Ultrafast Microwave Synthesis of Ru-Doped MoP with Abundant P Vacancies as the Electrocatalyst for Hydrogen Generation in a Wide pH Range.

Molybdenum phosphide (MoP) has received increasing attention for the hydrogen evolution reaction (HER) due to its Pt-like electronic structure and high electrical conductivity. In this work, a flake-like Ru-doped MoP with phosphorus vacancy (Ru-MoP-PV) electrocatalyst is synthesized for the first time by a simple and rapid room-temperature microwave approach within 30 s. The created abundant phosphorus vacancies provide rich active sites and favor rapid electron transfer. The introduced Ru also enhances the catalytic activity of the synthesized electrocatalyst efficiently. Then, the designed Ru-MoP-PV possesses low overpotentials for HER with 79, 100, and 161 mV in 1.0 M KOH, 0.5 M H2SO4, and 1.0 M phosphate-buffered saline to obtain 10 mA cm-2. The Ru-MoP-PV and NiFe-layered double hydroxide are used as the cathode and the anode, respectively, to drive water splitting and just need a low cell voltage of 1.6 V to achieve 10 mA cm-2. This work provides a feasible way for the rapid production of metal phosphides for energy conversion and storage applications.

Synergistic Effects of Pyrrolic N/Pyridinic N on Ultrafast Microwave Synthesized Porous CoP/Ni2P to Boost Electrocatalytic Hydrogen Generation.

Transition metal phosphides are ideal inexpensive electrocatalysts for water-splitting, but the catalytic activity still falls behind that of noble metal catalysts. Therefore, developing valid strategies to boost the electrocatalytic activity is urgent to promote large-scale applications. Herein, a microwave combustion strategy (20 s) is applied to synthesize N-doped CoP/Ni2P heterojunctions (N-CoP/Ni2P) with porous structure. The porous structure expands the specific surface area and accelerates the mass transport efficiency. Importantly, the pyrrolic N/pyridinic N content is adjusted by changing the amount of urea during the synthesis process and then optimizing the adsorption/desorption capacity for H*/OH* to enhance the catalyst activity. Then, the synthesized N-CoP/Ni2P exhibits small overpotentials of 111 and 133 mV for HER in acidic and alkaline electrolytes and 290 mV for OER in alkaline electrolytes. This work provides an original and efficient approach to the synthesis of porous metal phosphides.

Microwave Synthesis of Pt Clusters on Black TiO2 with Abundant Oxygen Vacancies for Efficient Acidic Electrocatalytic Hydrogen Evolution.

Oxygen vacancies-enriched black TiO2 is one promising support for enhancing hydrogen evolution reaction (HER). Herein, oxygen vacancies enriched black TiO2 supported sub-nanometer Pt clusters (Pt/TiO2 -OV ) with metal support interactions is designed through solvent-free microwave and following low-temperature electroless approach for the first time. High-temperature and strong reductants are not required and then can avoid the aggregation of decorated Pt species. Experimental and theoretical calculation verify that the created oxygen vacancies and Pt clusters exhibit synergistic effects for optimizing the reaction kinetics. Based on it, Pt/TiO2 -OV presents remarkable electrocatalytic performance with 18 mV to achieve 10 mA cm-2 coupled with small Tafel slope of 12 mV dec-1 . This work provides quick synthetic strategy for preparing black titanium dioxide based nanomaterials.

Experimentally measuring the mode indices of Laguerre-Gaussian beams by weak measurement.

As a special experimental technique, weak measurements extract very little information from the measured system and does not cause the measured state to collapse. When coupling the Laguerre-Gaussian (LG) state with a well-defined pre- and post-selected system of a weak measurement process, there will be an indirect interconnection between the expected value of coordinate operators of the final state and the mode indices of the measured LG state. The mode of the light is impacted very slightly after the weak measurement. Based on this we propose an experiment scheme and have managed to experimentally measure the mode indices of LG beams spanning from l = -6 to l = +6, p = 0 to p = +8 accurately with the final intensity distributions approximatly at their origin.

Depth from defocus measurement method based on liquid crystal lens.

