Search Results (16,580)

The Evevpenta gold–silver epithermal deposit, belonging to an adularia–sericite or low-sulfidation type, is in the northern part of the Kamchatka Peninsula within the Oligocene–Quaternary Central Kamchatka volcanic belt. Variously native gold, silver, and Au–Ag chalcogenides, including calaverite, petzite, hessite, acanthite, uytenbogaardtite-petrovskaite, and naumannite, constitute its Au–Ag mineralization. Extensive fluid inclusion studies, involving fluid inclusion petrography, Raman spectroscopy, and microthermometry, revealed that quartz from gold-bearing adularia–quartz veins crystallized from low-salinity fluids (T ice melting from −0.1 to −3.3 °C) at moderate to low temperatures (140 to 364 °C). The mineralizing fluids consisted of Na, K, and Mg sulfate and bicarbonate-bearing aqueous solutions and low-density CO₂. The gold-bearing mineral assemblages were formed within narrower temperature ranges. The gold–telluride–quartz assemblage was deposited between 325 and 175 °C, while the telluride–sulfide–quartz formed between 219 and 258 °C. Possible influx of meteoric waters led to progressive cooling and a decrease in salinity from the early to late fluid generations during mineral deposition. Overall data on ore and associated with metasomatic alteration mineralogy indicate that the ore formation occurred under relatively reduced or neutral conditions from weakly acidic to near-neutral aqueous solutions, possessing relatively high sulfur and tellurium fugacity. Full article

In the fiercely competitive global contracting market, effective knowledge transfer is paramount for the success of international construction projects (ICPs). However, the unique confluence of high cultural distance, temporary team structures, and knowledge hoarding within ICPs creates profound causal complexity, rendering traditional, net-effect analyses insufficient for developing actionable strategies. Existing research broadly identifies influencing factors but fails to delineate the specific, interconnected configurations of interventions necessary to achieve high knowledge transfer effectiveness (KTE) in this high-stakes context. To address this gap, this study analyzes data from 353 practitioners involved in ICPs using fuzzy-set Qualitative Comparative Analysis (fsQCA 3.0), a methodology uniquely suited to unpack complex causal recipes, to determine the combination strategies that drive superior KTE within ICPs. Drawing on a conceptual model validated through expert interviews and historical case analysis, this research examines a range of transfer subjects, relationship, context, and activity conditions. The configurational analysis yields three distinct, yet equally effective, strategic pathways for maximizing KTE: intercultural-driven, learning-driven, and combined-driven configurations. This research produces two significant contributions. Theoretically, it pioneers the use of configurational theory to structure the antecedent framework of knowledge transfer in ICPs, moving beyond single-factor causality. Practically, it furnishes project managers and business leaders with evidence-based strategic blueprints, enabling targeted resource allocation to achieve optimal KTE amidst the inherent complexity of international projects. Full article

Background: Sport-related concussion (SRC) is a recognised public health concern, with combat sport athletes particularly vulnerable due to frequent head impacts. In Taekwondo, concussion incidence is comparable to other contact sports, yet underreporting and misconceptions may hinder safe management. Understanding knowledge, attitudes, and behaviours in this cohort is critical for athlete safety. Methods: This cross-sectional online survey was distributed to Australian Taekwondo athletes (AKA). Participants completed demographic, concussion history, and the Rosenbaum Concussion Knowledge and Attitudes Survey. Knowledge (CKI) and attitudes (CAI) indices were derived. Group differences were analysed using non-parametric tests, with associations between knowledge, attitudes, and reporting behaviours explored via correlation and logistic regression. Results: Athletes (n = 98) demonstrated good knowledge (mean CKI 19.8/25) and positive attitudes (mean CAI 61.6/75), though misconceptions remained. While 92% indicated they would seek medical attention, 21% reported returning to play the same day as a suspected concussion, and over 20% admitted to concealing symptoms. Higher CAI scores, but not CKI, were associated with safer reporting intentions. Conclusions: AKA showed strong knowledge and attitudes towards concussion; however, risky behaviours persisted. Attitudes, rather than knowledge, were more predictive of reporting behaviours, underscoring the need for interventions that strengthen positive attitudes and cultural support for symptom disclosure. Full article

