On-device lead sequestration for perovskite solar cells.

Perovskite solar cells, as an emerging high-efficiency and low-cost photovoltaic technology1-6, face obstacles on their way towards commercialization. Substantial improvements have been made to device stability7-10, but potential issues with lead toxicity and leaching from devices remain relatively unexplored11-16. The potential for lead leakage could be perceived as an environmental and public health risk when using perovskite solar cells in building-integrated photovoltaics17-23. Here we present a chemical approach for on-device sequestration of more than 96 per cent of lead leakage caused by severe device damage. A coating of lead-absorbing material is applied to the front and back sides of the device stack. On the glass side of the front transparent conducting electrode, we use a transparent lead-absorbing molecular film containing phosphonic acid groups that bind strongly to lead. On the back (metal) electrode side, we place a polymer film blended with lead-chelating agents between the metal electrode and a standard photovoltaic packing film. The lead-absorbing films on both sides swell to absorb the lead, rather than dissolve, when subjected to water soaking, thus retaining structural integrity for easy collection of lead after damage.

Modulating CO2 Electrocatalytic Conversion to the Organics Pathway by the Catalytic Site Dimension.

Electrochemical reduction of carbon dioxide to organic chemicals provides a value-added route for mitigating greenhouse gas emissions. We report a family of carbon-supported Sn electrocatalysts with the tin size varying from single atom, ultrasmall clusters to nanocrystallites. High single-product Faradaic efficiency (FE) and low onset potential of CO2 conversion to acetate (FE = 90% @ -0.6 V), ethanol (FE = 92% @ -0.4 V), and formate (FE = 91% @ -0.6 V) were achieved over the catalysts of different active site dimensions. The CO2 conversion mechanism behind these highly selective, size-modulated p-block element catalysts was elucidated by structural characterization and computational modeling, together with kinetic isotope effect investigation.

Environmental Driving of Adaptation Mechanism on Rumen Microorganisms of Sheep Based on Metagenomics and Metabolomics Data Analysis.

Natural or artificial selection causes animals to adapt to their environment. The adaptive changes generated by the rumen population and metabolism form the basis of ruminant evolution. In particular, the adaptive drive for environmental adaptation reflects the high-quality traits of sheep that have migrated from other places or have been distant from their origins for a long time. The Hu sheep is the most representative sheep breed in the humid and low-altitude environments (Tai Lake region) in East Asia and has been widely introduced into the arid and high-altitude environments (Tibetan Plateau and Hotan region), resulting in environmental adaptive changes in the Hu sheep. In this study, a joint analysis of the rumen microbial metagenome and metabolome was conducted on Hu sheep from different regions (area of origin and area of introduction) with the objective of investigating the quality traits of Hu sheep and identifying microorganisms that influence the adaptive drive of ruminants. The results demonstrated that the growth performance of Hu sheep was altered due to changes in rumen tissue and metabolism following their introduction to the arid area at relatively high altitude. Metagenomic and metabolomic analyses (five ramsper area) revealed that 3580 different microorganisms and 732 different metabolites were identified in the rumen fluid of arid sheep. Among these, the representative upregulated metabolites were 4,6-isocanedione, methanesulfonic acid and N2-succinyl-L-arginine, while the dominant microorganism was Prevotella ruminicola. The downregulated metabolites were identified as campesterol, teprenone and dihydroclavaminic acid, while the disadvantaged microorganisms were Dialister_succinatiphilus, Prevotella_sp._AGR2160, Prevotella_multisaccharivorax and Selenomonas_bovis. The results of the Pearson analysis indicated that the rumen microbiota and metabolite content of sheep were significantly altered and highly correlated following their relocation from a humid lowland to an arid upland. In particular, the observed changes in rumen microorganisms led to an acceleration of body metabolism, rendering sheep highly adaptable to environmental stress. Prevotella_ruminicola was identified as playing an important role in this process. These findings provide insights into the environmental adaptation mechanisms of sheep.

Discovery of novel bicyclic[3.3.0]proline peptidyl α-ketoamides as potent 3CL-protease inhibitors for SARS-CoV-2.

The outbreak of SARS-CoV-2 has caused global crisis on health and economics. The multiple drug-drug interaction risk associated with ritonavir warrants specialized assessment before using Paxlovid. Here we report a multiple-round SAR study to provide a novel bicyclic[3.3.0]proline peptidyl α-ketoamide compound 4a, which is endowed with excellent antiviral activities and pharmacokinetic properties. Also, in vivo HCoV-OC43 neonatal mice model demonstrated compound 4a has good in vivo efficacy. Based on these properties, compound 4a worth further SAR optimization with the goal to develop compounds with better pharmacokinetic properties and finally to realize single agent efficacy in human.

