Showing papers by "Gaurav Sharma published in 2022"

Chitosan as a Tool for Sustainable Development: A Mini Review

Abstract: New developments require innovative ecofriendly materials defined by their biocompatibility, biodegradability, and versatility. For that reason, the scientific society is focused on biopolymers such as chitosan, which is the second most abundant in the world after cellulose. These new materials should show good properties in terms of sustainability, circularity, and energy consumption during industrial applications. The idea is to replace traditional raw materials with new ecofriendly materials which contribute to keeping a high production rate but also reducing its environmental impact and the costs. The chitosan shows interesting and unique properties, thus it can be used for different purposes which contributes to the design and development of sustainable novel materials. This helps in promoting sustainability through the use of chitosan and diverse materials based on it. For example, it is a good sustainable alternative for food packaging or it can be used for sustainable agriculture. The chitosan can also reduce the pollution of other industrial processes such as paper production. This mini review collects some of the most important advances for the sustainable use of chitosan for promoting circular economy. Hence, the present review focuses on different aspects of chitosan from its synthesis to multiple applications.

Triple-negative breast cancer metastasis involves complex epithelial-mesenchymal transition dynamics and requires vimentin

Abstract: Triple-negative breast cancer (TNBC) is an aggressive subtype associated with early metastatic recurrence and worse patient outcomes. TNBC tumors express molecular markers of the epithelial-mesenchymal transition (EMT), but its requirement during spontaneous TNBC metastasis in vivo remains incompletely understood. We demonstrated that spontaneous TNBC tumors from a genetically engineered mouse model (GEMM), multiple patient-derived xenografts, and archival patient samples exhibited large populations in vivo of hybrid E/M cells that lead invasion ex vivo while expressing both epithelial and mesenchymal characteristics. The mesenchymal marker vimentin promoted invasion and repressed metastatic outgrowth. We next tested the requirement for five EMT transcription factors and observed distinct patterns of utilization during invasion and colony formation. These differences suggested a sequential activation of multiple EMT molecular programs during the metastatic cascade. Consistent with this model, our longitudinal single-cell RNA analysis detected three different EMT-related molecular patterns. We observed cancer cells progressing from epithelial to hybrid E/M and strongly mesenchymal patterns during invasion and from epithelial to a hybrid E/M pattern during colony formation. We next investigated the relative epithelial versus mesenchymal state of cancer cells in both GEMM and patient metastases. In both contexts, we observed heterogeneity between and within metastases in the same individual. We observed a complex spectrum of epithelial, hybrid E/M, and mesenchymal cell states within metastases, suggesting that there are multiple successful molecular strategies for distant organ colonization. Together, our results demonstrate an important and complex role for EMT programs during TNBC metastasis. Description TNBC uses a vimentin-dependent hybrid EMT to generate metastases with diverse epithelial and mesenchymal characteristics. The dynamics of TNBC metastasis In breast cancer lacking expression of human epidermal growth factor receptor 2, estrogen receptor, or progesterone receptor [triple-negative breast cancer (TNBC)], the roles of epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition in metastasis are unclear. Here, Grasset and colleagues characterized genetically engineered mouse models of TNBC, patient-derived xenografts, and TNBC tumor tissues from patients, identifying that the mesenchymal protein vimentin was required for TNBC invasion and metastasis formation. Single-cell RNA sequencing analysis revealed that TNBC cancer cells progressed from epithelial to hybrid epithelial/mesenchymal states during both invasion and colony formation, with different transcription factors being required for invasion versus colony formation. This work suggests that EMT programs in TNBC metastasis are complex and might contribute to the development of treatment resistance.

Progress in Electrode and Electrolyte Materials: Path to All-solid-state Li-ion Batteries (ASSLIB)

Abstract: This review presents a brief scenario about the development of cathodes, anodes, and electrolytes for the next generation of Li-ion batteries (LIBs) and supercapacitors for future energy technologies. Specific capacity...

