bluuebunny/crossref_metadata_2025 huggingface dataset:
An Unstructured Mesh Coordinate Transformation‐Based FDTD Method
Authors: Albornoz‐Basto Armando , Denny Bud , Brio Moysey
Published: November 2024

We propose a novel unstructured mesh finite‐difference time‐domain (FDTD) method for solving electromagnetics problems with complicated geometries. The method, which solves the TE‐mode reduced form of Maxwell's equations, can handle both material interfaces and anisotropic material. Using the transformation optics principle, which describes how fields and material tensors change under coordinate transformations, we locally transform each cell in the mesh to a reference unit‐square computational domain where the usual FDTD update is performed. This comes at a cost: employing unstructured grids and coordinate transformations requires more complicated data structures, a mesh orientation process, and potentially introduces an anisotropic material tensor at every mesh cell. Nonetheless, we find that the method maintains the same desirable properties of the classic FDTD method (explicit, divergence‐free B‐field, nondissapative, and second‐order accuracy) while also gaining conforming material interfaces and boundaries in complicated geometry. Even further, we prove that the method is stable under a Courant condition and a fairly nonrestrictive mesh condition, hence defeating the late‐time stability issue plaguing prior nonorthogonal FDTD methods. To verify the method, we conduct convergence studies on three electromagnetic cavity problems with known exact solutions. For these numerical studies, we find that the method maintains second‐order convergence and stability.
Design and validation of finite element models for the assessment of post‐fixation distal femur fracture motion
Authors: Telfer Scott , Ledoux William R. , Grantham Aerie , Lack William D.
Published: November 2024

Fracture site motion is thought to play an important role in the healing of complex fractures of the distal femur via mechanotransduction. Measuring this motion in vivo is challenging, and this has led researchers to turn to finite element modeling approaches to gain insights into the mechanical environment at the fracture site. Developing a systematic understanding of the effect of different model choices for distal femur fractures may allow more accurate prediction of fracture site motion from these types of simulations. In this study, we aim to assess the effect of four different modeling choices and parameters. We looked at the effect of using bone specific density distributions vs generic values, employing landmark‐based geometry generation, varying fracture alignment within clinically relevant ranges, and determining whether direct apposition of the fracture to the plate was achieved. For validation, five cadaveric femurs had fractures created and repaired with plated constructs, and these were then loaded and fracture site motion was directly measured. We found that using landmark based bone geometry and patient‐specific bone density distributions had a minimal effect on the overall model predictions. Changing the alignment, particularly into varus and procurvatum could have a large (>50%) effect on predicted shear motion, as could direct apposition of the bone to the plate. These findings demonstrate that modeling choices can play an important role in simulating distal femur fracture mechanics, and it is particularly critical that patient customized models attempt to accurately represent alignment of the bone fragments and lateral plate apposition.
Novel foam‐draining and anti‐polymerization integrated agent for gas well application
Authors: Liang Jingying , Liu Qi , Li Tao , Zhou Rui , Qu Chengtun , Tang Ying
Published: November 2024

In this article, surfactants such as cetyl trimethyl ammonium chloride (CTAC) and coconut oil amide propyl betaine (CAB) were compounded (TCJ) and used as a double function with foam drainage and hydrate anti‐polymerization. According to the result it was found that 0.05% of CTAC and 0.7% of CAB exhibited both excellent foam property and hydrate anti‐polymerization property. For further clarifying the stability characteristic of foam, the foam half‐life, drainage process, microcosmic liquid film structure, and stability mechanism were investigated in this article. The high initial foam volume of 415 mL with relatively long half‐life time of 5.5 min under high‐speed agitation at 50°C after 25 min indicated a good temperature resistance. The excellent foam properties still remained even amount of methanol and NaCl was added, which indicated its well stability and salt resistance. Furthermore, it was found that TCJ exhibited high liquid carrying rate of 62.5% at 65°C and good compatibility with poly vinyl pyrrolidone (PVP), which played great potential to the application in oil field. By the results of DSC curves, it can be found that the phase transformation point of hydrate decreases after addition of TCJ, which indicates the inhibition to the formation of hydrate as thermodynamic inhibitors.
Characterization and application of citrus pectin composite film containing rosemary (Rosmarinus officinalis L.) essential oil for improving storage of chilled beef
Authors: Ma Yuying , Li Weizheng , Tan Siyi , Yu Qunli
Published: November 2024

BACKGROUND

This study used single‐factor experiments and response surface methodology to optimize ultrasound time (10–50 min), particle size (0–80 mesh) and extraction time (60–180 min) for the ultrasound‐assisted extraction of rosemary essential oil (REO). The resulting REO (0–2.5%, w/w) was then incorporated into citrus pectin (CP) to prepare CP/REO composite films before determining their microstructure, mechanical, barrier and antioxidant properties, alongside their ability to improve the shelf life of chilled beef.

RESULTS

A sonication time of 41 min, a crushing degree of 40 mesh and an extraction time of 135 min were optimum for extracting 1.91% of REO, with the essential oil also showing good antioxidant activity. Characterization of the composite film further revealed that CP had an excellent film‐forming ability and that REO was uniformly distributed in the pectin matrix through hydrogen bonding. The film displayed optimum mechanical and barrier properties at an REO concentration of 1.5% which also significantly enhanced antioxidant activity. Furthermore, the CP/1.5 REO film reduced the total viable count, delayed oxidative rancidity and maintained good color during beef storage, thereby extending the latter's shelf life by 6 days.

