Preparation Method Research Articles

Encapsulating Fe3O4 Nanoparticles and Carbon Dots in a Metal-Organic Framework for Magnetic Fluorescent Taggants.

Magnetic fluorescent composite nanomaterials have broad application prospects in the fields of biological imaging, anticounterfeiting identification, suspicious object tracking, and identification of latent fingerprints in forensic medicine. For an effective taggant, a clearly visible identifying mark is necessary to enable observers to capture labeling information quickly and accurately, even from a distance. The preparation method of magnetic fluorescent composite materials is complicated and usually needs different surface modification and assembly processes. The limited loading capacity of fluorescent materials also limits the fluorescence properties of the composite, so it is difficult to produce obvious fluorescence as a taggant to meet the requirements of visible labeling. In this study, a core-shell structure of a magnetic fluorescent composite was prepared by using the metal-organic framework ZIF-8 as the host of fluorescent materials and an encapsulation shell coated on the Fe3O4 nanoparticles. The porous ZIF-8 is beneficial for increasing the loading capacity of fluorescent materials to ensure the fluorescence performance of the composite materials. Further modification of the composite surface prevented the desorption of fluorescent materials from the pores of ZIF-8, enabling the samples to maintain good fluorescence properties even after multiple washing cycles. The preparation method is simple, rapid, and cost-effective, and the prepared magnetic fluorescent composite nanomaterial has high magnetic separation performance and fluorescence performance, making it a promising material for identification, marking, and tracking.

Carbon-Spaced Tandem-Disulfide Bond Bridge Design Addresses Limitations of Homodimer Prodrug Nanoassemblies: Enhancing Both Stability and Activatability.

Redox-responsive homodimer prodrug nanoassemblies (RHPNs) have emerged as a significant technology for overcoming chemotherapeutical limitations due to their high drug-loading capacity, low excipient-associated toxicity, and straightforward preparation method. Previous studies indicated that α-position disulfide bond bridged RHPNs exhibited rapid drug release rates but unsatisfactory assembly stability. In contrast, γ-disulfide bond bridged RHPNs showed better assembly stability but low drug release rates. Therefore, designing chemical linkages that ensure both stable assembly and rapid drug release remains challenging. To address this paradox of stable assembly and rapid drug release in RHPNs, we developed carbon-spaced double-disulfide bond (CSDD)-bridged RHPNs (CSDD-RHPNs) with two carbon-spaces. Pilot studies showed that CSDD-RHPNs with two carbon-spaces exhibited enhanced assembly stability, reduction-responsive drug release, and improved selective toxicity compared to α-/γ-position single disulfide bond bridged RHPNs. Based on these findings, CSDD-RHPNs with four and six carbon-spaces were designed to further investigate the properties of CSDD-RHPNs. These CSDD-RHPNs exhibited excellent assembly ability, safety, and prolonged circulation. Particularly, CSDD-RHPNs with two carbon-spaces displayed the best antitumor efficacy on 4T1 and B16-F10 tumor-bearing mice. CSDD chemical linkages offer novel perspectives on the rational design of RHPNs, potentially overcoming the design limitations regarding contradictory assembly ability and drug release rate.

NiOx Passivation in Perovskite Solar Cells: From Surface Reactivity to Device Performance.

Nonstoichiometric nickel oxide (NiOx) is one of the very few metal oxides successfully used as hole extraction layer in p-i-n type perovskite solar cells (PSCs). Its favorable optoelectronic properties and facile large-scale preparation methods are potentially relevant for future commercialization of PSCs, though currently low operational stability of PSCs is reported when a NiOx hole extraction layer is used in direct contact with the perovskite absorber. Poorly understood degradation reactions at this interface are seen as cause for the inferior stability, and a variety of interface passivation approaches have been shown to be effective in improving the overall solar cell performance. To gain a better understanding of the processes happening at this interface, we systematically passivated specific defects on NiOx with three different categories of organic/inorganic compounds. The effects on NiOx and the perovskite (MAPbI3) deposited on top were investigated using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Here, we find that the perovskite's structural stability and film formation can be significantly affected by the passivation treatment of the NiOx surface. In combination with density functional theory (DFT) calculations, a likely origin of NiOx-perovskite degradation interactions is proposed. The surface passivated NiOx layers were incorporated into MAPbI3-based PSCs, and the influence on device performance and operational stability was investigated by current-voltage (J-V) characterization, impedance spectroscopy (IS), and open circuit voltage decay (OCVD) measurements. Interestingly, we find that a superior structural stability due to interface passivation must not relate to high operational stability. The discrepancy comes from the formation of excess ions at the interface, which negatively impacts all solar cell parameters.

