Thiazole-Based Silver Ion Sensor for Sequential Colorimetric Visualization of Epinephrine in the Brain Tissues of an Alzheimer's Disease Model of Mouse

A thiazole-based probe, N'-((2-aminothiazol-5-yl)methylene)benzohydrazide (TBH), has been efficiently synthesized and characterized for the selective and sensitive detection of the neurotransmitter epinephrine (EP). The sensing strategy is based on the use of TBH for sequential colorimetric sensing of Ag+ and EP via in situ formation of Ag nanoparticles (Ag NPs) from the TBH-Ag+ complex. The generated Ag NPs lead to a bathochromic shift in absorption maximum and a change in color of the solution from light brown to reddish brown. TBH-Ag+ shows remarkable selectivity toward EP versus other drugs, common cations, anions, and some biomolecules. Moreover, TBH-Ag+ has a low detection limit for EP at 1.2 nM. The coordination of TBH-Ag+ has been proposed based on Job's plot, Fourier transform infrared spectroscopy (FT-IR), high-resolution mass spectrometry (HRMS), 1H NMR titration, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray analysis (EDAX), and density functional theory (DFT) studies. The composition and morphology of the generated Ag NPs have been analyzed by XPS, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The proposed sensing mechanism for EP has been supported by XPS of Ag after the reaction. Further, the sensitivity of TBH-Ag+ toward EP in brain tissues of an Alzheimer's disease model of mouse has been evaluated. A thorough comparison was done for evaluation of the proposed method.

A chromogenic diarylethene-based probe for the detection of Cu2+ in aqueous medium in Drosophila for early diagnosis of Alzheimer

A diarylethene-based probe (Z)-N'-((2-amino-5-chlorophenyl)(phenyl)methylene)-2-hydroxy benzohydrazide (KBH) has been proficiently developed and its structure has been confirmed by single crystal X-ray diffraction technique. It displays a selective and sensitive colorimetric sensing of Cu2+ ions in aqueous medium with a naked eye colour change from colourless to yellow. It exhibits a significantly low limit of detection as 1.5 nM. A plausible binding mechanism has been proposed using Job's plot, FT-IR, 1H NMR titration, HRMS and DFT studies. The chemosensor is effectively reversible and reusable with EDTA. Test strip kit and real water sample analysis have been shown to establish its practical applicability. Further, the potential of KBH for the early diagnosis of Cu2+ ion-induced amyloid toxicity has been investigated in eye imaginal disc of Alzheimer's disease model of Drosophila 3rd instar larvae. The in-vivo interaction of KBH with Cu2+ in gut tissues of Drosophila larvae establishes its sensing capability in biological system. Interestingly, the in-vivo detection of Cu2+ has been done using bright field imaging which eliminates the necessity of a fluorescent label, hence making the method highly economical.

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.

Fluorescent Turn-On Anthracene-Based Aluminum(III) Sensor for a Therapeutic Study in Alzheimer's Disease Model of Drosophila

A new anthracene-based probe (E)-N'-(1-(anthracen-9-yl)ethylidene)-2-hydroxybenzohydrazide (AHB) has been efficiently synthesized and characterized by various spectroscopic methods. It exhibits extremely selective and sensitive fluorometric sensing of Al3+ ions with a large enhancement in the fluorescent intensity due to the restricted photoinduced electron transfer (PET) mechanism with a chelation-enhanced fluorescence (CHEF) effect. The AHB-Al3+ complex shows a remarkably low limit of detection at 0.498 nM. The binding mechanism has been proposed based on Job's plot, 1H NMR titration, Fourier transform infrared (FT-IR), high-resolution mass spectrometry (HRMS), and density functional theory (DFT) studies. The chemosensor is reusable and reversible in the presence of ctDNA. The practical usability of the fluorosensor has been established by a test strip kit. Further, the therapeutic potential of AHB against Al3+ ion-induced tau protein toxicity has been tested in the eye of Alzheimer's disease (AD) model of Drosophila via metal chelation therapy. AHB shows great therapeutic potential with 53.3% rescue in the eye phenotype. The in vivo interaction study of AHB with Al3+ in the gut tissue of Drosophila confirms its sensing efficiency in the biological environment. A detailed comparison table included evaluates the effectiveness of AHB.

