bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing rheological properties of oxidized Moringa oleifera gum and carboxymethyl chitosan‐based self‐healing hydrogel for additive manufacturing applications
Authors: Verma Mehul , Kumar Jitendra , Pradhan Abhinav Ayush , Majumder Nilotpal , Ghosh Sourabh , Purwar Roli
Published: August 2024

Rheology plays a vital role in pneumatic three‐dimensional (3D) printing of hydrogels. This study investigates the rheological behavior of a novel self‐healing hydrogel (O‐MOG/CMCh) formed by a Schiff base crosslinking reaction between oxidized Moringa oleifera gum (O‐MOG), a biodegradable antimicrobial polysaccharide, and carboxymethyl chitosan (CMCh), a water‐soluble biocompatible chitosan derivative. Three hydrogel formulations were designed using 5% w/v of CMCh with varied concentrations of O‐MOG (3% w/v, 4% w/v, and 5% w/v) and evaluated through rheology analyses, including frequency sweeps, amplitude sweeps, oscillatory thixotropy, and gelation kinetics. These tests revealed that the material has shear thinning, self‐healing properties, a high linear viscoelastic region (LVE), and gel formation times (tgel) of 3.23–4.57 min. The hydrogel synthesized with 5% w/v of O‐MOG composition exhibited the best characteristics for printability based on rheological assessments, and this composition was used for further printing assessment, where bi‐layered 4 × 4 and 2 × 2 grids were successfully printed using 22 G (0.41 mm) and 23 G (0.34 mm) syringes. All the constructs had a printability index value of 1 ± 0.13 and spreading ratios <6.5, demonstrating the feasibility of employing the synthesized hydrogel as an acellular matrix via additive manufacturing.

Highlights

Self‐healing hydrogel was prepared by mixing the precursors through a cannula.

Rheology was examined using standard tests for printability assessment.

3D printability was achieved using two different gauze syringes.

Printability parameters were recorded and analyzed for the constructs.
Morphology and thermal properties of poly(lactic acid)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/graphene oxide polymeric composites
Authors: Mokoena Lesia Sydney , Mofokeng Julia Puseletso
Published: August 2024

Poly(lactic acid) (PLA)/poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) blends are typically phase‐separated, and there is limited research on using graphene oxide (GO) as their matrix filler. PLA/PHBV/GO composites using 1, 3, or 5 wt% GO were prepared by melt mixing, after which their morphology and thermal properties were determined. All the components were hydrophilic (Contact angles less than 90°), and the wetting coefficient value of 3.52 suggested that GO would be dispersed in PLA during surface energy evaluations (SEES). Scanning electron microscopy (SEM) showed that PLA/PHBV blends are immiscible and phase‐separated; however, adding GO brought partial miscibility. Differential scanning calorimetry (DSC) showed that GO plasticized the polymers at lower contents (1 wt%) and inhibited their crystallization at higher contents (3 and 5 wt%). Fourier‐transform infrared spectroscopy (FTIR) measurements showed that a chemical interaction exists between GO and the polymers, and X‐ray diffraction (XRD) results confirmed that GO inhibited crystallization in the polymers at high contents. Adding GO to the polymers generally improved the thermal stability of PLA, verifying the affinity thereof during thermogravimetric (TGA) analyses. Merging of the thermal degradation steps implied that GO induced partial miscibility on polymers. Concurrently, the polymers thermally masked the GO to prolong its lifespan. Composites with 1 wt% GO were the optimal and ideal materials.

Highlights

Melt mixed PLA/PHBV blends and their composites with GO as a filler.

GO brought partial miscibility to the blends and favored the PLA phase.

1 wt% GO contents provide optimal thermal and morphological properties.

3 and 5 wt% GO contents form chemical bonds with the polymers.

Initial GO loadings increase the crystallinity of the polymers.
Enhanced thermoregulation performance of knitted fabrics using phase change material incorporated thermoplastic polyurethane and cellulose acetate nanofibers
Authors: Akduman Çiğdem , Oğlakcıoğlu Nida , Çay Ahmet
Published: August 2024

Nanofibers act as carriers in systems containing functional materials produced via electrospinning method. By this way, it is possible to transport functional materials with polymer nanofibers, besides having a large surface area compared to their volume, the encapsulation process, which includes complex preparation processes, is eliminated here, and functional materials such as phase‐change materials (PCMs) can be conveniently integrated directly into the carrier material by electrospinning method. The resulting nanofiber membrane can also be used in combination with textile fabrics. This study aims to develop PCM containing nanofibrous membrane coated knitted fabric structures with heat regulation capabilities. Two types of PCMs, hexadecane and octadecane loaded into thermoplastic polyurethane (TPU) and cellulose acetate (CA) nanofibers, directly electrospun on cotton (CO), cotton/polyester (CO/PES), cotton/acrylic (CO/PAC) knitted fabrics for thermoregulation. These nanofiber‐coated fabrics were characterized by scanning electron microscopy (SEM) and differential scanning colorimetry (DSC), and their comfort properties were evaluated by water vapor and air permeability tests and compared with a commercial microcapsule impregnated fabric. According to DSC results, PCM incorporated CA nanofibers had better heat storage capacity than TPU nanofibers and microcapsule applied fabrics. Although PCM‐loaded CA nanofibers may not block airflow as effectively as TPU nanofibers, when a proper coating is achieved air permeability can be decreased to 21.70 L/m2/s, along with a heat storage capacity of 26.38 J/g and still having permeability to water vapor (%40).

