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1.
Rom J Ophthalmol ; 68(2): 114-121, 2024.
Article in English | MEDLINE | ID: mdl-39006331

ABSTRACT

Aim and objectives: Visual dysfunction in diabetes mellitus (DM) is multifactorial and can be due to vascular disease, and metabolic abnormalities that can affect the retina, optic nerve, and visual pathways. Visual evoked potential (VEP) is an electrophysiological test that can quantify the functional integrity of the visual pathways from the retina via the optic nerves, and optic tracts to the visual cortices. In this study, we aimed to investigate the visual pathway dysfunction among diabetics without retinopathy compared with healthy controls and to look for any correlation with diabetic neuropathy, duration of diabetes, or HbA1c level. Methods: The study included 75 diabetic patients and 75 age and sex-matched controls. VEPs were recorded using the pattern reversal stimulation method on the Medtronic EMG EP machine, and P100 latency and N75-P100 amplitude were recorded in both diabetic patients and healthy controls. Results: Mean P100 latency was significantly prolonged and N75-P100 amplitude significantly reduced among diabetic cases compared to healthy controls (p < 0.001). Among diabetics with peripheral neuropathy, P100 latency was significantly prolonged and N75-P100 amplitude was significantly reduced compared to diabetics without peripheral neuropathy. A significant positive correlation of VEP P100 latency (p < 0.001) and a negative correlation with N75-P100 amplitude (p < 0.001) with duration of disease were also found. Conclusion: VEP changes are observed in diabetics before the development of retinopathy or peripheral neuropathy indicating optic pathway dysfunction, which precedes the development of these complications. Early preclinical visual pathway dysfunction can warrant taking the necessary measures to reduce diabetic complications. Abbreviations: DM = Diabetes Mellitus, VEP = Visual Evoked Potential, HbA1c = Hemoglobin A1 c, MRI = Magnetic Resonance Imaging, EEG = Electroencephalography, P100 = Positive wave peak at latency 100 ms (millisecond), N75 = Negative wave peak at latency 75 ms (millisecond), N145 = Negative wave peak at latency 145 ms (millisecond), OCT = Optical coherence tomography, PRVEP = Pattern Reversal Visual Evoked Potential, NCS = Nerve Conduction Study, SSR = Sympathetic Skin Response, IL1 = Interleukin-1, LIF = Leukemia inhibitory factor, CNTF = Ciliary neurotrophic factor, TNF alpha = Tumor necrosis factor-alpha, TGF-beta = Transforming growth factor-beta.


Subject(s)
Diabetic Neuropathies , Diabetic Retinopathy , Evoked Potentials, Visual , Visual Pathways , Humans , Evoked Potentials, Visual/physiology , Male , Female , Diabetic Neuropathies/physiopathology , Diabetic Neuropathies/diagnosis , Diabetic Neuropathies/etiology , Middle Aged , Diabetic Retinopathy/physiopathology , Diabetic Retinopathy/diagnosis , Visual Pathways/physiopathology , Adult , Visual Acuity
2.
Neurobiol Dis ; 199: 106575, 2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38914170

ABSTRACT

CT1812 is a novel, brain penetrant small molecule modulator of the sigma-2 receptor (S2R) that is currently in clinical development for the treatment of Alzheimer's disease (AD). Preclinical and early clinical data show that, through S2R, CT1812 selectively prevents and displaces binding of amyloid beta (Aß) oligomers from neuronal synapses and improves cognitive function in animal models of AD. SHINE is an ongoing phase 2 randomized, double-blind, placebo-controlled clinical trial (COG0201) in participants with mild to moderate AD, designed to assess the safety and efficacy of 6 months of CT1812 treatment. To elucidate the mechanism of action in AD patients and pharmacodynamic biomarkers of CT1812, the present study reports exploratory cerebrospinal fluid (CSF) biomarker data from 18 participants in an interim analysis of the first set of patients in SHINE (part A). Untargeted mass spectrometry-based discovery proteomics detects >2000 proteins in patient CSF and has documented utility in accelerating the identification of novel AD biomarkers reflective of diverse pathophysiologies beyond amyloid and tau, and enabling identification of pharmacodynamic biomarkers in longitudinal interventional trials. We leveraged this technique to analyze CSF samples taken at baseline and after 6 months of CT1812 treatment. Proteome-wide protein levels were detected using tandem mass tag-mass spectrometry (TMT-MS), change from baseline was calculated for each participant, and differential abundance analysis by treatment group was performed. This analysis revealed a set of proteins significantly impacted by CT1812, including pathway engagement biomarkers (i.e., biomarkers tied to S2R biology) and disease modification biomarkers (i.e., biomarkers with altered levels in AD vs. healthy control CSF but normalized by CT1812, and biomarkers correlated with favorable trends in ADAS-Cog11 scores). Brain network mapping, Gene Ontology, and pathway analyses revealed an impact of CT1812 on synapses, lipoprotein and amyloid beta biology, and neuroinflammation. Collectively, the findings highlight the utility of this method in pharmacodynamic biomarker identification and providing mechanistic insights for CT1812, which may facilitate the clinical development of CT1812 and enable appropriate pre-specification of biomarkers in upcoming clinical trials of CT1812.