CONCLUSION

The novel food packaging film could successfully maintain the quality of chilled meat. © 2024 Society of Chemical Industry.
Effect of electron beam irradiation treatment on microstructure, physicochemical properties, and bioactive content of areca nut
Authors: Dai Jiahui , Kang Xiaoning , Zhang Jing , Dai Wenting , Wang Yanan , Sun Yicheng , Wang Yijue , Qin Hongjian , Ji Jianbang , Wang Shiping
Published: November 2024

Background

Electron beam irradiation treatment is a novel technology that uses low‐dose ionizing radiation for the treatment of crops or food to enhance their quality. This study investigated the effects of electron beam irradiation on the microstructure, physicochemical properties, and bioactive compounds of areca nuts.

Results

As the irradiation dose increased, the cellulose, hemicellulose, and lignin content in the areca nuts decreased significantly, whereas the polysaccharide and pectin content increased gradually. The hardness, chewiness, and adhesiveness of areca nuts reached their lowest values when the irradiation dose was within the range of 6–9 kGy, indicating that irradiation effectively reduced the hardness of the areca nut fibers. The decrease in crystallinity led to the formation of loose structures in the fibers upon irradiation, thereby improving their water retention, expansion, and oil‐holding capacity, which are beneficial for the subsequent processing of areca nut‐based chewable products. The water‐ and oil‐holding capacities of the areca nuts peaked when the irradiation dose was within the 6–9 kGy range. Electron irradiation also affected the content of active substances in the areca nuts, particularly alkaloids, flavonoids, and polyphenols, showing an overall trend of initial increase followed by subsequent decrease.

Conclusion

Electron irradiation was not only effective in softening the fibers but it also impacted the overall quality of the areca nuts significantly. The results provide valuable reference data for improving the quality of areca nuts through electron beam irradiation technology. © 2024 Society of Chemical Industry.
Zero incidence of culture‐positive septic arthritis and low infection rate following ACLR with all‐soft tissue quadriceps tendon autograft: An analysis of 1053 cases
Authors: Seilern und Aspang Jesse , Kopriva John , Garry Jason , Haley Rebecca , Collins Austin , Lamplot Joseph D. , Slone Harris , Xerogeanes John W.
Published: November 2024

Purpose

To evaluate the infection rate following anterior cruciate ligament reconstruction (ACLR) using all‐soft tissue quadriceps tendon (ASTQT) autograft.

Methods

All primary ASTQT autograft ACLRs within a single surgeon's prospectively collected database from 2011 to 2021 were retrospectively reviewed. No topical antibiotics were administered and no graft‐soaking with antibiotics was performed during the study period. Patients who underwent multiligament knee reconstruction or a cartilage restoration procedure were excluded. Patients who underwent a subsequent procedure, including irrigation and debridement (I&D) of the knee joint, were included. Case‐specific data, including fluid culture analysis, antibiotics (type, route of administration and duration), time to debridement and method of debridement, were collected. Descriptive statistics were utilized to analyze demographics, incidence and possible association between the need for I&D and concomitant meniscus surgery.

Results

Out of 1053 cases (mean age: 20.2 ± 6.3, 44.6% female), four patients (0.38%) (mean age: 18.5 ± 4.0, 25% female) underwent subsequent I&D (arthroscopic I&D only [n = 1], graft harvest site I&D only [n = 1], combined graft harvest site and arthroscopic I&D [n = 1] and tibia wound and arthroscopic I&D [n = 1]). There was no significant difference with regard to demographics. No joint fluid cultures returned positive; one wound culture returned positive for Methicillin‐susceptible Staphylococcus aureus from their graft harvest site. The time to I&D ranged from 18 to 23 days. Concomitant meniscectomy or meniscal repair was not associated with requiring surgical I&D. All patients who underwent I&D were prescribed antibiotics for a minimum of 10 days and a maximum of 31 days (mean: 16.25 days). Three patients (75%) who underwent I&D ultimately returned to sport. One patient was lost to follow‐up. ACL grafts were retained in all patients.

Conclusion

The incidence of culture‐positive septic arthritis following ASTQT autograft ACLR is 0%, while the overall need for I&D of 0.38% is low and not related to concomitant meniscal procedures or patient‐specific factors.

Level of Evidence

Level IV.
The Risk of Land Degradation in Areas Impacted by Tailings Mudflows: A Legal and Economic Assessment
Authors: de Carvalho Medeiros Lucimar , de Moura Maíse Soares , Navarro Isadora Fonseca , Fernandes Luís Felipe Sanches , Pacheco Fernando António Leal , da Costa Adriana Monteiro
Published: November 2024

