Resilient anatomy and local plasticity of naive and stress haematopoiesis.

The bone marrow adjusts blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses are unknown owing to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent haematopoiesis, erythropoiesis and lymphopoiesis in mice. We combine these with imaging of myelopoiesis1 to define the anatomy of normal and stress haematopoiesis. In the steady state, across the skeleton, single stem cells and multipotent progenitors distribute through the marrow enriched near megakaryocytes. Lineage-committed progenitors are recruited to blood vessels, where they contribute to lineage-specific microanatomical structures composed of progenitors and immature cells, which function as the production sites for each major blood lineage. This overall anatomy is resilient to insults, as it was maintained after haemorrhage, systemic bacterial infection and granulocyte colony-stimulating factor (G-CSF) treatment, and during ageing. Production sites enable haematopoietic plasticity as they differentially and selectively modulate their numbers and output in response to insults. We found that stress responses are variable across the skeleton: the tibia and the sternum respond in opposite ways to G-CSF, and the skull does not increase erythropoiesis after haemorrhage. Our studies enable in situ analyses of haematopoiesis, define the anatomy of normal and stress responses, identify discrete microanatomical production sites that confer plasticity to haematopoiesis, and uncover unprecedented heterogeneity of stress responses across the skeleton.

Discovery of low-molecular-weight phenylalanine derivatives as novel HIV capsid modulators with improved antiretroviral activity and metabolic stability.

The HIV capsid (CA) protein is a promising target for anti-AIDS treatment due to its critical involvement in viral replication. Herein, we utilized the well-documented CA inhibitor PF74 as our lead compound and designed a series of low-molecular-weight phenylalanine derivatives. Among them, compound 7t exhibited remarkable antiviral activity with a high selection index (EC50 = 0.040 µM, SI = 2815), surpassing that of PF74 (EC50 = 0.50 µM, SI = 258). Furthermore, when evaluated against the HIV-2 strain, 7t (EC50 = 0.13 µM) demonstrated approximately 14-fold higher potency than that of PF74 (EC50 = 1.76 µM). Insights obtained from surface plasmon resonance (SPR) revealed that 7t exhibited stronger target affinity to the CA hexamer and monomer in comparison to PF74. The potential interactions between 7t and the HIV-1 CA were further elucidated using molecular docking and molecular dynamics simulations, providing a plausible explanation for the enhanced target affinity with 7t over PF74. Moreover, the metabolic stability assay demonstrated that 7t (T1/2 = 77.0 min) significantly outperforms PF74 (T1/2 = 0.7 min) in human liver microsome, exhibiting an improvement factor of 110-fold. In conclusion, 7t emerges as a promising drug candidate warranting further investigation.

Harnessing weedy rice as functional food and source of novel traits for crop improvement.

A relative of cultivated rice (Oryza sativa L.), weedy or red rice (Oryza spp.) is currently recognized as the dominant weed, leading to a drastic loss of yield of cultivated rice due to its highly competitive abilities like producing more tillers, panicles, and biomass with better nutrient uptake. Due to its high nutritional value, antioxidant properties (anthocyanin and proanthocyanin), and nutrient absorption ability, weedy rice is gaining immense research attentions to understand its genetic constitution to augment future breeding strategies and to develop nutrition-rich functional foods. Consequently, this review focuses on the unique gene source of weedy rice to enhance the cultivated rice for its crucial features like water use efficiency, abiotic and biotic stress tolerance, early flowering, and the red pericarp of the seed. It explores the debating issues on the origin and evolution of weedy rice, including its high diversity, signalling aspects, quantitative trait loci (QTL) mapping under stress conditions, the intricacy of the mechanism in the expression of the gene flow, and ecological challenges of nutrient removal by weedy rice. This review may create a foundation for future researchers to understand the gene flow between cultivated crops and weedy traits and support an improved approach for the applicability of several models in predicting multiomics variables.

Synthesis, characterization and photophysical studies of dual-emissive base-modified fluorescent nucleosides.

