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1.
Nanotechnology ; 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39378893

RESUMO

Using a first-principles approach, this study delves into the effects of strain and electrostatic doping on the electronic and magnetic properties of the GaN/VTe2van der Waals heterostructure. The results reveal that when the GaN/VTe2van der Waals heterostructure is doped with 0.1h/0.2hof electrostatic charge, its magnetization direction undergoes a remarkable reversal, shifting from out-of-plane orientation to in-plane direction. Therefore, we conduct a thorough investigation into the influence of electron orbitals on magnetic anisotropy energy. In addition, as the strain changes from -1% to 1%, the 100% spin polarization region of the GaN/VTe2vdW heterostructure becomes smaller. It is worth noting that at a doping concentration of 0.1h, the GaN/VTe2vdW heterostructure has a Curie temperature of 30 K above room temperature. This comprehensive study provides valuable insights and provides a reference for analyzing the electronic and magnetic properties of low-dimensional systems.

2.
Sci Rep ; 14(1): 23735, 2024 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-39390208

RESUMO

This study develops explainable artificial intelligence for predicting safe balance using hospital data, including clinical, neurophysiological, and diffusion tensor imaging properties. Retrospective data from 92 first-time stroke patients from January 2016 to June 2023 was analysed. The dependent variables were independent mobility scores, i.e., Berg Balance Scales with 0 (45 or below) vs. 1 (above 45) measured after three and six months, respectively. Twenty-nine predictors were included. Random forest variable importance was employed for identifying significant predictors of the Berg Balance Scale and testing its associations with the predictors, including Berg Balance Scale after one month and corticospinal tract diffusion tensor imaging properties. Shapley Additive Explanation values were calculated to analyse the directions of these associations. The random forest registered a higher or similar area under the curve compared to logistic regression, i.e., 91% vs. 87% (Berg Balance Scale after three months), 92% vs. 92% (Berg Balance Scale after six months). Based on random forest variable importance values and rankings: (1) Berg Balance Scale after three months has strong associations with Berg Balance Scale after one month, Fugl-Meyer assessment scale, ipsilesional corticospinal tract fractional anisotropy, fractional anisotropy laterality index and age; (2) Berg Balance Scale after six months has strong relationships with Fugl-Meyer assessment scale, Berg Balance Scale after one month, ankle plantar flexion muscle strength, knee extension muscle strength and hip flexion muscle strength. These associations were positive in the SHAP summary plots. Including Berg Balance Scale after one month, Fugl-Meyer assessment scale or ipsilesional corticospinal tract fractional anisotropy in the random forest will increase the probability of Berg Balance Scale after three months being above 45 by 0.11, 0.08, or 0.08. In conclusion, safe balance after stroke strongly correlates with its initial motor function, Fugl-Meyer assessment scale, and ipsilesional corticospinal tract fractional anisotropy. Diffusion tensor imaging information aids in developing explainable artificial intelligence for predicting safe balance after stroke.


Assuntos
Inteligência Artificial , Imagem de Tensor de Difusão , Equilíbrio Postural , Acidente Vascular Cerebral , Humanos , Feminino , Masculino , Equilíbrio Postural/fisiologia , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Pessoa de Meia-Idade , Idoso , Imagem de Tensor de Difusão/métodos , Estudos Retrospectivos , Reabilitação do Acidente Vascular Cerebral/métodos
3.
J Mol Biol ; : 168816, 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39384035

RESUMO

DeepMind's AlphaFold3 webserver offers exciting new opportunities to make structural predictions of heterogeneous macromolecular systems. Here we attempt to apply AlphaFold3 to large RNA molecules whose 3D atomic structures are unknown but whose physical dimensions have been studied experimentally. One difficulty that we encounter is that models returned by AlphaFold3 often contain severe steric clashes and, less frequently, clear breaks in the phosphodiester backbone, with the probability of both events increasing with the length of the RNA. Restricting attention to those RNAs for which non-clashing models can be obtained, we find that hydrodynamic radii computed from the AlphaFold3 models are much larger than those reported experimentally under low salt conditions but are in better agreement with those reported in the presence of polyvalent cations. For two RNAs whose shapes have been imaged experimentally, the computed anisotropies of the AlphaFold3-predicted structures are too low, indicating that they are excessively spherical; extending this analysis to larger RNAs shows that they become progressively more spherical with increasing length. Overall, the results suggest that AlphaFold3 is capable of producing plausible models for RNAs up to ∼2000 nucleotides in length, but that thousands of predictions may be required to obtain models free of geometric problems.

