Lattice-disordered high-entropy metal hydroxide nanosheets as efficient precatalysts for bifunctional electro-oxidation

Electro-oxidation reactions (EORs) are important half reactions in overall and assisted water electrolysis, which are crucial in achieving economic and sustainable hydrogen production and realizing simultaneous wastewater treatment. Current studies indicate that the high-valence metal ions that are locally enriched in the catalysts or generated in situ during the anodic preoxidation process are active species for EORs. Hence, designing (pre)catalysts with enriched local active sites and boosted preoxidation is of great importance. In this work, with a focus on improving the EOR performance toward the oxygen evolution reaction (OER) and the urea oxidation reaction (UOR), we fabricated a lattice-disordered high-entropy FeCuCoNiZn hydroxide nanoarray catalyst that exhibits robust bifunctional OER and UOR behavior. The high-entropy feature could bring in a unique catalytic ensemble effect and remarkably improve the intrinsic OER/UOR activity. The lattice-disordered structure could not only enrich the local high-valence metal ions as active sites but also provide abundant reactive surface sites to accelerate the preoxidation process, thus leading to enriched active sites for the OER and UOR. Benefitting from the structural merits, the lattice-disordered high-entropy catalyst exhibits excellent OER and UOR activity with low overpotential, large current density and enhanced intrinsic activity, and no performance degradation but dramatic 35.3% and 88.7% enhancement in activity can be achieved during the long-term OER and UOR tests, respectively. The robust OER and UOR performance makes the lattice-disordered high-entropy catalyst a promising candidate for overall and urea-assisted water electrolysis from industrial, agricultural and sanitary wastewater.

Topotactic synthesis of high-entropy sulfide nanosheets as efficient pre-catalysts for water oxidation

Herein, quinary CoFeNiCuCr sulfide nanosheets with high-entropy feature and rough surface were fabricated via a topotactic transformation pathway from the high-entropy layered metal hydroxides, which display facile pre-oxidation and improved...

Sodium acetate/sodium butyrate alleviates lipopolysaccharide-induced diarrhea in mice via regulating the gut microbiota, inflammatory cytokines, antioxidant levels, and NLRP3/Caspase-1 signaling

Diarrhea is a word-widely severe disease coupled with gastrointestinal dysfunction, especially in cattle causing huge economic losses. However, the effects of currently implemented measures are still not enough to prevent diarrhea. Previously we found that dropped short-chain fatty acids in diarrhea yaks, and butyrate is commonly known to be related to the epithelial barrier function and intestinal inflammation. However, it is still unknown whether sodium acetate/sodium butyrate could alleviate diarrhea in animals. The present study is carried out to explore the potential effects of sodium acetate/sodium butyrate on lipopolysaccharide-induced diarrhea in mice. Fifty ICR mice were randomly divided into control (C), LPS-induced (L), and sodium acetate/sodium butyrate (D, B, A)-treated groups. Serum and intestine samples were collected to examine inflammatory cytokines, antioxidant levels, relative gene expressions via real-time PCR assay, and gut microbiota changes through high-throughput sequencing. Results indicated that LPS decreased the villus height (p < 0.0001), increased the crypt depth (p < 0.05), and lowered the villus height to crypt depth ratio (p < 0.0001), while sodium acetate/sodium butyrate supplementation caused a significant increase in the villus height (p < 0.001), decrease in the crypt depth (p < 0.01), and increase in the villus height to crypt depth ratio (p < 0.001), especially. In mice treated with LPS, it was found that the serum level of IL-1β, TNF-α (p < 0.001), and MDA (p < 0.01) was significantly higher; however, sodium acetate/sodium butyrate supplementation significantly reduced IL-1β (p < 0.001), TNF-α (p < 0.01), and MDA (p < 0.01), respectively. A total of 19 genera were detected among mouse groups; LPS challenge decreased the abundance of Lactobacillus, unidentified F16, unidentified_S24-7, Adlercreutzia, Ruminococcus, unclassified Pseudomonadales, [Ruminococcus], Acetobacter, cc 1, Rhodococcus, unclassified Comamonadaceae, Faecalibacterium, and Cupriavidus, while increased Shigella, Rhodococcus, unclassified Comamonadaceae, and unclassified Pseudomonadales in group L. Interestingly, sodium acetate/sodium butyrate supplementation increased Lactobacillus, unidentified F16, Adlercreutzia, Ruminococcus, [Ruminococcus], unidentified F16, cc 115, Acetobacter, Faecalibacterium, and Cupriavidus, while decreased Shigella, unclassified Enterobacteriaceae, unclassified Pseudomonadales, Rhodococcus, and unclassified Comamonadaceae. LPS treatment upregulated the expressions of ZO-1 (p < 0.01) and NLRP3 (p < 0.0001) genes in mice; however, sodium acetate/sodium butyrate solution supplementation downregulated the expressions of ZO-1 (p < 0.05) and NLRP3 (p < 0.05) genes in treated mice. Also, the LPS challenge clearly downregulated the expression of Occludin (p < 0.001), Claudin (p < 0.0001), and Caspase-1 (p < 0.0001) genes, while sodium acetate/sodium butyrate solution supplementation upregulated those gene expressions in treated groups. The present study revealed that sodium acetate/sodium butyrate supplementation alleviated LPS-induced diarrhea in mice via enriching beneficial bacterium and decreasing pathogens, which could regulate oxidative damages and inflammatory responses via NLRP3/Caspase-1 signaling. The current results may give insights into the prevention and treatment of diarrhea.

