Deciphering the microbial communities of alkaline hot spring in Panamik, Ladakh, India using a high-throughput sequencing approach.

Due to their distinctive physicochemical characteristics, hot springs are extremely important. The whole genome metagenomic sequencing technology can be utilized to analyze the diverse microbial community that thrives in this habitat due to the particular selection pressure that prevails there. The current investigation emphasizes on culture-independent metagenomic study of the Panamik hot spring and its nearby areas from Ladakh, India. Based on different diversity indices, sequence analysis of the soil reservoir showed higher species richness and diversity in comparison to water and sediment samples. The mineral content and various physicochemical pameters like temperature, pH had an impact on the composition of the microbial community of the geothermal springs. The phyla Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacter, Firmicutes, and Verrucomicrobia in bacterial domain dominate the thermos-alkaline spring at Panamik in different concentrations. Economically significant microbes from the genera Actinobacter, Thermosynechoccus, Candidatus Solibacter, Chthoniobacter, Synechoccus, Pseudomonas and Sphingomonas, were prevalent in hot spring. In the archaeal domain, the most dominant phylum and genera were Euryarchaeota and Thermococcus in all the samples. Further, the most abundant species were Methanosarcina barkeri, Nitrospumilus maritimus and Methanosarcina acetivorans. The present study which only examined one of the several thermal springs present in the Himalayan geothermal area, should be regarded as a preliminary investigation of the microbiota that live in the hot springs on these remote areas. These findings suggest that further investigations should be undertaken to characterize the ecosystems of the Panamik hot spring, which serve as a repository for unidentified microbial lineages.

Formulation and Characterization of Glucosamine Sulphate Potassium Chloride (GSPC) Loaded Emulgel for the Treatment of Osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is becoming a major medical burden worldwide due to changing lifestyles and aging populations. Osteoarthritis is a disease characterized by a variety of anatomic and physiological changes to joints, including cartilage degradation, bone remodeling, and the formation of osteophytes. These changes cause pain, stiffness, swelling, and limitations in joint function. Glucosamine serves as a fundamental constituent for cartilage, the resilient connective tissue responsible for cushioning joints. Glucosamine Sulphate Potassium Chloride (GSPC) supplementation is widely employed to mitigate symptoms linked to osteoarthritis, a degenerative joint disorder hallmarked by cartilage degradation. AIM: Palliative care aims at minimizing pain and disability and improving function, performance, and quality of life. In this study, the emulgel formulation of GSPC was developed and checked for its potential. OBJECTIVE: Currently, OA does not have a definitive treatment. Since conventional dosage forms cannot deliver the active drug content at a predefined target site in a predictable manner throughout the treatment period, a new carrier system is always required. Considering their reduced size, targeting potential, and site specificity, nanocarrier-based approaches could hold an answer to shortcomings associated with conventional routes. Thus, the objective of the current study was to formulate and characterize glucosamine sulphate potassium chloride-loaded emulgel for the treatment of osteoarthritis. METHODS: Microemulsion of glucosamine sulphate potassium chloride was formulated using a spontaneous emulsification method comprising of oleic acid (oil phase), Tween 80, Tween 20 (surfactant) and PEG 400, Span 80 (co-surfactant), and distilled water (aqueous phase). The microemulsions were evaluated for surface morphology, globule size, poly-dispersibility index (PDI), zeta potential, and viscosity, and the final batch of microemulsions was selected. RESULT: The optimized microemulsion contained 35% co-surfactant (propylene glycol), 20% surfactant (Tween 20), and 15% oil (oleic acid) and glucosamine sulphate potassium chloride in a dose of 60 mg, which has sufficient drug loading capacity with a droplet size of 182 nm for optimized formulation. The optimized microemulsion formulation was added to gel prepared by Carbopol 934 in a 1:1 (w/w) ratio, leading to the formulation of glucosamine sulphate potassium chloride- containing emulgel. The prepared emulgel was further evaluated for viscosity, drug content, pH, and in-vitro drug release. Emulgel formulation (F6) showed 88% drug release after 6 hours, and it followed the Higuchi model. CONCLUSION: Glucosamine Sulphate Potassium Chloride (GSPC) is used in the treatment of OA by increasing the production of proteoglycans, which can cause the cartilage to break down. Emulgel formulation (F3) showed 75.41% drug release, and formulation (F6) showed 88% drug release after 6 h. Therefore, it may be concluded that an emulgel of GSPC can be used as a controlled-release dosage form of the drug for local application in OA.