This paper describes a depth from defocus (DFD) method to recover the depth of scene from two images taken by a liquid crystal (LC) lens imaging system. The system is composed of a camera module and an LC lens. The system's focal length is electrically adjusted by the voltages that are applied on the LC lens. We use two images that are taken at maximum positive and negative, respectively, and the LC lens's optical power, to obtain the depth information via DFD. The principle is described and the experimental results are successfully obtained. The method is simple in that it needs not to involve any mechanical lens movements in the imaging system.

Integrated design of pi/2 converter and its experimental performance.

Transverse modes of light have been widely exploited in both classical and quantum optics in recent years. Among the devices to manipulate the transverse modes of light, a π/2 converter is a fundamental and important one that analogs to the quarter-wave plate in the polarization degree of freedom. While a π/2 converter is typically achieved by a pair of well-adjusted cylindrical lenses, it suffers from complexity in its installation and adjustment, which strongly limits its practical applications. In this paper an integrated design of a π/2 converter is reported. We compute the necessary parameters for manufacturing according to refractive theory of a cylindrical surface. Based on the change of refractive indices, we simulate the response of Gouy phase versus wavelengths. We also implement an experiment to verify the conversion between Laguerre-Gaussian modes and Hermite-Gaussian modes by using our compact π/2 converter to confirm its simple adjustment and reliable performance in practice.

Microwave Phosphine-Plasma-Assisted Ultrafast Synthesis of Halogen-Doped Ru/RuP2 with Surface Intermediate Adsorption Modulation for Efficient Alkaline Hydrogen Evolution Reaction.

Anionic modification engineering is a crucial approach to develop highly efficient electrocatalysts for hydrogen evolution reaction. Herein, halogen elements (X = Cl, Br, and I)-modified Ru-based nanosheets (X-Ru/RuP2) are designed by rapid and eco-friendly microwave-phosphide plasma approach within 60 s. Experimental and density functional theory calculations verify that the introduced halogen element, especially Br, can optimize the surface intermediates adsorption. Specially, the designed Br-Ru/RuP2 favors the water dissociation and following hydrogen adsorption/desorption process. Then, the as-synthesized Br-Ru/RuP2 exhibits low overpotential of 34 mV to reach 10 mA cm-2 coupled with small Tafel slope of 27 mV dec-1 in alkaline electrolyte with excellent long-term stability. Moreover, the electrocatalytic performances in acid and neutral media are also boosted via Br element modification. This work paves a novel way to regulate the electronic structure of Ru-based compounds, and then can boost the electrocatalytic kinetics.

Molecular mechanism of lipopolysaccharide (LPS) in promoting biomineralization on bacterial surface.

Biomineralization on bacterial surface is affected by biomolecules of bacterial cell surface. Lipopolysaccharide (LPS) is the main and outermost component on the extracellular membrane of Gram-negative bacteria. In the present study, the molecular mechanism of LPS in affecting biomineralization of Ag+/Cl- colloids was investigated by taking advantages of two LPS structural deficient mutants of Escherichia coli. The two mutants were generated by impairing the expression of waaP or wbbH genes with CRISPR/Cas9 technology and it induced deficient polysaccharide chain of O-antigen (ΔwbbH) or phosphate groups of core oligosaccharide (ΔwaaP) in LPS structures. There were significant changes of the cell morphology and surface charge of the two mutants in comparing with that of wild type cells. LPS from ΔwaaP mutant showed increased ΔHITC upon interacting with free Ag+ ions than LPS from wild type cells or ΔwbbH mutant, implying the binding affinity of LPS to Ag+ ions is affected by the phosphate groups in core oligosaccharide. LPS from ΔwbbH mutant showed decreased endotherm (ΔQ) upon interacting with Ag+/Cl- colloids than LPS from wild type or ΔwaaP mutant cells, implying LPS polysaccharide chain structure is critical for stabilizing Ag+/Cl- colloids. Biomineralization of Ag+/Cl- colloids on ΔwbbH mutant cell surface showed distinctive morphology in comparison with that of wild type or ΔwaaP mutant cells, which confirmed the critical role of O-antigen of LPS in biomineralization. The present work provided molecular evidence of the relationship between LPS structure, ions, and ionic colloids in biomineralization on bacterial cell surface.

