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排序方式: 共有809条查询结果,搜索用时 31 毫秒
1.
Coptidis Rhizoma is the dried rhizome from the Coptis chinensis Franch. that has been shown to have a number of beneficial pharmacological properties including antioxidant, anti-inflammatory, and anti-cancer effects. However, the anti-cancer effects of Coptidis Rhizoma on hepatocellular carcinoma (HCC) remain unclear. In this study, we investigated the anti-cancer properties of Coptidis Rhizoma ethanol extract (CR) in HCC Hep3B cells and in a xenograft mouse model. Our results showed that the CR significantly inhibited cell growth and induced apoptosis in Hep3B cells through increased expression of Bcl-2 associated x-protein (Bax) and cleavage of poly-ADP ribose polymerase (PARP), reduced expression of Bcl-2, and activated caspases. CR also increased the generation of intracellular reactive oxygen species (ROS), which caused a loss of mitochondrial membrane potential (MMP, ΔΨm) and activation of the mitochondria-mediated intrinsic apoptosis pathway. Moreover, N-acetylcysteine (NAC), a ROS inhibitor, markedly blocked the effects of CR on apoptotic pathways. CR also induced the expression of light chain 3 (LC3)-I/II, a key autophagy regulator, whereas CR-mediated autophagy was significantly suppressed by NAC. In addition, pre-treatment with NAC perfectly attenuated the inhibition of cell invasion and migration of CR-stimulated Hep3B cells. Furthermore, oral administration of CR suppressed Hep3B tumor growth in xenograft mice without toxicity, alterations to body weight, or changes in hematological and biochemical profiles. Taken together, our findings suggest that CR has anti-tumor effects that result from ROS generation, and may be a potential pharmacological intervention for HCC.  相似文献   
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杨柳  Cheong Enggan 《建筑施工》2006,28(3):205-207,212
用作生命科学研究的建筑物需要有专门的建设和服务元素的介入.才能提供和创造符合工艺流程状况的设施和环境。其中的专业实验室。布置时应针对用户进行环境定制和专业设施配置,并为对生物生命各个方面的高端观察提供便利。在分析生命科学建筑的特征厦发展趋势的同时,对其内部空间的使用进行了调查,为生命科学建筑设计提供佐证。  相似文献   
4.
Sekhar SC  Tham KW  Cheong KW 《Indoor air》2003,13(4):315-331
An integrated indoor air quality (IAQ)-energy audit methodology has been developed in this study in Singapore, which provides a rigorous and systematic method of obtaining the status-quo assessment of an 'IAQ signature' in a building. The methodology entails a multi-disciplinary model in obtaining measured data pertaining to different dimensions within the built environment such as the physical, chemical, biological, ventilation, and occupant response characteristics. This paper describes the audit methodology and presents the findings from five air-conditioned office buildings in Singapore. The research has also led to the development of an indoor pollutant standard index (IPSI), which is discussed in this paper. Other performance indicators such as, the ventilation index and the energy index as well as the building symptom index (BSI) are also presented and discussed in the context of an integrated approach to IAQ and energy. Several correlation attempts were made on the various symptoms, indoor air acceptability, thermal comfort, BSI and IPSI, and while BSI values are found to correlate among them as well as with IAQ and THERMAL COMFORT acceptability, no such correlation was observed between BSI and IPSI. This would suggest that the occupants' perception of symptoms experienced as well as environmental acceptability is quite distinct from IAQ acceptability determined from empirical measurements of indoor pollutants, which reinforces the complex nature of IAQ issues.  相似文献   
5.
This paper presents a study of local thermal sensation (LTS) and comfort in a field environmental chamber (FEC) served by displacement ventilation (DV) system. The FEC, 11.12 m (L)×7.53 m (W)×2.60 m (H), simulates a typical office layout. A total of 60 tropically acclimatized subjects, 30 male and 30 female, were engaged in sedentary office work for 3 h. Subjects were exposed to three vertical air temperature gradients, nominally 1, 3 and 5 K/m, between 0.1 and 1.1 m heights and three room air temperatures of 20, 23 and 26 °C at 0.6 m height. The objective of this study is to investigate the mutual effect of local and overall thermal sensation (OTS) and comfort in DV environment. The results show that in a space served by DV system, at OTS close to neutral, local thermal discomfort decreased with the increase of room air temperature. The OTS of occupants was mainly affected by LTS at the arm, calf, foot, back and hand. Local thermal discomfort was affected by both LTS and OTS. At overall cold thermal sensation, all body segments prefer slightly warm sensation. At overall slightly warm thermal sensation, all body segments prefer slightly cool sensation.  相似文献   
6.
