bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermoelectric Performance of Non-Stoichiometric Permingeatite Cu3+mSbSe4
Authors: Kim DanAh , Kim Il-Ho
Published: September 2024

Non-stoichiometric permingeatites Cu3+mSbSe4 (−0.04 ≤ m ≤ −0.02) were synthesized, and their thermoelectric properties were examined depending on the Cu deficiency. Phase analysis by X-ray diffraction revealed no detection of secondary phases. Due to Cu deficiency, the lattice parameters of tetragonal permingeatite decreased compared to the stoichiometric permingeatite, resulting in a = 0.5654–0.5654 nm and c = 1.1253–1.1254 nm, with a decrease in the c/a ratio in the range of 1.9901–1.9903. Electrical conductivity exhibited typical semiconductor behavior of increasing conductivity with temperature, and above 423 K, the electrical conductivity of all samples exceeded that of stoichiometric permingeatite; Cu2.96SbSe4 exhibited a maximum of 9.8 × 103 Sm−1 at 623 K. The Seebeck coefficient decreased due to Cu deficiency, showing p-type semiconductor behavior similar to stoichiometric permingeatite, with majority carriers being holes. Thermal conductivity showed negative temperature dependence, and both electronic and lattice thermal conductivities increased due to Cu deficiency. Despite the decrease in the Seebeck coefficient due to Cu deficiency, the electrical conductivity increased, resulting in an increase in the power factor (especially a great increase at high temperatures), with Cu2.97SbSe4 exhibiting the highest value of 0.72 mWm−1K−2 at 573 K. As the carrier concentration increased due to Cu deficiency, the thermal conductivity increased, but the increase in power factor was significant, with Cu2.98SbSe4 recording a maximum dimensionless figure-of-merit of 0.50 at 523 K. This value was approximately 28% higher than that (0.39) of stoichiometric Cu3SbSe4.
New Bipolar Host Materials Based on Indolocarbazole for Red Phosphorescent OLEDs
Authors: Park Sunwoo , Kwon Hyukmin , Park Sangwook , Oh Saeyoung , Lee Kiho , Lee Hayoon , Kang Seokwoo , Park Dongmin , Park Jongwook
Published: September 2024

We designed and synthesized new indolocarbazole-triazine derivatives, 9-di-tert-butyl-5,7-bis(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-5,7-dihydroindolo[2,3-b]carbazole (2TRZ-P-ICz) and 3,9-di-tert-butyl-5,7-bis(5′-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′:3′,1″-terphenyl]-2′-yl)-5,7-dihydroindolo[2,3-b]carbazole (2TRZ-TP-ICz), as new bipolar host materials for red phosphorescent OLEDs. In the film state, 2TRZ-P-ICz and 2TRZ-TP-ICz exhibited photoluminescence maxima at 480 nm and 488 nm, respectively. The dipole moment characteristics of the new compounds under various solvent conditions were investigated using the Lippert–Mataga equation. The results showed that the dipole moment of 2TRZ-P-ICz is 26.9D, while that of 2TRZ-TP-ICz is 21.3D. The delayed fluorescence lifetimes were 0.188 μs for 2TRZ-P-ICz and 2.080 μs for 2TRZ-TP-ICz, with 2TRZ-TP-ICz showing TADF characteristics. Additionally, 2TRZ-TP-ICz was found to have a ΔEST of less than 0.2 eV. The triplet energy levels of the newly synthesized bipolar host materials were found to be 2.72 and 2.75 eV, confirming their suitability for use in red phosphorescent OLEDs. To investigate the carrier mobility of the synthesized materials, hole-only devices and electron-only devices were fabricated and tested. The hole mobility value at 1V was found to be 3.43 × 10−3 cm2/Vs for 2TRZ-P-ICz and 2.16 × 10−3 cm2/Vs for 2TRZ-TP-ICz. For electron mobility at 1V, 2TRZ-P-ICz showed a value of 4.41 × 10−9 cm2/Vs, while 2TRZ-TP-ICz exhibited a value of 9.13 × 10−9 cm2/Vs. As a result, when the new material was used as a host in red phosphorescent OLEDs, 2TRZ-TP-ICz achieved a current efficiency of 9.92 cd/A, an external quantum efficiency of 13.7%, CIE coordinates of (0.679, 0.319), and an electroluminescence maximum wavelength of 626 nm.
Lightweight Network Bearing Intelligent Fault Diagnosis Based on VMD-FK-ShuffleNetV2
Authors: Jiang Wanlu , Qi Zhiqian , Jiang Anqi , Chang Shangteng , Xia Xudong
Published: September 2024

With the increasing complexity of mechanical equipment and diversification of deep learning models, vibration signals collected from such equipment are susceptible to noise interference. Moreover, traditional neural network models struggle to be effectively deployed in production environments with limited computational resources, severely impacting the accurate extraction and effective diagnosis of FK fault characteristics. In response to this challenge, this study proposes a fault diagnosis method for rolling bearings, integrating a lightweight ShuffleNetV2 network with variational mode decomposition (VMD) and the fast kurtogram (FK) algorithm. Initially, this paper introduces an enhanced FK method where the VMD algorithm is employed for data denoising, extracting FK post-denoising. These feature maps not only preserve critical signal information but also simplify data complexity. Subsequently, these feature maps are utilized to train and test the ShuffleNetV2 model, facilitating effective fault identification and classification. Ultimately, by conducting experimental comparisons with several mainstream lightweight network models, such as MobileNet and SqueezeNet, as well as traditional convolutional neural network models, this study validates the effectiveness of the proposed method in extracting fault characteristics from vibration signals, demonstrating superior diagnostic accuracy and computational efficiency. This provides a novel technical approach for health monitoring and fault diagnosis of industrial bearings and offers theoretical and experimental support for the deployment of lightweight networks in industrial applications.
Inference about a Common Mean Vector from Several Independent Multinormal Populations with Unequal and Unknown Dispersion Matrices
Authors: Kifle Yehenew G. , Moluh Alain M. , Sinha Bimal K.
Published: September 2024

