High Resistance Research Articles

Investigation of Various Toxigenic Genes and Antibiotic and Disinfectant Resistance Profiles of Staphylococcus aureus Originating from Raw Milk.

This study investigated the toxigenic genes and antimicrobial resistance profiles of Staphylococcus aureus strains isolated from 260 raw milk samples collected from dairy farms in Türkiye. The results indicated that 60.7% of staphylococcal enterotoxin genes (sea, seb, sed, seg, sei, sej, sek, seq, sem, seo, and seu) and 21.4% of the tst and eta genes were positive, with most enterotoxin-positive samples carrying more than one gene. The sec, see, seh, sel, sen, sep, and etb genes were not identified in any samples. The prevalence of antibiotic resistance genes (mecA, blaR, blaI, blaZ, vanA, ermT, tetK, aac/aph, ant, dfrA, tcaR, IS256, and IS257) was high at 89.2%, with bla being the most frequently detected gene (75%). The mecA gene was present in 14.2% of samples, while tcaR was detected in 78.5%. Nevertheless, the mecC was not identified. Disinfectant resistance genes (qacA/B, qacC, qacJ, smr) were detected in 21.4% of the samples. The results of the disk diffusion test showed that 64.2% of strains were resistant to penicillin G and ampicillin, with additional resistance found for cefoxitin, teicoplanin, levofloxacin, norfloxacin, and other antibiotics. These findings highlight a significant public health and food safety risk associated with raw milk due to the presence of S. aureus strains with toxigenic genes and high antimicrobial resistance.

In-situ reaction-generation self-healing superior antioxidation layer induced by Al-Y sol-gel film on the AISI304 steel

In this study, an Al-Y sol-gel film is prepared on the AISI304 steel and its effect on the high temperature oxidation resistance is evaluated by the cycle oxidation at 900 ℃ in the air. The resulting intact oxide layer, composed of (Al, Cr)2O3 and MnCr2O4 phases, effectively slowing down the oxidation rates at 900 ℃. The general cracks in the sol-gel film during the oxidation process are found to be self-healed by a growing spinel MnCr2O4 phase from the substrate, attributed to its low Gibbs free energy and the sufficient Cr source from the adjacent substrate. Furthermore, the oxide layer originates from the interaction between sol-gel film and the substrate which enhances the binding between the oxide layer and the substrate. Thus, it could be confirmed that a self-healing superior antioxidation layer is generated on the surface of AISI304 steel through an in-situ reaction induced by the Al-Y sol-gel film during high-temperature oxidation procedure.

Magnetoplasmonic Triblock Nanorods for Collective Linear Dichroism.

Polarized light detection is crucial for advancements in optical imaging, positioning, and obstacle avoidance systems. While optical nanomaterials sensitive to polarization are well-established, the ability to align these materials remains a significant challenge. Here, we introduce Au-Fe3O4-Au triblock nanorods as a novel solution. Synthesized via a space-confined seeded growth method, these magnetoplasmonic nanocomposites uniquely combine the strong polarization capabilities of Au nanorods with the magnetic alignment properties of Fe3O4 nanorods. This architecture results in exceptional collective linear dichroism, achieving a polarization ratio of approximately 14 at the device level. Our nanorods exhibit high detection sensitivity and laser damage resistance, positioning them as a promising platform for developing advanced optical devices.

Fracture resistance of the deposited metal under dynamic and cyclic loading

Analyses of experimental data are presented that enable the fracture resistance assessment of dynamically and cyclically loaded materials used for the manufacture and surfacing of rollers in continuous casting machines for beam blanks and crimping mill rollers. It has been noted that steels for manufacturing and surfacing of crimping rolls with different carbon content and alloying elements, differ in the determination fraction of the crack nucleation work in the integral value of the impact strength. The value of that fraction is much higher for corrosion-resistant steels of the Cr13 type which are also distinguished by high fracture resistance to cyclic loading. It is shown that the properties of these steels make it possible, along with the use of CCM rollers for surfacing, to recommend them for hardening the rollers in crimping mills. The possibility of an additional increase in the efficiency of the crimping rolls by eliminating uneven wear along the length of the barrel by surfacing a layer of Cr13 steel with a variable carbon content (0.10-0.25 %) is considered.