Understanding molecule–nanoparticle interactions is essential for theoretically describing the adsorption process. Here, we employ Kohn–Sham Fragment Energy Decomposition Analysis (KS–FEDA) to dissect the physical components driving pyridine adsorption on silver and gold nanoparticles. KS–FEDA is rooted in Density Functional Theory (DFT) and partitions the total energy into fragment-localized contributions, providing a rigorous decomposition into electrostatics, exchange–repulsion, polarization, dispersion, and exchange–repulsion terms. This framework offers a chemically intuitive interpretation of molecule–metal bonding at the DFT level, and for analyzing and parameterizing interactions at metal–molecule interfaces. The results highlight the relevant role of electrostatics and induction at localized sites and of dispersion over extended facets. Full article

Different ginseng species, such as Panax ginseng and Panax quinquefolius, have various medicinal and economic values. Industrially and commercially, it is important to differentiate them. We have adopted the DNA hybridization method based on a single-nucleotide polymorphism (SNP) found in the ginseng DNA. The ginseng DNA samples were placed on a nitrocellulose membrane, and hybridization of the target sample with the probes immobilized on the membrane occurred, resulting in red spots for unaided eye visualization. We managed to demonstrate a spot test and then a lateral flow assay. Genomic DNAs were extracted from ginseng root samples and DNA amplification was used to generate the PCR products that flank the SNP site. We conclude that ginseng DNA can be differentiated based on a DNA lateral flow assay, detecting ~3 ng (in 1 μL) of PCR amplicons. Full article

In recent years, the development of stretchable electronic devices with mechanical properties similar to those of human tissues has attracted increasing research interest in biomedical engineering, wearables, and other fields. These devices have demonstrated, and some other researchers have already shown, promising advancements towards applications that span from measurements of the disruption of model barrier tissues to wearable or implantable devices, soft robotics, and the development of flexible and stretchable batteries. For example, models of barrier tissues, consisting of two compartments separated by a porous membrane, have been used to measure their integrity as well as to investigate the passage of drugs, toxins, and cancer cells through these tissues. Some of these models include an elastomeric membrane which can be stretched to model processes such as breathing and gut peristalsis, while others include electrodes for real-time measurement of barrier tissue integrity. However, to date, microelectrodes have not been fabricated directly on a porous elastomeric membrane. Here, we present lithographically patterned gold electrodes on porous PDMS membranes that enable electronic sensing capabilities in addition to mechanical manipulation. These membranes are incorporated into vacuum-actuated devices which impart cyclic mechanical strain, and their suitability for electrical impedance measurements, even after 1000 stretching cycles under fluids similar to cell culture media, is demonstrated. In the future, we expect to use these electrodes to measure the disruption in model cell barriers as well as to dielectrophoretically trap cells in a region of interest for more rapid assembly of a model tissue. Other areas like wearables, robotics, and power sources will greatly benefit from the further development of this technology. Full article

The oxygen reduction reaction (ORR) is a pivotal electrochemical process in energy technologies and in the generation of hydrogen peroxide (H₂O₂), which serves as both an effective agent for dye degradation and a fuel in H₂O₂-based fuel cells. In this regard, a titanium (Ti) sheet was anodized to generate a TiO₂ layer, and then the oxide layer was modified with gold (presented as Au/TiO₂/Ti) via electrodeposition. The developed electrocatalyst was confirmed by X-ray photoelectron spectroscopy (XPS), which showed characteristic binding energies for Ti⁴⁺ in TiO₂ and metallic Au. In addition, the Nyquist plot verified the electrode modification process, since the diameter of the semicircular arc, corresponding to charge transfer resistance, significantly decreased due to Au deposition. Voltametric studies revealed that the TiO₂ layer with a Ti surface exhibited a good synergistic effect on Au and the ORR in a bicarbonate medium (0.1 M KHCO₃) by lowering the overpotential, enhancing current density, and boosting durability. The scan rate-dependent study of the ORR produced by the developed electrocatalyst showed a Tafel slope of 180 ± 2 mV dec⁻¹ over a scan rate range of 0.05–0.4 V s⁻¹, thereby indicating a 2e⁻ transfer process in which the initial electron transfer process was the rate-limiting step. The study also revealed that the Au/TiO₂/Ti electrode caused oxygen electro-reduction with a heterogenous rate constant (k⁰) of $4.40\times {10}^{-3}$ cm s⁻¹ at a formal potential (E⁰′) of 0.54 V vs. RHE. Full article