Highlights

Phase change materials were integrated directly to the carrier material by electrospinning

PCM integrated nanofiber coating reduced air permeability

PCM integrated nanofiber coating did not block water vapor permeability

Electrspun cellulose acetate +PCM coating had better heat storage capacity
The relationship of hip strength to walking and balance performance in unilateral lower limb prosthesis users differs by amputation level
Authors: Sawers Andrew , Fatone Stefania
Published: August 2024

Background

Safe and efficient locomotion is a frequently stated goal of lower limb prosthesis users, for which hip strength may play a central yet poorly understood role. Additional research to identify associations between hip strength, balance, and mobility among transtibial and transfemoral prosthesis users is required.

Objective

To test whether residual and/or intact limb isometric hip strength was associated with lower limb prosthesis users’ walking speed, endurance, and balance.

Design

Cross‐sectional study.

Setting

Research laboratory.

Participants

Convivence sample of 14 transtibial and 14 transfemoral prosthesis users.

Methods

Multiple linear regression was used to evaluate the relationship between isometric measures of residual and intact limb hip strength and walking and balance performance.

Main Outcome Measurements

Measures of isometric hip muscle strength, including peak torque, average torque, torque impulse, and torque steadiness (i.e. consistency with which an isometric torque can be sustained) were derived from maximum voluntary hip flexion, extension, abduction and adduction torque signals collected with a motor‐driven dynamometer. Walking speed, endurance, and balance were assessed by administering the 10‐meter walk test, 2‐minute walk test, Four Square Step Test, and Narrowing Beam Walking Test, respectively.

Results

Residual limb hip extensor max torque and abductor torque steadiness explained between 51% and 69% of the variance in transtibial prosthesis users’ walking speed, endurance, and balance. In contrast, intact limb hip abductor torque impulse explained between 33% and 48% of the variance in transfemoral prosthesis users’ walking speed, endurance, and balance.

Conclusions

Our results suggest that unilateral transtibial and transfemoral prosthesis users’ walking and balance performance may depend on different hip muscles, and different facets of hip strength. Amputation level‐specific hip strength interventions may therefore be required to improve walking and balance performance in unilateral transtibial and transfemoral prosthesis users. The “intact leg strategy” adopted by transfemoral prosthesis users may be due to a variety of prosthesis and biomechanical factors that limit the efficiency with which transfemoral prosthesis users can exploit the strength of their residual limb hip muscles while walking.
Advances in photocrosslinked natural hydrogel‐based microspheres for bone repair
Authors: Li Hao‐Ru , Zhou Jing , Zhou Yan‐Wen , Dao Jin‐Wei , Wei Dai‐Xu , Wang Yong
Published: August 2024

In recent years, the prevalence of bone diseases is showing an increasing trend, which is mainly attributed to the aging of the global population. However, bone repair and regeneration are still an unsolved problem in the treatment of bone diseases, which include a series of biological events. Photocrosslinked natural hydrogel‐based microspheres (PNHMs) are spherical particles composed of photocrosslinked natural hydrogel components. Due to their morphology, injectability, and biocompatibility, PNHMs are widely used in tissue regeneration, particularly for bone defects. In this article, we review the available photocrosslinked natural materials for PNHMs, and then introduce their preparation methods. After that, we summarize the important advanced functionalities of PNHMs. For example, PNHMs can be loaded with different active ingredients to exert anti‐inflammatory, antibacterial, and antioxidant effects, while also realizing lubrication due to their specific shape and size distribution. In addition, the function of capturing ions can be realized via coordination. When applied in bone tissue engineering, PNHMs can promote angiogenesis and osteogenesis, with great potential in the treatment of bone diseases. Finally, the challenges and prospects of PNHMs for bone repair are discussed.
Interactions between migration and immunity among oriental armyworm populations infected with the insect pathogenic fungus, Beauveria bassiana
Authors: Lv Weixiang , Jiang Xingfu , Li Ping , Xie Dianjie , Wang Dengjie , Stanley David , Zhang Lei
Published: August 2024

BACKGROUND

Migration and immunity are behavioral and physiological traits that protect organisms from environmental stressors or pathogen infection. Shifting from migration to residency has become more common in some wildlife populations owing to environmental changes. However, other biological shifts, such as interactions between migration and immunity among populations within a species are largely unexplored for many agricultural migratory pests. In the field, entomopathogenic fungi infection and transmission, particularly Beauveria bassiana, can cause reduced fitness and population declines across a broad range of insect species.

RESULTS

Here, we investigated migration–immunity interactions between migrant and resident populations of the oriental armyworm, Mythimna separata, infected with B. bassiana (the sole fungus used in this work). We found that migratory M. separata exerted stronger pathogen resistance, faster development and lower pupal weight than residents. High‐dose infections (5.0 × 105 and 5.0 × 106 conidia mL−1) led to seriously decreased reproductive capacity in migrants and residents. Low‐dose infections (1.0 × 104 and 5.0 × 104 conidia mL−1) led to significantly increased host flight capacities. Consecutive flight tests showed that five flight nights inhibited the reproduction of paternal infected M. separata populations. The flights also led to far‐reaching transgenerational impairment of larval development and immune defense among offspring populations. By contrast, two flight nights enhanced the reproductive capacities of both M. separata populations and did not exert negative transgenerational effects on offspring populations, which may facilitate migration.