4.
Philos Trans A Math Phys Eng Sci ; 382(2283): 20240010, 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39370801

RESUMO

We explore a new design strategy of leveraging kinematic bifurcation in creating origami/kirigami-based three-dimensional (3D) hierarchical, reconfigurable, mechanical metamaterials with tunable mechanical responses. We start from constructing three basic, thick, panel-based structural units composed of 4, 6 and 8 rigidly rotatable cubes in close-looped connections. They are modelled, respectively, as 4R, 6R and 8R (R stands for revolute joint) spatial looped kinematic mechanisms, and are used to create a library of reconfigurable hierarchical building blocks that exhibit kinematic bifurcations. We analytically investigate their reconfiguration kinematics and predict the occurrence and locations of kinematic bifurcations through a trial-correction modelling method. These building blocks are tessellated in 3D to create various 3D bifurcated hierarchical mechanical metamaterials that preserve the kinematic bifurcations in their building blocks to reconfigure into different 3D architectures. By combining the kinematics and considering the elastic torsional energy stored in the folds, we develop the geometric mechanics to predict their tunable anisotropic Poisson's ratios and stiffnesses. We find that kinematic bifurcation can significantly effect mechanical responses, including changing the sign of Poisson's ratios from negative to positive beyond bifurcation, tuning the anisotropy, and overcoming the polarity of structural stiffness and enhancing the number of deformation paths with more reconfigured shapes.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

5.
Front Psychiatry ; 15: 1414295, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39371910

RESUMO

Objective: Depression is a prevalent mental disorder characterized by persistent negative mood and loss of pleasure. Although there are various treatment modalities available for depression, the rates of response and remission remain low. Xiaoyaosan (XYS), a traditional Chinese herbal formula with a long history of use in treating depression, has shown promising effects. However, the underlying mechanism of its therapeutic action remains elusive. The aim of this study is to investigate the neuroimaging changes in the brain associated with the antidepressant-like effects of XYS. Methods: Here, we combined voxel-based morphometry of T2-weighted images and voxel-based analysis on diffusion tensor images to evaluate alterations in brain morphometry and microstructure between chronic social defeat stress (CSDS) model mice and control mice. Additionally, we examined the effect of XYS treatment on structural disruptions in the brains of XYS-treated mice. Furthermore, we explored the therapeutic effect of 18ß-glycyrrhetinic acid (18ß-GA), which was identified as the primary compound present in the brain following administration of XYS. Significant differences in brain structure were utilized as classification features for distinguishing mice with depression model form the controls using a machine learning method. Results: Significant changes in brain volume and diffusion metrics were observed in the CSDS model mice, primarily concentrated in the nucleus accumbens (ACB), primary somatosensory area (SSP), thalamus (TH), hypothalamus (HY), basomedical amygdala nucleus (BMA), caudoputamen (CP), and retrosplenial area (RSP). However, both XYS and 18ß-GA treatment prevented disruptions in brain volume and diffusion metrics in certain regions, including bilateral HY, right SSP, right ACB, bilateral CP, and left TH. The classification models based on each type of neuroimaging feature achieved high accuracy levels (gray matter volume: 76.39%, AUC=0.83; white matter volume: 76.39%, AUC=0.92; fractional anisotropy: 82.64%, AUC=0.9; radial diffusivity: 76.39%, AUC=0.82). Among these machine learning analyses, the right ACB, right HY, and right CP were identified as the most important brain regions for classification purposes. Conclusion: These findings suggested that XYS can prevent abnormal changes in brain volume and microstructure within TH, SSP, ACB, and CP to exert prophylactic antidepressant-like effects in CSDS model mice. The neuroimaging features within these regions demonstrate excellent performance for classifying CSDS model mice from controls while providing valuable insights into the antidepressant effects of XYS.

