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   108篇
  免费   7篇
  国内免费   5篇
综合类   2篇
化学工业   43篇
金属工艺   6篇
建筑科学   7篇
轻工业   48篇
无线电   8篇
一般工业技术   5篇
自动化技术   1篇
  2024年   2篇
  2023年   4篇
  2022年   18篇
  2021年   19篇
  2020年   12篇
  2019年   5篇
  2018年   2篇
  2017年   5篇
  2016年   4篇
  2015年   5篇
  2014年   4篇
  2013年   2篇
  2012年   5篇
  2011年   6篇
  2010年   4篇
  2009年   2篇
  2008年   1篇
  2007年   3篇
  2005年   5篇
  2004年   1篇
  2003年   1篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1998年   1篇
  1995年   1篇
  1993年   1篇
  1990年   1篇
  1983年   1篇
  1980年   1篇
  1979年   1篇
排序方式: 共有120条查询结果,搜索用时 15 毫秒
51.
The pathophysiology of allergic rhinitis (AR), one of the most common diseases in the world, is still not sufficiently understood. Extracellular vesicles (EVs), which are secreted by host and bacteria cells and take part in near and distant intracellular communication, can provide information about AR. Recently, attention has been drawn to the potential use of EVs as biomarkers, vaccines, or transporters for drug delivery. In this review, we present an up-to-date literature overview on EVs in AR to reveal their potential clinical significance in this condition. A comprehensive and systematic literature search was conducted following PRISMA statement guidelines for original, completed articles, available in English concerning EVs and AR. For this purpose, PubMed/MEDLINE, Scopus, Web of Science, and Cochrane, were searched up until 10 Novenmber 2022. From 275 records, 18 articles were included for analysis. The risk of bias was assessed for all studies as low or moderate risk of overall bias using the Office and Health Assessment and Translation Risk of Bias Rating Tool for Human and Animal Studies. We presented the role of exosomes in the pathophysiology of AR and highlighted the possibility of using exosomes as biomarkers and treatment in this disease.  相似文献   
52.
Intermittent hypoxia (IH) has been an issue of considerable research in recent years and triggers a bewildering array of both detrimental and beneficial effects in several physiological systems. However, the mechanisms leading to the effect are not yet clear. Consequently, we investigated the effects of IH on allergen-induced allergic asthma via the mitogen-activated protein kinase (MAPK) signaling pathway. Forty BALB/c mice were dived into four groups. We evaluated the influence of IH on the cell signaling system of the airway during the allergen-induced challenge in an animal model, especially through the MAPK (mitogen-activated protein kinase) pathway. The protein concentrations of p-ERK/ERK, p-JNK/JNK, p-p38/p38, and pMEK/MEK were significantly reduced in the allergen-induced+IH group, compared to the allergen-induced group (p-value < 0.05 as considered statistically significant). The number of eosinophils, neutrophils, macrophages, and lymphocytes in the bronchoalveolar lavage fluid and Dp (Dermatophagoides pteronyssinus)-specific IgG2a and interleukins 4, 5, 13, and 17 were significantly reduced in the Dp+IH group, compared to the Dp group. These findings suggest that the MAPK pathway might be associated with the beneficial effect of IH on the attenuation of allergic response in an allergen-induced mouse model.  相似文献   
53.
