EBSD investigation of microstructure and microtexture evolution on additively manufactured TiC-Fe based cermets-Influence of multiple laser scanning

Sustainable TiC-Fe-based cermets have been fabricated by adopting an Additive Manufacturing route based on laser powder bed fusion technology (L-PBF). The objective is to produce crack-free cermet components by employing novel multiple laser scanning techniques with variations in laser process parameters. Electron backscatter diffraction analysis (EBSD) was used to study the microstructure and microtexture evolution with variations in laser process parameters. The investigation revealed that adjusting the preheating scan speed (PHS) and melting scan speed (MS) influenced the growth and nucleation of TiC phases. Lowering these speeds resulted in grain coarsening, while higher scan speeds led to grain refinement with larger sub-grain boundaries. Moreover, a high scanning speed increases the degree of dislocation density and internal stress in the fabricated cermet parts. Notably, it is revealed that decreasing the laser scan speed enhanced the proportion of high-angle grain boundaries in the cermet components, signifying an increase in material ductility.

Interplay of halogen bonding and solvation in protein-ligand binding

Halogen bonding is increasingly utilized in efforts to achieve high affinity and selectivity of molecules designed to bind proteins, making it paramount to understand the relationship between structure, dynamics, and thermodynamic driving forces. We present a detailed analysis addressing this problem using a series of protein-ligand complexes involving single halogen substitutions - F, Cl, Br, and I - and nearly identical structures. Isothermal titration calorimetry reveals an increasingly favorable binding enthalpy from F to I that correlates with the halogen size and σ-hole electropositive character, but is partially counteracted by unfavorable entropy, which is constant from F to Cl and Br, but worse for I. Consequently, the binding free energy is roughly equal for Cl, Br, and I. QM and solvation-free-energy calculations reflect an intricate balance between halogen bonding, hydrogen bonds, and solvation. These advances have the potential to aid future drug design initiatives involving halogenated compounds.

Magneto-transport in the monolayer MoS2material system for high-performancefield-effect transistor applications

Electronic transport in monolayer MoS2is significantly constrained by several extrinsic factors despite showing good prospects as a transistor channel material. Our paper aims to unveil the underlying mechanisms of the electrical and magneto-transport in monolayer MoS2. In order to quantitatively interpret the magneto-transport behavior of monolayer MoS2on different substrate materials, identify the underlying bottlenecks, and provide guidelines for subsequent improvements, we present a deep analysis of the magneto-transport properties in the diffusive limit. Our calculations are performed on suspended monolayer MoS2and MoS2on different substrate materials taking into account remote impurity and the intrinsic and extrinsic phonon scattering mechanisms. We calculate the crucial transport parameters such as the Hall mobility, the conductivity tensor elements, the Hall factor, and the magnetoresistance over a wide range of temperatures, carrier concentrations, and magnetic fields. The Hall factor being a key quantity for calculating the carrier concentration and drift mobility, we show that for suspended monolayer MoS2at room temperature, the Hall factor value is around 1.43 for magnetic fields ranging from 0.001 to 1 Tesla, which deviates significantly from the usual value of unity. In contrast, the Hall factor for various substrates approaches the ideal value of unity and remains stable in response to the magnetic field and temperature. We also show that the MoS2over an Al2O3substrate is a good choice for the Hall effect detector. Moreover, the magnetoresistance increases with an increase in magnetic field strength for smaller magnetic fields before reaching saturation at higher magnetic fields. The presented theoretical model quantitatively captures the scaling of mobility and various magnetoresistance coefficients with temperature, carrier densities and magnetic fields.

Biofilm Inhibition on Medical Devices and Implants Using Carbon Dots: An Updated Review

Biofilms are an intricate community of microbes that colonize solid surfaces, communicating via a quorum-sensing mechanism. These microbial aggregates secrete exopolysaccharides facilitating adhesion and conferring resistance to drugs and antimicrobial agents. The escalating global concern over biofilm-related infections on medical devices underscores the severe threat to human health. Carbon dots (CDs) have emerged as a promising substrate to combat microbes and disrupt biofilm matrices. Their numerous advantages such as facile surface functionalization and specific antimicrobial properties, position them as innovative anti-biofilm agents. Due to their minuscule size, CDs can penetrate microbial cells, inhibiting growth via cytoplasmic leakage, reactive oxygen species (ROS) generation, and genetic material fragmentation. Research has demonstrated the efficacy of CDs in inhibiting biofilms formed by key pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Consequently, the development of CD-based coatings and hydrogels holds promise for eradicating biofilm formation, thereby enhancing treatment efficacy, reducing clinical expenses, and minimizing the need for implant revision surgeries. This review provides insights into the mechanisms of biofilm formation on implants, surveys major biofilm-forming pathogens and associated infections, and specifically highlights the anti-biofilm properties of CDs emphasizing their potential as coatings on medical implants.

1O2 Mediated Conversion of β-Enaminonitriles to α-Keto Amides Photosensitized by Recyclable H2TPP in Visible Light

We report a one-step approach for the conversion of β-enaminonitriles to synthetically versatile α-keto amides in moderate to high yields under visible light irradiation photosensitized by porphyrins. The method is mild, cost-effective, and sustainable and requires air as the sole reagent/oxidant. The reaction is believed to proceed via an ene-type pathway initiated by 1O2, followed by dehydration, imine hydrolysis, and subsequent nucleophilic substitution of the cyanide group by amine. The method offers a broad substrate scope and has also been extended for synthesis of α-keto esters with aliphatic alcohols as nucleophiles. The porphyrin recovered after the reaction can be reused multiple times.

Thoracoscopic blood patch instillation for persistent air leak in pneumothorax: a case series and systematic review

Persistent air leaks in patients with pneumothorax can lead to significant morbidity. If a patient with persistent air leak is medically unfit for thoracic surgery, medical pleurodesis via chest tube or thoracoscopy is either an option. Thoracoscopy offers the advantage of visualizing the site of the air leak and enabling direct instillation of the pleurodesis agent or glue at that location. Autologous blood patch instillation via chest tube has been reported to be a cheap and very effective technique for the management of persistent air leaks. However, thoracoscopic blood patch instillation has not been reported in the literature. We report two cases of secondary spontaneous pneumothorax in which patients had persistent air leaks for more than seven days and were subjected to thoracoscopy to locate the site of the leak. In the same sitting, 50 mL of autologous blood patch was instilled directly at the leak site. Post-procedure, the air leak subsided in both patients, and the chest tube was removed with complete lung expansion. We also conducted a systematic review of the use of medical thoracoscopic interventions for treating persistent air leaks.

Effect of dry heat and its combination with vacuum heat on physicochemical, rheological and release characteristics of Alocasia macrorrhizos retrograded starches

Retrograded starches have received increasing attention due to their potential excipient properties in pharmaceutical formulations. However, to evade its application-oriented challenges, modification of retrograded starch is required. The study emphasizes influence of dry heating and the dual heat treatment by dry heating amalgamation with the vacuum heat treatment on quality parameters of retrograded starch. The starch was isolated by using two different extraction media (0.05 % w/v NaOH and 0.03 % citric acid) from Alocasia macrorrhizos and then retrograded separately. Further, retrograded starches were first modified by dry heating and afterwards modified with combination of dry and vacuum heating. Modification decreased moisture, ash content and increased solubility. Modified Samples from NaOH media had higher water holding capacity and amylose content. X-ray diffraction revealed type A and B crystals with increasing crystallinity of retrograded heat-modified samples from NaOH media. Thermogravimetric analysis, differential scanning calorimetry confirmed thermal stability. Shear tests showed shear-thinning behavior whereas dominant storage modulus (G/) over loss modulus (G//), depicting gel-like behavior. Storage, loss, and complex viscosity initially increased, then decreased with temperature. In-vitro release reflects, modified retrograded starches offers versatile drug release profiles, from controlled to rapid. Tailoring starch properties enables precise drug delivery, enhancing pharmaceutical formulation flexibility and efficacy.

Author Response

How to cite this article: Ramaswamy A, Kumar R, Ish P, Gupta N. Author Response. Indian J Crit Care Med 2024;28(4):405.

