bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxygen Vacancies Enrichment in Citric Acid‐Assisted Synthesis of Zirconia Supported Ni Catalyst for Highly Selective Hydrogenolysis of 5‐Hydroxymethylfurfural
Authors: Guo Dongwen , Wang Feng , Xu Qiong , Yin Dulin , Liu Xianxiang
Published: June 2024

2, 5‐Dimethylfuran (DMF), which is a promising new‐generation liquid biofuel, has attracted widespread attention owing to the sustainability of biomass‐derived energy sources. In this study, a highly dispersed zirconia‐supported nickel catalyst (CA−Ni/ZrO2) was prepared via citric acid‐assisted wetness impregnation for the selective hydrogenolysis of 5‐hydroxymethylfurfural (HMF) to produce DMF. The characterization results confirmed the presence of Zr3+ species in the mesoporous CA−Ni/ZrO2 catalyst and the formation of oxygen vacancies during its preparation, which led to the formation of a large number of catalytically active sites for the adsorption and activation of the C=O/C−O groups. Under appropriate reaction parameters, an excellent DMF selectivity of 99.1 % and an HMF conversion of 98.4 % were achieved. A suitable kinetic model revealed that DMF was preferentially formed via the 2,5‐dihydroxymethylfuran intermediate route, although a 5‐methylfurfural route was also observed. Additionally, the interaction between Ni and ZrO2 significantly affected the stability of the catalyst. This study will provide guidelines for optimizing the catalytic conversion of furan derivatives over heterogeneous catalysts.
The Effect of Anti‐Procyclical Central Counterparty Margins On Trading
Authors: Bhanu Aniket
Published: June 2024

The last decade has seen substantial research and debates on the procyclicality of Central Counterparty (CCP) margins, but these are limited to the sensitivity of margin models to market conditions. This paper establishes the effect of feedback loop between the sensitivity of margin models and trading behavior. It utilizes unique design and high‐frequency data from Indian markets to conduct an event study surrounding the revisions in the margin models to enhance their anti‐procyclicality (APC) characteristics. The analysis shows that current period volatility influences position exits in the subsequent period and vice‐versa. The analysis further shows that for the same price movement, position exits are lowered under stronger APC margin. The effect is weaker for participants having variation losses, where limiting losses may be an additional incentive to exit positions in addition to rise in initial margins. The findings support the argument that better APC characteristics of CCP margins can attenuate volatility.
Brain Tumor Segmentation Based on α‐Expansion Graph Cut
Authors: Soloh Roaa , Alabboud Hassan , Shahin Ahmad , Yassine Adnan , El Chakik Abdallah
Published: June 2024

In recent years, there has been an increased interest in using image processing, computer vision, and machine learning in biological and medical imaging research. One area of this interest is the diagnosis of brain tumors, which is considered a difficult and time‐consuming task traditionally performed manually. In this study, we present a method for tumor detection from magnetic resonance images (MRI) using a well‐known graph‐based algorithm, the Boykov–Kolmogorov algorithm, and the α‐expansion method. This approach involves pre‐processing the MRIs, representing the image positions as nodes, and calculations of the weights between edges as differences in intensity. The problem is formulated as an energy minimization problem and is solved by finding the 0,1 score for the image. Post‐processing is also performed to enhance the overall segmentation. The proposed method is easy to implement and shows high accuracy, precision, and efficiency in the results. We believe that this approach will bring significant benefits to scientists and healthcare researchers in qualitative research and can be applied to various imaging modalities for future research.
HOXC6‐mediated transcriptional activation of ENO2 promotes oral squamous cell carcinoma progression through the Warburg effect
Authors: Feng Jing , Fang Jin
Published: June 2024

Oral squamous cell carcinoma (OSCC) requires an in‐depth exploration of its molecular mechanisms. The Warburg effect, along with the oncogenes enolase 2 (ENO2) and homeobox C6 (HOXC6), plays a central role in cancer. However, the specific interaction between ENO2 and HOXC6 in driving the Warburg effect and OSCC progression remains poorly understood. Through differential gene expression analysis in head and neck squamous cell carcinomas using Gene Expression Profiling Interactive Analysis, we identified upregulated ENO2 in OSCC. Silencing ENO2 in OSCC cells revealed its involvement in migration, invasion, and aerobic glycolysis of OSCC cells. Further exploration of ENO2's regulatory network identified HOXC6 as a potential transcriptional regulator. Subsequently, HOXC6 was silenced in OSCC cells, and expressions of ENO2 were assessed to validate its relationship with ENO2. Chromatin Immunoprecipitation and luciferase assays were utilized to investigate the direct transcriptional activation of ENO2 by HOXC6. A rescue assay co‐overexpressing ENO2 and silencing HOXC6 in OSCC cells affirmed HOXC6's role in ENO2‐associated glycolysis. High ENO2 expression in OSCC was validated through quantitative real‐time polymerase chain reaction, Western blot, and immunohistochemistry analyses, which correlated with poor patient survival. Functional assays demonstrated that ENO2 silencing inhibited glycolysis and attenuated the aggressiveness of OSCC cells. In vivo studies confirmed the oncogenic role of ENO2 in OSCC growth. Notably, HOXC6 exhibited a positive correlation with ENO2 expression in clinical samples. Mechanistically, HOXC6 was identified as a direct transcriptional activator of ENO2, orchestrating the Warburg effect in OSCC cells. This study reveals the intricate link between HOXC6‐mediated ENO2 transcriptional activation and the Warburg effect in OSCC, offering a potential therapeutic target for treating OSCC patients.
Exploring the influence of metal cations on individual hydrogen bonds in Watson–Crick guanine–cytosine DNA base pair: An interacting quantum atoms analysis
Authors: Pakzad F. , Eskandari K.
Published: June 2024

