Ionic Covalent Organic Framework as a Dual Functional Sensor for Temperature and Humidity.

Visual sensing of humidity and temperature by solids plays an important role in the everyday life and in industrial processes. Due to their hydrophobic nature, most covalent organic framework (COF) sensors often exhibit poor optical response when exposed to moisture. To overcome this challenge, the optical response is set out to improve, to moisture by incorporating H-bonding ionic functionalities into the COF network. A highly sensitive COF, consisting of guanidinium and diformylpyridine linkers (TG-DFP), capable of detecting changes in temperature and moisture content is fabricated. The hydrophilic nature of the framework enables enhanced water uptake, allowing the trapped water molecules to form a large number of hydrogen bonds. Despite the presence of non-emissive building blocks, the H-bonds restrict internal bond rotation within the COF, leading to reversible fluorescence and solid-state optical hydrochromism in response to relative humidity and temperature.

CFD analysis of the hyper-viscous effects on blood flow across abdominal aortic aneurysm in COVID patients: multiphysics approach.

Recent research has shown that individuals suffering from COVID-19 are accommodating an elevated level of blood viscosity due to the morphological changes in blood cells. As viscosity is a major flow parameter influencing the flow across a stenosis or an aneurysm, the examination of the significance of hyperviscosity in COVID patients is imperative in arterial pathologies. In this research, we have considered a patient-specific case in which the aneurysm is located along the abdominal aortal walls. Recent research on the side effects of COVID-19 voiced out the various effects on the circulatory system of humans. Also, as abdominal aneurysms exist very often among individuals, causing the death of 150-200 million every year, the hyper-viscous effects of blood on the flow across the diseased aorta are explored by considering the elevated viscosity levels. In vitro explorations contribute considerably to the clinical methods and treatments to be regarded. The objective of the present inquest is to research the flow field in aneurysmatic-COVID-affected patients considering the elastic nature of vessel walls, using the arbitrary Lagrangian-Eulerian approach. The study supports the various clinical findings that voiced the detrimental effects associated with blood hyperviscosity. The simulation results obtained, by solving the fluid mechanics' equations coupled with the solid mechanics' equations, employing a FEM solver suggest that the elevated stress imparted by the hyper-viscous flows on the walls of the aneurysmal aorta can trigger the fastening of the aneurysmal sac enlargement or rupture.

Highly Soluble Ambipolar anti-Perylene-3,4 : 9,10-bis(benzimidazole)s Stabilize a Room-Temperature Columnar Hexagonal Phase.

A new series of highly soluble perylene anti-bis(4,5-dialkoxybenzimidazole)s bearing branched flexible chains stabilizing room temperature columnar hexagonal phase and with balanced ambipolar charge carrier mobility is reported for the first time. Only the anti isomer was successfully separated and characterized. These compounds have a high extinction coefficient, small optical band gap and wide absorption range, thus making them a promising class of ambipolar organic semiconductors capable of self-organizing.

First example of ambipolar naphthalene diimide exhibiting a room temperature columnar phase.

A self-assembled ambipolar organic semiconductor based on naphthalene diimide with low clearing temperature, solution processability, and high molar extinction coefficient, exhibiting a room temperature columnar hexagonal liquid crystalline phase is reported.

Twist-bend nematic drops as colloidal particles: Structural features.

The mesogen CB7CB [1″,7″-bis(4-cyanobiphenyl-4'-yl)heptane], mixed with a small quantity of a long chain amphiphile, is examined for the structural features of twist-bend nematic (N_{TB}) drops acting as colloidal inclusions in the isotropic and nematic environments. In the isotropic phase, the drops nucleating in the radial (splay) geometry develop toward escaped radial, off-centered structures, involving both splay and bend distortions. With further growth, they transform into low-birefringence (near-homeotropic) objects, within which remarkably well-organized networks of parabolic focal conic defects evolve in time. In electrically reoriented near-homeotropic N_{TB} drops, the pseudolayers develop an undulatory boundary possibly attributable to saddle-splay elasticity. In the matrix of the planar nematic phase, N_{TB} droplets appearing as radial hedgehogs attain stability in the dipolar geometry, through their association with hyperbolic hedgehogs. With growth, on transformation of the hyperbolic defect into its topologically equivalent Saturn ring around the N_{TB} drop, the geometry turns quadrupolar. Significantly, dipoles are stable in smaller drops, while quadrupoles are stable in larger ones. The dipole-quadrupole transformation is reversible, but is hysteretic with respect to drop size. Importantly, this transformation is often mediated by nucleation of two loop disclinations, one appearing at a marginally lower temperature than the other. The existence of a metastable state with partial formation of a Saturn ring and persistence of the hyperbolic hedgehog raises a question relating to the conservation of topological charge. In twisted nematics, this state features in the formation of a giant unknot that binds all N_{TB} drops together.

