Shear-strained Pd Single-atom Electrocatalysts for Nitrate Reduction to Ammonia.

Electrochemical nitrate reduction method (NitRR) is a low-carbon, environmentally friendly, and efficient method for synthesizing ammonia, which has received widespread attention in recent years. Copper-based catalysts have a leading edge in nitrate reduction due to their good adsorption of *NO3. However, the formation of active hydrogen (*H) on Cu surfaces is difficult and insufficient, resulting in a large amount of the by-product NO2-. In this work, Pd single atoms suspended on the interlayer unsaturated bonds of CuO atoms formed due to dislocations (Pd-CuO) were prepared by low temperature treatment, and the Pd single atoms located on the dislocations were subjected to shear stress and the dynamic effect of support formation to promote the conversion of nitrate into ammonia. The catalysis had an ammonia yield of 4.2 mol.gcat-1. h-1, and a Faraday efficiency of 90% for ammonia production at -0.5 V vs. RHE. Electrochemical in-situ characterization and theoretical calculations indicate that the dynamic effects of Pd single atoms and carriers under shear stress obviously promote the production of active hydrogen, reduce the reaction energy barrier of the decision-making step for nitrate conversion to ammonia, further promote ammonia generation.

Dynamic Pore-Scale Model of Drainage in Granular Porous Media: The Pore-Unit Assembly Method.

Dynamics of drainage is analyzed for packings of spheres, using numerical experiments. For this purpose, a dynamic pore-scale model was developed to simulate water flow during drainage. The pore space inside a packing of spheres was extracted using regular triangulation, resulting in an assembly of grain-based tetrahedra. Then, pore units were constructed by identifying and merging tetrahedra that belong to the same pore, resulting in an assembly of pore units. Each pore unit was approximated by a volume-equivalent regular shape (e.g., cube and octahedron), for which a local capillary pressure-saturation relationship was obtained. To simulate unsaturated flow, a pore-scale version of IMPES (implicit pressure solver and explicit saturation update) was employed in order to calculate pressure and saturation distributions as a function of time for the assembly of pore units. To test the dynamic model, it was used on a packing of spheres to reproduce the corresponding measured quasi-static capillary pressure-saturation curve for a sand packing. Calculations were done for a packing of spheres with the same grain size distribution and porosity as the sand. We obtained good agreement, which confirmed the ability of the dynamic code to accurately describe drainage under low flow rates. Simulations of dynamic drainage revealed that drainage occurred in the form of finger-like infiltration of air into the pore space, caused by heterogeneities in the pore structure. During the finger-like infiltration, the pressure difference between air and water was found to be significantly higher than the capillary pressure. Furthermore, we tested the effects of the averaging, boundary conditions, domain size, and viscosity on the dynamic flow behavior. Finally, the dynamic coefficient was determined and compared to experimental data.

Musculoskeletal ultrasound to evaluate the efficacy of acupuncture: a review.

Acupuncture is a typical example of Traditional Chinese Medicine and has been used in China for hundreds of years to treat a wide range of illnesses. However, in the clinic, issues and deficiencies were primarily seen in four areas: loss of accuracy in the operation process; difficulty understanding the depth of acupuncture; difficulty using reinforcing and reducing techniques; and lack of a clear dynamic effect of acupuncture points following acupuncture. Musculoskeletal ultrasonography may quantitatively evaluate the acupuncture location and display the distribution of small nerves near and within the fascia of the acupuncture point in real time. The subjects were asked how they felt about receiving Qi when the needle body reached different depths and different tissues. The Qi obtained from an acupuncture point and the connective tissue of the fascia can be further understood by combining the physiological response of the acupuncture point with the anatomical structure, which offers a new method for defining the nature of the acupuncture point and standardizing the acupuncture point.

Exploration of the thickness-depended dynamic properties of differential phase contrast (DPC) and integrated differential phase contrast (iDPC).

A study on DPC and iDPC images of crystals is achieved with simulation. It highlights the use of electron wave intensity distribution to visualize the dynamic effect on DPC and iDPC contrasts. Electron waves near heavy atoms exhibit significant oscillations and rapid intensity decay. This oscillation causes DPC and iDPC signal inversion. Bloch wave theory is used to derive DPC and iDPC intensity distributions, elucidating the impact of dynamic effect on the contrast.

Green technology innovation and regional carbon emissions: analysis based on heterogeneous treatment effect modeling.

