Covalent immobilization of cholesterol esterase and cholesterol oxidase on polyaniline films for application to cholesterol biosensor

Cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) have been covalently immobilized on electrochemically prepared polyaniline (PANI) films. These PANI/ChEt/ChOx enzyme films have been characterized using UV-visible, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Electrochemical behavior of these films has been studied using cyclic voltammetry (CV) and amperometric techniques, respectively. The PANI/ChEt/ChOx enzyme films show broad oxidation peak from 0.2 to 0.5 V. These PANI/ChEt/ChOx biosensing electrodes have a response time of about 40s, linearity from 50 to 500 mg/dl of cholesterol oleate concentration. These PANI/ChEt/ChOx films are thermally stable up to 46 degrees C. This polyaniline based cholesterol biosensor has optimum pH in the range of 6.5-7.5, sensitivity as 7.5x10(-4) nA/mg dl and a lifetime of about 6 weeks.

Application of electrochemically prepared polypyrrole–polyvinyl sulphonate films to DNA biosensor

Double stranded calf thymus deoxyribonucleic acid (DNA) was physisorbed onto polypyrrole-polyvinyl sulphonate (PPY-PVS) films electrochemically deposited onto indium-tin-oxide (ITO) coated glass plates. These DNA immobilized PPY-PVS films optimized for various conditions, such as polymerization potential, pH of buffer, DNA concentration and scan rate were characterized using Fourier-transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM) and cyclic voltammetry (CV) techniques, respectively. The amperometric response studies of these DNA/PPY-PVS electrodes were carried out as a function of 2-aminoantharcene (2-AA, 0.01-20 ppm) and o-chlorophenol (OCP, 0.1-30 ppm) concentration, respectively at 25 degrees C. The observed amperometric current arising due to oxidation of guanine in the DNA/PPY-PVS films decreased linearly with the increase in the concentration of 2-AA and OCP. It has been revealed that 10 ppm of 2-AA is sufficient to reduce the observed guanine oxidation peak current by approximately -95+/-10% as compared to the reported values. A 25 ppm of OCP was capable enough to reduce the guanine oxidation current to zero. These DNA/PPY-PVS electrodes were found to have a shelf life of about 4 months when stored at 25 degrees C.

Immobilization of urease on poly(N-vinyl carbazole)/stearic acid Langmuir-Blodgett films for application to urea biosensor

Urease was immobilized in mixed monolayers of poly(N-vinyl carbazole) (PNVK) and stearic acid (SA) formed at an air-water interface. The monolayers were transferred onto indium-tin-oxide (ITO) coated glass plates using Langmuir-Blodgett (LB) film deposition technique. Urease immobilized on PNVK/SA LB films, characterized using FTIR and UV-visible spectroscopy, was found to exhibit increased stability over a wide pH (6.5-8.5) and temperature (25-50 degrees C) range. Potentiometric measurements on these urease electrodes were carried out using an ammonium ion analyzer. Two values for K(m)(app) were obtained at lower and higher concentrations of substrate urea.

A randomized phase 3 trial comparing nimotuzumab plus cisplatin chemoradiotherapy versus cisplatin chemoradiotherapy alone in locally advanced head and neck cancer

BACKGROUND

Because the addition of nimotuzumab to chemoradiation in patients with locally advanced head and neck cancer improved outcomes in a phase 2 study, the authors conducted a phase 3 study to confirm these findings.

METHODS

This open-label, investigator-initiated, phase 3, randomized trial was conducted from 2012 to 2018. Adult patients with locally advanced head and neck cancer who were fit for radical chemoradiation were randomized 1:1 to receive either radical radiotherapy (66-70 grays) with concurrent weekly cisplatin (30 mg/m² ) (CRT) or the same schedule of CRT with weekly nimotuzumab (200 mg) (NCRT).The primary endpoint was progression-free survival (PFS); key secondary endpoints were disease-free survival (DFS), duration of locoregional control (LRC), and overall survival (OS). An intent-to-treat analysis also was performed.

