Basic Research Research Articles

Theoretical and experimental research of filtration efficiency and resistance of multi-fiber air-filter materials

Abstract The filtration efficiency and resistance during the process of fluid flowing through filter materials is significantly influenced by the characteristic of filter materials, especially for air-filter materials which generally have a multi-fiber composite structure. Therefore, it is important to pay attention to the filtration efficiency and resistance of multi-fiber filter materials. In this study, theoretical equations of filtration efficiency and resistance were proposed based on uniform and multi-fiber composite filter materials, and series of experimental verifications had been implemented. The results indicated that the experimental results verified the theoretical equations well, which may accelerate the research and development of new air-filter materials.

Biological invasions negatively impact global protected areas

Protected areas underpin global biodiversity conservation and sustainability agendas. Biological invasions increasingly threaten the ecological functioning and long-term conservation value of protected areas, while a lack of information on impact impedes management decisions. We collated data from effects of biological invasions in protected areas to provide the first quantitative analysis of their global impacts. Based on 300 reported effects from 44 invasive species, we show that there are overall negative impacts from invasive species on both biotic and abiotic characteristics of protected areas globally. Impacts were pervasive across population, community, and ecosystem scales, and for the vast majority of invasive taxa with sufficient data. Negative impacts have been incurred around the world, with National Parks and World Heritage Sites in the Neartic and Neotropical regions the most studied. Notwithstanding context-dependencies and uneven research efforts, the recurrent negative impacts of invasive species indicate that current efforts are insufficient to curb current stressors and meet conservation and sustainability targets on land and in water. To address the risk of biological invasions in protected areas, it is imperative to prioritise fundamental research on ecological interactions, establish robust monitoring and prevention programs, and raise awareness through global initiatives.

Research and Application of Chitosan Nanoparticles in Orthopedic Infections.

Orthopedic infection is one of the most intractable orthopedic problems. Bacteria resistant to antibiotics also develop gradually. Chitosan is widely used in the Biomedical field because of its high biocompatibility, biodegradability, and antibacterial activity. Chitosan-based drug delivery systems are frequently utilized to produce controlled medication release. When combined with antibiotics, synergistic antibacterial effects can be achieved. Chitosan-based nanoparticles are one of the most widely used applications in drug delivery systems. The focus of this review is to provide information on new methods being developed for chitosan-based nanoparticles in the field of bone infection treatment, including chitosan nanoparticles for antibacterial purposes, Ch-loaded with antibiotics, Ch-loaded with metal, and used as immune adjuvants. It may Provide ideas for the fundamental research and the prospects of future clinical applications of orthopedic infections.

Chloroplast DNA methylation in the kelp Saccharina latissima is determined by origin and possibly influenced by cultivation.

DNA cytosine methylation is an important epigenetic mechanism in genomic DNA. In most land plants, it is absent in the chloroplast DNA. We detected methylation in the chloroplast DNA of the kelp Saccharina latissima, a non-model macroalgal species of high ecological and economic importance. Since the functional role of the chloroplast methylome is yet largely unknown, this fundamental research assessed the chloroplast DNA cytosine methylation in wild and laboratory raised kelp from different climatic origins (High-Arctic at 79° N, and temperate at 54° N), and in laboratory samples from these origins raised at different temperatures (5, 10 and 15°C). Results suggest genome-wide differences in methylated sites and methylation level between the origins, while rearing temperature had only weak effects on the chloroplast methylome. Our findings point at the importance of matching conditions to origin in restoration and cultivation processes to be valid even on plastid level.

Clean energy technologies and energy systems for industry and power generation: Current state, recent progress and way forward

This vision article accompanies a Special Issue of Applied Thermal Engineering dedicated to the Sustainable Development of Energy, Water and Environment Systems (SDEWES) conference series held during 2022, including the 5th SEE SDEWES Conference Vlore, 3rd LA SDEWES Conference Sao Paulo, and 17th SDEWES Conference Paphos. The article discusses a selection of papers presented at these conferences and selected for publication in Applied Thermal Engineering, all connected by a focus on clean energy technologies and systems for the advancement of sustainable thermal energy systems. This research area covers a wide range of technologies but is primarily focused on the power generation sector, energy storage and utilization, efficiency improvements, sustainable technical solutions, and the facilitation of the robust integration of renewable energy resources into wider energy systems. Additional work on previously established research topics is also present, but new directions have crystallized, especially research into thermal management for power devices and microelectronics. Based on the recent contributions to the research field presented in the included papers, this vision article discusses the development and application of cutting-edge technological solutions and identifies the challenges that require focused attention. Current shortcomings of developing and established technologies will be developed by the underlying fundamental research, reduction of prohibitively high costs, expansion of operating conditions, and the inclusion of advanced control approaches, sophisticated combinations of renewable energy sources, and modeling tools for system investigations. Scientists, researchers, and engineers can benefit from the summary of the topics at the forefront of the research field and find guidelines and ways forward for future research activities.

