Surface Distribution Research Articles

Rituximab-IgG2 is a phagocytic enhancer in antibody-based immunotherapy of B-cell lymphoma by altering CD47 expression

Antibody-dependent cellular phagocytosis (ADCP) by monocytes and macrophages contributes significantly to the efficacy of many therapeutic monoclonal antibodies (mAbs), including anti-CD20 rituximab (RTX) targeting CD20+ B-cell non-Hodgkin lymphomas (NHL). However, ADCP is constrained by various immune checkpoints, notably the anti-phagocytic CD47 molecule, necessitating strategies to overcome this resistance. We have previously shown that the IgG2 isotype of RTX induces CD20-mediated apoptosis in B-cell lymphoma cells and, when combined with RTX-IgG1 or RTX-IgG3 mAbs, can significantly enhance Fc receptor-mediated phagocytosis. Here, we report that the apoptotic effect of RTX-IgG2 on lymphoma cells contributes to changes in the tumor cell’s CD47 profile by reducing its overall expression and altering its surface distribution. Furthermore, when RTX-IgG2 is combined with other lymphoma-targeting mAbs, such as anti-CD59 or anti-PD-L1, it significantly enhances the ADCP of lymphoma cells compared to single mAb treatment. In summary, RTX-IgG2 acts as a potent phagocytic enhancer by promoting Fc-receptor mediated phagocytosis through apoptosis and reduction of CD47 in CD20+ malignant B-cells. RTX-IgG2 represents a valuable therapeutic component in enhancing the effectiveness of different mAbs targeting B-cell NHL.

Alumina Crucibles from Free Dispersant Suspensions: A Useful Labware to form Advanced Powders for Radiation Dosimetry

Background: Powder technology provides conditions to control particle-particle interactions that drive the formation of final-component/material, which also includes the crystalline structure, microstructure and features. Alumina (Al2O3) is the most studied ceramic based material due to its useful properties, disposal, competitive price, and wide technological applicability. This work aims to produce alumina crucibles with controlled size and shape from free dispensant suspensions. These crucibles will be used as containers for the synthesis of new materials for radiation dosimetry. Methods: The Al2O3 powders were characterized by XRD, SEM, PCS, and EPR. The stability of alumina particles in aqueous solvent was evaluated by zeta potential determination as a function of pH. Alumina suspensions with 30 vol% were shaped by slip casting in plaster molds, followed by sintering at 1600oC for 2 h in an air atmosphere. Alumina based crucibles were characterized by SEM and XRD. Results: ɑ-Al2O3 powders exhibited a mean particle diameter size (d50) of 983nm. Besides, the stability of particles in aqueous solvent was achieved at a range of pH from 2.0-6.0, and from 8.5-11.0. EPR spectra revealed two resonance peaks P1 and P2, with g-values of 2.0004 and 2.0022, respectively. The as-sintered ɑ-alumina based crucibles presented uniform shape and controlled size with no apparent defects. In addition, the final microstructure driven by solid-state sintering revealed a dense surface and uniform distribution of grains. Conclusion: The ɑ-Al2O3 crucibles obtained by slip casting of free dispensant alumina suspensions, followed by sintering, exhibited mechanical strength, and controlled shape and size. These crucibles will be useful labwares for the synthesis of new materials for radiation dosimetry.

Structural, optical, and dielectric Properties of Sr2+ substituted Ba1-xSrx(Co1/2W1/2)O3 ceramics for wireless application