Tris(boranil) Columnar Liquid Crystalline Fluorophores: pseudo-Triphenylene Boron(III) Complexes with Peripheral N-B-O Linkages.

The borate complexes derived from salicylaldimine ligands, called boranils, possess a wide range of photophysical and electronic characteristics intrinsically. The unique combination of molecular rigidity, rendered by four-coordinate boron bridges, and extended π-conjugation enable them to serve as technically feasible fluorescent materials (dyes). The incorporation of liquid crystallinity in these boron(III) complexes, especially the columnar (Col) mesomorphism, which is overlooked hitherto, would provide a new dimension to these complexes. Herein, we report the first examples of tris(boranil) discotic liquid crystal (LC) dyes that have been readily synthesized by treating tris(N-salicylideneaniline)s, (TSAN)s, with BF3 .Et2 O in the presence of an acid quencher. These C3 -symmetric borate complexes self-assemble into the Col phase, existing over a wide thermal span including room temperature. The 2D periodic order of the Col phases shows dependence on the length of the peripheral tails. The photophysical measurements reveal the fluorescence emission in their two condensed states viz., solid and Col phase, and in solution. Their electrochemical, two-step oxidation process coupled with the aforesaid features upholds their significance in applied research.

Extracranial schwannoma of the maxillary nerve misdiagnosed as trigeminal neuralgia in an elderly patient with schizophrenia - A diagnostic dilemma.

The present paper discusses the diagnostic challenges we faced in a 60-year-old woman with a history of schizophrenia, presenting with left unilateral facial pain for the past three months. Based on the elaborate clinical examination and diagnostic nerve blocks, the patient was diagnosed with trigeminal neuralgia (TN) and non-surgical therapy commenced. Further investigations with magnetic resonance imaging (MRI) and ultrasound-guided fine needle aspiration cytology (FNAC) revealed the presence of an extracranial schwannoma involving a branch of the maxillary nerve. The patient was symptomatically relieved after surgical excision of the benign tumor under general anesthesia. Hence, we emphasize the need for special care and attention in psychiatric patients presenting with orofacial pain.

Anisotropic sol-gel transition: the influence of sample thickness, pressure and strain.

We demonstrate an unprecedented influence of sample thickness (d) and pressure (P) on the gelation of a liquid crystalline nematic host. The temperature at which the anisotropic nematic sol transforms into a nematic gel is weakly dependent on 'd' down to its certain value, but surprisingly exhibits a precipitous drop below about 30 µm thickness. Temperature-dependent laser transmission exhibits characteristics of approach to a tricritical point, when d is varied. While the strain dependence of storage and loss moduli exhibit Payne effect/weak strain overshoot, the magnitudes of the moduli and their thermal variation present explicit dependence on d, both behaviours being well described by power-law expressions. Studies at elevated pressures also corroborate the observations of d-dependence with the nematic sol thermal range increasing with P, suggesting reduced favour for network formation. We strongly believe that these experiments pave a new pathway to realize the formation of gel fibres.

Chiral plasmonic liquid crystal gold nanoparticles: self-assembly into a circular dichroism responsive helical lamellar superstructure.