Accidents involving tailings dams are threatening because of their potential impacts. In many countries, despite the existence of legislation the population lives with the insecurity of potential dam breaks. Using Minas Gerais state in Brazil as an example, the aforementioned insecurity applies to hundreds of tailings dams, specifically the Vargem Grande dam of Vale mining company. The area affected by a dam failure is set through legal‐administrative instruments called “flood patches.” The purpose of this study was to analyze these patches, using the Vargem Grande dam as example, and assess the possible land degradation impacts of a failure, focused on the flooded native vegetation. The assessment resorted to the VERA—Economic Valuation of Environmental Resources method. The results exposed the potential destruction of 200 ha of Atlantic Forest and 55 ha of Cerrado vegetation within the flood patches. However, the simulated outcomes also reveal a significant decline in the flood patches in a short period (from 4.60 km2 in 2022 to 3.05 km2 in 2023), related with dam‐decommissioning risk‐reduction works allegedly implemented or to be implemented by the mining company. This reduction can be misleading because decommissioning works are legal‐administrative issues frequently used by the mining companies to minimize their responsibilities in the case of tailings dam breakup. It is worth mentioning that the patch reduction led to a convenient drop in the VERA results, from nearly 74 to 53 million dollars. Therefore, the official protocol used to delineate the flood patches must be improved to allow a more realistic evaluation. In that regard, the changes to flood patches overtime must be better defined in the legislation, namely through inclusion of potentially affected soil‐ and water‐bearing ecosystem services. Effective monitoring of dam‐decommissioning works is also paramount for a true evaluation of land degradation in the impacted areas.
WHAT WILL SUSTAIN THE DEMOCRACY?
Authors: McArthur Sarah
Published: November 2024

The author, Leader to Leader’s editor‐in‐chief, writes about the necessity for ordinary citizens to take responsibility for the health and wellbeing of their communities, and how this relates to sustaining our democracy. She builds on an anecdote about saving a tree that was damaged twice by a storm in her county. She recounts passages from Frances Hesselbein’s 2010 Harvard Business Review article “How Did Peter Drucker See Corporate Responsibility?”. She notes that Frances’ question was: “What must our organizations do today to help our country maintain its greatness and sustain the democracy?” In light of that article, the author writes that “democracy’s very survival is dependent on how we interact and support each other, how we work together towards a common purpose, and on our commitment to serving the greater good for all.” She also notes that “…we must ask ourselves, am I taking responsibility in my community, my organization, and I’n our world, or am I waiting for ‘them’ to fix it and blaming ‘them’ when it remains broken?”
HRMAS NMR for Studying Solvent‐Induced Mobility of Polymer Chains and Metallocene Migration Into Low‐Density Polyethylene (LDPE)
Authors: Hoefler John C. , Kimball Maxwell R. , Blümel Janet
Published: November 2024

HRMAS (high‐resolution magic angle spinning) nuclear magnetic resonance (NMR) spectroscopy of low‐density polyethylene (LDPE) affords 1H and 13C NMR spectra with superior resolution. For acquiring HRMAS NMR spectra, the polymer is first swollen with representative organic solvents. Then, the samples are measured with a conventional solid‐state NMR spectrometer in the wideline mode or at the low spinning speed of 2 kHz. Anisotropic interactions like CSA (chemical shift anisotropy) and dipolar interactions are reduced due to the additional mobility of the polymer chains in the presence of the solvent within the polymer network. The combined effect of this mobility and MAS leads to signals with substantially reduced halfwidths as compared to classic MAS of the dry polymer. With HRMAS, all signals of the polymer become visible, and the spectra can be used for a quick and easy assessment of the polymer swelling behavior in diverse solvents. Being able to characterize polymers on the molecular level, and identifying the solvents that penetrate the polymer network best, enables the study of post‐synthesis modifications of the polymers. It is demonstrated by paramagnetic HRMAS that the metallocene nickelocene (Cp2Ni) penetrates the LDPE network along with the solvent and is homogeneously dispersed in the polymer. SEM images prove that the structure of the polymer is not altered by the presence of a solvent and Cp2Ni. The impact of the paramagnetic Cp2Ni on the 1H signal halfwidth and T1 time of LDPE is studied. HRMAS allows a quick assessment of metal complexes regarding their ability to penetrate the LDPE network and therefore supports future studies of catalytic polymer degradation.
Clinical and Laboratory Characteristics of Pediatric Patients With ACKR1/DARC‐Associated Neutropenia
Authors: Oz‐Alcalay Lital , Steinberg‐Shemer Orna , Elron Eyal , Dvori Michal , Elitzur Sarah , Dgany Orly , Noy‐Lotan Sharon , Krasnov Tanya , Tamary Hannah , Brik‐Simon Dafna , Yacobovich Joanne , Gilad Oded
Published: November 2024

Background

ACKR1/DARC‐associated neutropenia (ADAN), resulting from homozygosity for a single nucleotide polymorphism (SNP) in the ACKR1/DARC gene (rs2814778), is a common cause of benign neutropenia that primarily affects individuals of African and Jewish Yemenite descent. We aimed to characterize ADAN in pediatric patients in Israel, given its ethnically diverse population.

Procedure

We assessed children with isolated neutropenia treated during 2018–2023 at one pediatric center, for the ACKR1/DARC polymorphism, using Sanger sequencing or targeted next‐generation sequencing.

Results

Of 115 patients evaluated, 49 (42.6%) were diagnosed with ADAN; of these, 29 (59%) had absolute neutrophil counts in the severe range (0–0.5 × 109/L) at diagnosis. The allele distribution revealed 37% of Muslim Arab and 61% of Jewish origin. Yemenite, Ethiopian, Mediterranean, Asian, and European ancestry were included; 59% had a family history of neutropenia. The median age at the first neutropenia detection was 1.2 years; 91.8% were identified during routine blood counts. The median absolute neutrophil count at diagnosis was 0.5 × 109/L (interquartile range: 0.3). An increased susceptibility to infections was not found either before or during the median follow‐up period of 2.5 years (interquartile range: 1.54) after the diagnosis of ADAN. In 34 patients (72.3%), neutrophil counts were in the normal range during febrile illnesses.

