首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1226篇
  免费   117篇
  国内免费   14篇
耳鼻咽喉   4篇
儿科学   47篇
妇产科学   47篇
基础医学   170篇
口腔科学   47篇
临床医学   108篇
内科学   230篇
皮肤病学   75篇
神经病学   81篇
特种医学   52篇
外国民族医学   3篇
外科学   91篇
综合类   34篇
预防医学   64篇
眼科学   28篇
药学   189篇
中国医学   5篇
肿瘤学   82篇
  2024年   2篇
  2023年   35篇
  2022年   23篇
  2021年   109篇
  2020年   75篇
  2019年   91篇
  2018年   104篇
  2017年   74篇
  2016年   72篇
  2015年   66篇
  2014年   60篇
  2013年   90篇
  2012年   111篇
  2011年   90篇
  2010年   57篇
  2009年   38篇
  2008年   47篇
  2007年   46篇
  2006年   44篇
  2005年   34篇
  2004年   19篇
  2003年   15篇
  2002年   18篇
  2001年   2篇
  2000年   1篇
  1998年   2篇
  1997年   4篇
  1996年   1篇
  1995年   1篇
  1994年   3篇
  1993年   1篇
  1992年   3篇
  1991年   1篇
  1990年   4篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1984年   2篇
  1983年   3篇
  1978年   3篇
  1972年   2篇
  1971年   1篇
排序方式: 共有1357条查询结果,搜索用时 294 毫秒
1.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
2.
Background: The balance of the oxidative state in the body is fundamental for the maintenance of homeostasis. It has been implicated in the onset and progression of several diseases including breast cancer. The way in which the Reactive Oxygen Species (ROS) / antioxidants balance leads to or responds to disease is still controversial. In this study, TAC is used as a reference for the total antioxidant power of the body and Coenzyme Q10 (CoQ10) for its vital importance in cellular antioxidant action and being the only lipid soluble antioxidant synthesized endogenously. Copper and zinc were measured as trace elements reflecting the antioxidant micronutrient profile of the body. Methods: After approval of the ethical committee, 60 recently diagnosed non-intervened breast cancer patients were recruited from the Medical Research Institute hospital, Alexandria University along with 20 apparently healthy volunteers as control group. Full patient history was taken including breastfeeding history, parity, hormone replacement therapy use, body mass index, pathological examination, metastatic work up results, past medical history and drug use. CA 15-3 and laboratory investigations evaluating blood glucose, kidney and liver functions were performed. Q10 levels were measured by HPLC using a kit from Recipe®. TAC was assayed spectrophotometrically (Biodiagnostics®). Copper and Zinc levels were determined by inductively coupled plasma-optical emission spectrometry. Results: There was a statistically significant increase in the CoQ10, TAC and copper levels in the breast cancer group when compared to the control group. Zinc showed no statistically significant difference between the studied groups. Conclusion: Inspite of the fact that a high antioxidant level is usually considered as a favourable state, TAC, CoQ10 and copper levels showed significantly higher levels in the breast cancer group when compared to the control group. It is worth mentioning that the cancer group were all recently diagnosed, non-intervened and showed no signs of metastasis. It is still unclear whether the increased antioxidant levels offer a selective growth advantage to tumor cells over their surrounding normal cells or serve as a protective measure by the body in an attempt to correct the assault triggered by the ROS.  相似文献   
3.
In this report we describe, herewith, a patient with primary pigmentary dystrophy of the retina (retinitis pigmentosa) associated with unilateral retinal arteriovenous communication and exudative retinal detachment. The patient had complete resolution of the retinal detachment following laser photocoagulation treatment. Such association has not been previously reported.  相似文献   
4.
