bluuebunny/crossref_metadata_2025 huggingface dataset:
N2-to-NH3 conversion by excess electrons trapped in point vacancies on 5f-element dioxide surfaces
Authors: Wang Gaoxue , Batista Enrique R. , Yang Ping
Published: January 2023

Ammonia (NH3) is one of the basic chemicals in artificial fertilizers and a promising carbon-free energy storage carrier. Its industrial synthesis is typically realized via the Haber−Bosch process using traditional iron-based catalysts. Developing advanced catalysts that can reduce the N2 activation barrier and make NH3 synthesis more efficient is a long-term goal in the field. Most heterogeneous catalysts for N2-to-NH3 conversion are multicomponent systems with singly dispersed metal clusters on supporting materials to activate N2 and H2 molecules. Herein, we report single-component heterogeneous catalysts based on 5f actinide dioxide surfaces (ThO2 and UO2) with oxygen vacancies for N2-to-NH3 conversion. The reaction cycle we propose is enabled by a dual-site mechanism, where N2 and H2 can be activated at different vacancy sites on the same surface; NH3 is subsequently formed by H− migration on the surface via associative pathways. Oxygen vacancies recover to their initial states after the release of two molecules of NH3, making it possible for the catalytic cycle to continue. Our work demonstrates the catalytic activities of oxygen vacancies on 5f actinide dioxide surfaces for N2 activation, which may inspire the search for highly efficient, single-component catalysts that are easy to synthesize and control for NH3 conversion.
Chemically diverse activity-based probes with unexpected inhibitory mechanisms targeting trypsin-like serine proteases
Authors: Ramos-Llorca Alba , Decraecker Lisse , Cacheux Valérie M. Y. , Zeiburlina Irena , De bruyn Michelle , Battut Louise , Moreno-Cinos Carlos , Ceradini Davide , Espinosa Eric , Dietrich Gilles , Berg Maya , De Meester Ingrid , Van Der Veken Pieter , Boeckxstaens Guy , Lambeir Anne-Marie , Denadai-Souza Alexandre , Augustyns Koen
Published: January 2023

Activity-based probes (ABP) are molecules that bind covalently to the active form of an enzyme family, making them an attractive tool for target and biomarker identification and drug discovery. The present study describes the synthesis and biochemical characterization of novel activity-based probes targeting trypsin-like serine proteases. We developed an extensive library of activity-based probes with “clickable” affinity tags and a diaryl phosphonate warhead. A wide diversity was achieved by including natural amino acid analogs as well as basic polar residues as side chains. A detailed enzymatic characterization was performed in a panel of trypsin-like serine proteases. Their inhibitory potencies and kinetic profile were examined, and their IC50 values, mechanism of inhibition, and kinetic constants were determined. The activity-based probes with a benzyl guanidine side chain showed the highest inhibitory effects in the panel. Surprisingly, some of the high-affinity probes presented a reversible inhibitory mechanism. On the other hand, probes with different side chains exhibited the expected irreversible mechanism. For the first time, we demonstrate that not only irreversible probes but also reversible probes can tightly label recombinant proteases and proteases released from human mast cells. Even under denaturing SDS-PAGE conditions, reversible slow-tight-binding probes can label proteases due to the formation of high-affinity complexes and slow dissociation rates. This unexpected finding will transform the view on the required irreversible nature of activity-based probes. The diversity of this library of activity-based probes combined with a detailed enzyme kinetic characterization will advance their applications in proteomic studies and drug discovery.
A new chiral phenomenon of orientational chirality, its synthetic control and computational study
Authors: Jin Shengzhou , Xu Ting , Tang Yao , Wang Jia-Yin , Wang Yu , Pan Junyi , Zhang Sai , Yuan Qingkai , Rahman Anis Ur , Aquino Adelia J. A. , Lischka Hans , Li Guigen
Published: January 2023

A new type of chirality, orientational chirality, consisting of a tetrahedron center and a remotely anchored blocker, has been discovered. The key structural element of this chirality is characterized by multiple orientations directed by a through-space functional group. The multi-step synthesis of orientational chiral targets was conducted by taking advantage of asymmetric nucleophilic addition, Suzuki-Miyaura cross-coupling and Sonogashira coupling. An unprecedented catalytic species showing a five-membered ring consisting of C (sp2)-Br-Pd-C (sp2) bonds was isolated during performing Suzuki-Miyaura cross-coupling. X-ray diffraction analysis confirmed the species structure and absolute configuration of chiral orientation products. Based on X-ray structures, a model was proposed for the new chirality phenomenon to differentiate the present molecular framework from previous others. DFT computational study presented the relative stability of individual orientatiomers. This discovery would be anticipated to result in a new stereochemistry branch and to have a broad impact on chemical, biomedical, and material sciences in the future.
Omic insights into various ceftazidime-avibactam-resistant Klebsiella pneumoniae isolates from two southern Italian regions
Authors: Bongiorno Dafne , Bivona Dalida A. , Cicino Claudia , Trecarichi Enrico M. , Russo Alessandro , Marascio Nadia , Mezzatesta Maria Lina , Musso Nicolò , Privitera Grete F. , Quirino Angela , Scarlata Giuseppe G. M. , Matera Giovanni , Torti Carlo , Stefani Stefania
Published: January 2023

