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To reveal the mechanism of shear failure of en-echelon joints under cyclic loading, such as during earthquakes, we conducted a series of cyclic shear tests of en-echelon joints under constant normal stiffness (CNS) conditions. We analyzed the evolution of shear stress, normal stress, stress path, dilatancy characteristics, and friction coefficient and revealed the failure mechanisms of en-echelon joints at different angles. The results show that the cyclic shear behavior of the en-echelon joints is closely related to the joint angle, with the shear strength at a positive angle exceeding that at a negative angle during shear cycles. As the number of cycles increases, the shear strength decreases rapidly, and the difference between the varying angles gradually decreases. Dilation occurs in the early shear cycles (1 and 2), while contraction is the main feature in later cycles (3−10). The friction coefficient decreases with the number of cycles and exhibits a more significant sensitivity to joint angles than shear cycles. The joint angle determines the asperities on the rupture surfaces and the block size, and thus determines the subsequent shear failure mode (block crushing and asperity degradation). At positive angles, block size is more greater and asperities on the rupture surface are smaller than at nonpositive angles. Therefore, the cyclic shear behavior is controlled by block crushing at positive angles and asperity degradation at negative angles.

To study the acoustic radiation characteristics of forced vibration of granular assemblies, the acoustic radiation model of a single particle and the acoustic radiation model of granular assemblies are established. Combined with experimental verification, the variation law of radiated sound power in the process of forced vibration of granular assemblies is studied. The effects of vibration characteristics, material characteristics, mass characteristics, and distance characteristics on the acoustic radiation of forced vibration of granular assemblies are explored. The radiation range of radiated ultrasound in the process of forced vibration of granular assemblies is analyzed. The research results show that under the condition of forced vibration, the radiated sound power of the granular assemblies is obvious. The internal vibration of the granular assemblies will cause the granular particles to radiate the sound power of multiple frequencies outward. The granular particles will produce obvious ultrasonic sound power in the violent vibration state. The frequency of the sound wave will generally have a significant attenuation effect at 10 cm. Considering the relevant experimental research and engineering application of granular materials, the ultrasonic radiation characteristics should be analyzed to avoid the influence of ultrasonic radiation caused by its severe vibration.

ABSTRACT: The present study investigated the effects of fermented bamboo powder (FPB) on gut odorant receptors (OR), intestinal health, and growth performance of dwarf yellow-feathered broiler chickens. Six hundred (600) healthy 1-day-old chicks were randomly assigned into 2 groups, with 10 replicates consisting of 30 chicks each. The control group was fed a basal diet. In contrast, the experimental group was fed the basal diet supplemented with 1.0, 2.0, 4.0, and 6.0 g/kg FBP for 4 different phases, namely phase I (1–22 d), phase II (23–45 d), phase III (46–60 d), and phase IV (61–77 d), respectively. The first 2 phases were considered pretreatment (0–45 d), and the remaining were experimental (46–77 d) periods. The tissue samples were collected from phase IV. The chickens in the FBP supplementation group exhibited a significant increment in body weight gain, evisceration yield, breast, thigh, and liver weight, while also experiencing a decrease in the FCR (P < 0.05). Furthermore, the villus height, crypt depth, and villus area exhibited significant increases in the FBP group (P < 0.01). Additionally, the secretion levels of gut hormones such as glucagon-like peptide-1, peptide YY, cholecystokinin, and 5-hydroxytryptamine were significantly elevated in the serum, duodenum, jejunum, and ileum tissues in the FBP group (P < 0.05). The results of qRT-PCR indicated that ORs had responsive expression in the gizzard, proventriculus, and small intestine of chickens when fed with the FBP diet (P < 0.05). Notably, the expression of the COR1, COR2, COR4, COR6, COR8, COR9, OR52R1, OR51M1, OR1F2P, OR5AP2, and OR14J1L112 genes was stronger in the small intestines compared to the gizzard and proventriculus. In conclusion, these results suggest that the FPB plays a crucial role in growth performance, activation of ORs, and gut health and development.

