Search Results (80)

Spodoptera frugiperda (fall armyworm) is a polyphagous pest with widespread resistance to synthetic insecticides, while essential oils (EOs) and biological control agents, such as the parasitoid Trichogramma pretiosum, represent promising strategies in integrated pest management (IPM) programs. This study evaluated the toxicity of Eugenia uniflora EO, popularly known as pitanga EO, and nanoemulsion (NEO) to S. frugiperda and the selectivity of the NEO to T. pretiosum. The EO of E. uniflora was characterized by GC-MS/DIC and then diluted in water and Tween 80^® for bioassays to estimate the LC₅₀ against S. frugiperda in Potter’s tower. The NEOs were produced by high-shear dispersion using an Ultra-Turrax and characterized for thermal stability, particle size, polydispersity index (PDI), zeta potential (ζ), temporal stability, and morphology. The NEO was diluted to the LC₅₀ (36.05 mg/mL) in 1% Tween 80^® solution and tested for toxicity to S. frugiperda and to the parasitoid. The majority compounds in the EO from E. uniflora were curzerene (34.07%), selina-1,3,7(11)-trien-8-one (10.51%), germacrene B (9.51%) and germacrene D (5.03%). The NEO stored at 25 °C remains stable for up to 30 days after preparation. In addition, the NEO showed a particle size of 283.2 nm, a PDI of 0.289, and a zeta potential (ζ) of −23.2 mV. The E. uniflora EO and NEO at a concentration of 36.05 mg/mL were toxic to S. frugiperda (36% probability of survival). Furthermore, NEO was selective for T. pretiosum in its immature stages. The NEO proved to be stable, effective, and selective, indicating potential for IPM. However, validation under semi-field and field conditions is still necessary. Full article

Ultra-soft injectable hydrogels are paramount in biomedical applications such as tissue fillers, drug depots, and tissue regeneration scaffolds. Synthetic approaches relying on linear polymers are confronted by the necessity for significant dilution of polymer solutions to reduce chain entanglements. Bottlebrush polymers offer an alternative approach due to suppressed chain overlap and entanglements, which facilitates lower solution viscosities and increased gel softness. Leveraging the bottlebrush architecture in linear-bottlebrush-linear (LBL) block copolymer systems, where L is a thermosensitive linear poly(N-isopropylacrylamide) block, and B is a hydrophilic polyethylene glycol brush block, injectable hydrogels were designed to mimic tissues as soft as the extracellular matrix at high polymer concentrations. Compared to an analogous system with shorter brush side chains, increasing the side chain length enables a decrease in modulus by up to two orders of magnitude within 1–100 Pa at 20 wt% polymer concentrations, near to the physiological water content of ~70%. This system further exhibits thermal hysteresis, enabling stability with inherent body temperature fluctuations. The observed features are ascribed to kinetically hindered network formation by bulky macromolecules. Full article

This article investigates the synergistic effect of metakaolin waste (MW) derived from the production of expanded glass granules and nano-silica (NS) on the hydration and other properties of ultra-high-performance concrete (UHPC) reinforced with steel fibres. The study focusses on cases where 5%, 10%, or 20% of cement is replaced with MW and 1% of NS is added. Various properties are evaluated, including the exothermic temperature, mineral composition (XRD), relative main compound quantities according to their decomposition (TG and DTG), shrinkage, density, and flexural and compressive strengths after 7 days, 28 days, and 2 years. In addition, changes in the concrete microstructure are analysed after 28 days and 2 years. The results demonstrate that the combined addition of MW and NS accelerates hydration by about 3 h compared to the control sample. The TG results confirmed a lower portlandite content due to the dilution effect of cement replacement. However, when both additives were used simultaneously, the portlandite content decreased further because of the intensified pozzolanic reaction, while the amount of C–S–H increased. Using MW and NS together significantly enhanced the long-term strength of concrete: after 2 years, the compressive strength of the mix with 5% of cement replaced by MW and 1% of NS was 182 MPa, compared to 146 MPa for the control sample. Full article

