bluuebunny/crossref_metadata_2025 huggingface dataset:
A Case Study on Recycling Industrial Wastewater with Nanofiltration Membrane Separation Technology
Authors: Deng Yiqiang , Bai Xiaoqian , Lin Jialong , Yang Linyan , Lin Yuqing , Lin Mingyue , Xiu Guangli
Published: December 2024

As pressure on water resources intensifies and stringent regulations for groundwater and surface water are enacted, wastewater recycling has emerged as a key research objective for many enterprises. In this study, based on the actual wastewater discharged from Eternal Electronic (Suzhou, China) Co., Ltd., the performance differences in different membrane materials in treating this wastewater were analyzed and compared. The NF90 membrane was ultimately selected as the most suitable choice for treating this wastewater with optimal operating conditions of 150 psi, 25 °C, and 1 L/min, respectively. All the indices of wastewater treatment can satisfy the standard of circulating cooling water. In addition, this work is closely combined with the practical applications by using an HCl solution (pH = 3–4) to clean the fouled membranes, thus effectively solving the membrane fouling in the treatment process. This approach not only satisfies the environmental management requirements of enterprises but also provides valuable insights for similar wastewater treatment projects.
Precipitation and Age-Hardening in Fe-25Co-15Mo Carbon-Free High-Speed Steel via Hot Isostatic Pressing
Authors: Lu Shiteng , Ge Xueyuan , Hu Qipeng , Gao Lei , Meng Yuan , Kuang Ya , Lu Lei
Published: December 2024

High resistance to tempering and extended service life are pivotal research directions for cutting tools utilized in the machining of industrial machine tool. The design of alloys and their manufacturing processes have become methods for the development of cutting tool materials. Carbon-free Fe-Co-Mo steel (FCM) has garnered attention due to its excellent magnetic properties and high-temperature performance, as well as its superior thermal conductivity, making it an ideal choice for applications in high-temperature and high-pressure environments. The µ-phase within this alloy exhibits exceptional high-temperature stability and resistance to aggregation. Its characteristics suggest that it has the potential to replace carbide reinforcement phases, which are prone to coarsening, in high-temperature applications of powder high-speed steel. This application of the µ-phase could lead to an enhancement in the resistance to tempering and the service life of powder metallurgy high-speed steel cutting tools. However, there is a relative scarcity of published research regarding the preparation of carbon-free high-speed steel via hot isostatic pressing (HIP) technology and the subsequent heat treatment processes. In this study, Fe-Co-Mo alloys reinforced with the intermetallic compound µ-phase were prepared at hot isostatic pressing sintering temperatures of 1200 °C, 1250 °C, and 1350 °C. Furthermore, to investigate the influence of the solid-solution treatment temperature on the microstructure and macroscopic properties of the alloy, the as-prepared materials were subjected to solution annealing treatment at different temperatures (1120 °C, 1150 °C, 1180 °C, and 1210 °C). The results demonstrate that by moderately reducing the sintering temperature, the segregation phenomenon of the reinforcing µ-phase was significantly reduced, leading to an optimization of the microstructural uniformity of the prepared sample, with the micro-scale µ-phase being uniformly dispersed within the α-Fe matrix. As the temperature of the solid-solution annealing increased, the microstructural uniformity was further enhanced, accompanied by a reduction in the quantity of the reinforcing phase and refinement of the grain size. Notably, after solid-solution annealing at 1180 °C, the hardness of the samples reached a peak value of 500.4 HV, attributed to the decrease in the reinforcing phase and grain refinement during the annealing process. Aging treatment at 600 °C for 3 h facilitated the uniform precipitation of the nano-scale µ-phase, resulting in a significant increase in sample hardness to approximately 900 HV. The prepared material exhibited excellent resistance to tempering, indicating its potential for application in high-temperature service environments.
Direct In Situ Fabrication of Strong Bonding ZIF-8 Film on Zinc Substrate and Its Formation Mechanism
Authors: Wang Haidong , Liu Jie , Liu Baosheng , Zhang Zhechao , Ren Xiaoxia , Wang Xitao , Wu Pengpeng , Zhang Yuezhong
Published: December 2024

There is much promise for creating metal organic framework (MOF) films on metal substrates in fields including sensing and electrical conduction. For these applications, direct production of MOF films with strong bonding on metal substrates is extremely desirable. In this study, a simple one-step method without the need for additives or pre-modification is used to directly create zeolitic imidazolate framework-8 (ZIF-8) films with strong bonding on zinc substrate. The formation mechanisms of ZIF-8 film are analyzed. The strong bonding ZIF-8 film can be attributed to an in-situ grown ZnO interlayer between the ZIF-8 and substrate. The growth process shows the formation time of zinc oxide on the substrate, which is subsequently covered by ZIF-8 crystals. The ZnO interlayer results from a combination of decomposition products of the solvent and the zinc ions. Furthermore, the ZnO interlayer serves as a sacrificial precursor for the in-situ nucleation and continuous growth of ZIF-8 film. It serves as an anchoring site between ZIF-8 film and substrate, resulting in strong adhesion. This paper describes a simple and straightforward production process that is expected to provide a theoretical basis for the laboratory preparation of ZIF films.
A Study on the Influence of the Rotating Speed and Load on the Grain Structure and Wear Properties of Bearing Steel GCr15 During Bearing Service
Authors: Cui Li , Wang Donghui , Zhang Chenxu , Wang Xin
Published: December 2024