This study delves into the nature of individual hydrogen bonds and the relationship between metal cations and hydrogen bonding in the Watson–Crick guanine–cytosine (GC) base pair and its alkali and alkaline earth cation‐containing complexes (Mn+–GC). The findings reveal how metal cations affect the nature and strength of individual hydrogen bonds. The study employs interacting quantum atoms (IQA) analysis to comprehensively understand three individual hydrogen bonds within the GC base pair and its cationic derivatives. These analyses unveil the nature and strength of hydrogen bonds and serve as a valuable reference for exploring the impact of cations (and other factors) on each hydrogen bond. All the HD interactions (H is hydrogen and D is oxygen or nitrogen) in the GC base pair are primarily electrostatic in nature, with the charge transfer component playing a substantial role. Introducing a metal cation perturbs all HD interatomic interactions in the system, weakening the nearest hydrogen bond to the cation (indicated by a) and reinforcing the other (b and c) interactions. Notably, the interaction a, the strongest HD interaction in the GC base pair, becomes the weakest in the Mn+–GC complexes. A broader perspective on the stability of GC and Mn+–GC complexes is provided through interacting quantum fragments (IQF) analysis. This approach considers all pairwise interactions between fragments and intra‐fragment components, offering a complete view of the factors that stabilize and destabilize GC and Mn+–GC complexes. The IQF analysis underscores the importance of electron sharing, with the dominant contribution arising from the inter‐fragment exchange‐correlation term, in shaping and sustaining GC and Mn+–GC complexes. From this point of view, alkaline and alkaline earth cations have distinct effects, with alkaline cations generally weakening inter‐fragment interactions and alkaline earth cations strengthening them. In addition, IQA and IQF calculations demonstrate that the hydration of cations led to small changes in the hydrogen bonding network. Finally, the IQA interatomic energies associated with the hydrogen bonds and also inter‐fragment interaction energies provide robust indicators for characterizing hydrogen bonds and complex stability, showing a strong correlation with total interaction energies.
Gp93 inhibits unfolded protein response‐mediated c‐Jun N‐terminal kinase activation and cell invasion
Authors: Xu Meng , Wu Zhihan , Li Wenzhe , Xue Lei
Published: June 2024

In eukaryotes, Hsp90B1 serves as a vital chaperonin, facilitating the accurate folding of proteins. Interestingly, Hsp90B1 exhibits contrasting roles in the development of various types of cancers, although the underlying reasons for this duality remain enigmatic. Through the utilization of the Drosophila model, this study unveils the functional significance of Gp93, the Drosophila ortholog of Hsp90B1, which hitherto had limited reported developmental functions. Employing the Drosophila cell invasion model, we elucidated the pivotal role of Gp93 in regulating cell invasion and modulating c‐Jun N‐terminal kinase (JNK) activation. Furthermore, our investigation highlights the involvement of the unfolded protein response‐associated IRE1/XBP1 pathway in governing Gp93 depletion‐induced, JNK‐dependent cell invasion. Collectively, these findings not only uncover a novel molecular function of Gp93 in Drosophila, but also underscore a significant consideration pertaining to the testing of Hsp90B1 inhibitors in cancer therapy.
Anatomy and micromorphology of Tilia species from Turkey and its taxonomic implication
Authors: Strelnikov Beste Gökhan , Gürdal Bahar
Published: June 2024

The genus Tilia L. belongs to Malvaceae and it is represented by four species in Turkey. These are T. cordata, T. platyphyllos, T. rubra subsp. caucasica, and T. tomentosa. Tilia species have medicinal importance, especially to treat colds, flu, and coughs, and are also used as sedatives. Inflorescence with bract is recorded in the pharmacopeia as used parts. This study aimed to investigate the differences in leaf and bract characteristics in distinguishing Tilia species. Leaves and bracts were examined anatomically and micromorphologically under light and scanning electron microscopes (LM and SEM). There is no comparative anatomical and micromorphological study of Tilia species from Turkey. Microscopic examination allows for the observation of stomata types, trichomes, and other anatomical structures. These features can vary among species and can aid in differentiation. Features of bract that is medicinally used part were evaluated to find efficient diagnostic characters. The leaves also possess distinct characteristics, and leaf morphology is already used in the identification key in Flora. The emphasis is on identifying the species of medically used drugs. A diagnostic key was created using LM and SEM based on bract features to differentiate taxa for the first time.

Research Highlights

Leaf and bract anatomy of Tilia taxa was studied via LM and SEM.

The raw plant material is inflorescence with bract so identification by bract is important for species adulteration.

An diagnostic key based on bract features was created for the first time.
Adjuvant imatinib in high‐risk resected gastrointestinal stromal tumors: Merely delaying the inevitable?
Authors: Sutton Thomas L. , Billingsley Kevin G. , Johnson Alicia J. , Corless Christopher L. , Blanke Charles D. , Heinrich Michael C. , Mayo Skye C.
Published: June 2024

Introduction

Patients with high‐risk resected gastrointestinal stromal tumors (GIST) receiving adjuvant imatinib have improved recurrence‐free survival (RFS), however whether a complete cytocidal effect exists is unknown. We investigated this using a normalized recurrence timeline measured from end of oncologic treatment (EOOT), defined as the later of resection or end of adjuvant therapy.