Two outstanding problems of particle physics and cosmology, namely the strong-CP problem and the nature of dark matter, can be solved with the discovery of a single new particle, the axion. The modular high magnetic field and flux hybrid magnet platform of LNCMI-Grenoble, which was recently put in operation up to 42 T, offers unique opportunities for axion/axion-like particle search using Sikivie-type haloscopes. In this paper, the focus will be on the 350–600 MHz frequency range corresponding to the 1–3 μeV axion mass range requiring a large-bore RF-cavity. It will be built by DMAG and integrated within the large-bore superconducting hybrid magnet outsert, providing a central magnetic field up to 9 T in 812 mm warm bore diameter. The progress achieved by Néel Institute in the design of the complex cryostat with its double dilution refrigerators to cooldown below 50 mK the ultra-light Cu RF-cavity of 650 mm inner diameter and the first stage of the RF measurement chain are presented. Perspectives for the targeted sensitivity, assuming less than 2-year integration time, are recalled. Full article

Background/Objectives: Accurate and rapid detection of Mycobacterium tuberculosis complex (MTBC) and drug resistance is essential for effective tuberculosis (TB) management, particularly in high-burden settings. The Cobas^® MTB and Cobas MTB/RIF-INH assays are moderate-complexity nucleic acid amplification tests that detect MTBC and resistance to rifampicin (RIF) and isoniazid (INH). Methods: This study evaluated the clinical diagnostic performance of the Cobas assays on sputum, using liquid culture as the reference standard and Xpert MTB/RIF Ultra (Xpert Ultra) for comparison. Diagnostic accuracy of the Cobas MTB assay on tongue swabs (TS) was also assessed. Results: In a study population (n = 354) with 56% HIV prevalence, the overall sensitivity and specificity of Cobas MTB on sputum was 93.8% (95% CI: 84.8–98.3) and 100% (95% CI: 98.7–100) compared with culture. The assay showed almost perfect agreement with Xpert Ultra (Cohen’s kappa = 0.904). Among HIV-positive participants, sensitivity was 88.2% (95% CI: 72.5–96.7). RIF resistance profiling by Cobas MTB/RIF-INH was fully concordant with culture and Xpert Ultra. Three INH-resistant cases were missed, likely due to genotypic–phenotypic discordance. Although specimen numbers were small, TS demonstrated better diagnostic accuracy when using a diluted (66%) microbial inactivation solution. Conclusions: The Cobas MTB and MTB/RIF-INH assays demonstrated high diagnostic accuracy compared to culture and Xpert Ultra on sputum. Findings support TS as an alternative specimen type for MTBC detection using an optimized protocol. These findings underscore the potential of the Cobas assays as reliable alternatives for TB and resistance diagnostics, particularly in settings where rapid, accurate detection of MTBC and RIF or INH resistance is crucial. Full article

Microbial detection in milk is crucial for food safety and quality, as beneficial and harmful microorganisms can affect consumer health and dairy product integrity. Identifying and quantifying these microorganisms helps prevent contamination and spoilage. The study employs advanced molecular techniques to detect and quantify the genomic DNA for the target hydrolytic enzyme coding genes lipA and aprX based on the multi-align sequence conserved region, specific primer pair, and hydrolysis probes designed using the singleplex qPCR and multiplex qPCR. Cultured isolates and artificially contaminated sterilized ultra-high-temperature (UHT) milk were analyzed for their specificity, cross-reactivity, and sensitivity. The finding indicated that strains with lipA and aprX genes were amplified while the other strains were not amplified. This indicated that the designed primer pairs/probes were very specific to the target gene of interest. The specificity of each design primer pair was checked using SYBR Green qPCR using 16 different isolate strains from the milk sample. The quantification specificity of each strain target gene was deemed to be with a mean Ct value for positive pseudomonas strain > 16.98 ± 1.76 (p < 0.0001), non-pseudomonas positive strain ≥ 27.47 ± 1.25 (p < 0.0001), no Ct for the negative control and molecular grade water. The sensitivity limit of detection (LOD) analyzed based on culture broth and milk sample was >10⁵ and >10⁴ in PCR amplification while it was >10⁴ and >10³ in real-time qPCR, respectively. At the same time, the correlation regression coefficient of the standard curve based on the pure culture cell DNA as the DNA concentration serially diluted (20 ng/µL to 0.0002 ng/µL) was obtained in multiplex without interference and cross-reactivity, yielding R² ≥ 0.9908 slope (−3.2591) and intercepting with a value of 37, where the efficiency reached the level of 95–102% sensitivity reached up to 0.0002 ng/µL concentration of DNA, and sensitivity of microbial load was up to 1.2 × 10² CFU/mL. Therefore, multiplex TaqMan qPCR simultaneous amplification was considered the best method developed for the detection of the lipA and aprX genes in a single tube. This will result in developing future simultaneous (three- to four-gene) detection of spoilage psychrotrophic bacteria in raw milk. Full article

