Biofuel produced from lignocellulosic materials, so-called second generation bioethanol shows energetic, economic and environmental advantages in comparison to bioethanol from starch or sugar. However, physical and chemical barriers caused by the close association of the main components of lignocellulosic biomass, hinder the hydrolysis of cellulose and hemicellulose to fermentable sugars. The main goal of pretreatment is to increase the enzyme accessibility improving digestibility of cellulose. Each pretreatment has a specific effect on the cellulose, hemicellulose and lignin fraction thus, different pretreatment methods and conditions should be chosen according to the process configuration selected for the subsequent hydrolysis and fermentation steps. This paper reviews the most interesting technologies for ethanol production from lignocellulose and it points out several key properties that should be targeted for low-cost and advanced pretreatment processes. less...

To improve the enzymatic digestibility of switchgrass at mild temperatures, lime pretreatment of switchgrass was explored at 50 and 21 degrees C, and compared with that at 121 degrees C. The effects of residence time, lime loading, and biomass washing on the sugar production efficiency were investigated. Pretreatments were evaluated based on the yields of biomass-derived sugars in the subsequent enzymatic hydrolysis. Under the best pretreatment conditions (50 degrees C, 24h, 0.10g Ca(OH)(2)/g raw biomass, and wash intensity of 100ml water/g raw biomass), the yields of glucose, xylose, and total reducing sugars reached 239.6, 127.2, and 433.4mg/g raw biomass, which were respectively 3.15, 5.78, and 3.61 times those of untreated biomass. The study on calcium-lignin bonding showed that calcium ions crosslinked lignin molecules under alkaline conditions, which substantially decreased lignin solubilization during pretreatment, but the resulting high lignin contents of the pretreated biomass did not compromise the improvement of enzymatic digestibility. less...

A peculiar form of hepatocerebral mtDNA depletion syndrome is caused by mutations in the MPV17 gene, which encodes a small hydrophobic protein of unknown function located in the mitochondrial inner membrane. In order to define the molecular basis of MPV17 variants associated with the human disorder we have previously taken advantage of S. cerevisiae as a model system thanks to the presence of an MPV17 ortholog gene, SYM1. We demonstrate here that the SYM1 gene product is essential to maintain OXPHOS, glycogen storage, mitochondrial morphology and mtDNA stability in stressing conditions such as high temperature and ethanol-dependent growth. To gain insight into the molecular basis of the Sym1-less phenotype, we identified and characterized multicopy suppressor genes and metabolic suppressor compounds. Our results suggest that (1) metabolic impairment and mtDNA instability occur independently from each other as a consequence of SYM1 ablation; (2) ablation of Sym1 causes depletion of glycogen storage, possibly due to defective anaplerotic flux of tricarboxylic acid (TCA) cycle intermediates to the cytosol; (3) flattening of mitochondrial cristae in Sym1-defective organelles suggests a role for Sym1 in the structural preservation of the inner mitochondrial membrane, which could in turn control mtDNA maintenance and stability. less...

The current study explores whether theorized risk factors in Western countries can be used to predict school violence perpetration in an Asian cultural context. The study examines the associations between risk factors and school violence perpetration in Taiwan. Data were obtained from a nationally representative sample of 14,022 students from elementary to high school (Grades 4 to 12) across Taiwan. The analysis reported in this study focuses on only junior high school students (Grades 7 to 9, N = 3,058). The results of a regression analysis show that gender, age, direct victimization, witness victimization, alcohol use, smoking, anger traits, lack of impulse control, attitudes toward violence, poor quality of student-teacher relationships, and involvement with at-risk peers were significantly associated with school violence in Taiwan. The overall results suggest strong similarities in risk factors found in the West and school violence in Taiwan. They therefore point toward using similar strategies developed in the West to enhance students' positive experiences in their personal, family, and school lives to decrease school violence. less...

The progression of periodontitis may be affected by ALDH2 genotypes with respect to the oxidation of acetaldehyde to acetate, which leads to the accumulation of acetaldehyde in plasma and potential toxic effects. We examined the prospective association of ALDH2 genotypes in terms of alcohol sensitivity between alcohol consumption and periodontal disease progression. In 2003, 224 of 256 (87.5%) individuals examined at baseline (1999) completed probing pocket depth measurements for the evaluation of periodontitis progression. Missing data on self-reported questionnaires and blood samples were excluded; therefore, 183 samples were analyzed. Individuals who consumed >/= 33.0 g/day of alcohol exhibited high periodontal disease progression risk (OR = 3.54). ALDH2 *1/*2 individuals who consumed >/= 33 g/day of alcohol displayed a significant odds ratio (OR = 4.28) of periodontitis progression risk, in contrast to ALDH2 *1/*1 individuals. These results suggested that alcohol consumption as well as alcohol sensitivity may be a risk factor for periodontitis progression. less...

