Hot carrier relaxation dynamics of an aza-covalent organic framework during photoexcitation: An insight from ab initio quantum dynamics.

In order to develop an efficient metal-free solar energy harvester, we herein performed the electronic structure calculation, followed by the hot carrier relaxation dynamics of two dimensional (2D) aza-covalent organic framework by time domain density functional calculations in conjunction with non-adiabatic molecular dynamics (NAMD) simulation. The electronic structure calculation shows that the aza-covalent organic framework (COF) is a direct bandgap semiconductor with acute charge separation and effective optical absorption in the UV-visible region. Our study of non-adiabatic molecular dynamics simulation predicts the sufficiently prolonged electron-hole recombination process (6.8 nanoseconds) and the comparatively faster electron (22.48 ps) and hole relaxation (0.51 ps) dynamics in this two-dimensional aza-COF. According to our theoretical analysis, strong electron-phonon coupling is responsible for the rapid charge relaxation, whereas the electron-hole recombination process is slowed down by relatively weak electron-phonon coupling, relatively lower non-adiabatic coupling, and quick decoherence time. We do hope that our results of NAMD simulation on exciton relaxation dynamics will be helpful for designing photovoltaic devices based on this two dimensional aza-COF.

Management and outcome of unusual pediatric brain tumors: challenges experienced at a tertiary care center of a developing country.

PURPOSE: Primary brain tumors are the most frequent solid pediatric tumors, accounting for 40-50% of all cancers in children. Eighty to ninety percent of the 250,000 new cases of pediatric cancer each year are discovered in low and middle-income nations, where nearly 88 percent of the world's children reside. This article aims to emphasize the unusual presentation, management, and surgical outcome of complex pediatric brain tumors. METHODS: We performed a retrospective study of patients who were admitted to the neurosurgery department with unusual pediatric brain tumors between March 1, 2019, and March 1, 2022. The study included pediatric patients up to age 18 years. We included those pediatric brain tumors whose (i) location was uncommon, or (ii) presented with unusual clinical presentation, or (iii) histopathology suggested to be a rare tumor, or (iv) radiological features were atypical. RESULTS: We included 9 cases of rare unusual pediatric brain tumors. Three out of 9 cases required preoperative embolization due to its hypervascular nature on digital subtraction angiography (DSA). All patients underwent surgical excision within 24-48 h of tumor devascularization. One out of 9 cases died in follow-up period due to pleural effusion and distant metastasis to lungs. CONCLUSION: Treatment considerations for unusual pediatric brain tumors include a comprehensive multidisciplinary approach, including community-based screening and proper referral system for early treatment, a variety of treatment modalities, and sophisticated follow-up strategy. Government shall work in coherence with tertiary centers to spread social awareness and provide various financial scheme to prevent treatment dropouts.

Ultrasound-guided aspiration of an orbital abscess.

A 10-year-old boy presented with severe proptosis due to a retrobulbar abscess. Ultrasound-guided needle aspiration was performed under intravenous sedation with complete abscess core decompression and resolution of proptosis.

High-definition two-dimension video telescope operating monitor-assisted brain and spinal surgery in pediatrics: is it an acceptable substitute for microscopic surgery?

PURPOSE: Vision and ergonomics are crucial variables for successful outcomes during neurosurgery procedures. Two-dimension video telescope operating monitor (VITOM) exoscope has emerged as an alternative, which is cheaper than microscope. The aim of this study is to evaluate the clinical utility of 2D VITOM and to compare its merits and demerits with respect to microscope. METHODS: VITOM 2D (Karl Storz, Germany) was used in 9 cranial and 5 spinal pediatric cases. While KINEVO operative microscope (Carl Zeiss, Germany) was used in 12 cranial and 6 spinal pediatric patients. All surgeries were performed by single senior neurosurgeon. The author's experience and opinions, as well as qualitative data, were analyzed. A comparison was made on image quality, illumination, field of view, and magnification of the operative field and ergonomics. RESULTS: Seven out of 9 cranial pediatric cases were switched from VITOM 2D to operative microscope due to low-image definition in depth of cranial cavity. Poor visualization of bleeding source in surgical field was another major drawback. Two cranial cases in which exoscope were used exclusively, included superficial tumors. In all 5 spinal cases, VITOM 2D was successfully used without any major difficulty. The exoscope's advantages were observed in ergonomics and ease in switching to naked eyes, but the microscope's field of view, illumination, magnification, and user-friendliness was considered superior. CONCLUSION: 2D-VITOM is best suited for spinal and superficial cranial tumors. However, a lot of modifications are to be done especially in optics to become a substitute for operative microscope.