Methods

We reviewed patients with resected high‐risk GIST at our cancer center from 2003 to 2018. RFS (measured from resection and EOOT), overall survival (OS), and time to imatinib resistance (TTIR) were analyzed using Kaplan‐Meier analysis and multivariable Cox proportional hazards modeling. The performance of the Memorial Sloan Kettering (MSK) GIST nomogram was assessed.

Results

We identified 86 patients with high‐risk GIST with a median 106 months of postsurgical follow‐up. One‐third (n = 29; 34%) did not receive adjuvant imatinib, while 57 (66%) did for a median of 3 years. The MSK nomogram‐predicted 5‐year RFS for patients receiving adjuvant imatinib was similar to those who did not (29% vs. 31%, p = 0.64). When RFS was measured from EOOT, the MSK‐predicted RFS was independently associated with EOOT RFS (hazard ratio 0.22, p = 0.02), while adjuvant imatinib receipt and duration were not. Neither receipt nor duration of adjuvant imatinib were associated with TTIR or OS (all p > 0.05).

Conclusions

Treatment with adjuvant imatinib delays, but does not clearly impact ultimate recurrence, TTIR, or OS, suggesting many patients with high‐risk GIST may receive adjuvant imatinib unnecessarily. Additional studies are needed to establish the benefit of adjuvant therapy versus initiating therapy at first radiographic recurrence.
Latrophilin‐3 as a downstream effector of the androgen receptor induces urothelial tumorigenesis
Authors: Goto Takuro , Yasui Masato , Teramoto Yuki , Nagata Yujiro , Mizushima Taichi , Miyamoto Hiroshi
Published: June 2024

Emerging evidence indicates that androgen receptor (AR) signaling plays a critical role in the pathogenesis of male‐dominant urothelial cancer. Meanwhile, latrophilins (LPHNs), a group of the G‐protein‐coupled receptor to which a spider venom latrotoxin is known to bind, remain largely uncharacterized in neoplastic diseases. The present study aimed to determine the functional role of LPHN3 (encoded by the ADGRL3 gene), in association with AR signaling, in urothelial tumorigenesis. In human normal urothelial SVHUC cells, AR overexpression and androgen treatment considerably increased the expression levels of ADGRL3/LPHN3, while chromatin immunoprecipitation assay revealed the binding of AR to the promoter region of ADGRL3. In SVHUC or SVHUC‐AR cells with exposure to a chemical carcinogen 3‐methylcholanthrene, LPHN3 activation via ligand (e.g., α‐latrotoxin, FLRT3) treatment during the process of the neoplastic/malignant transformation or LPHN3 knockdown via shRNA virus infection induced or reduced, respectively, the oncogenic activity. In N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine‐treated female mice, α‐latrotoxin or FLRT3 injection accelerated the development of bladder tumors. Immunohistochemistry in surgical specimens further showed the significantly elevated expression of LPHN3 in non‐muscle‐invasive bladder tumors, compared with adjacent normal urothelial tissues, which was associated with a marginally (p = 0.051) higher risk of disease recurrence after transurethral resection. In addition, positivity of LPHN3 and AR in these tumors was strongly correlated. These findings indicate that LPHN3 functions as a downstream effector of AR and promotes urothelial tumorigenesis.
Impact of concentration and aging time of pea starch‐based polymeric solutions on the fabrication of electrospun nanofibers
Authors: da Cruz Elder Pacheco , dos Santos Felipe Nardo , de Souza Jaqueline Ferreira , de Souza Estefania Júlia Dierings , Fonseca Laura Martins , Fajardo André Ricardo , da Zavareze Elessandra Rosa , Dias Alvaro Renato Guerra
Published: June 2024

Polymer concentration and aging time of polymeric solutions are crucial factors that can influence their viscosity, playing an essential role in the fabrication of electrospun nanofibers. Based on this, herein we evaluated the impact of aging time (24 and 48 h) and pea starch concentration (10%, 20%, and 30%, wt/vol) on the polymeric solutions to produce electrospun nanofibers. Solutions were evaluated by rheology, electrical conductivity, and degree of substitution. The nanofibers were analyzed by morphology, size distribution, chemical nature, and thermal properties. The degree of substitution of starches varied from 1.17 to 1.56. Overall, electrical conductivity decreased with increasing starch concentration and aging time of the polymeric solutions. The use of 10% starch displayed a transition from capsules to fibers, while 20% and 30% starch were able to manufacture homogenous, cylindrical, and random nanofibers with diameters varying from 89 to 373 nm. A significant impact of viscosity was not observed; on the other hand, aging time increased the average diameter of nanofibers. Besides, the fabricated nanofibers showed a lower decomposition temperature than raw starch. The fabricated nanofibers have great potential as wall materials for the encapsulation of different compounds and applications in the biomedical and food sectors.
Effects of temperature and low strain rate on tensile performance of aramid fiber bundle
Authors: Wang Haiwen , Gao Wenbo , Zhou Xinwei , Ren Peng
Published: June 2024

In this research, the effects of ultimate strain rate and environmental temperature on the mechanical performance of the aramid fiber bundles were experimentally investigated. The scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to detect the tensile failure mechanism of the aramid fiber bundle. The results indicated that the tensile strength, failure strain, elastic modulus, and toughness of the aramid fiber bundle were sensitive to the strain rate, which was represented as the typical bilinear monotonic relationships. In contrast, the impact of environmental temperature on the four parameters of aramid fiber bundle was more complex. The ultimate strength, failure strain and toughness of aramid fiber bundle increased with the temperature changing from −60 to 30°C, but rapidly decreased from 30 to 90°C. Finally, the dispersion of the mechanical performance was quantitatively analyzed based on the scale and shape parameters obtained from Weibull model.

