Diatomaceous Research Articles

Enhancing Diatomaceous Earth Characteristics for Adsorption of Heavy Metals from Acid Mine Drainage: The Impact of Dual Activation Process

This study investigates the effects of dual activation methods, including physical and chemical processes, on the characteristics of diatomaceous earth (DE) for the purpose of controlling heavy metal concentration in acid mine drainage. The DE is subjected to physical activation through calcination at 750 oC for 60 minutes, followed by chemical activation using 1N HCl at 80 oC for 24 hours under magnetic stirring. The resulting adsorbent is then characterized using XRD, SEM-EDX, and BET instruments. The analysis reveals that the dual activation methods increase the silica content and eliminate impurities in the DE, leading to a more amorphous structure with decreased crystallinity. The physical activation increases the surface area, while the dual activation process reduces the surface area and increases pore size. These findings provide valuable insights into the adsorption capacity of DE for reducing heavy metals in acid mine drainage.

Analysis of the Influence and Mechanism of Diatomaceous Earth Internal Curing on the Autogenous Shrinkage and Early Crack Resistance of Cement-Based Materials with Low Water–Binder Ratio

Diatomaceous earth (DE), a kind of natural and environmentally friendly concrete admixture with good pozzolanic and water absorption properties, is a potential high-quality internal curing material. DE internal curing agent was prepared by calcining excavated diatomaceous earth and applied in cement-based materials with a low water–binder ratio of 0.35 to study its effects on the autogenous shrinkage and early crack resistance of the materials. The results showed that DE was a kind of microfine powder with a unique and orderly microporous structure, and its main component was SiO2, which had good water-holding and -releasing properties. Pre-absorbed DE could effectively improve the internal relative humidity of cement-based materials with a low water–binder ratio. Under the standard of not reducing the 28 d compressive strength of mortar, compared to the benchmark group without DE, when 1% of cement is replaced by DE of equal mass, DE could effectively reduce the 7 d autogenous shrinkage of mortar by about 36.7% and delay the initial cracking time of mortar under the restraint condition of the ring by 10.7%. Therefore, it is an internal curing material with excellent performance.

Active release of diatomite-MgAl-layered double hydroxide nanostructures on corrosive inhibitors to effectively suppresses corrosion of LA51 alloy

Two-dimensional (2D) materials have been potentially applicable for the corrosive resistance of alloys in corrosive media. Nevertheless, a challenge remains in adapting the 2D nanomaterial layered double hydroxide (LDH) with diatomaceous earth (DE) as two inorganic nanocontainers homogeneously combined and loaded with controlled release corrosion inhibitors. In this research, the high-efficiency anti-corrosion nanofiller for LA51 alloy protection was obtained by integrating MgAl-LDH with Sodium phosphate (SP) utilizing the unique hollow porous structure of DE as a template. As a result, the incorporation of DE-LDH-P provides a 3-order of magnitude enhancement in coating immersion in 3.5 wt% NaCl solution for 40 days compared to pure epoxy. Furthermore, two nanocontainers of DE and LDH with corrosion inhibitor loading up to 15 wt% still demonstrated excellent corrosive protection after 120 h of salt spray. The key to its protective performance is promoting controlled corrosion inhibitor release through a scientific approach that fully utilizes the slow-release properties of DE and LDH. This strategy offers a straightforward and effective approach for formulating anti-corrosion additives tailored for use in corrosive settings, with potential applications across various industrial sectors. Specifically, we advocate for the utilization of maritime instrumentation, underwater armaments, and seawater-based power sources within the domains of ship construction and marine engineering.