Shift in prevalence and systemic inflammation levels from NAFLD to MAFLD: a population-based cross-sectional study.

BACKGROUND: Variations in the prevalence and systemic inflammatory (SI) status between non-alcoholic fatty liver disease (NAFLD) and newly defined metabolic dysfunction-associated fatty liver disease (MAFLD) have only been reported by few studies. Hence, this study aimed to compile data on the prevalence and the systemic inflammation levels of MAFLD and NAFLD in a general population from Southeast China was summarized to explore the potential effect of the transformation of disease definition. METHODS: A total of 6718 general population participants aged 35-75 were enrolled. Logistic regression and restricted cubic spline (RCS) models were used to examine the relationship between 15 SI indicators and NAFLD and MAFLD. The predicted values of MAFLD and NAFLD were analyzed using the receiver operating characteristic (ROC) curve. RESULTS: The prevalence of MAFLD and NAFLD was 34.7% and 32.4%, respectively. Their overlapping rate was 89.7%, while only 8.3% and 1.9% of participants were MAFLD-only and NAFLD-only. Among three FLD groups, the MAFLD-only group had the highest levels of 8 SI indicators, including CRP, WBC, LYMPH, NEUT, MONO, ALB, NLR, and SIRI. The non-FLD group had the lower levels of all 15 SI indicators compared with all FLD subgroups. The odds ratios (ORs) of 10 SI indicators were significant in both multivariable-adjusted logistic regression and RCS analyses of MAFLD or NAFLD, including CRP, WBC, LYMPH, NEUT, MONO, ALB, PLR, LMR, ALI and CA. ROC analysis showed that the AUC values of all SI were lower than 0.7 in both MAFLD and NAFLD. CONCLUSIONS: MAFLD could cover more FLD than NAFLD, and the MAFLD-only group had a more severe inflammation status, whereas the NAFLD-only exhibited lower levels. Moreover, there was not a high AUC and a high sensitivity of SI indicators, suggesting that SI indicators are not good indicators to diagnose NAFLD/MAFLD.

Transcriptome profiling of LncRNAs in sheep tail fat deposition.

LncRNAs have recently received special attention due to their critical role in many important biological processes. There are few reports on its regulatory function in sheep fat deposition. In this study, two sheep populations with different tail types in Xinjiang, Bashibai sheep (fat-tailed) and the hybrid population of Bashibai sheep and wild argali (small-tailed) were selected for whole transcriptome sequencing from their tail tissues. First, 728 differentially expressed LncRNAs of tail fat between Bashibai and F2 sheep were identified by RNA-seq. Second, the tissue expression profile and relative expression difference between Bashibai and F2 sheep of 2 of 728 DE LncRNAs were analyzed by RT-PCR. LncRNA-MSTRG.24995 was highly expressed in tail fat, while lncRNA-MSTRG.36913 was highly expressed in subcutaneous fat. In addition, the expressions of LncRNA-MSTRG.24995 and LncRNA-MSTRG.36913 in tail fat of F2 sheep were significantly lower than that of Bashibai sheep, while those patterns in longissimus dorsi, quadriceps femoris and rumen were reversed. Third, the expression pattern of target genes FASN and THRSP in each tissue was similar with that of corresponding LncRNAs. The LncRNA-MSTRG.24995 directly affects tail fat deposition by FASN gene, while the LncRNA-MSTRG.36913 indirectly affects that by THRSP gene. This will help us to understand molecular mechanism of fat tail deposition from transcriptomic perspectives.

Study on lactation performance and development of KASP marker for milk traits in Xinjiang donkey (Equus asinus).

Donkey milk has high nutritional and medicinal value, but there are few researches in donkey milk traits, especially on genome. The whole lactation of 89 donkeys was recorded and it was found that Xinjiang donkey had good lactation performance while great differences among individuals. In our previous study, four genes including LGALS2, NUMB, ADCY8 and CA8 were identified as milk-associated with Chinese Kazakh house, based on Equine 670k Chip genomic analysis. And then 15 SNPs of the four key genes were conducted for genotyping in Xinjiang donkey in this study, one of Chinese indigenous breed, 14 SNPs were successful classified. And those SNPs were correlation analysis with milk yield of Xinjiang donkeys. The results showed that NUMB g.46709914T > G was significantly correlated with daily milk yield of Xinjiang donkey in the early, middle, and late periods, while ADCY8 g.48366302T > C, CA8 g.89567442T > G and CA8 g.89598328T > A were significantly correlated with lactation in the late periods. These results indicate that NUMB g.46709914T > G can be as markers of candidate genes for lactating traits in donkeys, SNPs of ADCY8 and CA8 as potential. Our findings will not only help confirm key genes for donkey milk traits, but also provide future for genomic selection in donkeys.