CONCLUSIONS

This study provides insights into interactions between migration and immunity among M. separata populations. These insights will guide development of future monitoring and management technologies of this pest. © 2024 Society of Chemical Industry.
Agro‐input dealers' perspectives on the design of a certification scheme for pesticide risk reduction
Authors: Tambo Justice A , Holmes Keith , Aliamo Caroline , Mbugua Fredrick , Alokit Christine , Muzira Fred , Byamugisha Andrew , Mwambu Paul
Published: August 2024

BACKGROUND

While pesticides are essential for crop protection and food security, they pose serious risks to human health and the environment. Agro‐input dealers can play an important role in mitigating pesticide risks, given that they are a major source of pesticides and plant health information for many developing‐country farmers. In this article, we assess the willingness of agro‐input dealers to offer integrated pest management‐based advisory services and promote pesticide risk reduction through a voluntary certification scheme.

RESULTS

Using survey data from 557 agro‐input dealers in Uganda and a discrete choice experiment, we find that the proposed certification scheme is significantly valued by agro‐input dealers, particularly for its potential to provide training opportunities and ensure safety to human health and the environment. Agro‐input dealers have a positive attitude towards a certification scheme that restricts the sale of high‐risk pesticide products, especially if it stimulates additional income‐generating opportunities. Further analysis shows that preferences for voluntary certification attributes are influenced by certification experience, agro‐dealership experience, business ownership status and incidence of acute pesticide poisoning.

CONCLUSION

The study findings demonstrate that agro‐input dealers are conscious of pesticide risks to human and environmental health and are keen to participate in a certification scheme promoting safer plant protection products. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Bayesian Methods for Quality Tolerance Limit (QTL) Monitoring
Authors: Poythress J. C. , Lee Jin Hyung , Takeda Kentaro , Liu Jun
Published: August 2024

In alignment with the ICH guideline for Good Clinical Practice [ICH E6(R2)], quality tolerance limit (QTL) monitoring has become a standard component of risk‐based monitoring of clinical trials by sponsor companies. Parameters that are candidates for QTL monitoring are critical to participant safety and quality of trial results. Breaching the QTL of a given parameter could indicate systematic issues with the trial that could impact participant safety or compromise the reliability of trial results. Methods for QTL monitoring should detect potential QTL breaches as early as possible while limiting the rate of false alarms. Early detection allows for the implementation of remedial actions that can prevent a QTL breach at the end of the trial. We demonstrate that statistically based methods that account for the expected value and variability of the data generating process outperform simple methods based on fixed thresholds with respect to important operating characteristics. We also propose a Bayesian method for QTL monitoring and an extension that allows for the incorporation of partial information, demonstrating its potential to outperform frequentist methods originating from the statistical process control literature.
Carvacrol ameliorates skin allograft rejection through modulating macrophage polarization by activating the Wnt signalling pathway
Authors: Zhao Wentao , Tang Hong , Liang Zhi , Wang Ning , Sun Ruiqi , Su Rong , Yang Zhentao , Zhou Ke , Peng Yiyang , Zheng Shusen , Xie Haiyang
Published: August 2024

Post‐transplantation immune rejection remains an important factor for transplant patients. However, conventional immunosuppressants are associated with substantial adverse effects. Natural immunosuppressants present a promising alternative to conventional counterparts, boasting exceptional biological activity, minimal toxicity and reduced side effects. We identified carvacrol as a prospective immunosuppressive agent following T cell proliferation experiment and validated carvacrol's immunosuppressive efficacy in the murine allogeneic skin graft model. T cell proliferation assay was used to screen natural small molecule compounds and the immunosuppressive effect of compounds was evaluated in MHC‐mismatched murine allogeneic skin graft model. H&E and immunohistochemical staining were applied to evaluate the pathological grade. Furthermore, flow cytometry was uitlized to analyse the immunophenotype changes of immune cells. Western blotting and q‐PCR were used to detect the expression of key molecules in macrophages. In vitro, carvacrol demonstrates significant inhibition of the proliferation of CD4+ T and CD8+ T cells. It notably reduces inflammatory factor expression within the allografts, suppresses T cell differentiation toward Th1 phenotype and expansion. Furthermore, carvacrol prominently hinders M1‐type macrophages polarization by activating Wnt signaling. Notably, the anti‐rejection efficacy of carvacrol was significantly weakened upon the removal of macrophages in mice using chlorophosphate liposomes. Carvacrol could significantly inhibit T cell proliferation, alleviate graft rejection and has outstanding toxicological safety. The molecular mechanism of the anti‐rejection effect of carvacrol is closely related to its mediating activation of macrophage Wnt pathway, inhibiting M1 polarization and inducing T cell differentiation.
Interplay between traditional Chinese medicine polysaccharides and gut microbiota: The elusive “polysaccharides‐bond‐bacteria‐enzyme” equation
Authors: Rong XinQian , Shen CanTing , Shu QingLong
Published: August 2024