Through high-precision engraving, self-affine sandstone joint surfaces with various joint roughness coefficients (JRC = 3.21–12.16) were replicated and the shear sliding tests under unloading normal stress were conducted regarding various initial normal stresses (1–7 MPa) and numbers of shearing cycles (1–5). The peak shear stress of fractures decreased with shear cycles due to progressively smooth surface morphologies, while increased with both JRC and initial normal stress and could be verified using the nonlinear Barton-Bandis failure criterion. The joint friction angle of fractures exponentially increased by 62.22%–64.87% with JRC while decreased by 22.1%–24.85% with shearing cycles. After unloading normal stress, the sliding initiation time of fractures increased with both JRC and initial normal stress due to more tortuous fracture morphologies and enhanced shearing resistance capacity. The surface resistance index (SRI) of fractures decreased by 4.35%–32.02% with increasing shearing cycles due to a more significant reduction of sliding initiation shear stress than that for sliding initiation normal stress, but increased by a factor of 0.41–1.64 with JRC. After sliding initiation, the shear displacement of fractures showed an increase in power function. By defining a sliding rate threshold of 5 × 10−5 m/s, transition from “quasi-static” to “dynamic” sliding of fractures was identified, and the increase of sliding acceleration steepened with JRC while slowed down with shearing cycles. The normal displacement experienced a slight increase before shear sliding due to deformation recovery as the unloading stress was unloaded, and then enhanced shear dilation after sliding initiation due to climbing effects of surface asperities. Dilation was positively related to the shear sliding velocity of fractures. Wear characteristics of the fracture surfaces after shearing failure were evaluated using binary calculation, indicating an increasing shear area ratio by 45.24%–91.02% with normal stress.

Particle damping technology is applied in vibration and noise reduction because of its good broadband vibration reduction effect. The energy transfer and loss between particles are keys to the role of damping. This paper investigates the relationship between the thermal energy dissipation caused by the collision of particles and the input energy. The temperature rise characteristics under different vibration states are studied. The results show significant differences in the thermal dissipation characteristics of granular assemblies for different vibration states. Under equivalent excitation amplitudes, the frequency increases, and the thermal loss of the particles increases. At the same frequency, the excitation amplitudes increase, and the thermal loss of the particles decreases. Granular assemblies in strong vibrational states, such as a gas-like state, have intense vibrations and apparent temperature-increasing effects. However, in this vibration state, the input energy to the particles is considerable, and the thermal loss accounts for a small proportion of the total energy. In states such as solid-like states, micro-vibrational states, and intermediate vibrational states, the particles interact closely, and the input energy for the particles is small. Additionally, the movement of the particles is not intense, and the thermal loss accounts for a large proportion of the total energy. The thermal loss of the particles also shows a frequency variation characteristic. According to the different temperature rise characteristics of the particles, the proportion of thermal energy consumption is analyzed. The research shows that the proportion of thermal energy consumption is not more than 70%, so there are other forms of energy consumption in the vibration reduction and energy consumption of the particles.

Particle damping technology is a typical passive vibration damping technology. In order to further explore the energy dissipation characteristics of particle dampers under different excitation, the relationship between internal vibration state and energy dissipation is analyzed. Based on the analysis of the motion state of granular assembly inside three-dimensional cylindrical particles, the steady-state energy flow method is used to study the loss characteristics of the granular assembly with different vibration laws. The research is carried out under the condition of excitation reduced acceleration of 0–8 and excitation frequency of 0–300 Hz. The results show that the loss capacity of the particles is enhanced when the vibration state of the particles changes from solid-like to other motion states. At frequencies above 250 Hz, the particle microvibrational and intermediate-vibrational loss effects are more significant. The loss capacity of the granular assembly shows frequency-dependent characteristics and is affected by frequency and reduced acceleration. With the increase of the reduced acceleration, the loss capacity of particles is enhanced and shows a local peak effect as the frequency increases. The increase of the particle size enhances the loss ability in the microvibrational state and the intermediate-vibrational state. By changing the vibrational state, the energy dissipation capacity of particle damper can be enhanced, which may provide a new idea for designing optimal granular dampers.

Shear tests on rectangular plate sandstone containing two pre-existing holes were performed to analyze the shear mechanical responses and cracking evolution mechanisms. With generation of the penetrating fracture surfaces, both shear stress and normal displacement show a dramatic drop. Then, during the shear slipping process, the shear stress increases once again due to wear and shear off of the surface asperities, and three different variation trends of the normal deformation including shear dilation, fluctuation, and shear contraction are respectively identified. The role of ligament length and normal stress on several key indices such as peak shear stress, peak normal displacement and residual shear stress was investigated. Violent AE (acoustic emission) responses occur along with penetration of the fracture surfaces, and in the shear slipping process, AE events continue to occur due to wear of surface asperities, while the increase rate of accumulative AE events declines. Cracks coalesced at the rock bridge and running through the rock matrix form the main failure planes of the samples. From the PFC2D simulation results, the crack clusters first initiate from hole-walls and coalesce at the rock bridge for a small ligament length, while first produce the main failure planes at the right/left rock matrix for a large ligament length. The total number of micro cracks shows a “calm → rapid increase → decreasing growth amplitude” variation during shearing, and the induced cracks become more concentrated for a larger normal stress, implying a cumulative damage of the failure surfaces.

