Glowing discoveries: Schiff base-cyanostilbene probes illuminating metal ions and biological entities.

Schiff bases featuring cyanostilbene units have emerged as versatile and highly effective probes for the selective detection of various metal ions as well as biologically important species. This review comprehensively highlights recent advances in the development and application of the probes, which exhibit remarkable Aggregation-Induced Emission (AIE), Twisted Intramolecular Charge Transfer (TICT), and Excited-State Intramolecular Proton Transfer (ESIPT) properties. These unique structural characteristics facilitate their potential applications in the detection of biologically important metal ions such as Zn2+, Fe3+, Cu2+, Hg2+ and Co2+ ions with high sensitivity and selectivity. Furthermore, these probes have demonstrated significant potential in the recognition of vital biological species, including arginine, hydrazine and hypochlorite (ClO-). The present review discusses the underlying detection mechanisms, emphasizing the role of the Schiff base and cyanostilbene moieties for the selective detection of particular biologically important entities. Moreover, this discussion highlights the practical applications, problems, and future directions in this fast-growing field, emphasizing the vital importance of these probes in both analytical chemistry and bioassays.

Unveiling the Reactivity of Part Per Million Levels of Cobalt-Salen Complexes in Hydrosilylation of Ketones.

A series of air-stable cobalt(III)salen complexes Co-1 to Co-4 have been synthesized and employed in the hydrosilylation of ketones. Notably, the most intricately tailored Co-3 pre-catalyst exhibited exceptional catalytic activity under mild reaction conditions. The developed catalytic hydrosilylation protocol proceeded with an unusual ppm level (5 ppm) catalyst loading of Co-3 and achieved a maximum turnover number (TON) of 200,000. A wide variety of aromatic, aliphatic, and heterocyclic ketones encompassing both electron-donating and electron-withdrawing substituents were successfully transformed into the desired silyl ethers or secondary alcohols in moderate to excellent yields.

Tailoring Emission Color Shifts in Mechanofluorochromic-Active AIE Systems of Carbazole-Based D-π-A Conjugates: Impact of π Spacer Unit Variants.

The expanding field of organic electronics has led to the emergence of donor-π-acceptor (D-π-A) systems as promising candidates for various optoelectronic applications. Recent advancements in the design of organic fluorophores allow precise modulation of their optical properties in the solution and solid states, broadening their utility. Here, we synthesize and characterize two series of D-π-A systems based on carbazole-cyanostilbene compounds (3a-c and 4a-c), which feature differences in π-spacer groups and substitution on the acceptor cyanostilbene units. These compounds exhibit intramolecular charge transfer (ICT) characteristics, with 3c possessing a phenyl spacer and -CF3 substitution displaying notable solvatochromism and polarity-enhanced emission (PEE). Additionally, both series show aggregation-induced emission (AIE), with emission color shifts controlled by spacer groups. These compounds demonstrate diverse emissive behaviors, including locally excited (LE), twisted intramolecular charge transfer (TICT), and π-π stacked aggregated states, contributing to the AIE phenomenon. Compounds with phenyl spacers (3a-c) exhibit higher solid-state quantum yields than those of thiophene (4a-c). Furthermore, the impact of spacer groups and acceptor substitutions on the solid-state emissive properties and mechanofluorochromism (MFC) are highlighted. Compounds with phenyl spacers and substitution (3a, 3c) show a blue-shifted MFC, while those with thiophene (4a, 4c) display a red-shifted MFC. These findings offer insights into the development of advanced materials with tunable emission properties and high thermal stability for optoelectronic applications.

Ureteroscopic lithotripsy by thulium fiber laser versus holmium laser: A single-center prospective randomized study.