Highlights

Tensile tests for aramid fiber bundle under different strain rates and temperatures were conducted.

Strain rate and temperature effects on tensile properties of fiber bundle were quantified.

Tensile failure mechanism of fiber bundle was analyzed.

Dispersion of the mechanical performance was quantitatively analyzed.
Hydrophobic or hydrophilic microhelices: Crafting surfaces with electrospun magnetic polystyrene fiber and an innovative top‐down technique
Authors: Mohan Aakanksha , Ramanan Sutapa Roy
Published: June 2024

Microhelices are important structures capable of overcoming low Reynolds number limitations and can be used in various applications. The fabrication of such microhelices is a challenge as existing fabrication techniques are restrictive in material choices and require sophisticated equipment. In this work, we demonstrate a simple top‐down approach to fabricate microhelical structures using surface modification of helical electrospun fibers to produce both hydrophilic, silica‐coated (Si‐HMPF), and hydrophobic, caramel sol‐based (Ca‐HMPF) magnetic microhelices post‐modification. The glassy coating obtained on the surface in both cases facilitated obtaining magnetic microhelices via mechanical fracture of the fibers by grinding at room temperature. SEM images of the samples confirm the successful fabrication of microhelical structures which resemble the popular microswimmer morphology. The FTIR and VSM characterization were performed to study the functional groups present and the magnetic nature of the fabricated microhelices. The thermal stability of the samples was investigated using DSC and TGA studies. Both hydrophilic and hydrophobic magnetic microhelices were successfully fabricated through a simple sol‐based coating technique and confirmed by a wettability study.

Highlights

Helical microstructures are an important classification of micro/nanomaterial synthesis.

A simple method for the fabrication of magnetic polymeric microhelices is proposed and discussed in detail.

The current challenges in fabricating such structures are discussed.

The advantages of using a simple surface modification technique is summarized.
Thirty‐day risk of digoxin toxicity among older adults co‐prescribed trimethoprim‐sulfamethoxazole versus amoxicillin: A population‐based cohort study
Authors: Muanda Flory T. , Weir Matthew A. , Ahmadi Fatemeh , McArthur Eric , Sontrop Jessica M. , Abdullah Sheikh S. , Urquhart Brad L. , Sadeghi Hasti , Kim Richard B. , Garg Amit X.
Published: June 2024

Importance

Trimethoprim‐sulfamethoxazole (TMP‐SMX) may increase digoxin concentration, a medication with a narrow therapeutic index. Small changes in digoxin concentration could predispose individuals to the risk of toxicity.

Objective

To characterize the risk of digoxin toxicity in older adults taking digoxin following co‐prescription of TMP‐SMX compared with co‐prescription of amoxicillin.

Design, Settings, and Participants

Retrospective population‐based cohort study in Ontario, Canada (2002–2020) using linked health care data. Participants comprised 47,961 older adults taking digoxin (58% women; median age 80 years [interquartile range 74–86]) who were newly treated with TMP‐SMX (n = 10,273) compared with those newly treated with amoxicillin (n = 37,688).

Exposure

Co‐prescription of TMP‐SMX versus amoxicillin in older adults concurrently taking digoxin.

Main Outcome and Measure

The primary outcome was a hospital encounter (i.e., hospital admission or emergency department visit) with digoxin toxicity within 30 days of the antibiotic prescription. Inverse probability of treatment weighting on the propensity score was used to balance comparison groups on indicators of baseline health. Weighted risk ratios (RR) were obtained using modified Poisson regression and weighted risk differences (RD) using binomial regression. The number needed to harm (NNH) was calculated as 1/RD.

Results

A hospital encounter with digoxin toxicity occurred in 49/10,273 (0.48%) patients treated with TMP‐SMX versus 32/37,688 (0.08%) in those treated with amoxicillin (weighted RR, 5.71 [95% confidence interval (CI), 3.19 to 10.24]; weighted RD, 0.39% [95% CI, 0.25% to 0.53%]; NNH 256 [95% CI, 233 to 400]).

Conclusion and Relevance

In older adults taking digoxin, the 30‐day risk of a hospital encounter with digoxin toxicity was nearly 6 times higher in those co‐prescribed TMP‐SMX versus amoxicillin, although the absolute risk difference was low (0.4%). Physicians should prescribe an alternative antibiotic when clinically appropriate. If TMP‐SMX must be co‐prescribed with digoxin (if the benefit is believed to outweigh the risk), digoxin should be dose‐reduced on an individual basis.
Using the universal design for learning framework to improve child and adolescent mental health
Authors: Pereira Liane C. , Ith Deborah A.
Published: June 2024

