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The development of high-performance adsorbents for environmental remediation is a current need, and ionic porous organic polymers (iPOPs), due to their high physicochemical stability, high surface area, added electrostatic interaction, and easy reusability, have already established themselves as a better adsorbent. However, research on the structural design of high-performance iPOP-based adsorbents is still nascent. This study explored the building blocks’ role in optimizing the polymers’ charge density and surface area to develop better polymeric adsorbents. Among the three synthesized polymers, iPOP-ZN1, owing to its high surface area and high charge density in its active sites, proved to be the best adsorbent for adsorbing inorganic and organic pollutants in an aqueous medium. The polymers were efficient enough to capture and store iodine vapor in the solid state. Further, this study tried to address using iodine-loaded polymers in antibacterial action. Iodine-loaded iPOPs show impressive antibacterial behavior against E. coli, B. subtilis, and H. pylori.

Though metalloporphyrins have proved their efficiency as a class of efficient electrocatalysts, their practical use is often restricted due to poor stability and lack of an effective electrochemical surface. Combining metalloporphyrins in the skeleton of covalent organic polymers, though, is an effective strategy for developing efficient electrocatalysts for OER and HER; due to the restricted conductivity of such materials, addition of external additives or annealing is a must, which increases the cost of the material development. Here, we report two metalloporphyrin-based covalent organic polymers, COP-POR-Ni and COP-POR-Co, which work as excellent annealing- and additive-free electrocatalysts for overall water splitting in an alkaline medium. The polymers achieved a current density of 1 mA/cm2at 300 and 370 mV with turnover frequencies (TOFs) of 9.1 × 10–3and 2.68 × 10–3s–1at 2 mA/cm2for COP-POR-Ni and COP-POR-Co, respectively, for alkaline water oxidation. The catalysts are also active for the selective conversion of 5-hydroxymethylfurfural (HMF), a plant biomass carbohydrate, oxidation to a platform chemical 2,5-furandicarboxylic acid (FDCA) with the coproduction of hydrogen at the cathode. HER activity was also achieved with overpotentials of 468 and 348 mV at a current density of 1 mA cm–2for COP-POR-Ni and COP-POR-Co in an acidic medium, respectively.

Nanostructured 7–9-residue cyclic and unstructured lipopeptide-based facial detergents have been engineered to stabilize the model integral membrane protein, bacteriorhodopsin. Formation of a cylindrical-type micelle assembly induced by facial amphipathic lipopeptides resembles a biological membrane more effectively than conventional micelles. The hydrophobic face of this cylindrical-type micelle provides extended stability to the membrane protein and the hydrophilic surface interacts with an aqueous environment. In our present study, we have demonstrated experimentally and computationally that lipopeptide-based facial detergents having an unstructured or β-turn conformation can stabilize membrane proteins. However, constrained peptide detergents can provide enhanced stability to bacteriorhodopsin. In this study, we have computationally examined the structural stability of bacteriorhodopsin in the presence of helical, beta-strand, and cyclic unstructured peptide detergents, and conventional detergent-like peptides. Our study demonstrates that optimal membranomimetics (detergents) for stabilizing a specific membrane protein can be screened based on the following criteria: (i) hydrodynamic radii of the self-assembled peptide detergents, (ii) stability assay of detergent-encased membrane proteins, (iii) percentage covered area of detergent-encased membrane proteins obtained computationally and (iv) protein–detergent interaction energy.