[Analysis on individual dosage monitoring of some interventional radiology staffs in Tianjin City from 2016 to 2020]

Objective: To investigate the individual external dose level of some interventional radiology staffs from 2016 to 2020 in Tianjin City. Methods: All 2068 interventional radiology staffs who were included in the work of the Radiation Monitoring Project from 2016 to 2020 were selected as study subjects in March 2021. The individual dose monitoring results of interventional radiology staffs of different ages, working years, time and medical institutions were analyzed. Results: Among 2068 interventional radiology workers, 1406 (67.99%) were male and 662 (32.01%) were female. The age was 44.6 (39.2, 50.3) years, and the working years was 10.5 (4.3, 14.6) years. The annual effective doses per capita of 40-49 age group and ≥50 age group were higher than that of 30-39 age group (P<0.05) . The annual effective dose per capita of 5-9 working years was higher than that of <5 working years, and the annual effective dose per capita of 10-29 working years was higher than that of 5-9 working years (P<0.05) . The median per capita annual effective dose of the interventional radiology staffs was 0.164 mSv. There were 1976 interventional radiology staffs with an annual effective dose of <0.50 mSv/a (95.6%) . The collective dose distribution ration SR(0.5) was 41.1%. The difference of effective dose per capita in each year was statistically significant (H=19.23, P<0.05) . The per capita annual effective dose of interventional radiology staffs in tertiary medical institutions was higher than that in secondary medical institutions, and the difference was statistically significant (P<0.05) . Conclusion: The personal dose of interventional radiology staffs in Tianjin City is at a low level. It is necessary to emphasize the radiation hazard protection of interventional radiology staffs in tertiary medical institutions, 40-49 years old, ≥50 years old age groups and 5-9, 10-29 working years groups.

Oriented interlayered charge transfer in NiCoFe layered double hydroxide/MoO3 stacked heterostructure promoting the oxygen-evolving behavior

Oxygen evolution reaction (OER), the rate-limiting half reaction of water electrolysis, plays as a crucial role in improving the overall efficiency of the coupled hydrogen evolution. To date, earth-abundant OER catalysts have been extensively studied, while unfortunately their catalytic activity and operational stability still need to be further optimized. In this work, we fabricated a highly efficient OER catalyst based on two-dimensional (2D) NiCoFe layered double hydroxide (LDH)/MoO₃ stacked heterostructure with enriched active sites and optimal electronic structure via an electrostatic-driven self-assembly process. The rough surface of the 2D heterostructure could offer abundant reactive sites for the pre-oxidation reaction, thereby leading to fast generation of the high-valence active species for OER, and the multi-metal synergy and oriented interlayered charge transfer could further enhance the intrinsic OER activity, finally resulting in enhanced OER performance with low overpotential, large current density, high intrinsic activity and excellent operational stability.

Cerium-induced lattice disordering in Co-based nanocatalysts promoting the hydrazine electro-oxidation behavior

In this work, cerium-incorporated Co-based catalysts encapsulated in nitrogen-doped carbon were fabricated for the electrocatalytic hydrazine oxidation reaction (HzOR). The Ce incorporation could lead to the formation of surface oxide nanolayers with a disordered lattice, endowing the catalyst with enriched active sites and enhanced intrinsic activity for promoted HzOR.

Facile green synthesis of dahlia-like anatase/TiO2(B) phase junction for boosting photocatalytic degradation of persistent tetracycline

The simultaneous construction of phase junction and hierarchical porous architecture can efficiently promote the separation and transfer of photogenerated carriers and then greatly improve photocatalytic activity of nano-TiO2, while its...

Electrochemical reduction of nitrate on silver surface and the in situ Raman spectroscopy study

Electroreduction of nitrate to other essential fertilizer is becoming a crucial manner toward nitrate contamination treatment. In this report, Ag nanocrystals catalyst on quasi-cavity architecture of ZnO nanowalls has been...

Cobalt, iron co-incorporated Ni(OH)2 multiphase for superior multifunctional electrocatalytic oxidation

The cobalt, iron co-incorporated Ni(OH)₂ multiphase displays superior catalytic activity and stability for multifunctional electrocatalytic oxidation, ascribed to the multiphase synergy, enhanced charge transfer and well-exposed active sites.

Green preparation of porous hierarchical TiO2(B)/anatase phase junction for effective photocatalytic degradation of antibiotics

In this study, porous hierarchical bronze/anatase phase junction TiO₂ assembled by ultrathin two-dimensional nanosheets was prepared by a novel, green and simple deep eutectic solvent-regulated strategy. Due to its structural features, the TiO₂ sample exhibited enhanced photocatalytic activities for multiple kinds of antibiotics, including ofloxacin, ciprofloxacin and chloramphenicol.