Research on ballistic performance of green shear thickening functionalized fabric based on solid waste modification

Based on the solid waste-based modification, green shear-thickening functionalized ballistic composites were prepared. Silica aerosols were obtained from solid waste diatomaceous earth through sol–gel preparation, gel aging, and supercritical drying. The modified silica aerosols acted as the dispersed phase, regulating the green shear-thickening liquid. A comparison was made between the performance of the modified shear-thickening liquid (SG@STF) and traditional shear-thickening liquids. By modifying solid waste based shear thickener (SG@STF) Combined with aramid fabric (AF) to test Ballistic performance. Characterization tests revealed that the rheological properties of SG@STF were significantly enhanced by increasing the volume fraction of the dispersed phase in STF from 50 % to 60 %. This enhancement was attributed to the addition of reactive functional groups on the surface of the silica sol. Yarn pull-out tests demonstrated that SG@STF/AF improved the tensile strength by 120 % compared to AF fabric, thanks to its superior friction properties. Ballistic tests showed that SG@STF increased the ballistic ultimate velocity of AF fabric by 105 %, elevating AF’s ballistic limiting velocity from 51 m/s to 105 m/s. Consequently, SG@STF/AF exhibited superior ballistic properties compared to AF fabric. The doping of SG enhanced the friction between yarns and increased the load-bearing area of the fabrics, thereby improving the ballistic properties of SG@STF/AF and achieving the desired modulation of their ballistic properties.

In Situ Polymerization Bi-Functional Gel Polymer Electrolyte for High Performance Quasi-Solid-State Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are expected to be the next-generation energy storage system due to the ultrahigh theoretical energy density and low cost. However, the notorious shuttle effect of higher-order polysulfides and the uncontrollable lithium dendrite growth are the two biggest challenges for commercially viable Li-S batteries. Herein, these two main challenges are solved by in situ polymerization of bi-functional gel polymer electrolyte (GPE). The initiator (SiCl4) not only drives the polymerization of 1,3-dioxolane (DOL) but also induces the construction of a hybrid solid electrolyte interphase (SEI) with inorganic-rich compositions on the Li anode. In addition, diatomaceous earth (DE) is added and anchored in the GPE to obtain PDOL-SiCl4-DE electrolyte through in situ polymerization. Combined with density functional theory (DFT) calculations, the hybrid SEI provides abundant adsorption sites for the deposition of Li+, inhibiting the growth of lithium dendrites. Meanwhile, the shuttle effect is greatly alleviated due to the strong adsorption capacity of DE toward lithium polysulfides. Therefore, the Li/Li symmetric cell and Li-S full cell assembled with PDOL-SiCl4-DE exhibit excellent cycling stability. This study offers a valuable reference for the development of high performance and safe Li-S batteries.

Impact of manufacturing variables on product performance of contraceptive levonorgestrel intrauterine systems

The development of Levonorgestrel Intrauterine Systems (LNG-IUSs) stands as a formidable challenge due to their intricate design and reliance on specialized manufacturing methods. Pharmaceutical manufacturers face a labyrinth of process variables that demand precise identification and comprehension to establish a robust product design to ensure consistent performance. The current manuscript navigates through this complexity, describing a small-scale processing method for LNG-IUSs via addition and condensation curing processes, as well as investigating the influence of key manufacturing variables on LNG-IUS product performance. Different mixing speeds and time exhibited distinct impact on drug content uniformity within the IUS drug-polymer reservoirs. Surprisingly, no variation in drug release rates were observed. Curing temperature and time were the critical processing parameters of IUSs which were dependent on the polymer type (polydimethylsiloxane, PDMS) and drug loading. At lower curing temperatures, crosslinking in PDMS remained relatively unaffected, irrespective of drug loading. By contrast, elevating curing temperatures resulted in a drastic reduction in PDMS crosslinking densities at higher drug loading. This was attributed to increased drug volume fraction within the matrix, impeding optimal prepolymer chain mobility and rearrangement which is crucial for complete crosslinking. Interestingly, rapid curing led to increased PDMS crystallinity, thereby retarding drug release rates while concurrently compromising mechanical properties. PDMS curing chemistry, such as condensation cure (no filler) and addition cure (cured at room temperature), did not affect drug release rates of the LNG-IUSs. In the condensation cure-based LNG-IUS, the formulations prepared without filler had higher drug release rates than those containing silica or diatomaceous earth fillers. Overall, the present study unravels the intricate interplay between PDMS characteristics, processing variables, and product performance, offering fundamental insights into product design and manufacturing of brand and generic LNG-IUS products.

