Cyclin D-CDK4 Disulfide Bond Attenuates Pulmonary Vascular Cell Proliferation.

BACKGROUND: Pulmonary hypertension (PH) is a chronic vascular disease characterized, among other abnormalities, by hyperproliferative smooth muscle cells and a perturbed cellular redox and metabolic balance. Oxidants induce cell cycle arrest to halt proliferation; however, little is known about the redox-regulated effector proteins that mediate these processes. Here, we report a novel kinase-inhibitory disulfide bond in cyclin D-CDK4 (cyclin-dependent kinase 4) and investigate its role in cell proliferation and PH. METHODS: Oxidative modifications of cyclin D-CDK4 were detected in human pulmonary arterial smooth muscle cells and human pulmonary arterial endothelial cells. Site-directed mutagenesis, tandem mass-spectrometry, cell-based experiments, in vitro kinase activity assays, in silico structural modeling, and a novel redox-dead constitutive knock-in mouse were utilized to investigate the nature and definitively establish the importance of CDK4 cysteine modification in pulmonary vascular cell proliferation. Furthermore, the cyclin D-CDK4 oxidation was assessed in vivo in the pulmonary arteries and isolated human pulmonary arterial smooth muscle cells of patients with pulmonary arterial hypertension and in 3 preclinical models of PH. RESULTS: Cyclin D-CDK4 forms a reversible oxidant-induced heterodimeric disulfide dimer between C7/8 and C135, respectively, in cells in vitro and in pulmonary arteries in vivo to inhibit cyclin D-CDK4 kinase activity, decrease Rb (retinoblastoma) protein phosphorylation, and induce cell cycle arrest. Mutation of CDK4 C135 causes a kinase-impaired phenotype, which decreases cell proliferation rate and alleviates disease phenotype in an experimental mouse PH model, suggesting this cysteine is indispensable for cyclin D-CDK4 kinase activity. Pulmonary arteries and human pulmonary arterial smooth muscle cells from patients with pulmonary arterial hypertension display a decreased level of CDK4 disulfide, consistent with CDK4 being hyperactive in human pulmonary arterial hypertension. Furthermore, auranofin treatment, which induces the cyclin D-CDK4 disulfide, attenuates disease severity in experimental PH models by mitigating pulmonary vascular remodeling. CONCLUSIONS: A novel disulfide bond in cyclin D-CDK4 acts as a rapid switch to inhibit kinase activity and halt cell proliferation. This oxidative modification forms at a critical cysteine residue, which is unique to CDK4, offering the potential for the design of a selective covalent inhibitor predicted to be beneficial in PH.

Essential oils and their blends: mechanism of antibacterial activity and antibiofilm potential on food-grade maize starch packaging films.

Essential oils are highly complex volatile chemical compounds utilized for food preservation. The present study compares the antibacterial, and antibiofilm activities of essential oils (EOs) and their blends. Three EOs-basil, clove, and lemongrass-and their blends were evaluated against five food-borne bacterial pathogens. A concentration-dependent effect with maximum inhibition at minimum inhibitory concentration values was recorded while no synergistic activity was observed on blending of EOs. The mechanism of antibacterial action was identified as ROS burst, leakage of cytoplasmic content, and DNA degradation through fluorescence microscopy, electrical conductivity, and DNA cleavage studies. The role of EOs on biofilm growth was deciphered with lemongrass EO being most effective as it curbed biofilm formation on the surface of corn-starch packaging films. This work highlights the antibacterial action mechanism of EOs and their potential role in curtailing biofilm growth on food-grade packaging material.

Hazardous 2,4,6-Trinitrophenol (TNP) Detection in Water by Amine and Azine Functionalized Metal-Organic Framework.

A Zn(II)-based metal-organic framework (MOF) decorated with amine and azine functionalities, TMU-17-NH2 (formulated as [Zn(H2ata)(L)].2DMF; L = 1,4-bis(4-pyridyl)-2,3-diaza-2,3-butadiene and H2ata = 2-aminoterephthalic acid) has been successfully synthesized via a solvothermal method. According to crystallographic studies, the synthesized TMU-17-NH2 has three dimensional cuboidal structure with the pore surface decorated with free amine (-NH2) and azine (= N-N =) functional groups. The photoluminescence investigations proved that the synthesized MOF can be effectively utilized for selective detection of 2,4,6-trinitrophenol (TNP) in water with an apparent turn-off quenching response. Its limits of detection (LOD) for TNP was 9.4 ppb and competitive nitro explosive testing confirmed its higher selectivity towards TNP (over other nitro explosives). Calculations based on density functional theory (DFT) and spectrum overlap were utilized to evaluate the sensing mechanisms. This MOF-based fluorescence sensing technique for TNP had a high sensitivity (Ksv = 3.26 × 104 M-1).

