1 × 2 Graphene Surface Plasmon Waveguide Beam Splitter Based on Self-Imaging.

Based on the principle of self-imaging, a 1 × 2 graphene waveguide beam splitter is proposed in this work, which can split the graphene surface plasmons excited by far-infrared light. The multimode interference process in the graphene waveguide is analyzed by guided-mode propagation analysis (MPA), and then the imaging position is calculated. The simulation results show that the incident beam can be obviously divided into two parts by the self-imaging of the graphene surface plasmon. In addition, the influences of the excited light wavelength, Fermi level, dielectric environment on the transmission efficiency are studied, which provide a reference for the research of graphene waveguide related devices.

Visualization of Electrooxidation on Palladium Single Crystal Surfaces via In Situ Raman Spectroscopy.

The electrooxidation of catalyst surfaces is across various electrocatalytic reactions, directly impacting their activity, stability and selectivity. Precisely characterizing the electrooxidation on well-defined surfaces is essential to understanding electrocatalytic reactions comprehensively. Herein, we employed in situ Raman spectroscopy to monitor the electrooxidation process of palladium single crystal. Our findings reveal that the Pd surface's initial electrooxidation process involves forming *OH intermediate and ClO4 - ions facilitate the deprotonation process, leading to the formation of PdOx. Subsequently, under deep electrooxidation potential range, the oxygen atoms within PdOx contribute to creating surface-bound peroxide species, ultimately resulting in oxygen generation. The adsorption strength of *OH and the coverage of ClO4 - can be adjusted by the controllable electronic effect, resulting in different oxidation rates. This study offers valuable insights into elucidating the electrooxidation mechanisms underlying a range of electrocatalytic reactions, thereby contributing to the rational design of catalysts.

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OBJECTIVES: To develop effective measures to reduce antibiotic use duration in very low birth weight (VLBW) preterm infants in the neonatal intensive care unit through quality improvement methods. METHODS: The study population consisted of hospitalized VLBW preterm infants, with the percentage of hospitalization time during which antibiotics were used from November 2020 to June 2021 serving as the baseline. The specific quality improvement goal was to reduce the duration of antibiotic use. Factors affecting antibiotic use duration in preterm infants were analyzed using Pareto charts. Key drivers were identified, and specific interventions were formulated based on the stages of antibiotic use. Changes in the percentage of antibiotic use duration were monitored with run charts until the quality improvement target was achieved. RESULTS: From November 2020 to June 2021, the baseline antibiotic use duration percentage was 49%, with a quality improvement target to reduce this by 10% within 12 months. The Pareto analysis indicated that major factors influencing antibiotic duration included non-standard antibiotic use; delayed cessation of antibiotics when no infection evidence was present; prolonged central venous catheter placement; insufficient application of kangaroo care; and delayed progress in enteral nutrition. The interventions implemented included: (1) establishing sepsis evaluation and management standards; (2) educating medical staff on the rational use of antibiotics for preterm infants; (3) supervising the enforcement of antibiotic use standards during ward rounds; (4) for those without clear signs of infection and with negative blood cultures, discontinued the use of antibiotics 36 hours after initiation; (5) reducing the duration of central venous catheterization and parenteral nutrition to lower the risk of infection in preterm infants. The control chart showed that with continuous implementation of interventions, the percentage of antibiotic use duration was reduced from 49% to 32%, a statistically significant decrease. CONCLUSIONS: The application of quality improvement tools based on statistical principles and process control may significantly reduce the antibiotic use duration in VLBW preterm infants. Citation:Chinese Journal of Contemporary Pediatrics, 2024, 26(7): 736-742.

Synergistic Modulation of Multiple Sites Boosts Anti-Poisoning Hydrogen Electrooxidation Reaction with Ultrasmall (Pt0.9Rh0.1)3V Ternary Intermetallic Nanoparticles.

