Aqua­(2,2′-bipyridine-κ2 N,N′)[2-(3-thien­yl)malonato-κ2 O,O′]zinc(II) dihydrate

In the crystal structure of the title compound, [Zn(C7H4O4S)(C10H8N2)(H2O)]·2H2O, the ZnII ion assumes a trigonal–bipyramidal coordination geometry completed by two N atoms from a 2,2′-bipyridine ligand, two O atoms from a 2-(3-thien­yl)malonate anion and a water mol­ecule. The S atom of the 2-(3-thien­yl)malonate ligand is disordered over two sites with an occupancy ratio of 0.701 (5):0.299 (5). Inter­molecular O—H⋯O hydrogen bonding is present in the crystal structure

3-Carboxy­pyrazino[2,3-f][1,10]phenanthrolin-9-ium-2-carboxyl­ate

In the title zwitterionic compound, C16H8N4O4, the dihedral angle between the carboxyl and carboxyl­ate groups is 72.14 (2)°. In the crystal, mol­ecules are linked by strong inter­molecular O—H⋯O− and N+—H⋯O− hydrogen bonds into double chains extended along [001]. These chains are additionally stabilized by π–π stacking inter­actions between the pyridine and benzene rings [centroid–centroid distance = 3.5542 (8) Å]

Unraveling the Oxidation Mechanism of Formic Acid on Pd(111) Electrode: Implication from pH Effect and H/D Kinetic Isotope Effect

The pH effect and H/D kinetic isotope effect (KIE) of formic acid oxidation reaction (FAOR) on Pd(111) have been systematically investigated by cyclic voltammetry. In addition, the pH effect of acetate adsorption on Pd(111) is also studied to have a deep understanding of the role of adsorbates on Pd(111) during the FAOR process. The results clearly show: (1) In solutions with a fixed concentration of acetic acid, the onset potential of acetate desorption is almost unchanged on the reversible hydrogen electrode (RHE) scale with the increase of pH when the pH is lower than the pKa of acetic acid. However, when the pH is higher than the pKa of acetic acid, the onset potential of acetate desorption shifts positively with a slope of ca. 20 mV per pH unit; (2) In solutions with pH less than 6, the maximum coverage of acetate adsorbed on the Pd(111) electrode is about 0.26 ML; (3) In acidic solutions, FAOR on Pd(111) has obvious pH effect in the potential range of current increasing on SHE scale. After correcting the pHs-induced shift, the onset potential of FAOR shifts negatively by ca. 90 mV per pH unit. However, the pH effect disappears in the potential range after the peak; (4) In alkaline solutions, the onset potential of FAOR is influenced by OHad; (5) The H/D KIE factor of FAOR on Pd(111) is ca. 5 in the pH range of 1–14. Two possible mechanisms trying to explain these results have been proposed. In one, COOadλ– is the active intermediate and the formation of this intermediate is the rate-determining step (RDS), whereas, in the second one, monodentate adsorbed formate (HCOOm) is the active intermediate and its dissociation on the surface is the RDS. The simulated results with both mechanisms are compared with the experimental results and discussed critically.This work was financially supported by the National Natural Science Foundation of China (nos. 22172151 and 22372154). E.H. and J.M.F. acknowledge financial support from Ministerio de Ciencia, Innovación y Universidades (Project PID2022-137350NB-I00). Zhen Wei acknowledges support from the China Scholarship Council (award number 202106340060)

From one to many central plans: drug advertising inspections and intra-national protectionism in China

This paper provides the first micro-level evidence for the existence and patterns of intra-national protectionism in China. We demonstrate that drug advertising inspections are used by provincial governments to discriminate against firms from outside the province. We further reveal systematic patterns in the degree of discrimination across firms: those from neighboring areas, those from regions with more economic links to the destination province, those from provinces with stronger presence in the market, and those with political ties to “allied” provincial governments are less likely to be targeted. Our findings highlight the unique politico-economic structure in China and confirm that giving local governments strong incentives to compete with each other may exacerbate the market distortions inherent in a partially reformed economy

Preparation of Iron‐ and Nitrogen‐Codoped Carbon Nanotubes from Waste Plastics Pyrolysis for the Oxygen Reduction Reaction

A novel method to prepare iron and nitrogen co-doped carbon nanotubes (Fe-N-CNT) is proposed, based on catalytic pyrolysis of waste plastics. At first carbon nanotubes are produced from pyrolysis of plastic waste over Fe-Al2O3; then Fe-CNT and melamine are heated together in inert atmosphere. Different co-pyroysis temperatures are tested to optimize the electrocatalyst production. Working at a high doping temperature improved the degree of graphite formation and promoted the conversion of nitrogen to a more stable form. Compared with commercial platinum on carbon, the electrocatalyst obtained from pyrolysis at 850 °C, showed remarkable properties, with onset potential of 0.943 V vs RHE and half-wave potential of 0.811 V vs RHE and even better stability and anti-poisoning. In addition, zinc-air batteries tests were also carried out and the optimized catalyst exhibited high maximum power density

Surface passivation for highly active, selective, stable, and scalable CO2 electroreduction