Porphyrin Metal-organic Framework Sensors for Chemical and Biological Sensing.

Porphyrins and porphyrin derivatives have been intensively explored for a number of applications such as sensing, catalysis, adsorption, and photocatalysis due to their outstanding photophysical properties. Their usage in sensing applications, however, is limited by intrinsic defects such as physiological instability and self-quenching. To reduce self-quenching susceptibility, researchers have developed porphyrin metal-organic frameworks (MOFs). Metal-organic frameworks (MOFs), a unique type of hybrid porous coordination polymers comprised of metal ions linked by organic linkers, are gaining popularity. Porphyrin molecules can be integrated into MOFs or employed as organic linkers in the production of MOFs. Porphyrin-based MOFs are a separate branch of the huge MOF family that combines the distinguishing qualities of porphyrins (e.g., fluorescent nature) and MOFs (e.g., high surface area, high porosity) to enable sensing applications with higher sensitivity, specificity, and extended target range. The key synthesis techniques for porphyrin-based MOFs, such as porphyrin@MOFs, porphyrinic MOFs, and composite porphyrinic MOFs, are outlined in this review article. This review article focuses on current advances and breakthroughs in the field of porphyrin-based MOFs for detecting a variety of targets (for example, metal ions, anions, explosives, biomolecules, pH, and toxins). Finally, the issues and potential future uses of this class of emerging materials for sensing applications are reviewed.

Pure and Antimony-doped Tin Oxide Nanoparticles for Fluorescence Sensing and Dye Degradation Applications.

Luminescent antimony doped tin oxide nanoparticles have drawn tremendous attention from researchers due to its low cost, chemical inertness and stability. Herein, a quick, facile and economic hydrothermal/solvothermal method was utilized for the preparation of antimony doped (1%, 3%, 5%, 7% and 10%) tin oxide nanoparticles. The antimony doping in a reasonable range can change the properties of SnO2. As such, a lattice distortion increases with increase in doping, which is evidenced through crystallographic studies. It was found that the highest photocatalytic degradation efficiency of malachite green (MG) dye of about 80.86% was achieved with 10% Sb-doped SnO2 in aqueous media due to small particle size. Moreover, 10% Sb-doped SnO2 also showed the highest fluorescence quenching efficiency of about 27% for Cd2+ of concentration 0.11 µg/ml in the drinking water. The limit of detection (LOD) comes out as 0.0152 µg/ml. This sample selectively detected the cadmium ion even in the presence of other heavy metal ions. Notably, 10% Sb-doped SnO2 could appeared as a promising sensor for fast analysis of Cd2+ ions in real samples.

A Randomized Controlled Trial of Intrathecal versus Caudal Morphine-Bupivacaine on Postoperative Analgesia and Cortisol Levels in Pediatric Patients.

