Fabrication,microstructure characterization,and degradation performance of electrospun mats based on poly(3-hydroxybutyrate-co-3 hydroxyvalerate)/polyethylene glycol blend for potential tissue engineering

There have been strong demands for nanofibrous scaffolds fabricated by electrospinning for various fields due to their various advantages. Electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) fibre mats were prepared. The effects of processing variables as well as the inclusion of poly(ethylene glycol) (PEG) on the morphologies of generated fibres were investigated using Fourier-transform infrared spectroscopy and scanning electron microscopy. The average fibrous diameter was monitored in the range 400–3000 nm relying on the total content of PEG. The fluorescence cell imaging of electrospun mats was also explored. The results of cell viability demonstrated that skin fibroblast BJ-1 cells showed different adhesions and growth rates for the three kinds of PHBV fibres. Electrospun PHBV mats with low amount of PEG offer a high-quality medium for cell growth. Therefore, those mats exhibited high potential for soft tissue engineering, in particular wound healing.     

Hypoglycemic effect of methanol extract of Phyllanthus amarus Schum & Thonn on alloxan induced diabetes mellitus in rats and its relation with antioxidant potential

Methanolic extract of P. amarus was found to have potential anti-oxidant activity as it could inhibit lipid peroxidation, and scavenge hydroxyl and superoxide radicals in vitro. The amount required for 50% inhibition of lipid peroxide formation was 104 microg/ml and the concentrations needed to scavenge hydroxyl and superoxide radicals were 117 and 19 microg/ml respectively. The extract was found to reduce the blood sugar in alloxan diabetic rats at 4th hr by 6% at a dose level of 200 mg/kg body wt and 18.7% at a concentration of 1000 mg/kg body wt. Continued administration of the extract for 15 days produced significant (P < 0.001) reduction in blood sugar. On 18th day after alloxan administration values were almost similar to normal in the group taking 1000 mg/kg body wt.     

Phenotypic and molecular identification of Cellulosimicrobium cellulans isolated from Antarctic snow

We report for the first time the isolation of Cellulosimicrobium cellulans from Antarctic snow. This strain demonstrated physiological traits that were markedly different from that of the mesophilic C. cellulans type strain DSM 43879^T. The dominant cell wall sugars in C. cellulans were glucose, galactose and mannitol whereas rhamnose was the only major sugar in the type strain. Cellular fatty acid patterns were dominated by 12-methyltetradecanoic acid (ai-C_15:0), hexadecanoic acid (C_16:0) and 14-methylhexadecanoic acid (ai-C_17:0) but lacked iso fatty acids unlike the type strain. The ability of C. cellulans to survive in Antarctic snow could be due to these modified physiological properties that distinguish it from its mesophilic counterpart. Carbon utilization studies demonstrated that C. cellulans preferred complex carbon substrates over simple ones suggesting that it could play a potential role in carbon uptake in snow. Our study shows that this genus could be more cosmopolitan than hitherto thought of and is capable of living in extreme cold environments.     

Characterization of Novel Alleles of Toxin Co-Regulated Pilus A Gene (tcpA) from Environmental Isolates of Vibrio cholerae

Vibrio cholerae is causative agent of life threatening diarrheal disease, cholera. The toxin co-regulated pilus (TCP) is a critical colonization factor of V. cholerae and it also serves as receptor for CTXФ. In this study, we describe nucleotide sequence of four novel alleles of tcpA gene from toxigenic and non-toxigenic V. cholerae isolated from environmental sources. The phylogenetic analysis of tcpA revealed that it is related to tcpA of newly emerged O1 strain and unrelated to tcpA of wild type (classical and El Tor strains). All strains showed variant tcpA and also harbored intact Vibrio Pathogenicity Island (VPI). The expression of all variant alleles was demonstrated by RT-PCR.     

Electrospinning of poly(ethylene oxide)/glass hybrid nanofibres for anticounterfeiting encoding

The use of photochromism to increase the credibility of consumer goods has shown great promise. To provide mechanically dependable anticounterfeiting nanofibres, it has also been critical to improve the engineering processes of authentication patterns. Mechanically robust and photoluminescent electrospun poly(ethylene oxide)/glass (PGLS) nanofibres (150–350 nm) immobilized with nanoparticles of lanthanide-doped aluminate (NLA; 8–15 nm) were developed using electrospinning technology for anticounterfeiting purposes. The provided nanofibrous membranes changed colour from transparent to green when irradiated with ultraviolet light. By delivering NLA with homogeneous distribution without aggregations, we were able to keep the nanofibrous membrane transparent. When excited at 365 nm, NLA@PGLS nanofibres showed an emission intensity at 517 nm. The hydrophobicity of NLA@PGLS nanofibres improved by raising the pigment concentration as the contact angle was increased from 146.4° to 160.3°. After being triggered by ultraviolet light, NLA@PGLS showed quick and reversible photochromism without fatigue. It was shown that the suggested method can be applied to reliably produce various anticounterfeiting materials.     