Quinazoli-4-one ionic liquid as a fluorescent sensor for NH3 detection: Interaction with ctDNA, theoretical investigation and live cell bioimaging

A novel quinazoli-4-one based ionic liquid, 1-(3-aminopropyl)-3-methyl-4-oxo-3,4-dihydroquinazolin-1-ium bromide (QIL) for fluorometric determination of dissolved ammonia has been successfully synthesized and characterized by spectroscopic techniques such as ¹H and ¹³C NMR, FTIR and HRMS spectrometry. In the proposed method, QIL is converted to a fluorescent derivative by the reaction with ammonia in aqueous medium. The excitation and emission wavelengths were 250 and 436 nm, respectively. Remarkably with the reaction time of >1 s, the binding constant and detection limit was found to be 6.43 × 10⁸ M^-1 and 0.73 × 10^-8 M, respectively. QIL is found to be highly selective as no interference is observed from various cations, anions, organic molecules and amino acids. The sensing mechanism was further validated by the density functional theory studies. The fluorophore exhibited great sensing property in 3.0-14.0 pH range, hence, it can be employed in diverse matrices. In addition, the fluoro-sensor is highly reversible and reusable in the presence of ctDNA molecule. Moreover, a live-cell imaging study of QIL in Drosophila larval gut tissue has also been carried out to investigate the cell permeability of QIL and its efficiency for selective detection of NH₃ in cellular micro environment. To show practical applicability of the fluoro-sensor, test strip kit has been constructed. A detailed comparison table has been shown to evaluate the efficiency of this method.

A reversible and efficient probe for dual mode recognition of Al3+ and Cu2+ with logic gate behaviour: Crystal structure, theoretical and in-vivo bio-imaging investigations

This work presents the synthesis, characterization, crystal structure and spectroscopic investigations of isophthalohydrazide based probe. Among various tested metal ions, the probe selectively detects Al³⁺ and Cu²⁺ in aqueous ethanol via fluorometric and colorimetric methods, respectively. It displays a fluorescence "turn-on" response with Al³⁺ and visual colour change from colourless to yellow with Cu²⁺. Sensing mechanism is explored with UV-Vis, fluorescence spectroscopy and ¹H NMR titration, and confirmed with computational results. Suppression of CN isomerization and photo-induced electron transfer (PET) along with chelation enhanced fluorescence emission (CHEF) result in "turn-on" fluorescence with Al³⁺ while ligand to metal charge transfer (LMCT) accounts for visual colour change with Cu²⁺. Job's plot and HRMS confirm 1:2 (L:M) stoichiometry. The probe also exhibits efficient reversibility and reproducibility with EDTA which are successfully mimicked with combinatorial logic gate and truth table. Additionally, solid state applications and bio-imaging investigation on gut tissue of Drosophila 3rd instar larvae are performed.

A review on ferulic acid and analogs based scaffolds for the management of Alzheimer's disease

Alzheimer's disease (AD) is an age-related multifactorial neurodegenerative disorder characterized by severe central cholinergic neuronal loss, gradually contributing to cognitive dysfunction and impaired motor activity, resulting in the brain's cell death at the later stages of AD. Although the etiology of AD is not well understood, however, several factors such as oxidative stress, deposition of amyloid-β (Aβ) peptides to form Aβ plaques, intraneuronal accumulation of hyperphosphorylated tau protein, and low level of acetylcholine are thought to play a major role in the pathogenesis of AD. There is practically no drug for AD treatment that can address the basic factors responsible for the neurodegeneration and slow down the disease progression. The currently available therapies for AD in the market focus on providing only symptomatic relief without addressing the aforesaid basic factors responsible for the neurodegeneration. Ferulic acid (FA) is a phenol derivative from natural sources and serves as a potential pharmacophore that exerts multiple pharmacological properties such as antioxidant, neuroprotection, Aβ aggregation modulation, and anti-inflammatory. Several FA based hybrid analogs are under investigation as a multi-target directed ligand (MTDLs) to develop novel hybrid compounds for the treatment of AD. In the present review article, we are focused on the critical pathogenic factors responsible for the onset of AD followed by the developments of FA pharmacophore-based hybrids compounds as a novel multifunctional therapeutic agent to address the limitations associated with available treatment for AD. The rationale behind the development of these compounds and their pharmacological activities in particular to their ChE inhibition (ChEI), neuroprotection, antioxidant property, Aβ aggregation modulation, and metal chelation ability, are discussed in detail. We have also discussed the discovery of caffeic and cinnamic acids based MTDLs for AD. This review paper provides an in-depth insight into the research progress and current status of these novel therapeutics in AD and prospects for developing a druggable molecule with desired pharmacological affinity and reduced toxicity for the management of AD.

Logic gate behavior and intracellular application of a fluorescent molecular switch for the detection of Fe3+ and cascade sensing of F− in pure aqueous media

The nature and coordination sites of a Schiff base 3,3′-(1E,1′E)-(1,3-phenylenebis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)dinaphthalen-2-ol (APHN), are tuned by its selective reduction to design a highly efficient fluorescent probe RAPHN.

