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Kinetics of the reaction of IO radicals with methanol (MeOH) and ethanol (EtOH) were experimentally studied in the gas phase using pulsed laser photolysis-cavity ring-down spectroscopy (PLP-CRDS). IO radicals were produced in situ at the reaction zone by photolysing a mixture of precursors (CH

Hydroxychloroquine (HCQ) is an anti-malarial drug but also widely used to treat autoimmune diseases like arthritis and lupus. Although there have been multiple reports of the adverse effect of prolonged HCQ usage on the outer retina, leading to bull’s-eye maculopathy, the effect of HCQ toxicity on the inner retina as well as on overall visual functions has not been explored in detail. Furthermore, lack of an established animal model of HCQ toxicity hinders our understanding of the underlying molecular mechanisms. Here, using a small clinical study, we confirmed the effect of HCQ toxicity on the inner retina, in particular the reduction in central inner retinal thickness, and established a mouse model of chronic HCQ toxicity that recapitulates the effects observed in human retina. Using the mouse model, we demonstrated that chronic HCQ toxicity results in loss of inner retinal neurons and retinal ganglion cells (RGC) and compromises visual functions. We further established that HCQ treatment prevents autophagosome–lysosome fusion and alters the sphingolipid homeostasis in mouse retina. Our results affirm the notion that HCQ treatment causes early damage to the inner retina and affects visual functions before leading to characteristic toxicity in the macular region of the outer retina, ‘bull’s-eye maculopathy.’ We also provide insights into the underlying molecular mechanisms of HCQ retinal toxicity that may involve autophagy–lysosomal defects and alterations in sphingolipid metabolism.

Aggregation-induced enhancement (AIE) in the photoluminescence quantum yield (PLQY) from 12.5 to 51% in the

This work systematically summarizes the recent advances in the ortho C–H functionalization of 2-arylquinoxalines, with literature coverage from 2010 to 2022.

In the era of automatic task processing or designing complex algorithms, to analyse data, it is always pertinent to find real‐life solutions using cutting‐edge tools and techniques to generate insights into the data. The data‐driven machine learning models are now offering more or less worthy results when they are certainly balanced in the input data sets. Imbalanced data occurs when an unequal distribution of classes occurs in the input datasets. Building a predictive model on the imbalanced data set would cause a model that appears to yield high accuracy but does not generalize well to the new data in the minority class. Now the time has come to look into the datasets which are not so‐called ‘balanced’ in nature but such datasets are generally encountered frequently in a workspace. To prevent creating models with false levels of accuracy, the imbalanced data should be rearranged before creating a predictive model. Those data are, sometimes, voluminous, heterogeneous and complex in nature and generate from different autonomous sources with distributed and decentralized control. The driving force is to efficiently handle these data sets using latest tools and techniques for research and commercial insights. The present article provides different such tools and techniques, in different computing frameworks, to handle such Internet of Things and other related datasets to review common techniques for handling imbalanced data in data ecosystems and offers a comparative data modelling framework in Keras for balanced and imbalanced datasets.

The reactivity of 2-ethoxy ethanol with OH radicals was experimentally measured in the temperature range of 278-363 K using the pulsed laser photolysis-laser-induced fluorescence (PLP-LIF) technique. The rate coefficient at room temperature was measured to be (1.14 ± 0.03) × 10-11 cm3 molecule-1 s-1, and the Arrhenius expression was derived to be kexpt278-363K = (1.61 ± 0.35) × 10-13 exp{(1256 ± 236)/T} cm3 molecule-1 s-1. Computational calculations were performed to compute the kinetics of the titled reaction in the temperature range of 200-400 K using advanced methods incorporated with tunneling correction at the CCSD(T)/aug-cc-pVTZ//M06-2X/6-31+G(d,p) level of theory. The Arrhenius expression derived from the computationally calculated rate coefficients is ktheo200-400K = (1.59 ± 0.35) × 10-13exp{(1389 ± 62)/T} cm3 molecule-1 s-1. The feasibility of each reaction pathway was also determined using the calculated thermochemical parameters. Atmospheric implication parameters such as cumulative atmospheric lifetime and photochemical ozone creation potential were calculated and are discussed in this paper.

The thermal reaction between nitrogen dioxide and phenol in the gas phase under anaerobic conditions has been investigated by diluting the reactants in dry nitrogen in a glass reaction vessel. Infr...

