RESUMO
This study combined rice starch (RS) with cactus polysaccharide (CP) at different composites (0.6%, 1.2%, 1.8%, 2.4%, and 3.0%, w/w), and analyzed the variations in the complex gelatinization properties, rheological properties, thermal properties, structural properties, digestibility, and freeze-thaw stability. As a result, the pasting parameters (p < 0.05) and storage modulus (G') together with the loss modulus (Gâ³) decreased as the CP concentration increased; meanwhile, the RS and the CP-RS gels were pseudoplastic fluids. As revealed by differential scanning calorimetry (DSC), incorporating CP into the starch elevated the starch gelatinization temperature while decreasing gelatinization enthalpy, revealing that CP effectively retarded long-term retrogradation in RS. The gel microstructure and crystallization type altered after adding CP. Typically, CP inclusion could enhance the proportion of resistant starch and slowly digestible starch (SDS), thereby slowing RS hydrolysis. Concurrently, adding CP promoted the RS freeze-thaw stability. These findings could potentially aid in the innovation of CP-based food products.
RESUMO
Background: Background parenchymal enhancement (BPE) is defined as the enhanced proportion of normal fibroglandular tissue on enhanced magnetic resonance imaging. BPE shows promise as a quantitative imaging biomarker (QIB). However, the lack of consensus among radiologists in their semi-quantitative grading of BPE limits its clinical utility. Methods: The main objective of this study was to develop a BPE quantification model according to clinical expertise, with the BPE integral being used as a QIB to incorporate both the volume and intensity of the enhancement metrics. The model was applied to 2,786 cases to compare our quantitative results with radiologists' semi-quantitative BPE grading to evaluate the effectiveness of using the BPE integral as a QIB for analyzing BPE. Comparisons between multiple groups of nonnormally distributed BPE integrals were performed using the Kruskal-Wallis test. Results: Our study found a considerable degree of concordance between our BPE quantitative integral and radiologists' semi-quantitative assessments. Specifically, our research results revealed significant variability in BPE integral attained through the BPE quantification framework among all semi-quantitative BPE grading groups labeled by experienced radiologists, including mild-moderate (P<0.001), mild-marked (P<0.001), and moderate-marked (P<0.001). Furthermore, there was an apparent correlation between BPE integral and BPE grades, with marked BPE displaying the highest BPE integral, followed by moderate BPE, with mild BPE exhibiting the lowest BPE integral value. Conclusions: The study developed and implemented a BPE quantification framework, which incorporated both the volume and intensity of enhancement and which could serve as a QIB for BPE.
RESUMO
Correction for 'One-step mild preparation of tough and thermo-reversible poly(vinyl alcohol) hydrogels induced by small molecules' by Chuang Dong et al., Chem. Commun., 2021, 57, 3789-3792, https://doi.org/10.1039/D1CC00578B.
RESUMO
In this study, for the first time, a cluster-plus-glue-atom model was used to optimize the composition of lithium aluminosilicate glass-ceramics. Basic glass in glass-ceramics was considered to be a 16-unit combination of three-valence {M2O3} and one-valence {Li2O} units. By adjusting the ratio of {M2O3} and {Li2O}, the composition of basic glass could be optimized. After optimization, the average cation valence of the base glass was increased to 2.875. After heat treatment of the optimized base glass, it is found that the crystal size, proportion, and crystallinity changed obviously compared with that before optimization. The main crystalline phases of all the lithium aluminosilicate glass-ceramics prepared in this work were Li2Si2O5 and LiAlSi4O10. All optimized glass-ceramics had an obvious improvement in the crystallinity, with one of the largest having a crystallinity of over 90%. Furthermore, its bending strength was 159 MPa, the microhardness was 967 Hv, and the visible light transmission rate exceeded 90%. Compared with the widely used touch panel cover glass, the optical properties were close, and the mechanical properties were greatly improved. Due to its excellent performance, it could be used in microelectronics, aerospace, deep-sea exploration, and other fields.