Bisphenol S (BPS) is increasingly being used as an alternative for bisphenol A; however, its health effects remain unclear. We investigated the effects of oral exposure to low-dose BPS on allergic asthma. C3H/HeJ male mice were intratracheally administered with allergen (ovalbumin (OVA), 1 μg/animal) every 2 weeks from 6 to 11 weeks old. BPS was ingested by drinking water at doses equivalent to 0.04, 0.4, and 4 μg/kg/day. We then examined pulmonary inflammation, airway hyperresponsiveness, serum OVA-specific immunoglobulin (Ig) levels, Th2 cytokine/chemokine production, and mediastinal lymph node (MLN) cell activities. Compared with OVA alone, moderate-dose BPS (BPS-M) with OVA significantly enhanced pulmonary inflammation, airway hyperresponsiveness, and OVA-specific IgE and IgG1. Furthermore, interleukin (IL)-5, IL-13, IL-33, and CCL11/Eotaxin protein levels in the lungs increased. Conversely, these allergic responses were reduced in the high-dose BPS+OVA group. In MLN cells, BPS-M with OVA increased the total cell count and activated antigen-presenting cells including conventional dendritic cell subset (cDC2). After OVA restimulation, cell proliferation and Th2 cytokine production (IL-4, IL-5, and IL-13) in the culture supernatant also increased. Therefore, oral exposure to low-dose BPS may exacerbate allergic asthmatic responses by enhancing Th2-polarized responses and activating the MLN cells.  相似文献   
54.
Pulmonary fibrosis is becoming an increasingly common pathology worldwide. Unfortunately, this disorder is characterized by a bad prognosis: no treatment is known, and the survival rate is dramatically low. One of the most frequent reasons for pulmonary fibrosis is hypersensitivity pneumonitis (HP). As the main mechanism of pulmonary fibrosis is a pathology of the repair of wounded pulmonary epithelium with a pivotal role in epithelial–mesenchymal transition (EMT), we assumed that EMT silencing could prevent disease development. Because of several biological features including wound healing promotion, an ideal candidate for use in the treatment of pulmonary fibrosis seems to be cathelicidin. The aim of the studies was to understand the influence of cathelicidin on the EMT process occurring during lung fibrosis development in the course of HP. Cathelicidin’s impact on EMT was examined in a murine model of HP, wherein lung fibrosis was induced by chronic exposure to extract of Pantoea agglomerans (SE-PA) by real-time PCR and Western blotting. Studies revealed that mouse exposure to cathelicidin did not cause any side changes in the expression of investigated genes/proteins. Simultaneously, cathelicidin administered together or after SE-PA decreased the elevated level of myofibroblast markers (Acta2/α-smooth muscle actin, Cdh2/N-cadherin, Fn1/Fibronectin, Vim/vimentin) and increased the lowered level of epithelial markers (Cdh1/E-cadherin, Ocln/occludin). Cathelicidin provided with SE-PA or after cessation of SE-PA inhalations reduced the expression of EMT-associated factors (Ctnnd1/β-catenin, Nfkb1/NFκB, Snail1/Snail, Tgfb1/TGFβ1 Zeb1/ZEB1, Zeb2/ZEB2) elevated by P. agglomerans. Cathelicidin’s beneficial impact on the expression of genes/proteins involved in EMT was observed during and after the HP development; however, cathelicidin was not able to completely neutralize the negative changes. Nevertheless, significant EMT silencing in response to cathelicidin suggested the possibility of its use in the prevention/treatment of pulmonary fibrosis.  相似文献   
55.
A breached nasal epithelial barrier plays an important role in driving allergic rhinitis (AR). Corticosteroids remain the standard of care (SoC) but come with side effects, thus alternative safe and effective treatments able to avoid inflammation and restore barrier integrity are needed. The aim of the present study is to evaluate the barrier-forming capacity of a xyloglucan-based nasal spray (XG) and compare its efficacy to several SoC treatments (corticosteroid spray, oral mast-cell stabilizer and oral antihistamine) in reducing allergic responses in addition to its effect when concomitantly administered with an antihistamine. An ovalbumin (OVA)-induced mouse AR model was used. XG shows a significant efficacy in reducing histological damage in AR mice; improves nasal rubbing and histamine-induced hyper-responsiveness. Total and OVA-specific IgE as well as pro-inflammatory cytokines are significantly reduced compared to OVA challenged-mice, with im-proved efficacy when used as an add-on treatment. However, XG reduces mucous secreting cells (PAS-positive) and mucin mRNA expression similar to the corticosteroid-treated mice. XG-spray maintains tight junction protein expression (ZO-1) and conversely decreases HDAC1 significantly; the latter being highly expressed in AR patients. Moreover, the concomitant treatment showed in all of the endpoints a similar efficacy to the corticosteroids. This innovative approach may represent a novel therapeutic strategy for nasal respiratory diseases like AR, reducing undesirable side effects and improving the quality of life in patients.  相似文献   
56.