Method development for multielement determination of halogens and sulfur in teas

Abstract Microwave-induced combustion was evaluated as a sample preparation method for several types of tea (black, green, lemon balm, boldo, and mint) for further determination of bromine, chlorine, fluorine, iodine, and sulfur by ion chromatography. Parameters such as the sample mass efficiently decomposed and the most suitable absorbing solution (ultrapure water and 25, 50, 100, and 150 mmol L−1 NH4OH) were evaluated, considering the characteristics of the analytes and the determination technique used. The maximum sample mass possible to be decomposed was 900 mg of milled tea in the form of pellets, and the absorbing solution chosen was 100 mmol L−1 NH4OH, which provided suitable stabilization of the analytes (recoveries between 95 % and 103 %). To assess the accuracy of the proposed method, a certified reference material (BCR 060, aquatic plant) was analyzed. Agreements with the certified values ranged from 101 % to 107 %. The proposed method was used to analyze tea samples and the concentrations ranged from 549 to 2,549 mg kg−1 for chlorine, 223 to 828 mg kg−1 for fluorine, and 786 to 4,023 mg kg−1 for sulfur; bromine and iodine concentrations were below the limits of quantification (42 and 80 mg kg−1, respectively) in all evaluated samples.

From Ancient Practices to Modern Science: A Review on the Synthesis and Characterization of Ayurvedic Bhasmas

Ayurvedic Bhasma, an ancient form of Indian traditional medicine, represents a unique class of herbo-mineral formulations prepared through a meticulous process involving calcination. This review provides a comprehensive synthesis and characterization of Ayurvedic Bhasmas, focusing on its preparation methods, physicochemical properties, and characterization. The synthesis of Bhasma involves a series of Shodhana (purification), Marana (incineration), and Bhavana (soaking and drying) processes, each contributing to the transformation of raw minerals and herbs into bioavailable nanoparticles with enhanced efficacy and reduced toxicity. The review delves into the intricate processes involved in the production of various bhasmas, prepared in our laboratory as well as reports by other researchers. It also highlights modern scientific techniques used to characterize these formulations, including XRD, SEM, TEM, FTIR, AAS, NAA, DLS etc. These techniques reveal the nanoscale size, crystalline structure, and elemental composition of bhasmas, providing insights into their therapeutic potential and safety profiles.

Rotary barrel tumbling as a method of surface preparation for pin-on-disc wear testing samples

Abstract Surface preparation is essential to ensure sample homogeneity in terms of surface roughness and mechanical properties, as these factors can significantly affect wear behavior and test repeatability. Although conventional semi-automatic and automatic grinding and polishing processes are efficient and well established, limitations arise for the preparation of large numbers of samples of a hard material such as high-carbon steel, including issues with sample geometry, the need for on-demand sample holders, cost-related limitations, and even considerable human workload and expertise. This study aims to evaluate the use of rotary barrel tumbling—a polishing method that relies on the sliding of abrasive media over the samples’ surface inside a rotating barrel—as an alternative method to prepare the surface of wheel and rail steel samples for pin-on-disc wear testing. A 4-stage tumbling procedure was employed, using different compositions of tumbling media in each stage. Surface roughness and hardness were evaluated throughout the process via 2D and 3D profilometry, microhardness Vickers measurements, and optical microscopy. The proposed method resulted in significant reductions in the surface roughness and hardness of the samples, along with improved homogeneity between samples of different materials and within the same material. These findings suggest that rotary barrel tumbling is an effective alternative method for the surface preparation of pins and discs made of high-carbon steel, enhancing the samples’ suitability for subsequent wear tests.