RESUMO
Soft magnetic high-entropy alloy thin films (HEATFs) exhibit remarkable freedom of material-structure design and physical-property tailoring, as well as, high cut-off frequencies and outstanding electrical resistivities, making them potential candidates for high-frequency magnetic devices. In this study, a CoCrFeNi film with excellent soft magnetic properties is developed by forming a novel core-shell structure via native oxidation, with ferromagnetic elements Fe, Co, and Ni as the core and the Cr oxide as the shell layer. The core-shell structure enables a high saturation magnetization, enhances the electrical resistivity, and thus reduces the eddy-current loss. For further optimizing the soft magnetic properties, O is deliberately introduced into the HEATFs, and the O-incorporated HEATFs exhibit an electrical resistivity of 237 µΩ·cm, a saturation magnetization of 535 emu cm-3 , and a coercivity of 23 A m-1 . The factors that determine the ferromagnetism and coercivity of the CoCrFeNi-based HEATFs are examined in detail by evaluating the microstructures, magnetic domains, chemical valency, and 3D microscopic compositional distributions of the prepared films. These results are anticipated to provide insights into the magnetic behaviors of soft magnetic HEATFs, as well as aid in the construction of a promising material-design strategy for these unique materials.
RESUMO
Carbon fiber fabric-reinforced phenolic resin composites are widely used as thermal protection materials for thermal protection systems in hypersonic vehicles and capsules. In this work, carbon fiber fabric-reinforced boron phenolic resin composites modified with MoSi2 and B4C were prepared via a compression molding technique. The high-temperature performance of the composites as well as the oxidation behavior of the carbon fibers was studied. The results indicate that the incorporation of B4C improves the performance of composites at high temperatures. The residual weight rate of composites with 15 phr B4C (BP-15) sufficiently increased from 23.03% to 32.91% compared with the composites without B4C (BP-0). After being treated at 1400 °C for 15 min, the flexural strength of BP-15 increased by 17.79% compared with BP-0. Compared with BP-0, the line ablation rate and mass ablation rate of BP-15 were reduced by 53.96% and 1.56%, respectively. In addition, MoSi2 and B4C particles had a positive effect on the oxidation of carbon fibers in the composites. After treatment at 1400 °C, the diameter of the as-received carbon fiber was reduced by 31.68%, while the diameter of the carbon fiber in BP-0 and BP-15 decreased by 15.12% and 6.14%, respectively. At high temperatures, the liquid B2O3 from B4C and MoSi2-derived complex-phase ceramics (MoB, MoB2, Mo2C, Mo4.8Si3C0.6) acted as an oxygen barrier, effectively mitigating the oxidation degree of the carbon fibers.
RESUMO
Lung-resident memory B cells (MBCs) provide localized protection against reinfection in respiratory airways. Currently, the biology of these cells remains largely unexplored. Here, we combined influenza and SARS-CoV-2 infection with fluorescent-reporter mice to identify MBCs regardless of antigen specificity. We found that two main transcriptionally distinct subsets of MBCs colonized the lung peribronchial niche after infection. These subsets arose from different progenitors and were both class switched, somatically mutated, and intrinsically biased in their differentiation fate toward plasma cells. Combined analysis of antigen specificity and B cell receptor repertoire segregated these subsets into "bona fide" virus-specific MBCs and "bystander" MBCs with no apparent specificity for eliciting viruses generated through an alternative permissive process. Thus, diverse transcriptional programs in MBCs are not linked to specific effector fates but rather to divergent strategies of the immune system to simultaneously provide rapid protection from reinfection while diversifying the initial B cell repertoire.
Assuntos
COVID-19 , Memória Imunológica , Animais , Linfócitos B , Pulmão , Células B de Memória , Camundongos , Reinfecção , SARS-CoV-2RESUMO
BACKGROUND: Hematoma expansion is an independent predictor of patient outcome and mortality. The early diagnosis of hematoma expansion is crucial for selecting clinical treatment options. This study aims to explore the value of a deep learning algorithm for the prediction of hematoma expansion from non-contrast computed tomography (NCCT) scan through external validation. METHODS: 102 NCCT images of hypertensive intracerebral hemorrhage (HICH) patients diagnosed in our hospital were retrospectively reviewed. The initial computed tomography (CT) scan images were evaluated by a commercial Artificial Intelligence (AI) software using deep learning algorithm and radiologists respectively to predict hematoma expansion and the corresponding sensitivity, specificity and accuracy of the two groups were calculated and compared. Comparisons were also conducted among gold standard hematoma expansion diagnosis time, AI software diagnosis time and doctors' reading time. RESULTS: Among 102 HICH patients, the sensitivity, specificity, and accuracy of hematoma expansion prediction in the AI group were higher than those in the doctor group(80.0% vs 66.7%, 73.6% vs 58.3%, 75.5% vs 60.8%), with statistically significant difference (p < 0.05). The AI diagnosis time (2.8 ± 0.3 s) and the doctors' diagnosis time (11.7 ± 0.3 s) were both significantly shorter than the gold standard diagnosis time (14.5 ± 8.8 h) (p < 0.05), AI diagnosis time was significantly shorter than that of doctors (p < 0.05). CONCLUSIONS: Deep learning algorithm could effectively predict hematoma expansion at an early stage from the initial CT scan images of HICH patients after onset with high sensitivity and specificity and greatly shortened diagnosis time, which provides a new, accurate, easy-to-use and fast method for the early prediction of hematoma expansion.
