Excited state intramolecular proton transfer in 3-hydroxychromone: a DFT-based computational study

Potential energy (PE) curves for intramolecular proton transfer in the ground (GSIPT) and intramolecular proton transfer in the excited (ESIPT) states of 3-hydroxychromone (3HC) have been studied using DFT-B3LYP/6-31G(d,p) and TD-DFT/6-31G(d,p) level of theory, respectively. Our calculations suggest the non-viability of GSIPT in 3HC. Excited states PE calculations show the existence of ESIPT process in 3HC. ESIPT in 3HC has also been explained in terms of HOMO and LUMO electron densities of the enol and keto tautomers of 3HC.     

Combined strategies for liposome characterization during in vitro digestion

Three types of pyranine (HPTS)-containing liposomes were prepared by high-pressure homogenization under optimized conditions. At 37°C, they were 1) fluid-state vesicles made from soybean phosphatidylcholine (SPC), 2) gel-state liposomes made from hydrogenated SPC (HSPC), and 3) solid-disordered membranes obtained from HSPC and cholesterol (HSPC-Chol). These liposome formulations were characterized before, during, and after in vitro digestion, which involved the presence of pH gradients, enzymes, and bile salts. Mean sizes and size distributions of the vesicles were determined by DLS; ³¹P-NMR (nuclear magnetic resonance) was used to quantify lyso-PC forms; internal pH was monitored throughout digestion with two different fluorescent pH probes; and changes in bilayer permeability and HPTS encapsulation were determined by size-exclusion chromatography and fluorimetry. Differential scanning calorimetry analysis was also performed in order to study the effect of digestion on HSPC vesicles. SPC liposomes were physically stable during digestion; they presented 8% lyso-forms and an HPTS encapsulation around 85% after in vitro digestion. However, they were extremely permeable to ions, so that the internal pH immediately equilibrated with the bulk pH. HSPC liposomes were the most affected by the digestive process. Even though they were chemically stable, as inferred from the low lyso-PC content, very important changes in their size distribution were observed. A final 50% HPTS leakage was quantified after in vitro digestion. Nevertheless, they were the least permeable to protons under pH gradients. HSPC-Chol vesicles presented intermediate permeability to protons, having their internal pH decreased from approximately 6.8 to 4.6 after 1 hour of incubation at pH 2. This was the most chemically stable formulation and showed the highest encapsulation, even after in vitro digestion. Therefore, HSPC-Chol liposomes would be the most adequate choice for the design of lipid products for oral administration.     

Molecular Variation in the Paragonimus heterotremus Complex in Thailand and Myanmar

Paragonimiasis is an important food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. Of the 7 members of the genus known in Thailand until recently, only P. heterotremus has been confirmed as causing human disease. An 8th species, P. pseudoheterotremus, has recently been proposed from Thailand, and has been found in humans. Molecular data place this species as a sister species to P. heterotremus, and it is likely that P. pseudoheterotremus is not specifically distinct from P. heterotremus. In this study, we collected metacercariae of both nominal species (identification based on metacercarial morphology) from freshwater crabs from Phetchabun Province in northern Thailand, Saraburi Province in central Thailand, and Surat Thani Province in southern Thailand. In addition, we purchased freshwater crabs imported from Myanmar at Myawaddy Province, western Thailand, close to the Myanmar-Thailand border. The DNAs extracted from excysted metacercariae were PCR-amplified and sequenced for ITS2 and cox1 genes. The ITS2 sequences were nearly identical among all samples (99-100%). Phylogenies inferred from all available partial cox1 sequences contained several clusters. Sequences from Indian P. heterotremus formed a sister group to sequences from P. pseudoheterotremus-type metacercariae. Sequences of P. heterotremus from Thailand, Vietnam, and China formed a separate distinct clade. One metacercaria from Phitsanulok Province was distinct from all others. There is clearly considerable genetic variation in the P. heterotremus complex in Thailand and the form referred to as P. pseudoheterotremus is widely distributed in Thailand and the Thai-Myanmar border region.     

Selling transracial adoption: families,markets, and the colour line

This short review looks at the implications of the title of The Age of Migration. It argues that most ages, not specifically our own time, could be defined as ‘ages of migration’. It argues that the specific characteristics of our particular age are those of internal more than international migrations and a dramatic rise in a series of forms of non-permanent population movements that can better be captured under the term ‘mobility’. In terms of longer-term forms of migration, it is also deceptive to assume that they will necessarily continue to increase. The piece focuses on forms of internal migration and on mobility.     

Political mobilization of a regional minority: Han Chinese settlers in Xinjiang

The tumultuous events of summer 2009 have brought Uighur protests and minority mobilization in the Xinjiang Uighur Autonomous Region (XUAR) to the forefront. But this focus overlooks similar protests organized by various groups of Han Chinese settlers over the years. This paper contributes to the body of literature on minority mobilization and ethnic relations in Xinjiang by illustrating how the political mobilization of a group that is simultaneously a national majority and a regional minority differs substantially from ‘traditional’ minority mobilization. Reviewing the main instances of Han Chinese political mobilization since the XUAR was created in 1955, I argue that two factors are particularly important in enabling their mobilization: the Han Chinese's subjective perception of discrimination and their close ethnic ties to the state. This paper concludes with a discussion on the presence of a cycle of protests between Han settlers and the Uighurs in Xinjiang.     