Sustainable energy synergy for historic building: Conservation retrofit solution of hygrothermal control

Historic buildings require groundbreaking retrofit technology to prevent damage to the exterior appearance of the exterior. This paper presents a retrofit technology to increase the energy efficiency of old historic buildings that were heavily exposed to hygrothermal conditions. The study employed an innovative interior finishing material composed of diatomaceous earth and microencapsulated phase change materials to achieve a trade-off between performance improvement and heritage conservation. Based on previous studies, an optimal formulation was identified through evaluation. The developed retrofit technology displays crack resistance, high latent heat capacity, and remarkable moisture stability. Our analysis revealed that the application of this retrofit solution would effectively reduce moisture levels and mitigate condensation risks without compromising the building’s historical integrity. The retrofit technology yielded a reduction in cooling and heating energy consumption by over 10% while concurrently addressing moisture stability through a decrease in the thermal transmittance of the exterior walls. By utilizing passive technologies and the unique properties of diatomaceous earth, our pioneering research on the sustainable preservation of historic buildings has laid the foundation for widespread retrofit adoption in heritage conservation.

Scale-up of a sorption process working with molecularly imprinted adsorbents for enrichment of winemaking residues and improvement of bioactivity

This work presents the scale-up of a sorption process for the fractionation and enrichment of bioactive compounds in winemaking residues using molecularly imprinted adsorbents. The process works with hydroalcoholic solvents and the improvement of the bioactivity of the produced fractions, comparatively to the raw extracts, is demonstrated. The proposed approach was experimentally validated through the designing and running of a pilot size sorption prototype for the automation of the fractionation method. The synthesis of the molecularly imprinted adsorbents was made at the gram-scale and spent diatomaceous earth, used for wine filtration, was considered as a possible source of bioactive compounds in winemaking residues.The different fractions produced were evaluated for their antioxidant activity through three different assays, namely radical scavenging activity, reducing power and inhibition of lipid peroxidation. The results obtained show the improvement of the bioactivity of most of the fractions comparatively to the original diatomaceous earth extract. The most enriched fraction is estimated to have a total phenolic content c.a. 3.8 times higher than the original extract. The radical scavenging activity, the reducing power and the inhibition of lipid peroxidation for this fraction were measured to be 6.4, 4.2 and 4.5 times higher, respectively, than the initial diatomaceous earth extract.This work provides new insights on biomass valorisation and circular bioeconomy by combining in the same research materials development, process design and application to real extracts with proved improvement of the bioactivity of purified products.

Efficacy of steam and diatomaceous earth dust against the tropical bed bug Cimex hemipterus (F.) under laboratory and field conditions.

Over the past two decades, bed bugs (Cimex spp.) have resurged as common urban pests around the world. The search for efficient and safe control measures has become a key interest among researchers, manufacturers, and pest control professionals. In this study, we evaluated and compared the efficacy of steam, diatomaceous earth (DE) dust, and a combination of both against tropical bed bugs (Cimex hemipterus (F.)) under laboratory and field conditions. In the laboratory study, the mortality of bed bugs after 2 days of exposure to DE dust was 100%. When bed bugs stayed on the surface of an object or in cracks, a brief steam treatment (1 s) caused 100% mortality. However, when bed bugs were hidden under a fabric cover, steam application for 10 s only caused 89 ± 6% mortality. Bed bugs that survived steam treatment exhibited reduced feeding activity. In a 14-week long study, there was no significant difference in the reduction rate of bed bugs between steam treatment and DE dust treatment. A 37-week long control study showed that steam and steam plus DE dust treatments eliminated 97-100% of the infestations. Applying steam and DE dust are effective strategies for eliminating natural tropical bed bug infestations. Continuous follow-up monitoring and treatment until no bed bugs are found are crucial in completely eliminating the infestation of tropical bed bugs. © 2024 Society of Chemical Industry.