Production of bacteriocin-like inhibitory substance (BLIS) by Staphylococcus spp. isolates from dogs.

In the present study, 39 canine isolates of Staphylococcus spp. were tested for antimicrobial substance (AMS) production. Seven AMS producers were identified, whose products exhibited a non-acidic character and a proteinaceous nature, therefore being considered bacteriocin-like inhibitory substances (BLIS). The producer strains of BLIS P1, P16 and I3 showed a broad spectrum of antimicrobial activity. Human, veterinary and plant pathogens, such as Listeria monocytogenes, Klebsiella pneumoniae, Staphylococcus spp. and Clavibacter michiganensis, were among the inhibited micro-organisms, suggesting the potential biotechnological application of these peptides. MALDI-TOF mass spectrometry and 16S rDNA sequencing identified the producer strains of BLIS P1, P16 and I3 as Staphylococcus pseudintermedius P1, Staphylococcus schleiferi P16 and Staphylococcus pseudintermedius I3. The plasmid profile of these strains suggests that the BLIS production is linked to biosynthetic genes located on plasmids. PCR analyses revealed that BLIS P1, P16 and I3 are different from 11 staphylococcins already described in the literature and that their genomic DNAs do not carry the most prevalent staphylococcal enterotoxin genes. The highest levels of BLIS production were achieved after 18-24h of growth of the producer strains in TSB medium. Moreover, BLIS P1 and I3 exhibited high resistance to temperature and pH variations, and BLIS P16 maintained 100% of its activity in almost all conditions tested. The characteristics associated with BLIS P1, P16 and I3 described in this work encourage further investigation of these substances, in addition to this study being the first report of BLIS production by a strain of S. schleiferi.

Comparison of Three Different IBD Vaccination Protocols in Broiler Chicken-Efficacy, Serological Baselines and Histo-Pathological Lesions in the Bursa of Fabricius.

Infectious bursal disease (IBD) is a highly infectious disease of chicken found in all latitudes, due to the very high resistance to environmental conditions and commonly used disinfectants of the IBD virus (IBDV). This study was conducted to evaluate three IBD vaccination protocols in broiler chicken in terms of their effectiveness (clinical observations and production performance of the flock), estimation of serological baseline values (with the use of two different commercial ELISA kits) and the degree of progression of BF lesions (histopathological lesion score (HLS)) after vaccination. The three protocols were (I) single vaccination using an intermediate plus vaccine, (II) double vaccination with an intermediate vaccine and (III) double vaccination with an intermediate plus vaccine. Birds on farms vaccinated with protocol II were characterized by the lowest antibody titers in both ELISA tests and the lowest average HLS. The highest IDEXX titers were obtained in birds vaccinated with protocol III, while in the BIOCHEK test the highest titers were obtained for birds vaccinated with protocol I. Protocols I and III were characterized by similar HLSs. Birds vaccinated with protocols I and III had higher immune uniformity. The estimated serological baseline values and the degree of HLSs presents a clear picture of the differences between the different vaccination protocols and allows their adaptation for different farms depending on the current IBD epidemiological situation.