Conclusions

We identified ADAN in individuals of variable ethnicities, almost half with severe neutropenia. We recommend testing for ADAN in all children with isolated neutropenia without severe infections. Homozygosity for the ACKR1/DARC rs2814778 SNP may obviate the need for further investigation, follow‐up, or treatment in specific clinical scenarios.
Osteopathic Manipulative Treatment: A Safe and Feasible Adjunct in Sickle Cell Disease Pain Management
Authors: Brown Amber , Goubeaux Derrick , Jacob Seethal A. , Belsky Jennifer A.
Published: November 2024

Children and adolescents and young adults (CAYAs) with sickle cell disease (SCD) suffer from recurrent acute pain episodes that result in hospitalization and confer substantial morbidity. Pharmacologic pain control is often inadequate, thus non‐pharmacologic modalities are needed. Osteopathic manipulative treatment (OMT) is a potentially valuable non‐pharmacologic addition to pain management. We describe eight patients hospitalized with SCD pain who received OMT. OMT was safe, feasible, and a promising adjunctive option for management of SCD pain.
Dipodal silane‐treated ramie woven matt reinforced polylactic acid biocomposites for improved mechanical and thermal properties
Authors: Wagaye Bewuket Teshome , Abraha Kahsay Gebresilassie , Guo Jiansheng
Published: November 2024

Hot compression molding was used to produce biocomposites from ramie plain‐woven fabric‐reinforced polylactic acid (PLA). Prior to composite fabrication, alkali and dipodal silane (bis(3‐trimethoxysilylpropyl) amine) (BAS) were applied to improve fiber‐matrix adhesion. Mechanical tests revealed improvements in tensile and flexural strength due to interfacial adhesion. The flexural strength of ramie PLA composite samples treated only with silane (SR‐PLA) was the highest, at 136.35 MPa. Young's modulus was 7.51 GPa. BAS treatment was crucial for ensuring strong adhesion between the fabric and the PLA matrix. In combined alkali‐BAS‐treated composites (ASR‐PLA), the glass transition and crystallization temperatures disappeared completely, affecting PLA morphology. The maximum heat of absorption (373°C) was found in SR‐PLA composites, suggesting electrostatic interactions created a three‐dimensional network. In conclusion, the initial incorporation of dipodal silane resulted in the formation of six silanol linkages with ramie fabric, leading to enhancements in the mechanical and thermal characteristics of ramie–PLA composites.

Highlights

Alkali and BAS treated Fabrics ironed to remove treatment‐induced wrinkles.

Carded PLA fiber with consistent density and weighted in four equal portions.

Fabric and PLA lay alternatively in warp direction before compression molding.

SR‐PLA composites exhibited improved thermal and mechanical properties.
A novel thermoplastic material: Pre‐polymerized PMMA liquid resin and continuous glass fiber‐reinforced composite initiated by benzoyl peroxide/N,N‐dimethylaniline
Authors: Li Jing , Zhang Yiru , Gao Yafei , Zhang Chong , Wu Lulu , Zhang Jianmin
Published: November 2024

Thermoplastic PMMA was rarely exploited in continuous fiber‐reinforced composites due to its viscous high‐temperature molten fluid as well as pessimistic wettability into fiber fabric. Redox‐active polymerization is a green route to develop a new liquid PMMA resin at room temperature to provide an in situ curing with the advantages of energy saving and consumption reduction. In this paper, BPO/DMA was adopted as a redox initiator pair, and the effect of MMA:BPO:DMA ratio on curing time, Mn, Tg, and mechanical properties of PMMA were systematically studied. When the ratio of MMA:BPO:DMA is 200:1.2:1, PMMA‐200 achieved optimistic mechanical properties at 20°C (tensile strength, 64.7 MPa; tensile modulus, 3352 MPa; bending strength, 125.3 MPa; bending modulus, 3023 MPa). Moreover, the mechanical properties were further improved at low temperatures. The maximum tensile strength and tensile modulus were up to 97.43 and 4297 MPa (−40°C) respectively. The tensile strength (0°, 1103 MPa; 90°, 52.3 MPa) and tensile modulus (0°, 47.5 GPa; 90°, 14.2 GPa) of glass‐fiber‐reinforced PMMA composite at 20°C were found to be comparable with epoxy resin‐based composites and even higher at lower temperature. In summary, redox‐initiated PMMA and its fiber‐reinforced composites are promising thermoplastic materials as new lightweight alternatives.

Highlights

Preparation method of PMMA resin and glass fiber composite.

Research on the mechanical properties, molecular weight, glass transition temperature, curing time, etc. of PMMA resin.

Testing of mechanical properties of PMMA glass fiber composites at room temperature and low temperature.

Current applications and prospects of PMMA glass fiber composites.
Decomposition of matrix in basalt fiber‐reinforced composites using laser processing parameters for clear unveiling of fibers without damage
Authors: Ürgün Satılmış , Fidan Sinan , Özsoy Mehmet İskender , Bora Mustafa Özgür
Published: November 2024

This work investigates the effects of laser processing parameters on basalt fiber‐reinforced composites for the optimization of surface processing without fiber damage. Various conditions of laser power, speed, and stand‐off distance were applied using a CO₂ laser. Consequently, a well‐processed morphology with full matrix removal and clear fiber exposure was achieved under optimized conditions of 32 W power, 200 mm/s speed, and 5 mm SOD. Those parameters resulted in a surface roughness Sa of 6.11 μm. Using the optimum parameters obtained from the experiments, the surface energy density was computed as 0.89 J/mm2, while ensuring adequate material removal without damage to the fiber. Lower power input of 20 W resulted in incomplete removal of the matrix; on the other extreme, unreasonably high powers resulted in fiber degradation. The experiments determined that optimum laser parameters indeed play a critical role in the processing of basalt fiber composites surfaces.