Cryosphere all over the globe is thawing, be it the Arctic, Antarctic, Greenland or Himalaya. Studies have predicted that loss in the glacier mass over the Upper Indus Basin in Kashmir Himalaya would amount to 47 to 67% (Romshoo in 7th conference of Science and Geopolitics of Arctic and Antarctic, 2023). A similar trend prevails in the Bhaga basin of the Upper Chenab, where glaciers in size classes < 0.5 km2and 0.5–1km2show a higher relative loss of 25% (0.5% year−1) and 13% (0.3% year−1) respectively (Das et al. in Quat Sci Rev 316:108258; J Mt Sci 20:299–324, 2023). The loss in Eastern Himalaya (Sikkim) has been reported to range from 20 to 30% (Debnath in 7th conference of Science and Geopolitics of Arctic and Antarctic, 2023). On the basis of the compiled records of snout fluctuations of 285 glaciers and two regional means spanning 17 decades from the 1850s, it has been deduced that most of the Himalayan glaciers are retreating, and the retreat rates have accelerated in the past few decades, but the observed tendencies are not regionally uniform (Kulkarni et al. in Water Security 14(6557):100101; J Indian Soc Remote Sensing 49(8):1951–1963, 2021). The excessive ice mass loss has resulted in the formation and/or expansion of glacial melt water lakes posing a threat of Glacial Lake Outburst Flow (GLOF). The results of the studies on the response of climatic variability over the state of cryosphere, the role of debris on the melting of glaciers, changes in the winter precipitation pattern and consequent impact on the hydrological cycle, water availability and state of permafrost over Himalaya have also been a focus of studies, including developing models (Banerjee et al. in Geophys Res Lett 49:096989, 2020), in contemporary publications, enriching the data on the fundamental aspects of glacial processes that are of great societal relevance.

In this paper we extend the notions of statistical limit points and statistical cluster points of double sequences of real numbers to I-statistical limit points and I-statistical cluster points of double sequences of real numbers. We study some basic properties of the set of all I-statistical cluster points and the set of all I-statistical limit points of a double sequence of real numbers including their interrelationship. Also introducing additive property of double I-natural density zero sets we present I-statistical analogue of some well known theorems concerning double sequences that are equivalent to the completeness of the real line.

AbstractOne of the proposed materials for structural application in compact high-temperature reactors (CHTRs) is Nb-1Zr-0.1C alloy. Using the Variable Energy Cyclotron at the Variable Energy Cyclotron Centre, Kolkata, Nb-1Zr-0.1C alloy was irradiated with a 160-MeV oxygen (O6+) ion up to three different doses. Emulation of neutron irradiation by ion irradiation could be achieved as the weighted recoil spectra of the oxygen ion are found to be similar to the neutron recoil spectra of CHTRs within recoil energy ranging from 100 eV to 100 keV. The irradiated materials along with one as-received sample were characterized using different X-ray diffraction line profile analyses (XRDLPAs) to systematically evaluate microstructural parameters. A decrease in the domain size with an increase in microstrain and dislocation density is observed at first dose and then found to saturate with further irradiation. An increase in the Wilkens arrangement parameter indicates the formation of less correlated dislocations (clusters) after irradiation. Transmission electron microscopy analysis of as-received and highest-dose samples shows the formation of densely populated defect clusters after irradiation. Nanohardness increased after irradiation due to pinning of the dislocation movement by point defects and defect clusters/loops, as well as carbides in the matrix. The results extracted from the XRDLPAs are compared with our earlier studies of light ion–irradiated (H+) Nb-1Zr-0.1C alloy and oxygen-irradiated pure Nb to understand the effect of the type of ion and the alloying elements, respectively, on the evolution of the microstructure. It may be concluded that changes in dose and dose rate affect the movement of point defects toward sinks. Hence, possible correlated dislocation formation is observed in light ion–irradiated Nb alloy, but correlation is found to decrease with dose for heavy ion–irradiated Nb alloy. On the other hand, the presence of finely dispersed carbides restricts the formation of dislocation loops by making complexes with the defects in heavy ion (O6+)–irradiated Nb-1Zr-0.1C alloy, which is in contrast to pure Nb irradiated using the heavy ion (O6+) in a similar environment.

The merger of photocatalysis and transition-metal catalysis has recently emerged as an adaptable platform for the development of innovative and environmentally benign synthetic methodologies. In contrast to classical transformation by Pd complexes, photoredox Pd catalysis operates through a radical pathway in the absence of a radical initiator. Using the synergistic merger of photoredox and Pd catalysis, we have developed a highly efficient, regioselective, and general meta-oxygenation protocol for diverse arenes under mild reaction conditions. The protocol showcases the meta-oxygenation of phenylacetic acids and biphenyl carboxylic acids/alcohols and is also amenable for a series of sulfonyls and phosphonyl-tethered arenes, irrespective of the nature and position of the substituents. Unlike thermal C–H acetoxylation which operates through the PdII/PdIVcatalytic cycle, this metallaphotocatalytic C–H activation involves PdII/PdIII/PdIVintermediacy. The radical nature of the protocol is established through radical quenching experiments and EPR analysis of the reaction mixture. Furthermore, the catalytic path of this photoinduced transformation is established through control reactions, absorption spectroscopy, luminescence quenching, and kinetic studies.