[Establishment of a nomogram model for predicting necrotizing enterocolitis in very preterm infants]. / é¢„æµ‹æžæ—©äº§å„¿åæ­»æ€§å°è‚ ç»“è‚ ç‚Žå‘ç”Ÿé£Žé™©åˆ—çº¿å›¾æ¨¡åž‹çš„å»ºç«‹.

OBJECTIVES: To investigate the risk factors for necrotizing enterocolitis (NEC) in very preterm infants and establish a nomogram model for predicting the risk of NEC. METHODS: A total of 752 very preterm infants who were hospitalized from January 2015 to December 2021 were enrolled as subjects, among whom 654 were born in 2015-2020 (development set) and 98 were born in 2021 (validation set). According to the presence or absence of NEC, the development set was divided into two groups: NEC (n=77) and non-NEC (n=577). A multivariate logistic regression analysis was used to investigate the independent risk factors for NEC in very preterm infants. R software was used to plot the nomogram model. The nomogram model was then validated by the data of the validation set. The receiver operating characteristic (ROC) curve, the Hosmer-Lemeshow goodness-of-fit test, and the calibration curve were used to evaluate the performance of the nomogram model, and the clinical decision curve was used to assess the clinical practicability of the model. RESULTS: The multivariate logistic regression analysis showed that neonatal asphyxia, sepsis, shock, hypoalbuminemia, severe anemia, and formula feeding were independent risk factors for NEC in very preterm infants (P<0.05). The ROC curve of the development set had an area under the curve (AUC) of 0.833 (95%CI: 0.715-0.952), and the ROC curve of the validation set had an AUC of 0.826 (95%CI: 0.797-0.862), suggesting that the nomogram model had a good discriminatory ability. The calibration curve analysis and the Hosmer-Lemeshow goodness-of-fit test showed good accuracy and consistency between the predicted value of the model and the actual value. CONCLUSIONS: Neonatal asphyxia, sepsis, shock, hypoalbuminemia, severe anemia, and formula feeding are independent risk factors for NEC in very preterm infant. The nomogram model based on the multivariate logistic regression analysis provides a quantitative, simple, and intuitive tool for early assessment of the development of NEC in very preterm infants in clinical practice.

Dynamically Stable Active Sites from Surface Evolution of Perovskite Materials during the Oxygen Evolution Reaction.

Perovskite oxides are an important class of oxygen evolution reaction (OER) catalysts in alkaline media, despite the elusive nature of their active sites. Here, we demonstrate that the origin of the OER activity in a La1-xSrxCoO3 model perovskite arises from a thin surface layer of Co hydr(oxy)oxide (CoOxHy) that interacts with trace-level Fe species present in the electrolyte, creating dynamically stable active sites. Generation of the hydr(oxy)oxide layer is a consequence of a surface evolution process driven by the A-site dissolution and O-vacancy creation. In turn, this imparts a 10-fold improvement in stability against Co dissolution and a 3-fold increase in the activity-stability factor for CoOxHy/LSCO when compared to nanoscale Co-hydr(oxy)oxides clusters. Our results suggest new design rules for active and stable perovskite oxide-based OER materials.

Design, synthesis, and evaluation of a novel macrocyclic anti-EV71 agent.

We describe here the design, synthesis, and evaluation of a macrocyclic peptidomimetic as a potent agent targeting enterovirus A71 (EV71). The compound has a 15-membered macrocyclic ring in a defined conformation. Yamaguchi esterification reaction was used to close the 15-membered macrocycle instead of the typical Ru-catalyzed ring-closing olefin metathesis reaction. The crystallographic characterization of the complex between this compound and its target, 3C protease from EV71, validated the design and paved the way for the generation of a new series of anti-EV71 agents.

Hierarchical Nanoassembly of MoS2/Co9S8/Ni3S2/Ni as a Highly Efficient Electrocatalyst for Overall Water Splitting in a Wide pH Range.