RESULTS

In total, 536 patients were allocated equally to both treatment arms. The median follow-up was 39.13 months. The addition of nimotuzumab improved PFS (hazard ratio [HR], 0.69; 95% CI, 0.53-0.89; P = .004), LRC (HR, 0.67; 95% CI, 0.50-0.89; P = .006), and DFS (HR, 0.71; 95% CI, 0.55-0.92; P = .008) and had a trend toward improved OS (HR, 0.84; 95% CI, 0.65-1.08; P = .163). Grade 3 through 5 adverse events were similar between the 2 arms, except for a higher incidence of mucositis in the NCRT arm (66.7% vs 55.8%; P = .01).

CONCLUSIONS

The addition of nimotuzumab to concurrent weekly CRT improves PFS, LRC, and DFS. This combination provides a novel alternative therapeutic option to a 3-weekly schedule of 100 mg/m² cisplatin in patients with locally advanced head and neck cancer who are treated with radical-intent CRT.

Improved performance of polyaniline-uricase biosensor

Uricase has been covalently immobilized using glutaraldehyde as cross-linker onto electrochemically synthesized polyaniline (PANI) films. These PANI-uricase electrodes have been characterized using spectroscopic, cyclic voltammetry and impedance measurements. The morphology and covalent linkage of uricase lead to high enzyme loading and better shelf life. The value of the Michaelis-Menton constant obtained as 5.1x10(-3) mM L(-1) for the immobilized uricase compared to 3.4x10(-1) mM L(-1) for the free uricase enzyme, suggests enhancement in affinity and/or activity of uricase attached to PANI. The influence of pH, temperature and concentration on electrode activity were studied. The enzyme electrodes were found to retain 95% of activity after 17-18 weeks when stored at 4 degrees C. These electrodes have a response time of about 60 s and have been used to measure uric acid concentration in serum. These PANI-uricase electrodes can be used for about 30 times for electrochemical measurements while retaining about 90% of its activity indicating improved performance.

Langmuir-Blodgett Nanoassemblies of the MoS2-Au Composite at the Air-Water Interface for Dengue Detection

We report Langmuir-Blodgett (LB) films of molybdenum disulphide (MoS₂) and gold nanoparticles (AuNP) composite being utilized as a biosensing platform for dengue detection. The LB films of the MoS₂-AuNP composite have been transferred from the air-water interface to the indium tin oxide-coated glass substrate under optimized conditions. Further, antibodies specific to dengue NS1 antigen were immobilized onto these LB films. The fabricated immunosensor has been explored for NS1 antigen detection in standard samples as well as in spiked sera samples using electrochemical impedance spectroscopy. The NS1 antigen is present in the blood of infected persons from day one of the onset of clinical symptoms in primary dengue infection. The limit of detection for the standard and the spiked samples is found to be 1.67 and 1.19 ng mL^-1, respectively, which is suitable for clinical applications, as NS1 antigen levels in patient's sera range from 0.04 to 2 μg mL^-1 in primary infection and from 0.01 to 2 μg mL^-1 in secondary infection.

Signal amplification by substrate recycling on polyaniline/lactate oxidase/lactate dehydrogenase bienzyme electrodes

The bienzyme electrodes were fabricated by coimmobilization of lactate oxidase (LOD) and lactate dehydrogenase (LDH) onto electrochemically prepared polyaniline (PANI) films. These PANI/LOD/LDH bienzyme electrodes were shown to provide signal amplification by substrate recycling, making it possible to detect L-lactate at lower concentrations (0.1-1 mM). The PANI/LOD/LDH bienzyme electrodes were found to be stable for about 21 d at 4-10 degrees C.

