bluuebunny/crossref_metadata_2025 huggingface dataset:
Incremental value of C‐reactive protein to the MEESSI acute heart failure risk score
Authors: Wussler Desiree , Belkin Maria , Shrestha Samyut , Wernicke Hannah , Papachristou Androniki , Nowak Albina , Aliyeva Fatima , Mork Constantin , Strebel Ivo , Huré Gabrielle Valerie Francoi , Weil Dominic , Michou Eleni , Kozhuharov Nikola , Gualandro Danielle M. , Puelacher Christian , Miró Oscar , Rossello Xavier , Martín‐Sánchez Francisco Javier , Pocock Stuart J. , Goudev Assen , Breidthardt Tobias , Mueller Christian
Published: June 2024

Aims

We hypothesized that the current gold standard for risk stratification of patients with acute heart failure (AHF), the Multiple Estimation of risk based on the Emergency department Spanish Score In patients with AHF (MEESSI‐AHF) risk score, can be further improved by adding systemic inflammation as quantified by C‐reactive protein (CRP).

Methods and results

In a prospective multicentre diagnostic study (BASEL V), AHF was centrally adjudicated by two independent cardiologists. The MEESSI‐AHF risk score was calculated using an established reduced and recalibrated model containing 12 independent risk factors. Model extension was performed by refitting and adding CRP in the logistic regression model with 30‐day mortality as binary outcome. Discrimination, calibration and clinical usefulness were used to assess the performance of the extended Multiple Estimation of risk based on the Emergency department Spanish Score In patients (MEESSI) model. Validation was performed in an independent, retrospective and single‐centre AHF cohort. Among 1208 AHF patients with complete data allowing calculation of the recalibrated MEESSI and the extended MEESSI models, the prognostic accuracy for 30‐day mortality of the extended MEESSI model (c‐statistic 0.83, 95% confidence interval [CI] 0.79–0.87) was significantly higher compared to the recalibrated model (c‐statistic 0.79, 95% CI 0.75–0.83, p = 0.013). The extended model allowed to stratify a higher percentage of patients into the lowest risk group compared to the recalibrated model (33.1% vs. 20.3%). Demonstrating a calibration plot's slope of 1.00 (95% CI 0.81–1.19) and an intercept of 0.0 (95% CI −0.22 to 0.22), the extended MEESSI model achieved excellent and improved calibration. Results were confirmed in the independent validation cohort (n = 575).

Conclusions

Quantifying inflammation using CRP concentration provided incremental value in AHF risk stratification using the established MEESSI model.
The effect of dextrose prolotherapy on patients diagnosed with knee osteoarthritis: A comprehensive systematic review and meta‐analysis of interventional studies
Authors: Khateri Sorour , Nejad Fatemeh Behbahani , Kazemi Farnoush , Alaei Behnaz , Azami Mobin , Moradkhani Asra , Majidi Lobat , Moradi Yousef
Published: June 2024

Background and Aims

The primary objective of this systematic review and meta‐analysis was to assess the impact of dextrose prolotherapy on individuals diagnosed with knee osteoarthritis (KOA).

Methods

To conduct a thorough investigation, a variety of leading international databases were checked, including PubMed (Medline), Scopus, Web of Sciences, EMBASE (Elsevier), ClinicalTrials.gov, and the Cochrane Library. The search covered a period from January 2000 to the end of June 2023, which facilitated the collection of relevant studies.

Results

The findings of the study revealed that when the studies utilizing the Western Ontario McMaster Universities Index tool (WOMAC) were combined, patients with KOA who received prolotherapy experienced an improvement in function compared with those who received other treatments (SMD: 0.20; 95% Confidence Interval [1]: −0.11, 0.51; p value SMD = 0.221; I2: 78.49%; pheterogeneity < 0.001). Additionally, there was a decrease in mean pain and stiffness among patients who received prolotherapy compared with those who received other treatments or a placebo [(SMD: −0.95; 95% CI: ‐1.14, −0.76; p value SMD < 0.001; I2: 59.35%; pheterogeneity = 0.070) and (SMD: −0.21; 95% CI: −0.32, −0.10; p value SMD < 0.001; I2: 88.11%; pheterogeneity < 0.001)]. Furthermore, based on the Visual Analog Scale (VAS) score, there was a reduction of 0.81 units out of 10 in mean pain for patients with KOA who received prolotherapy (SMD: −0.81; 95% CI: −5.63, 4.10; p value SMD = 0.693; I2: 48.54%; pheterogeneity = 0.08).

Conclusion

Drawing from the data analysis performed in this meta‐analysis, it is apparent that dextrose prolotherapy exhibits promising effectiveness in reducing joint pain and stiffness, as well as improving functional performance in individuals suffering from KOA. Furthermore, it is recommended that forthcoming studies incorporate follow‐up periods to guide decisions concerning the duration of prolotherapy's effects.
Response of Bangladesh to the World Health Organization call to eliminate cervical cancer as a public health issue: An observational report
Authors: Reza Sejuti , Dewan Syed Masudur Rahman , Islam Mohammad Safiqul , Shahriar Mohammad
Published: June 2024

Background

Despite being preventable, cervical cancer remains a leading cause of mortality among Bangladeshi women. This article addresses the trends in Bangladesh's response to the World Health Organization's (WHO) request for the eradication of cervical cancer within the nation.