Hydrocarbon stapled temporin-L analogue as potential antibacterial and antiendotoxin agents with enhanced protease stability.

Antimicrobial resistance (AMR) is a serious global concern and a huge burden on the healthcare system. Antimicrobial peptides (AMPs) are considered as a solution of AMR due to their membrane-lytic and intracellular mode of action and therefore resistance development against AMPs is less frequent. One such AMPs, temporin-L (TL) is a 13-mer peptide reported as a potent and broad-spectrum antibacterial agent with significant immunomodulatory activity. However, TL is toxic to human erythrocytes at their antibacterial concentrations and therefore various analogues were synthesized with potent antimicrobial activity and lower hemolytic activity. In this work, we have selected a non-toxic engineered analogue of TL (eTL) and performed hydrocarbon stapling of amino acid residues at i to i + 4 positions at different part of sequence. The synthesized peptides were investigated against both the gram-positive and gram-negative bacteria as well as methicillin resistant S. aureus, its MIC was measured in the concentrations range of 0.9-15.2 µM. All analogues were found equal or better antibacterial as compared to parent peptide. Interestingly one analogue eTL [5-9] was found to be non-cytotoxic and stable in presence of the human serum. Mode of action studies revealed membrane depolarizing and disruptive mode of action with live MRSA. Further in vivo studies of antimicrobial against MRSA infection and anti-endotoxin activities in mice model revealed potential activity of the stapled peptide analogue. Overall, this reports on stapled analogue of the AMPs highlights an important strategy for the development of new antibacterial therapeutics against AMR.

Microbial diversity analysis of Chumathang geothermal spring, Ladakh, India.

In light of their unique and challenging environment, the high-altitude Chumathang geothermal springs in Ladakh, India, are undeniably intriguing for microbiological study. The purpose of this study was to employ a culture-independent sequencing approach to give a comprehensive characterization of the unknown bacterial and archaeal community structure, composition and networks in water and soil from the Chumathang geothermal spring. A total of 50%, and 42.86% bacterial phyla were found in the water, and soil samples respectively and this analysis also showed a total of 9.62% and 7.94% of archaeal phyla in both the samples, respectively. Further, the presence of unclassified (derived from other sequences, water: 17.31%, and soil: 19.05%) and unclassified (derived from bacteria, water: 13.46%, and soil: 12.70%) were also observed in the current metagenomics investigation. Firmicutes and Proteobacteria were the most abundant bacterial phyla in water, whereas Proteobacteria and Bacteroidetes were the most abundant bacterial phyla in geothermal soil. Crenarchaeota and Euryarchaeota dominated archeal communities in soil and water, respectively. This metagenomic study gave a detailed insight into the microbial diversity found in Chumathang geothermal spring and surrounding area, located in Ladakh, India. Surprisingly, this finding indicated the existence of geographically distinct microbial communities that were suited to various geothermal water habitats along the Himalayan Geothermal Belt. Future studies must take into account the metabolic pathways of these microbial communities that exist in these extreme environments. This will allow us to obtain a better knowledge of the microbial metabolisms that are common at these geothermal locations, which have a lot of potential for biotechnological applications. They will also enable us to establish links between the microbial community composition and the physicochemical environment of geothermal water and area.

Three-dimensional integration of two-dimensional field-effect transistors.