In order to study the wear failure mechanism and structure evolution law of bearings under different speeds and contact loads, an elastoplastic model of a 7009AC bearing was established in this paper. The stress, temperature rise and grain size during dry friction and wear of the bearing inner ring were simulated with the finite element method. The effects of the inner ring speed, load pressure and other parameters on the wear rate were studied. The relationship between the grain size and yield strength of GCr15 bearing steel was obtained. The effects of the initial grain size, rotational speed and load pressure on the bearing wear failure were studied. The evolutions of the grain size during service were predicted by means of the dynamic grain recrystallization (DRX), static grain recrystallization (SRX) and grain growth (GG) subprogram. The results show that the contact stress has a more significant effect on the early failure wear than the bearing speed, and the increase in the contact stress will aggravate the wear rate of the bearing inner ring. Under the same working conditions, the smaller the grain size, the more significant the influence of the cycle times on wear was. The heat-affected zone produced a local high temperature in the contact area, temperature flashes of up to 580 °C could occur in the central contact area, and the temperature decreased gradually with the increase in the depth from the contact area. It is noteworthy that both the surface and the subsurface of the material produced grain refinement; the grain size was refined from 20 μm to 0.4–12 μm under different working conditions. And the degree of refinement of the subsurface was higher than that of the surface.
A Comparative Study on the Wear Resistance of CrNiMo Cast Steels Under Dynamic Load and Ring Block Conditions
Authors: Li Chaoyong , Li Yi , Wang Mingli , Zhu Pengxiao , Tang Cai , Yang Xu , Zhang Jinyong , Qi Yulong
Published: December 2024

Low-alloy CrNiMo cast steels are often used in the caterpillar boards of excavators in mining engineering machinery due to their good mechanical properties and low cost. Three CrNiMo cast steels with different carbon contents (0.20%, 0.29%, and 0.35% by weight) were developed in this work. The mechanical properties of ingots of these cast steels can be optimized by heat-treated quenching and tempering (QT) and surface induction hardening (QTIH). The wear behavior of QT and QTIH specimens was evaluated under dynamic load and ring block conditions. The results show that the QT specimens exhibit a good mechanical performance and wear resistance. Compared to the QT specimens, the wear resistance can be further improved by QTIH treatment. The wear weight loss of QTIH specimens decreased by 42.7% and 73.2% under dynamic load and ring block wear tests, respectively. Additionally, the strength increased while plasticity and toughness decreased with increasing carbon content. Notably, when the carbon content is 0.29%, the CrNiMo cast steel exhibits an excellent combination of strength, ductility, and wear resistance.
Calcitriol Concentration in the Early Phase of Myocardial Infarction and Its Relation to Left Ventricular Ejection Fraction
Authors: Olędzki Szymon , Siennicka Aldona , Maciejewska-Markiewicz Dominika , Stachowska Ewa , Jakubiak Natalia , Kiedrowicz Radosław , Jakubczyk Karolina , Skonieczna-Żydecka Karolina , Gutowska Izabela , Kaźmierczak Jarosław
Published: December 2024

Vitamin D deficiency is one of the most common metabolic disorders in the European population. A low level of 25-OH vitamin D3 is related to an elevated risk of myocardial infarction (MI). The aim of our study was to examine the relationship between calcidiol and calcitriol serum concentration and left ventricular ejection fraction early after interventional treatment for acute coronary syndrome. A total of 80 patients diagnosed with MI, who underwent primary percutaneous coronary intervention, were included in the study. Blood samples for calcidiol, calcitriol, and vitamin D-binding protein were obtained 24 h after primary PCI and were measured using an enzyme-linked immunosorbent assay. Only 9% of patients had a proper level of 25-OHD3 in the serum (30–80 ng/mL). A total of 16% of patients revealed a suboptimal concentration of 25-OHD3 (20–30 ng/mL), and in 75% of patients, the concentration of 25-OHD3 was lower than 20 ng/mL. Moreover, patients with left ventricle ejection fraction of <40% had significantly lower concentrations of calcidiol and calcitriol. A low calcitriol serum concentration affects post-MI left ventricle ejection fraction early after myocardial infarction onset. It seems that 1.25(OH)D3 may contribute to acute myocardial infarction; however, there are insufficient clinical trials related to this topic, and the available evidence is mainly from in vitro studies. We hope these preliminary reports will provide a better understanding of post-MI.
Non-Targeted Metabolomics Analysis Reveals Metabolite Profiles Change During Whey Fermentation with Kluyveromyces marxianus
Authors: Gao Yansong , Gao Lei , Kang You , Yang Ge , Zhao Zijian , Zhao Yujuan , Li Shengyu
Published: December 2024

Background: Whey fermentation could produce bioactive substances with immunomodulatory effects, metabolic syndrome modulation, and antioxidant properties, thereby imparting functional characteristics to products and facilitating the development of novel foods with health-promoting potential. Methods: A non-targeted metabolomics approach using liquid chromatography–mass spectrometry (LC-MS) was employed to investigate changes in the metabolite profiles of whey fermented by Kluyveromyces marxianus strain KM812 over varying fermentation durations. Results: The findings demonstrated a progressive enrichment of metabolites over time. A total of 151 differential metabolites were identified and categorized primarily into amino acids, peptides, and analogues, fatty acids and conjugates, and carbohydrates and conjugates, as well as benzoic acids and derivatives. The highest relative content of whey metabolites was observed at 48 h of fermentation, with a cumulative increase of 1.45-fold, 1.49-fold, 3.39-fold, and 1.24-fold for peptides and amino acids, peptides, and analogues, fatty acids and conjugates, and carbohydrates and conjugates, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed associations with 23 specific metabolites and delineated 9 metabolic pathways, predominantly involved in amino acid and lipid metabolism. Conclusions: Based on the above, KM812 could effectively degrade macromolecular substances in whey into small molecules such as L-isoleucine, ornithine, betaine, α-linolenic acid, and palmitoleic acid, thereby influencing the nutritional and functional properties of whey. In-depth analysis of the metabolic products in KM812-fermented whey could provide a theoretical basis for the development of functional foods derived from small molecules in the future.
Near-Field Direct Writing Based on Piezoelectric Micromotion for the Programmable Manufacturing of Serpentine Structures
Authors: Chen Xun , Zhang Xuanzhi , Sun Jianfeng , Zhang Rongguang , Liang Xuanyang , Long Jiecai , Yao Jingsong , Chen Xin , Wang Han , Zhang Yu , Leng Jiewu , Lu Renquan
Published: December 2024