A new method of rapid-intelligent assessment for the dynamic service performance in high-speed railway subgrade

ABSTRACT There is a lack of a rapid, advanced, and comprehensive method for assessing the dynamic service performance in high-speed railway subgrade, which leads to an inability to pre-assess the health state of the subgrades in advance. In this paper, an innovative method of rapid-intelligent assessment for the dynamic service performance (RADSP) in high-speed railway subgrade was proposed. Firstly, a large-scale exciter was used to simulate the train loading effect, which could rapidly obtain the assessment metrics for subgrade dynamic service performance, including subgrade dynamic response (SDR) and subgrade cumulative deformation (SCD), where the SDR includes dynamic stress and acceleration. Then, to explore the future development trend of SCD during operation, an intelligent and advanced prediction of SCD was conducted using the optimal machine learning (ML) prediction model. Finally, by combining the results of the SDR and SCD assessments to achieve the RADSP in high-speed railway subgrade. Moreover, the method was applied to assess the dynamic service performance of diatomaceous earth subgrade structures with four different waterproofing structure layers (WSL): the middle of subgrade surface layer (WSL-1), the bottom of subgrade surface layer (WSL-2), the middle of subgrade bottom layer (WSL-3), and the bottom of subgrade bottom layer (WSL-4). The results indicate that: 1) During the excitation experiments, the maximum values for SDR (dynamic stress, acceleration) and SCD exceed the respective limits of 50 kPa, 10 m/s2, and 15 mm under WSL-1 and WSL-4. 2) The ensemble model, AdaBoost-GPR, is selected as the optimal ML model to predict the SCD values. Notably, the prediction SCD value exceeds the 15 mm limit under WSL-3, indicating that the SCD during future operation does not meet the requirements for pre-assessment. 3) Under WSL-2, both SDR and SCD assessments satisfy the limit value requirements, indicating that the dynamic service performance is better. Based on the proposed method, it is found that when designing waterproof-drainage subgrade structures in diatomaceous earth areas, it is recommended to position the WSL at the bottom of subgrade surface layer. The research findings serve as a crucial reference and valuable lesson for the health monitoring of high-speed railway subgrades.

Optimizing high-density polyethylene (HDPE) performance: utilizing diatomaceous earth filler and an innovative reversible crosslinking reaction agent (RXR)

Optimizing high-density polyethylene (HDPE) performance: utilizing diatomaceous earth filler and an innovative reversible crosslinking reaction agent (RXR)

Surface application of diatomaceous earth, SilicoSec® are effective on Sitophilus granarius and Rhyzopertha dominica, but less against Tribolium confusum

Diatomaceous earth (DE) has a promising potential in the control of stored-product pests. Most of the studies on the insecticidal potential of DE products are based on their persistent effects or the mortality they lead to via mixing with the grain. However, the knowledge on the performance of DEs on a particular surface is limited. In the current study, the insecticidal efficacy of a DE product, SilicoSec® was investigated against adults of Sitophilus granarius, Rhyzopertha dominica, and Tribolium confusum by surface application at 2.5, 5.0, 10.0, and 20.0 g/m2 on a concrete surface that is commonly used in storage structures. In S. granarius experiment, the highest immediate mortalities (89.2-99.2%) were obtained by the 5-day exposure even at the lowest rate (2.5 g/m2), while the highest delayed mortalities were 92.5% and 85% at rates of 2.5 and 20 g/m2, respectively by the 3-day exposure. In R. dominica experiment, the highest immediate mortalities (92.5-98.3%) were obtained by the 3-day exposure even at the lowest rate, while the highest delayed mortalities were 90.1 and 98.3% at rates of 10 and 20 g/m2, respectively, by the 1-day exposure. In T. confusum experiment, the highest immediate mortalities (83.3-91.0%) were obtained by the 7-day exposure at 10 or 20 g/m2, while the highest delayed mortalities were obtained by the 7-day exposure, and were 90.0 and 95.9% at rates of 10 and 20 g/m2, respectively. In conclusion, the insecticidal effect of surface application of SilicoSec® was high, moderate, and low against S. granarius, R. dominica, and T. confusum, respectively at concrete surfaces. A rate of 2.5 g/m2 of SilicoSec® provided an efficient control for S. granarius and R. dominica by 3- and 5-day exposures, respectively, while comparable mortality was obtained at a higher rate (10 or 20 g/m2) and exposure time (7-day) for T. confusum.

