Tailoring Indocyanine Green J-Aggregates for Imaging, Cancer Phototherapy, and Drug Delivery: A Review.

Indocyanine green J-aggregates (ICG-Jagg) have emerged as a significant subject of interest in biomedical applications due to their unique optical properties, tunable size, and excellent biocompatibility. This comprehensive review aims to provide an in-depth exploration of ICG-Jagg, with a focus on elucidating the diverse facets of their preparation and the factors that influence the preparation process. Additionally, the review discusses their applications in biomedical diagnostics, such as imaging and contrast agents, as well as their utilization in drug delivery and various phototherapeutic interventions.

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.

Factor defining the effects of tetraalkylammonium chloride on stability, folding, and dynamics of horse cytochrome c.

This article describes the molecular mechanism by which tetraalkylammonium chloride ([R4N]Cl: R- = methyl (Me), ethyl (Et), propyl (Pr),butyl (Bu)) modulates the stability, folding, and dynamics of cytochrome c (Cyt c). Analysis of [R4N]Cl effects on thermal/chemical denaturations, millisecond refolding/unfolding kinetics, and slow CO-association kinetics of Cyt c without and with denaturant providing some significant results: (i) [R4N]Cl decreasing the unfolding free energy estimated by thermodynamic and kinetic analysis of thermal/chemical denaturation curves and kinetic chevrons (Log kobs-[GdmCl]) of Cyt c, respectively (ii) hydrophobicity of R-group of [R4N]Cl, preferential inclusion of [R4N]Cl at the protein surface, and destabilizing enthalpic attractive interactions of [Me4N]Cl and steric entropic interactions of [Et4N]Cl,[Pr4N]Cl and [Bu4N]Cl with protein contribute to [R4N]Cl-induced decrease thermodynamic stability of Cyt c (iii) [R4N]Cl exhibits an additive effect with denaturant to decrease thermodynamic stability and refolding rates of Cyt c (iv) low concentrations of [R4N]Cl (≤ 0.5 M) constrain the motional dynamics while the higher concentrations (>0.75 M [R4N]Cl) enhance the structural-fluctuations that denture protein (v) hydrophobicity of R-group of [R4N]Cl alters the [denaturant]-dependent conformational stability, refolding-unfolding kinetics, and CO-association kinetics of Cyt c. Furthermore, the MD simulations depicted that the addition of 1.0 M of [R4N]Cl increased the conformational fluctuations in Cyt c leading to decreased structural stability in the order [Me4N]Cl < [Et4N]Cl < [Pr4N]Cl < [Bu4N]Cl consistent with the experimental results.

The Efficacy of LRINEC Scoring in Patients with Necrotizing Fasciitis and its Correlation with the Outcomes.

<b><br>Introduction:</b> Necrotizing fasciitis (NF) is an expeditiously escalating inflammatory infection of the fascia, with secondary necrosis of the subcutaneous tissues. To aid diagnosis, the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) scoring system was devised to stratify the likelihood of infection in patients on presentation.</br> <b><br>Aim:</b> The study aimed to investigate and quantify the relationships between the LRINEC scoring system and the outcomes such as the need for amputation, length of hospital stay, and mortality in patients with necrotizing fasciitis.</br> <b><br>Material and methods:</b> A total number of 90 patients were admitted with a provisional diagnosis of necrotizing fasciitis. LRINEC score was calculated for each case based on six laboratory variables at the time of presentation. Enrolled patients were divided into three groups on the basis of the LRINEC score. The differences in mortality, length of hospitalization, number of debridement procedures, and need for amputation between these groups were compared.</br> <b><br>Results:</b> Increasing age, male gender, and DM have a poor prognosis in necrotizing fasciitis patients. The amputation and mortality rates are better correlated with higher LRINEC scores.</br> <b><br>Conclusions:</b> The LRINEC score helps in stratifying the patients into three risk categories (low risk, moderate risk, and high risk) according to the severity in a much more organized way, and thus the appropriate management like surgical debridement can be introduced on time. LRINEC score is a robust index that is capable of detecting early cases of necrotizing fasciitis and is simple enough for routine use. It is a simplified bedside diagnostic tool for early diagnosis and prediction of outcomes in patients with necrotizing fasciitis.</br>.