Poor mental health in childhood and adolescence has a significant impact on both physical and mental health throughout life. However, growing evidence suggests that current levels of child and adolescent mental health (CAMH) care are insufficient to meet the needs of many children and adolescents in the United States as evidenced by increasing rates of mental health problems, inequities in diagnosis, and inaccessibility of services. This article provides a discussion of current problems in CAMH and school mental health services and emphasizes a developmental perspective of CAMH, including the co‐occurrence of school difficulties and mental health concerns. A universal design for learning framework for school‐wide mental health programs is suggested as a means of addressing barriers to care and promoting prevention and early intervention in CAMH.
Navigating academia: Designing and evaluating a multidimensional recommendation system for university and major selection
Authors: Somyürek Sibel , Aksoy Nevcan
Published: June 2024

Selecting the right academic major significantly shapes an individual's future career path, making it a longstanding focus of research. The shift to online platforms, accelerated by the challenges posed by the coronavirus pandemic, has transformed counseling and guidance systems. Consequently, developing robust online support systems has become imperative for extending guidance to all students. This article introduces the design, development, and evaluation of “My Future Career,” a multidimensional recommendation system (RS) crafted to aid students in navigating university and academic major selection decisions. The system relies on three key student‐driven parameters: central university entrance exam scores, rankings, and occupational personality types, utilizing cosine similarity and normalized distance to align user and item profiles. Following the system's completion, an assessment was conducted using data from real users, revealing an impressive accuracy (hit rate 100%, precision 88%) in recommendations following the inclusion of contextual post‐filtering features. The findings not only highlight the system's effectiveness but also underscore the positive user experience, as students express contentment with its ease of use and practical utility. The results emphasize the endorsement of expert's regarding the system's consistency (52%), relevance (96%), and acceptance (96%) in providing recommendations.
Effects of Fe and Li2MnO3‐like domains on structural stability in Co‐free Li‐rich layered oxide cathodes
Authors: Zhang Yu , Yan Mingxia , Guo Xin , Zhang Xu , Liu Jihong , Zhang Jiyang , Zhu Jiapeng , An Shengli , Jia Guixiao
Published: June 2024

The aggregation of Li2MnO3‐like domains in Li‐rich layered oxides (LLOs) causes severe capacity/voltage fading, which seriously impedes their commercial applications. Here, we design Co‐free Li‐rich LiFeNiMnO system with dispersed small‐sized Li2MnO3–like domains (D‐LFNMO) and aggregated Li2MnO3‐like domains (A‐LFNMO) to investigate effects of Li2MnO3‐like domain sizes and Fe content on structures and oxidation process using density function theory (DFT) calculations. De‐lithiation structures, structural stability and oxidization mechanism of lattice oxygen ions are explored. Structural stability is finished through calculating oxygen release energies and migration energy barriers of Mn4+ ions based on a climbing image nudged elastic band (CI–NEB) method. Research shows that LLOs with dispersed small‐sized Li2MnO3‐like domains and the moderate Fe content would possess highly reversible oxygen redox and excellent structural stability and would exhibit superior cycling stability of high capacity. The findings provide new perspectives and concepts for designing high‐energy Li‐rich cathodes.
High‐accuracy measurement of 36SF5+ signal using an ultrahigh‐resolution isotope ratio mass spectrometer
Authors: Sun Xiang , Tong Fengtai , Peng Yongbo , Bao Huiming
Published: June 2024

Rationale

The Δ36S standard deviation measured in a conventional isotope ratio mass spectrometer such as MAT 253 is ca 0.1‰ to 0.3‰. At this precision, it is difficult to resolve the origin of non‐mass‐dependent sulfur isotope fractionation in tropospheric sulfate aerosol and in Martian meteorites or small deviations from the canonical mass‐dependent fractionation laws. Interfering ions with m/z at 131 of 36SF5+ are suggested by the community as the cause of the poor precision, but the exact ion species has not been identified or confirmed.

Methods

Here we examined the potential interfering ions by using a Thermo Scientific ultrahigh‐resolution isotope ratio mass spectrometer to measure SF6 working gas and SF6 gases converted from IAEA‐S1/2/3 Ag2S reference materials.

Results

We found that there are two resolvable peaks to the right of the 36SF5+ peak when a new filament was installed, which are 186WF42+ followed by 12C3F5+. However, only the 12C3F5+ interference peak was observed after more than three days of filament use. 12C3F5+ is generated inside the instrument during the ionization process. Avoiding the interfering signals, we were able to achieve a Δ36S standard deviation of 0.046‰ (n = 8) for SF6 zero‐enrichment and 0.069‰ (n = 8) for overall measurement start from silver sulfide IAEA‐S1.

Conclusions

Aging the filament with SF6 gas can avoid the interference of 186WF42+. Minimizing the presence of carbon‐bearing compounds and avoiding the interfering signals of 12C3F5+ from 36SF5+, we can improve Δ36S measurement accuracy and precision, which helps to open new territories for research using quadruple sulfur isotope composition.
Benzylic rearrangement for urinary analysis of guanidino and ureido compounds in cardiac surgery–associated acute kidney injury using high‐performance liquid chromatography–tandem mass spectrometry
Authors: Bai Yunpeng , Zou Yuming , Zeng Yingjia , Hu Linhui , Huang Sumei , Wu Kunyong , Yi Qingxia , Chen Jingchun , Liang Guowu , Li Yingbang , Huang Wendong , Chen Chunbo
Published: June 2024

Rationale

Because acute kidney injury (AKI) is closely related to poor prognosis in critically ill patients, developing biomarkers for its prediction and early diagnosis is particularly important. Endogenous guanidino compounds (GCs) and ureido compounds (UCs) can participate in various biochemical processes because of their important physiological activities. The aim of this study was to investigate the alteration profiles of urinary GCs/UCs as potential biomarkers in patients with cardiac surgery–associated acute kidney injury (CSA‐AKI) at different stages.

