Degradation Characteristics Research Articles

Evolution and expression patterns of the neo-sex chromosomes of the crested ibis

Bird sex chromosomes play a unique role in sex-determination, and affect the sexual morphology and behavior of bird species. Core waterbirds, a major clade of birds, share the common characteristics of being sexually monomorphic and having lower levels of inter-sexual conflict, yet their sex chromosome evolution remains poorly understood. Here, by we analyse of a chromosome-level assembly of a female crested ibis (Nipponia nippon), a typical core waterbird. We identify neo-sex chromosomes resulting from fusion of microchromosomes with ancient sex chromosomes. These fusion events likely occurred following the divergence of Threskiornithidae and Ardeidae. The neo-W chromosome of the crested ibis exhibits the characteristics of slow degradation, which is reflected in its retention of abundant gametologous genes. Neo-W chromosome genes display an apparent ovary-biased gene expression, which is largely driven by genes that are retained on the crested ibis W chromosome but lost in other bird species. These results provide new insights into the evolutionary history and expression patterns for the sex chromosomes of bird species.

Development of a super-hydrophilic anaerobic tube for the optimization of platelet-rich fibrin

Horizontal platelet-rich fibrin (H-PRF) contains a variety of bioactive growth factors and cytokines that play a key role in the process of tissue healing and regeneration. The blood collection tubes used to produce Solid-PRF (plasmatrix (PM) tubes) have previously been shown to have a great impact on the morphology, strength and composition of the final H-PRF clot. Therefore, modification to PM tubes is an important step toward the future optimization of PRF. To this end, we innovatively modified the inner wall surface of the PM tubes with plasma and adjusted the gas environment inside the PM tubes to prepare super-hydrophilic anaerobic plasmatrix tubes (SHAP tubes). It was made anaerobic for the preparation of H-PRF with the aim of improving mechanical strength and bioactivity. The findings demonstrated that an anaerobic environment stimulated platelet activation within the PRF tubes. After compression, the prepared H-PRF membrane formed a fibrous cross-linked network with high fracture strength, ideal degradation characteristics, in addition to a significant increase in size. Thereafter, the H-PRF membranes prepared by the SHAP tubes significantly promoted collagen synthesis of gingival fibroblast and the mineralization of osteoblasts while maintaining excellent biocompatibility, and advantageous antibacterial properties. In conclusion, the newly modified PRF tubes had better platelet activation properties leading to better mechanical strength, a longer degradation period, and better regenerative properties in oral cell types including gingival fibroblast and alveolar osteoblasts. It also improves the success rate of H-PRF preparation in patients with coagulation dysfunction and expands the clinical application scenario.

Thermal degradation behavior and kinetics of porous polymer based on high functionality components

AbstractTwo kinds of porous polymer were prepared based on high functionality components. Thermogravimetric analysis (TGA) is used to compare the thermal degradation behavior and kinetics of these two materials. The thermogravimetric tests of rigid polyurethane foam (H‐RPUF) and polyurea aerogel (H‐PUA) were carried out in nitrogen atmosphere at different heating rates. The thermal degradation characteristics of the porous polymer were obtained. The apparent activation energy (Ea) of thermal degradation of the porous polymer was investigated by model‐free methods. The results showed that the thermal degradation temperature and ash content of H‐RPUF were higher than those of H‐PUA, and the volatile content was lower. With the rise of heating rate, thermal hysteresis effect of the two porous polymer was relatively high, while the release amount of volatiles was unchanged. For the Kissinger method, Ea of H‐PUA and H‐RPUF was 212.8 kJ mol−1 and 157.4 kJ mol−1, respectively. According to Starink method, the average activation energy of H‐PUA and H‐RPUF was 220.2 kJ mol−1 and 107.2 kJ mol−1, respectively. Obtained by Flynn‐Wall‐Ozawa model, the average activation energy of H‐PUA and H‐RPUF was 219.0 kJ mol−1 and 111.5 kJ mol−1, respectively. The data obtained from the three models all show that Ea of thermal degradation of H‐PUA is higher than that of H‐RPUF, and it is less likely to decompose.