A major cause of ageing is thought to be the accumulation of damage to macromolecules. Accumulation to DNA damage in cells therefore presupposes that aged cells are unable to repair this damage. We have used the in vitro model of cellular ageing to test the idea that senescent cells are deficient in some aspect of DNA repair. Using the alkaline single cell gel electrophoresis assay (comet assay), we have determined the responses of young and senescent human dermal fibroblasts to DNA damage caused by exposure to UVC light. At low doses of UVC, senescent cells generate smaller comets than young cells whilst at medium doses the situation is reversed. At high doses, young and senescent cells respond similarly to one another. Time course experiments revealing repair of DNA damage show that senescent cells generate larger comets than young cells at early stages of repair suggesting that either senescent cells bear more damage per genome than do young cells or that senescent cells are more efficient at excising bulky adducts from DNA. Cells maintained in low levels of serum irrespective of age are less able to repair DNA damage compared with cells maintained in high levels of serum, and furthermore young and senescent cells maintained in high levels of serum are equally able to repair DNA damage. Our data, therefore, reveal both age-dependent and age-independent responses to UV-induced DNA damage. Use of the comet assay highlights the heterogeneity of cellular responses to genotoxic stress.  相似文献   
5.

In this research we have used different cytokines and progesterone to enhance the immunomodulatory capacity of placental-derived stem cells (PLSCs) prior to their encapsulation. We assessed the effect of microencapsulation of the cells without (control) or after 3-day treatment with interferon gamma (INFγ), interleukin10 (IL-10), or progesterone (P4). Treated PLSCs demonstrated strong immunosuppressive effects on phytohemagglutinin (PHA)-activated peripheral blood mononuclear cells (PBMNCs). INFγ treatment resulted in the strongest immune inhibition among the treated groups. The treatments enhanced soluble human leukocyte antigen (sHLAG) secretion compared to control. The IL-10-treated group showed the highest effect on HLAG secretion compared to other groups. Alginate encapsulation of PLSCs did not affect cell viability, or sHLAG secretion. Also, after treatment the encapsulated PLSCs inhibited PHA-activated PBMNCs in the same manner as unencapsulated cells. We studied two groups of encapsulated PLSCs, one without perm-selective poly-l-ornithine (PLO)-coating and the other with PLO-coating, and measured levels of sHLAG secreted. We found no difference in sHLAG secretion between both groups. In summary, our data show that immunomodulatory function of the PLSC is not affected by encapsulation. These findings provide good promise for potential use of encapsulated PLSCs for immunomodulation treatment of disease by stem cell therapy.

  相似文献   
6.
BACKGROUND: Melasma is a chronic hypermelanotic disorder that is challenging to treat; no single effective therapeutic agent for it has been discovered. Methimazole, an oral antithyroid drug, has a skin depigmenting effect when used topically. OBJECTIVE: We sought to evaluate the efficacy and safety of methimazole, applied during microneedling sessions and additional topical use in between sessions, for the treatment of melasma. METHODS: This split-face study included 30 Egyptian patients with melasma, each of whom received 12 microneedling sessions once per week for 12 weeks followed by topical methimazole on the right side of face and placebo on the left side. In between the sessions, topical methimazole 5% cream was applied twice per day on the right side and placebo on the left side. Assessments were performed using the Hemi-melasma Area and Severity Index (hemi-MASI) percentage of improvement, patient satisfaction, dermoscopy, and thyroid-stimulating hormone (TSH) serum levels. RESULTS: There were significant clinical and dermoscopic improvements; hemi-MASI scores on the methimazole-treated right sides were decreased (p<0.001). The percent of hemi-MASI score improvement was significantly associated with the malar pattern (p=0.031) and epidermal type (p=0.04) of melasma. About 70 percent of our studied patients reported being satisfied with their treatment response (7% excellent, 33% good, 30% fair). No significant local or systemic side effects were observed. Pre- and posttreatment serum TSH levels were within the normal range in all treated cases. CONCLUSIONS: Methimazole has the potential to be a safe and promising therapeutic agent for the treatment of melasma via dermapen-delivered microneedling sessions with topical use in between sessions.  相似文献   
7.