A straightforward and efficient methodology has been employed for the synthesis of a diverse set of base-modified fluorescent nucleoside conjugates via Cu(I)-catalysed cycloaddition reaction of 5-ethynyl-2',3',5'-tri-O-acetyluridine/3',5'-di-O-acetyl-2'-deoxyuridine with 4-(azidomethyl)-N9-(4'-aryl)-9,10-dihydro-2H,8H-chromeno[8,7-e][1,3]oxazin-2-ones in tBuOH to afford the desired 1,2,3-triazoles in 92-95% yields. Treatment with NaOMe/MeOH resulted in the final deprotected nucleoside analogues. The synthesized 1,2,3-triazoles demonstrated a significant emission spectrum, featuring two robust bands in the region from 350-500 nm (with excitation at 300 nm) in fluorescence studies. Photophysical investigations revealed a dual-emissive band with high fluorescence intensity, excellent Stokes shift (140-164 nm) and superior quantum yields (0.068-0.350). Furthermore, the electronic structures of the synthesized triazoles have been further verified by DFT studies. Structural characterization of all synthesized compounds was carried out using various analytical techniques, including IR, 1H-NMR, 13C-NMR, 1H-1H COSY, 1H-13C HETCOR experiments, and HRMS measurements. The dual-emissive nature of these nucleosides would be a significant contribution to nucleoside chemistry as there are limited literature reports on the same.

Phenyliodine bis(trifluoroacetate) as a sustainable reagent: exploring its significance in organic synthesis.

Iodine-containing molecules, especially hypervalent iodine compounds, have gained significant attention in organic synthesis. They are valuable and sustainable reagents, leading to a remarkable surge in their use for chemical transformations. One such hypervalent iodine compound, phenyliodine bis(trifluoroacetate)/bis(trifluoroacetoxy)iodobenzene, commonly referred to as PIFA, has emerged as a prominent candidate due to its attributes of facile manipulation, moderate reactivity, low toxicity, and ready availability. PIFA presents an auspicious prospect as a substitute for costly organometallic catalysts and environmentally hazardous oxidants containing heavy metals. PIFA exhibits remarkable catalytic activity, facilitating an array of consequential organic reactions, including sulfenylation, alkylarylation, oxidative coupling, cascade reactions, amination, amidation, ring-rearrangement, carboxylation, and numerous others. Over the past decade, the application of PIFA in synthetic chemistry has witnessed substantial growth, necessitating an updated exploration of this field. In this discourse, we present a concise overview of PIFA's applications as a 'green' reagent in the domain of synthetic organic chemistry. A primary objective of this article is to bring to the forefront the scientific community's awareness of the merits associated with adopting PIFA as an environmentally conscientious alternative to heavy metals.

Recent developments on Junin virus, a causative agent for Argentine haemorrhagic fever.

Junin virus consists of ribonucleic acid as the genome and is responsible for a rapidly changing tendency of the virus. The virus is accountable for ailments in the human body and causes Argentine Haemorrhagic Fever (AHF). The infection is may be transmitted through contact between an infected animal/host and a person, and later between person to person. Prevention of outbreaks of AHF in humans can be a tough practice, as their occurrence is infrequent and unpredictable. In this review, recent information from the past 5 years available on the Junin virus including the risk of its emergence, infectious agents, its pathogenesis in humans, available diagnostic and therapeutic approaches, and disease management has been summarised. Altogether, this article would be highly significant in understanding the mechanistic basis behind virus interaction and other processes during the life cycle. Currently, no specific therapeutic options are available to treat the Junin virus infection. The information covered in this review could be important for finding possible treatment options for Junin virus infections.

Elucidating the synergistic effect of acidity and metalloid poisoning on the microbiome through metagenomics and machine learning approaches.