"Pit-dot" ultrathin nanosheets of hydrated copper pyrophosphate as efficient pre-catalysts for robust water oxidation

Herein, hydrated copper pyrophosphate ultrathin nanosheets with a unique "pit-dot" nanostructure were fabricated as efficient pre-catalysts for the oxygen evolution reaction, and systematic post-catalytic characterization studies confirmed the important role of the boosted pre-oxidation reaction in promoting the OER catalysis.

Lanthanum-incorporated β-Ni(OH)2 nanoarrays for robust urea electro-oxidation

Lanthanum-incorporated β-Ni(OH)₂ nanosheets display superior catalytic behavior and stability for urea electro-oxidation, which originates from the optimized electronic structure, the downshift of the d-band center and the increased number of exposed active sites.

In-plane β-Co(OH)2/Co3O4 hybrid nanosheets for flexible all-solid-state thin-film supercapacitors with high electrochemical performance

With the increasing demand for portable electronic devices, efficient power supplies with ultraflexibility have received considerable attention, among which the all-solid-state thin-film supercapacitors (ASSTFSs) have been considered as promising candidates for powering the portable devices with high performance and safety. In this work, we proposed in-plane β-Co(OH)₂/Co₃O₄ hybrid nanosheets with porous surface and controllable composition, which could be assembled as flexible electrodes for ASSTFSs. As the two-dimensional (2D) matrix of the hybrid nanosheets, the porous β-Co(OH)₂ component could offer a large surface area, thereby exposing more surface sites for surface redox reactions; the conductive Co₃O₄ component could effectively improve the intrinsic conductivity of the electrode material, thereby realizing good electrochemical performance synergistically. With the merits of the synergistic structural benefits, the ASSTFS device based on the β-Co(OH)₂/Co₃O₄ hybrid nanosheets exhibits high specific capacitance with good cycling stability and ultraflexibility, making our device an outstanding candidate for practical power supply in electronic devices.

Spatial variation of the soil bacterial community in major apple producing regions of China

AIMS

In China, apple production areas are largely from the coastal to inland areas and across varied climate zones. However, the relationship among soil micro-organisms, environmental factors and fruit quality has not been clearly confirmed in orchards. Here we attempted to identify the variation of soil bacteria in the main apple producing regions and reveal the relationship among climatic factor, soil properties, soil bacterial community and fruit quality.

METHODS AND RESULTS

Sixty soil samples were collected from six main apple producing areas in China. We examined the soil bacteria using bacterial 16S rRNA gene amplicon profiling. The results show that the soil bacterial diversity of apple orchards varied from the Bohai Bay Region to the Loess Plateau Region. Proteobacteria, Acidobacteria and Actinobacteria were the predominant taxa at the phylum level for all six areas. In the Bohai Bay and the Loess Plateau region, which are the two largest apple producing areas, Proteobacteria and Actinobacteria had the highest relative abundance, respectively. Furthermore, soil bacterial diversity showed positive correlation with the mean annual temperature (MAT), soil organic matter (SOM) and pH. Excluding a direct effect on the apple fruit quality, MAT exerted an indirect influence through soil SOM and pH to alter the relative abundance of dominant taxa and shift the bacterial diversity, which affects the apple fruit titratable acids and soluble solids.

CONCLUSIONS

Geographic variables underlie apple orchard soil bacterial communities vary according to spatial scale. Environmental factors exert an indirect effect on apple fruit quality via shaping soil bacterial community.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides a list of bacteria associated with environmental factors and the ecological attributes of their interactions in apple orchards, which will improve our ability to promote soil bacterial functional capabilities in order to reduce the fertilizer input and enhance the fruit quality.

[Investigation and analysis of work-related occupational musculoskeletal disorders and associated risk factors of manufacturing workers]

Objective: To investigate the prevalence of Work-related musculoskeletal disorders(WMSDs) and identify associated risk factors and provide evidence of taking measures for prevention. Methods: By Cluster sampling, 1 920 employees of 35 manufacturing enterprises were selected as study subjects from May to December 2017. The questionnnaire were including population characteristics、related factors of ergonomics、job burnout、insomnia and WMSDs. Results: The prevalence of waist was the highest among 9 body parts, with 52.0%, followed by the prevalence of neck 50.6%, more than 1 muscle diseases were by the prevalence of 74.7%. Single factor analysis showed that different levels of labor intensity, daily standing time (h) , daily sitting time(h) , daily bending time (h) , daily lifting of 5kg object time (h) group waist disease and prevalence of more than one musculoskeletal disease were different, The difference was statistically sig- nificant (P<0.05). More than 5 years of working year, labor intensity of Class III, daily bending time ≥2 h, depression, disorders (P<0.05). life satisfaction, job burnout, and insomnia are all risk factors for waist and musculoskeletal. The daily sitting time ≥2 h and the high life satisfaction were protective factors for waist and WMSDs (P<0.05). Conclusion: The prevalence rate of WMSDs among manufacturing workers is strong, and Manager should take the aspects of ergonomics and psychological factors meassure to reduce WMSDs, These meassure were including increasing sitting time, reducing bending time.