3.
Photochem Photobiol Sci ; 23(6): 1087-1115, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38763938

ABSTRACT

The protection of Earth's stratospheric ozone (O3) is an ongoing process under the auspices of the universally ratified Montreal Protocol and its Amendments and adjustments. A critical part of this process is the assessment of the environmental issues related to changes in O3. The United Nations Environment Programme's Environmental Effects Assessment Panel provides annual scientific evaluations of some of the key issues arising in the recent collective knowledge base. This current update includes a comprehensive assessment of the incidence rates of skin cancer, cataract and other skin and eye diseases observed worldwide; the effects of UV radiation on tropospheric oxidants, and air and water quality; trends in breakdown products of fluorinated chemicals and recent information of their toxicity; and recent technological innovations of building materials for greater resistance to UV radiation. These issues span a wide range of topics, including both harmful and beneficial effects of exposure to UV radiation, and complex interactions with climate change. While the Montreal Protocol has succeeded in preventing large reductions in stratospheric O3, future changes may occur due to a number of natural and anthropogenic factors. Thus, frequent assessments of potential environmental impacts are essential to ensure that policies remain based on the best available scientific knowledge.


Subject(s)
Stratospheric Ozone , Ultraviolet Rays , Humans , Stratospheric Ozone/analysis , Ultraviolet Rays/adverse effects , Ozone/chemistry , Climate Change
4.
Rev Sci Instrum ; 95(5)2024 May 01.
Article in English | MEDLINE | ID: mdl-38748817

ABSTRACT

In situ studies under severe plastic deformation at high pressures, employing shear diamond anvil cells, have recently gained much interest in the high-pressure community owing to their potential applications in material processing methods, mechanochemistry, and geophysics. These studies, combined with multi-scale computational simulations, provide important insights into the transient hierarchical microstructural evolution, structural phase transitions, and orientation relationship between parent and daughter phases and help establish the kinetics of strain-induced phase transitions under severe plastic deformation. The existing SDACs are mostly used in axial x-ray diffraction geometry due to geometrical constraints providing less reliable information about stress states and texture. Their asymmetric design also poses serious limitations to high-pressure shear studies on single crystals. To overcome these limitations, a new compact symmetric shear diamond anvil cell has been designed and developed for in situ high-pressure torsion studies on materials. The symmetric angular opening and short working distance in this new design help obtain a more reliable crystallographic orientation distribution function and lattice strain states up to a large Q range. Here, we present the advantages of the symmetric design with a few demonstrative studies.

5.
J Water Health ; 22(4): 639-651, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38678419

ABSTRACT

Stream flow forecasting is a crucial aspect of hydrology and water resource management. This study explores stream flow forecasting using two distinct models: the Soil and Water Assessment Tool (SWAT) and a hybrid M5P model tree. The research specifically targets the daily stream flow predictions at the MH Halli gauge stations, located along the Hemvati River in Karnataka, India. A 14-year dataset spanning from 2003 to 2017 is divided into two subsets for model calibration and validation. The SWAT model's performance is evaluated by comparing its predictions to observed stream flow data. Residual time series values resulting from this comparison are then resolved using the M5P model tree. The findings reveal that the hybrid M5P tree model surpasses the SWAT model in terms of various evaluation metrics, including root-mean-square error, coefficient of determination (R2), Nash-Sutcliffe efficiency, and degree of agreement (d) for the MH Halli stations. In conclusion, this study shows the effectiveness of the hybrid M5P tree model in stream flow forecasting. The research contributes valuable insights into improved water resource management and underscores the importance of selecting appropriate models based on their performance and suitability for specific hydrological forecasting tasks.