This paper addresses the problem of making inferences about a common mean vector from several independent multivariate normal populations with unknown and unequal dispersion matrices. We propose an unbiased estimator of the common mean vector, along with its asymptotic estimated variance, which can be used to test hypotheses and construct confidence ellipsoids, both of which are valid for large samples. Additionally, we discuss an approximate method based on generalized p-values. The paper also presents exact test procedures and methods for constructing exact confidence sets for the common mean vector, with a comparison of the local power of these exact tests. The performance of the proposed methods is demonstrated through a simulation study and an application to data from the Current Population Survey (CPS) Annual Social and Economic (ASEC) Supplement 2021 conducted by the U.S. Census Bureau for the Bureau of Labor Statistics.
Difference Schemes for Differential Equations with a Polynomial Right-Hand Side, Defining Birational Correspondences
Authors: Malykh Mikhail , Ayryan Edik , Lapshenkova Lyubov , Sevastianov Leonid
Published: September 2024

This paper explores the numerical intergator of ODE based on combination of Appelroth’s quadratization of dynamical systems with polynomial right-hand sides and Kahan’s discretization method. Utilizing Appelroth’s technique, we reduce any system of ordinary differential equations with a polynomial right-hand side to a quadratic form, enabling the application of Kahan’s method. In this way, we get a difference scheme defining the one-to-one correspondence between the initial and final positions of the system (Cremona map). It provides important information about the Kahan method for differential equations with a quadratic right-hand side, because we obtain dynamical systems with a quadratic right-hand side that have movable branch points. We analyze algebraic properties of solutions obtained through this approach, showing that (1) the Kahan scheme describes the branch points as poles, significantly deviating from the behavior of the exact solution of the problem near these points, and (2) it disrupts algebraic invariant variety, in particular integral relations describing the relationship between old and Appelroth’s variables. This study advances numerical methods, emphasizing the possibility of designing difference schemes whose algebraic properties differ significantly from those of the initial dynamical system.
A Fuzzy-Set Qualitative Comparative Analysis for Understanding the Interactive Effects of Good Governance Practices and CEO Profiles on ESG Performance
Authors: Remo-Diez Nieves , Mendaña-Cuervo Cristina , Arenas-Parra Mar
Published: September 2024

The impact of corporate governance mechanisms has been examined directly and independently, considering that such characteristics compete to explain environmental, social, and governance (ESG) performance. However, the nexus may be more complex than that suggested by most scholars, and more research is needed. This study applied a fuzzy-set qualitative comparative analysis to a sample of Spanish-listed companies in 2018–2020 to explore how good governance practices interact with CEO profiles to promote corporate sustainability practices. Our analysis discovered the importance of establishing sustainability committees and identified five pathways shaping governance practice bundles. Specifically, listed companies with a high code of good governance (GGC) compliance and a sustainability committee improve high ESG performance globally and for each ESG dimension. Furthermore, the effect is more relevant than the effect of the CEO profile, requiring either CEO duality (pathway 1) or extended CEO tenure (pathway 2). Concurrently, findings indicate three CEO profile configurations for GGC-neutral firms, providing companies with more flexibility in CEO selection. Two suggest that younger CEOs with longer tenure tend to be more motivated to engage in the G and S pillars (pathways 3 and 5). The third indicates that CEOs of older age and early tenure improve the E pillar (pathway 4).
Emergency Supply Alternatives for a Storage Facility of a Repairable Multi-Component System
Authors: Barron Yonit , Benshimol Chananel
Published: September 2024

This paper studies a continuous-review stochastic replenishment model for a multi-component system with regular and emergency orders. The system consists of N parallel and independent components, each of which has a finite life span. In addition, there is a warehouse with a limited stock of new components. Each broken component is replaced by a new component from the stock. When no component is available, an emergency supply is ordered. The stock is managed according to an ((s,S),(0,Qe)) policy, which is a combination of an (s,S) policy for the regular order and a (0,Qe) policy for the emergency order. The regular order is delivered after an exponentially distributed lead time, whereas the emergency order is delivered immediately. We study three sub-policies for emergency orders, which differ from each other in size and in relation to the regular order. Applying the results from queueing theory and phase-type properties, we derive the optimal thresholds for each sub-policy and then compare the economic benefit of each one.
Motivation to Run in One-Day Cricket
Authors: Pramanik Paramahansa , Polansky Alan M.
Published: September 2024

This paper presents a novel approach to identify an optimal coefficient for evaluating a player’s batting average, strike rate, and bowling average, aimed at achieving an optimal team score through dynamic modeling using a path integral method. Additionally, it introduces a new model for run dynamics, represented as a stochastic differential equation, which factors in the average weather conditions at the cricket ground, the specific weather conditions on the match day (including abrupt changes that may halt the game), total attendance, and home field advantage. An analysis of real data is been performed to validate the theoretical results.
A Case of Parinaud Oculoglandular Syndrome in Which Bartonella DNA Was Detected in the Cornea and Conjunctiva by Polymerase Chain Reaction
Authors: Saito Junya , Machida Akira , Inoue Daisuke , Shimizu Masumi Suzuki , Matsui Kohsuke , Harada Kohei , Kusano Mao , Mohamed Yasser Helmy , Uematsu Masafumi
Published: September 2024