Microbial pigments: Learning from Himalayan perspective to industrial applications.

Pigments are an essential part of life on earth, ranging from microbes to plants and humans. The physiological and environmental cues induce microbes to produce a broad spectrum of pigments, giving them adaptation and survival advantages. Microbial pigments are of great interest due to their natural origin, diverse biological activities, and wide applications in the food, pharmaceutical, cosmetics, and textile industries. Despite noticeable research on pigment-producing microbes, commercial successes are scarce, primarily from higher, remote, and inaccessible Himalayan niches. Therefore, substantial bioprospection integrated with advanced biotechnological strategies is required to commercialize microbial pigments successfully. The current review elaborates on pigment-producing microbes from a Himalayan perspective, offering tremendous opportunities for industrial applications. Additionally, it illustrates the ecological significance of microbial pigments and emphasizes the current status and prospects of microbial pigments production above the test tube scale.

Polyphenolic Profiling, Antioxidant, and Antimicrobial Activities Revealed the Quality and Adaptive Behavior of Viola Species, a Dietary Spice in the Himalayas.

BACKGROUND: Himalayan Viola species (Banksha) are traditionally important herbs with versatile therapeutic benefits such as antitussive, analgesic, antipyretic, antimalarial, anti-inflammatory, and anticancerous ones. The current investigation was focused on exploring polyphenolic profiles, antioxidant, and antimicrobial potentials of wild viola species at 15 gradient locations (375-1829 m). METHODS: Morphological, physiochemical, and proximate analyses were carried out as per WHO guidelines for plant drug standardization. Total polyphenolic and flavonoid content were carried out using gallic acid and rutin equivalent. UPLC-DAD was used to profile the targeted polyphenols (gallic acid, vanillic acid, syringic acid, p-coumaric acid, ferulic acid, rutin, quercetin, luteolin, caffeic acid, and epicatechin). Similarly, all samples were screened for antioxidant and antimicrobial activity. Statistical analysis was used to correlate polyphenolic and targeted activities to assess Viola species adaptation behavior patterns. RESULTS: Viola canescens (V. canescens) and Viola pilosa (V. pilosa) were found abundantly at their respective sites. Among flowers and leaves, flowers of V. canescens and V. pilosa showed higher total polyphenolic and flavonoid content (51.4 ± 1.13 mg GAE/g and 65.05 ± 0.85 mg RE/g, and 33.26 ± 0.62 mg GAE/g and 36.10 ± 1.41 mg RE/g, respectively). Furthermore, UPLC-DAD showed the uppermost content of p-coumaric acid in flowers and ferulic acid in leaves, while rutin was significant in both the tissues. CONCLUSIONS: The adaptive behavior of Viola species showed variability in morphological characters with the altitudes, while targeted polyphenols and activities were significant at mid-altitudes. This research helps in the selection of right chemotype for agrotechnological interventions and the development of nutraceutical products.

Metagenomic insights into Himalayan glacial and kettle lake sediments revealed microbial community structure, function, and stress adaptation strategies.

Glacial and kettle lakes in the high-altitude Himalayas are unique habitats with significant scope for microbial ecology. The present study provides insights into bacterial community structure and function of the sediments of two high-altitude lakes using 16S amplicon and whole-genome shotgun (WGS) metagenomics. Microbial communities in the sediments of Parvati kund (glacial lake) and Bhoot ground (kettle lake) majorly consist of bacteria and a small fraction of archaea and eukaryota. The bacterial population has an abundance of phyla Proteobacteria, Bacteroidetes, Acidobacteria, Actinobacteria, Firmicutes, and Verrucomicrobia. Despite the common phyla, the sediments from each lake have a distinct distribution of bacterial and archaeal taxa. The analysis of the WGS metagenomes at the functional level provides a broad picture of microbial community metabolism of key elements and suggested chemotrophs as the major primary producers. In addition, the findings also revealed that polyhydroxyalkanoates (PHA) are a crucial stress adaptation molecule. The abundance of PHA metabolism in Alpha- and Betaproteobacteria and less representation in other bacterial and archaeal classes in both metagenomes was disclosed. The metagenomic insights provided an incisive view of the microbiome from Himalayan lake's sediments. It has also opened the scope for further bioprospection from virgin Himalayan niches.