Ceftazidime-avibactam (CZA) is one of the best therapeutic options available for infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing bacteria. However, sporadic reports of CZA-resistant strains have been rapidly increasing in patients. Herein, we provide detailed case reports of the emergence of ceftazidime-avibactam resistance to identify their resistome and virulome using genomic molecular approaches. Sixteen isolates were collected from 13 patients at three hospitals in Catania and Catanzaro (Italy) between 2020-2021. Antimicrobial susceptibility was determined by broth microdiluition. The samples included in study were analyzed for resistome, virulome and Sequence Type (ST) using Whole Genome Sequencing (WGS). All strains were resistant to ceftazidime/avibactam, ciprofloxacin, extended-spectrum cephalosporins and aztreonam, 13/16 to meropenem, 8/16 to colistin and 7/16 to fosfomycin; 15/16 were susceptible to meropenem/vaborbactam; all strains were susceptible to cefiderocol. Molecular analysis showed circulation of three major clones: ST101, ST307 and ST512. In 10/16 strains, we found a blaKPC-3 gene; in 6/16 strains, four different blaKPC variants (blaKPC28-31-34-50) were detected. A plethora of other beta-lactam genes (blaSHV28-45-55-100-106-187-205-212, blaOXA1-9-48, blaTEM-181 and blaCTX-M-15) was observed; blaOXA-9 was found in ST307 and ST512, instead blaOXA48 in one out four ST101 strains. With regard to membrane permeability, ompK35 and ompK36 harbored frameshift mutations in 15/16 strains; analysis of ompK37 gene revealed that all strains harbored a non-functional protein and carry wild-type PBP3. There is an urgent need to characterize the mechanisms underlying carbapenem resistance and the intrinsic bacterial factors that facilitate the rapid emergence of resistance. Furthermore, it is becoming increasingly important to explore feasible methods for accurate detection of different KPC enzymes.
EBV LMP1-C terminal binding affibody molecule downregulates MEK/ERK/p90RSK pathway and inhibits the proliferation of nasopharyngeal carcinoma cells in mouse tumor xenograft models
Authors: Guo Yanru , Kamara Saidu , Zhang Jing , Wen He , Zheng Maolin , Liu Ying , Zhou Luqi , Chen Jun , Zhu Shanli , Zhang Lifang
Published: January 2023

Nasopharyngeal carcinoma (NPC), is an Epstein-Barr virus (EBV) associated malignancy most common in Southern China and Southeast Asia. In southern China, it is one of the major causes of cancer-related death. Despite improvement in radiotherapy and chemotherapy techniques, locoregional recurrence and distant metastasis remains the major causes for failure of treatment in NPC patients. Therefore, finding new specific drug targets for treatment interventions are urgently needed. Here, we report three potential ZLMP1-C affibody molecules (ZLMP1-C15, ZLMP1-C114 and ZLMP1-C277) that showed specific binding interactions for recombinant and native EBV LMP1 as determined by epitope mapping, co-localization and co-immunoprecipitation assays. The ZLMP1-C affibody molecules exhibited high antitumor effects on EBV-positive NPC cell lines and displayed minimal cytotoxicity towards EBV-negative NPC cell line. Moreover, ZLMP1-C277 showed higher antitumor efficacy than ZLMP1-C15 and ZLMP1-C114 affibody molecules. The ability of ZLMP1-C277 decrease the phosphorylation levels of up-stream activator phospho-Raf-1(Ser338), phospho-MEK1/2(Ser217/Ser221), phospho-ERK1/2(Thr202/Thr204), thereby leading to downstream suppression of phospho-p90RSK(Ser380) and transcription factor c-Fos. Importantly, tumor growth was reduced in tumor-bearing mice treated with ZLMP1-C277 and caused no apparent toxicity. Taken together, our findings provide evidence that ZLMP1-C277 as a promising therapeutic agent in EBV-associated NPC.
Development and validation of nomograms for predicting the risk probability of carbapenem resistance and 28-day all-cause mortality in gram-negative bacteremia among patients with hematological diseases
Authors: Jian Xing , Du Shuaixian , Zhou Xi , Xu Ziwei , Wang Kejing , Dong Xin , Hu Junbin , Wang Huafang
Published: January 2023

Objectives

Gram-negative bacteria (GNB) bloodstream infections (BSIs) are the most widespread and serious complications in hospitalized patients with hematological diseases. The emergence and prevalence of carbapenem-resistant (CR) pathogens has developed into a considerable challenge in clinical practice. Currently, nomograms have been extensively applied in the field of medicine to facilitate clinical diagnosis and treatment. The purpose of this study was to explore risk indicators predicting mortality and carbapenem resistance in hematological (HM) patients with GNB BSI and to construct two nomograms to achieve personalized prediction.

Methods

A single-center retrospective case-control study enrolled 244 hospitalized HM patients with GNB-BSI from January 2015 to December 2019. The least absolute shrinkage and selection operator (LASSO) regression analysis and multivariate logistic regression analysis were conducted to select potential characteristic predictors of plotting nomograms. Subsequently, to evaluate the prediction performance of the models, the prediction models were internally validated using the bootstrap approach (resampling = 1000) and 10-fold cross validation.