The solid solution of Ba1-xSrx(Co1/2W1/2)O3, (BSCWO), (0.0 ≤ x ≤ 0.60) ceramics has been prepared via conventional solid-state reaction route. In this work, the impact spawned by doping Sr2+ cation on the phase, dielectric, optical and morphological properties of (BSCWO), ceramics has been investigated with respect to the frequency range of 1-3GHz. The X-ray diffraction patterns revealed that the base sample has a tetragonal structure, while Sr+2 doped samples exhibit orthorhombic structure. The appearances of the surface and grain size distribution of samples are analyzed using scanning electron microscope (SEM). The FTIR study confirms the presence of metal-oxygen bond and functional groups. The dielectric properties of the prepared samples were strongly dependent on the frequencies and as well as on concentration. The UV-visible absorption spectra results, the band gap energy (Eg) drops from 2.56 to 2.37 eV with an increasing the Sr2+ contents. The EDX (energy dispersive x-rays) spectroscopy corroborate the presence of Ba, Sr, Co, and W elements. We observed the lowest dielectric loss (tan = 0.092) and the highest dielectric constant (εr = 51) at contents (x = 0.60), making it a promising option for wireless device applications.

Statistical analysis of HAADF-STEM images to determine the surface coverage and distribution of immobilized molecular complexes

Statistical analysis of HAADF-STEM images to determine the surface coverage and distribution of immobilized molecular complexes

Synthesis of double-shell microcapsule containing MOF as the curing agent of epoxy resin

Microcapsule-type curing agents that have a single polymer shell encounter challenges due to the inadequate airtightness of the shell material, which affects the storage stability of the epoxy resin (EP) once it has been mixed. In this work, a microcapsule-type latent curing agent with an extended storage period was successfully prepared by introducing a metal-organic framework (MOF) as its second-layer shell. Imidazole (Im), as a curing agent, was initially encapsulated in polyurethane (PU) via the interfacial polymerization to form the single-shell microcapsule (Im@PU), in which different morphologies and core contents (IPM1-7) were obtained by adjusting the mass ratio of the core to shell. The optimal formulation, designated as IPM2, was determined due to its smooth surface and uniform size distribution. Subsequently, ZIF-8 was co-coordinated and grown on the surface of IPM2 to form a double-shell microcapsule-type curing agent (Im@PU@ZIF-8). The Im@PU@ZIF-8 exhibits delayed kinetic behaviors and enhanced storage stability. Notably, the Im@PU@ZIF-8 can be reliably stored for over 35 days at 40 °C. Meanwhile, the shell material ZIF-8 can be employed as a functional filler to enhance the mechanical properties of epoxy composites. This feasible strategy develops innovative ideas for the EP-latent curing agent systems and aims to establish a general method.

Optical and molecular techniques are complementary to understand the characteristics of dissolved organic matter in the runoff from sloping croplands with various micro-topographies during rainfall

Dissolved organic matter (DOM) is a vital component of biogeochemical cycles in soil and aquatic ecosystems. The distribution of surface and sub-surface runoff was affected by surface micro-topographic conditions during rainfall, which results in the differences in DOM content and composition. Whereas, the connections between the optical and molecular characteristics of DOM in the runoff from different micro-topographies caused by tillage managements remains unclear. Therefore, optical spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were combined to explore the DOM chemistry in the runoff from different runoff plots with various micro-topographies caused by four typical tillage managements (i.e. flat tillage, longitudinal tillage, contour tillage, and artificial digging tillage) in this study. The results observed a significant difference in optical and molecular parameters between surface and sub-surface runoff for the specified runoff plot, but little variations in DOM chemistry between different runoff plots with various micro-topographies for the given runoff type. These differences in the DOM content and composition of runoff were limited by the flow carrying capacity and source supplying capacity of DOM. Significant correlations between optical and molecular parameters in surface and sub-surface runoff were found by Spearman correlation analysis. Furthermore, the bipartite networks further indicated the optical and molecular datasets in sub-surface runoff showed greater consistency and correlation intensity. These correlations and some of the inconsistencies indicated that optical and molecular technologies are complementary to trace DOM chemistry. This research is of significance to further clarify the migration patterns of DOM in global soil and aquatic ecosystems, and reveal the influence of rainfall-runoff processes on the migration of biogenic elements in ecosystems.

