bluuebunny/crossref_metadata_2025 huggingface dataset:
Vom Einzelkämpfer zur biblischen Plage
Authors: Tetsch Larissa
Published: August 2024

Schwärme aus Millionen von Wanderheuschrecken können an einem einzigen Tag ganze Landstriche kahl fressen. Die Entscheidung, sich zu einem Schwarm zusammenzuschließen, treffen die Insekten in Abhängigkeit von Umweltreizen und ihrer Populationsdichte. Die Kommunikation der Tiere untereinander erfolgt dabei über chemische Signale. Diese könnten eine Möglichkeit bieten, die Bildung von Heuschreckenschwärmen im Keim zu ersticken.
A case of intraductal papillary neoplasm of the bile duct suspected to be of peribiliary glands origin
Authors: Ogiso Takuya , Suzuki Hirotaka , Matsubara Hiroshi , Naito Takehito , Yamada Masahiro , Yamamoto Hideko , Hattori Shun , Aoba Taro , Arai Yoshifumi , Urano Fumihiro
Published: August 2024

Peribiliary glands are complex lobular structures containing mucus and serous glands, distributed along the extrahepatic and intrahepatic bile ducts. In this report, we describe a case of intraductal papillary neoplasm of the bile duct suspected to be of peribiliary glands origin. The patient was an 80‐year‐old man who was referred to our hospital for a hepatic mass. On further examination, a 38 × 34 mm cystic lesion with papillary growth was found in S1/4. Because the lesion was extensively bordered by both hepatic ducts and the connection was unclear, it was difficult to determine the extent of hepatic resection. To confirm the location, a peroral cholangioscopy was performed. The connection with the cyst was detected in the right hepatic duct and a villous tumor mucosa protruded through the conduit lumen. Since we found that the lesion communicated with the right hepatic duct, a right hepatectomy was subsequently performed. The postoperative pathological diagnosis was an intraductal papillary neoplasm of the blie duct with associated invasive carcinoma. The postoperative course was good, and the patient experienced no recurrence.
Circulating levels of endogenous complement inhibitors correlate inversely with complement consumption in systemic lupus erythematosus
Authors: van der Meulen Stef , Monahan Rory C. , Gelderman Kyra A. , van Kooten Cees , Teng Y.K. Onno , Huizinga Tom W.J. , Steup‐Beekman Gerda M. , Trouw Leendert A.
Published: August 2024

Systemic lupus erythematosus (SLE) is marked by excessive complement activation, contributing to tissue damage. Complement activation can be detected in many organs including the skin, kidney, and brain. The involvement of the central nervous system is particularly relevant to understanding neuropsychiatric SLE (NPSLE), one of the poorest understood manifestations of SLE for which no biomarkers are available. We studied the levels of complement inhibitors in SLE in relation to disease activity and as possible biomarkers to identify NPSLE. Serum levels of complement inhibitors C1‐inhibitor (C1‐INH), C4b‐binding protein (C4BP), Factor I, and Factor H were measured in 345 SLE patients (including 102 with NPSLE) and 108 healthy controls. Compared with controls, SLE patients had higher C1‐INH and C4BP but lower Factor I and H levels. All inhibitors positively correlated with total C3 and C4 levels. While correlating with the SLE Disease Activity Index (SLEDAI), no distinction in inhibitor levels was found between SLE and NPSLE patients. Over time, C1‐INH and Factor H levels normalized, but no significant changes were observed for C4BP and Factor I. In SLE the levels of circulating complement inhibitors are inversely correlated to complement consumption but do not serve as biomarkers for NPSLE.
Altered functional connectivity of primary olfactory cortex‐hippocampus‐frontal cortex in subjective cognitive decline during odor stimulation
Authors: Zhang Xin , Zhu Yajing , Lu Jiaming , Chen Qian , Chen Futao , Long Cong , Xu Xinru , Ge Danni , Bai Yijun , Liu Dongming , Du Shunshun , Zhu Zhengyang , Mai Xiaoli , Yang Qing X. , Zhang Bing
Published: August 2024

Subjective cognitive decline (SCD) is a high‐risk population in the preclinical stage of Alzheimer's disease (AD), and olfactory dysfunction is a risk factor for dementia progression. The present study aimed to explore the patterns of functional connectivity (FC) changes in the olfactory neural circuits during olfactory stimulation in SCD subjects. A total of 56 SCD subjects and 56 normal controls (NCs) were included. All subjects were assessed with a cognitive scale, an olfactory behavior test, and olfactory task‐based functional magnetic resonance imaging scanning. The FC differences in olfactory neural circuits between the two groups were analyzed by the generalized psychophysiological interaction. Additionally, we calculated and compared the activation of brain regions within the olfactory neural circuits during odor stimulation, the volumetric differences in brain regions showing FC differences between groups, and the correlations between neuroimaging indicators and olfactory behavioral and cognitive scale scores. During odor stimulation, the FC between the bilateral primary olfactory cortex (bPOC) and the right hippocampus in the SCD group was significantly reduced; while the FC between the right hippocampus and the right frontal cortex was significantly increased in the SCD group. The bPOC of all subjects showed significant activation, but no significant difference in activation between groups was found. No significant differences were observed in the volume of the brain regions within the olfactory neural circuits or in olfactory behavior between groups. The volume of the bPOC and right frontal cortex was significantly positively correlated with olfactory identification, and the volume of the right frontal cortex and right hippocampus was significantly correlated with cognitive functions. Furthermore, a significant correlation between the activation of bPOC and the olfactory threshold was found in the whole cohort. These results suggested that while the structure of the olfactory neural circuits and olfactory behavior in SCD subjects remained stable, there were significant changes observed in the FC of the olfactory neural circuits (specifically, the POC‐hippocampus‐frontal cortex neural circuits) during odor stimulation. These findings highlight the potential of FC alterations as sensitive imaging markers for identifying high‐risk individuals in the early stage of AD.
A systematic review of the economic burden of colorectal cancer
Authors: Jafari Abdosaleh , Hosseini Fatemeh A. , Jalali Faride S.
Published: August 2024

Background

Colorectal cancer is the third most common cancer in the Western Hemisphere. It is the third most common cancer in men after prostate and lung cancers and the second most common cancer in women after breast cancer. According to some studies, the incidence and prevalence of colorectal cancer is increasing rapidly.