Results

Of all 244 eligible patients with BSI attributed to GNB in this study, 77 (31.6%) were resistant to carbapenems. The rate of carbapenem resistance exhibited a growing tendency year by year, from 20.4% in 2015 to 42.6% in 2019 (p = 0.004). The carbapenem resistance nomogram constructed with the parameters of hypoproteinemia, duration of neutropenia ≥ 6 days, previous exposure to carbapenems, and previous exposure to cephalosporin/β-lactamase inhibitors indicated a favorable discrimination ability with a modified concordance index (C-index) of 0.788 and 0.781 in both the bootstrapping and 10-fold cross validation procedures. The 28-day all-cause mortality was 28.3% (68/240). The prognosis nomogram plotted with the variables of hypoproteinemia, septic shock, isolation of CR-GNB, and the incomplete remission status of underlying diseases showed a superior discriminative ability of poorer clinical prognosis. The modified C-index of the prognosis nomogram was 0.873 with bootstrapping and 0.887 with 10-fold cross validation. The decision curve analysis (DCA) for two nomogram models both demonstrated better clinical practicality.

Conclusions

For clinicians, nomogram models were effective individualized risk prediction tools to facilitate the early identification of HM patients with GNB BSI at high risk of mortality and carbapenem resistance.
HAS-BLED vs. ORBIT scores in anticoagulated patients with atrial fibrillation: A systematic review and meta-analysis
Authors: Liu Xuyang , Wang Shengnan , He Wenfeng , Guo Linjuan
Published: January 2023

Background

The 2021 UK National Institute for Health and Care Excellence guidelines tend to recommend the ORBIT score for predicting bleeding risk in patients with atrial fibrillation (AF) with anticoagulants. Herein, we comprehensively re-assessed the predicted abilities of the HAS-BLED vs. ORBIT score since several newly published data showed different findings.

Methods

We comprehensively searched the PubMed electronic database until December 2021 to identify relevant studies reporting the ORBIT vs. HAS-BLED scores in anticoagulated patients with AF. Their predicted abilities were assessed using the C-index, reclassification, and calibration analysis.

Results

Finally, 17 studies were included in this review. In the pooled analysis, the ORBIT score had a C-index of 0.63 (0.60–0.66), 0.59 (0.53–0.66), and 0.57 (0.48–0.67) for major bleeding, any clinically relevant bleeding, and intracranial bleeding, respectively, while the HAS-BLED score had a C-index of 0.61 (0.59–0.63), 0.59 (0.56–0.63), and 0.57 (0.51–0.64) for major bleeding, any clinically relevant bleeding, and intracranial bleeding, respectively. There were no statistical differences in the accuracy of predicting these bleeding events between the two scoring systems. For the outcome of major bleeding, the subgroup analyses based on vitamin K antagonists vs. direct oral anticoagulants suggested no differences in the discrimination ability between the HAS-BLED and ORBIT scores. Reclassification and calibration analyses of HAS-BLED vs. ORBIT should be further assessed due to the limited and conflicting data.

Conclusion

Our current findings suggested that the HAS-BLED and ORBIT scores at least had similar predictive abilities for major bleeding risk in anticoagulated (vitamin K antagonists or direct oral anticoagulants) patients with AF, supporting the use of the HAS-BLED score in clinical practice.
A comparison of the changes in serum lactate between surgical repair and transthoracic device closure of ventricular septal defects in pediatric patients
Authors: Huang Jiang-Shan , Chen Yu-Kun , Lin Shi-Hao , Chen Qiang , Cao Hua , Zheng Yi-Rong
Published: January 2023

Objective

The purpose of this study was to compare the changes in serum lactate between surgical repair and transthoracic device closure of ventricular septal defects (VSDs) in pediatric patients.

Methods

This study was a retrospective analysis, and 314 pediatric patients with simple VSD from October 2019 to October 2021 were selected. The patients were divided into the S group (surgical repair) and the D group (transthoracic device closure). The serum lactate value at ICU admission and 6 h after operation, as well as the highest serum lactate value were collected, and the 6-h serum lactate clearance rate was calculated.

Result

Through propensity score matching, 43 pairs of cases were successfully matched. Compared with the S group, the D group had a shorter operation duration, ventilation duration, and ICU duration, as well as a lower drainage volume and total hospitalization cost. There was no significant difference between the two groups in the initial and highest serum lactate values after VSD closure, while the 6-h serum lactate value in the D group was significantly lower than that in the S group, and the 6-h serum lactate clearance rate in the D group was five times faster than that in the S group. In addition, the 6-h serum lactate clearance rate in the S group was mainly related to the operation time, CPB time, and ventilation time, while the 6-h serum lactate clearance rate in the D group was only related to the operation time.