Shear tests on sandstone containing non-connected joints under the unloading normal stress but fixed shear stress conditions were conducted with various initial normal stress and unloading rate. During the unloading process, continuous shear dilation could be observed. For initial normal stress = 5–20 MPa, the sliding initiation normal displacement decreased by 17.14–66.32 % but the sliding initiation shear displacement increased by 21.91–98.19 %. The sliding initiation normal stress declined by 7.18–15.57 % for unloading rate = 0.002–0.01 MPa/s but increased by a factor of 3.18–3.53 with the initial normal stress. Shear sliding of the jointed samples was more prone to occur at a smaller initial normal stress with a larger unloading rate. From the numerical simulation results via PFC2D, during the unloading process, cracking was first initiated from central part of the rock bridge and propagated gradually to coalesce with cracks developed from the joint tips. The penetrating fracture surfaces led to shear sliding of the jointed samples, and shear wear occurred on the fractures as shear displacement continued increasing. For unloading rate = 0.002–20 MPa/s, quantity of cracks corresponding to shear displacement of 1.2 mm decreased by 12.18–36.34 %. Cracking degree was more serious for the samples at a low unloading rate due to progressively developed cracks near the main failure planes before shear sliding and more accumulated cracks in the shearing wear stage for fractures under a larger normal stress.

Abstract Parkinson’s disease (PD) can be classified into an akinetic-rigid (AR) and a tremor-dominant (TD) subtype based on predominant motor symptoms. Patients with different motor subtypes often show divergent clinical manifestations; however, the underlying neural mechanisms remain unclear. This study aimed to characterize the cortical and subcortical morphological alterations in motor subtypes of PD. T1-weighted MRI images were obtained for 90 patients with PD (64 with the AR subtype and 26 with the TD subtype) and 56 healthy controls (HCs). Cortical surface area, sulcal depth (measured by Freesurfer’s Sulc index), and subcortical volume were computed to identify the cortical and subcortical morphological alterations in the two motor subtypes. Compared with HCs, we found widespread surface area reductions in the AR subtype yet sparse surface area reductions in the TD subtype. We found no significant Sulc change in the AR subtype yet increased Sulc in the right supramarginal gyrus in the TD subtype. The hippocampal volumes in both subtypes were lower than those of HCs. In PD patients, the surface area of left posterior cingulate cortex was positively correlated with Mini-Mental State Examination (MMSE) score, while the Sulc value of right middle frontal gyrus was positively correlated with severity of motor impairments. Additionally, the hippocampal volumes were positively correlated with MMSE and Montreal Cognitive Assessment scores and negatively correlated with severity of motor impairments and Hoehn & Yahr scores. Taken together, these findings may contribute to a better understanding of the neural substrates underlying the distinct symptom profiles in the two PD subtypes.

IntroductionStudies have found a varying degree of cognitive, psychosocial, and functional impairments in patients with unruptured intracranial aneurysms (UIAs), whereas the neural correlates underlying these impairments remain unknown.MethodsTo examine the brain morphological alterations and white matter lesions in patients with UIA, we performed a range of structural analyses to examine the brain morphological alterations in patients with UIA compared with healthy controls (HCs). Twenty-one patients with UIA and 23 HCs were prospectively enrolled into this study. Study assessment consisted of a brain magnetic resonance imaging (MRI) scan with high-resolution T1-weighted and T2-weighted imaging data, a Montreal Cognitive Assessment (MoCA), and laboratory tests including blood inflammatory markers and serum lipids. Brain MRI data were processed for cortical thickness, local gyrification index (LGI), volume and shape of subcortical nuclei, and white matter lesions.ResultsCompared to the HCs, patients with UIA showed no significant differences in cortical thickness but decreased LGI values in the right posterior cingulate cortex, retrosplenial cortex, cuneus, and lingual gyrus. In addition, decreased LGI values correlated with decreased MoCA score (r = 0.498, p = 0.021) and increased white matter lesion scores (r = −0.497, p = 0.022). The LGI values were correlated with laboratory values such as inflammatory markers and serum lipids. Patients with UIA also showed significant regional atrophy in bilateral thalami as compared to the HCs. Moreover, the LGI values were significantly correlated with thalamic volume in the HCs (r = 0.4728, p = 0.0227) but not in the patients with UIA (r = 0.11, p = 0.6350).DiscussionThe decreased cortical gyrification, increased white matter lesions, and regional thalamic atrophy in patients with UIA might be potential neural correlates of cognitive changes in UIA.