In Situ Measurement of Vacuum Window Birefringence using 25Mg+ Fluorescence

Accurate control of the polarization states of laser light is important in precision measurement experiments. In experiments involving the use of a vacuum environment, the stress-induced birefringence effect of the vacuum windows will affect the polarization states of laser light inside the vacuum system, and it is very difficult to measure and optimize the polarization states of the laser light in situ. The purpose of this protocol is to demonstrate how to optimize the polarization states of the laser light based on the fluorescence of ions in the vacuum system, and how to calculate the birefringence of vacuum windows based on azimuthal angles of external wave plates with Mueller matrix. The fluorescence of ²⁵Mg⁺ ions induced by laser light that is resonant with the transition of |3²P3/2,F = 4, mF = 4 → |3²S1/2,F = 3, mF = 3 is sensitive to the polarization state of the laser light, and maximum fluorescence will be observed with pure circularly polarized light. A combination of half-wave plate (HWP) and quarter-wave plate (QWP) can achieve arbitrary phase retardation and is used for compensating the birefringence of the vacuum window. In this experiment, the polarization state of the laser light is optimized based on the fluorescence of ²⁵Mg⁺ ion with a pair of HWP and QWP outside the vacuum chamber. By adjusting the azimuthal angles of the HWP and QWP to obtain maximum ion fluorescence, one can obtain a pure circularly polarized light inside the vacuum chamber. With the information on the azimuthal angles of the external HWP and QWP, the birefringence of the vacuum window can be determined.

Controllable fabrication of TiO2 anatase/rutile phase junctions by a designer solvent for promoted photocatalytic performance

Highly active coin tree-like TiO₂ anatase–rutile phase junctions were constructed by tailored DESs and the two-phase ratios can be easily tuned.

A molten-salt protected pyrolysis approach for fabricating a ternary nickel–cobalt–iron oxide nanomesh catalyst with promoted oxygen-evolving performance

A NiCoFe oxide nanomesh with two-dimensional morphology, quasi-single-crystalline feature and remarkable OER performance was fabricated via a molten-salt protected pyrolysis approach.

Modulation of crystal water in cobalt phosphate for promoted water oxidation

Cobalt phosphate tetrahydrate was identified as the optimal Co-Pi phase for electrocatalytic oxygen evolution reaction.

A simple method for in situ measurement of vacuum window birefringence

We present a simple method to measure the degrees of circular polarization (DoCP) of laser light inside a vacuum chamber and the birefringence of a vacuum window by detecting the fluorescence emitted by Doppler cooled ions in an ion trap. Imperfect laser polarization will cause ions to be pumped to the dark state which will decrease the fluorescence rates of the ions. With a simulation based on the rate equations of the relevant energy levels of ²⁵Mg⁺ ions, we find that the fluorescence rate is sensitive to the DoCP of the laser. Based on the simulation result, we present a new method to optimize the DoCP of the laser inside the vacuum chamber by adjusting fast axis azimuthal angles of a half-wave plate and a quarter-wave plate outside the vacuum chamber. The laser light is optimized to be circularly polarized with an uncertainty of the DoCP of 7.8 × 10^-5. With the obtained polarization information on both sides of the vacuum window and treating the vacuum window as an unknown wave plate, the phase delay and the fast axis azimuthal angle of the vacuum window can be determined in the form of Mueller matrix. The phase delay is determined to be 197.60(39)°, and the fast axis azimuthal angle is determined to be 104.00(5)°.

Promoted water splitting by efficient electron transfer between Au nanoparticles and hematite nanoplates: a theoretical and experimental study

Au/Fe₂O₃ nanoplates can lead to efficient electron transfer at the interface and thus improve the efficiency of the generation/separation of carriers.

An iron incorporation-induced nickel hydroxide multiphase with a 2D/3D hierarchical sheet-on-sheet structure for electrocatalytic water oxidation

An Fe-incorporated Ni(OH)₂ multiphase with a unique 2D/3D hierarchical sheet-on-sheet structure exhibits superior catalytic activity contributed by synergistic effects, enhanced electron transport and well-exposed active sites.

Modified bluing treatment to produce nickel–cobalt–iron spinel oxide with promoted oxygen-evolving performance

A facile modified bluing treatment approach was proposed for low-cost, time-saving and batch synthesis of a ternary NiCoFe spinel oxide catalyst with high OER performance.