Peptidome Profiling of Bubalus bubalis Urine and Assessment of Its Antimicrobial Activity against Mastitis-Causing Pathogens

Urinary proteins have been studied quite exhaustively in the past, however, the small sized peptides have remained neglected for a long time in dairy cattle. These peptides are the products of systemic protein turnover, which are excreted out of the body and hence can serve as an important biomarker for various pathophysiologies. These peptides in other species of bovine have been reported to possess several bioactive properties. To investigate the urinary peptides in buffalo and simultaneously their bioactivities, we generated a peptidome profile from the urine of Murrah Buffaloes (n = 10). Urine samples were processed using <10 kDa MWCO filter and filtrate obtained was used for peptide extraction using Solid Phase Extraction (SPE). The nLC-MS/MS of the aqueous phase from ten animals resulted in the identification of 8165 peptides originating from 6041 parent proteins. We further analyzed these peptide sequences to identify bioactive peptides and classify them into anti-cancerous, anti-hypertensive, anti-microbial, and anti-inflammatory groups with a special emphasis on antimicrobial properties. With this in mind, we simultaneously conducted experiments to evaluate the antimicrobial properties of urinary aqueous extract on three pathogenic bacterial strains: S. aureus, E. coli, and S. agalactiae. The urinary peptides observed in the study are the result of the activity of possibly 76 proteases. The GO of these proteases showed the significant enrichment of the antibacterial peptide production. The total urinary peptide showed antimicrobial activity against the aforementioned pathogenic bacterial strains with no significant inhibitory effects against a buffalo mammary epithelial cell line. Just like our previous study in cows, the present study suggests the prime role of the antimicrobial peptides in the maintenance of the sterility of the urinary tract in buffalo by virtue of their amino acid composition.

Preliminary Evidence for Global Properties in Human Listeners During Natural Auditory Scene Perception

Theories of auditory and visual scene analysis suggest the perception of scenes relies on the identification and segregation of objects within it, resembling a detail-oriented processing style. However, a more global process may occur while analyzing scenes, which has been evidenced in the visual domain. It is our understanding that a similar line of research has not been explored in the auditory domain; therefore, we evaluated the contributions of high-level global and low-level acoustic information to auditory scene perception. An additional aim was to increase the field's ecological validity by using and making available a new collection of high-quality auditory scenes. Participants rated scenes on 8 global properties (e.g., open vs. enclosed) and an acoustic analysis evaluated which low-level features predicted the ratings. We submitted the acoustic measures and average ratings of the global properties to separate exploratory factor analyses (EFAs). The EFA of the acoustic measures revealed a seven-factor structure explaining 57% of the variance in the data, while the EFA of the global property measures revealed a two-factor structure explaining 64% of the variance in the data. Regression analyses revealed each global property was predicted by at least one acoustic variable (R2 = 0.33-0.87). These findings were extended using deep neural network models where we examined correlations between human ratings of global properties and deep embeddings of two computational models: an object-based model and a scene-based model. The results support that participants' ratings are more strongly explained by a global analysis of the scene setting, though the relationship between scene perception and auditory perception is multifaceted, with differing correlation patterns evident between the two models. Taken together, our results provide evidence for the ability to perceive auditory scenes from a global perspective. Some of the acoustic measures predicted ratings of global scene perception, suggesting representations of auditory objects may be transformed through many stages of processing in the ventral auditory stream, similar to what has been proposed in the ventral visual stream. These findings and the open availability of our scene collection will make future studies on perception, attention, and memory for natural auditory scenes possible.

Fe-based MOFs as promising adsorbents and photocatalysts for re-use water contained arsenic: Strategies and challenges

Arsenic (As) contaminated water, especially groundwater reservoirs, is a major issue worldwide owing to its hazardous consequences on human health and the global environment issues. Also, irrigating agricultural fields with As-contaminated water not only produces an accumulation of As in the soil but also compromises food safety due to As entering into agricultural products. Hence, there is an urgent need to develop an efficient method for As removal in water. Fe-based MOFs have attained special attention due to their low toxicity, high water stability, better physical and chemical properties, and high abundance of iron. The arsenic species removal by Fe-MOF follows the adsorption and oxidation mechanism where As (III) converts into As (V). Moreover, the adsorption mechanism is facilitated by electrostatic interactions, H-bonding, acid-base interaction, hydrophobic interactions, van der Waals forces, π-π stacking interactions, and coordinative bindings responsible for Fe-O-As bond generation. This review thoroughly recapitulates and analyses recent advancements in the facile synthesis and potential application of Fe-based MOF adsorbents for the elimination of As ions. The most commonly employed hydro/solvothermal, ultrasonic, microwave-assisted, mechanochemical, and electrochemical synthesis for Fe-MOF has been discussed along with their adsorptive and oxidative mechanisms involved in arsenic removal. The effects of factors like pH and coexisting ions have also been discussed. Lastly, the article also proposed the prospects for developing the application of Fe-based MOF in treating As-contaminated water.

Comparative life cycle assessment of environmental impacts and economic feasibility of tomato cultivation systems in northern plains of India

To meet the growing demand for vegetable production and promote sustainable agriculture, it is imperative to implement effective input management and adopt eco-friendly farming practices. This study aims to compare the environmental impacts of conventional and organic tomato cultivation in the northern plains of India. This study utilizes SimaPro 9.1.1 software for a comprehensive cradle-to-farm gate Life Cycle Assessment (LCA), assessing production stages, identifying key environmental factors, and incorporating ReCiPe Midpoint and Endpoint methods with one-hectare as a functional unit. Findings reveal that conventional cultivation is more affected by fertilizer application and transplanting, while organic cultivation emphasizes transplanting and irrigation. Organic cultivation contributes 904.708 kg CO2, while conventional cultivation contributes 1307.917 kg CO2 to Global Warming potential. Switching to organic cultivation leads to a significant 35.04% decrease in all impact categories. Using the endpoint method, organic cultivation achieves a notable 27.16% reduction, scoring 58.30 compared to conventional cultivation's 80.04. The LCA analysis of tomato cultivation highlights Fertilizer application as the predominant environmental concern, emphasizing the need for sustainable techniques to minimize waste and mitigate environmental impacts. This study recommends imposing restrictions on fertilizer and pesticide use and formulating effective policies to promote the adoption of sustainable practices.

Cytochrome bd oxidase: an emerging anti-tubercular drug target

Cytochrome bd (cyt-bd) oxidase, one of the two terminal oxidases in the Mycobacterium tuberculosis (Mtb) oxidative phosphorylation pathway, plays an indispensable role in maintaining the functionality of the metabolic pathway under stressful conditions. However, the absence of this oxidase in eukaryotic cells allows researchers to select it as a potential drug target for the synthesis of anti-tubercular (anti-TB) molecules. Cyt-bd inhibitors have often been combined with cytochrome bcc/aa3 super-complex inhibitors in anti-TB drug regimens to achieve a desired bactericidal response. The functional redundancy between both the terminal oxidases is responsible for this. The cryo-EM structure of cyt-bd oxidase from Mtb (PDB ID: 7NKZ) further accelerated the research to identify its inhibitor. Herein, we have summarized the reported anti-TB cyt-bd inhibitors, insight into the rationale behind targeting cyt-bd oxidase, and an outline of the architecture of Mtb cyt-bd oxidase.

Mediastinal Mass, Cancer, or Infection, Atypical Paraesophageal Actinomycosis Infection, Clinical and Surgical Approach

Actinomyces israelii (AI) is a Gram-positive, rod-shaped bacterium that lives commensally on and within humans as a typical colonizer within the gastrointestinal tract, including the mouth. As an opportunistic pathogen, infection often results from tissue injury or breach of the mucosal barrier (ie, during various dental or GI procedures, aspiration, or specific pathologies such as diverticulitis). Symptoms generally present slowly as a non-tender, indurated mass that evolves into multiple abscesses, fistulae, or draining sinus tracts without regard for anatomical barriers, including fascial planes or lymphatic drainage. However, it may also present as an acute suppurative infection with pain and rapid progression to abscess formation.