Granular Activated Bamboo Charcoal and Silica Gel as Water Treatment Against Microbial Contaminants: A Comparative Analysis

The growing demand for clean and safe water necessitates the investigation of innovative materials that can be utilized in water treatment applications. In this regard, a simple and cost-effective water treatment method was developed to address the water supply problem in rural areas. This study provided knowledge and conducted a comparative analysis of the effectiveness of two main methods for treating microbial contaminants in lake water: granular activated charcoal and silica gel. Furthermore, the experiment was subjected to before and after the application of activated carbon and silica gel. The pre-testing was conducted to identify the initial quantity of microbial contaminants. The preparation methods for bamboo into charcoal are initiated with the following steps: cutting, drying, loading, and sealing the drum kiln, heating, carbonization, cooling, and removing charcoal. Afterward, the bamboo charcoal underwent a chemical process to create activation using potassium hydroxide to generate a large surface area and enhance the adsorption capability. The two treatments were added to the lake water sample via filtration. Moreover, the post-testing involves performing serial dilution and microbial counts to determine the difference between before and after the contaminant's growth. Based on the results, the granular activated carbon is more effective than the silica gel because of its greater adsorption capacity resulting from its extensive pore spaces. This research study contributes significantly to researchers in the field and further advancements in utilizing granular activated carbon and silica gel to ensure clean and sustainable resources.

Utilization of coal gasification fine slag-derived mesoporous silica supports for enhanced dry reforming of methane catalysts

Utilizing industrial waste coal gasification fine slag (CGFS) for the preparation of dry reforming of methane (DRM) catalyst supports presents an innovative approach to waste utilization. This strategy not only addresses solid waste pollution but also reduces the production costs associated with DRM catalysts. Currently, the industrialization of the DRM reaction remains elusive. Therefore, selecting an appropriate catalyst preparation method is imperative for potential industrial applications. This study centers on the synthesis of mesoporous silica (MS) supports using coal gasification fine slag. The impact of support structure, catalyst preparation method, and active metal loading on the resistance to sintering and carbon deposition of the catalysts is explored through diverse characterization techniques. The MS support derived from coal gasification fine slag showcases a unique disordered mesoporous architecture that enhances the dispersion of the metal across the support surface. In addition, we report a MS catalyst prepared by a co-precipitation method (MS–CP), which exhibits excellent catalytic activity and stability due to its strong metal-support interaction. Results suggest that during synthesis, the MS–CP catalyst activates the inert MS support by strongly interacting with Ni metal, resulting in the formation of Ni3Si2O5(OH)4 species. The Ni–O–Si bond can activate CO2, thereby promoting the availability of interfacial oxygen during the reaction. This process accelerates the gasification of surface Cn generated by CH4 decomposition. Notably, the loading analysis indicates that MS–CP loaded with 10 wt% Ni demonstrates the highest resistance to carbon deposition and sintering. Thus, the unique strong metal-supported interactions provide a new avenue for the development of nickel-based DRM catalysts.

Ethnobotanical insights on the management of plant pests and diseases by smallholder farmers in Mpumalanga Province of South Africa