The abundance and diversity of the microflora in a complex environment such as soil is everchanging. Mica mining has led to metalloid poisoning and changes in soil biogeochemistry affecting the overall produce and leading to toxic dietary exposure. The study focuses on two prominent stressors acidity and arsenic, in mining-contaminated agricultural locations. Soil samples were collected from agricultural fields at a distance of 50 m (zone 1) and 500 m (zone 2) from active mines. Mean arsenic concentration was higher in zone 1 and pH was lower. Geostatistical and self-organizing maps were employed to report that the pattern of localization of soil acidity and arsenic content is similar indicating a causal relationship. Cluster and principal component analysis were further used to materialize a negative effect of soil acidity fractions and arsenic labile pool on soil enzymatic activity (fluorescein diacetate, dehydrogenase, ß-1,4-glucosidase, phosphatase, and urease), respiration and Microbial biomass carbon. Soil metagenomic analysis revealed significant differences in the abundance of microbial populations with zone 1 (contaminated zone) having lower alpha and beta diversity. Finally, the efficacy of several machine-learning tools was tested using Taylor diagrams and an effort was made to select a potent algorithm to predict the causal stressors responsible for depreciating soil microbial health. Random Forrest had superior predictive power based on numerical evidence and was therefore chosen as the best-fitted model. The aforementioned insights into soil microbial health and sustenance in stressed conditions can be beneficial for predicting remedial strategies and practicing sustainable agriculture.

Numerical Analysis of Non-Fourier Model-Based Bio-Heat Transfer in the Laser-irradiated Axisymmetric Living Tissue.

The current work is related to the numerical investigation of non-Fourier heat transfer inside the short-pulsed laser-irradiated axisymmetric soft tissue phantom. It utilizes the modified discrete ordinate method to solve the transient radiative transfer equation (TRTE) for determining the intensity field. The laser energy absorbed by the soft tissue phantom behaves like a source in the Fourier/non-Fourier heat conduction model based-bio-heat transfer equation (BHTE), which is solved by employing the finite volume method (FVM) to determine the temperature distribution. Despite the prevalent use of non-Fourier BHTE for this purpose, a second law analysis is considered crucial to detect any potential anomalies. Equilibrium entropy production rates (EPR) are initially computed based on classical irreversible thermodynamics (CIT), which may yield negative values, possibly contravening the second law. Consequently, the EPR based on CIT is adjusted using the extended irreversible thermodynamics (EIT) hypothesis to ensure positivity. After that, the current research findings are compared with the results from the literature, and found good agreement between them. Then, the independent study is performed to select the optimum grid size, control angle size, and time step. A comparative analysis of results between the traditional Fourier and non-Fourier models has been performed. The impact of different parameters on the temperature fields and EPRs, is discussed. The effect of the optical properties of the inhomogeneity on the temperature distribution has been investigated. This study may help to enhance the effectiveness of the laser-based photo-thermal therapy.

Exploring the role of neutral ligands in modulating the photoluminescence of samarium complexes with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione.

Four eight-coordinated luminescent samarium complexes of type [Sm(hfpd)3L2] and [Sm(hfpd)3L'] [where hfpd = 1,1,1,5,5,5-Hexafluoro-2,4-pentanedione L = tri-octyl-phosphine oxide (TOPO) and L' = 1,10-phenanthroline (phen), neocuproine (neoc) and bathocuproine (bathoc) were synthesized via a stoichiometrically controlled approach. This allows for precise control over the stoichiometry of the complexes, leading to reproducible properties. This investigation focuses on understanding the impact of secondary ligands on the luminescent properties of these complexes. Infrared (IR) spectra provided information about the molecular structures, whereas 1H and 13C nuclear magnetic resonance (NMR) spectra confirmed these structural details along with the coordination of ligands to trivalent Sm ion. The UV-vis spectra revealed the molar absorption coefficient and absorption bands associated with the hfpd ligand and photoluminescence (PL) spectroscopy demonstrated intense orange-red emission (648 nm relative to 4G5/2 → 6H9/2) from the complexes. The Commission Internationale de l'Éclairage (CIE) triangles indicated that the complexes emitted warm orange red light with color coordinates (x, y) ranging from (0.62, 0.36) to (0.40, 0.27). The investigation of the band gap as well as color parameters confirms the utility of these complexes in displays and LEDs.

Composition of heavy metals in sediment, water, and fish of the Ganga and Yamuna Rivers in two major cities of India.

