Non-enzymatic electrochemical impedance sensor for selective detection of electro-inactive organophosphate pesticides using Zr-MOF/ZrO2/MWCNT ternary composite

The existence of multiple pesticide residues in fruits and vegetables constitutes a direct peril to living organisms. Therefore, it is crucial to develop a low-cost screening method for determining organophosphate pesticides (OPPs) in food samples. This study describes the solvothermal synthesis of a ternary composite comprising multi-walled carbon nanotubes (MWCNT), zirconium oxide, and a zirconium-metal-organic framework (Zr-MOF). The ternary composite was characterised using XRD, FESEM, FTIR, and BET. The ternary composite provides a large surface area (1158 m2/g) compared with the pristine Zr-MOF (868 m2/g). The composite-modified glassy carbon electrode was used to determine nine pesticides, including organophosphate (malathion, dimethoate, chlorpyrifos, monocrotophos, and glyphosate) and non-organophosphate (thiophanate methyl, carbendazim, atrazine, and 2,4, D). In particular, various chemical combinations of OPPs were selected, such as S-P=S, P=S, P=O, and non-OPPs such as C=S (with sulphur), and without sulphur. The sensor results show that the sensor selectivity is high for OPPs containing both phosphorus and sulphur molecules. The low detection limit of the sensor was 2.02, 2.8, 2.5, 1.11, and 2.01 nM for malathion, chlorpyrifos, dimethoate, monocrotophos, and glyphosate, respectively. The electrode exhibited significant chemical stability (93%) after 100 cycles, good repeatability, and a long shelf life. The sensor is reliable for qualitative real-time applications.

Solvent Media on Nonlinear Optical Properties of Triarylmethane Dye via Facile Z-Scan Method

Solvent environment on third-order nonlinear optical (TNLO) features of triarylmethane dye namely, basic blue 7 in different solvents is reported herein using 650 nm diode laser with continuous wave mode. The basic blue 7 dye is dissolved in different solvent media including ethanol, methanol, dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO). The influence of solvent characteristics such as solvent polarizability and dipole moment on solute molecule is discussed. TNLO characteristics such as nonlinear optical index of refraction, nonlinear optical coefficient of absorption, real and imaginary components of the TNLO susceptibility are measured to be the order of 10‒7 cm2/W, 10‒3 cm/W, 10‒6 esu and 10‒7 esu, respectively. The dye exhibits large TNLO susceptibility by dissolving in DMSO. The TNLO susceptibility of basic blue 7 dye is measured to be the order of 10‒6 esu. The overall results revealed that the basic blue 7 dye is suitable material for optoelectronics applications.

Saturable and Reverse Saturable Absorption Features of Lissamine Green Dye in Different Solvent Media

Organic dyes have shown a remarkable nonlinear optical (NLO) characteristics under low power laser regime because of chemical stability, large nonlinearity and high susceptibility. With this view in mind, herein we report the third-order NLO features of lissamine green dye using 5 mW power laser with operating wavelength of 650 nm. The lissamine green dye is dissolved into various polar solvents such as ethanol, methanol, acetone and DMSO. The closed aperture Z‒scan approach discloses the information about nonlinear refractive index, whereas the open aperture Z‒scan technique provides the information about nonlinear absorption coefficient. The closed aperture curve shows the peak-valley transmittance is the result of self-defocusing nonlinearity and the open aperture transmittance curve switchover from saturable absorption to reverse absorption in high polar solvent due to polarizability and dipole moment. The third-order NLO features such as nonlinear refractive index (n2), nonlinear absorption coefficient (β), real and imaginary features of third-order NLO susceptibility of the dye is calculated to be the order of, 10-7 cm2/W 10-3 cm/W, and 10-7 esu respectively. The correlation between solvent polarizability and dipole moment on lissamine green dye is discussed. The results are revealed that the lissamine green dye is a good candidate for NLO applications.

Thermostable negative-marker foot-and-mouth disease virus serotype O induces protective immunity in guinea pigs

Foot-and-mouth disease (FMD) is a contagious viral disease of high economic importance, caused by FMD virus (FMDV), a positive-sense single-stranded RNA virus, affecting cloven-hoofed animals. Preventive vaccination using inactivated virus is in practice to control the disease in many endemic countries. While the vaccination induces antibodies mainly to structural proteins, the presence of antibodies to the non-structural proteins (NSP) is suggestive of infection, a criterion for differentiation of infected from vaccinated animals (DIVA). Also, there is a growing demand for enhancing the stability of the FMD vaccine virus capsid antigen as the strength of the immune response is proportional to the amount of intact 146S particles in the vaccine. Considering the need for a DIVA compliant stable vaccine, here we report generation and rescue of a thermostable and negative marker virus FMDV serotype O (IND/R2/1975) containing a partial deletion in non-structural protein 3A, generated by reverse genetics approach. Immunization of guinea pigs with the inactivated thermostable-negative marker virus antigen induced 91% protective immune response. Additionally, a companion competitive ELISA (cELISA) targeting the deleted 3A region was developed, which showed 92.3% sensitivity and 97% specificity, at cut-off value of 36% percent inhibition. The novel thermostable-negative marker FMDV serotype O vaccine strain and the companion cELISA could be useful in FMDV serotype O enzootic countries to benefit the FMD control program. KEY POINTS: • Thermostable foot-and-mouth disease virus serotype O with partial deletion in 3A. • Inactivated thermostable marker vaccine induced 91% protection in guinea pigs. • Companion cELISA based on deleted region in 3A could potentially facilitate DIVA.