Morphology and electronic structure modulation induced by fluorine doping in nickel-based heterostructures for robust bifunctional electrocatalysis

Fabrication of advanced electrocatalysts with high activity and durability is urgently needed to achieve energy conversion and pollution treatment at the same time. Herein, we highlight a fluorine-doped nickel-based heterostructure, in which fluorine doping displays a dual effect in Ni(OH)2 nanosheets/Ni3S2 heteronanorods. On the one hand, fluorine doping can facilitate the formation of Ni(OH)2 nanosheets/Ni3S2 heteronanorods through one-step in situ growth on nickel foams. The unique heterostructure enables good exposure of abundant active sites and highly active heterointerfaces. On the other hand, the uniform incorporation of fluorine can effectively modulate the electron density at the Fermi level of Ni3S2, contributing to the improved electrical conductivity and charge transfer efficiency, further improving the electrocatalytic activity in the oxygen evolution reaction (OER) and urea oxidation reaction (UOR). The optimal heterostructure presents a low overpotential of 360 mV to reach the OER current density of 100 mA cm-2. Finally, this heterostructure also displays a superior UOR anodic peak current of about 322.9 mA cm-2, almost the highest value at the anodic peak compared to the literature.

Metallic Intermediate Phase Inducing Morphological Transformation in Thermal Nitridation: Ni3FeN-Based Three-Dimensional Hierarchical Electrocatalyst for Water Splitting

Transition-metal nitrides have attracted a great deal of interest as electrocatalysts for water splitting due to their super metallic performance, high efficiency, and good stability. Herein, we report a novel design of hierarchical electrocatalyst based on Ni₃FeN, where the presence of carbon fiber cloth as a scaffold can effectively alleviate the aggregation of Ni₃FeN nanostructure and form three-dimensional conducting networks to enlarge the surface area and simultaneously enhance the charge transfer. The composition and morphological variations of NiFe precursors during annealing in different atmospheres were investigated. Such Ni₃FeN/CC hierarchical electrocatalyst shows much improved electrochemical properties for water splitting in terms of overpotentials (105 and 190 mV at 10 mA/cm² for hydrogen evolution reaction and oxygen evolution reaction, respectively) and stability.

Expression of profilin-1 in endothelial cells of rats with acute myocardial infarction

OBJECTIVE

To analyze the expression of profilin-1 in endothelial cells of rats with acute myocardial infarction.

MATERIALS AND METHODS

Twenty adult male Wistar rats were randomly divided into the myocardial infarction (model) group (n=10) and sham-operation (control) group (n=10). The expression of profilin-1 and phosphorylated extracellular signal kinase (pERK1/2) in aortic endothelial cells, indexes of endothelial injury [levels of endothelial microparticles (EMPs) and nitric oxide (NO)], indexes of myocardial injury [cardiac troponin T (cTnT) and creatine kinase-MB (CK-MB)], and mRNA levels of myocardial apoptotic factors (P53, Fas, Bax, and Bcl-2) in rats between the two groups were compared.

RESULTS

The expression of profilin-1 and pERK1/2 in aortic endothelial cells of rats in the model group was higher than in the control group (p<0.05), the levels of EMPs were increased, and NO levels were lower (p<0.05); cTnT and CK-MB in myocardial tissue, and mRNA of pro-apoptotic factors (P53, Fas, and Bax) were increased, whereas Bcl-2 mRNA was decreased (p<0.05). The protein expression of profilin-1 and pERK1 was positively correlated with the levels of cTnT, CK-MB, EMP, P53, Fas, and Bax, and negatively correlated with the levels of NO and Bcl-2 (p<0.05).

CONCLUSIONS

The high expression of profilin-1 is an important mechanism of acute myocardial infarction, and is expected to become a new target for the treatment of myocardial infarction.

1D Ni-Co oxide and sulfide nanoarray/carbon aerogel hybrid nanostructures for asymmetric supercapacitors with high energy density and excellent cycling stability

The fabrication of supercapacitor electrodes with high energy density and excellent cycling stability is still a great challenge. A carbon aerogel, possessing a hierarchical porous structure, high specific surface area and electrical conductivity, is an ideal backbone to support transition metal oxides and bring hope to prepare electrodes with high energy density and excellent cycling stability. Therefore, NiCo₂S₄ nanotube array/carbon aerogel and NiCo₂O₄ nanoneedle array/carbon aerogel hybrid supercapacitor electrode materials were synthesized by assembling Ni-Co precursor needle arrays on the surface of the channel walls of hierarchical porous carbon aerogels derived from chitosan in this study. The 1D nanostructures grow on the channel surface of the carbon aerogel vertically and tightly, contributing to the enhanced electrochemical performance with ultrahigh energy density. The energy density of NiCo₂S₄ nanotube array/carbon aerogel and NiCo₂O₄ nanoneedle array/carbon aerogel hybrid asymmetric supercapacitors can reach up to 55.3 Wh kg^-1 and 47.5 Wh kg^-1 at a power density of 400 W kg^-1, respectively. These asymmetric devices also displayed excellent cycling stability with a capacitance retention of about 96.6% and 92% over 5000 cycles.

Single-Molecule FRET to Measure Conformational Dynamics of DNA Mismatch Repair Proteins

Single-molecule FRET measurements have a unique sensitivity to protein conformational dynamics. The FRET signals can either be interpreted quantitatively to provide estimates of absolute distance in a molecule configuration or can be qualitatively interpreted as distinct states, from which quantitative kinetic schemes for conformational transitions can be deduced. Here we describe methods utilizing single-molecule FRET to reveal the conformational dynamics of the proteins responsible for DNA mismatch repair. Experimental details about the proteins, DNA substrates, fluorescent labeling, and data analysis are included. The complementarity of single molecule and ensemble kinetic methods is discussed as well.