Enhancer demethylation-regulated gene score identified molecular subtypes, inspiring immunotherapy or CDK4/6 inhibitor therapy in oesophageal squamous cell carcinoma

The 5-year survival rate of oesophageal squamous cell carcinoma (ESCC) is approximately 20%. The prognosis and drug response exhibit substantial heterogeneity in ESCC, impeding progress in survival outcomes. Our goal is to identify a signature for tumour subtype classification, enabling precise clinical treatments. Utilising pre-treatment multi-omics data from an ESCC dataset (n=310), an enhancer methylation-eRNA-target gene regulation network was constructed and validated by invitro experiments. Four machine learning methods collectively identified core target genes, establishing an Enhancer Demethylation-Regulated Gene Score (EDRGS) model for classification. The molecular function of EDRGS subtyping was explored in scRNA-seq (n=60) and bulk-seq (n=310), and the EDRGS's potential to predict treatment response was assessed in datasets of various cancer types. EDRGS stratified ESCCs into EDRGS-high/low subtypes, with EDRGS-high signifying a less favourable prognosis in ESCC and nine additional cancer types. EDRGS-high exhibited an immune-hot but immune-suppressive phenotype with elevated immune checkpoint expression, increased T cell infiltration, and IFNγ signalling in ESCC, suggesting a better response to immunotherapy. Notably, EDRGS outperformed PD-L1 in predicting anti-PD-1/L1 therapy effectiveness in ESCC (n=42), kidney renal clear cell carcinoma (KIRC, n=181), and bladder urothelial carcinoma (BLCA, n=348) cohorts. EDRGS-low showed a cell cycle-activated phenotype with higher CDK4 and/or CDK6 expression, demonstrating a superior response to the CDK4/6 inhibitor palbociclib, validated in ESCC (n=26), melanoma (n=18), prostate cancer (n=15) cells, and PDX models derived from patients with pancreatic cancer (n=30). Identification of EDRGS subtypes enlightens ESCC categorisation, offering clinical insights for patient management in immunotherapy (anti-PD-1/L1) and CDK4/6 inhibitor therapy across cancer types. This study was supported by funding from the National Key R&D Program of China (2021YFC2501000, 2020YFA0803300), the National Natural Science Foundation of China (82030089, 82188102), the CAMS Innovation Fund for Medical Sciences (2021-I2M-1-018, 2022-I2M-2-001, 2021-I2M-1-067), the Fundamental Research Funds for the Central Universities (3332021091).

Clean energy technologies and energy systems for industry and power generation: Current state, recent progress and way forward

This vision article accompanies a Special Issue of Applied Thermal Engineering dedicated to the Sustainable Development of Energy, Water and Environment Systems (SDEWES) conference series held during 2022, including the 5th SEE SDEWES Conference Vlore, 3rd LA SDEWES Conference Sao Paulo, and 17th SDEWES Conference Paphos. The article discusses a selection of papers presented at these conferences and selected for publication in Applied Thermal Engineering, all connected by a focus on clean energy technologies and systems for the advancement of sustainable thermal energy systems. This research area covers a wide range of technologies but is primarily focused on the power generation sector, energy storage and utilization, efficiency improvements, sustainable technical solutions, and the facilitation of the robust integration of renewable energy resources into wider energy systems. Additional work on previously established research topics is also present, but new directions have crystallized, especially research into thermal management for power devices and microelectronics. Based on the recent contributions to the research field presented in the included papers, this vision article discusses the development and application of cutting-edge technological solutions and identifies the challenges that require focused attention. Current shortcomings of developing and established technologies will be developed by the underlying fundamental research, reduction of prohibitively high costs, expansion of operating conditions, and the inclusion of advanced control approaches, sophisticated combinations of renewable energy sources, and modeling tools for system investigations. Scientists, researchers, and engineers can benefit from the summary of the topics at the forefront of the research field and find guidelines and ways forward for future research activities.

