Controlled Ring-Opening Polymerization of Methyl Glycolide with Bifunctional Organocatalyst.

A bifunctional thiourea-amine-based organocatalyst (Takemoto's catalyst), employing a metal-free approach, is presented for the regioselective ring-opening polymerization (ROP) of optically active (D and L) methyl glycolide (MG). In this study, a chiral version of Takemoto's catalyst efficiently promotes the ROP of MG at room temperature, yielding poly(lactic-co-glycolic acids) (PLGAs) with predicted molecular weights and narrow polydispersity indices (PDI≤1.2).

Variability in addictive and carcinogenic potential of smokeless tobacco products marketed in Mumbai, India: a surveillance study.

Background: India has the highest incidence worldwide of smokeless tobacco (SLT)-associated oral cancer, accounting for nearly 70% of all SLT users globally. Nicotine and tobacco-specific -nitrosamines (TSNA) play critical roles in the addictive and carcinogenic potential, respectively, of SLT products. Our group has previously reported substantial variability in nicotine and TSNA levels across a small SLT product sample in India, calling for systematic surveillance.

Influence of Wavy Arteries and Veins on Hemodynamic Characteristics: A Numerical Study.

The present work is focused on the study of hemodynamic characteristics for tortuous arteries/veins. Tortuosity in arteries/veins is defined by introducing waviness in the wall of the tube. Analysis is further extended for bifurcated veins with and without wavy walls.

A Clinical Study of Malignant Sino-Nasal Tumors.

The sino-nasal cavities represent an anatomical region affected by a variety of tumors with clinical, etiological, genetic and pathological features, which are distinct from tumors commonly encountered in the area of head and neck cancers. We have undertaken this study with the aim of assessing clinical profile, various treatment modalities and outcome of patients with malignant sino-nasal tumors. In this prospective study of two years, done in a rural tertiary care hospital of India, 40 patients with malignant neoplastic tumors of nasal cavity, sinuses and nasopharynx were analyzed for their clinic-pathological and radiological profile and surgical management.

Comparative Study of Various Techniques of Mastoid Obliteration following Canal Wall Down Mastoidectomy.

The primary objective of mastoid obliteration is the eradication of the disease and prevention of its recurrence. We intend to evaluate the impact of mastoid obliteration using autologous materials on the achievement of a dry mastoid bowl and frequency of maintenance care and hearing outcome of the operated ear. This was a hospital-based, non - randomized, prospective study.

Resorbable barrier polymers for flexible bioelectronics.

Resorbable, implantable bioelectronic devices are emerging as powerful tools to reliably monitor critical physiological parameters in real time over extended periods. While degradable magnesium-based electronics have pioneered this effort, relatively short functional lifetimes have slowed clinical translation. Barrier films that are both flexible and resorbable over predictable timelines would enable tunability in device lifetime and expand the viability of these devices.

Enantioselective Separation of Amino Acids Using Chiral Polystyrene Microspheres Synthesized by a Post-Polymer Modification Approach.

The enantioselective separation of a racemic mixture of amino acids was achieved by chiral amino acid-modified polystyrene (PS) that was developed by a post-polymer modification approach. Styrene was polymerized using the reversible addition-fragmentation chain-transfer (RAFT) polymerization technique and further post-polymer modification was applied by Friedel-Crafts acylation reaction with chiral -phthaloyl-l-leucine acid chloride to obtain the protected PS-l-Leu. The chiral PS (protected PS-l-Leu) was assembled into microspheres using a surfactant and was used for carrying out the enantioselective separation of amino acid racemic mixtures by enantioselective adsorption followed by a simple filtration process.

Trehalose transporter-like gene diversity and dynamics enhances stress response and recovery in Helicoverpa armigera.

Trehalose is a primary sugar and its distribution across the insect body, regulated by trehalose transporters (TRETs), is essential for sugar metabolism and energy homeostasis. The large diversity of Tret-like sugar transporters (ST), belonging to SLC2A transporter family, in polyphagous insects probably contributes to their extremely adaptive nature. We aim to study spatio-temporal expression dynamics and functional relevance of ST transcript variants in the lepidopteran model organism, Helicoverpa armigera.

Anti-adhesive bioresorbable elastomer-coated composite hernia mesh that reduce intraperitoneal adhesions.

Intraperitoneal adhesions (IAs) are a major complication arising from abdominal repair surgeries, including hernia repair procedures. Herein, we fabricated a composite mesh device using a macroporous monofilament polypropylene mesh and a degradable elastomer coating designed to meet the requirements of this clinical application. The degradable elastomer was synthesized using an organo-base catalyzed thiol-yne addition polymerization that affords independent control of degradation rate and mechanical properties.

Influence of Touch-Spun Nanofiber Diameter on Contact Guidance during Peripheral Nerve Repair.

Peripheral nerve regeneration across large gaps remains clinically challenging and scaffold design plays a key role in nerve tissue engineering. One strategy to encourage regeneration has utilized nanofibers or conduits to exploit contact guidance within the neural regenerative milieu. Herein, we report the effect of nanofiber topography on two key aspects of regeneration: Schwann cell migration and neurite extension.

Powder Reuse in Laser-Based Powder Bed Fusion of Ti6Al4V-Changes in Mechanical Properties during a Powder Top-Up Regime.

The properties of Extra Low Interstitials (ELI) Ti6Al4V components fabricated via the laser-based powder bed fusion (L-PBF) process are prone to variation, particularly throughout a powder reuse regime. Interstitial pick-up of interstitial elements within the build chamber during processing can occur, most notably, oxygen, nitrogen, and hydrogen, which can impair the mechanical properties of the built component. This study analyses ELI Ti6Al4V components manufactured by the L-PBF process when subjected to a nine-stage powder reuse sequence.

