Highly Active and Water-Resistant Cu-Doped OMS-2 Catalysts for CO Oxidation: The Importance of the OMS-2 Synthesis Method and Cu Doping

Porous cryptomelane-type Mn oxide (OMS-2) has an outstanding redox property, making it a highly desirable substitute for noble metal catalysts for CO oxidation, but its catalytic activity still needs to be improved, especially in the presence of water. Given the strong structure-performance correlation of OMS-2 for oxidation reactions, herein, OMS-2 is synthesized by solid state (OMS-2S), reflux (OMS-2R), and hydrothermal (OMS-2H) methods, aiming to improve its CO oxidation performance through manipulating synthesis parameters to tailor its particle size, morphology, and crystallinity. Characterization shows that OMS-2S has the highest CO oxidation activity in the absence of water due to its low crystallinity, high specific surface area, large oxygen vacancy content, and good redox property, but the presence of water can greatly reduce its CO oxidation activity. Doping Cu into an OMS-2 can not only improve its CO oxidation activity but also greatly improve its water tolerance. The Cu-doped OMS-2S catalyst with ∼4 wt % Cu can achieve a T90 of 49 °C (1% CO/10% O2/N2 and WHSV = 60,000 mL·g-1·h-1), ranking among the lowest reported T90 values for Mn oxide-based CO oxidation catalysts, and it can maintain nearly 100% CO conversion in the presence of 5 vol % water for over 50 h. In situ DRIFTs characterization indicates that the good water resistance of Cu-doped OMS-2S can be attributed to the significantly suppressed surface hydroxyl group generation because of Cu doping. This work demonstrates the importance of the synthesis method and Cu doping in determining the CO oxidation activity and water resistance of OMS-2 and will provide guidance for synthesizing highly active and water-resistant CO oxidation catalysts.

Comparison of peripheral artery plaque characteristics between ACS patients with plaque rupture and plaque erosion in culprit coronary artery: an OCT and ultrasound study

Background

Recent research has found that the characteristics of peripheral arterial plaque are related to the increased risk of cardiovascular disease, however, the relationship of plaque characteristics between peripheral artery and coronary is still unknown.

Purpose

To assess the correlation between coronary plaque characteristics assessed by optical coherence tomography (OCT) and peripheral artery plaque characteristics assessed by ultrasound.

Methods

150 patients with acute coronary syndrome (ACS) underwent coronary angiography were prospectively enrolled. OCT imaging of culprit vessel were performed during the procedure and ultrasound examination of bilateral carotid, iliofemoral and popliteal arteries was performed during hospitalization after procedure. Panvascular disease was defined as the presence of observable plaques in two or more vascular beds. Patients were divided into plaque rupture (PR) group and plaque erosion (PE) group according to culprit plaque characteristics on OCT.

Results

There were 132 (88%) ACS patients had panvascular disease in which 36 (24%) with generalized atherosclerosis (4 sites) and the prevalence of panvascular atherosclerosis in PR group was significantly higher than in PE group especially in carotid arteries and iliofemoral arteries (Figure 1, Figure 2). Compared to PE group, PR group had higher carotid plaque score (p=0.001) which indicates more plaques and severer atherosclerosis. Moreover, there were larger intima-media thickness (IMT) of iliofemoral arteries (6.9±1.4mm vs. 6.5±1.1mm, p=0.036) and more calcified plaques in PR group.

Conclusions

Panvascular disease is highly prevalent in ACS patients especially in patients with plaque rupture in culprit vessel, in which more than half of the patients had plaques in more than 3 sites of vascular beds. In addition, patients with plaque rupture had thicker iliofemoral IMT and higher panvascular atherosclerosis burden, which indicates that characteristics of coronary plaques are the focal expression of plaques in the whole panvcascular system.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Key R&D Program of China Figure 1. Prevalence of panvascular disease in ACSFigure 2. Comparison of peripheral artery plaques

[Clinical characteristics of anti-CV2 antibody-associated neurological diseases]