Here, we report the design and synthesis of a redox-active multifunctional ionic porous organic polymer iPOP-Bpy with exchangeable Br–ions, incorporating viologen as a redox-active building block. The material shows not only excellent iodine uptake capacity in the vapor phase (540 wt %) but also in the organic (1009.77 mg g–1) and aqueous phases (3921.47 mg g–1) with very fast adsorption kinetics in all cases. The material also shows its utility in being used as a solid-state NH3vapor sensor as it shows very fast color switching in the presence of NH3vapor. Furthermore, the material found application as a p-type complementary electrochromic electrode and was fabricated into a bilayer device. Excellent coloration efficiency, high switching speed, and good color contrast were obtained as investigated using bias-dependent optical and spectroelectrochemical studies, paving the way for fabricating power-efficient solid-state electrochromic devices.

Hydrate formation is a significant issue while drilling into deep-water reservoirs containing gas hydrates. They may form in the drilling fluid flowlines, wellbore annulus, and ram cavities of blowout preventers. The natural gums, i.e., xanthan gum (XG) and gum acacia (GA), and their two graft copolymers with acrylamide (AAm), i.e., XG-g-PAAm and GA-g-PAAm, have been synthesized and tested as low-dosage hydrate inhibitors using THF hydrate systems via temperature-augmented visual method. XG-g-PAAm and GA-g-PAAm have shown better inhibition efficiencies and higher induction times than XG and GA. All of these inhibitors are then tested as drilling fluid additives to the formulated water-based drilling fluid systems (WBDFs). The formulated WBDFs contained 0.4 w/v % of each carboxymethyl cellulose (CMC), polyanionic cellulose (PAC), and 5 w/v % of potassium chloride (KCl). The rheology of the formulated WBDFs has been tested at an ambient temperature (293 K) and low temperature (275 K). The rheological parameters of WBDFs obtained from the experiments are within permissible limits with an inhibitor concentration of 0.5 w/v %. The rheological data are then fitted to the Bingham–Plastic (B–P) model and Herschel–Bulkley (H–B) model. The coefficient of determination’s (R2) upper and lower limits for the B–P model is 0.9715–0.9969 for 0.5 w/v % GA- and 0.5 w/v % XG-g-PAAm-containing WBDF systems. Again, for the H–B model, the range for R2is from 0.9891 to 0.9980 for 0.5 w/v % GA- and 0.5 w/v % XG-containing WBDFs. Hence, the R2showed a better agreement with the H–B model than with the B–P model. These observations suggest that XG, GA, XG-g-PAAm, and GA-g-PAAm may be used as hydrate inhibitors in the formulated WBDFs while drilling into gas hydrate reservoirs.

abstract:Though Tagore does not specify Neerja's illness in his novella, The Garden, readers are made aware of its terminal nature following her surgery and the loss of her child. As the novella progresses, what draws the readers' attention is not Neerja's physical ill health but the "unreasonable torment" plaguing her mind. Tagore's depiction of her distressful mental suffering and its corresponding psychological repercussions—chronic anxiety, low self-esteem, guilt, depression, and obsessional jealousy—tend to preoccupy the central focus of the narrative. In the early twentieth century, the general awareness of mental health issues was still at a formative stage in colonial Bengal. In the absence of requisite palliative care and appropriate treatment of Neerja's underlying psychological distress, she remains a hapless victim of her tragic circumstances. Undertaking a close psychoanalytic exploration of the text, this analysis argues that through his keen observation and a meticulously detailed portrayal of his female protagonist's predicament, Tagore represents the helpless despair endured by mentally challenged victims of his time.

