Theoretical Insights into the Structural and Optical Properties of D-π-A-based Cyanostilbene Systems of α and ß Variants.

The π-conjugated organic molecules containing cyanostilbene motifs have been extensively investigated due to their great potential applications in several optoelectronic and biological fields. Developing efficient molecules in this respect requires strategic structural engineering and a deep understanding of the structure-property relationship at the molecular level. In this context, understanding the impact of positional isomerism in cyanostilbene systems is a fundamental aspect of designing desired materials with improved photophysical properties. Herein, we designed ten donor-π-acceptor (D-π-A) type cyanostilbene derivatives (P1 - P10) with different π linkers and compared their structural and optoelectronic properties arising from the positional variations of the -CN group (α and ß- variations) through the utilization of density functional theory (DFT) and time-dependent DFT (TDDFT) methods. The topological analyses of the electron density are used to explain the relatively high stability of α isomer compared to that of ß. Frontier molecular orbital analysis reveals that 17 molecules tend to show a reduced highest occupied molecular orbital-lowest unoccupied molecular orbital gap, and most of them showed a greater nonlinear optical (NLO) character compared to the parent molecule. TDDFT calculations indicate that ß isomers show higher absorption maxima compared to their α counterparts. Among all the scrutinized molecules, the absorption maximum extended up to 602 nm for P9 and it possesses the highest first-order hyperpolarizability. This study sheds light on positional isomers and their reactivity, absorption spectra, and NLO properties of D-π-A type architecture that can be suitably tuned by appropriating the π-bridge for practical applications.

Intramolecular Charge Transfer and Stimuli-Responsive Emission in Cholesterol-Appended Phenothiazine-Cyanostyryl-Based Donor-Acceptor Systems.

Organic fluorescent molecules have received considerable attention owing to their various optoelectronic applications. Herein, we report the design and synthesis of two cholesterol-functionalized cyanostyrene-phenothiazine-based D-π-A systems that are emissive in both the solution and solid states. The newly synthesized cholesterol-appended phenothiazine-cyanostyrene diads PTCS-1 and PTCS-2 vary in the N-alkylation of phenothiazine, respectively, with─octyl and─hexyl chains. Both molecules are highly fluorescent and show reasonably good quantum yields in nonpolar solvents because of twisted intramolecular charge transfer (TICT). The molecules exhibit aggregation-induced emission in the solid state. Due to the presence of flexible alkyl chains in the phenothiazine and cholesterol moieties, PTCS-1 and PTCS-2 show mechanochromic luminescence switching in response to external shear stress and emission recovery under methanol vapor. Powder X-ray diffraction studies prove that the emission switching on the applied stimuli in both PTCS-1 and PTCS-2 is attributed to the reversible transformation between the crystalline and amorphous states. Time-dependent density functional theory (TD-DFT) studies are carried out to gain insight into the ICT interactions. TD-DFT analysis at the TD-M06-2X/def2-TZVP level further revealed that in both molecules, the lowest unoccupied molecular orbital (LUMO) + 2, LUMO, highest occupied molecular orbital (HOMO), and HOMO - 1 orbitals are responsible for the charge transfer interactions. These ICT interactions are identified as π-π* type interactions.

A study to determine the effect of hydroxychloroquine (HCQ) on central corneal thickness (CCT) in patients with rheumatoid arthritis (RA).

PURPOSE: Corneal thinning is common in rheumatoid arthritis (RA), thereby affecting the central corneal thickness (CCT). Effect of hydroxychloroquine (HCQ) in RA has abounding literature on retinal toxicity, but there is lack of data on its corneal effects. METHODS: A cross-sectional study was carried out to compare CCT in RA patients before treatment initiation (Group 1) with CCT in those on HCQ for ≥3 months (Group 2). RESULTS: Fifty patients were enrolled in each group. The mean age was 44.36 years with similar age, gender distribution and visual acuity in both groups. The mean CCT of patients in the cohort was 521.80 µm ± 32.57 µm and 523.94 µm ± 33.40 µm in the right eye (RE) and left eye (LE), respectively. Mean CCT in Group 1 was (RE) 522.80 µm/(LE) 524.26 µm and in Group 2 was (RE) 520.80 µm/(LE) 523.62 µm, and there was no significant difference in CCT between both the groups. Median duration of HCQ usage in Group 2 was 24 months, with the median cumulative dosage being 171 g and a majority having a dosage of 200 mg/day. There was no significant correlation between the duration/cumulative dosage of HCQ intake and CCT. No corneal deposits were identified in any patient. CONCLUSION: CCT of RA patients was similar to those reported in the Indian literature. However, there was no significant change in CCT or corneal deposits identified with an HCQ dosage of 200-400 mg/day. Longer follow-up would provide clarity on the impact of duration and cumulative dosage of HCQ on corneal changes and CCT.