Discussion

When it comes to cervical cancer, healthcare institutions need to be concerned in terms of protocols for diagnosis and treatment, staff education, and available resources. More than a quarter of all female cancers in Bangladesh are caused by cervical cancer, which can be prevented through better healthcare infrastructure, earlier diagnosis, more qualified healthcare professionals, improved urban and rural hospital infrastructure, community‐based clinics, expanded affordable vaccinations, school‐based delivery systems, adoption of single‐dose vaccine schedules, raising awareness, and compiling a registry of previously affected results. WHO applauds Bangladesh's Ministry of Health and Family Welfare for its efforts to develop the National Strategy for cervical cancer prevention and control, which will guide and strengthen the country's activities to prevent and treat cervical cancer.

Conclusion

The endeavor to eradicate this global disease burden should not be limited to Bangladesh; all nations should participate collectively to prevent the malignancy from returning and threatening human civilization.
Sculpting the future: A narrative review of 3D printing in plastic surgery and prosthetic devices
Authors: Zahid Muhammad Jawad , Mavani Parit , Awuah Wireko Andrew , Alabdulrahman Mohammad , Punukollu Rachana , Kundu Arnab , Mago Arpit , Maher Karam , Adebusoye Favour T. , Khan Tehreem Naseer
Published: June 2024

Background and Aims

The advent of 3D printing has revolutionized plastic surgery and prosthetic devices, providing personalized solutions for patients with traumatic injuries, deformities, and appearance‐related conditions. This review offers a comprehensive overview of 3D printing's applications, advantages, limitations, and future prospects in these fields.

Methods

A literature search was conducted in PubMed, Google Scholar, and Scopus for studies on 3D printing in plastic surgery.

Results

3D printing has significantly contributed to personalized medical interventions, with benefits like enhanced design flexibility, reduced production time, and improved patient outcomes. Using computer‐aided design (CAD) software, precise models tailored to a patient's anatomy can be created, ensuring better fit, functionality, and comfort. 3D printing allows for intricate geometries, leading to improved aesthetic outcomes and patient‐specific prosthetic limbs and orthoses. The historical development of 3D printing, key milestones, and breakthroughs are highlighted. Recent progress in bioprinting and tissue engineering shows promising applications in regenerative medicine and transplantation. The integration of AI and automation with 3D printing enhances surgical planning and outcomes. Emerging trends in patient‐specific treatment planning and precision medicine are potential game‐changers. However, challenges like technical considerations, economic implications, and ethical issues exist. Addressing these challenges and advancing research in materials, design processes, and long‐term outcomes are crucial for widespread adoption.

Conclusion

The review underscores the increasing adoption of 3D printing in healthcare and its impact on plastic surgery and prosthetic devices. It emphasizes the importance of evaluating the current state and addressing knowledge gaps through future research to foster further advancements
The biological and therapeutic assessment of a P(3HB‐co‐4HB)‐bioactive glass‐graphene composite biomaterial for tissue regeneration
Authors: Sharifulden Nik S. A. N. , Barrios Silva Lady V. , Mandakhbayar Nandin‐Erdene , Shin Seong‐Jin , Kim Hae‐Won , Knowles Jonathan C. , Nguyen Linh T. B. , Chau David Y. S.
Published: June 2024

An ideal wound dressing should create a healing environment that relieves pain, protects against infections, maintains moisture, removes debris, and speeds up wound closure and repair. However, conventional options like gauze often fall short in fulfilling these requirements, especially for chronic or nonhealing wounds. Hence there is a critical need for inventive formulations that offer efficient, cost‐effective, and eco‐friendly alternatives. This study focuses on assessing the innovative formulation based on a microbial‐derived copolymer known as poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate), P(3HB‐co‐4HB) bioactive glass and graphene particles, and exploring their biological response in vitro and in vivo—to find the best combination that promotes cell adhesion and enhances wound healing. The formulation optimized at concentration of bioactive glass (1 w/w%) and graphene (0.01 w/w%) showed accelerated degradation and enhanced blood vessel formation. Meanwhile biocompatibility was evaluated using murine osteoblasts, human dermal fibroblasts, and standard cell culture assays, demonstrating no adverse effects after 7 days of culture and well‐regulated inflammatory kinetics. Whole thickness skin defect using mice indicated the feasibility of the biocomposites for a faster wound closure and reduced inflammation. Overall, this biocomposite appears promising as an ideal wound dressing material and positively influencing wound healing rates.
On eigenfunctions of the block graphs of geometric Steiner systems
Authors: Goryainov Sergey , Panasenko Dmitry
Published: June 2024

This paper lies in the context of the studies of eigenfunctions of graphs having minimum cardinality of support. One of the tools is the weight‐distribution bound, a lower bound on the cardinality of support of an eigenfunction of a distance‐regular graph corresponding to a nonprincipal eigenvalue. The tightness of the weight‐distribution bound was previously shown in general for the smallest eigenvalue of a Grassmann graph. However, a characterisation of optimal eigenfunctions was not obtained. Motivated by this open problem, we consider the class of strongly regular Grassmann graphs and give the required characterisation in this case. We then show the tightness of the weight‐distribution bound for block graphs of affine designs (defined on the lines of an affine space with two lines being adjacent when intersect) and obtain a similar characterisation of optimal eigenfunctions.
The role of sirtuins in intervertebral disc degeneration: Mechanisms and therapeutic potential
Authors: Tu Heng , Gao Qian , Zhou Yumeng , Peng Li , Wu Dan , Zhang Demao , Yang Jing
Published: June 2024