The rapid industrial development in the Indian capital region has led to significant waste generation, which, despite undergoing treatment prior to disposal, contributes substantially to water body contamination. Given the diverse nature of these wastes and their potential repercussions across the food chain, a study was conducted to evaluate heavy metal contamination levels in the Ganga and Yamuna Rivers of two major cities. Six heavy metals (Pb, Cd, Hg, Cu, Cr, and Zn) were analyzed in fish, water, and sediment samples by utilizing flame atomic absorption spectrophotometry (Avanta Σ) from March 2019 to February 2020. Results revealed distinct heavy metal distribution patterns, with Cr > Zn > Pb > Cu > Cd > Hg in the Ganga River and Zn > Cr > Pb > Cu > Cd > Hg in the Yamuna River for fish samples. Additionally, levels of Hg in Cyprinus carpio and Sperata oar from the Ganga River, and Pb, Cd, Hg, and Cr in Salmophasia bacaila and Mystus cavasius from the Yamuna River exceeded WHO/FAO permissible limits. In water samples, the predominant heavy metal sequences were Pb > Cu > Zn > Cr > Cd > Hg for the Ganga River and Cr > Zn > Pb > Cu > Cd > Hg for the Yamuna River, with Pb, Cr, Zn, and Cd surpassing WHO standards. Sediment analysis revealed varying heavy metal compositions, with Zn > Cr > Pb > Cu > Cd > Hg in the Ganga River and Cr > Zn > Pb > Cu > Cd > Hg in the Yamuna River. While drinking water and fish from the Ganga River were deemed safe for consumption, those from the Yamuna River were not. Given the toxic nature of heavy metals and their detrimental health impacts, regular monitoring and effective management strategies are imperative.

Empowering Nursing Students to Prevent Medication Error-Related Harms: A Step Toward Improving Patient Safety.

Aim: Existing gaps in nursing curriculum particularly related to medication management such as administration and monitoring increase the propensity of nurses to commit medication errors during clinical practice. The present training program was conducted with an aim to sensitize and educate undergraduate nursing students on medication errors' related aspects. Methods: The participants were students pursuing bachelors nursing degree course (second and third year). The training "Medication errors: Role of Nurse practitioners" comprised of blended teaching methods such as theme lectures, hands on training exercises, small group case­based learning, role plays, and nursing officer's practical experiences. The participants' knowledge and perception about medication errors were assessed at baseline (pre-intervention phase) and 1 week after program (post-intervention phase) with the help of a structured self-administered questionnaire in English language. Results: A total of 110 nursing students participated in the program. Post program there was a consistent increase in the number of correct responses to all knowledge-based questions with a significant improvement in knowledge scores from baseline [Baseline: (mean ± SD) 12.62 ± 2.33; Post-training: 18.52 ± 2.22; P < .001]. There was a positive change in the perception about medication errors among students. The participants rated the overall quality of program as excellent [66 (60%)] or very good [40 (36.4%)]. More than 90% agreed on its applicability in their future practice. Conclusions: The training was quite successful in educating nursing students on medication errors. There is a constant need to educate nurses and other healthcare providers including doctors and pharmacists on medication safety related aspects with an ultimate goal to improve patient safety.

Bridging the Gap between Nonliving Matter and Cellular Life.

A cell, the fundamental unit of life, contains the requisite blueprint information necessary to survive and to build tissues, organs, and systems, eventually forming a fully functional living creature. A slight structural alteration can result in data misprinting, throwing the entire life process off balance. Advances in synthetic biology and cell engineering enable the predictable redesign of biological systems to perform novel functions. Individual functions and fundamental processes at the core of the biology of cells can be investigated by employing a synthetically constrained micro or nanoreactor. However, constructing a life-like structure from nonliving building blocks remains a considerable challenge. Chemical compartments, cascade signaling, energy generation, growth, replication, and adaptation within micro or nanoreactors must be comparable with their biological counterparts. Although these reactors currently lack the power and behavioral sophistication of their biological equivalents, their interface with biological systems enables the development of hybrid solutions for real-world applications, such as therapeutic agents, biosensors, innovative materials, and biochemical microreactors. This review discusses the latest advances in cell membrane-engineered micro or nanoreactors, as well as the limitations associated with high-throughput preparation methods and biological applications for the real-time modulation of complex pathological states.

