Targeting an allosteric site in dynamin-related protein 1 to inhibit Fis1-mediated mitochondrial dysfunction

The large cytosolic GTPase, dynamin-related protein 1 (Drp1), mediates both physiological and pathological mitochondrial fission. Cell stress triggers Drp1 binding to mitochondrial Fis1 and subsequently, mitochondrial fragmentation, ROS production, metabolic collapse, and cell death. Because Drp1 also mediates physiological fission by binding to mitochondrial Mff, therapeutics that inhibit pathological fission should spare physiological mitochondrial fission. P110, a peptide inhibitor of Drp1-Fis1 interaction, reduces pathology in numerous models of neurodegeneration, ischemia, and sepsis without blocking the physiological functions of Drp1. Since peptides have pharmacokinetic limitations, we set out to identify small molecules that mimic P110's benefit. We map the P110-binding site to a switch I-adjacent grove (SWAG) on Drp1. Screening for SWAG-binding small molecules identifies SC9, which mimics P110's benefits in cells and a mouse model of endotoxemia. We suggest that the SWAG-binding small molecules discovered in this study may reduce the burden of Drp1-mediated pathologies and potentially pathologies associated with other members of the GTPase family.

Flame Aerosol Synthesis of Metal Sulfides at High Temperature in Oxygen-Lean Atmosphere

The development of a novel reactive spray technology based on the well-known gas-phase metal oxide synthesis route provides innumerable opportunities for the production of non-oxide nanoparticles. Among these materials, metal sulfides are expected to have a high impact, especially in the development of electrochemical and photochemical high-surface-area materials. As a proof-of-principle, MnS, CoS, Cu₂ S, ZnS, Ag₂ S, In₂ S₃ , SnS, and Bi₂ S₃ are synthesized in an O₂ -lean and sulfur-rich environment. In addition, the formation of Cu₂ S in a single-droplet combustion experiment is reported. The multiscale approach combining flame sprays with single-droplet combustion is expected to pave the way toward a fundamental understanding of the gas-phase formation of metal sulfides in the future. The knowledge acquired can open the possibility for the development of a next-generation gas-phase technology facilitating the scalable synthesis of functional binary/ternary metal sulfides.

TiO2 nanoparticles' library toxicity (UV and non-UV exposure) - High-throughput in vivo transcriptomics reveals mechanisms

The hazards of nanomaterials/nanoparticles (NMs/NPs) are mostly assessed using individual NMs, and a more systematic approach, using many NMs, is needed to evaluate its risks in the environment. Libraries of NMs, with a range of identified different but related characters/descriptors allow the comparison of effects across many NMs. The effects of a custom designed Fe-doped TiO₂ NMs library containing 11 NMs was assessed on the soil model Enchytraeus crypticus (Oligochaeta), both with and without UV (standard fluorescent) radiation. Effects were analyzed at organism (phenotypic, survival and reproduction) and gene expression level (transcriptomics, high-throughput 4x44K microarray) to understand the underlying mechanisms. A total of 48 microarrays (20 test conditions) were done plus controls (UV and non-UV). Unique mechanisms induced by TiO₂ NPs exposure included the impairment in RNA processing for TiO₂_10nm, or deregulated apoptosis for 2%FeTiO₂_10nm. Strikingly apparent was the size dependent effects such as induction of reproductive effects via smaller TiO₂ NPs (≤12 nm) - embryo interaction, while larger particles (27 nm) caused reproductive effects through different mechanisms. Also, phagocytosis was affected by 12 and 27 nm NPs, but not by ≤11 nm. The organism level study shows the integrated response, i.e. the result after a cascade of events. While uni-cell models offer key mechanistic information, we here deliver a combined biological system level (phenotype and genotype), seldom available, especially for environmental models.

Potent and selective covalent inhibition of the papain-like protease from SARS-CoV-2

Direct-acting antivirals are needed to combat coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The papain-like protease (PLpro) domain of Nsp3 from SARS-CoV-2 is essential for viral replication. In addition, PLpro dysregulates the host immune response by cleaving ubiquitin and interferon-stimulated gene 15 protein from host proteins. As a result, PLpro is a promising target for inhibition by small-molecule therapeutics. Here we design a series of covalent inhibitors by introducing a peptidomimetic linker and reactive electrophile onto analogs of the noncovalent PLpro inhibitor GRL0617. The most potent compound inhibits PLpro with kinact/KI = 9,600 M-1 s-1, achieves sub-μM EC50 values against three SARS-CoV-2 variants in mammalian cell lines, and does not inhibit a panel of human deubiquitinases (DUBs) at >30 μM concentrations of inhibitor. An X-ray co-crystal structure of the compound bound to PLpro validates our design strategy and establishes the molecular basis for covalent inhibition and selectivity against structurally similar human DUBs. These findings present an opportunity for further development of covalent PLpro inhibitors.

Cu-doped TiO2 nanoparticles improve local antitumor immune activation and optimize dendritic cell vaccine strategies

Nanoparticle-mediated cancer immunotherapy holds great promise, but more efforts are needed to obtain nanoformulations that result in a full scale activation of innate and adaptive immune components that specifically target the tumors. We generated a series of copper-doped TiO₂ nanoparticles in order to tune the kinetics and full extent of Cu²⁺ ion release from the remnant TiO₂ nanocrystals. Fine-tuning nanoparticle properties resulted in a formulation of 33% Cu-doped TiO₂ which enabled short-lived hyperactivation of dendritic cells and hereby promoted immunotherapy. The nanoparticles result in highly efficient activation of dendritic cells ex vivo, which upon transplantation in tumor bearing mice, exceeded the therapeutic outcomes obtained with classically stimulated dendritic cells. Efficacious but simple nanomaterials that can promote dendritic cancer cell vaccination strategies open up new avenues for improved immunotherapy and human health.