Background/Objectives: Spray drying is a technique widely employed in the food and nutraceutical industries to convert liquid extracts into stable powders, preserving their functional properties. Ginger (Zingiber officinale) is rich in bioactive compounds such as gingerols, shogaols, and zingerone, which contribute to its health benefits. This study aimed to investigate the impact of spray drying on the chemical profile of ginger, particularly focusing on the transformation of gingerols into shogaols and related compounds. Methods: Fresh ginger juice was spray-dried using various carrier agents, including Clear Gum (CO03), pea protein, and inulin. Mass spectra of the resulting powders were acquired using High-Resolution Flow Infusion Electrospray Ionisation Mass Spectrometry (HR-FIE-MS) to obtain fingerprint data. Key bioactive compounds were tentatively identified to Level 2, and their relative intensities were assessed to evaluate the effects of different carriers on the chemical composition of the ginger powders. Results: Spray drying with the commercial carrier CO03 resulted in an increase in shogaol analogues ([10]-, [8]-, and cis-[8]-shogaol), gingerenone B, and oxidation products such as 6-hydroxyshogaol, 6-dehydroshogaol, and zingerone. In contrast, natural carriers like pea protein and inulin led to lower relative intensities of these bioactives, suggesting limited capacity for promoting thermal transformations. Spray drying without a carrier produced a shogaol-dominant profile but resulted in powders with poor handling properties, such as stickiness and agglomeration. Antioxidant and total polyphenol assays showed that spray drying reduced antioxidant capacity, while total polyphenol content was more preserved; natural carriers such as inulin better maintained bioactivity compared to modified starch or pea protein. Conclusions: Among the five formulations evaluated—ginger juice with no carrier, with CO03 (two dilutions), pea protein, or inulin—CO03-based samples showed the greatest chemical transformation, while inulin and pea protein better preserved antioxidant capacity but induced fewer metabolite changes. Thus, choice of carrier in the spray-drying process influences the chemical profile and functional characteristics of resultant ginger powders. While CO03 effectively enhances the formation of bioactive shogaols and related compounds, its ultra-processed nature may not align with clean-label product trends. Natural carriers, although more label-friendly, may not create the desired chemical transformations. Therefore, optimising carrier selection is important to balance bioactivity, product stability, and consumer acceptability in the development of ginger-based functional products. Full article

A method for the determination of trace selenium in water enriched by metal–organic−framework material (MIL−125−NH₂) and reversed−phase ultra−high−performance liquid chromatography−diode array detection (UPLC−DAD) was established. The MIL−125−NH₂ material, synthesized by the microwave method, was characterized by SEM, XRD, and FT−IR. The MIL−125−NH₂ material was added to the water sample to enrich the selenium, the enriched selenium was desorbed with dilute HCl, and then the derivative reaction with 0.1 mol·L⁻¹ 4−nitro−o−phenylenediamine was performed to produce piaselenole. After extraction with cyclohexane, the retention time and the spectrogram were qualitatively detected by a liquid chromatography−diode array detector, and the peak area was quantitatively detected. The pH, time, amount of material, extractant, and other conditions of derivation and enrichment were optimized in the experiment, and the methodology was verified under optimized conditions. The results showed that the linear correlation coefficient R² was 0.9998, the detection limit of 0.13 μg·L⁻¹ without enrichment was close to that of the ICP−MS method, the detection limit after 10−fold enrichment was 0.013 μg·L⁻¹, the RSD was 0.7~2.7%, and the recovery was 87.8~102.1%, in the range of 2~1000 μg·L⁻¹. Therefore, the method can be applied for the determination of trace selenium in tap water, river water, mountain spring water, packaged drinking water, and industrial sewage. Full article

This study explores the physicochemical changes provoked by the physical transmission of highly diluted (HD) solutions of Arnica montana extract on three receiver solutions differing by their pH. Three dilutions (potencies), one modest (D6), one very high (C30), and another ultra-high (C200) extract of A. montana, were used as a source of HD signal transfer. The HD signal transfer was enhanced by an initial knocking at the start of the experiment and then allowed to interact with the receiver solution for 24 h of exposure. The results confirmed the detectability of the HD signal transfer in solutions with different pH, the general effect of this signal on pH increase, the differential effect of the signal depending on the initial dilution level (potency), and the effect on the decrease in both the electrical voltage in water (ORP) and the conductivity. The overall findings of the study offer valuable new insights and suggest innovative approaches for further research, particularly in detecting the HD signal in solutions with varying pH levels, focusing on interactions with hydroxide and hydronium ions. Full article