Background and Objectives: Parinaud oculoglandular syndrome (POS) is unilateral granulomatous follicular conjunctivitis with ipsilateral afferent lymphadenopathy, primarily caused by cat-scratch disease, tularemia, and sporotrichosis. We report a case of POS in which Bartonella DNA was detected using polymerase chain reaction (PCR) in corneal and conjunctival specimens. Methods: A 29-year-old man, who started keeping a stray cat two months prior, became aware of right preauricular lymphadenopathy and right ocular conjunctival hyperemia one month prior. Subsequently, he developed a fever of approximately 37.9 °C, with a purulent ocular discharge appearing 1 week before being referred to our department for a detailed ophthalmological examination. The patient’s right eye showed hyperemia and edema in the bulbar conjunctiva, along with palpebral conjunctival hyperemia, follicles, and white ulcers. Two weeks later, his serum IgM titer for Bartonella henselae was 1:20, and Bartonella DNA was detected by PCR in the corneal and conjunctival specimens. Based on these findings, the patient was diagnosed with POS caused by cat-scratch disease (CSD). Oral doxycycline, rifampicin, topical gatifloxacin, betamethasone phosphate, and erythromycin eye ointments were prescribed. Results: After 2 weeks of oral treatment and 2 months of eye drop treatment, the deterioration of the cornea and conjunctiva improved when the patient recovered good visual acuity. Conclusions: PCR assays of corneal and conjunctival specimens are useful for the diagnosis of CSD presenting with POS. These results suggested that Bartonella may be directly involved in the ocular surface pathogenesis of POS.
Thyroid Eye Disease and Glaucoma: A Cross-Sectional Study Comparing Clinical Characteristics and Disease Severity
Authors: Ghenciu Laura Andreea , Șișu Alina Maria , Stoicescu Emil Robert , Dănilă Alexandra-Ioana , Iacob Roxana , Săndesc Mihai-Alexandru , Hațegan Ovidiu Alin
Published: September 2024

Background and Objectives: This study investigates the relationship between thyroid eye disease (TED) and open-angle glaucoma (OAG), focusing on disease severity and clinical features. Materials and Methods: Conducted at the Timis County Emergency Clinical Hospital, the research included 106 patients, with 53 having both conditions and 53 having only OAG. Key metrics analyzed included intraocular pressure (IOP) using a Goldmann applanation tonometer, the retinal nerve fiber layer (RNFL) thickness, and optic nerve head (ONH) characteristics evaluated using optical coherence tomography (OCT). Results: Results indicated that patients with both TED and OAG experienced a 6.09% reduction in RNFL thickness and showed more rapid disease progression, with 48.35% having active TED. The mean IOP in TED patients was 27.5 ± 4.9 mmHg, which was similar to those with only OAG. Demographic factors, including age and gender, influenced the clinical course and disease severity. Conclusions: These findings underscore the importance of specialized monitoring and treatment strategies for patients with coexisting TED and OAG to prevent vision loss.
A Survey of Lithuanian Pregnant Women’s Knowledge about Periodontal Disease, Its Prevalence and Possible Influence on Pregnancy Outcomes
Authors: Ramanauskaite Egle , Maciulskiene Vita , Baseviciene Nomeda , Anuzyte Rugile
Published: September 2024

Background: This study aimed to subjectively assess the changes in the oral health status of pregnant women, to find out their attitudes and knowledge about possible changes in the oral cavity that occurred during pregnancy, and their influence on the outcomes of pregnancy. Methods: 112 pregnant women who visited the Republican Siauliai Hospital during their pregnancy participated in the study. An anonymous self-administered questionnaire was used to conduct the research, surveying their demographic characteristics, oral health changes and habits during pregnancy, and awareness of possible negative pregnancy outcomes. Results: The study involved 112 pregnant women, with 35 in the first trimester, 28 in the second, and 48 in the third trimester. The findings revealed that pregnant women do not take sufficient care of their oral health: more than half of the respondents did not visit an oral care specialist during pregnancy; 22.3% of women reported brushing their teeth only once a day or less; and 35.7% did not clean interdental surfaces at all. Statistically, significantly more urban women believed there is a relationship between maternal oral health and adverse pregnancy outcomes than women living in rural areas (p = 0.013). While significant oral health changes were not observed in the first trimester, more women in the second and third trimesters reported issues such as bleeding gums, swelling, plaque accumulation, tartar, and caries (p < 0.001). Conclusions: The attitude of women towards oral health during pregnancy and their understanding of the possible risks for unfavorable pregnancy outcomes are insufficient. Notably, oral health issues become more prominent in the second and third trimesters, necessitating appropriate oral care to reduce the incidence of oral and dental diseases during pregnancy. This underscores the importance of educational and preventive public health policies focused on oral care for pregnant women, aimed at increasing awareness and promoting practices that safeguard both maternal and fetal health.
Lipid-Lowering Treatment Gaps in Patients after Acute Myocardial Infarction: Using Global Database TriNetX
Authors: Talviste Grete , Leinsalu Mall , Ross Peeter , Viigimaa Margus
Published: September 2024