SGLT2 inhibitor ameliorates endothelial dysfunction associated with the common ALDH2 alcohol flushing variant

The common aldehyde dehydrogenase 2 (ALDH2) alcohol flushing variant known as ALDH2*2 affects ∼8% of the world's population. Even in heterozygous carriers, this missense variant leads to a severe loss of ALDH2 enzymatic activity and has been linked to an increased risk of coronary artery disease (CAD). Endothelial cell (EC) dysfunction plays a determining role in all stages of CAD pathogenesis, including early-onset CAD. However, the contribution of ALDH2*2 to EC dysfunction and its relation to CAD are not fully understood. In a large genome-wide association study (GWAS) from Biobank Japan, ALDH2*2 was found to be one of the strongest single-nucleotide polymorphisms associated with CAD. Clinical assessment of endothelial function showed that human participants carrying ALDH2*2 exhibited impaired vasodilation after light alcohol drinking. Using human induced pluripotent stem cell-derived ECs (iPSC-ECs) and CRISPR-Cas9-corrected ALDH2*2 iPSC-ECs, we modeled ALDH2*2-induced EC dysfunction in vitro, demonstrating an increase in oxidative stress and inflammatory markers and a decrease in nitric oxide (NO) production and tube formation capacity, which was further exacerbated by ethanol exposure. We subsequently found that sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin mitigated ALDH2*2-associated EC dysfunction. Studies in ALDH2*2 knock-in mice further demonstrated that empagliflozin attenuated ALDH2*2-mediated vascular dysfunction in vivo. Mechanistically, empagliflozin inhibited Na⁺/H⁺-exchanger 1 (NHE-1) and activated AKT kinase and endothelial NO synthase (eNOS) pathways to ameliorate ALDH2*2-induced EC dysfunction. Together, our results suggest that ALDH2*2 induces EC dysfunction and that SGLT2i may potentially be used as a preventative measure against CAD for ALDH2*2 carriers.

Potent and Selective Covalent Inhibition of the Papain-like Protease from SARS-CoV-2

Direct-acting antivirals are needed to combat coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The papain-like protease (PLpro) domain of Nsp3 from SARS-CoV-2 is essential for viral replication. In addition, PLpro dysregulates the host immune response by cleaving ubiquitin and interferon-stimulated gene 15 protein (ISG15) from host proteins. As a result, PLpro is a promising target for inhibition by small-molecule therapeutics. Here we have designed a series of covalent inhibitors by introducing a peptidomimetic linker and reactive electrophile onto analogs of the noncovalent PLpro inhibitor GRL0617. The most potent compound inhibited PLpro with kinact/KI = 10,000 M- 1 s- 1, achieved sub-μM EC50 values against three SARS-CoV-2 variants in mammalian cell lines, and did not inhibit a panel of human deubiquitinases at > 30 μM concentrations of inhibitor. An X-ray co-crystal structure of the compound bound to PLpro validated our design strategy and established the molecular basis for covalent inhibition and selectivity against structurally similar human DUBs. These findings present an opportunity for further development of covalent PLpro inhibitors.

Potent and Selective Covalent Inhibition of the Papain-like Protease from SARS-CoV-2

Direct-acting antivirals are needed to combat coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The papain-like protease (PLpro) domain of Nsp3 from SARS-CoV-2 is essential for viral replication. In addition, PLpro dysregulates the host immune response by cleaving ubiquitin and interferon-stimulated gene 15 protein (ISG15) from host proteins. As a result, PLpro is a promising target for inhibition by small-molecule therapeutics. Here we have designed a series of covalent inhibitors by introducing a peptidomimetic linker and reactive electrophile onto analogs of the noncovalent PLpro inhibitor GRL0617. The most potent compound inhibited PLpro with k inact /K I = 10,000 M - 1 s - 1 , achieved sub-µM EC 50 values against three SARS-CoV-2 variants in mammalian cell lines, and did not inhibit a panel of human deubiquitinases at > 30 µM concentrations of inhibitor. An X-ray co-crystal structure of the compound bound to PLpro validated our design strategy and established the molecular basis for covalent inhibition and selectivity against structurally similar human DUBs. These findings present an opportunity for further development of covalent PLpro inhibitors.

A Point Prevalence Study of the Use of Antibiotics in Six Tertiary Care Hospitals in the Kathmandu Valley, Nepal

Background Point prevalence survey (PPS) on antibiotic use developed by the WHO has already been used in many hospitals globally. Objective To obtain information on antibiotic prescribtion using point prevalence survey methodology in six private hospitals in the Kathmandu valley. Method This descriptive cross-sectional study was completed during 20th July to 28th July 2021 using point prevalence survey methodology. The study was conducted among inpatients admitted at or before 8:00 AM on the day of survey in various wards. Data was presented as frequencies and percentages. Result Maximum number of patients were above 60 years [34 (18.7%)]. Number of male and female participants were equal [91 (50%)]. Only one antibiotic was used in 81 patients (44.5%) followed by two antibiotics in 71 (39%) patients. Duration of prophylactic antibiotic use was one day in 66 (63.7%) patients. Blood, urine, sputum, and wound swabs were the common samples for culture. Cultures were positive for 17 (24.7%) samples. The common organisms isolated were E. Coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. Ceftriaxone was the most used antibiotic. Drug and therapeutics, infection control committee and pharmacovigilance activities were present in 3/6 (50%) study sites. Antimicrobial stewardship was present in 3/6 (50%) and microbiological services was present in all hospitals. Antibiotic formulary and antibiotic guideline were present in 4/6 sites and facilities to audit or review surgical antibiotic prophylaxis choice in 2/6 (33.3%) sites, facility to monitor antibiotic use in 4/6 (66.6%) and cumulative antibiotic susceptibility reports in 2/6 (33.3%) study sites. Conclusion Ceftriaxone was the most used antibiotic. E. Coli, Pseudomonas aeruginosa and Klebsiella pneumonia were the commonly isolated organisms. Not all parameters for infrastructure, policy and practice and monitoring and feedback were present at the study sites. KEY WORDS.