Highlights

Ideal laser settings: 32 W, 200 mm/s, 5 mm SOD.

Full‐matrix removal and fiber exposition realized without any damage.

The achieved surface roughness Sa is 6.11 μm for optimized laser parameters.

Excessive laser power leads to a fiber damage.
Lab‐scale manufacturing of thermoplastic matrix‐continuous carbon fiber filaments for additive manufacturing: Melt impregnation, properties of the filaments and its printed composites
Authors: Sütcüler Yunus Alp , Bex Guy J. P. , Stupp Cesar A. , Kodal Mehmet , ten Cate A. Tessa , Özkoç Güralp
Published: November 2024

Additive manufacturing encounters significant barriers to its broader application in large‐scale production. This research seeks to mitigate critical limitations, including a trade‐off between impregnation speed and quality in filament preparation and inconsistent fiber distribution in continuous carbon filaments (CCFs), mainly attributed to the rounding process of unidirectional tapes and insufficient interlayer adhesion. A novel lab‐scale impregnation line was engineered to address these challenges, facilitating the production of CCFs using three distinct types of carbon fiber in conjunction with recycled glycol‐modified poly(ethylene terephthalate) (rPETG) resin. This new lab‐scale process produces uniform fiber distribution within PETG matrix and prevents S‐shaped distortions typically observed in conventionally rounded tapes. The type of carbon fiber sizing influences the impregnation process and tensile strength of the CCFs. Specifically, CCFs with flexible sizing demonstrated a 15% reduction in tensile strength due to fuzz formation during impregnation. These CCFs were subsequently employed in 3D printing applications, with the fabricated composite components subjected to interlaminar shear strength (ILSS) testing. The study concludes that recycled PETG is a viable additive manufacturing material when combined with appropriately sized carbon fibers. Additionally, it highlights the advantages of omitting the rounding stage, which enhances the quality of CCF and optimizes production efficiency.

Highlights

A lab‐scale direct melt impregnation system was designed in this study.

The impact of different sizing types on carbon fibers was investigated.

3D‐printed continuous fiber filaments were prepared.

New lab‐scale process produces uniform fiber distribution within PETG matrix.

S‐shaped distortions observed in conventionally rounded tapes were prevented.
Experimental study on the maximum static friction coefficient of fiber winding based on semi‐geodesic method
Authors: Dai Yuchen , Zheng Chuanxiang , Lin Jiao , Liu Yangtao , Wang Dawei
Published: November 2024

In the fiber winding process, the maximum static friction coefficient significantly influences the designable range of non‐geodesic winding trajectories and the behavior of fiber stacking and sliding. To accurately and conveniently measure the maximum static friction coefficient for fiber winding, a method based on semi‐geodesic trajectories was proposed. This method assesses the maximum static friction coefficient between fibers and mandrels, as well as between fibers, without requiring additional component fabrication. Its effectiveness was investigated, and two methods for determining fiber yarn slip were proposed. Additionally, measurement errors and variations in the slip coefficient before and after fiber yarn slip were examined. The research results indicate that the proposed measurement method has an error margin of approximately ±6%. After fiber yarn slip, the slip coefficient gradually decreases along the winding trajectory. The maximum static friction coefficient is independent of both winding speed and winding tension.

Highlights

A method for measuring the maximum static friction coefficient was proposed.

Two methods were proposed for determining the slip of fiber yarn.

The method allows for direct measurement using the mandrel to be wound.

The maximum static friction coefficient between fibers can be measured.
Printability and mechanical behaviors of continuous polyamide fiber reinforced polycaprolactone composites
Authors: Yan Yongzhe , Sun Shuo , Pillay Selvum , Ning Haibin
Published: November 2024

Polycaprolactone (PCL) is a biodegradable material that has received significant attention in the last decade. It is characterized by low toxicity and biocompatibility, making it a common choice as a tissue scaffold material in the medical field. However, its low mechanical performance has limited its application. This work focuses on the development and characterization of a PCL based printing material reinforced with continuous polyamide 6 fiber (PA6/PCL). PA6/PCL filaments were produced through a hot melt impregnation process. A custom fused deposition modeling (FDM) printer was used to print the PA6/PCL composites. Thermal analysis was conducted to assess the thermal properties of the composite materials. Mechanical tests were performed to evaluate the mechanical properties of the printed composites and determine the effect of PA6 continuous fiber on their mechanical properties. The study showed that adding continuous PA6 fibers significantly improved the strength and modulus of PCL. When 7.9 wt% PA6 fiber is added, the tensile strength of PCL printed parts increased by more than 300%, and the tensile modulus increased by 36%. In addition, flexure strength increased by 130% and flexure modulus by 150%. Scanning electron microscope was used to study the fracture surfaces of the composites and it was found that the main failure modes were fiber fracture and debonding between fiber and matrix. This research demonstrates that adding continuous PA6 fibers tremendously enhances the mechanical properties of printed PCL parts. This novel composite material can potentially broaden the applications of FDM technology and provide more material options for biomedical applications.

Highlight

A novel FDM composite material with excellent tensile strength was developed.

Continuous PA6 fiber has been used to reinforce PCL.

A new test method was developed for evaluating filament material for FDM.