Activation of peroxomonosulfate by manganese-containing non-homogeneous catalysts prepared via a soft template calcination strategy for efficient degradation of carbamazepine

Manganese (Mn)-containing inhomogeneous catalysts have demonstrated potential to activate peroxymonosulfate (PMS), but may be constrained by low efficiency and poor resistance to environmental disturbances. According to the soft template calcination strategy, g-C3N4 with Mn doping was synthesized to improve PMS activation through an effective Mn(II)/Mn(III)/Mn(IV) cycle. The constructed Mn25@CN/PMS system achieved complete and rapid removal of carbamazepine (CBZ) at 0.3 g/L catalyst and 2 mM PMS. Its corresponding rate constant of pseudo-first-order was 0.3424 min−1, and it was 3424 and 16.15 times higher than that of pure g-C3N4/PMS system and CN/PMS system, respectively. More strikingly, the catalysts exhibited excellent resistance to environmental impacts, with CBZ removal rates exceeding 95% under the influence of different anions, cations, aqueous pH values, and humic acid (HA) concentrations. Subsequently, it was proposed a reliable catalytic mechanism for CBZ removal and PMS activation derived from electron paramagnetic resonance (EPR) tests and quenching experiments. The O2·- and 1O2 played a major role in the CBZ removal process. This research provides a perspective soft template strategy for PMS activation using highly efficient catalysts with high resistance to environmental impacts, which provides new ideas to alleviate environmental issues.

Hot isostatic pressing of ball milled novel grade high entropy alloys at different sintering time and the investigation of their mechanical and corrosion resistance properties

Abstract With the discovery of high entropy alloys, new materials with superior properties have emerged. According to recent research, high-entropy alloys’ multi-component structure and mixing entropy have made them more prominent than other alloys. Because of their excellent chemical and mechanical properties—such as high hardness, high-temperature resistance, high wear resistance, chemical stability, and high corrosion resistance—high entropy alloys outperform other material types in various applications. A new grade of mechanically alloyed high entropy alloy (HEA) of composition 23Fe-21Cr-18Ni-20Ti-18Mn was consolidated by a hot isostatic pressing (HIP) at a temperature of 1000 °C, at different sintering time of 30, 60, and 90 min respectively. We have investigated the impact of sintering time on the microstructure, mechanical, corrosion, and wear-resistance properties. The x-ray diffraction (XRD) spectra of the 30 min HIPed HEA sample showed dominant s-FeCr phases and traces of γ-Fe, and the Ni-Ti phases. Whereas, the 90 min HIPed HEA samples showed more dominant Ni-Ti and traces of γ-Fe, and β-Mn phases. There is a phase transformation from BCC to HCP of consolidated HEA at increased holding time. The density of the samples increases from 5.882 to 6.327 g cm−3 and the porosity percentage decreases from 12.93 to 6.35% with the increase in the holding time. The Vickers microhardness value for 30, 60, and 90 min HIPed 23Fe-21Cr-18Ni-20Ti-18Mn HEA at 1000 °C was found to be 433, 513, and 793 HV respectively at an indentation load of 0.1 kgf. The consolidated HEA sample undergoes an abrasive and oxidative wear mechanism with ploughing and plastic deformation modes. The morphology of the wear debris was investigated using SEM. The 90 min sintered sample showed an excellent corrosion resistance due to the high rate of material densification and minimum surface flaws.

CsSnBr3 and Cs3Bi2Br9: Structural, Optical Characteristics, and Application in a Schottky Barrier Diode

The search for alternatives to Pb‐based perovskites, due to concerns about stability and toxicity, has led to the exploration of Pb‐free options. Tin (Sn) and bismuth (Bi) are promising candidates, given their similar ionic radii to Pb and the isoelectronic nature of Pb2+ and Bi3+, which suggest comparable chemical properties. Among these, CsSnBr3 and Cs3Bi2Br9 are relatively underexplored but offer lower toxicity and enhanced stability while demonstrating optoelectronic properties suitable for various applications. In this study, CsSnBr3 and Cs3Bi2Br9 nanocrystals are synthesized using a colloidal method and integrated into Schottky diodes. X‐ray photoelectron spectroscopy analysis of the surface chemistry confirms improved thermal and phase stability compared to Pb‐based perovskites. Schottky diode parameters, including ideality factor, barrier height, and series resistance are assessed using conventional thermionic emission, modified Cheung's, and Norde's models. The Cs3Bi2Br9‐based Schottky diode exhibits superior electrical performance with the lowest series resistance and optimal barrier height. Electrical impedance spectroscopy results indicated that CsSnBr3 has higher resistances and lower capacitances than Cs3Bi2Br9, reflecting lower charge carrier mobility and more defects, although the R1C1 regions in both materials demonstrated faster charge dynamics, making them ideal for high‐speed applications.