Novel Ringdown Amplitude-Phase Consistency Test.

The ringdown signal emitted during a binary black hole coalescence can be modeled as a linear superposition of the characteristic damped modes of the remnant black hole that get excited during the merger phase. While checking the consistency of the measured frequencies and damping times against the Kerr BH spectrum predicted by general relativity (GR) is a cornerstone of strong-field tests of gravity, the consistency of measured excitation amplitudes and phases have been largely left unexplored. For a nonprecessing, quasicircular binary black hole merger, we find that GR predicts a narrow region in the space of mode amplitude ratio and phase difference, independently of the spin of the binary components. Using this unexpected result, we develop a new null test of strong-field gravity which demands that the measured amplitudes and phases of different ringdown modes should lie within this narrow region predicted by GR. We call this the amplitude-phase consistency test and introduce a procedure for performing it using information from the ringdown signal. Lastly, we apply this test to the GW190521 event, using the multimodal ringdown parameters inferred by Capano et al. [arXiv:2105.05238]. While ringdown measurements errors for this event are large, we show that GW190521 is consistent with the amplitude-phase consistency test. Our test is particularly well suited for accommodating multiple loud ringdown detections as those expected in the near future, and can be used complementarily to standard black-hole spectroscopy as a proxy for modified gravity, compact objects other than black holes, binary precession and eccentricity.

Electrically Mediated Static Contact Angle and Hysteresis of Polyelectrolyte Solutions.

Manipulating a droplet by electrowetting-on-dielectric (EWOD) is vital in various fields ranging from industrial applications to life sciences. As of now, EWOD research has focused primarily on aqueous electrolytes and ionic liquids. This paper investigates the electrowetting behavior of weak polyelectrolyte solutions containing poly(acrylic acid) (PAA). The study reveals distinct wetting behavior of weakly and fully charged PAA droplets controlled by their solution pH. Under an applied electric field, strongly ionized PAA wets more effectively than weakly charged PAA. The electrowetting hysteresis of fully ionized PAA droplets was also higher than that of weakly charged droplets. The reason may be the suppression of retraction flow near the contact line. In this thin region, the electric field aligns the stretched polymer chains perpendicular to the dielectric surface, thus affecting the bulk rheological properties. The results reveal how charge-connectivity and polyelectrolyte conformation under an external electric field can control the electrowetting gain and the hysteresis. This previously unexplored electrowetting mechanism of polyelectrolyte solutions might help order and manipulate biological polyelectrolytes, such as deoxyribonucleic acid (DNA), polypeptides, and glycosaminoglycans.

Smart Anisotropic Colloidal Composites: A Suitable Platform for Modifying the Phase Transition of Diblock Copolymers by Gold Nanoparticles.

Surface modification of metallic nanoparticles (NPs) by stimuli-responsive polymers is a benign method to prepare smart colloidal composites which tune the characteristic properties of individual systems. The temperature-dependent transition of diblock copolymer poly(N-isopropylacrylamide)-block-poly(N-vinylcaprolactam) (PNIPMA-b-PVCL) synthesized using reversible addition-fragmentation chain transfer polymerization was studied by incorporating anisotropic gold NPs (AGPs) such as spheres (AuNSs), rods (AuNRs), cubes (AuNCs), and rhombic dodecahedrals (AuRDs). Shape-dependent physiochemical properties of nanostructures alter the lower critical solution temperature (LCST) of the chemical inhomogeneous diblock copolymer. Heterogeneous nucleation of AuNPs was facilitated by seed-mediated synthesis for incorporating uniformity. In the mixed system, the presence of PNIPAM-b-PVCL modifies the surface of AGPs through physisorption which is supported by transmission electron microscopy and field emission scanning electron microscopy showing the NPs embedding in the polymeric matrix. Furthermore, steady state fluorescence spectroscopy and Fourier transform infrared spectroscopy were performed to examine the phase transition behavior of PNIPAM-b-PVCL in AGPs. The formation of a smart polymer nanocomposite alters the physiochemical properties of the diblock copolymer as demonstrated from the variation of LCST in the dynamic light scattering measurement. Henceforth, functionalizing the surfaces of AGPs with a thermoresponsive diblock copolymer provides combinatorial benefits in the properties of smart polymeric colloidal systems with potential applications in bioimaging and drug delivery.