Main Body

In the present study, a systematic review of the articles related to the economic burden of colorectal cancer was carried out. The articles were taken from the following databases: SID, Medline/Pubmed, Embase, Scopus, Web of Science, NHS Economic Evaluation Database (EED), Econlit, and Google Scholar. Furthermore, the PICOTS model was used to select the inclusion criteria. The quality of the articles' methodologies was evaluated using Drummond's checklist. Then, some data were extracted from relevant articles, in terms of year, place of research, sample size, costing approach, type of measured costs, average direct medical costs, average direct nonmedical costs, and average indirect costs. The data from 37 studies dealing with the costs of patients with colorectal cancer were extracted. Most of the studies were conducted in the United States, and the social perspective was the most common perspective to measure the costs. According to the majority of the studies, direct medical costs were considered the greatest driver in causing the economic burden of colorectal cancer. The costs of hospitalization, medicine, surgery, chemotherapy, and radiotherapy accounted for the largest share of direct medical costs, and the costs of transportation, accommodation, and home care were the greatest share of direct nonmedical costs. Furthermore, the costs associated with disability, absenteeism, and premature death were identified as the main drivers of indirect costs.

Conclusion

The findings of this study showed that colorectal cancer imposes great direct and indirect costs on families, the health system, and society. The best way to deal with this disease and, hence, to reduce its economic burden is to take comprehensive preventive measures and modify the lifestyle. In addition, health policymakers can limit the costs of this disease by expanding the screening program.
Toxicity of soil leaching liquor from coking plant in developmental zebrafish embryos/larvae model
Authors: Yang Guangchao , Liu Jining , Yang Qian , Gu Wen
Published: August 2024

The coking industry in China is the largest coke supplier in the world. Contaminated soil in industrial areas poses a serious threat to human and ecosystems. Most of the studies investigated the toxicity of soil from coking plant on soil microorganisms, while the toxic effects of soil leaching liquor on aquatics are limited. In this study, the composition of soil leaching liquor from a coking plant in Taiyuan (TY) was analyzed, and the developmental toxicity on zebrafish was evaluated. The results showed that a total of 91 polycyclic aromatic hydrocarbons were detected in the leaching liquor, followed by phenols and benzene series. The leaching liquor induced developmental impairment in zebrafish larvae, including delayed incubation, deficits in locomotor behavior, vascular and cardiac dysplasia, and impaired neurodevelopment. The results of metabolomics analysis showed that TY soil leaching liquor induced significant metabolic profile disturbances in zebrafish embryos/larvae. The developmental toxicity of the leaching liquor metabolic disorders may be associated with the leaching liquor‐induced abnormalities in zebrafish embryonic development. Metabolic pathways were identified by arginine and proline metabolism, phosphotransferase system, starch and sucrose metabolism, steroid biosynthesis, beta‐alanine metabolism, and nucleotide metabolism pathways.
Placental and umbilical cord anomalies detected by ultrasound as clinical risk factors of adverse perinatal outcome: Case series review of selected conditions. Part 1: Placental abnormalities
Authors: Tonni Gabriele , Lituania Mario , Cecchi Alessandro , Carboni Elisa , Grisolia Gianpaolo , Bonasoni Maria Paola , Rizzo Giuseppe , Ruano Rodrigo , Araujo Júnior Edward , Werner Heron , Sepulveda Waldo ,   the: International Perinatology Research Group (IPRG)
Published: August 2024

Background

The aim of this extended review of multicenter case series is to describe the prenatal ultrasound features and pathogenetic mechanisms underlying placental and umbilical cord anomalies and their relationship with adverse perinatal outcome. From an educational point of view, the case series has been divided in three parts; Part 1 is dedicated to placental abnormalities.

Methods

Multicenter case series of women undergoing routine and extended prenatal ultrasound and perinatal obstetric care.

Results

Prenatal ultrasound findings, perinatal care, and pathology documentation in cases of placental pathology are presented.

Conclusions

Our case series review and that of the medical literature confirms the ethiopathogenetic role and involvement of placenta abnormalities in a wide variety of obstetrics diseases that may jeopardize the fetal well‐being. Some of these specific pathologies are strongly associated with a high risk of poor perinatal outcome.
Roseburia intestinalis‐derived extracellular vesicles ameliorate colitis by modulating intestinal barrier, microbiome, and inflammatory responses
Authors: Han Hwa Seung , Hwang Soonjae , Choi Seung Young , Hitayezu Emmanuel , Humphrey Mabwi A. , Enkhbayar Altai , Song Dae‐Geun , Kim Myungsuk , Park Jong‐Sung , Park Young‐Tae , Park Jin‐Soo , Cha Kwang Hyun , Choi Ki Young
Published: August 2024