Simultaneous analysis of urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, N'-nitrosonornicotine, and cotinine by liquid chromatography-tandem mass-spectrometry.

Biomarkers of exposure to harmful tobacco constituents are key tools for identifying individuals at risk and developing interventions and tobacco control measures. However, tobacco biomarker studies are scarce in many parts of the world with high prevalence of tobacco use. Our goal was to establish a robust method for simultaneous analysis of urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), N'-nitrosonornicotine (NNN), and cotinine at the Advanced Centre for Treatment, Research and Education in Cancer (ACTREC) in Mumbai, India.

Identifying Risk Factors for Complications During Exposure for Anterior Lumbar Interbody Fusion.

Introduction An anterior approach to lumbar interbody fusion is a widely utilized method of access to the lumbar spine. Due to the potential for vascular complications with spine exposure, vascular surgeons are frequently included in the care of these patients as part of a team-based approach. Identifying risk factors for such complications is difficult and not well-defined in the literature.

Osmolyte enhanced aqueous two-phase system for virus purification.

Due to the high variation in viral surface properties, a platform method for virus purification is still lacking. A potential alternative to the high-cost conventional methods is aqueous two-phase systems (ATPSs). However, optimizing virus purification in ATPS requires a large experimental design space, and the optimized systems are generally found to operate at high ATPS component concentrations.

Correction to "Experimental Study of the Effect of Different Parameters on the Adsorption and Desorption of Trichloroethylene Vapor on Activated Carbon Particles".

[This corrects the article DOI: 10.1021/acsomega.0c03648.

Experimental Study of the Effect of Different Parameters on the Adsorption and Desorption of Trichloroethylene Vapor on Activated Carbon Particles.

Trichloroethylene (TCE) is used as a solvent in various industrial processes. During its use, TCE vaporizes and its vapor pollutes the working atmosphere. Its recovery is very important and activated carbon may be used for this purpose.

Five concomitant polymorphs of a green fluorescent protein chromophore (GFPc) analogue: understanding variations in photoluminescence with π-stacking interactions.

The synthetically modified green fluorescent protein chromophore analogue 3,4,5-trimethoxybenzylidene imidazolinone (1) yielded five polymorphs (I, II, III, IV, V) concomitantly irrespective of the solvent used for crystallization. The pentamorphic modification of 1 is solely due to the interplay of iso-energetic weak intermolecular interactions in molecular associations as well as the conformational flexibility offered by a C-C single bond, which connects the electron-deficient moiety imidazolinone with the electron-rich trimethoxybenzylidene group. A common structural feature observed in all the polymorphs is the formation of a `zero-dimensional' centrosymmetric dimeric unit through a short and linear C-H.

Zwitterion Surface-Functionalized Thermoplastic Polyurethane for Antifouling Catheter Applications.

Immobilizing zwitterionic molecules on material surfaces has been a promising strategy for creating antifouling surfaces. Herein, we show the ability to surface derivatize an allyl-ether-functionalized thermoplastic polyurethane (TPU) with a zwitterionic thiol in a radically induced thiol-ene reaction. The thermoplastic polyurethane was synthesized to have an allyl-ether side functionality using a modified chain extender molecule.

Antibiotic eluting poly(ester urea) films for control of a model cardiac implantable electronic device infection.

Cardiac implantable electronic device (CIED) infections acquired during or after surgical procedures are a major complication that are challenging to treat therapeutically, resulting in chronic and sometimes fatal infections. Localized delivery of antibiotics at the surgical site could be used to supplement traditional systemic administration as a preventative measure. Herein, we investigate a cefazolin-eluting l-valine poly(ester urea) (PEU) films as a model system for localized antibiotic delivery for CIEDs.

Pulsed laser deposited CoFeO thin films as supercapacitor electrodes.

The influence of the substrate temperature on pulsed laser deposited (PLD) CoFeO thin films for supercapacitor electrodes was thoroughly investigated. X-ray diffractometry and Raman spectroscopic analyses confirmed the formation of CoFeO phase for films deposited at a substrate temperature of 450 °C. Topography and surface smoothness was measured using atomic force microscopy.

Enantioselective Separation Using Chiral Amino Acid Functionalized Polyfluorene Coated on Mesoporous Anodic Aluminum Oxide Membranes.

Homochiral mesoporous anodic aluminum oxide membranes (AAO) were prepared by coating protected chiral D/L aspartic acid appended polyfluorene in the pores. These chiral AAO membranes successfully demonstrated enantioselective recognition and separation of a range of amino acids from their aqueous racemic mixture by simple filtration. Enantioselective separation was achieved by selective adsorption of one enantiomer from the aqueous racemic mixture into the chiral pores of the AAO membrane leaving the filtrate enriched with the other enantiomer.

Implication of in vivo circulating fibrocytes ablation in experimental pulmonary hypertension murine model.

Background And Purpose: Recruitment and involvement of bone-/blood-derived circulating fibrocytes (CF) in the promotion of fibrotic tissue remodelling processes have been shown. However, their direct contribution to pathological changes is not clear. The present study investigates the causal role of CF in the pathogenesis of pulmonary hypertension (PH).

Fenestrated endovascular aneurysm repair with concomitant horseshoe kidney.

Horseshoe kidney (HSK) is a rare anatomic anomaly that poses surgical challenges in the setting of abdominal aortic aneurysm repair. An endovascular approach is safer for patients yet carries technical challenge because of variable renal vasculature. We present the case of a patient with an infrarenal abdominal aortic aneurysm and concomitant HSK who underwent successful repair with a custom fenestrated endograft with preservation of a midaortic renal artery.