Preparation and characterization of polyhydroxyalkanoates macroporous scaffold through enzyme-mediated modifications

Polyhydroxyalkanoates (PHAs) are hydrophobic biodegradable thermoplastics that have received considerable attention in biomedical applications due to their biocompatibility, mechanical properties, and biodegradability. In this study, the degradation rate was regulated by optimizing the interaction of parameters that influence the enzymatic degradation of P(3HB) film using response surface methodology (RSM). The RSM model was experimentally validated yielding a maximum 21 % weight loss, which represents onefold increment in percentage weight loss in comparison with the conventional method. By using the optimized condition, the enzymatic degradation by an extracellular PHA depolymerase from Acidovorax sp. DP5 was studied at 37 °C and pH 9.0 on different types of PHA films with various monomer compositions. Surface modification of scaffold was employed using enzymatic technique to create highly porous scaffold with a large surface to volume ratio, which makes them attractive as potential tissue scaffold in biomedical field. Scanning electron microscopy revealed that the surface of salt-leached films was more porous compared with the solvent-cast films, and hence, increased the degradation rate of salt-leached films. Apparently, enzymatic degradation behaviors of PHA films were determined by several factors such as monomer composition, crystallinity, molecular weight, porosity, and roughness of the surface. The hydrophilicity and water uptake of degraded salt-leached film of P(3HB-co-70%4HB) were enhanced by incorporating chitosan or alginate. Salt-leached technique followed by partial enzymatic degradation would enhance the cell attachment and suitable for biomedical as a scaffold

Regulating the molar fraction of 4-hydroxybutyrate in Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by biological fermentation and enzymatic degradation

The regulation of 4-hydroxybutyrate (4HB) molar fraction in the poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] of a local isolate Cupriavidus sp. USMAA1020 was attempted by employing a feeding strategy through fed-batch fermentation in 100-L fermenter. The growth of Cupriavidus sp. USMAA1020 was enhanced by frequently feeding carbon and nitrogen at a ratio of 5 (C/N 5) using a DO-stat with cascade mode at 20% (v/v) dissolved oxygen (DO). The feeding of C/N 5 and the use of the DOstat mode were able to regulate the 4HB composition from 0–67 mol% by sequential feeding of c-butyrolactone and supplementing oleic acid. A high 4HB molar fraction of 67 mol% with a PHA concentration of 5.2 g/L was successfully obtained by employing this feeding strategy. Notably, enzymatic degradation carried out enhanced the 4HB composition of the copolymer synthesized. PHB depolymerase enzyme from Acidovorax sp. was used to degrade this P(3HB-co-70-mol%4HB) copolymer and the 4HB composition could be increased up to 83 mol%. The degradation process was observed by monitoring the timedependent change in the weight loss of copolymer films. The percentage of weight loss of solvent-cast film increased proportionally up to 19% within 3 h, whereas salt-leached films showed 90% of weight loss within 3 h of incubation and were completely degraded by 4 h. The molecular weight (Mn) of the films treated with enzyme demonstrated a slight decrease. SEM observation exhibited a rough surface morphology of the copolymer degraded with depolymerase enzyme

Pharmacological and therapeutic potential of Oxalis corniculata

Oxalis corniculata is commonly known as Indian wood Sorrel. In Unani it is called as Hummaz and distributed in the whole northern temperate zone, United State of America, Arizona and throughout India. Oxalis corniculata is used in Unani medicine in the management of liver disorders, jaundice, skin diseases, urinary diseases etc. The plant been proven to possess various pharmacological activities like liver tonic, appetizer, diuretic, anthelmintic, emmenagogue, anti-inflammatory, analgesic, anti-pyretic, blood purifier etc. Here we summarize the therapeutic potential of Oxalis corniculat

Cyclic Kite Configuration with Variable Mass of the Fifth Body in R5BP

This paper presents a numerical investigation on some characteristics and parameters related to the motion of an infinitesimal body with variable mass in five-body problem. The other four bodies are considered as primaries. The whole system forms a cyclic kite configuration and moves on a circle, the center of which is taken as the origin.We assume that the motion of the fifth infinitesimal body is affected by the other components of the system but it has no effect on their behavior. We started by setting the equations of motion of the fifth body by using Jeans’ law and Meshcherskii’s space-time transformations. Further, we determined numerically, using Mathematica software, the positions of Lagrangian points and basins of attraction in various planes. Finally, we investigated the linear stability of the Lagrangian points and noticed that all the Lagrangian points are unstable

Global Prevalence of Tobacco Use in Adolescents and Its Adverse Oral Health Consequences