Tests were carried out at passive mine water treatment sites in South Korea to determine how flow and pH affected other water quality parameters. Computational flow analysis and tracer tests revealed that the water took surprisingly direct flow routes in the oxidation ponds, while other areas remained stagnant. Furthermore, ferrous iron concentration, dissolved oxygen, pH, electrical conductivity, total dissolved solids, turbidity, and water depth were all directly affected by the flow patterns due to the relationship between retention time and iron precipitation.  相似文献   
7.
Indoor environment quality audits were performed in six European countries and in Singapore using the same methodology. Five to eight office buildings were audited in each country. The audits included airflow rate measurements, energy audit, indoor air quality (VOC1 CO2, dust concentrations), and questionnaires to occupants. Questions to occupants addressed their health, their comfort and well-being, as well as their perception of their environment. This paper compares the results obtained from these audits, with particular attention to the effects of ventilation or air conditioning systems and climate.

The number of building related symptoms is, on the average, significantly smaller in the buildings audited in Singapore than in Europe. One of the reasons may be the non-smoking policy common in Singapore. It is also once more observed that buildings are often over-warmed in cold climates and overcooled in warm climates. Surprising, but not new, is that there are no correlations between specific air flow rates and perceived air quality or health, as long as airflow rates are within accepted standards.  相似文献   
8.
Human milk fat substitutes (HMFSs) with triacylglycerol profiles highly similar to those of human milk fat (HMF) were prepared from lard by physical blending followed by enzymatic interesterification. Based on the fatty acid profiles of HMF, different vegetable and single‐cell oils were selected and added to the lard. Blend ratios were calculated based on established physical blending models. The blended oils were then enzymatically interesterified using a 1,3‐regiospecific lipase, Lipozyme RM IM (RML from Rhizomucor miehei immobilized on Duolite ES562; Novozymes A/S, Bagsværd, Denmark), to approximate HMF triacylglycerol (TAG) profiles, particularly with respect to the distribution of palmitic acid in the sn?2 position. The optimized blending ratios were determined to be: lard:sunflower oil:canola oil:palm kernel oil:palm oil:algal oil:microbial oil = 1.00:0.10:0.50:0.13:0.12:0.02:0.02. The optimized reaction conditions were determined to be: enzyme load of 11 wt%, temperature of 60 °C, water content of 3.5 wt%, and reaction time of 3 hours. The resulting product was evaluated for total and sn?2 fatty acids, polyunsaturated fatty acids, and TAG composition. A high degree of similarity was obtained, indicating the great potential of the product as a fat alternative for use in infant formulas.  相似文献   
9.
Staphylococcus aureus (S. aureus) is a widespread cutaneous pathogen responsible for the great majority of bacterial skin infections in humans. The incidence of skin infections by S. aureus reflects in part the competition between host cutaneous immune defenses and S. aureus virulence factors. As part of the innate immune system in the skin, cationic antimicrobial peptides (CAMPs) such as the β-defensins and cathelicidin contribute to host cutaneous defense, which prevents harmful microorganisms, like S. aureus, from crossing epithelial barriers. Conversely, S. aureus utilizes evasive mechanisms against host defenses to promote its colonization and infection of the skin. In this review, we focus on host-pathogen interactions during colonization and infection of the skin by S. aureus and methicillin-resistant Staphylococcus aureus (MRSA). We will discuss the peptides (defensins, cathelicidins, RNase7, dermcidin) and other mediators (toll-like receptor, IL-1 and IL-17) that comprise the host defense against S. aureus skin infection, as well as the various mechanisms by which S. aureus evades host defenses. It is anticipated that greater understanding of these mechanisms will enable development of more sustainable antimicrobial compounds and new therapeutic approaches to the treatment of S. aureus skin infection and colonization.  相似文献   
10.
The study investigates the effect of inherent structural properties of liquid substrates on physical vapor-deposited metallic condensates. Due to the limitations in characterizing the atomic structure of different kinds of liquids, quantitative analysis of all the influencing parameters of the liquid substrate is difficult. Real time considered computing simulation is called for to realize the effects of such properties, which gives direct analyzable results. As representatives of physical and chemical properties of substrates, the molecular frequency and adsorption probability (~binding energy) are utilized as the key simulation parameters. Nucleation kinetics represented by conventional equations and an adapted time algorithm are employed to guarantee a correct, comparable and efficient simulation technique. The results show the substrates’ influence on the ‘morphology’ and ‘formation time’ of the film. In particular, the non-uniform morphology and low coverage observed under ‘liquid-substrate conditions’ are in agreement with experimental observations. The method can also be applied for predicting the condensate morphology for various vapor/substrate systems with known conditions.  相似文献   
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