Promoting the hydrogen oxidation reaction (HOR) activity and poisoning tolerance of electrocatalysts is crucial for the large-scale application of hydrogen-oxygen fuel cell. However, it is severely hindered by the scaling relations among different intermediates. Herein, lattice-contracted Pt-Rh in ultrasmall ternary L12-(Pt0.9Rh0.1)3V intermetallic nanoparticles (~2.2 nm) were fabricated to promote the HOR performances through an oxides self-confined growth strategy. The prepared (Pt0.9Rh0.1)3V displayed 5.5/3.7 times promotion in HOR mass/specific activity than Pt/C in pure H2 and dramatically limited activity attenuation in 1000 ppm CO/H2 mixture. In situ Raman spectra tracked the superior anti-CO* capability as a result of compressive strained Pt, and the adsorption of oxygen-containing species was promoted due to the dual-functional effect. Further assisted by density functional theory calculations, both the adsorption of H* and CO* on (Pt0.9Rh0.1)3V were reduced compared with that of Pt due to lattice contraction, while the adsorption of OH* was enhanced by introducing oxyphilic Rh sites. This work provides an effective tactic to stimulate the electrocatalytic performances by optimizing the adsorption of different intermediates severally.

Uncovering the dual role of dimensionless radius in buckling of spherical shells with random geometric imperfections.

Localized deformation and randomly shaped imperfections are salient features of buckling-type instabilities in thin-walled load-bearing structures. However, it is generally agreed that their complex interactions in response to mechanical loading are not yet sufficiently understood, as evidenced by buckling-induced catastrophic failures which continue to today. This study investigates how the intimate coupling between localization mechanisms and geometric imperfections combine to determine the statistics of the pressure required to buckle (the illustrative example of) a hemispherical shell. The geometric imperfections, in the form of a surface, are defined by a random field generated over the nominally hemispherical shell geometry, and the probability distribution of the buckling pressure is computed via stochastic finite element analysis. Monte-Carlo simulations are performed for a wide range of the shell's radius to thickness ratio, as well as the correlation length of the spatial distribution of the imperfection. The results show that over this range, the buckling pressure is captured by the Weibull distribution. In addition, the analyses of the deformation patterns observed during the simulations provide insights into the effects of certain characteristic lengths on the local buckling that triggers global instability. In light of the simulation results, a probabilistic model is developed for the statistics of the buckling load that reveals how the dimensionless radius plays a dual role which remained hidden in previous deterministic analyses. The implications of the present model for reliability-based design of shell structures are discussed.

Rediscovery and systematics of the enigmatic genus Helicostoa reveals a new species of sessile freshwater snail with remarkable sexual dimorphism.

Helicostoa sinensis E. Lamy, 1926 is a unique freshwater gastropod species with a sessile habit. This enigmatic species was first found cemented on river limestones from China about 120 years ago and described together with the genus. It was never collected again and has been considered monotypic. Here, we report the rediscovery of Helicostoa from several rivers in China, and describe a second species of this genus based on a comprehensive study. In addition to the unique sessile habit of both species, the new Helicostoa species presents one of the most remarkable cases of sexual dimorphism within molluscs. Only the adult female is sessile and the original aperture of the female is sealed by shell matter or rock, while an opening on the body whorl takes the function of the original aperture. The male is vagile, with a normal aperture. Our results confirm the recently suggested placement of Helicostoa within the family Bithyniidae. The sessility of Helicostoa species is considered as an adaption to the limestone habitat in large rivers. The extreme sexual dimorphism and secondary aperture of females are considered as adaptations to overcome the obstacles for mating and feeding that come with a sessile life style.