Inflammatory bowel disease (IBD) is a chronic disorder characterized by recurrent gastrointestinal inflammation, lacking a precise aetiology and definitive cure. The gut microbiome is vital in preventing and treating IBD due to its various physiological functions. In the interplay between the gut microbiome and human health, extracellular vesicles secreted by gut bacteria (BEVs) are key mediators. Herein, we explore the role of Roseburia intestinalis (R)‐derived EVs (R‐EVs) as potent anti‐inflammatory mediators in treating dextran sulfate sodium‐induced colitis. R was selected as an optimal BEV producer for IBD treatment through ANCOM analysis. R‐EVs with a 76 nm diameter were isolated from R using a tangential flow filtration system. Orally administered R‐EVs effectively accumulated in inflamed colonic tissues and increased the abundance of Bifidobacterium on microbial changes, inhibiting colonic inflammation and prompting intestinal recovery. Due to the presence of Ile‐Pro‐Ile in the vesicular structure, R‐EVs reduced the DPP4 activity in inflamed colonic tissue and increased the active GLP‐1, thereby downregulating the NFκB and STAT3 via the PI3K pathway. Our results shed light on the impact of BEVs on intestinal recovery and gut microbiome alteration in treating IBD.
“Protection for the public, better use of resources and clearer lines”: Interviews with genetic counselors and their colleagues on the need for regulation in Quebec
Authors: Knoppers Terese , Haley Cassandra E. , Patrinos Dimitri , Zawati Ma'n H.
Published: August 2024

In Canada, the field of genetic counseling is rapidly evolving alongside the increasing integration of and demand for genetics in healthcare practice. In tandem, there is a growing body of literature advocating for the regulation of genetic counseling, as legal recognition can protect patients from potential risk of harm and provide counselors with support by legally defining their roles and duties. However, there is a need for empirical qualitative research regarding the risks and challenges associated with the current lack of regulation to help inform these discussions. This article presents findings from 23 interviews with genetic counselors and their professional healthcare colleagues in Quebec. Themes were identified via interdisciplinary social scientific and legal content analysis. Notably, all participants were in favor of regulation, for varied reasons. Participant responses highlighted legal, organizational, and structural risks and challenges associated with the lack of legal recognition. First, the lack of role clarity creates issues with genetic counselors' working relationships and public recognition. Second, the autonomy of practitioners varies significantly, raising risks of liability and clinical preparedness when counselors have high autonomy or perform controlled acts. Third, the lack of recognition ultimately exacerbates structural strains on delivery and access to care. Results indicate that legal recognition stands to foster safer and more efficient provision of genetics services by increasing public awareness, instituting title protection and accountability mechanisms, clarifying professional scope, and mitigating liability risks. To the best of our knowledge, this is the first qualitative study to bring practicing stakeholders from across genetics services to the discussion on the lack of regulation of genetic counseling. Findings support the continued pursuit of legal recognition in Quebec and can inform similar initiatives in other jurisdictions.
Assessment the Impact of IDH Mutation Status on MRI Assessments of White Matter Integrity in Glioma Patients: Insights From Peak Width of Skeletonized Mean Diffusivity and Free Water Metrics
Authors: Li Yuanhao , Zhu Hongquan , Liu Yufei , Ding Yujie , Li Shihui , Li Li , Zhang Jiaxuan , Jiang Jingjing , Shen Nanxi , Zhu Wenzhen
Published: August 2024

Background

Gliomas are highly invasive brain tumors that evade accurate geographic assessment by conventional MRI due to microscopic invasion along white matter (WM) tracts. Advanced diffusion MRI techniques are needed to assess occult WM involvement.

Purpose

To evaluate peak width of skeletonized mean diffusivity (PSMD) and peak width of skeletonized free water (PSFW), and axonal water fraction (AWF) for assessing glioma‐induced alterations in normal‐appearing WM and their relationship with isocitrate dehydrogenase 1 (IDH1) mutation.

Study Type

Retrospective.

Population

One hundred five glioma patients (46 ± 13 years), 53 healthy controls (HCs) (46 ± 9 years).

Field Strength/Sequence

3.0 T, T1WI, T1‐CE, T2WI, T2FLAIR, and DKI.

Assessment

PSMD and PSFW were compared between lesion and contralateral sides in glioma patients and between patients and HCs. The associations between these metrics and clinical variables, including IDH1 mutation, was assessed. Corpus callosum (CC) injury, quantified by the AWF, was evaluated for its mediated effect of IDH1 mutation on contralesional PSMD and PSFW.

Statistical Tests

Paired‐t tests, ANCOVA, univariate and multivariate linear regression, and mediation analysis with significance set at P < 0.05.

Results

Contralateral PSMD and PSFW were significantly higher in left‐sided gliomas (PSMD: 0.206 ± 0.027 vs. 0.193 ± 0.023; PSFW: 0.119 ± 0.019 vs. 0.106 ± 0.020) than in HCs, with similar increases in right‐sided gliomas (PSMD: 0.219 ± 0.036 vs. 0.195 ± 0.023; PSFW: 0.129 ± 0.031 vs. 0.109 ± 0.020). IDH1 wild‐type gliomas were associated with higher contralateral PSMD and PSFW (β = −0.302 and −0.412). AWF of CC mediated the impact of IDH1 mutations on contralesional PSMD and PSFW (mediated proportion: 42.7% and 53.7%).

Data Conclusion

PSMD and PSFW are effective biomarkers for assessing WM integrity in gliomas, significantly associated with IDH1 mutation status. AWF of CC mediates the relationship between IDH1 mutation and contralesional PSMD and PSFW.

Evidence Level

4

Technical Efficacy

Stage 2
Multiparametric MRI‐Based Deep Learning Radiomics Model for Assessing 5‐Year Recurrence Risk in Non‐Muscle Invasive Bladder Cancer
Authors: Huang Haolin , Huang Yiping , Kaggie Joshua D. , Cai Qian , Yang Peng , Wei Jie , Wang Lijuan , Guo Yan , Lu Hongbing , Wang Huanjun , Xu Xiaopan
Published: August 2024

Background

Accurately assessing 5‐year recurrence rates is crucial for managing non‐muscle‐invasive bladder carcinoma (NMIBC). However, the European Organization for Research and Treatment of Cancer (EORTC) model exhibits poor performance.