Between Anthropogenic Influence and Resource Management: Impacts of Risks and Preservation Strategies in the Ikopa Watershed, Madagascar

The impacts of anthropogenic risks on water resource management underscore the necessity for a careful and adaptable approach to ensure long-term sustainability. In the Ikopa Watershed in Madagascar, numerous human activities present significant challenges. Water quality is impacted by pollution resulting from agricultural practices. Uncontrolled deforestation intensifies watershed degradation, jeopardizing the availability of water resources. Rapid urbanization and escalating human activities further contribute to the deterioration of water quality. The hypothesis posits that responsible exploitation of natural resources contributes to the preservation and sustainability of water resources in the Ikopa Watershed. This study concentrates on investigating potential anthropogenic risks that influence resource degradation and the perception of mitigation measures. The main objective of this section is to assess the anthropogenic risk factors contributing to water resource degradation in the watershed. The study employs change detection studies through remote sensing and GIS approaches, complemented by social analysis. This methodology aims to identify potential anthropogenic risks affecting responsible water resource management, along with an exploration of local mitigation strategies. The results underscored potential risks faced by the local population in the watershed, including challenges associated with agriculture, urbanization, inadequate drainage network management, and high population density. Binary logistic regression analysis reveals significant connections between anthropogenic risks and the mitigation strategies adopted by local communities in the Ikopa Watershed. The findings indicate that specific characteristics of degradation or local interventions can either positively or negatively influence the adoption of these strategies.

Synthesis, Properties, and Degradation of Poly(butylene succinate-co-sebacicate-co-salicylicate) Copolyesters

Since monomers in backbone of poly(butylene succinate-co-adipate) (PBSA) are not entirely derived from bio-based sources, limiting its application in the face of increasingly stringent environmental policies. In this study, a novel full bio-based biodegradable random copolyester poly(butylene succinate-co-sebacicate-co-salicylicate) was successfully synthesized. Detailed investigations were conducted on the structural, mechanical, and degradation characteristics resulting from the introduction of salicylicate and sebacicate units. Introduction of salicylicate units effectively enhanced the mechanical performance. In comparison to PBSA, the tensile modulus of copolymer increased by 20.2% with 10% salicylic acid. Introduction of sebacicate units significantly altered the crystalline structure of copolymer and promote the degradation efficiency. Considering both mechanical strength and degradation efficiency, the copolyester with 2% salicylic acid and 20% sebacic acid was found to meet practical application requirements. Relative to PBSA, this copolymer demonstrated a 13.7% increase in tensile modulus and a remarkable 143.1% improvement in degradation efficiency. Importantly, this study focused on the effect of the bio-based rigid monomer salicylic acid and the soft monomer sebacic acid on the degradability of biodegradable polymers. The insights gained provide valuable guidance for tailoring the synthesis of degradable plastics to meet diverse degradation cycle requirements.

Comparison of Hyaluronidase-Mediated Degradation Kinetics of Commercially Available Hyaluronic Acid Fillers In Vitro.

The ability to degrade hyaluronic acid (HA)-based fillers with hyaluronidase allows for better management of adverse effects and reversal of suboptimal treatment outcomes. The aim of this study was to compare the enzymatic degradation kinetics of 16 commercially available HA-based fillers, representing 6 manufacturing technologies. In this nonclinical study, a recently developed in vitro multidose hyaluronidase administration protocol was used to induce degradation of HA-based fillers, enabling real-time evaluation of viscoelastic properties under near-static conditions. Each filler was exposed to repeated doses of hyaluronidase at intervals of 5 minutes to reach the degradation threshold of G' ≤ 30 Pa. Noticeable differences in degradation characteristics were observed based on the design and technology of different filler classes. Vycross fillers were the most difficult to degrade and the Cohesive Polydensified Matrix filler was the least difficult to degrade. Preserved Network Technology products demonstrated proportional increases in gel degradation time and enzyme volume required for degradation across the individual resilient hyaluronic acid (RHA) products and indication categories. No obvious relationship was observed between gel degradation characteristics and the individual parameters of HA concentration, HA chain length, or the degree of modification of each filler when analyzed separately; however, a general correlation was identified with certain physicochemical properties. Manufacturing technology was the most important factor influencing the reversibility of an HA product. An understanding of the differential degradation profiles of commercially available fillers will allow clinicians to select products that offer a higher margin of safety due to their preferential reversibility.