Serpentine microstructures offer excellent physical properties, making them highly promising in applications in stretchable electronics and tissue engineering. However, existing fabrication methods, such as electrospinning and lithography, face significant challenges in producing microscale serpentine structures that are cost-effective, efficient, and controllable. These methods often struggle with achieving precise control over fiber morphology and scalability. In this study, we developed a near-field direct writing (NFDW) technique incorporating piezoelectric micromotion to enable the precise fabrication of serpentine micro-/nanofibers by incorporating micromotion control with macroscopic movement. Modifying the fiber structure allowed for adjustments to the mechanical properties, including tunable extensibility and distinct characteristics. Through the control of the frequency and amplitude of the piezoelectric signal, the printing errors were reduced to below 9.48% in the cycle length direction and 6.33% in the peak height direction. A predictive model for the geometrical extensibility of serpentine structures was derived from Legendre’s incomplete elliptic integral of the second kind and incorporated an error correction factor, which significantly reduced the calculation errors in predicting geometric elongation, by 95.85%. The relationship between microstructure bending and biomimetic non-linear mechanical behavior was explored through tensile testing. By controlling the input electrical signals, highly ordered serpentine microstructures were successfully fabricated, demonstrating potential for use in biomimetic mechanical scaffolds.
Hospital Context Determinants of Variability in Healthcare-Associated Infection Prevalence: Multi-Level Analysis
Authors: Malheiro Rui , Gomes André Amaral , Fernandes Carlos , Fareleira Ana , Lebre Ana , Pascoalinho Dulce , Gonçalves-Pereira João , Paiva José-Artur , Sá-Machado Rita
Published: December 2024

Healthcare-associated infections (HAIs) represent a major challenge in patient safety that affects services disproportionally. This paper aimed to assess how the HAI prevalence varies between hospital services and what contextual characteristics may explain such variance. A cross-sectional study was conducted on adult patients in Portuguese hospitals, using data from the European point prevalence survey of HAI prevalence. The study variables included patient, structural, and process variables, tested as risk factors, with patients clustered in hospitals. Variables with a p-value ≤ 0.2 in univariate analyses were retested in a multivariable model. A total of 18,261 patients from 119 hospitals were included: 736 from 56 intensive care units (ICUs), 3160 from 72 surgical departments, and 8081 from 90 medical departments. The HAI prevalence was 7.9%, 5.9%, and 1.7%, respectively. In ICUs, only the number of devices was associated with the HAI prevalence. In surgical departments, age, comorbidities, being a specialized hospital, and a higher ratio of infection prevention and control (IPC) personnel were associated with higher SSI. The safety climate was associated with lower SSI. In medical departments, age and devices were positively associated, whereas a larger ratio of IPC nurses was negatively associated. These results may help implement targeted interventions to achieve optimal results in each department.
Evaluating the Effects of Sugar Shift® Symbiotic on Microbiome Composition and LPS Regulation: A Double-Blind, Placebo-Controlled Study
Authors: García Gissel , Soto Josanne , Netherland Michael , Hasan Nur A. , Buchaca Emilio , Martínez Duniesky , Carlin Martha , de Jesus Cano Raúl
Published: December 2024

(1) Background: This study evaluated the effects of BiotiQuest® Sugar Shift®, a novel probiotic formulation, for its impact on gut microbiome composition and metabolic health in type 2 diabetes mellitus (T2D). T2D is characterized by chronic inflammation and gut microbiome imbalances, yet the therapeutic potential of targeted probiotics remains underexplored. (2) Methods: In a 12-week randomized, double-blind, placebo-controlled trial, 64 adults with T2D received either Sugar Shift or placebo capsules twice daily. Each dose provided 18 billion CFU of eight GRAS-certified bacterial strains and prebiotics. Clinical samples were analyzed for metabolic markers, and microbiome changes were assessed using 16S rRNA sequencing and metagenomics. (3) Results: Sugar Shift significantly reduced serum lipopolysaccharide (LPS) levels, improved insulin sensitivity (lower HOMA-IR scores), and increased short-chain fatty acid (SCFA)-producing genera, including Bifidobacterium, Faecalibacterium, Fusicatenibacter, and Roseburia. Pro-inflammatory taxa like Enterobacteriaceae decreased, with reduced LPS biosynthesis genes and increased SCFA production genes. The Lachnospiraceae:Enterobactericeae ratio emerged as a biomarker of reduced inflammation. (4) Conclusions: These findings demonstrate the potential of Sugar Shift to restore gut homeostasis, reduce inflammation, and improve metabolic health in T2D. Further studies are warranted to explore its long-term efficacy and broader application in metabolic disease management.
Characterization and Transcriptional Regulation of the 2-Ketogluconate Utilization Operon in Pseudomonas plecoglossicida
Authors: Sun Lei , Yang Wenqi , Li Lulu , Wang Daming , Zan Xinyi , Cui Fengjie , Qi Xianghui , Sun Ling , Sun Wenjing
Published: December 2024

