Fundamentals of Unanticipated Efficiency of Gd2O3-based Catalysts in Oxidative Coupling of Methane

Improving the selectivity in the oxidative coupling of methane to ethane/ethylene poses a significant challenge for commercialization. The required improvements are hampered by the uncertainties associated with the reaction mechanism due to its complexity. Herein, we report about 90 % selectivity to the target products at 11 % methane conversion over Gd2O3-based catalysts at 700 °C using N2O as the oxidant. Sophisticated kinetic studies have suggested the nature of adsorbed oxygen species and their binding strength as key parameters for undesired methane oxidation to carbon oxides. These descriptors can be controlled by a metal oxide promoter for Gd2O3.

Exquisitely Constructing a Robust MOF with Dual Pore Sizes for Efficient CO2 Capture

Developing metal-organic framework (MOF) adsorbents with excellent performance and robust stability is of critical importance to reduce CO2 emissions yet challenging. Herein, a robust ultra-microporous MOF, Cu(bpfb)(bdc), with mixed ligands of N, N'-(1,4-phenylene)diisonicotinamide (bpfb), and 1,4-dicarboxybenzene (bdc) was delicately constructed. Structurally, this material possesses double-interpenetrated frameworks formed by two staggered, independent frameworks, resulting in two types of narrow ultra-micropores of 3.4 × 5.0 and 4.2 × 12.8 Å2, respectively. The above structural properties make its highly selective separation at 273~298 K with a CO2 capacity of 71.0~86.2 mg/g. Its adsorption heat over CO2 and IAST selectivity were calculated to be 27 kJ/mol and 52.2, respectively. Remarkably, cyclic breakthrough experiments corroborate its impressive performance in CO2/N2 separation in not only dry but also 75% RH humid conditions. Molecular simulation reveals that C-H···OCO2 in the pores plays a pivotal role in the high selectivity of CO2 adsorption. These results point out the huge potential application of this material for CO2/N2 separation.

Andrographolide restored production performances and serum biochemical indexes and attenuated organs damage in Mycoplasma gallisepticum-infected broilers

1. This study aimed to study the preventive and therapeutic effects of andrographolide (Andro) during Mycoplasma gallisepticum HS strain (MG) infection in ArborAcres (AA) broilers.2. The minimum inhibitory concentration (MIC) of Andro against MG was measured. Broiler body weight, feed efficiency, morbidity, cure rate and mortality were recorded during the experiment. Air sac lesion scores and immune organ index were calculated. Expression of pMGA1.2 in lung tissue and serum biochemical indices were examined. Histopathological examinations of immune organs, liver, trachea and lung tissue were conducted by Haematoxylin and Eosin stain.3. MIC was 3.75 μg/mL and Andro significantly inhibited the expression of pMGA1.2 (P ≤ 0.05). Compared with control MG-infected group, Andro low-dose and high-dose prevention reduced the morbidity of chronic respiratory disease in 40.00% and 50.00%, respectively. Mortality of C, D and E group was 16.67%, 10.00% and 6.67%, respectively. Cure rate of E, F, G and H group was 92.00%, 92.86%, 93.33% and 100.0%, respectively. Compared with control MG-infected group, Andro treatment significantly increased average weight gain (AWG), relative weight gain rate (RWG) and feed conversion rate (FCR) at 18 to 24 days (P ≤ 0.05). Compared with control group, Andro alone treatment significantly increased AWG in broilers (P ≤ 0.05).4. Compared with control MG-infected group, Andro significantly attenuated MG-induced air sac lesion, immune organs, liver, trachea and lung damage in broilers. Andro alone treatment did not induce abnormal morphological changes in these organs in healthy broilers. Serum biochemical analysis results showed, comparing with control MG-infected group, Andro significantly decreased the content of total protein, albumin, globulin, alanine aminotransferase, aspartate aminotransferase, total bilirubin, urea, creatinine, uric acid, total cholesterol, and increased the albumin/globulin ratio and content of alkaline phosphatase, apolipoprotein B and apolipoprotein A-I in a dose-dependent manner (P ≤ 0.05).5. Andro could act as a potential agent against MG infection in broilers.

Effects of wearing personal protective equipment during COVID-19 pandemic on composition and diversity of skin bacteria and fungi of medical workers

BACKGROUND

During the COVID-19 pandemic, wearing PPE can induce skin damage such as erythema, pruritus, erosion, and ulceration among others. Although the skin microbiome is considered important for skin health, the change of the skin microbiome after wearing PPE remain unknown.

OBJECTIVE

The present study aimed to characterize the diversity and structure of bacterial and fungal flora on skin surfaces of healthcare workers wearing personal protective equipment (PPE) during the COVID-19 pandemic using metagenomic next-generation sequencing (mNGS).