A study of Heart Rate Variability (HRV) in healthy offsprings with parental history of type 2 diabetes mellitus

Introduction: Type 2 diabetes mellitus (T2DM) is a heterogeneous polygenic metabolic disease condition that is caused by insulin resistance leading to hyperglycemia. Since, T2DM is genetically inherited and autonomic dysfunction is its major complications, healthy offsprings of diabetic parents are highly vulnerable to manifest dysautonomia leading to insulin resistance. Objectives: We aimed to assess cardiac autonomic function using heart rate variability (HRV) parameters in healthy offsprings having parental history of T2DM. Methodology: A comparative cross-sectional study was carried out in the laboratory of department of Physiology enrolling 30 healthy offsprings of non-diabetic parents (Group 1) and 30 healthy offsprings of diabetic parents (Group 2). Anthropometric, biochemical and cardiovascular variables were assessed using standard procedures. Time domain and frequency domain parameters of HRV spectrum were assessed using photoplethysmography principle. Results: HRV findings revealed that markers of sympathetic regulation were significantly higher and those of parasympathetic function were significantly reduced in subject group having parental history of T2DM. LF/HF ratio was significantly increased suggesting sympatho-vagal imbalance in offspring of diabetic parents even in their euglycemic state. Conclusion:  Alteration of cardiovascular autonomic function is found in healthy offspring of diabetic parents, characterized by reduced vagal activity and pronounced sympathetic regulation. Assessment of cardiac autonomic function would help in timely detection of such dysautonomia and reducing the life-threatening effects on offspring having parental history of T2DM.

Egg-Derived Anti-SARS-CoV-2 Immunoglobulin Y (IgY) With Broad Variant Activity as Intranasal Prophylaxis Against COVID-19

COVID-19 emergency use authorizations and approvals for vaccines were achieved in record time. However, there remains a need to develop additional safe, effective, easy-to-produce, and inexpensive prevention to reduce the risk of acquiring SARS-CoV-2 infection. This need is due to difficulties in vaccine manufacturing and distribution, vaccine hesitancy, and, critically, the increased prevalence of SARS-CoV-2 variants with greater contagiousness or reduced sensitivity to immunity. Antibodies from eggs of hens (immunoglobulin Y; IgY) that were administered the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein were developed for use as nasal drops to capture the virus on the nasal mucosa. Although initially raised against the 2019 novel coronavirus index strain (2019-nCoV), these anti-SARS-CoV-2 RBD IgY surprisingly had indistinguishable enzyme-linked immunosorbent assay binding against variants of concern that have emerged, including Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529). This is different from sera of immunized or convalescent patients. Culture neutralization titers against available Alpha, Beta, and Delta were also indistinguishable from the index SARS-CoV-2 strain. Efforts to develop these IgY for clinical use demonstrated that the intranasal anti-SARS-CoV-2 RBD IgY preparation showed no binding (cross-reactivity) to a variety of human tissues and had an excellent safety profile in rats following 28-day intranasal delivery of the formulated IgY. A double-blind, randomized, placebo-controlled phase 1 study evaluating single-ascending and multiple doses of anti-SARS-CoV-2 RBD IgY administered intranasally for 14 days in 48 healthy adults also demonstrated an excellent safety and tolerability profile, and no evidence of systemic absorption. As these antiviral IgY have broad selectivity against many variants of concern, are fast to produce, and are a low-cost product, their use as prophylaxis to reduce SARS-CoV-2 viral transmission warrants further evaluation.

Clinical Trial Registration

https://www.clinicaltrials.gov/ct2/show/NCT04567810, identifier NCT04567810.

Sexual Dimorphism in Maxillary First Molar among Nepalese Population of Eastern Nepal

Introduction: Sexual dimorphism refers to differences in size, stature and appearance between male and female. It is a known fact that tooth crown is formed to full size in childhood even before eruption into oral cavity. The shape and size of the teeth permits an interesting dimension of study for sexual dimorphism, we aimed to delineate the sexual dimorphism by measuring the mesiodistal (MD) and buccolingual (BL) diameters of permanent maxillary first molar in Nepalese population of Eastern Nepal. Objectives: The aim of this study was to evaluate the sexual dimorphism in maxillary first molar among Nepalese population of eastern Nepal Methodology: 100 participants of either sex (50 males & 50 females) aged between 17 to 25 years were enrolled in the study. After thorough dental examination, impression of the maxillary arch was made and MD diameter and BL diameters were measured with the help of vernier caliper. A P value of <0.05 was considered as statistically significant. Results: Sexual dimorphism was found in MD and BL diameters of maxillary first molar in males measuring higher than females. Right mesiodistal showed the highest sexual dimorphism, whereas right buccolingual showed the least. Conclusions: This study confirms that permanent maxillary first molar shows significant sexual dimorphism, out of which mesiodistal measurement stands out to be the best parameter in Nepalese population of Eastern region.

Knowledge and Practices of Child Protection among the School Health Nurses of Nepal

Background Child protection is burning issues in developing countries including Nepal. Child protection is one of the key works of the school health nurses. Objective To find out about the existing knowledge and practices of child protection among the school health nurses. Method This descriptive cross-sectional study was conducted among 130 school health nurses working in different schools throughout Nepal. The participants were selected using purposive sampling technique and were invited to participate via various online networks. Self-administered questionnaire was used to collect data. Duration of data collection was 20 December 2020 to 10 February 2021. Descriptive statistics was used to analyze and interpret the data. Result Among the 130 Participants, 88.5% belonged to less than 29 years age group and 67.7% had Proficiency Certificate Level in Nursing education. None of them has received training related to child protection recognition and response and 90.8% had work experience of less than 5 years. Eighty percent and 96.9% participants had knowledge regarding the meaning of child right and child abuse respectively. But 45.4% had knowledge on meaning of child neglect; 53.1% and 72.3% had the knowledge of physical abuse and noncontact sexual abuse respectively. Majority (86.9%) of the participants reported as relatives were the abuser and 63.8% replied as home is the common place for abuse. Similarly, 85.4% had received the information regarding child protection via television radio and newspaper. Only 36.1% has already been involved in child protection. The participants who went to local government (Palika), police and Non-government Organizations for coordination for child right issues were 9(19.1%), 7(14.8%) and 8(17.0%) respectively. Conclusion Most of the school health nurses are young without having experience of childhood abuse and received any child protection training before joining the job. They have good knowledge of child right, physical, sexual abuse except child neglect and existing legal arrangements. There is gap in knowledge and practice.

