Search Results (18,769)

In this study, a methacrylic derivative of xylan (XYLMA) was synthesized through transesterification reactions, with the aim of evaluating its physicochemical behavior and its interaction with kaolinite particles. Structural characterization by FT-IR and NMR spectroscopy confirmed the incorporation of methacrylic groups into the xylan (XYL) structure, with a degree of substitution of 0.67. Thermal analyses (TGA and DSC) showed a decrease in melting temperature and enthalpy in XYLMA compared to XYL, attributed to a loss of structural rigidity. Thermal analyses (TGA and DSC) revealed a decrease in the melting temperature and enthalpy of XYLMA compared to XYL, which is attributed to a loss of structural rigidity and a reduction in the crystalline order of the biopolymer. Aggregation tests in solution revealed that XYLMA exhibits amphiphilic behavior, forming micellar structures at a critical aggregation concentration (CAC) of 62 mg L⁻¹. In adsorption studies on kaolinite, XYL showed greater affinity than XYLMA, especially at acidic pH, due to reduced electrostatic forces and a greater number of hydroxyl groups capable of forming hydrogen bonds with the mineral surface. In contrast, modification with methacrylic groups in XYLMA reduced its adsorption capacity, probably due to the formation of supramolecular aggregates. These results suggest that interactions between xylan and kaolinite clay are key to understanding the role that hemicelluloses play in increasing copper recovery when added to flotation cells during the processing of copper sulfide ores with high clay content. Full article

This study presents a novel approach to FTIR spectroscopy at low temperatures under atmospheric pressure. The work aimed to confirm the efficiency of a fundamentally new cryogenic setup that enables material research under the specified conditions. The new technique combines a nitrogen-based cryogenic capillary cooling system with precise temperature monitoring via a PID controller, along with DRIFT spectroscopy for hydrocarbon materials. New fundamental data were obtained on the properties and behavior of hydrocarbon compounds such as methanol, kerosene, and ethanol. The IR spectra of these samples contain key characteristic vibrations of hydrocarbon functional groups, which demonstrate the effective operability of the cryogenic device. A detailed description of the setup and measurement technique is provided, along with a thorough comparison of the results with data from other authors. The application scope of the cryogenic device, the relevance of the research, and potential future developments are also discussed. Full article

This study analyzes the feasibility of energy mixes composed of different shares of various types of power generation units, including photovoltaic (PV) and wind farms, hydropower, fossil fuel-based plants, and nuclear power. The analysis uses the concept of Energy Return on Investment (EROI), which is considered the most reliable indicator for comparing different technologies as it measures the energy required rather than monetary costs needed to build and operate each technology. Literature-based EROI values for individual generation technologies were used, along with the minimum EROI thresholds for the entire energy mix that are necessary to sustain developed societies and a high quality of life. The results show that, depending on the assumed minimum EROI value, which ranges from 10 to 30, the maximum share of intermittent renewable energy sources (IRESs), such as PV and wind farms, in the system cannot exceed 90% or 60%, respectively. It is important to emphasize that this EROI-based analysis does not account for power grid stability, which currently can only be maintained by the inertia of large synchronous generators. Therefore, the scenario with a 90% IRES share should be regarded as purely theoretical. Full article

After reviewing the state of the art of the fluorination of inorganic solid electrolytes, an application of gas/solid fluorination is given and how it can be processed. Garnet-type oxide has been chosen. These oxides with an ideal structure of chemical formula A₃B₂(XO₄)₃ are mainly known for their magnetic and dielectric properties. Certain garnets may have a high enough Li⁺ ionic conductivity to be used as solid electrolyte of lithium ion battery. The surface of LLZO may be changed in contact with the moisture and CO₂ present in the atmosphere that results in a change of the conductivity at the interface of the solid. LiOH and/or lithium carbonate are formed at the surface of the garnet particles. In order to allow for handling and storage under normal conditions of this solid electrolyte, surface fluorination was performed using elemental fluorine. When controlled using mild conditions (temperature lower or equal to 200 °C, either in static or dynamic mode), the addition of fluorine atoms to LLZO with Li_6,4Al_0,2La₃Zr₂O₁₂ composition is limited to the surface, forming a covering layer of lithium fluoride LiF. The effect of the fluorination was evidenced by IR, Raman, and NMR spectroscopies. If present in the pristine LLZO powder, then the carbonate groups disappear. More interestingly, contrary to the pristine LLZO, the contents of these groups are drastically reduced even after storage in air up to 45 days when the powder is covered with the LiF layer. Surface fluorination could be applied to other solid electrolytes that are air sensitive. Full article