Recent Advances on CO2 Electrochemical Reduction over Cu‐Based Nanocrystals

The electrochemical CO2 reduction reaction (CO2RR) has recently attracted increasing attention of chemists for converting CO2 to value‐added chemicals with the assistance of electrical energy. Over the past decades, substantial efforts have been devoted to CO2RR, however, this process still suffers the challenges of low conversion and poor selectivity to target product due to the thermodynamic stability and kinetic inertness of CO2. Among those catalysts, Cu has been widely used for CO2RR to produce hydrocarbons with relatively high efficiency in spite of the poor selectivity to products. Therefore, it is highly desired to developed highly active and selective Cu based catalysts for CO2RR. This mini‐review will summary the recent advances on CO2RR over Cu‐based nanocrystals (NCs) with a special focus on the control of selectivity of product via surface modification. We hope this mini‐review will motivate chemists to develop efficient catalysts for CO2RR, and also promote the fundamental research on catalyst design in heterogeneous catalysis.

Production and optical characterisation of blended Polyethylene Terephthalate (PET)/Polyethylene Naphthalate (PEN) scintillator samples

In Particle and Nuclear Physics research and related applications, organic scintillators provide a cost-effective technology for the detection of ionising radiation. The next generation of experiments in this field is driving fundamental research and development on these materials, demanding improved light yield, radiation hardness, and fast response. Common materials such as PEN and PET have been found to offer scintillation properties competitive to commercial alternatives without the use of dopants. Motivated by their complementarity in terms of light yield, radiation hardness, and time response, there is an increasing interest in investigating PET:PEN mixtures to ascertain whether they exhibit synergistic blending. This paper presents results from the systematic development of samples of PET, PEN, and PET:PEN blends with varied mass proportions. The manufacturing technique, involving injection moulding of granule raw material, is detailed. The effects of doping the polymer base substrate with fluorescent dopants are explored. Finally, the emission spectra of the different material compositions and their relative light output are presented.

Density and speed of sound measurements of aqueous solutions of potassium formate, potassium bicarbonate and their mixtures

Potassium formate and potassium bicarbonate are currently subject of research in a variety of new potential technical applications. One example of this is the use of the mixture of both salts in solution as a reversible hydrogen storage system and thus as a potential renewable energy carrier. In order to develop these new technologies, knowledge of the thermophysical properties of the individual salt solutions and mixtures is essential. Due to the limited data available in literature, which are only available for the single salt solutions, measurements of density and speed of sound as well as mathematical correlations based on the data were carried out in order to predict the behaviour of the salt solutions as a function of concentration and temperature. Good approximation equations were found for both properties, which agree with the existing data in the literature and result in deviations well below 1% over wide concentration and temperature ranges. The large number of measurements, the clear trends in the results and the good agreement with existing data from the literature allow to assume that reliable predictions of concentration, and thus degree of hydrogen charging, can be realized utilizing density measurements. With the help of this fundamental research, it will not only be possible to investigate the newly discussed applications in more detail in the future, but also enable more precise design calculations, models and simulations. In addition, material properties that result from the measured variables or are related to them, such as thermal expansion or isentropic compressibility, can be analysed.

Testing the consistency of performance scores reported for binary classification problems

Binary classification is a fundamental task in machine learning, with applications across various scientific domains. Whether conducting fundamental research or refining practical applications, scientists typically assess and rank classification techniques based on performance metrics such as accuracy, sensitivity, and specificity. However, reported performance scores may not always provide a reliable basis for research ranking. The unreliability can be attributed to undisclosed or unconventional practices related to cross-validation, typographical errors, and other factors.In a given experimental setup with a specific number of positive and negative test items, performance scores can only assume specific, interrelated values. Based on this observation, in this paper, we introduce numerical techniques to assess the consistency of reported performance scores with the assumed experimental setup. Importantly, the proposed approaches do not rely on statistical inference. Instead, they use numerical methods (interval computing and integer linear programming) to identify inconsistencies with certainty.Through three applications in different fields of medicine, we demonstrate how the proposed tests can detect inconsistencies, thereby safeguarding the integrity of research fields. The power analyses of the tests in these applications show at least 71% of power when the performance scores are reported to four decimal places. In the investigated areas, the tests have so far identified inconsistencies in more than 100 scientific papers. To benefit the scientific community, we have made the consistency tests available in the open-source Python package mlscorecheck.

ECR Spotlight – Bharath Kumar A. K.

ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Bharath Kumar A K is an author on ‘ Tropical and montane Apis cerana show distinct dance–distance calibration curves’, published in JEB. Bharath Kumar is a Research Assistant in the lab of Dr Axel Brockmann at the National Centre for Biological Sciences, Tata Institute of Fundamental Research, India, investigating bee behavior and pollination biology.

