NIMBYism as a barrier to housing and social mix in San Francisco

Journal of Housing and the Built Environment - We explore the participation levels of NIMBY (‘Not In My Backyard’) proponents versus other voices at public hearings San Francisco, a...     

Interfacing Materials Science and Biology for Drug Carrier Design

Over the last ten years, there has been considerable research interest in the development of polymeric carriers for biomedicine. Such delivery systems have the potential to significantly reduce side effects and increase the bioavailability of poorly soluble therapeutics. The design of carriers has relied on harnessing specific variations in biological conditions, such as pH or redox potential, and more recently, by incorporating specific peptide cleavage sites for enzymatic hydrolysis. Although much progress has been made in this field, the specificity of polymeric carriers is still limited when compared with their biological counterparts. To synthesize the next generation of carriers, it is important to consider the biological rationale for materials design. This requires a detailed understanding of the cellular microenvironments and how these can be harnessed for specific applications. In this review, several important physiological cues in the cellular microenvironments are outlined, with a focus on changes in pH, redox potential, and the types of enzymes present in specific regions. Furthermore, recent studies that use such biologically inspired triggers to design polymeric carriers are highlighted, focusing on applications in the field of therapeutic delivery.     

对明串珠菌及其他细菌的抑制效果

在从压榨间直到蔗汁澄清的蔗糖生产过程中,蔗汁中微生物活动是破坏蔗糖品质的一个重要因素。蔗糖损失和葡聚糖的形成通常与蔗汁中微生物引起的变质有关。多年来,这一直成为糖厂试图改善蔗糖品质时所面临的问题。本文以直接影响得糖率的微生物减少和相对纯度为指标,研究了不同杀菌方法在蔗汁中的效果。浓度为0.007%的S抑制剂显示了对某糖厂初压汁和混合汁中的微生物菌群的抗菌效应。在对照组中,12h后观察到4.8单位的纯度降低。加入S抑制剂后,只降低2个单位。且蔗汁的稳定性在3个样品中几乎完全一致。以S抑制剂处理的蔗汁保持深褐色和清新的气味,且pH与初始相比无显著变化,而未处理的蔗汁变浅褐色,产生很强的酒味,pH和纯度显著降低。这种稳定效应尚未被其他常用的糖用杀菌剂所报导。同样,本文证明了有可能通过使用S抑制剂来稳定混合汁。经S抑制剂处理后,游离的还原物质和多聚糖比不经处理的样品低6倍。这些结果表明,形成的葡聚糖以及随之形成的游离果糖减少。     

Comparison of physicochemical pretreatments of banana peels for bioethanol production

Pretreatments with different concentrations of sulfuric acid (0, 0.5, and 1% v/v) and temperatures (28 and 121 °C at 103 kPa in an autoclave) were performed on banana peels (BP) milled by mechanical grinding and grinding in a blender as well as without grinding. Cellulose, hemicellulose, lignin, ash, and total and reducing sugar contents were evaluated. The highest yields of cellulose enzymatic hydrolysis (99%) were achieved with liquefied autoclaved BP treated with 0.5 and 1% acid after 48 h of hydrolysis. Ethanol production by Kluyveromyces marxianus fermentation was assayed using hydrolyzed BP at 10, 15, and 20% (w/w). The highest ethanol level (21 g/L) was reached after 24 h of fermentation with 20% (w/w) BP. Kinetics of the consumption of reducing sugars under this fermentation condition demonstrates the presence of a lag period (about 8 h). Thus, BP are a good source for ethanol production.     

Effects of Early Life Exposure to Sex Hormones on Neurochemical and Behavioral Responses to Psychostimulants in Adulthood: Implications in Drug Addiction

Early life exposure to sex hormones affects several brain areas involved in regulating locomotor and motivation behaviors. Our group has shown that neonatal exposure to testosterone propionate (TP) or estradiol valerate (EV) affected the brain dopamine (DA) system in adulthood. Here, we studied the long-lasting effects of neonatal exposure to sex hormones on behavioral and neurochemical responses to amphetamine (AMPH) and methylphenidate (MPD). Our results show that AMPH-induced locomotor activity was higher in female than male control rats. The conditioned place preference (CPP) to AMPH was only observed in EV male rats. In EV female rats, AMPH did not increase locomotor activity, but MPD-induced CPP was observed in control, EV and TP female rats. Using in vivo brain microdialysis, we observed that AMPH-induced extracellular DA levels were lower in nucleus accumbens (NAcc) of EV and TP female rats than control rats. In addition, MPD did not increase NAcc extracellular DA levels in EV rats. Using in vivo fast-scan cyclic voltammetry in striatum, MPD-induced DA reuptake was higher in EV than control rats. In summary, our results show that early life exposure to sex hormones modulates mesolimbic and nigrostriatal DA neurons producing opposite neurochemical effects induced by psychostimulant drugs in NAcc or striatum.     