The tensile strength of PCL is improved by 300% when 7.9 wt% PA6 fiber is added.

The printability of the FDM composite material has been confirmed.
The technique of transforming symptom's symbol into emptiness: A mind–body therapy in the Chinese context
Authors: Niu Haiqun , Chen Yi , Zhou Wen , Tao Yanqiang , Liu Tianjun
Published: November 2024

The technique of transforming symptom's symbol into emptiness (TSSE) is a new mind–body treatment method proposed by Tianjun Liu in 2008. It integrates Qigong and concrete object‐image thinking rooted in traditional Chinese culture into modern psychotherapy and proposes that mental and physical problems can be alleviated or eliminated in the process of movement. Accordingly, the therapist needs to guide the client with various symptoms to psychological nothingness where the client cannot see or feel these symptoms, and the purpose of healing can be achieved through the experience of emptiness. TSSE is divided into static and dynamic operations and consists of 10 steps. The static operation includes trio relaxation exercises (the body, breath, and mind), identifying the target symptom, visualizing the target symptom as an object‐image, visualizing a symbolic carrier, and filling out record sheet A. The dynamic operation includes trio relaxation exercises again, moving the symbolic object into the carrier, moving the carrier with the symbolic object into psychological nothingness, moving back and assessment, and filling out record sheet B. The effectiveness of TSSE can be evaluated by the therapist's judgment based on the client's performance and by the difference between the symptom impact scores recorded in sheets A and B. TSSE has been proven to be an effective psychosomatic treatment solution by some empirical studies conducted in China. Future research can combine other technologies, such as fMRI and fNIRS, to further explore the potential effective mechanisms of TSSE.
Hyaluronan‐protein interactions: Lilliput revisited
Authors: Day Anthony J.
Published: November 2024

Hyaluronan (HA) is a huge linear polysaccharide composed entirely of a simple repeating disaccharide that has been preserved unchanged since the evolution of vertebrates ~520 million years ago. It is present in all mammalian tissues, being synthesised within the cell membrane and extruded into the extracellular space where it dictates tissue elasticity, hydration and permeability. HA also directs cell behaviour via engagement with cell surface receptors. These properties allow it to mediate diverse functions in a wide range of physiological and pathological processes, including development, mammalian reproduction and inflammation. There is growing evidence that the way in which the HA biopolymer is differentially organised, through its interaction with a repertoire of HA‐binding proteins (HABPs), is key to the diversity of its biological functions. This review summarises current knowledge of HA‐protein interactions and how their diversity may lead to the formation of HA/protein complexes with distinct molecular architectures that in turn underpin different physical properties and receptor‐mediated effects. Potentially controversial areas such the pro‐inflammatory effects of low molecular weight HA fragments and how short HA‐binding peptides modulate HA function are considered from a molecular perspective.
Experimental study on the mechanical evolution for waste tire rubber powder‐modified asphalt and its mixture considering the temperature characteristics in seasonal freezing regions
Authors: Jie Shaolong , Mao Shuai , Yue Zurun , Hu Tianfei , Sun Zhiqi , Qing Caolin
Published: November 2024

The study focused on preparing modified asphalt and its mixtures using waste tire rubber powder and polystyrene–butadiene–styrene (SBS). The modified asphalt was divided into two types: single‐doped waste tire rubber powder and SBS/waste tire rubber powder, and modified asphalt mixtures were prepared by dry or wet processes. Based on the temperature and freeze–thaw characteristics of seasonal freezing areas, the mechanical evolution for waste tire rubber powder‐modified asphalt and its mixture was analyzed. The results showed the following. (1) The waste tire rubber powder‐modified asphalt viscosity was closely related to the amount and particle size of rubber powder. A particle size of 60 mesh or 80 mesh and an amount between 18% and 25% were suitable. (2) Combined with dynamic mechanical analysis and needle penetration test, the single‐doped waste tire rubber powder‐modified asphalt with 80 mesh rubber powder particles and 18–25% rubber powder content was suitable. The SBS/waste tire rubber powder compound‐modified asphalt (SBS 3%; rubber powder 16%, particle size 80 mesh; aromatic oil 4%; stabilizer 3‰) had better high‐ and low‐temperature performance improvement. (3) The splitting tensile strength of modified asphalt mixture deteriorated rapidly during the first 10 freeze–thaw cycles, and then tended to stabilize. The SBS/waste tire rubber powder compound‐ or single‐doped waste tire rubber powder‐modified asphalt mixture had better frost resistance. (4) The unified calculation model for strength deterioration obtained by using a single logarithmic coordinate transformation could reflect the strength and deterioration rate through the material parameters. (5) At high or low temperatures, the modified asphalt mixture presented flexible or brittle failure, respectively, with a critical brittle failure temperature near −10 °C. While, the dry process modified asphalt mixture was not suitable for service in seasonal freezing regions. The study was used to further understand the mechanical characteristics of waste tire rubber powder‐modified asphalt and its mixture under environmental load in seasonal freezing regions. © 2024 Society of Chemical Industry.
Female contact sex pheromone recognition in the German cockroach (Blattella germanica) is mediated by two male antennae‐enriched sensory neuron membrane proteins
Authors: Feng Hong‐Yan , Zhao Ya‐Qin , Yang Tao , Zhou Yang‐Yuntao , Gong Lang‐Lang , Zhang Meng‐Qi , Ma Yun‐Feng , Hull J. Joe , Dewer Youssef , Zhang Fan , Smagghe Guy , He Ming , He Peng
Published: November 2024