Altered levels of neurobiological biomarkers at the interface of depression and gestational diabetes mellitus in Asian Indian women

AIM

Gestational diabetes mellitus (GDM) might predispose the mothers to depression. Studies have reported the role of biomarkers either in GDM or depression, but very few have examined them in GDM with depression. The present study profiled the circulating levels of brain-derived neurotrophic factor (BDNF), Beta Endorphin (BE) and nesfatin-1 in women with GDM (with and without depression).

METHODS

160 pregnant women at 24-28 weeks of pregnancy (NGT/GDM with & without depression, n = 40 each) were randomly selected from the ongoing STRiDE (STratification of Risk of Diabetes in Early pregnancy) study. Depression score was derived using PHQ-9 questionnaire and ELISA was used to quantify the biomarkers.

RESULTS

Circulatory levels of BDNF, BE and nesfatin-1 were lower in GDM women with or without depression compared to NGT without depression, however, nesfatin-1 levels were higher in NGT with depression. Notably, GDM with depression had the lowest levels of BDNF and BE. Both BDNF and BE levels were negatively correlated with depression, 1 h and 2 h plasma glucose. Regression analysis confirmed that each standard deviation decreases in BDNF and BE were independently associated with higher odds of GDM with or without depression even after adjusting for potential confounders.

CONCLUSION

Our study has identified altered levels of a panel of neurobiological biomarkers (BDNF/BE/nesfatin-1) in those with combined GDM and depression. BDNF/BE could be potential biomarkers to assess the higher risk of coexisting depression and GDM.

Evidences of microplastics in Hawassa Lake, Ethiopia: A first-hand report

Investigation on freshwater MPs has increased gradually across the world, since they are main trajectory for the transportation of MPs from inland to ocean. The present study aims to identify the presence, distribution and the type of MPs in the lake Hawassa, Ethiopia. Twenty-five shoreline surface sediments were separated using ZnCl₂ solution and was microphotographed using SEM and type of MP was identified using FTIR spectra. The abundance of MPs was in range of 11-74 items/m³ near the catchment area of the lake in the eastern side. Fiber (90%), fragments (5%) and pellets (5%) were the commonly observed form with varied colour such as white, black, blue, red and others. Our results infer that the common polymer detected in the study area were polyester (82%), polyethylene (15%) and polystyrene (3%) infer their origin from fishing nets, ropes and plastics bags. The industries near the lake contributes more MPs, where the waste water effluents are drained directly into the lake. Spearman's correlation matrix applied among the MPs characters endorses the fate of MPs in the lake environment indicating the weathering process (especially due to bleaching process). Comparative studies with other lake regions around the globe indicate higher values which is entirely and it depends on various factors surrounding the study area. Being, highly polluted lake in Ethiopia, this study extremely acclaims that some monitoring studies in fresh water components in the lake Hawassa helps to mitigate the prevailing MPs pollution.

Association between number of abnormal glucose values and severity of fasting plasma glucose in IADPSG criteria and maternal outcomes in women with gestational diabetes mellitus

AIMS

The International Association for Diabetes in Pregnancy Study Group (IADPSG) criteria recommend a single-step diagnostic oral glucose tolerance test (OGTT) for diagnosis of gestational diabetes mellitus (GDM). The aim of this study was to examine the association between the number of abnormal glucose values and levels of FPG with pregnancy outcomes.

METHODS

Pregnant women (n=1,044) were screened for GDM at maternity centers in South India using IADPSG criteria. OGTTs were classified based on the number of abnormal glucose values (any one value or more than one value high) and fasting plasma glucose (FPG) values (<92mg/dl,92-100mg/dl,>100mg/dl) and correlated with pregnancy outcomes. Odds ratio were adjusted for age, BMI, gestational week at diagnosis, family history of diabetes, previous history of GDM, gestational week at delivery and birth weight. For macrosomia and large for gestation age, birth weight was excluded from the model.

RESULTS

Risk of caesarean section was significantly higher in women with any one abnormal glucose value (OR: 1.49; 95%CI: 1.07-2.09). This further increased in those with >1 value (OR: 1.35; 95%CI: 0.87-2.10), when compared to women with all values normal. Risk of large for gestation age (LGA) was higher in women with FPG 92-100mg/dl (OR: 1.37; 95%CI: 0.80-2.35) and in those with FPG >100mg/dl (OR: 1.87; 95%CI: 1.04-3.35), compared to those with FPG <92mg/dl.

CONCLUSIONS

The risk for poor pregnancy outcomes starts in those with one abnormal value in the OGTT or with FPG >92mg/dl but becomes significantly higher in those with higher abnormal values.

Synthesis and characterization of nano zerovalent iron-kaolin clay (nZVI-Kaol) composite polyethersulfone (PES) membrane for the efficacious As2O3 removal from potable water samples

In this study, Kaolin clay, a mining material, was used as an abundant and available mineral as zero-valent iron-kaolinite composites for As₂O₃ removal from the water samples. The composites were made by the sodium borohydrate reduction method. The existence of Fe⁰ in the produced composites was confirmed by X-ray diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR) analysis. The membranes are prepared with zerovalent nano Iron-Kaolin and PES. The synthesized composites were then mixed with polyethersulfone to prepare the membranes S1, S2, and S3 with varying compositions. Field Emission Scanning Electron Microscopy (FESEM) analysis of the produced membranes showed the porous structure and the contact angle of membranes increased the hydrophilicity. The membranes were explored for the removal of As₂O₃ (AsIII) in potable water samples. The filtration studies were carried out using the syringe filtration setup. Analysis of the arsenic (III) solution was carried out, before and after the filtration process using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), which showed a maximum of 50% reduction in its original concentration. The filtered membrane is analyzed for arsenic by Energy Dispersive X-ray (EDX) technique. Thus, the synthesized membrane effectively sieves the arsenic in water samples.