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.

Internet of Things Framework for Oxygen Saturation Monitoring in COVID-19 Environment.

The pandemic/epidemic of COVID-19 has affected people worldwide. A huge number of lives succumbed to death due to the sudden outbreak of this corona virus infection. The specified symptoms of COVID-19 detection are very common like normal flu; asymptomatic version of COVID-19 has become a critical issue. Therefore, as a precautionary measurement, the oxygen level needs to be monitored by every individual if no other critical condition is found. It is not the only parameter for COVID-19 detection but, as per the suggestions by different medical organizations such as the World Health Organization, it is better to use oximeter to monitor the oxygen level in probable patients as a precaution. People are using the oximeters personally; however, not having any clue or guidance regarding the measurements obtained. Therefore, in this article, we have shown a framework of oxygen level monitoring and severity calculation and probabilistic decision of being a COVID-19 patient. This framework is also able to maintain the privacy of patient information and uses probabilistic classification to measure the severity. Results are measured based on latency of blockchain creation and overall response, throughput, detection, and severity accuracy. The analysis finds the solution efficient and significant in the Internet of Things framework for the present health hazard in our world.

Improving incidence trends of severe intraventricular haemorrhages in preterm infants <32 weeks gestation: a cohort study.

OBJECTIVE: To describe the trend and risk factors for severe intraventricular haemorrhage (IVH) among infants <32 weeks gestation. DESIGN: Population-based cohort study. SETTING: Australia and New Zealand. PATIENTS: All preterm infants <32 weeks gestation in the Australian and New Zealand Neonatal Network (ANZNN) from 1995 to 2012. INTERVENTIONS: Comparison of IVH incidence between 6-year epochs. MAIN OUTCOME MEASURES: Overall IVH and severe IVH incidence. RESULTS: A total of 60 068 infants were included, and overall survival to discharge increased from 89% to 93% over the three epochs. As the percentage of infants with IVH decreased from 23.6% to 21.3% and 21.4% (p<0.001) from epoch 1 to 3, respectively, fewer survivors had severe IVH (4.0%, 3.3% and 2.8%, respectively, p<0.001). Over time, there were fewer antenatal complications, higher antenatal steroid usage and more caesarean-section births. Fewer infants were intubated at birth, had low 5 min Apgar score, had sepsis or pneumothorax needing drainage. Adjusted for perinatal confounders, there was significant reduction in odds of severe IVH from epoch 1 to 3 (adjusted OR (AOR) 0.8, 95% CI 0.7 to 0.9). Factors associated with development of severe IVH include no antenatal steroids (AOR 1.7, 95% CI 1.5 to 1.9), male (AOR 1.3, 95% CI 1.2 to 1.4), 5 min Apgar score <7 (AOR 2.0, 95% CI 1.9 to 2.2), intubated at birth (AOR 2.0, 95% CI 1.8 to 2.2), extremely low gestational age (AOR 4.0, 95% CI 3.7 to 4.4), outborn (AOR 1.6, 95% CI 1.5 to 1.8) and vaginal delivery (AOR 1.4, 95% CI 1.3 to 1.6). CONCLUSIONS: Along with increased survival among infants born <32 weeks gestation, the incidence of severe IVH has decreased over the 18 years, especially in the most recent period. This coincided with reduction in rates of risk factors for severe IVH development.

Enhanced functional properties of soft polymer-ceramic composites by swift heavy ion irradiation.

The physical and chemical properties of soft polymer-ceramic composites with 50 MeV swift heavy, Li3+ ion irradiation were studied. A solution-casting technique was employed to synthesize free standing, flexible composite films of ferroelectric polymer PVDF and ferroelectric ceramic BNBT mixtures with 0-3 connectivity. However, only 35 wt% ceramic was chosen for the study as it showed the highest dielectric constant and enhanced ferroelectric properties without irradiation. The effects of ion irradiation on the structural, microstructural, morphological, dielectric and ferroelectric properties of this particular composition were systematically investigated and conclusions were drawn. The mechanism for the enhancement of the electroactive ß-phase due to the swift heavy ion irradiation was discussed and the enhancement was well correlated with its ferroelectric and dielectric properties.

Ovarian Teratoma presenting as Anti NMDAR Antibody Negative Limbic Encephalitis.

Anti NMDA receptor (NMDAR) antibody mediated limbic encephalitis is the most common type of autoimmune encephalitis. Nearly half of the females presenting with anti NMDAR encephalitis have associated ovarian teratoma. Almost all of them have positive anti NMDAR antibody. Here we present a case of ovarian teratoma associated limbic encephalitis, with clinical picture typical of anti NMDAR mediated encephalitis, who was found to be negative for the antiNMDAR antibody. Clinicians should not defer from investigating a case of suspected anti NMDAR encephalitis for ovarian teratoma, even if antibody is negative.