Study curing of epoxy resin by Isophoronediamine/ Triethylenetetramine and reinforced with montmorillonite and effect on compressive strength

Epoxy is a widely used thermosetting resin recognized for its exceptional performance in adhesives, coatings, and various other applications, attributed to its high tensile strength, stiffness, electrical performance, and chemical resistance. Epoxy-clay nanocomposites are extensively employed across diverse industries. The physical and chemical properties of these nanocomposites are influenced by the processing methods, clay modifiers, and curing agents used during their preparation. In this study, epoxy/nanoclay composites based on Diglycidyl Ether Bisphenol-A (DGEBA) will be cross-linked using Isophorone Diamine (IPD), a cycloaliphatic amine, and Triethylenetetramine (TETA), a linear aliphatic amine. The initial phase of the research will assess the impact of different types of cross-linkers, both individually and in combination at various molar ratios (such as Isophorone Diamine: Triethylenetetramine (IPA: TETA) / 25:75 and 75:25), on the compressive strength of the epoxy mortar. In the subsequent phase, the epoxy formulation with an Isophorone Diamine: Triethylenetetramine (IPD: TETA / 75:25), which demonstrates the highest compressive strength, will be selected for further investigation. This formulation will be used to evaluate the effects of different weight percentages (3%, 5%, and 7%) of organically modified montmorillonite (OMMT). The prepared epoxy composites will be characterized using a range of techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM). The epoxy/nanoclay composite with an IPD: TETA / 75:25 and 3 wt % OMMT is expected to show the highest compressive strength, which is 94 MPa.

Temperature-controlled in-situ construction of composition-tunable nanoparticle-decorated SOFC cathodes with enhanced oxygen reduction kinetics and CO2 tolerance

High oxygen reduction reaction (ORR) catalytic activity and CO2 resistance of the cathode are fundamental to the commercial application of solid oxide fuel cells (SOFCs). Therefore, we develop a temperature-driven reduction-reoxidation strategy to in-situ construct heterostructured perovskite cathodes decorated with different nanoparticles by controlling the reduction temperature. For (Pr0.4Sr0.6)0.95Co0.2Fe0.8-xNixO3-δ (PSCFN, x = 0.05, 0.1), reduction (@700 °C)-reoxidation results in the exsolution of a ComFenNi3-m-nO4 spinel phase on the perovskite scaffold surface, while reduction (@750 °C)-reoxidation leads to the formation of both ComFenNi3-m-nO4 spinel phase and NiO nanoparticles. The exsolution of these highly active species increases the quantity of oxygen reduction active sites and effectively suppresses Sr segregation. The simultaneous formation of ComFenNi3-m-nO4 spinel phase and NiO nanoparticles induces B-site ion vacancies in the main phase, therefore facilitates the formation of oxygen vacancies. Additionally, the presence of ComFenNi3-m-nO4/NiO/PSCFN heterointerfaces promotes oxygen adsorption and transfer. The strong interactions among ComFenNi3-m-nO4, NiO, and PSCFN significantly enhance the structural stability. At 800 °C, Reo2-PSCFN0.1 achieves an output performance of 1.12 W cm−2, representing a 36.6 % enhancement compared to PSCFN0.1. Moreover, the Rp of Reo2-PSCFN0.1 is merely 0.0186 Ω cm2, marking a 40.4 % decrease relative to PSCFN0.1. This temperature-driven reduction-reoxidation strategy shows great promise as a novel approach for creating high-performance IT-SOFC cathodes.

