Experimental and theoretical insights to demonstrate the hydrogen evolution activity of layered platinum dichalcogenides electrocatalysts

Abstract Hydrogen is a highly efficient and clean renewable energy source and water splitting through electrocatalytic hydrogen evolution is a most promising approach for hydrogen generation. Layered transition metal dichalcogenides-based nano-structures have recently attracted significant interest as robust and durable catalysts for hydrogen evolution. We systematically investigated the platinum (Pt) based dichalcogenides (PtS2, PtSe2 and PtTe2) as highly energetic and robust hydrogen evolution electrocatalysts. PtTe2 catalyst unveiled the rapid hydrogen evolution process with the low overpotentials of 75 and 92 mV (vs. RHE) at a current density of 10 mA cm−2, and the small Tafel slopes of 64 and 59 mV/dec in acidic and alkaline medium, respectively. The fabricated PtTe2 electrocatalyst explored a better catalytic activity than PtS2 and PtSe2. The density functional theory estimations explored that the observed small Gibbs free energy for H-adsorption of PtTe2 was given the prominent role to achieve the superior electrocatalytic and excellent stability activity towards hydrogen evolution due to a smaller bandgap and the metallic nature. We believe that this work will offer a key path to use Pt based dichalcogenides for hydrogen evolution electrocatalysts

Tuning of undoped ZnO thin film via plasma enhanced atomic layer deposition and its application for an inverted polymer solar cell

We studied the tuning of structural and optical properties of ZnO thin film and its correlation to the efficiency of inverted solar cell using plasma-enhanced atomic layer deposition (PEALD). The sequential injection of DEZn and O2 plasma was employed for the plasma-enhanced atomic layer deposition of ZnO thin film. As the growth temperature of ZnO film was increased from 100 ??C to 300??C, the crystallinity of ZnO film was improved from amorphous to highly ordered (002) direction ploy-crystal due to self crystallization. Increasing oxygen plasma time in PEALD process also introduces growing of hexagonal wurtzite phase of ZnO nanocrystal. Excess of oxygen plasma time induces enhanced deep level emission band (500 ??? 700 nm) in photoluminescence due to Zn vacancies and other defects. The evolution of structural and optical properties of PEALD ZnO films also involves in change of electrical conductivity by 3 orders of magnitude. The highly tunable PEALD ZnO thin films were employed as the electron conductive layers in inverted polymer solar cells. Our study indicates that both structural and optical properties rather than electrical conductivities of ZnO films play more important role for the effective charge collection in photovoltaic device operation. The ability to tune the materials properties of undoped ZnO films via PEALD should extend their functionality over the wide range of advanced electronic applications.open2

Radioprotective Effect of Epigallocatechin-3-Gallate on Salivary Gland Dysfunction After Radioiodine Ablation in a Murine Model

Objectives. Radioiodine (RI) therapy is known to subject cellular components of salivary glands (SG) to oxidative stress leading to SG dysfunction. However, the protective effects of antioxidants on RI-induced SG damage have not been well investigated. The authors investigated the morphometric and functional effects of epigallocatechin-3-gallate (EGCG) administered prior to RI therapy and compared this with the effects of amifostine (a well-known antioxidant) in a murine model of RI sialadenitis. Methods. Four-week-old female C57BL/6 mice (n=48) were divided into four groups; a normal control group, a RI-treated group (0.01 mCi/g mouse, orally), an EGCG and RI-treated group, and an amifostine and RI-treated group. Animals in these groups were divided into 3 subgroups and euthanized at 15, 30, and 90 days post-RI treatment. Salivary flow rates and lag times were measured, and morphologic and histologic examinations and TUNEL (terminal deoxynucleotidyl transferase biotin-dUDP nick end labeling) assays were performed. Changes in salivary 99mTc pertechnetate uptake and excretion were followed by single-photon emission computed tomography. Results. Salivary flow rates and lag times to salivation in the EGCG or amifostine groups were better than in the RI-treated group. Histologic examinations of SGs in the EGCG or amifostine group showed more mucin-rich parenchyma and less periductal fibrosis than in the RI-treated group. Fewer apoptotic cells were observed in acini, ducts, and among endothelial cells in the EGCG or amifostine group than in the RI group. In addition, patterns of 99mTc pertechnetate excretion were quite different in the EGCG or amifostine group than in the RI group. Conclusion. EGCG supplementation before RI therapy could protect from RI-induced SG damage in a manner comparable to amifostine, and thus, offers a possible means of preventing SG damage by RI

Radish microgreens produced without substrate in a vertical multi-layered growing unit are rich in nutritional metabolites