Activated Carbon as Superadsorbent and Sustainable Material for Diverse Applications

Abstract: Activated carbon is a carbonaceous material with highly porous structure. Different functionalities can be introduced to its surface by various physical and chemical treatments. Various precursors can be used for the synthesis of activated carbon such as fossil fuels, agricultural wastes, and lignocellulosic wastes, etc. Number of papers have been reported in literature devoted to the synthesis, characterization, and various applications of activated carbon. Herein, in this review, special attention has been paid to the basic properties of activated carbon and its surface chemistry originated due to physical and chemical treatment. In addition, a general introduction to adsorption process, various adsorption isotherms, and adsorption kinetics is also included. A brief description of mechanism of adsorption onto activated carbon is also presented. At last, most probable applications of activated carbon such as adsorption of pollutants (e.g., dyes, heavy metal ions, pesticides, pharmaceutical waste products, and volatile organic organic), as catalyst support, anduse in food and pharmaceutical industries is also presented.

HRS phosphorylation drives immunosuppressive exosome secretion and restricts CD8+ T-cell infiltration into tumors

Abstract: Abstract The lack of tumor infiltration by CD8 + T cells is associated with poor patient response to anti-PD-1 therapy. Understanding how tumor infiltration is regulated is key to improving treatment efficacy. Here, we report that phosphorylation of HRS, a pivotal component of the ESCRT complex involved in exosome biogenesis, restricts tumor infiltration of cytolytic CD8 + T cells. Following ERK-mediated phosphorylation, HRS interacts with and mediates the selective loading of PD-L1 to exosomes, which inhibits the migration of CD8 + T cells into tumors. In tissue samples from patients with melanoma, CD8 + T cells are excluded from the regions where tumor cells contain high levels of phosphorylated HRS. In murine tumor models, overexpression of phosphorylated HRS increases resistance to anti-PD-1 treatment, whereas inhibition of HRS phosphorylation enhances treatment efficacy. Our study reveals a mechanism by which phosphorylation of HRS in tumor cells regulates anti-tumor immunity by inducing PD-L1 + immunosuppressive exosomes, and suggests HRS phosphorylation blockade as a potential strategy to improve the efficacy of cancer immunotherapy.

Attention Beats Concatenation for Conditioning Neural Fields

Abstract: Neural fields model signals by mapping coordinate inputs to sampled values. They are becoming an increasingly important backbone architecture across many fields from vision and graphics to biology and astronomy. In this paper, we explore the differences between common conditioning mechanisms within these networks, an essential ingredient in shifting neural fields from memorization of signals to generalization, where the set of signals lying on a manifold is modelled jointly. In particular, we are interested in the scaling behaviour of these mechanisms to increasingly high-dimensional conditioning variables. As we show in our experiments, high-dimensional conditioning is key to modelling complex data distributions, thus it is important to determine what architecture choices best enable this when working on such problems. To this end, we run experiments modelling 2D, 3D, and 4D signals with neural fields, employing concatenation, hyper-network, and attention-based conditioning strategies -- a necessary but laborious effort that has not been performed in the literature. We find that attention-based conditioning outperforms other approaches in a variety of settings.

Green synthesis of ZnO nanoparticles using Ficus palmata: Antioxidant, antibacterial and antidiabetic studies