6.
J Mol Biol ; : 168813, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39374888

RESUMO

In mammalian cells, DNA ligase 1 (LIG1) functions as the primary DNA ligase in both genomic replication and single-strand break repair. Several reported mutations in human LIG1, including R305Q, R641L, and R771W, cause LIG1 syndrome, a primary immunodeficiency. While the R641L and R771W mutations, respectively located in the nucleotidyl transferase and oligonucleotide binding domains, have been biochemically characterized and shown to reduce catalytic efficiency, the recently reported R305Q mutation within the DNA binding domain (DBD) remains mechanistically unexplored. The R641L and R771W mutations are known to decrease the catalytic activity of LIG1 by affecting both interdomain interactions and DNA binding during catalysis, without significantly impacting overall DNA affinity. To elucidate the molecular basis of the LIG1 syndrome-causing R305Q mutation, we purified this single-residue mutant protein and investigated its secondary structure, protein stability, DNA binding affinity, and catalytic efficiency. Our findings reveal that the R305Q mutation significantly impairs the function of LIG1 by disrupting the DBD-DNA interactions, leading to a 7 to 21-fold lower DNA binding affinity and a 33 to 300-fold reduced catalytic efficiency of LIG1. Additionally, the R305Q mutation slightly decreases LIG1's protein stability by 2 to 3.6 °C, on par with the effect observed previously with either the R641L or R771W mutant. Collectively, our results uncover a new mechanism whereby the R305Q mutation impairs LIG1-catalyzed nicked DNA ligation, resulting in LIG1 syndrome, and highlight the crucial roles of the DBD-DNA interactions in tight DNA binding and efficient LIG1 catalysis.

7.
Artigo em Inglês | MEDLINE | ID: mdl-39375310

RESUMO

Four experiments examined whether representational gravity, in which memory for the location of a previously-viewed target is displaced in the direction of implied gravitational attraction, occurs uniformly across a target. Participants viewed stationary, vertically-moving, or horizontally-moving targets of different sizes and at different heights within the picture plane. After a target vanished, participants indicated the remembered location of the top edge or bottom edge of that target. Significant anisotropies were found, as the remembered location of the top edge was displaced downward, whereas the remembered location of the bottom edge was not displaced or was displaced upward. Anisotropies along the vertical axis were not influenced by whether participants knew prior to target presentation which edge to remember or by whether targets were stationary or moved vertically, although there was a trend for anisotropies along the vertical axis to be reduced when targets moved horizontally. Larger targets and targets higher in the picture plane resulted in larger displacement when targets were stationary, although effects of size and height were diminished when targets were moving. If the top edge and bottom edge of a target are considered analogous to the trailing edge and leading edge of a moving target, respectively, then anisotropies related to representational gravity are similar to anisotropies previously reported for representational momentum for horizontally-moving targets (as direction of implied gravitational attraction is downward). The existence of such anisotropies has implications for the representation of space and for the localization of and interaction with stimuli in the environment.

8.
Artigo em Inglês | MEDLINE | ID: mdl-39354289

RESUMO

Social networks are fundamental for social interactions, with the social brain hypothesis positing that the size of the neocortex evolved to meet social demands. However, the role of fractional anisotropy (FA) in white matter (WM) tracts relevant to mentalizing, empathy, and social networks remains unclear. In this study, we investigated the relationships between FA in brain regions associated with social cognition (superior longitudinal fasciculus (SLF), cingulum (CING), uncinate fasciculus, inferior fronto-occipital fasciculus), social network characteristics (diversity, size, complexity), and empathy (cognitive, affective). We employed diffusion tensor imaging, tract-based spatial statistics, and mediation analyses to examine these associations. Our findings revealed that increased social network size was positively correlated with FA in the left SLF. Further, our mediation analysis showed that lower FA in left CING was associated with increased social network size, mediated by cognitive empathy. In summary, our findings suggest that WM tracts involved in social cognition play distinct roles in social network size and empathy, potentially implicating affective brain regions. In conclusion, our findings offer new perspectives on the cognitive mechanisms involved in understanding others' mental states and experiencing empathy within supportive social networks, with potential implications for understanding individual differences in social behavior and mental health.