Purpose

To investigate whether integrating multiparametric MRI (mp‐MRI) with clinical factors improves NMIBC 5‐year recurrence risk assessment.

Study Type

Retrospective.

Population

One hundred ninety‐one patients (median age, 65 years; age range, 54–73 years; 27 females) underwent mp‐MRI between 2011 and 2017, and received ≥5‐year follow‐ups. They were divided into a training cohort (N = 115) and validation/testing cohorts (N = 38 in each). Recurrence rates were 23.5% (27/115) in the training cohort and 23.7% (9/38) in both validation and testing cohorts.

Field Strength/Sequence

3‐T, fast spin echo T2‐weighted imaging (T2WI), single‐shot echo planar diffusion‐weighted imaging (DWI), and volumetric spoiled gradient echo dynamic contrast‐enhanced (DCE) sequences.

Assessment

Radiomics and deep learning (DL) features were extracted from the combined region of interest (cROI) including intratumoral and peritumoral areas on mp‐MRI. Four models were developed, including clinical, cROI‐based radiomics, DL, and clinical‐radiomics‐DL (CRDL) models.

Statistical Tests

Student's t‐tests, DeLong's tests with Bonferroni correction, receiver operating characteristics with the area under the curves (AUCs), Cox proportional hazard analyses, Kaplan–Meier plots, SHapley Additive ExPlanations (SHAP) values, and Akaike information criterion for clinical usefulness. A P‐value <0.05 was considered statistically significant.

Results

The cROI‐based CRDL model showed superior performance (AUC 0.909; 95% CI: 0.792–0.985) compared to other models in the testing cohort for assessing 5‐year recurrence in NMIBC. It achieved the highest Harrell's concordance index (0.804; 95% CI: 0.749–0.859) for estimating recurrence‐free survival. SHAP analysis further highlighted the substantial role (22%) of the radiomics features in NMIBC recurrence assessment.

Data Conclusion

Integrating cROI‐based radiomics and DL features from preoperative mp‐MRI with clinical factors could improve 5‐year recurrence risk assessment in NMIBC.

Evidence Level

3

Technical Efficacy

Stage 3
The Effects of Service Recovery Actions on Customers' Post‐Recovery Responses to Online Travel Agencies (OTAs): The Moderating Role of Price
Authors: Hwang Jungjin
Published: August 2024

The main purpose of this study is to investigate the impacts of service recovery actions on customers' post‐recovery responses to initial service failure and a double deviation and to investigate the moderating effect of price on the relationship between recovery actions and these responses. The findings show that active recovery actions led to more favorable post‐recovery responses than passive actions in both initial and double deviation situations. No moderating effect of price was found between recovery actions and customers' post‐recovery responses. From an academic perspective, this study helps researchers understand how customers positively perceive recovery actions that reflect procedural and interactional justice in service failure situations. The findings also suggest that practitioners of OTAs should engage in active recovery actions that include prompt communication on the progress of the incident (i.e., procedural justice) and a sincere apology (interactional justice) to alleviate customers' negative responses due to service failures.
Ethanol Extract of Propolis Attenuates Liver Lipid Metabolism Disorder in High‐Fat Diet‐Fed SAMP8 Mice
Authors: Xie Quan‐yuan , Shu Xin , Liu Tao , Chen Li‐li , Luo Li‐ping
Published: August 2024

Scope

The prevalence of high‐fat diet (HFD) consumption is increasing among middle‐aged and older adults, which accelerates the aging process of this population and is more likely to induce lipid metabolism disorders. But the alleviation of ethanolic extract of propolis (EEP) on lipid metabolism disorders during aging remains unclear.

Methods and results

This study assesseed the impact of EEP intervention (200 mg kg−1 bw) on aging and lipid metabolism disorders in HFD‐fed senescence accelerate mouse prone 8 (SAMP8) mice. Findings indicate that EEP ameliorates hair luster degradation and weight gain, reduces systemic inflammation and metabolism levels, enhances hepatic antioxidant enzyme activities, and improves the hepatic expression of senescence‐associated secretory phenotype and aging‐related genes in HFD‐fed SAMP8 mice. Histological staining demonstrates that EEP improves hepatic lipid deposition and inflammatory cell infiltration. Transcriptomic and lipidomic analysis reveal that EEP promotes fatty acid β‐oxidation by activating PPAR pathway, resulting in reduced hepatic lipid deposition, and attenuates bile acid (BA) accumulation by improving BA metabolism, which were ensured through qPCR validation of key genes and immunoblot validation of key proteins.

Conclusions 

EEP can regulate lipid metabolic dysregulation during aging accompanied by an HFD, potentially delaying the onset and progression of age‐related diseases. This provides new approach for supporting healthy aging.
Students' core competence performance during fundamental nursing practicum: A cross‐sectional survey with importance–performance analysis
Authors: Chang Yu‐Hsuan , Shun Shiow‐Ching , Lin Pao‐Chen
Published: August 2024

Aim

Limited available studies compare the core competence performance of students undertaking their practicum at different level‐of‐care practicum sites. This study aimed to (1) compare the gaps between the perception of importance for competence and the perceived performance of nursing students at practicum sites involving different level‐of‐care and (2) identify low competencies that must be prioritized for improvement at different sites during the fundamental nursing practicum.

Design

Cross‐sectional design.