Assessing the potential of low-carbon technologies in the German energy system.

With the introduction of its energy concept in 2010, the German government set ambitious targets for the country's energy and climate policy. According to this concept, greenhouse gas (GHG) emissions will have to be reduced by 80% by 2050, as compared to 1990 levels, and renewables will have to supply 80% of all electricity needs by the same year. Additionally, Germany has decided to phase out its nuclear energy by 2022. This study investigates the possible components to achieve these targets. The analysis is based on an hourly simulation model EnergyPlan. Three scenarios are developed to investigate the potential development of the German energy supply system until 2050. The results indicate renewable shares of 92% and 81% for scenarios B and A, respectively, by 2050 compared to 69% in the reference scenario. The proposed renewable energy system is even found to involve lower costs than today's energy system (i.e. total annual cost for scenario B is € 260 bn compared to € 293 bn in the reference scenario). The results show that a massive decarbonization of the German energy system until 2050 seems technically and economically feasible, if smart grid costs are disregarded and if this sustainable energy transformation is accompanied by political and genuine public willingness to actually achieve the set goals and take the necessary steps.

Acute Necrotizing Encephalitis as a Probable Association of COVID-19.

BACKGROUND: Meanwhile, over 50 lakh people have now been affected by coronavirus disease-2019 (COVID-19) across the globe. There are various reports on neurological manifestations of COVID-19, which have attracted broad attention. Acute necrotizing encephalopathy (ANE) is a rare complication of influenza and other viral infections and has been related to intracranial cytokine storm, which results in breach in blood-brain barrier leading to encephalitis like presentation. We report an unusual case of acute necrotizing encephalitis as a solitary presentation of COVID-19. CASE DESCRIPTION: We report a case of 35-year-old man from Bihar, presented to our emergency department in unconscious state, with high-grade fever and vomiting since last 5 days. Previous magnetic resonance imaging (MRI) brain showed a left parasellar-middle cranial fossa mass looks most likely like an invasive meningioma. Urgent noncontrast computed tomography scan (NCCT) brain showed that mass as well as hypodensities in both thalami and left caudate nucleus. As per our institutional protocol, clinical management of raised intracranial pressure was initiated. As there is no current evidence from any randomized control trails (RCTs) to recommend any specific treatment for suspected or confirmed patients with COVID-19 with acute necrotizing encephalitis. CONCLUSION: Our case highlights the importance of identifying encephalitis as a presenting sign of COVID-19 based on NCCT findings with normal cerebrospinal fluid (CSF) and normal chest X-ray (CXR) findings. HOW TO CITE THIS ARTICLE: Kumar N, Kumar S, Kumar A, Pati BK, Kumar A, Singh C, et al. Acute Necrotizing Encephalitis as a Probable Association of COVID-19. Indian J Crit Care Med 2020;24(10):991-994.

Intermittent CT fluoroscopic guided lung biopsy - Retrospective analysis of success rate, radiation exposure, complications and duration of procedure.