Rationale and Objective: Medical imaging, particularly computed tomography (CT), is the largest man-made contributor to collective radiation exposure. This study compares methods for assessing CT radiation dose, focusing on thoracic examinations. Population investigated: We retrospectively analyzed 3956 non-contrast thoracic CT exams from 1553 females (mean age 70 ± 12 years) and 2403 males (mean age 69 ± 12 years). Methods: Data were acquired using a Siemens Somatom Force CT-Scanner (installed in 2015). Exposure parameters and patient somatic data were recorded and used as inputs for the Virtual Dose Simulator (VDS), which served as the gold standard for effective dose (ED^ref) measurement. Additionally, ED was calculated using two ICRP-103 K-factor methods: Shrimpton et al. (ED^shr) and Romanyukha et al. (ED^rom). Results: Regression analysis demonstrated strong linear relationships between ED^ref and both weight and BMI (R² ≥ 0.84), with ED^ref values ranging from 1.55 to 4.59 mSv. Even stronger linear relationships were observed between ED^ref and CT scanner tube current, particularly for women (R² = 0.93) and men (R² = 0.90). Similar trends emerged for dose-length product (DLP), which showed high correlations for both women (R² = 0.95) and men (R² = 0.94). Compared to VDS, ED^rom underestimated women’s doses by 10% and slightly overestimated men’s doses by 1%, while ED^shr underestimated the effective dose by 18% for women and 9% for men. Conclusion: This study demonstrates that K-factor methods provide a simple, efficient, and clinically practical approach for both individual cumulative dose monitoring (critical for patients requiring repeated imaging) and population-level dose assessment (essential for epidemiological risk evaluation). The high reliability of K-factor-based estimates, as demonstrated in this work, underscores their potential for integration into clinical practice to enhance dose optimization and patient safety. Full article

Background/Objectives: Thoracic trauma remains a leading cause of trauma-related illness and death. Despite advances in imaging, ventilation strategies, and surgical fixation, its management remains a topic of debate, with varying practices across hospitals. Current Gaps: Although surgical stabilization of rib fractures (SSRF) has shown a mortality benefit in cases of flail chest and in elderly patients, its indications for non-flail cases remain uncertain. Analgesia strategies are evolving, and epidural remains the gold standard; however, it is limited by contraindications. In contrast, regional blocks, such as the erector spinae plane block (ESPB) and serratus anterior plane block (SAPB), are emerging as safer alternatives to opioid and thoracic epidural analgesia (TEA). Artificial intelligence (AI) is transforming imaging interpretation and risk stratification; however, its integration into daily trauma care is still in its early stages of development. Perspective: This article examines the integration of surgical innovation, regional anesthesia, and AI-powered diagnostics as integral components of future thoracic trauma care. We emphasize the importance of standardized surgical criteria, multimodal pain management approaches, and AI-assisted decision-making tools. Conclusions: Thoracic trauma care is shifting toward a personalized, multidisciplinary, and technology-enhanced approach. Incorporating evidence-based SSRF, advanced pain management techniques, and AI-supported imaging can help reduce mortality, enhance recovery, and optimize resource utilization. Full article