Films of functionalised multiwalled carbon nanotubes (MWCNTs) were fabricated as interlayers (interfacial layers between the cathode and separator) in a lithium–sulfur battery (LSB). Phenylsulfonate functionalisation of commercial MWCNTs was achieved via diazotisation to attach lithium phenylsulfonate groups and was characterised by IR and XPS spectroscopies. SEM-EDX showed sulfur and oxygen colocations due to the sulfonate groups on the interlayer surface. However, CHNS elemental microstudies showed a low degree of functionalisation. Without an interlayer, the LSB produced stable cycling at a capacity of 600 mA h g⁻¹_sulfur at 0.05 C for 40 cycles. Using an unfunctionalised interlayer as a control gave a capacity of 1400 mA h g⁻¹_sulfur for the first cycle but rapidly decayed to the same 600 mA h g⁻¹_sulfur at the 40th cycle at 0.05 C, suggesting a high degree of polysulfide shuttling. Adding a lithium phenylsulfonated interlayer gave an initial capacity increase to 1100 mA h g⁻¹_sulfur that lowered to 800 mA h g⁻¹_sulfur at 0.05 C by the 40th cycle, showing an increase in charge storage (33%) relative to the other cells. This performance increase has been attributed to lessened polysulfide shuttling due to repulsion by the phenylsulfonate groups, increased conductivity at the separator-cathode interface and an increase in surface area. Full article

High-voltage unipolar square wave pulsed electric fields (PEFs) can cause cell membrane rupture and cell death during a process termed irreversible electroporation (IRE). PEF effects are influenced by pulse parameters like number of pulses (NP), voltage (PV), width (PW), and interval (PI). This study systematically evaluates their effects on the conductivity and relative conductivity changes between untreated and PEF-treated regions of potato tissue across a frequency range of 1 Hz to 5 MHz by means of electrochemical impedance spectroscopy (EIS), using a custom-made four-point EIS probe with RG58/U coaxial cables. Potatoes were chosen as a plant-based PEF model to reduce animal experiments and untreated tissue showed minimal conductivity variation across regions. Relative conductivity changes were maximal at 1000 Hz. At 1000 Hz, significant conductivity differences between untreated and PEF-treated regions were observed from PV = 200 V, NP = 10, PW = 10 µs, and PI = 50 ms onwards (most significant changes occurred for PV = 700 V; NP = 70; PW = 70 µs; PI = 250 ms and 500 ms). Our results may be beneficial for multiphysics modelling of IRE with specific electrical properties, conductivity mapping with optimal contrast—such as in electrical impedance tomography—and development of IRE procedures. Full article