Neuroimaging studies have found significant structural alterations of the cerebral cortex in patients with nasopharyngeal carcinoma (NPC) following radiotherapy (RT) or concomitant chemoradiotherapy (CCRT), while their effects on the shape of subcortical structures remain largely unknown. In this study, we investigated the subcortical shape alterations between three groups: 56 untreated NPC patients (pre-RT group), 37 RT-treated NPC patients (post-RT group), and 108 CCRT-treated NPC patients (post-CCRT group). Using FSL-FIRST, we found that, compared with the pre-RT group, the post-CCRT group exhibited significant inward atrophy in the bilateral thalamus, bilateral putamen, left pallidum, and left caudate and outward inflation in the left caudate, while the post-RT group only exhibited inward atrophy in the bilateral thalamus. In addition, greater maximum dosage of RT for temporal lobes was associated with more severe inward atrophy of the bilateral thalamus in treated NPC patients. These results indicated that there may be an interaction between RT and CT that can cause subcortical damage.

The alkali mercerizing process of semicrystalline cotton fiber (CF) is widely used in the printing and dyeing industry. The crystallinity change in the mercerizing process has been studied and certain laws have been obtained, but there is still a certain distance between the theoretical research results and the practical applications. CF is almost composed of cellulose, combined with the photoluminescence (PL) phenomenon of cellulose; herein, the varying crystallinity is correlated with its PL behavior after being treated with different concentrations of NaOH. In line with the characteristics of nonconventional luminogens, CF enjoys excitation-dependent emission and persistent room temperature phosphorescence (p-RTP) behavior. The emission spectra of all samples under the same excitation wavelength indicate that the change of CF crystallinity has a significant impact on its fluorescence and p-RTP emission. As the concentration of NaOH increases, the varying trend of quantum efficiency (QY) is consistent with the changed crystallinity of CF. Interestingly, the lifetime of p-RTP is exactly the opposite of the crystallinity change law. Clustering-triggered emission (CTE), crystallization-Induced Phosphorescence (CIP) mechanism, and the swelling due to hydrated sodium ions can reasonably explain these interesting photophysical processes, which also can be supported by theoretical calculations. The above studies have basically clarified the inherent law between the crystalline change of CF and the PL emission behavior during the alkali treatment process, which can be used as a theoretical reference for real-time monitoring of CF crystallinity changes using the spectral method in the actual cotton mercerizing process.

Intracortical myelin is involved in speeding and synchronizing neural activity of the cerebral cortex and has been found to be disrupted in various psychiatric disorders. However, its role in obsessive–compulsive disorder (OCD) has remained unknown. In this study, we investigated the alterations in intracortical myelin and their association with white matter (WM) microstructural abnormalities in OCD. T1-weighted and diffusion-weighted brain images were obtained for 51 medication-naïve patients with OCD and 26 healthy controls (HCs). The grey/white matter contrast (GWC) was calculated from T1-weighted signal intensities to characterize the intracortical myelin profile in OCD. Diffusion parameters, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD), were extracted from diffusion-weighted images to examine the WM microstructure in OCD. Compared with HCs, patients with OCD showed increased GWC in the bilateral orbitofrontal, cuneus, lingual and fusiform gyrus, left anterior cingulate, left superior parietal, right inferior parietal, and right middle frontal cortices, suggesting reduced intracortical myelin. Patients with OCD also showed decreased FA in several WM regions, with a topology corresponding to the GWC alterations. In both groups, the mean GWC of the significant clusters in between-group GWC analysis was correlated negatively with the mean FA of the significant clusters in between-group FA analysis. In patients with OCD, the FA of a cluster in the right cerebellum correlated negatively with the Yale-Brown obsessive–compulsive scale scores. Our results suggest that abnormal intracortical and WM myelination could be the microstructural basis for the brain connectivity alterations and disrupted inhibitory control in OCD.