The design of low-cost yet high-efficiency electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) over a wide pH range is highly challenging. We now report a hierarchical co-assembly of interacting MoS2 and Co9S8 nanosheets attached on Ni3S2 nanorod arrays which are supported on nickel foam (NF). This tiered structure endows high performance toward HER and OER over a very broad pH range. By adjusting the molar ratio of the Co:Mo precursors, we have created CoMoNiS-NF- xy composites ( x: y means Co:Mo molar ratios ranging from 5:1 to 1:3) with controllable morphology and composition. The three-dimensional composites have an abundance of active sites capable of universal pH catalytic HER and OER activity. The CoMoNiS-NF-31 demonstrates the best electrocatalytic activity, giving ultralow overpotentials (113, 103, and 117 mV for HER and 166, 228, and 405 mV for OER) to achieve a current density of 10 mA cm-2 in alkaline, acidic, and neutral electrolytes, respectively. It also shows a remarkable balance between electrocatalytic activity and stability. Based on the distinguished catalytic performance of CoMoNiS-NF-31 toward HER and OER, we demonstrate a two-electrode electrolyzer performing water electrolysis over a wide pH range, with low cell voltages of 1.54, 1.45, and 1.80 V at 10 mA cm-2 in alkaline, acidic, and neutral media, respectively. First-principles calculations suggest that the high OER activity arises from electron transfer from Co9S8 to MoS2 at the interface, which alters the binding energies of adsorbed species and decreases overpotentials. Our results demonstrate that hierarchical metal sulfides can serve as highly efficient all-pH (pH = 0-14) electrocatalysts for overall water splitting.

Silicene-supported TiO2 nanostructures: a theoretical study of electronic and optical properties.

Titania (TiO2) is a material of choice for energy-related applications, such as photovoltaics and photocatalysis. The presence of a large band gap and fast electron-hole recombination occurring in the lattice significantly reduce the material's quantum efficiency, and therefore limit industrial-scale applications. In this article, we investigate whether silicene can be a viable substrate for TiO2 nanostructures in photocatalytic applications. Calculations based on density functional theory find a strong electronic coupling between silicene and oxide nanostructures. Electron transfer from silicene to the nanostructures results in the production of active photoreduction sites involving Ti3+ ions in the system. The hybrid TiO2/silicene system also exhibits modification of optical characteristics with the capability of absorbing light in the visible range and spatially separating charges, thus displaying superior photocatalytic activity relative to pristine TiO2 for energy-related applications.

Structure-activity relationship study of a series of caspase inhibitors containing γ-amino acid moiety for treatment of cholestatic liver disease.

A series of caspase inhibitors containing γ-amino acid moiety have been synthesized. A systemic study on their structure-activity relationship of anti-apoptotic cellular activity is presented. These efforts led to the discovery of compound 20o as a potent caspase inhibitor, which demonstrated preclinical ameliorating total bilirubin efficacy with a significantly improved pharmacokinetic profile.

Discovery of novel substituted octahydropyrrolo[3,4-c]pyrroles as dual orexin receptor antagonists for insomnia treatment.

A series of octahydropyrrolo[3,4-c]pyrroles were synthesized and evaluated by orexin 1 and 2 receptor (OX1 & 2 R) antagonists assays. Compound 14l with potent OXR antagonist activity and suitable pharmacokinetic behavior was chosen to be investigated in an EEG study, which demonstrated effects of sleep promotion comparable to Suvorexant. Furthermore, the di-fluro substituted analogs exhibited reduced hERG inhibition while maintaining moderate potency.

Electrochemical reduction of CO2 on graphene supported transition metals - towards single atom catalysts.

In this study, we have investigated the use of single metal atoms supported on defective graphene as catalysts for the electrochemical reduction of CO2 using the first-principles approach and the computational hydrogen electrode model. Reaction pathways to produce a variety of C1 products CO, HCOOH, HCHO, CH3OH and CH4 have been studied in detail for five representative transition metals Ag, Cu, Pd, Pt, and Co. Different pathways were revealed in contrast to those found for metallic crystalline surfaces and nanoparticles. These single atom catalysts have demonstrated a general improvement in rate limiting potentials to generate C1 hydrocarbons. They also show distinct differences in terms of their efficiency and selectivity in CO2 reduction, which can be correlated with their elemental properties as a function of their group number in the periodic table. Six best candidates for CH4 production are identified by conducting computational screening of 28 d-block transition metals. Ag has the lowest overpotential (0.73 V), and is followed by Zn, Ni, Pd, Pt and Ru with overpotentials all below 1 V. Cu in the supported single atom form shows a strong preference towards producing CH3OH with an overpotential of 0.68 V well below the value of 1.04 V for producing CH4.