Objective: Laser lithotripsy has been the standard of care for lower and mid-ureteric calculi. Thulium fiber laser (TFL) is a new introduction to this field, which has been extensively studied for retrograde intrarenal surgery. We have done a prospective randomized study of ureteroscopic lithotripsy between TFL and holmium: Yttrium-aluminum-garnet (HO: YAG) laser to know the efficacy of stone fragmentation, stone-free rate, and complications. Methodology: A prospective randomized study was done in our hospital from March 2021 to May 2022 on patients planned for ureteroscopic laser lithotripsy. Patients with distal and mid-ureteral stones from 4 mm to 15 mm were included. The laser was used to fragment the stone. All the stones were fragmented from the center to periphery. The setting used was up to 10 W (6-10 Hz, 1J) for TFL and up to 10 W for HO: YAG (5-10 Hz, 0.5-1J). Once the stones were fragmented, they were retrieved until complete visual clearance. Demographic data and stone parameters such as stone size, volume, density, laterality, laser usage time, total operative time, and total energy used were recorded. Operative time, lasering time, retropulsion rate, ablation speed, and visibility score were recorded. Results: Each group had 90 randomized patients. Both the groups had similar kinds of patient and stone profiles. The mean operating time was 18.5 ± 1.5 min (95% confidence interval [CI] 16.2-25.6) in the TFL group, which was shorter than the holmium group 31.6 ± 1.2 min (95% CI 18.4-38.5), and it was statistically significant (P = 0.024,). Lasering time was also statistically significant with less lasering time with TFL group 7.4 ± 1.8 min (95% CI 5.2-10.3) versus holmium group 14.8 ± 1.5 min (95% CI 12.3-18.4) (P = 0.011). Laser efficacy and ablation speed were better in the TFL group compared to the HO: YAG group and were statistically significant. The visual score was better in HO: YAG group compared to the TFL group. Conclusion: TFL is more efficacious and faster than Holmium: Yag laser. Complications were similar between the groups. Stone-free rate was also similar between both the groups.

Jamun Seed-Derived Nitrogen-Doped Carbon Dots: A Novel Microwave-Assisted Synthesis for Ultra-Bright Fluorescence and Mn7+ Detection.

For the synthesis of heteroatom-doped carbon nanostructures, biomass is considered as a promising option. Utilizing the microwave-assisted method, we have demonstrated an easy and straightforward one-pot synthesis of nitrogen-doped luminous carbon dots (NCDs) from jamun seed powder and guanidine hydrochloride. Structural and morphological analyses were performed using various analytical techniques. Under ultraviolet light of 315 nm, NCDs emit a bright blue fluorescence, possess a high quantum yield of 26.90%, exhibit strong water dispersion, and demonstrated excellent stability. The average particle size of the NCDs was found to be 7.5±1.2 nm, with a spherical shape. NCDs exhibit high selectivity and sensitivity in fluorescence quenching when exposed to Mn7+ ions. Over a concentration range of 2-30 µM, the fluorescence response (F0/F) shows a linear relationship with Mn7+ concentration, with a detection limit of 0.81 µM. The probe exhibited negligible interference and proved to be effective in accurately quantifying Mn7+ in spiked real-water samples.

Discovery of potential Aurora-A kinase inhibitors by 3D QSAR pharmacophore modeling, virtual screening, docking, and MD simulation studies.

The Aurora-kinase family comprises of cell cycle-regulated serine/threonine kinases playing a vital role during mitosis. Aurora-A kinase is involved in multiple mitotic events in cell cycle and is a major regulator of centrosome function during mitosis. Aurora-A is overexpressed in breast, lung, colon, ovarian, glial, and pancreatic cancer. Hence, Aurora-A kinase is a promising target in cancer therapy. In our current study, a four-point 3D QSAR pharmacophore model has been generated using substituted pyrimidine class of Aurora-A kinase inhibitors. It had a fixed cost value 88.7429. The model mapped well to the external test set comprising of clinically active molecules, with a correlation coefficient r = 0.99. From the mapping, it was found that the hydrophobic features (HY) of a molecule play an important role for Aurora-A kinase inhibitory activity, whereas the ring aromatic feature provides geometric constraint for spatial alignment of different functional group. The hypothesis, with one hydrogen bond acceptor, two ring aromatic features, and one hydrophobic feature, was selected to screen miniMaybridge database. The screened ligands were filtered on the basis of activity, shape, and drug likeliness. This led to the identification of five top hits. These identified potential leads were further subjected to docking with the ATP-binding site of Aurora-A kinase. The molecular dynamic simulation studies of top lead molecules having diverse scaffolds endorsed that the identified molecules had distinctive ability to inhibit Aurora-A kinase. Thus, this study may facilitate the medicinal chemists to design promising ligands with various scaffolds to inhibit Aurora-A kinase. Communicated by Ramaswamy H. Sarma.

Design, synthesis of 1,2,4-triazine derivatives as antidepressant and antioxidant agents: In vitro, in vivo and in silico studies.