Macrolides are widely used antibacterial agents. Although generally well tolerated, they have a number of important additional pharmacological effects, which can sometimes result in significant adverse reactions. This review focuses on three of these side effects: the prokinetic action associated with stimulation of motilin receptors, the proarrhythmic effect due to prolongation of the QT interval of the electrocardiogram and the potential for drug interactions due to inhibition of drug metabolising enzymes. For macrolides that have obtained marketing authorisation in Italy, United Kingdom or United States of America, we also considered whether these actions are properly reported in the approved summaries of the product characteristics and tried to provide strategies to identify patients at risk of significant side effects when macrolides are administered.  相似文献   
8.
Mothers are often responsible for preparing nutritious foods in their households. However, the quality of mother's diets is often neglected, which may affect both mother's and child's nutrition. Because no single food contains all necessary nutrients, diversity in dietary sources is needed to ensure a quality diet. We aimed to study the association between mother's dietary diversity and stunting in children <2 years attending Dhaka Hospital of icddr,b, a diarrhoeal disease hospital in Dhaka, Bangladesh. A case–control study (n = 296) was conducted from November 2016 to February 2017. Data were collected from mothers of stunted children <2 years (length‐for‐age z score [LAZ] < ?2) as “cases” and nonstunted (LAZ ≥ ?1) children <2 years as “controls.” Mothers were asked to recall consumption of 10 defined food groups 24 hr prior to the interview as per Guidelines for Minimum Dietary Diversity for Women. Among the mothers of cases, 58% consumed <5 food groups during the last 24 hr, compared with 45% in control mothers (P = 0.03). Children whose mothers consumed <5 food groups were 1.7 times more likely to be stunted than children whose mothers consumed ≥5 food groups (P = 0.04). Intake of food groups such as pulses, dairy, eggs, and vitamin A rich fruit was higher in control mothers. Proportion of mother's illiteracy, short stature, monthly family income <BDT 11,480, absence of bank account, and poor sanitation was also found to be higher in stunted group. Further study particularly intervention or longitudinal study to see the causality of mother's dietary diversity with child stunting is recommended.  相似文献   
9.
ObjectiveSinonasal surgery is one of the shared airway surgeries that are not uncommonly complicated intra or postoperatively. The proper anesthetic management of these cases plays a crucial role creating a bloodless field. Sugammadex is a new selective relaxant binding drug as it provides a rapid decrease in free rocuronium in the plasma and at nicotinic receptor that help proper awakening of these patients which is extremely important for minimizing the postoperative respiratory complications. The aim of this study is to compare recovery profile in sinonasal surgery in patients reversed by conventional anticholine esterase (Neostigmine) versus those reversed by Sugammadex.MethodsThis study included 40 patients ASA physical status I and II aged 20–45 years with chronic sinusitis undergoing endoscopic sinus surgery with or without septoplasty, hypotensive anesthesia to maintain MAP (50–60 mm Hg), muscle relaxation throughout the procedure at 1–2 posttetanic count (PTCs) by rocuronium infusion, and anesthetic depth maintained using BIS (50–60). Patients were allocated randomly into two equal groups to receive either Sugammadex 4 mg/kg (group I) or Neostigmine 0.05 mg/kg and atropine 0.02 mg/kg (group II) as a reversal agent, and assessment of postoperative respiratory complications was performed using the Postoperative Respiratory System Evaluation Score (PRSES) at 1st and 5th minutes after extubation.ResultsThe reversal time showed highly significant difference between the two groups. Patients in the Sugammadex group could reach a TOF of 0.9 in a mean time 2.47 (0.51) min versus 24.21 (4.7) min for the Neostigmine group; postoperative respiratory complications, the Sugammadex group and the Neostigmine group did not differ statistically; however, more patients in Neostigmine group showed respiratory complications at 1st and 5th minutes after extubation as shown by PRSES Scoring System.ConclusionThis study showed that the use of Sugammadex in reversing rocuronium induced neuromuscular block in patients undergoing functional endoscopic surgery is superior to Neostigmine. Further studies are required to weigh the cost benefit relationship of the use of Sugammadex in routine clinical practice.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号