Polysaccharides are one of the most important components of traditional Chinese medicine (TCM) and have been extensively studied for their immunomodulatory properties. The functions and effects of TCM polysaccharides are closely related to the gut microbiota, making the study of their interaction a hot topic in the field of TCM metabolism. This review follows two main inquiries: first, how the gut microbiota breaks down TCM polysaccharides to produce bioactive metabolites; and second, how TCM polysaccharides reshape the gut microbiota as a carbon source. Understanding the interaction mechanism involves a challenging equation of the structural association of TCM polysaccharides with the metabolic activities of the microbiota. This review has meticulously searched, partially organized literature spanning the past decade, that delves into the interaction mechanism between TCM polysaccharides and gut microbiota. It also gives an overview of the complex factors of the elusive “polysaccharides‐bond‐bacteria‐enzyme” equation: the complexity of polysaccharide structures, the diversity of glycosidic bond types, the communal nature of metabolizing microbiota, the enzymes involved in functional degradation by microbiota, and the hierarchical roles of polysaccharide utilization locus and gram‐positive PULs. Finally, this review aims to facilitate discussion among peers in the field of TCM microbiota and offers prospects for research in related fields, paving the way for pharmacological studies on TCM polysaccharides and gut microbiota therapeutics, and providing a reference point for further clinical research.
Enhancing Packaging Design for Dynamic Loads: A Methodological Approach for Corner Impact Situations in Packaging
Authors: Cáceres‐Naranjo D. , González Pablo , Pérez María Ángeles , Calvo S.
Published: August 2024

This study addresses the challenges in designing packaging to withstand dynamic loads while considering environmental impact and avoiding polymeric materials. It introduces a novel experimental equipment capable of measuring packaging behaviour under corner impacts. The research aims to fill the gap in design tools for non‐flat impact scenarios. By measuring acceleration through dummy products, the study overcomes limitations in cushioning curves. Results offer insights into the dynamic response of packaging systems, aiding in the selection of suitable materials and configurations. Visual analysis enhances understanding of corner protection placement, optimizing energy dissipation. The developed experimental device facilitates rapid data generation, enabling scalable application to corner drop designs, thus serving as a valuable tool in packaging optimization efforts.
Design and Research of the Grasping Force Feedback Mechanism of Flexible Surgical Robots
Authors: Wang Fuhao , Wang Ye , Pan Qiqi , Luo Jingjing , Wang Hongbo , Kang Xiaoyang , Zhang Xueze
Published: August 2024

Background

Robot‐assisted microsurgery (RAMS) is gradually becoming the preferred method for some delicate surgical procedures. However, the lack of haptic feedback reduces the safety of the surgery. Surgeons are unable to feel the grasping force between surgical instruments and the patient's tissues, which can easily lead to grasping failure or tissue damage.

Methods

This paper proposes a tendon‐driven grasping force feedback mechanism, consisting of a follower hand and a leader hand, to address the lack of grasping force feedback in flexible surgical robots. Considering the friction in the tendon transmission process, a grasping force estimation model is established for the follower hand. The admittance control model is designed for force/position control of the leader hand.

Results

Through experimental validation, it has been confirmed that the grasping force sensing range of the follower hand is 0.5–5 N, with a sensing accuracy of 0.3 N. The leader hand is capable of providing feedback forces in the range of 0–5 N, with a static force accuracy of 0.1 N.

Conclusions

The designed mechanism and control strategy can provide the grasping force feedback function. Future work will focus on improving force feedback performance.

Trial Registration

This research has no clinical trials.
Adaptive robust safety‐critical control of switched systems via single barrier function
Authors: Huang Chunxiao , Long Lijun
Published: August 2024

This paper addresses the problem of adaptive robust safety‐critical control (ARSCC) for switched systems, where the safety of subsystems is not necessary. A novel ARSCC framework and an executable algorithm are presented to solve the ARSCC problem by finding a switching signal and controllers of subsystems. To estimate uncertainties, a novel switched piecewise‐constant adaptive law is presented, which guarantees a pre‐computable estimation error boundary. A single barrier function (SBF) method is proposed to ensure safety of switched systems with uncertainties, where the safety of subsystems is satisfied only in some subregion of a given safe set, instead of the whole safe set. Based on the SBF method, a novel state‐dependent switching law possessing different dwell times for different subsystems, is established to orchestrate the switching among potentially unsafe subsystems. As a special case of the SBF method, a common barrier function method is presented to achieve safety of switched systems with uncertainties under switching signals with given dwell times. In addition, some sufficient conditions are derived to obtain safety and asymptotic stability for switched systems with uncertainties by combining SBF and single Lyapunov function. Finally, a switched RLC circuit system is given to illustrate the effectiveness of the theoretical results.
eZ flow metrics: Using z‐scores to estimate deviations from natural flow in the Colorado River below Glen Canyon Dam
Authors: Palmquist Emily C. , Deemer Bridget R. , Metcalfe Anya N. , Kennedy Theodore A. , Bair Lucas S. , Fairley Helen C. , Grams Paul E. , Sankey Joel B. , Yackulic Charles B.
Published: August 2024