Rev-erbα regulate neurogenesis through suppression of Sox2 in neuronal cells to regenerate dopaminergic neurons and abates MPP+ induced neuroinflammation.

Parkinson's disease is a progressive neurodegenerative disease that affects the motor and non-motor circuits of the brain. Currently, there are no promising therapeutic measures for Parkinson's disease, and most strategies designed to alleviate the Parkinson's disease are palliative. The dearth of therapeutic interventions in Parkinson's disease has driven attention in the search for targets that may augment dopamine secretion, promote differentiation towards dopaminergic neuronal lineage, or aid in neuroprotection from neuronal stress and inflammation, and prevent Parkinson's disease associated motor impairment and behavioural chaos. The study first reports that Rev-erbα plays an important role in regulating the differentiation of undifferentiated neuronal cells towards dopaminergic neurons through abating Sox2 expression in human SH-SY5Y cells. Rev-erbα directly binds to the human Sox2 promoter region and represses their expression to promote differentiation towards dopaminergic neurons. We have reported a novel mechanism of Rev-erbα which effectively abrogates 1-methyl-4-phenylpyridinium induced cytotoxicity, inflammation, and oxidative stress, exerted a beneficial effect on transmembrane potential, and suppressed apoptosis in the neuronal in vitro model of Parkinson's disease. Rev-erbα ligand SR9011 was observed to ease the disease severity in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine induced mouse model of Parkinson's disease. Rev-erbα alleviates the locomotor behavioural impairment, prevents cognitive decline and promotes motor coordination in mice. Administration of Rev-erbα ligand also helps in replenishing the dopaminergic neurons and abrogating the neurotoxin mediated toxicity in an in vitro and in vivo Parkinson's disease model. We conclude that Rev-erbα emerges as a moonlighting nuclear receptor that could be targeted in the treatment and alleviation of Parkinson disease.

Red luminescent water stable lead-free 2D tin halide perovskite nanocrystals for photodetectors.

In this report, we have synthesized an environmentally friendly hybrid organic-inorganic layered two-dimensional (2D) lead-free perovskite nanomaterial. The synthesized perovskites, namely (OleylAm)2SnI4 (MHP1), exhibit outstanding water stability and emit luminous red light. The photodetector constructed using our material showcases superior characteristics, including a faster response than comparable devices and improved rise and fall times compared to other 2D perovskite nanomaterials.

Improved Survival With Chemotherapy in Patients With Malignant Biliary Tract Obstruction After Percutaneous Transhepatic Biliary Drainage (PTBD).

Introduction Biliary tree stenting for malignant biliary tract obstructions is a routine modality for the relief of jaundice. Treatment is palliative in most circumstances. However, adequate reduction in bilirubin levels after percutaneous transhepatic biliary drainage (PTBD) may help to offer chemotherapy, which may improve survival in a limited number of cases. Materials and methods Between March 2017 and March 2023, patients who were treated with PTBD to relieve malignant biliary tract obstruction were included in the analysis. Patients who achieved bilirubin levels ≤5 mg/dL after PTBD were considered for chemotherapy. For survival analysis, a comparison was done between patients treated with chemotherapy after PTBD versus patients who did not receive any treatment after PTBD.  Results Data was available for 43 (100%) patients. After PTBD, 16 (37.2%) patients responded and were considered for further treatment. One patient who was advised of radical surgery refused treatment and did not return for further treatment or follow-up. The remaining 15 cases (34.9%) received Gemcitabine and platinum-based chemotherapy as a first-line option. Out of 15 cases who received chemotherapy only one patient (6.6%) received neoadjuvant chemotherapy and the rest of 14 (32.5.%) cases received palliative chemotherapy in view of metastatic disease. PTBD complications including leakage, dislodgement of PTBD catheter, pain, and bleeding were seen in 16 (37.2%) cases. Overall survival was 57% for the entire population. Patients treated with chemotherapy after PTBD had better overall survival compared to patients who did not receive any treatment after PTBD (73.3% vs 33% (p=0.008)). Conclusion PTBD is an excellent technique for the relief of biliary obstruction. More than one-third (34.9%) of the cases received further cancer-directed treatment after relief of jaundice by PTBD. Chemotherapy after PTBD is associated with improvement in overall survival in malignant biliary obstructions.