Analysis of chemical constituents and comprehensive quality evaluation of Rhamni Songoricae Fructus / 中国药房

OBJECTIVE To identify the chemical constituents of Rhamni Songoricae Fructus and to establish their fingerprints and the method for simultaneous determination of four constituents to comprehensively evaluate the quality of Rhamni Songoricae Fructus. METHODS The chemical constituents in Rhamni Songoricae Fructus were qualitatively analyzed by ultra-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry. The fingerprints of 15 batches of Rhamni Songoricae Fructus were established by HPLC and chemometric analysis was performed by using SPSS 26.0 and SIMCA 14.1 software； the contents of quercetin， kaempferol， kaempferide and emodin were determined by the same method. RESULTS A total of 35 constituents were identified， including 28 kinds of flavonoids， 5 kinds of anthraquinones and 2 kinds of organic acids. A total of 19 common peaks were identified in the HPLC fingerprints， recognizing quercetin， kaempferol， kaempferide and emodin. The similarities between HPLC fingerprints of 15 batches of samples and control chromatograms were greater than 0.9. The results of cluster analysis showed that 15 batches of samples were divided into 2 classes， of which S1-S5， S7 and S9 were one class and the rest were one class， similar to the results of principal component analysis. The results of the orthogonal partial least squares- discriminant analysis showed that the variable importance projections of peaks No. 2， 6， 1， 11 （quercetin）， 3， 14， 8， 10， 19 （emodin）， 5 were all greater than 1. The contents of quercetin， kaempferol， kaempferide and emodin ranged from 0.710 to 10.478 mg/g， 0.236 to 0.660 mg/g， 0.334 to 3.039 mg/g， and 0.261 to 0.504 mg/g. CONCLUSIONS The constructed chemical constituent identification， fingerprint and content determination methods are simple， feasible and reproducible， which combined with chemometric analysis can be used for comprehensive evaluation of the quality of Rhamni Songoricae Fructus.

Molecular understanding of cation effects on double layers and their significance to CO-CO dimerization.

Cation effects have been shown in numerous experiments to play a significant role in electrocatalysis. To understand these effects at the molecular level, we systematically investigate the structures and capacitances of electric double layers with a variety of cations as counter charges at Pt(111)-COad/water interfaces with ab initio molecular dynamics. It is encouraging to find that the computed Helmholtz capacitances for different cations are in quantitative agreement with experiments, and that the trend of cation effects on capacitances shows clear correlation with the structures of interface cations of differing sizes and hydration energies. More importantly, we demonstrate the Helmholtz capacitance as the key descriptor for measuring the activity of CO-CO dimerization, the rate-determining step for C2+ formation in electroreduction of CO and CO2. Our work provides atomistic insights into cation effects on electric double layers and electrocatalysis that are crucial for optimizing electrode and electrolyte materials.

Revealing the role of interfacial water and key intermediates at ruthenium surfaces in the alkaline hydrogen evolution reaction.

Ruthenium exhibits comparable or even better alkaline hydrogen evolution reaction activity than platinum, however, the mechanistic aspects are yet to be settled, which are elucidated by combining in situ Raman spectroscopy and theoretical calculations herein. We simultaneously capture dynamic spectral evidence of Ru surfaces, interfacial water, *H and *OH intermediates. Ru surfaces exist in different valence states in the reaction potential range, dissociating interfacial water differently and generating two distinct *H, resulting in different activities. The local cation tuning effect of hydrated Na+ ion water and the large work function of high-valence Ru(n+) surfaces promote interfacial water dissociation. Moreover, compared to low-valence Ru(0) surfaces, high-valence Ru(n+) surfaces have more moderate adsorption energies for interfacial water, *H, and *OH. They, therefore, facilitate the activity. Our findings demonstrate the regulation of valence state on interfacial water, intermediates, and finally the catalytic activity, which provide guidelines for the rational design of high-efficiency catalysts.

Understanding the Effects of Electrode Material, Single Crystal Facet, and Electrolyte Ion on the Helmholtz Capacitance of Metal/Aqueous Solution Interfaces.