A new cyclic RGD peptide dimer for integrin αvβ3 imaging

OBJECTIVE

To design a new Arg-Gly-Asp (RGD) peptide that can specifically bind integrin αvβ3 and evaluate the possibility of using 131I-labeled peptide for imaging αvβ3-positive tumors.

MATERIALS AND METHODS

The structure of the RGD monomer was selected using V-life software. Based on the RGD monomer, a dimer of cyclic RGD [c(RGD)2] linked by Tyr-(D)Ser-Lys-(D)Ser-Ser with a Gly-Gly-(D)Ala-Gly side chain on the lysine residue was synthesized. 131I-c(RGD)2 was synthesized using the chloramine-T (ChT) method, and the octanol-water partition coefficient was experimentally measured. To evaluate its binding affinity and selectivity, its equilibrium dissociation constant (Kd) with U87 MG glioma cells was measured in vitro, while whole body imaging and biodistribution were assessed in vivo in mice bearing U87 MG xenografts.

RESULTS

The optimal structure of the monomer was cyclic [-Cys-Arg-Gly-Asp-(D)Ser-Cys-]. The 131I-c(RGD)2 molecule exhibited good stability and was highly hydrophilic. The Kd value was (3.87 ± 0.05) × 10(-9) M, suggesting a high αvβ3-binding affinity and specificity. The tumors were clearly visualized at 3 and 6 h post-injection. Biodistribution data of the 131I-c(RGD)2 molecule showed rapid clearance from the blood and predominant accumulation in the tumor and kidney. The tumor-to-normal tissue (T/NT) ratio increased over time. At 24 h post-injection, the tumor-to-liver, tumor-to-muscle, and tumor-to-blood ratios were 4.92, 4.29, and 5.00, respectively.

CONCLUSIONS

These results suggest that the 131I-c(RGD)2 molecule may serve as a promising tracer for the detection of αvβ3-positive tumors.

The hybrid nanostructure of MnCo2O4.5 nanoneedle/carbon aerogel for symmetric supercapacitors with high energy density

Current applications of carbon-based supercapacitors are limited by their low energy density. One promising strategy to enhance the energy density is to couple metal oxides with carbon materials. In this study, a porous MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure was synthesized by assembling MnCo2O4.5 nanoneedle arrays on the surface of channel walls of hierarchical porous carbon aerogels derived from chitosan for the supercapacitor application. The synthetic process of the hybrid nanostructure involves two steps, i.e. the growth of Mn-Co precursors on carbon aerogel by a hydrothermal process and the conversion of the precursor into MnCo2O4.5 nanoneedles by calcination. The carbon aerogel exhibits a high electrical conductivity, high specific surface area and porous structure, ensuring high electrochemical performance of the hybrid nanostructure when coupled with the porous MnCo2O4.5 nanoneedles. The symmetric supercapacitor using the MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure as the active electrode material exhibits a high energy density of about 84.3 Wh kg(-1) at a power density of 600 W kg(-1). The voltage window is as high as 1.5 V in neutral aqueous electrolytes. Due to the unique nanostructure of the electrodes, the capacitance retention reaches 86% over 5000 cycles.

Prediction of virological response by pretreatment hepatitis B virus reverse transcriptase quasispecies heterogeneity: the advantage of using next-generation sequencing

Prediction of antiviral efficacy prior to treatment remains largely unavailable. We have previously demonstrated the clinical value of on-treatment hepatitis B virus (HBV) reverse transcriptase (RT) quasispecies (QS) evolution patterns. In this study, we aimed to elucidate the relevance for prediction of pretreatment HBV RT QS characteristics by comparing the performance of next-generation sequencing (NGS) and clone-based Sanger sequencing (CBS). Thirty-six lamivudine-treated patients were retrospectively studied, including 18 responders and 18 non-responders. CBS and NGS data of pretreatment serum HBV were used to generate RT QS genetic complexity and diversity scores, according to our previous studies. The ability of both methods to predict responsiveness was evaluated with receiver operating characteristic (ROC) curves. A cut-off value was generated on the basis of prediction ability. Responders had significantly higher pretreatment RT QS genetic complexity and diversity (in the first two parts, which overlapped with the S gene, at both the nucleotide and amino acid levels) than non-responders by NGS-based testing. NGS-based algorithms predicted response better than CBS in the ROC curve analysis. The mean distance of the second contig had the highest area under the curve (AUC) value. When the cut-off value was set to 0.007186, the difference between survival curves was significant (p 0.0090). Pretreatment HBV RT QS heterogeneity in the overlapping region of the RT and S genes could be a predictor of antiviral efficacy. NGS improves the predictions of virological outcomes relative to CBS algorithms. This may have important implications for the clinical management of subjects chronically infected with HBV.