Abstract: Nanotechnology is becoming a furious field among researchers and have paved the way for novel and more efficient methods for the treatment of various diseases like cancer and type 2 diabetes mellitus. In this study, the leaf extract of Ficus palmata was used as stabilizing and reducing agent for the synthesis of zinc oxide nanoparticles (ZnO NPs) using zinc acetate solution. The prepared ZnO NPs were identified and characterized using UV-Vis spectroscopy, Dynamic light scattering (DLS), Fourier transformed infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), and Energy-dispersive spectrum (EDS). The green synthesized ZnO NPs by Ficus palmata (FP ZnONPs) were evaluated for their antioxidant, antimicrobial activity, and cytotoxicity against the human FR2 cell line. They exhibited potential antioxidant activity and good antibacterial activity against Staphylococcus aureus, Bacillus subtilus, Escherichia coli, Salmonella typhi, Klebsiella pneumoniae. Further, green synthesized FP ZnO NPs were also evaluated for In vitro and In vivo antidiabetic activity. According to the results obtained, the synthesized nanoparticles have high dispersed nanostructures with great crystallinity and hexagonal or some spherical shaped structures and particle size distribution profile was found to be 35 nm. The results showed that nanoparticles exhibit better antidiabetic activity as compared to the plant extracts. The percentage of inhibition for amylase and glucosidase was higher in FP ZnONPs. It was found to be 70.07 ± 0.07 µg/ml in amylase and 68.49 ± 0.43 µg/ml in the glucosidase inhibition assay. The FP ZnONPs showed a significant (p < 0.05) decrease in blood glucose level as compared to a diabetic control group from 21st to till 42nd day. Furthermore, in extension to these experiments, the synthesized nanoparticles showed an antidyslipidaemic effect on streptozotocin (STZ) induced diabetic rats. It improves the lipid profile by decreasing the levels of triglycerides, total cholesterol, low-density lipoprotein (LDL) cholesterol and increasing the high-density lipoprotein (HDL) cholesterol level. Overall, the results highlight the effectiveness and potential applications of FP ZnO NPs for therapeutic purposes.

Synthesis of silica and carbon-based nanomaterials from rice husk ash by ambient fiery and furnace sweltering using a chemical method

Abstract: Silica nanoparticles (n-SiO2), graphene nanosheets (n-Gr) and graphene oxide nanosheets (n-GO) were synthesized from the cost-effective biomass rice husk ash (RHA) by the simple chemical process. The crystallite size and micro-strain of all samples were calculated from XRD-peak profile analysis to be 1.5 - 5.4 nm and 8.11 - 28.64 MPa, respectively. FE-SEM images confirmed SiO2 nanoparticles with clustered spherical shapes and petals form of n-Gr and n-GO named RHA-1, RHA-2, RHA-3, respectively. The symmetric stretching band vibrations Si-O and O-Si-O were detected at 472, and 620 cm−1 in the FTIR spectrum, which confirmed the presence of n-SiO2. Bands at 1067, 1106, 1624 cm−1 are related to C-O stretching vibration, anhydrides C-O stretching and C=C stretching vibration of n-Gr, and n-GO, respectively. The core-level of XPS of C showed the binding energy of C‒C (283.21 eV), (291.11 eV), and O‒C=O (294.11 eV), which augmented the formation of graphene. The ratio of Raman peaks (ID/IG <1) is further confirmed the formation n-Gr of graphitic structure of sp2 carbon.

Low Complexity Interference Mitigation Technique in IRCI-Free SAR Imaging Algorithms

Abstract: Inter range cell interference (IRCI)-free synthetic aperture radar (SAR) imaging algorithms experience antenna-based interference which severely degrades the SAR image. In this letter, we propose a low complexity interference mitigation technique based on array processing for IRCI-free SAR imaging algorithms. A low complexity array processing is proposed, by designing a linear array with a limited number of fully controllable elements. The complex weight of array elements is optimized for the desired array pattern with constraints on close-in sidelobe levels (SLL). The proposed methodology reduces the desired two-way SLL to 40.5 dB by using only 18 fully controllable elements out of 100 array elements. The state-of-the-art improved-gray wolf optimization (I-GWO) is used for optimization and is shown to be computationally more efficient than some well-known optimization algorithms. Finally, simulated SAR images validate the effectiveness of the proposed technique.

Pros and Cons of Biochar to Soil Potentially Toxic Element Mobilization and Phytoavailability: Environmental Implications

Abstract: Abstract While the potential of biochar (BC) to immobilize potentially toxic elements (PTEs) in contaminated soils has been studied and reviewed, no review has focused on the potential use of BC for enhancing the phytoremediation efficacy of PTE-contaminated soils. Consequently, the overarching purpose in this study is to critically review the effects of BC on the mobilization, phytoextraction, phytostabilization, and bioremediation of PTEs in contaminated soils. Potential mechanisms of the interactions between BC and PTEs in soils are also reviewed in detail. We discuss the promises and challenges of various approaches, including potential environmental implications, of BC application to PTE-contaminated soils. The properties of BC (e.g., surface functional groups, mineral content, ionic content, and π-electrons) govern its impact on the (im)mobilization of PTEs, which is complex and highly element-specific. This review demonstrates the contrary effects of BC on PTE mobilization and highlights possible opportunities for using BC as a mobilizing agent for enhancing phytoremediation of PTEs-contaminated soils.