METHODS

A total of 10 Chinese volunteers were recruited and the microbiome of their face, hand, and back were analyzed before and after wearing PPE. Moreover, VISIA was used to analyze skin features.

RESULTS

Results of alpha bacterial diversity showed that there was statistically significant decrease in alpha diversity indice in the skin samples from face, hand, and three sites after wearing PPE as compared with the indice in the skin samples before wearing PPE. Further, the results of evaluated alpha fungal diversity show that there was a statistically significant decrease in alpha diversity indices in the skin samples from hand after wearing PPE as compared with the indices in the skin samples before wearing PPE (P<0.05). Results of the current study found that the main bacteria on the face, hand, and back skin samples before wearing the PPE were Propionibacterium spp. (34.04%), Corynebacterium spp. (13.12%), and Staphylococcus spp. (38.07%). The main bacteria found on the skin samples after wearing the PPE were Staphylococcus spp. (31.23%), Xanthomonas spp. (26.21%), and Cutibacterium spp. (42.59%). The fungal community composition was similar in three skin sites before and after wearing PPE.

CONCLUSION

It was evident that wearing PPE may affect the skin microbiota, especially bacteria. Therefore, it was evident that the symbiotic microbiota may reflect the skin health of medical workers during the COVID-19 pandemic.

In situ formation of ZnOx species for efficient propane dehydrogenation

Propane dehydrogenation (PDH) to propene is an important alternative to oil-based cracking processes, to produce this industrially important platform chemical1,2. The commercial PDH technologies utilizing Cr-containing (refs. 3,4) or Pt-containing (refs. 5-8) catalysts suffer from the toxicity of Cr(VI) compounds or the need to use ecologically harmful chlorine for catalyst regeneration9. Here, we introduce a method for preparation of environmentally compatible supported catalysts based on commercial ZnO. This metal oxide and a support (zeolite or common metal oxide) are used as a physical mixture or in the form of two layers with ZnO as the upstream layer. Supported ZnOx species are in situ formed through a reaction of support OH groups with Zn atoms generated from ZnO upon reductive treatment above 550 °C. Using different complementary characterization methods, we identify the decisive role of defective OH groups for the formation of active ZnOx species. For benchmarking purposes, the developed ZnO-silicalite-1 and an analogue of commercial K-CrOx/Al2O3 were tested in the same setup under industrially relevant conditions at close propane conversion over about 400 h on propane stream. The developed catalyst reveals about three times higher propene productivity at similar propene selectivity.

Synergistic construction of bifunctional and stable Pt/HZSM-5-based catalysts for efficient catalytic cracking of n-butane

Efficient conversion of light alkanes is of essential significance for enhancing the utilization efficiency of resources and exploring the activation and evolution regulation of C-C and C-H bonds in stable molecules. The processes are often executed with catalysts under harsh conditions. The olefin yield and metal stability have been the long-standing concerns. Herein, we report a facile strategy of constructing a bifunctional Pt/HZSM-5-based catalyst by two-step atomic layer deposition (ALD) to achieve a high light olefin formation rate of 0.48 mmol gcat-1·min-1 in the catalytic cracking of n-butane at 600 °C, which is ∼2.2 times higher than that of the conventional Pt/HZSM-5 catalyst (0.22 mmol gcat-1·min-1). Moreover, the bifunctional Pt/HZSM-5-based catalyst exhibited outstanding recyclability and excellent metal stability against sintering in comparison with conventional Pt/HZSM-5. Detailed microscopic and spectroscopic characterization studies demonstrate that the metal oxide (TiO2 or Al2O3) coating not only prevents the metal from high-temperature sintering, but also regulates the proportion of coordinately unsaturated platinum surface atoms. Theoretical calculations further confirm the preference of nucleation of TiO2 or Al2O3 on coordinately unsaturated platinum sites, which in turn modulates the bifunctional dehydrogenation-cracking pathway to improve the olefin formation rate.

Revealing fundamentals affecting activity and product selectivity in non-oxidative propane dehydrogenation over bare Al2O3

A detailed study was carried out to elucidate the factors affecting the activity and, particularly, selectivity of bare Al₂O₃ in the non-oxidative propane dehydrogenation (PDH) to propene under industrially relevant conditions.

Current status and perspectives in oxidative, non-oxidative and CO2-mediated dehydrogenation of propane and isobutane over metal oxide catalysts

Conversion of propane or isobutane from natural/shale gas into propene or isobutene, which are indispensable for the synthesis of commodity chemicals, is an important environmentally friendly alternative to oil-based cracking processes.