BackgroundPests and diseases are a major contributor to yield losses in sub-Saharan Africa, prompting smallholder farmers to seek cost-effective, accessible and ecologically friendly alternatives for crop protection. This study explored the management of pests and diseases affecting crops across eight selected villages in Ehlanzeni District, Mpumalanga Province, South Africa.MethodsA total of 120 smallholder farmers were purposefully selected utilising the snowball technique. Information on the management of plant pests and diseases was collected through interviews and focus group discussions using semi-structured interview schedules. Ethnobotanical indices, including relative frequency of citation (RFC), use-value (UV) and informant consensus factor (Fic), were used to quantify and rank the plants used for crop protection in the study area.ResultsTwenty-three plant species (16 naturalised exotics and seven indigenous plants) belonging to 16 families were used for managing pests (vertebrates and invertebrates) and diseases (fungal and bacterial related) affecting crops in the study area. The dominant (100%) crops cultivated by the participants were Allium cepa L., Mangifera indica L., Solanum lycopersicum L. and Zea mays L. The RFC value ranged from 0.08 to 0.83 and the three most popular plants for crop protection were Capsium annuum L. (0.83), A. cepa (0.63) and Dichrostachys cinerea (L.) Wight & Arn. (0.43). In terms of the UV, the five most promising plants used as biocontrol were Tulbaghia violacea (0.13), A. cepa (0.12), C. annuum L. (0.09), Solanum campylacanthum Hochst. Ex A.Rich.(0.09) and Pinus pinaster (0.08). Based on the Fic, four categories were established and dominated by fungal diseases (0.64). Furthermore, T. violacea and A. cepa were the most often mentioned plants used against fungal conditions. Other categories cited were bacterial diseases (0.3), invertebrate pests (0.11) and vertebrate pests (0.14), an indication that smallholder farmers had limited agreement or common knowledge about the plants used for their management. The preparation methods included maceration (38%), decoction (38%) and burning (24%). Foliar application (67%) and soil drenching (33%) were used for administering plant extracts during the management of crop pests and diseases.ConclusionThe study highlights the importance of botanicals and associated indigenous knowledge among smallholder farmers in Mpumalanga Province, South Africa. It is pertinent to explore the valorisation of these botanicals by generating empirical data on their biological efficacies and phytochemical profiles.

Advanced MXene materials: Paving the way for next-generation lithium-sulfur batteries in energy storage

In recent years, lithium-sulfur (Li-S) batteries, with high theoretical energy density and low cost, have become one of the most promising energy storage systems. However, the insulation of sulfur, the "shuttle effect" of polysulfides and volume expansion hinder their practical applications. MXenes have excellent electrical conductivity, high specific surface area, and a strong adsorption capacity for polysulfides, which helps to overcome the shortcomings of traditional Li-S batteries. In this paper, the structure, properties and preparation methods of MXenes are reviewed, and the applications of MXenes in the cathode, separator and anode of Li-S batteries are introduced. Finally, the future directions of MXenes in the field of Li-S batteries are prospected.

Synthesis of Cellulose Acetate Butyrate Microspheres as Precursor for Hard Carbon-Based Electrodes in Symmetric Supercapacitors

Cellulose microspheres have a wide range of applications due to their unique properties and versatility. Various preparation methods have been explored to tailor these microspheres for specific applications. Among these methods, the acetate method using cellulose acetate is well known. However, replacement of the acetate group through the butyrate group significantly extends the variety of morphological properties. In the present work, microspheres based on cellulose acetate butyrate are being developed with modified characteristics in terms of particle size, porosity, surface morphology and the inner structure of the microspheres. While the inner structure of cellulose acetate microspheres is predominantly porous, microspheres prepared from cellulose acetate butyrate are mainly filled or contain several smaller microspheres. Carbon materials from cellulose acetate butyrate microspheres exhibit a high specific surface area of 567 m2 g−1, even without further activation. Activation processes can further increase the specific surface area, accompanied by an adaptation of the pore structure. The prepared carbons show promising results in symmetrical supercapacitors with aqueous 6 M KOH electrolytes. Activated carbons derived from cellulose acetate butyrate microspheres demonstrate an energy density of 12 Wh kg−1 at a power density of 0.9 kW kg−1 .