This study reviewed the clinical data of patients who were hospitalized in the Department of Neurology of Henan Provincial People's Hospital from January 2017 to October 2020. A total of 46 patients with positive serum anti-CV2 antibody were included. The average age of the patients was (54±15) years old, with a male to female ratio of 1.88∶1. Twenty-six patients were diagnosed with paraneoplastic neurological syndrome (PNS). The most malignant tumors were thymoma, small cell lung cancer, and prostate cancer. The most common PNS included myasthenia gravis, subacute cerebellar degeneration, and subacute/chronic sensorimotor neuropathies. Twenty non-PNS patients exhibited subacute/old cerebral infarction, Parkinson's disease, Alzheimer's disease, and so on. Among them, brain magnetic resonance imaging (MRI) of 10 cases showed different degrees of white matter demyelination, some of which were accompanied by brain atrophy. The current study found that the positive predictive value of anti-CV2 antibody for the diagnosis of PNS was 56.5%, which was relatively weak. As an accompanying antibody, it may be a coincidence, and it may also be related to the involvement of family members in the pathological process of the diseases.

Highly porous Fe/N/C catalyst for oxygen reduction: the importance of pores

Fe/N/C full of ultrafine Fe-based species and pores is synthesized by pyrolyzing a g-C₃N₄-coordinated Fe matrix embedded in carbon for oxygen reduction. Enhanced oxygen reduction activity is observed on Fe/N/C with higher pore volume and the Fe/N/C catalyst with the largest pore volume shows the highest half-wave potential of 0.890 V.

Multi-role graphitic carbon nitride-derived highly porous iron/nitrogen co-doped carbon nanosheets for highly efficient oxygen reduction catalyst

Pyrolyzing precursors containing iron, nitrogen and carbon elements is a commonly used process for synthesizing FeNC catalysts for oxygen reduction reaction (ORR). Generally, aggregation of iron-based species is prone to occur because of a lack of chemical bonds between iron-based species and carbon matrix and synthesizing highly porous FeNC catalysts is difficult because carbon skeleton is prone to collapse during pyrolysis. Herein, highly porous FeNC catalysts with fine iron-based species are synthesized by selecting glucose as carbon source, FeCl₃ as iron source, and urea-derived g-C₃N₄ as nitrogen source, iron anchoring and stabilizing species, and pore-forming template. The multi-role g-C₃N₄-derived catalyst synthesized at 1100 °C (FeNC1100) has fine iron-based species, large specific surface area (737 m² g^-1), and extremely high pore volume (2.66 cm³ g^-1). Accordingly, FeNC1100 shows a larger half-wave potential (E_1/2 = 0.894 V), a higher stability (ΔE_1/2 = 6 mV) after 10,000 potential cycles in alkaline media, and a higher peak power density (P = 152 mW cm^-2) when employed as ORR catalyst of zinc-air battery, which are all superior to those of the commercial Pt/C catalyst (E_1/2 = 0.864 V, ΔE_1/2 = 30 mV, P = 134 mW cm^-2). The present work brings a new method for synthesizing highly porous FeNC catalysts decorated with fine active sites for ORR.

Zinc, sulfur and nitrogen co-doped carbon from sodium chloride/zinc chloride-assisted pyrolysis of thiourea/sucrose for highly efficient oxygen reduction reaction in both acidic and alkaline media