The comprehensive interpretation of the measured differential Helmholtz capacitance curve is vital for advancing our understanding of the interfacial structure. While several possible physical effects contributing to the Helmholtz capacitance have been proposed theoretically, combining those factors to explain the experimentally observed potential-dependent capacitance profile remains a significant challenge. In this study, we employ ab initio molecular dynamics simulations to model various metal/solution interfaces. Our investigation primarily emphasizes the substantial effect of water chemisorption on the potential-dependent behavior of the Helmholtz capacitance. Additionally, we identify other critical factors that profoundly impact the Helmholtz capacitance: (1) Ions with low hydration energy hinder the availability of surface sites for water adsorption, resulting in a diminished enhancement of capacitance from water chemisorption. (2) Using large-sized ions leads to an expansion of the Helmholtz layer, causing a decrease in the Helmholtz capacitance. (3) Metal surfaces with higher affinity for water attract water adsorption at lower potentials, resulting in a lower peak potential for the differential Helmholtz capacitance curve.

Renewable galactomannan-based biogums with structure regulation to protect zinc metal anodes via blocking and confinement effect.

Galactomannan-based biogums were derived from fenugreek, guar, tara, and carob and consisted of mannose and galactose with different ratios, as well as the implementation of high-value utilization was very significant for sustainable development. In this work, renewable and low-cost galactomannan-based biogums were designed and developed as functional coatings protected on the Zn metal anodes. The molecule structure of galactomannan-based biogums were explored on the effect of anticorrosion ability and uniform deposition behavior through the introduction of fenugreek gum, guar gum, tara gum, and carob gum with different ratios of mannose to galactose as 1.2:1, 2:1, 3:1, and 4:1. The existence of biogum protective layers can reduce the contact area between Zn anodes and aqueous electrolyte to enhance the anticorrosion ability of Zn anodes. Rich oxygen-containing groups in galactomannan-based biogums can coordinate with Zn2+ and Zn atoms to form ion conductivity gel layer and adsorb closely on the surface of Zn metal, which can induce uniform deposition of Zn2+ to avoid dendrite growth. Zn electrodes protected by biogums can cycle impressively for 1980 h with 2 mA cm-2 and 2 mAh cm-2. This work can provide a novel strategy to enhance Zn metal anodes' electrochemical performance, as well as implement the high-value application of biomass-based biogums as functional coatings.

Surface Control Behavior toward Crystal Regulation and Anticorrosion Capacity for Zinc Metal Anodes.

The commercial application of high-safety aqueous zinc (Zn) secondary batteries is hindered by the poor cycling life of Zn metal anodes. Here we propose a dendrite growth and hydrogen evolution corrosion reaction mechanism from the binding energy of the deposited crystal plane on the Zn surface and the adsorption energy of H2O molecules on different crystal planes as well as the binding energy of H2O molecules with Zn2+ ions. The biomass-based alkyl polyglucoside (APG) surfactant is adopted as an electrolyte additive of 0.15% to regulate the preferential growth of a parallel Zn(002) plane and enhance the anticorrosion ability of Zn metal anodes. The robust binding and adsorption energies of APG with Zn2+ ions in the aqueous electrolyte and the Zn(002) plane on Zn surface generate a synergistic effect to increase the concentration of Zn2+ ions on the APG-adsorbed Zn(002) plane, endowing the continuous growth of the preferential parallel Zn(002) plane and the excellent anticorrosion capacity. Accordingly, the long-term cycle stability of 4000 h can be achieved for Zn anodes with APG additives, which is better than that with pure ZnSO4 electrolyte. With the addition of APG in the anolyte electrolyte, Zn-I2 full cells display excellent cycling performance (70 mAh g-1 after 20000 cycles) as compared with that without APG additives.

Identification through machine learning of potential immune- related gene biomarkers associated with immune cell infiltration in myocardial infarction.