River flow patterns are primary drivers of lotic ecosystems, and hundreds of metrics have been developed to quantify flow attributes. Although existing metrics have been a powerful tool in designing environmental flows, they are often developed with specific resources in mind and are rarely directly comparable with each other (i.e., units are often different). Here, we focus on natural flows as the resource of interest and develop z‐score metrics that measure the naturalness of regulated flows, incorporating natural means and interannual variation. These “eZ metrics” summarize whole year, subdaily, and functional flow patterns as standard deviations from natural such that their values are directly comparable. We illustrate their utility with a case study from the Colorado River downstream of Glen Canyon Dam in Arizona, USA. We calculated metrics for 1964–2022, spanning >5 decades of changing water policy, hydropower generation, and flow experimentation. We evaluate four options for estimating natural baseline flows. Across metrics, we found that subdaily stage variation deviated the most from baseline. Flows to satisfy regional water policy and power demands altered metrics more than designer flows (which target specific resource outcomes), and years with low water releases were closest to natural. Most of the designer flows have not made flow patterns more natural, due to incorrect seasonal timing, small magnitude, or short duration. By explicitly considering interannual variability and quantifying how regulated flows differ from natural using standard deviations, these metrics can inform management when the goal is to restore a natural flow regime.
The devil's staircase for chip‐firing on random graphs and on graphons
Authors: Kiss Viktor , Levine Lionel , Tóthmérész Lilla
Published: August 2024

We study the behavior of the activity of the parallel chip‐firing upon increasing the number of chips on an Erdős–Rényi random graph. We show that in various situations the resulting activity diagrams converge to a devil's staircase as we increase the number of vertices. Such a phenomenon was proved in an earlier paper by Levine for complete graphs, by relating the activity to the rotation number of a cycle map. Our method in this article is to generalize the parallel chip‐firing to graphons. Then we show that the earlier results on complete graphs generalize to constant graphons. Moreover, we prove a continuity result for the activity on graphons. These statements enable us to prove results on the activity of the parallel chip‐firing on large random graphs. We also address several problems concerning chip‐firing on graphons, and pose open problems. In particular, we show that the activity of a chip configuration on a graphon does not necessarily exist, but it does exist for every chip configuration on a large class of graphons.
A spectroscopic ellipsometry study of TiO2:ZrO2 on TiN/Si thin films prepared by Chemical Beam Vapor Deposition
Authors: Agnihotri Pratiksha , Verma Aman , Saini Anjali , Rani Rashmi , Maudez William , Wagner Estelle , Benvenuti Giacomo , Banerjee Chandan , Dutta Mrinal , Rai Radheshyam
Published: August 2024

The application of variable angle spectroscopic ellipsometry (VASE) to the characterization of thin films is very important because it facilitates the understanding of their physical and optical properties. To prepare a series of film samples consisting of TiO2:ZrO2 on a TiN/Si substrate, we employed the SYBILLA P200 equipment (manufactured by ABCD Technology) through the process of Chemical Beam Vapor Deposition (CBVD). TiO2:ZrO2 on TiN/Si thin films is a composite material that has gained significant attention in various technological applications, particularly in the field of thin film coatings on semiconductor substrates like TiN/Si. TiO2:ZrO2 thin films exhibit excellent dielectric properties and good thermal stability, making them suitable for various electronic and semiconductor applications. From FESEM and EDX analysis, it is found that with increase of Ti/Zr atomic ratio, grain size increases. Ellipsometric analysis reveals increase in film thickness and refractive index with increase in Ti/Zr atomic ratio. As the film continues to grow, changes in its microstructural phase led to a transition from a monolayer physical ellipsometry model to a bilayer physical model. This transition is due to the appearance of inhomogeneity in the TiO2:ZrO2 thin film. Dynamic fits obtained using a two‐layer physical model and a Cauchy–Lorentz optical model show three distinct phases in the film growth phase: a nucleation phase, a fusion phase, and a continuous layer phase. Although our proposed model shows satisfactory performance in most cases, the determination of the refractive index can be problematic for very thin thicknesses. The developed VASE modeling process should be able to generate TiO2:ZrO2characterization on TiN/Si substrate films using comparable physical and optical modeling considerations.
Production and Evaluation of Hydroxypropyl Starch as a Viscosifying Agent for Enhanced Oil Recovery
Authors: de Aguiar Kelly Lúcia Nazareth Pinho , de Sá Gomes Karen , da Silva Licht Matheus Ferreira , Palermo Luiz Carlos Magalhães , Mansur Claudia Regina Elias
Published: August 2024

In this study, starch was obtained from rice wastes and the maximum extraction yield was 90.95 %. Chemical modification reactions were carried out by hydroxypropylation to obtain a modified starch extract, named 005A, soluble in synthetic injection brine. Extract 005A had a modified starch concentration of 1.24 %, with a pseudoplastic rheological profile and viscosities of 325.54 cP and 121.03 cP at temperatures of 25 and 60 °C, respectively. The application of extract 005A was evaluated by injectivity/filterability tests, which indicated a good filtration rate and viscosity loss of 3.81 % when passing the fluid through the filtering membrane. Stability tests indicated that the 005A extract had a viscosity loss of 21.35 %, at the temperature of 60 °C, after 60 days. The application of this extract enabled additional mineral oil recovery of 12.19 % in simulated core flooding tests. Therefore, the extract of hydroxypropyl starch is a promising viscosifying agent for Enhanced Oil Recovery (EOR) fluids.
Preparation of UV Curable Resins and their Toughening Effect on Bisphenol A‐Type Epoxy Acrylate
Authors: Jiang Honggang , Chen Jiahui , Zou Jiajun , Cui Yanyan , Ai Jiaoyan , Song Lina , Liu Baohua
Published: August 2024