Background and Objectives: Patients with previous acute myocardial infarction are at significantly higher risk of recurrent events. Early and intensive lipid-lowering therapy targeting low-density lipoprotein cholesterol is a key strategy for reducing cardiovascular risk in post-acute myocardial infarction patients worldwide. This study aimed to assess patients’ real-life lipid-lowering treatment gaps after acute myocardial infarction using a global network, TriNetX, of anonymous, real-time patient data. The uniqueness of the study was the use of the novel, evolving, and constantly improving TriNetX platform and the evaluation of its feasibility for clinical research. Materials and Methods: A retrospective study was conducted on global repository patients in 2020, diagnosed with acute myocardial infarction, with a three-year follow-up. Results: After acute myocardial infarction, the prescribing rate of lipid-lowering medication (statins, ezetimibe and PCSK9I) was insufficient to reach target LDL-C values. The mean LDL-C level decreased from 2.7 mmol/L (103 mg/dL) as measured on the day of AMI to 1.97 mmol/L (76 mg/dL) between 31D and 3M. During the second and third years, the mean LDL-C value was stable (around 2.0 mmol/L (78 mg/dL)). LDL-C goals were not sufficiently reached, as only 7–12% of patients were reported to have LDL-C values < 55 mg/dL (1.4 mmol/L) and 13–20% of patients were reported to have LDL-C values < 70 mg/dL (1.8 mmol/L) during the follow-up periods. This means that a substantial number of patients remain at a very high risk for CV complications and mortality. Most cardiovascular complications happen within three months after acute myocardial infarction. Conclusions: Gaps remain between the recommendations for managing LDL-C in guidelines and what occurs in real life. The TriNetX platform is an innovative platform with significant potential and should be further developed for clinical research, as it enables the use of valuable interinstitutional data.
GDF15 Targeting for Treatment of Hyperemesis Gravidarum
Authors: Thygerson Jamie , Oyler Dallin , Thomas Jackson , Muse Brandon , Brooks Benjamin D. , Pullan Jessica E.
Published: September 2024

Nausea and vomiting during pregnancy (NVP), particularly its severe form, Hyperemesis gravidarum (HG), affects up to 70% of pregnancies and significantly impacts the quality of life for those with the condition as well as generates a great economic burden, with annual costs exceeding $1.7 billion in the United States. Despite the available treatments targeting neurotransmitters like serotonin and dopamine, many patients experience inadequate relief and suffer from severe side effects, including headaches and dizziness. Recent research has underscored the role of GDF15, a protein mainly produced by the placenta and linked to NVP symptoms. This protein, part of the TGF-β superfamily, has been implicated in appetite and weight regulation and is altered in those with HG due to specific genetic mutations. Addressing the challenges of delivering effective treatments, current innovations focus on targeting GDF15 to reduce symptoms while ensuring fetal safety. Promising therapeutic strategies include non-IgG immunotherapies, small peptide and molecule antagonists, and novel administration methods such as transdermal patches. These approaches aim to optimize dosage and reduce adverse effects. The effective development and testing of these treatments necessitate advanced animal models that closely resemble human pregnancy physiology, highlighting the need for further research and funding. This ongoing research holds significant potential to improve the clinical outcomes for HG patients and decrease the economic impact on healthcare systems, urging a dedicated response from the scientific and medical communities to advance these promising treatments.
Perioperative and Long-Term Outcomes of Acute Stanford Type A Aortic Dissection Repair in Octogenarians
Authors: Masraf Hannah , Navaratnarajah Manoraj , Viola Laura , Sef Davorin , Malvindi Pietro G. , Miskolczi Szabolcs , Velissaris Theodore , Luthra Suvitesh
Published: September 2024

Background: The aims of this study were to assess the perioperative morbidity, mortality and long-term survival of octogenarians undergoing acute type A aortic dissection repair (ATAAD), and to compare open and closed distal anastomosis techniques. Methods: This was a single-centre retrospective study (2007–2021). Open versus closed distal anastomosis were compared. Uni- and multivariable logistic regression analyses were performed to identify independent predictors of in-hospital mortality. Kaplan–Meier and Cox proportional hazards methods were used to compare long-term survival. Results: Fifty octogenarian patients were included (median age—82 years; closed distal—22; open distal—28). Median cardiopulmonary bypass time was 187 min (open distal vs. closed distal group; 219 min vs. 115.5 min, p < 0.01, respectively). Median cross-clamp time was 93 min (IQR; 76–130 min). Median circulatory arrest time was 26 min (IQR; 20–39 min) in the open-distal group. In-hospital mortality was 18% (open distal; 14.2% vs. closed distal; 22.7%, p = 0.44). Stroke was 26% (open distal; 28.6% vs. closed distal; 22.7%, p = 0.64). Median survival was 7.2 years (IQR; 4.5–11.6 years). Survival was comparable between open and closed distal groups (median 10.6 vs. 7.2 years, p = 0.35, respectively). Critical preoperative status (HR; 3.2, p = 0.03) and composite endpoint (renal replacement therapy, new neurological event, length of stay > 30 days or return to theatre; HR; 4.1, p = 0.02) predicted adverse survival. Open distal anastomosis did no impact survival. Conclusions: ATAAD repair in selected octogenarians has acceptable short- and long-term survival. There is no significant difference between open versus closed distal anastomosis strategies.
Engineering Corrosion Resistance in Magnesium Alloys for Biomedical Applications: A Synergy of Zn/Ca Atomic Ratio and Texture-Based Approach
Authors: Behera Manisha , Shabadi Rajashekhara , Gruescu Cosmin
Published: September 2024