A phononic crystal with particle assembly dampers was constructed. A high-speed camera was used to record and observe the vibration phenomenon of the particle assembly under external excitation. By analyzing the vibrations of the particle assembly, a continuous system equivalent to the discrete particle assembly was proposed. The particle damping equivalent model was fitted to data using an artificial neural network. Two particle damping phononic crystal plates were designed. Based on the equivalent model, a particle damping phononic crystal model was established. The results of the simulations and experiments showed that the average damping effect of the particle damping structure was greater than 75%. Particle damping phononic crystals possess excellent low vibration transmission characteristics, narrow bandgap characteristics at low frequencies, and high damping characteristics.

This paper investigates the damping performance of the main structure with a concentrated mass and particle dampers at different particle filling rates and sinusoidal sweep amplitudes under the same mass ratio by means of a controlled experiment, with the concentrated mass and particle dampers attached to the free end of the cantilever beam. As the order increases, the effect becomes progressively weaker. For cantilevered beam structures, a reasonable design with only a small mass ratio of particle dampers can effectively suppress the vibration of the first order. For the second- and third-order bending vibration, particle dampers with high mass ratios show a better damping effect, and when the strength of the excitation reaches a certain value, the damping performance of the particle dampers is basically better than that of the concentrated mass under the same conditions. The reason for this is that particle damping not only dampens the vibration by tuning the mass but also dissipates the energy of the main structure by means of collisions, impacts, and friction between the particles or between the particles and the damper cavity.

The inferior parietal lobule (IPL) is one of the most expanded cortical regions in humans relative to other primates. It is also among the most structurally and functionally asymmetric regions in the human cerebral cortex. Whether the structural and connectional asymmetries of IPL subdivisions differ across primate species and how this relates to functional asymmetries remain unclear. We identified IPL subregions that exhibited positive allometric in both hemispheres, scaling across rhesus macaque monkeys, chimpanzees, and humans. The patterns of IPL subregions asymmetry were similar in chimpanzees and humans, but no IPL asymmetries were evident in macaques. Among the comparative sample of primates, humans showed the most widespread asymmetric connections in the frontal, parietal, and temporal cortices, constituting leftward asymmetric networks that may provide an anatomical basis for language and tool use. Unique human asymmetric connectivity between the IPL and primary motor cortex might be related to handedness. These findings suggest that structural and connectional asymmetries may underlie hemispheric specialization of the human brain.

Diabetic peripheral neuropathy (DPN) is one of the most common forms of peripheral neuropathy, and its incidence has been increasing. Mounting evidence has shown that patients with DPN have been associated with widespread alterations in the structure, function and connectivity of the brain, suggesting possible alterations in large-scale brain networks. Using structural covariance networks as well as advanced graph-theory-based computational approaches, we investigated the topological abnormalities of large-scale brain networks for a relatively large sample of patients with DPN (N = 67) compared to matched healthy controls (HCs; N = 88). Compared with HCs, the structural covariance networks of patients with DPN showed an increased characteristic path length, clustering coefficient, sigma, transitivity, and modularity, suggestive of inefficient global integration and increased local segregation. These findings may improve our understanding of the pathophysiological mechanisms underlying alterations in the central nervous system of patients with DPN from the perspective of large-scale structural brain networks.

To further reduce the vertical stiffness of the air spring, appropriately reduce its lateral stiffness to attenuate the transmission of vibration along the lateral and longitudinal directions, a compound structure air spring (CSAS) was designed. It is a laminated structure with a hard elastic layer at the lower end of the original air spring. Prototypes of the air spring and the CSAS were produced, then related static and dynamic characteristics tests were conducted. Compared with the test results of the air spring, it can be found that under the same air pressure, the bearing capacity of the CSAS is decreased slightly; under rated load, the vertical static/dynamic stiffness and natural frequency is decreased slightly, and the lateral static/dynamic stiffness is decrease significantly. Furthermore, the CSAS was subjected to the safety and reliability tests, and its performance was stable without damage. This article expands the stiffness range of the air spring, and provides a new idea for the design of the air spring with low lateral to vertical stiffness ratio and low natural frequency.