The novel series of substituted-N-(5,6-diphenyl-1,2,4-triazin-3-yl) benzamides (R: 1-12) were designed, synthesized and evaluated for in-vitro and in-vivo antidepressant-like activity. In MAO-A inhibition assay, compound R: 5 and R: 9 displayed most potent activity with IC50 = 0.12 and 0.30 µM. R: 5 and R: 9 were also evaluated for in-vivo antidepressant using FST and TST. In both models, the test samples R: 5 and R: 9 showed noteworthy antidepressant effect. R: 5 showed 46.48 % and 45.96 % reduction in immobility in FST and TST respectively at dosage of 30 mg/kg (p.o). Whereas compound R: 9 reduced the immobility time by 52.76 % and 47.14 % as compared to control in FST and TST, respectively at same dosage. Both the compounds were also tested for behavioural study using actophotometer and grip tests. None of compounds exhibited decrease in locomotor activity. Further, these compounds were subjected to in silico studies to determine their ADME properties along with binding energies and binding orientions. In ADME studies none of the compounds violated the Lipinski rule and all other parameters were also within the acceptable ranges. In docking study R: 5 (-10.7) and R: 9 (-10.4) were also displayed highest docking score. These encouraging results present the pharmacophoric features of substituted-N-(5,6-diphenyl-1,2,4-triazin-3-yl) benzamides as interesting lead for further development of new antidepressant drug molecules.

Occult penile fracture: An atypical presentation.

Penile fracture is a urological emergency. Most cases are under reported due to social stigma. It is caused by rupture of the tunica -albuginea of corpora cavernosa. Here we present an atypical case of penile fracture, with normal physical examination findings. But characteristic history and ultrasonography, led us to penile exploration and timely repair. Delay in diagnosis and treatment could have led to complications. Objective of our case report is to raise suspicion of fracture penis in patients with typical history, even without physical findings with normal appearing penis. This helps in early repair and prevent complications.

Direct Asymmetric Hydrogenation and Dynamic Kinetic Resolution of Aryl Ketones Catalyzed by an Iridium-NHC Exhibiting High Enantio- and Diastereoselectivity.

A chiral iridium carbene-oxazoline catalyst is reported that is able to directly and efficiently hydrogenate a wide variety of ketones in excellent yields and good enantioselectivity (up to 93 % ee). Moreover, when using racemic α-substituted ketones, excellent diastereoselectivities were obtained (dr 99:1) by dynamic kinetic resolution of the in situ formed enolate. Overall, the herein described hydrogenation occurs under ambient conditions using low hydrogen pressures, providing a direct and atom efficient method towards chiral secondary alcohols.

Prognostic factors of in-hospital complications after hip fracture surgery: a scoping review.

INTRODUCTION: To examine prognostic factors that influence complications after hip fracture surgery. To summarize proposed underlying mechanisms for their influence. METHODS: We reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Scoping Review extension. We searched MEDLINE, Embase, CINAHL, AgeLine, Cochrane Library, and reference lists of retrieved studies for studies of prognostic factor/s of postoperative in-hospital medical complication/s among patients 50 years and older treated surgically for non-pathological closed hip fracture, published in English on January 2008-January 2018. We excluded studies of surgery type or in-hospital medications. Screening was duplicated by two independent reviewers. One reviewer completed the extraction with accuracy checks by the second reviewer. We summarized the extent, nature, and proposed underlying mechanisms for the prognostic factors of complications narratively and in a dependency graph. RESULTS: We identified 44 prognostic factors of in-hospital complications after hip fracture surgery from 56 studies. Of these, we identified 7 patient factors-dehydration, anemia, hypotension, heart rate variability, pressure risk, nutrition, and indwelling catheter use; and 7 process factors-time to surgery, anesthetic type, transfusion strategy, orthopedic versus geriatric/co-managed care, multidisciplinary care pathway, and potentially modifiable during index hospitalization. We identified underlying mechanisms for 15 of 44 factors. The reported association between 12 prognostic factors and complications was inconsistent across studies. CONCLUSIONS: Most factors were reported by one study with no proposed underlying mechanism for their influence. Where reported by more than one study, there was inconsistency in reported associations and the conceptualization of complications differed, limiting comparison across studies. It is therefore not possible to be certain whether intervening on these factors would reduce the rate of complications after hip fracture surgery.

Synthetic Evolution of the Multifarene Cavity from Planar Predecessors.

The stepwise evolution of curved multifarene structures from planar precursors is demonstrated, highlighting three architectural design elements: 1) employment of various aromatic units, 2) changing the hybridization of the linking atoms from sp2 to sp3 , and 3) rigidification of the system by the introduction of five-membered rings. Similar design elements have been employed to transform graphene sheets into curved carbon structures. Specifically, the stepwise synthetic evolution of multifarene[2+2], which has a curved, quite rigid structure, begins with a planar, tetraimine precursor, conversion to pairs of vicinal diamines, and the transformation of these pairs to cyclic thiourea groups. This process was probed by NMR spectroscopy and X-ray crystallography. Since varying the carbonylation conditions resulted in carbamates or thiocarbamates rather than the urea or thiourea isomers, the isomeric interconversion was studied both experimentally and by DFT computations. The carbamate versus urea preference was found to reflect either kinetic or thermodynamic control, respectively.