In the field of semiconductors, three-dimensional (3D) integration not only enables packaging of more devices per unit area, referred to as 'More Moore'1 but also introduces multifunctionalities for 'More than Moore'2 technologies. Although silicon-based 3D integrated circuits are commercially available3-5, there is limited effort on 3D integration of emerging nanomaterials6,7 such as two-dimensional (2D) materials despite their unique functionalities7-10. Here we demonstrate (1) wafer-scale and monolithic two-tier 3D integration based on MoS2 with more than 10,000 field-effect transistors (FETs) in each tier; (2) three-tier 3D integration based on both MoS2 and WSe2 with about 500 FETs in each tier; and (3) two-tier 3D integration based on 200 scaled MoS2 FETs (channel length, LCH = 45 nm) in each tier. We also realize a 3D circuit and demonstrate multifunctional capabilities, including sensing and storage. We believe that our demonstrations will serve as the foundation for more sophisticated, highly dense and functionally divergent integrated circuits with a larger number of tiers integrated monolithically in the third dimension.

Tuning Polarity in WSe2/AlScN FeFETs via Contact Engineering.

Recent advancements in ferroelectric field-effect transistors (FeFETs) using two-dimensional (2D) semiconductor channels and ferroelectric Al0.68Sc0.32N (AlScN) allow high-performance nonvolatile devices with exceptional ON-state currents, large ON/OFF current ratios, and large memory windows (MW). However, previous studies have solely focused on n-type FeFETs, leaving a crucial gap in the development of p-type and ambipolar FeFETs, which are essential for expanding their applicability to a wide range of circuit-level applications. Here, we present a comprehensive demonstration of n-type, p-type, and ambipolar FeFETs on an array scale using AlScN and multilayer/monolayer WSe2. The dominant injected carrier type is modulated through contact engineering at the metal-semiconductor junction, resulting in the realization of all three types of FeFETs. The effect of contact engineering on the carrier injection is further investigated through technology-computer-aided design simulations. Moreover, our 2D WSe2/AlScN FeFETs achieve high electron and hole current densities of ∼20 and ∼10 µA/µm, respectively, with a high ON/OFF ratio surpassing ∼107 and a large MW of >6 V (0.14 V/nm).

Compositional induced structural phase transitions in (1 - x)(K0.5Na0.5)NbO3-x(Ba0.5Sr0.5)TiO3 ferroelectric solid solutions.

Ferroelectric materials exhibiting switchable and spontaneous polarization have strong potential to be utilized in various novel electronic devices. Solid solutions of different perovskite structures induce the coexistence of various phases and enhance the physical functionalities around the phase coexistence region. The construction of phase diagrams is important as they describe the material properties, which are linked to the underpinning physics determining the system. Here we present the phase diagram of (K0.5Na0.5NbO3)-(Ba0.5Sr0.5TiO3) (KNN-BST) system as a function of composition and their associated physical properties. Lead-free (1 - x)KNN-xBST (0 ≤ x ≤ 0.3) solid solution ceramics were synthesized by conventional solid-state reaction technique. The X-ray diffraction and Raman spectroscopic studies indicate composition-dependent structural phase transitions from an orthorhombic phase for x = 0 to orthorhombic + tetragonal dual-phase (for 0.025 ≤ x ≤ 0.15), then a tetragonal + cubic dual-phase (x = 0.2) and finally a cubic single phase for x ≥ 0.25 at room temperature (RT). Among these, the orthorhombic + tetragonal dual-phase system shows an enhanced value of the dielectric constant at room temperature. The phase transition temperatures, orthorhombic to tetragonal (TO-T) and tetragonal to cubic (TC), decrease with the increase in BST concentrations. The ferroelectric studies show a decrease of both 2Pr and EC values with a rise in BST concentration and x = 0.025 showed a maximum piezoelectric coefficient.

Impact of Large Gate Voltages and Ultrathin Polymer Electrolytes on Carrier Density in Electric-Double-Layer-Gated Two-Dimensional Crystal Transistors.