Assuntos
Hemorragia Cerebral , Aprendizado Profundo , Inteligência Artificial , Hemorragia Cerebral/diagnóstico por imagem , Hematoma/diagnóstico por imagem , Humanos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodosRESUMO
Solid solutions are the basis for most industrial alloys. However, the relationships between their characteristic short-range orders and chemical compositions have not been established. The present work combines Cowley parameter α with our cluster-plus-glue-atom model to accurately derive the chemical units of binary solid-solution alloys of face-centered cubic type. The chemical unit carries information on atomic structure and chemical composition, which explains prevailing industrial alloys. For example, chemical units in Cu68.9Zn31.1 alloy with α1 = - 0.137 are formulated as [Zn-Cu10Zn2]Zn2Cu2 and [Zn-Cu10Zn2]Zn3Cu1, with 64.0-70.0 wt% Cu corresponding to the most widely used cartridge brass C26000 (68.5-71.5 Cu). This work answers the long-standing question on the composition origin of solid-solution-based industrial alloys, by tracing to the molecule-like chemical units implied in chemical short-range ordering in solid solutions.
RESUMO
During the last several decades, since the discovery of a decagonal quasicrystal, a 2 nm cluster model has been widely accepted as its basic quasi-unit-cell (QUC). Instead of the traditional 2 nm QUC, a 3.2 nm QUC is proposed in this paper. The 3.2 nm QUC can fill all the blank areas. The 3.2 nm QUC consists of 251 atoms. The element type and position of each atom are determined using high-angle annular detector dark-field (HAADF) images taken along three projection directions, i.e., one along the ten-fold symmetry and the other two along the two-fold symmetry with an intersection angle of 18 degrees. The proposed model opens an avenue for further investigation of the aperiodic atomic structure of other quasicrystals.
RESUMO
Rapid and accurate detection of fluoroquinolones (FQs) antibiotics residues in food substrate are of great significance to food safety. In this study, terahertz spectroscopy was employed to conduct the spectral and imaging analysis to explore its feasibility for detection concentrations of FQs in fish meal feeds (FMF). Four methods (frequency of maximum difference in frequency-domain, characteristic absorption peak, successive projections algorithm and stepwise regression) were used to selected characteristic frequencies of sample. Terahertz imaging was formed at selected characteristic frequency and back propagation neural network was used to establish quantitative evaluation models to select optimal characteristic imaging frequency. Finally, relationship between concentrations of FQs and their gray values was revealed, and each data had a small range of error bar. The results showed that terahertz spectral and imaging technique can visualize norfloxacin and enrofloxacin concentrations in FMF precisely. This study explored a brand-new visualization method for quantitative detection of FQs in FMF based on terahertz spectral and imaging technology.
Assuntos
Fluoroquinolonas , Norfloxacino , Antibacterianos , Enrofloxacina , TecnologiaRESUMO
Reaching simultaneously high mechanical strength and low electrical resistivity is difficult as both properties are based on similar microstructural mechanisms. In our previous work, a new parameter, the tensile strength-over-electrical resistivity ratio, is proposed to evaluate the matching of the two properties in Cu alloys. A specific ratio of 310 × 108 MPa·Ω-1·m-1, independent of the alloy system and thermal history, is obtained from Cu-Ni-Mo alloys, which actually points to the lower limit of prevailing Cu alloys possessing high strength and low resistivity. The present paper explores the origin of this specific ratio by introducing the dual-phase mechanical model of composite materials, assuming that the precipitate particles are mechanically mixed in the Cu solid solution matrix. The strength and resistivity of an alloy are respectively in series and parallel connections to those of the matrix and the precipitate. After ideally matching the contributions from the matrix and the precipitate, the alloy should at least reach half of the resistivity of pure Cu, i.e., 50%IACS, which is the lower limit for industrially accepted highly conductive Cu alloys. Under this condition, the specific 310 ratio is related to the precipitate-over-matrix ratios for strength and resistivity, which are both two times those of pure Cu.