Evaluation of impervious surface extraction based on Qimingxing-1 nighttime light and point of interest data

ABSTRACT Impervious surface extraction is essential for environmental management and urban studies. Although nighttime light data have been widely used for this purpose, few studies have utilized the high-resolution (21 m) Qimingxing-1 data released in 2022, which offer significantly higher spatial resolution compared to the widely used NPP-VIIRS product (750 m). In this study, the effectiveness of Qimingxing-1 nighttime light data for impervious surface extraction was investigated for the first time using the highly urbanized city of Dongguan as an example. We combined nighttime light data with POI data to create a ‘Nighttime-POI’ (NP) index and extracted impervious surfaces from four datasets (Qimingxing-1, NPP-VIIRS, QM_NP, and NPP_NP) using the thresholding method. Comparisons with reference data from Landsat 8 and Sentinel-2 revealed that the Qimingxing-1 data improved extraction accuracy by 2.7% over NPP-VIIRS. The Qimingxing-1 data could more accurately reflect the spatial distribution of impervious surfaces and imperviousness degree. Additionally, combining nighttime light data with POI data further enhanced accuracy by 2–3%, resulting in more accurate boundaries and detailed information on impervious surfaces. In conclusion, the Qimingxing-1 data are highly advantageous for impervious surface extraction. The high-precision impervious surface results can assist the government in promptly comprehending the dynamics of urban development.

Role of Loading Rate on Cracking Behavior in Granite Disks With Laboratory Experiments and Grain‐Based Modeling

ABSTRACTThe investigation of the tensile properties of rock materials is essential for understanding the failure mechanism of engineering rock masses. In this study, we conducted a series of Brazilian splitting tests on granite specimens under three different loading rates, concurrently monitored using acoustic emission (AE) and digital image correlation (DIC) techniques. The results show that the mechanical parameters of granite disks are positively correlated with the loading rate. The AE waveforms are found to be associated with the lower frequency band, suggesting that this frequency range primarily dominates the failure mechanism in granite disks. Furthermore, the onset of micro‐tensile fractures precedes the development of micro‐shear ones. The elevation distribution of the fractured surfaces of the granite disks follows a Gaussian function. The fractal dimension increases progressively with the loading rate, whereas the complexity and irregularity of the fractured surface decrease. Moreover, the cracking mechanism of granite disks at the microscale was revealed using grain‐based modeling (GBM). The intergranular tensile cracks predominantly form along the radial direction, and the proportion of intergranular shear cracks is the smallest.

Characterizing the marine iodine cycle and its relationship to ocean deoxygenation in an Earth system model

Abstract. Iodine (I) abundance in marine carbonates (measured as an elemental ratio with calcium, I / Ca) is of broad interest as a proxy for local/regional ocean redox. This connection arises because the speciation of iodine in seawater, the balance between iodate (IO3-) and iodide (I−), is sensitive to the prevalence of oxic vs. anoxic conditions. However, although I / Ca ratios are increasingly commonly being measured in ancient carbonate samples, a fully quantitative interpretation of this proxy requires the availability of a mechanistic interpretative framework for the marine iodine cycle that can account for the extent and intensity of ocean deoxygenation in the past. Here we present and evaluate a representation of marine iodine cycling embedded in an Earth system model (“cGENIE”) against both modern and paleo-observations. In this framework, we account for IO3- uptake and release of I− through the biological pump, the reduction in ambient IO3- to I− in the water column, and the re-oxidation of I− to IO3-. We develop and test a variety of different plausible mechanisms for iodine reduction and oxidation transformation and contrast model projections against an updated compilation of observed dissolved IO3- and I− concentrations in the present-day ocean. By optimizing the parameters controlling previously proposed mechanisms involved in marine iodine cycling, we find that we can obtain broad matches to observed iodine speciation gradients in zonal surface distribution, depth profiles, and oxygen-deficient zones (ODZs). However, we also identify alternative, equally well performing mechanisms which assume a more explicit mechanistic link between iodine transformation and environment – an ambiguity that highlights the need for more process-based studies on modern marine iodine cycling. Finally, to help distinguish between competing representations of the marine iodine cycle and because our ultimate motivation is to further our ability to reconstruct ocean oxygenation in the geological past, we conducted “plausibility tests” of different model schemes against available I / Ca measurements made on Cretaceous carbonates – a time of substantially depleted ocean oxygen availability compared to modern and hence a strong test of our model. Overall, the simultaneous broad match we can achieve between modeled iodine speciation and modern observations, and between forward proxy modeled I / Ca and geological elemental ratios, supports the application of our Earth system modeling in simulating the marine iodine cycle to help interpret and constrain the redox evolution of past oceans.