Magnesium (Mg) and Magnesium-Zinc-Calcium alloys present a compelling option for biodegradable implant materials. Utilizing Vacuum Induction Casting, Mg–2.5Zn-xCa (with x = 0.3, 0.5, 0.9, 1.15 wt%) alloys were fabricated and subjected to hot-rolling for thermo-mechanical processing. The hot-rolled Mg–2.5Zn-0.3Ca alloy exhibits the lowest corrosion rate along with the highest basal texture. Increasing the Zn/Ca atomic ratio intensifies the basal texture and enhances corrosion resistance. Elevated Zn concentration improves corrosion resistance via Ca2Mg6Zn3 phase formation, while increased Ca content diminishes corrosion resistance due to the Mg2Ca phase. Advancement of this alloy is poised to extend Mg alloy use in innovative biomedical bone implants.
The Effect of Ultrafast Heating on the Microstructure and Mechanical Properties of the 2.2 GPa Grade Hot Forming Steel
Authors: Wang Mai , Chang Jiang , Wu Hongyi , Mi Zhenli , Wu Yanxin , Zhang Qi
Published: September 2024

The aim of the present work is to evaluate the effect of ultrafast heating on the microstructure and mechanical properties of hot forming steel. The initial microstructure utilized in this study was a cold-rolled microstructure, and the test steel was heated to full austenitization at a rate of 200 °C/s, followed by water quenching. It was observed that the ultrafast heating process significantly refines both the prior austenite grains and martensite laths while inheriting high-density dislocations from the initial cold-rolled microstructure. Consequently, the coupling mechanism between dislocation strengthening and grain refinement strengthening remarkably enhanced both the yield strength and ultimate tensile strength of the test steel. Eventually, the yield strength of the hot forming steel reached 1524 MPa, along with an ultimate tensile strength of 2221 MPa and uniform elongation of 5.2%.
Impact of Phenylketonuria on the Serum Metabolome and Plasma Lipidome: A Study in Early-Treated Patients
Authors: Weerd Jorine C. van der , Wegberg Annemiek M. J. van , Boer Theo S. , Engelke Udo F. H. , Coene Karlien L. M. , Wevers Ron A. , Bakker Stephan J. L. , Blaauw Pim de , Groen Joost , Spronsen Francjan J. van , Heiner-Fokkema M. Rebecca
Published: September 2024

Background: Data suggest that metabolites, other than blood phenylalanine (Phe), better and independently predict clinical outcomes in patients with phenylketonuria (PKU). Methods: To find new biomarkers, we compared the results of untargeted lipidomics and metabolomics in treated adult PKU patients to those of matched controls. Samples (lipidomics in EDTA-plasma (22 PKU and 22 controls) and metabolomics in serum (35 PKU and 20 controls)) were analyzed using ultra-high-performance liquid chromatography and high-resolution mass spectrometry. Data were subjected to multivariate (PCA, OPLS-DA) and univariate (Mann–Whitney U test, p < 0.05) analyses. Results: Levels of 33 (of 20,443) lipid features and 56 (of 5885) metabolite features differed statistically between PKU patients and controls. For lipidomics, findings include higher glycerolipids, glycerophospholipids, and sphingolipids species. Significantly lower values were found for sterols and glycerophospholipids species. Seven features had unknown identities. Total triglyceride content was higher. Higher Phe and Phe catabolites, tryptophan derivatives, pantothenic acid, and dipeptides were observed for metabolomics. Ornithine levels were lower. Twenty-six metabolite features were not annotated. Conclusions: This study provides insight into the metabolic phenotype of PKU patients. Additional studies are required to establish whether the observed changes result from PKU itself, diet, and/or an unknown reason.
Comparative Analysis of the Chemical Constituents of Chrysanthemum morifolium with Different Drying Processes Integrating LC/GC–MS−Based, Non-Targeted Metabolomics
Authors: Chen Na , Fan Jizhou , Li Gang , Guo Xuanxuan , Meng Xiao , Wang Yuqing , Duan Yingying , Ding Wanyue , Liu Kai , Liu Yaowu , Xing Shihai
Published: September 2024

Chrysanthemum morifolium is a perennial herbaceous plant in the Asteraceae family that is used as a medicine and food owing to its superior pharmacological properties. Irrespective of its application, C. morifolium must be dried before use. Shade drying (YG) and heat drying (HG) are the two drying methods used in most origins. Given the abundance of flavonoids, phenolic acids, and terpenoids, the primary medicinal active constituents of C. morifolium, it is important to determine whether the composition and content of these compounds are altered during the drying processes. To test this, the changes in the chemical composition of C. morifolium flowers after YG and HG using full-spectrum, non-targeted LC/GC–MS−based metabolomics and, subsequently, the three indicator components of C. morifolium—chlorogenic acid, 3,5−dicaffeoylquinic acid, and luteolin−7−O−glucoside—were accurately quantified by HPLC. The results of the non-targeted metabolomics analysis revealed that YG- and HG-processed C. morifolium differed significantly with respect to chemical contents, especially flavonoids, phenolic acids, and terpenoids. The levels of the indicator components and their precursors also differed significantly between the YG and HG treatments. The contents of most of the flavonoids and key phenolic acids, terpenoids, and carbohydrates were higher with YG than with HG pre-treatment. These results revealed the changes in the chemical composition of C. morifolium during the YG and HG processes, thus providing a reference for the further optimization of the production and processing of chrysanthemums.
Current Research Status and Future Trends of Vibration Energy Harvesters
Authors: Qu Guohao , Xia Hui , Liang Quanwei , Liu Yunping , Ming Shilin , Zhao Junke , Xia Yushu , Wu Jianbo
Published: September 2024