BACKGROUND: Morphine is commonly used in pediatric caudal blocks. We compared the analgesic efficacy and effect on cortisol levels of intrathecal morphine and bupivacaine with caudal morphine and bupivacaine in children undergoing lower abdominal surgeries. METHODS: Forty children undergoing lower abdominal surgeries were randomized to receive 4 µg/kg of intrathecal morphine and 0.5% hyperbaric bupivacaine (n = 20), or caudal morphine 40 µg/kg and 0.25% bupivacaine (n = 20). Postoperative analgesia was provided with intravenous (IV) paracetamol (PCM). The primary outcome was time to reach Face, Legs, Activity, Cry, and Consolability (FLACC) score ≥4 postoperatively. Secondary outcomes were perioperative serum cortisol levels, analgesic requirement, and parent satisfaction. RESULTS: Since seventy 5% of patients receiving intrathecal morphine and bupivacaine did not reach a FLACC score ≥4 within 24 hours, the primary outcome was presented as the Kaplan-Meier curve. The probability of FLACC score <4 was significantly higher with intrathecal morphine and bupivacaine than with caudal morphine and bupivacaine (P < .001). The unadjusted and adjusted (for gender) hazard ratio (95% confidence interval [CI]) of occurrence of pain (FLACC score ≥4) was 0.07 (0.03-0.15, P < .001) and 0.06 (0.03-0.14, P < .001), respectively. The difference in means (95% CI) of cortisol levels between caudal morphine (with bupivacaine) and intrathecal morphine (with bupivacaine) groups were after intubation -0.667 (-4.99 to 3.65, P = .76), at 2 hours intraoperatively 7.88 (3.55-12.2, P < .001), 6 hours postoperatively 16.8 (12.5-21.1, P < .001), and 24 hours postoperatively 15.4 (11.1-19.7, P < .001) µg/dL. Intraoperatively, rescue fentanyl was required by 60% of patients on caudal morphine and bupivacaine against 20% of patients receiving intrathecal morphine and bupivacaine (absolute risk-reduction [95% CI] of 40% [12%-68%]; P = .010). Postoperative rescue fentanyl was required in 45% of patients on caudal morphine and bupivacaine and 5% of patients on intrathecal morphine and bupivacaine. All (100%) patients on caudal morphine and bupivacaine required postoperative PCM against 6 (30%) patients on intrathecal morphine and bupivacaine (absolute risk-reduction [95% CI] of 70% [50%-90%]; P < .001).The median (interquartile range [IQR]) parent satisfaction score for patients on caudal morphine (with bupivacaine) and intrathecal morphine (with bupivacaine) was 0(0-0) and 2(2-2) at 12 hours postoperatively (P < .001) and 0(0-1) and 2(1.5-2) at 24 hours postoperatively (P < .001). One patient in each group developed nausea and vomiting, and 1 patient in the intrathecal group developed pruritus. There was no incidence of respiratory depression. CONCLUSIONS: Intrathecal morphine and bupivacaine results in longer duration of analgesia, lower analgesic consumption, prevents surgical-stress-related elevation of serum cortisol, and improves parent satisfaction compared to caudal morphine with bupivacaine in children undergoing lower abdominal surgeries.

Microbial Nanotechnology for Precision Nanobiosynthesis: Innovations, Current Opportunities and Future Perspectives for Industrial Sustainability.

A new area of biotechnology is nanotechnology. Nanotechnology is an emerging field that aims to develope various substances with nano-dimensions that have utilization in the various sectors of pharmaceuticals, bio prospecting, human activities and biomedical applications. An essential stage in the development of nanotechnology is the creation of nanoparticles. To increase their biological uses, eco-friendly material synthesis processes are becoming increasingly important. Recent years have shown a lot of interest in nanostructured materials due to their beneficial and unique characteristics compared to their polycrystalline counterparts. The fascinating performance of nanomaterials in electronics, optics, and photonics has generated a lot of interest. An eco-friendly approach of creating nanoparticles has emerged in order to get around the drawbacks of conventional techniques. Today, a wide range of nanoparticles have been created by employing various microbes, and their potential in numerous cutting-edge technological fields have been investigated. These particles have well-defined chemical compositions, sizes, and morphologies. The green production of nanoparticles mostly uses plants and microbes. Hence, the use of microbial nanotechnology in agriculture and plant science is the main emphasis of this review. The present review highlights the methods of biological synthesis of nanoparticles available with a major focus on microbially synthesized nanoparticles, parameters and biochemistry involved. Further, it takes into account the genetic engineering and synthetic biology involved in microbial nanobiosynthesis to the construction of microbial nanofactories.

A case of antenatally undiagnosed laryngeal atresia with tracheo-esophageal fistula with airway obstruction at birth and its management.

Laryngeal atresia is a rare congenital anomaly that is usually diagnosed by antenatal ultrasound, however, if undiagnosed presents with desaturation after birth. A term neonate presented with airway obstruction after birth with multiple failed attempts at intubation and was rescued by proseal laryngeal mask airway (LMA). An esophagoscopy using an Ambuscope utilizing a modified connector assembly revealed an opening on the anterior wall of the esophagus with no esophageal atresia, leading to a diagnosis of H-type tracheo-esophageal fistula (TEF) with laryngeal atresia. The ability to ventilate the neonate via LMA with an absent glottic opening raised the possibility of TEF.