Recently, direct C-H bond activation and functionalization has become a prodigious and hot topic among synthetic organic chemists due to its step-economic nature and substantial synthetic versatility. On the other hand, quinoxaline, a fused bicycle of benzene and pyrazine, has omnipresent applications in medicinal-, industrial- and materials chemistry. The presence of the N-1 atom in 2-arylquinoxaline enables chelation formation with a metal catalyst leading to the formation of

Formyl (HCO) radicals were generated in situ in the gas phase via the photolysis of glyoxal in N

The gas-phase kinetics of the reactions of IO radicals with ethyl formate (EF) and ethyl acetate (EA) were investigated experimentally using cavity ring-down spectroscopy (CRDS). IO radicals were generated in situ in the CRD reaction zone by photolyzing a mixture of (CH3I + O3 + N2) at 248 nm and thereby probed at 445.04 nm. The rate coefficients for the reactions (IO + EF) and (IO + EA) were measured at a total pressure of 65 Torr of N2 in the temperature range of 258–358 and 260–360 K, respectively. The rate coefficients for the reactions (IO + EF) and (IO + EA) were measured experimentally at room temperature to be kExpt,298KIO+EF = (3.38 ± 0.67) × 10−14 and kExpt,298KIO+EA = (1.56 ± 0.30) × 10−13 cm3 molecule−1 s−1, respectively. The effects of pressure and photolysis laser fluence on the kinetics of test reactions were found to be negligible within the experimental uncertainties for the studied range. To complement our experimental findings, the kinetics of the title reactions were investigated theoretically using canonical variational transition state theory (CVT) with small curvature tunnelling (SCT) at the CCSD(T)//M06-2X/def2-SV(P) level of theory in temperatures between 200 and 400 K. Very good agreement was observed between the experimentally measured and theoretically calculated rate coefficients for both the reactions at 298 K. The thermochemical parameters as well as the branching ratios for the title reactions are also discussed in this study.

Cavity ring-down spectroscopy (CRDS) was employed to investigate the kinetics of the reaction between phenyl radicals (C6H5•) and ethyl acetate (EtOAc) in the gas phase. Nitrosobenzene (C6H5NO) was used as the radical precursor to generate C6H5• at 248 nm, and the generated radicals were subsequently probed at 504.8 nm. The rate coefficients were investigated experimentally in the temperature range of 258–358 K with an interval of 20 K and at a total pressure of 55 Torr in the nitrogen atmosphere. The obtained Arrhenius expression for the title reaction (C6H5• + EtOAc) in the temperature range of 258–358 K was kphenyl + EtOAcExpt – (258 – 358 K) = (9.33 ± 0.11) × 10–16 exp[(883.7 ± 181.0)/T] cm3 molecule–1 s–1, and the rate coefficient at room temperature (298 K) was kphenyl + EtOAcExpt – 298 K = (2.20 ± 0.12) × 10–14 cm3 molecule–1 s–1. Negligible effects of pressure and photolysis laser fluence were found on the experimentally measured rate coefficients. To complement our experimental findings, rate coefficients of the title reaction were computationally investigated employing the canonical variational transition-state theory with small curvature tunnelling (CVT/SCT) at the CCSD­(T)/cc-pVDZ//B3LYP/6-31+G­(d,p) level of theory in the temperature range of 200–400 K. The temperature-dependent rate coefficient in the studied temperature range was obtained to be kphenyl + EtOAcTheory – (200 – 400 K) = (7.68 ± 0.12) × 10–17 exp[(1731.6 ± 216.0)/T] cm3 molecule–1 s–1, and the rate coefficient at 298 K was obtained as kphenyl + EtOAcTheory – 298 K = 2.45 × 10–14 cm3 molecule–1 s–1. Both the experimentally measured and computed rate coefficients show good agreement at 298 K. A negative temperature dependency was observed for both the experimentally measured and computed rate coefficients. A detailed discussion of the thermochemical parameters and branching ratios of the title reaction are also presented in this Article.