BACKGROUND: To investigate the potential role of immune-related genes (IRGs) and immune cells in myocardial infarction (MI) and establish a nomogram model for diagnosing myocardial infarction. METHODS: Raw and processed gene expression profiling datasets were archived from the Gene Expression Omnibus (GEO) database. Differentially expressed immune-related genes (DIRGs), which were screened out by four machine learning algorithms-partial least squares (PLS), random forest model (RF), k-nearest neighbor (KNN), and support vector machine model (SVM) were used in the diagnosis of MI. RESULTS: The six key DIRGs (PTGER2, LGR6, IL17B, IL13RA1, CCL4, and ADM) were identified by the intersection of the minimal root mean square error (RMSE) of four machine learning algorithms, which were screened out to establish the nomogram model to predict the incidence of MI by using the rms package. The nomogram model exhibited the highest predictive accuracy and better potential clinical utility. The relative distribution of 22 types of immune cells was evaluated using cell type identification, which was done by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm. The distribution of four types of immune cells, such as plasma cells, T cells follicular helper, Mast cells resting, and neutrophils, was significantly upregulated in MI, while five types of immune cell dispersion, T cells CD4 naive, macrophages M1, macrophages M2, dendritic cells resting, and mast cells activated in MI patients, were significantly downregulated in MI. CONCLUSION: This study demonstrated that IRGs were correlated with MI, suggesting that immune cells may be potential therapeutic targets of immunotherapy in MI.

Molecular understanding of the Helmholtz capacitance difference between Cu(100) and graphene electrodes.

Unraveling the origin of Helmholtz capacitance is of paramount importance for understanding the interfacial structure and electrostatic potential distribution of electric double layers (EDL). In this work, we combined the methods of ab initio molecular dynamics and classical molecular dynamics and modeled electrified Cu(100)/electrolyte and graphene/electrolyte interfaces for comparison. It was proposed that the Helmholtz capacitance is composed of three parts connected in series: the usual solvent capacitance, water chemisorption induced capacitance, and Pauling repulsion caused gap capacitance. We found the Helmholtz capacitance of graphene is significantly lower than that of Cu(100), which was attributed to two intrinsic factors. One is that graphene has a wider gap layer at interface, and the other is that graphene is less active for water chemisorption. Finally, based on our findings, we provide suggestions for how to increase the EDL capacitance of graphene-based materials in future work, and we also suggest that the new understanding of the potential distribution across the Helmholtz layer may help explain some experimental phenomena of electrocatalysis.

Countermeasures for the construction of occupational health information standard system / 中华劳动卫生职业病杂志

As an important part of health information standard system, occupational health information standard system is the foundation and guarantee of promoting the construction of occupational health information. This article is based on the literature research about current situation of domestic and foreign health information standards and occupational health information standard system, thus take "the National Health Information Standardization System" and "the National Public Health Information Construction Standards and Norms" into account, focus on the requirements of occupational health information construction and related work. Thus, put forward suggestions on the construction of occupational health information standard system, to accelerate the occupational health information construction, data collection, transmission and application.

Preparation and properties of a new artificial bone composite material / 中国修复重建外科杂志

OBJECTIVE@#To study the preparation and properties of the hyaluronic acid (HA)/α-calcium sulfate hemihydrate (α-CSH)/β-tricalcium phosphate (β-TCP) material (hereinafter referred to as composite material).@*METHODS@#Firstly, the α-CSH was prepared from calcium sulfate dihydrate by hydrothermal method, and the β-TCP was prepared by wet reaction of soluble calcium salt and phosphate. Secondly, the α-CSH and β-TCP were mixed in different proportions (10∶0, 9∶1, 8∶2, 7∶3, 5∶5, and 3∶7), and then mixed with HA solutions with concentrations of 0.1%, 0.25%, 0.5%, 1.0%, and 2.0%, respectively, at a liquid-solid ratio of 0.30 and 0.35 respectively to prepare HA/α-CSH/ β-TCP composite material. The α-CSH/β-TCP composite material prepared with α-CSH, β-TCP, and deionized water was used as the control. The composite material was analyzed by scanning electron microscope, X-ray diffraction analysis, initial/final setting time, degradation, compressive strength, dispersion, injectability, and cytotoxicity.@*RESULTS@#The HA/α-CSH/β-TCP composite material was prepared successfully. The composite material has rough surface, densely packed irregular block particles and strip particles, and microporous structures, with the pore size mainly between 5 and 15 μm. When the content of β-TCP increased, the initial/final setting time of composite material increased, the degradation rate decreased, and the compressive strength showed a trend of first increasing and then weakening; there were significant differences between the composite materials with different α-CSH/β-TCP proportion ( P<0.05). Adding HA improved the injectable property of the composite material, and it showed an increasing trend with the increase of concentration ( P<0.05), but it has no obvious effect on the setting time of composite material ( P>0.05). The cytotoxicity level of HA/α-CSH/β-TCP composite material ranged from 0 to 1, without cytotoxicity.@*CONCLUSION@#The HA/α-CSH/β-TCP composite materials have good biocompatibility. Theoretically, it can meet the clinical needs of bone defect repairing, and may be a new artificial bone material with potential clinical application prospect.