In Vivo Toxicological Analysis of the ZnFe2O4@poly(tBGE-alt-PA) Nanocomposite: A Study on Fruit Fly

Recently, the use of hybrid nanomaterials (NMs)/nanocomposites has widely increased for the health, energy, and environment sectors due to their improved physicochemical properties and reduced aggregation behavior. However, prior to their use in such sectors, it is mandatory to study their toxicological behavior in detail. In the present study, a ZnFe2O4@poly(tBGE-alt-PA) nanocomposite is tested to study its toxicological effects on a fruit fly model. This nanocomposite was synthesized earlier by our group and physicochemically characterized using different techniques. In this study, various neurological, developmental, genotoxic, and morphological tests were carried out to investigate the toxic effects of nanocomposite on Drosophila melanogaster. As a result, an abnormal crawling speed of third instar larvae and a change in the climbing behavior of treated flies were observed, suggesting a neurological disorder in the fruit flies. DAPI and DCFH-DA dyes analyzed the abnormalities in the larva's gut of fruit flies. Furthermore, the deformities were also seen in the wings and eyes of the treated flies. These obtained results suggested that the ZnFe2O4@poly(tBGE-alt-PA) nanocomposite is toxic to fruit flies. Moreover, this is essential to analyze the toxicity of this hybrid NM again in a rodent model in the future.

A comparative study of indocyanine green instillation in inguinal node versus foot web space using da Vinci indocyanine green FireFly™ technology in identifying thoracic duct during robotic-assisted transthoracic oesophagectomy

INTRODUCTION

Chyle leak is a serious complication following oesophagectomy with incidence varies from 1% to 9%. Near infra-red fluorescence imaging of thoracic duct (TD) can provide real-time dynamic imaging during the surgery. In this study, we intend to compare indocyanine green (ICG) dye instillation through inguinal node with subcutaneous first web space instillation for visualisation of TD during robotic-assisted minimally invasive oesophagectomy (RAMIE) procedure.

PATIENTS AND METHODS

A prospective study of 50 patients underwent RAMIE with da Vinci X System. After general anaesthesia, patients were divided into inguinal node and foot first web space ICG instillation group. The former group had 1 ml of ICG dye instilled on bilateral inguinal nodes under ultrasound guidance and while the other group received 1 mL of ICG dye injected at bilateral foot first web space and then underwent surgery. TD was visualised using ICG FireFly™ fluorescence technology, first at the time of docking and subsequently for every 5 min until 60 min of instillation time and analysed.

RESULTS

Twenty-five patients were enrolled in each group. The mean docking time for thoracic phase was 13.76 ± 3.43 min. TD was visualised in 72% (18/25) of cases of first web space instillation group, whereas 100% in ultrasound guidance inguinal node instillation group. None of the patients had a chyle leak.

CONCLUSION

ICG FireFly™ fluorescence technology for the identification of TD during oesophageal mobilisation is safe and effective and provides real-time dynamic visualisation with high accuracy in ultrasound-guided bilateral inguinal node instillation group. It is an effective method for the surgeons planning to negotiate their initial learning curve in RAMIE procedures.

Emerging Trends in Zinc Ferrite Nanoparticles for Biomedical and Environmental Applications

Over the last few decades, the application of nanoparticles (NPs) gained immense attention towards environmental and biomedical applications. NPs are ultra-small particles having size ranges from 1 to 100 nm. NPs loaded with therapeutic or imaging compounds have proved a versatile approach towards healthcare improvements. Among various inorganic NPs, zinc ferrite (ZnFe2O4) NPs are considered as non-toxic and having an improved drug delivery characteristics . Several studies have reported broader applications of ZnFe2O4 NPs for treating carcinoma and various infectious diseases. Additionally, these NPs are beneficial for reducing organic and inorganic environmental pollutants. This review discusses about various methods to fabricate ZnFe2O4 NPs and their physicochemical properties. Further, their biomedical and environmental applications have also been explored comprehensively.

Nodular type but not vitamin D levels increases the risk of second primary cancers in melanoma patients: An observational study of 663 patients

BACKGROUND

Vitamin D deficiency associates with the risk of developing many diseases, including cancer. At the molecular level, vitamin D appears to have an antineoplastic effect. However, the role of vitamin D deficiency in cancer pathogenesis remains unelucidated and numerous studies have resulted in discordant results. This study aimed to determine whether vitamin D deficiency during melanoma diagnosis increases the risk of developing non-cutaneous second primary cancers (SPC).

MATERIALS AND METHODS

A retrospective study on 663 patients diagnosed with melanoma between 1 January 2011 and 31 October 2022. The effect of each variable on the development of a subsequent non-cutaneous cancer was performed using Kaplan-Meier curves and differences were assessed by log-rank tests. Cox proportional hazard univariate and multivariate models were used to quantify the effect of each variable in the time to develop a non-cutaneous neoplasia.

RESULTS

Out of 663 patients, 34 developed a non-cutaneous SPC. There was no statistically significant association between vitamin D levels and non-cutaneous SPC development (log-rank, p=0.761). Age>60 years, stage III/IV, and nodular melanoma subtype were significantly associated with the development of a SPC. After multivariate analysis, only age>60 years (HR 3.4; HR CI 95%: 1.5-7.6) and nodular melanoma subtype (HR 2.2; HR CI 95%: 1.0-4.8) were included in the final model.

CONCLUSIONS

Our results suggest that vitamin D deficiency is not associated with an increased risk of developing non-cutaneous SPC in melanoma patients. However, age over 60 years and nodular melanoma subtype increase the risk for non-cutaneous SPC development.

Thermoresponsive and Injectable Pluronic F127 Hydrogel for Loading Adipose-Derived Mesenchymal Stem Cells

BACKGROUND

Stem cell-based therapies display immense potential in regenerative medicine, highlighting the crucial significance of devising efficient delivery methods. This study centers on a pioneering approach that utilizes Pluronic F127 (PF127) as a thermoresponsive and injectable hydrogel designed for the encapsulation of adipose-derived mesenchymal stem cells (AdMSCs).

METHODS

The degradation profile, gelation time, and microstructure of the PF127 hydrogel were thoroughly examined. AdMSCs were isolated, expanded, and characterized based on their multi-lineage differentiation potential. AdMSCs from the third passage were specifically employed for encapsulation within the PF127 hydrogel. Subsequently, the cytotoxicity of the AdMSC-loaded PF127 hydrogel was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and apoptosis assays.

RESULTS

Characterized by scanning electron microscopy (SEM), the PF127 hydrogel exhibited a porous structure, indicating its suitability for accommodating AdMSCs and facilitating wound healing. The PF127 hydrogel demonstrated reversible phase transitions, rendering it suitable for in vivo applications. Studies on the gelation time of PF127 hydrogel unveiled a concentration-dependent decrease in gelation time, offering adaptability for diverse medical applications. Analysis of the degradation profile showcased a seven-day degradation period, leading to the decision for weekly topical applications. Cytotoxicity assessments confirmed that AdMSCs loaded into the PF127 hydrogel maintained heightened metabolic activity for up to one week, affirming the safety and appropriateness of the PF127 hydrogel for encapsulating cellular therapeutics. Furthermore, cell apoptosis assays consistently indicated low rates of apoptosis, emphasizing the viability and robust health of AdMSCs when delivered within the hydrogel.

CONCLUSIONS

These findings underscore the vast potential of PF127 hydrogel as a versatile and biocompatible delivery system for AdMSCs in the realm of regenerative medicine. Boasting adjustable gelation properties and a remarkable capacity for cell encapsulation, this pioneering delivery system presents a promising path for applications in tissue engineering and wound healing. Ultimately, these advancements propel and elevate the landscape of regenerative medicine.

Nodular Type but Not Vitamin D Levels Increases the Risk of Second Primary Cancers in Melanoma Patients: An Observational Study of 663 Patients

BACKGROUND

Vitamin D deficiency associates with the risk of developing many diseases, including cancer. At the molecular level, vitamin D appears to have an antineoplastic effect. However, the role of vitamin D deficiency in cancer pathogenesis remains unelucidated and numerous studies have resulted in discordant results. This study aimed to determine whether vitamin D deficiency during melanoma diagnosis increases the risk of developing non-cutaneous second primary cancers (SPC).