Electric-double-layer (EDL) gating can induce large capacitance densities (∼1-10 µF cm-2) in two-dimensional (2D) semiconductors; however, several properties of the electrolyte limit performance. One property is the electrochemical activity which limits the gate voltage (VG) that can be applied and therefore the maximum extent to which carriers can be modulated. A second property is electrolyte thickness, which sets the response speed of the EDL gate and therefore the time scale over which the channel can be doped. Typical thicknesses are on the order of micrometers, but thinner electrolytes (nanometers) are needed for very-large-scale-integration (VLSI) in terms of both physical thickness and the speed that accompanies scaling. In this study, finite element modeling of an EDL-gated field-effect transistor (FET) is used to self-consistently couple ion transport in the electrolyte to carrier transport in the semiconductor, in which density of states, and therefore quantum capacitance, is included. The model reveals that 50 to 65% of the applied potential drops across the semiconductor, leaving 35 to 50% to drop across the two EDLs. Accounting for the potential drop in the channel suggests that higher carrier densities can be achieved at larger applied VG without concern for inducing electrochemical reactions. This insight is tested experimentally via Hall measurements of graphene FETs for which VG is extended from ±3 to ±6 V. Doubling the gate voltage increases the sheet carrier density by an additional 2.3 × 1013 cm-2 for electrons and 1.4 × 1013 cm-2 for holes without inducing electrochemistry. To address the need for thickness scaling, the thickness of the solid polymer electrolyte, poly(ethylene oxide) (PEO):CsClO4, is decreased from 1 µm to 10 nm and used to EDL gate graphene FETs. Sheet carrier density measurements on graphene Hall bars prove that the carrier densities remain constant throughout the measured thickness range (10 nm-1 µm). The results indicate promise for overcoming the physical and electrical limitations to VLSI while taking advantage of the ultrahigh carrier densities induced by EDL gating.

Proximity-induced superconductivity in epitaxial topological insulator/graphene/gallium heterostructures.

The introduction of superconductivity to the Dirac surface states of a topological insulator leads to a topological superconductor, which may support topological quantum computing through Majorana zero modes1,2. The development of a scalable material platform is key to the realization of topological quantum computing3,4. Here we report on the growth and properties of high-quality (Bi,Sb)2Te3/graphene/gallium heterostructures. Our synthetic approach enables atomically sharp layers at both hetero-interfaces, which in turn promotes proximity-induced superconductivity that originates in the gallium film. A lithography-free, van der Waals tunnel junction is developed to perform transport tunnelling spectroscopy. We find a robust, proximity-induced superconducting gap formed in the Dirac surface states in 5-10 quintuple-layer (Bi,Sb)2Te3/graphene/gallium heterostructures. The presence of a single Abrikosov vortex, where the Majorana zero modes are expected to reside, manifests in discrete conductance changes. The present material platform opens up opportunities for understanding and harnessing the application potential of topological superconductivity.

Toward a Mechanistic Understanding of the Formation of 2D-GaNx in Epitaxial Graphene.

Ultrathin 2D-GaNx can be formed by Ga intercalation into epitaxial graphene (EG) on SiC followed by nitridation in ammonia. Defects in the graphene provide routes for intercalation, but the nature and role of the defects have remained elusive. Here we examine the influence of graphene layer thickness and chemical functionalization on Ga intercalation and 2D-GaNx formation using a combination of experimental and theoretical studies. Thin buffer layer regions of graphene near steps on SiC readily undergo oxygen functionalization when exposed to air or a He/O2 plasma in contrast to thicker regions which are not chemically modified. Oxygen functionalization is found to inhibit Ga intercalation leading to accumulation of Ga droplets on the surface. In contrast, Ga readily intercalates between EG and SiC in the thicker graphene regions that do not contain oxygen. When NH3 annealing is carried out immediately after Ga exposure, 2D-GaNx formation is observed only in the oxygen-functionalized regions, and Ga intercalated under thicker nonfunctionalized graphene does not convert to GaNx. Density functional theory calculations demonstrate that oxygen functionalization of graphene alters the binding energy of Ga and NH3 species to the graphene surface. The presence of hydroxyl groups on graphene inhibits binding of Ga to the surface; however, it enhances the chemical reactivity of the graphene surface to NH3 which, in turn, enhances Ga binding and facilitates the formation of 2D-GaNx. By modifying the EG process to produce oxygen-functionalized buffer layer graphene, uniformly intercalated 2D-GaNx is obtained across the entire substrate surface.