Pseudomonas plecoglossicida JUIM01 is an industrial 2-keto-d-gluconate (2KGA)-producing strain. However, its regulation mechanism of 2KGA metabolism remains to be clarified. Among other reported Pseudomonas species, the 2-ketogluconate utilization operon (kgu operon) plays key roles in 2KGA catabolism. In this study, the structural genes of the kgu operon and its promoter in P. plecoglossicida JUIM01 were identified using reverse transcription PCR and lacZ reporter gene fusion. The results showed the kgu operon in P. plecoglossicida was composed of four structural genes: kguE, kguK, kguT, and kguD. The ptxS gene located upstream of kguE was excluded from the kgu operon. Then, the knockout and corresponding complementation strains of kguE, kguK, kguT, and kguD were constructed, respectively, to prove the kgu operon was involved in 2KGA catabolism of P. plecoglossicida. The knockout stains, especially JUIM01ΔkguE, showed potential as industrial production strains for 2KGA. Moreover, the transcriptional regulation mechanism of PtxS on the kgu operon was elucidated using multiple methods. In P. plecoglossicida, the LacI-family transcription regulator PtxS could recognize a 14 bp palindrome (5′-TGAAACCGGTTTCA-3′) within the promoter region of the kgu operon and specifically bind to a 26 bp region where the palindrome was located. As the binding sites overlapped with the transcription start site of the kgu operon, the binding of PtxS possibly hindered the binding of RNA polymerase, thus repressing the transcription of the kgu operon and further regulating 2KGA catabolism. 2KGA bound to PtxS as an effector to dissociate it from the kgu operon promoter region, so as to relieve the transcription repression. The results will provide strategies for improving the product accumulation in 2KGA industrial production and theoretical bases for the construction of a Pseudomonas chassis.
Detection and Characterisation of Colistin-Resistant Escherichia coli in Broiler Meats
Authors: Tanzin Abu Zubayer , Nath Chandan , Nayem Md. Raihan Khan , Sayeed Md Abu , Khan Shahneaz Ali , Magalhaes Ricardo Soares , Alawneh John I. , Hassan Mohammad Mahmudul
Published: December 2024

The irrational use of antimicrobials has led to the emergence of resistance, impacting not only pathogenic bacteria but also commensal bacteria. Resistance against colistin, a last-resort antibiotic, mediated by globally disseminated plasmid-borne mobile colistin resistance (mcr) genes, has raised significant global concerns. This cross-sectional study aimed to investigate the antimicrobial resistance patterns of colistin-resistant Escherichia coli (E. coli) and mobilised colistin resistance (mcr 1–5) genes from broiler meat. A total of 570 broiler samples (285 liver and 285 muscle) were collected from 7 supermarkets and 11 live bird markets (LBMs) in Chattogram metropolitan areas of Bangladesh. The isolation and identification of E. coli were carried out using standard bacteriological and molecular techniques. Antimicrobial susceptibility testing (AST) was performed using the Kirby–Bauer disc diffusion method, and colistin’s minimum inhibitory concentration (MIC) was determined by the broth microdilution (BMD) method. Colistin-resistant isolates were further tested for the presence of mcr (1–5) genes using polymerase chain reaction (PCR). Out of the 570 samples, 311 (54.56%; 95% confidence interval: 50.46–58.60) were positive for E. coli. AST results showed the highest resistance to sulphamethoxazole–trimethoprim (89.39%), while the highest susceptibility was observed for cefalexin (62.70%). A total of 296 isolates (95.18%) were found to be multidrug-resistant (MDR), with the multiple antibiotic resistance (MAR) index ranging from 0.38 to 1. Additionally, 41 isolates (13.18%) exhibited resistance to five antimicrobial classes, with resistance patterns of CIP + SXT + AMP + DO + TE + CT. A total of 233 isolates (74.92%) were resistant to colistin (MIC > 2 mg/L). A strong correlation between colistin resistance and the presence of the mcr-1 gene was observed (r = 1). All phenotypic colistin-resistant E. coli isolates carried the mcr-1 gene, while no isolates were positive for mcr (2–5). The detection of mcr genes in E. coli strains from poultry sources poses a significant risk, as these resistance genes can be transferred to humans through the food chain. The prevalence of multidrug-resistant Escherichia coli and the mcr-1 gene in poultry products in Bangladesh presents a significant public health and food safety concern.
Mechanistic Insights into Succinic Acid as an Adjuvant for Ciprofloxacin in Treating Pseudomonas aeruginosa Growing Within Cystic Fibrosis Airway Mucus
Authors: Monteiro Rosana , Silva Eduarda , Pereira Maria Olivia , Sousa Ana Margarida
Published: December 2024