The impact of green technology innovation on regional carbon emissions has been a contentious issue in academic research. In this study, we attempt to analyze the influence of green technology innovation on regional carbon emissions using panel data from 28 Chinese provinces for the period of 2007-2020. Utilizing a heterogeneous treatment effect model, we systematically examine the effects of green technology innovation on regional carbon emissions. Firstly, we conduct a feature selection analysis on the factors influencing regional carbon emissions using causal inference methods based on machine learning. Subsequently, we explore the conditional and marginal treatment effects of green technology innovation on regional carbon emissions using the heterogeneous treatment effect model. Finally, we investigate the dynamic effects of green technology innovation on regional carbon emissions across different periods. Empirical results indicate that firstly, green technology innovation indirectly reduces regional carbon emissions by promoting energy efficiency improvement; secondly, the impact of green technology innovation on carbon emissions exhibits significant regional heterogeneity, with the largest effect observed in the eastern region, followed by the western region and the smallest effect in the central region; thirdly, at a significance level of 5%, green technology innovation has a direct inhibitory effect on carbon emissions in certain regions.

Time-varying effect in older patients with early-stage breast cancer: a model considering the competing risks based on a time scale.

Background: Patients with early-stage breast cancer may have a higher risk of dying from other diseases, making a competing risks model more appropriate. Considering subdistribution hazard ratio, which is used often, limited to model assumptions and clinical interpretation, we aimed to quantify the effects of prognostic factors by an absolute indicator, the difference in restricted mean time lost (RMTL), which is more intuitive. Additionally, prognostic factors of breast cancer may have dynamic effects (time-varying effects) in long-term follow-up. However, existing competing risks regression models only provide a static view of covariate effects, leading to a distorted assessment of the prognostic factor. Methods: To address this issue, we proposed a dynamic effect RMTL regression that can explore the between-group cumulative difference in mean life lost over a period of time and obtain the real-time effect by the speed of accumulation, as well as personalized predictions on a time scale. Results: A simulation validated the accuracy of the coefficient estimates in the proposed regression. Applying this model to an older early-stage breast cancer cohort, it was found that 1) the protective effects of positive estrogen receptor and chemotherapy decreased over time; 2) the protective effect of breast-conserving surgery increased over time; and 3) the deleterious effects of stage T2, stage N2, and histologic grade II cancer increased over time. Moreover, from the view of prediction, the mean C-index in external validation reached 0.78. Conclusion: Dynamic effect RMTL regression can analyze both dynamic cumulative effects and real-time effects of covariates, providing a more comprehensive prognosis and better prediction when competing risks exist.

Diverting the food-freezing technology improves the cryopreservation efficiency of induced pluripotent stem cells and derived neurospheres.

Introduction: Recent advances in induced pluripotent stem (iPS) technology and regenerative medicine require effective cryopreservation of iPSC-derived differentiated cells and three-dimensional cell aggregates (eg. Spheroids and organoids). Moreover, innovative freezing technologies for keeping food fresh over the long-term rapidly developed in the food industry. Therefore, we examined whether one of such freezing technologies, called "Dynamic Effect Powerful Antioxidation Keeping (DEPAK)," could be effective for the cryopreservation of biological materials. Methods: We evaluated the efficiency of cryopreservation using DEPAK and Proton freezers, both of which are used in the food industry, compared with conventional slow-freezing methods using a programmable freezer and a cell-freezing vessel. As they are highly susceptible cells to freeze-thaw damage, we selected two suspension cell lines (KHYG-1 derived from human natural killer cell leukemia and THP-1 derived from human acute monocyte leukemia) and two adherent cell lines (OVMANA derived from human ovarian tumors and HuH-7 derived from human hepatocarcinoma). We used two human iPS cell lines, 201B7-Ff and 1231A3, which were either undifferentiated or differentiated into neurospheres. After freezing using the above methods, the frozen cells and neurospheres were immediately transferred to liquid nitrogen. After thawing, we assessed the cryopreservation efficiency of cell viability, proliferation, neurosphere formation, and neurite outgrowth after thawing. Results: Among the four cryopreservation methods, DEPAK freezing resulted in the highest cell proliferation in suspension and adherent cell lines. Similar results were obtained for the cryopreservation of undifferentiated human iPS cells. In addition, we demonstrated that the DEPAK freezing method sustained the neurosphere formation capacity of differentiated iPS cells to the same extent as unfrozen controls. In addition, we observed that DEPAK-frozen neurospheres exhibited higher viability after thawing and underwent neural differentiation more efficiently than slow-freezing methods. Conclusions: Our results suggest that diversifying food-freezing technologies can overcome the difficulties associated with the cryopreservation of various biological materials, including three-dimensional cell aggregates.