Antioxidant, antimicrobial and cytotoxic potential of silver nanoparticles synthesized using flavonoid rich alcoholic leaves extract of Reinwardtia indica

The present work discusses the establishment of a green route for the rapid synthesis of silver nanoparticles (AgNPs) using an alcoholic extract of Reinwardtia indica (AERI) leaves which act as a reducing as well as a capping agent. The change in color from yellowish green to dark brown confirmed the synthesis of AgNPs. A characteristic surface plasmon resonance (SPR) band at 436 nm advocated the presence of AgNPs. The synthesis process was optimized using one factor at a time approach where 1.0 mM AgNO₃ concentration, 5 mL 0.4% (v/v) of AER inoculum dose and 30 min of sunlight exposure were found to be the optimum conditions. The synthesized AgNPs was characterized by several characterizing techniques such as HR- TEM, SAED, HR-SEM, EDX, XRD, FTIR and AFM analysis. For evaluation and comparison of AgNPs with AERI used human pathogen E. coli, P. aeurogenosa, S. aeurus and C. albicans for antimicrobial, for cytotoxicity study SiHa cell line at concentration of (10, 50, 100, 250 and 500 µg mL^-1) and for enzymatic assay superoxide dismutase, catalase, malondialdehyde and glutathione peroxidase method were used. The size of nanoparticle in the range of 3-15 nm was confirmed TEM, spherical shape by SEM and crystal lattice nature by XRD. AFM results revealed the 2 D and 3 D pattern of particle scatter nature on the surface. This protocol as simple, rapid, one step, eco-friendly, nontoxic and AgNPs showed strong antimicrobial activity as well as cytotoxic potential in comparison to AERI.

Prevalence of picky eating behavior and its impact on growth in preschool children

Background: Almost two-thirds of parents report one or more problems with their children’s eating. Although knowledge of the health-related outcomes of picky eating is limited due to a lack of longitudinal studies, research suggests that picky eating is associated with nutrient deficiency, underweight, behavioral problems and symptoms of anxiety and depression. Aim of present study was to assess the Parental perception and maternal strategies in solving feeding difficulties in relation with parenting style.Methods: The present cross sectional study conducted on 1652 parents of preschool children of 1-6 yrs age group. A structured parental questionnaire was administered to parents by Pediatricians based on Stanford feeding Questionnaire on Child- parent feeding.Results: About 58.9% of the children were found to be picky eaters. The prevalence is increasing with age and higher at 6 years age. The mean height and weight are seen affected significantly in picky eaters. Infantile Anorexia is the commonest type of Feeding difficulties, followed by Highly selective intake category. Commonest Parenting style is Authoritarian type, followed by Permissive parenting.Conclusions: As the prevalence of picky eating behaviour is increasing with age, causing parental anxiety and conflict in the family, disrupting parent child bonding, Paediatricians should be thoroughly equipped with knowledge of different Feeding difficulties and their specific management and help parents in doing their best by correcting their parenting style.

Role of composite endpoints as an outcome assessment tool in urogenital prolapse

Our aim was to assess the role of composite endpoints as outcome assessment tools in urogenital prolapse. Women undergoing surgery for urogenital prolapse were recruited and followed-up over 1 year. 'Cure' following surgery was defined as: (1)

OBJECTIVE

POP-Q ordinal = 0 (pelvic organ prolapse quantification system); (2) Subjective: PGI-I = 1 or 2 (patient global impression of improvement); (3) Composite endpoint of cure: POP-Q ordinal = zero and patient goal achievement = 60%. Our results showed 'Composite cure' of POP was in 88.7%, while objective and subjective cure were 85.3% and 95.5%, respectively. Defining 'success' or 'failures' based on PGI-I scores was most discriminatory. Quality of life (QoL) was similar in treatment success or failure groups, where cure was measured objectively or using the composite endpoint. Composite endpoints should accurately represent cure as they combine objective measures and patient goals. However, these were not demonstrated as valid methods in defining success of prolapse surgery.

Is transvaginal ultrasound a worthwhile investigation for women undergoing vaginal hysterectomy?

Vaginal hysterectomy (VH) is the definitive surgical management for uterine prolapse. It is also the preferred route for other pelvic pathology where a hysterectomy is warranted, as it is associated with lower complication rate and faster recovery time. The aim of this study was to determine the usefulness of transvaginal ultrasound scan (TVS) as an investigation prior to vaginal hysterectomy. A total of 103 patients were reviewed over 1 year. Associated gynaecological pathology was found in 46.6% of patients on TVS and this led to a change in planned management in 2.9% of cases. Consequently, preoperative TVS would appear to be a worthwhile investigation.