Design and preparation of durable intelligent haze removal and self-cleaning protective coatings

Conventional superhydrophobic coatings lose effectiveness over due to degradation from ultraviolet (UV) radiation, contaminants, and abrasion. Moreover, external cleaning methods are often needed to maintain self-cleaning performance in the presence of oils and organic contaminants. This study develops an organic-inorganic hybrid coating comprising polymethylhydrosiloxane (PMHS)-modified diatomaceous earth (DE) loaded with titanium dioxide (TiO2) on a room-temperature vulcanized rubber (RTV) substrate. The PMHS-DE-TiO2 coating achieves a synergistic effect, combining superhydrophobicity and photocatalysis. Notably, it exhibits a water contact angle (WCA) of 162.2°, a sliding angle (SA) of 5°, and achieves complete degradation of methylene blue (MB). It maintains hydrophobicity, integrity and functionality under UV radiation, prolonged abrasion, and acidic/alkaline salt solution immersion. The coating also degrades NO at 73.09 % maximum rate. Integration with a negative air ion generator further harnesses the timely superhydrophobic self-cleaning and photocatalysis to significantly enhance dust and fog removal efficiency beyond conventional commercial ion generators. Aligning with green low-carbon principles, this multifunctional coating provides an innovative solution for environmentally-friendly construction materials suitable for long-lasting exterior and interior usage. It resists pollution while mitigating airborne hazards, meeting growing demands for healthy buildings.

Functionalization of aerosil, titanium dioxide and diatomaceous earth powders by wetting with a low surface energy agent, and study of their properties

The conditions for functionalization of micro- and nanopowders of aerosil, titanium dioxide and diatomaceous earth by wetting them with a liquid hydrophobic agent (tetraethoxysilane) and giving them fobno/philic properties are investigated. Using infrared spectroscopy, derivatography, scanning electron microscopy, and ξ-metry, the mechanism of tetraethoxysilane interaction with the surface of these powders and their morphology were studied. All powders thus modified are characterized by a non-homogeneous distribution of particles with different aggregation levels: predominantly micrometer-sized particle population (diatomaceous earth), micrometer-sized formation combined with nanoclusters (aerosil, titanium dioxide). Diluted suspensions of functionalized powders in fluorinated varnish were used for hydrophobization of glass, aluminum, and steel surfaces. The highest value of the water wetting edge angle (156°) was observed for aluminum coatings obtained using a composition containing functionalized aerosil.

Dried crickets (Gryllus sigillatus) or black soldier fly (Hermetia illucens) larvae meal for broiler chickens: nutrient composition and digestibility

Abstract This study explores the potential of cricket meal and black soldier fly larvae meal (BSFLM) as alternative protein sources in broiler chicken diets. With the use of the substitution method, using diatomaceous earth as an external marker, we investigated the nutrient availability and apparent metabilizeable energy content of oven-dried full-fat cricket meal (OD-CM), freeze-dried full-fat cricket meal (FD-CM), and defatted BSFLM in a feeding trial involving 320 Ross 308 broilers housed in 32 pens (8 replicates / treatment; 8 birds / pen). Feed intake, daily weight gain, and feed conversion ratio were measured between days 15 and 21. Excreta collected on days 19, 20, and 21 were analyzed for nutrient content. Both cricket treatments were high in crude protein. Additionally, FD-CM demonstrated the highest fat content, surpassing OD-CM. OD-CM displayed a significantly higher apparent digestibility coefficient for crude protein compared to BSFLM (). FD-CM had the highest apparent digestibility coefficient for gross energy (). The nitrogen-corrected apparent metabolizable energy of OD-CM and FD-CM were significantly higher than that of BSFLM (). Furthermore, OD-CM exhibited a significantly higher available crude protein content compared to BSFLM and FD-CM (). This research sheds light on the potential of OD-CM and FD-CM as valuable alternative protein sources for broiler chickens, providing critical insights for the poultry industry’s sustainable future. This research is important as the apparent digestibility coefficients, as well as available nutrients calculated for the three ingredients may be used to accurately formulate poultry diets on an available nutrient basis.