Angle-based residual strength estimation between geotextile/textured geomembrane interface

Geotextile and geomembrane are widely used in landfill liner systems, but the relationship between geomembrane roughness and geotextile/geomembrane interface residual shear strength remains to be studied. In this paper, by using a large-scale ring shear apparatus, a series of ring shear tests between geotextile/geomembrane was conducted, and the profile inclined angle distribution of the textured geomembrane surface was obtained by a profilometer. The experiment results showed that the geotextile/geomembrane interface has reached the residual status after a shear displacement of 3 m, and the average inclined angle of textured geomembrane was close to zero. With the increase of geomembrane asperity height, the interface residual strength increases. Through force analysis and statistical analysis, quantitative relationships between residual shear strength between geotextile/co-extruded geomembrane and geotextile/cone-shape structured geomembrane interfaces and inclined angle distribution were established. The model was validated by test results and case analysis. This study helps understand the mechanism that how the textured geomembrane surface caused high interface residual strength, and choose geomembrane with appropriate roughness to provide adequate residual strength in engineering applications.

Nano-Pd/SiO2 aerogel catalyst prepared via ambient pressure drying process using perlite powder in hydrogenation and cross-coupling reactions

Perlite, a cheap silica source with abundant reserves in countries such as Türkiye, China, and Greece, was used to produce nano Pd-doped silica aerogel powder for the first time in this study. The microstructure and morphology of the prepared silica aerogel powder were examined using SEM, FE-SEM, and TEM. The phases of the silica aerogel powders were analyzed via XRD (X-ray Diffraction) technique. The chemical bonding of the surface modifier with aerogels was analyzed by Fourier transform infrared spectroscopy (FTIR, Spectrum RX-1, Perkin Elmer). Surface areas, pore volumes, distributions, and particle sizes of the alumina-silica-based aerogel powders with a porous structure were measured using a Micromeritics/ASAP 2020 brand BET (Brunauer, Emmet, and Teller) device in a liquid nitrogen gas environment at 77K.The efficiency of this nano Pd-doped silica aerogel powder was investigated as a heterogeneous catalyst for well-known transformations in organic synthesis, such as alkene hydrogenation and cross-linking reactions. The results indicated that the developed method is chemoselective, reducing only carbon-carbon multiple bonds without affecting C-N or C-O multiple bonds, such as carbonyl and nitrile. The effectiveness of the newly developed catalyst was also investigated in Heck and Suzuki-Miyaura reactions, yielding the targeted products with high efficiency.Thus, an inexpensive, economical, and environmentally friendly method has been developed that is potentially applicable in the hydrogenation and cross-coupling reactions of alkenes.

Multifold Topological Point with Quadratic Order in Binary Skutterudite Rhodium Triarsenide.

The exploration of topological nodal point states has recently evolved, moving beyond traditional linear crossings to include higher-order dispersions and multifold degeneracies. This study utilizes first-principles calculations to uncover an ideal multifold nodal point of quadratic order in the binary skutterudite rhodium triarsenide. The band structures around this nodal point show not only simple configuration but also clean distribution. Notably, a type-III dispersion condition has also been identified. When considering the effects of spin-orbit coupling, the nodal point retains both its multiple degeneracy and quadratic characteristics, although the band degeneracy transitions from 3-fold to quadruple. Detailed symmetry argument and model analysis have been provided, and precise band surface distribution has been obtained. Furthermore, the material is characterized by multiple significant arc surface states, as confirmed by the projected topological surface states. The clear separation of these states from the bulk bands facilitates experimental investigation. In summary, the multifold nodal point state identified in this research, along with the corresponding material candidate, presents an exceptional platform for the further study of higher-order topological point states, potentially catalyzing advancements in this emerging field.