In single-cell RNA-seq (scRNA-seq) experiments, the number of individual cells has increased exponentially, and the sequencing depth of each cell has decreased significantly. As a result, analyzing scRNA-seq data requires extensive considerations of program efficiency and method selection. In order to reduce the complexity of scRNA-seq data analysis, we present scedar, a scalable Python package for scRNA-seq exploratory data analysis. The package provides a convenient and reliable interface for performing visualization, imputation of gene dropouts, detection of rare transcriptomic profiles, and clustering on large-scale scRNA-seq datasets. The analytical methods are efficient, and they also do not assume that the data follow certain statistical distributions. The package is extensible and modular, which would facilitate the further development of functionalities for future requirements with the open-source development community. The scedar package is distributed under the terms of the MIT license at https://pypi.org/project/scedar.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the loss of both upper and lower motor neurons. Studies using metrics derived from the diffusion tensor model have documented decreased fractional anisotropy (FA) and increased mean diffusivity in the corticospinal tract (CST) and the corpus callosum (CC) in ALS. These studies, however, only focused on microstructural white matter (WM) changes, while the macrostructural alterations of WM tracts in ALS remain unknown. Moreover, studies conducted based on the diffusion tensor model cannot provide information related to specific fiber bundles and fail to clarify which biological characteristics are changing. Using a novel fixel-based analytical method that can characterize the fiber density (FD) and the fiber-bundle cross-section (FC), this study investigated both microstructural and macrostructural changes in the WM in a large cohort of patients with ALS (N = 60) compared with demographically matched healthy controls (N = 60). Compared with healthy controls, we found decreased FD, FC and fiber density and cross-section (FDC, a combined measure of the FD and FC) values in the bilateral CST and the middle posterior body of the CC in patients with ALS, suggesting not only microstructural but also macrostructural abnormalities in these fiber bundles. Additionally, we found that the mean FD and FDC values in the bilateral CST were positively correlated with the revised ALS Functional Rating Scale, indicating that these two indices may serve as potential markers for assessing the clinical severity of ALS. Thus, these findings provide initial evidence for the existence of microstructural and macrostructural abnormalities of the fiber bundles in ALS.

Abstract A sensitive, selective and recyclable electrochemical sensor is designed for ATP detection based on amino-functionalized metal-organic framework. The functional MOF as the sensor is constructed by one-step synthesis Ce-MOF and sequentially modified on the Au electrode and conjugated with the aptamer of ATP. The presence of target ATP leads to the conformational change of aptamer strands and strong electrochemical impedance. The electrochemical sensor can detect ATP down to 5.6 nM with the linear range of 10 nm to 1000 μM. The present study is the first report on the use of MOF as an electrochemical sensor for ATP at nM level. This strategy has been successfully applied in detection of ATP in serum of cancer patients, which reveals its potential application in clinical diagnosis.

Radiation encephalopathy (RE) is deemed to be a disease induced only by radiotherapy (RT), with the effects of chemotherapeutic agents on the brains of nasopharyngeal carcinoma (NPC) patients being largely overlooked. In this study, we investigated structural and functional brain alterations in NPC patients following RT with or without chemotherapy. Fifty-six pre-RT, 37 post-RT, and 108 post-CCRT (concomitant chemo-radiotherapy) NPC patients were enrolled in this study. A surface-based local gyrification index (LGI) was obtained from high resolution MRI and was used to evaluate between-group differences in cortical folding. Seed-based functional connectivity (FC) analysis of resting-state fMRI data was also conducted to investigate the functional significance of the cortical folding alterations. Compared with the Pre-RT group, patients in the Post-CCRT group showed LGI reductions in widespread brain regions including the bilateral temporal lobes, insula, frontal lobes, and parietal lobes. Compared with the Post-RT group, patients in the Post-CCRT group showed LGI reductions in the right insula, which extended to the adjacent frontal lobe. Seed-based FC analysis showed that patients in the Post-CCRT group had lower FC between the insula and the left middle frontal gyrus than patients in the Pre-RT group. The follow-up results showed that patients in the Post-CCRT group had a much higher RE incidence rate (20.4%) than patients in the Post-RT group (2.7%; P = 0.01). These findings indicate that chemotherapy potentially facilitated the occurrence of RE in NPC patients who underwent radiotherapy.