Racial Disparities in Bowel Preparation and Post-Operative Outcomes in Colorectal Cancer Patients

Background: Combined pre-operative bowel preparation with oral antibiotics (OAB) and mechanical bowel preparation (MBP) is the current recommendation for elective colorectal surgery. Few have studied racial disparities in bowel preparation and subsequent post-operative complications. Methods: This retrospective cohort study used 2015–2021 ACS-NSQIP-targeted data for elective colectomy for colon cancer. Multivariate regression evaluated predictors of post-operative outcomes: post-operative ileus, anastomotic leak, surgical site infection (SSI), operative time, and hospital length of stay (LOS). Results: 72,886 patients were evaluated with 82.1% White, 11.1% Black, and 6.8% Asian or Asian Pacific Islander (AAPI); 4.2% were Hispanic and 51.4% male. Regression accounting for age, sex, ASA classification, comorbidities, and operative approach showed Black, AAPI, and Hispanic patients were more likely to have had no bowel preparation compared to White patients receiving MBP+OAB. Compared to White patients, Black and AAPI patients had higher odds of prolonged LOS and pro-longed operative time. Black patients had higher odds of post-operative ileus. Conclusions: Racial disparities exist in both bowel preparation administration and post-operative complications despite the method of bowel preparation. This warrants exploration into discriminatory bowel preparation practices and potential differences in the efficacy of bowel preparation in specific populations due to biological or social differences, which may affect outcomes. Our study is limited by its use of a large database that lacks socioeconomic variables and patient data beyond 30 days.

Research Progress on the Preparation of Manganese Dioxide Nanomaterials and Their Electrochemical Applications

Manganese dioxide (MnO2) nanomaterials have shown excellent performance in catalytic degradation and other fields because of their low density and great specific surface area, as well as their tunable chemical characteristics. However, the methods used to synthesize MnO2 nanomaterials greatly affect their structures and properties. Therefore, the present work systematically illustrates common synthetic routes and their advantages and disadvantages, as well as examining research progress relating to electrochemical applications. In contrast to previous reviews, this review summarizes approaches for preparing MnO2 nanoparticles and describes their respective merits, demerits, and limitations. The aim is to help readers better select appropriate preparation methods for MnO2 nanomaterials and translate research results into practical applications. Finally, we also point out that despite the significant progress that has been made in the development of MnO2 nanomaterials for electrochemical applications, the related research remains in the early stages, and the focus of future research should be placed on the development of green synthesis methods, as well as the composition and modification of MnO2 nanoparticles with other materials.

Determining Risk Factors for Detachment After Endothelial Keratoplasties: Nine-Year Review of a Single Institution.

To determine roles of patient history, donor tissue characteristics, tissue preparation methods, and surgeon technique for graft detachment requiring rebubbling after Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) procedures. Retrospective analysis of all eyes undergoing first-time DSAEK or DMEK at the study institution between 2013 and 2022. Data were collected regarding recipients' history, donors' medical history, tissue preparation methods, intraoperative details, and postoperative clinical outcomes. Multivariate statistical analysis was conducted to identify risk factors for graft detachment necessitating rebubbling. Of 1240 eyes meeting inclusion criteria, 746 (60.2%) underwent DSAEK, and 494 (39.8%) underwent DMEK. DSAEK procedures had 12.5% rebubbling rate, whereas DMEK procedures had 18.4% rebubbling rate (P = 0.005). Sub50-DSAEK (<50 μm) grafts had 16.0% rebubble rate, whereas sub100-DSAEK (51-99 μm) and >100 μm DSAEKs had rebubble rate of 9.9% and 9.5%, respectively (P = 0.006). Significant risk factors for DSAEK graft detachment included history of retinal surgery (OR = 2.59), preloaded tissue (OR = 2.70), forceps insertion (OR = 2.33), use of sub50-DSAEK lenticules versus sub100-DSAEK (OR = 2.44) and >100 μm DSAEK (OR = 2.38) lenticules, and donor history of noninsulin-dependent diabetes mellitus (OR = 4.18). DMEK risk factors included recipient history of cancer (OR = 2.51) and use of higher SF6 gas concentration (OR = 1.09). Although rebubbled DMEK eyes had comparable refractive outcomes to nonrebubbled eyes (P >0.05), rebubbled DSAEK eyes had worse refractive outcomes at all time points (P < 0.05). Graft detachments in DSAEK and DMEK are influenced by various factors, including donor tissue characteristics, tissue preparation, and surgical technique. Identifying and understanding these factors can potentially improve postoperative outcomes.