Subject(s)
Models, Theoretical , Rain , India , Rivers , Water Movements , Hydrology , Environmental Monitoring/methods , Forecasting
6.
Nat Commun ; 14(1): 5955, 2023 Sep 23.
Article in English | MEDLINE | ID: mdl-37741842

ABSTRACT

Various phenomena (phase transformations (PTs), chemical reactions, microstructure evolution, strength, and friction) under high pressures in diamond-anvil cell are strongly affected by fields of stress and plastic strain tensors. However, they could not be measured. Here, we suggest coupled experimental-analytical-computational approaches utilizing synchrotron X-ray diffraction, to solve an inverse problem and find fields of all components of stress and plastic strain tensors and friction rules before, during, and after α-ω PT in strongly plastically predeformed Zr. Results are in good correspondence with each other and experiments. Due to advanced characterization, the minimum pressure for the strain-induced α-ω PT is changed from 1.36 to 2.7 GPa. It is independent of the plastic strain before PT and compression-shear path. The theoretically predicted plastic strain-controlled kinetic equation is verified and quantified. Obtained results open opportunities for developing quantitative high-pressure/stress science, including mechanochemistry, synthesis of new nanostructured materials, geophysics, astrogeology, and tribology.

7.
J Environ Sci Health B ; 58(5): 389-398, 2023.
Article in English | MEDLINE | ID: mdl-37231743

ABSTRACT

Cowpea is known for its high protein content (18-25%) and also chiefly raised for green fodder. The infesting pests, pod borer and aphids are the most destructive ones. To control these pests, chlorantraniliprole emerges as a promising molecule. Thus, its needs to assess the dissipation nature of the chlorantraniliprole. Hence, a trial was conducted at IIVR, Varanasi, India. The residue analysis was done through solid phase extraction method followed by gas chromatoghraphy analysis. The analytical method was standardized and validated according to international standard. The half-life of chlorantraniliprole in cowpea pods was estimated in the range of 2.79- 2.33 days in the year-I and 2.51-2.32 days in the year-II for single dose (SD) and double dose (DD) respectively. Similarly, half-life of the chlorantraniliprole in leaves 2.43-2.27 days whereas, 1.94-1.70 days in case of soil. The exposure of the residues in pods were less than maximum permissible intake (MPI). The RQ values revealed that there could be negligible risk to earthworms and arthropods. Washing with boiling water was found the most effective decontamination treatment to remove residue from cowpea pods. Thus, it could be concluded that chlorantraniliprole does not pose any significant threat when uses in cowpea in a particular dose.


Subject(s)
Insecticides , Pesticide Residues , Vigna , Kinetics , Insecticides/analysis , Decontamination/methods , Environmental Monitoring , Half-Life , Food Safety , Pesticide Residues/analysis
8.
Photochem Photobiol Sci ; 22(5): 1177-1202, 2023 May.
Article in English | MEDLINE | ID: mdl-37039962

ABSTRACT

The deleterious effects of solar ultraviolet (UV) radiation on construction materials, especially wood and plastics, and the consequent impacts on their useful lifetimes, are well documented in scientific literature. Any future increase in solar UV radiation and ambient temperature due to climate change will therefore shorten service lifetimes of materials, which will require higher levels of stabilisation or other interventions to maintain their lifetimes at the present levels. The implementation of the Montreal Protocol and its amendments on substances that deplete the ozone layer, controls the solar UV-B radiation received on Earth. This current quadrennial assessment provides a comprehensive update on the deleterious effects of solar UV radiation on the durability of natural and synthetic materials, as well as recent innovations in better stabilising of materials against solar UV radiation-induced damage. Pertinent emerging technologies for wood and plastics used in construction, composite materials used in construction, textile fibres, comfort fabric, and photovoltaic materials, are addressed in detail. Also addressed are the trends in technology designed to increase sustainability via replacing toxic, unsustainable, legacy additives with 'greener' benign substitutes that may indirectly affect the UV stability of the redesigned materials. An emerging class of efficient photostabilisers are the nanoscale particles that include oxide fillers and nanocarbons used in high-performance composites, which provide good UV stability to materials. They also allow the design of UV-shielding fabric materials with impressive UV protection factors. An emerging environmental issue related to the photodegradation of plastics is the generation of ubiquitous micro-scale particles from plastic litter exposed to solar UV radiation.