Pseudomonas aeruginosa is a major cause of chronic respiratory infections in patients with cystic fibrosis (CF), with biofilm formation contributing to its persistence and antibiotic resistance. This study aimed to gain insights into the mechanistic action of succinic acid as a ciprofloxacin adjuvant against clinically relevant CF isolates, including small colony variants and mucoid strains, and a ciprofloxacin-resistant strain grown within CF dense mucus. Time-kill assays in artificial CF mucus, along with planktonic and surface-attached biofilm experiments, were used to assess the activity of succinic acid alone and in combination with sublethal ciprofloxacin concentrations. Succinic acid demonstrated an adjuvant effect of ciprofloxacin against P. aeruginosa grown within CF mucus at pH levels below pKa1 during the early bacterial growth stages. In examining planktonic growth and biofilms under these conditions, we found that succinic acid demonstrated strong antibacterial and antibiofilm properties. Conversely, succinic acid activity decreased at later growth stages, though it enhanced the ciprofloxacin effect, especially against mucoid biofilms. Moreover, we noted that, in dense CF mucus, succinic acid activity was attenuated compared to a non-CF environment, indicating diffusion challenges. These findings underscore the potential of succinic acid as a therapeutic adjuvant for improving antibiotic treatment outcomes and overcoming biofilm-associated resistance in CF.
Thermochronological Constraints on the Tectonic History of the Arabian–Nubian Shield’s Northern Tip, Sinai, Egypt
Authors: Mansour Sherif , Abdelfadil Khaled M. , Hasebe Noriko , Tamura Akihiro , Abdelrahman Kamal , Gharib Mohamed A. , Fnais Mohammed S. , Shehata Amer A.
Published: December 2024

The effects of different regional tectonic events on the Neoproterozoic basement rocks of the Arabian–Nubian Shield in Sinai, as well as the Egyptian unstable and stable shelves, remain uncertain. Coupling fission-track thermochronometry findings with the modeling of the time–temperature history has proved to be an effective method for tackling these issues. The obtained zircon fission-track ages were differentiated into two groups from the Ediacaran–Cambrian and the Ordovician–Carboniferous periods, while the apatite fission-track data revealed two separate groups of cooling ages of the Carboniferous–Triassic and Late Cretaceous ages. The integration of these cooling ages and modeling of the time–temperature history revealed four discrete cooling pulses during the Neoproterozoic, Devonian–Carboniferous, Cretaceous, and Oligocene–Miocene eras. After integrating our findings with the regional tectonic historical and sedimentological records, these could be identified as cooling/exhumation pulses activated in response to the post-accretional event of erosion, Variscan tectonism, the disintegration of Gondwana, and the Gulf of Suez rifting, respectively. Furthermore, the southern border of the Egyptian unstable shelf was found to extend southward to South Sinai and south of the Bahariya depression.
Long-Lasting Magmatic, Metamorphic Events in the Cathaysia Block: Insights from the Geochronology and Geochemistry of Inherited Zircons in Jurassic A-Type Granites
Authors: Xiao Wenzhou , Zi Feng , Zhang Chenguang , Xie Fenquan , Sanislav Ioan V. , Fnais Mohammed S. , Sami Mabrouk
Published: December 2024

The Paleoproterozoic basement underlying the Cathaysia Block remains relatively understudied, and its contribution to the region’s tectonic evolution requires further investigation. In this study, we examined Jurassic Laiziling and Jianfengling A-type granites and identified a significant number of zircon grains exhibiting varied CL imaging characteristics. These zircons yielded four distinct age groups: <100 Ma, 200–100 Ma, 500–200 Ma, and >700 Ma. Detailed trace element analysis revealed that these age groups correspond to different zircon types: metamorphic recrystallized zircons (<100 Ma), primary magmatic zircons (200–100 Ma), and inherited zircons (500–200 Ma and >700 Ma). Through host rock and tectonic setting discrimination, we consider that the inherited zircons have host rocks of S-type granites and basic rocks, and these were formed in subduction-compression tectonic environments. In comparison to local significant geological events in history, we propose that these zircons record multiple tectonic events in the South China Block, including the amalgamation of the Yangtze and Cathaysia Blocks during the Neoproterozoic; an intracontinental orogenic event that occurred during the Middle Paleozoic; and subduction–exhumation processes related to the Paleo-Pacific slab; as well as extensional metamorphic events from the Cretaceous to Tertiary events. A comparison of Hf isotopic compositions revealed that zircons aged 500–200 Ma and >700 Ma share a 2.5–1.6 Ga crustal evolution zone, indicating that multiple re-melting events have occurred within the Paleoproterozoic basement of the Cathaysia Block.
Pore Structure and Heterogeneity in the Lacustrine Shale of the Second Member of the Paleogene Funing Formation, Subei Basin, China
Authors: Zhu Zhiwei , Fu Qiang , Hu Zongquan , Duan Hongliang , Yang Baoliang , Xing Lele , Chen Guo
Published: December 2024

Characterization of pore structure and heterogeneity is crucial for exploring and evaluating shale oil and gas resources. Existing methodologies exhibit various limitations, and intuitive, quantitative description techniques are lacking. To address these issues, shales from the second member of the Funing Formation (E1f2) in the Subei Basin were studied in this study. A comprehensive research methodology was employed that combined petrological analysis, physical structure testing, and SEM images supplemented with multifractal analysis and partial least squares regression (PLSR) data processing to achieve nuanced qualitative and quantitative characterization of the heterogeneity in lacustrine shale pore structures. This study revealed that E1f2 shale pores predominantly consist of mesopores (2–50 nm) and macropores (>50 nm). A positive correlation was observed between the development of mesopores and calcite content, while a negative correlation exists with orthoclase content. Conversely, a positive correlation with plagioclase content was found in macropore development. The growth in total pore volume is inhibited by the total organic carbon (TOC) content. Employing multifractal methods to analyze pore morphology data extracted from scanning electron microscopy (SEM) images facilitated a quantitative characterization of the heterogeneity within the pore structures. The results showed that organic-medium mixed shale (OMMS) has the strongest heterogeneity. The weakest heterogeneity is exhibited by the organic-medium calcareous shale (OMCS). PLSR analysis indicates that the structural heterogeneity of the E1f2 shales is positively correlated with TOC content and negatively correlated with orthoclase content. Additionally, the type of pore influences the degree of heterogeneity. Increasing the total and macropore volume reduces the heterogeneity, while increasing the micropore (<2 nm) volume enhances it in the E1f2 shales.
Characteristics of Lamination in Deep Marine Shale and Its Influence on Mechanical Properties: A Case Study on the Wufeng-Longmaxi Formation in Sichuan Basin
Authors: Tan Jingqiang , Shen Baojian , Wu Huricha , Wang Yaohua , Ma Xinyao , Ma Xiao , Liu Wenhui
Published: December 2024

