An indoor air quality evaluation in a residential retrofit project using spray polyurethane foam

Understanding of indoor air quality (IAQ) during and after spray polyurethane foam (SPF) application is essential to protect the health of both workers and building occupants. Previous efforts such as field monitoring, micro-chamber/spray booth emission studies, and fate/transport modeling have been conducted to understand the chemical exposure of SPF and guide risk mitigation strategies. However, each type of research has its limitation and can only reveal partial information on the relationship between SPF and IAQ. A comprehensive study is truly needed to integrate the experimental design and analytical testing methods in the field/chamber studies with the mathematical tools employed in the modeling studies. This study aims to bridge this gap and provide a more comprehensive understanding on the impact of SPF to IAQ. The field sampling plan of this research aims to evaluate the airborne concentrations of methylene diphenyl diisocyanate (MDI), formaldehyde, acetaldehyde, propionaldehyde, tris(1-chlor-2-propyl)phosphate (TCPP), trans-1-chloro-3,3,3-trifluoropropene (Solstice^TM), and airborne particles. Modifications to existing MDI sampling and analytical methods were made so that level of quantification was improved. In addition, key fate and transport modeling input parameters such as air changes per hour and airborne particle size distribution were measured. More importantly, TCPP accumulation onto materials was evaluated, which is important to study the fate and transport of semi-volatile organic compounds. The IAQ results showed that after spray application was completed in the entire building, airborne concentrations decreased for all chemicals monitored. However, it is our recommendation that during SPF application, no one should return to the application site without proper personal protection equipment as long as there are active spray activities in the building. The comparison between this field study and a recent chamber study proved surface sorption and particle deposition is an important factor in determining the fate of airborne TCPP. The study also suggests the need for further evaluation by employing mathematical models, proving the data generated in this work as informative to industry and the broader scientific community.     

直缘乌头内生真菌Alternaria solani化学成分研究

摘 要 目的：对直缘乌头内生真菌Alternaria solani 的化学成分进行研究。方法: 采用各种柱色谱对直缘乌头内生真菌Alternaria solani的甲醇提取物进行分离纯化,经波谱数据 (¹ H-NMR,¹³ C-NMR,MS) 进行结构鉴定。结果:分离得到15个化合物,分别鉴定为：20 羟基麦角甾 4,6,8(14),22-四烯-3-酮（1）、(22E,24R)- 麦角甾-4,6,8(14),22-四烯-3-酮（2）、(22E,24R)-麦角甾-7,22-二烯-3-β-醇（3）、24-亚甲基-麦角甾-7-烯-3β-醇（4）、过氧麦角甾醇（5）、cyclo(D)-Pro-(D)-Leu（6）、cyclo-(L-Val-L-Pro)（7）、cyclo-(S-Pro-S-Ile)（8）、tentoxin（9）、porrotoxin（10）、7-dehydroxyl-zinniol（11）、zinniol（12）、8-zinniol methyl ether（13）、3-甲氧基-4-甲基-5-(3’,3′-二甲基烯丙氧基)-2-甲氧基甲基苯甲酸（14）、拟盘多毛孢H2-倍半萜内酯（15）。结论:从直缘乌头内生真菌Alternaria solani中分离得到15个化合物,其中化合物2~10,12~15是首次从该植物内生真菌中分离得到。     

注射用甲泼尼龙琥珀酸钠致速发型超敏反应22例分析

摘 要 目的：探讨注射用甲泼尼龙琥珀酸钠所致速发型超敏反应的一般规律及特点,为临床合理用药提供参考。方法: 采用回顾性研究方法,分析22例应用甲泼尼龙琥珀酸钠致速发型超敏反应的患者资料,对其临床表现、影响因素、治疗和转归等进行探讨。结果: 甲泼尼龙琥珀酸钠所致的速发型超敏反应从用药后30 s至用药后24 h内皆可发生,22例中有18例出现在用药30 min内,构成比为81.82%,主要累及皮肤、呼吸、消化、循环、神经系统或器官,以皮肤反应最为常见,严重者可致过敏性休克,须停药并积极治疗。结论: 临床应重视甲泼尼龙琥珀酸钠所致的速发型超敏反应,尤其是合并使用其他药物过程中,以免延误诊治。     

Using previous trial results to inform hypothesis testing of new interventions

Results of industry-sponsored Phase III trials registered at clinicaltrials.gov include a rich amount of information on the efficacy of medical interventions. We propose that these results can be used to inform hypothesis testing of a new intervention through the Bayes principle. The posterior probability of positive efficacy offers an accessible interpretation of the uncertainty of efficacy and a convenient metric for global false-positive control.     