Zn and N co-doped carbon (Zn-N-C) shows encouraging catalytic stability for oxygen reduction reaction (ORR) because of the fulfilled d orbital of Zn, but its catalytic activity is not satisfactory. Herein, hierarchically porous Zn, S and N co-doped carbon (Zn-S-N-C) with large specific surface area (2433 m² g^-1) and pore volume (3.007 cm³ g^-1) is synthesized by using NaCl/ZnCl₂-assisted pyrolysis of sucrose and thiourea. The Zn-S-N-C catalyst exhibits superior ORR activity with half-wave potentials (E_1/2) up to 0.774 V in 0.1 M HClO₄ and 0.894 V in 0.1 M KOH, good ORR stability with 19- and 4-mV loss in E_1/2 values after 10,000 potential cycles in 0.1 M HClO₄ and 0.1 M KOH, respectively, and excellent methanol tolerance. The good ORR performance of Zn-S-N-C can be attributed to its enhanced intrinsic ORR activity resulting from the formation of S, N doped carbon and ZnS in Zn-S-N-C, its hierarchically porous structure resulting from the pore-forming roles played by ZnCl₂, NaCl and thiourea, and its improved graphitization degree resulting from the added ZnCl₂ during Zn-S-N-C synthesis. This work will provide a novel strategy for the synthesis of hierarchically porous Zn, S and N co-doped carbon materials for ORR.

Electrogenerated alkaline hydrogen peroxide for rice straw pretreatment to enhance enzymatic hydrolysis

In this work, alkaline hydrogen peroxide (AHP) solution with 1 wt% H₂O₂ was electrogenerated by oxygen reduction with a current efficiency of 75.2% in a home-made gas diffusion electrode-based electrochemical cell and used for rice straw pretreatment (0.1 g H₂O₂/g rice straw, 10% (w/v) biomass loading, 55 °C, 2 h). Results showed that the AHP pretreatment removed 97.56% of the initial lignin, 85.75% of the initial hemicellulose, and only 0.56% of the initial cellulose, and the specific surface area and porosity of the AHP pretreated rice straw (AHP-RS) were greatly increased. Saccharification results showed that after 48 h of enzymatic hydrolysis AHP-RS achieved a 3.2-fold increase in reducing sugar concentration compared to the untreated rice straw (5.81 and 1.81 g L^-1), highlighting the potential use of this AHP solution for lignocellulose pretreatment.

A ZIF-derived hierarchically porous Fe–Zn–N–C catalyst synthesized via a two-stage pyrolysis for the highly efficient oxygen reduction reaction in both acidic and alkaline media

A ZIF-derived Fe–Zn–N–C catalyst synthesized by a two-stage pyrolysis process exhibits superior activity for the ORR.

Effect of iron salt type and dosing mode on Fenton-based pretreatment of rice straw for enzymatic hydrolysis

Fenton-based processes with four different iron salts in two different dosing modes were used to pretreat rice straw (RS) samples to increase their enzymatic digestibility. The composition analysis shows that the RS sample pretreated by the dosing mode of iron salt adding into H₂O₂ has a much lower hemicellulose content than that pretreated by the dosing mode of H₂O₂ adding into iron salt, and the RS sample pretreated by the chloride salt-based Fenton process has a much lower lignin content and a slightly lower hemicellulose content than that pretreated by the sulphate salt-based Fenton process. The higher concentration of reducing sugar observed on the RS sample with lower lignin and hemicellulose contents justifies that the Fenton-based process could enhance the enzymic hydrolysis of RS by removing hemicellulose and lignin and increasing its accessibility to cellulase. FeCl₃·6H₂O adding into H₂O₂ is the most efficient Fenton-based process for RS pretreatment.

Ultrasound-assisted alkaline pretreatment for enhancing the enzymatic hydrolysis of rice straw by using the heat energy dissipated from ultrasonication

Rice straw samples were exposed to ultrasound-assisted alkaline (NaOH) pretreatment by using the heat energy dissipated from ultrasonication to increase their enzymatic digestibility for saccharification. The characterization shows that the pretreatment could selectively remove lignin and hemicellulose without degrading cellulose, and increase porosity and surface area of rice straw. The porosity, surface area and cellulose content of rice straw increased with the increasing concentration of NaOH used. The rice straw sample pretreated by using the heat energy dissipated from ultrasonication has a higher surface area and a lower crystallinity index value than that pretreated by using the external source of heating, and the amount of reducing sugar released from the former sample at 48h of enzymatic saccharification, which is about 3.5 times as large as that from the untreated rice straw sample (2.91vs. 0.85gL^-1), is slightly larger than that from the latter sample (2.91vs. 2.73gL^-1). The ultrasound-assisted alkaline pretreatment by using the heat energy dissipated from ultrasonication was proved to be a reliable and effective method for rice straw pretreatment.