Acute Polyarticular Gout due to Chronic Kidney Disease

Gout is a crystal deposition disorder that typically presents as an acute flare of the first metatarso-phalangeal joint of the great toe. Rarely gout can present as an acute poly-articular disease with involvement of multiple joints. Evaluation of patients with poly-articular arthropathy with appropriate investigations like uric acid levels, renal function tests and synovial fluid analysis helps in the early diagnosis of poly-articular gout. Immediate treatment with urate lowering agents during the acute flare provides immediate pain relief and prevents progression of disease & bone destruction.

Infection and protection responses of deletion mutants of non-structural proteins of foot-and-mouth disease virus serotype Asia1 in guinea pigs

The development of a negative marker vaccine against the foot-and-mouth disease virus (FMDV) will enhance the capabilities to differentiate vaccinated from infected animals and move forward in the progressive control pathway for the control of FMD. Here, we report the development of mutant FMDV of Asia1 with partial deletion of non-structural proteins 3A and 3B and characterization of their infectivity and protection response in the guinea pig model. The deleted FMDV Asia1/IND/63/1972 mutants, pAsia^Δ3A and pAsia^Δ3A3B1 were constructed from the full-length infectious clone pAsia^WT, the viable virus was rescued, and the genetic stability of the mutants was confirmed by 20 monolayer passages in BHK21 cells. The mutant Asia1 viruses showed comparable growth pattern and infectivity with that of Asia^WT in the cell culture. However, the Asia^Δ3A3B1 virus showed smaller plaque and lower virus titer with reduced infectivity in the suckling mice. In guinea pigs, the Asia^Δ3A3B1 virus failed to induce the disease, whereas the Asia^Δ3A virus induced typical secondary lesions of FMD. Vaccination with inactivated Asia1 mutant viruses induced neutralizing antibody response that was significantly lower than that of the parent virus on day 28 post-vaccination (dpv) in guinea pigs (P < 0.05). Furthermore, challenging the vaccinated guinea pigs with the homologous vaccine strain of FMDV Asia1 conferred complete protection. It is concluded that the mutant Asia^Δ3A3B1 virus has the potential to replace the wild-type virus for use as a negative marker vaccine after assessing the vaccine worth attributes in suspension cell and protective efficacy study in cattle.Key points• Deletion mutant viruses of FMDV Asia1, developed by PCR-mediated mutagenesis of NSP 3A and 3B1, were genetically stable.• The growth kinetics and antigenic relatedness of the mutant viruses were comparable with that of the wild-type virus.• Vaccination of guinea pigs with the deletion mutant viruses conferred complete protection upon challenge with the homologous virus.

Development of nanobiomaterial for wound healing based on silver nanoparticles loaded on chitosan hydrogel

The objective of this study was to develop nanobiomaterial containing silver nanoparticles (AgNPs) for wound healing. AgNPs were synthesized using Saussurea lappa (Sl) aqueous root extract as reducing agent and were characterized physico-chemically using UV-vis spectral studies, XRD, FESEM, TEM, FTIR spectral analysis, DLS, and TG-DSC. Sl AgNPs production was optimized using response surface methodology. The cytotoxicity of Sl AgNPs was assessed by THP1 cell lines, which showed that Sl AgNPs were nontoxic with an IC50 of 151.10 μg/mL at 24 h. For topical application, Sl AgNPs was loaded on chitosan hydrogel was characterized through spreadability, in vitro release, antibacterial activity, swelling behavior, and SEM analysis. The chitosan Sl AgNPs hydrogel was subjected acute dermal toxicity test using Wistar albino rats and was found to be nontoxic. The excisional wound model was created along with Pseudomonas aeruginosa as an inoculant in Wistar albino rats. The chitosan Sl AgNPs hydrogel treated rats showed excellent wound healing qualities, lower bacterial counts, and enhanced production of connective tissues. Our findings strongly suggest that AgNPs synthesized from Saussurea lappa root extract loaded on chitosan hydrogel possibly applied for the remedy of infectious wounds at a concentration of 0.1 mg of Sl AgNPs/g of hydrogel.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-03030-0.

Baseline distributions and sources of polycyclic aromatic hydrocarbons (PAHs) in reef-associated sediments of Vembar group of Islands, Gulf of Mannar, India

The study aims to investigate the source and concentration of PAH fractions in the reef sediments of the Vembar group of Islands, Gulf of Mannar, India. The concentration of PAHs ranged from 0.36 to 15.98 ng/g. The reef environment was less contaminated with low-molecular-weight PAH fractions. The accumulation of the LMW-PAH fraction was very less, whereas the HMW fraction was derived from pyrolytic sources. The level of low and high molecular weight PAHs was lower than the level of Effective Range Median (ERM) and Effective Range Low (ERL).The calculated total TEQ value ranged from ND to 10.24 ng/g in the reef sediments.