Polyaniline-carboxymethyl cellulose nanocomposite for cholesterol detection

Cholesterol oxidase (ChOx) has been covalently immobilized onto polyaniline-carboxymethyl cellulose (PANI-CMC) nanocomposite film deposited onto indium-tin-oxide (ITO) coated glass plate using glutaraldehyde as a cross-linker. Fourier transform infrared (FTIR) spectroscopic and electrochemical studies have been used to characterize the PANI-CMC/ITO nanocomposite electrode and ChOx/PANI-CMC/ITO bioelectrode. Scanning electron microscopy (SEM) studies reveal the formation of PANI-CMC nanocomposite fibers of size approximately 150 nm in diameter. The ChOx/PANI-CMC/ITO bioelectrode exhibits linearity as 0.5-22 mM, detection limit as 1.31 mM, sensitivity as 0.14 mA/mM cm2, response time as 10 s and shelf-life of about 10 weeks when bioelectrode is stored at 4 degrees C. The low value of Michaelis-Menten constant (K(m)) obtained as 2.71 mM reveals high affinity of immobilized ChOx for PANI-CMC/ITO nanocomposite electrode.

Prevalence of MLR blocking antibodies before and after immunotherapy

Immunologically specific blocking factors (BF) are believed to play a protective role in the maintenance of pregnancy. We compared the levels of BF in normal pregnant women and in patients with recurrent spontaneous abortion (RSA) and observed that the two groups differ significantly from one another. MLC inhibitory activity was present throughout normal pregnancy and was found to be specific to the husband's HLA antigens. Immunotherapy was performed in 28 recurrent aborters using husband's lymphocytes, after which levels of blocking antibodies increased in 23 patients. The difference in the label of MLR BF in the preimmunotherapy and postimmunotherapy groups was statistically significant and was associated with successful pregnancy outcome in 82.15% of cases. The appearance of the MLR BF and its continuation in a successful pregnancy might represent an appropriate immune state that may be playing an important role in maintenance of pregnancy.

Understanding Omics Driven Plant Improvement and de novo Crop Domestication: Some Examples

In the current era, one of biggest challenges is to shorten the breeding cycle for rapid generation of a new crop variety having high yield capacity, disease resistance, high nutrient content, etc. Advances in the "-omics" technology have revolutionized the discovery of genes and bio-molecules with remarkable precision, resulting in significant development of plant-focused metabolic databases and resources. Metabolomics has been widely used in several model plants and crop species to examine metabolic drift and changes in metabolic composition during various developmental stages and in response to stimuli. Over the last few decades, these efforts have resulted in a significantly improved understanding of the metabolic pathways of plants through identification of several unknown intermediates. This has assisted in developing several new metabolically engineered important crops with desirable agronomic traits, and has facilitated the de novo domestication of new crops for sustainable agriculture and food security. In this review, we discuss how "omics" technologies, particularly metabolomics, has enhanced our understanding of important traits and allowed speedy domestication of novel crop plants.

Highlighting the compound risk of COVID-19 and environmental pollutants using geospatial technology

The new COVID-19 coronavirus disease has emerged as a global threat and not just to human health but also the global economy. Due to the pandemic, most countries affected have therefore imposed periods of full or partial lockdowns to restrict community transmission. This has had the welcome but unexpected side effect that existing levels of atmospheric pollutants, particularly in cities, have temporarily declined. As found by several authors, air quality can inherently exacerbate the risks linked to respiratory diseases, including COVID-19. In this study, we explore patterns of air pollution for ten of the most affected countries in the world, in the context of the 2020 development of the COVID-19 pandemic. We find that the concentrations of some of the principal atmospheric pollutants were temporarily reduced during the extensive lockdowns in the spring. Secondly, we show that the seasonality of the atmospheric pollutants is not significantly affected by these temporary changes, indicating that observed variations in COVID-19 conditions are likely to be linked to air quality. On this background, we confirm that air pollution may be a good predictor for the local and national severity of COVID-19 infections.

