全文获取类型
收费全文 | 152831篇 |
免费 | 31760篇 |
国内免费 | 2403篇 |
专业分类
耳鼻咽喉 | 5171篇 |
儿科学 | 5482篇 |
妇产科学 | 2555篇 |
基础医学 | 3586篇 |
口腔科学 | 1619篇 |
临床医学 | 26792篇 |
内科学 | 47871篇 |
皮肤病学 | 7468篇 |
神经病学 | 15049篇 |
特种医学 | 6511篇 |
外科学 | 41066篇 |
综合类 | 278篇 |
现状与发展 | 72篇 |
一般理论 | 2篇 |
预防医学 | 7211篇 |
眼科学 | 3366篇 |
药学 | 1047篇 |
中国医学 | 12篇 |
肿瘤学 | 11836篇 |
出版年
2024年 | 692篇 |
2023年 | 4788篇 |
2022年 | 1205篇 |
2021年 | 3107篇 |
2020年 | 6044篇 |
2019年 | 2186篇 |
2018年 | 7425篇 |
2017年 | 7356篇 |
2016年 | 8429篇 |
2015年 | 8420篇 |
2014年 | 15534篇 |
2013年 | 15663篇 |
2012年 | 5565篇 |
2011年 | 5543篇 |
2010年 | 10398篇 |
2009年 | 14240篇 |
2008年 | 5848篇 |
2007年 | 4112篇 |
2006年 | 6573篇 |
2005年 | 3860篇 |
2004年 | 3109篇 |
2003年 | 2073篇 |
2002年 | 2150篇 |
2001年 | 3868篇 |
2000年 | 3061篇 |
1999年 | 3245篇 |
1998年 | 3672篇 |
1997年 | 3489篇 |
1996年 | 3394篇 |
1995年 | 3231篇 |
1994年 | 1958篇 |
1993年 | 1582篇 |
1992年 | 1432篇 |
1991年 | 1457篇 |
1990年 | 1113篇 |
1989年 | 1244篇 |
1988年 | 1067篇 |
1987年 | 895篇 |
1986年 | 932篇 |
1985年 | 754篇 |
1984年 | 576篇 |
1983年 | 542篇 |
1982年 | 538篇 |
1981年 | 424篇 |
1980年 | 386篇 |
1979年 | 345篇 |
1978年 | 359篇 |
1977年 | 417篇 |
1975年 | 297篇 |
1972年 | 315篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
- DNA is the sequence that codes for proteins.
- Messenger RNA is transcribed from the DNA sequence of genes and translated into protein.
- It can be difficult to predict how a change in the DNA sequence will affect messenger RNA and protein quantity and quality.
- DNA translocation changes can cause the joining of sequences from two different genes or different parts of the same gene.
- DNA sequencing is often used clinically to predict how DNA changes might affect proteins.
- Alternatively, RNA sequencing can be used as a more direct measure of the effect of DNA changes on the protein products.
- This sequencing is important for identifying changes in cancer that may indicate response to targeted therapy, prognosis, or diagnosis.
2.
- Children with cancer receive many medications outside the hospital administered by their caregivers.
- The study by Walsh et al. shows the number and types of medication errors in these patients. The study includes data from three different centers.
- Importantly, the study shows the types of errors that cause harm. The authors describe how the harmful errors can be prevented.
- We suggest ways these results can be used to identify which patients and families will benefit from additional attention. Providing more help at clinic and in the home may help prevent harmful medication errors in children with cancer.
3.
Eman Hamid MD PhD Biniyam A. Ayele MD Daniel Gams Massi MD Samia Ben Sassi MD Houyam Tibar MD Emmanuel Epenge Djonga MD Sarah Misbah El-Sadig MD Wahiba AMER EL KHEDOUD MD Julien Razafimahefa MSc Ange Eric Kouame-Assouan MD Djibrilla Ben-Adji MD Yilédoma Thierry Modeste Lengané MD Abdu Kisekka Musubire MD Muhyadin Hassan Mohamed MSc Tiwonge Elisa Phiri MBBS FCN Nsengiyumva Nestor MD Wael Abdulgader Alwahchi MSc Saara Ndinelago Neshuku MBChB FCN MMed Cassandra Ocampo MD Foksouna Sakadi MD Moulid Ali Maidal MBBS Gift Wilson Ngwende MBChB MMed FCP Juzor Hooker MB ChB MMed DCN FCP Kigocha Okeng'o MD Med MSc Augustina Charway-Felli MD PhD FGCPS Masharip Atadzhanov PhD FRCP Jonathan Carr MBChB PhD Njideka U. Okubadejo MBChB FMCP FAAN Ali Shalash MD PhD 《Movement disorders》2021,36(10):2393-2407
4.
AbstractBackground: Increasing access to buprenorphine treatment is a critical tool for addressing the opioid epidemic in the United States. In 2016, a federal policy change allowed physicians who meet specific requirements to treat up to 275 concurrent buprenorphine patients. This study examines state-level measures of buprenorphine treatment supply over 21?months since this policy change and estimates associations between the supply of 275-patient waivers and state characteristics. Methods: Monthly state-level measures of the number of physicians holding the 275-patient waiver per 100,000 residents were constructed from September 2016 to May 2018 using the Drug Enforcement Agency’s Controlled Substance Act database. State characteristics were obtained from publicly available sources. Mixed-effects regression models were estimated to examine change over time. Results: During the 21-month period, the number of physicians waivered to treat 275 patients increased from 153 to 4009 physicians. The mean supply of 275-patient physicians per 100,000 state residents significantly increased from 0.07 (SD?=?0.21) in September 2016 to 1.43 (SD?=?1.08) in May 2018 (t?=??9.84, df?=?50, P?<?.001). The final mixed-effects regression model indicated that Census division and the preexisting supply of 100-patient waivered physicians were correlated with the rate of growth in 275-patient waivers over the study period. Conclusions: Although uptake of the 275-patient waiver has exceeded initial projections, growth is uneven across the United States. Unequal patterns of growth pose a challenge to efforts to increase treatment availability as a means of addressing the opioid epidemic. 相似文献
5.