Comparison of gastric emptying time between breast-fed and formula milk-fed infants less than 6 months old, using gastric ultrasound-An observational study.

BACKGROUND: Fasting before elective anesthesia care is a standardized practice worldwide. The aim is to decrease the risk of aspiration leading to pulmonary complications such as aspiration pneumonitis during anesthesia care. There are different guidelines for elective preoperative fasting in children. However, there is insufficient literature measuring gastric emptying time after breast milk or formula milk feeding in infants. OBJECTIVE: This study used gastric ultrasound to determine the gastric emptying time for breast milk and formula milk in children below 6 months of age. We also compared the calculated gastric volumes among breast-fed and formula milk-fed based on Schmitz's and Spencer's formula. MATERIALS AND METHODS: This prospective observational study was conducted at a tertiary care center in India between November (2017-2019). A total of 52 infants less than 6 months of age were recruited. The study population was divided into two groups (breast-fed and formula milk-fed) of 26 patients each. Ultrasound was used to measure the antral cross-sectional area of the stomach and to calculate the gastric volume using the two classical formulas (Schmitz and Spencer's). Gastric emptying was reported when the bull's eye appearance of the gastric antrum was seen or when the antral cross-sectional area was less than 3.07 cm2. RESULTS: The number of breast-fed children whose antral cross-sectional was greater than 3.07 cm2 (cut-off value for aspiration risk) beyond 1 h was 14/26 (53.84%) while none (0) children went beyond 3 h. The number of formula-fed children whose antral cross-sectional was greater than 3.07 cm2 beyond 1 h was 17/26 (65.38%) while one child (3.84%) went beyond 3 h. Using Schmitz's formula, mean (SD) gastric emptying times were 0.35 ± 0.68 h (95% CI 0.35 ± 0.185, range 0.165-0.535) for breast-fed patients and 0.35 ± 0.69 h (95% CI 0.35 ± 0.188, range 0.162-0.538) for formula-fed patients, and were thus neither clinically nor statistically different (p = .73) Using Spencer's formula, the mean gastric emptying times were 0.12 ± 0.33 h (95% CI 0.12 ± 0.09, range 0.03-0.21) for breast-fed patients and 0.04 ± 0.20 h (95% CI 0.04 ± 0.05, range -0.01 to 0.09) for formula-fed patients, and were also neither clinically nor statistically different p = .13. CONCLUSION: In our series, the gastric emptying times in breast-fed and formula-fed infants less than 6 months old were similar. Our results support the fasting guidelines of the European Society of Anaesthesiology and Intensive Care 2022, that is, 3 h for breastfeeding and 4 h for formula milk feeding. In addition, this shows that the Schmitz's and Spencer's formulae used to calculate the gastric volume based on ultrasound measurement of the antral cross-sectional area are not comparable in infants less than 6 months.

Analysis of Molecular Genetic Variants of Lgals4 in Esophageal Cancer: A Preliminary Report.

Esophageal cancer is the eighth most common cancer worldwide and fourth most common in developing countries. Altered glycosylation pattern of cell membrane molecules along with inflammation is a characteristic attribute of oncogenesis. Galectin-4, a tandem repeat galectin, has shown effect on cancer progression/metastasis in digestive system cancers. This role of galectin-4 can be attributed to variations in LGALS4, gene encoding galectin-4. The present case-control study was designed to analyze four intronic SNPs in LGALS4 with susceptibility toward esophageal cancer.Esophageal cancer cases and age- and gender-matched apparently healthy individuals were recruited for the present study. Genotyping of rs8113319, rs4802886, rs4802887, and rs12610990 was carried out using Sanger sequencing and PCR-RFLP. MedCalc software, SNPStats and SHEsis online platform were used for statistical analysis.Genotypic analyses revealed an overall increased heterozygosity of rs12610990, rs4802886, and rs4802887, and AA genotype of rs8113319 in the study participants. Haplotypic analyses also revealed a predominance of AAAT haplotype in the cases. Moreover, combined presence of wild alleles of rs4802886 and rs4802887 could influence protection toward disease, and combined presence of wild alleles of rs12610990 and rs8113319 could influence disease susceptibility. Furthermore, a strong linkage disequilibrium was also observed between the SNPs. Further studies are underway to validate galectin-4 and its genetic variants as blood-based biomarkers in early disease diagnosis, improving treatment outcome.