Delivery of radix ophiopogonis polysaccharide via sucrose acetate isobutyrate-based in situ forming systems alone or combined with its mono-PEGylation

This work aimed to achieve long-lasting delivery of radix ophiopogonis polysaccharide (ROP) by sucrose acetate isobutyrate (SAIB)-based in situ forming systems (ISFSs) alone or combined with mono-PEGylation of ROP. When the ‘90%SAIB/10% solvent’ system was used, the mean residence time (MRT) of ROP was prolonged by 4.3 5?～?7.00 times and the initial release rate was reduced significantly. However, this system was only suitable for days-long sustained release of ROP in short-term therapy. As to the ‘SAIB/additives/solvent’ system containing mono-PEGylated ROP, the results indicated that SAIB/poly(d,l-lactide-co-glycolide) (PLGA)/N-methyl-2-pyrrolidone (NMP) was superior to SAIB/polylactic acid (PLA)/NMP and SAIB/PLA/ethanol in controlled release. Moreover, weeks- to months-long (16–60 d) smooth release of ROP could be achieved by varying the concentration (10–30%) and molecular weight (MW) of PLGA (10–50?kDa) or by employing a moderate MW of PEGylated ROP (～20 or ～30?kDa). With further increasing the conjugate MW to ～40?kDa, the contribution of drug elimination to its plasma retention seemed to surpass that of the SAIB-based system, resulting in that the system no longer had an obvious influence on the in vivo behavior of the conjugate. Besides, the results of host response confirmed that with less solvent being used, the SAIB-based systems showed a higher biocompatibility than the PLGA-based systems, suggesting that they could be freely chosen in the prevention and/or cure of chronic diseases.     

Ratiometric delivery of two therapeutic candidates with inherently dissimilar physicochemical property through pH-sensitive core–shell nanoparticles targeting the heterogeneous tumor cells of glioma

Currently, combination drug therapy is one of the most effective approaches to glioma treatment. However, due to the inherent dissimilar pharmacokinetics of individual drugs and blood brain barriers, it was difficult for the concomitant drugs to simultaneously be delivered to glioma in an optimal dose ratio manner. Herein, a cationic micellar core (Cur-M) was first prepared from d-α-tocopherol-grafted-ε-polylysine polymer to encapsulate the hydrophobic curcumin, followed by dopamine-modified-poly-γ-glutamic acid polymer further deposited on its surface as a anion shell through pH-sensitive linkage to encapsulate the hydrophilic doxorubicin (DOX) hydrochloride. By controlling the combinational Cur/DOX molar ratio at 3:1, a pH-sensitive core–shell nanoparticle (PDCP-NP) was constructed to simultaneously target the cancer stem cells (CSCs) and the differentiated tumor cells. PDCP-NP exhibited a dynamic diameter of 160.8?nm and a zeta-potential of –30.5?mV, while its core–shell structure was further confirmed by XPS and TEM. The ratiometric delivery capability of PDCP-NP was confirmed by in vitro and in vivo studies, in comparison with the cocktail Cur/DOX solution. Meanwhile, the percentage of CSCs in tumors was significantly decreased from 4.16% to 0.95% after treatment with PDCP-NP. Overall, PDCP-NP may be a promising carrier for the combination therapy with drug candidates having dissimilar physicochemical properties.     