Luminescence Patterns on Multimillimeter Single-Crystal MAPbBr3 Microplatelets via Thermal Ablation Effects.

The single crystal distinguishes itself as the most outstanding representative of excellent optoelectronic performance among perovskite semiconductors due to its exceptional charge carrier properties, extraordinary optophysics, precise structural geometries, and superior material stabilities. However, it exhibits mediocre performance in light emission, which can be attributed to its excessive carrier diffusion lengths and extremely low recombination rates. To address this challenge, this study puts forward a controllable high-temperature annealing treatment strategy concentrating on multimillimeter-scale MAPbBr3 micrometer-thick platelet single crystals (MPSCs). Through the utilization of thermal ablation effects to convert the surface monocrystalline lattices into polycrystalline perovskite nanocrystals (PNCs) with a remarkably increased specific surface area, the fluorescence intensity arising from the rapid recombination of free carriers on the PNC surface is enhanced by 320 times compared to the pristine MPSC surface. These PNCs produced through surface annealing, with the characteristic of loose adhesion to surfaces, can be mechanically wiped away and regenerated in situ via reannealing the residual MAPbBr3 MPSCs, guaranteeing high intensity, durability, and standard geometric fluorescence. Moreover, by regulating the surface distributions of thermal ablation effects and carrying out embossing annealing treatment or laser direct writing, we can design and fabricate relatively complex, high-contrast (255×), and clearly resolved fluorescence patterns on MPSC surfaces.

Adaptive Beamforming for On-Orbit Satellite-Based ADS-B Based on FCNN.

Digital multi-beam synthesis technology is generally used in the on-orbit satellite-based Automatic Dependent Surveillance-Broadcast (ADS-B) system. However, the probability of successfully detecting aircraft with uneven surface distribution is low. An adaptive digital beamforming method is proposed to improve the efficiency of aircraft detection probability. The current method has the problem of long operation time and is not suitable for on-orbit operation. Therefore, this paper proposes an adaptive beamforming method for the ADS-B system based on a fully connected neural network (FCNN). The simulation results show that the calculation time of this method is about 2.6 s when more than 15,000 sets of data are inputted, which is 15-80% better than the existing methods. Its detection success probability is 10% higher than those of existing methods, and it has better robustness against large amounts of data.

Voltage-induced rearrangement in silver nanoparticles spatial distribution produced by EAFD method and its LSPR optimization

Abstract This paper presents a voltage-induced and thermal annealing rearrangement (VITAR) method based on modified electric field assisted film dissolution method as a flexible and powerful tool for manipulating nanoparticles spatial distribution based on drift and diffusion mechanisms that occur due to external DC voltage and thermal annealing processes. Different samples with various arrangements of external DC voltage and thermal annealing processes have been produced. The extinction and attenuated total reflection (ATR) spectra, as well as atomic force microscope (AFM) images, have been employed to investigate their optical and morphological properties. Four cases with arrangements of DV-Anl, DV-Anl-DV, DV-Anl-IV, and DV-IV-Anl have been studied. The AFM images show that by applying secondary voltage (direct or inverse voltage), it is possible to drift nanoparticles and change its morphology (size and shape) as well as surface and volume distributions. As a result, by applying a secondary direct voltage (in the DV-Anl-DV case), the surface density of nanoparticles decreases due to direct drift force. It is notable that in this case, the extinction peak and ATR depth have not significantly changed. By applying a secondary inverse voltage (in the DV-Anl-IV, and DV-IV-Anl cases), an increase in the surface density of the nanoparticles has been observed. Also, the extinction peak has increased, and the ATR depth has decreased in the DV-Anl-IV case, but in the DV-IV-Anl case, due to the uniform size of surface nanoparticles, the resonance power has shown a significant increase in both extinction and ATR spectra compared to other cases. The resulting changes in extinction and ATR spectra show that by using the VITAR process, the surface structure, morphology and its optical properties can be optimized and this method provides a great opportunity to enhance Localized Surface Plasmon Resonance effects, which can be employed in nano-optical devices.