Background: Immune checkpoint inhibitors (ICIs) have reshaped the treatment landscape of metastatic melanoma. While combination regimens often demonstrate improved response and survival compared to monotherapy, they are also associated with a higher incidence of immune-related adverse events (irAEs). Understanding the balance between benefit and risk is essential for making informed treatment decisions, especially given the variability in reported outcomes across clinical trials. Methods: We conducted a systematic review and meta-analysis of 14 clinical trials (comprising 22 treatment arms and >5000 patients) comparing ICI monotherapy (nivolumab, ipilimumab, or pembrolizumab) and combination therapy (nivolumab + ipilimumab) in advanced melanoma. Treatment-related outcomes were synthesized using fixed-effects, random-effects, or generalized linear mixed models (GLMMs), depending on study variability. Survival data were extracted from published Kaplan–Meier curves and analyzed using longitudinal GLMMs to capture trends over time. Results: Compared to monotherapy, combination immunotherapy achieved higher clinical benefit, with an overall response of 52.2% (vs. 31.6%), a five-year overall survival of 55.7% (vs. 34.3%), and a five-year progression-free survival of 39.0% (vs. 17.2%). However, this benefit came with a higher risk of toxicity: immune-related adverse events occurred in 93.2% of patients receiving combination therapy versus in 81.9% receiving monotherapy. Differences were consistent across all individual severe toxicities. Conclusions: Combination immunotherapy offers greater long-term clinical benefit than monotherapy in metastatic melanoma but at the cost of increased toxicity. By applying models adapted to study variability, we provide more reliable estimates of treatment efficacy and risk. GLMMs provide the most robust estimates and enable the modeling of survival dynamics over time. These findings support evidence-based decision-making and highlight the value of model-informed meta-analysis in oncology. Full article

Skeletal muscle function is determinant for maintaining functional performance and independence in older adults. Muscle is a primary target of aging and insulin resistance (IR)—two conditions associated with functional decline. Sex-related differences may influence these effects at structural and functional levels. We aimed to evaluate the individual and combined effects of aging and IR on the function and structure of extensor digitorum longus (EDL) and soleus muscles in male and female rats. Animals aged 3 and 20 months were studied, with IR induced by 8 weeks of 20% fructose in drinking water. Muscle contractility was assessed alongside histological and hormonal analyses. In males, aging impaired EDL and soleus contractile force, free testosterone levels, and muscle mass. IR decreased muscle function only in young animals. In females, aging led to muscle loss without affecting contractile strength, but the combination of aging and IR reduced muscle contraction, decreased estradiol and exacerbated muscle loss. Both sexes showed aging-related loss of EDL glycolytic fibers, altered regenerative capacity, and increased fibrosis. IR alone reduced glycolytic fibers in young animals of both sexes but increased fibrosis only in males. These results highlight sex-specific effects of aging and IR on muscle function, relevant for targeted strategies to prevent and treat age- and IR-related muscle function decline. Full article

This work represents the first use of a phosphonium salt-functionalized β-Cyclodextrin polymer (β-CDP) as a highly selective sensing membrane for monitoring the safety of drinking water against perchlorate ions (ClO₄⁻) using electrochemical impedance spectroscopy (EIS). Structural confirmation via ¹H NMR, ¹³C NMR, ³¹P NMR, and FT-IR spectroscopies combined with AFM and contact angle measurements demonstrate how the enhanced solubility of modified cyclodextrin improves thin film quality. The innovation lies in the synergistic combination of two detection mechanisms: the “Host-Guest” inclusion in the cyclodextrin cavity and anionic exchange between the bromide ions of the phosphonium groups and perchlorate anions. Under optimized functionalization conditions, EIS reveals high sensitivity and selectivity, achieving a record-low detection limit (LOD) of ~10⁻¹² M and a wide linear range of detection (10⁻¹¹ M–10⁻⁴ M). Sensing mechanisms at the functionalized transducer interfaces are examined through numerical fitting of Cole-Cole impedance spectra via a single relaxation equivalent circuit. Real water sample analysis confirms the sensor’s practical applicability, with recoveries between 96.9% and 109.8% and RSDs of 2.4–4.8%. Finally, a comparative study with reported membrane sensors shows that β-CDP offers superior performance, wider range, higher sensitivity, lower LOD, and simpler synthesis. Full article

The robust detection of small targets is crucial in infrared (IR) search and tracking applications. Considering that many state-of-the-art (SOTA) methods are still unable to suppress various edges satisfactorily, especially under complex backgrounds, an effective infrared small target detection algorithm inspired by modified fast saliency and the weighted guided image filter (WGIF) is presented in this paper. Initially, the fast saliency map modulated by the steering kernel (SK) is calculated. Then, a set of edge-preserving smoothed images are produced by WGIF using different filter radii and regularization parameters. After that, utilizing the fuzzy sets technique, the background image is predicted reasonably according to the results of the saliency map and smoothed or non-smoothed images. Finally, the differential image is calculated by subtracting the predicted image from the original one, and IR small targets are detected through a simple thresholding. Experimental results on four sequences demonstrate that the proposed method can not only suppress background clutter effectively under strong edge interference but also detect targets accurately with a low false alarm rate. Full article