OBJECTIVE: Intermittent CT fluoroscopic biopsy is a new technology, but has not been studied widely. This study aims to investigate correlation between the radiation dose and fluoroscopic CT exposure factors to establish the low dose parameters for performing percutaneous lung biopsies, as well as the relationship of the mean diameter and depth of lesions with radiation dose, procedure time, success and complication rates. MATERIALS AND METHODS: This is a retrospective study to analyse lung biopsies performed using intermittent CT fluoroscopic technique with 18 G semi-automated coaxial gun on 256 slice scanner. A total of 50 patients were included in the study. Biopsy was done in three mAs and KVp settings (30 and 70, 10 and 120, 30 and 120, respectively). The statistical data analysis was performed using SPSS Statistics software. RESULTS: Pneumothorax occurred in 22 % of cases. Sampling rate was 98% but histopathological diagnosis was made in 94% cases. Mean procedure time was 30.5±11.1 minutes. Low dose protocol (30 mAs and 70 KVp) had least radiation exposure during biopsy procedure (p < 0.001) with similar success rate, complications and procedure time (p > 0.05) in comparison with high dose protocol (10 and 120, 30 and 120 mAs and KVp, respectively). Mean diameter of lesions didn't correlate with radiation dose, success rate, complications and duration of procedure (p > 0.05) while significant association was found when depth was correlated with radiation exposure during fluoroscopic biopsy, duration of procedure and complication rates (p < 0.05) while no association was found with success rates. CONCLUSION: On third generation dual energy source CT scanner, reducing mAs and KVp to 30 and 70 during fluoroscopy biopsy can produce images whose complications and success rates are comparable to high dose CT. In general, intermittent CT fluoroscopy guided lung biopsy has good success rates with acceptable complications, while utilising less radiation dose and procedure time.

Ultrasound-guided polidocanol foam sclerotherapy for treating venous malformations.

AIM: To evaluate clinical and imaging outcomes after ultrasound (US)-guided 3% polidocanol (POL) foam-sclerotherapy of venous malformations (VMs). METHODS: We retrospectively evaluated consecutive VM cases over 1.5 years, with 6-month follow-up. US findings were used to classify VMs into four types depending upon extent of anechoic channels, connections to adjacent veins, and dysmorphism. Single or multiple needles were inserted depending upon lesion size, and used to inject up to 8 mL POL per session, every 2 to 4 weeks. We evaluated reduction in pain and swelling, lesion resolution on imaging, and patient satisfaction. RESULTS: There were 15, 24, 9, and 5 patients (total 53) with type I, II, III, and IV VMs, respectively. The average number of sessions was 5.3, 4.3, and 4, and the average amount of POL injected was 14.24 mL, 16.1 mL, and 23.2 mL for type I, II, III VMs, respectively. The number of sessions correlated with lesion volume (P < .0001). Imaging showed good resolution in 4/15, 18/24, 6/9, and 4/5 patients respectively with type I, II, III, and IV VMs. Patient satisfaction was not related to lesion type (P = .1). ROC analyses showed cut-off values of 4.9 mL lesion volume, three sessions, and 12 mL POL volume for patient satisfaction. At 6 months, 23 patients having pain had significant improvement (P < .00001). Local (n = 30) and chest pain (n = 2) were the only complications. CONCLUSIONS: US-guided sclerotherapy with 3% POL foam is safe and effective. Lesions with up to 50% anechoic areas had better resolution, without correlation with patient satisfaction.

Antifungal attributes of siderophore produced by the Pseudomonas aeruginosa JAS-25.

Siderophores produced by Pseudomonas sp. play a vital role in controlling several plant diseases. Public concern about chemical pesticides has fostered an interest to seek alternative control strategies. Production of siderophore by Pseudomonas aeruginosa JAS-25 in King B medium was estimated at 400 nm and was partially purified by gel filtration chromatography using Sephadex G 25. Antifungal activity and inhibition of spore germination was studied against the phytopathogens like Fusarium oxysporum f. sp. ciceri, Fusarium udum, and Aspergillus niger by well plate assay and microphotographic method. Zone of inhibition of 3.0 cm was observed for F. udum and A. niger, proving it as potential biocontrol agent against phytopathogens. Partial 16S rRNA sequence analysis showed that the isolate JAS-25 exhibited 99% homology with P. aeruginosa and could be of novel species and the sequence of the strain was deposited in Genbank with the accession number JX104229.

Truncus bicaroticus with aberrant right subclavian artery and origin of right vertebral from right common carotid artery.

We describe a rare constellation of variant anatomy of the aortic arch branches, seen on a magnetic resonance angiographic examination during the course of investigation for recent onset memory loss in a 52-year-old patient. There was a common origin of both the common carotid arteries (CCA), the common trunk being the first major branch of the aortic arch, the right vertebral artery arising from the right CCA and the right subclavian artery arising as the last branch of the arch. In isolation, the three components of this constellation have been reported with different frequencies, but as per the authors' knowledge, this entire constellation has been rarely reported. We review the literature and propose an embryological mechanism for this variant anatomy.