Intervertebral disc degeneration (IDD) is one of the main causes of low back pain, which affects the patients' quality of life and health and imposes a significant socioeconomic burden. Despite great efforts made by researchers to understand the pathogenesis of IDD, effective strategies for preventing and treating this disease remain very limited. Sirtuins are a highly conserved family of (NAD+)‐dependent deacetylases in mammals that are involved in a variety of metabolic processes in vivo. In recent years, sirtuins have attracted much attention owing to their regulatory roles in IDD on physiological activities such as inflammation, apoptosis, autophagy, aging, oxidative stress, and mitochondrial function. At the same time, many studies have explored the therapeutic effects of sirtuins‐targeting activators or micro‐RNA in IDD. This review summarizes the molecular pathways of sirtuins involved in IDD, and summarizes the therapeutic role of activators or micro‐RNA targeting Sirtuins in IDD, as well as the current limitations and challenges, with a view to provide possible solutions for the treatment of IDD.
The association between dynamic changes in vitamin D and frailty alterations: A prospective analysis of UK Biobank participants
Authors: Zhang Pan , Zhong Jinghui , Liu Xinfeng , Sun Wen
Published: June 2024

Background

Frailty is a common geriatric syndrome associated with reduced reserves and increased vulnerability to stressors among older adults. Vitamin D deficiency has been implicated in frailty, as it is essential for maintaining musculoskeletal functions. The relationship between dynamic changes in vitamin D levels and frailty over time has not been extensively studied.

Methods

This study utilized data from the UK Biobank. Baseline and longitudinal changes in vitamin D levels were measured. Frailty status was assessed using both the frailty phenotype and frailty index approaches and classified as robust, pre‐frail, or frail. Changes in frailty status were assessed by frailty phenotype at baseline (2006–2010) and the follow‐up (2012–2013). Mixed effect model was performed to examine the association between vitamin D levels and frailty status. Using multistate transition models, we assessed the impact of increasing vitamin D levels on the probabilities of transitioning between robust, pre‐frail, and frail states.

Results

Based on the frailty phenotype, 287 926 individuals (64.8%) were identified as having various degrees of frailty (median age 58.00 [51.00, 64.00] years, 55.9% females). Using the frailty index approach, 250 566 individuals (56%) were found to have different levels of frailty (median age 59.00 [51.00, 64.00] years, 55.3% females). Baseline vitamin D levels were found to be significantly associated with frailty status (frailty phenotype: ORfrail 0.78, 95% CI [0.76, 0.79], P < 0.001; frailty index: ORfrail 0.80, 95% CI [0.78, 0.81], P < 0.001). Dynamic changes in vitamin D levels were also found to be associated with changes in frailty over time. Furthermore, increasing vitamin D levels were associated with a transition from frailty to a healthier status. A higher degree of vitamin D (estimated at 1 nmol/L) was associated with a lower risk of transitioning from robust to prefrail (HR 0.997, 95% CI [0.995, 0.999]) and from prefrail to frail (HR 0.992, 95% CI [0.988, 0.995]).

Conclusions

This study highlights the importance of vitamin D in the context of frailty. Low vitamin D levels are associated with increased frailty risk, while increasing vitamin D levels may contribute to improving frailty status. Recognizing the relationship between vitamin D levels and frailty can inform personalized management and early interventions for frail individuals. Further research is needed to explore the potential effects of vitamin D interventions on frailty and deepen our understanding of the biological connections between vitamin D and frailty.
Micromorphological study of some Salsola species (Amaranthaceae) in Iran and its systematic significance using scanning electron microscopy
Authors: Amini Elham , Sattarian Ali , Nasrollahi Fatemeh , Daneshvar Abolfazl , Esmaeili Majid Mohammad , Sani Leila Hamidzadeh , Haghighi Sona
Published: June 2024

Using scanning electron microscopy (SEM), six Salsola species from Iran were examined for their epidermis, seed, and fruit micromorphology. Among them were S. brachiata from section Heterotricha, S dendroides, S. incanescens, and S. orientalis from section Caroxylon, S. kali from section Kali, and S. turcomanica from section Physurus. Epidermal cells are divided into three types. There were diamond, irregular, and polygonal cells, as well as straight and undulated walls. Studied species of Salsola have smooth or sculptured fruit surfaces, and there are three main types of fruit surface ornamentation. There is a significant difference between these species based on the type of hair and density of the fruit. Seed shape and color have little systematic significance. The seed epidermis is composed of polygonal, elongated polygonal, irregular, and diamond cells. Although polygonal and irregular testa cells are most common, their size and shape can provide additional information and useful diagnostic characteristics at both specific and infraspecific levels. For taxonomic separation, the current study provides novel insights at micromorphological levels.

Research Highlights

This article reports halophyte are shown as models for adaptation to extreme habitats.

These plants are placed among the ecological communities of xerophytes. Here, for the first time, the microstructural analysis of Salsola has been investigated.