Sphingolipids (SPL) are a class of lipid molecules that play important functional and structural roles in our body and are a component of meibum. Sphingomyelinases (SMases) are key enzymes in sphingolipid metabolism that hydrolyze sphingomyelin (SM) and generate ceramide (Cer). The purpose of this study was to examine relationships between ocular surface SMases, SPL composition, and parameters of Meibomian gland dysfunction (MGD).Individuals were grouped by meibum quality (n = 25 with poor-quality, MGD, and n = 25 with good-quality, control). Meibum and tears were analyzed with LC-MS to quantify SPL classes: Cer, Hexosyl-Ceramide (Hex-Cer), SM, Sphingosine (Sph), and sphingosine 1-phosphate (S1P). SMase activity in tears were quantified using a commercially available 'SMase assay'. Statistical analysis included multiple linear regression analyses to assess the impact of SMase activity on lipid composition, as well as ocular surface symptoms and signs of MGD.Demographic characteristics were similar between the two groups. nSMase and aSMase levels were lower in the poor vs good quality group. aSMase activity in tears negatively correlated with SM in meibum and tears and positively with Sph in meibum and S1P in tears. Lower SMase activity were associated with signs of MGD, most notably Meibomian gland dropout.This study suggests that individuals with MGD have reduced enzymatic activity of SMases in tears. Specifically, individuals with poor vs good meibum quality were noted to have alterations in SMase activity and SPL composition of meibum and tears which may reflect deviations from normal lipid metabolism in individuals with MGD.

The random laser (RL) is now becoming an essential tool for various photonics applications, and a plethora of research advancements in RL coupled with developments in the field of techniques of syntheses of various nanostructured materials is taking place. But the realization of tuning the peak emission wavelength of RL is still very challenging. However, in this report we have demonstrated an emission peak shifted tunable low threshold incoherent RL in the visible region in a gain medium of a commercially available dye laser material and by employing the rarely used scatterer materials of triangular silver nanoparticles (TSN), microbubbles, and the waveguiding mechanism. The scattering properties of trapped microbubbles, along with the localized surface plasmon resonance property of TSN of appropriate concentration within waveguided thin films composed of glass substrates, have been methodically investigated to demonstrate the reduction in lasing threshold and tunability in the peak emission wavelength. A two-fold reduction in RL threshold by addition of TSN in the disordered system, along with a considerable narrowing down of the emission spectra to a few nanometers, are obtained. Furthermore, the peak emission wavelength shift of 6 nm is reported by suitably changing the system configuration by the addition of an optimum concentration of TSN along with trapped microbubbles. The as-developed system shows high-quality laser performance with the maximum value of η=0.64, a quantity describing the ratio of the number of stimulated radiative photons within RL and the total number of emissive photons. We propose that the total internal reflections from the microbubble surface, along with plasmonic enhancement and scattering from the TSN, mediate the waveguided RL to achieve the low threshold. Therefore, this report is an early step towards demonstrating efficient RL in a ternary scattering system. Many more avenues for investigating this developing research issue may be helpful for the future development of affordable and robust optoelectronic devices.

Most of the outstanding applications of silver nanoparticles (Ag NPs) have arisen from their tunable localized surface plasmon resonance (LSPR). In this report, we have systematically studied the photothermal transformation of morphology of triangular-shaped Ag NPs (TSNP) under irradiation of a nanosecond (ns)-pulsed laser of 1064-nm wavelength with the pulse duration of 10 ns at different laser fluence and irradiation time. Interestingly, at a typical value of fluence of 104–174 J/cm2 both the triangular and plate-like Ag NPs are transformed into spherical Ag NPs of size ~ 5 nm in just 20–40 min of irradiation that is found to be very much faster when it is compared with the results of well-known chemically etching–based reshaping process in the presence of KBr. We have also demonstrated the possible use of the plasmonic absorption properties of the triangular, plate-like and transformed spherical Ag NPs for the development of a broad-band visible-NIR light absorber by just mixing these Ag NPs of three different morphologies. We have got almost 20% average (overall below 35%) transmission in the wavelength range from 400 to 800 nm in the liquid phase and 57% (overall below 65%) when NPs are put into PVA matrix in 16 vol%. The applicability of the prepared broadband absorber is being verified by monitoring the current response of a light-dependent resistor and degradation process of rhodamine 6G dye in sunlight.