Giant Gastric Lipoma Presenting as Gastric Outlet Obstruction - A Case Report

Gartric lipomas are rare. They are mostly small in size, and usually remain asymptomatic. We report a case of giant (14×11cm) gastric lipoma in a 46-year-old male who presented with features of gastric outlet obstruction clinically mimicking gastric malignancy. Upper endoscopy showed a large smooth polypoid mass with broad base arising from posterior wall of gastric antrum with areas of superficial ulcerations. Multiple endoscopic biopsy specimens were nondiagnostic. A computed tomography (CT) scan of the abdomen revealed a huge cauliflower- like intraluminal mass with lobulated surface projecting into gastric lumen and pyloric canal. The mass demonstrated uniform fat density consistent with lipoma. The case is presented to stress the diagnostic problems related to this condition, and emphasize the role of CT in arriving at a correct diagnosis of lipomatous gastrointestinal tract tumours.

Insights on Genetic Diversity, Population Structure, and Linkage Disequilibrium in Globally Diverse Coconut Accessions Using Genotyping-by-Sequencing

Genotyping-by-sequencing (GBS) has emerged as a cost-effective approach for genome-wide discovery of single-nucleotide polymorphism (SNP) markers and high-throughput genotyping. In this study, 96 coconut palms, representing 16 accessions from globally diverse origins, were genotyped using the GBS strategy. A total of 10,835 high-quality SNPs, which were identified after stringent filtering, were utilized to assess genetic diversity, population structure, and linkage disequilibrium (LD) analyses. The polymorphism information content (PIC) values of SNPs ranged from 0.1 to 0.4, with a large proportion of SNPs (8633 nos.; 79.7%) having a higher PIC in the range of 0.3-0.4. The genetic diversity analysis revealed the existence of a high level of variation in coconut accessions, with an average expected heterozygosity (H_e) value of 0.43. Unweighted neighbor-joining phylogenetic tree and Bayesian-based model population structure grouped coconut genotypes into four main clusters. The accessions are generally clustered based on their height (tall or dwarf), with a few accession clusterings based on geographical origins. Investigation of LD pattern in coconut indicated a relatively rapid LD decay with a short range (9 kb). The results obtained in this study will contribute to enhancing the capacity of coconut researchers to utilize genetic diversity for further genetic improvement. In addition, it would open up possibilities for performing genomic studies such as genome-wide association studies and genomic selection to accelerate the efficiency and speed of coconut genetic improvement.

Ultrasensitive Immunosensor Based on Langmuir-Blodgett Deposited Ordered Graphene Assemblies for Dengue Detection

In this manuscript partially reduced graphene oxide (RGO) nanosheet-based electrodes have been utilized for quantification of the NS1 protein and subsequently for dengue detection. NS1 is the biomarker found circulating in the body of dengue-infected persons on or after first day of the appearance of disease symptoms. Graphene oxide (GO) has been synthesized using a modified Hummer's method, and its ordered nanostructured films have been electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates using Langmuir-Blodgett (LB) deposition. Deposited LB films of GO have been reduced with hydrazine vapors to obtain RGO-coated ITO electrodes. NS1 antibodies have been grafted onto the ordered thin films using covalent linking, and the bioelectrodes have been utilized for the specific detection of NS1 antigen. The electrochemical performance of the fabricated bioelectrodes for NS1 antigen detection has been explored in standard and spiked sera samples. The limit of detection for the standard samples and spiked serum samples is found to be 0.069 ng mL^-1 and 0.081 ng mL^-1, respectively, with a sensitivity of 8.41 and 36.75 Ω per ng mL, respectively, in the detection range of 10¹ to 10⁷ ng mL^-1.