Methods

A total of 659 students who had passed their fundamental nursing practicum within 1 month from six nursing colleges in Taiwan were recruited. The students completed the 25‐item Core Competence in Fundamental Nursing Practicum Scale, wherein both the importance and performance level of each item are indicated. One‐way analysis of variance along with the Scheffe post hoc test and importance–performance analysis were used to explore the gaps between the perception of importance for competence and the perceived performance and to identify weak competencies that must be prioritized for improvement, respectively.

Results

Compared with nursing students practicing in district hospitals (predominantly caring for chronically ill patients), nursing students practicing in medical centres (predominantly caring for patients with severe and critical conditions) had larger gaps in total scores and the application of nursing processes. Students in medical centres also had larger gaps in professional attitude than their counterparts in long‐term care facilities. Importance–performance analysis identified a common shortfall in communication skills among nursing students for all level‐of‐care practicum sites. Students at long‐term facilities had the highest number of weak competencies that required improvement. The results of this study can guide instructors in designing curricular activities focused on the weaker core competencies of the students at a practicum site for each level of care.

Patient or Public Contribution

No patient or public contributions.
Synthesis of azabenzotriazole‐terminated liquid crystal poly(ester imide)s for improving their adhesion to copper foils
Authors: Li Xiangyi , Guo Yuanqin , Liu Shumei , Zhao Jianqing
Published: August 2024

Liquid crystal polymers (LCPs) should be widely used as substrates in flexible copper clad laminate (FCCL) owing to their unique advantages. However, the poor adhesion of LCPs to copper foils hinders their applications. Considering the good adhesion between polyimides and copper foils, imide groups have previously been introduced into the main chains of LCP molecules. In the present paper, to further enhance the adhesion of the LCPEIs, the 1‐hydroxy‐7‐azabenzotriazole (HOAt) is used to terminate the main chains of LCPEI molecules, which arises from the excellent coordination interaction between the azabenzotriazole groups and copper ions. Thus, the liquid crystal poly(ester imide) (t‐LCPEI), carboxyl‐terminated liquid crystal poly(ester imide) (c‐LCPEI), and azabenzotriazole‐terminated liquid crystal poly(ester imide) (a‐LCPEI) were synthesized. The results showed that LCPEIs possessed liquid crystallinity, and the peel strength of a‐LCPEI film to copper foils was increased by about 140% and nearly 43%, respectively, compared to that of LCP and t‐LCPEI. Moreover, a‐LCPEI showed higher glass transition temperature (Tg = 211°C) than conventional LCP resins (Tg = 155°C, Vectra A), and excellent thermal properties. Meanwhile, the dielectric constant and loss of a‐LCPEI were as low as 3.04 and 9.7 × 10−3 at 10 GHz, respectively. These findings indicate that the azabenzotriazole‐terminated LCPEI is suitable to be used as the substrate material for high‐performance FCCL, and the work provides a feasible approach to enhance the adhesion and maintain the other outstanding properties of LCP.
Evaluation of fatigue characteristics of 3D printed/composites reinforced with carbon fiber using design of experiments
Authors: Jamadar Imran M. , Kamate Pavankumara , Samal Prasanta Kumar
Published: August 2024

This study investigates the fatigue characteristics of 3D‐printed composites made from polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS), reinforced with carbon fiber. It involves designing and building a rotating bending fatigue machine, creating standard specimens via FDM, and applying DOE using Taguchi method. Standard specimens are subjected to cyclic loading with a print orientation of 0°, 45°/−45°, and 90°, motor speed and load. Materials such as PLA, ABS, PLA‐CF, and ABS‐CF are tested by maintaining a consistent layer thickness of 0.16 mm and 99.99% infill density while varying stress levels. PLA‐CF outperforms PLA, ABS, and ABS‐CF in fatigue life, with 0° print orientation exhibiting superior fatigue strength. Statistical analysis underscores the significance of print direction, material composition, and stress level. Additionally, the study aims to construct S‐N curves for 3D‐printed PLA/ABS composites with carbon fiber reinforcement, advancing our understanding of mechanical properties and print parameter optimization for enhanced fatigue performance in 3D‐printed composites.

Highlights

Fatigue characteristics of 3D printed composites made from PLA and ABS, reinforced with carbon fiber investigated.

Four polymer composites were used: PLA, ABS, PLA‐CF (short carbon fiber), and ABS‐CF (short carbon fiber).

The research focused on the impact of 3D print orientation on fatigue properties, considering print angles of 0°, 45°/−45°, and 90°, alongside adjustable factor like motor speed and load.

With a consistent layer thickness of 0.16 mm and 99.99% infill density, the fatigue tests were conducted under stress‐controlled conditions at varying stress levels.

Results demonstrate that PLA‐CF specimens exhibit superior fatigue lifetimes compared to PLA, ABS, and ABS‐CF samples.
Monocyclopentadienyltitanium trichloride (CpTiCl3)/modified methylaluminoxane‐catalyzed polymerization of 2‐phenyl[3]dendralene: Homopolymerization and copolymerization of 2‐phenyl[3]dendralene with isoprene or styrene
Authors: Toda Tomoyuki , Kudo Shinya , Takenaka Katsuhiko
Published: August 2024

The control of the microstructures of polymer materials derived from diene‐based monomers is crucial, and various synthetic methods, including anionic, radical, and coordination polymerization reactions, have been extensively explored. Here, we demonstrated the coordination polymerization of 2‐phenyl[3]dendralenes (P3D) as a diene monomer. The polymerization process using monocyclopentadienyltitanium trichloride (CpTiCl3) as a catalyst and modified methylaluminoxane (MMAO) as a cocatalyst (CpTiCl3/MMAO) yielded polymers with an exclusive 4,6‐structure that is distinct from those produced by anionic polymerization. Furthermore, the copolymerization of P3D with isoprene and styrene proceeded randomly.
Stereoregular polyamides with optically‐pure aspartame‐type diketopiperazine derivatives
Authors: Takada Kenji , Yin Hongrong , Kaneko Tatsuo
Published: August 2024