The Influence of Environmental Factors on the Degradation of PLA/Diatomaceous Earth Composites.

In the present study, tests were carried out on composite samples on a polylactide matrix containing 25% by weight of mineral filler in the form of diatomaceous earth, base, and silanized with GPTMOS (3-glycidoxypropyltrimethoxysilane), OTES (n-octyltriethoxysilane), and MTMOS (methyltrimethoxysilane) silanes. The addition of two types of waxes, synthetic polyamide wax and natural beeswax, were used as a factor to increase the rheological properties of the composites. The obtained samples were characterized in terms of the effect of filler silanization on the degradation rate of the composites. The tests were conducted under different conditioning conditions, i.e., after exposure to strong UV radiation for 250 and 500 h, and under natural sunlight for 21 days. The conditioning carried out under natural conditions showed that the modified samples exhibit up to twice the degradation rate of pure polylactide. The addition of synthetic wax to the composites increases the tendency to agglomerate diatomaceous earth, while natural wax has a positive effect on filler dispersion. For composites modified with GPTMOS and OTES silanes, it was noted that the addition of natural wax inhibited the degree of surface degradation, compared to the addition of synthetic wax, while the addition of MTMOS silane caused the opposite effect and samples with natural wax degraded more strongly. It was shown that, despite the high degree of surface degradation, the process does not occur significantly deep into the composite and stops at a certain depth.

Lime for Lyme: Treatment of Leaf Litter with Dolomitic Lime Powder Impairs Activity of Immature Ixodes scapularis Ticks.

Background: Tick-borne diseases are an emerging threat to public health throughout the temperate world, leading to a growing field of research aimed at developing and testing intervention strategies for reducing human-tick encounters or prevalence of infection in ticks. Various wide-spectrum chemical acaricides have proven effective for controlling tick populations, but many of these have potential deleterious side-effects on health and the environment. In addition to chemical acaricides, certain compounds such as diatomaceous earth have been shown to have physical acaricidal properties. We hypothesized that dolomitic lime (CaMg(CO3)2, a corrosive, desiccant mineral that is already used extensively in agricultural and forestry contexts to balance the pH of soils, may affect ticks' locomotory activity, habitat position, or survival and that this should manifest as a reduction in the number of questing ticks collected by dragging. Objective: This study aimed to formally assess this hypothesis in a controlled laboratory setting. Methods: We carried out a microcosm experiment, with one control and three treated microcosm trays, each replicating the natural substrate characterizing I. scapularis habitat in northeastern North America. Each tray was infested with 200 living larvae and 50 nymphs, and then treated with 0 (control), 50, 100, or 500 g/m2 of lime powder. Ticks were collected by microdragging 24 and 72 h postliming. Results: Efficacy of liming at reducing the number of collected questing ticks ranged from 87% to 100% for larvae and 0% to 69% for nymphs 24 h postliming and from 91% to 93% for larvae and -47% to 65% for nymphs 72 postliming. Conclusion: This study provides the first experimental evidence of the potential efficacy of liming for impairing activity of questing immature ticks. Given that lime is a low-cost material, that methods for widespread application in deciduous woodlands already exist, and that it has been documented as having a limited negative impact on the environment, further assessment of lime application as a public health risk reduction intervention for tick-borne diseases is warranted.

Evaluating Diatomaceous Earth for Long-Term Use in Hydrogen Storage.