Microbial Fermentation as an Efficient Method for Eliminating Pyrethroid Pesticide Residues in Food: A Case Study on Cyfluthrin and Aneurinibacillus aneurinilyticus D-21.

The microbial fermentation of food has emerged as an efficient means to eliminate pesticide residues in agricultural products; however, the specific degradation characteristics and mechanisms remain unclear. In this study, a Gram-positive bacterium, Aneurinibacillus aneurinilyticus D-21, isolated from fermented Pixian Douban samples exhibited the capability to degrade 45 mg/L of cyfluthrin with an efficiency of 90.37%. Product analysis unveiled a novel cyfluthrin degradation pathway, involving the removal of the cyanide group and ammoniation of the ester bond into an amide. Whole genome analysis discovered the enzymes linked to cyfluthrin degradation, including nitrilase, esterase, carbon-nitrogen ligases, and enzymes associated with aromatic degradation. Additionally, metabolome analysis identified 140 benzenoids distributed across various aromatic metabolic pathways, further substantiating D-21's catabolic capability toward aromatics. This study underscores the exceptional pyrethroid degradation prowess of A. aneurinilyticus D-21, positioning it as a promising candidate for the biotreatment of pesticide residues in food systems.

Anatomical Brushite-Coated Mg-Nd-Zn-Zr Alloy Cage Promotes Cervical Fusion: One-Year Results in Goats.

In this study, an anatomical brushite-coated Mg-Nd-Zn-Zr alloy cage was fabricated for cervical fusion in goats. The purpose of this study was to investigate the cervical fusion effect and degradation characteristics of this cage in goats. The Mg-Nd-Zn-Zr alloy cage was fabricated based on anatomical studies, and brushite coating was prepared. Forty-five goats were divided into three groups, 15 in each group, and subjected to C2/3 anterior cervical decompression and fusion with tricortical bone graft, Mg-Nd-Zn-Zr alloy cage, or brushite-coated Mg-Nd-Zn-Zr alloy cage, respectively. Cervical radiographs and computed tomography (CT) were performed 3, 6, and 12 months postoperatively. Blood was collected for biocompatibility analysis and Mg2+ concentration tests. The cervical spine specimens were obtained at 3, 6, and 12 months postoperatively for biomechanical, micro-CT, scanning electron microscopy coupled with energy dispersive spectroscopy, laser ablation-inductively coupled plasma-time-of-flight mass spectrometry, and histological analysis. The liver and kidney tissues were obtained for hematoxylin and eosin staining 12 months after surgery for biosafety analysis. Imaging and histological analysis showed a gradual improvement in interbody fusion over time; the fusion effect of the brushite-coated Mg-Nd-Zn-Zr alloy cage was comparable to that of the tricortical bone graft, and both were superior to that of the Mg-Nd-Zn-Zr alloy cage. Biomechanical testing showed that the brushite-coated Mg-Nd-Zn-Zr alloy cage achieved better stability than the tricortical bone graft at 12 months postoperatively. Micro-CT showed that the brushite coating significantly decreases the corrosion rate of the Mg-Nd-Zn-Zr alloy cage. In vivo degradation analysis showed higher Ca and P deposition in the degradation products of the brushite-coated Mg-Nd-Zn-Zr alloy cage, and no hyperconcentration of Mg was detected. Biocompatibility analysis showed that both cages were safe for cervical fusion surgery in goats. To conclude, the anatomical brushite-coated Mg-Nd-Zn-Zr alloy cage can promote cervical fusion in goats, and the brushite-coated Mg-Nd-Zn-Zr alloy is a potential material for developing absorbable fusion cages.

Investigations on the Degradation Behavior of Processed FeMnSi-xCu Shape Memory Alloys.