Microplastic contamination in edible sea salt from the largest salt-producing states of India

The presence of microplastics in all ecological and environmental conditions has been identified as a global problem. This article aimed to study edible salt-associated microplastics from the major salt-producing states of India. The crystal and powder salt from Tamil Nadu and Gujarat (five samples of powder salt and three samples of crystal salt from each state) were collected and analyzed for their microplastic content. The total microplastic content in the salts ranged from 46 to 115 particles per 200 g in Gujarat salt and 23 to 101 particles per 200 g in Tamil Nadu salt. The microplastics are dominated by red and blue color fibrous-shaped materials. The most common microplastics identified in the edible salts were polyethylene, polyester, and polyvinyl chloride derived from marine and salt-processing units.

Establishing minimally invasive cardiac surgery in a low-volume mitral surgery centre

INTRODUCTION

Despite early enthusiasm, minimally invasive cardiac surgery has had a low uptake compared with novel techniques in interventional cardiology. Steep learning curves from high-volume centres have deterred smaller units from engaging, even though low-volume centres undertake a large proportion of surgical interventions worldwide. We sought to identify the safety and experience of learning minimally invasive cardiac surgery after undertaking a structured fellowship at Blackpool Victoria Hospital, a low-volume centre.

MATERIALS AND METHODS

A retrospective analysis of outcomes for all consecutive minimally invasive cardiac surgery procedures performed via a right mini-thoracotomy at our institution between 2007 and 2017 was undertaken. Clinical outcomes included death, conversion to sternotomy, stroke, renal failure and other organ support. Cardiopulmonary bypass, aortic cross-clamp times and learning cumulative sum sequential probability method curves were also assessed to determine how safely the procedure was adopted.

RESULTS

A total of 316 patients were operated on for mitral, tricuspid, atrial fibrillation, septal defects or other conditions. The mean logistic European System for Cardiac Operative Risk Evaluation score was 7.0 (± 8.5). Conversion to sternotomy occurred in 12 patients (3.8%) and in-hospital mortality was 7 (2.2%). None of the converted patients died. The learning curves showed an accelerated process of adoption, similar to reference figures from a high-volume German centre.

DISCUSSION

It is possible for low-volume cardiac surgical centres to undertake minimally invasive surgical programmes with good outcomes and short learning curves. Despite technical complexities, with a team approach, the learning curve can be navigated safely.

Short-term effect of foot-and-mouth disease (FMD) vaccination on the milk yield in the Deoni and crossbred cows

Biannual vaccination of the cattle with inactivated foot-and-mouth disease (FMD) vaccine is the control strategy in endemic countries. Reduction in the milk yield is one of the main reasons for poor compliance of the cattle owners to FMD vaccination. As it can adversely affect the herd immunity, the present study aimed to quantify the losses in the milk yield post-FMD vaccination. Retrospective data on the milk yield (kg) recordings, days in milk, parity, and age at vaccination of the Deoni and crossbred cows were collected from 10 days before (-10) to 10 days after (+10) FMD vaccination (dpv). Days in milk were categorized into three stages of lactation for Deoni and crossbred cows. Age (month) was categorized into four classes. Least squares means of the milk yield were generated after adjusting for year, age, parity, and stage of lactation. Based on exploratory data analysis, the corrected milk yield records from -2 to +2 dpv for 5 years comprising 614 data points on Deoni cows (n=54) and 488 data points on crossbred cows (n=55) were used for the final analysis. Because of the correlated errors on the corrected milk yield, linear mixed model ANOVA was done by fitting dpv as fixed effect and cow as random effect, and the results revealed the effect of dpv was non-significant (P>0.05) in either breed. With respect to dpv 0, a marginal reduction of 90 g in the corrected milk yield in the Deoni cow was recorded on dpv 1, while the reduction was about 360 g on dpv 0 as compared dpv -1 in the crossbred cow. It was concluded that FMD vaccination caused a transient non-significant reduction in the milk yield in the Deoni and crossbred cows.

Ensemble Gaussian mixture model-based special voice command cognitive computing intelligent system

Dysarthria is a speech disorder caused by stroke, Parkinson’s disease, neurological injury, or tumors that damage the nervous system and weaken the speech quality. Developing a unique voice command system for Dysarthric speech helps to recognize impaired speech and convert them into text or input commands. Hidden Markov Model (HMM) is one of the widely used generative model-based classifiers for Dysarthric speech recognition. But due to insufficient training data, HMM doesn’t provide optimal results on overlapping classes. We propose an ensemble Gaussian mixture model to recognize impaired speech more accurately. Our model converts the sequence of feature vectors into a fixed dimensional representation of patterns with varying lengths. The performance efficiency of the proposed model is evaluated on the Dysarthric UA-speech benchmark dataset. The discriminatory information provided by the proposed approach yields better classification accuracy even for shallow intelligibility words compared to conventional HMM.

Trace element concentrations and their potential ecological risk in the reef sediments of coral islands, Vembar group of islands, Gulf of Mannar, India

The present work was undertaken to assess the impact of trace element concentration and the status of potential ecological risk in the reef sediments of the Vembar group of islands, Gulf of Mannar Marine National Park, India. Totally, 114 reef sediments (surface) were collected from the Vembar group of islands (Nallathanni Island - 36 samples; Upputhanni Island - 48 samples; Puluvinichalli Island-30 samples). The reef sediments are enriched with sand-sized calcareous particles. The calcium carbonate percentage (CaCO₃) was primarily controlled by the distribution of coral colonies and available lithogenic grains. The pollution load index (PLI) reveals that the majority of the sediments fall under the unpolluted category. Moreover, the potential ecological risk (PERI) and sediment pollution index (SPI) reveals that the Vembar group of islands fall under the low ecological risk category.