Machine learning and materials modelling interpretation of in vivo toxicological response to TiO2 nanoparticles library (UV and non-UV exposure)

Assessing the risks of nanomaterials/nanoparticles (NMs/NPs) under various environmental conditions requires a more systematic approach, including the comparison of effects across many NMs with identified different but related characters/descriptors. Hence, there is an urgent need to provide coherent (eco)toxicological datasets containing comprehensive toxicity information relating to a diverse spectra of NPs characters. These datasets are test benches for developing holistic methodologies with broader applicability. In the present study we assessed the effects of a custom design Fe-doped TiO₂ NPs library, using the soil invertebrate Enchytraeus crypticus (Oligochaeta), via a 5-day pulse via aqueous exposure followed by a 21-days recovery period in soil (survival, reproduction assessment). Obviously, when testing TiO₂, realistic conditions should include UV exposure. The 11 Fe-TiO₂ library contains NPs of size range between 5-27 nm with varying %Fe (enabling the photoactivation of TiO₂ at energy wavelengths in the visible-light range). The NPs were each described by 122 descriptors, being a mixture of measured and atomistic model descriptors. The data were explored using single and univariate statistical methods, combined with machine learning and multiscale modelling techniques. An iterative pruning process was adopted for identifying automatically the most significant descriptors. TiO₂ NPs toxicity decreased when combined with UV. Notably, the short-term water exposure induced lasting biological responses even after longer-term recovery in clean exposure. The correspondence with Fe-content correlated with the band-gap hence the reduction of UV oxidative stress. The inclusion of both measured and modelled materials data benefitted the explanation of the results, when combined with machine learning.

Paired SARS-CoV-2 spike protein mutations observed during ongoing SARS-CoV-2 viral transfer from humans to minks and back to humans

A mutation analysis of SARS-CoV-2 genomes collected around the world sorted by sequence, date, geographic location, and species has revealed a large number of variants from the initial reference sequence in Wuhan. This analysis also reveals that humans infected with SARS-CoV-2 have infected mink populations in the Netherlands, Denmark, United States, and Canada. In these animals, a small set of mutations in the spike protein receptor binding domain (RBD), often occurring in specific combinations, has transferred back into humans. The viral genomic mutations in minks observed in the Netherlands and Denmark show the potential for new mutations on the SARS-CoV-2 spike protein RBD to be introduced into humans by zoonotic transfer. Our data suggests that close attention to viral transfer from humans to farm animals and pets will be required to prevent build-up of a viral reservoir for potential future zoonotic transfer.

Natural variants in SARS-CoV-2 Spike protein pinpoint structural and functional hotspots with implications for prophylaxis and therapeutic strategies

In December 2019, a novel coronavirus, termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified as the cause of pneumonia with severe respiratory distress and outbreaks in Wuhan, China. The rapid and global spread of SARS-CoV-2 resulted in the coronavirus 2019 (COVID-19) pandemic. Earlier during the pandemic, there were limited genetic viral variations. As millions of people became infected, multiple single amino acid substitutions emerged. Many of these substitutions have no consequences. However, some of the new variants show a greater infection rate, more severe disease, and reduced sensitivity to current prophylaxes and treatments. Of particular importance in SARS-CoV-2 transmission are mutations that occur in the Spike (S) protein, the protein on the viral outer envelope that binds to the human angiotensin-converting enzyme receptor (hACE2). Here, we conducted a comprehensive analysis of 441,168 individual virus sequences isolated from humans throughout the world. From the individual sequences, we identified 3540 unique amino acid substitutions in the S protein. Analysis of these different variants in the S protein pinpointed important functional and structural sites in the protein. This information may guide the development of effective vaccines and therapeutics to help arrest the spread of the COVID-19 pandemic.

Increased elastase sensitivity and decreased intramolecular interactions in the more transmissible 501Y.V1 and 501Y.V2 SARS-CoV-2 variants' spike protein-an in silico analysis

Two SARS-CoV-2 variants of concern showing increased transmissibility relative to the Wuhan virus have recently been identified. Although neither variant appears to cause more severe illness nor increased risk of death, the faster spread of the virus is a major threat. Using computational tools, we found that the new SARS-CoV-2 variants may acquire an increased transmissibility by increasing the propensity of its spike protein to expose the receptor binding domain via proteolysis, perhaps by neutrophil elastase and/or via reduced intramolecular interactions that contribute to the stability of the closed conformation of spike protein. This information leads to the identification of potential treatments to avert the imminent threat of these more transmittable SARS-CoV-2 variants.

Double Flame-Fabricated High-Performance AlPO4/LiMn2O4 Cathode Material for Li-Ion Batteries

The spinel LiMn₂O₄ (LMO) is a promising cathode material for rechargeable Li-ion batteries due to its excellent properties, including cost effectiveness, eco-friendliness, high energy density, and rate capability. The commercial application of LiMn₂O₄ is limited by its fast capacity fading during cycling, which lowers the electrochemical performance. In the present work, phase-pure and crystalline LiMn₂O₄ spinel in the nanoscale were synthesized using single flame spray pyrolysis via screening 16 different precursor-solvent combinations. To overcome the drawback of capacity fading, LiMn₂O₄ was homogeneously mixed with different percentages of AlPO₄ using versatile multiple flame sprays. The mixing was realized by producing AlPO₄ and LiMn₂O₄ aerosol streams in two independent flames placed at 20° to the vertical axis. The structural and morphological analyses by X-ray diffraction indicated the formation of a pure LMO phase and/or AlPO₄-mixed LiMn₂O₄. Electrochemical analysis indicated that LMO nanoparticles of 17.8 nm (d _BET) had the best electrochemical performance among the pure LMOs with an initial capacity and a capacity retention of 111.4 mA h g^-1 and 88% after 100 cycles, respectively. A further increase in the capacity retention to 93% and an outstanding initial capacity of 116.1 mA h g^-1 were acquired for 1% AlPO₄.