Subject(s)
Solar Energy , Ultraviolet Rays , Stratospheric Ozone , Sunlight , Plastics
9.
Photochem Photobiol Sci ; 21(3): 275-301, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35191005

ABSTRACT

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth's surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1-67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.


Subject(s)
Ozone Depletion , Ozone , Climate Change , Ecosystem , Humans , Ozone/chemistry , Stratospheric Ozone , Ultraviolet Rays
10.
Kathmandu Univ Med J (KUMJ) ; 19(73): 140-142, 2021.
Article in English | MEDLINE | ID: mdl-34812173

ABSTRACT

Coronavirus disease 2019 (COVID-19) pandemic has caused significant impact on the health care system. As a consequence, diagnosis and treatment of vector borne diseases including dengue has been equally affected. Nepal is no exception to this, where COVID-19 cases is exponentially increased and all resources are concentrated on its prevention, control and management. Dengue, one of the major vector-borne diseases in Nepal, is apparently overlooked despite approaching the peak season of the disease. The aim of this paper is to describe the double burden of COVID-19 and dengue in Nepal, particularly highlighting the co-circulation and possible coinfections. This has posed higher risk of increased severity, more severe cases and deaths in Nepal. Moreover, potential misdiagnosis of these viral diseases may lead to delayed or, inappropriate treatment and poor allocation of resources.


Subject(s)
COVID-19 , Dengue , Dengue/diagnosis , Dengue/epidemiology , Dengue/therapy , Humans , Nepal/epidemiology , Pandemics , SARS-CoV-2
11.
Acta Histochem ; 123(7): 151792, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34634674

ABSTRACT

Prolonged inorganic arsenic (iAs) exposure is widely associated with brain damage particularly in the hippocampus via oxidative and apoptotic pathways. Resveratrol (RES) has gained considerable attention because of its benefits to human health. However, its neuroprotective potential against iAs-induced toxicity in CA1 region of hippocampus remains unexplored. Therefore, we investigated the neuroprotective efficacy of RES against arsenic trioxide (As2O3)-induced adverse effects on neuronal morphology, apoptotic markers and oxidative stress parameters in mouse CA1 region (hippocampus). Adult female Swiss albino mice of reproductive maturity were orally exposed to either As2O3 (2 and 4 mg/kg bw) alone or in combination with RES (40 mg/kg bw) for a period of 45 days. After animal sacrifice on day 46, the perfusion fixed brain samples were used for the observation of neuronal morphology and studying the morphometric features. While the freshly dissected hippocampi were processed for biochemical estimation of oxidative stress markers and western blotting of apoptosis-associated proteins. Chronic iAs exposure led to significant decrease in Stratum Pyramidale layer thickness along with reduction in cell density and area of Pyramidal neurons in contrast to the controls. Biochemical analysis showed reduced hippocampal GSH content but no change in total nitrite (NO) levels following iAs exposure. Western blotting showed apparent changes in the expression levels of Bax and Bcl-2 proteins following iAs exposure, however the change was statistically insignificant. Contrastingly, iAs +RES co-treatment exhibited substantial reversal in morphological and biochemical observations. Together, these findings provide preliminary evidence of neuroprotective role of RES on structural and biochemical alterations pertaining to mouse hippocampus following chronic iAs exposure.