Hot water extraction (HE), enzyme-assisted hot water extraction (EAHE), ultrasonic-assisted extraction with NADES (UAE-NADES) and ultrasonic-assisted extraction with NADES and enzyme pretreatment (UAE-NADES-E) were employed to extract polysaccharides from Peucedani Decursivi Radix (PDR) and their structures were characterized for the first time. UAE-NADES-E was found to be the most effective extraction method, and the extraction process was optimized by Box–Behnken design (BBD)-response surface methodology (RSM) experiments. The optimal extraction process was determined by using a NADES system with a molar ratio of betaine to 1,3-butanediol of 1:3, a water content of 30%, a liquid/solid ratio of 40:1 mL/g, an ultrasound time of 30 min, an ultrasound temperature of 45 °C and an alcohol precipitation time of 6 h; the polysaccharide extraction yield reached 19.93%. Further, the structures of polysaccharides from PDR extracted by the above four methods were characterized by FT-IR, SEM, gel and anion-exchange chromatography. Eight monosaccharides were detected in the PDR polysaccharides extracted by the four methods. The PDR polysaccharides extracted by the UAE-NADES-E method had lower molecular weights compared with those extracted by the other methods. Moreover, the PDR polysaccharides exhibited obvious antioxidant activity, as revealed by DPPH, ABTS+ and hydroxyl radical scavenging experiments, meaning they have the potential to be developed as natural antioxidants. Full article

Background: Immune checkpoint inhibitors (ICIs) transformed cancer treatment, producing significant survival benefits. However, ICIs can trigger toxicities called immune-related adverse events (irAEs), including inflammatory arthritis (IA) and polymyalgia rheumatica (PMR)-like syndromes. Our study aimed to systematically further characterize musculoskeletal ultrasound (MSKUS) findings in patients with ICI-IA and ICI-PMR, collectively referred to as “MSK-irAEs”, and explore the role of US in guiding treatment. Methods: The authors conducted a comprehensive chart review for patients receiving ICIs undergoing MSKUS at our center’s rheumatology clinics. US examinations were performed and reviewed by two MSKUS-certified rheumatologists. Descriptive statistics were performed to summarize demographic, clinical, and treatment-related variables. US findings were categorized with a novel scoring system: 0—no signs of inflammatory arthropathy or tendinopathy, 1—potential signs of inflammation (grayscale ≥ 2, effusion without power Doppler, synovial hypertrophy in the joint), and 2—active inflammation in joints and/or tendons (characterized by power Doppler) and signs of inflammation. Results: Twenty-three patients were included. The median age was 63 years, 52% were male, and 87% were White. Melanoma was the most common cancer (48%). MSK-irAEs were diagnosed in nineteen (83%), with MSKUS showing inflammation in seventeen (74%). Sixteen (70%) received escalation in MSK-irAE treatment after MSKUS. Four (17%) had erosive disease due to MSK-irAEs, while one had erosive osteoarthritis. Individuals with inflammatory erosive changes experienced prolonged intervals between symptom onset and MSKUS, ranging from 17 to 82 months, suggesting that erosions may reflect chronic, under-recognized inflammation. On MSK-irAE therapy, nine (47%) experienced symptomatic improvement, five (26%) achieved resolution, and in four (21%) cases, it was too early to assess the response. MSKUS detected other causes of MSK symptoms besides MSK-irAEs in several patients, allowing ICI resumption in one. Conclusions: Our study highlights the clinical utility of MSKUS not only as a diagnostic tool but also to guide therapeutic decision-making. Full article