Control of Porous Layer Thickness in Thermophoretic Deposition of Nanoparticles

The film thickness plays an important role in the performance of materials applicable to different technologies including chemical sensors, catalysis and/or energy materials. The relationship between the surface and volume of the functional layers is key to high performance evaluations. Here we demonstrate the thermophoretic deposition of different thicknesses of the functional layers designed using flame combustion of tin 2-ethylhexanoate dissolved in xylene, and measurement of thickness by scanning electron microscopy and focused ion beam. The parameters such as spray fluid concentration (differing Sn2+ content), substrate-nozzle distance and time of the spray were considered to investigate the layer growth. The results showed ≈ 23, 124 and 161 μm thickness of the SnO2 layer after flame spray of 0.1, 0.5 M and 1.0 M tin 2-EHA-Xylene solutions for 1200 s. While Sn2+ concentration was 0.5 M for all the flame sprays, the substrates placed at 250, 220 and 200 mm from the flame nozzle had layer thicknesses of 113, 116 and 132 µm, respectively. Spray time dependent thickness growth showed a linear increase from 8.5 to 152.1 µm when the substrates were flame sprayed for 30 s to 1200 s using 0.5 M tin 2-EHA-Xylene solutions. Changing the dispersion oxygen flow (3-7 L/min) had almost no effect on layer thickness. Layers fabricated were compared to a model found in literature, which seems to describe the thickness well in the domain of varied parameters. It turned out that primary particle size deposited on the substrate can be tuned without altering the layer thickness and with little effect on porosity. Applications depending on porosity, such as catalysis or gas sensing, can benefit from tuning the layer thickness and primary particle size.

Metal Sulfide Nanoparticles: Precursor Chemistry

Fascination with and the need for evermore increasing efficiency, power, or strength have been the cornerstones for developing new materials and methods for their creation. Higher solar cell conversion efficiencies, increased battery storage power, and lightweight strong materials are some that have been at the forefront of attention for these efforts. Materials created for most applications start as simple chemical compounds. A study of how these chemicals have been used in the past can be used to create new materials and new methods of production. Herein, a class of materials that are valuable in a multitude of applications, metal sulfide nanoparticles, are examined, along with how they are being produced and how new methods can be established that will help to standardize and increase production capabilities. Precursor–solvent combinations that can be used to create metal sulfide nanoparticles in the gas phase are also explored.

Knowledge of Adverse Drug Reactions Reporting among Doctors and Nurses in a Tertiary Care Hospital: A Descriptive Cross-sectional Study

INTRODUCTION

Doctors and nurses have a significant role in the detection of serious and unusual drug reactions. Effective implementation of an adverse drug reaction reporting system is required to ensure patient safety and quality care. This study's objective was to find the prevalence of good knowledge of adverse drug reaction reporting among the Doctors and nurses working in a tertiary care hospital.

METHODS

A descriptive cross-sectional study was conducted among doctors and nurses from 15 February 2020 to 15 July 2020 at Birat Medical College and Teaching Hospital. The convenience sampling method was used to select 192 study participants. A semi-structured questionnaire was used to know the knowledge concept of adverse drug reaction reporting. Ethical clearance was taken from IRC (PA-047/2076-77) of Birat Medical College and Teaching Hospital. Written informed consent was taken from each study participant. Collected data were entered in Microsoft Excel 2010 and analyzed by Statistical Package for the Social Sciences v23.

RESULTS

In total, 192 doctors and nurses, the questionnaires were distributed to 52 (27.1%) doctors and 140 (72.9%) nurses. The mean age of study participants was 28.14 years (SD±4.5). To know the prevalence of knowledge, 15 knowledge related questions of adverse drug reaction had asked. The majority of doctors and nurses had good knowledge about adverse drug reaction reporting, 75% and 64%, respectively.

CONCLUSIONS

Overall, doctors and nurses have had good knowledge of adverse drug reaction reporting. Data shows there is still more gap in training and experience on adverse drug reaction reporting systems.

Study of peripheral blood smear findings in patients of anemia and to compare it with automated hematology analyzer generated red cell parameters

Introduction: Anemia is one of the common medical conditions prevalent in our society. The correct categorization of varying types of anemia is essential for therapeutic purposes. Various laboratory tests are done to find out its underlying cause, but peripheral smear (PS) study of red blood cells (RBCs) morphology is important along with study of red blood cell indices in the classification of anemia. Objectives: This study was done to evaluate RBC morphology on peripheral smear examination in patients of anemia and to compare these findings with cell counter generated red blood cells indices comprising of Mean corpuscular volume (MCV), Mean corpuscular hemoglobin concentration (MCHC) and Mean corpuscular hemoglobin (MCH) Methodology: Red blood cell morphology on peripheral blood smear was studied in 350 patients of anemia irrespective of age and gender received under six months duration  from 1st January 2019 to 30 th June 2019 and  findings  were compared with  cell counter generated  red cell parameters generated by automated  hematology analyzer. Results: Most common anemia seen on smear examination was microcytic hypochromic anemia which accounted for 210 (60%) cases followed by dimorphic anemia in 73 (20.86%) cases. Most of the patients were female, comprising of 227 (64.85%) cases. Highest numbers of patient were in the age group of 21-30 years (20.30%). Sensitivity of MCV was 78%, MCHC was 14% and MCH was 80% in detection of microcytic hypochromic anemia. The sensitivity of MCV and MCH was found to be 100 %  in detection of macrocytic anemia. Sensitivity of MCHC was only 10% for detection of macrocytic anemia. The sensitivity of MCV, MCHC and MCH was 78%, 100% and 67 % respectively in detection of normocytic normochromic anemia.  Conclusion: The peripheral smear examination should always be interpreted along with the red blood cell indices generated by an automated analyzer in order to classify various types of anemia.