Application of Lightweight Structure in Automobile Bumper Beam: A Review.

The bumper beam is an important device to ensure the safety of the car, which can effectively alleviate the force and absorb energy when the car collides. Traditional bumper beams are mostly made of high-strength steel, which has high strength and a low production cost but a heavy weight. With the requirement of being lightweight, high-strength steel is not able to meet the needs of lightweight cars, and composite materials have become the answer to the problem of a light weight in cars due to their excellent performance of being lightweight and high strength. This article introduces the case study on materials of bumper beams and presents the application of traditional materials and composite materials in bumper beams. Then, the fabrications and processes of bumper beams, a performance assessment, experimental tests, and a finite element analysis of the bumper beam are carried out. This paper also represents the study of optimization in automobile bumper beams.

Surface Treat Method to Improve the Adhesion between Stainless Steel and Resin: A Review.

Combining metal and polymer into hybrid composite materials is finding increasing interest in many industries. Special attention is being paid to increase the adhesion between the metal and polymer interface. In this paper, the current research progress of surface treatment methods for improving the interfacial adhesion of stainless steel and resin is reviewed. It involves the stainless steel surface treatment method, resin surface treatment method, and adhesion test methods of stainless steel and resin. The methods of improving the interfacial adhesion of stainless steel and resin are summarized and prospected according to the research status.

Full Endoscopy Combined with Allogeneic Bone Grafting for Benign Spinal Lesions: Technical Notes and Preliminary Clinical Results.

Benign lesions of the spine include benign tumors and tumor-like lesions of the spine, which usually occur in the thoracic and lumbar vertebrae. The incidence rate is low, accounting for about 1% of primary bone tumors. Few cases of endoscopic treatment of benign spinal lesions have been reported in the literature. Here, we introduce a new surgical technique using full endoscopy and allogeneic bone grafting to treat benign spinal lesions. All patients in this study successfully underwent the operation, and their pain was significantly relieved postoperatively. The patient VAS scores decreased from 3.07 ± 0.70 preoperatively to 0.33 ± 0.49 at the last follow-up visit (p < 0.05). The mean total blood loss (including drainage blood) was 16.67 ± 6.98 mL. The mean operative time was 63.33 ± 7.23 min. No patients developed numbness in the corresponding segmental distribution after surgery, none of the patients had serious postoperative complications, and none had focal recurrence during follow-up requiring reoperation. Patients reported symptom relief throughout the whole follow-up period. We believe that endoscopic surgery preserves the ligaments and soft tissues around the vertebral body, and that this technique is feasible with minimal trauma, rapid recovery, and good outcomes at short-term follow-up. This minimally invasive treatment modality offers a new option for the treatment of patients with benign spinal lesions.

Ultrafast synthesis of halogen-doped Ru-based electrocatalysts with electronic regulation for hydrogen generation in acidic and alkaline media.

Developing a facile and time-saving method for preparing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts can accelerate the practical applications of hydrogen energy. In this study, halogen (X = F, Cl, Br and I) doped Ru-RuO2 on carbon cloth (CC) (X-Ru-RuO2/MCC) was synthesized via an ultrafast microwave-assisted method for 30 s. Particularly, the doped Br (Br-Ru-RuO2/MCC) significantly improved the electrocatalytic performances of the catalyst through the regulation of electronic structures. Then, the Br-Ru-RuO2/MCC catalyst featured HER overpotentials of 44 mV and 77 mV in 1.0 M KOH and 0.5 M H2SO4, and the OER overpotential of 300 mV at 10 mA cm-2 in 1.0 M KOH. This study provides a novel method for developing of halogen-doped catalysts.

Lipopolysaccharide-stabilized ionic colloids induce biomineralization.