Strain-driven magnetic transition of intercalated pressure-stabilized cobalt and cobalt oxide nanoparticles in linked graphene oxide nanoscale reactors

The study of the evolution and metamorphosis of nanoparticles under high pressure and in nanoscale confinement is a rapidly developing field that promises a diverse range of fundamental research and application opportunities. Here, we demonstrate how a linked and strained graphene oxide (GO)-based confinement system, functioning as a nanoscale reactor at high pressures, allows the evolution of the magnetic properties of an in situ generated composite cobalt (Co) nanoparticle system and further enables the retention of such properties when the pressure of the system is returned to ambient. We posit that this phenomenon is due to an ‘induced pressure’ created by strain, on the flexible planes of the 2D GO system, created by the intercalated Co-based nanoparticles. For graphene/GO this strain is characterized by shifts in the Raman "G-band". Specifically, the studied system comprises in situ generated Co-containing nanoparticles confined between linked GO layers upon pressurization between 0 and 25 GPa. After quenching to ambient pressure, each of these samples exhibited innate ferromagnetic behaviors, demonstrating that our confinement system can be used to ‘lock in’ phase changes created by the application of transient high pressure. Importantly, while the unpressurized sample exhibited antiferromagnetic Co3O4 nanoparticles of ∼4 nm size, the samples pressurized to 10 GPa and 25 GPa, presented ferromagnetic order on the shell of an antiferromagnetic core of Co3O4 and CoO.

Electron Spin Resonance Spectroscopy on Magnetic van der Waals Compounds

AbstractThe field of research on magnetic van der Waals compounds—a special subclass of quasi-two-dimensional materials—is currently rapidly expanding due to the relevance of these compounds to fundamental research where they serve as a playground for the investigation of different models of quantum magnetism and also in view of their unique magneto-electronic and magneto-optical properties pertinent to novel technological applications. The electron spin resonance (ESR) spectroscopy plays an important role in the exploration of the rich magnetic behavior of van der Waals compounds due to its high sensitivity to magnetic anisotropies and unprecedentedly high energy resolution that altogether enable one to obtain thorough insights into the details of the spin structure in the magnetically ordered state and the low-energy spin dynamics in the ordered and paramagnetic phases. This article provides an overview of the recent achievements in this field made by the ESR spectroscopic techniques encompassing representatives of antiferro- and ferromagnetic van der Waals compounds of different crystal structures and chemical composition as well as of a special category of these materials termed magnetic topological insulators.

Thickness-modulated electronic band structures and exciton behavior of non-van-der-waals 2D Bi2O2Se films

Bi2O2Se, as a non-van-der-waals (non-vdW) interlayer coupling two-dimensional material, its electronic band structures and exciton behavior still merit further in-depth studies, especially in the consideration of thickness tuning degrees of freedom. Here, we reveal the broadband excitonic performance and critical point properties of Bi2O2Se films with different thicknesses (3.54–16.33 nm). Five critical points are determined and assigned to specific optical transitions. Moreover, we observe that electronic bandstructures in the Γ valley are stable with variable thicknesses, while the deeper electron levels received more pronounced thickness modulation. And we first report four excitons in wide spectral range (1.24–6.20 eV) through absorption coefficient fitting. Significantly, due to the strong localization of electrons and holes induced by the intralayer built-in electric field, the exciton binding energy (Eb) value of 3.54 nm-Bi2O2Se (234 meV at Γ position) is apparently larger than typical multi-layer TMDCs, which offering unprecedented opportunities in applications in optoelectronic devices. Furthermore, Eb of two excitons at low energy region (Eb1, Eb2) red-shift with increasing thickness, while Eb of higher-energy excitons (Eb3, Eb4) blue-shift, owing to the dispersion characteristic of the effect dielectric screening effects. Our results are vital to wide-ranging applications of Bi2O2Se from fundamental science to optoelectronic devices.

Tailoring the interfacial electron redistribution of ball-in-ball structured CuO-Co3O4 nanocomposites for synergistic enhancement in hydrolytic dehydrogenation of ammonia borane

Construction of high-efficiency and affordable catalysts for hydrogen production from hydrolysis of ammonia borane is highly desirable, but significant challenges still exist. In this study, a series of ball-in-ball hollow structured CuO-Co3O4 nanocomposites with varied Cu/Co molar ratio were constructed via simple solvothermal method combined with a post-calcination. The CuO-Co3O4 composite featuring a Cu/Co molar ratio of 1: 2 displayed the highest catalytic efficiency, achieving a turnover frequency (TOF) value of 25.0 molH2 molcat.−1 min−1 for AB hydrolysis. An evident synergistic enhancement in catalytic activity was confirmed between CuO and Co3O4. Experimental and theoretical researches uncovered that the enhancement of activity is originated from the electron transfer between Cu and Co ingredients, which is beneficial for the adsorption and activation of H2O and ammonia borane. In addition, the DFT calculations results revealed that the actual active sites for AB hydrolysis in CuO-Co3O4 composite catalyst is the Co site. These findings should provide some insightful recommendations for designing robust and cost-effective composite catalysts for the hydrolytic dehydrogenation of ammonia borane.