BACKGROUND

The German cockroach Blattella germanica is a notorious urban health pest that has developed resistance to multiple pesticides. Thus, novel non‐lethal pest control agents are urgently needed. Olfaction interference via disruption of sex pheromone recognition‐related genes offers a promising approach. The German cockroach has a unique courtship behavior in which female adults emit contact sex pheromones (CSPs) in response to antennal touching, which subsequently triggers distinctive male sex behavioral responses. Due to the limited volatility of CSPs, the molecular mechanisms underlying their recognition and the specific olfactory pathways activated remain poorly defined. Although the odorant receptor coreceptor (Orco) is critical for most insect olfaction, sensory neuron membrane proteins (SNMPs), in particular SNMP1, also play crucial roles in sex pheromone recognition in moths and flies. While multiple SNMP1 homologs have been identified in multiple insect species, they have yet to be fully functionally characterized in cockroaches.

RESULTS

In this study, RNA‐interference (RNAi)‐mediated knockdown of BgerOrco reduced both the electrophysiology responses and courtship behaviors of males, indicating CSP perception proceeds via an olfaction pathway. Similar RNAi knockdown of BgerSNMP1e and BgerSNMP1d, which are predominantly expressed in male antennae, revealed critical roles in perceiving the major component of the Blattella germanica CSP blend. Unlike BgerSNMP1e, BgerSNMP1d was also found to function in the perception of the minor CSP component. Molecular docking analyses revealed no differences in the binding affinities of BgerSNMP1d for the major and minor CSP components, whereas the binding affinities of BgerSNMP1e displayed clear selectivity for the major component.

CONCLUSION

Our results show that the olfactory pathway is critical for CSP recognition and that two male‐enriched SNMP genes, BgerSNMP1e and BgerSNMP1d, are crucial factors mediating the male response to CSP stimulation in German cockroaches. This study lays a foundation for studying the mechanisms of CSP recognition and provides novel molecular targets with potential to be exploited as disruptors of courtship behavior. © 2024 Society of Chemical Industry.
Investigation of Single Atom Catalysts by X‐Ray Absorption Spectroscopy
Authors: Lützenkirchen‐Hecht Dirk , Yuan Kai , Eckelt Franz , Braun Frederic , Voss Lukas , Li Longbin , Tang Xiannong , Zhuang Xiaodong , Chen Yiwang
Published: November 2024

Recently, Pt‐free and highly efficient, nanostructured M–N–C catalysts employing earth‐abundant metals (M = Fe, Co, Ni, Mn, Cu, etc.) have been recognized as a very promising alternative to noble metal (in particular platinum)‐ based oxygen reduction reaction materials. Structural engineering of the M–N–C catalysts is expected to further boost their catalytic performance, and thus, intense efforts are currently ongoing. Herein, a report is prepared on X‐ray absorption fine structure (EXAFS) studies of different carbon‐based catalyst materials. EXAFS with its intrinsic sensitivity toward the local atomic arrangement around the X‐ray absorbing element allows to characterize isolated, active single‐atom transition metal centers and their atomic environments. In the case of Co and Fe, the analysis suggests in particular asymmetric, penta‐coordinated Co‐N5 and dual‐coordinated Fe–N–P sites. In both cases, a symmetric environment of the metals with only four nitrogen atoms appears to be unfavorable for the catalytic activity. In addition, for Fe–N4 centers embedded in a graphene host matrix, the EXAFS analysis allows to precisely determine the atomic arrangement around the iron atom, and thereby the geometry of the catalytic site. A discussion will be done on how EXAFS investigations can support the further development of single‐atom catalysts.
Ionic Liquid Assisted Green Synthesis of Quinoxaline Based Bisspirooxindoles: Anticancer Evaluation and Molecular Dynamics
Authors: Kanchrana Madhu , Krishna Gamidi Rama , Dey Biswajit , Pandey Nandita , Guru Santosh Kumar , Sangolkar Akanksha Ashok , Pawar Ravinder , Basavoju Srinivas
Published: November 2024

In this study, we have synthesized a series of novel quinoxaline based bisspirooxindoles through green protocol using ionic liquid [Bmim]BF4. All the compounds were well characterized by spectroscopic methods like FT‐IR, 1H NMR, 13C NMR, mass and finally the structures were authenticated by single crystal X‐ray diffraction (SCXRD) (4e). The target compounds were evaluated for their anticancer activity with different cancer cell lines like MDAMB‐231, MCF‐7, MCF‐10A, HCC‐1395, Molt‐4, and FaDU. The compounds 4d, 4g, 4m, and 4n showed 42.0%, 43.3%, 52.7%, and 56.0 percentage of growth inhibition respectively with the T cell acute lymphoblastic Molt‐4 cell line. The compounds 4b, 4c, 4 h, 4k, and 4m have shown 30%–39% of growth inhibition against FaDU cell line. Further, anticancer activity was validated with in silico molecular docking and molecular dynamics simulations. The outcomes of dynamics simulations exclusively emphasize that the compounds bind to HIS862 and TYR896 residues which are among the catalytic triad of PARP1. Finally, the results of ADME is also used to assess the drug likeness, which clearly shows that our target compounds are adaptable as potential drug pathways for medicinal chemists.
Recent Advances in Radical Reactions of 1,n‐Enynes with Phosphorus‐Centered Radicals
Authors: Ni Hairui , Fan Siyan , Yu Tongyan , Shi Zhuang‐zhi , You Siliang , Deng Chao
Published: November 2024