煤矿开采行业工人下背痛与职业应激关联探讨

目的探讨煤矿开采行业工人下背痛与职业应激的关联性。方法2015年1月至2016年12月,选择山西省某大型煤矿开采企业某矿区的一线生产工人472名作为研究对象,采用问卷调查方法调查其基本信息、下背痛患病信息、职业应激水平,二分类Logistic回归法分析下背痛与职业应激的关系。结果研究对象472人中186人在过去一年内发生过下背痛,下背痛年患病率为39.41%。下背痛组的职业应激任务得分高于非下背痛组,差异有统计学意义(P<0.01)。二分类Logistic回归分析结果显示:年龄、婚姻情况、工龄、职业应激任务、劳动强度、工作中保持同一姿势、倒班可能是下背痛的危险因素(P<0.01),吸烟可能是下背痛的保护因素(P<0.01)。结论职业应激任务可能是煤矿开采工人发生下背痛的危险因素(P<0.01),合理分配工作任务、及时疏解煤矿开采工人的职业应激,可能是预防和控制下背痛的有效途径之一。     

Quercetin attenuates domoic acid-induced cognitive deficits in mice

Domoic acid (DA) is one of the best known marine toxins, causative of important neurotoxic alterations. DA effects are documented both in wildlife and experimental assays, showing that this toxin causes severe injuries principally in the hippocampal area. Accumulating evidence indicates that mitochondrial dysfunction and oxidative stress are involved in DA-induced cognitive functional impairment. Therefore, therapeutics targeted to improve mitochondrial function and increase oxidative stress defence could be bene?cial. Quercetin, a bio?avanoid, has been reported to have potent neuroprotective effects and anti-oxidative ability, but its preventive effects on DA-induced mitochondrial dysfunction and cognitive impairment have not been well characterised. In this study, we evaluated the effects of quercetin on DA-induced cognitive deficits in mice and explored its potential mechanism. Our results showed that the oral administration of quercetin to DA-treated mice significantly improved their behavioural performance in a novel objective recognition task and a Morris water maze task. These improvements were mediated, at least in part, by a stimulation of PPARγ coactivator 1α-mediated mitochondrial biogenesis signalling and an amelioration of mitochondrial dysfunction. Moreover, quercetin activated nuclear factorerythroid-2-related factor-2 (Nrf2)-mediated phase II enzymes and decreased reactive oxygen species and protein carbonylation. Furthermore, the AMP-activated protein kinase (AMPK) activity significantly increased in the quercetin-treated group. Taken together, these findings suggest that a reduction in mitochondrial dysfunction through the increase of AMPK activity, coupled with an increase in Nrf2 pathway mediated oxidative defence, may be one of the mechanisms by which quercetin improves cognitive impairment induced by DA in mice.     

Longitudinal associations of lifetime adiposity with leukocyte telomere length and mitochondrial DNA copy number

Adiposity may cause adverse health outcomes by increasing oxidative stress and systemic inflammation, which can be reflected by altered telomere length (TL) and mitochondrial DNA copy number (mtCN) in peripheral blood leukocytes. However, little is known about the influence of lifetime adiposity on TL and mtCN in later life. This study was performed to investigate the associations of lifetime adiposity with leukocyte TL and mtCN in 9613 participants from the Nurses’ Health Study. A group-based trajectory modelling approach was used to create trajectories of body shape from age 5 through 60 years, and a genetic risk score (GRS) was created based on 97 known adiposity susceptibility variants. Associations of body shape trajectories and GRS with dichotomized TL and mtCN were assessed by logistic regression models. After adjustment for lifestyle and dietary factors, compared with the lean-stable group, the lean-marked increase group had higher odds of having below-median TL (OR?=?1.18, 95% CI 1.04, 1.35; P?=?0.01), and the medium-marked increase group had higher odds of having below-median mtCN (OR?=?1.28, 95% CI 1.00, 1.64; P?=?0.047). There was a suggestive trend toward lower mtCN across the GRS quartiles (P for trend?=?0.07). In conclusion, telomere attrition may be accelerated by marked weight gain in middle life, whereas mtCN is likely to be reduced persistently by adiposity over the life course. The findings indicate the importance of lifetime weight management to preserve functional telomeres and mitochondria.