Innovative Materials in Architecture and Construction: Magnesite Panels

Magnesite panels studied herein, are characterized by high fire resistance, moisture resistance, strength, sound insulation and environmental properties. The relevance is due to the modern trends in sustainable development, imposing high demands on building materials and products. Preference is given to those products or technologies that can potentially be marked as eco-friendly.Purpose: The purpose of this work is to study magnesite panels, an innovative building material, to determine their performance characteristics, including fire resistance, moisture resistance, strength and environmental friendliness. The paper analyzes their effectiveness in comparison with other building materials.Methodology/approach: The paper analyzes the properties of panels made of magnesium oxide as the most environmentally friendly and safe innovative building material. Their advantages are assessed through a comparative analysis of the physical and mechanical properties of magnesium oxide panels with other available building panels (gypsum panels, oriented strand panels).Research findings: It is found that magnesite panels are an environmentally friendly and universal material in architecture and construction. It is shown that magnesite panels are superior to other building panels in the selected parameters, but are more expensive.

Impact of EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) on optimal antimicrobial therapy in gram-negative bloodstream infections

ObjectivesTo evaluate the possible impact of RAST on optimal antimicrobial therapy via de-escalation or escalation, and to determine the reduction in antibiotic susceptibility reporting time with RAST. MethodsIn this single-center, prospective descriptive study, RAST was performed on clinical blood cultures containing E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii isolates. Very major error, major error, and categorical agreements with VITEK 2 were analyzed. ResultsOne hundred and three isolates were included in the study, out of which 29.1 % were carbapenem-resistant and 36.9 % were multidrug-resistant according to VITEK 2. Categorical agreement of the RAST method with standard antimicrobial susceptibility test (AST) was > 90 % at 6 h, except for piperacillin/tazobactam. Antibiotic revision could be carried out in 79.6 % of the patients either by de-escalation (61.2 %) or escalation (18.4 %) for optimal therapy based on the RAST 6 h result. RAST could provide carbapenem-sparing therapy in 24 % of patients. Reduction in antibiotic susceptibility reporting time was 41.5 h (38.8 to 63.2, median (IQR)). ConclusionsRAST can provide early antibiotic revision in a majority of patients with significantly reduced antibiotic susceptibility reporting time. Six hours is the shortest optimal time for antibiotic revision with RAST. In countries where empirical broad-spectrum antibiotics are prevalent due to high antibiotic resistance pressure, RAST should be proposed primarily in de-escalation and carbapenem-sparing strategies.

Functinal assessment in Angina and Non-Obstructive Coronary Arteries (ANOCA) patients: from Microvascular Resistance Reserve (MRR) to different subtypes of Coronary Microvascular Dysfunction (CMD)

Abstract Background Coronary microvascular dysfunction (CMD) is a heterogeneous condition defined by a reduced coronary flow reserve (CFR) and low/high values of index of microvascular resistance (IMR). A new index, the microvascular resistance reserve (MRR) has been developed, but its clinical significance is unclear. Purpose We aimed to investigate the relationships between functional indices in ANOCA (Angina and No Obstructive Coronary Arteries) patients and to assess the hemodynamic and clinical characteristics of different CMD subtypes. Materials and methods We prospectively enrolled consecutive ANOCA patients who underwent a comprehensive functional assessment of microvascular domain by thermodilution technique. CFR, IMR and MRR were estimated and correlated each other. Patients were divided in two groups according to the presence of CMD (defined by a CFR<2.5). Subsequently High Hyperaemic Resistance (HHR) and Low Hyperaemic Resistance (LHR) CMD subtypes were defined according to low or high IMR values respectively (cut-off 25). Microvascular flow and resistance were estimated both at rest and during hyperaemia with Tmnrest /IMRrest and Tmnhyp/IMR respectively. All functional indices were compared between groups. Results one hundred and eight patients were available for the analysis. 66 patients in the Normal Group (CFR≥2.5), 20 patients in HHR CMD (CFR<2.5 and IMR≥25), 22 patients in LHR CMD (CFR<2.5 and IMR<25). MRR showed a strong correlation (r 0.966, p <0.01) with CFR, while a mild and negatively correlation was found between CFR and IMR (r -0.242, p=0.01) and MMR and IMR (r -0.261, p<0.01). MRR showed a good discriminatory power (AUC 0.97, 95% CI 0.94 – 0.99) and accuracy (85%) in detecting CMD when compared to CFR. LHR CMD patients showed reduced microvascular resistance (IMRrest 34.3±15.1 vs 90.1±54.5 Normal Group vs 75.8±28.9 HHR CMD, p<0.01) and increased flow at rest (Tmnrest 0.37±0.17 vs 0.96±0.62 Normal Group vs 0.81±0.43 HR CMD, p<0.01), while HHR CMD patients had impaired flow during hyperemia (Tmnhyp 0.45±0.24 vs 0.26±0.18 Normal Group vs 0.21±0.07 LR CMD p<0.01). MRR was reduced in CMD patients (Normal 4.70±1.78 vs CMD 2.20±0.59, p<0.01), with no differences between CMD subtypes (HHR 2.17±0.47 vs LHR CMD 2.24±0.70, p=0.66). Conclusions In INOCA patients, MRR and CFR are strongly correlated and could be considered as functionally interchangeable tools. LHR CMD subtype is characterized by a pathological low resistance and high flow at rest while HHR CMD presented an impaired flow during hyperaemia.