Biomineralization inducing by bacteria is common in nature. It involves interactions between bacterial surface and metal ions that are usually present in the form of ionic colloids. Lipopolysaccharide (LPS) is the major component of Gram-negative bacterial surfaces. In the present study, interactions between LPS and metal ions (Ag+, Fe3+, Cd2+, Co2+, Cu2+, Mn2+, Ni2+), as well as ionic colloids (Ag+/Cl-, Fe3+/OH-) were evaluated by means of isothermal titration calorimetry and Zeta potential measurement. It was found that LPS increases the energy barrier for the collapse of ionic colloids and prevents ionic colloids from aggregation. The roles of LPS-stabilized ionic colloids in inducing biomineralization on the bacterial surface were explored by means of scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray Diffraction. It showed that reducing colloidal stability by increasing the ionic strength significantly inhibited biomineralization of ionic colloids on bacterial surfaces. While the formation of ionic colloids promoted biomineralization on bacterial surfaces. This study provides a novel insight into biomineralization as well as biomineralization-based techniques with biological stabilizers for producing biominerals.

Efficacy Analysis of Percutaneous Endoscopic Spinal Surgery for Young Patients with Discogenic Low Back Pain.

Purpose: To evaluate the application value of percutaneous endoscopic spinal surgery for young patients with discogenic low back pain (DLBP) and to judge its clinical efficacy. Methods: We retrospectively analyzed young patients with single-segment discogenic lumbago from July 2018 to June 2020 in our department who underwent percutaneous endoscopic surgery according to the inclusion and exclusion criteria. We finally enrolled 20 patients. The follow-up time was 6-30 months. In all patients, we recorded the visual analog scale (VAS) score for waist pain and the Oswestry Disability Index (ODI) preoperatively, immediately postoperatively and at the last follow-up. We used the modified MacNab criteria to assess the curative effect at the last follow-up. Results: All 20 patients underwent successful operations without complications. No recurrence was observed during follow-up. The VAS score of low back pain was 5.05±1.19 points before surgery, 1.50±051 points immediately after surgery, and 1.10±0.72 points at the last follow-up (P < 0.05 preoperative vs both postoperative). At the last follow-up, the VAS scores of all 20 patients were ≤2, and 4 patients had no pain. The ODI was 46.66±7.03% before surgery, 9.78±4.05% immediately after surgery, and 4.11±3.18% at the last (P < 0.05, preoperative vs both postoperative). According to the evaluation under the modified MacNab standard, the good-excellent rate of clinical efficacy at the last follow-up was 95%. Conclusion: Percutaneous endoscopic spinal surgery can significantly improve the symptoms and dysfunction of young patients with DLBP and has little effect on the biomechanical stability of the lumbar spine. This surgery has great clinical application value.

Hollow-structured amorphous Cu(OH)x nanowires doped with Ru for wide pH electrocatalytic hydrogen production.

Developing efficient and stable catalysts for electrocatalytic hydrogen evolution reaction (HER) with low overpotential is the key point to realizing large-scale hydrogen commercialization. Herein, Ru doped amorphous hollow copper hydroxide nanowires on copper foam (Ru-Cu(OH)x/CF) is prepared by surface chemical oxidization and following solvothermal process. The hollow 3D nanowire structure can provide abundant accessibility active sites, promote electrolyte in filtration and facilitate gas diffusion in the process of the electrochemical reaction. Then, the as-synthesized Ru-Cu(OH)x/CF electrocatalyst exhibits impressive electrocatalytic performance for HER with 45, 80 and 50 mV to drive 10 mA cm-2 in 1.0 M KOH, 1.0 M phosphate-buffered saline (PBS) and 0.5 M H2SO4, respectively, with remarkable long-term stability. Moreover, sustainable energies can power the two-electrode setup with amounts of hydrogen generation. The strategy may be particularly beneficial to explore simple synthesis and high-performance catalysts for HER.

Escherichia coli templated iron oxide biomineralization under oscillation.

Motility is significant in organisms. Studying the influence of motility on biological processes provides a new angle in understanding the essence of life. Biomineralization is a representative process for organisms in forming functional materials. In the present study, we investigated the biomineralization of iron oxides templated by Escherichia coli (E. coli) cells under oscillation. The formation of iron oxide minerals with acicular and banded morphology was observed. The surface charge of E. coli cells contributed to the biomineralization process. The surface components of E. coli cells including lipids, carbohydrates and proteins also have roles in regulating the formation and morphology of iron oxide minerals. As-prepared mineralized iron oxide nanomaterials showed activity in photocatalytic degradation of methylene blue as well as in electrocatalytic hydrogen evolution reaction. This study is helpful not only in understanding motility in biological processes, but also in developing techniques for fabricating functional nanomaterials.