The extensive development of lamination structures in shale significantly influences its mechanical properties. However, a systematic analysis of how laminae affect the macroscopic mechanical behavior of rocks remains absent. In this study, field emission scanning electron microscopy (FE-SEM), thin section observation, X-ray diffraction (XRD), triaxial compression and Brazilian tests were carried out on the deep marine shale of the Wufeng-Longmaxi Formation in Sichuan Basin. The results reveal four distinct laminasets: grading thin silt–thick mud (GSM1), grading medium thick silt–mud (GSM2), grading thick silt–thin mud (GSM3) and alternating thick silt–thin mud (ASM). GSM3 and ASM laminasets exhibit the weakest mechanical properties and the simplest fracture patterns, while GSM2 demonstrates moderate mechanical properties and more complex fracture patterns. GSM1 shows the highest mechanical strength and the most intricate fracture patterns. Mechanical properties are positively correlated with siliceous mineral content and negatively correlated with clay mineral content and scale of laminae development (average density and thickness), revealing that lamination plays a key role in fracture behavior, with more intensively developed laminasets leading to the concentrated distribution of brittle silty minerals, facilitating microcrack propagation. Moreover, microstructure has an important effect on both mechanical properties and fracture pattern. In grain-supported structures, closely packed silty brittle mineral grains reduce the energy required for crack extension. In matrix-supported structures, widespread silty brittle mineral grains increase energy requirements for crack extension, leading to more irregular and complex fracture networks. This study enhances the understanding of the effects of lamination on the rock mechanical behavior of shales, optimizing hydraulic fracturing design in shale reservoirs.
Hydrocarbon Accumulation and Overpressure Evolution of the Ordovician Carbonate Reservoirs in the Tahe Area, Tarim Basin, NW China
Authors: Jiang Xinyi , Guo Xiaowen , Zhu Yingzhong , Luo Tao , Chen Junlin , Xu Hao , Zhao Xiaolin
Published: December 2024

The recovery of reservoir paleo-pressure has been a key focus in hydrocarbon accumulation research. The evolution of paleo-pressure in carbonate reservoir rocks has long been a research challenge for researchers. Using the Tahe area in the Tarim Basin as a case study, this paper proposes an idea for studying the paleo-pressure evolution in carbonate rocks through fluid inclusions. A series of methods, including cathodoluminescence, fluid inclusion petrography, laser in situ U–Pb isotope dating, and microthermometry, were employed to determine the stages of hydrocarbon accumulation. Additionally, the paleo-pressure of oil inclusions from different stages has been restored, and the pressure evolution of the Ordovician carbonate reservoirs in the Tahe area was reconstructed. The study identifies four stages of oil charging in Ordovician carbonate reservoirs. The four oil-charging events occurred during the Caledonian (459–450 Ma), Hercynian (320–311 Ma), late Indosinian (227–213 Ma), and Yanshanian (134–117 Ma) periods. The overpressure evolution indicates that the Cambrian source rocks reached the first oil generation peak and started to expel hydrocarbons during the late Caledonian period. Oil mainly migrated vertically along strike-slip faults and accumulated in fracture-cavity karst reservoirs. At the same time, the reservoir pressure increased rapidly. Subsequent tectonic compression caused uplift and erosion, leading to the destruction of the oil reservoirs and a decrease in pressure. During the Hercynian period, hydrocarbons migrated and accumulated in reservoirs, leading to an increase in reservoir pressure. Subsequently, a slight formation uplift occurred, which caused a decrease in pressure. During the late Indosinian period, the third stage of oil accumulation led to an increase in reservoir pressure. Tectonic uplift during the Yanshanian period caused reservoir destruction and adjustment, resulting in a decrease in pressure. Reservoir pressure increased with oil charging during the Yanshanian period. Subsequently, a large number of faults developed in the study area, causing further destruction and re-adjustment of the oil reservoirs, which led to a decrease in pressure to the current state of normal pressure or weak overpressure.
Synthesis, Characterization and Antimicrobial Activity of Trimethylantimony(V) Biscyanoximates, a New Family of Antimicrobials
Authors: Amankrah Seth A. , Salpadoru Tarosha , Cotton Kaitlyn , Patrauchan Marianna A. , Wozniak Karen L. , Gerasimchuk Nikolay
Published: December 2024