MATERIALS AND METHODS

A retrospective study on 663 patients diagnosed with melanoma between 1 January 2011 and 31 October 2022. The effect of each variable on the development of a subsequent non-cutaneous cancer was performed using Kaplan-Meier curves and differences were assessed by log-rank tests. Cox proportional hazard univariate and multivariate models were used to quantify the effect of each variable in the time to develop a non-cutaneous neoplasia.

RESULTS

Out of 663 patients, 34 developed a non-cutaneous SPC. There was no statistically significant association between vitamin D levels and non-cutaneous SPC development (log-rank, p=0.761). Age>60 years, stage III/IV, and nodular melanoma subtype were significantly associated with the development of a SPC. After multivariate analysis, only age>60 years (HR 3.4; HR CI 95%: 1.5-7.6) and nodular melanoma subtype (HR 2.2; HR CI 95%: 1.0-4.8) were included in the final model.

CONCLUSIONS

Our results suggest that vitamin D deficiency is not associated with an increased risk of developing non-cutaneous SPC in melanoma patients. However, age over 60 years and nodular melanoma subtype increase the risk for non-cutaneous SPC development.

LSD1 inhibition suppresses ASCL1 and de-represses YAP1 to drive potent activity against neuroendocrine prostate cancer

Lysine-specific demethylase 1 (LSD1 or KDM1A ) has emerged as a critical mediator of tumor progression in metastatic castration-resistant prostate cancer (mCRPC). Among mCRPC subtypes, neuroendocrine prostate cancer (NEPC) is an exceptionally aggressive variant driven by lineage plasticity, an adaptive resistance mechanism to androgen receptor axis-targeted therapies. Our study shows that LSD1 expression is elevated in NEPC and associated with unfavorable clinical outcomes. Using genetic approaches, we validated the on-target effects of LSD1 inhibition across various models. We investigated the therapeutic potential of bomedemstat, an orally bioavailable, irreversible LSD1 inhibitor with low nanomolar potency. Our findings demonstrate potent antitumor activity against CRPC models, including tumor regressions in NEPC patient-derived xenografts. Mechanistically, our study uncovers that LSD1 inhibition suppresses the neuronal transcriptional program by downregulating ASCL1 through disrupting LSD1:INSM1 interactions and de-repressing YAP1 silencing. Our data support the clinical development of LSD1 inhibitors for treating CRPC - especially the aggressive NE phenotype.

Statement of Significance

Neuroendocrine prostate cancer presents a clinical challenge due to the lack of effective treatments. Our research demonstrates that bomedemstat, a potent and selective LSD1 inhibitor, effectively combats neuroendocrine prostate cancer by downregulating the ASCL1- dependent NE transcriptional program and re-expressing YAP1.

Lanthanide Mimicking by Magnesium for Oxazolidinone Synthesis

In the last decade, magnesium complexes have emerged as a viable alternative to transition-metal catalysts for the hydrofunctionalization of unsaturated bonds. However, their potential for advanced catalytic reactions has not been thoroughly investigated. To address this gap, we have developed a novel magnesium amide compound (3) using a PNP framework that is both bulky and flexible. Our research demonstrates that compound 3 can effectively catalyze the synthesis of biologically significant oxazolidinone derivatives. This synthesis involves a tandem reaction of hydroalkoxylation and cyclohydroamination of isocyanate using propargyl alcohol. Furthermore, we conducted comprehensive theoretical calculations to gain insights into the reaction mechanism. It is important to note that these types of transformations have not been reported for magnesium and would significantly enhance the catalytic portfolio of the 7th most abundant element.

Utilising BC observations to estimate CO contributions from fossil fuel and biomass burning in the Central Himalayan region

The Himalayan region is adversely affected by the increasing anthropogenic emissions from the adjacent Indo-Gangetic plain. However, source apportionment studies for the Himalayan region that are crucial for estimating CO concentration, are grossly insufficient, to say the least. It is in this context that our study reported here assumes significance. This study utilizes five years (2014-2018) of ground-based observations of eBC and multiple linear regression framework (MLR) to estimate CO and segregate its fossil fuel and biomass emission fractions at a high-altitude (1958 m) site in the Central Himalayas. The results show that MERRA2 always underestimates the observed CO; MOPITT has a high monthly difference ranging from -32% to +57% while WRF-Chem simulations underestimate CO from February to June and overestimate in other months. In contrast, CO estimated from MLR replicates diurnal and monthly variations and estimates CO with an r2 > 0.8 for 2014-2017. The CO predicted during 2018 closely follows the observed variations, and its mixing ratios lie within ±17% of the observed CO. The results reveal a unimodal diurnal variation of CO, COff (ff: fossil fuel) and CObb (bb: biomass burning) governed by the boundary layer evolution and upslope winds. COff has a higher diurnal amplitude (39.1-67.8 ppb) than CObb (5.7-33.5 ppb). Overall, COff is the major contributor (27%) in CO after its background fraction (58%). CObb fraction reaches a maximum (28%) during spring, a period of increased agricultural and forest fires in Northern India. In comparison, WRF-Chem tracer runs underestimate CObb (-38% to -98%) while they overestimate the anthropogenic CO during monsoon. This study thus attempts to address the lack of continuous CO monitoring and the need to segregate its fossil fuel and biomass sources, specifically over the Central Himalayas, by employing a methodology that utilizes the existing network of eBC observations.

Comparative yield of transbronchial cryo-nodal biopsy, transbronchial intra-nodal forceps biopsy, and transbronchial needle aspiration for mediastinal lesions at a tertiary care center in India (COLD-FORCEPS study)

Endobronchial ultrasound (EBUS) guided mediastinal cryobiopsy, and intranodal forceps biopsy are newer modalities for sampling mediastinal lymph nodes. The data regarding the diagnostic yield of both modalities is scarce. Patients were recruited retrospectively from our existing database. Patients who had undergone both an EBUS guided mediastinal cryobiopsy and an intranodal forceps biopsy were enrolled in the study. The final diagnosis was made with a clinical-pathological-radiological assessment and clinico-radiological follow-up after one month. A total of 34 patients were enrolled in the study who had undergone both EBUS guided mediastinal cryobiopsy and intranodal forceps biopsy and had complete data available, including 1-month follow-up data. The sample adequacy rate of EBUS-transbronchial needle aspiration (EBUS-TBNA), EBUS-TBNA with mediastinal cryobiopsy, and EBUS-TBNA with intranodal forceps biopsy was 94.11%, 97.05%, and 94.11%, respectively (p=0.56). The diagnostic yield achieved in EBUS-TBNA, EBUS-TBNA with mediastinal cryobiopsy, and EBUS-TBNA with intranodal forceps biopsy was 73.52%, 82.35%, and 79.41%, respectively (p=0.38). No major complications were seen in any patient. To conclude, adding EBUS guided mediastinal cryobiopsy and intranodal forceps biopsy to EBUS-TBNA may not be superior to routine EBUS-TBNA.

An advanced deep learning method to detect and classify diabetic retinopathy based on color fundus images

BACKGROUND

In this article, we present a computerized system for the analysis and assessment of diabetic retinopathy (DR) based on retinal fundus photographs. DR is a chronic ophthalmic disease and a major reason for blindness in people with diabetes. Consistent examination and prompt diagnosis are the vital approaches to control DR.

METHODS

With the aim of enhancing the reliability of DR diagnosis, we utilized the deep learning model called You Only Look Once V3 (YOLO V3) to recognize and classify DR from retinal images. The DR was classified into five major stages: normal, mild, moderate, severe, and proliferative. We evaluated the performance of the YOLO V3 algorithm based on color fundus images.

RESULTS

We have achieved high precision and sensitivity on the train and test data for the DR classification and mean average precision (mAP) is calculated on DR lesion detection.

CONCLUSIONS

The results indicate that the suggested model distinguishes all phases of DR and performs better than existing models in terms of accuracy and implementation time.

Strain imaging as an early predictor in acute myocardial infarction - An augmented cross-sectional study

INTRODUCTION

Cardiac fibres are affected invariably in myocardial infarction, with longitudinal strain being the earliest to be detected in the ischaemic cascade. The present study aims to assess strain imaging in acute myocardial infarction (AMI) patients admitted to the cardiology department at our institute and correlate GLS and DESL findings with other markers for myocardial function.