Growing microgreens on trays without substrate in a vertical multilayered growing unit offers several advantages over traditional agriculture methods. This study investigated the yield performance and nutritional quality of five selections of radish microgreens grown in sprouting trays, without a substrate using only water, in an indoor multilayer cultivation system using artificial light. Various parameters were measured, including fresh weight, dry matter, chlorophyll, minerals, amino acids, phenolics, flavonoids, anthocyanins, vitamin C, glucosinolates, and antioxidant activity with four different in vitro assays. After ten days, the biomass had increased by 6-10 times, and the dry matter varied from 4.75-7.65%. The highest yield was obtained from ‘Asia red’, while the lowest was from ‘Koregon red’. However, ‘Koregon red’ and ‘Asia red’ had the highest dry matter. ‘Asia red’ was found to have the highest levels of both Chls and vitamin C compared to the other cultivars, while ‘Koregon red’ exhibited the highest levels of total phenolics and flavonoids. Although variations in the levels of individual glucosinolates were observed, there were no significant differences in the total content of glucosinolates among the five cultivars. ‘Asia purple’ had the highest anthocyanin content, while ‘Asia green 2’ had the lowest. The K, Mg, and Na concentrations were significantly highest in ‘Asia green 2’, and the highest Ca was recorded in ‘Asia purple’. Overall, ‘Asia purple’ and ‘Koregon red’ were the best cultivars in terms of nutritional quality among the tested radish microgreens. These cultivars exhibited high levels of dry weight, total phenolics, flavonoids, anthocyanins, essential and total amino acids, and antioxidant activities. Moreover, the implementation of this vertical cultivation method for microgreens, which relies solely on water and seeds known for their tall shoots during the sprouting could hold promise as a sustainable approach. This method can effectively be utilized for cultivar screening and fulfilling the nutritional and functional needs of the population while minimizing the environmental impacts associated with traditional agriculture practices

Effect of steroids and relevant cytokine analysis in acute tubulointerstitial nephritis

Background Acute tubulointerstitial nephritis (ATIN) is an important cause of acute kidney injury and often a potentially reversible disease. However, the role of steroids in ATIN remains controversial and the underlying mechanisms remain unresolved. Methods A total of 113 adult patients with biopsy-proven ATIN were recruited from three tertiary referral centers. Of 102 patients with idiopathic or drug-induced ATIN, outcomes such as renal recovery, end-stage renal disease, and all-cause mortality were compared between the steroid-treated and non-treated groups. Plasma and urine inflammatory cytokine levels at the time of biopsy were analyzed in patients (n = 33) using a bead-based multiplex assay and compared with those of healthy individuals (n = 40). Results Steroids were used in 92 (81.4%) of the total patients and in 82 (80.3%) patients with idiopathic or drug-induced ATIN. The rate of renal recovery and the risks of end-stage renal disease and mortality were not different between the steroid-treated and non-treated groups. Despite using a propensity score matching method (n = 20 in each group), none of the outcomes were different between the two groups. Several cytokines, such as monocyte chemotactic protein-1, interferon-α, and interleukin-6 and interleukin-8 levels, were markedly elevated in plasma and urine of patients compared with those in healthy individuals. However, cytokines related to Th2 response, such as IL-10, IL-33, were not different between the two groups. Conclusions Steroid use does not affect the overall outcome of ATIN. Based on the fact that targeting therapy should be investigated to improve outcomes, the present cytokine results will be helpful for developing a novel therapy for ATIN.This work was supported by a grant from the Basic Science Research Program through the National Research Foundation of Korea (NRF), which is funded by the Ministry of Education (NRF-2017R1D1A1B03031642)

Neuroprotective effects of consuming bovine colostrum after focal brain ischemia/reperfusion injury in rat model

To investigate the neuroprotective effects of bovine colostrums (BC), we evaluate the ability of consuming BC after focal brain ischemia/reperfusion injury rat model to reduce serum cytokine levels and infarct volume, and improve neurological outcome. Sprague-Dawley rats were randomly divided into 4 groups; one sham operation and three experimental groups. In the experimental groups, MCA occlusion (2 h) and subsequent reperfusion (O/R) were induced with regional cerebral blood flow monitoring. One hour after MCAO/R and once daily during the experiment, the experimental group received BC while the other groups received 0.9% saline or low fat milk (LFM) orally. Seven days later, serum pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) and anti-inflammatory cytokine (IL-10) levels were assessed. Also, the infarct volume was assessed by using a computerized image analysis system. Behavioral function was also assessed using a modified neurologic severity score and corner turn test during the experiment. Rats receiving BC after focal brain I/R showed a significant reduction (-26%/-22%) in infarct volume compared to LFM/saline rats, respectively (P < 0.05). Serum IL-1β, IL-6, and TNF-α levels were decreased significantly in rats receiving BC compared to LFM/saline rats (P < 0.05). In behavioral tests, daily BC intake showed consistent and significant improvement of neurological deficits for 7 days after MCAO/R. BC ingestion after focal brain ischemia/reperfusion injury may prevent brain injury by reducing serum pro-inflammatory cytokine levels and brain infarct volume in a rat model