CpeT is the phycoerythrobilin lyase for Cys-165 on β-phycoerythrin from Fremyella diplosiphon and the chaperone-like protein CpeZ greatly improves its activity

Bilin lyases are enzymes which ligate linear tetrapyrrole chromophores to specific cysteine residues on light harvesting proteins present in cyanobacteria and red algae. The lyases responsible for chromophorylating the light harvesting protein phycoerythrin (PE) have not been fully characterized. In this study, we explore the role of CpeT, a putative bilin lyase, in the biosynthesis of PE in the cyanobacterium Fremyella diplosiphon. Recombinant protein studies show that CpeT alone can bind phycoerythrobilin (PEB), but CpeZ, a chaperone-like protein, is needed in order to correctly and efficiently attach PEB to the β-subunit of PE. MS analyses of the recombinant β-subunit of PE coexpressed with CpeT and CpeZ show that PEB is attached at Cys-165. Purified phycobilisomes from a cpeT knockout mutant and wild type (WT) samples from F. diplosiphon were analyzed and compared. The cpeT mutant contained much less PE and more phycocyanin than WT cells grown under green light, conditions which should maximize the production of PE. In addition, Northern blot analyses showed that the cpeCDESTR operon mRNAs were upregulated while the cpeBcpeA mRNAs were downregulated in the cpeT mutant strain when compared with WT, suggesting that CpeT may also play a direct or indirect regulatory role in transcription of these operons or their mRNA stability, in addition to its role as a PEB lyase for Cys-165 on β-PE.

Flame-made Particles for Sensors, Catalysis, and Energy Storage Applications

Flame spray pyrolysis of precursor-solvent combinations with high enthalpy density allows the design of functional nanoscale materials. Within the last two decades, flame spray pyrolysis was utilized to produce more than 500 metal oxide particulate materials for R&D and commercial applications. In this short review, the particle formation mechanism is described based on the micro-explosions observed in single droplet experiments for various precursor-solvent combinations. While layer fabrication is a key to successful industrial applications toward gas sensors, catalysis, and energy storage, the state-of-the-art technology of innovative in situ thermophoretic particle production and deposition technology is described. In addition, noble metal stabilized oxide matrices with tight chemical contact catalyze surface reactions for enhanced catalytic performance. The metal-support interaction that is vital for redox catalytic performance for various surface reactions is presented.

Peri-operative COVID-19 infection in urgent elective surgery during a pandemic surge period: a retrospective observational cohort study

Maintaining safe elective surgical activity during the global coronavirus disease 2019 (COVID-19) pandemic is challenging and it is not clear how COVID-19 may impact peri-operative morbidity and mortality in this population. Therefore, adaptations to normal care pathways are required. Here, we establish if implementation of a bespoke peri-operative care bundle for urgent elective surgery during a pandemic surge period can deliver a low COVID-19-associated complication profile. We present a single-centre retrospective cohort study from a tertiary care hospital of patients planned for urgent elective surgery during the initial COVID-19 surge in the UK between 29 March and 12 June 2020. Patients asymptomatic for COVID-19 were screened by oronasal swab and chest imaging (chest X-ray or computed tomography if aged ≥ 18 years), proceeding to surgery if negative. COVID-19 positive patients at screening were delayed. Postoperatively, patients transitioning to COVID-19 positive status by reverse transcriptase polymerase chain reaction testing were identified by an in-house tracking system and monitored for complications and death within 30 days of surgery. Out of 557 patients referred for surgery (230 (41.3%) women; median (IQR [range]) age 61 (48-72 [1-89])), 535 patients (96%) had COVID-19 screening, of which 13 were positive (2.4%, 95%CI 1.4-4.1%). Out of 512 patients subsequently undergoing surgery, 7 (1.4%) developed COVID-19 positive status (1.4%, 95%CI 0.7-2.8%) with one COVID-19-related death (0.2%, 95%CI 0.0-1.1%) within 30 days. Out of these seven patients, four developed pneumonia, of which two required invasive ventilation including one patient with acute respiratory distress syndrome. Low rates of COVID-19 infection and mortality in the elective surgical population can be achieved within a targeted care bundle. This should provide reassurance that elective surgery can continue, where possible, despite high community rates of COVID-19.

The gas-phase formation of tin dioxide nanoparticles in single droplet combustion and flame spray pyrolysis

Tin dioxide (SnO₂) nanoparticles synthesized via flame spray pyrolysis (FSP) have promising applications for gas sensors. The formation of SnO₂ nanoparticles in the gas-phase has been investigated using single droplet combustion and FSP. Precursor solutions of Tin (II) 2-ethylhexanoate dissolved in Xylene with varying Sn concentrations were selected as the precursor-solvent system. The selected precursor-solvent system has its stability and ability to synthesize homogeneous nanoparticles, compared to metal nitrate based precursor solutions. The precursor-solvent system was studied using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and thermogravimetric analysis (TGA). The SnO₂ nanoparticles were characterized using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and transmission electron microscopy (TEM). Droplet surface micro-explosions were observed during the single droplet combustion of the precursor solutions. It is because of the heterogeneous vapor-phase nucleation, which is beneath the liquid droplet surface and caused by precursor thermal decomposition. The results show that the size of nanoparticles obtained both from FSP and single droplet combustion increases with increasing metal-precursor concentration. The TEM images of the particles from such droplet combustion reveal two types of nanoparticles with different sizes and morphologies. The current work provides fundamental understanding of precursor decomposition and particle formation during single droplet combustion, which help in-depth understanding of the flame spray pyrolysis.

Redox Activity and Nano-Bio Interactions Determine the Skin Injury Potential of Co3O4-Based Metal Oxide Nanoparticles toward Zebrafish

Redox-active metal oxide nanoparticles show varying oxidizing capacities and injury potentials toward biological systems. Here, two metal oxide libraries including transition-metal-doped Co₃O₄ and PdO-Co₃O₄ with strong chemical contacts were design-synthesized and used to investigate their biological injury potential and mechanisms using zebrafish as a model organism. Among different dopants, Cu significantly increased the oxidizing capacity of Co₃O₄. An increased amount of PdO resulted in higher density of heterojunctions, which also led to higher oxidizing capacity. The oxidizing capacity of these nanoparticles was positively correlated with higher mortality of dechorionated embryos and severe larval skin injury upon exposure. Using transgenic zebrafish Tg(LysC:eGFP), we show in real time that the redox-active nanoparticles induced skin injury and activated the infiltration of immune cells. Such inflammatory response was confirmed by the increased mRNA expression level of Nrf2a, HO-1, IL-1β, and IL-6 genes. Although the exposure to the nanoparticles alone was not lethal, the skin injury did lower the tolerance level against other environmental contaminants. More importantly, after withdrawing from the nanoparticle exposure, larvae with skin injury could recover within 24 h in uncontaminated medium, indicating such injury was transient and recoverable.