METHODS AND MATERIAL

This augmented cross-sectional study was conducted amongst the patients admitted with diagnosis of AMI. During the study period, 157 subjects were sampled through convenience sampling, and examined as well as tested with routine investigations at baseline. The subjects were then followed through at first, third and six months, and findings noted. Chi-square was used to assess the crude association between sample characteristics. Pearson correlation and student t-test were used to find association between continuous variables.

RESULTS

After screening 564 patients, 157 patients were included in the study after fulfilment of inclusion and exclusion criteria. A significant difference was found in baseline GLS scores and NTproBNP levels at 6 months in alive patients with STEMI, t (21.728) = -5.717, p < .001. Out of the 50 NSTEMI patients, 35 (70 %) were positive for ESL, similarly out of 43 STEMI patients without any RWMA, ESL was positive in 39 (90.02 %) patients.

CONCLUSIONS

GLS by STE has good correlation with LVEF, WMSI and NT pro-BNP and it is an independent predictor of mortality and heart failure among patients with AMI.

Design, Synthesis and Molecular Docking Studies of Pyrazoline Derivatives as PI3K Inhibitors

AIM

Design, synthesis and molecular docking studies of quinoline/naphthalene containing pyrazoline derivatives as PI3K inhibitors.

BACKGROUND

Phosphatidylinositol 3-kinases (PI3Ks) belong to the family of enzymes, which are associated with various cellular functions such as cell growth, proliferation, differentiation etc. Overexpression or any changes in these functions may result in various abnormalities, which in turn cause cancer.

OBJECTIVES

To perform synthesis and molecular docking studies of quinoline/naphthalene containing pyrazoline derivatives as PI3K inhibitors.

METHODS

2-Chloroquinoline-3-carbaldehyde was synthesized by a reaction of acetanilide and POCl3. The latter was reacted with substituted acetophenones to synthesize chalcones, which were reacted with substituted phenyl hydrazines to yield pyrazoline derivatives (Series I). Similarly, pchloro benzaldehyde was reacted with 2-acetonapthone to yield chalcone with substituted phenyl hydrazines to yield pyrazoline derivatives (Series II).

RESULTS

The synthetic compounds were subjected to molecular modelling experiments using Schrodinger 2016 software and evaluated in silico for their PI3K binding affinities. All the compounds had better docking scores than AMG-319 (-4.36 Kcal/mol) and comparable docking scores with PI-103 (-6.83 Kcal/mol).

CONCLUSION

Compounds 5 and 3 had the best docking scores (-7.85 and -7.17 Kcal/mol, respectively). The synthesized compounds have better docking scores than the reference drug AMG-319. As a result, they might be used as lead molecules in investigating PI3K inhibitors.

Patient mortality after total hip arthroplasty revision surgery

Background

Complications following revision total hip arthroplasty can cause significant morbidity and have a high mortality rate. Patient age and American Society of Anaesthesiologists (ASA) physical status classification system score are important determinants of mortality following revision hip arthroplasty. There is a paucity of high-quality evidence assessing the risk of mortality following revision hip arthroplasty stratified by indications of surgery. The aim of this study is to compare survival of patients undergoing revision THA for different indications.

Methods

This retrospective case series reviewed the mortality rate following revision hip surgery performed by a single surgeon between 2009 and 2016 with a minimum 2 year follow up. Kaplan Meir analysis was performed using mortality as the end point. Log rank testing was used to determine if the indication for surgery conferred a difference in survival.

Results

One hundred and ninety-eight consecutive cases were done using a tapered modular uncemented stem in 183 patients and were followed up for a mean period of 51.8 months (range, 24-121). Sixty patients died (67 % survivorship) during the follow up period with a 5-year survival rate of 78 %. Revision surgery performed for aseptic loosening had the best survival and hemiarthroplasty had the worst and differences in survival were statistically significant (P = 0.000002).

Conclusion

The indication for revision surgery is an important criterion which must be given weightage along with age, functional status of patient and ASA physical status score while planning revision surgery and counselling patients.

Synthesis of Pectin and Eggshell Biowaste-Mediated Nano-hydroxyapatite (nHAp), Their Physicochemical Characterizations, and Use as Antibacterial Material

The current study reports the synthesis of sustainable nano-hydroxyapatite (nHAp) using a wet chemical precipitation approach. The materials used in the green synthesis of nHAp were obtained from environmental biowastes such as HAp from eggshells and pectin from banana peels. The physicochemical characterization of obtained nHAp was carried out using different techniques. For instance, X-ray diffractometer (XRD) and FTIR spectroscopy were used to study the crystallinity and synthesis of nHAp respectively. In addition, the morphology and elemental composition of nHAP were studied using FESEM equipped with EDX. HRTEM showed the internal structure of nHAP and calculated its grain size which was 64 nm. Furthermore, the prepared nHAp was explored for its antibacterial and antibiofilm activity which has received less attention previously. The obtained results showed the potential of pectin-bound nHAp as an antibacterial agent for various biomedical and healthcare applications.

Understanding the goethite role on stibnite oxidative dissolution and transformation: Spectroscopic and DFT study

The geochemical cycling of antimony (Sb) in aquatic system is primarily influenced by the dissolution and transformation of stibnite (Sb2S3) in the presence of iron minerals. Here, Sb2S3 oxidative dissolution and sequestration on goethite were investigated to mimic the environmental fate of Sb2S3. The results demonstrated that goethite accelerated the rate of Sb2S3 oxidative dissolution by a factor of 9.4 times under sunlight. The significant Sb2S3 oxidation on goethite was attributed to a heterogeneous electron transfer from Sb2S3 to goethite, as proved by XANES analysis. This electron transfer facilitated the generation of hydroxyl radicals (OH) on Sb2S3, and superoxide radicals (O2-) on goethite. Radical trapping experiments confirmed that O2- was the dominant oxidant for Sb(III) oxidation with 91 % contribution. Thus, goethite plays a dominant role in O2- generation and Sb2S3 oxidative dissolution. Meanwhile, the total dissolved Sb was decreased by 69 % in Sb2S3 and goethite coexisting system compared to a single Sb2S3 system, indicating the retention of dissolved Sb on goethite. Density functional theory (DFT) calculations deciphered that Sb(III) oxidation on mineral-water interfaces with O2- radicals was thermodynamically preferential to OH radicals. Additionally, the Sb was anchored on goethite as a bidentate binuclear structure with a favorable adsorption energy. Our findings shed the light to understand the geochemical cycles of Sb2S3 in natural environment.

Effects of different biofuels and their mixtures with diesel fuel on diesel engine performance and exhausts

In this study, a compression ignition engine that ran on recycled used cooking oil (RUCO), Jatropha curcas (JC), Pongamia Pinnata (PP), and petroleum diesel fuel (PDF) was investigated for its energy, performance, and exhaust emissions. The 20 % by volume RUCO, JC, and PP biofuel mix with PDF is taken. According to the American Society for Testing and Material (ASTM) standard, the blend qualities are evaluated. Viscosity, density, flash point, and heating value have all been tested for the 20 % blend. The outcome indicated that for a 20 % mix, the viscosity, density and flash point were all greater than in the PDF but heat value lower. Because studies have demonstrated that diesel engines can operate on 20 % replacement without any modifications, this study focused on 20 % blend. The engine was tested with loads (Ls) ranging from 0 % to 100 % of its entire capacity while the compression ratios (CRs) was varied. The experimental result demonstrated that the thermal efficiency, as measured by the PDF, was much greater than that of the DRUCO20, DJC20, and DPP20 blends. After the addition of RUCO, JC, and PP to PDF, the temperature of the exhaust gases reduced, and the engine used more gasoline as a result. It was discovered that an engine emissions of hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) were lower than those of PDF. Even though it produced a greater amount of carbon dioxide (CO2) emissions, the DRUCO20 was superior to both the DCJ20 and the DPP20.

Does strengths of a positive direct antiglobulin test predicts the need for phototherapy and duration of phototherapy? - a single center, retrospective study

BACKGROUND

Use of Direct Antiglobulin test (DAT) in management of neonatal hyperbilirubinemia is conflicting.

OBJECTIVE

whether strength of positive DAT predicts the need for phototherapy, duration of phototherapy and need for major interventions.

