Search Results (4,904)

Tropaeolum tuberosum (mashua) is a native Andean tuber recognized for its high nutritional and bioactive compound content. Among the various morphotypes, the black and yellow variants show potential differences in composition and functionality. This study aimed to compare the thermo-energetic, nutritional, and physicochemical characteristics of two morphotypes (black and yellow) of Tropaeolum tuberosum flour from the Peruvian Andes. Flours were obtained from tubers harvested in Ayacucho, Peru, and analyzed using elemental analysis for carbon, hydrogen, nitrogen, and sulfur (CHNS), inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and bomb calorimetry. The empirical formula is CH_1.74O_0.91N_0.06S_0.005 for black mashua and CH_1.78O_0.92N_0.05S_0.005 for yellow mashua. Black flour exhibited higher protein (17.6% vs. 14.8%) and fat contents (8.0% vs. 6.7%), along with nearly double the iron content. Both flours showed similar starch granule morphology and gelatinization enthalpy (~2 J/g), but the black flour had higher gelatinization temperatures. Calorimetric analysis revealed a greater net calorific value (qNCV) in black mashua flour (4157 ± 22 kcal/kg) than in yellow flour (4022 ± 19 kcal/kg). The thermogravimetric profiles indicated good thermal stability with approximately 30% residual mass. These findings suggested that black mashua flour possesses superior nutritional and energy characteristics, supporting its application in functional food formulations and energy-rich gluten-free products. Full article

Shaft alignment is adversely affected by the increasingly severe coupled hull–raft deformation in deep-diving, highly integrated submersibles, thereby compromising operational safety and potentially amplifying vibration noise. To address to this issue, this paper investigates an intelligent alignment control method for the floating raft air spring mounting system (ASMS) applied to marine propulsion unit (MPU) under coupled hull–raft deformation conditions. A multi-objective alignment control algorithm was developed based on the NSGA-II optimization method within an N-step receding horizon optimal control framework, enabling simultaneous achievement of shaft alignment attitude adjustment, hull deformation compensation, raft deformation suppression, and pneumatic energy consumption. Experimental validation was conducted on two distinct ASMS prototypes to evaluate the control algorithm. Tests performed on the ASMS for MPU (MPU-ASMS) prototype demonstrated effective compensation of hull-induced deformations, maintaining shaft alignment offsets within ±0.3 mm and angularities within ±0.5 mm/m. Concurrently, experiments on the floating raft ASMS for the stern compartment (SC-FR-ASMS) achieved precise control of axial offsets within ±0.3 mm, angularities within ±0.5 mm/m, and vertical displacements of critical monitoring points within ±1 mm. The adaptive control strategy additionally proved effective in suppressing raft deformation while simultaneously optimizing pneumatic energy consumption. This research provides robust theoretical and technical foundations for intelligent vibration isolation systems in deep-sea equipment to accommodate extreme-depth-induced hull deformation and large-scale raft deformation. Full article

Influenza A viruses that cause pandemics, as well as other harmful pathogens (e.g., SARS-CoV-2 variants), are known as the ‘silent bioterrorists’ of the 21st century. Due to high mutability, anti-influenza chemotherapeutic treatment is a vital defense strategy to combat both seasonal and pandemic influenza strains, especially when vaccines fail. Consequently, the development of novel therapies to combat this serious threat is of great concern. Hence, in this study, 3-(2-thienyl) acrylic acid (TA) was converted into amides of anti-influenza drugs (aminoadamantanes and oseltamivir) through TBTU-mediated coupling. The crystal structures of the thienyl-based amide hybrids (TA-Am (1), TA-Rim (2), TA-Os-OEt (3), and TA-OsC (4)) were also investigated using single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). Moreover, the antiviral activities of the hybrids against influenza virus A/Fort Monmouth/1/1947 (H1N1), clinically isolated influenza strain A/Wuhan/359/1995 (H3N2), and oseltamivir-resistant A/Jinnan/15/2009 (H1N1) were evaluated in vitro. Amongst the tested thienyl-based amides, bisamide 8 (Boc-Os-Hda-TA) exhibited the most potent activity against influenza virus A (A/Wuhan/359/1995) with an IC₅₀ value of 18.52 μg/mL and a selectivity index (SI) = 13.0. Full article