Polyamides (PAs) with aspartame‐derived diketopiperazine (DKP) form specific particles and exhibit high heat resistance. In this study, we investigated the stereostructures of aspartic acid and phenylalanine, which constitute aspartame DKP. Diketopiperazines with different stereostructures were synthesized from D‐ and L‐aspartic acid and D‐ and L‐phenylalanine, and LL‐, DD‐, and LD‐type aminodiketopiperazines (LL, DD, and LD‐ADKPs) were obtained. These ADKPs differed in their crystal forms depending on their stereoisomeric structures. Furthermore, PAs were formed from these ADKPs via polycondensation using triphenyl phosphite/pyridine, and their heat resistance was approximately 300 °C. The secondary structure of each PA was evaluated by circular dichroism, which suggested that LD‐type PAs had a mixed secondary structure of coils and helical structures, unlike the LL and DD types. Precipitated LL, DD, and LLcoDD PAs formed similar particles, whereas the particles of the large LD‐type PA had different particle shapes owing to their different conformations.
A comparison of antibody–antigen complex sequence‐to‐structure prediction methods and their systematic biases
Authors: McCoy Katherine Maia , Ackerman Margaret E. , Grigoryan Gevorg
Published: August 2024

The ability to accurately predict antibody–antigen complex structures from their sequences could greatly advance our understanding of the immune system and would aid in the development of novel antibody therapeutics. There have been considerable recent advancements in predicting protein–protein interactions (PPIs) fueled by progress in machine learning (ML). To understand the current state of the field, we compare six representative methods for predicting antibody–antigen complexes from sequence, including two deep learning approaches trained to predict PPIs in general (AlphaFold‐Multimer and RoseTTAFold), two composite methods that initially predict antibody and antigen structures separately and dock them (using antibody‐mode ClusPro), local refinement in Rosetta (SnugDock) of globally docked poses from ClusPro, and a pipeline combining homology modeling with rigid‐body docking informed by ML‐based epitope and paratope prediction (AbAdapt). We find that AlphaFold‐Multimer outperformed other methods, although the absolute performance leaves considerable room for improvement. AlphaFold‐Multimer models of lower quality display significant structural biases at the level of tertiary motifs (TERMs) toward having fewer structural matches in non‐antibody‐containing structures from the Protein Data Bank (PDB). Specifically, better models exhibit more common PDB‐like TERMs at the antibody–antigen interface than worse ones. Importantly, the clear relationship between performance and the commonness of interfacial TERMs suggests that the scarcity of interfacial geometry data in the structural database may currently limit the application of ML to the prediction of antibody–antigen interactions.
An analytical model for daily‐periodic slope winds. Part 2: Solutions
Authors: Marchio Mattia , Farina Sofia , Zardi Dino
Published: August 2024

This article presents an analytical model for the diurnal cycle of slope‐normal profiles of potential temperature and wind speed characterizing thermally driven slope winds, generated by a daily‐periodic surface energy budget. The model extends the solution proposed by Zardi and Serafin, originally formulated for a pure sinusoidal surface forcing temperature. To account for the asymmetric features characterizing the daytime and nighttime phases, a full Fourier series expansion is derived, the coefficients and phases of which are prescribed from the surface energy budget driven by the daily‐periodic radiation model described in Part 1 of the present work. The model is applicable for any slope angle () and orientation, at any latitude and elevation (up to 2500 m), and for all seasons. Despite some inherent limitations, the most remarkable being the absence of moist processes and latent heat fluxes, the model captures most key features of daily‐periodic slope wind systems, in particular the asymmetry between daytime and nighttime phases. Moreover, it allows exploration of the sensitivity of these flows to the various factors concurring in their development, and offers a basis for more realistic analytical solutions for slope winds.
Exploring Carbon Dots: Green Nanomaterials for Unconventional Lasing
Authors: Minervini Gianluca , Panniello Annamaria , Dibenedetto Carlo Nazareno , Madonia Antonino , Fanizza Elisabetta , Curri Maria Lucia , Striccoli Marinella
Published: August 2024

In recent years, the progress toward lighting miniaturization is focused on luminescent nanomaterials. Among them, fluorescent carbon dots (CDs) are receiving increasing attention thanks to their astonishing optical properties complemented by their intrinsic biocompatibility and low toxicity. The CDs can be easily dispersed in water, organic solvents or incorporated in polymeric matrices, preserving their emission properties. However, the relationship between their structural and optical properties is still not fully elucidated, motivating a consistent research effort for the comprehension of their features. Nevertheless, CDs demonstrate to be efficient gain materials for lasing, thanks to their high quantum yield (QY), emission tunability in the visible and near infrared (NIR) range, short lifetimes, and high absorption cross section, even if the synthetic reproducibility, the low reaction yield and the spectral width of the emission may limit their effective exploitation. This review summarizes the latest advancements in the investigation of the characteristic properties of CDs that make laser action possible, illustrating optical geometries for lasing and random lasing, both in solution and solid state, and the few currently demonstrated breakthroughs. While the journey toward their effective application is still long, the potential of CD‐based laser sources is promising in various technological fields and futuristic perspectives will be discussed.
An Ion‐Pumping Quasi‐Solid Electrolyte Enabled by Electrokinetic Effects for Stable Aqueous Zinc Metal Batteries
Authors: Gao Qixin , Zhao Jingteng , Xiao Huang , Gao Jian , Cheng Xin , Li Fang , Song Congying , Li Guoxing
Published: August 2024