Conclusion

The initial and highest serum lactate levels were not significantly different between surgical repair and transthoracic device closure of VSD, but the 6-h serum lactate clearance rate of device closure was five times faster than that of surgical repair.
Application of the in-situ stress testing technology for the design of operating pressure of underground gas storage reservoir
Authors: Wang Qun-yi , Shang Lin , Xin Chun-yan , Sun Yan-chun , Gao Guang-liang , Wang Miao , Gu Xiao
Published: January 2023

The appropriate design of the operating pressure of underground gas storages (UGSs) is of great significance to their safe and profitable operation. In situ stress is basic data for determining the upper limit pressure of UGSs, analyzing fault stability in reservoir areas, and evaluating trap tightness. Generally, the design of the upper limit gas injection pressure of UGSs is a comprehensive geomechanical problem. After research and comparison of measurement methods, it is believed that the measurement of in situ stress induced by hydraulic fracturing can accurately obtain the in situ stress value near the wellbore, and having knowledge about the reservoir stress path will considerably decrease the risk of reservoir and cap rock instability during gas injection and production. Taking Well C1, an oil reservoir-type UGS in Block M, eastern China as an example, this paper introduces the use of hydraulic fracturing (HF) in situ stress testing technology to obtain the minimum principal stress values of the caprock, reservoir and floor intervals of Well C1. The measured minimum principal stress of the caprock is 32.8–36.8 MPa. Because it is an old well, the minimum principal stress of the reservoir is 33.7–34.2 MPa after correction of the in situ stress measurement according to the theory of elasticity. Based on the comprehensive analysis of the measured in situ stress data, it is believed that the safe upper limit of the reservoir-type gas storage in Block M is 27.2 MPa.
Application of the improved dynamical–Statistical–Analog ensemble forecast model for landfalling typhoon precipitation in Fujian province
Authors: Su Zhizhong , Ma Yunqi , Jia Li , Ren Fumin , Ding Chenchen
Published: January 2023

The forecasting performance of the Dynamical–Statistical–Analog Ensemble Forecast (DSAEF) model for Landfalling Typhoon [or tropical cyclone (TC)] Precipitation (DSAEF_LTP), with new values of two parameters (i.e., similarity region and ensemble method) for landfalling TC precipitation over Fujian Province, is tested in four experiments. Forty-two TCs with precipitation over 100 mm in Fujian Province during 2004–2020 are chosen as experimental samples. Thirty of them are training samples and twelve are independent samples. First, simulation experiments for the training samples are used to determine the best scheme of the DSAEF_LTP model. Then, the forecasting performance of this best scheme is evaluated through forecast experiments. In the forecast experiments, the TSsum (the sum of threat scores for predicting TC accumulated rainfall of ≥250 mm and ≥100 mm) of experiments DSAEF_A, B, C, D is 0.0974, 0.2615, 0.2496, and 0.4153, respectively. The results show that the DSAEF_LTP model performs best when both adding new values of the similarity region and ensemble method (DSAEF_D). At the same time, the TSsum of the best performer of numerical weather prediction (NWP) models is only 0.2403. The improved DSAEF_LTP model shows advantages compared to the NWP models. It is an important method to improve the predictability of the DSAEF_LTP model by adopting different schemes in different regions.
Estimation of the ground-level SO2 concentration in eastern China based on the LightGBM model and Himawari-8 TOAR
Authors: Xu Tan , Chen Bin , Ren Yuxiang , Zhao Lin , Hu Jiashun , Wang Yufei , Song Zhihao , Li Xiang
Published: January 2023

Sulfur dioxide (SO2) is one of the main pollutants in China’s atmosphere, but the spatial distribution of ground-based SO2 monitors is too sparse to provide a complete coverage. Therefore, obtaining a high spatial resolution of SO2 concentration is of great significance for SO2 pollution control. In this study, based on the LightGBM machine learning model, combined with the top-of-atmosphere radiation (TOAR) of Himawari-8 and additional data such as meteorological factors and geographic information, a high temporal and spatial resolution TOAR-SO2 estimation model in eastern China (97–136°E, 15–54°N) is established. TOAR and meteorological factors are the two variables that contribute the most to the model, and both of their feature importance values exceed 30%. The TOAR-SO2 model has great performance in estimating ground-level SO2 concentrations with 10-fold cross validation R2 (RMSE) of 0.70 (16.26 μg/m3), 0.75 (12.51 μg/m3), 0.96 (2.75 μg/m3), 0.97 (2.16 μg/m3), and 0.97 (1.71 μg/m3) when estimating hourly, daily, monthly, seasonal, and annual average SO2. Taking North China as main study area, the annual average SO2 is estimated. The concentration of SO2 in North China showed a downward trend since 2016 and decreased to 15.19 μg/m3 in 2020. The good agreement between ground measured and model estimated SO2 concentrations highlights the capability and advantage of using the model to monitor spatiotemporal variations of SO2 in Eastern China.
Shear behaviors of recycled aggregate sand in constant volume simple shear tests interrelated with particle shape
Authors: Chen Guanyu , Wu Dazhi , Wang Zhe , Liu Shu , Zhou Pan , Hu Juntao
Published: January 2023

Compared with quartz sand, recycled aggregate sand is characterized by the high liquefaction and shear resistance because of its irregular particle shape. However, the interrelationship between its particle shape and shear behaviors is seldom investigated. This paper investigates the role of the particle shape on the shear behaviors of recycled aggregate sand by conducting a series of monotonic and cyclic simple shear tests under undrained constant volume conditions. The particles’ morphology parameters are assessed in terms of sphericity, roundness and regularity with microscopic observation and image processing. According to the experimental results, the recycled aggregate sand with irregular shapes mobilizes greater gradients of the flow liquefaction lines under monotonic shear conditions. The irregularity of the particle shape also leads to greater peak shear stress and dynamic shear modulus, indicating stronger shear and liquefaction resistances under the cyclic shearing. Furthermore, the interrelationships between the peak shear stress, dynamic shear modulus and particle shape of the samples are revealed and established by well fitted functions, which could serve as references for the selection of recycled aggregate sand and corresponding designs of the foundation.
Settlement analysis of the giant open caisson during the construction of the Changtai Yangtze River Bridge
Authors: Guo Mingwei , Dong Xuechao , Yang Zhi
Published: January 2023