Ocular adverse effects of COVID-19 vaccines: A systematic review.

The COVID-19 pandemic has led to the development and rollout of several vaccines worldwide at unprecedented pace. This systematic review of published literature has been undertaken to spread awareness among general physicians and ophthalmologists about the various reported adverse effects in the eye following COVID-19 vaccination. A systematic search was performed on 25 January 2022 through PuBMed, Medline and Google scholar for publications on ocular adverse effects after COVID-19 vaccination. One brief communication, four retrospective case series, sixteen case reports, and five letters to editors were included. Ocular manifestations most commonly appear in the uvea and retina. Other manifestations are seen on the eyelid, cornea and ocular surface, and in cranial nerves innervating the eye. The incidence rate of these manifestations is quite low after COVID-19 vaccinations. Our systematic review meticulously enumerates various adverse effects of COVID -19 vaccine on the eye. Most of these adverse effects are transient and observed to resolve without any sequelae except for cases of retinal and ophthalmic vascular occlusions and corneal graft rejections. An emphasis on close follow-up and a need to delay vaccination and modified therapy to control flare up of signs and symptoms in certain sub-populations, Graves' disease (autoimmune etiology), pre-existing uveal inflammation and corneal graft cases are warranted. We need long-term, larger, multicentric studies to substantiate our findings and establish the causal relationship with certainty. Mass vaccinations to curb this pandemic after outweighing the ocular risks associated with it is warranted.

Correlation Between Carotid Intima Media Thickness and Non-Alcoholic Fatty Liver Disease.

CONTEXT: Non-alcoholic fatty liver disease (NAFLD) is considered a potential independent risk factor for cardiovascular disease. Increased carotid intima-media thickness (CIMT) is a sign of early atherosclerosis and is linked to an increased risk of myocardial infarction, stroke, and peripheral vascular disease. AIM: To study correlation between CIMT and NAFLD and its association with increase in grades of NAFLD. Material and Study Design: An observational case control study of 40 cases and 40 controls (age and sex matched) was done. The difference of CIMT between the two groups was analysed. CIMT was also measured among the various grades of NAFLD cases. MATERIALS AND METHODS: 40 cases with NAFLD and 40 controls falling within the age group of 18-45 years were taken in the study. Patients with history of significant alcohol consumption, acute or chronic liver disease, diabetes mellitus, hypertension, malignancy, hypothyroidism and having dyslipidaemia, CAD and stroke were excluded from the study. All the subjects underwent abdominal and carotid ultrasound in order to assess NAFLD and CIMT measurement. The left and right common carotid artery was examined using PHILIPS HD11XE high-definition ultrasound system equipped with a 3-12 MHz linear array transducer in B mode. OBSERVATION AND RESULTS: There was a statistically significant difference between the 2 groups in terms of CIMT with a p value of <0.001. The mean CIMT in the Case group was 0.86 mm while in Control group was 0.52 mm. There was a significant difference between the 3 Grades of NAFLD in terms of CIMT with a p value of <0.001 with maximum CIMT being in Grade 3 of NAFLD. Body Mass Index, Alanine Transaminase, Aspartate Transaminase, Alkaline Phosphatase, Total Cholesterol, Triglycerides, Low Density Lipoprotein were also found to have statistical significant difference between cases and controls. Age, gender, Blood pressure, Fasting Blood Sugar, HbA1c, Hemoglobin, Total leucocyte Count, Platelet count, Serum Bilirubin, Total protein and Albumin were found to be statistically insignificantly different between cases and controls. CONCLUSION: CIMT is increased in NAFLD patients. Increase in CIMT is significantly correlated with increasing grades of NAFLD. Hence CIMT can be used as screening tests in NALFD patients to assess cardiovascular risks.

