Spontaneous Deposition of Single Platinum Atoms on Anatase TiO2 for Photocatalytic H2 Evolution.

Single-atom (SA) decoration has emerged as a frontier in catalysis due to its unique characteristics. Recently, decorated Pt single atoms on titania have shown promise in photocatalytic hydrogen evolution. In this work, we demonstrate that Pt SAs can spontaneously deposit on the surface, driven by electrostatic forces; the key is to determine the golden pH and surface potential. We conducted a comprehensive investigation into the influence of the pH of the deposition precursor on the spontaneous adsorption of Pt SAs onto TiO2 nanosheets (TiNSs). We introduced a straightforward pH-dependent and charge-dependent strategy for the solid electrostatic anchoring of Pt SAs on TiO2. Furthermore, we established that the level of Pt loading can be controlled by adjusting the precursor pH. X-ray photoelectron spectroscopy (XPS) and high-angle annular dark-field imaging scanning transmission electron microscopy (HAADF-STEM) were used to evaluate the Pt SA-decorated samples. Photocatalytic hydrogen production activity was assessed under ultraviolet (UV) (365 nm) irradiation. Notably, we found that at a pH of 8, slightly below the measured point of zero charge (PZC), a unique mixture of Pt clusters and single atoms was deposited on the surface of TiNSs. This unique composition significantly improved hydrogen production, resulting in ∼3.7 mL of hydrogen generated after 8 h of UV exposure by only 10 mg of the Pt-decorated TiNS (with Pt loadings of 0.12 at. %), which is ∼300 times higher than the undecorated TiNS.

Development of homogeneous dispersive solid phase extraction using albumin as a green sorbent and its combination with dispersive liquid-liquid microextraction: application in extraction of pesticides from fruit juices.

In the current study, salt- and pH-induced homogeneous dispersive solid phase extraction was developed using albumin as a sorbent for the extraction of some pesticides (diazinon, diniconazole, haloxyfop-R-methyl, and hexaconazole) from fruit juice of orange, pomegranate, and barberry. The extracted analytes were more concentrated by dispersive liquid-liquid microextraction to obtain high enrichment factors and low detection limits prior to their determination by gas chromatography-mass spectrometry. In the extraction process, human serum albumin solution was added to the sample solution at the µL-level and a homogeneous solution was obtained. Then, albumin was precipitated into the solution by adding an inorganic salt and decreasing the solution pH. By doing so, the analytes were adsorbed by albumin effectively due to their high adsorption capacity and large surface area. Following this, the pesticides were eluted from the albumin sorbent using an elution solvent and used in a dispersive liquid-liquid microextraction step. Under the optimum extraction conditions, low limits of detection and quantification were achieved in the ranges of 0.02-0.04 and 0.07-0.13 ng mL-1, respectively. The calibration curves were linear in the range of 0.13-250 ng mL-1. Relative standard deviation as a criterion for precision and the method repeatability were in the ranges of 2.9-4.2% for intra- (n = 5, C = 5 or 50 ng mL-1) and 3.2-5.2% for inter-day (n = 5, 50 ng mL-1) precisions. The enrichment factors and extraction recoveries were in the ranges of 390-460 and 78-92%, respectively. Finally, the offered procedure was applied for the analysis of pesticide residues in some fruit juice samples.

Diagnosis of acute myocardial infarction: highlighting cardiac troponins as vital biomarkers.

The molecular marker, cardiac troponin (cTn) is a complex protein that is attached to tropomyosin on the actin filament. It is an essential biomolecule in terms of the calcium-mediated regulation of the contractile apparatus in myofibrils, the release of which is an indication of the dysfunction of cardiomyocytes and hence the initiation of ischemic phenomena in the heart tissue. Fast and accurate analysis of cTn may help the diagnosis and management of acute myocardial infarction (AMI), for which electrochemical biosensors and microfluidics devices can be of great benefit. This editorial aims to highlight the importance of cTn as vital biomarkers in AMI diagnosis.

Liquid Phase Microextraction of Hazardous Compounds in Dairy Products; Principal and Practical Aspects.