Multifarious Responses of Forest Soil Microbial Community Toward Climate Change.

Forest soils are a pressing subject of worldwide research owing to the several roles of forests such as carbon sinks. Currently, the living soil ecosystem has become dreadful as a consequence of several anthropogenic activities including climate change. Climate change continues to transform the living soil ecosystem as well as the soil microbiome of planet Earth. The majority of studies have aimed to decipher the role of forest soil bacteria and fungi to understand and predict the impact of climate change on soil microbiome community structure and their ecosystem in the environment. In forest soils, microorganisms live in diverse habitats with specific behavior, comprising bulk soil, rhizosphere, litter, and deadwood habitats, where their communities are influenced by biotic interactions and nutrient accessibility. Soil microbiome also drives multiple crucial steps in the nutrient biogeochemical cycles (carbon, nitrogen, phosphorous, and sulfur cycles). Soil microbes help in the nitrogen cycle through nitrogen fixation during the nitrogen cycle and maintain the concentration of nitrogen in the atmosphere. Soil microorganisms in forest soils respond to various effects of climate change, for instance, global warming, elevated level of CO2, drought, anthropogenic nitrogen deposition, increased precipitation, and flood. As the major burning issue of the globe, researchers are facing the major challenges to study soil microbiome. This review sheds light on the current scenario of knowledge about the effect of climate change on living soil ecosystems in various climate-sensitive soil ecosystems and the consequences for vegetation-soil-climate feedbacks.

Solvent-free synthesis and in-silico molecular docking study of (E)-3-(ß-C-glycosylmethylidene)-N-aryl/alkyl succinimides.

Globally, human papillomavirus (HPV) infection is the leading cause of mortality associated with cervical cancer, oral cancer (oropharyngeal), and head and neck squamous cell carcinoma (HNSCC). It is essential to explore anti-cancer drugs against life-threatening HPV infections. Aiming to search for potentially better anticancer agents, a small library of ß-C-glycosylated methylidene succinimides have been synthesized under bulk and mechanical grinding conditions using the Wittig olefination reaction. Thus, the reaction of different 2,3,4,6-tetra-O-benzyl-C-glycosyl aldehydes with N-aryl/alkyl maleimides in the presence of PPh3 at 25 °C under bulk and mechanical grinding conditions results in the formation of stereochemically defined (E)-3-(2,3,4,6-tetra-O-benzyl-C-glycosylmethylidene)-N-alkyl/phenyl succinimides, which upon debenzylation with 1 M BCl3 in DCM at -78 °C lead to the synthesis of (E)-3-(C-glycosylmethylidene)-N-alkyl/phenyl succinimides in good to excellent yields. The developed methodology is efficient and environmentally benign because there is no use of organic solvents, and the products are obtained in a stereochemically defined form and in high yields. The aqueous solubility of all synthesized ß-C-glycosylated methylidene succinimides makes them potential candidates for the evaluation of their different biological activities. In the present work, the synthesized glycosylated alkylidine succinimides were subjected to an in-silico molecular docking study against the E6 oncoprotein of high-risk type HPV16, which is responsible for the inactivation of the tumor suppressor p53 protein. Analysis of the molecular docking data revealed that the synthesized compounds are effective inhibitors of HPV infection, which is the cause of oral, head and neck, and cervical cancer. In comparison with the positive control 5-FU, an anti-cancer drug used in chemotherapy, more than fifteen compounds were found to be better E6 protein inhibitors.

Remediation of contaminants from wastewater using algal nanoparticles via green chemistry approach: an organized review.