In this study, a novel adsorbent, UiO-66-H₃IMDC, was successfully prepared by functionalizing UiO-66 with imidazole-4,5-dicarboxylic acid (H3IMDC). The effective functionalization of H₃IMDC on UiO-66 was confirmed by powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FT-IR). The relationships between the adsorption of U(VI) on UiO-66-H₃IMDC and the contact time, the pH of the solution, as well as the initial concentration of U(VI) were investigated. Additionally, the selective adsorption of U(VI) by UiO-66-H₃IMDC and its cyclic regeneration performance were also studied. The results demonstrate that the UiO-66-H₃IMDC adsorbent exhibits excellent adsorption performance for uranium in aqueous solutions. Full article

Purpose: To investigate if radiomics signatures generated from longitudinal CT scans could predict IRE treatment effectiveness and outcomes in patients with locally advanced pancreatic cancer (LAPC). Methods: A cohort of 50 (60% male, mean [SD] age 60.7 [8.7] years) LAPC patients treated with IRE were retrospectively selected. Preoperative and 12-week follow-up CT scans were reviewed by two radiologists for tumor segmentation. A total of 2078 features were extracted: shape (n = 16), texture (n = 68), filter (n = 1892), intensity (n = 18), and local texture (n = 84). Principal component analysis (PCA) was applied to develop composite radiomics features. Composite signatures and clinically relevant radiomics features were correlated with time to recurrence (TTR), time to local recurrence (TTLR), time to distant recurrence (TTDR), recurrence-free survival (RFS) and overall survival (OS). Risk stratification performance was evaluated using hazard ratios (HRs), and significance was evaluated using the log-rank test. Results: Statistically significant separation between high and low patient TTR risk groups was observed in the following: gray-level co-occurrence matrix (HR = 2.65, p < 0.01, median survival difference = 6.6 mo); composite radiomics features derived from the following feature groups: all radiomics features (HR = 2.27, p = 0.01, median survival difference = 6.4 mo), intensity features (HR = 3.13, p < 0.01, median survival difference = 14.0 mo), and filter features (HR = 2.27, p = 0.01, median survival difference = 6.4 mo). Conclusions: Pre-treatment radiomics signatures were significantly associated with LAPC patient outcomes. The observed correlations used pre-treatment CT scans, implying that the features predict the individual risk of disease recurrence. Full article

Background: Ligusticum L. plants exhibit significant morphological variation in leaves, flowers, bracteoles and mericarps, thus the classifications of members for the genus have always been controversial. Among them, the taxonomic problem of Ligusticum multivittatum Franch. is the most prominent, which has not been sufficiently resolved so far. Methods: to clarify the taxonomic position of Ligusticum multivittatum, we performed phylogenetic analyses based on plastome data and ITS sequences. Meanwhile, we conducted comprehensively comparative plastome analyses between Ligusticum multivittatum and fifteen Ligusticopsis species. Results: Both analyses robustly supported that Ligusticum multivittatum nested in genus Ligusticopsis Leute and formed a clade with fifteen Ligusticopsis species, belonged to the Selineae tribe, which was distant from the type species of Ligusticum (Ligusticum scoticum), located in the Acronema clade.The comparative results showed that sixteen plastomes were highly similar and conservative in genome structure, size, gene content and arrangement, codon bias, SSRs and SC/IR. These findings imply that Ligusticum multivittatum is a member of Ligusticopsis, which was further verified by their shared morphological characters: stem base clothed in fibrous remnant sheaths, white petals, pinnate bracteoles, dorsally compressed mericarps with slightly prominent dorsal ribs, winged lateral ribs and numerous vittae in the commissure and in each furrow. Therefore, combining with the evidences of phylogenetic analyses, plastome comparison and morphological features, we affirmed that Ligusticum multivittatum indeed belonged to Ligusticopsis and transformed it into Ligusticopsis conducted by Pimenov was reasonable. Conclusions: Our study not only confirms the classification of Ligusticum multivittatum by integrating evidences, but also provides a reference for resolving taxonomy of contentious taxa. Full article