9.
Neuroimage ; 301: 120881, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39362507

RESUMO

White matter (WM) development has been studied extensively, but most studies used cross-sectional data, and to the best of our knowledge, none of them considered the possible effects of biological (vs. chronological) age. Therefore, we conducted a longitudinal multimodal study of WM development and studied changes in fractional anisotropy (FA) in the different WM tracts and their relationship with cortical thickness-based measures of brain aging in young adulthood. A total of 105 participants from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) prenatal birth cohort underwent magnetic resonance imaging (MRI) at the age of 23-24, and the age of 28-30 years. At both time points, FA in the different WM tracts was extracted using the JHU atlas, and brain age gap estimate (BrainAGE) was calculated using the Neuroanatomical Age Prediction using R (NAPR) model based on cortical thickness maps. Changes in FA and the speed of cortical brain aging were calculated as the difference between the respective variables in the late vs. early 20s. We demonstrated tract-specific increases as well as decreases in FA, which indicate that the WM microstructure continues to develop in the third decade of life. Moreover, the significant interaction between the speed of cortical brain aging, tract, and sex on mean FA revealed that a greater speed of cortical brain aging in young adulthood predicted greater decreases in FA in the bilateral cingulum and left superior longitudinal fasciculus in young adult men. Overall, these changes in FA in the WM tracts in young adulthood point out the protracted development of WM microstructure, particularly in men.

10.
Acta Biomater ; 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39368719

RESUMO

Textile fabrics have unique mechanical properties, which make them ideal candidates for many engineering and medical applications: They are initially flexible, nonlinearly stiffening, and ultra-anisotropic. Various studies have characterized the response of textile structures to mechanical loading; yet, our understanding of their exceptional properties and functions remains incomplete. Here we integrate biaxial testing and constitutive neural networks to automatically discover the best model and parameters to characterize warp knitted polypropylene fabrics. We use experiments from different mounting orientations, and discover interpretable anisotropic models that perform well during both training and testing. Our study shows that constitutive models for warp knitted fabrics are highly sensitive to an accurate representation of the textile microstructure, and that models with three microstructural directions outperform classical orthotropic models with only two in-plane directions. Strikingly, out of 214=16,384 possible combinations of terms, we consistently discover models with two exponential linear fourth invariant terms that inherently capture the initial flexibility of the virgin mesh and the pronounced nonlinear stiffening as the loops of the mesh tighten. We anticipate that the tools we have developed and prototyped here will generalize naturally to other textile fabrics-woven or knitted, weft knit or warp knit, polymeric or metallic-and, ultimately, will enable the robust discovery of anisotropic constitutive models for a wide variety of textile structures. Beyond discovering constitutive models, we envision to exploit automated model discovery for the generative material design of wearable devices, stretchable electronics, and smart fabrics, as programmable textile metamaterials with tunable properties and functions. Our source code, data, and examples are available at https://github.com/LivingMatterLab/CANN. STATEMENT OF SIGNIFICANCE: Textile structures are rapidly gaining popularity in many biomedical applications including tissue engineering, wound healing, and surgical repair. A precise understanding of their unique mechanical properties is critical to tailor them to their specific functions. Here we integrate mechanical testing and machine learning to automatically discover the best models for knitted polypropylene fabrics. We show that warp knitted fabrics possess a complex symmetry with three distinct microstructural directions. Along these, the behavior is dominated by an exponential linear term that characterize the initial flexibility of the virgin mesh and the nonlinear stiffening as the loops of the fabric tighten. We expect that our technology will generalize naturally to other fabrics and enable the robust discovery of complex anisotropic models for a wide variety of textile structures.

11.
J R Soc Interface ; 21(219): 20240378, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39353562

RESUMO

Convection-enhanced delivery (CED) can effectively overcome the blood-brain barrier by infusing drugs directly into diseased sites in the brain using a catheter, but its clinical performance still needs to be improved. This is strongly related to the highly anisotropic characteristics of brain white matter, which results in difficulties in controlling drug transport and distribution in space. In this study, the potential to improve the delivery of six drugs by adjusting the placement of the infusion catheter is examined using a mathematical model and accurate numerical simulations that account simultaneously for the interstitial fluid (ISF) flow and drug transport processes in CED. The results demonstrate the ability of this direct infusion to enhance ISF flow and therefore facilitate drug transport. However, this enhancement is highly anisotropic, subject to the orientation of local axon bundles and is limited within a small region close to the infusion site. Drugs respond in different ways to infusion direction: the results of our simulations show that while some drugs are almost insensitive to infusion direction, this strongly affects other compounds in terms of isotropy of drug distribution from the catheter. These findings can serve as a reference for planning treatments using CED.