Point defect-mediated hot carrier relaxation dynamics of lead-free FASnI3 perovskites.

In search of a promising optoelectronic performance, we herein investigated the hot carrier relaxation dynamics of a lead-free cubic phased bulk formamidinium tin triiodide (FASnI3) perovskite. To gain detailed theoretical insights, we should estimate the carrier relaxation dynamics of this pristine perovskite. To control the dynamics, point defects like central tin (Sn), iodine(I) anions, and formamidinium (FA) cations were introduced. With the iodine vacancy in the FASnI3 perovskite, the system seems to be unstable at room temperature, whereas the other three types of FASnI3 perovskites (pristine, Sn vacancy, and FA vacancy) are significantly stable at 300 K having semiconducting nature and excellent optical absorption in the UV-visible range. The computed electron-hole recombination time for the pristine system is 3.9 nanoseconds, which is in good agreement with the experimental investigation. The exciton relaxation processes in Sn and FA vacancy perovskites require 2.8 and 4.8 nanoseconds, respectively. These variations in the hot carrier relaxation dynamics processes are caused by the generation of significant changes in non-adiabatic coupling between energy levels, electron-phonon coupling, and quantum decoherence in different point defect analogous systems. The results presented here offer deeper insight into the temperature-dependent carrier relaxation dynamics of FASnI3 perovskites and thus open up opportunities for future exploration of their optoelectronic properties.

Biochemical characterization of glutaminase-free L-asparaginases from Himalayan Pseudomonas and Rahnella spp. for acrylamide mitigation.

L-asparaginase having low glutaminase activity is important in clinical and food applications. Herein, glutaminase-free L-asparaginase (type I) coding genes from Pseudomonas sp. PCH182 (Ps-ASNase I) and Rahnella sp. PCH162 (Rs-ASNase I) was amplified using gene-specific primers, cloned into a pET-47b(+) vector, and plasmids were transformed into Escherichia coli (E. coli). Further, affinity chromatography purified recombinant proteins to homogeneity with monomer sizes of ~37.0 kDa. Purified Ps-ASNase I and Rs-ASNase I were active at wide pHs and temperatures with optimum activity at 50 °C (492 ± 5 U/mg) and 37 °C (308 ± 4 U/mg), respectively. Kinetic constant Km and Vmax for L-asparagine (Asn) were 2.7 ± 0.06 mM and 526.31 ± 4.0 U/mg for Ps-ASNase I, and 4.43 ± 1.06 mM and 434.78 ± 4.0 U/mg for Rs-ASNase I. Circular dichroism study revealed 29.3 % and 24.12 % α-helix structures in Ps-ASNase I and Rs-ASNase I, respectively. Upon their evaluation to mitigate acrylamide formation, 43 % and 34 % acrylamide (AA) reduction were achieved after pre-treatment of raw potato slices, consistent with 65 % and 59 % Asn reduction for Ps-ASNase I and Rs-ASNase I, respectively. Current findings suggested the potential of less explored intracellular L-asparaginase in AA mitigation for food safety.

Image-Guided Percutaneous Sclerotherapy for Orbital Low-Flow Malformation: Our Experience.

For a safe sclerotherapy session to be completed in the orbital low-flow malformation (namely lymphovenous malformation or venolymphatic malformation), accurate identification of the target lesion for the drug injection is crucial. Regarding the dependability and viability of the injection approach, the authors have discussed their experiences with image-guided percutaneous sclerotherapy on a few patients.

Lysine and citric acid based pegylated polymeric dendritic nano drug delivery carrier and their bioactivity evaluation.

