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Bulky bis-guanidine ligand-based neutral and cationic zinc alkyl, halide, and hydride complexes: synthesis, characterization, and catalytic application
No full textThe tetra-aryl substituted bis-guanidine ligand L(3H) (L(3H) = {(ArHN)(ArNH)-CvN-C=(NAr)(NHAr)}, Ar = 2,6-iPr2-C6H3) was used for the synthesis of mononuclear zinc(II) alkyl [L(2H)ZnR, R = Me (Zn-1), Et (Zn-2)], iodide [L(2H)ZnI, (Zn-3)], and hydride [L(2H)ZnH, (Zn-4)] complexes. Moreover, the reactions of Zn-1, Zn-2, and Zn-3 with [PhNMe2H]+ [B(C6F5)4]− yielded the biguanide zinc alkyl [L(3H)ZnR]+ [B(C6F5)4]− (R = Me (Zn-5), Et (Zn-6)) and iodide [L(3H)ZnI]+ [B(C6F5)4]− (Zn-7) cationic compounds in good yields. All newly isolated and thermally stable zinc complexes (Zn-1-Zn-7) were well characterized by multinuclear NMR (1H, 13C{1H}, with additional 11B and 19F{1H} for Zn-5-Zn-7), HRMS, and single crystal X-ray diffraction studies. Moreover, the well-defined zinc iodide cation (Zn-7) [L(3H)ZnI]+ [B(C6F5)4]− was further used as a catalyst for the synthesis of cyanohydrin enol ether products (RCR’CNOSiMe3) by TMSCN addition to carbonyl compounds (RCOR’, R’ = alkyl/aryl) under mild reaction conditions
Magnetic nanoparticle loaded ozone microbubbles for effective degradation of organic pollutants from sewage water
No full textPharmaceutical compounds contaminating water bodies is a threat to public health. It is therefore necessary to remove these pharmaceutical residues from sewage water. In order to effectively remove traces of pharmaceutical pollutants, various techniques such as oxidation ozonation, photocatalysis, membrane filtrations, and activated carbon adsorption have been employed by many researchers. However, the aforementioned techniques do not effectively remove traces of pharmaceutical pollutants from water completely. In the current work, magnetic catalyst nanoparticles loaded ozone microbubbles were synthesized for the efficient degradation of trace quantities of pharmaceutical pollutants in sewage water. Ozone microbubbles, typically smaller than 100 μm, were used for the effective degradation of ciprofloxacin, a commonly used antibiotic drug. The degraded intermediates of ciprofloxacin produced during the treatment process were estimated using Liquid Chromatography Mass Spectrometry (LCMSMS), which enabled the formulation of pathway for fragmentation/degradation of ciprofloxacin using magnetic nanoparticle-coated ozone microbubbles. The catalyst nanoparticles could be retrieved completely without any traces left behind in the treated water. This method of purification can be easily scaled up and can be used in large-scale water treatment plants. Toxicity studies were performed using zebrafish larvae to confirm the safety of water obtained after treatment of sewage water using catalyst-coated ozone microbubbles
Sky view factor analysis for a compact self-contained urban university campus: a case study of IIT Gandhinagar
No full textClimate change has led to increasing incidences of heat waves in urban India over the past decade. Despite this, many residents need to walk from one area to another to meet their livelihoods. Their thermal comfort during these times depends on factors like heat retention and air circulation. The Sky View Factor (SVF) is a simple metric that represents all of these factors and is a strong determinant of thermal comfort in urban areas. In this study, the SVF of a densely populated and compact urban campus of IIT Gandhinagar was measured across different urban morphologies to investigate the variation of thermal comfort. Findings reveal that SVF significantly differs across campus zones, with densely built hostel areas showing low SVF due to buildings and trees, while open sports facilities exhibit high SVF. Academic and parking areas demonstrate moderate SVF values. A statistical analysis revealed that the campus broadly consists of distinct areas with low and moderate-to-high SVF, largely based on similarities in urban morphology and the presence of trees. The findings show that campus residents are exposed to varying levels of SVF and, thus, different levels of thermal comfort within a relatively small geographical area. Incorporating SVF into urban planning considerations may improve thermal comfort and make cities more sustainable
Constructing strictly sign regular matrices of all sizes and sign patterns
No full textThe class of strictly sign regular (SSR) matrices has been extensively studied by many authors over the past century, notably by Schoenberg, Motzkin, Gantmacher, and Krein. A classical result of Gantmacher–Krein assures the existence of SSR matrices for any dimension and sign pattern. In this article, we provide an algorithm to explicitly construct an SSR matrix of any given size and sign pattern. (We also provide in the Appendix, a Python code implementing our algorithm.) To develop this algorithm, we show that one can extend an SSR matrix by adding an extra row (column) to its border, resulting in a higher order SSR matrix. Furthermore, we show how inserting a suitable new row/column between any two successive rows/columns of an SSR matrix results in a matrix that remains SSR. We also establish analogous results for SSR (Formula presented.) matrices of order (Formula presented.) for any (Formula presented.)