Quantitative analysis of ochratoxin A in wine and beer using solid phase extraction and high performance liquid chromatography-fluorescence detection

A reliable and accurate method is described for the quantitative analysis of ochratoxin A (OTA) in wine and beer. The method involves the use of disposable non-polar polymeric and aminopropyl solid-phase extraction cartridges to isolate the mycotoxin from alcoholic beverages. Extracts were subsequently analysed using reverse-phase high-performance liquid chromatography-fluorescence detection with post column ammoniation to improve the limit of detection. The precision of the method determined at three levels in both wine and beer was less than 5% (RSD). Standard addition studies in both wine and beer showed that the recovery of OTA varied between 90 and 106% over a concentration range of 0.016-1.284 µg l^-1. The detection and quantification limits were shown to be better than 0.004 (S/N = 3) and 0.016 µg l^-1 (S/N = 10) for both beer and wine.     

Adsorption of nitrogen compounds from diesel fuels over alumina-based adsorbent towards ULSD production

The aim of this work is to estimate some nitrogen (N)-adsorption properties and the N-adsorption capacity (q) required for commercial application in the ultra-low sulfur diesel production. Hydroxyl (OH) groups and interactions among the commercial adsorbent Selexsorb® CDX (CDX) and pyridine and indole were studied by means of Fourier transform infrared spectroscopy. The adsorption of N-compounds from three diesel fuels over CDX was estimated at CDX/fuel ratio: 0.01–0.09 g/g, Contact time: 1–60 m, 303 K, and 0.078 MPa in a batch setup. It was concluded that an appropriate N-adsorbent should have high densities of suface OH groups and Lewis and Brønsted strong-acid sites and a q ≥ 0.70 mmol/g.     

Ultrathin, responsive polymer click capsules

We report a general click chemistry approach for the layer-by-layer assembly of ultrathin, polymer films on particles and the subsequent formation of polymer click capsules (CCs). Poly(acrylic acid) copolymers, synthesized with a minor component of either alkyne (PAA-Alk) or azide (PAA-Az) functionality, were alternately assembled on silica particles. The (PAA-Az/PAA-Alk)-coated particles were subsequently functionalized by exploiting the free alkyne click moieties present in the film upon exposure to an azide-modified rhodamine dye. Further, PAA CCs, obtained following removal of the silica particle template, were shown to exhibit pH-responsive behavior. This was demonstrated by reversible size changes of the CCs upon cycling between basic and acidic solutions. Polymer CCs are anticipated to find applications in various fields, including drug delivery and sensing.     

Effect of Soybean 7S Protein Fractions, Obtained from Germinated and Nongerminated Seeds, on Dough Rheological Properties and Bread Quality

Germinated soybean flour has been proposed for use in bread making as a product to improve bread quality when small amounts are added to wheat flour. However, it is not clear which soybean components promote this action, and how these components may influence bread quality. The aim of this work was to evaluate the effect of the addition of soybean 7S protein fraction obtained from germinated and nongerminated seeds in dough rheological properties (farinographic and extensographic) and bread quality, including loaf volume, texture (firmness, compression force, resilience), colour (L*, a*, b*), crumb grain structure (cell density, mean cell area, shape factor), and consumer acceptance (sensory analysis). Results showed that this protein fraction just slightly affects bread quality, since no significant changes (P > 0.05) on bread volume and texture were obtained. Only crust and crumb colour were affected in a small amount, and a coarser crumb structure was also observed when adding 7S protein obtained from germinated soybean at its highest concentration. As the proportion of protein increased in the flour, both kinds of 7S fraction (germinated and nongerminated) were related to the increment in water absorption, as well as to the increment in extensographic maximum resistance to extension, specifically when adding 7S protein obtained from nongerminated soybean seeds. These results showed that the 7S soybean protein, as obtained in this work, is not related to the reported loaf bread quality improving effect of this legume when it is added in small quantities.     

Determination of Trichinella spiralis in pig muscles using Mid-Fourier Transform Infrared Spectroscopy (MID-FTIR) with Attenuated Total Reflectance (ATR) and Soft Independent Modeling of Class Analogy (SIMCA)

The aim of this work was to study the feasibility of detection of Trichinella spiralis in swine meat using Middle Infrared Spectroscopy Fourier Transform with Attenuated Total Reflectance (ATR) and Soft Independent Modeling of Class Analogy (MID-FTIR-ATR-SIMCA). Five male Pigs were orally infected at different larvae concentrations (13,000, 6500, 3500, 1625, 812 larvae/pig) and after 24 weeks the animals were euthanized. Five types of muscles were studied (leg, loin, rib, masseter, and diaphragm). Results showed that MID-FTIR-ATR-SIMCA was useful to determine the presence of T. spiralis in the samples, as the interclass distance between infected and non infected muscles varied from 13.5 to 36.8. This technique was also useful to discriminate among pig muscles, where masseter showed the largest interclass distance, while rib presented the smallest one. In all cases the recognition and rejection rates were 100%, which means that the methodology is capable of accurately separating T. spiralis infected from non infected swine meat.