The practical application of aqueous zinc (Zn) metal batteries (ZMBs) is hindered by the complicated hydrogen evolution, passivation reactions, and dendrite growth of Zn metal anodes. Here, an ion‐pumping quasi‐solid electrolyte (IPQSE) with high Zn2+ transport kinetics enabled by the electrokinetic phenomena to realize high‐performance quasi‐solid state Zn metal batteries (QSSZMBs) is reported. The IPQSE is prepared through the in situ ring‐opening polymerization of tetramethylolmethane‐tri‐β‐aziridinylpropionate in the aqueous electrolyte. The porous polymer framework with high zeta potential provides the IPQSE with an electrokinetic ion‐pumping feature enabled by the electrokinetic effects (electro‐osmosis and electrokinetic surface conduction), which significantly accelerates the Zn2+ transport, reduces the concentration polarization and overcomes the diffusion‐limited current. Moreover, the Zn2+ affinity of the polymer and hydrogen bonding interactions in the IPQSE changes the Zn2+ coordination environment and reduces the amount of free H2O, which lowers the H2O activity and inhibits H2O‐induced side reactions. Consequently, the highly reversible and stable Zn metal anodes are achieved. The assembled QSSZMBs based on the IPQSE display excellent cycling stability with high capacity retention and Coulombic efficiency. The high‐performance quasi‐solid state Zn metal pouch cells are demonstrated, showing great promise for the practical application of the IPQSE.
Deciphering the Degradation Mechanisms and Realize High‐Voltage Stability of A3V2(PO4)3 (A = Li+, Na+) in Aqueous Dual‐Ion Batteries
Authors: Dong Chongrui , Chen Yuanjing , Ding Yan , Pu Xiangjun , Cao Yuliang , Ma Zhongyun , Chen Zhongxue
Published: August 2024

Polyanionic A3V2(PO4)3 (A = Li+, Na+) with open channels have been extensively utilized as cathode materials for aqueous zinc‐metal batteries (AZMBs), whereas suffering from severe capacity fading and rapid operation voltage decay during cycling. when used as In this work, it is disclosed that the rapid degradation is induced by an irreversible phase change from electrochemical active Li3V2(PO4)3 to nonactive monoclinic LiZnPO4, as well as active Na3V2(PO4)3 to nonactive rhombic Zn3(PO4)2(H2O)4. Subsequently, a rational dual‐cation (Al‐Fe) doping strategy is proposed to suppress these detrimental transformations. Such dual‐cation doping entails stronger P–O and V–O bonds, thus stabilizing the initial polyanionic structures. Consequently, the optimized member of Li3V1.775Al0.075Fe0.225(PO4)3 (LVAFP) exhibits desirable cycling stability (1000 cycles, 68.5% capacity retention) and notable rate capability (92.1% of the initial capacity at 10 C). Moreover, the dual‐cation doping methodology is successfully extended to improve the stability of Na3V2(PO4)3 cathode in aqueous dual‐ion batteries, signifying the versatility and feasibility of this strategy. The comprehensive identification of local structural evolution in these polyanions will broaden the scope of designing high‐performance alkali‐vanadyl‐phosphates for multivalent aqueous batteries.
Untersuchungen zur Schubtragfähigkeit von Blechen aus nichtrostendem Stahl
Authors: Ungermann Dieter , Schweyher Janik
Published: August 2024

Die Bemessungsregeln zur Schubtragfähigkeit von Blechen aus nichtrostendem Stahl nach DIN EN 1993‐1‐4 sind konservativer als für Bleche aus Baustahl nach DIN EN 1993‐1‐5. Dies führt zu einem erhöhten Materialverbrauch bei Konstruktionen aus nichtrostendem Stahl. Aus diesem Grund wurden experimentelle und numerische Untersuchungen zur Schubtragfähigkeit von Blechen aus nichtrostendem Stahl an torsionsbelasteten Hohlkastenquerschnitten durchgeführt, die zu einer Überarbeitung der Bemessungsvorschrift für die Schubtragfähigkeit von nichtrostenden Stählen für verformbare wie auch starre Auflagersteifen geführt haben.
Knicklängen im digitalen Zeitalter – ein didaktisch‐technisches Werkzeug
Authors: Lang Robert , Timmers Ralph , Enzinger Maximilian
Published: August 2024

Die Verzweigungslast eines stabilitätsgefährdeten Stabs bildet die Grundlage für die Bemessung nach dem Ersatzstabverfahren der EN 1993‐1‐1. Es hat sich eingebürgert, dass die Verzweigungslast über die Knicklänge des Stabs bestimmt wird. Die Knicklänge selbst entspricht im einfachsten Fall einem der Eulerschen Grundfälle, die bei den üblichen Strukturen des Stahlbaus jedoch nur selten vorkommen. Bei komplexeren Systemen hängt die Knicklänge häufig auch von anschließenden Strukturen bzw. deren Steifigkeiten ab. Die Bedeutung der Knicklängenermittlung ist derart groß, dass sie im Bereich der Lehre häufig am Stahlbau angesiedelt ist, obwohl sie eigentlich ein klassisches Problem der Baustatik darstellt. Am Innsbrucker Stahlbaulehrstuhl ist dies nicht anders, und so wurde im Rahmen der Modernisierung der Lehre ein Werkzeug entwickelt, das didaktisch und technisch dem Stand der Zeit entspricht und die Lehre unterstützen soll. Dieses Werkzeug ist in der Lage, spielerisch den Zugang zur Ermittlung von Knicklängen an komplexeren Strukturen zu vermitteln, während im Hintergrund moderne numerische Verfahren die eigentliche Rechenarbeit übernehmen. Die entwickelte Software buckL.ing (Freeware) steht auf der Homepage des Arbeitsbereichs für Stahlbau und Mischbautechnologie zum Download zur Verfügung (www.uibk.ac.at/stahlbau/software).
Experimental study on bond performance of recycled coarse aggregates concrete with circular steel tubes after freeze–thaw cycling
Authors: Hu Dongxia , Wu Jin , Feng Zhe , Liu Liqiang
Published: August 2024