METHODS

We retrospectively collected data on all DAT positive neonates with birth gestational age ≥32 weeks over six years (2014-2019). Data regarding blood group, DAT and clinical details were obtained from a hospital database. We also collected data on serial hemoglobin and other relevant laboratory parameters. We also collected data on infants receiving major interventions such as exchange transfusion, in-utero transfusion, immunoglobulins, and postnatal transfusion for the duration of the study period. All of these infants were electronically followed up for a period of 6 weeks. This study was approved by institutional audit authority. All the statistics were performed using SPSS software.

RESULTS

Out of 1285 DAT tests performed, only 91 infants were positive (7%), and 78 DAT positive infants were available for analysis. There were 54 infants with DAT (1+), 15 infants with DAT (2+), 7 infants with DAT (3+) and 2 infants with DAT (4+). There was no significant statistical difference in terms of need for phototherapy, duration of phototherapy, need for major interventions and hemoglobin levels at different time points between the groups (DAT 1+ Vs DAT ≥2+; DAT ≤2+ Vs DAT >2). A Total of 10 infants received major intervention, with one infant receiving all three interventions (DAT 3+ with significant maternal antibodies), 2 additional infants (both DAT1+) received exchange transfusion, 6 additional infants received immunoglobulin (2 infants: DAT 2+; 4 infants: DAT 1+) and one additional infant (DAT 1+) with significant maternal antibodies received a postnatal transfusion.

CONCLUSION

Strength of a DAT did not predict the need for phototherapy, duration of phototherapy, and the need for major hemolysis related intervention in the first 6 weeks of life.

Long-Term Cryopreservation of Peripheral Blood Stem Cell Harvest Using Low Concentration (4.35%) Dimethyl Sulfoxide with Methyl Cellulose and Uncontrolled Rate Freezing at -80 °C: An Effective Option in Resource-Limited Settings

Long-term cryopreservation of peripheral blood stem cells (PBSCs) is highly useful in the setting of tandem/multiple transplantations or treatment of relapse in the autologous hematopoietic stem cell transplantation (HSCT) setting. Even in allogeneic HSCT, donor lymphocyte infusions may be stored for months to years if excess stem cells are collected from donors. Cryopreservation is a delicate, complex, and costly procedure, and higher concentrations of dimethyl sulfoxide (DMSO), a commonly used cryoprotectant, can be toxic to cells and cause adverse effects in the recipient during infusions. In this study, we examined the effect of long-term cryopreservation using 4.35% DMSO (as final concentration) with methyl cellulose and uncontrolled rate freezing in a mechanical freezer (-80 °C) on the viability and colony-forming ability of CD34+ human PBSCs. For patients undergoing autologous HSCT, PBSCs were cryopreserved using DMSO (final concentration of 4.35%) with methyl cellulose. The post-thaw viability of PBSCs was determined using Trypan blue exclusion and flow cytometry-based 7-amino-actinomycin-D (FC-7AAD) methods. Concentrations of CD34+ stem cells and immune cell subsets in post-thaw PBSC harvest samples were assessed using multicolor flow cytometry, and the clonogenic potential of post-thaw stem cells was studied using a colony-forming unit (CFU) assay. CD34+ stem cell levels were correlated with the prestorage CD34 levels using the Pearson correlation test. The viability results in the Trypan blue dye exclusion method and the flow cytometry-based method were compared using Bland-Altman plots. We studied 26 PBSC harvest samples with a median cryopreservation duration of 6.6 years (range, 3.8 to 11.5 years). The median viability of post-thaw PBSCs was >80% using both methods, with a weak agreement between them (r = .03; P = .5). The median CD34+ stem cell count in the post-thaw samples was 9.13 × 106/kg (range, .44 to 26.27 × 106/kg). The CFU assay yielded a good proliferation and differentiation potential in post-thaw PBSCs, with a weak correlation between granulocyte macrophage CFU and CD34+ stem cell levels (r = .4; P = .05). Two samples that had been cryopreserved for >8 years showed low viability. Cryopreservation of PBSCs using 4.35% DMSO with methyl cellulose and uncontrolled freezing in a mechanical freezer at -80 °C allows the maintenance of long-term viability of PBSC for up to 8 years.

Genetic architecture of source-sink-regulated senescence in maize

Source and sink interactions play a critical but mechanistically poorly understood role in the regulation of senescence. To disentangle the genetic and molecular mechanisms underlying source-sink-regulated senescence (SSRS), we performed a phenotypic, transcriptomic, and systems genetics analysis of senescence induced by the lack of a strong sink in maize (Zea mays). Comparative analysis of genotypes with contrasting SSRS phenotypes revealed that feedback inhibition of photosynthesis, a surge in reactive oxygen species, and the resulting endoplasmic reticulum (ER) stress were the earliest outcomes of weakened sink demand. Multienvironmental evaluation of a biparental population and a diversity panel identified 12 quantitative trait loci and 24 candidate genes, respectively, underlying SSRS. Combining the natural diversity and coexpression networks analyses identified 7 high-confidence candidate genes involved in proteolysis, photosynthesis, stress response, and protein folding. The role of a cathepsin B like protease 4 (ccp4), a candidate gene supported by systems genetic analysis, was validated by analysis of natural alleles in maize and heterologous analyses in Arabidopsis (Arabidopsis thaliana). Analysis of natural alleles suggested that a 700-bp polymorphic promoter region harboring multiple ABA-responsive elements is responsible for differential transcriptional regulation of ccp4 by ABA and the resulting variation in SSRS phenotype. We propose a model for SSRS wherein feedback inhibition of photosynthesis, ABA signaling, and oxidative stress converge to induce ER stress manifested as programed cell death and senescence. These findings provide a deeper understanding of signals emerging from loss of sink strength and offer opportunities to modify these signals to alter senescence program and enhance crop productivity.

Ligand Sulfur Oxidation State Progressively Alters Galectin-3-Ligand Complex Conformations To Induce Affinity-Influencing Hydrogen Bonds

Galectins play biological roles in immune regulation and tumor progression. Ligands with high affinity for the shallow, hydrophilic galectin-3 ligand binding site rely primarily on a galactose core with appended aryltriazole moieties, making hydrophobic interactions and π-stacking. We designed and synthesized phenyl sulfone, sulfoxide, and sulfide-triazolyl thiogalactoside derivatives to create affinity-enhancing hydrogen bonds, hydrophobic and π-interactions. Crystal structures and thermodynamic analyses revealed that the sulfoxide and sulfone ligands form hydrogen bonds while retaining π-interactions, resulting in improved affinities and unique binding poses. The sulfoxide, bearing one hydrogen bond acceptor, leads to an affinity decrease compared to the sulfide, whereas the corresponding sulfone forms three hydrogen bonds, two directly with Asn and Arg side chains and one water-mediated to an Asp side chain, respectively, which alters the complex structure and increases affinity. These findings highlight that the sulfur oxidation state influences both the interaction thermodynamics and structure.

Catalytic Amination of Alcohols Using Diazo Compounds under Manganese Catalysis Through Hydrogenative N-Alkylation Reaction

Sustainable chemical production requires fundamentally new types of catalysts and catalytic technologies. The development of coherent and robust catalytic systems based on earth-abundant transition metals is essential, but highly challenging. Herein, we systematically explored a general hydrogenative cleavage/N-alkylation tandem of cyclic and acyclic diazo (N=N) compounds to value-added amines under manganese catalysis. The reaction is catalyzed by a single-site molecular manganese complex and proceeds via tandem dehydrogenation, transfer hydrogenation, and borrowing hydrogenation strategies. Interestingly, the reaction involves abundantly available renewable feedstocks, such as alcohols, that can act as (transfer)hydrogenating and alkylating agents. The synthetic application of our approach in large-scale pharmaceutical synthesis and easy access to highly demanding N-CH3 /CD3 derivatives are also demonstrated. Kinetic studies show that the reaction rate depends on the concentration of alcohol and Mn-catalyst and follows fractional orders. Several selective bond activation/formation reactions occur sequentially via amine-amide metal-ligand cooperation.