Bioavailable trace metals and their ecological risks in the tourist beaches of the Southeast coast of India

The concentration of Acid Leachable Trace Metals (ALTMs) was assessed in urbanized tourist beaches (96 samples from Marina beach, 34 samples from Edward Elliot's beach, and 28 samples from Silver beach) of southeast coast of India. The concentration of metals accumulated in the beach sediment was less than the Upper Continental Crust (UCC) background reference values. The mean enrichment of ALTMs in the studied urban tourist beaches showed the following descending order: Marina beach - Cr > Pb > Ni > Zn > Cu > Mn > Co; Edward Elliot's beach - Cr > Pb > Ni > Mn > Co > Zn > Cu; Silver beach - Cr > Pb > Ni > Co > Mn > Cu > Zn. The ALTMs such as Fe, Mn, Co, Cu, and Zn were probably derived from natural weathering and mild anthropogenic influences whereas other metals were derived from anthropogenic induced factors.

Metal concentration and its ecological risk assessment in the beach sediments of Coromandel Coast, Southern India

The present study investigates the concentration of acid leachable trace metals (ALTMs) and their ecological risk in the beach sediments of Coromandel Coast, Southern India. In total, thirty-six beach sediments (eighteen samples from low tide and eighteen samples from high tide) were collected from the study area. The results of the study of the ALTMs suggest that the sediments are enriched by natural processes with significant anthropogenic influences. The distribution of ALTMs in beach sediments is in the following descending order: Fe > Cr > Mn > Pb > Ni > Cu > Co > Zn. The statistical results indicate that the metal concentrations were chiefly originated from natural processes such as leaching, weathering, and fluvial action. In addition, the textural characteristics, organic matter, and calcium carbonate percentage play an important role in the distribution of metals in the beach sediments.

Correction: Compliments of confinements: substitution and dimension induced magnetic origin and band-bending mediated photocatalytic enhancements in Bi1-xDyxFeO3 particulate and fiber nanostructures

Correction for 'Compliments of confinements: substitution and dimension induced magnetic origin and band-bending mediated photocatalytic enhancements in Bi_1-xDy_xFeO₃ particulate and fiber nanostructures' by M. Sakar et al., Nanoscale, 2015, 7, 10667-10679.

Efficient inhibition of foot-and-mouth disease virus replication in vitro by artificial microRNA targeting 3D polymerase

Foot-and-mouth disease (FMD) is a devastating acute viral disease of livestock with cloven hooves. Among various therapeutic control measures, RNA interference (RNAi) is one of the methods being explored to inhibit FMD virus replication and spread. The RNAi is achieved by short hairpin RNAs or artificial microRNAs (amiRNAs). Utility of amiRNAs as antiviral, targeting conserved regions of the viral genome is gaining importance. However, delivery of miRNA in vivo is still a challenge. In this study, the efficacy of amiRNAs in preventing FMD virus replication in a permissive cell culture system was investigated, by generating stable cell lines expressing amiRNAs targeting three functional regions of the FMD virus (FMDV) genome (IRES, 3B3 and 3D). The results showed that amiRNA targeting 3D polymerase is relatively more efficient. However, expression of multiple microRNAs targeting the three regions did not exhibit additive effect. The data suggest that 3D specific miRNA is a potential valid strategy in developing novel antiviral measures against FMDV infection. Keywords: artificial microRNA; foot-and-mouth disease virus; virus inhibition.

Influence of He and N2 plasma on in situ surface passivated Fe nanopowders by plasma arc discharge

DC transferred arc plasma method was employed for the synthesis of core (Fe)-shell (Fe oxide) nanopowders under N₂ and He atmospheres. The phase and elemental compositions were studied by x-ray diffraction (XRD) and energy-dispersive x-ray spectroscopy (EDS) techniques. The structural and magnetic properties were investigated by high-resolution transmission electron microscopy (HRTEM), vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. XRD and EDS results confirmed the presence of iron and iron oxide. From HRTEM, the average particle sizes of 32, 47 and 71 nm and 20, 26 and 37 nm were obtained against processing currents of 50, 100 and 150 A under N₂ and He atmospheres respectively. The average particle size values were found to increase with increases in processing current. Spherical and hollow hexagonal nano-structures were obtained under N₂ atmosphere whereas spherical and distorted cubes were formed under He atmosphere. The elemental mapping revealed the presence of oxygen on the surface and Fe in the core of the nanoparticles.

Comparison of chemical extraction methods for determination of 146S content in foot-and-mouth disease oil-adjuvanted vaccine

AIMS

To compare antigen extraction efficiency of chemical methods such as benzyl alcohol, chloroform, sodium citrate, extraction buffer with Tween-20 (EBT) and isopropyl myristate for determination of 146S content in the fresh and stored FMD oil-adjuvanted vaccines.