Synthesis of scaly Sn3O4/TiO2 nanobelt heterostructures for enhanced UV-visible light photocatalytic activity

A novel scaly Sn3O4/TiO2 nanobelt heterostructured photocatalyst was fabricated via a facile hydrothermal route. The scaly Sn3O4 nanoflakes can be synthesized in situ and assembled on surface coarsened TiO2 nanobelts through a hydrothermal process. The morphology and distribution of Sn3O4 nanoflakes can be well-controlled by simply tuning the Sn/Ti molar ratio of the reactants. Compared with single phase nanostructures of Sn3O4 and TiO2, the scaly hybrid nanobelts exhibited markedly enhanced photoelectrochemical (PEC) response, which caused higher photocatalytic hydrogen evolution even without the assistance of Pt as a co-catalyst, and enhanced the degradation ability of organic pollutants under both UV and visible light irradiation. In addition to the increased exposure of active facets and broad light absorption, the outstanding performance is ascribed to the matching energy band structure between Sn3O4 and TiO2 at the two sides of the heterostructure, which efficiently reduces the recombination of photo-excited electron-hole pairs and prolongs the lifetime of charge carriers. Both photocatalytic assessment and PEC tests revealed that Sn3O4/TiO2 heterostructures with a molar ratio of Sn/Ti of 2/1 exhibited the highest photocatalytic activity. This study provides a facile and low-cost method for the large scale production of Sn3O4 based materials in various applications.

From UV to near-infrared, WS2 nanosheet: a novel photocatalyst for full solar light spectrum photodegradation

Narrow-bandgap semiconductor WS2 nanosheets are active photocatalysts, either under visible or under NIR irradiation. The photocatalyst functions are confirmed via photogeneration of an electron-hole pair, with a low rate of recombination.

Radioactive iodine labeling of monoclonal antibody against Hsp90α and its use in diagnostic imaging in prostate cancer xenograft model

OBJECTIVE

Heat shock protein (Hsp90) resides exclusively in the cytosol in normal cells, but is activated and then removes to the cell surface in tumor cells. The detecting upregulation or activation of Hsp90 is an early indicator of malignant behavior of cancer cells. Hsp90 has emerged as an important target for diagnosis or therapy of prostate cancer. In this study, we labeled Hsp90α specific monoclonal antibody (Hsp90α-mAb) with radioiodine Na131I and investigated its potential usage in diagnostic imaging of prostate tumor in xenograft mice model.

METHODS

Hsp90α-mAb was radioiodinated by using chloramine-T. The radiolabeling efficiency and radiochemical purity were assessed in vitro. 131I-Hsp90α-mAb was then injected into the nude mice bearing human prostate carcinoma. The planar gamma Imaging was performed at 3, 6, 9 and 12 h after injection.

RESULTS

The radiochemical purity of 131I-Hsp90α-mAb exceeded 95% after purification. This radiolabeled mAb was stable in human blood serum. In planar gamma imaging study, the prostate tumors in mice model were imaged clearly at 3h after injection of 131I-Hsp90α-mAb.

CONCLUSIONS

The results suggest that 131I-HSP90α-mAb could be a new promising molecular probe for diagnostic imaging of prostate tumors.

Hierarchical porous carbon aerogel derived from bagasse for high performance supercapacitor electrode

Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon aerogels by using bagasse as a raw material. Macro and mesoporous carbon was first prepared by carbonizing the freeze-dried bagasse aerogel; consequently, microporous structure was created on the walls of the mesoporous carbon by chemical activation. Interestingly, it was observed that the specific surface area, the pore size and distribution of the hierarchical porous carbon were affected by the activation temperature. In order to evaluate the ability of the hierarchical porous carbon towards the supercapacitor electrode performance, solid state symmetric supercapacitors were assembled, and a comparable high specific capacitance of 142.1 F g(-1) at a discharge current density of 0.5 A g(-1) was demonstrated. The fabricated solid state supercapacitor displayed excellent capacitance retention of 93.9% over 5000 cycles. The high energy storage ability of the hierarchical porous carbon was attributed to the specially designed pore structures, i.e., co-existence of the micropores and mesopores. This research has demonstrated that utilization of sustainable biopolymers as the raw materials for high performance supercapacitor electrode materials is an effective way to fabricate low-cost energy storage devices.

Enhanced photocatalytic property of reduced graphene oxide/TiO2 nanobelt surface heterostructures constructed by an in situ photochemical reduction method

A facile method is proposed to assemble graphene oxide (GO) on the surface of a TiO2 nanobelt followed by an in situ photocatalytic reduction to form reduced graphene oxide (rGO)/TiO2 nanobelt surface heterostructures. The special colloidal properties of GO and TiO2 nanobelt are exploited as well as the photocatalytic properties of TiO2 . Using water-ethanol solvent mixtures, GO nanosheets are tightly wrapped around the surface of the TiO2 nanobelts through an aggregation process and are then reduced in situ under UV-light irradiation to form rGO/TiO2 nanobelt surface heterostructures. The heterostructures enhance the separation of the photoinduced carriers, which results in a higher photocurrent due to the special electronic characteristics of rGO. Compared to TiO2 nanobelts, the rGO/TiO2 nanobelt surface heterostructures possess higher photocatalytic activity for the degradation of methyl orange and for the production of hydrogen from water, as well as excellent recyclability, with no loss of activity over five cycles.