IMPLICATION OF THREAT FACTORS AND PREEXISTING DISORDERS IN DIFFERENT ISCHEMIC STROKE SUBGROUPS IN ELDERLY PEOPLE: A SYSTEMATIC STUDY

Ischemic stroke is a major health issue, especially for the older population and it may have severe effects. Stroke diagnosis and treatment have advanced over the last 20 years, which has resulted in considerable reductions in death, long-term impairment, and the need for institutional care. Younger age groups have seen the majority of trials for acute, interventional, and preventive therapy. The purpose of this research was to identify distinct subgroups of older people who had suffered an ischemic stroke and examine the role that risk factors and previous illnesses played in their development. Ischemic stroke risk factors varied by age, gender and exhibited their own unique features. Smoking, cholesterol, and psychological/emotional stress were shown to have the greatest prevalence (p<0.06) among stroke patients aged 45-60. Smoking is associated with a significant (p<0.07) decline in health in elderly people. Our results imply that there are significant patterns of risk factors and preexisting illnesses among the various subgroups of older people who have had an ischemic stroke. Atherosclerotic (large-artery) and cardio embolic (small-artery) ischemic strokes were shown to be the most prevalent among the elderly. Strong associations were found between these subtypes and other risk factors, including higher cholesterol, diabetes, high blood pressure, and atrial fibrillation. This research emphasizes the need for individualized preventative methods and therapeutic therapy, as well as the need to recognize the variability of ischemic stroke in the elderly.

In-vivo lymphoscintigraphy of sinonasal tumors identifies retropharyngeal node and level I as predominant sentinel nodes

OBJECTIVE

To evaluate by in- vivo lymphoscintigraphy and SPECT-CT imaging, the lymphatic drainage patterns of para-nasal sinus(PNS) tumors. To confirm or refute the belief of the retropharyngeal lymph node (RPLN) being the significant draining lymph node for such tumors.

METHODS

Prospective cohort study conducted on previously untreated PNS tumors with no clinico-radiological evidence of lymph node metastasis. Lymphoscintigraphy undertaken by nasal endoscopic assisted peritumoral injection of 99mTc Sulfur colloid. Injections were classified as anterior or posterior as per a vertical line along the maxillary sinus ostium.

RESULTS

17 patients were included. Lymphoscintigraphy successfully identified 17 sentinel nodes in 15 patients and was unsuccessful (lymphoscintigraphy failure) in 2 patients. Predominant sites of sentinel lymphatic drainage were noted to be the RPLN (n = 8; 47%), and Level I (n = 7; 42%). Occasional drainage was identified at the peri-parotid node(n = 1) and at Level II (n = 1). Contralateral drainage was noted in 2 patients (level I-1 and RPLN-1). Anterior injections drained predominantly to Level I (6/8) and RPLN (2/8), while posterior injections drained predominantly to the RPLN ( 6/7). The relative risk of RPLN being identified as the sentinel node was significantly higher for posteriorly placed injections than for anteriorly placed injections (RR- 3.43; 95% CI-1.0-11.8, p = 0.05).

CONCLUSION

The RPLN is noted as a frequent draining node for sino-nasal tumours and merits routine attention in all sino-nasal tumors. The radio-colloid SPECT-CT technique described here offers an excellent in-vivo technique to further explore and validate the lymphatic drainage pathways of these tumours.

Giant Cell Tumor: A Case Series of Seven Patients with GCT at Atypical Sites

Introduction

Giant cell tumor (GCT) represents 5% of all primary bone tumors and 20% of biopsy analyzed benign tumors. More than half of these lesions occur in the 3rd and 4th decades of life. There is no absolute treatment method selection. Techniques ranging from intralesional curettage to wide resection can be used. Goal is to eradicate the tumor, preserve limb function, and prevent local recurrence and distant metastasis.

Case Report

We are presenting seven cases of GCT at five different and rare sites involving tibia, calcaneum, metatarsal, proximal humerus, and clavicle with tumor being limited to bone in all seven cases not involving the soft tissue. There were three male patients and four female patients. Six patients underwent intralesional curettage using high-speed burr and curette, along with adjuvant irrigation with hydrogen peroxide and normal saline followed by polymethyl methacrylate reconstruction. One patient with GCT clavicle underwent wide resection.

Results

In all seven cases, we were able to able to remove the tumor completely. Six patients had a gradual and complete recovery with return to near normal activity within 6 month-1 year after surgery. One patient with proximal humerus GCT had a recurrence which got resolved with injection denosumab. All patients have been followed up for a minimum duration of 2 years.

Conclusion

Intervention in the early stages can avoid radical procedures such as wide local excision or amputation. We recommend aggressive surgical approach with close follow-up to detect recurrence if any, at an early stage.

Clinical Relevance of Sternal Foramina: A Morphometric Study

Objectives

The present study aimed at determining the incidence of sternal foramina in adult dry bones of North Indian descent. We also aimed to determine the number, precise location of the sternal foramina with a standard reference point which might have considerable importance with regard to procedures involving sternal puncture.

Methods

This cross sectional descriptive study was conducted on 72 dry adult human sternums. Various measurements in relation to the sternal foramina were taken with a non-stretchable measuring tape and digital vernier calliper and expressed as: [A]-total sternal length, [B]-distance between the jugular notches to the foramen, [C]-distance between the angle of Louis to the foramen and [D]-distance of the foramen from the mid sternal plane. Statistical analysis was performed with Microsoft Excel version 2019. A p-value of <0.05 was considered significant.

Results

We found 6.94% (5 out of 72 sternums) incidence of sternal foramina which corroborates well with the existing literature. Mean sternal length was 127.7 ± 09 mm. The mean distance of the foramina from suprasternal notch, sternal angle and from the median plane were 118.12 ± 0.3 mm, 116.7 mm and 2.4 mm respectively. Incidence of sternal foramina was almost similar to previously reported studies.

Conclusions

The precise knowledge about the expected location of sternal foramina is imperative to avoid intra-thoracic visceral injury during commonly performed acupuncture needle insertion and while doing bone marrow aspiration for diagnostic evaluation.

Collision in double-image encryption scheme based on spatial encoding and phase-truncation Fourier transforms

In this paper, the security strength of a double-image cryptosystem using spatial encoding and phase-truncation Fourier transforms (PTFTs) is evaluated. Unlike the conventional PTFT-based cryptosystem, where two random phase masks (RPMs) are used as public keys to provide enough phase constrains in the estimation, in the improved cryptosystem, the RPM generated by a random amplitude mask (RAM) is treated as an unknown parameter. Due to this fixed RAM, the number of constraints in the estimation decreases to achieve high robustness against potential iterative attacks. Moreover, instead of two phase-only masks (POMs), here the two POMs and the RAM are utilized as the private keys in the improved cryptosystem; thus, the key space of the double-image cryptosystem has been enlarged. However, we noticed that the RAM used to encode plaintexts spatially and to generate the phase encryption key is independent of the plaintexts. This could be recovered by a known pair of plaintexts and the ciphertext. Once the information of the RAM is retrieved, the phase key RPM can also be produced making the cryptosystem vulnerable. Based on this finding, new hybrid algorithms, including a known-plaintext attack and a known key attack are proposed to crack the enhanced PTFT-based cryptosystem. The information of the plaintexts can be retrieved from one POM using the proposed algorithms without any knowledge of another POM and the corresponding ciphertext. Numerical simulations have been carried out to validate the information disclosure problem still exists in the double-image cryptosystem based on spatial encoding and PTFTs.

Visible light induced regioselective C-3 thiocyanation of imidazoheterocycles through naphthalimide dye based photoredox catalysis

A visible light induced C-3 thiocyanation of imidazo[1,2-a]pyridines by using a naphthalimide based photoredox catalyst has been reported. Tolerance of electron withdrawing and donating groups at different positions of the imidazo[1,2-a]pyridine ring led to a wide substrate accessibility of this method. This methodology is further reproducible with other heterocycles like benzo[d]imidazo[2,1-b]thiazoles, indoles, azaindoles, and anilines.