Multimode VCSELs coupled into waveguides can be a practical path toward realizing commercially viable photonic interposer chips. The experimental coupling of multimode VCSEL light to a non-silicon waveguide fabricated using a CMOS-compatible process is demonstrated. The GaP prism was tested and adopted as a coupling method. Both conventional and cavity-type optical waveguides, fabricated from CMOS-compatible PECVD SiO₂, Si₃N₄, and SiO_xN_y materials, were evaluated. The average propagation loss transmitted through the cavity-type waveguide was measured as 0.444 dB/cm. A polyimide micro-lens, cavity-type waveguide, and a GaP prism coupler are developed to inject the multimode VCSEL light into the waveguide measuring the net coupling loss of 0.762 dB. The packaged size of VCSEL has an area of 0.4 mm² and a height of 0.64 mm. MUX/DeMUX was designed on the bottom of the prism. A light source, a modulator, and MUX/DeMUX are all located in the same area of the prism bottom in VCSEL-based interconnections. Full article

With the advancement of oil and gas exploration and development technologies into deeper and ultra-deep reservoirs, complex geological conditions here render them highly susceptible to severe lost circulation. However, conventional bridging plugging methods struggle with large-sized lost circulation channels, while chemical gel plugging faces challenges such as low success rates and insufficient pressure-bearing capacity. To address this, a novel leak plugging method combining bridging and gel plugging is proposed herein. From structural stability and mechanical properties perspectives, the enhancing effect of nanomaterials on the gel system is revealed, and the synergistic mechanism of gel-bridging coupled plugging is elucidated. For the experimental setup, orthogonal experiments determined a base formulation with controllable gelation time: 10 wt% main agent, 2 wt% crosslinking agent, and a 1:3 pH regulator ratio. Introducing 1.0 wt% nanosilica enhanced gel properties, achieving 30 N strength at 120 °C aging. An optimized walnut shell bridging agent constructed the supporting skeleton, yielding a coupled plugging formulation with up to 8 MPa pressure for a 7 mm fracture. Lost circulation volume is controlled at 163 mL, outperforming single plugging methods. Research results demonstrate gel-bridging coupled plugging’s advantages for large fractures, providing new technical insights for severe lost circulation field construction. Full article

Solute carrier family 12 (SLC12) encodes electroneutral cation-coupled chloride cotransporters responsible for transmembrane ion transport (Na⁺, K⁺, and Cl⁻), which play a critical role in aquatic osmoregulation. However, the SLC12 gene of Exopalaemon carinicauda (EcSLC12) has not been systematically identified or functionally characterized. In this study, six EcSLC12 genes were identified across the genome and classified into N(K)CC, KCC, CCC9, and CIP subfamilies. Three NKCC1 homologous genes (EcSLC12A2.1, EcSLC12A2.2, and EcSLC12A2.3) were reported for the first time in crustaceans. The EcSLC12 family exhibited distinct expression patterns in response to low-salinity, high-alkalinity, and saline–alkaline stress. EcSLC12A2.2 was highly expressed in the gill, and its expression was closely correlated with saline–alkaline acclimation. Additionally, EcSLC12A2.2 knockdown decreased E. carinicauda survival under saline–alkaline stress. Thus, EcSLC12A2.2 plays critical roles in osmotic regulation and saline–alkaline acclimation. This study provides crucial insights into E. carinicauda’s saline–alkaline tolerance mechanisms, and the discovery of multiple NKCC1 homologs fills a gap in the crustacean SLC12 gene family research. Full article