A new functional Fe-30Mn-5Si-xCu (x = 1.5 and 2 wt%) biomaterial was obtained from the levitation induction melting process and evaluated as a biodegradable material. The degradation characteristics were assessed in vitro using immersion tests in simulated body fluid (SBF) at 37 ± 1 °C, evaluating mass loss, pH variation that occurred in the solution, open circuit potential (OCP), linear and cyclic potentiometry (LP and CP), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and nano-FTIR. To obtain plates as samples, the cast materials were thermo-mechanically processed by hot rolling. Dynamic mechanical analysis (DMA) was employed to evaluate the thermal properties of the smart material. Atomic force microscopy (AFM) was used to show the nanometric and microstructural changes during the hot rolling process and DMA solicitations. The type of corrosion identified was generalized corrosion, and over the first 3-5 days, an increase in mass was observed, caused by the compounds formed at the metal-solution interface. The formed compounds were identified mainly as oxides that passed into the immersion liquid. The degradation rate (DR) was obtained as a function of mass loss, sample surface area and immersion duration. The dynamic mechanical behavior and dimensions of the sample were evaluated after 14 days of immersion. The nanocompounds found on the surface after atmospheric corrosion and immersion in SBF were investigated with the Neaspec system using the nano-FTIR technique.

Construction of Shale Gas Oil-Based Drilling Cuttings Degrading Bacterial Consortium and Their Degradation Characteristics.

Oil-based drilling cuttings (OBDCs) contain petroleum hydrocarbons with complex compositions and high concentrations, which have highly carcinogenic, teratogenic, and mutagenic properties. In this study, three highly efficient petroleum hydrocarbon-degrading bacteria were screened from OBDCs of different shale gas wells in Chongqing, China, and identified as Rhodococcus sp. and Dietzia sp. Because of their ability to degrade hydrocarbons of various chain lengths, a new method was proposed for degrading petroleum hydrocarbons in shale gas OBDCs by combining different bacterial species. Results showed that the bacterial consortium, consisting of the three strains, exhibited the highest degradation rate for petroleum hydrocarbons, capable of degrading 74.38% of long-chain alkanes and 93.57% of short-chain alkanes, respectively. Moreover, the petroleum hydrocarbon degradation performance of the bacterial consortium in actual OBDCs could reach 90.60% in the optimal conditions, and the degradation kinetic process followed a first-order kinetic model. This study provides a certain technical reserve for the bioremediation of shale gas OBDCs.

Assessing the degradation profiles of a thermoresponsive polyvinyl alcohol (PVA)‐based hydrogel for biomedical applications

AbstractPrimary challenges associated with the design and success of polymeric biomedical devices are generally related to the control of the biomaterial in terms of degradability characteristics, sufficient processability characteristics, and required mechanical strength that may be altered during sterilization or manufacturing procedures. Polyvinyl alcohol‐based thermoresponsive biomaterials provide a distinct advantage for biomedical applications as their physiochemical properties can be easily modified according to their desired use. In this work, we evaluated the thermal degradation characteristics of a polyvinyl alcohol (PVA)/polyethylene glycol (PEG)/polyvinylpyrrolidone (PVP) hydrogel that undergoes a steam sterilization autoclave cycle at 121°C to induce fluid‐like behavior. FTIR was used to characterize the evolution of the area of the carbonyl region between 1800 and 1525 cm−1. The carbonyl area increased at temperatures beyond 121°C which were used to accelerate the onset of degradation during both thermal oxidation and pyrolysis. The change in the carbonyl region was shown to correlate with respect to both temperature and time of exposure. The carbonyl region increased significantly in the presence of oxygen at temperatures above 150°C. Despite showing signs of thermal degradation at temperatures exceeding 150°C, our biomaterial was shown to be stable at 121°C during thermal degradation testing. Furthermore, bulk property analysis showed the hydrogel's mechanical and swelling properties were preserved even after being subject to multiple autoclave cycles beyond what would be experienced during a sterilization or clinical procedure.