Traumatic brain injury (TBI) causes neuroinflammation and neurodegeneration leading to various pathological complications such as motor, and sensory (visual) deficits, cognitive impairment, and depression. N-3 polyunsaturated fatty acid (n-3 PUFA) containing lipids are known to be anti-inflammatory, whereas the sphingolipid, ceramide (Cer) is an inducer of neuroinflammation and degeneration. Using Fat1+-transgenic mice that contain elevated levels of systemic n-3 PUFA, we tested whether they are resistant to mild TBI-mediated sensory-motor and emotional deficits by subjecting Fat1-transgenic mice and their WT littermates to focal cranial air blast (50-psi) or sham blast (0-psi, control). We observed that visual function in WT mice was reduced significantly following TBI but not in Fat1+-blast animals. We also found Fat1+-blast mice were resistant to the decline in motor functions, depression, and fear-producing effects of blast, as well as the reduction in the area of oculomotor nucleus and increase in activated microglia in the optic tract in brain sections seen following blast in WT mice. Lipid and gene expression analyses confirmed an elevated level of the n-3 PUFA eicosapentaenoic acid (EPA) in the plasma and brain, blocking of TBI-mediated increase of Cer in the brain, and decrease in TBI-mediated induction of Cer biosynthetic and inflammatory gene expression in the brain of the Fat1+ mice. Our results demonstrate that suppression of ceramide biosynthesis and inflammatory factors in Fat1+-transgenic mice is associated with significant protection against the visual, motor, and emotional deficits caused by mild TBI. This study suggests that n-3 PUFA (especially, EPA), has a promising therapeutic role in preventing neurodegeneration after TBI.

Hydroxychloroquine (HCQ) is an anti-malarial drug but also widely used to treat autoimmune diseases like arthritis and lupus. Although there have been multiple reports of the adverse effect of prolonged HCQ usage on the outer retina, leading to bull's-eye maculopathy, the effect of HCQ toxicity on the inner retina as well as on overall visual functions has not been explored in detail. Furthermore, lack of an established animal model of HCQ toxicity hinders our understanding of the underlying molecular mechanisms. Here, using a small clinical study, we confirmed the effect of HCQ toxicity on the inner retina, in particular the reduction in central inner retinal thickness, and established a mouse model of chronic HCQ toxicity that recapitulates the effects observed in human retina. Using the mouse model, we demonstrated that chronic HCQ toxicity results in loss of inner retinal neurons and retinal ganglion cells (RGC) and compromises visual functions. We further established that HCQ treatment prevents autophagosome-lysosome fusion and alters the sphingolipid homeostasis in mouse retina. Our results affirm the notion that HCQ treatment causes early damage to the inner retina and affects visual functions before leading to characteristic toxicity in the macular region of the outer retina, 'bull's-eye maculopathy.' We also provide insights into the underlying molecular mechanisms of HCQ retinal toxicity that may involve autophagy-lysosomal defects and alterations in sphingolipid metabolism.

The gas-phase kinetics of phenyl radical (·C6H5) with ethyl formate (HCO2Et, EF) was investigated experimentally using ultrasensitive laser-based cavity ring-down spectroscopy (CRDS). Phenyl radicals were generated by photolyzing nitrosobenzene (C6H5NO) at 248 nm and thereby probed at 504.8 nm. The rate coefficients for the (phenyl radical + EF) reaction were investigated between the temperatures of 260 and 361 K and at a pressure of 61 Torr with nitrogen (N2) as diluent. The temperature-dependent Arrhenius expression for the test reaction was obtained as: $${\mathrm{k}}_{\mathrm{phenyl}+\mathrm{EF}}^{\mathrm{Expt}, 260-361\mathrm{K}}$$ =(1.20 ± 0.16) × 10–13 exp[−(435.6 ± 50.0)/T] cm3 molecule−1 s−1 and the rate coefficient at room temperature was measured out to be: $${\mathrm{k}}_{\mathrm{phenyl}+\mathrm{EF}}^{\mathrm{Expt},298\mathrm{K}}$$ =(4.54 ± 0.42) × 10–14 cm3 molecule−1 s−1. The effects of pressure and laser fluence on the kinetics of the test reaction were found to be negligible within the experimental uncertainties. To complement the experimental findings, kinetics for the reaction of phenyl radicals with EF was investigated theoretically using Canonical Variational Transition State Theory (CVT) with Small Curvature Tunnelling (SCT) at CCSD(T)/cc-pVDZ//B3LYP/6–31 + G(d,p) level of theory in the temperatures between 200 and 400 K. The theoretically calculated rate coefficients for the title reaction were expressed in the Arrhenius form as: $${\mathrm{k}}_{\mathrm{phenyl}+\mathrm{EF}}^{\mathrm{Theory},200-400\mathrm{K}}$$ = (1.48 ± 0.56) × 10–38 × T8.47 × exp[(2431.3 ± 322.0)/T] cm3 molecule−1 s−1 and the corresponding rate coefficient at room temperature was calculated to be: $${\mathrm{k}}_{\mathrm{phenyl}+\mathrm{EF}}^{\mathrm{Theory},298\mathrm{K}}$$ = 4.91 × 10–14 cm3 molecule−1 s−1. A very good agreement was observed between the experimentally measured and theoretically calculated rate coefficients at 298 K. Thermochemical parameters as well as branching ratios for the reaction of (phenyl radical + EF) are also discussed in this manuscript.