METHODS AND RESULTS

Standard vaccine with antigen payload of 10, 5 and 5 µg per cattle dose (2 ml) for serotypes O, A and Asia1, respectively, was used to compare the antigen extraction efficiency of five chemical methods: benzyl alcohol, chloroform, sodium citrate, EBT buffer and isopropyl myristate. The purity of the extracted 146S antigen was quantified by caesium chloride (CsCl) ultracentrifugation. Serotype-specific sandwich ELISA (sELISA) was developed to identify the serotype and to compare the 146S in aqueous phase and ultrafractions. The antigen recovery was also tested in stored trivalent vaccine. Coefficient of regression was calculated to assess the predictive power of the benzyl alcohol extraction method. Of the five methods, benzyl alcohol showed consistent antigen recovery of >90% in monovalent as well as trivalent vaccines. Ultrafraction showed a 1·4 ratio at A259/239 nm in UV spectrophotometry indicating the presence of 146S. sELISA revealed that the antigen recovery was significantly less in ultrafractions than that of aqueous phase. Further, there was no significant difference in antigen recovery from stored trivalent vaccine for 12 months, indicating the usefulness of the benzyl alcohol method. Linear regression model revealed R²  = 0·99 with a narrow band of predictive interval.

CONCLUSIONS

The benzyl alcohol method was efficient in extracting 146S from the monovalent and trivalent fresh and stored FMD vaccines. CsCl density gradient precisely quantified the 146S, while sELISA identified the serotype of the vaccine.

SIGNIFICANCE AND IMPACT OF THE STUDY

When the benzyl alcohol method is coupled with CsCl density gradient and sELISA, it has the potential to determine the 146S content of FMD vaccine.

Generation of acid resistant virus like particles of vaccine strains of foot-and-mouth disease virus (FMDV)

Foot-and-mouth disease (FMD) is a contagious viral disease affecting cloven hoofed livestock. Insect cell expressed virus like particles (VLPs) are potential alternative to overcome the limitations of inactivated vaccine. However, at pH < 6.5, virus particles disassociate into pentameric structure resulting in loss of antigenicity. Accordingly, we generated seven mutant VLPs containing mutations in the structural genes of FMDV vaccine strains (N17D and/or H145Y for serotypes O/IND/R2/75 and Asia1/IND/63/72; and H142D for serotype A/IND/40/00) by PCR based site directed mutagenesis. Acid resistant VLPs produced by baculovirus expression system were tested for acid stability at pH 7.5, 6.5, 6.0 and 5.5 followed by reactivity in sandwich-ELISA (s-ELISA), which revealed mutant-1 (N17D) of serotype O and Asia1 retained the antigenicity in s-ELISA even at pH 5.5 as compared to other VLPs and wild-types. Further, the 75S empty capsids obtained in sucrose density gradient, when tested in liquid phase blocking ELISA (LPBE) in comparison to cell culture antigen indicated that the VLPs were stable at acidic pH. Transmission electron microscopy of OM-1 confirmed the intact morphology of the empty VLPs. It is concluded that acid resistant VLPs could be useful for developing new generation vaccine or diagnostic for FMDV.

A facile method for high level dual expression of recombinant and congener protein in a single expression system

Protein engineering is an emerging field for developing novel therapeutic proteins and commercial enzymes, along with a major impact on the global market. In recent decades, advanced methods employing protein modification through expansion of the genetic code have led to the development of proteins with new biochemical and physical properties. These techniques have produced engineered proteins with improved attribute comprising substrate relaxation, protein drug conjugation and high stability under extreme conditions of high temperatures, pH and organic solvents. Furthermore, residue specific incorporation is the simplest method for the global incorporation of non-canonical amino acid (NCAA) for protein modification; however it has the major drawbacks of high production cost and manpower requirement. In the present study, we developed a method for the incorporation of single NCAA in two different proteins by using Escherichia coli (E. coli) expression system. For that, the dual protein expressing Escherichia coli JW2581 strain was constructed by transforming pQE80L and pD881-PpiBT vectors with different promoters, selectable markers and AnnexinV, GFPHS gene. To modify the protein, the 3,4 dihydroxy phenyl alanine (DOPA) was globally incorporated into the GFPHS and Annexin V protein using dual protein expression system. The incorporation efficiency during the dual protein expression was achieved through optimized concentrations of amino acids, carbohydrate and inducers in minimal medium. This method for the incorporation of single NCAA into two different proteins using a single expression host system saves the production cost, manpower and time substantially.

Gestational dyslipidaemia and adverse birthweight outcomes: a systematic review and meta-analysis

BACKGROUND

Low and high birthweight is known to increase the risk of acute and longer-term adverse outcomes, such as stillbirth, infant mortality, obesity, type 2 diabetes and cardiovascular diseases. Gestational dyslipidaemia is associated with a numbers of adverse birth outcomes, but evidence regarding birthweight is still inconsistent to reliably inform clinical practice and treatment recommendations.

OBJECTIVE

The aim of this study was to explore the relationship between maternal gestational dyslipidaemia and neonatal health outcomes, namely, birthweight, metabolic factors and inflammatory parameters.

METHODS

We searched systematically Embase, MEDLINE, PubMed, CINAHL Plus and Cochrane Library up to 1 August 2016 (with an updated search in MEDLINE at the end of July 2017) for longitudinal studies that assessed the association of maternal lipid levels during pregnancy with neonatal birthweight, or metabolic and inflammatory parameters up to 3 years old.