With the increasing size of open caissons in large-span bridge projects, the overall settlement of giant open caissons is vital to the safe construction of bridge superstructures. Taking the engineering case of the Changtai Yangtze River Bridge, the overall deformation of an open caisson was studied during the construction stage of the bridge’s superstructures. First, the theoretical layer-wise summation method was utilized to analyze the settlement of the open caisson. Then, a 3-D finite element model was established to simulate the installation stage of the bridge superstructure. Finally, a large centrifuge model test was performed to obtain the deformation of the open caisson at each step of bridge’s construction. The results of these approaches demonstrated that final settlements were quite consistent—approximately 225 mm when the bridge superstructure was completely installed—and the settlement deformation curve could be divided into three stages: slowly increasing, rapid, and stabilizing. This study can provide significant guidance for the construction of the Changtai Yangtze River Bridge and be a reference for similar open caisson engineering projects.
Automatic retrieval of volcanic SO2 emission source from TROPOMI products
Authors: Markus Balazs , Valade Sébastien , Wöllhaf Manuel , Hellwich Olaf
Published: January 2023

Volcanic sulfur dioxide (SO2) satellite observations are key for monitoring volcanic activity, and for mitigation of the associated risks on both human health and aviation safety. Automatic analysis of this data source, including robust source emission retrieval, is in turn essential for near real-time monitoring applications. We have developed fast and accurate SO2 plume classifier and segmentation algorithms using classic clustering, segmentation and image processing techniques. These algorithms, applied to measurements from the TROPOMI instrument onboard the Sentinel-5 Precursor platform, can help in the accurate source estimation of volcanic SO2 plumes originating from various volcanoes. In this paper, we demonstrate the ability of different pixel classification methodologies to retrieve SO2 source emission with a good accuracy. We compare the algorithms, their strengths and shortcomings, and present plume classification results for various active volcanoes throughout the year 2021, including examples from Etna (Italy), Sangay and Reventador (Ecuador), Sabancaya and Ubinas (Peru), Scheveluch and Klyuchevskoy (Russia), as well as Ibu and Dukono (Indonesia). The developed algorithms, shared as open-source code, contribute to improving analysis and monitoring of volcanic emissions from space.
Linearly combined ground motion model using quadratic programming for low- to mid-size seismicity region: South Korea
Authors: Jang Dongil , Ahn Jae-Kwang , Kim Tae-Woong , Kwak Dong Youp
Published: January 2023

This study suggests a linearly combined ground motion model (GMM) optimized for the within-rock conditions of South Korea. Ground motions recorded by accelerometers positioned in within-rock layers are used as target intensity measures (IMs), and five local GMMs and four global GMMs are used as candidates for combination. Optimization, which seeks to find a weight vector minimizing the uncertainty of the combined model, is performed using the quadratic programming (QP) technique, which provides very fast and solid results for the linear combination problem. This study illustrates how to use the QP technique for the linear combination problems. Also, we suggest optimized weight vectors for GMM combinations for two conditions: 1) the IM prediction of a scenario event without observations and 2) the IM prediction of a past event with observations. Among the local and global GMMs considered, JB03, Eea15, JH21, and BSSA14 are selected as the best four GMMs for the first condition, and Jea02, JB03, JH21, and CB14 are selected as the best four GMMs for the second condition. The combined model reduces the standard deviation of residuals in natural logarithms by 10% and 8% for the first and second conditions, respectively, compared to the best individual GMM at each period. Among the GMMs considered, the prediction by Eea15 is only applicable for magnitudes less than 5. Hence, for large magnitude (Mw > 5) prediction, CB14 is recommended instead of Eea15 for the best four models for the first condition.
Seismic response of a mid-story-isolated structure considering soil–Structure interaction in sloping ground under three-dimensional earthquakes
Authors: Wan Feng , Li Cheng , Li Hong , Liu Dewen , Yao Shunzhong , Lei Min
Published: January 2023

A mid-story-isolated structure is developed from a base-isolated structure. Mid-story-isolated structures located in sloping ground have become a research hotspot in recent years. It is important to consider the soil–structure interaction (SSI) effects and multi-dimensional earthquakes on these structures. This paper established a model of the mid-story-isolated structure considering SSI in sloping ground. An elastic–plastic time history analysis was carried out under the one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) earthquakes. Under 3D earthquakes, the traditional 2D isolated bearing has limited damping capacity. Therefore, two kinds of 3D isolated bearings were designed. Results show that the seismic response of the mid-story-isolated structure considering SSI in sloping ground can be amplified compared with that of the mid-story-isolated structure without considering SSI. The seismic response of the structure under 3D earthquakes is more significant than that under 2D earthquakes and 1D earthquakes. For the two kinds of 3D isolated bearings, the minimum reduction rate of tensile and compressive stress is about 46% compared with that of the traditional 2D isolated bearings. When the 3D isolated bearings are used, the stress of the soil foundation decreases, which is more conducive to the stability of the soil foundation.
A revised method with a temperature constraint for assimilating satellite-derived humidity in forecasting sea fog over the Yellow Sea
Authors: Gao Xiaoyu , Gao Shanhong , Li Ziru , Wang Yongming
Published: January 2023