Developing a Chatbot to Support Individuals With Neurodevelopmental Disorders: Tutorial.

Families of individuals with neurodevelopmental disabilities or differences (NDDs) often struggle to find reliable health information on the web. NDDs encompass various conditions affecting up to 14% of children in high-income countries, and most individuals present with complex phenotypes and related conditions. It is challenging for their families to develop literacy solely by searching information on the internet. While in-person coaching can enhance care, it is only available to a minority of those with NDDs. Chatbots, or computer programs that simulate conversation, have emerged in the commercial sector as useful tools for answering questions, but their use in health care remains limited. To address this challenge, the researchers developed a chatbot named CAMI (Coaching Assistant for Medical/Health Information) that can provide information about trusted resources covering core knowledge and services relevant to families of individuals with NDDs. The chatbot was developed, in collaboration with individuals with lived experience, to provide information about trusted resources covering core knowledge and services that may be of interest. The developers used the Django framework (Django Software Foundation) for the development and used a knowledge graph to depict the key entities in NDDs and their relationships to allow the chatbot to suggest web resources that may be related to the user queries. To identify NDD domain-specific entities from user input, a combination of standard sources (the Unified Medical Language System) and other entities were used which were identified by health professionals as well as collaborators. Although most entities were identified in the text, some were not captured in the system and therefore went undetected. Nonetheless, the chatbot was able to provide resources addressing most user queries related to NDDs. The researchers found that enriching the vocabulary with synonyms and lay language terms for specific subdomains enhanced entity detection. By using a data set of numerous individuals with NDDs, the researchers developed a knowledge graph that established meaningful connections between entities, allowing the chatbot to present related symptoms, diagnoses, and resources. To the researchers' knowledge, CAMI is the first chatbot to provide resources related to NDDs. Our work highlighted the importance of engaging end users to supplement standard generic ontologies to named entities for language recognition. It also demonstrates that complex medical and health-related information can be integrated using knowledge graphs and leveraging existing large datasets. This has multiple implications: generalizability to other health domains as well as reducing the need for experts and optimizing their input while keeping health care professionals in the loop. The researchers' work also shows how health and computer science domains need to collaborate to achieve the granularity needed to make chatbots truly useful and impactful.

Characterization of halotolerant microalga isolated from waterlogged habitats: Deciphering the biochemical profiling and unraveling the molecular identity.

The primary objective of this study was to comprehensively explore the biochemical profile of the novel halotolerant microalgae strain, biogas laboratory scenedesmus (BGLRS), previously isolated from waterlogged regions in the southwest zone of Punjab, India. To achieve this, three distinct drying methods viz. freeze-drying, oven-drying, and shade-drying were employed and biochemical composition and antioxidant analyses on the microalgal biomass were conducted. Utilizing advanced analytical techniques, including high-performance liquid chromatography (HPLC), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and gas chromatography-mass spectroscopy (GC-MS) on freeze-dried biomass, its carbohydrate profile, micronutrient composition, and presence of bioactive compounds with potential therapeutic and nutraceutical significance were sought to unravel. Among the drying methods evaluated, freeze-drying exhibited the most promising experimental results, prompting its selection for further investigation. Notably, ICP-AES unveiled elevated concentrations of essential elements such as calcium, iron, magnesium, and phosphorus in BGLRS, with negligible traces of heavy metals, underscoring its safety for human consumption. GC-MS analysis further divulged the existence of numerous biologically active compounds, indicating potential applications in medical and nutraceutical fields. Through molecular identification using sequencing of the internal transcribed spacer (ITS) region, a close taxonomic resemblance between BGLRS and Scenedesmus sp. MKB was established, solidifying its unique position within the microalgal taxonomy. The deposition of ITS sequences into the NCBI GenBank, obtaining accession number MN796425, attests to the rigor and transparency of this research. Overall, these findings strongly suggest that microalgae BGLRS possesses high-quality biochemical attributes of significant therapeutic and nutraceutical importance.