Sodium Ion-Conducting Electrolytes Based on Chloroaluminate Ionic Liquids and δ-NaCl.

Sodium-containing ionic liquids are very promising candidates as ion-conducting materials in alternative to electrolytes based on lithium chemistry. Here we investigate a series of seven ionic liquids with formula (EMImCl/(AlCl3)1.5)/(δ-NaCl)x (0≤x≤0.74). The salt is comprised of a disordered form of NaCl prepared by metalorganic synthesis, which assures faster dissolution in high concentration. The vibrational investigation carried out by FT-IR spectroscopy in the medium IR region shed light on salt-IL interactions. The ionic conductivity was investigated by Broadband Electric Spectroscopy. The direct current conductivity (σdc) profiles versus the reciprocal temperature exhibited a Vogel-Tamman-Fulcher behavior indicating the assistance of micro-Brownian motions to ionic migration. The value of σdc at 25 °C for x=0.74 was found to be 1.2×10-2 S cm-1. Reversible deposition of Na and Al-containing species take place with high Coulombic efficiency (up to 97 %) and a high Na+ cation transport number (up to 0.95). The understanding of ionic speciation was investigated in comparison with aqueous acid-base systems exploring the benefits and limitations of such analogy. The role of a Grotthuss-type mechanism facilitating the exchange of chlorides between acidic catenated chloroaluminate species in anionic domains of the ILs is considered.

Optimizing white light emission in Dy(iii) complexes: impact of energy transfer from mono and bidentate ligands on luminescence.

Complexes of dysprosium(iii) ions with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione featuring various mono and bi-dentate neutral ligands have been prepared and thoroughly investigated. The synthesized complexes exhibit an octa-coordinated environment, achieved by stoichiometrically combining organic ligands and Dy(iii) ions. This octa-coordination environment of Dy(iii) ion was confirmed by FT-IR spectroscopy, thermogravimetry and elemental analysis. Near-white light (NWL) is emitted when complexes were exposed to UV radiation, indicating a significant flow of energy from the sensitizing moieties towards the Dy(iii) ion. This NWL emission might have resulted due to a balance between the intensities corresponding to emission peaks at 480 nm (blue) and 575 nm (yellow) in Dy1-Dy3. Emission spectra recorded at different excitation wavelength were utilized to study the tunability of CIE color coordinates. In addition to their high thermal stability, the complexes display bipolar paramagnetic shifts in their NMR spectra. The 4F9/2 → 6H13/2 transition, contributing ∼62% of the total emission, stands out as a promising candidate for laser amplification due to its dominance in the emission spectra. Additionally, NWL emission observed in a solid Dy(iii) complex opens intriguing possibilities for its application in next-generation white-light emitting devices.

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.

Assessment of prevalence and distribution of congenital missing teeth among patients visiting tertiary care hospital: A radiographic study.

Introduction: Dental Agenesis is the usual developmental dental anomaly involving both primary and permanent dentition but most commonly it affects the permanent teeth. Genetic mutations in genes like MSX, PAX9,TGFA and AXIN2 are the likely primary contributors to tooth agenesis. Identifying the prevalence and distribution of congenital missing teeth allows for early detection and intervention which is crucial for preventing or mitigating potential dental issues that may arise due to missing teeth. Aim & objectives: To assess the prevalence and distribution of congenitally missing teeth across different quadrants of the jaw among patients visiting to the Dental out patient department at Tertiary Care Centre of Lucknow city. Material & method: A Questionnaire and orthopantomogram based cross-sectional study was conducted on both male and female patients aged between 15 and 30 years, coming for evaluation of their dental health problems to the hospital. Written informed consent was obtained. Results: The overall prevalence of CMT was found to be 33.3 %. The significant difference was observed in proportion of CMT between Maxilla and Mandible sites (p = 0.008). Higher prevalence was in females compared to males for both maxillary and mandibular congenital missing teeth. (p = 0.020). Conclusion: The most common CMT were third molars followed by lateral incisors. The insights derived from the study would aid dental professional in gaining a deeper comprehension of tooth agenesis.

Design of antipodal vivaldi antenna with patch and corrugations for 5G applications.