A case of Diphyllobothrium latum infection in Dalian and a brief review of diphyllobothriasis in China

Diphyllobothrium latum infection in human is not common in China and only 15 cases have been reported since 1927. We document a case of Diphyllobothrium latum infection caused by the ingestion of raw fish in a 23-year-old woman in Dalian (Liaoning Province), and diphyllobothriasis latum in China is briefly reviewed. The patient experienced abdominal discomfort for about 6 months with a history of discharging proglottids in the feces. The morphologic characteristic of the gravid proglottids and eggs were identified as that of Diphyllobothrium latum. The patient was treated with pumpkin seed powder (100g) and betel nut(100g) on an empty stomach. The majority of reported human cases occurred due to the ingestion of raw or uncooked fish, such as pikes, burbots, trouts, perch and salmons. The patient is the first case reported in Dalian (Lianning Province).

Pretreatment of rice straw by ultrasound-assisted Fenton process

Fenton's reagent, ultrasound, and the combination of Fenton's reagent and ultrasound were used to pretreat rice straw (RS) to increase its enzymatic digestibility for saccharification. The characterization shows that compared with ultrasound, Fenton's reagent pretreatment was more efficient in increasing the specific surface area and decreasing the degree of polymerization (DP) of RS. The enzymatic hydrolysis results showed that the RS pretreated by ultrasound-assisted Fenton's reagent (U/F-RS), which exhibited the largest specific surface area and the lowest DP value, had the highest enzymatic activity, and the amount of reducing sugar released from U/F-RS at 48h of enzymatic saccharification is about 4 times as large as that from raw RS and 1.5 times as large as that from Fenton's reagent pretreated RS. The ultrasound-assisted Fenton process provides a reliable and effective method for RS pretreatment.

Depolymerization of microcrystalline cellulose by the combination of ultrasound and Fenton reagent

In this study, the combined use of Fenton reagent and ultrasound to the pretreatment of microcrystalline cellulose (MCC) for subsequent enzyme hydrolysis was investigated. The morphological analysis showed that the aspect ratio of MCC was greatly reduced after pretreatment. The X-ray diffraction (XRD) and degree of polymerization (DP) analyses showed that Fenton reagent was more efficient in decreasing the crystallinity of MCC while ultrasound was more efficient in decreasing the DP of MCC. The combination of Fenton reaction and ultrasound, which produced the lowest crystallinity (84.8 ± 0.2%) and DP (124.7 ± 0.6) of MCC and the highest yield of reducing sugar (22.9 ± 0.3 g/100 g), provides a promising pretreatment process for MCC depolymerization.

[Jaridonin, a new diterpenoid from Isodon rubescens, induces cell cycle arrest in gastric cancer cells through activating ataxia telangiectasia mutated kinase]

OBJECTIVE

To study the effects of Jaridonin, a novel diterpenoid from isodon rubescens, on the cell cycle of human gastric cancer cells and its molecular mechanism of action.

METHODS

Flow cytometry was used to analyze the cell cycle distribution and expression of ataxia telangiectasia mutated kinase (ATM) after Jaridonin treatment. Western blot was performed to detect the expression of cell cycle-related proteins.

RESULTS

The results of flow cytometry showed that the percentages of MGC-803 cells in G(2)/M phase at 6 hours after 0, 10, 20 μmol/L Jaridonin-treatment were (10.8±2.2)%, (18.2±2.5)%, (27.3±3.2)%, respectively; those at 12 hours after Jaridonin-treatment were (12.0±1.5)%, (24.1±2.0)% and (39.7±5.2)%, respectively, indicating a G2/M phase arrest of MGC-803 cells was resulted in a time- and dose-dependent manner. The expressions of ATM, Chk1, Chk2, phosphorylated Cdc2 and CDK2 were up-regulated in the MGC-803 cells after Jaridonin treatment, while the levels of Cdc2 and CDK2 were decreased. KU-55933, an inhibitor of ATM, reversed the expression of relevant proteins and G(2)/M phase arrest induced by Jaridonin.