Enhancing orthogonal finishing machining of Ti6Al4V with laser-ablated tool geometry modifications

Finishing machining of Ti6Al4V, known for its high strength and heat conduction resistance, demands optimisation to achieve high-quality end products. This study explores modifying the chip contact length on the rake face and altering the flank face with a cavity to minimise process forces and temperatures while maintaining cutting edge integrity. The research validates the manufacturability of ultra-short pulsed laser-ablated tool geometry modifications, indicating potential for industrial scale-up. Extensive experimental evaluations under dry conditions assess the impact of tool modifications at various feed rates for planing and turning. Significant reductions in process forces and temperatures were observed with rake face modifications, particularly at a cavity distance of approximately 34 µm. Ideal performance was noted for feed rates between 0.035 and 0.045 mm for planing and 0.040 to 0.045 mm/rev for turning. Smoothed Particle Hydrodynamics (SPH) simulations employing a Johnson-Cook material model were used to analyse chip formation and to predict the process forces. These simulations revealed a clear change in the chip formation and lower process forces and temperatures. The SPH results closely matched experimental outcomes, with a discrepancy of less than 7 % in cutting forces for both tool types, although feed forces were underestimated by about 50 %. The effect of the tool modification is reflected accurately at the respective feeds.

The interplay between coronary microvascular resistance, arterial reservoir function and coronary flow reserve: unravelling the significance of high microvascular resistance