Organophosphorus compounds have been widely used as achiral and chiral ligands in organic synthesis (PPh3, BINAP, dppe, Duphos, Xantphos, PPFA, Chiraphos, SEGPHOS), flame retardants, functional materials (LED, PV), as well as agrochemicals and medicines due to their broad biological activities. As the privileged versatile building blocks, 1,n‐enynes have been successfully applied in the synthesis of various functionalized cyclic compounds based on their two active unsaturated chemical bonds (C═C double and C≡C triple bonds). With the development of highly selective and efficient methods in organic chemistry, various organophosphorus cyclic compounds synthesis through radical cascade strategy has attracted considerable attention in recent years. In here, we have summarized the recent main achievements in the radical cascade reactions of 1,n‐enynes with phosphorus‐centered radicals. Furthermore, we also displayed the detailed reaction mechanisms in this review.
Improving the Energy Density of Potassium‐Ion Batteries Through Defect Engineering
Authors: Wang Chen , Cai Hongtu , Zheng Shumin , Wang Bao , Wang Shaoyan
Published: November 2024

Potassium‐ion batteries (PIBs) have a significant cost advantage in resources, making their commercial application imminent. Presently, the cycling lifespan and energy density of PIBs lag behind those of lithium‐ion batteries, highlighting the crucial need for anode materials suitable for potassium storage. This paper used high‐pressure heat treatment and extraction methods to obtained toluene insoluble (TI) as a carbon matrix, followed by nickel and nitrogen co‐doping to synthesized anode materials (NiNTI). NiNTI is characterized by defect engineering such as thermal condensation polymerization and template doping, which destroys the flattening of the material, provides more active sites, forms more disordered carbon structures, generates a large number of defects and structural vacancies, and improves the electronic conductivity of NiNTI materials. In the NiNTI half‐cell configuration, operating at a current density of 0.1 A g−1, the reversible specific capacity reaches 364 mAh g−1, with an initial coulombic efficiency of 64.9%.
Silver Nanoparticle‐Decorated Cellulose Nanocrystal Reinforced Ionic Polymer Hydrogel With High Conductivity and Environmental Tolerance for Multifunctional Sensing and Emergency Alarm System
Authors: Wang Yafang , Yao Anrong , Zhong Hualan , Mo Yunbo , Zhang Han , Shang Jiaojiao , Lan Jianwu , Fan Wuhou , Chen Xiaotian , Lin Shaojian
Published: November 2024

Conductive hydrogels hold great promise for flexible electronics. However, the simultaneous achievement of satisfactory mechanical strength, outstanding environmental tolerance, high sensitivity, and multiple sensing applications in a single conductive hydrogel remains a significant challenge. Herein, ionic polymer‐based hydrogels with a double conductive network consisting of [2‐(methacryloyloxy)ethyl] trimethyl ammonium chloride (DMC), 2‐hydroxyethyl acrylate (HEA) and silver nanoparticle decorated cellulose nanocrystal (CNC@Ag) are prepared by a facile one‐pot method. The resultant hydrogel (CDH) exhibits high stretchability, satisfactory self‐adhesion, excellent environment tolerance (from −60 to 60 °C), long‐term stability (60 days), effective UV‐shielding, and strong antibacterial properties. Significantly, the CDH hydrogel displays high conductivity and rapid response due to its double conductive network of ionic polymer and CNC@Ag. Therefore, the CDH‐assembled sensor can accurately detect signals from both strain and pressure deformations, exhibiting outstanding sensitivity and reliability for human motion detection, signal transmission, object recognition, and tactile sensing. More interestingly, collaborating with a development board, the CDH‐based sensor can be developed as an emergency alarm to realize prompt alarms in dangerous situations. Overall, this work presents a strategy for the fabrication of conductive hydrogel with remarkable properties, making it possible for multifunctional sensing applications in wearable electronics.
From Optical Fiber Communications to Bioimaging: Wavelength Division Multiplexing Technology for Simplified in vivo Large‐depth NIR‐IIb Fluorescence Confocal Microscopy
Authors: Mou Xuanjie , Wu Tianxiang , Zhao Yunlong , He Mubin , Wang Yalun , Zhang Mingxi , Qian Jun
Published: November 2024

Near‐infrared II (NIR‐II, 900–1880 nm) fluorescence confocal microscopy offers high spatial resolution and extensive in vivo imaging capabilities. However, conventional confocal microscopy requires precise pinhole positioning, posing challenges due to the small size of the pinhole and invisible NIR‐II fluorescence. To simplify this, a fiber optical wavelength division multiplexer (WDM) replaces dichroic mirrors and traditional pinholes for excitation and fluorescence beams, allowing NIR‐IIb (1500–1700 nm) fluorescence and excitation light to be coupled into the same optical fiber. This streamlined system seamlessly integrates key components—excitation light, detector, and scanning microscopy—via optical fibers. Compared to traditional NIR‐II confocal systems, the fiber optical WDM configuration offers simplicity and ease of adjustment. Notably, this simplified system successfully achieves optical sectioning imaging of mouse cerebral blood vessels up to 1000 µm in depth. It can discern tiny blood vessels (diameter: 4.57 µm) at 800 µm depth with a signal‐to‐background ratio (SBR) of 5.34. Additionally, it clearly visualizes liver vessels, which are typically challenging to image, down to a depth of 300 µm.