Efficacy of atropine for myopia control in children: A meta-analysis of randomized controlled trials.

Objective: To conduct a meta-analysis of randomized controlled trials (RCTs) on the effects of atropine eye drop in slowing myopia progression. Methods: A systematic search of relevant articles was done through a computerized search on PubMed, Medline, Cochrane Library, and Google Scholar on June 16, 2022. A supplementary search was done on ClinicalTrials.gov on the same date. After thorough search and analysis, seven relevant RCTs, double-masked with atropine eye drop as intervention arm and placebo as control arm, were selected for meta-analysis. Jadad scoring was used to evaluate the quality of RCTs. The outcome measurements included in the present meta-analysis are mean changes in the spherical equivalent (SE) of myopic error, and mean changes in axial length (AL) during the study period. Result: Pooled summary effect size, calculated by random effect model, for SE of myopia progression was 1.08 with 95% confidence interval (CI) (0.31-1.86) which was statistically significant (P-value = 0.006). Pooled summary effect size, calculated by random effect model, for axial length was - 0.89 with 95% CI (-1.48 to - 0.30) which was statistically significant (P-value = 0.003). Conclusion: In summary, atropine was demonstrated to be effective in controlling myopia progression in children. Both outcome measures, mean SE changes and mean AL elongation responded to atropine intervention compared to placebo.

Refractive and visual outcomes of plate-haptic toric intraocular lens implantation for astigmatic correction after uncomplicated microincision cataract surgery.

Objective: To evaluate visual and refractive outcomes with plate-haptic toric intraocular lens implantation (ph-toric) after uncomplicated microincision cataract surgery (MICS) to correct moderate-to-severe astigmatism. Design: Prospective cross-sectional study. Methods: The study was conducted at a tertiary eye care center in New Delhi, India, on patients with visually-significant cataract and moderate-to-severe astigmatism (>1.00 diopters [D]). Preoperative parameters like visual-acuity, keratometry and astigmatism values and lens power calculation were noted. After MICS via 1.8 mm incision, a ph-toric IOL was implanted. The outcome measures noted were uncorrected and corrected distant visual-acuity (UDVA, CDVA), decrease in astigmatism and rotational stability. Follow-up was done on day 1, day 7, 1-month and 3-months postoperative. Results: This study involved 30 eyes of 30 patients. 27 patients (90%) gained UDVA of 6/ 9 or better. Out of these, 27 patients (90%) achieved CDVA of 6/ 6. Mean CDVA changed from 0.967 ± 0.101 postoperative to 0.176 ± 0.82 preoperatively (p<0.001). The mean preoperative astigmatism was 2.08 ± 0.59 D and the mean postoperative astigmatism was 0.35 ± 0.39 D. The mean correction achieved was 1.28 ± 0.32 D. Statistically significant (p<0.001) correction of astigmatism was observed by use of ph-toric IOL. The mean reduction in astigmatism was 84.16 ± 10.61 with excellent reduction in 43.3%. IOL rotation was <10 degrees in all the eyes. No complications were observed. Patients had satisfaction with the procedure and visual outcomes. Conclusion: Implantation of a plate-haptic toric IOL after uncomplicated MICS via 1.8 mm incision is a feasible and safe option in cataract cases with astigmatism to provide good visual and refractive outcomes. No major drawbacks were observed attributable to ph-toric IOL. Abbreviations: SIA - surgically induced astigmatism, D - diopters, MICS - microincision cataract surgery, ph-toric IOL - plate-haptic toric IOL, IOL - intraocular lens, UDVA - uncorrected distant visual acuity, CDVA - corrected distant visual acuity.

A decision analysis model for reducing carbon emission from coal-fired power plants and its compensatory units.