Polyfunctional Lewis acids: intriguing solid-state structure and selective detection and discrimination of nitroaromatic explosives.

Synthesis and crystal structures of three porphyrin-based polyfunctional Lewis acids 1-3 are reported. Intermolecular HgCl⋅⋅⋅HgCl (linear and µ-type) interactions in the solid state of the peripherally ArHgCl-decorated compound 3 lead to a fascinating 3D supramolecular architecture. Compound 3 shows a selective fluorescence quenching response to picric acid and discriminates other nitroaromatic-based explosives. For the first time, an electron-deficient polyfunctional Lewis acid is shown to be useful for the selective detection and discrimination of nitroaromatic explosives. The Stern-Volmer quenching constant and detection limits of compound 3 for picric acid are the best among the reported small-molecular receptors for nitroaromatic explosives. The electronic structure, Lewis acidity, and selective sensing characteristics of 3 are well corroborated by DFT calculations.

Prediabetes in South Indian rural adolescent school students.

Prediabetes is a condition with blood glucose levels higher than normal but not high enough to be diagnosed as diabetes. Most people with prediabetes are asymptomatic but are considered to be at a high risk of developing heart disease and stroke. 140 students of both sexes between ages 14-18 years were given a predesigned questionnaire to obtain information on socio-economic status and family history of Diabetes mellitus. A fasting plasma glucose level was measured and 6.8% of students were in the prediabetic range (> 100 mg/dl). No significant correlation was found between fasting plasma glucose and Body Mass Index or waist to hip ratio. 41.5% of the boys and 10.3% of the girls had a family history of DM but were in euglycemic range. It is beneficial to identify people with prediabetes so that appropriate lifestyle modification may be done to prevent or postpone onset of Diabetes mellitus.

Critical role of NKT cells in posttransplant alloantibody production.

We previously reported that posttransplant alloantibody production in CD8-deficient hosts is IL-4+ CD4+ T cell-dependent and IgG1 isotype-dominant. The current studies investigated the hypothesis that IL-4-producing natural killer T cells (NKT cells) contribute to maximal alloantibody production. To investigate this, alloantibody levels were examined in CD8-deficient WT, CD1d KO and Jα18 KO transplant recipients. We found that the magnitude of IgG1 alloantibody production was critically dependent on the presence of type I NKT cells, which are activated by day 1 posttransplant. Unexpectedly, type I NKT cell contribution to enhanced IgG1 alloantibody levels was interferon-γ-dependent and IL-4-independent. Cognate interactions between type I NKT and B cells alone do not stimulate alloantibody production. Instead, NKT cells appear to enhance maturation of IL-4+ CD4+ T cells. To our knowledge, this is the first report to substantiate a critical role for type I NKT cells in enhancing in vivo antibody production in response to endogenous antigenic stimuli.

Multichannel-emissive V-shaped boryl-BODIPY dyads: synthesis, structure, and remarkably diverse response toward fluoride.

Three new V-shaped boryl-BODIPY dyads (1-3) were synthesized and structurally characterized. Compounds 1-3 are structurally close molecular siblings differing only in the number of methyl substituents on the BODIPY moiety that were found to play a major role in determining their photophysical behavior. The dyads show rare forms of multiple-channel emission characteristics arising from different extents of electronic energy transfer (EET) processes between the two covalently linked fluorescent chromophores (borane and BODIPY units). Insights into the origin and nature of their emission behavior were gained from comparison with closely related model molecular systems and related photophysical investigations. Because of the presence of the Lewis acidic triarylborane moiety, the dyads function as highly selective and sensitive fluoride sensors with vastly different response behaviors. When fluoride binds to the tricoordinate borane center, dyad 1 shows gradual quenching of its BODIPY-dominated emission due to the ceasing of the (borane to BODIPY) EET process. Dyad 2 shows a ratiometric fluorescence response for fluoride ions. Dyad 3 forms fluoride-induced nanoaggregates that result in fast and effective quenching of its fluorescence intensity just for ∼0.3 ppm of analyte (i.e., 0.1 equiv ≡ 0.26 ppm of fluoride). The small structural alterations in these three structurally close dyads (1-3) result in exceptionally versatile and unique photophysical behaviors and remarkably diverse responses toward a single analyte, i.e., fluoride ion.

Triarylborane-appended new triad and tetrad: chromogenic and fluorogenic anion recognition.

