Biobased poly(propylene sebacate) as shape memory polymer with tunable switching temperature for potential biomedical applications

From the point of better biocompatibility and sustainability, biobased shape memory polymers (SMPs) are highly desired. We used 1,3-propanediol, sebacic acid, and itaconic acid, which have been industrially produced via fermentation or extraction with large quantities as the main raw materials for the synthesis of biobased poly(propylene sebacate). Diethylene glycol was used to tailor the flexibility of the polyester. The resulted polyesters were found to be promising SMPs with excellent shape recovery and fixity (near 100% and independent of thermomechanical cycles). The switching temperature and recovery speed of the SMPs are tunable by controlling the composition of the polyesters and their curing extent. The continuously changed switching temperature ranging from 12 to 54 °C was realized. Such temperature range is typical for biomedical applications in the human body. The molecular and crystalline structures were explored to correlate to the shape memory behavior. The combination of potential biocompatibility and biodegradability of the biobased SMPs makes them suitable for fabricating biomedical devices.     

人热休克蛋白gp96基因的克隆及其在大肠杆菌中的表达与纯化

热休克蛋白gp96是热休克蛋白90家族成员,能够引起非特异性和特异性免疫反应。得到大量高纯度的蛋白质是研究开发gp96的关键。然而重组的gp96容易在E．coli中降解,并在一定条件下形成多聚体。实验先将人gp96基因克隆到pET-30a载体上并在E．coli Blstar中表达,再经过亲和层析、阴离子交换、分子筛分别纯化gp96。最终去掉了大部分的降解片段和多聚体,得到一定量的可溶性gp96,为进一步研究其结构和功能打下一定的基础。     

Temperament in Rhesus,Long‐Tailed,and Pigtailed Macaques Varies by Species and Sex

Temperament differs among individuals both within and between species. Evidence suggests that differences in temperament of group members may parallel differences in social behavior among groups or between species. Here, we compared temperament between three closely related species of monkey—rhesus (Macaca mulatta), long‐tailed (M. fascicularis), and pigtailed (M. nemestrina) macaques—using cage‐front behavioral observations of individually housed monkeys at a National Primate Research Center. Frequencies of 12 behaviors in 899 subjects were analyzed using a principal components analysis to identify temperament components. The analysis identified four components, which we interpreted as Sociability toward humans, Cautiousness, Aggressiveness, and Fearfulness. Species and sexes differed in their average scores on these components, even after controlling for differences in age and early‐life experiences. Our results suggest that rhesus macaques are especially aggressive and unsociable toward humans, long‐tailed macaques are more cautious and fearful, and pigtailed macaques are more sociable toward humans and less aggressive than the other species. Pigtailed males were notably more sociable than any other group. The differences observed are consistent with reported variation in these species’ social behaviors, as rhesus macaques generally engage in more social aggression and pigtailed macaques engage in more male–male affiliative behaviors. Differences in predation risks are among the socioecological factors that might make these species‐typical behaviors adaptive. Our results suggest that adaptive species‐level social differences may be encoded in individual‐level temperaments, which are manifested even outside of a social context. Am. J. Primatol. 75:303‐313, 2013. © 2012 Wiley Periodicals, Inc.     

毛乌素沙地南缘沙丘生物结皮对凝结水形成和蒸发的影响

在水分极度匮乏的荒漠生态系统,凝结水是除降雨之外最重要的水分来源之一,它对荒漠生态系统结构、功能和过程的维持产生重要的影响。为探明半干旱沙区生物结皮表面的凝结水形成和蒸发特征,采用自制的微型蒸渗计(直径7 cm、高5 cm的PVC管)实验观测了不同类型地表(裸沙、浅灰色藻类结皮、黑褐色藻类结皮和苔藓结皮)对凝结水形成和蒸发的影响。结果表明:(1)观测期间共有20次凝结水形成记录,除降雨天气外,几乎每天都能观测到水分凝结现象;(2)不同类型地表凝结水总量依次为(1.998±0.075),(2.326±0.083),(2.790±0.058)和(3.416±0.068) mm,生物结皮表面的凝结水总量显著大于裸沙(P < 0.05);随生物结皮的发育,不同类型生物结皮表面的凝结水总量呈增加的趋势,凝结水总量之间差异显著(P < 0.05);观测期间不同类型地表日平均凝结水量依次为(0.100±0.003),(0.116±0.004),(0.140±0.002)和(0.171± 0.003) mm,不同类型地表日平均凝结水量之间差异极显著(P < 0.01);(3)凝结水形成过程的观测结果显示,凝结水19:00开始形成,23:00-凌晨1:00形成不明显,1:00-7:00继续形成,除浅灰色藻类结皮外,太阳升出后在黑褐色藻类结皮和苔藓结皮表面继续形成少量的凝结水;凝结水7:30开始蒸发,10:30到11:00之间结束蒸发,凝结水在裸沙和浅灰色藻类结皮中的保持时间显著大于黑褐色藻类结皮和苔藓结皮中的保持时间(P < 0.05);(4)凝结水的形成受大气温度、地表温度、空气相对湿度和大气地表温度差等气象因素的影响,但其形成过程不与某一个气象因素呈简单的线性关系。     