The continuous worsening of the natural surroundings requires accelerating the exploration of green energy technology. Utilising ambient vibration to power electronic equipment constitutes an important measure to address the power crisis. Vibration power is widely dispersed in the surroundings, such as mechanical vibration, acoustic vibration, wind vibration, and water wave vibration. Collecting vibration energy is one of the research hotspots in the field of energy. Meanwhile, it is also an important way to solve the energy crisis. This paper illustrates the working principles and recent research progress of five known methods of vibrational energy harvesting, namely, electromagnetic, piezoelectric, friction electric, electrostatic, and magnetostrictive vibrational energy harvesters. The strengths and weaknesses of each method are summarised. At the end of the article, the future trends of micro-nano vibrational energy collectors are envisioned.
Monitoring Escherichia coli in Water through Real-Time Loop-Mediated Isothermal Amplification on Biochips
Authors: Wang Yuxin , Chan Yun-Sheng , Lee Eugene , Shi Donglu , Lee Chen-Yi , Diao Jiajie
Published: September 2024

Access to clean water is fundamental to public health and safety, serving as the cornerstone of well-being in communities. Despite the significant investments of millions of dollars in water testing and treatment processes, the United States continues to grapple with over 7 million waterborne-related cases annually. This persistent challenge underscores the pressing need for the development of a new, efficient, rapid, low-cost, and reliable method for ensuring water quality. The urgency of this endeavor cannot be overstated, as it holds the potential to safeguard countless lives and mitigate the pervasive risks associated with contaminated water sources. In this study, we introduce a biochip LAMP assay tailored for water source monitoring. Our method swiftly detects even extremely low concentrations of Escherichia coli (E. coli) in water, and 10 copies/μL of E. coli aqueous solution could yield positive results within 15 min on a PC-MEDA biochip. This innovation marks a significant departure from the current reliance on lab-dependent methods, which typically necessitate several days for bacterial culture and colony counting. Our multifunctional biochip system not only enables the real-time LAMP testing of crude E. coli samples but also holds promise for future modifications to facilitate on-site usage, thereby revolutionizing water quality assessment and ensuring rapid responses to potential contamination events.
Opportunities and Challenges in the Synthesis of Noble Metal Nanoparticles via the Chemical Route in Microreactor Systems
Authors: Pach Adrianna , Szot Aleksandra , Fitzner Krzysztof , Luty-Błocho Magdalena
Published: September 2024

The process of noble metal nanoparticle synthesis is complex and consists of at least two steps: slow nucleation and fast autocatalytic growth. The kinetics of these two processes depends on the reductant “power” and the addition of stabilizers, as well as other factors (e.g., temperature, pH, ionic strength). Knowing these parameters, it is possible to synthesize materials with appropriate physicochemical properties, which can be simply adjusted by the type of the used metal, particle morphology and surface property. This, in turn, affects the possibility of their applications in various areas of life, including medicine, catalysis, engineering, fuel cells, etc. However, in some cases, the standard route, i.e., the chemical reduction of a metal precursor carried out in the batch reactor, is not sufficient due to problems with temperature control, properties of reagents, unstable or dangerous intermediates and products, etc. Therefore, in this review, we focused on an alternative approach to their chemical synthesis provided by microreactor systems. The use of microreactors for the synthesis of noble metal nanomaterials (e.g., Ag, Au, Pt, Pd), obtained by chemical reduction, is analyzed, taking into account investigations carried out in recent years. A particular emphasis is placed on the processes in which the use of microreactors removed the limitations associated with synthesis in a batch reactor. Moreover, the opportunities and challenges related to the synthesis of noble nanomaterials in the microreactor system are underlined. This review discusses the advantages as well as the problems of nanoparticle synthesis in microreactors.
Development of a Miniaturized 2-Joule Pulsed Plasma Source Based on Plasma Focus Technology: Applications in Extreme Condition Materials and Nanosatellite Orientation
Authors: Soto Leopoldo , Pavez Cristian , Pedreros José , Jain Jalaj , Moreno José , San Martín Patricio , Castillo Fermín , Zanelli Daniel , Altamirano Luis
Published: September 2024

Plasma focus devices represent a class of hot and dense plasma sources that serve a dual role in fundamental plasma research and practical applications. These devices allow the observation of various phenomena, including the z-pinch effect, nuclear fusion reactions, plasma filaments, bursts, shocks, jets, X-rays, neutron pulses, ions, and electron beams. In recent years, considerable efforts have been directed toward miniaturizing plasma focus devices, driven by the pursuit of both basic studies and technological advancements. In this paper, we present the design and construction of a compact, portable pulsed plasma source based on plasma focus technology, operating at the ~2–4 Joule energy range for versatile applications (PF-2J: 120 nF capacitance, 6–9 kV charging voltage, 40 nH inductance, 2.16–4.86 J stored energy, and 10–15 kA maximum current at short circuit). The components of the device, including capacitors, spark gaps, discharge chambers, and power supplies, are transportable within hand luggage. The electrical characteristics of the discharge were thoroughly characterized using voltage and current derivative monitoring techniques. A peak current of 15 kiloamperes was achieved within 110 nanoseconds in a short-circuit configuration at a 9 kV charging voltage. Plasma dynamics were captured through optical refractive diagnostics employing a pulsed Nd-YAG laser with a 170-picosecond pulse duration. Clear evidence of the z-pinch effect was observed during discharges in a deuterium atmosphere at 4 millibars and 6 kilovolts. The measured pinch length and radius were approximately 0.8 mm and less than 100 μm, respectively. Additionally, we explore the potential applications of this compact pulsed plasma source. These include its use as a plasma shock irradiation device for analyzing materials intended for the first wall of nuclear fusion reactors, its capability in material film deposition, and its utility as an educational tool in experimental plasma physics. We also show its potential as a pulsed plasma thruster for nanosatellites, showcasing the advantages of miniaturized plasma focus technology.
Editorial for the Special Issue on Micro and Nanosensors: Fabrication, Applications and Performance Enhancements
Authors: Smajdor Joanna
Published: September 2024