Additionally, it provides new insights into plant species' response to extreme conditions, as well as possible adaptation strategies at the micromorphological level.
Circulation pattern and genetic variation of rhinovirus infection among hospitalized children on Hainan Island, before and after the dynamic zero‐COVID policy, from 2021 to 2023
Authors: Xiao Meifang , Banu Afreen , Jia Yibo , Chang Meng , Wang Gaoyu , An Jing , Huang Yi , Hu Xiaoyuan , Tang Chuanning , Li Zihan , Niu Yi , Tian Xiuying , Deng Wanxin , Tang Cheng , Du Jiang , Cui Xiuji , Chan Jasper Fuk‐Woo , Peng Ruoyan , Yin Feifei
Published: June 2024

Throughout the COVID‐19 pandemic, rhinovirus (RV) remained notable persistence, maintaining its presence while other seasonal respiratory viruses were largely suppressed by pandemic restrictions during national lockdowns. This research explores the epidemiological dynamics of RV infections among pediatric populations on Hainan Island, China, specifically focusing on the impact before and after the zero‐COVID policy was lifted. From January 2021 to December 2023, 19 680 samples were collected from pediatric patients hospitalized with acute lower respiratory tract infections (ARTIs) at the Hainan Maternal and Child Health Hospital. The infection of RV was detected by tNGS. RV species and subtypes were identified in 32 RV‐positive samples representing diverse time points by analyzing the VP4/VP2 partial regions. Among the 19 680 pediatric inpatients with ARTIs analyzed, 21.55% were found to be positive for RV infection, with notable peaks observed in April 2021 and November 2022. A gradual annual decline in RV infections was observed, alongside a seasonal pattern of higher prevalence during the colder months. The highest proportion of RV infections was observed in the 0–1‐year age group. Phylogenetic analysis on 32 samples indicated a trend from RV‐A to RV‐C in 2022. This observation suggests potential evolving dynamics within the RV species although further studies are needed due to the limited sample size. The research emphasizes the necessity for ongoing surveillance and targeted management, particularly for populations highly susceptible to severe illnesses caused by RV infections.
The impact of storage, handling, and treatment on nutritional quality and safety of animal milk: A protocol for the systematic review and meta‐analysis
Authors: Alwasila Roba , Berg Alaina , Colaizy Tarah , Smith Abigail , Evans James , Murad Mohammad Hassan , Bhutta Zulfiqar Ahmed , Imdad Aamer
Published: June 2024

Objectives

Human milk has been shown to reduce severe morbidity in preterm/low‐birth‐weight infants and is therefore the recommended nutritional source. When infants cannot receive maternal milk, donor human milk (DHM) is recommended. The use of human milk banking facilities is increasing to meet the need for DHM. DHM is unique compared to maternal milk as it must be processed and stored. The processing and storage of animal milk has been more rigorously studied than human milk and can serve as proxy to create DHM banking guidelines.

Methods and Analysis

We will search electronic databases, grey literature, and the websites of relevant international organizations. We will include studies that evaluated the impact of storage, handling, and treatment on the nutritional quality and safety of animal milk. We will not restrict study date, language, or design. If sufficient homogeneity exists between studies, we will conduct a meta‐analysis. We will evaluate the methodological quality of each study using the SYRCLE's (Systematic Review Centre for Laboratory Animal Experimentation) risk of bias tool. (1) We will evaluate the overall certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach.

Conclusion

In this systematic review and meta‐analysis, commissioned by the World Health Organization, we will synthesize the available literature regarding the impact of various storage, handling, and treatment practices on the nutritional quality and safety of animal milk.
An alternative macro‐Raman mapping algorithm, adapting the numbers of accumulations
Authors: Vandenabeele Peter
Published: June 2024

Macro‐Raman mapping is an approach that is well suited to study the distribution of molecules over a surface of typically several cm2, such as the pigment distribution on a painting. During such an experiment, thousands Raman spectra are recorded in a predefined array of points. As there can be a huge difference in Raman sensitivity between different molecules, an alternative approach is proposed, where measurement times are adapted according to the quality of the Raman scatterer. Therefore, an iterative process is implemented, involving recording short accumulations, followed by a quick evaluation. As soon as the accumulated spectrum reaches a quality criterium, measurement of the next point is started, while in the other case further accumulations are added. The influence of using multiple accumulations opposite to a single measurement for a prolonged period has been assessed by comparing the overall measurement time and the spectral intensity of the main Raman band (520.5 cm−1) of silicon. Another prerequisite for this algorithm to be successful is the need for a quick and reliable evaluation of the spectral quality. This was examined by applying this function on the accumulations of Raman spectra of 49 paint samples from a colour chart. Finally, the variable‐accumulation algorithm is applied during a macro‐Raman mapping experiment of a watercolour painting on paper. Despite a significant gain in overall measuring time, this novel approach yields a qualitative data set that can be used for creating clear Raman maps, using different data processing methods.
Injectable Self‐Healing Antibacterial Hydrogels with Tailored Functions by Loading Peptide Nanofiber‐Biomimetic Silver Nanoparticles
Authors: Zhang Mingze , Gu Guanghui , Xu Youyin , Luan Xin , Liu Jianyu , He Peng , Wei Gang
Published: June 2024