The increasing carbon dioxide level in the earth's atmosphere and continuously changing climate creates a significant challenge to sustainability in the world. It is not easy to control pollution due to carbon dioxide emissions from coal-fired power plants into the atmosphere. However, carbon capture technology provides an advantage for capturing carbon from power plants. Various researchers suggested the non-linear optimization model with post-combustion carbon capture technology in coal-fired power plants to reduce carbon emission. However, in their research articles, most researchers did not include loss of power due to retrofitting carbon capture technology in power plants and carbon emission from the compensatory power plant. This paper proposes a linear optimization model that minimizes the emission release from the power plant and its compensatory plant by appropriate selection of carbon capture technology. Our proposed model incorporates loss of power due to adopting carbon capture technology and emission release from the power plant and compensatory power plant in the problem formulation. We have also generated the Pareto curve that determines the trade-off solutions between emission release and the overall electricity cost. The applicability of our model is illustrated through power sector data from two Indian states. The net reduction of emissions in the two states are 27.17 % and 26.29 %, achieved by a mixed integer linear programming approach in coal-fired power plants. The model developed is generic and provides a sustainable environment for the generation of electricity.

Magnetoelectric Composites: Applications, Coupling Mechanisms, and Future Directions.

Multiferroic (MF)-magnetoelectric (ME) composites, which integrate magnetic and ferroelectric materials, exhibit a higher operational temperature (above room temperature) and superior (several orders of magnitude) ME coupling when compared to single-phase multiferroic materials. Room temperature control and the switching of magnetic properties via an electric field and electrical properties by a magnetic field has motivated research towards the goal of realizing ultralow power and multifunctional nano (micro) electronic devices. Here, some of the leading applications for magnetoelectric composites are reviewed, and the mechanisms and nature of ME coupling in artificial composite systems are discussed. Ways to enhance the ME coupling and other physical properties are also demonstrated. Finally, emphasis is given to the important open questions and future directions in this field, where new breakthroughs could have a significant impact in transforming scientific discoveries to practical device applications, which can be well-controlled both magnetically and electrically.

Poly(N-isopropylacrylamide)-Based Polymers as Additive for Rapid Generation of Spheroid via Hanging Drop Method.

Multicellular tumor spheroid (MCTS) mimics microenvironment for tumor formation and provides predictive insight for in vivo tests. The hanging drop (HD) method of spheroid generation is cost effective, but it is limited by a long time duration for spheroid development and a low rate of formation of larger spheroids. Toward addressing those limitations, thermoresponsive copolymers with poly(N-isopropylacrylamide) (p(NIPA)) backbone are developed, to be used as additives in the MCTS formation via HD method. Upon investigation it is found that in the presence of the polymer, robust and compact spheroids are formed in a short duration of 48 h. Larger spheroids (350-600 µm) can be formed by increasing the number of cells. Spheroids are characterized for their 3D shape and different cellular layers, and drug uptake study is done to prove the efficacy of the spheroids generated in drug screening.

Self assembly and hydrogelation of N-terminal modified tetrapeptide for sustained release and synergistic action of antibacterial drugs against methicillin resistant S. aureus.

Self assembly is a ubiquitous process of complex bio-molecules to perform various biological functions. This bottom-up approach applies in engineering of various nanostructures in different technological and biomedical applications. Here we report design and synthesis of phenolic acid conjugated tetra peptides which self assembled in uniform nanofibrils upon dissolution in aqueous solutions at physiological pH and formed stiff and transparent hydrogel. Gel inversion assay, HR-TEM, FT-IR, CD spectroscopy and rheometric analysis characterized the developed hydrogel (HG-2). This gel exhibits characteristics of thixotropy and injectability. Structure-gelation relationship studies of peptide revealed the importance of π-π interactions in self assembly and hydrogelation. Further, this hydrogel used for entrapment and sustained release of antibiotics, rifampicin and ciprofloxacin at physiological pH and temperature for 5 days. The hydrogelator peptide has shown moderate antibacterial activity alone, whereas in combination with rifampicin and ciprofloxacin showed a remarkable synergistic antibacterial activity against clinically relevant multidrug resistant methicillin resistant S. aureus (MRSA). Interestingly, this hydrogel neither cause significant damage to hRBCsnor to human keratinocyte up to hydrogelation concentrations tested by haemolytic and MTT assay. These characteristics of present peptide hold future promising soft materials for treatment of infections and drug delivery applications.