PTPN22 gene polymorphism in Egyptian alopecia areata patients and its impact on response to diphencyprone immunotherapy

PTPN22 1858C>T gene polymorphism has been associated with several autoimmune disorders including alopecia areata. The aim of the current study was to investigate the effect of the inherited genetic polymorphism 1858C>T of PTPN22 gene on the predisposition to severe forms of alopecia areata and its effect on the response to DPC treatment. To achieve our aim, PTPN22 1858C>T genotyping was performed by PCR-based restricted fragment length polymorphism (PCR-RFLP) analysis. The study included 103 Egyptian patients with extensive alopecia areata treated by DPC. Hundred healthy age and sex matched blood donors were included in the current study as a control group. Results of genotyping showed that PTPN22 CT and TT mutant genotypes were significantly higher in AA patients compared to controls and conferred increase risk of AA (OR = 2.601, 95% CI = 1.081–6.255). Statistical comparison between AA patients with wild and mutant genotypes revealed that the duration of the illness was significantly longer in those harboring the mutant genotypes. Moreover, the association of other autoimmune diseases as atopy and diabetes mellitus was higher in patients with mutant genotypes. Furthermore, PTPN22 1858C>T genetic polymorphism did not affect the patients' response to DPC immunotherapy.     

Biodeterioration of Mayan buildings at uxmal and tulum,Mexico

Uxmal and Tulum are two important Mayan sites in the Yucatan peninsula. The buildings are mainly composed of limestone and grey/black discoloration is seen on exposed walls and copious greenish biofilms on inner walls. The principal microorganisms detected on interior walls at both Uxmal and Tulum were cyanobacteria; heterotrophic bacteria and filamentous fungi were also present. A dark‐pigmented mitosporic fungus and Bacillus cereus, both isolated from Uxmal, were shown to be acidogenic in laboratory cultures. Cyanobacteria belonging to rock‐degrading genera Synechocystis and Gloeocapsa were identified at both sites. Surface analysis previously showed that calcium ions were present in the biofilms on buildings at Uxmal and Tulum, suggesting the deposition of biosolubilized stone. Apart from their potential to degrade the substrate, the coccoid cyanobacteria supply organic nutrients for bacteria and fungi, which can produce organic acids, further increasing stone degradation.     

Palatability and feeding preferences of Uresiphita maorialis (Lepidoptera: Crambidae) for three Sophora species

In a three-hour bioassay, we tested the palatability and feeding preferences of Uresiphita maorialis (kōwhai moth) for Sophora tetraptera, Sophora microphylla and Sophora prostrata. Palatability tests showed no differences among the Sophora species. Feeding preferences, on the other hand, showed that S. tetraptera and S. microphylla leaves are preferred over S. prostrata leaves. Our results support our field observations in Wellington city parks and gardens showing that S. tetraptera and S. microphylla plants frequently have higher densities of larvae than S. prostrata.     

ECHOCARDIOGRAPHIC ABNORMALITIES OF THE MITRAL VALVE ASSOCIATED WITH A LARGE PERICARDIAL EFFUSION

Features of mitral stenosis and systolic anterior motion of the mitral valve were observed on the echocardiogram of a patient with a large posterior pericardial effusion. The abnormal findings disappeared with resolution of the fluid. Because pericardial effusion may result in the echocardiographic alteration of cardiac structures, repeat study is necessary after the effusion has cleared.     

ETHYL ALCOHOL REDUCTION OF SALMONELLA TYPHIMURIUM IN POULTRY FEED

This study was designed to evaluate the effect of ethyl alcohol as a potential treatment for reduction of Salmonella populations in poultry feed. Growth rate of S. typhimurium in tryptic soy broth was significantly reduced by addition of greater than 0.3% volume/volume of ethyl alcohol and growth was completely inhibited by addition of 5% ethyl alcohol. Ethyl alcohol concentrations of 20% volume/weight and greater significantly reduced initial S.typhimurium populations in poultry feed (for 20% treated, 2.31 ± 0.31 vs 3.39 ± 0.29 for untreated; P < 0.05). When feed treatment was administered either before or after inoculation of S. typhimurium with 60% ethyl alcohol or 0.04% buffered propionic acid, populations in feeds treated after inoculation were decreased to a nondetection level (< 1.0 log₁₀ CFU/g) by ethyl alcohol treatment but not by other treatments. Ethyl alcohol treatment may have the potential for reducing Salmonella spp. contamination in poultry feed.