Astrocyte-Derived Exosomes in an iPSC Model of Bipolar Disorder

Bipolar I Disorder (BP) is a serious, recurrent mood disorder that is characterized by alternating episodes of mania and depression. To begin to identify novel approaches and pathways involved in BP, we have obtained skin samples from BP patients and undiagnosed control (C) individuals, reprogrammed them to form induced pluripotent stem cells (iPSC), and then differentiated the stem cells into astrocytes. RNAs from BP and C astrocytes were extracted and RNAseq analysis carried out. 501 differentially expressed genes were identified, including genes for cytoskeletal elements, extracellular matrix, signaling pathways, neurodegeneration, and notably transcripts that identify exosomes. When we compared highly expressed genes using hierarchial cluster analysis, "Exosome" was the first and most highly significant cluster identified, p < 5 × 10^-13, Benjamini correction. Exosomes are membrane-bound vesicles that package and remove toxic proteins from cells and also enable cell to cell communication. They carry genetic material, including DNA, mRNA and microRNAs, proteins, and lipids to target cells throughout the body. Exosomes are released by cortical neurons and astrocytes in culture and are present in BP vs C postmortem brain tissue. Little is known about what transcripts and proteins are targeted to neurons, how they regulate biological functions of the acceptor cell, or how that may be altered in mood disorders. Since astrocyte-derived exosomes have been suggested to promote neuronal plasticity, as well as to remove toxic proteins in the brain, alterations in their function or content may be involved in neurodevelopmental, neuropathological, and neuropsychiatric conditions. To examine exosome cargos and interactions with neural precursor cells, astrocytes were differentiated from four bipolar disorder (BP) and four control (C) iPSC lines. Culture supernatants from these astrocytes were collected, and exosomes isolated by ultra-centrifugation. Western blot analysis demonstrated the presence of the exosome markers CD9, CD81, and Hsp70. Nanosight technology was used to characterize exosomes from each astrocyte cell line, suggesting that exosomes were slightly more concentrated in culture supernatants derived from BP compared with C astrocytes but there was no difference in the mean sizes of the exosomes. Analysis of their function in neuronal differentiation is being carried out by labeling exosomes derived from bipolar patient and control astrocytes and adding them to control neural progenitor cells. Given the current interest in clearing toxic proteins from brains of patients with neurodegenerative disorders, exosomes may present similar opportunities in BP.

Do food and stress biomarkers work for wastewater-based epidemiology? A critical evaluation

Dietary characteristics and oxidative stress are closely linked to the wellbeing of individuals. In recent years, various urinary biomarkers of food and oxidative stress have been proposed for use in wastewater-based epidemiology (WBE), in efforts to objectively monitor the food consumed and the oxidative stress experienced by individuals in a wastewater catchment. However, it is not clear whether such biomarkers are suitable for wastewater-based epidemiology. This study presents a suite of 30 urinary food and oxidative stress biomarkers and evaluates their applicability for WBE studies. This includes 22 biomarkers which were not previously considered for WBE studies. Daily per capita loads of biomarkers were measured from 57 wastewater influent samples from nine Australian catchments. Stability of biomarkers were assessed using laboratory scale sewer reactors. Biomarkers of consumption of vitamin B2, vitamin B3 and fibre, as well as a component of citrus had per capita loads in line with reported literature values despite susceptibility of degradation in sewer reactors. Consumption biomarkers of red meat, fish, fruit, other vitamins and biomarkers of stress had per capita values inconsistent with literature findings, and/or degraded rapidly in sewer reactors, indicating that they are unsuitable for use as WBE biomarkers in the traditional quantitative sense. This study serves to communicate the suitability of food and oxidative stress biomarkers for future WBE research.

The Influence of Pore Structure and Acidity on the Hydrodesulfurization of Dibenzothiophene over NiMo-Supported Catalysts

A series of mesoporous materials of SBA-16 were in situ incorporated into ZSM-5 crystallites via a two-step self-assemble method, and hydrodesulfurization (HDS) catalysts were prepared on the corresponding ZSM-5/SBA-16 (ZS) composites. The characterization results indicated that ZSM-5 nanoseeds were fabricated into the silica framework of the ZS composites, and the three-dimensional Im3m cubic structure of SBA-16 was retained simultaneously. In addition, the ZS series materials possessed open pores and large surfaces, which would facilitate the diffusion of reactants in the mesoporous channels. Moreover, the introduction of ZSM-5 seeds into composites could enhance the acidities of supports. As a result, the NiMo/ZS series catalysts exhibited high activities for DBT HDS processes. The NiMo/ZS-160 catalyst exhibited the highest catalytic efficiency (96.5%), which was apparently attributed to the synergistic contributions of the physicochemical properties of ZS supports and the dispersion states of active metals. Correspondingly, DBT HDS reactions over the NiMo/ZS series catalysts mainly proceeded via a hydrogenation desulfurization route that benefitted from the enhanced acidities especially the total Brønsted acid.