Owing to their proven and promising potential in various technological endeavors ranging from catalysis and sensing to invisibility cloaks made from metamaterials, chiral plasmonic superstructures resulting from the directed self-assembly of optically active metal nanoparticles (MNPs) have been pursued intensively in recent years. Several strategic efforts have emerged especially to accomplish advanced nanomaterials assembling into liquid crystalline (LC) helical structures, where MNPs are regularly packed in fluid/frozen arrays/layers or wires (columns). While the helical fluid columnar arrays (molecular wires) showing circular dichroism (CD) have been realized, the discovery of fluid chiral lamellar ordering, where the dielectric and conducting regimes are arranged alternatively, has hitherto remained highly elusive. Herein we report the first examples of monodisperse LC-gold NPs (LC-GNPs) self-assembling into a fluid/frozen lamellar structure exhibiting CD activity. Notably, these new, exceptional LC-GNPs have been realized by simple, hassle-free protocols that involve the room temperature addition of LC dimer-like arylamines to Au(iii), where the amines not only reduce Au(iii) to Au(0) but also bind strongly to the central GNP scaffold. Their molecular structure, mesomorphism, and ability to interact with circularly polarized light have been evidenced unambiguously and could play an important role in realizing metamaterials in the visible region.

A 2D FSI mathematical model of blood flow to analyze the hyper-viscous effects in atherosclerotic COVID patients.

Recent researches on COVID 19 has been extended to analyze the various morphological and anatomical changes in a patient's body due to the invasion of the virus. These latest studies have concluded that there happens a high rise in the viscosity of the blood in a COVID 19 patient, supported by the extensive analysis of the clinical data. In the present paper, a mathematical model in the form of a differential equation system has been proposed to disclose the various changes that occur in the flow across the stenosis of an arterial segment. The consequences of the hyperviscosity of blood on the blood flow characteristics in a stenosed artery are analyzed by solving the model using a finite element method (FEM) solver. A laminar flow coupled with solid mechanics through the Fluid-Structure Interaction (FSI) interface has been studied using an Arbitrary Lagrangian-Eulerian (ALE) method. For the first time, the mathematical model was used to analyze the hyper-viscous flow condition in COVID 19 patients. The present research is mainly based on the numerous clinical reports enlisting the various morphological, hematological, and rheological changes in the blood.

Topological defects due to twist-bend nematic drops mimicking colloidal particles in a nematic medium.

Colloids formed of solid/fluid particle dispersions in oriented nematic liquid crystals are known to be an ideal means of realizing fundamentally significant topological defect geometries. We find, experimentally, that twist-bend nematic (NTB) droplets formed in the N-NTB biphasic regime, either of pure compounds or mesogenic mixtures, completely mimic colloidal particles in their ability to generate a rich variety of defects. In the biphasic regime, the topological features of both liquid crystal colloids and chiral nematic droplets are revealed by (i) topological dipoles, quadrupoles and their patterned clusters formed in planar nematic liquid crystals orientationally perturbed by coexisting NTB drops, (ii) the transformation of hyperbolic hedgehogs into knotted Saturn rings encircling the NTB drops dispersed in a 90°-twisted nematic matrix and (iii) the Frank-Pryce defect texture evident in smaller (relative to sample thickness) NTB drops. In larger drops with fingerlike outgrowths, additional line defects appear; most of these are deemed to be pairs of disclinations to which are attached pairs of screw dislocations intervening in the growth process of the NTB droplets.

Combined cardiac anomalies in Noonan syndrome: A case report.

INTRODUCTION: Noonan syndrome is the second most common syndromic cause of congenital heart disease. Most patients have an autosomal dominant inheritance, but some cases may be sporadic. Pulmonary stenosis is the most common cardiac manifestation in Noonan syndrome, associated with the atrial septal defect and hypertrophic cardiomyopathy. A combination of these three is present only in 5% of patients. PRESENTATION OF CASE: We report a case of a 21-year-old female who presented to our hospital concomitant cardiac lesions associated with pulmonary stenosis, atrial septal defect, and hypertrophic cardiomyopathy. This combination of cardiac defects is an infrequent manifestation of Noonan syndrome. The patient presented with complaints of exertion syncope over the past two years. 2D-Echocardiography showed biventricular hypertrophy, dysplastic pulmonary valve, severe pulmonary stenosis, asymmetric septal hypertrophy and large atrial septal defect. The genetic analysis report showed autosomal dominant inheritance with Ras/MAPK (mitogen-activated protein kinase) Positive. DISCUSSION: Due to the wide spectrum of symptoms and presentations in Noonan cases, accurate clinical and genetic diagnosis, and comprehensive management of the disorder are strongly recommended. CONCLUSION: We have described a case of rare combination of cardiovascular defects in Noonan Syndrome with a view to achieve better insight into the disease course and advantages of timely treatment and follow up. Our patient is currently in follow-up after treatment with percutaneous balloon pulmonary valvuloplasty, has improved symptoms, and is awaiting heart transplant.