6.
Venous thromboembolism (VTE) is often associated with malignant diseases and notably contributes to morbidity and mortality in patients with cancer. Cancer-associated thrombosis (CAT) brings additional costs to health expenditures and has a negative impact on oncological outcomes. Either the recurrence rate of VTE or bleeding complications are also higher in patients with cancer. Prophylactic anticoagulation has been recommended in peri-surgical periods, inpatient settings, and high-risk ambulatory patients. Although various risk stratification scores are used, none are ideal for identifying patients who can benefit from anticoagulant prophylaxis. New risk scoring systems or biomarkers are needed to identify patients who are more likely to benefit from prophylaxis with low bleeding risk. The questions about the patients who will be given prophylaxis and those who develop thromboembolism, with which drug, and how long they will be treated are still not fully answered. Anticoagulation is the cornerstone of the treatment, but management of CAT remains complex. Low molecular weight heparins and direct oral anticoagulants are effective and safe options for the treatment of CAT. Recognizing adverse effects, drug–drug interactions, and accompanying conditions that cause dose adjustment is crucial. Prevention and treatment of VTE in patients with cancer require a multidisciplinary and patient-based approach.
Plain Language Summary
- Cancer-associated thrombosis is a significant cause of mortality and morbidity in patients with cancer.
- Chemotherapy, surgery, and/or use of central venous access remarkably increase the risk of thrombosis.
- Prophylactic anticoagulation should be considered not only in inpatient follow-up and during peri-surgical period but also ambulatory patients with a high risk of thrombosis.
- Many parameters, such as drug–drug interactions, primary side of cancer, and comorbidities of patients should be considered when selecting anticoagulant drugs.
- More accurate risk stratification scores or biomarkers are still an unmet need.
7.
8.
9.
New,Immunomodulatory, Oral Nutrition Formula for Use Prior to Surgery in Patients With Head and Neck Cancer: An Exploratory Study 下载免费PDF全文
Samara Palma‐Milla MD Bricia López‐Plaza PhD MSc Beatriz Santamaría BSc Álvaro de Arriba‐Sánchez MD Laura M. Bermejo PhD MSc Carmen Gómez‐Candela MD PhD 《JPEN. Journal of parenteral and enteral nutrition》2018,42(2):371-379
Background: The perioperative use of immunomodulatory nutrition formulas in patients with head and neck cancer reduces the number of postoperative infections and the length of hospital stay. Objective: An exploratory, randomized, controlled, blind, clinical trial was designed to examine the effect of the preoperative consumption of a new, immunomodulatory, oral nutrition formula in patients with head and neck cancer. Methods: Thirty‐eight patients were randomized to receive either 400 mL/d of either the new immunomodulatory formula (IF) or that commonly used in clinical practice (CF) over 10 days prior to surgery. Thirty‐three patients completed the study. Compliance, tolerance, the length of hospital stay, the incidence of infections and noninfectious complications before discharge, and the same up to 15 and 30 days after discharge were recorded. Results: The percentage of patients who developed infections before discharge was significantly lower in the IF than in the CF group (P = .013), as was the number of infections/100 patients/d (P = .035). The length of hospital stay was significantly shorter in the IF group (P = .001). Both formulas were safe and well tolerated. No other differences were detected. These results suggest preoperative consumption of the new formula to be beneficial for patients with neck and head cancer. Further trials are needed to confirm these results and to test the efficacy of the formula in patients with other conditions. Conclusion: The new formula can be safely prescribed as part of the preoperative treatment of patients with head and neck cancer and might reduce the problem of postoperative infection. 相似文献
10.
Comparative Efficacy and Safety of Phosphate Binders in Hyperphosphatemia Patients With Chronic Kidney Disease 下载免费PDF全文
Xiuqin Yang MD Qingning Bai MD Yanguo Li MD Haijun Liu MD Haiying Guo MD Xiaolei Zhang MD 《JPEN. Journal of parenteral and enteral nutrition》2018,42(4):766-777
Background: In this study, we coordinated a network meta‐analysis to establish the efficacy and safety of different agents used in the treatment of hyperphosphatemia patients with chronic kidney disease. Methods: PubMed, CNKI, and Embase were systematically searched to retrieve relevant studies. Outcomes were presented by mean differences, odds ratios, and corresponding 95% credible intervals for continuous outcomes and binary outcomes, respectively. Each therapy was ranked according to the value of surface under the cumulative ranking curve. Consistencies between direct and indirect comparisons were assessed with a node‐splitting plot. Results: In terms of efficacy end points (including levels of serum phosphate, serum calcium, serum intact parathyroid hormone, and serum calcium × phosphorus product), all 7 kinds of agents outperformed or performed at least equally to placebo, with iron‐based phosphate‐binding agents being potentially the most effective. As for safety end points (including mortality, adverse events, and all‐cause discontinuation), almost all agents were equivalent in term of mortality and all‐cause discontinuation except in the comparison between iron‐based phosphate‐binding agents and placebo. Meanwhile, iron‐based phosphate‐binding agents colestilan and nicotinic acid performed poorly compared with placebo in terms of adverse events. Furthermore, iron‐based phosphate‐binding agents were potentially the safest agents followed sequentially by calcium‐based phosphate‐binding agents and placebo. Conclusion: Iron‐based phosphate‐binding agents were the preferable agents when considering efficacy and safety simultaneously. 相似文献