Optimization of the performance of copper/graphite system for GIL Tri‐post grounding electrode based on plasma sintering technology

Grounding electrodes, as crucial components of GIL bushings, experience friction with the GIL shell during long-term operation, generating metal particles that induce partial discharge. This phenomenon can lead to internal insulation breakdown, severely compromising GIL operation. This study focuses on enhancing the wear resistance of grounding electrodes by proposing a solution involving copper-graphite composites. Copper/graphite composite materials were fabricated using Spark Plasma Sintering technology. Additionally, the impact of graphite content and particle size on wear resistance, hardness, and electrical conductivity was comprehensively analyzed. Performance evaluation using radar chart analysis identified the optimal solution. The results indicate that at a sintering temperature of 960 °C, pressure of 45 MPa, and holding time of 15 min, with a graphite mass fraction of 7 %, the grounding electrode material exhibits a smooth surface and uniform distribution of graphite. Furthermore, when the graphite particle size is 4 μm, the friction coefficient remains approximately 0.7 with minimal fluctuations. The abrasion produces scratches measuring only 190 μm, and the wear rate is recorded at 2.1128 × 10−4 mm³/N·m, while the hardness reaches 59.6 HV, an increase of 19.6 HV compared to a particle size of 40 μm. In conclusion, an appropriate graphite content effectively enhances the wear resistance of the grounding electrode, and a reduction in graphite particle size optimizes overall performance. When the composite material contains 7 % graphite with a particle size of 4 μm, the performance is optimal, allowing the grounding electrode to maintain its original properties while demonstrating excellent wear resistance. This study provides a significant approach to optimizing the performance of grounding electrodes.

Enhancing 4‐D Landslide Monitoring and Block Interaction Analysis With a Novel Kalman‐Filter‐Based InSAR Approach

AbstractIn recent years, Synthetic Aperture Radar Interferometry (InSAR) has become widely utilized for slow‐moving landslide monitoring due to its high resolution, accuracy, and extensive coverage. By integrating data from various orbits/platforms and monitoring sources, one‐dimensional (1‐D) line‐of‐sight (LOS) InSAR measurements can be explored to infer three‐dimensional (3‐D) movements. However, inconsistencies in observation times among different orbits and monitoring sources pose challenges in accurately capturing dynamic 3‐D movements over time (referred to as 4‐D). In this study, we propose a novel method, termed KFI‐4D that incorporates spatiotemporal constraints into the traditional Kalman filter. This enhancement transforms the underdetermined problem of 4‐D movement acquisition into a dynamic parameter estimation problem, enabling precise monitoring of landslide movements. The KFI‐4D method was evaluated using both synthetic data sets and real data from the Hooskanaden landslide, demonstrating an improvement exceeding 50% in root mean square errors (RMSEs) compared to conventional methods. Additionally, the high‐resolution characteristics of InSAR‐derived 4‐D movements allow for the analysis of strain invariants, providing insights into block interactions and landslide dynamics. Our findings reveal that strain invariants effectively indicate the distribution and activity of landslide blocks and slip surfaces as well as their response to triggers. Notably, abnormal signals identified in strain invariants prior to the catastrophic event at Hooskanaden suggest potential for early warning of landslides. The future integration of data from advanced satellites, such as NISAR, ALOS4 PALSAR3, and Sentinel‐1C, is expected to further enhance the KFI‐4D method's capabilities, improving temporal resolution and early warning potential for landslide monitoring.