RESUMO
Conventional type 1 dendritic cells (cDC1s) are critical for antitumor immunity. They acquire antigens from dying tumor cells and cross-present them to CD8+ T cells, promoting the expansion of tumor-specific cytotoxic T cells. However, the signaling pathways that govern the antitumor functions of cDC1s in immunogenic tumors are poorly understood. Using single-cell transcriptomics to examine the molecular pathways regulating intratumoral cDC1 maturation, we found nuclear factor κB (NF-κB) and interferon (IFN) pathways to be highly enriched in a subset of functionally mature cDC1s. We identified an NF-κB-dependent and IFN-γ-regulated gene network in cDC1s, including cytokines and chemokines specialized in the recruitment and activation of cytotoxic T cells. By mapping the trajectory of intratumoral cDC1 maturation, we demonstrated the dynamic reprogramming of tumor-infiltrating cDC1s by NF-κB and IFN signaling pathways. This maturation process was perturbed by specific inactivation of either NF-κB or IFN regulatory factor 1 (IRF1) in cDC1s, resulting in impaired expression of IFN-γ-responsive genes and consequently a failure to efficiently recruit and activate antitumoral CD8+ T cells. Last, we demonstrate the relevance of these findings to patients with melanoma, showing that activation of the NF-κB/IRF1 axis in association with cDC1s is linked with improved clinical outcome. The NF-κB/IRF1 axis in cDC1s may therefore represent an important focal point for the development of new diagnostic and therapeutic approaches to improve cancer immunotherapy.
Assuntos
Células Dendríticas/imunologia , Fator Regulador 1 de Interferon/imunologia , Melanoma/imunologia , NF-kappa B/imunologia , Neoplasias Cutâneas/imunologia , Animais , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Fator Regulador 1 de Interferon/genética , Interferon gama/imunologia , Estimativa de Kaplan-Meier , Masculino , Melanoma/genética , Melanoma/mortalidade , Camundongos Transgênicos , NF-kappa B/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/mortalidadeRESUMO
To overcome shortcomings of the traditional freeze-thaw method for PVA hydrogel preparation, we develop a one-step mild method, which induces PVA crystallization to form hydrogels through small molecules containing hydroxyl and carboxyl groups. The obtained hydrogels showed high mechanical properties, untypical plasticity with short gelation time and repeatable sol-gel transformation.
RESUMO
The phase-type of a stainless steel is generally predicted by equivalent equations in terms of a major austenitic (γ) or ferritic (α) stabilizer Ni or Cr. The present paper attempts to understand the equivalent methods in stainless steels via the slopes of the phase boundary lines separating γ and γ + α phase zones. The prevailing equivalent coefficients are well interpreted using the slope ratios of the alloying elements divided by that of Ni or Cr, after analyzing over one hundred common stainless steels. Different from traditional composition equivalents which evaluate γ stabilizers and α stabilizers separately; the new equivalent scheme provides a unified phase stabilizing parameter for all alloying elements in stainless steels. This parameter is defined as γ stabilizing efficiency. Its negative or positive sign indicates γ stabilizer or α stabilizer, and its value represents the stabilizing efficiency.
RESUMO
We suggest a simple idea of bio-based adhesives with strong adhesion even under water. The adhesives simply prepared via polycondensation of 3,4-dihydroxyhydrocinnamic acid (DHHCA) and lactic acid (LA) in one pot polymerization. Poly(DHHCA-co-LA) has a hyperbranched structure and demonstrated strong dry and wet adhesion strength on diverse material surfaces. We found that their adhesion strength depended on the concentration of DHHCA. Poly(DHHCA-co-LA) with the lowest concentration of DHHCA showed the highest adhesion strength in water with a value of 2.7 MPa between glasses, while with the highest concentration of DHHCA it exhibited the highest dry adhesion strength with a value of 3.5 MPa, which was comparable to commercial instant super glue. Compared to underwater glues reported previously, our adhesives were able to spread rapidly under water with a low viscosity and worked strongly. Poly(DHHCA-co-LA) also showed long-term stability and kept wet adhesion strength of 2.2 MPa after steeping in water for 1 month at room temperature (initial strength was 2.4 MPa). In this paper, Poly(DHHCA-co-LA) with strong dry and wet adhesion properties and long-term stability was demonstrated for various kinds of applications, especially for wet conditions.