Numerical forecast of sea fog is very challenging work because of its high sensitivity to model initial conditions. For better depicting the humidity structure of the marine atmospheric boundary layer (MABL), Wang et al. (2014) assimilated satellite-derived humidity from sea fog at its initial stage over the Yellow Sea (W14 method), using an extended three-dimensional variational data assimilation (3DVAR) with the Weather Research and Forecasting model (WRF). This article proposes a revised version of the W14 method. The major ingredient of the revision is the inclusion of a temperature constraint into the satellite-derived humidity, not only for the missed fog area that the W14 method primarily considers, but also for the false fog area that is not handled in the W14 method. The numerical experiment results of 10 sea fog cases over the Yellow Sea show that the revised method can effectively alleviate the wet bias occasionally occurring in the W14 method, resulting in an improvement by about 15% for an equitable threat score of the simulated fog area. In addition, a detailed case study is conducted to illustrate the working mechanism of the revised method, including sensitivity experiments focusing on the roles of two kinds of background error covariances (CV5 and CV6) in the assimilation by the WRF-3DVAR. The results suggest that CV6 with multivariate cross-correlation is probably more beneficial to the revised method’s performance.
Tin-bearing magnetite with nanoscale Mg-Si defects: Evidence for the early stages of mineralization in a skarn system
Authors: Xu Jing , Ciobanu Cristiana L. , Cook Nigel J. , Slattery Ashley D. , Ehrig Kathy , Wade Benjamin P. , Courtney-Davies Liam , Wang Liyuan
Published: January 2023

Tin-bearing magnetite is reported from several types of magmatic-hydrothermal ore deposits. The question of whether tin is incorporated within solid solution, as Sn4+, or as nanoinclusions remains open, however. We report a micron- to nanoscale investigation of Sn (Mg, Si)-bearing magnetite from serpentinite in the Dulong Zn-Sn-In skarn, South China, with the dual aims of understanding the mechanisms involved in accommodating Sn and associated elements into the Fe-oxide, and the inferences that this carries for constraining the early stages of skarn formation. Magnetite preserves a range of textures that record the evolution of metasomatism during prograde growth of grain cores and retrograde rim replacement. Observations reveal the presence of chondrodite and sellaite (MgF2) as nanoscale inclusions preserved in magnetite. This implies initiation of the Dulong mineralizing system during a humite-bearing, magnesium skarn stage. Magnesium-Si defects, forming along (110) planes prior to Sn-enrichment, are recognized for the first time. Release of high volatile, F-rich fluids is interpreted to lead to precipitation of cassiterite inclusions along <111*> directions in magnetite.
The future treatment for type 1 diabetes: Pig islet- or stem cell-derived β cells?
Authors: Naqvi Raza Ali , Naqvi Afsar Raza , Singh Amar , Priyadarshini Medha , Balamurugan Appakalai N. , Layden Brian T.
Published: January 2023

Replacement of β cells is only a curative approach for type 1 diabetes (T1D) patients to avoid the threat of iatrogenic hypoglycemia. In this pursuit, islet allotransplantation under Edmonton’s protocol emerged as a medical miracle to attain hypoglycemia-free insulin independence in T1D. Shortage of allo-islet donors and post-transplantation (post-tx) islet loss are still unmet hurdles for the widespread application of this therapeutic regimen. The long-term survival and effective insulin independence in preclinical studies have strongly suggested pig islets to cure overt hyperglycemia. Importantly, CRISPR-Cas9 technology is pursuing to develop “humanized” pig islets that could overcome the lifelong immunosuppression drug regimen. Lately, induced pluripotent stem cell (iPSC)-derived β cell approaches are also gaining momentum and may hold promise to yield a significant supply of insulin-producing cells. Theoretically, personalized β cells derived from a patient’s iPSCs is one exciting approach, but β cell-specific immunity in T1D recipients would still be a challenge. In this context, encapsulation studies on both pig islet as well as iPSC–β cells were found promising and rendered long-term survival in mice. Oxygen tension and blood vessel growth within the capsules are a few of the hurdles that need to be addressed. In conclusion, challenges associated with both procedures, xenotransplantation (of pig-derived islets) and stem cell transplantation, are required to be cautiously resolved before their clinical application.
Predictive model for diabetic retinopathy under limited medical resources: A multicenter diagnostic study
Authors: Yang Yanzhi , Tan Juntao , He Yuxin , Huang Huanhuan , Wang Tingting , Gong Jun , Liu Yunyu , Zhang Qin , Xu Xiaomei
Published: January 2023

Background

Comprehensive eye examinations for diabetic retinopathy is poorly implemented in medically underserved areas. There is a critical need for a widely available and economical tool to aid patient selection for priority retinal screening. We investigated the possibility of a predictive model for retinopathy identification using simple parameters.

Methods

Clinical data were retrospectively collected from 4, 159 patients with diabetes admitted to five tertiary hospitals. Independent predictors were identified by univariate analysis and least absolute shrinkage and selection operator (LASSO) regression, and a nomogram was developed based on a multivariate logistic regression model. The validity and clinical practicality of this nomogram were assessed using concordance index (C-index), area under the receiver operating characteristic curve (AUROC), calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC).