CONCLUSIONS

Jaridonin can significantly induce G(2)/M arrest in gastric cancer MGC-803 cells. Its mechanism may be related to the activation of ATM and Chk1/2, and inactivation of Cdc2 and CDK2 phosphorylation.

The Impact of Clinical Pharmacist Support on Patients Receiving Multi-drug Therapy for Coronary Heart Disease in China

The study determined pharmacist support on patients receiving multi-drug therapy for coronary heart disease by evaluating patient self-care ability, quality of life, and drug therapy compliance. In this study, ninety patients were randomly assigned to an experimental group (n=45) and a control group (n=45). The control group received conventional clinical care. The experimental group received clinical care plus pharmacist support that included medication review, patient education, lifestyle management, discharge guidance, and telephone follow-up. Eighty-five patients completed the study. Self-care ability and quality of life were evaluated before hospital discharge. The experimental group understood their condition better than the control group (P<0.05), the differences between the groups in understanding treatment goals, drug regimens, lifestyle modifications, psychogenic disorders, and satisfaction evaluations were more pronounced (P<0.01). At six-month follow-up, the difference between the groups in drug therapy compliance was P<0.01, as was success rate by intention-to-treat (77.8% vs. 48.9%) and per-protocol (81.4% vs. 52.4%). Two adverse drug reactions occurred in the experimental group and three in the control group. Pharmacist support improved self-care ability, quality of life, drug therapy compliance, and treatment success rate in coronary heart disease patients.

Serum lipid abnormalities are not associated with apoB 3' VNTR polymorphism in nephrotic children

Apolipoprotein B (apoB) gene 3' variable number of tandem repeat (VNTR) is highly variable, and therefore can be an informative marker for associative analysis of lipid metabolism. This is the first report focusing on a possible association of apoB VNTR polymorphism with nephrotic hyperlipidemia. Genomic DNA was extracted from 500 children with primary nephrotic syndrome (PNS) and 500 healthy controls. The apoB genotype was determined by PCR analysis. Allele size distribution followed a unimodal curve, with the main peak at the hypervariable element 35 (HVE35); the most prevalent genotype was HVE35/35 in both control and PNS children. The genotype and allele distributions of apoB variants in PNS children were not significantly different from controls. There was significant variation in serum lipid profiles among different genotypes in control children. Individuals with the long (L) allele exhibited significantly higher total cholesterol, low-density lipoprotein cholesterol (LDL-C) and apoB levels than those with the medium (M) or short (S) allele; consequently, M/L carriers had significantly higher total cholesterol, LDL-C and apoB concentrations than did S/S, S/M, S/L, or M/M carriers. However, in PNS children, no significant differences in serum lipid levels were observed among individuals with different genotypes and alleles of apoB 3' VNTR. We conclude that hyperlipidemia in nephrotic children is not associated with apoB 3' VNTR polymorphism.

Molecular and cytogenetic paternity testing of a male offspring of a hinny

An alleged male foal of a female mule, whose sire and grandparents were unknown, was identified for its pedigree. Parentage testing was conducted by comparing polymorphism of 12 microsatellite DNA sites and mitochondrial D-loop sequences of the male foal and the female mule. Both the sequence analysis of species-specific DNA fragments and a cytogenetic analysis were performed to identify the species of the foal and its parents. The results showed that the alleged female mule is actually a hinny, and the male foal, which possesses 62 chromosomes, qualifies as an offspring of the female hinny and a jack donkey.