Measuring the Topological Charge of Orbital Angular Momentum Beams by Utilizing Weak Measurement Principle.

According to the principle of weak measurement, when coupling the orbital angular momentum (OAM) state with a well-defined pre-selected and post-selected system of a weak measurement process, there will be an indirect coupling between position and topological charge (TC) of OAM state. Based on this we propose an experiment scheme and experimentally measure the TC of OAM beams from -14 to 14 according to the weak measurement principle. After the experiment the intrinsic OAM of the beams changed very little. Weak measurement, Topological Charge, OAM beams.

Promoting Tag Removal of a MBP-Fused Integral Membrane Protein by TEV Protease.

Tag removal is a prerequisite issue for structural and functional analysis of affinity-purified membrane proteins. The present study took a MBP-fused membrane protein, MrpF, as a model to investigate the tag removal by TEV protease. Influences of the linking sequence between TEV cleavage site and MrpF on protein expression and predicted secondary structure were investigated. The steric accessibility of TEV protease to cleavage site of MBP-fused MrpF was explored. It was found that reducing the size of hydrophilic group of detergents and/or extending the linking sequence between cleavage site and target protein can significantly improve the accessibility of the cleavage site and promote tag removal by TEV protease.

Adherence and interaction of cationic quantum dots on bacterial surfaces.

Understanding molecular mechanisms of interactions between nanoparticles and bacteria is important and essential to develop nanotechnology for medical and environmental applications. Quantum dots (QDs) are specific nanoparticles with unique optical properties and high photochemical stability. In the present study, direct interactions were observed between cationic QDs and bacteria. Distinct fluorescence quenching patterns were developed when cationic QDs interacted with Gram negative and Gram positive bacteria. The aggregation of QDs on bacterial surface as well as fluorescence quenching depends upon the chemical composition and structure of the bacterial cell envelopes. The presence of lipopolysaccharide is unique to Gram-negative bacterial surface and provides negatively charge areas for absorbing cationic QDs. The effects of lipopolysaccharide were proved on fluorescence quenching of cationic QDs. In contrast to Gram-negative bacteria, the presence of teichoic acids is unique to Gram-positive bacterial cell wall and provides negatively charged sites for cationic QDs along the chain of teichoic-acid molecules, which may protect QDs from aggregation and fluorescence quenching. This study may not only provide insight into behaviors of QDs on bacterial cell surfaces but also open a new avenue for designing and applying QDs as biosensors in microbiology, medicine, and environmental science.

The Japanese quail: a model for studying reproductive aging of hypothalamic systems.

During aging, the decline of neuroendocrine, endocrine, and behavioral components of reproduction ultimately leads to reproductive failure. These studies considered both neuroendocrine and behavioral aspects of reproductive aging in Japanese quail, using chronological age and reproductive status to separate animals into experimental groups. In Study I, age-related changes in the gonadotropin releasing hormone (GnRH-I) system were investigated and a sharp decrease was observed in GnRH-I concentration in the median eminence of aging animals of both sexes, whereas preoptic-lateral septal region GnRH-I concentrations declined only in aging males. Immunohistochemistry confirmed these findings since aging females retained, whereas males lost GnRH-I cells. Functional changes were assessed by in vitro incubation of parasaggittal hypothalamic slices collected from young and old inactive males and females. Results showed reduced baseline GnRH-I release and diminished response to norepinephrine (NE). Deteriorating fertility also correlated with decreased male sexual behavior and loss of aromatase immunoreactive (AROM-ir) neurons in the medial, but not lateral preoptic nucleus (POA). Sexual behavior and AROM-ir were restored with exogenous testosterone, which was associated with increased cell size in the medial POA. Comparison of cell size and number of AROM-ir cells showed that aged sexually active males had fewer, larger AROM-ir cells when compared to young males, suggesting neuroplasticity of specific neural systems and a critical role of estradiol in maintaining reproductive function.