Assuntos
Sistemas de Liberação de Medicamentos , Humanos , Anisotropia , Convecção , Modelos Biológicos , Barreira Hematoencefálica/metabolismo , Simulação por Computador , Líquido Extracelular/metabolismo , Encéfalo/metabolismo
12.
3D Print Addit Manuf ; 11(3): e1324-e1333, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39359575

RESUMO

The microstructure, mechanical properties (tensile, fatigue, etc.) and the anisotropies of the Al-Mg alloy fabricated by wire arc additive manufacturing are studied in this work. The results show that the microstructure of the deposited alloy is composed of coarse columnar grains in the inner-layer region and fine equiaxed grains in the interlayer region. The tensile and fatigue properties exhibit strong anisotropies. The ultimate tensile strength (258 MPa), yield strength (140 MPa), elongation (21.3%), and fatigue life (2.56 × 105) of the sample along travel direction (0° direction) are the best, whereas those of the sample along the deposited direction (90° direction) are the lowest and those of the sample along 45° direction are the medium. It is found that the lowest strength and elongation of the sample in the deposited direction can be attributed to the large weak bonding areas between the deposition layers, whereas the lowest fatigue property is associated with the fatigue crack propagation along the grain boundaries of the columnar grains.

13.
Nanomaterials (Basel) ; 14(17)2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39269119

RESUMO

The surface symmetry of the substrate plays an important role in the epitaxial high-quality growth of 2D materials; however, in-depth and in situ studies on these materials during growth are still limited due to the lack of effective in situ monitoring approaches. In this work, taking the growth of MoSe2 as an example, the distinct growth processes on Al2O3 (112¯0) and Al2O3 (0001) are revealed by parallel monitoring using in situ reflectance anisotropy spectroscopy (RAS) and differential reflectance spectroscopy (DRS), respectively, highlighting the dominant role of the surface symmetry. In our previous study, we found that the RAS signal of MoSe2 grown on Al2O3 (112¯0) initially increased and decreased ultimately to the magnitude of bare Al2O3 (112¯0) when the first layer of MoSe2 was fully merged, which is herein verified by the complementary DRS measurement that is directly related to the film coverage. Consequently, the changing rate of reflectance anisotropy (RA) intensity at 2.5 eV is well matched with the dynamic changes in differential reflectance (DR) intensity. Moreover, the surface-dominated uniform orientation of MoSe2 islands at various stages determined by RAS was further investigated by low-energy electron diffraction (LEED) and atomic force microscopy (AFM). By contrast, the RAS signal of MoSe2 grown on Al2O3 (0001) remains at zero during the whole growth, implying that the discontinuous MoSe2 islands have no preferential orientations. This work demonstrates that the combination of in situ RAS and DRS can provide valuable insights into the growth of unidirectional aligned islands and help optimize the fabrication process for single-crystal transition metal dichalcogenide (TMDC) monolayers.

14.
Molecules ; 29(17)2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39274986

RESUMO

The interface connects the reinforced phase and the matrix of materials, with its microstructure and interfacial configurations directly impacting the overall performance of composites. In this study, utilizing seven atomic layers of Mg(0001) and Ti(0001) surface slab models, four different Mg(0001)/Ti(0001) interfaces with varying atomic stacking configurations were constructed. The calculated interface adhesion energy and electronic bonding information of the Mg(0001)/Ti(0001) interface reveal that the HCP2 interface configuration exhibits the best stability. Moreover, Si, Ca, Sc, V, Cr, Mn, Fe, Cu, Zn, Y, Zr, Nb, Mo, Sn, La, Ce, Nd, and Gd elements are introduced into the Mg/Ti interface layer or interfacial sublayer of the HCP2 configurations, and their interfacial segregation behavior is investigated systematically. The results indicate that Gd atom doping in the Mg(0001)/Ti(0001) interface exhibits the smallest heat of segregation, with a value of -5.83 eV. However, Ca and La atom doping in the Mg(0001)/Ti(0001) interface show larger heat of segregation, with values of 0.84 and 0.63 eV, respectively. This implies that the Gd atom exhibits a higher propensity to segregate at the interface, whereas the Ca and La atoms are less inclined to segregate. Moreover, the electronic density is thoroughly analyzed to elucidate the interfacial segregation behavior. The research findings presented in this paper offer valuable guidance and insights for designing the composition of magnesium-based composites.