Electrochemical conversion of CO2 to formic acid using Bismuth catalysts is one the most promising pathways for industrialization. However, it is still difficult to achieve high formic acid production at wide voltage intervals and industrial current densities because the Bi catalysts are often poisoned by oxygenated species. Herein, we report a Bi3S2 nanowire-ascorbic acid hybrid catalyst that simultaneously improves formic acid selectivity, activity, and stability at high applied voltages. Specifically, a more than 95% faraday efficiency was achieved for the formate formation over a wide potential range above 1.0 V and at ampere-level current densities. The observed excellent catalytic performance was attributable to a unique reconstruction mechanism to form more defective sites while the ascorbic acid layer further stabilized the defective sites by trapping the poisoning hydroxyl groups. When used in an all-solid-state reactor system, the newly developed catalyst achieved efficient production of pure formic acid over 120 hours at 50 mA cm–2 (200 mA cell current)

The FengYun-3C radio occultation sounder GNOS: a review of the mission and its early results and science applications

The Global Navigation Satellite System (GNSS) Occultation Sounder (GNOS) is one of the new-generation payloads on board the Chinese FengYun 3 (FY-3) series of operational meteorological satellites for sounding the Earth's neutral atmosphere and ionosphere. FY-3C GNOS, on board the FY-3 series C satellite launched in September 2013, was designed to acquire setting and rising radio occultation (RO) data by using GNSS signals from both the Chinese BeiDou Navigation Satellite System (BDS) and the US Global Positioning System (GPS). So far, the GNOS measurements and atmospheric and ionospheric data products have been validated and evaluated and then been used for atmosphere- and ionosphere-related scientific applications.This paper reviews the FY-3C GNOS instrument, RO data processing, data quality evaluation, and preliminary research applications according to the state-of-the-art status of the FY-3C GNOS mission and related publications. The reviewed data validation and application results demonstrate that the FY-3C GNOS mission can provide accurate and precise atmospheric and ionospheric GNSS (i.e., GPS and BDS) RO profiles for numerical weather prediction (NWP), global climate monitoring (GCM), and space weather research (SWR). The performance of the FY-3C GNOS product quality evaluation and scientific applications establishes confidence that the GNOS data from the series of FY-3 satellites will provide important contributions to NWP, GCM, and SWR scientific communities.</p

Accurate Prediction of Protein Structural Class

Because of the increasing gap between the data from sequencing and structural genomics, the accurate prediction of the structural class of a protein domain solely from the primary sequence has remained a challenging problem in structural biology. Traditional sequence-based predictors generally select several sequence features and then feed them directly into a classification program to identify the structural class. The current best sequence-based predictor achieved an overall accuracy of 74.1% when tested on a widely used, non-homologous benchmark dataset 25PDB. In the present work, we built a multiple linear regression (MLR) model to convert the 440-dimensional (440D) sequence feature vector extracted from the Position Specific Scoring Matrix (PSSM) of a protein domain to a 4-dimensinal (4D) structural feature vector, which could then be used to predict the four major structural classes. We performed 10-fold cross-validation and jackknife tests of the method on a large non-homologous dataset containing 8,244 domains distributed among the four major classes. The performance of our approach outperformed all of the existing sequence-based methods and had an overall accuracy of 83.1%, which is even higher than the results of those predicted secondary structure-based methods

Association of inpatient use of angiotensin converting enzyme inhibitors and angiotensin II receptor blockers with mortality among patients with hypertension hospitalized with COVID-19

Rationale: Use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) is a major concern for clinicians treating coronavirus disease 2019 (COVID-19) in patients with hypertension. Objective: To determine the association between in-hospital use of ACEI/ARB and all-cause mortality in COVID-19 patients with hypertension. Methods and Results: This retrospective, multi-center study included 1128 adult patients with hypertension diagnosed with COVID-19, including 188 taking ACEI/ARB (ACEI/ARB group; median age 64 [IQR 55-68] years; 53.2% men) and 940 without using ACEI/ARB (non-ACEI/ARB group; median age 64 [IQR 57-69]; 53.5% men), who were admitted to nine hospitals in Hubei Province, China from December 31, 2019 to February 20, 2020. Unadjusted mortality rate was lower in the ACEI/ARB group versus the non-ACEI/ARB group (3.7% vs. 9.8%; P = 0.01). In mixed-effect Cox model treating site as a random effect, after adjusting for age, gender, comorbidities, and in-hospital medications, the detected risk for all-cause mortality was lower in the ACEI/ARB group versus the non-ACEI/ARB group (adjusted HR, 0.42; 95% CI, 0.19-0.92; P =0.03). In a propensity score-matched analysis followed by adjusting imbalanced variables in mixed-effect Cox model, the results consistently demonstrated lower risk of COVID-19 mortality in patients who received ACEI/ARB versus those who did not receive ACEI/ARB (adjusted HR, 0.37; 95% CI, 0.15-0.89; P = 0.03). Further subgroup propensity score-matched analysis indicated that, compared to use of other antihypertensive drugs, ACEI/ARB was also associated with decreased mortality (adjusted HR, 0.30; 95%CI, 0.12-0.70; P = 0.01) in COVID-19 patients with hypertension. Conclusions: Among hospitalized COVID-19 patients with hypertension, inpatient use of ACEI/ARB was associated with lower risk of all-cause mortality compared with ACEI/ARB non-users. While study interpretation needs to consider the potential for residual confounders, it is unlikely that in-hospital use of ACEI/ARB was associated with an increased mortality risk