目的: 研究芍药苷(paeoniflorin,Pae)对肥大细胞(P815)活化及脱颗粒的影响,并探索其作用机制。方法: CCK-8法评价Pae的细胞毒性,ELISA法及显色法测定Pae对P815释放组胺和β-氨基己糖苷酶(β-HEX)及IL-1β、IL-4、IL-8、IL-12的影响。实时荧光定量PCR(qRT-PCR)检测上述炎症因子及蛋白酶激活受体(PARs)在mRNA水平上的表达。Western blot测定磷脂酰肌醇3激酶(PI3K)、蛋白激酶B(AKT)、哺乳动物雷帕霉素靶体蛋白(m-TOR)的磷酸化水平。结果: 当芍药苷的浓度为1,10,100 μg/mL时对P815无毒性,且能有效抑制组胺、β-HEX的释放及IL-1β、IL-4、IL-8、IL-12的分泌,并降低PARs的表达。Western blot显示,Pae能抑制PI3K、AKT、m-TOR的磷酸化。结论: Pae可能通过抑制PI3K/AKT/m-TOR信号通路实现对肥大细胞活化及脱颗粒的抑制作用。  相似文献   
57.
目的建立一种可同时快速测定海产品中8种生物胺的丹磺酰氯柱前衍生反相高效液相色谱法。方法样品经5%三氯乙酸提取,丹磺酰氯柱前衍生后,采用Agilent zorbax SB-C_(18)色谱柱(4.6 mm×150 mm,5μm),以甲醇和水作为流动相,进行梯度洗脱。柱温30℃,流速为1.5 m L/min,采用UV紫外检测器,检测波长254 nm,对8种生物胺进行分离分析。结果结果显示,色胺、2-苯乙胺、腐胺、尸胺、组胺、酪胺、亚精胺和精胺在15 min内得到有效分离,在1~100 mg/L范围内线性系数r~2﹥0.999,8种生物胺测定方法的检出限范围为0.02~0.17 mg/L,定量限范围为0.067~0.57 mg/L,且重复性良好,向秋刀鱼中分别添加生物胺标准品20.0、50.0、100.0 mg/L 3个含量水平,8种生物胺平均回收率介于79%~117%之间,相对标准偏差为0.84%~12.57%。采用该方法测定了秋刀鱼等5类海产品中8种生物胺的含量,结果显示生物胺总含量在23~208 mg/kg之间。结论该方法简单、快速,灵敏度和准确度符合要求,适用于海产品中多种生物胺的同时检测。  相似文献   
58.
59.
60.
Dry eye disease (DED) and allergic conjunctivitis affect a large number of patients, and many patients usually have both symptoms. We investigated the interactions between DED and allergic conjunctivitis in mice. Four experimental groups were compared: control, DED, allergy, and allergy with DED. DED was induced by removing the extraorbital lacrimal glands of the mice. Allergic conjunctivitis was induced by intraperitoneal administration of ovalbumin and antigen eye drops. The early phase reaction of the allergy was evaluated using the clinical score, scratching behavior, and vascular permeability in the conjunctiva. Epithelial barrier function was assessed by an LC-biotin assay. Tear fluid volume and corneal fluorescein staining decreased in the DED and allergy with DED groups. LC-biotin penetrated the entire epithelium of both the cornea and conjunctiva in DED mice. The clinical score of the early phase reaction was higher in allergy-induced mice than in non-allergy mice. Edema of the eyelid and conjunctiva were aggravated in mice with DED. The number of scratching episodes and leakage of Evans blue into the conjunctiva were higher in allergy-induced DED mice than in control mice. The presence of aqueous-deficient dry eye caused ocular surface epithelial damage and exacerbated allergic signs and symptoms.  相似文献   
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