Experimental Study on the Deterioration of Nickel Cadmium Battery Based on External Characteristic Analysis

Although nickel cadmium batteries have good comprehensive performance and have been used in rail transit auxiliary power systems for a long time, battery degradation is inevitable during long-term use, which largely limits its power output capability and increases the cost of use. Unlike lithium batteries, the degradation study of nickel cadmium batteries has many shortcomings, mostly limited to a certain characteristic data for degradation prediction, and lack of systematic experimental study. Therefore, this article investigates the external characteristics of nickel cadmium battery degradation from multiple points, such as electrochemical impedance, heat production, thermal stability, gas production, etc. Through the experimental analysis, it can be seen that the degradation leads to an advance in the time of oxygen production, a decrease in the thermal stability, an increase in the heat production per unit time, an increase in the charge transfer impedance and a decrease in the interface double layer capacitance.

Degradation Characteristics of Glass Fiber Reinforced Plastics Using Unsaturated Polyester as Matrix in Weak Alkaline Aqueous Solution

Degradation Characteristics of Glass Fiber Reinforced Plastics Using Unsaturated Polyester as Matrix in Weak Alkaline Aqueous Solution

Plant fiber‐reinforced composites based on injection molding process: Manufacturing, service life, and remanufacturing

AbstractResource depletion and environmental degradation have become important issues affecting the human development process. Plant fiber‐reinforced composites (PFRCs) are characterized by high natural availability, good mechanical properties, low density, recyclability, and eco‐friendliness. Expanding human applications of plant fibers is an important measure to combat resource and environmental problems. The injection molding process has the characteristics of strong product size adaptability, high molding precision, and high production efficiency. It is suitable for large‐scale production in the industry and is one of the main molding methods of PFRCs. Currently, there are still challenges and opportunities for high‐performance manufacturing of PFRCs based on the injection molding process. This article reviews the complete process of manufacturing‐service life‐remanufacturing of PFRCs based on the injection molding process. Emphasis is placed on the pretreatment technology and selection strategy of multi‐phase blended raw materials, the molding process conditions, functional applications, and simulation analysis, the aging and degradation characteristics during service, and the remanufacturing characteristics of the composites. Finally, the future research focus is summarized and prospected. The research in this paper will help promote the continuous progress of key technologies in the production process of PFRCs and help the industry to truly realize high‐performance green manufacturing in the future.Highlights Plant fibers exhibit variability in morphology and properties. The link between the structure and performance of PFRCs is unclear. The degradability and durability of PFRCs are contradictory. The functionality and mechanical properties of PFRCs are contradictory. PFRCs have good characteristics for remanufacturing.

Assessing Fermentation Quality, Aerobic Stability, In Vitro Digestibility, and Rumen Degradation Characteristics of Silages Mixed with Sweet Sorghum and Aerial Parts of Licorice

Assessing Fermentation Quality, Aerobic Stability, In Vitro Digestibility, and Rumen Degradation Characteristics of Silages Mixed with Sweet Sorghum and Aerial Parts of Licorice

Characteristics of the steam degradation of poly(lactic acid) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

The introduction of biodegradable plastics is considered a practical approach to reducing plastic waste accumulation in the environment. Regardless of their biodegradability, plastics should be recycled to effectively utilize and circulate carbon as a resource. Herein, the use of pyrolysis was examined as a method for recycling two common biobased/biodegradable plastics: PLA and PHBH. The pyrolysis of PLA produced lactides (10.7 wt% at 400 °C), but the yield was decreased when the pyrolysis temperature was increased. The presence of steam promoted the hydrolysis of PLA: a steam concentration of 25 vol % increased, the production of lactides at 400 °C to 17.4 wt%. The pyrolysis of PHBH primarily yielded crotonic acid (30.1 wt% at 400 °C), and the yield increased with increasing pyrolysis temperature (71.8 wt% at 800 °C). Steam injection increased the hydrolysis of oligomers, resulting in a 76.1 wt% yield of crotonic acid at 600 °C with a steam concentration of 25 vol %. Thus, we determined that hydrolysis and pyrolysis progress simultaneously under a steam atmosphere, increasing the chemical feedstock recovery from PLA and PHBH. These findings may lead to the proposal of effective degradation methods for treating biobased/biodegradable plastic wastes and ways to maximize the conversion efficiency and target product yields.