Một số giải pháp hoàn thiện công tác quản trị chất lượng toàn diện tại ngân hàng

Facing intensifying competition from domestic and foreign banks, enhancing service quality and customer satisfaction is a prerequisite for Vietnamese commercial banks (VCBs) to ensure sustainable development. Total Quality Management (TQM) has emerged as a breakthrough solution, providing the key to success in this challenging landscape for all organizations, regardless of industry.TQM is a management model that starts with leadership commitment, through communication and the involvement of all members of the organization to build a customer-centric culture together, towards the common goal of the organization is to develop and develop sustainably through continuous improvement of product/service quality, meeting customer needs and increasing competitiveness.Therefore, the effective application of TQM will help VCBs create a customer-centric culture, improve operational efficiency and optimize profits. Using a theoretical research method, the author has synthesized and analyzed data from many reputable sources such as documents, books, newspapers, and specialized journals. Thereby, analyzing the current status of TQM application in VCBs, comprehensively evaluating the strengths and weaknesses, and proposing a number of solutions to improve the work of total quality management in VCBs.

Broad spectral response of large array CIS with BSI-PD from visible light to near ultraviolet

The narrow spectral response range of traditional CMOS image sensors (CISs) limits their application such as weak-light and ultraviolet (UV) scenes. In the paper, a novel method of broadening spectral response range of traditional CISs is proposed by the design of a wide-PN photodiode (PD), which can be achieved by both back-illuminated (BSI) and gradient-doping structure using traditional process. Theoretical research shows that the wide-PN junction near illuminated surface can broaden the spectral range of the BSI-PD from visible light to near UV, which is conducive to weak-light imaging due to the generation of more photogenerated electrons. Moreover, the gradient potential in the BSI-PD with gradient-doping can inhibit the recombination of photogenerated electron-hole pairs, leading to the improvement of QE. The above BSI-PD is used for a large array CIS with 8520×9448 pixels, which was taped out by 110 nm CMOS process. The testing results indicate the large array CIS has a good imaging effect in different scenes.

Một số giải pháp hoàn thiện công tác quản trị chất lượng toàn diện tại ngân hàng

Facing intensifying competition from domestic and foreign banks, enhancing service quality and customer satisfaction is a prerequisite for Vietnamese commercial banks (VCBs) to ensure sustainable development. Total Quality Management (TQM) has emerged as a breakthrough solution, providing the key to success in this challenging landscape for all organizations, regardless of industry.TQM is a management model that starts with leadership commitment, through communication and the involvement of all members of the organization to build a customer-centric culture together, towards the common goal of the organization is to develop and develop sustainably through continuous improvement of product/service quality, meeting customer needs and increasing competitiveness.Therefore, the effective application of TQM will help VCBs create a customer-centric culture, improve operational efficiency and optimize profits. Using a theoretical research method, the author has synthesized and analyzed data from many reputable sources such as documents, books, newspapers, and specialized journals. Thereby, analyzing the current status of TQM application in VCBs, comprehensively evaluating the strengths and weaknesses, and proposing a number of solutions to improve the work of total quality management in VCBs.

Uncertainty relations in thermodynamics of irreversible processes on a mesoscopic scale

Studies of mesoscopic structures have become a leading and rapidly evolving research field ranging from physics, chemistry, and mineralogy to life sciences. The increasing miniaturization of devices with length scales of a few nanometers is leading to radical changes in the realization of new materials and in shedding light on our understanding of the fundamental laws of nature that govern the dynamics of systems at the mesoscopic scale. We investigate thermodynamic processes in small systems in Onsager’s region based on recent experimental results and previous theoretical research. We show that fundamental quantities such as the total entropy production, the thermodynamic variables conjugate to the thermodynamic forces, and the Glansdorff-Prigogine’s dissipative variable may be discretized at the mesoscopic scale. We establish the canonical com- mutation rules (CCRs) valid at the mesoscopic scale. The numerical value of the discretization constant is estimated experimentally. The ultraviolet divergence problem is solved by applying the correspondence principle with Einstein-Prigogine’s fluctuations theory in the limit of macroscopic systems. Examples of quantization of thermodynamic systems out of the Onsager region are currently being finalized.