
Objective: To quantify gadolinium-related enhancement in the bone marrow of the spine in normals and in patients with homogeneous diffuse
malignant bone marrow infiltration. Design and patients: The patients consisted of two groups: group 1 comprised 94 healthy adults (18–86 years) without bone marrow disease and group
2 comprised 30 patients with homogeneous diffuse malignant bone marrow infiltration due to myeloma (n=20) or breast carcinoma (n=10). All patients received intravenous gadopentetate dimeglumine (Gd-DTPA), 0.1 mmol/kg body weight. Pre- and postcontrast
signal intensity (SI) on T1-weighted spin-echo (SE) images (TR/TE: 572 ms/15 ms) was measured over a region of interest (ROI)
and the percentage SI increase was calculated. The results were confirmed by bone marrow biopsy (n=20) and clinical parameters (n=10). Dynamic contrast-enhanced studies using a spoiled gradient-recalled-echo (GRE) sequence (TR/TE/α: 68 ms/6 ms 75°) were
performed in 10 controls with normal bone marrow.
Results and conclusion: Contrast material enhancement in healthy persons can vary greatly (range 3–59%, mean 21%, SD 11%). With increasing age there
is a significant decrease in contrast enhancement (Pearson’s correlation, P<0.01). The percentage SI increase in patients with intermediate-grade (biopsy 20–50 vol%) and high-grade (biopsy >50 vol%)
diffuse malignant bone marrow infiltration was significantly higher than in normals (mean 67%, SD 34%, P<0.001). Low-grade (biopsy <20 vol%) diffuse malignant bone marrow infiltration can not be assessed by non-enhanced T1-weighted
SE images or Gd-DTPA application. In conclusion, contrast material enhancement in healthy persons can vary greatly and is
dependent on age, while intermediate-grade and high-grade diffuse malignant bone marrow infiltration can be objectively assessed
with SI measurements. 相似文献
10.
目的 探讨淋巴瘤骨髓浸润患者的治疗与预后。方法 34例淋巴瘤骨髓浸润患者分为单纯化疗组、化疗+放疗组、大剂量化疗+自体干细胞移植组进行治疗,长期随访,分析其预后状况。结果 全组中位生存期为20个月;1年和3年生存率分别为76.47%和26.47%,最初疗效为完全缓解和部分缓解患者的1年和3年生存率均大于未缓解患者(P<0.05);大剂量化疗+自体干细胞移植组的3年生存率大于单纯化疗组和化疗+放疗组(P<0.05)。结论 淋巴瘤骨髓浸润患者的生存率与最初疗效有关;大剂量化疗+自体干细胞移植能提高其生存率,改善预后。 相似文献