Comparison of vertical and horizontal flow planted and unplanted subsurface flow wetlands treating municipal wastewater

In the search for design criteria for constructed wetlands (CWs) in Nepal a semi-scale experimental setup including horizontal flow (HF) and vertical flow (VF) CWs was developed. This paper compares the performance of HF and VF wetlands, and planted with unplanted beds. The experimental setup consists of two units of HF and VF beds of size 6 m × 2 m × 0.6 m and 6 m × 2 m × 0.8 m (length × width × depth) respectively. For both HF and VF systems, one unit was planted with Phragmites karka (local reed) and one was not planted. The systems were fed with wastewater drawn from the grit chamber of a municipal wastewater treatment plant. The media consisted of river gravel. In the first phase of the experiment the hydraulic loading rate (HLR) was varied in steps; 0.2, 0.08, 0.04 m(3)/m(2)/d and the percent removal increase with decrease in HLR for all beds and parameters except for total phosphorus. In the second phase the loading rate of 0.04 m(3)/m(2)/d was run for 7 months. In both parts of the experiment the planted beds performed better than the unplanted beds and the VF better than the HF beds. To meet Nepalese discharge standards HF beds are sufficient, but to meet stricter requirements a combination of HF and VF beds are recommended.

Comparative pathology, molecular pathogenicity, immunological features, and genetic characterization of three highly pathogenic human coronaviruses (MERS-CoV, SARS-CoV, and SARS-CoV-2)

The last two decades have witnessed the emergence of three deadly coronaviruses (CoVs) in humans: severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are still no reliable and efficient therapeutics to manage the devastating consequences of these CoVs. Of these, SARS-CoV-2, the cause of the currently ongoing coronavirus disease 2019 (COVID-19) pandemic, has posed great global health concerns. The COVID-19 pandemic has resulted in an unprecedented crisis with devastating socio-economic and health impacts worldwide. This highlights the fact that CoVs continue to evolve and have the genetic flexibility to become highly pathogenic in humans and other mammals. SARS-CoV-2 carries a high genetic homology to the previously identified CoV (SARS-CoV), and the immunological and pathogenic characteristics of SARS-CoV-2, SARS-CoV, and MERS contain key similarities and differences that can guide therapy and management. This review presents salient and updated information on comparative pathology, molecular pathogenicity, immunological features, and genetic characterization of SARS-CoV, MERS-CoV, and SARS-CoV-2; this can help in the design of more effective vaccines and therapeutics for countering these pathogenic CoVs.

Phenolic Acid Changes in Mycelia of Sclerotium rolfsii After Garlic and Onion Supplementation in a Broth Medium

High performance liquid chromatographic (HPLC) analysis of mycelia of Sclerotium rolfsii grown in broth medium supplemented with garlic (Allium sativum) and onion (Allium cepa) was carried out to estimate qualitative and quantitative changes in phenolic acids. Several phenolic acids, such as gallic, chlorogenic, ferulic, o-coumaric and cinnamic acids were detected in varied amounts in mycelia grown on such media as compared to control. Phenolic acids represents a wide range of secondary metabolite found in the cells of plants and microbes including fungi. The growth characters of S. rolfsii in various supplements also varied from thin and transparent to thick and opaque.

Large Tubullo-villous Adenoma of Duodenum Presenting as Gastric Outlet Obstruction

Tubullo-villous adenoma of duodenum is a rare entity. These are potentially malignant tumours and therefore, complete excision is the treatment of choice. However, at times preoperative diagnosis could not be always achieved posing difficulty in choosing the optimal surgical method of excision. We report a 40-year-old male patient presented with vague upper abdominal pain and vomiting for last 6 months. His computed tomography and endoscopy demonstrated intraluminal polypoidal mass. Endoscopic biopsies were negative for malignancy. Local surgical excision with tumour free margin was performed and histology revealed tubullo-villous adenoma.

Two cases of eyelid tuberculosis - An uncommon presentation of ocular tuberculosis

Mycobacterium tuberculosis apart from being the causative agent of pulmonary tuberculosis is also notorious to cause tuberculosis at various sites in the human body and ocular tuberculosis is one of the extra pulmonary manifestations of this organism. The most common presentation of ocular tuberculosis is anterior uveitis or choroiditis caused by hematogenous infection or hypersensitivity after another organ infection. Eyelid involvement by tuberculosis is most of the times secondary to orbital involvement and often seen in the form of drainage sinus. Isolated eyelid tuberculosis is however uncommon. Here we report two such cases of eyelid tuberculosis in different age groups; first case in a young female and second case of an old aged female with different presentation. Fortunately both of them responded well to the antitubercular treatment.