Subject(s)
Arsenic Trioxide/toxicity , Brain Injuries , Hippocampus , Pyramidal Cells , Resveratrol/pharmacology , Animals , Arsenic/toxicity , Brain Injuries/chemically induced , Brain Injuries/metabolism , Brain Injuries/pathology , Brain Injuries/prevention & control , Female , Hippocampus/injuries , Hippocampus/metabolism , Hippocampus/pathology , Mice , Pyramidal Cells/metabolism , Pyramidal Cells/pathology
12.
J Family Med Prim Care ; 10(1): 295-299, 2021 Jan.
Article in English | MEDLINE | ID: mdl-34017743

ABSTRACT

CONTEXT: Inherited bleeding disorders are common in India and hemophila and von Willebrand diseases are the most common among them. These patients can present in any department including paediatrics, medicine, orthopaedics and even gynaecology so knowledge about hemophilias and facilities for specialized tests for diagnosis are required. Few centres of north-eastern part of India perform these tests so hemophilias remain an underdiagnosed and underreported disease. AIMS: The objective of this study was to estimate the prevalence of hemophilia in patients referred to this tertiary care centre and study the clinicopathological profile of these patients. SETTINGS AND DESIGN: Prospective study. METHODS AND MATERIAL: Patients referred with suspicion of bleeding disorders in a time period of 4 years were evaluated. Complete clinical details, family history was retrieved and tests like complete blood counts, bleeding time, prothrombin time, activated partial thromboplastin time and factor assays were performed. RESULTS: A total of 1126 patients with suspected bleeding disorder were tested and 237 were diagnosed of inherited bleeding disorders. Hemophilia A (HA) was diagnosed in 151 patients (63.7%), Hemophilia B (HB) in 31 (13%). Mean age was 10 years in HA and 11 years in HB patients. Clinical features of hemophilia varied according to Factor VIII levels. Coagulation type of bleeding such as hemarthrosis and hematoma were much more frequent than mucosal type bleeding. CONCLUSIONS: The present study is one of the very few studies from the north-eastern part of India estimating the prevalence and clinicopathological features of hemophilia, highlighting the need of specialized diagnostic facilities in this part of India.

13.
Photochem Photobiol Sci ; 20(1): 1-67, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33721243

ABSTRACT

This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595-828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.

14.
Micron ; 140: 102957, 2021 01.
Article in English | MEDLINE | ID: mdl-33120164

ABSTRACT

The shoot and fruit borer, Earias vittella Fab. (Lepidoptera: Nolidae) is an important and most devastating insect pest on okra and cotton. The pest mainly responsible for causing significant direct damage to tender shoots and fruits of okra, flowers and green bolls of cotton causing net yield loss in both crops. Many non-chemical control strategies have been developed under the insect pest management program, A complete knowledge on the antennal morphology of E. vitella is essential for future electrophysiological and behavioural studies. In the present study, the antennal morphology and types of sensilla on the antennae of both sexes of E. vitella were examined using light and scanning electron microscopy. Nine distinct types of sensilla were identified on the antennae of both sexes: sensilla trichodea, sensilla basiconica, sensilla coeloconica, sensilla auricillica (multiporous), sensilla chaetica, uniporous peg sensilla (uniporous), sensilla styloconica, sensilla squamiformia and bohm bristles (aporous). Among all sensilla, the most widespread are multiporous sensilla trichodea with 42.90 ± 1.77/flagellomere in male and 37.38 ± 1.38/flagellomere in female. Sensilla basiconica were the second most common sensillum type in male antennae with 15.67 ± 1.92/flagellomere. Other multiporous sensilla such as auricillica (11.90 ± 0.99) and coeloconica (4.57 ± 0.25) were significantly more abundant in female than in male antennae. Results of the study provide morphological evidence that E. vitella antennae possess microscopic cuticular structures that can play a role in perception of pheromones, plant odours and other chemical stimulants. This will open up opportunities to assess the possibility of using pheromones and plant-derived compounds for the monitoring or management of E. vittella moths in the agricultural landscapes.