Results

The predictive factors in the multivariate model included the duration of diabetes, history of hypertension, and cardiovascular disease. The three-variable model displayed medium prediction ability with an AUROC of 0.722 (95%CI 0.696-0.748) in the training set, 0.715 (95%CI 0.670-0.754) in the internal set, and 0.703 (95%CI 0.552-0.853) in the external dataset. DCA showed that the threshold probability of DR in diabetic patients was 17-55% according to the nomogram, and CIC also showed that the nomogram could be applied clinically if the risk threshold exceeded 30%. An operation interface on a webpage (https://cqmuxss.shinyapps.io/dr_tjj/) was built to improve the clinical utility of the nomogram.

Conclusions

The predictive model developed based on a minimal amount of clinical data available to diabetic patients with restricted medical resources could help primary healthcare practitioners promptly identify potential retinopathy.
Integrated photovoltaic storage joint smoothing strategy based on simultaneous perturbation stochastic approximation algorithm
Authors: Yujing He , Jie Chen , Xueqin Tian , Yafei Wang
Published: January 2023

In order to realize the real-time control of photovoltaic power generation smoothly connected to the grid under the condition that the energy storage equipment can operate safely, a control strategy combining the simultaneous perturbation stochastic approximation (SPSA) algorithm with rule control is designed. Firstly, the photovoltaic data are processed to extract the data characteristics of the power ramp, and then the grid-connected reference power is obtained through SPSA algorithm. Secondly, considering the state of charge (SOC) of energy storage equipment and the safe operating power range of hydrogen storage equipment, 24 hybrid energy storage power allocation rules are formulated by using the rule control method. Finally, according to the sampling data of every 10 s interval in typical day, the simulation is carried out on MATLAB/simulink platform. The results show that, compared with the first-order low-pass filtering algorithm and recursive fuzzy neural network (RFNN) algorithm, the SPSA algorithm has stronger smoothing ability, and the rule control can also complete the allocation according to the characteristics of the hybrid storage device while ensuring its normal operation.
Economic benefit evaluation model of distributed energy storage system considering custom power services
Authors: Fang Jun , Pei Zhigang , Chen Tianheng , Peng Zhihui , Kong Shiwei , Chen Jiaming , Huang Shanhe
Published: January 2023

This paper proposes an economic benefit evaluation model of distributed energy storage system considering multi-type custom power services. Firstly, based on the four-quadrant operation characteristics of the energy storage converter, the control methods and revenue models of distributed energy storage system to provide reactive power compensation, new energy consumption, peak-valley arbitrage and other customized power services are analyzed. Secondly, an economic benefit evaluation model of custom power services is formulated, considering the life cycle degradation cost, investment payback period, net present value, and internal return rate of energy storage. Finally, demonstrate the effectiveness and superior performance of the proposed methodology through comparative studies on the economic benefits and practical value. The influence of reserve capacity ratio of energy storage converter, additional price for power quality management, peak-valley price difference, battery cost and project cycle on the annual return and internal rate of return is revealed through the sensitivity analysis, which provides the decision-making reference for battery selection and capacity allocation of distributed energy storage system participating in various custom power services.
Machine learning predictive model for electronic slurries for smart grids
Authors: Liu Xiaofeng , Yan Zhiyong , Leng Fangling , Bao Yubin , Huang Yijie
Published: January 2023

Electricity is a fundamental energy that is essential to the growth of industrialization and human livelihood. Electric power resources can be used to meet living and production needs more steadily, effectively, and intelligently with the help of an intelligent power grid. The accuracy and stability of component requirements have increased due to the rapid growth of intelligent power networks. One of the fundamental components for component production is electronic slurry, so optimizing electronic paste’s properties is crucial for smart grids. In the field of materials science, the process of discovering new materials is drawn out and chance-based. The traditional computation process takes a very long time. Scientists have recently applied machine learning techniques to anticipate material properties and hasten the creation of novel materials. These techniques have proven to offer amazing benefits in a variety of fields. Machine learning techniques, such as the cross-validated nuclear ridge regression algorithm to predict double perovskite structure materials and the machine learning algorithm to predict the band gap value of chalcopyrite structure materials, have demonstrated excellent performance in predicting the band gap value of some specific material structures. The performance value of other structural materials cannot be predicted directly by this targeted prediction model; it can only forecast the band gap value of a single structural material. This study presents two model techniques for dividing data sets into element kinds using regression models and dividing data sets into clusters using regression models, both of which are based on the fundamental theory of physical properties, band gap theory. This plan is more efficient than the classification-regression model. The MAE dropped by 0.0455, the MSE dropped by 0.0425, and the R2 rose by 0.022. The effectiveness of machine learning in forecasting the material band gap value has increased, and the model trained by this design strategy to predict the material band gap value is more reliable than previously.
The National Criticality Experiments Research Center and its role in support of advanced reactor design
Authors: Thompson Nicholas W. , Maldonado Alexis , Cutler Theresa E. , Trellue Holly R. , Amundson Kelsey M. , Rao Dasari Venkateswara , Goda Joetta M. , Grove Travis J. , Hayes David K. , Hutchinson Jesson D. , Kistle Hadyn M. , Kostelac Cole M. , Lamproe Juliann R. , Matthews Christopher , McKenzie George , McMath Garrett E. , McSpaden Alexander T. , Sanchez Rene G. , Stolte Kristin N. , Walker Jessie L. , Weldon Robert , Whitman Nicholas H.
Published: January 2023