Liquid phase microextraction techniques are considered as the miniaturized version of traditional liquid-liquid extraction, which use only several microliters of a proper solvent to extract the analytes from sample. In these methods, the target analytes are migrated into a water-immiscible organic solvent (acceptor phase) from an aqueous sample (donor phase). They are mainly classified into three main groups including (a) single-drop microextraction, (b) dispersive liquid-liquid microextraction, and (c) hollow fiber-liquid phase microextraction. These techniques have been successfully applied to the assessment of different analytes in food samples, pharmaceuticals, beverages, and so on. This review mainly focuses on up-to-date information on the application of liquid phase microextraction techniques in dairy products. The advantages and disadvantages of the developed liquid phase microextraction methods were discussed.

Effect of supplemental vitamin D3 on bone mineral density: a systematic review and meta-analysis.

CONTEXT: There is still controversy over the effect of vitamin D3 supplementation on bone health. OBJECTIVE: The effects of vitamin D3 supplementation on bone mineral density (BMD) and markers of bone turnover, as well as the dose-response relationship between vitamin D3 and bone health in adults, were evaluated. DATA SOURCES: The PubMed, Scopus, Cochrane, Web of Science, and AGRIS databases were searched for articles published through April 30, 2022. Thirty-nine of the 6409 records identified met the inclusion criteria. DATA EXTRACTION: Data were extracted from articles by 2 authors, and data extraction was cross-checked independently. A random-effects model was used to estimate the pooled effect size and the associated 95%CI for the effect of vitamin D3 for each outcome. A one-stage random-effects dose-response model was used to estimate the dose-response relationship between vitamin D3 supplementation and BMD. DATA ANALYSIS: Results of meta-analysis showed a beneficial effect of vitamin D3 at the lumbar spine (standardized mean difference [SMD] = 0.06; 95%CI, 0.01-0.12) and femoral neck (SMD = 0.25; 95%CI, 0.09-0.41). Dose-response analysis revealed a linear relationship between vitamin D3 supplementation doses and BMD at the femoral neck, lumbar spine, and total hip sites. No significant effect of vitamin D3 supplementation on whole-body or total hip BMD was observed (P > 0.05). Vitamin D3 supplementation significantly decreased BMD at both proximal and distal forearm (SMD = -0.16; 95%CI, -0.26 to -0.06). The variables of ethnicity, age, baseline 25-hydroxyvitamin D (25[OH]D), menopause status, vitamin D3 dosing frequency, and bone health status (P interaction = 0.02) altered the effect of vitamin D3 supplementation on BMD. Additionally, a nonlinear relationship between vitamin D3 supplement doses and markers of bone turnover was found. CONCLUSION: A protective effect of vitamin D3 supplementation on BMD of the lumbar spine, femoral neck, and total hip is implicated. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42017054132.

Recent Advances in Impedimetric Biosensors Focusing on Myocardial Infarction Diagnosis.

Acute myocardial infarction is the most common cardiovascular disease and 85% of cardiovascular disease-related deaths are associated with it. The variation in the cardiac troponin concentration is considered as the most significant judge index for acute myocardial infarction diagnosis. Here, a comprehensive insights is given about the impedimetric methods as powerful electrochemical biosensing platforms for cardiac troponin evaluation. Focusing on nano materials, various impedimetric techniques including faradaic and non-faradaic techniques and different transducer modification techniques are addressed. The steps taken by each of the studied platforms to solve the existing problems are discussed and their advantages and drawbacks are highlighted. A glance at the provided table is given a mind into the features of each impedimetric sensors and their comparison are provided.

Needling, lasers, and Meso-Botox for hypertrophic and keloidal scars: A comprehensive review study on promising procedural treatments.

Scars are among the most prevalent referral cases of dermatology clinics, including atrophic, hypertrophic, or keloidal scars. Approach to scar usually needs a holistic trend, attention to individualized characteristics, and combination therapy. Scars usually need multiple sessions of therapy and the use of combination therapeutic approaches to reach the most acceptable outcomes by safe modalities. Studies on scars are always one of the most important fields of research in medicine, especially in dermatology. For writing this review study, we searched all the databases to find the most relevant and the newest studies related to our topic, because based on expert opinion, this topic may be really practical and interesting for dermatologists and all physicians of various specialties or subspecialties who manage and treat various kinds of scars, including hypertrophic scars and keloids. Based on our results, we concluded that different procedures, which basically use needling, lasers, especially pulsed dye laser (PDL) and carbon dioxide (CO2) laser, and MesoBotox (micro-injection of botulinum toxin), are really promising therapeutic options for hypertrophic and keloidal scars and a combination of these therapies results in more efficacy and lesser side effects in the field of scar management.