Effect of video distraction on preoperative anxiety scores in pediatric patients undergoing general anesthesia in ophthalmic daycare procedures: A randomized controlled trial.

Background and Aims: Parental separation, fear, and exposure to the operating room environment lead to stress and anxiety in pediatric patients. This study aims to identify the research gaps in the effect of video distraction on pediatric patients of Indian origin. We hypothesized that video distraction along with parental presence would reduce preoperative anxiety in pediatric patients undergoing ophthalmic procedures under general anesthesia compared with parental presence alone. Material and Methods: In this prospective randomized trial, 145 patients aged 2-8 years, ASA I-II, with at least one functional eye undergoing elective ophthalmic daycare procedures were enrolled. They were randomly allocated to two Groups: Group V had distraction by watching a video/playing a video game together with parental presence, whereas control Group C had parental presence alone without any video distraction. The primary objective of the study was to compare preoperative anxiety using the Modified Yale Preoperative Anxiety score (mYPAS) and heart rate (HR), whereas the secondary objective was to compare child fear, emergence delirium, and parental satisfaction between the two groups. The three time points for intergroup comparisons were the preoperative holding area 10 min before induction (T0), transport of the child to the operating room (T1), and face mask introduction (T2). Results: There was a statistically significant difference between mYPAS score in groups V and C at all time points (P = 0.036, P = 0.0001, P = 0.0000), parental satisfaction score at all three time points (P = 0.0049, P = 0.0000, P = 0.0000), and Child Fear Score at T1 and T2 (P = 0.0001, P = 0.0001, respectively). However, there was no statistically significant difference in the emergence of delirium between the two groups. Conclusions: Video distraction together with parental presence has a promising role for implementation in hospitals with heavy workload settings where pharmacological intervention would not be feasible, to alleviate preoperative anxiety in children. However, preoperative anxiety may not translate into increased postoperative emergence delirium as was earlier believed.

Multifaceted role of galectin-4 in cancer: A systematic review.

BACKGROUND: Galectins are ß-galactoside-binding proteins. Galectin-4 has shown an effect on cancer progression/metastasis, especially in cancers of the digestive system. This can be attributed to altered glycosylation pattern of cell membrane molecules, which is a characteristic attribute of oncogenesis. The aim of this paper is to systematically review galectin-4 in different cancers and its role in disease progression. METHODS: The study was designed on the basis of Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. PubMed, Scopus, Web of Science, and Science Direct were used to search relevant literature with keywords "galectin-4 AND cancer", "galectin-4", "LGALS4", and "LGALS4 AND cancer". Inclusion criteria for study selection were availability of full-text articles, articles in English language and articles relevant to current topic, that is, galectin-4 and cancer. Exclusion criteria were studies that investigated other disease conditions, interventions unrelated to cancer or galectin-4 and bias outcome. RESULTS: A total of 73 articles were retrieved after removing duplication from databases, out of which 40 studies were included in the review that followed the inclusion criteria, including low to moderate bias. These included 23 studies in digestive system, 5 in reproductive system, 4 in respiratory system, and 2 in brain and urothelial cancers. CONCLUSIONS: A differential expression of galectin-4 was observed in different cancer stages/ and types. Furthermore, galectin-4 was found to modulate disease progression. A meta-analysis and comprehensive mechanistic studies, pertaining to different aspects of galectin-4 biology, could give statistically driven correlations, elucidating multifaceted role of galectin-4 in cancer.

Microalgal bioactive metabolites as promising implements in nutraceuticals and pharmaceuticals: inspiring therapy for health benefits.

The rapid increase in global population and shrinkage of agricultural land necessitates the use of cost-effective renewable sources as alternative to excessive resource-demanding agricultural crops. Microalgae seem to be a potential substitute as it rapidly produces large biomass that can serve as a good source of various functional ingredients that are not produced/synthesized inside the human body and high-value nonessential bioactive compounds. Microalgae-derived bioactive metabolites possess various bioactivities including antioxidant, anti-inflammatory, antimicrobial, anti-carcinogenic, anti-hypertensive, anti-lipidemic, and anti-diabetic activities, thereof rapidly elevating their demand as interesting option in pharmaceuticals, nutraceuticals and functional foods industries for developing new products. However, their utilization in these sectors has been limited. This demands more research to explore the functionality of microalgae derived functional ingredients. Therefore, in this review, we intended to furnish up-to-date knowledge on prospects of bioactive metabolites from microalgae, their bioactivities related to health, the process of microalgae cultivation and harvesting, extraction and purification of bioactive metabolites, role as dietary supplements or functional food, their commercial applications in nutritional and pharmaceutical industries and the challenges in this area of research.