In vitro drug metabolism and pharmacokinetics of a novel thiazolidinedione derivative, a potential anticancer compound.

Thiazolidinediones are known for their activity against Type 2 diabetes and are currently being repurposed for their potent anti-cancer activity. In the present study, we have assessed in vitro metabolic properties and in vivo pharmacokinetic parameters of a novel thiazolidinedione derivative, BIT-15-67, a potential anticancer compound. BIT-15-67 showed low solubility in aqueous buffers at different pH values. The permeability was determined across the Caco-2 monolayer and BIT-15-67 showed high permeability and an efflux ratio of less than 2 suggesting that it is not a substrate of the efflux transporters (P-gp & BCRP). The plasma protein binding was evaluated by equilibrium dialysis and the compound exhibited moderate binding to mouse and rat plasma proteins. BIT-15-67 was stable (half-life > 30 min.) in mouse, rat, dog and human liver microsomes and unstable (half-life <15 min.) in rat hepatocytes suggesting possible Phase II metabolism. Liquid chromatography-tandem mass spectrometry was used to identify Phase I and Phase II metabolites. One of each Phase I and Phase II metabolites have been identified in rat hepatocytes samples. The BIT-15-67 is not an inhibitor of CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4. The PK parameters were determined in both male and female Wistar rats after single intravenous dose administration of BIT-15-67. In rats, the mean plasma clearance of BIT-15-67 was higher in males than in females and the terminal plasma elimination half-life was shorter in males than in females. The compound was highly distributed in the tissues. Overall, the absolute oral bioavailability was 5-fold higher in females (38 %) than in males (7 %). In female nude mice with tumors, BIT-15-67 was well distributed among the collected tissues with the highest concentration in the liver. The ratio of the concentrations in tumor vs. the plasma was 0.5 which could be an important attribute in the development of the compound for anti-cancer research.

Plummeting Broadcast Storm Problem in Highways by Clustering Vehicles Using Dominating Set and Set Cover.

"Vehicular Ad-hoc Networks" (VANETs): As an active research area in the field of wireless sensor networks, they ensure road safety by exchanging alert messages about unexpected events in a decentralized manner. One of the significant challenges in the design of an efficient dissemination protocol for VANETs is the broadcast storm problem, owing to the large number of rebroadcasts. A generic solution to prevent the broadcast storm problem is to cluster the vehicles based on topology, density, distance, speed, or location in such a manner that only a fewer number of vehicles will rebroadcast the alert message to the next group. However, the selection of cluster heads and gateways of the clusters are the key factors that need to be optimized in order to limit the number of rebroadcasts. Hence, to address the aforementioned issues, this paper presents a novel distributed algorithm CDS_SC: Connected Dominating Set and Set Cover for cluster formation that employs a dominating set to choose cluster heads and set covering to select cluster gateways. The CDS_SC is unique among state-of-the-art algorithms, as it relies on local neighborhood information and constructs clusters incrementally. Hence, the proposed method can be implemented in a distributed manner as an event-triggered protocol. Also, the stability of cluster formation is increased along with a reduction in rebroadcasting by allowing a cluster head to be passive when all its cluster members can receive the message from the gateway vehicles. The simulation was carried out in dense, average, and sparse traffic scenarios by varying the number of vehicles injected per second per lane. Besides, the speed of each individual vehicle in each scenario was varied to test the degree of cohesion between vehicles with different speeds. The simulation results confirmed that the proposed algorithm achieved 99% to 100% reachability of alert messages with only 6% to 10% of rebroadcasting vehicles in average and dense traffic scenarios.

An improved robust heteroscedastic probabilistic neural network based trust prediction approach for cloud service selection.