RESUMO
Multiprincipal-element alloys (MPEAs), including high-entropy alloys, are a new class of materials whose thermodynamical properties are mainly driven by configuration entropy, rather than enthalpy in the traditional alloys, especially at high temperatures. Herein, the design of a novel soft-magnetic nonequiatomic, quaternary MPEA is described, via tuning its chemical composition to deliberately manipulate its microstructure, such that it contains ultrafine ferromagnetic body-centered-cubic (BCC) coherent nanoprecipitates (3-7 nm) uniformly distributed in a B2-phase matrix. The new alloy Al1.5 Co4 Fe2 Cr exhibits high saturation magnetization (MS = 135.3 emu g-1 ), low coercivity (HC = 127.3 A m-1 ), high Curie temperature (TC = 1061 K), and high electrical resistivity (ρ = 244 µΩ cm), promising for soft magnets. More importantly, these prominent soft-magnetic properties are observed to be retained even after the alloy is thermally exposed at 873 K for 555 h, apparently attributable to the excellent stability of the coherent microstructure. The versatility of the magnetic properties of this new alloy is discussed in light of the microstructural change induced by tuning the chemical composition, and the enhanced performance of the alloy is compared directly with that of the traditional soft-magnetic alloys. The perspective is also addressed to design high-performance soft-magnetic alloys for high-temperature applications.
RESUMO
This paper focuses on the revelation of structural relationship of the ordered and disordered states in Cu-(Zr, Ti) binary systems. The atomic radial distributions in real space and the electron scattering behavior in reciprocal space between crystalline and amorphous phases are compared. The spherical-periodic order, characteristic of disordered structures, is clearly present in the crystalline phases, suggesting the structural homology of crystalline and the corresponding amorphous states. Furthermore, the diameters of Brillouin- or Jones-zones at the Fermi level in the crystalline and amorphous states are also similar and they fall close to those of the calculated Fermi spheres, verifying the resonance between the static atomic structure and the electron wave.
RESUMO
The present work investigated the composition evolution of the TMS series of Ni-base single crystal (SC) superalloys in light of the cluster formula approach systematically. The cluster formula of SC superalloys could be expressed with [Formula: see text], in which all the alloying elements were classified into three groups, Al series ([Formula: see text]), Cr series ([Formula: see text]), and Ni series ([Formula: see text]). It was found that the total atom number (Z) of the cluster formula units for TMS series of superalloys varies from Z ~ 17 to Z ~ 15.5, and then to Z ~ 16 with the alloy development from the 1st to the 6th generation, in which the superalloys with prominent creep resistance possess an ideal cluster formula of [Formula: see text] with Z = 16. Similar tendency of composition evolution also appears in the PWA and CMSX series of SC superalloys. Typical TMS series of superalloys with prominent creep properties generally exhibit a moderate lattice misfit of γ/γ' which could render alloys with appropriate particle size of cuboidal γ' precipitates to acquire a maximum strength increment by precipitation strengthening mechanism. More importantly, the relationship between the lattice misfit (δ) of γ/γ' and the creep rupture lifetime (tr) of superalloys was then established, showing a linear correlation in the form of lgtr-lg|δ|3/2 at both conditions of 900 °C/392 MPa and 1100 °C/137 MPa. Combined with the lattice misfit, the cluster formula approach would provide a new way to modify or optimize the compositions of Ni-base superalloys for further improvement of creep property.
RESUMO
A high-angle annular dark field scanning transmission electron microscopy study of the intermetallic compound Al74Cr15Fe11 reveals a quasiperiodic structure significantly differing from the ones known so far. In contrast to the common quasi-unit-cells based on Gummelt decagons, the present structure is related to a covering formed by Lück decagons, which can also be described by a Hexagon-Bow-Tie tiling.