Designing mixed-metal electrocatalyst systems for photoelectrochemical dinitrogen activation.

Efficient artificial photosynthesis systems are currently realized as catalyst- and surface-functionalized photovoltaic tandem-and triple-junction devices, enabling photoelectrochemical (PEC) water oxidation while simultaneously recycling CO2 and generating hydrogen as a solar fuel for storable renewable energy. Although PEC systems also bear advantages for the activation of dinitrogen - such as a high system tunability with respect to the electrocatalyst integration and a directly controllable electron flux to the anchoring catalyst through the adjustability of incoming irradiation - only a few PEC devices have been developed and investigated for this purpose. We have developed a series of photoelectrodeposition procedures to deposit mixed-metal electrocatalyst nanostructures directly on the semiconductor surface for light-assisted dinitrogen activation. These electrocatalyst compositions containing Co, Mo and Ru in different atomic ratios follow previously made recommendations of metal compositions for dinitrogen reduction and exhibit different physical properties. XPS studies of the photoelectrode surfaces reveal that our electrocatalyst films are to a large degree nitrogen-free after their fabrication, which is generally difficult to achieve with traditional magnetron sputtering or e-beam evaporation techniques. Initial chronoamperometric measurements of the p-InP photoelectrode coated with the Co-Mo alloy electrocatalyst show higher photocurrent densities in the presence of N2(g) than in the presence of Ar at -0.09 V vs. RHE. Indications of successful dinitrogen activation have also been found in consecutive XPS studies, where both N 1s and Mo 3d spectra reveal evidence of nitrogen-metal interactions.

Imine-Decorated Copper-Based Metal-Organic Framework for the Photodegradation of Methylene Blue.

A low cost imine-decorated linker, 4,4'-(hydrazine-1,2-diylidenedimethylylidene)dibenzoic acid was utilized for the preparation of copper-based metal-organic framework (MOF) denoted as Cu-L via a solvothermal technique. The synthesized MOF material has been fully characterized by different analytical techniques such as Fourier-transform infrared (FT-IR) spectroscopy, powder X-Ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDX), nitrogen adsorption-desorption isotherm analysis, and thermogravimetric analysis (TGA). It has been found that the coordination of Cu2+ with L considerably reduced the band gap of the L of nearly about 1 eV, which is approximately 26% decline in total. Notably, a narrow band gap of the photocatalyst is an essential requirement for the proficient photodegradation of organic contaminants. An excellent optical properties and narrow band gap of (2.8 eV) of Cu-L ensure their suitability as a photocatalyst for the degradation of methylene blue (MB) dye. In the presence of Cu-L photocatalyst, 84.22% degradation of MB dye was observed after 150 min under sunlight exposure. It is the first time that imine-functionalized MOF was utilized for the degradation of MB dye under sunlight irradiation. For understanding the photodegradation of MB dye by the Cu-L photocatalyst, all the plausible mechanistic studies have been carried out in detail. Both theoretical (with the help of density functional theory (DFT) calculations) as well as experimental studies have been conducted to justify the possible mechanisms for the photodegradation of MB dye by Cu-L. The current work may open a new opportunity to construct a cheap MOF-based photocatalysts for fast degradation of dye contaminants.

Experimental and Theoretical Studies of Fluorescent "Turn Off" Sensor Functionalized With Carboxylic Acid and Naphthalene Group for Selective Detection of 2,4,6-Trinitrophenol.