Polymer hydrogels find extensive application in biomedicine, serving specific purposes such as drug delivery, biosensing, bioimaging, cancer therapy, tissue engineering, and others. In response to the growing threat of bacterial infections and the escalating resistance to conventional antibiotics, this research introduces a novel injectable, self‐healing antimicrobial hydrogel comprising bioactive aldolized hyaluronic acid (AHA) and quaternized chitosan (QCS). This designed QCS/AHA hydrogel incorporates self‐assembling peptide nanofibers (PNFs) and small‐sized silver nanoparticles (AgNPs) for tailored functionality. The resulting hybrid QCS/AHA/PNF/AgNPs hydrogel demonstrates impressive rheological characteristics, broad‐spectrum antimicrobial efficacy, and high biocompatibility. Notably, its antimicrobial effectiveness against Escherichia coli and S. aureus surpasses 99.9%, underscoring its potential for treating infectious wounds. Moreover, the rheological analysis confirms its excellent shear‐thinning and self‐healing properties, enabling it to conform closely to irregular wound surfaces. Furthermore, the cytotoxicity assessment reveals its compatibility with human umbilical vein endothelial cells, exhibiting no significant adverse effects. The combined attributes of this bioactive QCS/AHA/PNF/AgNPs hydrogel position it as a promising candidate for antimicrobial applications and wound healing.
Analysis of manufacturers' dual‐source and dual‐channel strategies under the trend of brand weakening
Authors: Ma Jingpei , Shen Jiahui , Sun Xuejun , Meng Yuan
Published: June 2024

In the context of the world economic downturn, consumers are showing a trend of brand weakening. In order to explore the product advantages of the source manufacturer, that is, the competitive supplier, we establish a game theory model to study the strategy choice of original equipment manufacturers (OEM), competitive suppliers (CS), and noncompetitive suppliers (NS) based on consumer heterogeneity. By dividing consumers into quality consumers and ordinary consumers and considering horizontal competition (between suppliers) and vertical competition (between OEM and suppliers), it is found that the products of the source manufacturers are becoming more and more popular with consumers. Contrary to the traditional view, we find that under the trend of brand weakening, the products of the source manufacturers should be positioned above the price range acceptable to consumers, and the OEM products of the brand owners should be appropriately reduced. The interesting question is whether CS will discontinue the supply of OEM components once it has its own branded products. Further, we analyze that CS terminating the component sales business is an untrustworthy threat to OEM. Finally, we find that there will be a “win–win” zone between OEM and competing suppliers, and the “win–win” region will decrease as the manufacturing cost of the competing supplier increases and increase as the manufacturing cost of the noncompeting supplier increases.
Tensile properties at various strain rates of flexible carbon nanotube film densified by the combination of chlorosulfuric acid and uniaxial drawing
Authors: Tang Yu , Yin Chenxi , Li Yuanyuan , Zhang Yan , Wang Ping , Hu Dongmei
Published: June 2024

The quasi‐static tensile properties of carbon nanotube (CNT) films have been extensively investigated, yet research on their impact tensile properties at high strain rates remains scarce. In this article, CNT films prepared by floating catalyst chemical vapor deposition (FCCVD) method were densely arranged by chlorosulfuric acid (CSA) under wet stretching. The Instron 3365 and miniaturized split Hopkinson tension bar (SHTB) were used to conduct tensile testing at different strain rates. The findings reveal that CSA wet‐stretching markedly enhances the density and orientation of CNT films, resulting in significant improvements in tensile properties with a notable strain rate effect. Specifically, when immersed for 60 s under a draft ratio of 40% and a strain rate of 1900 s−1, the densified CNT films exhibit maximum stress and energy absorption values of 777.44 MPa and 54.79 MJ/m3, respectively, achieving a 637.1% and 425.7% increase compared with the original film. This research provides a convenient and feasible strategy to prepare CNT films with high energy absorption tolerance across various strain rates, thus expanding the practical application potential of CNT films.

Highlights

The study innovates a posttreatment way to produce superior FCCVD CNT films.

CSA treatment and wet stretching enhance CNT films' mechanical properties.

Dynamic fracture strength boosts over 600% and energy absorption raises over 400%.

CSA can purify FCCVD‐prepared CNT films, greatly improving their properties.

The Prep can be effectively integrated with the direct spinning process.
Mechanical properties of carbon nanotube (CNT) reinforced polymers using electron‐deficient aromatics as additives
Authors: Bauer Florian , Söthje Dominik , Schlachter Herbert , Wehnert Gerd
Published: June 2024

In initial experiments the effects of aromatic model substances on carbon nanotube (CNT) dispersions in dimethylformamide (DMF) were investigated. Electron‐deficient aromatics interact strongly with CNTs, causing increased agglomeration and sedimentation. Conversely, electron‐donating aromatics stabilize CNT dispersions in DMF. Polymers with electron‐deficient aromatics, such as polydinitrostyrene (PDNS), exhibit a concentration‐dependent effect: low concentrations lead to stabilization of dispersions, while higher concentrations lead to sedimentation. This suggests that such polymers can enhance attraction between the matrix of CNT‐reinforced polymers as well as stabilize the dispersed CNTs. Polycarbonate, modified with polydinitrocarbonate (PDNC) and reinforced with CNTs showed improved mechanical properties. The addition of 6 wt.% CNTs and 6 wt.% PDNC resulted in a notable improvement with a 22% increase in tensile strength, a 29% increase in flexural strength, a 39% increase in Young's modulus and a 47% increase in flexural modulus. This enhancement resulted in an overall mechanical performance comparable to the high‐performance polymer polyetherimide. However, there must be noted, that the addition of PDNC increases the CNT particle size, which can negatively affect mechanical properties. The results highlight the additive's dual role in enhancing adhesive interactions while potentially increasing CNT agglomerate sizes.

Highlights

Interactions of CNTs dispersed in DMF and various aromatics were investigated.

Polydinitrocarbonate (PDNC) was synthesized as a new additive for CNT‐composites.

Polycarbonate/CNT‐composites were obtained using extrusion.

Test specimens with CNT contents up to 6 wt.% were obtained.