Given the aging population, healthcare systems need to be established to deal with health issues such as injurious falls. Wearable devices can be used to detect falls. However, most wearable devices are obtrusive, and patients generally do not like or may forget to wear them. In this study, we developed an unobtrusive monitoring system using infrared technology to unobtrusively detect locations and recognize human activities such as sitting, standing, walking, lying, and falling. We prototyped a system consisting of two 24×32 thermal array sensors and collected data from healthy young volunteers performing ten different scenarios. A supervised deep learning (DL)-based approach classified activities and detected locations from images. The performance of the DL approach was also compared with the machine learning (ML)-based methods. In addition, we fused the data of two sensors and formed a stereo system, which resulted in better performance compared to a single sensor. Furthermore, to detect critical activities such as falling and lying on floor, we performed a binary classification in which one class was falling plus lying on floor and another class was all the remaining activities. Using the DL-based algorithm on the stereo dataset to recognize activities, overall average accuracy and F1-score were achieved as 97.6%, and 0.935, respectively. These scores for location detection were 97.3%, and 0.927, respectively. These scores for binary classification were 97.9%, and 0.945, respectively. Our results suggest the proposed system recognized human activities, detected locations, and detected critical activities namely falling and lying on floor accurately.

We prove some basic properties of strong ℐλ{\mathcal{I}_{\lambda}}-statistical convergence of sequences in probabilistic metric spaces and introduce the notion of strong ℐλ{\mathcal{I}_{\lambda}}-statistical cluster point. We also introduce the notion of strong ℐλ{\mathcal{I}_{\lambda}}-statistical Cauchy sequences in probabilistic metric spaces. Further, we establish a connection between strong ℐλ{\mathcal{I}_{\lambda}}-statistical convergence and strong ℐλ{\mathcal{I}_{\lambda}}-statistical Cauchy sequences.

The Fujiwara–Moritani reaction has had a profound contribution in the emergence of contemporary C–H activation protocols. Despite the applicability of the traditional approach in different fields, the associated reactivity and regioselectivity issues had rendered it redundant. The revival of this exemplary reaction requires the development of a mechanistic paradigm that would have simultaneous control on both the reactivity and regioselectivity. Often, the high thermal energy required to promote olefination leads to multiple site functionalizations. To this aim, we established a photoredox catalytic system constituting a merger of palladium/organo-photocatalyst (PC) that forges oxidative olefination in an explicit regioselective fashion with diverse arenes and heteroarenes. Visible light plays a significant role in executing “regioresolved” Fujiwara–Moritani reactions without the requirement of silver salts and thermal energy. The catalytic system is also amenable toward proximal and distal olefination aided by the respective directing groups (DGs), which entails the versatility of the protocol in engaging the entire spectrum of C(sp2)–H olefination. Furthermore, streamlining the synthesis of natural products, chiral molecules, drugs, and diversification through late-stage functionalizations underscore the importance of this sustainable protocol. The photoinduced attainment of this regioselective transformation is mechanistically established through control reactions and kinetic studies.

An ionic multifunctional gelator molecule triethylammonium 5-(3,5-bis((1H-tetrazol-5-yl)carbamoyl)benzamido)tetrazol-1-ide G7is synthesized and characterized by spectroscopic tools and mass spectrometry. G7tends to form a stable organogel in a mixture of N,N-dimethylformamide/dimethylsulfoxide (DMF/DMSO) and water. Introduction of different metal perchlorate salts in a DMSO solution of G7furnished a series of metallogels M1G7, M2G7, M3G7, M4G7, M5G7, M6G7, and M7G7[M1= Fe(III), M2= Co(II), M3= Cu(II), M4= Zn(II), M5= Ag(I), M6= Ni, and M7= Fe(II)]. Among them, M1G7, M3G7, M4G7, M6G7, and M7G7help individually in the synthesis and stabilization of bimetallic nanocomposites containing silver nanoparticles (AgNPs). Iron(III)-containing nanocomposites M1G7AgNPshave been utilized in the form of catalysts in the reduction reaction of nitroaromatic compounds to corresponding amines with a quantitative yield. The organogel G7has also shown the abilities to absorb different metal ions from aqueous solutions and allow selective transition of M1G7from the gel state to the crystalline state. Fe(III) formed dual metallogels with Zn(II), which can be used for further applications. Furthermore, the nanocomposite M1G7AgNPpowder, in the presence of the organogel G7, gets converted into a nanostructured metallogel, which shows exclusive self-healing properties. This is the first example where a nanocomposite powder contains the dual-metal system (Fe(III) and Ag(0)) and shows a reduction catalytic property, and its nanostructured dual-metallogel form manifests the self-healing property in a fabricated metallogel.