The advancement of electrochemical sensors is an expanding area of research that is drawing growing interest from scientists worldwide [...]
Calcium Rescues Streptococcus pneumoniae D39 ΔmntE Manganese-Sensitive Growth Phenotype
Authors: Opoku Reuben , Carrasco Edgar , De Lay Nicholas R. , Martin Julia E.
Published: September 2024

Calcium (Ca2+) functions as a universal signal messenger in eukaryotes but in bacteria, the physiological roles for Ca2+ are limited. Here, we examine the role of Ca2+ in Streptococcus pneumoniae during manganese (Mn2+) intoxication. S. pneumoniae mntE mutants, lacking the Mn2+ efflux transporter, exhibit impaired growth due to accumulation of Mn2+ when exposed to elevated exogenous Mn2+. This Mn2+-sensitive growth defect is restored to wild-type growth level by exogenous Ca2+, in a Ca2+-dependent manner. Despite growth restoration of the mntE mutant to wild-type levels, cellular Mn2+ remains elevated in this strain. Bacterial capsule production is also increased for the mntE mutant, resulting in reduced adherence capacity to surfaces and poor biofilm formation, which is consistent with it experiencing Mn2+ intoxication. Ca2+ presence did not significantly impact bacterial capsule production or biofilm formation. Further analysis of the cell morphology demonstrates that Ca2+ contributes to cell division and reduces cell chain lengths. Together, these data describe the first role of Ca in S. pneumoniae that has potential implications in bacterial virulence since Ca affects cell division and likely Mn2+-associated cellular processes.
Molecular Evolutionary Analyses of Shiga toxin type 2 subunit A Gene in the Enterohemorrhagic Escherichia coli (EHEC)
Authors: Kimura Ryusuke , Kimura Hirokazu , Shirai Tatsuya , Hayashi Yuriko , Sato-Fujimoto Yuka , Kamitani Wataru , Ryo Akihide , Tomita Haruyoshi
Published: September 2024

To better understand the molecular genetics of the Shiga toxin type 2 subunit A gene (stx2A gene), we collected many subtypes of stx2A genes and performed detailed molecular evolutionary analyses of the gene. To achieve the aim of the study, we used several bioinformatics technologies, including time-scaled phylogenetic analyses, phylogenetic distance analyses, phylodynamics analyses, selective pressure analyses, and conformational epitope analyses. A time-scaled phylogeny showed that the common ancestor of the stx2A gene dated back to around 18,600 years ago. After that, the gene diverged into two major lineages (Lineage 1 and 2). Lineage 1 comprised the stx2a–2d subtypes, while Lineage 2 comprised the stx2e, 2g, 2h, and 2o subtypes. The evolutionary rates of the genes were relatively fast. Phylogenetic distances showed that the Lineage 2 strains had a wider genetic divergence than Lineage 1. Phylodynamics also indicated that the population size of the stx2A gene increased after the 1930s and spread globally. Moreover, negative selection sites were identified in the Stx2A proteins, and these sites were diffusely distributed throughout the protein. Two negative selection sites were located adjacent to an active site of the common Stx2A protein. Many conformational epitopes were also estimated in these proteins, while no conformational epitope was found adjacent to the active site. The results suggest that the stx2A gene has uniquely evolved and diverged over an extremely long time, resulting in many subtypes. The dominance of the strains belonging to Lineage 1 suggests that differences in virulence may be involved in the prosperity of the offspring. Furthermore, some subtypes of Stx2A proteins may be able to induce effective neutralizing antibodies against the proteins in humans.
A Genome-Focused Investigation Reveals the Emergence of a Mycobacterium tuberculosis Strain Related to Multidrug-Resistant Tuberculosis in the Amazon Region of Brazil
Authors: Conceição Emilyn Costa , Loubser Johannes , Guimarães Arthur Emil dos Santos , Sharma Abhinav , Rutaihwa Liliana Kokusanilwa , Dippenaar Anzaan , Salvato Richard Steiner , de Paula Souza e Guimarães Ricardo José , da Silva Lourenço Maria Cristina , Barros Wandyra Araújo , Cardoso Ninarosa Calzavara , Warren Robin Mark , Gagneux Sebastien , Grinsztejn Beatriz Gilda Jegerhorn , Suffys Philip Noel , Lima Karla Valéria Batista
Published: September 2024

A previous study in Pará, Northern Brazil, described a strain of Mycobacterium tuberculosis with a unique genotype (SIT2517/T1) associated with multidrug-resistant tuberculosis (MDR-TB). To improve our understanding of MDR-TB transmission dynamics of these strains within this region, we performed phenotypic and genotypic drug susceptibility testing (pDST/gDST), 24-loci mycobacterial interspersed repetitive units (MIRU-VNTR) genotyping, whole-genome sequencing (WGS) and geo-epidemiology analysis. Of the 28 SIT2517/T1 isolates, 19 (67.9%) could be genotyped by 24-loci MIRU-VNTR and 15 by WGS. All belonged to sublineage 4.1.1.3, distinct from other representative Lineage 4 isolates identified in Brazil. The MDR phenotype determined by pDST was confirmed by gDST, the latter also demonstrating the presence of additional mutations conferring pre-extensively drug-resistance (pre-XDR). Discrepancies between gDST and pDST were observed for pyrazinamide and fluoroquinolones. Thirteen out of 15 isolates analyzed by WGS were clustered when applying a 12 single nucleotide polymorphisms (SNPs) cutoff. The SIT2517/T1 isolates were distributed across the metropolitan regions of Belém and Collares municipalities, showing no geographic clustering. WGS-transmission network analysis revealed a high likelihood of direct transmission and the formation of two closely linked transmission chains. This study highlights the need to implement TB genomic surveillance in the Brazilian Amazon region.
Isolation and Characterization of High-Temperature-Tolerant Mutants of Bradyrhizobium diazoefficiens USDA110 by Carbon-Ion Beam Irradiation
Authors: Satoh Katsuya , Takeda Kiyoko , Nagafune Ikuko , Chik Wan Dalila Wan , Ohkama-Otsu Naoko , Okazaki Shin , Yokoyama Tadashi , Hase Yoshihiro
Published: September 2024