The National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site (NNSS) in the Device Assembly Facility (DAF) and operated by Los Alamos National Laboratory (LANL) is the only general purpose critical experiments facility in the United States. Experiments from subcritical to critical and above prompt critical are carried out at NCERC on a regular basis. In recent years, NCERC has become more involved in experiments related to nuclear energy, including the Kilopower/KRUSTY demonstration and the recent Hypatia experiment. Multiple nuclear energy related projects are currently ongoing at NCERC. This paper discusses NCERC’s role in advanced reactor design and how that role may change in the future.
Optimization of volume fracturing technology for shallow bow horizontal well in a tight sandstone oil reservoir
Authors: Gao Chaoli , Cheng Shiqing , Wang Mingwei , Wu Wen , Gao Zhendong , Li Song , Meng Xuangang
Published: January 2023

The physical property of Chang 6 reservoir in Yanchang oilfield is poor, and the heterogeneity is strong. Multistage fracturing of horizontal wells is easy to form only one large horizontal fracture, but it is difficult to control the fracture height and length. The new mining method of “bow horizontal well + multistage horizontal joint” can effectively increase the multistage horizontal joint’s spatial position, which improves the drainage area and stimulation efficiency of oil wells. Due to the reservoir’s low permeability and strong heterogeneity, the single well mode of “bow horizontal well + multistage horizontal fracture” cannot effectively produce Chang 6 reservoir. To improve the production degree of the g 6 reservoir, the fracture model is established using equivalent conductivity and the multigrid method. The pressure response functions of horizontal wells and volume fracturing horizontal wells are established by using the source function, and the relationship between reservoir permeability and starting pressure gradient in the block is calculated. On this basis, the reservoir productivity equation of the block is established, which provides a basis for optimizing the fracturing design parameters of horizontal wells. It is proposed that the flow unit should be considered in the design of fracturing parameters of horizontal fractures, the number of fractures should comprehensively consider whether the fractures can make each flow unit be used, and have large controlled reserves, and the scale of fracturing should comprehensively consider the output and cost. The fracture network model is established by using equivalent conductivity and multi-gridthod, and the volume fracturing design parameters of horizontal wells are optimized, considering the seepage characteristics of the flow unit. The fracturing design parameters of the horizontal section are further defined, which provides a theoretical basis for the efficient development of shallow tight reservoirs.
Mechanical characteristics and damage evolution of granite under freeze–thaw cycles
Authors: Chen Dun , Li Guoyu , Li Jinming , Du Qingsong , Zhou Yu , Mao Yuncheng , Qi Shunshun , Tang Liyun , Jia Hailiang , Peng Wanlin
Published: January 2023

Rocks in cold regions experience freeze–thaw (F–T) cycles, which have a significant impact on their mechanical properties, causing a series of engineering challenges that threaten engineering stability. To investigate the mechanical characteristics and damage evolution of granite under the influence of F–T cycles, the microstructural evolution and macroscopic mechanical properties of granite were analyzed by conducting P-wave velocity tests, computed tomography scanning, and uniaxial compression tests subjected to different F–T cycles. The results revealed the following: 1) the number of F–T cycles and saturated water content significantly impact on the mechanical properties of granite; 2) as the number of F–T cycles increases, the P-wave velocity, peak strength, elastic modulus, and coefficient of frost resistivity of granite gradually decrease, but the F–T damage values increase; 3) when the number of F–T cycles is less than 40 but within a certain range (0–100), the damage variable of granite increases rapidly, but then gradually tends to stabilize; 4) the damage gradually steadily spreads to the central region of the granite sample as the number of F–T cycles increases, and the ends and marginal regions of the granite samples are more susceptible to damage, and 5) three damage variables with different definitions (elastic modulus, density, and porosity) can be used to predict the degree of damage of granite under F–T cycles.
State asset management paradigm in the quasi-public sector and environmental sustainability: Insights from the Republic of Kazakhstan
Authors: Zhanbayev Rinat A. , Yerkin Albina Y. , Shutaleva Anna V. , Irfan Muhammad , Gabelashvili Kakhaberi , Temirbaeva G. R. , Chazova Irina Yu. , Abdykadyrkyzy Rimma
Published: January 2023

This study aims to improve state regulation and administration of quasi-state sector of environmental sustainability in the Republic of Kazakhstan within the social sustainability paradigm. This study is due to the need to search the balance of business interests, and efficient use of resources and their conservation on a global scale. The issues of state asset management are identified and ways to resolve them are proposed based on the corporate foresight methodology using the strategic planning mechanism. As a result of the analysis of the tools introduced into the practice of leading transnational corporations, the main directions are identified in which it is advisable to take measures aimed at streamlining and optimizing the quasi-public sector in the Republic of Kazakhstan. This article presents proposals for improving state regulation and administration of quasi-public companies in the Republic of Kazakhstan. The outcomes of this study can assist policymakers, experts, and stakeholders in gaining awareness about these problems while simultaneously improving sustainability practices.