Water sorption studies of hybrid biofiber-reinforced natural rubber biocomposites

Hybrid biofibers (sisal and oil palm) were incorporated into natural rubber matrix. The water absorption characteristics of the composites were evaluated with reference to fiber loading. The influence of temperature on water sorption of the composites is also analyzed. Moisture uptake was found to be dependent on the properties of the biofibers. The mechanism of diffusion in the gum sample was found to be Fickian in nature, while in the loaded composites, it was non-Fickian. Sisal and oil palm fibers were subjected to different treatments such as mercerization and silanation. The effect of chemical modification on moisture uptake was also analyzed. Chemical modification was seen to decrease the water uptake in the composites. The thermodynamic parameters of the sorption process were also evaluated. Activation energy was found to be maximum for the gum sample.     

Are Women Deciding against Home Births in Low and Middle Income Countries?

Background

Although there is evidence to tracking progress towards facility births within the UN Millennium Development Goals framework, we do not know whether women are deciding against home birth over their reproductive lives. Using Demographic and Health Surveys (DHS) data from 44 countries, this study aims to investigate the patterns and shifts in childbirth locations and to determine whether these shifts are in favour of home or health settings.

Methods and Findings

The analyses considered 108,777 women who had at least two births in the five years preceding the most recent DHS over the period 2000–2010. The vast majority of women opted for the same place of childbirth for their successive births. However, about 14% did switch their place and not all these decisions favoured health facility over home setting. In 24 of the 44 countries analysed, a higher proportion of women switched from a health facility to home. Multilevel regression analyses show significantly higher odds of switching from home to a facility for high parity women, those with frequent antenatal visits and more wealth. However, in countries with high infant mortality rates, low parity women had an increased probability of switching from home to a health facility.

Conclusions

There is clear evidence that women do change their childbirth locations over successive births in low and middle income countries. After two decades of efforts to improve maternal health, it might be expected that a higher proportion of women will be deciding against home births in favour of facility births. The results from this analysis show that is not the case.     

Chromosome numbers and genome size variation in Indian species of Curcuma (Zingiberaceae)

BACKGROUND AND AIMS: Genome size and chromosome numbers are important cytological characters that significantly influence various organismal traits. However, geographical representation of these data is seriously unbalanced, with tropical and subtropical regions being largely neglected. In the present study, an investigation was made of chromosomal and genome size variation in the majority of Curcuma species from the Indian subcontinent, and an assessment was made of the value of these data for taxonomic purposes. METHODS: Genome size of 161 homogeneously cultivated plant samples classified into 51 taxonomic entities was determined by propidium iodide flow cytometry. Chromosome numbers were counted in actively growing root tips using conventional rapid squash techniques. KEY RESULTS: Six different chromosome counts (2n = 22, 42, 63, >70, 77 and 105) were found, the last two representing new generic records. The 2C-values varied from 1.66 pg in C. vamana to 4.76 pg in C. oligantha, representing a 2.87-fold range. Three groups of taxa with significantly different homoploid genome sizes (Cx-values) and distinct geographical distribution were identified. Five species exhibited intraspecific variation in nuclear DNA content, reaching up to 15.1 % in cultivated C. longa. Chromosome counts and genome sizes of three Curcuma-like species (Hitchenia caulina, Kaempferia scaposa and Paracautleya bhatii) corresponded well with typical hexaploid (2n = 6x = 42) Curcuma spp. CONCLUSIONS: The basic chromosome number in the majority of Indian taxa (belonging to subgenus Curcuma) is x = 7; published counts correspond to 6x, 9x, 11x, 12x and 15x ploidy levels. Only a few species-specific C-values were found, but karyological and/or flow cytometric data may support taxonomic decisions in some species alliances with morphological similarities. Close evolutionary relationships among some cytotypes are suggested based on the similarity in homoploid genome sizes and geographical grouping. A new species combination, Curcuma scaposa (Nimmo) Skornick. & M. Sabu, comb. nov., is proposed.