Fungi (Neolentinus lepideus, Nl, and Trametes versicolor, Tv) impart wood rot, leading to economic and environmental issues. To overcome this issue, toxic chemicals are commonly employed for wood preservation, impacting the environment and human health. Surface coatings based on antimicrobial chitosan (CS) of high molar mass (145 × 10⁵ Da) were tested as wood preservation agents using an innovative strategy involving ultra-pressurizing CS solutions to deposit organic coatings on wood samples. Before coating deposition, the antifungal activity of CS in diluted acetic acid (AcOOH) solutions was evaluated against the rot fungi models Neolentinus lepideus (Nl) and Trametes versicolor (Tv). CS effectively inhibited fungal growth, particularly in solutions with concentrations equal to or higher than 0.125 mg/mL. Wood samples (Eucalyptus sp. and Pinus sp.) were then coated with CS under ultra-pressurization at 70 bar. The polymeric coating deposition on wood was confirmed through X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) images, and water contact angle measurements. Infrared spectroscopy (FTIR) spectra of the uncoated and coated samples suggested that CS does not penetrate the bulk of the wood samples due to its high molar mass but penetrates in the surface pores, leading to its impregnation in wood samples. Coated and uncoated wood samples were exposed to fungi (Tv and Nl) for 12 weeks. In vivo testing revealed that Tv and Nl fungi did not grow on wood samples coated with CS, whereas the fungi proliferated on uncoated samples. CS of high molar mass has film-forming properties, leading to a thin hydrophobic film on the wood surface (water contact angle of 118°). This effect is mainly attributed to the high molar mass of CS and the hydrogen bonding interactions established between CS chains and cellulose. This hydrophobic film prevents water interaction, resulting in a stable coating with insignificant leaching of CS after the stability test. The CS coating can offer a sustainable strategy to prevent wood degradation, overcoming the disadvantages of toxic chemicals often used as wood preservative agents. Full article

Ultra-precision machining has higher requirements for the performance of abrasive tools, but the traditional grinding wheel has some problems such as irregular grain arrangement, limited chip space, and high grinding temperature. Therefore, a structured grinding wheel suitable for ultra-precision machining is proposed. In this study, the laser cladding method and ultrasonic vibration technology were combined to study the preparation process of a structured grinding wheel. Firstly, the quality evaluation system of the printing layer was established, and the shape coefficient and dilution rate were used to evaluate the laser cladding quality. The effects of laser power, sweep speed, powder feeding speed, and ultrasonic power on the shape coefficient and dilution rate of the printing layer were analyzed by single-factor experiments. The level range of each factor in the orthogonal experiment was established to optimize the process parameters. The surface morphology was observed, and the influence of ultrasonic vibration on the morphology was analyzed. The structured grinding wheel was prepared according to the optimized parameters. Full article

This paper presents an experimental and numerical evaluation of the pre-chamber induced HCCI combustion concept (PC-HCCI) in terms of engine performance, emissions, and controllability. In this concept, a spark-initiated combustion in the pre-chamber is utilized to trigger the kinetically controlled combustion of an ultra-lean mixture in the main combustion chamber. The experimental measurements were performed on a single-cylinder engine with a custom-made active pre-chamber. A high compression ratio of 17.5 was used, which limits the maximum achievable engine load due to high knocking tendency but enables both standard PCSI combustion (flame propagation) at very high dilution levels and HCCI combustion at reasonable intake temperatures. The analysis of combustion characteristics and the resulting performance is performed at indicated mean effective pressures (IMEPs) of 3.5 and 3.0 bars, and three different intake temperatures of 80 °C, 90 °C, and 100 °C. The variation in engine load was achieved by adjusting the excess air ratio in the main chamber. On each combination of intake temperature and engine load, a spark sweep and an injected PC fuel mass sweep were performed to obtain the highest indicated efficiency while satisfying the restrictions in terms of combustion stability and knock intensity. It was shown that, unlike in a conventional HCCI engine, the combustion phasing can be directly and reliably controlled by adjusting either spark timing or the reactivity of the pre-chamber mixture, ensuring adequate combustion stability and eliminating potential misfires. A similar indicated efficiency as with conventional HCCI combustion was obtained, while the NOx emissions, although slightly elevated, are still insignificant. Compared to PCSI combustion at the same engine load, a 4-percentage-point increase in indicated efficiency and two times lower NOx emissions were achieved. Compared to the most efficient PCSI operating point, it was 1 percentage point lower, indicating that efficiency was achieved, but the specific NOx emissions are reduced by approximately 70%. Most importantly, very similar performance was obtained with significant variations in intake temperature, proving the reliability and adaptability of this combustion concept. Full article