Methods

GCs/UCs were reacted with benzil via benzylic rearrangement, and their derivatives were used to investigate fragmentation mechanisms using tandem mass spectrometry (MS/MS) in positive ion mode. Furthermore, a high‐performance liquid chromatography (HPLC)–MS/MS method was developed to measure the concentrations of GCs/UCs in urine samples taken from patients with CSA‐AKI at different time points.

Results

MS/MS analysis in positive ion mode showed that benzylic GCs/UCs exhibited similar fragmentation processes, which could produce the characteristic ion (C13H12N+) at m/z 182.0. Furthermore, an obviously different fragmentation pattern of benzylic UCs in the positive ion mode might be due to the neutral loss of the H2CO2 group under low collision energy. Of the eight selected GCs/UCs, methylguanidine exhibited significantly increased concentrations in urine when CSA‐AKI occurred, whereas guanidinoethyl sulfonate (GDS), homoarginine (HArg) and homocitrulline (HCit) exhibited decreased concentrations. After recovery from AKI, the urinary concentrations of the aforementioned GCs/UCs returned to normal. Some of the aforementioned metabolites with significant changes (GDS, HArg and HCit) had large areas under the curve in the receiver operating characteristic curve for distinguishing AKI stages on the third day after surgery.

Conclusions

In patients with CSA‐AKI, urinary GCs/UCs were significantly disrupted due to injured kidney, and some GC/UC metabolites exhibited a good ability to become potential biomarkers for AKI stages. The present study provides essential resources and new therapeutic targets for further research on CSA‐AKI.
Sustainable Plasma‐Catalytic Nitrogen Fixation with Pyramid Shaped μ‐Electrode DBD and Titanium Dioxide
Authors: Lamichhane Pradeep , Pourali Nima , Rebrov Evgeny V. , Hessel Volker
Published: June 2024

This research explores the potential of electric field enforcement in dielectric barrier discharge using specially designed pyramid‐shaped μ‐electrodes for a plasma‐assisted nitrogen fixation process. The obtained results are compared under varying conditions, including the presence and absence of titanium dioxide (
), different oxygen concentrations in the nitrogen‐feeding gas, and residence time. The results demonstrate that the μ‐electrodes lead to an enhancement of nitrogen oxidation, which is further intensified by
. The introduction of 60–70 % oxygen with nitrogen achieves the highest level of
production. The synergistic effect of plasma and the catalytic effect of
increase the rate of
production by 20 %, resulting in a 23 % increase in energy yield. The introduction of
leads to a sharp increase in
production even at lower oxygen concentrations. The crucial role played by ultraviolet light‐induced electron‐hole pairs in
is highlighted to promote nitrogen oxidation. Nevertheless, it is crucial to emphasize that prolonged residence times may cause the photocatalytic effect to generate alternative byproducts rather than
, consequence of excessive oxidation that could prove counterproductive. These findings emphasize the potential of plasma‐assisted nitrogen fixation technology in reducing energy costs and meeting the growing demand for sustainable nitrogen‐based fertilizers.
Recent Advancements and Developments in the Biological Importance of Pyrimido[4,5‐b]Quinoline Scaffolds
Authors: Hammouda Mohamed M. , Rashed Marwa M. , Abo El‐Yazeed Wafaa S. , Elattar Khaled M.
Published: June 2024

This study highlights the biological efficiency of pyrimido[4,5‐b]quinolines as inhibitors of cancer cell growth and antioxidants and anti‐inflammatory properties, etc. Recent research studies have revealed their promising biological activity to inhibit the growth of many disease‐causing yeasts, fungi, and bacteria. The structural composition greatly affects the biological effectiveness, as these compounds exceed the value of some standard compounds against pathogenic microbes. The antioxidant potential of these derivatives is also explored. Several glycosylated and non‐glycosylated derivatives exhibited potent free radical scavenging activity and protected against DNA damage, exceeding reference standards in some cases. Furthermore, the review examines the anti‐inflammatory and analgesic properties of pyrimidoquinoline derivatives. Studies suggest their efficacy is comparable to known drugs like diclofenac and aspirin in carrageenan‐induced paw edema and hot plate tests. Pyrimidoquinoline derivatives also demonstrate promising anticancer activity. While some have minimal effects, others exhibit notable activity against various human cancer cell lines. This review documents over two decades of research, covering the period from 2000 to 2024. Overall, pyrimidoquinoline derivatives signify an auspicious class of compounds with therapeutic potential across various areas. Further research is necessary to elucidate their mechanisms of action, optimize their efficacy and selectivity, and assess their safety profiles for clinical development.
Application of Poly Dl‐Phenylalanine Modified Carbon Nanotube Electrode for Sensitive and Selective Detection of Tinidazole
Authors: Moulya K. P. , Manjunatha J. G. , Aljuwayid Ahmed M. , Ataollahi N.
Published: June 2024