Trustworthiness is a comprehensive quality metric which is used to assess the quality of the services in service-oriented environments. However, trust prediction of cloud services based on the multi-faceted Quality of Service (QoS) attributes is a challenging task due to the complicated and non-linear relationships between the QoS values and the corresponding trust result. Recent research works reveal the significance of Artificial Neural Network (ANN) and its variants in providing a reasonable degree of success in trust prediction problems. However, the challenges with respect to weight assignment, training time and kernel functions make ANN and its variants under continuous advancements. Hence, this work presents a novel multi-level Hypergraph Coarsening based Robust Heteroscedastic Probabilistic Neural Network (HC-RHRPNN) to predict trustworthiness of cloud services to build high-quality service applications. HC-RHRPNN employs hypergraph coarsening to identify the informative samples, which were then used to train HRPNN to improve its prediction accuracy and minimize the runtime. The performance of HC-RHRPNN was evaluated using Quality of Web Service (QWS) dataset, a public QoS dataset in terms of classifier accuracy, precision, recall, and F-Score.

Ferroelectric Liquid Crystals: Synthesis and Thermal Behavior of Optically Active, Three-Ring Schiff Bases and Salicylaldimines.

The chiral ferroelectric smectic C (SmC*) phase, characterized by a helical superstructure, has been well exploited in developing high-resolution microdisplays that have been effectively employed in the fabrication of a wide varieties of portable devices. Although, an overwhelming number of optically active (chiral) liquid crystals (LCs) exhibiting a SmC* phase have been designed and synthesized, the search for new systems continues so as to realize mesogens capable of meeting technical necessities and specifications for their end-use. In continuation of our research work in this direction, herein we report the design, synthesis, and thermal behavior of twenty new optically active, three-ring calamitic LCs belonging to four series. The first two series comprise five pairs of enantiomeric Schiff bases whereas the other two series are composed of five pairs of enantiomeric salicylaldimines. In each pair of optical isomers, the configuration of a chiral center in one stereoisomer is opposite to that of the analogous center in the other isomer as they are derived from (3 S)-3,7-dimethyloctyloxy and (3 R)-3,7-dimethyloctyloxy tails. To probe the structure-property correlations in each series, the length of the n-alkoxy tail situated at the other end of the mesogens has been varied from n-octyloxy to n-dodecyloxy. The measurement of optical activity of these chiral mesogens was carried out by recording their specific rotations. As expected, enantiomers rotate plane polarized light in the opposite direction but by the same magnitude. The thermal behavior of the compounds was established by using a combination of optical polarizing microscopy, differential scanning calorimetry, and powder X-ray diffraction. These complementary techniques demonstrate the existence of the expected, thermodynamically stable, chiral smectic C (SmC*) LC phase besides blue phase I/II (BPI or BPII) and chiral nematic (N*) phase. However, as noted in our previous analogous study, the vast majority of the Schiff bases show an additional metastable, unfamiliar smectic (SmX) phase just below the SmC* phase. Notably, the SmC* phase persists over the temperature range ≈80-115 °C. Two mesogens chosen each from Schiff bases and salicylaldimines were investigated for their electrical switching behavior. The study reveals the ferroelectric switching characteristics of the SmC* phase featuring the spontaneous polarization (PS ) in the range 69-96 nC cm-2 . The helical twist sense of the SmC* phase as well as the N* phase formed by a pair of enantiomeric Schiff bases and salicylaldimines has been established with the help of circular dichroism (CD) spectroscopic technique. As expected, the SmC* and the N* phase of a pair of enantiomers showed mirror image CD signals. Most importantly, the reversal of helical handedness from left to right and vice versa has been evidenced during the N* to SmC* phase transition, implying that the screw sense of the helical array of the N* phase and the SmC* phase of an enantiomer is opposite.

A Hypergraph and Arithmetic Residue-based Probabilistic Neural Network for classification in Intrusion Detection Systems.

Over the past few decades, the design of an intelligent Intrusion Detection System (IDS) remains an open challenge to the research community. Continuous efforts by the researchers have resulted in the development of several learning models based on Artificial Neural Network (ANN) to improve the performance of the IDSs. However, there exists a tradeoff with respect to the stability of ANN architecture and the detection rate for less frequent attacks. This paper presents a novel approach based on Helly property of Hypergraph and Arithmetic Residue-based Probabilistic Neural Network (HG AR-PNN) to address the classification problem in IDS. The Helly property of Hypergraph was exploited for the identification of the optimal feature subset and the arithmetic residue of the optimal feature subset was used to train the PNN. The performance of HG AR-PNN was evaluated using KDD CUP 1999 intrusion dataset. Experimental results prove the dominance of HG AR-PNN classifier over the existing classifiers with respect to the stability and improved detection rate for less frequent attacks.