Iron-Doping of Copper Oxide Nanoparticles Lowers Their Toxic Potential on C6 Glioma Cells

Copper oxide nanoparticles (CuO-NPs) are well known for their cytotoxicity which in part has been attributed to the release of copper ions from CuO-NPs. As iron-doping has been reported to reduce the susceptibility of CuO-NPs to dissolution, we have compared pure CuO-NPs and CuO-NPs that had been doped with 10% iron (CuO-Fe-NPs) for copper release and for their toxic potential on C6 glioma cells. Physicochemical characterization revealed that dimercaptosuccinate (DMSA)-coated CuO-NPs and CuO-Fe-NPs did not differ in their size or zeta potential. However, the redox activity and liberation of copper ions from CuO-Fe-NPs was substantially slower compared to that from CuO-NPs, as demonstrated by cyclic voltammetry and by the photometric quantification of the copper ion-bathocuproine complex, respectively. Exposure of C6 cells to these NPs caused an almost identical cellular copper accumulation and each of the two types of NPs induced ROS production and cell toxicity. However, the time- and concentration-dependent loss in cell viability was more severe for cells that had been treated with CuO-NPs compared to cells exposed to CuO-Fe-NPs. Copper accumulation and toxicity after exposure to either CuO-NPs or CuO-Fe-NPs was prevented in the presence of copper chelators, while neutralization of the lysosomal pH by bafilomycin A1 prevented toxicity without affecting cellular copper accumulation or ROS production. These data demonstrate that iron-doping does not affect cellular accumulation of CuO-NPs and suggests that the intracellular liberation of copper ions from CuO-NPs is slowed by the iron doping, which in turn lowers the cell toxic potential of iron-doped CuO-NPs.

Model-Based Nanoengineered Pharmacokinetics of Iron-Doped Copper Oxide for Nanomedical Applications

The progress in nanomedicine (NM) using nanoparticles (NPs) is mainly based on drug carriers for the delivery of classical chemotherapeutics. As low NM delivery rates limit therapeutic efficacy, an entirely different approach was investigated. A homologous series of engineered CuO NPs was designed for dual purposes (carrier and drug) with a direct chemical composition-biological functionality relationship. Model-based dissolution kinetics of CuO NPs in the cellular interior at post-exposure conditions were controlled through Fe-doping for intra/extra cellular Cu2+ and biological outcome. Through controlled ion release and reactions taking place in the cellular interior, tumors could be treated selectively, in vitro and in vivo. Locally administered NPs enabled tumor cells apoptosis and stimulated systemic anti-cancer immune responses. We clearly show therapeutic effects without tumor cells relapse post-treatment with 6 % Fe-doped CuO NPs combined with myeloid-derived suppressor cell silencing.

Pattern of Cephalic Index among Medical Students of a Medical College of Eastern Nepal

Background Cephalic index (CI) is one of the important anthropometric parameters to determine racial variation.  Studies done in Nepal has made a comparison of cephalic index for castes (Tharu, Brahmin, Chhetri, Newar), races (Mongoloids and Aryans) but lacks sex variation. The objective of this study was to find the difference in the cephalic index between two genders and to find the sequence of most predominant to least common head type in different genders among the Medical Students of Birat Medical College & Teaching Hospital (BMCTH). Methods A cross-sectional study conducted in the department of Anatomy of BMCTH from 1 July 2019 to 1 September 2019 comprising of 256 medical students (133 male and 123 female) aged between 18 to 24 years. Head length, head breadth and cephalic index were the variables measured using standard devices and techniques. Ethical clearance was taken from the Institutional Review Committee (IRC) of Birat Medical College & Teaching Hospital, Nepal. Results The mean cephalic index in male and female is found to be 81.41 ± 4.52 and 83.62 ± 4.08 respectively. Statistically significant difference found between gender in terms of head length males (18.78±0.69) and females (17.71 ± 0.60); head breadth males (15.28 ±0.62) and females (14.79 ±0.57). The mean cephalic index in males is 81.41 ± 4.52 varying from 69.31 to 94.48. In females, the cephalic index varied from 74.74 to 93.14 and the mean cephalic index is 83.62 ± 4.08. The difference between male and female cephalic index is found to be statistically significant. Majority (43.75%) had Brachycephalic head (CI>79.9) followed by Hyperbrachycephalic (26.95%), Mesocephalic (25.39%), and Dolicocephalic (3.90%). Conclusion Cephalic index is significantly high in female as compared to male whereas head length and breadth are significantly high in males than females. It confirms sexual dimorphism exists. Brachycephalic is the commonest head type.  

Morphometric Evaluation of Dry Humerus Bone in a Medical College of Eastern Nepal

Introduction: Anthropometric measurement of dry bones are helpful to estimate the stature. It is useful for differentiating unidentified bodies, skeletal remains, surgical procedures and are helpful for anthropologists, anatomists, forensic and surgery. Objective: The objective of this study was to find the morphometric measurements of dry Humerus bone available at Birat Medical College and Teaching Hospital of Eastern Nepal. Methodology: A cross- sectional study was conducted from 28th June- 28th July 2019 in the department of Anatomy of Birat Medical College and Teaching Hospital by taking 59 dry humerus bone. Various parameters such as maximum length, circumference of surgical neck, epicondylar breadth together with position and number of nutrient foramina were measured. Data was collected using osteometric board, vernier caliper and tape. The number, direction and location of nutrient foramina were observed macroscopically by using a fine wire. Ethical clearance was taken from Institutional Review Committee of Birat Medical College and Teaching Hospital. Results: Among 59 dry humerus bone, majority (32) were left humerus. No statistical significant difference was found in morphometric measurements between right and left side of dry Humerus bone. The single nutrient foramen was present in 85.18% and 81.25% of right and left humeri respectively. Double nutrient foramina in 14.81% of right humeri and 15.62% of left humeri. Triple nutrient foramina was only seen in left humeri (3.12%). Conclusion: Single nutrient foramen is most common in both sides of humeri. No statistical significant difference was found between right and left humeri in the different parameters such as maximum humeral length (MHL), vertical diameter of superior articular surface (VDSAS), circumference of surgical neck (CSN), circumferences of middle shaft (CMS), epicondylar breath (EB), medial epicondyle to capitulum (ME - C), transverse diameter inferior articular surface (TDIAS), maximum transverse diameter of trochlea (MTDT), anteroposterior diameter of the trochlea (APDT) and position of nutrient foramina (PNF).  