The impact of laryngopharyngeal reflux disease on 95 hospitalized patients with COVID-19 in Wuhan, China: A retrospective study

Studies have demonstrated that comorbidities, especially cardiovascular and endocrine diseases, correlated with poorer clinical outcomes. However, the impact of digestive system diseases has not been issued. The aim of this study is to determine the impact of laryngopharyngeal reflux disease (LPRD) on hospitalized patients with coronavirus disease 2019 (COVID‐19). We extracted clinical data regarding 95 patients in Wuhan Jinyintan Hospital, Wuhan, China, between 26 January and 21 February 2020. The Reflux Symptom Index (RSI) was used to assess the presence and severity of LPRD. An RSI  greater than  13 is considered to be abnormal. A total of 95 patients with COVID‐19 were enrolled, with 61.1% (58/95), 32.6% (31/95), and 6.3% (6/95) being moderately ill, severely ill, and critically ill, respectively. In this study, 38.9% (37/95) of the patient had an RSI score over 13, which was indicative of LPRD. In univariable analysis, the age and RSI scores of severely or critically ill patients were statistically significantly higher than patients with moderate disease (P  =  .026 and P = .005, respectively). After controlling for age difference in a multivariable model, the RSI greater than 13, compared to RSI equal to  0, was associated with significantly higher risk of severe infection (P < .001; odds ratio [OR] = 11.411; 95% confidence interval [CI], 2.95‐42.09) and critical infection (P = .028; OR= 19.61; 95% CI, 1.38‐277.99). Among hospitalized patients with COVID‐19, RSI scores greater than 13, indicative of LPRD, correlated with poorer clinical outcomes. The prevalence of LPRD may be higher than the general population, which indicated that COVID‐19 can impair the upper esophageal sphincter and aggravate reflux.

The imapct of laryngopharyngeal reflux disease (LPRD) has been analyzed. The prevalence of LPRD in patients with COVID‐19 may be higher than the general population. The RSI score greater than 13, indicative of LPRD, correlated with poorer clinical outcomes.

TiO2-Supported catalysts with ZnO and ZrO2 for non-oxidative dehydrogenation of propane: mechanistic analysis and application potential

Non-oxidative dehydrogenation of propane is one of the most promising technologies for propene production in terms of environmental impact and sustainability.

The Chinese National Twin Registry: a 'gold mine' for scientific research

The Chinese National Twin Registry (CNTR) currently includes data from 61 566 twin pair from 11 provinces or cities in China. Of these, 31 705, 15 060 and 13 531 pairs are monozygotic, same-sex dizygotic and opposite-sex dizygotic pairs, respectively, determined by opposite sex or intrapair similarity. Since its establishment in 2001, the CNTR has provided an important resource for analysing genetic and environmental influences on chronic diseases especially cardiovascular diseases. Recently, the CNTR has focused on collecting biologic specimens from disease-concordant or disease-discordant twin pairs or from twin pairs reared apart. More than 8000 pairs of these twins have been registered, and blood samples have been collected from more than 1500 pairs. In this review, we summarize the main findings from univariate and multivariate genetic effects analyses, gene-environment interaction studies, omics studies exploring DNA methylation and metabolomic markers associated with phenotypes. There remains further scope for CNTR research and data mining. The plan for future development of the CNTR is described. The CNTR welcomes worldwide collaboration.

ZnO Nanoparticles Encapsulated in Nitrogen-Doped Carbon Material and Silicalite-1 Composites for Efficient Propane Dehydrogenation

Non-oxidative propane dehydrogenation (PDH) is an attractive reaction from both an industrial and a scientific viewpoint because it allows direct large-scale production of propene and fundamental analysis of C-H activation respectively. The main challenges are related to achieving high activity, selectivity, and on-stream stability of environment-friendly and cost-efficient catalysts without non-noble metals. Here, we describe an approach for the preparation of supported ultrasmall ZnO nanoparticles (2–4 nm, ZnO NPs) for high-temperature applications. The approach consists of encapsulation of NPs into a nitrogen-doped carbon (NC) layer in situ grown from zeolitic imidazolate framework-8 on a Silicalite-1 support. The NC layer was established to control the size of ZnO NPs and to hinder their loss to a large extent at high temperatures. The designed catalysts exhibited high activity, selectivity, and on-stream stability in PDH. Propene selectivity of about 90% at 44.4% propane conversion was achieved at 600°C after nearly 6 h on stream.

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Supported catalysts with stable ultrasmall ZnO nanoparticles were prepared

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The N-doped carbon layer helps to protect ZnO NPs from sintering and volatilization

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The catalysts exhibited excellent activity and stability in propane dehydrogenation