Evaluation of dynamic effects of dietary medium-chain monoglycerides on performance, intestinal development and gut microbiota of broilers in large-scale production.

Medium-chain monoglycerides (MG) have been reported to affect the productive performance, gut microbiota and health of broiler chickens reared in ideal experimental conditions at home and abroad. However, the effects of MG on performance, intestinal development and gut microbiota of chickens in large-scale farms during different feed stages remain unknown. The present study was conducted on a modern farm with a total of 12,000 yellow feathered broiler chicks that were randomly allotted to 2 groups (1000 chicks/replicate, 6 replicates/group) for a 70-day trial. The control group (CON group) received a basal diet, and the treated group (MG group) was fed a basal diet containing 300 mg/kg mixed MG. The results revealed that dietary MG significantly (P < 0.05) increased the body weight and average feed intake, but notably reduced the feed conversion and mortality of chickens in large-scale production during the starter phase. The villus height of the duodenum in the MG group at 1, 2 and 7 wk of age increased notably, and the villus height to crypt depth ratio at 1, 2, 5 and 10 wk of age was improved. Dietary MG decreased the serum insulin content of chickens at 5, 7 and 10 wk of age, and decreased the serum lipopolysaccharide at 3 and 7 wk of age. The triglyceride level of chickens at 3, 5 and 10 wk of age and the low-density lipoprotein cholesterol level of chickens at 7 and 10 wk of age in the MG group decreased notably, while the high-density lipoprotein cholesterol increased significantly. Moreover, MG supplementation selectively increased the relative abundance of genus Bacteroides (family Bacteroidaceae) and Lachnospiraceae_NK4A136_group, but decreased the content of genus Rikenellaceae_RC9_gut_group, Collinsella and family Barnesiellaceae in the cecum of chickens at 3, 7 and 10 wk of age. Conclusively, these findings showed that dietary MG notably enhanced chicken performance, health and feed nutrient utilization at early ages by regulating gut microbiota, intestinal development and serum biochemical indices.

The Dynamic Effect of the Valleculae on Singing Voice - An Exploratory Study Using 3D Printed Vocal Tracts.

BACKGROUND AND OBJECTIVES: The valleculae can be seen as a pair of side branches of the human vocal tract like the piriform fossae. While the acoustic properties of the piriform fossae have been explored in detail, there is little evidence of full exploration of the acoustic properties of the valleculae. A recent investigation (Vampola, Horácek, & Svec, 2015), using a finite element model of a single vowel /a/, suggests that the valleculae created two antiresonances and two resonances in the high frequency region (above 4kHz) along with those produced by the piriform sinuses. In the current study, we investigate, in multiple vowels, the acoustic influences of the valleculae in singing voice, using 3-D printed vocal tracts. METHOD: MRI data were collected from an operatic tenor singing English vowels /a/, /u/, /i/. The images of each vowel were segmented and edited to create a pair of tracts, where one is the original and one had the valleculae digitally removed.The printed tracts were then placed atop a vocal tract organ loudspeaker, excited by white noise. Recordings were made with a microphone placed in front of the mouths of the tracts, to measure their frequency responses. RESULTS: Dimensional changes were observed in valleculae of different vowels, with the long-term average spectra of the recordings illustrating clear differences between the frequency responses of the va-nova (valleculae - no valleculae) pairs, which varies with vowels. CONCLUSION: The experiment demonstrates the dynamic1 nature of the shapes of the valleculae in the human vocal tract and its acoustic consequences. It provides evidence that the valleculae have similar acoustic properties to the piriform fossae but with larger variations, and in some cases can influence acoustically the frequency region below 4kHz. The results suggest that large volume valleculae have the potential to impede to some extent the acoustic effect of the singers formant cluster and small valleculae may do the reverse. Since the volume of the valleculae is observed to be largely dependent on tongue movement and also with changes to the uttered vowel, it can be assumed that the high frequency energy, including that within the singer's formant region, could be vowel dependent. Strategies to control valleculae volumes are likely to be highly relevant to voice pedagogy practice as well as singing performance.