Unifying double flame spray pyrolysis with lanthanum doping to restrict cobalt–aluminate formation in Co/Al2O3 catalysts for the dry reforming of methane

Atomic-sized lanthanum doping via double flame spray pyrolysis leads to remarkable dry reforming of methane performance.

The impact of nanoparticle-driven lysosomal alkalinization on cellular functionality

BACKGROUND

The biomedical use of nanosized materials is rapidly gaining interest, which drives the quest to elucidate the behavior of nanoparticles (NPs) in a biological environment. Apart from causing direct cell death, NPs can affect cellular wellbeing through a wide range of more subtle processes that are often overlooked. Here, we aimed to study the effect of two biomedically interesting NP types on cellular wellbeing.

RESULTS

In the present work, gold and SiO₂ NPs of similar size and surface charge are used and their interactions with cultured cells is studied. Initial screening shows that at subcytotoxic conditions gold NPs induces cytoskeletal aberrations while SiO₂ NPs do not. However, these transformations are only transient. In-depth investigation reveals that Au NPs reduce lysosomal activity by alkalinization of the lysosomal lumen. This leads to an accumulation of autophagosomes, resulting in a reduced cellular degradative capacity and less efficient clearance of damaged mitochondria. The autophagosome accumulation induces Rac and Cdc42 activity, and at a later stage activates RhoA. These transient cellular changes also affect cell functionality, where Au NP-labelled cells display significantly impeded cell migration and invasion.

CONCLUSIONS

These data highlight the importance of in-depth understanding of bio-nano interactions to elucidate how one biological parameter (impact on cellular degradation) can induce a cascade of different effects that may have significant implications on the further use of labeled cells.

Electrochemical Behavior of Single CuO Nanoparticles: Implications for the Assessment of their Environmental Fate

The electrochemical behavior of copper oxide nanoparticles is investigated at both the single particle and at the ensemble level in neutral aqueous solutions through the electrode-particle collision method and cyclic voltammetry, respectively. The influence of Cl^- and NO₃^- anions on the electrochemical processes occurring at the nanoparticles is further evaluated. The electroactivity of CuO nanoparticles is found to differ between the two types of experiments. At the single-particle scale, the reduction of the CuO nanoparticles proceeds to a higher extent in the presence of chloride ion than of nitrate ion containing solutions. However, at the multiparticle scale the CuO reduction proceeds to the same extent regardless of the type of anions present in solution. The implications for assessing realistically the environmental fate and therefore the toxicity of metal-based nanoparticles in general, and copper-based nanoparticles in particular, are discussed.

Influence of nanoparticle doping on the colloidal stability and toxicity of copper oxide nanoparticles in synthetic and natural waters

Engineered nanoparticles (NPs) are often doped with other elements to improve their functionality and, at times, physical and/or chemical stability. However, the effect of doping on the environmental implications of NPs is not well-understood. We investigated the colloidal stability and effects of CuO NPs doped with Fe (0-10%). Colloidal stability of the Fe-doped CuO NPs in aqueous media, as determined by critical coagulation concentrations of NaCl, decreased with increased Fe-doping. However, decrease in the overall particle density led to slower sedimentation of Fe-doped CuO NPs than would have been predicted from their aggregation behavior. Fe-doping significantly affected CuO dissolution (p < .001), promoting Cu leaching out from the doped NPs due to increased reactivity at neutral pH and increased surface area with Fe-doping. Fe-doping did not increase the toxicity of CuO to a marine phytoplankton, Isochrysis galbana, despite promoting ionic Cu release. Total suspended Cu was dominated by dissolved Cu complexes in seawater and particulate Cu in freshwater. Based on the abundance of different size fractions analyzed in freshwater, the particles detected in water suspension were mostly (≥50%) larger than 200 nm in diameter. However, these large-sized particles are mainly composed of aggregated nanosized particles held together by van der Waals attraction.

Nanoparticle-induced inflammation can increase tumor malignancy

Nanomaterials, such as aluminum oxide, have been regarded with high biomedical promise as potential immune adjuvants in favor of their bulk counterparts. For pathophysiological conditions where elevated immune activity already occurs, the contribution of nanoparticle-activated immune reactions remains unclear. Here, we investigated the effect of spherical and wire-shaped aluminum oxide nanoparticles on primary splenocytes and observed a clear pro-inflammatory effect of both nanoparticles, mainly for the high aspect ratio nanowires. The nanoparticles resulted in a clear activation of NLRP3 inflammasome, and also secreted transforming growth factor β. When cancer cells were exposed to these cytokines, this resulted in an increased level of epithelial-to-mesenchymal-transition, a hallmark for cancer metastasis, which did not occur when the cancer cells were directly exposed to the nanoparticles themselves. Using a syngeneic tumor model, the level of inflammation and degree of lung metastasis were significantly increased when the animals were exposed to the nanoparticles, particularly for the nanowires. This effect could be abrogated by treating the animals with inflammatory inhibitors. Collectively, these data indicate that the interaction of nanoparticles with immune cells can have secondary effects that may aggravate pathophysiological conditions, such as cancer malignancy, and conditions must be carefully selected to finely tune the induced aspecific inflammation into cancer-specific antitumor immunity.

STATEMENT OF SIGNIFICANCE

Many different types of nanoparticles have been shown to possess immunomodulatory properties, depending on their physicochemical parameters. This can potentially be harnessed as a possible antitumor therapy. However, in the current work we show that inflammation elicited by nanomaterials can have grave effects in pathophysiological conditions, where non-specific inflammation was found to increase cancer cell mobility and tumor malignancy. These data show that immunomodulatory properties of nanomaterials must be carefully controlled to avoid any undesired side-effects.