RESULTS

Data from 46 publications including 31,402 pregnancies suggest that maternal high triglycerides and low high-density-lipoprotein cholesterol levels throughout pregnancy are associated with increased birthweight, higher risk of large for gestational age and macrosomia and lower risk of small-for-gestational age. The findings were consistent across the studied populations, but stronger associations were observed in women who were overweight or obese prior to pregnancy.

CONCLUSIONS

This meta-analysis suggested that the potential under-recognized adverse effects of intrauterine exposure to maternal dyslipidaemia may warrant further investigation into the relationship between maternal dyslipidaemia and birthweight in large prospective cohorts or in randomized trials.

Mutation in the VP2 gene of P1-2A capsid protein increases the thermostability of virus-like particles of foot-and-mouth disease virus serotype O

Foot-and-mouth disease (FMD) is an economically important, global disease of cloven-hoofed animals. The conventional vaccine could bring down the incidence of disease in many parts of the world but has many limitations and in India, the disease is enzootic. More promisingly, the alternate vaccine candidates, virus-like particles (VLPs) are as immunogenic as a native virus but are more labile to heat than the live virus capsids. To produce stable VLPs, a single amino acid residue was mutated at 93 and 98 positions at VP2 inter-pentamer region of the P1-2A gene of FMD virus serotype O (IND/R2/75). The mutated capsid protein was expressed in insect cells and characterized for temperature and varying pH stability. Out of S93Y, S93F, S93C, S93H, and Y98F mutant, VLPs, S93Y, S93F, and Y98F showed improved stability at 37 °C for 75 days compared to wild capsid, which was evaluated by sandwich ELISA. Further, the stability analysis of purified VLPs either by differential scanning fluorescence (DSF) stability assay at different temperatures and pH conditions or by dissociation kinetics showed that the Y98F mutant VLPs were more stable than S93Y, S93F, S93C, and S93H mutant and wild-type VLPs. Immunization of guinea pigs with Y98F VLPs induced neutralizing antibodies and 60% of the animals were protected from the FMDV "O" 100 GPID₅₀ challenge virus.

Elemental concentration based potential ecological risk (PER) status of the surface sediments, Pulicat lagoon, Southeast coast of India

Eighty-three surface sediments were collected to investigate the element concentration based sediment pollution and potential ecological risk status of the Pulicat lagoon, southeast coast of India. The textural characteristics, Fe and Mn concentration in the surface sediments are chiefly controlled by the confluence of riverine inputs and vicinity of the marine environment. The varied distribution of CaCO₃ concentration is due to the depth of the lagoon followed by the sand and silty sand characteristics of the substratum. The surface sediments are derived from riverine sources. Sediment Pollution Index (SPI), Potential Ecological Risk Index of the sediments suggests that they are falling under less polluted and low potential ecological risk category.

A baseline study on trace element based sediment pollution and potential ecological risk of reef sediments of Musal, Manoli and Manoli putti Islands, Gulf of Mannar, India

The aim of the present study is to assess the baseline level of the trace element, sediment pollution and potential ecological risk of reef associated sediments of Musal, Manoli and Manoli putti Islands, Gulf of Mannar, India. The grain size distribution of the sediments is chiefly controlled by corals and broken shell debris. The distribution of lithoclastic fractions and element concentration are most probably derived from longshore sediment transport and fluvial process from nearby mainland. The enrichment of organic matter is chiefly controlled by mangrove litters and sea grasses. The concentration of lead in the marine sediments is subjected to sediment matrix, vicinity of the local pollutant sources and distance from the mainland coast. The ecological risk assessment clearly reveals that the sediments belong to the low risk category.

A preliminary study on coastal debris in Nallathanni Island, Gulf of Mannar Biosphere Reserve, Southeast coast of India

Nine sampling stations were fixed to carry out the preliminary investigation on coastal debris from Nallathanni island, Gulf of Mannar Biosphere Reserve, Southeast coast of India. The coastal debris were separated and identified using hand picking, visual identification and microscopic studies. The coastal areas of the study region were less dominated by micro plastic contamination. The coastal debris was dominated by polyethylene bottles and fibrous fishnet materials. The distribution of the coastal debris along the coastal region is chiefly controlled by winnowing action of sea waves and Aeolian action along the berm region.

Elemental concentration and potential ecological risk assessment of reef associated surface sediments of Appa Island, Gulf of Mannar Biosphere Reserve, Southeast coast of India

Thirty three surface sediments were collected for the present study to assess the elemental concentration and its associated ecological risk in the reef associated surface sediments, Appa Island, Gulf of Mannar Biosphere Reserve, South east coast of India. The distribution of calcium carbonate in the reef sediments is controlled by coral debris and shell fragments whereas the Organic matter (OM) content are chiefly derived from mangroves and sea grasses. The circulation of trace elements and Fe, Mn are controlled by the fluvial process and re-suspended sediments. The concentration of Pb was primarily controlled by migration of pollutants through long shore sediment transport process. The main source of Pb in the study area is from coal incinerating power plants and coal handling operations from harbors.

An update on vitamin B12-related gene polymorphisms and B12 status

Background

Vitamin B12 is an essential micronutrient in humans needed for health maintenance. Deficiency of vitamin B12 has been linked to dietary, environmental and genetic factors. Evidence for the genetic basis of vitamin B12 status is poorly understood. However, advancements in genomic techniques have increased the knowledge-base of the genetics of vitamin B12 status. Based on the candidate gene and genome-wide association (GWA) studies, associations between genetic loci in several genes involved in vitamin B12 metabolism have been identified.