A novel composite electrode with multiple pore structures for efficient treatment of heavy metal ions in capacitive deionization

Multiple porous carbon materials have great promise and potential in the capacitive deionization (CDI) field. Specific surface area (SSA), pore size distribution, and preparation method of CDI electrode materials are essential for the treatment of heavy metal ions. In this work, PPy composited porous carbon electrodes (hypercrosslinked polymers/polypyrrole, HCPs/PPy) were obtained by one-step crosslinked carbonization preparation and electro-deposition. The diverse pore structure gives the composite electrode a large SSA and excellent adsorption performance. HCPs/PPy-4 gives a high SSA of 251.26 m2/g. In the CDI process, the adsorption capacity of HCPs/PPy-4 for Fe3+, Cu2+, Pb2+, and Ag+ is 20.69 mg/g, 37.81 mg/g, 26.86 mg/g, and 40.95 mg/g. The negative electrode recoveries for the adsorption of the four ions were reached 81.2%, 89.2%, 85.5%, and 100%, respectively. It indicates that HCPs/PPy is a novel and potentially porous carbon electrode for high-performance CDI.

The nature of synergy effects between VOx and TiO2 in low temperature NH3-SCR reaction

In this study, we investigated the low-temperature activity of selective catalytic reduction of NO by NH3 (NH3-SCR) with the effect of different vanadium oxide (VOx) loading in the VOx/TiO2 catalyst. By calculating the specific rate of activity, it was found that the fastest specific rate of activity was achieved when the loading of V2O5 reached 10 wt%, and the nitrogen oxides (NOx) conversion of the above optimal catalyst reached over 80 % in the temperature range of 180–465 °C. The effects of preparation method, calcination temperature, and support on the aggregation state of the vanadium species and the SCR activity of the catalyst were also investigated on the basis of the ideal ratio. Combining the activity and characterization results, it is found that the impregnation method and calcination at 410 °C are more favorable for the moderate dispersion of the vanadium species on the TiO2 surface, producing more highly reactive polymorphic VOx, which is more readily dispersed on the surface of the TiO2 support and interacts more strongly with the TiO2. The interaction between the two can promote the transfer of electrons, resulting in the production of more active O species and low-valent vanadium. The aforementioned species can enhance the catalyst's low- temperature denitrification activity.

Simultaneous quantification of two commonly used anticoagulant drugs and three hypolipidemic drugs in human plasma using gradient high-performance liquid chromatography

The combination of an anticoagulant and a hypolipidemic agent is commonly used in patients at risk for stroke because it controls thrombosis and lowers cholesterol levels. However, the use of anticoagulants carries a high risk of life-threatening bleeding. To address the need for personalized clinical monitoring and risk management, we developed a rapid and sensitive HPLC method with a streamlined sample preparation process. This method enables the simultaneous determination of concentrations for two commonly used anticoagulant drugs (apixaban and rivaroxaban) and three hypolipidemic drugs (rosuvastatin, atorvastatin calcium, and simvastatin). The chromatographic conditions and sample preparation methods were optimized. The drugs were well separated by the gradient elution of phosphoric acid (0.01%, v/v) and acetonitrile at a flow rate of 1.0 mL/min within 40 min on an Athena C18-WP column (4.6 × 150 mm, 5-μm particle size). The proposed method was linear (r 2 ≥ 0.994) within the concentration ranges of 0.22–20 μg·mL−1 for the five analytes, including the expected range of therapeutic concentrations. This method enables simultaneous monitoring of the levels of the mentioned drugs in clinical practice. Furthermore, the chromatographic conditions were simple and feasible, making them highly suitable for emergency clinical medication monitoring in basic medical institutions.