A compact 1 × 4 antipodal Vivaldi antenna (AVA) array designed for 5 G applications is introduced in this study. An elliptical-shaped parasitic patch and corrugation are strategically employed to enhance gain and bandwidth, making it well-suited for 5 G applications. The resulting AVA array with corrugation and parasitic patch (AVA-PC) is designed and simulated on ANSYS HFSS, demonstrating a stable gain ranging from 10 dBi to 11.7 dBi over the frequency range of 23.45 GHz to 28.74 GHz. The antenna, with 25.8 mm x 22.4 mm x 0.5 mm dimensions, is implemented on Roger's RT/Duroid substrate 5880. •Design uses an antipodal Vivaldi antenna to build a 1 × 4 AVA.•The array employs corrugations and an elliptical patch as a performance enhancement technique.•Simulated results confirm the designed antenna's practical utility for 5 G applications in a band of 23.45 GHz to 28.74 GHz.

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.

Diagnostic Accuracy of Artificial Intelligence-Based Algorithms in Automated Detection of Neck of Femur Fracture on a Plain Radiograph: A Systematic Review and Meta-analysis.

Objectives: To evaluate the diagnostic accuracy of artificial intelligence-based algorithms in identifying neck of femur fracture on a plain radiograph. Design: Systematic review and meta-analysis. Data sources: PubMed, Web of science, Scopus, IEEE, and the Science direct databases were searched from inception to 30 July 2023. Eligibility criteria for study selection: Eligible article types were descriptive, analytical, or trial studies published in the English language providing data on the utility of artificial intelligence (AI) based algorithms in the detection of the neck of the femur (NOF) fracture on plain X-ray. Main outcome measures: The prespecified primary outcome was to calculate the sensitivity, specificity, accuracy, Youden index, and positive and negative likelihood ratios. Two teams of reviewers (each consisting of two members) extracted the data from available information in each study. The risk of bias was assessed using a mix of the CLAIM (the Checklist for AI in Medical Imaging) and QUADAS-2 (A Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies) criteria. Results: Of the 437 articles retrieved, five were eligible for inclusion, and the pooled sensitivity of AIs in diagnosing the fracture NOF was 85%, with a specificity of 87%. For all studies, the pooled Youden index (YI) was 0.73. The average positive likelihood ratio (PLR) was 19.88, whereas the negative likelihood ratio (NLR) was 0.17. The random effects model showed an overall odds of 1.16 (0.84-1.61) in the forest plot, comparing the AI system with those of human diagnosis. The overall heterogeneity of the studies was marginal (I2 = 51%). The CLAIM criteria for risk of bias assessment had an overall >70% score. Conclusion: Artificial intelligence (AI)-based algorithms can be used as a diagnostic adjunct, benefiting clinicians by taking less time and effort in neck of the femur (NOF) fracture diagnosis. Study registration: PROSPERO CRD42022375449. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-024-01130-6.

Advances in chromone-based copper(ii) Schiff base complexes: synthesis, characterization, and versatile applications in pharmacology and biomimetic catalysis.

Chromones are well known as fundamental structural elements found in numerous natural compounds and medicinal substances. The Schiff bases of chromones have a much wider range of pharmacological applications such as antitumor, antioxidant, anti-HIV, antifungal, anti-inflammatory, and antimicrobial properties. A lot of research has been carried out on chromone-based copper(ii) Schiff-base complexes owing to their role in the organometallic domain and promise as potential bioactive cores. This review article is centered on copper(ii) Schiff-base complexes derived from chromones, highlighting their diverse range of pharmacological applications documented in the past decade, as well as the future research opportunities they offer.

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.

Nuclear receptor Rev-erbα role in fine-tuning erythropoietin gene expression.