The main objective of this work is to synthesize multifunctional nanodendritic structural molecules that can effectively encapsulate hydrophilic as well as hydrophobic therapeutic agents. Four different types of fourth-generation lysine-citric acid based dendrimer have been synthesized in this work: PE-MC-Lys-CA-PEG, TMP-MC-Lys-CA-PEG, PE-MS-Lys-CA-PEG, and TMP-MS-Lys-CA-PEG. The antibacterial drug cefotaxime (CFTX) was further conjugated to these dendrimers. The dendrimer and drug-dendrimer conjugate structures were characterized with the help of FTIR,1H-NMR, and 13C-NMR spectroscopy. Zeta sizer, AFM, and HR-TEM techniques were used to investigate the particle size, surface topography, and structural characteristics of drug-dendrimer conjugates. In vitro drug release was then investigated using dialysis method. Various kinetic drug release models were examined to evaluate the type of kinetic drug release mechanism of the formulations. Cytotoxicity study revealed that the dendrimers encapsulated with CFTX exhibited 2-3% toxicity against healthy epithelial cells, indicating their safe use. Plain dendrimers show 10-15% hemolytic toxicity against red blood cells (RBC), and the toxicity was reduced to 2-3% when CFTX was conjugated to the same dendrimers. The 3rd and 4th generation synthesized drug-dendrimer conjugates exhibit a significantly effective zone of inhibition (ZOI) against both Gram-positive and Gram-negative bacteria. For Gram-positive bacteria, the lower concentration of 0.1 mg/mL showed more than 98% inhibition of drug-dendrimer conjugate samples against B. subtilis and more than 50% inhibition against S. aureus using 0.2 mg/mL, respectively. Moreover, samples with concentrations of 0.5 and 1.0 mg/mL exhibited more than 50% inhibition against S. typhimurium and E. coli, respectively.

Comprehensive polyphenolic profiling, antioxidant, antimicrobial, and cytotoxicity studies of Rhynchostylis retusa (L.) Blume: a medicinal orchid.

Rhynchostylis retusa (L.) Blume, commonly known as the Foxtail orchid, has garnered worldwide attention for its diverse medicinal properties. In this study, root extract and its fractions were evaluated for total polyphenols, flavonoids, targeted polyphenols, and antioxidant potential. The antimicrobial activity was assessed against Gram-positive and Gram-negative bacterial strains while cytotoxicity was assessed using the A549 and HCT-116 cell lines. The investigations showed that chloroform and ethyl acetate are the most effective solvents for fractionation of polyphenols from the parent extract. These fractions also exhibited strong antioxidant and cytotoxic potentials. The chloroform fraction showed maximum cell death of 87.35 and 92.36% in A549 and HCT- 116 cell lines respectively. All samples showed growth inhibition against bacterial strains except the n-hexane fraction, whereas the n-butanol fraction showed comparable antimicrobial activity with the tetracycline standard. The possible health benefits and thereby, application of R. retusa were thus revealed in this investigation.

Survival benefit of exenteration in COVID-19-associated rhino-orbital mucormycosis.

PURPOSE: There has been a sudden increase in the number of rhino-orbital mucormycosis cases, primarily affecting patients recovering from COVID-19 infection. The local health authorities have declared the current situation an epidemic. In this study, we assess the role of exenteration in preventing disease progression and improving survival in patients with rhino-orbital mucormycosis. METHODS: The patients undergoing exenteration were grouped into the exenteration arm and those denying exenteration were grouped into the nonexenteration arm. The patients were followed at 1 month and 3 months. The 6-month survival data were collected telephonically. Continuous data were presented as Mean ± SD/Median (IQR) depending on the normality distribution of data, whereas the frequency with percentages was used to present the categorical variables. Kaplan-Meier survival curves were created to estimate the difference in survival of patients with exenteration in rhino-orbital mucormycosis versus those without exenteration. RESULTS: A total of 14 patients were recruited for our study based on the inclusion and exclusion criteria. All the patients were qualified for exenteration; however, only eight patients underwent exenteration and six patients did not consent to exenteration. At the end of 3 months in the exenteration group, four (50%) patients died. Two patients died within a week of exenteration, whereas two patients died after 2 weeks of exenteration. The deaths in the first week were attributed to septic shock and the deaths happening beyond 2 weeks were attributed to severe meningitis. The Kaplan-Meier survival analysis showed the cumulative probability of being alive at 1 month in the exenteration arm to be 85%, and it decreased to 67% by 53 days and subsequently remained stable until the end of 3 months. CONCLUSION: The Kaplan-Meier survival analysis did not show a survival benefit of exenteration at 3 months and 6 months in COVID-associated rhino-orbital mucormycosis.