Inheritance patterns of ITS1, chloroplasts and mitochondria in artificial hybrids of the seaweeds Fucus serratus and F. evanescens (Phaeophyceae)

Patterns of nuclear and organelle inheritance among artificial hybrids of the seaweeds Fucus serratus and F. evanescens were detected using single-strand conformation polymorphism (SSCP). Three alleles were identified in the 231?bp rDNA-ITS1 gene (nuclear): two in F. serratus and one in F. evanescens. Alleles differed by 1–2?bp and all hybrids possessed one allele from each parent. Two haplotypes were present in the 288?bp Rubisco spacer (chloroplast), differentiated by a 33?bp indel. Two haplotypes differing by a single nucleotide were found in a 135?bp region of nad11 gene (mitochondrion). Both organelles are maternally inherited, as all hybrids contained the haplotypes of the parent contributing the egg. Although laboratory hybrids among Fucus spp. have been produced previously, this is the first time that both nuclear and cytoplasmic genetic markers have been used to document inheritance patterns. SSCPs analysed on an automated sequencer offer a rapid and powerful approach for identifying suspected hybrids from field samples, as well as a screen for intraspecific and intra-individual variation in DNA regions prior to confirmation of variations by sequencing.     

海南海口温泉真菌、细菌多样性及其环境影响因素分析

【目的】海南海口含有丰富的温泉资源,对温泉微生物多样性进行研究,有助于进一步开发和利用海南温泉微生物资源。【方法】本文采用Illumina Hi Seq高通量测序技术对海口3个温泉[海甸岛荣域温泉(S1)、火山口开心农场温泉(S2)和西海岸海长流温泉(S3)]水样中微生物ITS序列和16Sr RNA基因V3-V4区进行测序及生物信息学分析,探究海口市3个不同区域的温泉真菌多样性与细菌多样性。【结果】(1)α多样性分析表明,真菌群落中,S3(29)S1(29)S2,而在细菌群落中,S2(29)S1(29)S3。β多样性分析表明,3个温泉真菌群落和细菌群落组成差异皆显著。(2)分类分析表明,温泉真菌群落优势菌门为子囊菌门(Ascomycota)和担子菌门(Basidiomycota),细菌群落优势菌门为变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、Thermi、硝化螺旋菌门(Nitrospirae)、绿菌门(Chlorobi)、厚壁菌门(Firmicutes)、绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)。(3) CCA (Canonical correspondence analysis)分析表明,3个温泉的真菌群落主要影响因子是温度,细菌群落主要影响因子是总磷。【结论】海南省海口市温泉中含有丰富的微生物资源,其微生物群落组成受多种环境因子影响,且影响真菌和细菌的主要环境因子不同。     

The rpb2 gene represents a viable alternative molecular marker for the analysis of environmental fungal communities

Although the commonly used internal transcribed spacer region of rDNA (ITS) is well suited for taxonomic identification of fungi, the information on the relative abundance of taxa and diversity is negatively affected by the multicopy nature of rDNA and the existence of ITS paralogues. Moreover, due to high variability, ITS sequences cannot be used for phylogenetic analyses of unrelated taxa. The part of single‐copy gene encoding the second largest subunit of RNA polymerase II (rpb2) was thus compared with first spacer of ITS as an alternative marker for the analysis of fungal communities in spruce forest topsoil, and their applicability was tested on a comprehensive mock community. In soil, rpb2 exhibited broad taxonomic coverage of the entire fungal tree of life including basal fungal lineages. The gene exhibited sufficient variation for the use in phylogenetic analyses and taxonomic assignments, although it amplifies also paralogues. The fungal taxon spectra obtained with rbp2 region and ITS1 corresponded, but sequence abundance differed widely, especially in the basal lineages. The proportions of OTU counts and read counts of major fungal groups were close to the reality when rpb2 was used as a molecular marker while they were strongly biased towards the Basidiomycota when using the ITS primers ITS1/ITS4. Although the taxonomic placement of rbp2 sequences is currently more difficult than that of the ITS sequences, its discriminative power, quantitative representation of community composition and suitability for phylogenetic analyses represent significant advantages.     

不同方法修复Pilon骨折的临床疗效比较

目的:比较不同方法修复Pilon骨折的临床疗效。方法:选取我院收治的Pilon骨折患者156例为研究对象,根据手术方法不同,将患者分成研究组和对照组,每组78例。研究组给予分步延期切开复位内固定手术治疗,对照组给予有限内固定结合外固定的手术治疗。观察并比较两组患者的踝关节功能、术中出血量、骨折愈合时间、住院时间以及术后不良反应的发生情况等。结果:与术前比较,两组患者术后踝关节功能均获得改善,且研究组踝关节功能优秀率高于对照组,差异具有统计学意义(P0.05);研究组患者术中出血量、骨折愈合时间、住院时间均明显低于对照组,差异具有统计学意义(P0.05);研究组不良反应发生率低于对照组,差异具有统计学意义(P0.05)。结论:分步延期切开复位内固定手术治疗pilon骨折的临床效果显著,是临床治疗pilon骨折的理想方案。但在临床实践中,应根据患者病情选择合适的治疗方案。