Abstract Background Beyond the observation that patients with low CFR indicating presence of coronary microvascular dysfunction (CMD) have an unfavourable prognosis compared to patients with preserved CFR, recent large multicentre trials [1-2] have shown that increased minimal hyperaemic microvascular resistance (HMR or IMR) ,neither on top of the low CFR nor alone, does not play a role as a prognostic factor for ischemia in nonobstructive coronary artery disease (INOCA) patients. Purpose This study investigates the pathophysiological interactive processes in CMD and no-CMD groups with high and low HMR taking into account potential adaptive mechanisms that alter arterial reservoir function [3] associated with microvascular resistance and systemic vasomotor response in INOCA patients. Methods Analysis was conducted on 312 unique unobstructed vessels (FFR>0.80) from 258 patients (73% male) enrolled in the DEFINE-FLOW [4] study. CFR and HMR were quantified using intracoronary Doppler and pressure measurements. Vessels were categorized into four groups based on high and low CFR and HMR using the best available cut-off values (2.5 for both). Arterial reservoir capacity (ARC) and related parameters [3] were quantified using reservoir-excess pressure (Preservoir and Pexcess) analysis of averaged aortic and distal coronary pressure waveforms in CMD (CFR<2.5) and no-CMD (CFR≥2.5) subgroups. (Figure 1-2) Results Compared to vessels without CMD, functional and structural CMD have increased Pexcess (p:0.007) and a rapid decline in diastolic pressure (DRCcoronary p<0.001, DRCaortic, p<0.05), indicating the ongoing systemic hemodynamic superfluous state despite locally suppressed resting blood flow in the structural CMD. Higher baseline microvascular resistance (BMR) was associated with increased reservoir pressure (r:0.302, p<0.001). The vessels with preserved CFR despite high HMR are characterised by uniquely increased ARC (p:0.014), effectively diminished Pexcess (p:0.010), which parallels the local (highest BMR p<0.001) and global (lowest DRCaortic, p<0.05) vasomotor response, that normalizes the systemic and local hyperperfusion, and ultimately regains an adequate flow reserve (CFR) (p<0.001). The high HMR in this group was mainly due to increased resting tonus unlike structural CMD, evident by the highest RRR (BMR/HMR).(p<0.001) (Figure 1-2) Conclusion(s) The high HMR despite preserved CFR vessels form a unique-adaptive group, characterised by substantially increased arterial reservoir capacity and effectively diminished Pexcess, by means of an adaptive vasomotor response which manifests locally in the coronary bed as pronouncedly augmented BMR & RRR, and globally as reduced DRC in the aortic pressure waveform. This adaptive myogenic response normalising resting flow and ongoing systemic and local hyperperfusion ultimately regains an adequate flow reserve (CFR).Figure 1.Methods and Main FindingsFigure 2.Visual Abstract

Historical Quarry Landscapes of Three Finnish Granites

The quarry landscapes of Virolahti, Uusikaupunki, and Vehmaa are results of quarry operations during the most important periods of natural stone quarrying in Finland. The quarry landscape in Virolahti was formed in connection to the quarrying of red Virolahti pyterlite for the construction of St. Petersburg in Russia from the middle of 1700s to the beginning of the 1900s, while in Uusikaupunki, the quarry landscape is connected to the start of the modern Finnish stone industry and the National Romantic architecture at the beginning of the 1900s. The quarry landscape in Vehmaa is related to the start of the modern Finnish stone industry and export of Finnish granite at the beginning of the 1900s. In Virolahti, several small quarries can be seen, while in Vehmaa, a tendency towards fewer, but larger quarries start to emerge. In each area, human settlement was formed around the quarries. The geological basis for all areas is a rock type suitable for natural stone quarrying. The geotechnical features of each rock type indicate high resistance to wear and the products from these areas are early examples of durable construction. The quarry landscapes represent well the typical quarrying technology of the time and its development from channelling by chisels through hand drilling to mechanical drilling and blasting. The quarry areas form unique industrial and cultural heritage landscapes in Finland.

Essential oils of thyme (Thymus vulgaris) and oregano (Origanum vulgare) as an alternative for the control of pesticide-resistant Fusarium spp. in quinoa seeds.

The phytopathogenic genus Fusarium can cause damage such as root and stem rot in economically important crops, with significant implications. To seek a sustainable method for controlling this phytopathogen in seeds, the antifungal activity of essential oils (EOs) from thyme (Thymus vulgaris) and oregano (Origanum vulgare) was evaluated against isolates of F. graminearum, F. equiseti, F. culmorum and F. oxysporum originating from quinoa (Chenopodium quinoa) crops in the Boyacá (Colombia). Initially, the effectiveness of commercial fungicides against the mentioned phytopathogenic fungi was evaluated. Upon verifying that these isolates exhibited high resistance to these compounds, the EOs were assessed as a potential control alternative. A disk diffusion assay demonstrated complete in vitro inhibition of the growth of the evaluated phytopathogens when undiluted EOs were used. Subsequently, the minimum inhibitory concentration (MIC) of these oils was determined using the agar well diffusion technique, revealing a MIC of 10 and 1 μL mL-1 for thyme and oregano oil, respectively. Following this, the antifungal activity of the EOs applied to quinoa seeds was evaluated, and germination indices were measured as an indirect indicator of their toxicity. Despite both EOs successfully inhibiting microbial growth in the seeds, it was also found that thyme EO at 100 μL mL-1 and oregano EO at 10 μL mL-1 inhibited seed emergence and germination. However, lower concentrations exhibited a reduction in fungal population without affecting these germination indices. Therefore, it is suggested that the use of these compounds has potential in the treatment and disinfection of quinoa seeds. © 2024 Society of Chemical Industry.