Subject(s)
Moths/anatomy & histology , Sensilla/anatomy & histology , Animals , Female , Male , Microscopy, Electron, Scanning/methods , Microscopy, Electron, Transmission/methods , Moths/metabolism , Pheromones , Sensilla/ultrastructure
15.
Cytokine ; 145: 155208, 2021 09.
Article in English | MEDLINE | ID: mdl-32736961

ABSTRACT

Dendritic cells (DCs), as antigen-presenting cells, can reportedly be infected withLeishmaniaparasites and hence provide a better option to trigger T-cell primary immune responses and immunological memory. We consistently primed DCs during culture with purified recombinant cytosolic tryparedoxin (rcTXN) and then evaluated the vaccine prospect of presentation of rcTXN against VL in BALB/c mice. We reported earlier the immunogenic properties of cTXN antigen derived fromL. donovani when anti-cTXN antibody was detected in the sera of kala-azar patients. It was observed that cTXN antigen, when used as an immunogen with murine DCs acting as a vehicle, was able to induce complete protection against VL in an infected group of immunized mice. This vaccination triggered splenic macrophages to produce more IL-12 and GM-CSF, and restricted IL-10 release to a minimum in an immunized group of infected animals. Concomitant changes in T-cell responses against cTXN antigen were also noticed, which increased the release of protective cytokine-like IFN-γ under the influence of NF-κß in the indicated vaccinated group of animals. All cTXN-DCs-vaccinated BALB/c mice survived during the experimental period of 120 days. The results obtained in our study suggest that DCs primed with cTXN can be used as a vaccine prospect for the control of visceral leishmaniasis.


Subject(s)
Dendritic Cells/immunology , Leishmania donovani/immunology , Leishmaniasis Vaccines/immunology , Leishmaniasis, Visceral/immunology , Animals , Cytokines/immunology , Dendritic Cells/parasitology , Immunity, Cellular/immunology , Interleukin-10/immunology , Interleukin-12/immunology , Leishmaniasis, Visceral/parasitology , Macrophages/immunology , Macrophages/parasitology , Mice , Mice, Inbred BALB C , Protozoan Proteins/immunology , T-Lymphocytes/immunology , T-Lymphocytes/parasitology
16.
Photochem Photobiol Sci ; 19(5): 542-584, 2020 May 20.
Article in English | MEDLINE | ID: mdl-32364555

ABSTRACT

This assessment, by the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP), one of three Panels informing the Parties to the Montreal Protocol, provides an update, since our previous extensive assessment (Photochem. Photobiol. Sci., 2019, 18, 595-828), of recent findings of current and projected interactive environmental effects of ultraviolet (UV) radiation, stratospheric ozone, and climate change. These effects include those on human health, air quality, terrestrial and aquatic ecosystems, biogeochemical cycles, and materials used in construction and other services. The present update evaluates further evidence of the consequences of human activity on climate change that are altering the exposure of organisms and ecosystems to UV radiation. This in turn reveals the interactive effects of many climate change factors with UV radiation that have implications for the atmosphere, feedbacks, contaminant fate and transport, organismal responses, and many outdoor materials including plastics, wood, and fabrics. The universal ratification of the Montreal Protocol, signed by 197 countries, has led to the regulation and phase-out of chemicals that deplete the stratospheric ozone layer. Although this treaty has had unprecedented success in protecting the ozone layer, and hence all life on Earth from damaging UV radiation, it is also making a substantial contribution to reducing climate warming because many of the chemicals under this treaty are greenhouse gases.


Subject(s)
Climate Change , Stratospheric Ozone , Ultraviolet Rays , Environmental Health , Humans , Microplastics , United Nations
17.
J Phys Chem A ; 124(10): 1993-2000, 2020 Mar 12.
Article in English | MEDLINE | ID: mdl-32039598

ABSTRACT

Diisopropylammonium salts have drawn attention in recent years due to their room-temperature ferroelectric properties. Triclinic diisopropylammonium perchlorate (DIPAP) exhibits ferroelectricity at room temperature. We have carried out density functional theory calculations to assign the phonon modes in DIPAP. High-pressure Raman spectra of DIPAP are recorded up to ∼3 GPa. Discontinuity in the NH2 bending and stretching mode frequencies and the appearance of new bands at 0.7 GPa suggest a phase transition by a rearrangement in the hydrogen network. Broadening of lattice modes at 1.3-1.7 GPa indicates a loss of crystalline nature above 1.7 GPa. High-pressure synchrotron X-ray diffraction of DIPAP shows an isostructural phase transition at 0.6 GPa and confirms amorphization at 1.5 GPa that may lead to a loss of ferroelectricity above this pressure. The ambient phase becomes reversible after releasing the pressure. The bulk modulus of DIPAP is determined to be 16.5 GPa.