Assessment of the geomorphic indices in relation to tectonics along selected sectors of Borpani River Basin, Assam using Cartosat DEM data

Abstract: We studied geomorphic indices related to tectonics along the Borpani River using Cartosat 10 m spatial resolution Digital Elevation Model (DEM) data. A total of 11 geomorphic indices such as transverse topographic symmetry factor (Tt), drainage basin asymmetry (AF), valley floor width to valley height ratio (Vf), bifurcation ratio (Rb), hypsometric integral (HI), basin elongation ratio (Re), basin shape index (Bs), circularity ratio (Rc), drainage density (Dd), relief ratio (Rh), hypsometric curves (HC) were studied to access the tectonics along the river in selected locations. Five locations along the river were selected for detailed analysis (sub-basin I, II a, II b, III, and IV). Horton's (1945) scheme was adopted for watershed delineation, while stream ordering was performed using Strahler's (1964) method. The results infer that the sub-basins along the Borpani River are tectonically active. In the case of sub-basin I, 3 geomorphic indices out of 11 falls in the category of highly active, and 2, 1, 2, and 4 indices out of 11 falls in the category of highly active in the case of sub-basins II a, II b, III, and IV. Similarly, 4, 1, 3, 6, 1 and 4, 8, 7, 3, 6 indices fall under moderately active and low active classes in sub-basins I, II a, II b, III, and IV. On average, 23.86 %, 29.54%, and 46.58% of the geomorphic indices fall in the active, moderately active, and low active classes.

"Magnetic Ni-Zn ferrite anchored on g-C3N4 as nano-phocatalyst for efficient photo-degradation of doxycycline from water".

Abstract: In the present work, mixed-spinel ferrite anchored onto graphitic carbon nitride (GCN) was synthesized for mineralization of antibiotic pollutant from waste water. A Z-scheme g-C3N4/Ni0.5Zn0.5Fe2O4 nano heterojunction was fabricated by three step procedure: pyrolysis, solution combustion and mechanical grinding followed by annealing. The prepared photocatlyst was tested for degradation of Doxycycline (DC) drug under the natural sun light. Results revealed that the prepared heterojunction has maximum degradation efficiency of 97.10% pollutant in 60 min experiment. The Z-scheme heterojunction between g-C3N4 and Ni-Zn ferrite improves the photoinduced charges separation and protection of redox capability and therby increases the photo degradation efficiency. The scavenging experiments suggested that O2-● and h+ as main active species responsible for degradation of the antibiotic. In addition, the dopant variation can drive the shists in band gap and energy band positiong too which makes then excellent candidates for synthesizing tunable heterostructures with organic semiconductors. The work focusses on designing and developing of saimpler but efficient magnetic heterojunctions with superior redox capability for solar powered waste water treatment.

Bibliometric Mapping of Trends, Applications and Challenges of Artificial Intelligence in Smart Cities