Aiming at the problems of borehole shrinkage and pipe sticking caused by creep in salt-gypsum rock formations during deep well drilling, multi-field coupling creep experiments on deep salt-bearing gypsum mudstone were carried out. Furthermore, a nonlinear creep constitutive model was constructed based on the Drucker–Prager criterion, and the critical value of liquid column pressure for borehole shrinkage was determined through numerical simulation. Experiments show that at 140 °C, salt-gypsum rock is mainly subjected to brittle failure with single shear fracture, while at 180 °C, multiple sets of cross-cutting shear bands form, shifting to plastic flow-dominated composite failure. The coupling effect of confining pressure and deviatoric stress is temperature-dependent; the critical deviatoric stress is independent of confining pressure at 140 °C, but decreases significantly with increasing confining pressure at 180 °C, revealing that salt-gypsum rock is more prone to plastic flow under high temperatures and confining pressure. The creep constitutive equation was further determined, and fitting parameters show that the stress exponent m = 2–5 and the time exponent n decrease linearly with the increase in deviatoric stress, and the model can accurately describe the characteristics of three-stage creep. The numerical simulation found that there is a nonlinear relationship between the drilling fluid density and borehole shrinkage; the shrinkage rate exceeds 1.47% when the density is ≤2.0 g/cm³, and the expansion amount is >1.0 mm when ≥2.4 g/cm³. The critical safe density range is 2.1–2.3 g/cm³, which is consistent with the field data in the Bayan area. The research results provide an experimental basis and quantitative method for the dynamic regulation of drilling fluid density in deep gypsum rock formations, and have engineering guiding significance for preventing borehole wall instability. Full article

Pyridinecarbonitriles (pyCN), also referred to as cyanopyridines, are promising ligands for the formation of pyridine-based coordination compounds due to their two different N-donor atoms, which enable versatile coordination modes. Copper(II) complexes containing pyCN derivatives are of particular interest for their potential applications in medicinal chemistry and materials science. In this study, the synthesis, structural characterization, and thermal and magnetic properties of three new copper(II) complexes with 3-pyCN, 4-pyCN, and ethyl picolinimidate, obtained in situ by means of alcoholysis of 2-pyCN, are reported: [Cu₂(μ-Ac)₄(3-pyCN)₂] (1), [Cu(H₂O)₂(Etpic)₂]NO₃ (2), and [Cu(NO₃)₂(CH₃CN)(4-pyCN)₂]·CH₃CN (3). Single-crystal X-ray diffraction confirmed that complex 1 features a dinuclear paddle-wheel structure with bridging acetato ligands and monodentate 3-pyCN molecules, coordinated through the ring nitrogen, while complexes 2 and 3 are mononuclear. Thermal analysis showed an intense and highly exothermic decomposition of complex 3, containing nitrate ligands. Magnetic measurements revealed strong antiferromagnetic coupling in the dinuclear complex 1, whereas complexes 2 and 3 displayed paramagnetic behavior with effective magnetic moments ranging from 1.8 μ_B to 2.0 μ_B, consistent with isolated Cu(II) centers. Full article

The 1:1 stoichiometric reactions of α-amino isobutyric acid (H₂Aib) and diaminosilanes of the type SiRR′(NR¹R²)₂ (SiMe₂(imidazol-1-yl)₂, SiMe₂(NHnPr)₂, and SiRR′(pyrrolidin-1-yl)₂ with R,R′ = Me,Me, Me,H, Me,Vi, and Et,Et) afforded the pentacoordinate silicon complexes (Aib)SiRR′(HNR¹R²) with the release of one equivalent of HNR¹R². Single-crystal X-ray diffraction analyses confirmed the coordination of the N-donor Lewis base (i.e., imidazole, n-propylamine, and pyrrolidine, respectively) in an axial position of the distorted trigonal-bipyramidal Si-coordination sphere, trans to the carboxylate O atom of the Si-chelating Aib-dianion. The N–H moieties of the adduct-forming Lewis bases are involved in N–H⋯O hydrogen bonds with carboxylate groups of adjacent complex molecules, thus supporting the supramolecular structures of these adducts. The equatorially bound NH group of the Aib-dianion is involved in N–H⋯O hydrogen bonds in most cases, and it gives rise to residual dipolar coupling of the ¹⁴N nucleus with its directly bound atoms C and Si, thus causing characteristic shapes of both the ²⁹Si and ¹³C NMR signals of these two atoms in the solid-state spectra. In contrast to the adduct-formation reactions, the analogous conversion of H₂Aib and SiMe₂(NHtBu)₂ did not afford an amine adduct. Instead, a second equivalent of H₂Aib entered the reaction, and the ionic silicon complex [tBuNH₃]⁺[(Aib)₂SiMe]⁻ was obtained and characterized by crystallography and solution NMR spectroscopy. Full article