The present study aimed to design an electrochemical sensor for the detection of tinidazole (TN) by carbon nanotube electrode (CNTE) modified with dl‐phenylalanine (DL‐PA). The unmodified carbon nanotube electrode (UMCNTE) and poly (DL‐PA) modified carbon nanotube electrode (P(DL‐PA) MCNTE) were characterized by Scanning emission microscopy (SEM) images. Electrochemical techniques like cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV), were implemented to evaluate the efficiency of the developed electrode toward the detection of TN. The impact of pH on the modified electrode showed that the P(DL‐PA) MCNTE gave a good voltammetric response at pH 3.5. The effect of accumulation time, scan rate, and variation of concentration of TN at the surface of the developed sensor was analyzed. The scan rate study showed that the reduction reaction of TN involves a two‐electron transfer process and it is adsorption‐controlled. The detection limit studies for CV and DPV gave good linearity in the linear range 0.6 μM to 100.0 μM and 3.0 μM to 100.0 μM respectively. The limit of quantification (LOQ) and limit of detection (LOD) concerning CV were found to be 0.65 μM and 0.19 μM respectively. The LOQ and LOD for DPV were calculated to be 0.33 μM and 0.10 μM respectively. The P(DL‐PA) MCNTE showed good anti‐interferent properties. The developed sensor has good stability, repeatability, and reproducibility for the analysis of TN. The P(DL‐PA) MCNTE was successfully employed in the real sample analysis.
Photo‐Induced Difluoromethylation‐Cyclization of Indoles Using Tetrazole Sulfone Reagent Under Visible Light
Authors: Zhu Yuping , Huang Yong‐Sheng , Zhou Xuan‐Yu , Jin Hong‐Xian , Long Lipeng , Luo Wenjun , Peng Xiangjun , Chen Zhengwang , Yu Daohong
Published: June 2024

Polycyclic indoles are prevailed in natural products, pharmaceuticals and biologically active compounds. Herein is described photo‐induced difluoromethylation‐cyclization of N‐alkene tethered indoles to synthesis of tetrahydropyrido[1,2‐a]indole using 5‐((difluoromethyl)sulfonyl)‐1‐phenyl‐1H‐tetrazole as a CF2H radical source. This photochemical reaction tolerates an array of functional groups like ester, cyano, ketone, halide, ether, aldehyde and heteocycles. Mechanistic experiments indicated that the difluoromethyl radical and the single electron transfer were involved.
Conformational Switch of a Peptide Provides a Novel Strategy to Design Peptide Loaded Porous Organic Polymer for Pyroptosis Pathway Mediated Cancer Therapy
Authors: Mishra Snehasis , Sannigrahi Achinta , Ruidas Santu , Chatterjee Sujan , Roy Kamalesh , Misra Deblina , Maity Barun Kumar , Paul Rabindranath , Ghosh Chandan Kumar , Saha Krishna Das , Bhaumik Asim , Chattopadhyay Krishnananda
Published: June 2024

While peptide‐based drug development is extensively explored, this strategy has limitations due to rapid excretion from the body (or shorter half‐life in the body) and vulnerability to protease‐mediated degradation. To overcome these limitations, a novel strategy for the development of a peptide‐based anticancer agent is introduced, utilizing the conformation switch property of a chameleon sequence stretch (PEP1) derived from a mycobacterium secretory protein, MPT63. The selected peptide is then loaded into a new porous organic polymer (PG‐DFC‐POP) synthesized using phloroglucinol and a cresol derivative via a condensation reaction to deliver the peptide selectively to cancer cells. Utilizing ensemble and single‐molecule approaches, this peptide undergoes a transition from a disordered to an alpha‐helical conformation, triggered by the acidic environment within cancer cells that is demonstrated. This adopted alpha‐helical conformation resulted in the formation of proteolysis‐resistant oligomers, which showed efficient membrane pore‐forming activity selectively for negatively charged phospholipids accumulated in cancer cell membranes. The experimental results demonstrated that the peptide‐loaded PG‐DFC‐POP‐PEP1 exhibited significant cytotoxicity in cancer cells, leading to cell death through the Pyroptosis pathway, which is established by monitoring numerous associated events starting from lysosome membrane damage to GSDMD‐induced cell membrane demolition. This novel conformational switch‐based drug design strategy is believed to have great potential in endogenous environment‐responsive cancer therapy and the development of future drug candidates to mitigate cancers.
The role of predation, forestry and productivity in moose harvest at different spatial levels of management units
Authors: Wikenros Camilla , Sand Håkan , Di Bernardi Cecilia , Zimmermann Barbara
Published: June 2024

Management of ungulate populations to the desired density and/or demographic composition are challenged by contrasting aims of different stakeholders. For example, hunters may want to maximize hunting opportunities whereas commercial forest owners may want to minimize moose densities to mitigate browsing damage. In addition, the return of large predators such as wolves Canis lupus affects the possible harvest yield of ungulates and influences the population composition through their selection of specific age classes. The aim of this study was to gain a better understanding of factors related to the variation in moose Alces alces harvest. We used moose harvest statistics from the period 2012–2020, wolf annual monitoring data, annual brown bear Ursus arctos density, proportion of young forest per management unit, and proportion of agricultural land per management unit (index for productivity and roe deer Capreolus capreolus density) to explain variation in moose harvest across different management units at two spatial levels in two bordering countries, Sweden and Norway. The results showed variable responses in total harvest to changes in wolf territory density both at the regional and local management level. The proportion of young forest was correlated with both increased total harvest and proportion of calves. Increased proportion of agricultural land was linked to both increased total harvest and proportion of calves, likely due to that increased roe deer densities re‐directed wolf predation from moose to roe deer, and an inverse relationship with brown bear density. Differences between countries may be due to differences in the management regime of moose, both in an historical and present perspective. Improved monitoring for individual hunting areas over time will be important for both the understanding of how different ungulate populations are affected by various factors and for the desired management of wildlife populations shared across borders.
Review of flood hazards in Kosi River—A way forward for disaster risk reduction
Authors: Kumar Savan , Shrinkhal Rashwet , Shukla Sushil Kumar , Singh Ajai
Published: June 2024