A fluorescent sensor, 5-((2-hydroxynaphthalen-1-yl)methyleneamino)benzene-1,3-dicarboxylic acid (coded as SB), containing both π-π interacting sites (such as π-electron-rich moieties) and hydrogen bonding (H-bonding) interacting sites (such as highly acidic protons) has been developed via high yield reflux method. It was characterized by the various analytical techniques such as Fourier transform-infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1 H-NMR), thermogravimetric analysis (TGA), field emission scanning electron microscope (Fe-SEM), elemental mapping, and UV - visible spectroscopy etc. The spectral response of the as-synthesized SB sensor has been investigated for various nitro explosives (NEs). It has been found that the SB sensor selectively and sensitive sense highly toxic 2,4,6-trinitrophenol (TNP) via the "turn-off" quenching response. Its limit of detection for TNP was calculated to be 30 ppb. Spectral overlap, detailed mechanistic studies for their mode of action, and density functional theory (DFT) calculations reveals that photo-induced electron transfer process (PET), fluorescence energy transfers process (FRET), and electrostatic interactions (i.e. H-bonding) are the key factors for the turn-off response of SB towards TNP. Notably, the synthesis of the sensor is cost-effective, energy efficient, and economic.

Schiff Base-functionalized Metal-organic Frameworks for Selective Sensing of Chromate and Dichromate in Water.

In this research, Zn- or Cd-based metal-organic frameworks (coded ZnMOF-1 and CdMOF-1) containing benzene-1,4-dicarboxylic acid (H2bdc) and pyridyl-based Schiff base (4-pyridylcarboxaldehydeisonicotinoylhydrazone (L)) dual ligands were successfully assembled via a conventional solvothermal method. The photoluminescence quenching response of ZnMOF-1 and CdMOF-1 and their sensing sensitivity and selectivity towards various inorganic anions were evaluated in aqueous media. Crystallographic and thermogravimetric studies confirm the formation of both MOFs with good crystallinity and thermal stability. Photoluminescence studies also verify the selectivity of ZnMOF-1 and CdMOF-1 for efficient sensing of inorganic oxyanions (like chromate/dichromate: CrO42- and Cr2O72-). Further, it was noted that only chromate/dichromate (CrO42-/Cr2O72-) anions showed a significant turn-off quenching effect while other anions (like F-, Br-, I-, Cl-, ClO4-, SCN-, SO42-, NO3-, and NO2-) have a low/negligible effect on the photoluminescence intensity of both MOFs. The limit of detection (LOD) of chromate/dichromate by ZnMOF-1 and CdMOF-1 was 9.79/10.94 µM and 2.68/1.48 µM, respectively. A probable mechanism for turn-off quenching response towards chromate and dichromate anions could be attributed to the spectral overlap of both excitation and emission spectra of ZnMOF-1/CdMOF-1 with the absorption spectra of chromate/dichromate anions. As a result, the energy transfer from ZnMOF-1 or CdMOF-1 to the target chromate and dichromate anions decreased fluorescence intensity (i.e., fluorescence quenching effect).

A Novel Composite of Zinc-based Metal Organic Framework Embedded with SnO2 Nanoparticle as a Photocatalyst for Methylene Blue Dye Degradation as well as Fluorometric Probe for Nitroaromatic Compounds Detection.

A facile bottom up synthesis technique is opted for the preparation of novel composite SnO2@Zn-BTC. This synthesized composite is fully characterized by Fourier Transform Infrared (FTIR) Spectroscopy, Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and Elemental mapping techniques. Optical analysis was performed using UV-Visible absorption spectroscopy and fluorescence studies. Further this composite was utilized for the first time as a photocatalyst for methylene blue (MB) dye degradation under sunlight irradiation. This photocatalyst shows degradation efficiency of 89% within 100 min of exposure of sunlight. In addition to that, the synthesized composite can be utilized as a fluorescence probe for detection of NACs via 'turn-off" quenching response. This composite is extremely sensitive towards 3-NA in aqueous medium with quenching efficiency of 75.42%, which is highest quenching rate till reported. There occurs no interference for detecting 3-NA in the presence of other NACs. The linear fitting of the Stern-Volmer plot for 3-NA shows large quenching constant (KSV) of 0.0115 ppb-1 with correlation coefficient R2 = 0.9943 proves higher sensitivity of composite in sensing process. The outstanding sensitivity of composite for 3-NA is certified by the low detection limit (LOD) of 25 ppb (0.18 µM). Photoinduced Electron Transfer (PET) and Fluorescence Resonance Energy Transfer (FRET) are the mechanisms used for clarification of quenching response of PL intensity by NACs via density functional theory (DFT) calculations and extent spectral overlap, respectively. Hence, synthesized composite is verified as multi-component system to act as excellent photocatalyst as well as fluorescent sensor.