Objective

The objective of this literature review was to identify and discuss reports of associations between single-nucleotide polymorphisms (SNPs) in vitamin B12 pathway genes and their influence on the circulating levels of vitamin B12.

Methods

Relevant articles were obtained through a literature search on PubMed through to May 2017. An article was included if it examined an association of a SNP with serum or plasma vitamin B12 concentration. Beta coefficients and odds ratios were used to describe the strength of an association, and a P < 0.05 was considered as statistically significant. Two reviewers independently evaluated the eligibility for the inclusion criteria and extracted the data.

Results

From 23 studies which fulfilled the selection criteria, 16 studies identified SNPs that showed statistically significant associations with vitamin B12 concentrations. Fifty-nine vitamin B12-related gene polymorphisms associated with vitamin B12 status were identified in total, from the following populations: African American, Brazilian, Canadian, Chinese, Danish, English, European ancestry, Icelandic, Indian, Italian, Latino, Northern Irish, Portuguese and residents of the USA.

Conclusion

Overall, the data analyzed suggests that ethnic-specific associations are involved in the genetic determination of vitamin B12 concentrations. However, despite recent success in genetic studies, the majority of identified genes that could explain variation in vitamin B12 concentrations were from Caucasian populations. Further research utilizing larger sample sizes of non-Caucasian populations is necessary in order to better understand these ethnic-specific associations.

Sediment textural characteristics and elemental distribution in the core sediments, Pullivasal and Kurusadai Island, Gulf of Mannar, Southeast coast of India

Two core samples were collected in order to assess the textual characteristics and elemental distribution of the sediments, from the lagoonal environment of Pullivasal and Kurusadai island, Gulf of Mannar, Southeast coast of India. The distribution of the organic matter and calcium carbonate is chiefly controlled by the coral debris, shell fragments and mangrove litters. The elemental distribution is controlled by natural process and other trace elements are controlled by anthropogenic land based activities.

Experimental and Statistical Analysis of MgO Nanofluids for Thermal Enhancement in a Novel Flat Plate Heat Pipes

Metallic fluids like CuO, Al2O3, ZnO, SiO2 and TiO2 nanofluids were widely used for the development of working fluids in flat plate heat pipes except magnesium oxide (MgO). So, we initiate our idea to use MgO nanofluids in flat plate heat pipe as a working fluid material. MgO nanopowders were synthesized by wet chemical method. Solid state characterizations of synthesized nanopowders were carried out by Ultraviolet Spectroscopy (UV), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) techniques. Synthesized nanopowders were prepared as nanofluids by adding water and as well as water/ethylene glycol as a binary mixture. Thermal conductivity measurements of prepared nanofluids were studied using transient hot-wire apparatus. Response surface methodology based on the Box–Behnken design was implemented to investigate the influence of temperature (30–60[Formula: see text]C), particle fraction (1.5–4.5 vol.%), and solution pH (4–12) of nanofluids as the independent variables. A total of 17 experiments were accomplished for the construction of second-order polynomial equations for target output. All the influential factors, their mutual effects and their quadratic terms were statistically validated by analysis of variance (ANOVA). The optimum stability and thermal conductivity of MgO nanofluids with various temperature, volume fraction and solution pH were predicted and compared with experimental results. The results revealed that increase in particle fraction and pH of MgO nanofluids at certain points would increase thermal conductivity and become stable at nominal temperature.

Effect of Pre-Annealing on Thermal and Optical Properties of ZnO and Al–ZnO Thin Films

Zinc oxide (ZnO) nanoparticles were synthesized by a simple solution route method using zinc acetate as the precursor and ethanol as the solvent. At a temperature of 60[Formula: see text]C, a clear homogenous solution is heated to 100[Formula: see text]C for ethanol evaporation. Then the obtained precursor powder is annealed at 600[Formula: see text]C for the formation of ZnO nanocrystalline structure. Doped ZnO particle is also prepared by using aluminum nitrate nonahydrate to produce aluminum (Al)-doped nanoparticles using the same solution route method followed by annealing. Thin film fabrication is done by air evaporation method using the polymer polyvinyl alcohol (PVA). To analyze the optical and thermal properties for undoped and doped ZnO nanocrystalline thin film by precursor annealing, characterizations such as UV, FTIR, AFM, TGA/DTA, XRD, EDAX and Photoluminescence (PL) were also taken. It was evident that precursor annealing had great influence on thermal and optical properties of thin films while ZnO and AZO film showed low crystallinity and intensity than in the powder form. TGA/DTA suggests pre-annealing effect improves the thermal stability, which ensures that Al ZnO nanoparticle can withstand at high temperature too which is the crucial advantage in the semiconductor devices. UV spectroscopy confirmed the presence of ZnO nanoparticles in the thin film by an absorbance peak observed at 359[Formula: see text]nm with an energy bandgap of 3.4[Formula: see text]eV. A peak obtained at 301[Formula: see text]nm with an energy bandgap of 4.12[Formula: see text]eV shows a blue shift due to the presence of Al-doped ZnO nanoparticles. Both ZnO and AZO bandgap increased due to precursor annealing. In this research, PL spectrum is also studied in order to determine the optical property of the nanoparticle embedded thin film. From PL spectrum, it is observed that the intensity of the doped ZnO is much more enhanced as the dopant concentration is increased to 1[Formula: see text]wt.% and 2[Formula: see text]wt.% of Al in ZnO.