Diabetes mellitus (DM) is a systemic metabolic disease that affects 463 million adults worldwide and is a leading cause of cardiovascular disease, blindness, nephropathy, peripheral neuropathy, and lower-limb amputation. Lipids have long been recognized as contributors to the pathogenesis and pathophysiology of DM and its complications, but recent discoveries have highlighted ceramides, a class of bioactive sphingolipids with cell signaling and second messenger capabilities, as particularly important contributors to insulin resistance and the underlying mechanisms of DM complications. Besides their association with insulin resistance and pathophysiology of type 2 diabetes, evidence is emerging that certain species of ceramides are mediators of cellular mechanisms involved in the initiation and progression of microvascular and macrovascular complications of DM. Advances in our understanding of these associations provide unique opportunities for exploring ceramide species as potential novel therapeutic targets and biomarkers. This review discusses the links between ceramides and the pathogenesis of DM and diabetic complications and identifies opportunities for novel discoveries and applications.

Over 11 million people in the United States alone have some form of age-related macular degeneration (AMD). Oxidative stress, cell death, and the degeneration of retinal pigment epithelial (RPE) cells contribute to AMD pathology. Recent evidence suggests that ceramide (Cer), a cellular sphingolipid mediator that acts as a second messenger to induce apoptosis, might play a role in RPE cell death. The lysosomal breakdown of Cer by acid ceramidase [N-acylsphingosine amidohydrolase (ASAH)1] into sphingosine (Sph) is the major source for Sph 1-phosphate production, which has an opposing role to Cer and provides cytoprotection. Here, we investigated the role of Cer in human RPE-derived ARPE19 cells under hydrogen peroxide-induced oxidative stress, and show that Cer and hexosyl-Cer levels increase in the oxidatively stressed ARPE19 cells, which can be prevented by overexpression of lysosomal ASAH1. This study demonstrates that oxidative stress generates sphingolipid death mediators in retinal cells and that induction of ASAH1 could rescue retinal cells from oxidative stress by hydrolyzing excess Cers.

The Folk medicinal practitioner (FMP) or Kabiraj plays a key role to provide health support mainly to village people. They are mainly dependent on the pants parts available around them and many modern medicines are being synthesized by extracting the active chemicals from plants. The main objective of this study is to document the plants used by the FMPs of two villages of Jamalpur sadar upazila. For this study, we conducted a survey based on semi structured method. We found they use mainly 31 plants belonging to 25 families. The part mostly used is leave (31.75%) and the least used is the flower (6.34%). It is found that almost 18 types of diseases are being cured by their formulation. This study also suggested that, the FMPs treat many common disorder like gastro intestinal disorder, Respiratory tract infection, diabetes, Skin disorder etc. and also various complicated disorder such as debility, anemia, neural disorder etc. This study may be helpful to create scientific view about the plants used by the FMPs of Jamalpur sadar upazila and these plants might be used to synthesize drug molecule of interest. Asian J. Med. Biol. Res. December 2018, 4(4): 422-426

Cullin-RING ligases (CRLs) comprise a large group of modular eukaryotic E3 ubiquitin ligases. Within this family, the CRL4 ligase (consisting of the Cullin4 [CUL4] scaffold protein, the Rbx1 RING finger domain protein, the DNA damage-binding protein 1 [DDB1], and one of many DDB1-associated substrate receptor proteins) has been intensively studied in recent years due to its involvement in regulating various cellular processes, its role in cancer development and progression, and its subversion by viral accessory proteins. Initially discovered as a target for hijacking by the human immunodeficiency virus accessory protein r, the normal targets and function of the CRL4 substrate receptor protein DDB1–Cul4-associated factor 1 (DCAF1; also known as VprBP) had remained elusive, but newer studies have begun to shed light on these questions. Here, we review recent progress in understanding the diverse physiological roles of this DCAF1 in supporting various general and cell type-specific cellular processes in its context with the CRL4 E3 ligase, as well as another HECT-type E3 ligase with which DCAF1 also associates, called EDD/UBR5. We also discuss emerging questions and areas of future study to uncover the dynamic roles of DCAF1 in normal physiology.