Antimicrobial compounds play a critical role in combating microbial infections. However, the emergence of antibiotic and antifungal resistance and the scarcity of new antibiotic developments pose a significant threat and demand the discovery of new antimicrobials for both bacterial and fungal pathogens. Our previous work described the first generation (G1) of organoantimony-based compounds that showed antimicrobial activity against several bacterial and fungal pathogens. Here, we present our efforts in modifying these compounds by replacing the tetraphenyl backbone in G1 compounds with a trimethyl group, thereby generating a new series of compounds we refer to as “generation 2”, G2. In addition to the novel backbone structure, we introduced three new anionic chloro-cyanoxime ligand groups, namely 2,4-diCl-PhCO−, 2,6-diCl-PhCO− and 2Cl-PhCO−, which were found to be biologically active in the past. Nine new compounds of SbMe3L2 composition were obtained in high yields and characterized by NMR, IR spectroscopies, thermogravimetric TG/DSC and X-ray single crystal analyses. The antibacterial activity of the cyanoximates was tested against three bacterial (Pseudomonas aeruginosa PAO1, Escherichia coli S17 and methicillin-resistant Staphylococcus aureus (MRSA) NRS70) and two fungal (Candida albicans strain SC5314 and Cryptococcus neoformans strain H99) pathogens. Two compounds, SbMe3(MCO)2 and SbMe3(2,4-diClPhCO)2, were active against bacterial strains and inhibited the growth of PAO1 and MRSA with MICs of 50 and 100 µg/mL, respectively. Three compounds, SbMe3(MCO)2, SbMe3(ECO)2 and SbMe3(TCO)2, were active against fungal strains and inhibited either one of or both C. albicans and C. neoformans at MICs of 2.6–66.67 μg/mL. In addition, SbMe3(TCO)2 and SbMe3(MCO)2 were fungicidal at MFC 33.33–66.67 μg/mL. Ultra-thin-layer TEM imaging suggested that SbMe3(MCO)2 targets the integrity of bacterial membranes. Overall, four of the studied G2 series compounds possess antimicrobial activity against a broad range of microbial pathogens, with particular potential against fungal pathogens, which will be explored in further studies.
The Effect of Polyethylene Glycol Addition on Improving the Bioconversion of Cellulose
Authors: Szentner Kinga , Waśkiewicz Agnieszka , Imbiorowicz Robert , Borysiak Sławomir
Published: December 2024

In recent years, many studies have focused on improving the bioconversion of cellulose by adding non-ionic surfactants. In our study, the effect of the addition of a polymer, polyethylene glycol (PEG 4000), on the bioconversion of different cellulose materials was evaluated, focusing on the hydrolysis efficiency and structural changes in pure cellulose after the enzymatic hydrolysis process. The obtained results showed that the addition of non-ionic surfactant significantly improved the digestibility of cellulosic materials. The highest hydrolysis efficiency was observed for Sigmacel 101 (Cel-S101) cellulose, which consists mainly of amorphous regions. In the case of Avicel cellulose (Cel-A), PEG had a lesser effect on the bioconversion’s efficiency due to limited access to the crystal structure and limited substrate–cellulase interactions. The consistency of the obtained results is confirmed by qualitative and quantitative analyses (XRD, FTIR, and HPLC). Our findings may be helpful in further understanding the mechanism of the action of surfactants and improving the enzymatic hydrolysis process.
Addressing the Evolution of Cardenolide Formation in Iridoid-Synthesizing Plants: Site-Directed Mutagenesis of PRISEs (Progesterone-5β-Reductase/Iridoid Synthase-like Enzymes) of Plantago Species
Authors: Dorfner Maja , Klein Jan , Senkleiter Katharina , Lanig Harald , Kreis Wolfgang , Munkert Jennifer
Published: December 2024

Enzymes capable of processing a variety of compounds enable plants to adapt to diverse environmental conditions. PRISEs (progesterone-5β-reductase/iridoid synthase-like enzymes), examples of such substrate-promiscuous enzymes, are involved in iridoid and cardenolide pathways and demonstrate notable substrate promiscuity by reducing the activated C=C double bonds of plant-borne and exogenous 1,4-enones. In this study, we identified PRISE genes in Plantago media (PmdP5βR1) and Plantago lanceolata (PlP5βR1), and the corresponding enzymes were determined to share a sequence identity of 95%. Despite the high sequence identity, recombinant expressed PmdP5βR1 was 70 times more efficient than PlP5βR1 for converting progesterone. In order to investigate the underlying reasons for this significant discrepancy, we focused on specific residues located near the substrate-binding pocket and adjacent to the conserved phenylalanine “clamp”. This clamp describes two phenylalanines influencing substrate preferences by facilitating the binding of smaller substrates, such as 2-cyclohexen-1-one, while hindering larger ones, such as progesterone. Using structural analysis based on templates PDB ID: 5MLH and 6GSD from PRISE of Plantago major, along with in silico docking, we identified positions 156 and 346 as hot spots. In PlP5βR1 amino acid residues, A156 and F346 seem to be responsible for the diminished ability to reduce progesterone. Moreover, the double mutant PlP5βR_F156L_A346L, which contains the corresponding amino acids from PmdP5βR1, showed a 15-fold increase in progesterone 5β-reduction. Notably, this modification did not significantly alter the enzyme’s ability to convert other substrates, such as 8-oxogeranial, 2-cyclohexen-1-one, and methyl vinyl ketone. Hence, a rational enzyme design by reducing the number of hotspots selectively, specifically improved the substrate preference of PlP5βR1 for progesterone.
Deciphering the Phytochemical Potential of Hemp Hairy Roots: A Promising Source of Cannabisins and Triterpenes as Bioactive Compounds
Authors: Kaminsky Naomi , Hubert Jane , Guerin Cédric , Mazlani Malak , Kotland Alexis , Pozzobon Victor , Marant Blandine , Mailhac Héloïse , Poigny Stéphane
Published: December 2024