15.
ACS Nano ; 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39276102

RESUMO

A complex based on a Ni(II) porphyrin exhibiting spin crossover on Ag(111) is studied on Pb(100) by scanning tunneling microscopy at 0.3 K. Strong molecular interactions between the phenyl and pentafluorophenyl moieties lead to the formation of molecular chains and cause a faceting of the substrate surface. The chains are located along double and multiple substrate steps that deviate from high-symmetry directions. Tunneling spectroscopy reveals spin-flip excitations of an S = 1 system. Measurements in high magnetic fields are used to identify a tilt of the complex and its hard anisotropy axis with respect to the surface normal. Electron injection into the substrate near the molecular rows induces a transition to a state with larger inelastic cross section, leaving the spin state unchanged.

16.
Int J Pharm ; 665: 124716, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39278287

RESUMO

Establishing structure-mechanical property relationships is crucial for understanding and engineering the performance of pharmaceutical molecular crystals. In this study, we employed nanoindentation, a powerful technique that can probe mechanical properties at the nanoscale, to investigate the hardness and elastic modulus of single crystals of succinic acid and L-alanine. Nanoindentation results reveal distinct mechanical behaviors between the two compounds, with L-alanine exhibiting significantly higher hardness and elastic modulus compared to succinic acid. These differences are attributed to the underlying variations in molecular crystal structures - the three-dimensional bonding network and high intermolecular interaction energies of L-alanine molecules leads to its stiffness compared to the layered and weakly bonded crystal structure of succinic acid. Furthermore, the anisotropic nature of succinic acid is reflected in the directional dependence of the mechanical responses where it has been found that the (111) plane is more resistant to indentation than (100). By directly correlating the nanomechanical properties obtained from nanoindentation with the detailed crystal structures, this study provides important insights into how differences in molecular arrangements can translate into different macroscopic mechanical performance. These findings have implications on the selection of molecular crystals for optimized drug manufacturability.


Assuntos
Alanina , Cristalização , Ácido Succínico , Alanina/química , Alanina/análogos & derivados , Ácido Succínico/química , Módulo de Elasticidade , Dureza , Nanotecnologia/métodos
17.
ACS Nano ; 18(40): 27317-27326, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39312741

RESUMO

Anisotropic domains with 180° periodicity are known to be universally present on graphene as well as on other two-dimensional (2D) crystals. The physical origin of the domains and the mechanism of its anisotropy are, however, still unclear. Here, by employing in-plane elastic imaging by torsional resonance atomic force microscopy (TR-AFM), we demonstrate that the observed domains on graphene are of in-plane elastic (shear) anisotropy but not of friction anisotropy as commonly believed. Our results also support that the anisotropic domains originate from self-assembled environmental adsorbates on graphene surfaces. The more densely packed backbone of the highly ordered molecules within a domain defines the major axis of the shear anisotropy of the latter. This work suggests a quantitative understanding of the characteristics of anisotropic domains on 2D materials. It also demonstrates TR-AFM as a powerful tool to study the in-plane elastic anisotropy of materials, including organic molecular crystals.