18.
RSC Adv ; 10(36): 21277-21282, 2020 Jun 02.
Article in English | MEDLINE | ID: mdl-35518770

ABSTRACT

A hydrothermal synthesis method was employed for the preparation of tin sulfide (α-SnS) microrod samples (SnS-A and SnS-B) using ethylenediamine and deionized water as the surfactant at ratios from 50 : 50 to 100 : 00. The atomic structures of the α-SnS microrods were studied using atomic pair distribution function (PDF) analysis and total synchrotron X-ray scattering data. The synchrotron X-ray diffraction (ScXRD) patterns and PDF data reveal that the structure of the SnS microrods is orthorhombic. From the refinement of the PDF, the first and second peaks correspond to nearest (Sn2+-S2-) and second nearest distances (Sn2+-Sn2+) of 2.546 (0.003) Å and 4.106 (0.004) Å, and 2.527 (0.005) Å and 4.087 (0.006) Å for SnS-A and SnS-B samples, respectively. The TEM results show that samples SnS-A and SnS-B have a microrod structure, with microrod diameters of 800 nm and 500 nm with lengths of tens of micrometers, respectively. The SnS-A and SnS-B samples show a direct band gap of 1.6 eV and 2 eV, respectively, using the Kubelka-Munk transformation of the UV-visible spectra. The micro-Raman spectra of the SnS-A and SnS-B microrods exhibited an Ag mode of SnS at 228.4 and 223 cm-1, respectively. The second peaks at 306.7, and 309 cm-1 are associated with the secondary phases of the SnS2 phase, whereas the third broad peaks at 616.5, and 613 cm-1 revealed that there was a deformation mode of sulfate in the SnS-A and SnS-B samples.

19.
J Phys Chem B ; 124(2): 373-379, 2020 01 16.
Article in English | MEDLINE | ID: mdl-31869224

ABSTRACT

Benzoic acid derivatives are important molecular systems in the pharmaceutical industry. Salicylic acid is distinct among the derivatives of benzoic acid due to the presence of an intramolecular hydrogen bond. With a view to study the evolution of inter and intramolecular hydrogen bonding at shorter length scales, in situ high pressure Raman spectroscopic measurements, angle dispersive X-ray diffraction experiments, and density functional theory (DFT) based first principle calculations have been carried out on crystalline salicylic acid. Subtle structural modifications are noted across ∼1 GPa leading to structural phase transition to a new crystalline phase above 7 GPa which is reversible. Substantial softening of the OH stretching Raman mode associated with intramolecular hydrogen bond is observed prior to the transition pressure. Possible molecular configurations associated with tautomerization are discussed with the aid of DFT calculations.

20.
J Laryngol Otol ; 133(12): 1050-1052, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31722774

ABSTRACT

OBJECTIVE: Opioid analgesics are often prescribed following rhinology surgery. This study aimed to evaluate whether the quantity of opioid analgesics prescribed is justified. METHODS: Patients were asked about their pain management post-operatively. Parameters recorded included: current pain (using a 10-point Likert scale); type of operation; the opioid analgesics prescribed; and the quantity of opioid tablets taken and other methods of pain relief used. RESULTS: Thirty-five patients were successfully contacted. The median pain score at one week post-operation was 1 (interquartile range, 0-3). Of these 35 patients, 16 were prescribed opioids, whilst 19 were not. Patients prescribed opioids took a median of 8 tablets (interquartile range, 0.8-10.5) out of the 28 tablets prescribed. CONCLUSION: The study shows that the quantity of post-operative opioid analgesics prescribed does not compare with the amount consumed by patients to relieve pain, resulting in a surplus of opioid medication which has the potential to be abused.


Subject(s)
Analgesics, Opioid/administration & dosage , Codeine/analogs & derivatives , Drug Prescriptions/statistics & numerical data , Nasal Surgical Procedures/adverse effects , Pain, Postoperative/drug therapy , Adult , Codeine/administration & dosage , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Pain Management/methods , Pain, Postoperative/etiology , Postoperative Period , Practice Patterns, Physicians'/statistics & numerical data , Prospective Studies , Treatment Outcome , Young Adult
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