UV‐curable oligomers were synthesized by the reaction of ethylene glycol (EG) or 1,4‐butanediol (BDO) with isophorone diisocyanate (IPDI), and then terminated with hydroxyethyl acrylate (HEA). The chemical structures and molecular weight of the two oligomers were analyzed by Fourier transform infrared spectroscopy (FT‐IR), nuclear magnetic resonance (1H NMR and 13C NMR) and high performance liquid chromatography (HPLC). The obtained UV‐curable oligomers were separately mixed with bisphenol A‐type epoxy acrylate (EA) in different mass ratios. The resulting mixture was then mixed with the active diluent tetrahydrofuran acrylate (THFA) and the photoinitiator ethyl 2,4,6‐trimethylbenzoylphosphonate (TPO‐L) for UV curing. The curing reactions were performed at UV light intensity of 120 mW/cm2. The unsaturation conversion was monitored by real‐time infrared spectroscopy (real‐time FT‐IR). The mechanical properties and coating properties of the UV‐cured products were analyzed. The results showed that the synthesized UV‐curable oligomers had good toughening effect on EA, and the tensile strength of EA was also improved.
Cadmium Exposure in Male Rats Results in Ovarian Granulosa Cell Apoptosis in Female Offspring and Paternal Genetic Effects
Authors: Li Qingyu , Li Yuchen , Zhu Jianlin , Liu Zhangpin , Sun Yi , Lv Yake , Li Jingwen , Luo Lingfeng , Zhang Chenyun , Zhang Wenchang
Published: August 2024

The aim of this study was to investigate whether the damage to male offspring induced by cadmium (Cd) exposure during embryonic period leads to the apoptosis of ovarian granulosa cells (OGCs) in the next generation of female offspring, and whether this apoptosis in the offspring was due to paternal genetic effects. Pregnant Sprague–Dawley (SD) rats were exposed to CdCl2 (0, 0.5, 2.0, or 8.0 mg/kg) by gavage daily for 20 days to produce the filial 1 (F1) generation. F1 males were mated with newly purchased females to produce the F2 generation, and the F3 generation was generated in the same way. No apoptotic bodies were observed in the OGCs of either the F2 or F3 generation as shown by electron microscopy, and a reduced OGC apoptosis rate (detected by flow cytometry) was observed in F2 OGCs from the Cd‐exposed group. Moreover, the mRNA (qRT‐PCR) levels of Bax and Bcl‐2 and the protein (western blotting) level of pro‐caspase‐8 increased in the F2 generation (p < 0.05). The expression of apoptosis‐related miRNAs (qRT‐PCR) and methylation of apoptosis‐related genes (determined via bisulfite‐sequencing PCR) in OGCs were further determined. Compared with those of the controls, the expression patterns of microRNAs (miRNAs) in the F2 offspring were different in the Cd‐exposed group. The miR‐92a‐2‐5p expression levels were decreased in both the F2 and F3 generations (p < 0.05), while the average methylation level of apoptosis‐related genes did not change significantly (except for individual loci). In summary, this study showed that the paternal genetic intergenerational effect of male Cd exposure during embryonic period induced apoptosis of OGCs in the offspring was weakened, and the transgenerational effect disappeared; nevertheless, intergenerational and transgenerational changes in apoptosis‐related genes, epigenetic modifications, DNA methylation, and miRNAs were observed, and may be important for understanding the homeostatic mechanisms of the body to alleviate the intergenerational transmission of Cd‐induced damage.
Overview of the various methods used to assess walking ability in broiler chickens
Authors: Wurtz Kaitlin E. , Riber Anja B.
Published: August 2024

Background

Walking ability is a highly important animal‐based indicator of welfare in broilers that warrants monitoring across commercial production.

Methods

A review of the technical and scientific literature on existing methods for assessing walking ability in broilers was conducted, and the reliability, validity and feasibility of the different methods were assessed when relevant information was available.

Results

Visual gait scoring has high validity, minimal equipment needs and is relatively quick to perform; however, this method is subjective and requires extensive training. Due to this, more objective tests, such as the latency to lie test, have been developed, although more validation of these tests is required. Other identified methods, such as obstacle courses, the rotarod test and kinetic and kinematic approaches, require considerable amounts of equipment, making them impractical for use during on‐farm inspections. Automated methods that rely on movement or activity data have potential for future development but currently lack the resolution of traditional gait scoring and require equipment such as cameras or accelerometers.