Molecular Crankshaft Effect Converting Piston-like Molecular Motion to Continuous Rotation of Macro Objects.

A molecular system inducing an accumulative unidirectional rotation motion of glass flakes with about 100 µm in size is introduced. The molecular system is a chiral nematic liquid crystal containing a chiral azobenzene derivative which shows a reversible E- Z photoisomerization accompanying a large helical twisting power change. A film of the molecular system shows different texture change paths upon UV and visible light irradiations inducing " E to Z" and " Z to E" photoisomerizations, respectively, of the chiral azobenzene dopant. Namely, a polygonal fingerprint texture inducing the rotation of glass flakes on the film surface was maintained during UV irradiation, while a focal conic texture inducing no rotation of glass flakes emerged during visible light irradiation. As a result, cycles of the alternative irradiation of UV and visible lights afforded many rotations toward a single direction of the glass flakes which can be considered as a continuous conversion of light energy to mechanical work. We may compare the effect of this molecular system converting "back and forth" structural change between E and Z isomers of the chiral azobenzene to a continuous rotational motion of glass flakes with the crankshaft effect converting a piston-like motion to a rotational motion seen in engines in the real world.

Improved Location Estimation in Wireless Sensor Networks Using a Vector-Based Swarm Optimized Connected Dominating Set.

Location estimation in wireless sensor networks (WSNs) has received tremendous attention in recent times. Improved technology and efficient algorithms systematically empower WSNs with precise location identification. However, while algorithms are efficient in improving the location estimation error, the factor of the network lifetime has not been researched thoroughly. In addition, algorithms are not optimized in balancing the load among nodes, which reduces the overall network lifetime. In this paper, we have proposed an algorithm that balances the load of computation for location estimation among the anchor nodes. We have used vector-based swarm optimization on the connected dominating set (CDS), consisting of anchor nodes for that purpose. In this algorithm, major tasks are performed by the base station with a minimum number of messages exchanged by anchor nodes and unknown nodes. The simulation results showed that the proposed algorithm significantly improves the network lifetime and reduces the location estimation error. Furthermore, the proposed optimized CDS is capable of providing a global optimum solution with a minimum number of iterations.

Hyperglycemia-induced seizures - Understanding the clinico- radiological association.

OBJECTIVES: To highlight the typical magnetic resonance imaging (MRI) findings in hyperglycemia-induced seizures and compare the results with similar previous studies with a brief mention of pathophysiological mechanisms. MATERIALS AND METHODS: This retrospective study included medical and imaging records of six consecutive patients with hyperglycemia-induced seizures. The data analysis included a clinical presentation and biochemical parameters at admission. The MRI sequences were evaluated for region involved, presence of subcortical T2 hypo-intensity, cortical hyper-intensity, and restricted diffusion. Similar previous studies from the National Library of Medicine (NLM) were analyzed and compared with our study. RESULTS: Twenty-four patients were included from four studies in previous literature for comparison. In our study, on imaging, posterior cerebral region was predominantly involved, with parietal involvement in 83.3%, followed by occipital, frontal, and temporal involvement in 33.3% patients compared with occipital in 58.3%, parietal in 45.8%, and frontal and temporal in 16.6% of patients in previous literature. The subcortical T2 hypo-intensity was present in 83.3% of the patients, cortical hyper-intensity in all patients, and restricted diffusion in 66.6% of the patients in our study compared with subcortical T2 hypo-intensity in 95.8% of the patients, cortical hyper-intensity in 62.5%, and restricted diffusion in 58.3% of the patients in previous literature. CONCLUSION: Although many etiologies present with subcortical T2 hypointensity, cortical hyperintensity, restricted diffusion, and postcontrast enhancement on MRI, the clinical setting of seizures in a patient with uncontrolled hyperglycemia, hyperosmolar state, and absence of ketones should suggest hyperglycemia-induced seizures to avoid misdiagnosis, unnecessary invasive investigations, and initiate timely management. ADVANCES IN KNOWLEDGE: Our study highlights the presence of posterior predominant subcortical T2, fluid-attenuated inversion recovery (FLAIR), and susceptibility-weighted angiography (SWAN) hypointensity; cortical hyperintensity; and restricted diffusion in hyperglycemia-induced seizures. The presence of T2 and SWAN hypointensity could support the hypothesis of possible deposition of free radicals and iron in the subcortical white matter.

The effect of inhaled steroids on the intraocular pressure.