Green Biosynthesis and Catalytic Application in Environmental Pollutants of Functionalized Pd‐Ag Bimetallic Nanoparticle by Deinococcus Radiodurans Extracts

AbstractCatalytic reduction of organic pollutants using metal nanoparticles (MNPs) as nanocatalyst is a promising approach. The widespread application of MNPs have led to an increase demand for their production. The green biosynthesis of MNPs using microbes is becoming increasingly important as they are benign and environmentally friendly. In this work, Deinococcus wulumuqiensis (D. wulumuqiensis) with high resistance to stresses was applied for the green preparation of different MNPs, including palladium nanoparticles (Pd NPs), silver nanoparticles (Ag NPs), and Pd−Ag bimetallic nanoparticles (Pd−Ag BNPs). The resultant MNPs exhibited a face‐centered cubic structure, with average size of 6.70 (Pd NPs), 6.24 (Ag NPs), and 6.13 nm (Pd−Ag BNPs), respectively. FT‐IR spectra indicated that the proteins and polysaccharides expressed by D. wulumuqiensis could potentially contributed to the formation of MNPs. The application of as‐prepared biocatalyst in catalytic degradation of pollutant dyes demonstrated that Pd−Ag BNPs had greater degradation ability of 4‐nitrophenol (95.1 %) and Rhodamine B (85.1 %) than monometallic nanoparticles. The pseudo‐first‐order kinetics results further indicated the superior catalytic ability of Pd−Ag BNPs, with rate constant of 0.450±0.009 (4‐nitrophenol) and 1.54×10−2 min−1 (Rhodamine B), respectively. Thus, the present study confirms that D. wulumuqiensis represents a promising candidate for the biosynthesis of Pd‐based nanoparticles with small size, which exhibited potential applications as bionanocatalyst in the degradation of water pollutants.

Integrating Resource-Based Theory and Contingency Theory for Enhancing Supply Chain Resilience in Malaysia: A Post-Pandemic Analysis

The COVID-19 pandemic has significantly disrupted global supply chains, exposed their vulnerabilities and underscored the urgent need for enhanced resilience. In Malaysia, the pandemic's impact on supply chains has been profound, prompting a re-evaluation of existing strategies and frameworks. This study explores the integration of Resource-Based Theory (RBT) and Contingency Theory (CT) to enhance supply chain resilience in Malaysia. Through in-depth case studies and semi-structured interviews with senior managers and supply chain professionals, this research identifies key factors contributing to the successful implementation of an integrated resilience framework. The findings reveal that firms leveraging advanced technology, skilled workforce, and strategic partnerships can maintain operational efficiency and adaptability. Context-specific strategies such as diversifying suppliers, local sourcing, strategic stockpiling, and flexible logistics solutions are essential in responding to disruptions. Common challenges include high initial costs, coordination issues, regulatory hurdles, and cultural resistance to change. The integration of RBT and CT results in improved supply chain visibility, flexibility, robustness, and stakeholder collaboration. This study contributes to the academic discourse by offering practical insights for firms seeking to enhance supply chain resilience. It underscores the importance of combining internal strengths with adaptive strategies tailored to the external environment. The findings provide valuable guidance for both academia and industry in developing more robust and adaptive supply chain strategies in the post-pandemic landscape. Future research should explore the integration of RBT and CT across different contexts and industries and investigate the role of emerging technologies in enhancing supply chain resilience.