Conclusions

Objective, seemingly valid, repeatable and feasible options exist for the assessment of walking ability that would facilitate the monitoring of commercial broiler welfare; however, more validation of these methods is required, especially in commercial farm settings.
A Unique Synthetic Route toward a 1,2‐Dihydrodigermene via Formal α‐Elimination of Bromo and Silyl Groups from a Bromo(phenylsilyl)germane
Authors: Uchida Daichi , Yukimoto Mariko , Tokitoh Norihiro , Yamada Hiroko , Mizuhata Yoshiyuki
Published: August 2024

A 1,2‐dihydrodigermene bearing Tbb {4‐t‐butyl‐1,3‐bis[bis(trimethylsilyl)methyl]phenyl} groups was successfully synthesized and isolated via formal α‐elimination of bromo and silyl groups from the corresponding Tbb‐substituted boromo(phenylsilyl)germane. This novel synthetic method is conducted under mild conditions, representing a significant advantage in the field concerned. The synthesized 1,2‐dihydrodigermene was characterized by NMR spectroscopy, mass spectrometry, and single‐crystal X‐ray crystallography. In the 1H NMR spectrum, the Ge−H unit was found to be less electronically affected from the substituents compared to that of the previously reported 1,2‐dihydrodigermene. Moreover, the UV/vis spectra at various temperatures indicated the formation of the isomeric (dihydrogermyl)germylene. In fact, the 1,2‐dihydrodigermene once isolated reacted with DMAP in solution to afford the corresponding complex of the (dihydrogermyl)germylene.
Analysis of entropy generation and MHD thermo‐solutal convection flow of Ellis nanofluid through inclined microchannel
Authors: Das Debabrata , Makinde O. D. , Kairi Rishi Raj
Published: August 2024

This study investigates heat, mass transport, and entropy production in Ellis nanofluid flow through an inclined permeable microchannel, considering Navier's slip effects with convective boundary conditions. It incorporates nanoparticle's thermophoresis and Brownian motion effects under a transverse magnetic field, with fluid suction and injection at microchannel walls. Under appropriate physical assumptions, the problem is presented as nonlinear ordinary differential equations, which are later nondimensionalized. The MATLAB bvp4c solver is used for numerical solutions of the transformed equations. Graphical depictions in the study illustrate how various factors influence velocity, temperature, concentration, Bejan number, and entropy generation. Engineering parameters, affected by changes in critical factors, are presented in tabular format, including the skin friction coefficient, Nusselt number, and Sherwood number. Notably, the enhancement in Ellis fluid parameter has a dual effect, enhancing velocity and Bejan number in the microchannel's lower half, while reversing in the upper half. For the increment in Ellis parameter, the impact on Bejan number for 0.5 is significant and the effect on entropy production contrasts with that of Bejan number. This research offers practical insights for designing efficient microfluidic heat exchangers and developing advanced nanofluids for improved thermal performance while minimizing entropy generation. Additionally, it underscores the potential for innovation within the domain of microfluidics and nanomaterial‐driven heat transfer systems. Furthermore, it should be noted that the flow behavior of Ellis nanofluids within microchannels can closely replicate natural flow patterns found in biological systems, offering insights that could have numerous applications in biology and related fields.
Anomalous thresholds in B → (P, V)γ* form factors
Authors: Mutke Simon , Hoferichter Martin , Kubis Bastian
Published: August 2024

Abstract

We study the effects of anomalous thresholds on the non-local form factors describing the hadronization of the light-quark contribution toB→ (P, V)γ*transitions. Starting from a comprehensive discussion of anomalous thresholds in the triangle loop function for different mass configurations, we detail how the dispersion relation forππintermediate states is affected by contour deformations mandated by the anomalous branch points. Phenomenological estimates of the size of the anomalous contributions to the form factors are provided with couplings determined from measured branching fractions and Dalitz plot distributions. Our key finding is that anomalous effects are suppressed on theρ(770) resonance, while off-peak the effects can become as large as$$ \mathcal{O} $$O(10%) of the full (light-quark-loop induced) non-local form factors. We comment on future generalizations towards higher intermediate states and the charm loop, outlining how the dispersive framework established in this work could help improve the non-local form factors needed as input for a robust interpretation ofB →(P, V)ℓ+ℓ−decays.
Spectra of correlators in the relaxation time approximation of kinetic theory
Authors: Bajec Matej , Grozdanov Sašo , Soloviev Alexander
Published: August 2024

Abstract

The relaxation time approximation (RTA) of the kinetic Boltzmann equation is likely the simplest window into the microscopic properties of collective real-time transport. Within this framework, we analytically compute all retarded two-point Green’s functions of the energy-momentum tensor and a conserved U(1) current in thermal states with classical massless particles (a ‘CFT’) at non-zero density, and in the absence and presence of broken translational symmetry. This is done in 2 + 1 and 3 + 1 dimensions. RTA allows a full explicit analysis of the analytic structure of different correlators (poles versus branch cuts) and the transport properties that they imply (the thermoelectric conductivities, and the hydrodynamic, quasihydrodynamic and gapped mode dispersion relations). Our inherently weakly coupled analysis thereby also enables a direct comparison with previously known strongly coupled results in holographic CFTs dual to the Einstein-Maxwell-axion theories.
Positivity bounds on electromagnetic properties of media
Authors: Creminelli Paolo , Janssen Oliver , Salehian Borna , Senatore Leonardo
Published: August 2024

Abstract

We study the constraints imposed on the electromagnetic response of general media by microcausality (commutators of local fields vanish outside the light cone) and positivity of the imaginary parts (the medium can only absorb energy from the external field). The equations of motion for the average electromagnetic field in a medium — the macroscopic Maxwell equations — can be derived from the in-in effective action and the effect of the medium is encoded in the electric and magnetic permeabilities ε(ω, |k|) and μ(ω, |k|). Microcausality implies analyticity of the retarded Green’s functions when the imaginary part of the 4-vector (ω, k) lies in forward light cone. With appropriate assumptions about the behavior of the medium at high frequencies one derives dispersion relations, originally studied by Leontovich. In the case of dielectrics these relations, combined with the positivity of the imaginary parts, imply bounds on the low-energy values of the response, ε(0, 0) and μ(0, 0). In particular the quantities ε(0, 0) – 1 and ε(0, 0) – 1/μ(0, 0) are constrained to be positive and equal to integrals over the imaginary parts of the response. We discuss various improvements of these bounds in the case of non-relativistic media and with additional assumptions about the UV behavior.
Holographic spin alignment of J/ψ meson in magnetized plasma
Authors: Zhao Yan-Qing , Sheng Xin-Li , Li Si-Wen , Hou Defu
Published: August 2024