Abstract: INTRODUCTION: The continued growth of urbanization presents new challenges. This, in turn, will lead to pressure for sustainable environment initiatives, with demands for more and better infrastructure in the diminishing space available and improved quality of life for city dwellers at a more affordable cost. Smart Cities are part of the solution to the growing challenges of urbanization. The adoption of new technologies like artificial intelligence (AI) is transforming cities, making them smarter, faster, and predicting opportunities for improvement. OBJECTIVES: This study is conducting a detailed bibliometric survey to investigate the applications and trends of Artificial Intelligence research for different areas of smart cities and emphasizing the potential effects and challenges of AI adaptation in smart cities over the past 30.5 years. METHODS: For this study, the Scopus database was used to collect a total of 1925 documents published between 1991-2021 (July). The bibliometric analysis includes document types, subject categorization, document growth, as well as top contributing sources, countries, authors, and funding sponsors. It also analyses keywords, abstracts, titles, and characteristics of most cited documents. RESULTS: The analyzed findings of this research study reflect not only the significance of AI technology for various applications within numerous sectors in the smart city but also major obstacles in AI research for various sectors of smart cities. CONCLUSION: The research demonstrates that AI has the ability to construct today’s and tomorrow’s smart cities, but that each region’s potentials, conditions, and circumstances must be addressed in order to achieve a smooth internet city development.

Harmonizing Prokaryotic Nomenclature: Fixing the Fuss over Phylum Name Flipping

Abstract: Lloyd and Tahon recently criticized proposed bacterial phylum nomenclature changes (K.G. Lloyd, G. Tahon, Nat Rev Microbiol 20:123-124, 2022, https://doi.org/10.1038/s41579-022-00684-2) precipitated by the International Committee on Systematics of Prokaryotes (ICSP)’s official recognition of phylum nomenclature rules. Here, we extend the critique. ABSTRACT Lloyd and Tahon recently criticized proposed bacterial phylum nomenclature changes (K.G. Lloyd, G. Tahon, Nat Rev Microbiol 20:123-124, 2022, https://doi.org/10.1038/s41579-022-00684-2) precipitated by the International Committee on Systematics of Prokaryotes (ICSP)’s official recognition of phylum nomenclature rules. Here, we extend the critique. While we applaud bringing consistency to phylum names, we prognosticate what this minute but momentous change entails for the future of microbial nomenclature and how this will sow confusion among researchers. Several pitfalls of the proposed ICSP framework-based nomenclature are also detailed, including (i) improper type genus name and suffix usage, (ii) loss of Bacteria/Archaea distinctions, (iii) disruption of major phylum name prefixes, and (iv) absence of organism name prevalidation. Finally, we suggest new names for the key bacterial phyla Proteobacteria (Proteobacteriota), Firmicutes (Firmicuteota), Actinobacteria (Actinobacteriota), and Tenericutes (Tenericuteota), while keeping the archaeal phylum names Crenarchaeota, Thaumarchaeota, and Euryarchaeota. Together, these changes will help researchers attain chaos-free uniform nomenclature.

Case Report: Secondary Hemophagocytic Lymphohistiocytosis (sHLH) and Candida auris Fungemia in Post-acute COVID-19 Syndrome: A Clinical Challenge

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a disease (COVID-19) with multisystem involvement. The world is now entering a phase of post-COVID-19 manifestations in this pandemic. Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory event triggered by viral infections, including SARS-CoV-2. Both Multisystem Inflammatory Syndrome-Adults (MIS-A) and Cytokine Storm Syndrome (CSS) are considered close differentials of sHLH and add to the spectrum of Post-acute COVID-19 syndrome (PACS). In this report, we presented the case of a middle-aged Asian man who was initially discharged upon recovery from severe COVID-19 infection after 17 days of hospitalization to a private institute and later came to our hospital 13 days post-discharge. Here, he was diagnosed with sHLH, occurring as an extension of CSS, with delayed presentation falling within the spectrum of PACS. The diagnosis of sHLH was made holistically with the HLH-2004 criteria. Our patient initially responded to intravenous immunoglobulin (IVIG) and dexamethasone, later complicated by disseminated Candida auris infection and had a fatal outcome. Though many cases of HLH during active COVID-19 and a few cases post COVID-19 recovery have been reported, based on H-score, which has limitations as a diagnostic tool. We report the first case report of post-COVID-19 sHLH using the HLH-2004 criteria, complicated by disseminated Candidemia, emphasizing that the care of patients with COVID-19 does not conclude at the time of hospital discharge. We highlight the importance of surveillance in the post-COVID phase for early detection of sHLH which may predispose to fatal opportunistic infections (OIs).