Designing highly active hydrotalcite-derived NiAl catalysts for methane cracking to H2

Designing nickel-based methane cracking catalysts with excellent catalytic activity and surveying their transition during the catalytic process with varied reaction condition have been challenge. In this paper, NiAl catalysts were prepared by reduced hydrotalcite precursor for efficient catalytic methane cracking to produce hydrogen. The catalysts were characterized by XRD, N2 physisorption, XPS, SEM, TEM, Raman and TGA. The effects of preparation method, Ni/Al ratio and reaction temperature on methane cracking performance were revealed and the transformation for the Ni particles during the reaction process was analyzed. The results indicated that the catalyst performance of hydrotalcite-derived NiAl catalysts is superior to Ni/Al2O3 catalysts prepared by the conventional impregnation method, which maybe due to the better Ni dispersion and uniform average particle size distribution with around 12.7 nm compared with the agglomeration of the Ni/Al2O3 particles for up to 53.2 nm. The catalyst with a Ni/Al molar ratio of 3 exhibited the optimal catalytic activity with a stability for 75 min at nearly 90 % hydrogen yield at 700 °C. The reaction temperature also suggested a positive correlation between the hydrogen yield and the reaction temperature from 600 °C to 800 °C. Moreover, based on the investigation of the catalysts during the reaction transition state, Ni particles sintered rapidly from 10.2 nm to 31.2 nm at the beginning reaction time with the high hydrogen yield and then tended to be stable, which may be correlated well with the degree of graphitization of the deposited carbon. This paper provides a valuable design for efficient methane cracking catalysts.

Types of stress and methods of stress reduction in cattle

Recently, stress has become the most urgent problem of modern animal husbandry. With the industrialization of agriculture, this problem is becoming more and more acute, as a result, livestock enterprises and farms suffer significant economic losses. Throughout its life, the animal is exposed to numerous stressors that have a completely different nature of occurrence, but invariably lead to the same changes in the body. The animal noticeably loses weight, weakens, its resistance to diseases decreases. A review of scientific sources on some types of stress loading on cattle: heat stress, transportation stress, pre-slaughter stress is given. According to many studies, the stress state of an animal depends on feeding and maintenance by 70-80% and only 20-30% on genetics. The body of farm animals is constantly affected by various environmental factors. These include production technology, method of maintenance, density of accommodation, size of groups, microclimate of premises, type and level of feeding, biological full-value of diets, methods of preparation and distribution of feed, quality of drinking water, veterinary and preventive and zootechnical measures (vaccination, sanitary treatment of animals, weighing, castration, etc.). When the above factors change, certain reactions occur in the animal body. The nature of stress can be different: mechanical, physical, chemical, biological, mental. Knowledge of the causes of stress, the patterns of its course, its consequences, outlined in the mentioned scientific sources, will allow rational use of the proposed ways to reduce the adverse effects of various stress factors on animals to preserve their health and high productivity.

Highly stable planted MXene auxiliary layer for high-performance zinc anode deposition regulation

Aqueous zinc-ion batteries have good application prospects in large-scale energy storage, but severe dendrite behavior hinders their development. This article reports a method of planting MXene on the surface of zinc foil, that is, while mechanically polishing with a high-speed rotating wire brush, MXene solution is added dropwise, and MXene is anchored on the surface of the zinc foil with the help of a certain pressure. The MXene layer under this preparation method is stronger than the traditional self-assembled MXene layer. The MXene layer therefore acts as a physical barrier, protecting the underlying active zinc from damage. At the same time, the good hydrophilicity of the planted MXene layer reduces the concentration gradient of the interfacial electrolyte and redistributes the zinc ion flux. The unique electric field effect of MXene reduces the desolvation energy barrier, improves the transfer kinetics of Zn ions, and promotes the deposition of zinc ions in the (002) crystal plane. Experimental results show that the symmetrical battery prepared by this method can cycle stably for more than 1000 h at 0.8 mA cm−2, while its Zn\\\\Cu asymmetric battery exhibits cycle stability of more than 700 times at 0.5 mA cm−2. While maintaining a high Coulombic efficiency of over 99 %. Full cells assembled from zinc foil anodes and VO2 cathodes protected by a planted MXene layer also demonstrate higher capacity advantages. Therefore, this more stable MXene layer provides a direction for the practical application of zinc metal anodes.