ABSTRACT: The regulation of red blood cell (RBC) homeostasis by erythropoietin (EPO) is critical for O2 transport and maintaining the adequate number of RBCs in vertebrates. Therefore, dysregulation in EPO synthesis results in disease conditions such as polycythemia in the case of excessive EPO production and anemia, which occurs when EPO is inadequately produced. EPO plays a crucial role in treating anemic patients; however, its overproduction can increase blood viscosity, potentially leading to fatal heart failure. Consequently, the identification of druggable transcription factors and their associated ligands capable of regulating EPO offers a promising therapeutic approach to address EPO-related disorders. This study unveils a novel regulatory mechanism involving 2 pivotal nuclear receptors (NRs), Rev-ERBA (Rev-erbα, is a truncation of reverse c-erbAa) and RAR-related orphan receptor A (RORα), in the control of EPO gene expression. Rev-erbα acts as a cell-intrinsic negative regulator, playing a vital role in maintaining erythropoiesis at the correct level. It accomplishes this by directly binding to newly identified response elements within the human and mouse EPO gene promoter, thereby repressing EPO production. These findings are further supported by the discovery that a Rev-erbα agonist (SR9011) effectively suppresses hypoxia-induced EPO expression in mice. In contrast, RORα functions as a positive regulator of EPO gene expression, also binding to the same response elements in the promoter to induce EPO production. Finally, the results of this study revealed that the 2 NRs, Rev-erbα and RORα, influence EPO synthesis in a negative and positive manner, respectively, suggesting that the modulating activity of these 2 NRs could provide a method to target disorders linked with EPO dysregulation.

Nr1h4 and Thrb ameliorate ER stress and provide protection in the MPTP mouse model of Parkinson's.

Elevated ER stress has been linked to the pathogenesis of several disease conditions including neurodegeneration. In this study, we have holistically determined the differential expression of all the nuclear receptors (NRs) in the presence of classical ER stress inducers. Activation of Nr1h4 and Thrb by their cognate ligands (GW4064 and T3) ameliorates the tunicamycin (TM)-induced expression of ER stress genes. A combination of both ligands is effective in mitigating cell death induced by TM. Further exploration of their protective effects in the Parkinson's disease (PD) model shows that they reduce MPP+-induced dissipation of mitochondrial membrane potential and ROS generation in an in vitro PD model in neuronal cells. Furthermore, the generation of an experimental murine PD model reveals that simultaneous treatment of GW4064 and T3 protects mice from ER stress, dopaminergic cell death, and functional deficits in the MPTP mouse model of PD. Thus, activation of Nr1h4 and Thrb by their respective ligands plays an indispensable role in ER stress amelioration and mounts protective effects in the MPTP mouse model of PD.

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.

Unusual redox stability of pentavalent uranium with hetero-bifunctional phosphonocarboxylate: insight into aqueous speciation.

The +5 state is an unusual oxidation state of uranium due to its instability in the aqueous phase. As a result, gaining information about its aqueous speciation is extremely difficult. The present work is an attempt in that direction and it provides insight into the existence of a new pentavalent species in the presence of hetero-bifunctional phosphonocarboxylate (PC) chelators, other than the carbonate ion, in the aqueous medium. The aqueous chemistry of pentavalent uranium species with three environmentally relevant PCs was probed using electrochemical and DFT methods to understand the redox energy and kinetics of conversion of the U(VI)/U(V) couple, stability, structure, stoichiometry, binding modes, etc. Interestingly, pentavalent uranium complexes with PCs are quite persistent over a wide range of pH starting from acidic to alkaline conditions. The PC chelators block the cation-cation interaction (CCI) of U(V) through strong hetero-bidentate chelation and intermolecular hydrogen bonding (IMHB) interactions which stabilize the pentavalent metal ion against disproportionation. For uranyl species in the presence of PCs, acting as chelators, CV plots were obtained at varying pH values from 2 to 8. The obtained results indicate an irreversible single redox peak involving U(VI) to U(V) conversion and association of a coupled chemical reaction with the electron transfer step. ESI-MS studies were performed to understand the speciation effect on the U(VI)/U(V) redox couple with varying pH. Speciation modelling of U(V) with the PC ligands was carried out, which indicated that the U(V) is redox stable in nearly 47% of the pH region in the presence of the PCs as compared to the carboxylate-based chelators. The free energy and reduction potential of the U(V) complexes and the reduction free energy and disproportionation free energy for the U(VI)/U(V) couple were determined by DFT computations in the presence of the PCs. In situ spectroelectrochemical spectra were recorded to provide evidence for the existence of U(V) species with PCs in the aqueous medium and to acquire its absorption spectra. The present study is highly significant for understanding the coordination chemistry of pentavalent uranium species, accurate modelling of uranium, and isolation of U(V).