Biofertilizers are promising technologies for achieving sustainable agriculture. However, high-temperature tolerance is a constraint that limits the function of microbial inoculants. To characterize the genetic changes responsible for the high-temperature tolerance of rhizobia, mutant screening was performed using Bradyrhizobium diazoefficiens USDA110. The wild-type cells were mutagenized with carbon-ion irradiation, and two mutant strains, designated M10 and M14, were obtained after a three-day heat-shock treatment at 43 °C. In particular, M14 showed superior growth at 36 °C, at which temperature growth of the wild type was extremely slow, whereas M14 grew more slowly than the wild type at 32 °C. Whole-genome sequencing revealed that M10 had seven point mutations, whereas M14 had eight point mutations together with a 1.27 Mb inversion. RNA sequencing showed that the number of differentially expressed genes greatly exceeded the actual number of induced mutations. In M14, a gene cluster associated with pyruvate metabolism was markedly downregulated, probably because of disjunction with the promoter region after inversion, and was considered to be the cause of the slow growth rate of M14 at 32 °C. Notably, transmembrane proteins, including porins, were enriched among the genes upregulated in both M10 and M14. M14 was confirmed to retain symbiotic functions with soybeans. These results indicate that high-temperature tolerance was conferred by random mutagenesis while the symbiotic functions of rhizobia was maintained.
Hyperpolarized 13C NMR Reveals Pathway Regulation in Lactococcus lactis and Metabolic Similarities and Differences Across the Tree of Life
Authors: Meier Sebastian , Zahid Alexandra L. N. , Jørgensen Lucas Rebien , Wang Ke-Chuan , Jensen Peter Ruhdal , Jensen Pernille Rose
Published: September 2024

The control of metabolic networks is incompletely understood, even for glycolysis in highly studied model organisms. Direct real-time observations of metabolic pathways can be achieved in cellular systems with 13C NMR using dissolution Dynamic Nuclear Polarization (dDNP NMR). The method relies on a short-lived boost of NMR sensitivity using a redistribution of nuclear spin states to increase the alignment of the magnetic moments by more than four orders of magnitude. This temporary boost in sensitivity allows detection of metabolism with sub-second time resolution. Here, we hypothesized that dDNP NMR would be able to investigate molecular phenotypes that are not easily accessible with more conventional methods. The use of dDNP NMR allows real-time insight into carbohydrate metabolism in a Gram-positive bacterium (Lactoccocus lactis), and comparison to other bacterial, yeast and mammalian cells shows differences in the kinetic barriers of glycolysis across the kingdoms of life. Nevertheless, the accumulation of non-toxic precursors for biomass at kinetic barriers is found to be shared across the kingdoms of life. We further find that the visualization of glycolysis using dDNP NMR reveals kinetic characteristics in transgenic strains that are not evident when monitoring the overall glycolytic rate only. Finally, dDNP NMR reveals that resting Lactococcus lactis cells use the influx of carbohydrate substrate to produce acetoin rather than lactate during the start of glycolysis. This metabolic regime can be emulated using suitably designed substrate mixtures to enhance the formation of the C4 product acetoin more than 400-fold. Overall, we find that dDNP NMR provides analytical capabilities that may help to clarify the intertwined mechanistic determinants of metabolism and the optimal usage of biotechnologically important bacteria.
Investigation of the Structural Properties and Antioxidant Potency of Pectic Polysaccharides Derived from Rohdea japonica (Thunb.) Roth
Authors: Yan Su , Lin Zhiying , Cui Kuo , Zang Hao , Zhou Yifa , Zhang Lihui , Liu Duo
Published: September 2024

This study investigated the structural composition and antioxidant properties of pectic polysaccharides extracted from Rohdea japonica (Thunb.) Roth. Pectins, which belong to a complex category of acidic polysaccharides, possess a wide range of biological effects stemming from their distinctive structural domains. The polysaccharides were extracted using water, and were subsequently purified through ion exchange and gel permeation chromatography. In order to elucidate their structural features, Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance techniques were applied. Two specific polysaccharides, WRJP-A2a and WRJP-A3b, with molecular weights of 42.7 kDa and 64.1 kDa, respectively, were identified to contain varying proportions of homogalacturonan, rhamnogalacturonan I, and rhamnogalacturonan II domains. Regarding antioxidant capacity, WRJP-A3b exhibited superior scavenging capabilities against DPPH, ABTS, and hydroxyl radicals, potentially attributed to its higher galacturonic acid content and abundance of homogalacturonan domains. These results enhance our comprehension of the structure–activity interplay of pectic polysaccharides sourced from Rohdea japonica (Thunb.) Roth and their potential utility in the healthcare and functional food sectors.