The Yanlinsi gold deposit, located in the middle section of the Jiangnan Orogenic Belt, is one of the typical gold deposits in northeastern Hunan Province. Diabase dikes are exposed by underground workings and drill holes in the mining area. The dikes strike NW and cut the NE-trending gold ore body. To investigate the petrogenetic age, characteristics of the magmatic source area, and tectonic setting of the diabase dikes in the Yanlinsi gold mining area, northeastern Hunan, and to determine the mineralization age of the deposit, in this paper, diabase dike LA-ICP-MS zircon U-Pb dating, whole-rock geochemistry, and gold-bearing quartz vein LA-ICP-MS zircon U-Pb dating were studied. The results of LA-ICP-MS zircon U-Pb dating indicate that the diabase was emplaced at an age of 219.5 Ma, belonging to the late Indosinian. The investigated diabase dikes are characterized by low SiO₂ (43.68%–46.55%), high MgO (7.78%–9.84%), and high Mg# (65.0–68.7) values, belonging to the alkaline basalt series with high potassium. The chondrite-normalized REEs patterns show highly fractionated LREEs and HREEs ((La/Yb)_N = 11.21–14.82), and the primitive mantle-normalized spider patterns show enrichment in large ion lithophile elements (e.g., Rb, Ba, K and Sr) and relative depletion in high field strength elements (e.g., Nb, Ta, and P), similar to those of ocean island-like basalt (OIB). Rock geochemical characteristics indicate that the magma of the Yanlinsi diabase was formed by partial melting of the enriched mantle (EM II), with the source region being spinel-garnet lherzolite. The degree of partial melting was approximately 10%–15%, and the assimilation and contamination with continental crustal materials were weak. Meanwhile, weak fractional crystallization of olivine, clinopyroxene, and apatite occurred during the magma evolution process. On the basis of a synthesis of previous research results, it is concluded that the Yanlinsi diabase formed in an extensional tectonic setting after intracontinental collisional orogeny. The LA-ICP-MS U-Pb age of hydrothermal zircons from quartz veins in the main mineralization stage of the Yanlinsi gold deposit is 421.9 ± 1.5 Ma. Combined with the cross-cutting relationships between mafic dikes and gold veins (ore bodies), it is determined that the main mineralization stage of the deposit formed during the Caledonian Period. Full article

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic compound produced by certain fungi (e.g., Aspergillus flavus and Aspergillus parasiticus). Rapid and ultra-sensitive detection methods for AFB1 in various commodities are in high demand. This study aimed to enhance the sensitivity of a competitive lateral flow immunoassay (LFIA) for AFB1 detection by leveraging a previously developed experimental design strategy, named 4S. This approach comprises four phases—START, SHIFT, SHARPEN, and STOP—and involves the analysis of two reference conditions: NEG (0 ng/mL AFB1) and POS (1 ng/mL AFB1). By generating and overlaying response surfaces, regions of optimal NEG signal and POS/NEG signal ratio (IC%) were identified. Four variables were optimized: two related to the labeled antibody (its concentration and antibody-to-label ratio) and two to the competitor antigen (its concentration and hapten-to-protein ratio). An initial design defined the parameter space, while three subsequent designs did not yield further improvements in sensitivity. A strong anti-correlation was observed between the IC% and competitor parameters. The optimized LFIA-1 exhibited enhanced sensitivity, achieving a limit of detection of 0.027 ng/mL compared to 0.1 ng/mL for the original device. Additionally, the amount of expensive antibody required for device fabrication was reduced by around a factor of four. Full article

Agricultural water conservancy facilities serve as the foundation and lifeline for the development of sustainable agriculture in a nation. In response to the evolving natural environment and food security demands, ancient agricultural water conservancy facilities coexist with rural areas, establishing a harmonious and sustainable symbiotic coordination mechanism. This study constructs a theoretical framework for the symbiosis between rural areas and ancient agricultural water conservancy facilities based on symbiotic theory. The Lotka-Volterra model is employed to validate the symbiotic evolutionary relationship between rural areas and ancient agricultural water conservancy facilities and to explore the mechanistic patterns of their symbiotic evolution process. Additionally, numerical simulations are conducted using MATLAB software to investigate the optimal solutions for the symbiotic relationship model between rural areas and ancient agricultural water conservancy facilities. The research findings indicate that: (1) The symbiotic model between rural areas and ancient agricultural water conservancy facilities undergoes evolutionary stages, including commensalism, parasitism, competitive symbiosis, and asymmetric mutualism. (2) The evolutionary pattern of their symbiotic relationship is influenced by the symbiotic coefficients of their interactions. (3) The results demonstrate that symmetric mutualism represents the most stable and effective symbiotic model. Therefore, governments and relevant authorities should adopt appropriate measures to guide the evolution of rural areas and agricultural water conservancy facilities toward the symmetric mutualism model. This approach provides a scientific basis for the future development strategies of rural areas and agricultural water conservancy facilities. Full article