Employing some simple physics-inspired density-based information-theoretic approach (ITA) quantities to predict the electron correlation energies remains an open challenge. In this work, we expand the scope of the LR(ITA) (LR means linear regression) protocol to more complex systems, including (i) 24 octane isomers; (ii) polymeric structures, polyyne, polyene, all-trans-polymethineimine, and acene; (iii) molecular clusters, such as metallic Be_n and Mg_n, covalent S_n, hydrogen-bonded protonated water clusters H⁺(H₂O)_n, and dispersion-bound carbon dioxide (CO₂)_n, and benzene (C₆H₆)_n clusters. With LR(ITA), one can simply predict the post-Hartree-Fock (such as MP2 and coupled cluster) electron correlation energies at the cost of Hartree-Fock calculations, even with chemical accuracy. For large molecular clusters, we employ the linear-scaling generalized energy-based fragmentation (GEBF) method to gauge the accuracy of LR(ITA). Employing benzene clusters as an illustration, the LR(ITA) method shows similar accuracy to that of GEBF. Overall, we have verified that ITA quantities can be used to predict the post-Hartree-Fock electron correlation energies of various complex systems. Full article

Polycyclic aromatic hydrocarbons (PAHs) are recognized carcinogens that enter the food chain through pre-existing environmental contamination (air, water, soil), and their formation and accumulation during food preparation and processing involve high temperatures. We established a modified QuEChERS GC-MS method that couples n-hexane-saturated acetonitrile containing 1% toluene with a freeze-out step. Compared to the previously reported ACN QuEChERS protocol, this method enhanced PAH desorption and suppressed lipid interference across four matrices. The method linearity (R² ≥ 0.99), limit of detection (LOD, from 0.03 to 0.20 μg/kg), limit of quantitation (LOQ, from 0.10 to 0.60 μg/kg), and intra-/inter-day precision (≤5.7% RSD) all satisfied AOAC criteria. The modified QuEChERS reduced solvent consumption and shortened preparation time compared to other conventional extraction methods. The developed method was applied to 302 retail food samples, and Kezuribushi was found to have the highest concentration of the 4PAHs, reaching 22.0 µg/kg. Risk assessment based on EFSA’s margin-of-exposure (MOE) approach identified grilled chicken feet (MOE = 7604) as a potential health concern, as this value falls below EFSA’s threshold of 10,000 for potential risk characterization. The validated method enables sensitive and scalable monitoring of PAHs in complex food matrices within the tested matrices and conditions. Full article

Aims: Diabetes mellitus (DM) increases cardiovascular risk by inducing atherosclerotic plaque instability. StemBell therapy (i.e., adipose tissue-derived stem cells (ASCs) coupled to ultrasound-activated microbubbles) previously improved plaque stability in non-DM ApoE^−/− mice. Here, we investigated the effect of StemBell therapy on atherosclerotic plaque characteristics in a streptozotocin-induced DM mouse model. Methods: DM was induced in male C57BL/6 ApoE^−/− mice (n = 18) via intraperitoneal streptozotocin (STZ) injection (0.05 mg/g bodyweight) for 5 consecutive days. Eight weeks after the first STZ injection, the mice received either 5 × 10⁵ StemBells or vehicle intravenously. Due to unexpected mortality, the experiment was halted and restarted in week 9 with a final reduced dose of 1.25 × 10⁵ StemBells to avoid complications. The effect of StemBell therapy on plaque characteristics was determined 4 weeks post-treatment in five vehicle-treated and five StemBell-treated mice via (immuno)histochemical analyses. Furthermore, plasma monocyte subsets within 3 days pre- and 3 days post-treatment, and 3 weeks post-treatment, were studied via flow cytometry. Results: StemBell therapy did not significantly affect atherosclerotic plaque size or intra-plaque inflammation. StemBell-treated mice had less intra-plaque Ly6G+ neutrophils (0.4 ± 0.5%) and intra-plaque Mac3+ pan-macrophages (17.7 ± 3.4%), but more CD163+ anti-inflammatory M2 macrophages (p = 0.5) compared to vehicle-treated mice, although this was non-significant. Conclusions: StemBell therapy did not significantly affect atherosclerotic plaque size or intra-plaque inflammation in a streptozotocin-induced DM mouse model. Future research is essential to explore the potential and limitations of StemBell therapy in DM-related atherosclerosis. The higher mortality of StemBell therapy in diabetic mice compared to the previous non-diabetic mice also warrants further investigation. Full article