Construction and prospect of healthy enterprises in the new era / 中华劳动卫生职业病杂志

The construction of health enterprises practice the concept of big health. It is an important solution to protect the overall health of occupational groups in the new era, which is of great significance to promoting a healthy city and helping to build a healthy China. This paper clarifies the connotation of healthy enterprises in the new era, discusses the key points of healthy enterprise construction around the "four in one" construction content, "PDCA" construction procedures, and evaluation methods of healthy enterprises. It focuses on the progress of healthy enterprise construction, analyzes the problems faced by the construction of health enterprises in China, and puts forward suggestions to improve the construction efficiency, with a view to providing ideas for further promoting the construction of health enterprises in China.

Modeling stepped Pt/water interfaces at potential of zero charge with ab initio molecular dynamics.

It is worth understanding the potentials of zero charge (PZCs) and structures of stepped metal/water interfaces, because for many electrocatalytic reactions, stepped surfaces are more active than atomically flat surfaces. Herein, a series of stepped Pt/water interfaces are modeled at different step densities with ab initio molecular dynamics. It is found that the structures of Pt/water interfaces are significantly influenced by the step density, particularly in regard to the distribution of chemisorbed water. The step sites of metal surfaces are more preferred for water chemisorption than terrace sites, and until the step density is very low, water will chemisorb on the terrace. In addition, it is revealed that the PZCs of stepped Pt/water interfaces are generally smaller than that of Pt(111), and the difference is mainly attributed to the difference in their work function, providing a simple way to estimate the PZCs of stepped metal surfaces. Finally, it is interesting to see that the Volta potential difference is almost the same for Pt/water interfaces with different step densities, although their interface structures and magnitude of charge transfer clearly differ.

Reducing Compaction Temperature of Asphalt Mixtures by GNP Modification and Aggregate Packing Optimization.

Compaction of hot mix asphalt (HMA) requires high temperatures in the range of 125 to 145 °C to ensure the fluidity of asphalt binder and, therefore, the workability of asphalt mixtures. The high temperatures are associated with high energy consumption, and higher NOx emissions, and can also accelerate the aging of asphalt binders. In previous research, the authors have developed two approaches for improving the compactability of asphalt mixtures: (1) addition of Graphite Nanoplatelets (GNPs), and (2) optimizing aggregate packing. This research explores the effects of these two approaches, and the combination of them, on reducing compaction temperatures while the production temperature is kept at the traditional levels. A reduction in compaction temperatures is desired for prolonging the paving window, extending the hauling distance, reducing the energy consumption for reheating, and for reducing the number of repairs and their negative environmental and safety effects, by improving the durability of the mixtures. A Superpave asphalt mixture was chosen as the control mixture. Three modified mixtures were designed, respectively, by (1) adding 6% GNP by the weight of binder, (2) optimizing aggregate packing, and (3) combining the two previous approaches. Gyratory compaction tests were performed on the four mixtures at two compaction temperatures: 135 °C (the compaction temperature of the control mixture) and 95 °C. A method was proposed based on the gyratory compaction to estimate the compaction temperature of the mixtures. The results show that all the three methods increase the compactability of mixtures and thus significantly reduce the compaction temperatures. Method 3 (combining GNP modification and aggregate packing optimization) has the most significant effect, followed by method 1 (GNP modification), and method 2 (aggregate packing optimization).