Efficient hydrogen storage is essential for its use as a sustainable energy carrier. Diatomaceous earth, a high-surface-area siliceous geomaterial, shows potential as a physisorption material for hydrogen storage. This study analyzes diatomaceous earth's long-term characteristics when subjected to high-pressure hydrogen injection. The diatomaceous earth was subjected to a hydrogen pressure of 1200 psi for a period of 80 days at room temperature. Neither notable morphological or mineralogical changes were observed. Nevertheless, there was a slight reduction in fine particles and a slight increase in larger particles. The Brunauer-Emmett-Teller (BET) surface area decreased slightly with a significant decrease in pore width. However, the hydrogen adsorption at 77 K temperature was increased significantly (45.5%) after the hydrogen storage test. Moreover, there was a delayed release of molecular water as the temperature increased. These changes suggest that a condensation reaction has occurred involving some of the opal-A silanol groups (Si-O-H), producing molecular water. Bonding through siloxane bridges (Si-O-Si) results in a significant decrease in pore width and increased hydrophobicity (i.e., the interaction between diatomaceous surface and H2 was increased), thereby enhancing hydrogen adsorption capacity. These findings indicate that diatomaceous earth holds promise as a material for hydrogen storage, with the potential for its hydrogen adsorption capacity to improve over time.

Diatomite-incorporated hierarchical scaffolds for osteochondral regeneration

Osteochondral regeneration involves the highly challenging and complex reconstruction of cartilage and subchondral bone. Silicon (Si) ions play a crucial role in bone development. Current research on Si ions mainly focuses on bone repair, by using silicate bioceramics with complex ion compositions. However, it is unclear whether the Si ions have important effect on cartilage regeneration. Developing a scaffold that solely releases Si ions to simultaneously promote subchondral bone repair and stimulate cartilage regeneration is critically important. Diatomite (DE) is a natural diatomaceous sediment that can stably release Si ions, known for its abundant availability, low cost, and environmental friendliness. Herein, a hierarchical osteochondral repair scaffold is uniquely designed by incorporating gradient DE into GelMA hydrogel. The adding DE microparticles provides a specific Si source for controlled Si ions release, which not only promotes osteogenic differentiation of rBMSCs (rabbit bone marrow mesenchymal stem cells) but also enhances proliferation and maturation of chondrocytes. Moreover, DE-incorporated hierarchical scaffolds significantly promoted the regeneration of cartilage and subchondral bone. The study suggests the significant role of Si ions in promoting cartilage regeneration and solidifies their foundational role in enhancing bone repair. Furthermore, it offers an economic and eco-friendly strategy for developing high value-added osteochondral regenerative bioscaffolds from low-value ocean natural materials.

Coxiella burnetii in domestic doe goats in the United States, 2019-2020.

Coxiella burnetii is a bacterial pathogen capable of causing serious disease in humans and abortions in goats. Infected goats can shed C. burnetii through urine, feces, and parturient byproducts, which can lead to infections in humans when the bacteria are inhaled. Goats are important C. burnetii reservoirs as evidenced by goat-related outbreaks across the world. To better understand the current landscape of C. burnetii infection in the domestic goat population, 4,121 vaginal swabs from 388 operations across the United States were analyzed for the presence of C. burnetii by IS1111 PCR as part of the United States Department of Agriculture, Animal Plant Health Inspection Service, Veterinary Services' National Animal Health Monitoring System Goats 2019 Study. In total, 1.5% (61/4121) of swabs representing 10.3% (40/388) (weighted estimate of 7.8, 95% CI 4.4-13.5) of operations were positive for C. burnetii DNA. The quantity of C. burnetii on positive swabs was low with an average Ct of 37.9. Factors associated with greater odds of testing positive included suspected Q fever in the herd in the previous 3 years, the presence of wild deer or elk on the operation, and the utilization of hormones for estrus synchronization. Factors associated with reduced odds of testing positive include the presence of kittens and treatment of herds with high tannin concentrate plants, diatomaceous earth, and tetrahydropyrimidines. In vitro analysis demonstrated an inhibitory effect of the tetrahydropyrimidine, pyrantel pamoate, on the growth of C. burnetii in axenic media as low as 1 μg per mL. The final multivariable logistic regression modeling identified the presence of wild predators on the operation or adjacent property (OR = 9.0, 95% CI 1.3-61.6, p value = 0.0248) as a risk factor for C. burnetii infection.