Perigraft Seroma Presenting as Discharging Sinus and Spontaneous Exteriorization of Vascular Graft - A Rare Entity Following Vascular Repair with PTFE Graft

Perigraft seroma presenting as discharging sinus and spontaneous exteriorization of vascular graft are rare complication of vascular injury repair with polytetrafluoroethylene (PTFE) grafts. We hereby report a case of young boy who presented with discharging sinuses and vascular graft coming out from one of the sinuses following vascular repair of femoral artery with PTFE graft after a follow-up of six months but the limb was salvaged. On evaluation PTFE graft was found to be thrombosed and collaterals were formed for distal perfusion. Because of persistent discharging sinuses, PTFE graft was removed and femoral artery was ligated proximal and distal to the graft. This case highlights an unusual complication of PTFE grafts that is commonly used in vascular surgery and also highlights the fact that these graft buy time for gradual collaterals formation for distal perfusion and hence when thrombosed and complicated can be safely removed.

Phonon dispersion in polyinosinic acid

A study of the normal modes of vibration and their dispersion in polyinosinic acid [poly (I)] along the helix axis based on Urey-Bradley force field is reported. It leads to a better interpretation of Raman and FTIR spectra. A comparison of dispersion curves of poly (I) with poly (G) has been made. Characteristic features of dispersion curves, such as regions of high density-of-states, repulsion and character mixing are discussed. Predictive value of heat capacity as a function of temperature is reported.

Optimizing whole grain rice fortification using microwave-assisted screw conveying spraying and drying setup: Exploring solution absorption, gelatinization, and micronutrient retention

This study presents a novel gelatinization-induced whole-grain rice fortification (GIWGRF) technology using a microwave-assisted screw conveying spraying and drying setup (MASCSD). The process involves microwave-assisted soaking of pregelatinized rice in a micronutrient solution, followed by steam-assisted gelatinization and drying. Rice with an initial degree of gelatinization (DG) of 58.87 ± 2.11 % was subjected to microwave-assisted spray-soaking with NaFeEDTA solution (2125 mg/400 mL) at 0.6 kW/kg microwave power density (MPD) for 20 min, achieving approximately 50 % moisture content. The rice was then steamed for 100 s to enhance gelatinization and micronutrient embedding, increasing DG from 58.23 ± 3.50 % to 75.86 ± 4.15 %. Subsequently, the rice was microwave-assisted dried at 0.6 kW/kg MPD for 65 min, resulting in a final moisture content of 13.21 ± 2.71 % (db). GIWGFRK exhibits similar physicochemical and cooking properties and offers 97.12 ± 2.26 % micronutrient uptake during spray soaking, 89.19 ± 2.33 % washing retention, and 65.77 ± 4.19 % cooking retention. Thus, this technique can be suggested as a practical approach to whole-grain-rice-fortification.

A general class of improved population variance estimators under non-sampling errors using calibrated weights in stratified sampling

This paper proposes a new calibration estimator for population variance within a stratified two-phase sampling design. It takes into account random non-response and measurement errors, specifically applying this method to estimate the variance in Gas turbine exhaust pressure data. The study integrates additional information from two highly positively correlated auxiliary variables to develop a general class of estimators tailored for the stratified two-phase sampling scheme. The properties of these estimators, in terms of their biases and mean square errors, have been thoroughly examined and extensively analyzed through numerical and simulation studies. Furthermore, the calibrated weights of the strata are derived. The proposed estimators outperform the natural estimator of population variance. Finally, suitable recommendations have been made for survey statisticians intending to apply these findings to real-life problems.