Evaluating the dynamic effects of mitigation instruments on CO2 emissions in China's nonferrous metal industry: A vector autoregression analysis.

Reducing carbon dioxide (CO2) emissions in China's nonferrous metal industry is important for reaching China's ambitious goals for carbon peaking and neutrality. Prior research identified several carbon abatement instruments for the industry. However, the dynamic influence of different mechanisms on CO2 emissions in the industry remains unclear, and few studies have researched CO2 emission reductions in two nonferrous metal related industrial subsectors: nonferrous metal ore mining and nonferrous metal smelting. This research evaluated the dynamic effect of abatement instruments on the CO2 emissions in these two subsectors. The research discovered the factors that are highly linked with CO2 emissions by using an enhanced Stochastic Impacts by Regression on Population, Affluence, and Technology model. The dynamic influence of these factors on CO2 emissions in the two subsectors was investigated using a vector autoregressive model. Findings show that in the two subsectors, labour productivity and industrial value-added are the most important factors explaining CO2 changes. The two variables have a negative long-term effect on CO2 emissions in the nonferrous metal ores mining, and increase CO2 emissions in the smelting of nonferrous metals. Improving energy efficiency in the nonferrous metal smelting industry decreases the CO2 emissions only in the short term. In all sectors, lowering the electrical carbon emission factors and changing the energy structure using different techniques are expected to help reduce long-term CO2 emissions. These results are critical for the Chinese government in creating long- and short-term energy plans for the nonferrous metal sector.

The treatment effect of the Shanxi Comprehensive Reform Area policy on PM2.5 concentrations: A study based on a quasi-experiment.

Based on panel data on 248 prefecture-level cities in China from 2003 to 2018, this study first estimates the treatment effect of the Shanxi Comprehensive Reform Area policy on PM2.5 concentrations using a PSM-DID method within the counterfactual framework. The average treatment effect shows that contrary to the naive before-after analysis, on average, the Shanxi Comprehensive Reform Area policy significantly increased the PM2.5 concentrations of prefecture-level cities in Shanxi Province by 0.211% annually, and the place-based placebo test shows that the treatment effect obtained above is robust. Second, the dynamic treatment effects show a continuous decrease in incremental effects during 2011-2018, gradually decreasing from a significant positive increment during 2011-2015 to a zero or even a negative increment during 2016-2018, indicating that the Shanxi Comprehensive Reform Area policy gradually increased in environmental friendliness. Third, the mediating effects estimated by the causal steps procedure show that the Shanxi Comprehensive Reform Area policy influenced PM2.5 concentrations by increasing the intensity of resource exploitation and decreasing the intensity of environmental regulations, but the capacity of scientific and technological innovations had no mediating effect on the relationship between the policy and PM2.5 concentrations. Therefore, the government should further reduce the intensity of resource exploitation, strengthen the intensity of environmental regulations, and promote environmentally focused scientific and technological innovations to reduce PM2.5 concentrations in Shanxi Province.

The heterogeneous dynamic effect of financial development and environmental regulation on Chinese urban green technology management efficiency.

China is facing the large-scale urbanization and great pressure of energy consumption and environmental protection in the past few decades. In this process, urban green technology management efficiency (GMEC) is of great importance for the future work of greener transformation. Using China's 286 city-level panel data from 2006 to 2018, this paper proposes a global Malmquist index, PVAR, and panel quantile regression model to explore the heterogeneous dynamic effect of financial development (FIN) and environmental regulation (ER) on GMEC. The results indicate that during 2006-2018, (1) the growth rate of GMEC fluctuated violently, with a change of more than 28%. In addition, there is "one tight and one loose" phenomenon of GMEC. This indicates that there is much room for the improvement of GMEC; (2) in northeast cities, FIN is not conductive to GMEC, but in other regional cities, FIN has dynamic beneficial effect on GMEC. In addition, FIN represents a changing trend of dropping at first to rising afterwards in all regional cities; (3) furthermore, from time angle, ER has the heterogenous dynamic effect on GMEC among regional cities. Specifically, in northeast, eastern, central, and western cities, GMEC has an "M," "N," "U," and "U"-shaped relationship with the level of ER, respectively. From space angle, there is distinct heterogeneous effect of ER on GMEC at different quantiles within regional cities. Therefore, the local government are supposed to establish and implement policies based on regional cities' characteristics.