Mechanical properties of polycarbonate reached the level of polyetherimide.
Flame retardant characteristics of natural fibre reinforced polymer composites: A thematic review
Authors: Muralidharan Nivedhitha Durgam , Subramanian Jeyanthi , Rajamanickam Sathish Kumar , Krishnasamy Prabu , Thiagamani Senthil Muthu Kumar , Khan Anish
Published: June 2024

Globally, with the advancement of industrialization and globalization, the automotive sector has drastically increased for transportation and commercial purposes. Hence, to maximize efficiency and minimize the weight of automobiles, the automotive and aerospace industries have welcomed synthetic fibre‐reinforced composites, vastly replacing conventional metals. Despite the superior performance, the usage of synthetic fibre composites has led to the massive dumping of automotive waste in landfills, making the land unfit for future purposes. Therefore, natural fibre‐reinforced composites (NFRCs) quickly replace synthetic fibres with their unique features, such as being lightweight, biodegradable, and non‐toxic, en routing a new path towards a sustainable environment. Though NFRCs are finding new applications in various industries, researchers are trying to enhance their thermal, electrical, and mechanical properties to make them synergic composites. However, with the presence of cellulose, lignin, and wax, natural fibres become highly responsive toward flammability, limiting their use in various emerging applications. As the subject of the flammability of NFRCs has a limited amount of literature, the current review article aims to address the current flammability studies and strategies adopted to improve the flame‐retardant characteristics of NFRCs exclusively. Also, this review covers the factors and influence of different types of flame‐retardant fillers adopted to improve the flame retreatant characteristic of NFRCs and their mechanism. Additionally, this review article summarises various official and laboratory flame‐testing techniques such as radial panel test (RPT), cone calorimetry, and limited oxygen index (LOI) adopted to characterize the flammable properties of NFRCs.

Highlights

Natural fiber biocomposites are becoming a potential candidate for structural and interior applications in the automotive and aircraft industries.

Flammability becomes a major alarm as it concerns with the safety of passengers.

The flammability behavior of natural fiber composites is extensively discussed.

Mechanisms, factors, and selection of flame‐retardant materials are reviewed to improve the flame‐retardant characteristics.

The influence of surface treatments, fiber content, and flame‐retardant nanofillers are also elaborately discussed.

Advanced flame testing techniques were conversed with pictorial representation.
Preparation and properties of poly (butylene adipate‐co‐terephthalate) composites with high bamboo flour content
Authors: Ren Mingtian , Jiang Sike , Zhang Yaqing , Wang Huiling , Wu Qiangxian
Published: June 2024

This study focused on the preparation of bamboo flour/Poly (butylene adipate‐co‐terephthalate) (PBAT) composites with high bamboo flour content and high mechanical strength using polyurethane prepolymer as chemical–physical compatibilizer via in‐situ reaction. Additionally, this work explored the effects of different bamboo flour contents and different types of polyurethane prepolymers on the mechanical properties, morphology, thermodynamics, water absorption, and surface wettability of the bamboo flour/PBAT composites. The results showed that PBA‐based polyurethane prepolymer (PBAPU) was an effective compatibilizer, promoting the interfacial adhesion between bamboo flour and PBAT. The strength at break, elongation at break, and impact strength of composites with 50% bamboo flour content reached 19.56 MPa, 25.53%, and 12.8 KJ/m2. With the increase of bamboo flour content, the strength of composites was still higher. The addition of PBAPU enhanced the thermal stability, mechanical properties, water resistance, and hydroscopicity of the bamboo flour/PBAT composites. Furthermore, the compatibilization of PBA‐based polyurethane prepolymer on composites was better than that of PCL‐based polyurethane prepolymer. Overall, we provided an effective strategy for preparing renewable, green, and practical high‐bamboo flour composites.

Highlights

This work successfully prepared bamboo flour/PBAT composites with high bamboo content using an in‐situ melt blending reaction.

A new interface structure of physical PBA‐PBA interaction between the PBAPU layer and PBAT matrix improved the compatibilization of the composites.

PBAPU as a compatibilizer effectively improved the interface compatibility, thermal stability, and water resistance of Bamboo flour/PBAT blends.

Bamboo flour/PBAT composites with high bamboo flour content have excellent mechanical properties.
Quantitative assessment of impact damage in stitched foam‐filled Aluminium honeycomb Sandwich panels by experimental and machine learning methods
Authors: Dhanesh E. , Nagarajan V. A. , Vinod Kumar K. P. , Karthik B.
Published: June 2024

Novel Stitched Foam‐filled Honeycomb Sandwich (SFHS) panels have been fabricated using vacuum‐assisted resin transfer molding to address the weak interfaces between the face sheets and the core in the Foam‐filled Honeycomb Sandwich (FHS) panel. The SFHS panels have shown better load‐bearing capacity and performance characteristics compared to FHS panel after Low‐Velocity Impact (LVI) tests. After the LVI test, MATLAB image processing was used to analyze the impact damage areas and failure mechanisms. In addition, Machine Learning regression algorithms were employed to predict the optimal amount of energy absorbed during low‐velocity impact testing of fabricated panels with a maximum impactor drop height of 700 mm. The results indicated that nylon yarn stitching significantly improved energy absorption and interfacial behavior compared to unstitched honeycomb panels. This research also revealed that SFHS1 panels with adjacent honeycomb cell stitching are more impact resistant, provide increased load carrying capacity, and are cost‐effective. These panels can be utilized by modern engineers to increase economy, durability, and functionality in industrial, automotive, and construction applications.