Differentiating among horse (Equus caballus), donkey (Equus asinus) and their hybrids with combined analysis of nuclear and mitochondrial gene polymorphism

A novel and brief method of differentiating among horse (Equus caballus) and donkey (Equus asinus) and their hybrids (mule, E. asinus x E. caballus and hinny, E. caballus x E. asinus) with combined analysis of nuclear and mitochondrial gene polymorphism (CANMGP) was reported in the present report. A nuclear gene, protamine P1 gene of donkey was sequenced and compared with the known horse sequence from GenBank while a published equid mitochondrial gene, cytochrome b gene of donkey was compared with that of horse. In each of the two genes, a fixed nucleotide substitution within an exon that could be recognized by Dpn II restriction enzyme was found between the two species. Two pairs of primers were designed for amplifying the fragments within the two genes containing the informative nucleotide positions in 65 horses and 41 donkeys and 38 hybrids and conditions of polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis were optimized. Horse, donkey and mule and hinny had their own specific cleavage patterns after the PCR-RFLP analysis was performed, which made it very easy to identify them from each other. As multiplex PCR can be conducted with the two pairs of primers and only one restriction enzyme is involved in PCR-RFLP analysis, the method described in the present study is a convenient way to identify horse and donkey and their hybrids. The idea involved in the method of CANMGP can be also used to differentiate other animal species or breeds and their hybrids.

Inhibition of the specific 3H-DL-Glu binding in the hippocampus of rat brain by lead

The effect of Pb2+ on 3H-DL-Glutamate (3H-DL-Glu) binding in the membrane preparations from the hippocampus of rat brain was investigated with a view to explaining the cognitive and learning deficits produced by the heavy metal. The results indicated that Pb2+ (3.1-25.0 mumol.L-1) inhibited 3H-DL-Glu binding in a concentration-dependent manner. Scatchard analysis further revealed that at a concentration of 6.3 mumol.L-1 Pb2+ interfered with binding mainly through significantly decreasing the density of binding sites. This finding provided an important insight into Pb2(+)-induced impairments in learning and memory previously documented in children and in experimental animals chronically exposed to Pb2+.

[Immunological change in pigmentary degeneration of retina and its relation to traditional Chinese medicine differentiation of syndromes]

Using monoclonal antibody technique, T lymphocyte cell subgroups, immunoglobins, complements, and circulating immune complexes (CIC) were measured in 60 patients with pigmentary degeneration of retina (RP) and 40 normal subjects. The results indicated that T1, T4, T8, C3 and C4 of the patients were lower than those of the controls; T4/T8, IgM and CIC of the patients were more than those of the controls. The differences between the patients and the controls were remarkably significant. Similarly, by investigating the objective quota of TCM differentiation of syndromes, the authors divided the RP patients into Liver-Kidney deficiency of Yin and Spleen-Kidney deficiency of Yang groups, and compared them with normal subjects. The results indicated that the two groups underwent similar change of immunology. But they had their own characteristics. The Yin-deficiency group showed remarkable increase of T4/T8 and normal T4; the Yang-deficiency group showed remarkable reduction of T1 and reduction of T4.

Metabolism of 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-tetrachlorobenzene in the rat

Adult male rats were given orally single doses of 14C-labeled 1,2,3,4-, 1,2,3,5-, or 1,2,4,5-tetrachlorobenzene (TCB) at 10 mg/kg body weight, and were housed in individual metabolism cages to collect urine and feces for radioassay. For 1,2,3,4- and 1,2,3,5-TCB, approximately 46-51% of the doses were excreted in urine and feces within 48 h after administration. During the same period only 8% of the administered 1,2,4,5-tetrachlorobenzene was excreted. Analysis of urine indicted that the tetrachlorobenzenes were biotransformed to a number of polar compounds. The metabolites for each of the three TCBs in decreasing order of quantities were as follows: 1,2,3,4-TCB, to 2,3,4,5- and 2,3,4,6-tetrachlorophenol and a trace of tetrachlorothiophenol and 2,3,4-trichlorophenol; 1,2,3,5-TCB, to 2,3,4,6-tetrachlorophenol, isomeric hydroxythrichlorothiophenols, and a trichlorophenol; 1,2,4,5-TCB, to 2,3,5,6-tetrachlorophenol, tetrachloroquinol, and a trichlorophenol.