Self-Assembling and Luminescent Properties of Chiral Bisoxadiazole Derivatives in Solution and Liquid-Crystalline Phases.

Herein, we report the synthesis, self-assembly, and electroluminescence characteristics of a new green-emitting, pseudodiscoid chiral molecule, OXDC, containing an electron-donating stilbene core and an electron-accepting oxadiazole substituent. The helical organization and specific interaction of the chiral pseudodiscoid molecule resulted in the formation of self-assembled nanofibers with a columnar superstructure. Macroscopic chirality was observed in both the liquid-crystalline phases and the self-assembled nanofibers of OXDC, a feature which was absent in the analogous achiral oxadiazole derivative reported earlier [ Sivadas , A. P. ; Supergelation via Purely Aromatic π-π Driven Self-Assembly of Pseudodiscotic Oxadiazole Mesogens . J. Am. Chem. Soc. 2014 , 136 , 5416 - 5423 ]. A high-performance organic light-emitting device was demonstrated using OXDC as the emitting material, with a luminous intensity of 10 115 cd m-2 at 5 V and chromaticity coordinates of (0.32, 0.51).

Masseter Muscle Thickness in Unilateral Partial Edentulism: An Ultrasonographic Study.

INTRODUCTION: Teeth and facial muscles play a very important role in occlusal equilibrium and function. Occlusal derangement, seen in unilateral partially edentulous individuals, has an effect on masseter muscle anatomy and function. The present study aims to evaluate masseter muscle thickness in unilateral partial edentulism. PATIENTS AND METHODS: Institutional ethics committee approval was obtained before the commencement of the study. The study involved patients who routinely visited the Department of Oral Medicine and Radiology, Sri Ramachandra University. The study sample included 27 unilateral edentulous patients (Group E) and 30 controls (Group C). The masseter muscle thickness was evaluated using high-resolution ultrasound real-time scanner (linear transducer - 7.5-10 MHz) at both relaxed and contracted states. STATISTICAL ANALYSIS USED: The results were analyzed using paired t-test and independent t-test. Duration of edentulism and muscle thickness was assessed using Pearson's correlation coefficient. RESULTS: The study patients' age ranged between 25 and 48 years (mean - 36 years). The comparative evaluation of masseter muscle thickness between the dentulous and edentulous sides of experimental group was statistically significant (P < 0.05). However, no statistically significant difference in masseter muscle thickness was found between the dentulous side of control and experimental groups. The correlation between the duration of partial edentulism and muscle thickness was statistically insignificant. CONCLUSION: The study proves masseter atrophy in the edentulous side. However, since the difference is found to be marginal with the present sample, a greater sample is necessary to establish and prove the present findings as well as to correlate with the duration of edentulism. Further studies are aimed to assess the muscle morphology after prosthetic rehabilitation.

Effect of Atomic-Scale Differences on the Self-Assembly of Thiophene-based Polycatenars in Liquid Crystalline and Organogel States.

Two series of polycatenars are reported that contain a central thiophene moiety connected to two substituted oxadiazole or thiadiazole units. The number, position, and length of the peripheral chains connected to these molecules were varied. The oxadiazole-based polycatenars exhibited columnar phases with rectangular and hexagonal or oblique symmetry, whereas the thiadiazole-based polycatenars exhibited columnar phases with rectangular and/or hexagonal symmetry. All of the compounds exhibited bright emission in the solution and thin-film states. Two oxadiazole-based molecules and one thiadiazole-based molecule exhibited supergelation ability in hydrocarbon solvents, which is mainly supported by attractive π-π interactions. These gels showed aggregation-induced enhanced emission, which is of high technological importance for applications in solid-state emissive displays. X-ray diffraction studies of the xerogel fibers of oxadiazole-based polycatenars revealed a columnar rectangular organization, whereas a hexagonal columnar arrangement was observed for thiadiazole-based polycatenars. Rheological measurements carried out on the samples quantitatively confirmed the formation of gels and showed that these gels are mechanically robust. The impact of an atomic-scale difference (oxygen to sulfur, <2 % of the molecular weight) on the self-assembly and the macroscopic properties of those self-assembled structures are clearly visualized.