全文获取类型
收费全文 | 690550篇 |
免费 | 54052篇 |
国内免费 | 24520篇 |
专业分类
耳鼻咽喉 | 8089篇 |
儿科学 | 14762篇 |
妇产科学 | 11096篇 |
基础医学 | 92855篇 |
口腔科学 | 17380篇 |
临床医学 | 62958篇 |
内科学 | 91803篇 |
皮肤病学 | 11103篇 |
神经病学 | 39205篇 |
特种医学 | 17536篇 |
外国民族医学 | 253篇 |
外科学 | 68035篇 |
综合类 | 103421篇 |
现状与发展 | 93篇 |
一般理论 | 31篇 |
预防医学 | 47546篇 |
眼科学 | 11444篇 |
药学 | 63872篇 |
440篇 | |
中国医学 | 41551篇 |
肿瘤学 | 65649篇 |
出版年
2024年 | 1826篇 |
2023年 | 10037篇 |
2022年 | 18385篇 |
2021年 | 25086篇 |
2020年 | 23050篇 |
2019年 | 27762篇 |
2018年 | 25927篇 |
2017年 | 24250篇 |
2016年 | 22957篇 |
2015年 | 23770篇 |
2014年 | 40669篇 |
2013年 | 44962篇 |
2012年 | 37929篇 |
2011年 | 42241篇 |
2010年 | 34105篇 |
2009年 | 32511篇 |
2008年 | 32996篇 |
2007年 | 33815篇 |
2006年 | 30355篇 |
2005年 | 26876篇 |
2004年 | 22556篇 |
2003年 | 19388篇 |
2002年 | 15623篇 |
2001年 | 14047篇 |
2000年 | 11691篇 |
1999年 | 10133篇 |
1998年 | 9170篇 |
1997年 | 8461篇 |
1996年 | 7525篇 |
1995年 | 7047篇 |
1994年 | 6422篇 |
1993年 | 5272篇 |
1992年 | 4792篇 |
1991年 | 4357篇 |
1990年 | 3741篇 |
1989年 | 3420篇 |
1988年 | 3132篇 |
1987年 | 2700篇 |
1986年 | 2470篇 |
1985年 | 5664篇 |
1984年 | 6426篇 |
1983年 | 4481篇 |
1982年 | 5133篇 |
1981年 | 4578篇 |
1980年 | 4089篇 |
1979年 | 3655篇 |
1978年 | 3104篇 |
1977年 | 2332篇 |
1976年 | 2544篇 |
1975年 | 1790篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
中药生产过程质量控制关键技术研究进展 总被引:10,自引:8,他引:2
中医药发展已上升到国家战略层面,在医药行业贯彻实施"中国制造2025"战略的新形势下,中药生产过程质量控制是中药工业需要加快突破的关键领域之一。对中药生产过程质量控制领域在工艺设计、分析检测、过程建模、制造装备等方面的关键共性问题进行解析,综述了中药生产过程质量控制体系中工艺过程理解、生产过程实时分析方法开发、过程控制策略建立3个方面的研究进展;并结合企业研究实践,介绍了质量源于设计(quality by design,Qb D)、过程分析技术(process analytical technology,PAT)、实验设计(design of experiment,DOE)、多变量统计分析等关键技术在上述3个研究方向中的应用进展,分析了实际工业应用的难点问题并对其应用前景进行展望,旨在为中药企业应用和提升生产过程质量控制技术提供参考。 相似文献
2.
3.
4.
Aaron Pitzele Mohammad Rahimi Eric Armbrecht 《The journal of maternal-fetal & neonatal medicine》2015,28(15):1770-1773
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion. 相似文献
5.
Well‐being,health and fitness of children who use wheelchairs: Feasibility study protocol to develop child‐centred ‘keep‐fit’ exercise interventions 下载免费PDF全文
6.
Quality of life in stroke survivor–caregiver dyads: a new conceptual framework and longitudinal study protocol 下载免费PDF全文
7.
Hui-Ju Ch’ang 《World journal of hepatology》2015,7(16):2029-2040
The success of sorafenib in prolonging survival of patients with hepatocellular carcinoma (HCC) makes therapeutic inhibition of angiogenesis a component of treatment for HCC. To enhance therapeutic efficacy, overcome drug resistance and reduce toxicity, combination of antiangiogenic agents with chemotherapy, radiotherapy or other targeted agents were evaluated. Nevertheless, the use of antiangiogenic therapy remains suboptimal regarding dosage, schedule and duration of therapy. The issue is further complicated by combination antiangiogenesis to other cytotoxic or biologic agents. There is no way to determine which patients are most likely respond to a given form of antiangiogenic therapy. Activation of alternative pathways associated with disease progression in patients undergoing antiangiogenic therapy has also been recognized. There is increasing importance in identifying, validating and standardizing potential response biomarkers for antiangiogenesis therapy for HCC patients. In this review, biomarkers for antiangiogenesis therapy including systemic, circulating, tissue and imaging ones are summarized. The strength and deficit of circulating and imaging biomarkers were further demonstrated by a series of studies in HCC patients receiving radiotherapy with or without thalidomide. 相似文献
8.
Sevim Turanli Nazan Bozdogan Hakan Mersin Ugur Berberoglu 《The Indian journal of surgery》2015,77(6):489-494
Helicobacter pylori has been associated with diverse pathologies of varying severity. We investigated the H. pylori infection status and its association with the pathologic features and clinical outcomes in stage III gastric cancer patients treated with adjuvant therapy after curative resection. Between 2004 and 2009, the records of 76 consecutive patients were retrospectively reviewed. H. pylori infection was confirmed by examination of pathological specimen. The relationship between H. pylori and the clinicopathological features was analyzed by Fisher exact test, Student’s t test, and Kaplan-Meier method. Of the 76 patients, 16 patients (21.1 %) were confirmed for H. pylori infection. The median age was 59 years. Twenty-three patients received chemotherapy and remainder received chemoradiotherapy. H. pylori status did not correlate with the clinicopathologic features. It was greater in non-neoplastic tissue than the tumor tissue (21.1 vs 7.9 %). Median follow-up was 21 months. During this period, 88.2 % patients had experienced tumor recurrence, and 85.5 % patients had died. Recurrence was observed in 87.5 % patients and in 88.3 % patients in H. pylori-positive and H. pylori-negative patients, respectively (P = 0.92). Disease-free survival was 28.4 ± 7.9 months and overall survival was 31.5 ± 7.4 months in H. pylori-positive patients compared with 28.3 ± 3.7 and 33.2 ± 3.4 months, respectively, in H. pylori-negative patients. H. pylori infection status did not have effect on the overall or disease-free survival (p = 0.85 and P = 0.86), respectively. H. pylori status might not be useful as a prognostic and predictive factor for clinical outcomes. 相似文献
9.
Hsiao-Hsuan Kuo Ran Fan Nina Dvorina Andres Chiesa-Vottero William M. Baldwin III 《Journal of the American Society of Nephrology : JASN》2015,26(4):855-863
Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses. 相似文献
10.
Anuj Shrestha Zeeshan Jawa Kathryn L. Koch Amy B. Rankin Qun Xiang Anand Padmanabhan Matthew S. Karafin Joshua J. Field 《Journal of clinical apheresis》2015,30(6):353-358
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc. 相似文献