OBJECTIVE:: Few epidemiological studies have examined the relationship between age at menopause and stroke incidence, and none have done so in Japanese women. Here, we investigated the relationship between age at menopause and stroke incidence in a large group of Japanese women. METHODS:: The study participants were 4,790 postmenopausal women aged 36 to 89 years enrolled in the Jichi Medical School Cohort Study, a population-based prospective study. Baseline data were obtained by questionnaire and health checkups between April 1992 and July 1995 in 12 rural areas in Japan. The incidence of all strokes and stroke subtypes was monitored. RESULTS:: Mean (SD) participant age was 61.0 (6.7) years, and mean (SD) age at menopause was 48.3 (4.8) years. A total of 185 strokes were observed during a mean follow-up of 10.8 years. On adjustment for age, systolic blood pressure, total cholesterol, body mass index, smoking habits, and alcohol drinking habits, hazard ratios (95% CIs) of stroke for women who underwent menopause before age 40 years, at 40 to 44 years, at 45 to 49 years, and at 55 years or after relative to those who underwent menopause at age 50 to 54 years were 1.56 (0.78-3.12), 1.59 (1.00-2.51), 1.28 (0.92-1.78), and 0.83 (0.38-1.81), respectively. However, hazard ratios (95% CI) of cerebral infarction for women who underwent menopause before age 40 years, at 40 to 44 years, at 45 to 49 years, and at 55 years or after relative to those who underwent menopause at age 50 to 54 years were 2.57 (1.20-5.49), 1.49 (0.80-2.78), 1.06 (0.67-1.68), and 1.08 (0.43-2.74), respectively. CONCLUSIONS:: Our data suggest that Japanese women who undergo menopause before age 40 years are at an increased risk of cerebral infarction. Premature menopause should be considered an indicator of the need for more aggressive medical intervention aimed at the prevention of cerebral infarction. less...

Chronic alcoholism leads to gray matter shrinkage and induces the formation of superoxide anions (O(2)(-)) that can cause neuronal cell death. The mitochondrial superoxide dismutase 2 (SOD2) enzyme is critical in the metabolism of superoxide. An Ala16Val polymorphism putatively affects SOD2 enzyme activity in vivo. Brain volumes of 76 treatment-seeking alcohol-dependent individuals were measured with a 1.5T MRI. Intracranial tissue margins were manually outlined on coronal sections. Gray matter, white matter, sulcal, and ventricular CSF volumes were estimated using intensity-based K-means clustering. Ala16Val (rs4880) and a second haplotype tagging SNP, rs10370, were genotyped. The q-value package was used to correct for multiple comparisons. In the alcoholics, cerebrospinal fluid and intra-cranial volumes showed significant differences across the six diplotype categories. The homozygous Ala16-containing diplotype rs10370TT-rs4880GG was associated with lowest gray matter ratio (greater shrinkage; p=0.005). Presence of one or two copies of the low activity Ala16 allele was a risk factor for lower gray matter volume in alcoholics below the median alcohol consumption (p=0.03) but not in alcoholics above this level. White matter ratio was associated with sex (p=0.002) and lifetime total alcohol consumption (p=0.01) but not with diplotypes. In this exploratory analysis, a putative functional missense variant of SOD2 appears to influence gray matter loss in alcoholics. This may be due to impaired clearance of reactive oxygen species formed as a result of alcohol exposure. The risk/protective effect was observed in alcoholics with lower levels of lifetime alcohol consumption. Highest levels of exposure may overwhelm the protective action of the SOD2 enzyme.Neuropsychopharmacology advance online publication, 30 December 2009; doi:10.1038/npp.2009.217. less...

Increasing pancreatic islet survival and function is a starting point for obtaining a valuable bioartificial pancreas for the treatment of type 1 diabetes. In this context, decellularized matrices, obtained after the removal of tissue cellular part, are known to support in vitro adhesion, growth, and function of several cell types. We demonstrate that a homologous acellular pancreatic matrix is a suitable scaffold for rat islet cultures maintaining their long-term viability and function. Islets adhered to the pancreatic matrix showed a constant glucose-induced insulin release during long-term in vitro incubation, while islets cultured without a matrix or on the liver matrix showed a progressive reduction. In order to obtain implantable devices, acellular matrix/islet cultures were entrapped into poly(vinyl alcohol) (PVA)/ poly(ethylene glycol) (PEG) tubes obtained by the freezing/thawing procedure. Under this condition, an in vitro constant insulin release was detected. The devices were then implanted into diabetic rats where reduced insulin requirement was noted suggesting insulin secretory activity of islets contained in the device. Indeed, immunofluorescence confirmed the presence of insulin- and glucagon-producing cells into the explanted devices. These data show that PVA/PEG semi-permeable membrane can obtain devices that restore, at least in part, insulin secretion less...

Follow-up rates reported among longitudinal studies that focus on runaway adolescents and their families are relatively low. Identifying factors associated with follow-up completion might be useful for improving follow-up rates and therefore study validity. The present study explored how individual- and family-level constructs, as well as research project activities, influence the follow-up completion rate among runaway adolescents (N = 140) and their primary caregiver. Results showed that follow-up completion rates decreased as the number of research assistants (RA) assigned to each case increased and as participants' address changes increased. Additionally, among adolescents, more frequent alcohol use was associated with lower follow-up rates. The current findings suggest that researchers should (1) design their research so that one RA is assigned to each specific case, and (2) adjust their retention strategies to account for the differences in follow-up rates based upon the participants' drug of choice and residential stability. less...

This study surveyed young American men traveling to Tijuana, Mexico from San Diego, California for a weekend night out, collecting responses both southbound at the outset of the evening and northbound upon return at the end of the evening. Among 650 males, we examined the relationship between sexual histories and attitudes and alcohol use, both historically and on their night in Tijuana. Respondents with a history of coercing sex drank more in Tijuana and were more likely to binge drink. Although estimating sexual assaults committed by these males on the evening in question was not possible, this research establishes the link between a history of sexual assault and the blood alcohol concentration of young men resulting from an evening in a timeout environment. less...