AbstractNature serves as a recurrent metaphor in Rabindranath Tagore’s Ghare Baire. Throughout the narrative, environmental motifs are constantly evoked not only to highlight the agrarian backdrop of the society but also to explore human relationships and attitudes towards life in general. In chapter eight of the novel, when Nikhil says: ‘It is my desire to plant something greater than Swadeshi. I am not after dead logs but living trees – and these will take time to grow,’ he articulates a symbiotic voice of empathy, nurture, nourishment and preservation. However, the history student’s reply to Nikhil is a sneering one: ‘I am afraid, sir, that you will get neither log nor tree. Sandip Babu rightly teaches that in order to get, you must snatch’. It is this contrary impulse of ‘snatching’ from and exploiting nature that concurrently runs through the novel. According to Sandip, Earth with its wonderful resources needs to be tamed into submission and exploited. This essay undertakes an eco-critical reading of the novel exploring the contrary forces of preservation and abuse, thereby, also taking a closer look at issues of gender and class that recur in the novel.

Engineering bioinspired peptide-based molecular medicine is an emerging paradigm for the management of traumatic coagulopathies and inherent bleeding disorder. A hemostat-based strategy in managing uncontrolled bleeding is limited due to the lack of adequate efficacy and clinical noncompliance. In this study, we report an engineered adhesive peptide-based hybrid regenerative medicine, sealant 5, which is designed integrating the structural and functional features of fibrin and mussel foot-pad protein. AFM studies have revealed that sealant 5 (55.8 ± 6.8 nN adhesive force) has higher adhesive force than fibrin (46.4 ± 7.3 nN adhesive force). SEM data confirms that sealant 5 retains its network-like morphology both at 37 and 60 °C, inferring its thermal stability. Both sealant 5 and fibrin exhibit biodegradability in the presence of trypsin, and sealant 5 also showed biocompatibility in the presence of fibroblast cells. Engineered sealant 5 efficiently promotes hemostasis with enhanced adhesiveness and less blood-loss than fibrin. In vivodata suggests that in heparinized conditions, sealant 5 ceases bleeding at 212.3 ± 15.1 s, whereas fibrin halts bleeding at 294.3 ± 21.4 s and blood-loss is ∼4-fold less in sealant 5 than in fibrin. In a heparinized system, sealant 5 facilitates faster blood-clotting than fibrin (∼82 s faster) and RADA-16, a reported peptide-based sealant (∼113 s faster). Additionally, in the case of sealant 5, the process of clotting mimicry-like fibrin is independent of the body’s own coagulation system. Sealant 5 efficiently halts bleeding for both external and internal wounds, even for a heparinized system overcoming the bacterial infection. ELISA data and PMBC cell proliferation data support the non-immunogenic feature of sealant 5. Though fibrin and sealant 5 have exhibited comparable efficacy in suture-free wound closure, in vivoH&E staining images have revealed infiltration of very few immune cells as well as the presence of abundant collagen formation in the case of sealant 5-treated wound. Such nature-inspired non-immunogenic sealants offer exciting possibilities for the treatment of uncontrolled bleeding vis-à-vis wound closure.

Hydrogen peroxide, an environmentally friendly oxidant, is in high demand in various industrial sectors. Electrochemical H2O2production by 2e–reduction of O2is a suitable and greener alternative to the traditional anthraquinone process. However, developing metal-free electrocatalysts that predominantly follow the 2e–reduction process over the more favorable 4e–reduction is challenging. Here, we report a viologen-based redox-active ionic porous organic polymer (iPOP-TAPA-Cl) toward selective production of H2O2(86%) electrocatalytically. By varying the counteranion (Cl–) with other halogen anions (F–, Br–, and I–), a maximum H2O2selectivity of 98.5% with exceptional current efficiency was achieved in the case of iPOP-TAPA-F.

The histopathologic findings, imaging appearances, and management of uncommon intraluminal tumors of the bile ducts and gallbladder are reviewed, with an emphasis on intraductal papillary neoplasm of the bile duct.