This research looks at how floods are handled in the Kosi River, which goes through China's Tibet region, Nepal, and India, supporting the lives and livelihoods of millions of people in these countries. The emphasis is on the institutional framework and efforts and the plan of the Bihar government to reduce the ill impacts of floods. Drawing from global experiences in transboundary river flood control and considering the unique characteristics of the Kosi River, the study proposes measures that could enhance flood management. It is observed that due to its downstream location in the basin, India is particularly vulnerable to the devastating impacts of floods from the river. Approaches to flood mitigation is a combined approach that includes flood control structural elements and other systems such as transport, finance, and communication systems that can contribute to building up social resiliency.
Analysis of the Opinions of Users of the Tripadvisor Web Platform on the Cultural Tourism Resources of Málaga
Authors: Soto-Rumiche Marco Antonio , Caro José Luis
Published: June 2024

This study analyses the experiences of visitors to cultural tourism resources in the municipality of Malaga (Spain) through sentiment analysis. The online reviews shared by visitors on TripAdvisor and other platforms are relevant to know the valuation of users, being an influencing factor in decision-making by other users. The aim of this research work is to shed light on the online reputation of the cultural heritage of the city of Málaga through reviews on social networks or TripAdvisor opinion web platforms. The basis of the study were the reviews issued by TripAdvisor users, expressing the satisfaction and emotions experienced in the experiences at the destination, focusing interest on museum exhibitions, and highlighting the architectural spaces that complement the visit. Likewise, our results highlight that the emotions and feelings experienced are mostly positive in visits to heritage monuments, highlighting the historical value and the synergy with green areas as an ideal complement that make up the urban landscape of the city of Malaga. The findings of this study will not only contribute to the existing literature on consumer behaviour towards online reviews but may also provide valuable information for organisations involved in the cultural tourism sector.
Voltammetric detection of Neuropeptide Y using a modified sawhorse waveform
Authors: Alyamni Nadiah , Abot Jandro L. , Zestos Alexander G.
Published: June 2024

The hormone Neuropeptide Y (NPY) plays critical roles in feeding, satiety, obesity, and weight control. However, its complex peptide structure has hindered the development of fast and biocompatible detection methods. Previous studies utilizing electrochemical techniques with carbon fiber microelectrodes (CFMEs) have targeted the oxidation of amino acid residues like tyrosine to measure peptides. Here, we employ the modified sawhorse waveform (MSW) to enable voltammetric identification of NPY through tyrosine oxidation. Use of MSW improves NPY detection sensitivity and selectivity by reducing interference from catecholamines like dopamine, serotonin, and others compared to the traditional triangle waveform. The technique utilizes a holding potential of −0.2 V and a switching potential of 1.2 V that effectively etches and renews the CFME surface to simultaneously detect NPY and other monoamines with a sensitivity of 5.8 ± 0.94 nA/µM (n = 5). Furthermore, we observed adsorption-controlled, subsecond NPY measurements with CFMEs and MSW. The effective identification of exogenously applied NPY in biological fluids demonstrates the feasibility of this methodology for in vivo and ex vivo studies. These results highlight the potential of MSW voltammetry to enable fast, biocompatible NPY quantification to further elucidate its physiological roles.

Graphical Abstract
An Extremely Sensitive Ultra-High Throughput Growth Selection Assay for the Identification of Amidase Activity
Authors: Branson Yannick , Schnell Bjarne , Zurr Celine , Bayer Thomas , Badenhorst Christoffel P.S. , Wei Ren , Bornscheuer Uwe T.
Published: June 2024

In the last decades, biocatalysis has offered new perspectives for the synthesis of (chiral) amines, which are essential building blocks for pharmaceuticals, fine and bulk chemicals. In this regard, amidases have been employed due to their broad substrate scope and their independence from expensive cofactors. To expand the repertoire of amidases, tools for their rapid identification and characterization are greatly demanded. In this work an ultra-high throughput growth selection assay based on the production of the folate precursor p-aminobenzoic acid (PABA) is introduced to identify amidase activity. PABA-derived amides structurally mimic the broad class of commonly used chromogenic substrates derived from p-nitroaniline. This suggests that the assay should be broadly applicable for the identification of amidases. Unlike conventional growth selection assays that rely on substrates as nitrogen or carbon source, our approach requires PABA in sub-nanomolar concentrations, making it exceptionally sensitive and ideal for engineering campaigns that aim at enhancing amidase activities from minimally active starting points, for example. The presented assay offers flexibility in the adjustment of sensitivity to suit project-specific needs using different expression systems and fine-tuning with the antimetabolite sulfathiazole. Application of this PABA-based assay facilitates the screening of millions of enzyme variants on a single agar plate within two days, without the need for laborious sample preparation or expensive instruments, with transformation efficiency being the only limiting factor.

Key points

• Ultra-high throughput assay (tens of millions on one agar plate) for amidase screening

• High sensitivity by coupling selection to folate instead of carbon or nitrogen source

• Highly adjustable in terms of sensitivity and expression of the engineering target