Cannabis sativa L., specifically hemp, is a traditional herbaceous plant with industrial and medicinal uses. While much research has focused on cannabinoids and terpenes, the potential of hemp roots is less explored due to bioproduction challenges. Still, this material is rich in bioactive compounds and demonstrates promising anti-inflammatory, antimicrobial, and antioxidant properties. Biotechnological methods, such as hairy root cultures, enable the efficient production of specialized metabolites while avoiding the issues of outdoors cultures. Despite these benefits, the chemical diversity understanding of hemp hairy roots remains limited. In this study, we conducted an extensive NMR and LC/MS chemical profiling of hemp hairy roots to determine their chemical composition, revealing the presence of cannabisins for the first time. We then investigated the accumulation of cannabisins and triterpenes in both hemp hairy roots and hemp aeroponic roots. Our findings reveal that hairy roots produce 12 times more cannabisins and 6 times more triterpenes than aeroponic roots, respectively, in addition to yielding 3 times more biomass in bioreactors. Preliminary bioassays also suggest antioxidant and antifungal properties. This research underscores the potential of hemp hairy roots as a valuable source of specialized metabolites and calls for further exploration into their bioactive compounds and applications.
MXene Anchored with Platinum Cobalt Alloy as an Efficient and Stable Electrocatalyst for Hydrogen Evolution
Authors: Xiao Jing , Wang Buxiang , Shu Qing
Published: December 2024

It is a great challenge to prepare efficient and stable electrocatalysts for hydrogen evolution (HER) using non-precious metals. In this study, a series of PtCo/Ti3C2Tx-Y (Y: 16, 32, and 320, Y indicates the quality of Co(NO3)2) catalysts were synthesized by loading PtCo alloy on Ti3C2Tx. The PtCo/Ti3C2Tx-32 catalyst showed the best HER performance, reaching a current density of 10 mA cm−2 with low overpotential (36 and 101 mV) and small Tafel slopes (66.37 and 105.17 mV dec−1) in 0.5 mol L−1 H2SO4 and 1 mol L−1 KOH solution. The excellent HER activity of PtCo/Ti3C2Tx-32 can be attributed as follows: Ti3C2Tx has a unique two-dimensional structure, which can provide a large number of attachment sites for the PtCo alloy, hence exposing more active sites; on the other hand, it can also provide a fast and efficient conductive network for electron transport during electrocatalytic processes, thus enhancing the connectivity between electrolyte and catalyst. PtCo alloy makes the PtCo/Ti3C2Tx catalyst more hydrophilic, accelerating the release rate of bubbles. The DFT calculation results showed that the energy barrier of HER is reduced because the charge around Pt is redistributed by Co after alloying Pt and Co, so that the PtCo/Ti3C2Tx catalyst has a suitable ΔGH* value. This study can be expected to provide some references for the design and synthesis of Ti3C2Tx-supported alloy electrocatalysts with high activity and stability for HER.
Formulation of Ready-to-Use Broccoli Extracts Rich in Polyphenols and Glucosinolates Using Natural Deep Eutectic Solvents
Authors: Karaula Ivona , Vasung Emma , Damjanović Anja , Panić Manuela , Radović Mia , Radošević Kristina , Bagović Kolić Martina , Cvjetko Bubalo Marina , Radojčić Redovniković Ivana
Published: December 2024

Broccoli is rich in biologically active compounds, especially polyphenols and glucosinolates, known for their health benefits. Traditional extraction methods have limitations, leading to a shift towards using natural deep eutectic solvents (NADESs) to create high-quality extracts with enhanced biological activity. This study focuses on preparing broccoli extracts in NADES, enriched with polyphenols and glucosinolates, without additional purification steps. Using the COSMOtherm software, the solubility of polyphenols and glucosinolates in NADESs was predicted, and five biocompatible betaine-based NADESs were prepared with glucose (B:Glc1:1 and B:Glc5:2), sucrose (B:Suc), glycerol (B:Gly), and malic acid (B:MA) as hydrogen bond donors. The resulting extracts were assessed for total polyphenol and glucosinolate content, along with antioxidant capacity, using the ORAC assay. The results demonstrated that NADES extracts contained higher polyphenol content and exhibited enhanced antioxidant effects compared to the reference ethanol extract, with B:Glc1:1 extract showing the highest performance among all the extracts tested. On the other hand, the extract based on B:MA exhibited nearly six times higher total glucosinolate content compared to the ethanol extract. Additionally, polyphenols and glucosinolates were generally more stable in NADES extracts than in the reference solvent. Finally, the B:Glc1:1 extract, identified as optimal in terms of polyphenol and glucosinolate content and stability, exhibited mild stimulation of HaCaT cells growth and facilitated the wound-healing process. Through green chemistry parameter calculations, we demonstrated that the extraction of broccoli bioactives using B:Glc1:1 can be considered sustainable, underscoring the potential of NADESs for producing ready-to-use plant extracts.
First-Principles Study of Titanium-Doped B7 Cluster for High Capacity Hydrogen Storage
Authors: Huang Haishen , Li Guoxu , Li Zhenqiang , Zhou Tingyan , Li Ping , Yang Xiude , Wu Bo
Published: December 2024

The geometrical structure, stability, electronic properties, and hydrogen storage capabilities of a titanium-doped B7 cluster was calculated using density functional theory computations. The results show that the TiB7 cluster is predicted to be stable under near-ambient conditions based on an ab initio molecular dynamic simulation. The transition state analysis found that the H2 molecule can dissociate on the TIB7 cluster surface to form a hydride cluster. The Ti atom within the TiB7 cluster demonstrates an impressive capacity to adsorb up to five H2 molecules, achieving a peak hydrogen storage mass fraction of 7.5%. It is worth noting that the average adsorption energy of H2 molecules is 0.27–0.32 eV, which shows that these configurations are suited for reversible hydrogen storage under mild temperature and pressure regimes. In addition, calculations found that both polarization and hybridization mechanisms play pivotal roles in facilitating the adsorption of H2 molecules onto the TiB7 cluster. Our research results show that the TiB7 cluster has potential for hydrogen storage applications under near-ambient conditions.