Spin-dependent electron transport in C and Ge doped BN monolayers.

Recent advances in the synthesis and characterization of h-BN monolayers offer opportunities to tailor their electronic properties via aliovalent substitutions in the lattice. In this paper, we consider a h-BN monolayer doped with C or Ge, and find that dopants modify the Fermi level of the pristine monolayer. Three-fold coordinated dopants relax to the convex-shaped structures, while four-fold coordinated ones retain the planar structures. These modifications, in turn, lead to unique features in the electron transport characteristics including significant enhancement of current at the dopant site, diode-like asymmetric current-voltage response, and spin-dependent current. We find that the spin-polarized transport properties of the doped BN monolayers could be used for the next-generation devices at the nanoscale.

Design, synthesis, and biological evaluation of anti-EV71 agents.

Enterovirus 71 (EV71) is a major causative agent of hand, foot and mouth disease (HFMD), which can spread its infections to the central nervous and other systems with severe consequences. In this article, design, chemical synthesis, and biological evaluation of various anti-EV71 agents which incorporate Michael acceptors are described. Further SAR study demonstrated that lactone type of Michael acceptor provided a new lead of anti-EV71 drug candidates with high anti-EV71 activity in cell-based assay and enhanced mouse plasma stability. One of the most potent compounds (2K, cell-based anti-EV71 EC50=0.028µM), showed acceptable stability profile towards mouse plasma, which resulted into promising pharmacokinetics in mouse via IP administration.

Michael acceptor in gambogic acid--Its role and application for potent antitumor agents.

Gambogic acid (GA), a natural product with unique structure, was reported to have broad antiproliferation activities against cancer cell lines. As a reactive Michael acceptor, the 10-position of GA is susceptible to nucleophiles, thus limiting its clinical application as an anticancer agent. Moreover, the 6-OH forms an intramolecular hydrogen bond with 8-CO, which can make the 9, 10 double bond more reactive to nucleophiles. In this essay, two strategies (A and B) were applied to solve the above-mentioned problems. Strategy A was to increase the steric hindrance of C-10 to reduce the activity of GA towards nucleophiles. Strategy B was to replace the hydroxyl of C-6 with other substituents based on the assumption that the intra-molecular hydrogen bond could increase the electrophilicity of C-10. Results showed the electrophilicity of C-10 disappeared as well as the antiproliferation activity against cancer cell lines by introducing a methyl group at C-10. Strategy B showed that the electrophilicity of C-10 was reduced dramatically while maintained the activity by replacement of the hydroxyl of C-6 with neutral or basic groups.

Pressure and electric field-induced metallization in the phase-engineered ZrX2 (X = S, Se, Te) bilayers.

The phase-, pressure- and electric field-induced changes in the electronic properties of Zr dichalcogenide, ZrX2 (X = S, Se, Te), bilayers are investigated using density functional theory. On going from the trigonal (T) to hexagonal (H) phase, a significant modulation in the electronic structure of bilayer dichalcogenides is predicted. This is mainly due to the distinct stacking nature of the bilayer in two phases leading to a delicate difference in the interplanar interaction, which is concurrently affected by the nature of X-X bonding. Application of the pressure reduces the band gap of layered dichalcogenides leading to the metallization of the ZrTe2 bilayer for ≈6 GPa. Similarly, application of the transverse electric field (0.05-0.25 V Å(-1)) induces a complete metallization in dichalcogenide bilayers. Our results show that band gap engineering by changing the phase, applying pressure and electric field can be an effective strategy to modulate the electronic properties of bilayer dichalcogenides for the next-generation device applications.

Computational studies of electrochemical CO2 reduction on subnanometer transition metal clusters.

Computational studies of electrochemical reduction of CO2 to CO, HCOOH and CH4 were carried out using tetra-atomic transition metal clusters (Fe4, Co4, Ni4, Cu4 and Pt4) at the B3LYP level of theory. Novel catalytic properties were discovered for these subnanometer clusters, suggesting that they may be good candidate materials for CO2 reduction. The calculated overpotentials for producing CH4 are in the order, Co4 < Fe4 < Ni4 < Cu4 < Pt4, with both Co4 and Fe4 having overpotentials less than 1 V. Investigation of the effects of supports found that a Cu4 cluster on a graphene defect site has a limiting potential for producing CH4 comparable to that of a Cu (111) surface. However, due to the strong electronic interaction with the Cu4 cluster, the defective graphene support has the advantage of significantly increasing the limiting potentials for the reactions competing with CH4, such as the hydrogen evolution reaction (HER) and CO production.