Effects of Oxygen Modification on the Structural and Magnetic Properties of Highly Epitaxial La0.7Sr0.3MnO3 (LSMO) thin films.

La0.7Sr0.3MnO3, a strong semi-metallic ferromagnet having robust spin polarization and magnetic transition temperature (TC) well above 300 K, has attracted significant attention as a possible candidate for a wide range of memory, spintronic, and multifunctional devices. Since varying the oxygen partial pressure during growth is likely to change the structural and other physical functionalities of La0.7Sr0.3MnO3 (LSMO) films, here we report detailed investigations on structure, along with magnetic behavior of LSMO films with same thickness (~30 nm) but synthesized at various oxygen partial pressures: 10, 30, 50, 100, 150, 200 and 250 mTorr. The observation of only (00 l) reflections without any secondary peaks in the XRD patterns confirms the high-quality synthesis of the above-mentioned films. Surface morphology of the films reveals that these films are very smooth with low roughness, the thin films synthesized at 150 mTorr having the lowest average roughness. The increasing of magnetic TC and sharpness of the magnetic phase transitions with increasing oxygen growth pressure suggests that by decreasing the oxygen growth pressure leads to oxygen deficiencies in grown films which induce oxygen inhomogeneity. Thin films grown at 150 mTorr exhibits the highest magnetization with TC = 340 K as these thin films possess the lowest roughness and might exhibit lowest oxygen vacancies and defects. Interpretation and significance of these results in the 30 nm LSMO thin films prepared at different oxygen growth pressures are also presented, along with the existence and growth pressure dependence of negative remanent magnetization (NRM) of the above-mentioned thin films.

Lead palladium titanate: A room temperature nanoscale multiferroic thin film.

The discovery of single-phase multiferroic materials and the understanding of coupling mechanisms between their spin and polarization is important from the point of view of next generation logic and memory devices. Herein we report the fabrication, dielectric, ferroelectric, piezo-response force microscopy, and magnetization measurements of Pd-substituted room-temperature magnetoelectric multiferroic PbPd0.3Ti0.7O3 (PbPdT) thin films. Highly oriented PbPdT thin films were deposited on {(LaAlO3)0.3(Sr2AlTaO6)0.7} (LSAT) substrates in oxygen atmosphere using pulsed laser deposition technique. X-ray diffraction studies revealed that the films had tetragonal phase with (001) orientation. Surface morphology studies using atomic force and scanning electron microscopy suggest a smooth and homogeneous distribution of grains on the film surface with roughness ~2 nm. A large dielectric constant of ~1700 and a low-loss tangent value of ~0.3 at 10 kHz were obtained at room temperature. Temperature dependent dielectric measurements carried out on Pt/PbPdT/La0.7Sr0.3MnO3 (LSMO) metal-dielectric-metal capacitors suggest a ferroelectric to paraelectric transition above 670 K. The measured polarization hysteresis loops at room temperature were attributed to its ferroelectric behavior. From a Tauc plot of (αhν)2 versus energy, the direct band gap Eg of PbPdT thin films was calculated as 3 eV. Ferroelectric piezoelectric nature of the films was confirmed from a strong domain switching response revealed from piezo-response force microscopy. A well-saturated magnetization M-H loop with remanent magnetization of 3.5 emu/cm3 was observed at room temperature, and it retains ferromagnetic ordering in the temperature range 5-395 K. Origin of the magnetization could be traced to the mixed oxidation states of Pd2+/Pd4+ dispersed in polar PbTiO3 matrix, as revealed by our x-ray photoelectron spectroscopic results. These results suggest that PbPdT thin films are multiferroic (ferroelectric-ferromagnetic) at room temperature.