Tough and Water-Resistant Bioelastomers with Active-Controllable Degradation Rates.

Biodegradable electronic devices have gained significant traction in modern medical applications. These devices are generally desired to have a long enough working lifetime for stable operation and allow for active control over their degradation rates after usage. However, current biodegradable materials used as encapsulations or substrates for these devices are challenging to meet the two requirements due to the constraints of inadequate water resistance, poor mechanical properties, and passive degradation characteristics. Herein, we develop a novel biodegradable elastomer named POC-SS-Res by introducing disulfide linkage and resveratrol (Res) into poly(1,8-octanediol-co-citrate) (POC). Compared to POC, POC-SS-Res exhibits good water resistance and excellent mechanical properties in PBS, providing effective protection for devices. At the same time, POC-SS-Res offers the unique advantage of an active-controllable degradation rate, and its degradation products express low biotoxicity. Good biocompatibility of POC-SS-Res is also demonstrated. Bioelectronic components encapsulated with POC-SS-Res have an obvious prolongation of working lifetime in PBS compared to that encapsulated with POC, and its degradation rate can be actively controlled by the addition of glutathione (GSH).

Fault Diagnosis of PV Array Based on Time Series and Support Vector Machine

This paper proposes a diagnosis method based on time series and support vector machine (SVM) to improve the timeliness, accuracy, and feasibility of fault diagnosis for photovoltaic (PV) arrays. It obtains the nominal output power of the PV array based on real-time collected data such as voltage, current, radiation, and temperature and normalizes the power values at different time points throughout the day to form a time series. Using the time series values as input data for a “one-to-one” multiclass classifier, we can identify and classify typical operational faults such as random shading, fixed shading, and aging degradation of PV arrays. The developed algorithmic model is trained and tested for different fault conditions using the data sets generated by the PV array simulation device. The experimental results show that our model has fairly good reliability and accuracy, and to some extent, it solves the problem of classifying shading and aging faults, two of which exhibit rather similar degradation characteristics.

Voltage ramp stress based lifetime-prediction model of advanced Al-doped HfO[formula omitted] dielectric for 2.5D MIMCAPs

The reliability of an Al-doped HfO2 dielectric used in a high density 2.5D MIMCAP is investigated by constant voltage stress (CVS) and voltage ramp stress (VRS) measurements. The good agreement of the results from the two techniques allows to propose a model for lifetime prediction based on the breakdown characteristics. The extracted activation energy shows a voltage dependence associated with a change in the degradation characteristics of the high-κ material at high fields.

Morphological features of magnetorheological elastomer degradation under a natural weathering environment

It is well known in the field of materials science that a substance’s longevity is significantly influenced by its environment. Everything begins with the initial contact on a material’s surface. This influence will then deteriorate and have an extended negative impact on the strength of the material. In this study, the effect of natural weathering in tropical climates on magnetorheological elastomer (MRE) was investigated through microstructural evaluation to understand the aging behavior of the environmentally exposed MRE. To understand and elucidate the process, MREs made of silicone rubber and 70 wt% micron-sized carbonyl iron particles were prepared and exposed to the natural weathering of a tropical climate for 90 days. The MRE samples were then mechanically tensile tested, which revealed that Young’s modulus increased, while elongation at break decreased. Surface degradation due to weathering was suspected to be the primary cause of this condition. Using scanning electron microscopy (SEM), the degradation of MRE was investigated as a function of morphological evidence. Upon examination through SEM, it was noted that the weathering effects on the morphology of the exposed samples showed distinct characteristics on the degraded surfaces of the MRE, including numerous microvoids, cavities, and microcracks. While these features were not prominent for the MRE itself, they bear resemblance to the effects observed in similar materials like rubber and elastomer. An atomic force microscope (AFM) is used to investigate the surface topography and local degradation conditions. This observation revealed a distinctive degradation characteristic of the MRE in connection to natural weathering in tropical climates. The surface damage of the MRE samples became severe and inhomogeneous during the environmental aging process, and degradation began from the exposed MRE surface, causing the mechanical characteristics of the MRE to significantly change.