Alcohol ingestion and colorectal neoplasia: a meta-analysis based on a Mendelian randomization approach

AIM

Observed associations of alcohol with colorectal cancer are prone to distortion by confounding and reverse causation. A Mendelian randomization approach provides an unbiased estimate of the association using the aldehyde dehydrogenase 2 (ALDH2) variant as a surrogate of alcohol exposure.

METHOD

A meta-analysis was performed to assess the association between the ALDH2 genotype and colorectal neoplasia, using the ALDH2 genotype as a marker of alcohol intake.

RESULTS

The pooled odds ratio (OR) of colorectal neoplasia was 1.31 (95%CI, 1.01-1.70) for the Glu/Glu vs the Lys/Lys genotype. There was no evidence of interstudy heterogeneity (P = 0.12, I² = 42.7). The overall risk for Glu/Lys heterozygotes relative to Lys/Lys homozygotes (under a fixed-effects model) was 1.13 (95%CI, 0.86-1.48). There was no evidence of publication bias for Glu/Glu or Glu/Lys analysis.

CONCLUSION

The result supports the role of alcohol in colorectal carcinogenesis based on a Mendelian randomization approach.

Prevalence of donor-specific anti-HLA antibodies during episodes of renal allograft rejection

BACKGROUND

Recent studies suggest that the appearance of anti-HLA antibodies in the early posttransplant period is associated with an increased incidence of acute and chronic rejection months later. However, very little is known about the prevalence of anti-HLA antibodies at the time that the rejection episodes are diagnosed. The purpose of this study was to analyze retrospectively 420 sera from 263 renal allograft recipients who were readmitted to the hospital for any reason between 1989 and 1998 in order to determine if a correlation existed between the presence of donor-specific anti-HLA antibodies and graft rejection.

METHODS

Sera were assayed for IgG HLA class I and II antibodies by ELISA. The ELISA results were analyzed using contingency tables with Fisher's exact test and compared with mismatched antigens in the donor.

RESULTS

Antibodies to donor HLA class I molecules in the posttransplant sera were extremely rare, occurring in only 6 of the 420 sera (1.4%) analyzed. Antibodies to donor class II antigens were slightly more common, occurring in 25 of the 420 sera (6%). In 21 of these 25 cases (84%), the presence of donor-specific HLA class II antibodies was associated with episodes of either acute (n=14) or chronic rejection (n=7). Five patients had antibodies to both class I and class II donor antigens, and all five of them lost their grafts to rejection.

CONCLUSION

Although the presence of donor-specific HLA antibodies presented a significant risk for acute or chronic rejection, 77% of all acute and chronic rejections occurred in patients without detectable HLA antibodies.

Suppression of human IL-1beta, IL-2, IFN-gamma, and TNF-alpha production by cigarette smoke extracts

BACKGROUND

Although cigarette smoking is known to have detrimental effects on the immune system, the nature of the immunosuppressive agent or agents is poorly understood.

OBJECTIVE

The purpose of the current study was to evaluate the effects of cigarette smoke extracts from high-tar (unfiltered Camel), medium-tar (Marlboro), and low-tar (Carlton) cigarettes on the in vitro production of IL-1beta, IL-2, IFN-gamma, and TNF-alpha.

METHODS

The concentrations of hydroquinone and catechol in cigarette smoke extracts were determined by using HPLC. Human PBMCs were treated with cigarette smoke extracts, hydroquinone, or catechol, and stimulated with anti-CD3 and phorbol-12-myristate-13-acetate. Cytokine levels in the supernatants were quantified by ELISA.

RESULTS

Pretreatment of PBMCs with cigarette smoke extracts derived from a single high- or low-tar cigarette suppressed the production of IL-1beta, IL-2, IFN-gamma, and TNF-alpha by greater than 90% without significant loss of cell viability. Nicotine, at a concentration comparable with that found in the highest-tar cigarettes (200 microg/mL), suppressed the production of IL-2, IFN-gamma, and TNF-alpha by only 21% to 38%. Catechol (50 micromol/L) inhibited production of IL-2 and IL-1beta by 62% to 73% but had little effect on TNF-alpha or IFN-gamma production. In contrast, hydroquinone inhibited the production of all 4 cytokines with IC(50) values ranging from 3 micromol/L(IL-1beta) to 29 micromol/L (IFN-gamma). However, HPLC determination of the hydroquinone concentrations in cigarette smoke extracts from single Camel (33+/-4 micromol/L), Marlboro (13+/-2 micromol/L), and Carlton (<1 micromol/L) cigarettes clearly demonstrated that the potent inhibitory effects of the low-tar cigarettes could not be accounted for by either hydroquinone or catechol.

CONCLUSION

These studies indicate that cigarette smoke contains potent inhibitors of cytokine production, at least one of which is present even in low-tar cigarettes.