The extraction of high-quality DNA is essential for molecular analyses in grapevine, yet differences among commonly used protocols remain underexplored. This study compared two cetyltrimethylammonium bromide (CTAB)-based methods, with and without polyvinylpyrrolidone (PVP), and three commercial kits (peqGOLD Plant DNA Mini Kit, Qiagen DNeasy Plant Mini Kit, and SPINeasy DNA Kit for Plant MP) using grapevine leaves and other tissues and further validated the CTAB protocol across 34 cultivars. DNA yield, purity, and integrity were assessed spectrophotometrically and by electrophoresis, while PCR suitability was confirmed for all methods. CTAB provided the highest yields and purity at low cost, with densitometry showing approximately 70–85% high-molecular-weight DNA (>20 kb). The Qiagen kit yielded reproducible results with moderate integrity (about 40–60% HMW fraction), making it suitable for high-throughput applications. The MP kit produced high concentrations but severe fragmentation (<10% HMW fraction) due to bead-beating, while the VWR kit performed worst in yield and purity. The addition of PVP improved DNA purity in polyphenol-rich tissues but reduced yield. All protocols generated DNA sufficient for PCR amplification. Overall, CTAB was robust and cost-effective across cultivars and tissues, Qiagen offered speed and reproducibility, and MP provided high concentration at the expense of integrity. Full article

Background/Objectives: Insulin resistance is a major public health issue in Mexico, closely linked to obesity, prediabetes, and type 2 diabetes. The euglycemic–hyperinsulinemic clamp is the diagnostic gold standard but is impractical for routine use. The triglyceride–glucose (TyG) index has been proposed as a simple alternative validated in diverse populations. We aimed to assess the utility of TyG relative to HOMA-IR and QUICKI as an early diagnostic tool in young Mexican adults. Methods: We performed an analytical cross-sectional study in young adults. Clinical, anthropometric, and fasting biochemical variables were collected to compute TyG. We compared TyG with HOMA-IR and QUICKI and evaluated diagnostic performance using receiver operating characteristic analysis to estimate area under the curve (AUC) and identify the optimal cut-off. Results: We analyzed 115 participants; 66.9% were insulin resistant by HOMA-IR, 79.1% by QUICKI, and 42.6% by TyG. TyG showed significant associations with anthropometric and biochemical measures. Diagnostic performance was good (AUC 0.707 vs. HOMA-IR; 0.960 vs. QUICKI). The optimal cut-off was 4.38, yielding sensitivity of 70.1% and specificity of 68.4% for diagnosing insulin resistance compared with HOMA-IR. Conclusions: The TyG index appears to be a useful, accessible, and cost-effective biomarker for early detection of insulin resistance in young Mexican adults. Its implementation could facilitate earlier diagnosis and prevention of cardiometabolic complications. Longitudinal, multicenter studies are warranted to establish population-specific reference values and to confirm its predictive value for adverse outcomes. Full article

Background: Central precocious puberty (CPP) is diagnosed through a combination of clinical, auxological, and biochemical parameters, with pharmacological stimulation tests considered the diagnostic gold standard. In recent years, triptorelin, a long-acting Gonadotropin-Releasing Hormone (GnRH) analog, has been increasingly adopted in clinical practice due to limited availability of native GnRH. Objective: To compare the clinical, auxological, and hormonal profiles of girls diagnosed with idiopathic CPP using either the classical GnRH stimulation test or the triptorelin test. Methods: This retrospective study included 136 female patients diagnosed with CPP and followed for at least two years at a single pediatric endocrinology unit. Of these, 101 underwent a GnRH stimulation test, and 35 were assessed using the triptorelin test. Baseline and stimulated hormonal parameters, growth data, and IGF-1 levels were collected. A multivariate linear regression model was used to explore the influence of age, test type, and other covariates on the LH peak response. Results: Anthropometric and baseline hormonal parameters were comparable between the two groups. The LH peak was significantly higher in the GnRH group (9.8 ± 3.1 IU/L at 60 min) than in the triptorelin group (6.8 ± 2.4 IU/L at 4 h). FSH levels were also significantly lower following triptorelin stimulation (p = 0.004), while the LH/FSH ratio did not differ significantly. Multivariate analysis confirmed that triptorelin was associated with a lower LH peak (β = −2.2, p = 0.008), particularly in younger patients, with a significant interaction between age and test type (β = 0.6, p = 0.022). Conclusions: Both GnRH and triptorelin stimulation tests are valid tools for CPP diagnosis. However, the GnRH test appears to elicit a more robust LH response, especially in younger patients, whereas the triptorelin test is associated with delayed and lower LH peaks. Full article