Magnetic Nanoparticles Linked to Pyridinium Hydrotribromide Groups as Catalysts for Selective Oxidation of Alcohols and Protection of Alcohols.

In this research, a novel magnetic nanocatalyst based on iron oxide nanoparticles linked with pyridinium hydrotribromide (Fe3O4@PyHBr3) was synthesized in three steps. In the first step, 3-(aminopropyl)triethoxysilane (APTES) was reacted with 4-(bromomethyl)pyridine hydrobromide. In the second step, the product obtained in the first step was reacted with iron oxide nanoparticles. In the last step, a grinding reaction was carried out with KBr and HIO4 in a mortar. The Fe3O4@PyHBr3 nanocatalyst was characterized by FT-IR, CHN, XRD, SEM, TGA and VSM analysis. The magnetic nanocatalyst was used as a catalyst for the selective oxidation of alcohols to aldehydes and ketones using 30% H2O2 as oxidant in a short time and with high yields. Moreover, no overoxidation of the alcohols was observed. The nanocatalyst was efficiently recycled in five consecutive cycles without significant loss of its catalytic activity. Moreover, trimethylsilylation and tetrahydropyranylation of alcohols were carried out in the presence of this nanocatalyst.

Monitoring of trace amounts of heavy metals in different food and water samples by flame atomic absorption spectrophotometer after preconcentration by amine-functionalized graphene nanosheet.

We are introducing graphene oxide modified with amine groups as a new solid phase for extraction of heavy metal ions including cadmium(II), copper(II), nickel(II), zinc(II), and lead(II). Effects of pH value, flow rates, type, concentration, and volume of the eluent, breakthrough volume, and the effect of potentially interfering ions were studied. Under optimized conditions, the extraction efficiency is >97 %, the limit of detections are 0.03, 0.05, 0.2, 0.1, and 1 µg L(-1) for the ions of cadmium, copper, nickel, zinc, and lead, respectively, and the adsorption capacities for these ions are 178, 142, 110, 125, and 210 mg g(-1). The amino-functionalized graphene oxide was characterized by thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectrometry. The proposed method was successfully applied in the analysis of environmental water and food samples. Good spiked recoveries over the range of 95.8-100.0 % were obtained. This work not only proposes a useful method for sample preconcentration but also reveals the great potential of modified graphene as an excellent sorbent material in analytical processes.

Effect of lithium on secretory factors and growth stimulation by bombesin in rat pancreas and salivary glands.

Lithium, a drug of choice in bipolar affective disorders, also affects the metabolism and cell proliferation in a diverse array of organisms. In this study, we investigated the effect of lithium on bombesin-mediated function in excretion and growth of the pancreas and the salivary glands. The weight, protein content, amylase concentration and salivary flow rate of the pancreas, parotid and the submandibular glands were determined in male Wistar rats after consumption of either water or lithium chloride (600 mg/l) for 14 days and each group received s.c. injection of either saline or bombesin (10 microg/kg) during the last 4 days of experiment. Our results revealed that administration of bombesin in lithium-treated group not only suppressed pancreas and parotid weight augmentation due to bombesin, but also significantly decreased pancreas growth. Chronic lithium consumption significantly inhibited the protein content augmentation due to bombesin in the salivary glands. Getting bombesin, as well as saline in lithium-treated group, resulted in notable decrease in salivary protein content. Protein content of pancreatic gland increased considerably in the bombesin-injected groups either treated with saline or lithium. In conclusion, the stimulatory effect of bombesin on the growth and protein content of the pancreas and the salivary gland was inhibited by lithium. Lithium seems to be a potent inhibitor of growth factors induced by bombesin probably through inhibiting phosphatidylinositol 4,5,bisphosphate hydrolysis.