Neuroimaging studies of patients with amyotrophic lateral sclerosis (ALS) have shown widespread alterations in structure, function, and connectivity in both motor and non-motor brain regions, suggesting multi-systemic neurobiological abnormalities that might impact large-scale brain networks. Here, we examined the alterations in the topological organization of structural covariance networks of ALS patients (N = 60) compared with normal controls (N = 60). We found that structural covariance networks of ALS patients showed a consistent rearrangement towards a regularized architecture evidenced by increased path length, clustering coefficient, small-world index, and modularity, as well as decreased global efficiency, suggesting inefficient global integration and increased local segregation. Locally, ALS patients showed decreased nodal degree and betweenness in the gyrus rectus and/or Heschl's gyrus, and increased betweenness in the supplementary motor area, triangular part of the inferior frontal gyrus, supramarginal gyrus and posterior cingulate cortex. In addition, we identified a different number and distribution of hubs in ALS patients, showing more frontal and subcortical hubs than in normal controls. In conclusion, we reveal abnormal topological organization of structural covariance networks in ALS patients, and provide network-level evidence for the concept that ALS is a multisystem disorder with a cerebral involvement extending beyond the motor areas. Keywords: Amyotrophic lateral sclerosis, Structural covariance network, Gray matter volume, Small-world, Modularity

This paper mainly focuses on the elastic support of thrust bearings. The dynamic characteristics of the shafting system are studied. Firstly, the multi-DOF transfer matrix expressions of the simplified mass element and spring element are derived. A three-DOF transfer matrix-coupling model in XOZ plane is established by using force coupling conditions at thrust bearings. Then, a test rig is built to test the propulsion shafting. The bending vibration characteristics of the shafting under the support conditions of thrust bearings are studied. And finally, the transmission characteristics of vertical and longitudinal forces of propellers under different support conditions of thrust bearings are emphatically analyzed.

In this paper, a combination of physical model tests and numerical simulations were carried out to explore the overlying strata movement laws, failure mechanism, and cracks evolution of the gob-side entry driven in a thick coal seam. The physical experimental results indicated that the hanging cantilever beam was easily developed above the coal pillar after mining out the 2101 panel, resulting in a larger and stronger stress concentration. The overburden loads acting on the coal pillar can be greatly released after the hanging roof strata were cut down with an 18 m cutting line. Additionally, we adopted Universal Discrete Element Code (UDEC) software to investigate the deformation and crack evolution mechanism of the gob-side entry under different conditions. The primary-supported roadway underwent severe deformation, filling with a great quantity of tensile and shear cracks to the inner coal pillar. Both the physical and numerical results proved that the optimized-support parameters combined with roof-cutting measures could effectively guarantee the stability of the gob-side entry. This research can provide valuable guidance for the stability control of the gob-side entry in mines under similar conditions.

The tire tread pattern affects driving significantly on icy roads, and different kinds of rubber pattern mean different friction coefficients when moving on the ice surface. Based on the latest friction test rig, a simulation method of such tests was created. Therefore, the continuous sampling at low slip velocity was proposed. During the sampling, the typical pattern of the rubber specimen was employed. The friction test of the tire tread specimen on the ice surface was implemented with different slip velocities and pressure, and the results were fitted and analyzed. To research the effect of tire tread on the friction coefficient, the rubber ratio parameter (the ratio of the rubber contact area to the total contact area) was given for proper evaluation. It is found that rubber as the major component of the tire possesses a special friction property, which is against Coulomb’s law. In addition to that, the friction coefficient of rubber is influenced by the contact state to a great extent, especially in some extreme conditions. The experiment of rubber friction on ice can serve as an important reference for the study on tire mechanical properties.

Gold based structures such as nanoparticles (NPs) and nanowires (NWs) have widely been used as building blocks for sensing devices in chemistry and biochemistry fields because of their unusual optical, electrical and mechanical properties. This article gives a detailed review of the new properties and fabrication methods for gold nanostructures, especially gold nanowires (GNWs), and recent developments for their use in optical and electrochemical sensing tools, such as surface enhanced Raman spectroscopy (SERS).

Many rock engineering accidents have proven that the coalescence of discontinuities in surrounding rock can have a major impact on the security and stable operation of energy infrastructure. To give an insight into the understanding of the crack propagation and coalescence in fissured rock masses, a series of uniaxial compression experiments were conducted on rock-like specimens containing nonpersistent fissures. The digital speckle correlation method (DSCM) and the acoustic emission (AE) monitoring system were adopted to capture the real-time strain field on the specimens’ surfaces and microfracturing events within specimens, respectively. The experimental results indicated that the strength and deformation modulus of specimens were significantly affected by fissure inclination. The damage process showed obvious progressive stain localization failure characteristics. The clear and intuitive full-field strain field development was successfully monitored by the DSCM technique. The real-time strain accumulation, crack initiation, propagation, and coalescence were also analyzed. Each time, the saltation of the strain field was usually accompanied by the fluctuation of the stress curve and obvious AE events. Crack coalescence modes between fissures changed from tension coalescence mode to mixed tension-shear coalescence mode, then to shear coalescence mode with an increase in fissure inclination. Five basic failure modes were identified from the experimental results: Tensile failure across the fissure planes, rotation failure of newly generated blocks, mixed failure mode, shear failure, and splitting failure. An investigation of the fracture processes of rock-like specimens containing nonpersistent fissures using these methods can enhance understanding of the fracture behavior of jointed rocks.