Extrusion tests were conducted on recycled coarse aggregate concrete with circular steel tubes (RCCST, 100% replacement of recycled coarse aggregate) to investigate the impact of freeze–thaw cycles on bond properties. RCCST samples were subjected to 0, 25, 50, 75, 100, 125 and 150 freeze–thaw cycles and their bond properties were then compared with those of natural coarse aggregate concrete with circular steel tubes (NCCST) after 0, 100 and 150 freeze–thaw cycles. The experimental results indicate that freeze–thaw cycling damages the internal structure of RCCST, causing a significant decrease in interfacial bond strength with an increase in the number of freeze–thaw cycles. Freeze–thaw RCCST exhibits lower peak load and higher peak slip compared to NCCST, with increases of 25.2%, 73.2%, and 70.3% after 0, 100, and 150 freeze–thaw cycles, respectively. Regression analysis was used to derive an exponential equation that describes the relationship between longitudinal strain and strain gauge position. Additionally, a segmented fitting method was employed to obtain an expression for the bond slip of the freeze–thaw RCCST with a circular steel pipe.
Coordination Networks from [Te4]2+ Clusters and Polynitriles
Authors: Zink Marcus , Thönnes Dominik , Ernsthäuser Doris , Daniels Jörg , Bredow Thomas , Beck Johannes
Published: August 2024

The reactions of a series of organic polynitriles with [Te4][AsF6]2 in liquid SO2 solution lead either to reduction of [Te4]2+ to elemental tellurium or to the formation of coordination polymers. With 1,3‐dicyanobenzene (1,3‐DCB), 1,4‐dicyanobenzene (1,4‐DCB), 1,2,4,5‐tetracyanobenzene (TCB), tetracyanoethylene (TCNE) and tetracyanochinodimethane (TCNQ) the coordination complexes [Te4][AsF6]2 ⋅ 2(1,3‐DCB), [Te4][AsF6]2 ⋅ 3(1,4‐DCB) ⋅ 2SO2, [Te4][AsF6]2 ⋅ TCB, [Te4][AsF6]2 ⋅ TCNE and [Te4][AsF6]2 ⋅ TCNQ ⋅ 8 SO2 were isolated and characterized by crystal structure analyses and vibrational Raman spectroscopy. The nitriles are coordinated to the square‐planar clusters forming 1D chains, 2D arrangements and 3D networks. Tetrakis(dicyanomethylene)cyclobutendiide [C4(C{CN}2)4]2− is oxidized by [Te4]2+ to the neutral cyanocarbon C4(C{CN}2)4, structurally representing a 4[radialene]. The ionization potentials and electron affinities of the cyanamide anion, cyanogen, 1,2‐DCB, 1,3‐DCB, 1,4‐DCB, TCB, C4(C{CN}2)4, TCNE and TCNQ and those polynitriles, which cause reduction of [Te4]2+, were calculated at coupled‐cluster level of theory in order to examine possible reasons for the stability of the coordination polymers based on electronic properties of the nitriles.
Perceptions and Experiences of Severe Content in Content Moderation Teams: A Qualitative Study
Authors: Strongylou Dimitra Eleftheria , Savio Marlyn Thomas , Steiger Miriah , Bharucha Timir , Manuel Wilfredo R. Torralba , Huang Xieyining , Guevara Rachel Lutz
Published: August 2024

Existing Trust & Safety policies predominantly focus on protecting content moderators’ (CoMos) safety against severe content violations. Nevertheless, in reality, CoMos might encounter content across a broad severity spectrum while perceptions of content severity among CoMos are yet to be fully understood in relation to their well-being and job accuracy. The current study employs a sequential study design to qualitatively examine the views of 34 CoMos in the USA and the Philippines and of 166 professionals (i.e., mental health and learning experience staff, team leads) supporting CoMos on content severity and its perceived impact on CoMos well-being and job accuracy. Of note, consistent with ethical guidelines and wellness best practices, all CoMos received tiered wellness support services from TaskUs Inc. Collected data were thematically analyzed and two overarching themes emerged. Within the first theme, namely, ‘perceived content categories’, both CoMos and professionals, after considering the potential distress caused by various contents, broadly distinguished between ‘moderate’ and ‘graphic’ content, while they further attributed their own definitions to each of the two categories. Under theme two—‘content impact on perceived stress- most study participants discussed how reviewing moderate content might have a more detrimental impact upon CoMos stress and job accuracy compared to reviewing graphic content in the lack of wellness support and care. This study is the first of its kind to give voice to both CoMos and support staff to discuss in depth their views on content moderation while also making participant-led recommendations for work policy and future research.
User Perceptions of Progressive Web App Features: An Analytical Approach and a Systematic Literature Review
Authors: Marchetto Tulio , Morandini Marcelo
Published: August 2024

This article presents an in-depth analysis of the usability of progressive web apps (PWAs) across different operating systems, based on a survey that had 226 responses. The study covers five different apps and two operating systems, providing a comprehensive understanding of user experiences and preferences. Key findings include the relative ease of installation across all apps and operating systems, with iOS users reporting lower levels of difficulty. The visibility of app icons on home screens was generally high, underscoring the importance of app accessibility and user engagement. However, there is room for improvement in certain areas. The dataset obtained from the responses also reveals a high level of user engagement and willingness to provide feedback, which is crucial for the continual improvement of apps. The insights gleaned from this survey are invaluable for developers seeking to optimise their PWAs, ensuring they meet user expectations and deliver a superior app experience.