Abstract

We study the mass spectra and spin alignment of vector meson J/ψ in a thermal magnetized background using a generalized theoretical framework based on gauge/gravity duality. Utilizing a soft wall model for the QGP background and a massive vector field for the J/ψ meson, we delve into the meson’s spectral function and spin parameters (λθ, λφ, λθφ) for different cases, assessing their response to variations in magnetic field strength, momentum, and temperature. We initially examine scenarios where a meson’s momentum aligns parallel to the magnetic field in helicity frame. Our results reveal a magnetic field-induced positive $$ {\lambda}_{\theta}^{\textrm{H}} $$

λ
θ
H

for low meson momentum, transitioning to negative with increased momentum. As a comparison, we also study the case of momentum perpendicular to the magnetic field and find the direction of magnetic field does not affect the qualitative behavior for the eB-dependence of $$ {\lambda}_{\theta}^{\textrm{H}} $$

λ
θ
H

. Moreover, we apply our model to real heavy-ion collisions for three different spin quantization directions. Further comparisons with experimental data show qualitative agreement for spin parameters λθ and λφ in the helicity and Collins-Soper frames.
Teleparallel Geroch geometry
Authors: Bossard Guillaume , Cederwall Martin , Palmkvist Jakob
Published: August 2024

Abstract

We construct the teleparallel dynamics for extended geometry where the structure algebra is (an extension of) an untwisted affine Kac-Moody algebra. This provides a geometrisation of the Geroch symmetry appearing on dimensional reduction of a gravitational theory to two dimensions. The formalism is adapted to the underlying tensor hierarchy algebra, and will serve as a stepping stone towards the geometrisation of other infinite-dimensional, e.g. hyperbolic, symmetries.
Holographic fluids from 5D dilaton gravity
Authors: Fichet Sylvain , Megías Eugenio , Quirós Mariano
Published: August 2024

Abstract

We study a solvable class of five-dimensional dilaton gravity models that continuously interpolate between anti-de Sitter (AdS5), linear dilaton (LD5) and positively curved spacetimes as a function of a continuous parameter ν. The dilaton vacuum expectation value is set by a potential localized on a flat brane. We chart the elementary properties of these backgrounds for any admissible ν, and determine stability conditions of the brane-dilaton system. We find that the spectrum of metric fluctuations can be either continuous or discrete. It features a massless graviton mode confined between the brane and the curvature singularity, and a massive radion mode tied to brane-dilaton stability. We show that, in the presence of a bulk black hole, the holographic theory living on the brane features a perfect fluid. The equation of state of the holographic fluid interpolates between radiation, pressureless matter and vacuum energy as a function of ν. This extends earlier findings on holographic fluids. Our results suggest that the thermodynamics of the fluid mirrors precisely the thermodynamics of the bulk black hole.
Pileup density estimate independent on jet multiplicity
Authors: Berta P. , Smieško J. , Spousta M.
Published: August 2024

Abstract

The hard-scatter processes in hadronic collisions are often largely contaminated with soft background coming from pileup in proton-proton collisions, or underlying event in heavy-ion collisions. There are multiple methods to remove the effect of pileup for jets. Two such methods, Area Subtraction and Constituent Subtraction, use the pileup density as the main ingredient to estimate the magnitude of pileup contribution on an event-by-event basis. The state-of-the-art approaches to estimating pileup density are sensitive to the number of hard-scatter jets in the event. This paper presents a new pileup-density estimation method that minimizes the sensitivity on the presence of hard-scatter jets in the event. Using a detector-level simulation, we provide a comparison of the new method with the state-of-the-art estimation methods. We observe a significantly lower bias for the estimated pileup density when using the new method. We conclude that the new method has the potential to significantly improve pileup mitigation in proton-proton collisions or the underlying event subtraction in heavy-ion collisions.
Consistent actions for massive particles interacting with electromagnetism and gravity
Authors: Lindwasser Lukas W.
Published: August 2024

Abstract

Consistent interactions with electromagnetism and gravity for mass m particles of any spin are obtained. This is done by finding interactions which preserve the covariantized massive gauge symmetry present in recently constructed massive particle actions. This gauge principle is sufficient for finding consistent completions of minimal as well as non-minimal couplings of any type. For spins s ≥ 3/2, consistency requires infinitely many interaction terms in the action, including arbitrarily high order derivatives of electromagnetic and gravitational curvatures, with correspondingly high powers of 1/m. These interactions may be formally resummed and expressed in terms of non-local operators. Finally, although the interactions appear non-local, evidence is presented for the existence of a field redefinition which makes the interacting action local. This work provides the first explicit realization of an exactly gauge invariant formulation of massive particles interacting with electromagnetism and gravity.