18.
ACS Nano ; 18(40): 27752-27763, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39321467

RESUMO

Electricity consumption for building cooling accounts for a significant portion of global energy usage and carbon emissions. To address this challenge, passive daytime radiative cooling (PDRC) has emerged as a promising technique for cooling buildings without electricity input. However, existing radiative coolers face material mismatch issues, particularly on cementitious composites like concrete, limiting their practical application. Here, we propose a cementitious radiative cooling armor based on a particle-solid transition architecture (PSTA) to overcome these challenges. The PSTA design features an asymmetric yet monolithic morphology and an all-inorganic nature, decoupling radiative cooling from building compatibility while ensuring UV resistance. In the PSTA design, nanoparticles on the surface serve as sunlight scatterers and thermal emitters, while those embedded within a cementitious substrate provide build compatibility and cohesiveness. This configuration results in enhanced interfacial bonding strength, high solar reflectance, and strong mid-infrared emittance. Specifically, the PSTA delivers an enhanced interfacial shear strength (0.93 MPa), several-fold higher than that in control groups (metal, glass, plastic) along with a cooling performance (a subambient temperature drop of ∼6.6 °C and a cooling power of ∼92.8 W under a direct solar irradiance of ∼680 W/m2) that rivals or outperforms previous reports. Importantly, the design concept of the PSTA is applicable to various particles and solids, facilitating the practical application of PDRC technology in building scenarios.

19.
Psychiatry Res Neuroimaging ; 344: 111878, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39226869

RESUMO

Significant evidence links obesity and schizophrenia (SZ), but the brain associations are still largely unclear. 48 people with SZ were divided into two subgroups: patients with lower waist circumference (SZ-LWC: n = 24) and patients with higher waist circumference (SZ-HWC: n = 24). Healthy controls (HC) were included for comparison (HC: n = 27). Using tract-based spatial statistics, we compared fractional anisotropy (FA) of the whole-brain white matter skeleton between these three groups (SZ-LWC, SZ-HWC, HC). Using Free Surfer, we compared whole-brain cortical thickness and the selected subcortical volumes between the three groups. FA of widespread white matter and the mean cortical thickness in the right temporal lobe and insular cortex were significantly lower in the SZ-HWC group than in the HC group. The FA of regional white matter was significantly lower in the SZ-LWC group than in the HC group. There were no significant differences in mean subcortical volumes between the groups. Additionally, the cognitive performances were worse in the SZ-HWC group, who had more severe triglycerides elevation. This study provides evidence for microstructural abnormalities of white matter, cortical thickness and neurocognitive deficits in SZ patients with excessive abdominal obesity.


Assuntos
Obesidade Abdominal , Esquizofrenia , Substância Branca , Humanos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/patologia , Masculino , Adulto , Feminino , Obesidade Abdominal/diagnóstico por imagem , Obesidade Abdominal/patologia , Obesidade Abdominal/complicações , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Imagem de Tensor de Difusão , Pessoa de Meia-Idade , Circunferência da Cintura , Encéfalo/patologia , Encéfalo/diagnóstico por imagem
20.
Psychiatry Res Neuroimaging ; 344: 111884, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39236485

RESUMO

Obsessive-compulsive disorder (OCD) is characterized by structural alteration within white matter tissues of cortico-striato-thalamo-cortical, temporal and occipital circuits. However, the presence of microstructural changes in the white matter tracts of unaffected first-degree relatives of patients with OCD as a vulnerability marker remains unclear. Therefore, here, diffusion-tensor magnetic resonance imaging (DTI) data were obtained from 29 first-degree relatives of patients with OCD and 59 healthy controls. We investigated the group differences in FA using whole-brain analysis (DTI analysis). For additional regions of interest (ROI) analysis, we focused on the posterior thalamic radiation and sagittal stratum, shown in recent meta-analysis of patients with OCD. In both whole-brain and ROI analyses, using a strict statistical threshold (family-wise error rate [FWE] corrected p<.05 for whole-brain analyses, and p<.0125 (0.05/4) with Bonferroni correction for ROI analyses), we found no significant group differences in FA. Subtle reductions were observed in the anterior corona radiata, forceps minor, cingulum bundle, and corpus callosum only when a lenient statistical was applied (FWE corrected p<.20). These findings suggest that alterations in the white matter microstructure of first-degree relatives, as potential vulnerability markers for OCD, are likely subtle.


Assuntos
Imagem de Tensor de Difusão , Família , Transtorno Obsessivo-Compulsivo , Substância Branca , Humanos , Transtorno Obsessivo-Compulsivo/diagnóstico por imagem , Transtorno Obsessivo-Compulsivo/patologia , Transtorno Obsessivo-Compulsivo/genética , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Masculino , Adulto , Feminino , Imagem de Tensor de Difusão/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Pessoa de Meia-Idade , Adulto Jovem
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