Highlights

Stitched Foam Filled Honeycomb Sandwich (SFHS) panels, manufactured via resin transfer molding, and eliminates weak interfaces between the face sheets and core.

SFHS panels outperformed unstitched panels in load‐bearing and energy absorption during low‐velocity impact, as confirmed by MATLAB image analysis showing reduced damage and failure.

Machine learning algorithms particularly polynomial regression model predicted maximum absorption energy precisely with 99.9% accuracy, close to experimental results.

SFHS panels can be used in automotive and industrial applications due to their through‐thickness stitching.
The effect of tetra‐needle‐like zinc oxide whisker as additive on the crystallization kinetics of polybutylene adipate terephthalate/polylactic acid blend
Authors: Zhao Zhibo , Balu Rajkamal , Choudhury Namita Roy , Dutta Naba Kumar
Published: June 2024

Herein, we investigate the effect of the addition of tetra‐needle‐like zinc oxide whisker (T‐ZnOw), a novel reinforcing additive, on the melt crystallization behavior of biodegradable polybutylene adipate terephthalate (PBAT)/polylactic acid (PLA) polymer blends. PBAT and PLA were blended in a Haake mixer at a fixed weight ratio of 70/30, and the contents of T‐ZnOw varied from 0 to 7 wt%. The melt thermal properties and crystallization behavior of PBAT/PLA blends and PBAT/PLA/T‐ZnOw composites were studied using differential scanning calorimetry. The kinetics of melt crystallization have been quantitatively explained using a range of mathematical formalisms. The Avrami equation is adopted to analyze the isothermal crystallization process and kinetics of PBAT/PLA/T‐ZnOw composites. For its nonisothermal crystallization process and kinetics, the Ozawa equation cannot describe the entire process, while the Jeziomy‐modified Avrami equation can only describe the initial stage of its nonisothermal crystallization. Using Mo‐analysis, the impact of T‐ZnOw contents on the composite's nonisothermal crystallization kinetic has been thoroughly examined. Given that the PBAT/PLA blend system's crystal formation may be inhibited by T‐ZnOw, the observation demonstrates that T‐ZnOw only marginally alters this process. The work is of significant scientific value and adds a new concept to the development of sustainable thin film for packaging.

Highlights

T‐ZnOw is used as a novel additive for PBAT/PLA polymer blends.

The crystallization of PBAT/PLA/T‐ZnOw composite systems is thoroughly examined.

T‐ZnOw marginally reduces the kinetics of the crystallization process of PBAT/PLA blends.

PBAT/PLA/T‐ZnOw composites follow volume nucleation with mixed 2D/1D growth.

The nonisothermal crystallization of PBAT/PLA/T‐ZnOw composites is validated by Mo‐analysis.
Anti‐inflammatory and anti‐hyperalgesic effects induced by an aqueous aged black garlic extract in rodent models of ulcerative colitis and colitis‐associated visceral pain
Authors: Libero Maria Loreta , Lucarini Elena , Recinella Lucia , Ciampi Clara , Veschi Serena , Piro Anna , Chiavaroli Annalisa , Acquaviva Alessandra , Nilofar Nilofar , Orlando Giustino , Generali Daniele , Ghelardini Carla , di Cesare Mannelli Lorenzo , Montero‐Hidalgo Antonio J. , Luque Raúl M. , Ferrante Claudio , Menghini Luigi , di Simone Simonetta Cristina , Brunetti Luigi , Leone Sheila
Published: June 2024

Inflammatory bowel disease (IBD) is a morbid condition characterized by relapsing–remitting inflammation of the colon, accompanied by persistent gut dysmotility and abdominal pain. Different reports demonstrated biological activities of aged black garlic (ABG), including anti‐inflammatory and antioxidant effects. We aimed to investigate beneficial effects exerted by ABGE on colon inflammation by using ex vivo and in vivo experimental models. We investigated the anti‐inflammatory effects of an ABG water extract (ABGE) on rat colon specimens exposed to E. coli lipopolysaccharide (LPS), a known ex vivo experimental model of ulcerative colitis. We determined gene expression of various biomarkers involved in inflammation, including interleukin (IL)‐1β, IL‐6, nuclear factor‐kB (NF‐kB), tumor necrosis factor (TNF)‐α. Moreover, we studied the acute effects of ABGE on visceral pain associated with colitis induced by 2,4‐di‐nitrobenzene sulfonic acid (DNBS) injection in rats. ABGE suppressed LPS‐induced gene expression of IL‐1β, IL‐6, NF‐kB, and TNF‐α. In addition, the acute administration of ABGE (0.03–1 g kg−1) dose‐dependently relieved post‐inflammatory visceral pain, with the higher dose (1 g kg−1) able to significantly reduce both the behavioral nociceptive response and the entity of abdominal contraction (assessed by electromyography) in response to colorectal distension after the acute administration in DNBS‐treated rats. Present findings showed that ABGE could represent a potential strategy for treatment of colitis‐associated inflammatory process and visceral pain. The beneficial effects induced by the extract could be related to the pattern of polyphenolic composition, with particular regard to gallic acid and catechin.
A mechanism for coastal fog genesis at evening transition
Authors: Hintz Thomas J. , Huang Kelly Y. , Hoch Sebastian W. , Bardoel Stef L. , Gaberšek Saša , Gultepe Ismail , Ruiz‐Plancarte Jesus , Pardyjak Eric R. , Wang Qing , Fernando Harindra J. S.
Published: June 2024