EFT corrections to Majumdar-Papapetrou black holes
No full textRecent studies on extremal black holes within effective field theories (EFT) of gravity have revealed an intriguing phenomenon: tidal forces near the horizon experience significant enhancement due to EFT corrections, potentially leading to a breakdown of the EFT framework. In this work, we investigate this effect in a two-black-hole Majumdar-Papapetrou spacetime modified by four-derivative EFT correction terms. Our analysis shows that while the scaling exponents, which measure the strength of the tidal forces near the horizon, remain unchanged under EFT corrections in D=4, they decrease for higher dimensions, enhancing the near-horizon tidal forces. We find an expression for the EFT corrections to the scaling exponents till D≤10 and demonstrate that the metric corrections can be structured such that only the near-horizon AdS2 throat undergoes angle-dependent modifications, while the transverse SD−2 sector remains unaffected
To develop injectable cerium-rutin nanocomplex embedded hydrogel for accelerated tissue regeneration and infection control
No full textA Long-term Study of Mrk 50: Appearance and Disappearance of Soft Excess
No full textWe present an extensive temporal and spectral study of the Seyfert 1 AGN Mrk 50 using 15 yr (2007-2022) of multiwavelength observations from XMM-Newton, Swift, and NuSTAR for the first time. From the timing analysis, we found that the source exhibited variability of ∼20% during the 2007 observation, which reduced to below 10% in the subsequent observations and became nonvariable in the observations from 2010 onward. From the spectral study, we found that the spectra are nearly featureless. Nondetection of absorption in the low-energy domain during the 15 yr of observation infers the absence of obscuration around the central engine, rendering the nucleus a “bare” type. A prominent soft X-ray excess below 2 keV was detected in the source spectrum during the observations between 2007 and 2010, which vanished during the later observations. To describe the nature of the soft excess, we use two physical models, such as warm Comptonization and blurred reflection from the ionized accretion disk. Both of the physical models explain the nature and origin of the soft excess in this source. Our analysis found that Mrk 50 accretes at a sub-Eddington accretion rate (λEdd = 0.13-0.02) during all of the observations used in this work
Towards adoption of secure communication protocol in Software Defined Networks
No full textSoftware Defined Networking (SDN) decouples the forwarding data plane from the network control plane to provide centralized control and programmability of the data plane elements like switches and routers. Traditionally, this commu-nication between control plane and the data plane (southbound communication) for e.g., using OpenFlow were based on the non-secure protocol like transmission control protocol (TCP), which over-the-years resulted in several security incidents. In order to facilitate secure data communication, the adoption of transport layer security (TLS) has become unavoidable. To this extent, we first present the key qualitative aspects and suitability of using TLS 1.2 and the newer TLS 1.3 for southbound communication. Further, we present extensive quantitative evaluation on Mininet emulator testbed to assess the performance impact of using the TLS 1.2 and TLS 1.3 (for most widely used cipher suites) over TCP to secure the controller-switch communication. Our work shows that the adoption of secure communication channel TLS incurs significant overheads (2 - 6 �) when compared to baseline TCP (unsecure channel), while TLS 1.3 adds marginal overheads in terms of latency and throughput (? 5 %) in comparison to TLS 1.2. Also, we observed that the memory and processing (computational cost) overheads with TLS 1.2 and TLS 1.3 to be negligible, even when supporting a large number of flows. Further, we also discuss the potential adoption of QUIC protocol as an alternative to provide high performance secure communication for the southbound interface. � 2023 Elsevier B.V., All rights reserved
L3D-Pose: lifting pose for 3D avatars from a single camera in the wild
No full textWhile 2D pose estimation has advanced our ability to interpret body movements in animals and primates, it is limited by the lack of depth information, constraining its application range. 3D pose estimation provides a more comprehensive solution by incorporating spatial depth, yet creating extensive 3D pose datasets for animals is challenging due to their dynamic and unpredictable behaviours in natural settings. To address this, we propose a hybrid approach that utilizes rigged avatars and the pipeline to generate synthetic datasets to acquire the necessary 3D annotations for training. Our method introduces a simple attention-based MLP network for converting 2D poses to 3D, designed to be independent of the input image to ensure scalability for poses in natural environments. Additionally, we identify that existing anatomical keypoint detectors are insufficient for accurate pose retargeting onto arbitrary avatars. To overcome this, we present a lookup table based on a deep pose estimation method using a synthetic collection of diverse actions rigged avatars perform. Our experiments demonstrate the effectiveness and efficiency of this lookup table-based retargeting approach. Overall, we propose a comprehensive framework with systematically synthesized datasets for lifting poses from 2D to 3D and then utilize this to re-target motion from wild settings onto arbitrary avatars
Evaluation of Exosomal Proteins as Potential Biomarkers from RBC Stages of Plasmodium falciparum 3D7
No full textFalciparum malaria relies extensively on cell-to-cell communication, and earlier research on the function of exosomal proteins derived from infected red blood cells (iRBCs) has been classified into numerous important roles. In this study, the exosomes were derived from Pf3D7-iRBCs cultured in vitro during synchronized trophozoite stages. The isolated exosomes were assessed using NTA, FE-SEM, and flow cytometry. Our study reported heterogeneous populations of exosomes during the infection. Additionally, label-free quantification based on LC/MS-MS for protein profiling revealed the presence of both parasitic and host (RBC) proteins; out of a total of 124 proteins detected, 20 Pf3D7 proteins and 80 RBC proteins were identified. Exosomal RBC protein expression is different in cRBCs-Exo and iRBCs-Exo, which shows how the parasite and RBCs interact with each other. Functional classification reported that the majority of these Pf3D7 proteins are uncharacterized with unknown functions, few of which are involved in biological processes such as regulation of complement activation, response to external stimuli, immune system-mediated signaling pathway, protein processing, etc. Hence, studying these exosomal proteins and comparing them to previous research has helped us understand how exosomes help cells to communicate in malaria. It may also reveal new potential biomarkers for diagnostic methods or therapies for malaria