Background: Steroids are known to play a role in the pathogenesis of glaucoma, but little is known about the effect of inhaled corticosteroids (ICS). The purpose of this study was to investigate whether there is a clinically significant association between inhalational steroids and intraocular pressure (IOP). Methods: This was a cross-sectional, case-control study performed at St John's Medical College, Bengaluru, India, from October 2013 to July 2015 of 200 patients using 800 mcg of budesonide or its equivalent dose of ICS and 200 healthy controls not using any form of steroids. Patients using ICS for a period of at least 6 months with no usage of oral or topical steroids within the last 3 months were included as cases. Age- and sex-matched controls were recruited from among the general patient population of the ophthalmological department. IOP and central corneal thickness (CCT) were analyzed. Cases were divided into two subgroups. Group 1 had IOP of <21 mm Hg and cup-to-disc ratio of <0.5. Group 2 had IOP of ≥21 mm Hg or cup-to-disc ratio of ≥0.5 or cup-disc asymmetry ≥0.2. These two subgroups were analyzed to determine whether there was an increased risk of developing ocular hypertension or glaucoma with extended use of ICS. Results: A total of 400 subjects participated, with 200 in each group. The mean IOP of cases was 15.31 ± 3.27 mm Hg, statistically significantly higher than the mean of 13.39 mm Hg ± 1.95 in controls (P < 0.001). The mean CCT in cases was 522.02 ± 30.47 µm, lower than the mean of 528.73 ± 29.09 µm of the control group (P > 0.001). Of the 200 cases, 11 (5.5%) had ocular hypertension and 2 (1%) had open-angle glaucoma. There was no statistically significant correlation between duration of inhaled steroids usage and increase in IOP (P = 0.62). There was no development of ocular hypertension or glaucoma among the controls. Conclusions: Our findings suggest a probable association between ICS and IOP and that it may be advisable to measure baseline IOPs and CCT and to follow patients on ICS at regular intervals.

Susceptibility-weighted angiography and diffusion-weighted imaging in posterior reversible encephalopathy syndrome - Is there an association between hemorrhage, cytotoxic edema, blood pressure and imaging severity?

PURPOSE: To assess the significance of association and possible correlation between hemorrhage, cytotoxic edema, blood pressure and imaging severity in posterior reversible encephalopathy syndrome (PRES). MATERIALS AND METHODS: This retrospective study included the medical and imaging records of 35 consecutive patients with PRES. The clinical data analysis included the highest recorded blood pressure (BP) on the day of the ictus, MRI including spin-echo echo planar diffusion-weighted imaging (DWI), susceptibility weighted angiography (SWAN) and conventional sequences. The presence of hemorrhage and cytotoxic edema was evaluated for the significance of correlation and association with each other and with blood pressure and imaging severity. RESULTS: On MR imaging, hemorrhage was found in 25.7%, and cytotoxic edema in 20% of patients. There was no statistically significant association of hemorrhage (P=0.403) and cytotoxic edema (P=0.162) with BP in contrast to significant association of hemorrhage (P<0.001) and cytotoxic edema (P=0.011) with imaging severity and with each other (P=0.002). There was a significant correlation of hemorrhage (Cramer's V - 0.672) and cytotoxic edema (Cramer's V - 0.506) with imaging severity and with each other (Cramer's V - 0.523). CONCLUSION: The extent of imaging severity in PRES showed significant association and correlation with hemorrhage and cytotoxic edema. There was no statistically significant association of blood pressure with imaging severity, hemorrhage, and cytotoxic edema. Further prospective studies are needed to elucidate the pathophysiological mechanisms and their correlation with imaging findings in PRES.

A Complementary Metal Oxide Semiconductor Process-Compatible Ferroelectric Tunnel Junction.

In recent years, experimental demonstration of ferroelectric tunnel junctions (FTJ) based on perovskite tunnel barriers has been reported. However, integrating these perovskite materials into conventional silicon memory technology remains challenging due to their lack of compatibility with the complementary metal oxide semiconductor process (CMOS). This communication reports the fabrication of an FTJ based on a CMOS-compatible tunnel barrier Hf0.5Zr0.5O2 (6 unit cells thick) on an equally CMOS-compatible TiN electrode. Analysis of the FTJ by grazing angle incidence X-ray diffraction confirmed the formation of the noncentrosymmetric orthorhombic phase (Pbc21, ferroelectric phase). The FTJ characterization is followed by the reconstruction of the electrostatic potential profile in the as-grown TiN/Hf0.5Zr0.5O2/Pt heterostructure. A direct tunneling current model across a trapezoidal barrier was used to correlate the electronic and electrical properties of our FTJ devices. The good agreement between the experimental and theoretical model attests to the tunneling electroresistance effect (TER) in our FTJ device. A TER ratio of ∼15 was calculated for the present FTJ device at low read voltage (+0.2 V). This study suggests that Hf0.5Zr0.5O2 is a promising candidate for integration into conventional Si memory technology.