Particulate and gaseous emissions were studied from a large two-stroke slow-speed diesel engine equipped with an open-loop scrubber, installed on a 78,200 metric tonnes (deadweight) containership, under real operation. This paper presents the on-board emission measurements conducted upstream and downstream of the scrubber with heavy fuel oil (HFO) and ultra-low sulfur fuel oil (ULSFO). Particle emissions were examined under various dilution ratios and temperature conditions, and with two thermal treatment setups, involving a thermodenuder (TD) and a catalytic stripper (CS). Our results show a 75% SO₂ reduction downstream of the scrubber with the HFO to emission-compliant levels, while the use of the ULSFO further decreased SO₂ levels. The operation of the scrubber produced higher particle number levels compared to engine-out, attributed to the condensational growth of nanometer particle cores, salt and the formation of sulfuric acid particles in the smaller size range, induced by the scrubber. The use of a TD and a CS eliminates volatiles but can generate new particles when used in high-sulfur conditions. The results of this study contribute to the generally limited understanding of the particulate and gaseous emission performance of open-loop scrubbers in ships and could feed into emission and air quality models for estimating marine pollution impacts. Full article

Monodisperse and semi-faceted ultra-small templated mesoporous silica nanoparticles (US-MSNs) of 20–25 nm were synthesized using short-time hydrolysis of tetraethoxysilane (TEOS) at room temperature, followed by a dilution for nucleation quenching. According to dynamic light scattering (DLS), a two-step pH adjustment was necessary for growth termination and colloidal stabilization. The pore size was controlled by cetyltrimethylammonium bromide (CTAB), and a tiny amount of neutral surfactant F127 was added to minimize the coalescence between US-MSNs and to favor the transition towards internal ordering. Flocculation eventually occurred, allowing us to harvest a powder by centrifugation (~60% silica yield after one month). Scanning transmission electron microscopy (STEM) and 3D high-resolution transmission electron microscopy (3D HR-TEM) images revealed that the US-MSNs are partially ordered. The 2D FT transform images provide evidence for the coexistence of four-, five-, and sixfold patterns characterizing an “on-the-edge” crystallization step between amorphous raspberry and hexagonal pore array morphologies, typical of a protocrystalline state. Calcination preserved this state and yielded a powder characterized by packing, developing a hierarchical porosity centered at 3.9 ± 0.2 (internal pores) and 68 ± 7 nm (packing voids) of high potential for support for separation and catalysis. Full article

Soil is one of the main destinations for pesticides and veterinary drugs used in agriculture and animal production. The negative consequences of the accumulation of these compounds in the environment make it important to monitor these compounds in the soil. In this study, we compared different extraction procedures using solvent shaking, ultrasound, or QuEChERS, and their combinations, for the simultaneous determination of 75 pesticide and seven veterinary drug residues in agricultural soil by ultra-high performance liquid chromatography coupled to serial mass spectrometry (UHPLC–MS/MS). The method using QuEChERS combined with shaking showed the best results for soil using the addition of water, followed by extraction with acetonitrile acidified with acetic acid and shaking in a shaker. For partitioning, anhydrous magnesium sulfate and anhydrous sodium acetate were used. The extract was centrifuged, filtered, and diluted (1:4, v/v) in water for determination by UHPLC–MS/MS. Method validation showed adequate accuracy and precision results, with recoveries between 70 and 120% and RSD ≤ 20% for the vast majority of the compounds evaluated at the spike levels of 10, 25, 50, and 100 μg kg⁻¹. The method limits of detection (LOD) and quantification (LOQ) ranged from 3.0 to 7.5 μg kg⁻¹ and from 10 to 25 μg kg⁻¹, respectively. The method was applied to different agricultural soil samples and proved to be efficient for routine analysis. Full article