Precise Measurement of the D_{s}^{+} Lifetime at Belle II

We measure the lifetime of the D_{s}^{+} meson using a data sample of 207  fb^{-1} collected by the Belle II experiment running at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The lifetime is determined by fitting the decay-time distribution of a sample of 116×10^{3} D_{s}^{+}→ϕπ^{+} decays. Our result is τ_{D_{s}^{+}}=(499.5±1.7±0.9)  fs, where the first uncertainty is statistical and the second is systematic. This result is significantly more precise than previous measurements.

Comparison of immediate withdrawal and stepwise reduction in duration of non-invasive ventilation in chronic obstructive pulmonary disease patients presenting with acute hypercapnic respiratory failure

There is no universally acceptable protocol for the withdrawal of non-invasive ventilation (NIV) in chronic obstructive pulmonary disease (COPD) patients presenting with acute hypercapnic respiratory failure (AHcRF). This study was carried out to evaluate immediate against stepwise reduction in NIV. Sixty COPD patients with AHcRF who were managed with NIV were randomized into two groups - immediate NIV withdrawal (Group A), and stepwise reduction of NIV duration (Group B). The rate of successful NIV withdrawal, time to recurrence of hypercapnic respiratory failure, total duration of NIV use, and hospital length of stay (LOS), were compared among the 2 groups. NIV was successfully withdrawn in 51/60 (85%) patients. NIV was successfully withdrawn in 24/30 (80%) patients in Group A and 27/30 (90%) patients in Group B (p=0.472). The total duration of NIV use was significantly lower in Group A (38.97±17 hours) as compared to Group B (64.3±7.74 hours) (p<0.0001). The hospital LOS was significantly lower in group A (5.8±1.6 days) as compared to Group B (7.7±0.61 days) (p<0.0001). To conclude, immediate withdrawal of the NIV after recovery of respiratory failure among patients with exacerbation of COPD is feasible and does not increase the risk of weaning failure.

Structure of a ribonucleotide reductase R2 protein radical

Aerobic ribonucleotide reductases (RNRs) initiate synthesis of DNA building blocks by generating a free radical within the R2 subunit; the radical is subsequently shuttled to the catalytic R1 subunit through proton-coupled electron transfer (PCET). We present a high-resolution room temperature structure of the class Ie R2 protein radical captured by x-ray free electron laser serial femtosecond crystallography. The structure reveals conformational reorganization to shield the radical and connect it to the translocation path, with structural changes propagating to the surface where the protein interacts with the catalytic R1 subunit. Restructuring of the hydrogen bond network, including a notably short O-O interaction of 2.41 angstroms, likely tunes and gates the radical during PCET. These structural results help explain radical handling and mobilization in RNR and have general implications for radical transfer in proteins.

The Landscape of Genetic Alterations Associated with Metachronous Metastasis in Patients with Pancreatic Ductal Adenocarcinoma and Its Prognostic Significance

PURPOSE/OBJECTIVE(S)

Metachronous metastasis is one of the major pathologic processes which significantly increases the mortality of patients with pancreatic ductal adenocarcinoma (PDA) who completed initial curative treatment. Genetic signatures that drive the metachronous mutations are not well investigated. In this study, we aimed to identify the landscape of genetic alterations associated with metachronous metastasis in patients with PDA and its prognostic significance.

MATERIALS/METHODS

We retrospectively identified patients with histologically confirmed PDA who underwent next-generation sequencing using a panel of 324 pre-specified genes. The landscape of somatic mutations was stratified by metastasis types [no metastasis (nMet) vs. de novo metastasis (dMet) vs. metachronous metastasis (mMet)]. Outcomes of interest included overall survival (OS), local recurrence (LR) following radiotherapy, and association of CA 19-9 level with metastasis types. The OS was calculated using the Kaplan-Meier estimates and log-rank test, and LR was measured using cumulative incidence. A multivariate cox-regression analysis was performed to identify prognostic factors. Pathway analysis of mMet exclusive genes was performed using DAVID (Database for Annotation, Visualization, and Integrated Discovery).

RESULTS

A total of 328 patients with PDA were included. Among them, 56 (17%), 145 (44%), and 127 (39%) patients had nMet, dMet, and mMet, respectively. The median follow up was 21.6 months (range 0.7 -136 months). The median age at the time of diagnosis was 65.5 years (range 26.77 -87.31 years). ANOVA test showed that CA 19-9 level was associated with metastasis types (p = 0.034). The median OS was 48.4 (95% CI 28.3-NA), 27.4 (95% CI 23.3-33.9), and 15 (95% CI 13.9-17.8) months for patients with nMet, mMet, and dMet, respectively (p<0.0001). The multivariate analysis (MVA) revealed that KRAS mutation (HR 2.31; 95% CI 1.37-3.9; p = 0.001), mMet (HR 0.45; 95% CI 0.34-0.61; p<0.0001), nMet (HR 0.27; 95% CI 0.16-0.45; p<0.0001), age (HR 1.01; 95% CI 1-1.02; p = 0.03), and male gender (HR 1.5; 95% CI 1.15-2.01; p = 0.002) were associated with OS. Mutations in other PDA driver genes (TP53, SAMD4, CDKN2A) were not associated with OS (p>0.05). The LR rate at 12 months post-radiotherapy was 28% and 27% for nMet and mMet, respectively (p = 0.5). Heatmap analysis identified 31 genes that were exclusively mutated in patients with mMet. These genes were enriched in pathways of transcription regulation by RNA polymerase II promoter binding, a negative regulator of apoptosis, and telomerase maintenance.

CONCLUSION

This study identified metachronous metastasis-associated genetic alterations and molecular pathways. Future prospective studies incorporating whole exome sequencing are warranted to validate these findings.

Early Bone Mineral Density Changes and Endocrinal Dysfunction in Childhood Brain Tumor Patients: A Prospective Study

PURPOSE/OBJECTIVE(S)

Reduced bone mineral density (BMD) and hormonal dysfunction are considered as a late effect of cranial radiation (RT). Only few studies have reported the occurrence of these problems soon after the diagnosis of brain tumor or RT initiation, emphasizing that these are not necessarily the late effects of RT. Thus, we conducted the study to analyze the incidence of low BMD and hormonal dysfunction prior to or within 6 months of RT (early change) in children with brain tumors.

MATERIALS/METHODS

The study was conducted as a part of intramural funding program at a tertiary care center in India. Childhood and adolescent brain tumor patients were advised for dual energy X-ray absorptiometry scan (DXA) and hormonal evaluation prior to RT. In some patients, first DXA was done within 6 months of RT due to logistics. To see the effect of radiation, we have planned to repeat hormonal evaluation after 6 and 12 months and DXA after 12 months of RT.

RESULTS

Twenty-five patients were analyzed. Median age at diagnosis was 11 years with a male to female ratio of 5.2:1. Medulloblastoma was the commonest diagnosis (n = 12), followed by glioma (n = 8), pineal tumors (n = 3) and ependymoma (n = 2). Nineteen and six patients underwent DXA before RT and within 6 months of RT respectively. For BMD assessment, Z score was calculated at hip and lumbar spine. BMD was defined as low (Z score = -1 to-1.99), very low (Z score = -2 to -2.5) and secondary osteoporosis (Z score ≤ -2.5). Median Z score at femur neck and spine was -2 and -1.9 respectively. Overall; 6, 3 and 9 patients had normal, low and very low BMD respectively. Seven patients had secondary osteoporosis (Table 1). Two patients with secondary osteoporosis had low vitamin D levels. None of the patient had compression fracture. On statistical analysis, no correlation was found between BMD changes and age, sex and site of the tumor. Pre RT endocrinal assessment (N = 25) was done by tanner staging and serum hormonal levels (GH, T3/T4/TSH, ACTH, cortisol and prolactin). Gonadal hormonal assessment was done in children with early or delayed puberty. Three patients were found to have endocrinal abnormality before RT (precautious puberty, central hypothyroidism and low sex hormones in 1 patient each). Follow up DXA and hormonal evaluation are awaited to see the effect of RT.

CONCLUSION

The index study is one of the very few studies evaluating the early changes in BMD and hormonal dysfunction soon after brain tumor diagnosis or within 6 months of RT. We observed that a significant proportion of children had reduced BMD and hormonal dysfunction before RT, highlighting the importance of early assessment and referral to the specialist for better quality of life. Table 1: BMD and endocrinal dysfunction before or within 6 months of RT.