Facile synthesis of triad 3 and tetrad 4 incorporating -B(Mes)2 (Mes = mesityl (2,4,6-trimethylphenyl)), boron dipyrromethene (BODIPY), and triphenylamine is reported. Introduction of two dissimilar acceptors (triarylborane and BODIPY) on a single donor resulted in two distinct intramolecular charge transfer processes (amine-to-borane and amine-to-BODIPY). The absorption and emission properties of the new triad and tetrad are highly dependent on individual building units. The nature of electronic communication among the individual fluorophore units has been comprehensively investigated and compared with building units. Compounds 3 and 4 showed chromogenic and fluorogenic responses for small anions such as fluoride and cyanide.

Dual binding site assisted chromogenic and fluorogenic recognition and discrimination of fluoride and cyanide by a peripherally borylated metalloporphyrin: overcoming anion interference in organoboron based sensors.

Peripherally triarylborane decorated porphyrin (2) and its Zn(II) complex (3) have been synthesized. Compound 3 contains of two different Lewis acidic binding sites (Zn(II) and boron center). Unlike all previously known triarylborane based sensors, the optical responses of 3 toward fluoride and cyanide are distinctively different, thus enabling the discrimination of these two interfering anions. Metalloporphyrin 3 shows a multiple channel fluorogenic response toward fluoride and cyanide and also a selective visual colorimetric response toward cyanide. By comparison with model systems and from detailed photophysical studies on 2 and 3, we conclude that the preferential binding of fluoride occurs at the peripheral borane moieties resulting in the cessation of the EET (electronic energy transfer) process from borane to porphyrin core and with negligible negetive cooperative effects. On the other hand, cyanide binding occurs at the Zn(II) core leading to drastic changes in its absorption behavior which can be followed by the naked eye. Such changes are not observed when the boryl substituent is absent (e.g., Zn-TPP and TPP). Compounds 2 and 3 were also found to be capable of extracting fluoride from aqueous medium.

Triarylborane-dipyrromethane conjugates bearing dual receptor sites: the synthesis and evaluation of the anion binding site preference.

The synthesis and optical properties of four new triarylborane-dipyrromethane (TAB-DPM) conjugates (3a-d) containing dual binding sites (hydrogen bond donor and Lewis acid) have been reported. The new compounds exhibit a selective fluorogenic response towards the F(-) ion. The NMR titrations show that the anions bind to the TAB-DPM conjugates via the Lewis acidic triarylborane centre in preference to the hydrogen bond donor (dipyrromethane) units.

Comparison of the volatile oil composition of three Atalantia species.

The members of the genus Atalantia belonging to the family Rutaceae have many uses in traditional medicine. The aim of the present study was to investigate and compare the chemical composition of essential oils of three species of Atalantia namely Atalantia monophylla (Roxb.) DC., Atalantia racemosa Wight. and Atalantia wightii Tanaka. The extract percentage of the obtained essential oil was found to be 0.2, 0.17 and 0.31% in A. monophylla, A. racemosa and A. wightii respectively. The major compounds identified were alpha-Asarone (28.82%), Sabinene (13.19%), Eugenol methyl ether (12.71%), 1,2-Dimethoxy-4-(2-methoxyethenyl)benzene (11.63%) and beta-Pinene (5.3%) in the essential oil of A. monophylla. In A. racemosa, T-Cadinol (11.08%), Caryophyllene oxide (9.78%), beta-Caryophyllene (9.20%), Spathulenol (7.21%), beta-Phellandrene (5.67%) and Decanal (4.01%) and in A. wightii beta-Caryophyllene (16.37%), D-Limnonene (12.15%), Decanal (10.49%), beta-Myrcene (7.67%), Tetradecanal (6.99%), Caryophyllene oxide (6.29%) and Hexadecylene oxide (5.87%) were the main constituents. Sesquiterpenes were the major class of compounds in A. racemosa and A. wightii, while in A. monophylla the essential oil was predominated by ether compounds. The results showed that GC/MS analysis of essential oils is a significant step in the bio-chemical profiling and bio-prospecting of Atalantia species.

A validated stability-indicating LC method for the separation of enantiomer and potential impurities of Linezolid using polar organic mode.

Although a number of methods are available for evaluating Linezolid and its possible impurities, a common method for separation if its potential impurities, degradants and enantiomer in a single method with good efficiency remain unavailable. With the objective of developing an advanced method with shorter runtimes, a simple, precise, accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. This method is capable of separating all the related substances of Linezolid along with the chiral impurity. This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product. The method was developed using Chiralpak IA (250 mm×4.6 mm, 5 µm) column. A mixture of acetonitrile, ethanol, n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v) ratio was used as a mobile phase. The eluted compounds were monitored at 254 nm. Linezolid was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, limit of detection, limit of quantification, precision, linearity, accuracy, robustness and system suitability.