Transitional changes in the atmospheric boundary layer (ABL) are known to facilitate the onset of terrestrial fog, which is defined as a condition with near‐surface visibility <1 km due to airborne water droplets. In particular, the evening transition from a daytime convective ABL to a night‐time stable ABL provides favorable conditions for fog. This article describes a local fog event observed during the evening transition at a Canadian islet in the north Atlantic known as Sable Island during the “Fog and Turbulence Interactions in the Marine Atmosphere (Fatima)” field campaign. The comprehensive set of data collected using a myriad of instruments covering a wide range of scales allowed identification of a novel mechanism underlying this fog event. Therein an ocean–land discontinuity created a flow regime consisting of several stacked boundary layers, interplay of which produced a thin low‐level cloud that then diffused downward to the surface, causing visibility reduction. This mechanism offers useful insights on the role of boundary layers, stratification, and turbulence in fog genesis over oceanic islands.
Isotopic and mineralogic bias introduced by pulverization of aragonite
Authors: Schmitt Katharina E. , Fink Laura J. , Jantschke Anne , Vigelius Daniel , Schöne Bernd R.
Published: June 2024

Rationale

Stable carbon and oxygen isotope data of biogenic and abiogenic aragonite are of fundamental relevance in paleoclimate research. Wet‐chemical analysis of such materials requires well‐homogenized, fine‐grained powder. In the present study, the effect of different grinding/milling methods on sample homogeneity and the potential risk of unintentional calcite formation and isotope shift were evaluated.

Methods

Shells of Arctica islandica and aragonite sputnik crystals were pulverized using a set of commonly used methods, including a hand‐held drill, a vibromill operated at various settings (with and without liquid nitrogen cooling, changes in ball diameters, frequencies, and processing durations), and an agate mortar and pestle. Stable isotope values were measured using an isotope ratio mass spectrometer operated in continuous flow mode. Identification of mineral phases was obtained by powder X‐ray diffraction (PXRD), Raman spectroscopy, and attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy. Calcite content was quantified by PXRD Rietveld refinement.

Results

Samples showed substantial homogeneity, in particular after vibromilling (duration 3–10 min). More vigorous grinding resulted in larger fractions of calcite (0.5–4.2 wt%) and a concomitant δ18O and δ13C decrease, specifically in bivalve shells. The only method for producing pure aragonite powder was by pounding the aragonite sputniks manually with an agate mortar and pestle.

Conclusions

None of the studied, commonly used machine‐based pulverization methods produced pure aragonite powder from samples consisting originally of aragonite. These findings have significant implications for light‐stable isotope‐based paleoclimate reconstructions. Except for abiogenic aragonite powder produced by pounding in an agate mortar, paleotemperatures would be overestimated.
Alder‐Longo Method Derived Cationic Porphyrin‐Based Porous Polymer as Physical Antibacterial Agent for the Bacteria‐Infected Wound Synergy Therapy
Authors: Li Juan , Fu Yiyue , Chu Lichao , Shi Lin , Zhang Junshan , Ju Hui
Published: June 2024

The widespread of drug‐resistant genes has greatly exacerbated the difficulty for the effectively tre atment of diseases associated with bacterial infections. The ineffectiveness of antibiotics poses great challenges to the development of new antimicrobial agents, especially those does not cause bacterial resistance. Herein, a cation porous organic polymer (CPOP) denoted as BDPP, was facilely prepared via the Alder‐Longo method skipping the tedious porphyrin‐bearing monomer synthesis procedure. The repeated porphyrin units endowed excellent photoactivity with the porous skeletons, and the inherent cations significantly improved the binding ability of BDPP with the bacterial cell membrane. As a result, the as‐synthesized POPs could be used as a physical broad spectrum sterilization agent, amalgamating the cation and photothermal therapy to exert synergistic amplified antibacterial effects. In vivo assay demonstrated BDPP with good biocompatibility, could also significantly promote the healing of wounds with bacteria‐infection. This work paves a facile way for the rational construction of material‐based antibacterial agent for the bacteria inactivation.
Growth of 1D Carbon Nanotube@Perovskite Core–Shell van der Waals Heterostructures through Chemical Vapor Deposition
Authors: Zhu Mengjia , Xia Kailun , Wang Haomin , Li Shuo , Zhang Mingchao , Wang Huimin , Liang Xiaoping , Chen Ke , Zhang Yingying
Published: June 2024

Perovskite is an emerging material with immense potential in the field of optoelectronics. 1D perovskite nanowires are crucial building blocks for the development of optoelectronic devices. However, producing perovskite nanowires with high quality and controlled alignment is challenging. In this study, the direct epitaxial growth of perovskite on oriented carbon nanotube (CNT) templates is presented through a chemical vapor deposition method. The deposition process of lead iodide and methylammonium iodide is systematically investigated, and a layer plus island growth mechanism is proposed to interpret the experimental observations. The aligned long CNTs serve as 1D templates and allow the growth of CNT@perovskite core‐shell heterostructure with a high aspect ratio to withstand large deformation. The obtained 1D perovskite materials can be easily manipulated and transferred, enabling the facile preparation of microscale flexible devices. For proof of concept, a photodetector based on an individual CNT@methylammonium lead iodide heterostructure is fabricated. This work provides a new approach to prepare 1D hetero‐nanostructure and may inspire the design of novel flexible nanophotodetectors.