Effect of Pulse Electrodeposition Mode on Microstructures and Properties of Ni-TiN Composite Coatings

Mild steel is a kind of material commonly used in the chemical industry and to manufacture machinery, farm tools, and other parts in order to improve the surface performance of the parts and prolong their service life. The Ni-TiN composite coating was fabricated through ultrasonic electroplating using a Ni-based sulfamic acid bath with added nano-TiN particles. The effects of three distinct current modes, direct current (DC), positive pulse current (PC), and positive–negative pulse current (PNPC), on various aspects of the coating, including surface morphology, TiN content and distribution, interface bonding strength, microhardness, friction and wear properties, as well as corrosion resistance, were investigated. The findings demonstrated that, in comparison to DC electroplating, PC electrodeposited Ni-TiN composite coatings yielded finer grains, smoother surfaces, reduced surface cracks, increased interface bonding strength, and enhanced corrosion resistance. Furthermore, PNPC electrodeposited Ni-TiN composite coatings showed higher interface bonding strength than those of PC electrodeposited Ni-TiN coatings and had the densest structure, leading to the best corrosion resistance. Pulse current electroplating enhanced the incorporation of nano-TiN particles, with a higher deposition rate observed in positive–negative pulse current electroplating compared to positive pulse current electroplating. Furthermore, the PNPC electrodeposited coating displayed improved microhardness and demonstrated the best friction and wear properties, while the DC electroplated coating displayed the least favorable performance in these aspects.

Investigating Pt/Pumice catalyst for efficient 3-methyl-1-butanol conversion

The objective of this study was to obtain a modified Pt/pumice catalyst to support the conversion reaction of 3-methyl-1-butanol under specific reaction conditions. To achieve this objective, the first step involved preparing modified pumice catalyst pellets by impregnating them with Pt metal followed by activation at a temperature of 500 °C. The second step involved characterizing the Pt/pumice catalyst, including the surface distribution of Pt metal using SEM. The third step involved conducting the catalyst activity test against 3-methyl-1-butanol in a reactor (furnace) at temperatures ranging from 400 to 500°C with a flow system for the feed. The fourth step involved analyzing the conversion results using GC-MS chromatograms. The research results showed that the Si/Al ratio in the modified Pt/Pumice catalyst using a PtCl4 solution with a concentration of 0.0321 M for impregnation was 4:1, compared to 4.8:1 for Pt/Zeolite and 3.2:1 for Pt/ABP. The modified catalyst activity test for 3-methyl-1-butanol showed the following conversion results: Pt/Pumice 27.63%, Pt/Zeolite 23.85%, Pt/Black Pumice 14.81%, and for platinum catalyst, the conversion was 22.35%. These results indicated that the highest conversion was observed in the treated sample A-3 under the reaction condition of 450°C. The conversion products analyzed using GC-MS showed the presence of three molecules: 3-methylbutanal, 2-methylbutanal, and anhydrous isobutanoate.

Extraction of Soluble Dietary Fiber from Sunflower Receptacles (Helianthus annuus L.) and Its Alleviating Effect on Constipation in Mice.

Sunflower receptacles are the main by-product of the processing of Helianthus annuus L. In this study, several extraction methods of soluble dietary fiber (SDF) from sunflower receptacles were evaluated, and then, the physicochemical structure and functional properties of these SDFs were examined. Finally, a mouse constipation model was established to explore its therapeutic potential for constipation. The results showed that the SDF yield of citric acid extraction and enzyme extraction was better than that of hot-water extraction. Structural characterization showed that the three SDF functional groups were similar and amorphous, while the surface distribution of the SDF obtained by the citric acid extraction method (ASDF) had more fine pores. Physicochemical analysis showed that ASDF had the best water-holding capacity, oil-holding capacity, and expansion force. Animal experiments showed that the first black stool defecation time of the model group changed significantly (p < 0.001), indicating that the model was successful. Compared with the model group, the middle- and high-dose groups reduced the first black stool defecation time (p < 0.05 or p < 0.01) and increased the fecal water content (p < 0.05). The high-dose group significantly promoted the intestinal peristalsis of mice (p < 0.05). From hematoxylin-eosin (H&E) staining, it can be seen that the three dose groups of ASDF can improve the damage of mouse colon tissue induced by loperamide hydrochloride to a certain extent. Our results show that ASDF has good physical and chemical properties and laxative properties and has broad development space in the field of health food.