BACKGROUND: Smoking is associated with various systemic conditions and contributes to a huge financial burden to economies around the world. AIM: The study aimed to evaluate global data about the prevalence of tobacco use among male and female adolescents and to discuss smoking-related oral complications. METHODS: The prevalence data of tobacco use among adolescents (13-15 years) was retrieved from the World Health Organization (Global Health Observatory). The World Bank’s statistics about gross national income (GNI) per capita were used to categorise low-income, lower-middle-income, upper-middle-income, and high-income countries. PubMed, Web of Science, Scopus, and Embase databases were searched to gather updated evidence about the adverse consequences of smoking on oral health among adolescents. RESULTS: The prevalence of tobacco use was 19.33%, and there were 23.29% of male and 15.35% female smoker adolescents in 133 countries (p < 0.001). The highest prevalence of tobacco use in male (24.76%) and female (19.4) adolescents was found in high-income countries. Significantly higher proportions of male adolescents were smokers than female counterparts in low-income, lower-middle-income, and upper-middle-income (p < 0.001). However, there were no statistically significant differences in tobacco use between male and female adolescents in high-income countries. Low-income countries had the lowest prevalence (14.95%) of tobacco use, while high-income countries had the highest prevalence estimates (22.08). Gingivitis (72.8%), gingival bleeding (51.2%), oral malodor or halitosis (39.6%) is common oral conditions among smoker adolescents. Smoking habit is significantly associated with dental caries, periodontal disease, hairy tongue, smoking-related melanosis, and hyperkeratosis among adolescents. CONCLUSION: There was a high prevalence of tobacco use among male and female adolescents around the globe. Available evidence suggests a strong association between smoking and compromised oral health among adolescents. Globally, measures should be taken to prevent and control the menace of tobacco use to reduce systemic and oral complications

ON MULTIPLICATIVE LIE n-HIGHER DERIVATIONS OF TRIANGULAR ALGEBRAS

Let $\mathrm{R}$ be a commutative ring with unity, $\mathrm{A},\mathrm{B}$ be $\mathrm{R}$-algebras and $\mathrm{M}$ be an $(\mathrm{A}, \mathrm{B})$-bimodule. Let $\mathfrak{T}=Tri(\mathrm{A},\mathrm{M},\mathrm{B})$ be a $(n-1)$-torsion free triangular algebra. In this article, we prove that every multiplicative Lie $n$-higher derivation on triangular algebras has the standard form. Also, the main result is applied to some classical examples of triangular algebras such as upper triangular matrix algebras and nest algebras

Spectrum on demand : a competitive open market model for spectrum sharing for UAV-assisted communications

Unmanned aerial vehicles (UAVs)-assisted communication has gathered significant interest of the industry, especially with regards to the vision of providing ubiquitous connectivity for beyond 5G (B5G) networks. In this article, we motivate the need for utilizing licensed spectrum for UAV-assisted communication and discuss its advantages such as reliability and security. Moreover, we explore a new dimension to spectrum sharing by proposing a decentralized competitive open market approach based model, where the different mobile network operators (MNOs) have the opportunity to lease the spectrum to UAV base stations (UAV-BSs), leading to new revenue generation opportunities. The proposed spectrum sharing mechanism is based on the logarithmic utility function and willingness to pay of each UAV-BS. We provide a tradeoff analysis between spectrum sharing and price offered by the MNOs, highlighting the impact of the willingness to pay on the spectrum sharing. The results also highlight the behaviour of price and spectrum shared w.r.t. time, thereby providing an insight into different performance regions until the algorithm converges to it’s optimal value. In addition, we also present future directions that could lead to interesting analyses, especially with regards to incentive-based spectrum sharing and security

Energy-aware AI-driven Framework for Edge Computing-based IoT Applications

The significant growth in the number of Internetof- things (IoT) devices has given impetus to the idea of edge computing for several applications. In addition, energy harvestable or wireless-powered wearable devices are envisioned to empower the edge intelligence in IoT applications. However, the intermittent energy supply and network connectivity of such devices in scenarios including remote areas and hard-to-reach regions such as in-body applications can limit the performance of edge computing-based IoT applications. Hence, deploying stateof-the-art convolutional neural networks (CNNs) on such energy constrained devices is not feasible due to their computational cost. Existing model compression methods such as network pruning and quantization can reduce complexity, but these methods only work for fixed computational or energy requirements, which is not the case for edge devices with an intermittent energy source. In this work, we propose a pruning scheme based on deep reinforcement learning (DRL), which can compress the CNN model adaptively according to the energy dictated by the energy management policy and accuracy requirements for IoT applications. The proposed energy policy uses predictions of energy to be harvested and dictates the amount of energy that can be used by the edge device for deep learning inference. We compare the performance of our proposed approach with existing state-of-the-art CNNs and datasets using different filter-ranking criteria and pruning ratios.We observe that by using DRL driven pruning, the convolutional layers that consume relatively higher energy are pruned more as compared to their counterparts. Thereby, our approach outperforms existing approaches by reducing energy consumption and maintaining accuracy

Air Conditioning Using Radiant Cooling System

A Radiant cooling system alludes to a temperature-controlled surface that cools indoor temperatures by evacuating sensible heat and where the greater part of heat exchange happens through thermal radiation. Heat will spill out of objects, occupants, equipment and lights in a space to a cooled surface the length of their temperatures are hotter than that of the cooled surface and they are inside the observable pathway of the cooled surface. The procedure of radiant exchange negligibly effects on air temperature, yet through the procedure of convection, the air temperature will be brought down when air interacts with the cooled surface. Radiant cooling system utilizes the inverse impact of Radiant cooling system, which depends on the procedure of heat spill out of a warmed surface to items and inhabitants