Bio-nanotechnology is one of the new and sound techniques that have various advantages over conventional methods of wastewater treatment. The utilization of nanomaterials like nanoparticles for wastewater treatment is emerging field of research. Both physical and chemical methods can be used for nanoparticle synthesis, but synthesis based on algae (biological method) has numerous advantages over others as it is environmentally friendly and sustainable. Top-down and bottom-up are the two approaches used for nanoparticle synthesis, generally, bio-reduction (bottom-up approach) is used to synthesize nanoparticles. Nanoparticles can be synthesized inside the cell of algae called intracellular synthesis and outside on the surface of the cell called extracellular synthesis. Temperature, pH, and reaction time are some of the factors that can influence the synthesis, size, and properties of nanoparticles. Characterization of nanoparticles is carried out with the help of the techniques like UV-visible spectroscopy (UV-vis), x-ray diffraction, Fourier transfer infrared spectroscopy, etc. Algal nanoparticles are highly efficient in the remediation of contaminants like heavy metals and dyes from wastewater. In the present review, the utilization of algal nanoparticles for wastewater treatment containing contaminants like heavy metals, and dye, and various methods of synthesis of nanoparticles from algae are discussed. Moreover, the challenges and opportunities present in this field are also highlighted. As this field is in its initial stage, therefore, a lot of research gaps are present, which can only be filled by further new research.

A Novel Rhodamine Probe Acting as Chemosensor for Selective Recognition of Cu2+ and Hg2+ Ions: An Experimental and First Principle Studies.

Copper and Mercury ions have vital role to play in biological world as their excess or deficiency can cause different type of diseases in human being as well as biological species including plants and animals. Therefore, their detection at trace level becomes very important in term of biological. The current studies embody the fabrication, structural characterization and recognition behavior of a novel rhodamine B hydrazone formed when hydrazide of rhodamine B was condensed with 5-Allyl-3-methoxy salicylaldehyde (RBMA). RBMA was found to be responsive towards the very trace level of Cu2+ and Hg2+ among other tested cations so far. The sensing procedure is based on the classical opening of the spiroatom ring of rhodamine. The limit of detection (LOD) and binding constant is 5.35 ppm, 2.06 × 104 M-1 and 5.16 ppm, 1.26 × 104 M-1 for Cu2+ and Hg2+ ions respectively. The probable mechanism correlates the specific binding of RBMA with Cu2+ and Hg2+ ions. The 1:1 stoichiometry of RBMA with Cu2+ and Hg2+ ions have been supported by HRMS, FT-IR data, Job's plot, and binding constant data. Reversibility is well exhibited by RBMA by the involvement of CO32- ions via demetallation process. The real time application is well demonstrated by the use of paper strip test. The DFT study also carried out which agrees well with the experimental findings. The results displayed the novelty of this current work towards the trace level analysis of the Cu2+ and Hg2+ of the cations which are play the crucial role in industry.

Intrinsic viscosity and dielectric relaxation of ring polymers in dilute solutions.

The absence of chain ends makes ring polymers distinctly different from their linear analogues. The intrinsic viscosity, complex viscosity and the dielectric relaxation of ring polymers are investigated within the tenets of the optimized Rouse-Zimm theory. The distance dependent excluded volume interactions (EVIs) are obtained from Flory's mean field theory. The hydrodynamic interactions (HIs) between the pairs of monomers are estimated using the preaveraged Oseen tensor. The intrinsic viscosity of linear and ring polymers both with and without EVI are compared as a function of ring size. A monotonically increasing trend of the intrinsic viscosity is observed in both cases. The intrinsic viscosity of both linear and ring polymers both with and without EVI show a very good agreement with the experimental results of polystyrene over a wide range of molecular weights in both good and theta solvents, respectively. The fractal dimensions of the ring polymers with EVI lie between that of a random walk and a self-avoiding walk model of linear polymers in three dimensions. The ring size increases with EVI and the effect of EVI is stronger on larger rings than that on smaller rings. The dielectric relaxation follow a connectivity independent universal scaling behavior at low and high frequency regions. The imaginary part of the complex dielectric susceptibility displays a local maxima in the intermediate frequency region, which reveals a structure dependent behavior of the rings. The theoretically calculated dielectric loss of ring polymers with HI matches well with those obtained from experiments.