The structure of N-[(2H-1,3-benzodioxol-5-yl)methyl]-2-(2,2,2-trichloroacetamido)benzamide was verified by using a combination of 1D and 2D NMR techniques. Fully assigned data from 1D NMR (¹H, ¹³C and DEPT 135) and 2D NMR (COSY, HMQC, HMBC) spectra was presented for the compound. The ¹H NMR spectrum of the ABX spin system in the benzodioxol moiety was simulated to predict the corresponding ⁿJ_HH coupling constants. The spectral assignments for the structure were supported by interpretive library search and HOSE predictions. Full article

MRGPRX2 (Mas-related G protein-coupled receptor member X2) is implicated in mast cell (MC)-driven disorders due to its ability to bind diverse ligands, which may be G-protein-biased or balanced, with the latter activating both G-proteins and the β-arrestin pathway. Icatibant, a peptide drug, produces injection-site reactions in most patients and is used experimentally to probe MRGPRX2 function in skin tests. While reported to be G-protein-biased, it is unknown how skin MCs respond to icatibant, although these are the primary target cells during therapy. We therefore compared responses to icatibant with those induced by the balanced agonist substance P (SP) in skin MCs. Degranulation and desensitization were assessed via β-hexosaminidase release, receptor internalization by flow cytometry, and downstream signaling by immunoblotting. Skin MCs degranulated in response to SP and icatibant, relying on Gi proteins and calcium channels; Gq and PI3K (Phosphoinositide 3-kinase) contributed more strongly to exocytosis following icatibant, while JNK (c-Jun n-terminal kinase) was more relevant for SP. Both agonists activated ERK, PI3K/AKT, and (weakly) p38. Surprisingly, and in contrast to the LAD2 (Laboratory of Allergic Diseases 2 mast cell line) MC line, icatibant was at least as potent as SP in eliciting MRGPRX2 internalization and (cross-)desensitization in skin MCs. These findings suggest that icatibant functions differently in primary versus transformed MCs, acting as a fully balanced ligand in the former by triggering not only degranulation but also receptor internalization and desensitization. Therefore, not only the ligand but also the MRGPRX2-expressing cell plays a decisive role in whether a ligand is balanced or biased. These findings are relevant to our understanding of icatibant’s clinical effects on edema and itch. Full article

Cyanobacterial blooms in urban rivers present critical ecological threats worldwide, yet their mechanisms in fluvial systems remain inadequately explored compared to lacustrine environments. This study addresses this gap by investigating bloom dynamics in the eutrophic Majiagou River (Harbin, China) through phytoplankton resource use efficiency (RUE), calculated as chlorophyll-a per unit TN/TP. Seasonal sampling (2022–2024) across 25 rural-to-urban sites revealed distinct spatiotemporal patterns: urban sections exhibited 1.9× higher cyanobacterial relative abundance (RAC, peaking at 40.65% in autumn) but 28–30% lower RUE than rural areas. Generalized additive models identified nonlinear RAC–RUE relationships with critical thresholds: in rural sections, RAC peaked at TN-RUE 40–45 and TP-RUE 25–30, whereas urban sections showed lower TN-RUE triggers (20–25) and suppressed dominance above TP-RUE 10. Seasonal extremes drove RUE maxima in summer and minima during freezing/thawing periods. These findings demonstrate that hydrological stagnation (e.g., river mouths) and pulsed nutrient inputs reduce nutrient conversion efficiency while lowering bloom-triggering thresholds under urban eutrophication. The study establishes RUE as a predictive indicator for bloom risk, advocating optimized N/P ratios coupled with flow restoration rather than mere nutrient reduction. This approach provides a science-based framework for sustainable management of urban river ecosystems facing climate and anthropogenic pressures. Full article