Sports experts represent a population of people who have acquired expertise in sports training and competition. Recently, the number of studies on sports experts has increased; however, neuroanatomical changes following extensive training are not fully understood. In this study, we used cortical thickness measurement to investigate the brain anatomical characteristics of professional divers with extensive training experience. A comparison of the brain anatomical characteristics of the non-athlete group with those of the athlete group revealed three regions with significantly increased cortical thickness in the athlete group. These regions included the left superior temporal sulcus, the right orbitofrontal cortex and the right parahippocampal gyrus. Moreover, a significant positive correlation between the mean cortical thickness of the right parahippocampal gyrus and the training experience was detected, which might indicate the effect of extensive training on diving players' brain structure.

Mental retardation is a developmental disorder associated with impaired cognitive functioning and deficits in adaptive behaviors. Many studies have addressed white matter abnormalities in patients with mental retardation, while the changes of the cerebral cortex have been studied to a lesser extent. Quantitative analysis of cortical integrity using cortical thickness measurement may provide new insights into the gray matter pathology. In this study, cortical thickness was compared between 13 patients with mental retardation and 26 demographically matched healthy controls. We found that patients with mental retardation had significantly reduced cortical thickness in multiple brain regions compared with healthy controls. These regions include the bilateral lingual gyrus, the bilateral fusiform gyrus, the bilateral parahippocampal gyrus, the bilateral temporal pole, the left inferior temporal gyrus, the right lateral orbitofrontal cortex and the right precentral gyrus. The observed cortical thickness reductions might be the anatomical substrates for the impaired cognitive functioning and deficits in adaptive behaviors in patients with mental retardation. Cortical thickness measurement might provide a sensitive prospective surrogate marker for clinical trials of neuroprotective medications.

Recently, many researchers have used graph theory to study the aberrant brain structures in Alzheimer's disease (AD) and have made great progress. However, the characteristics of the cortical network in Mild Cognitive Impairment (MCI) are still largely unexplored. In this study, the gray matter volumes obtained from magnetic resonance imaging (MRI) for all brain regions except the cerebellum were parcellated into 90 areas using the automated anatomical labeling (AAL) template to construct cortical networks for 98 normal controls (NCs), 113 MCIs and 91 ADs. The measurements of the network properties were calculated for each of the three groups respectively. We found that all three cortical networks exhibited small-world properties and those strong interhemispheric correlations existed between bilaterally homologous regions. Among the three cortical networks, we found the greatest clustering coefficient and the longest absolute path length in AD, which might indicate that the organization of the cortical network was the least optimal in AD. The small-world measures of the MCI network exhibited intermediate values. This finding is logical given that MCI is considered to be the transitional stage between normal aging and AD. Out of all the between-group differences in the clustering coefficient and absolute path length, only the differences between the AD and normal control groups were statistically significant. Compared with the normal controls, the MCI and AD groups retained their hub regions in the frontal lobe but showed a loss of hub regions in the temporal lobe. In addition, altered interregional correlations were detected in the parahippocampus gyrus, medial temporal lobe, cingulum, fusiform, medial frontal lobe, and orbital frontal gyrus in groups with MCI and AD. Similar to previous studies of functional connectivity, we also revealed increased interregional correlations within the local brain lobes and disrupted long distance interregional correlations in groups with MCI and AD.

BACKGROUND: Strabismus is a disorder in which the eyes are misaligned. Persistent strabismus can lead to stereopsis impairment. The effect of strabismus on human brain is not unclear. The present study is to investigate whether the brain white structures of comitant exotropia patients are impaired using combined T1-weighted imaging and diffusion tensor imaging (DTI). PRINCIPAL FINDINGS: Thirteen patients with comitant strabismus and twelve controls underwent magnetic resonance imaging (MRI) with acquisition of T1-weighted and diffusion tensor images. T1-weighted images were used to analyze the change in volume of white matter using optimized voxel-based morphology (VBM) and diffusion tensor images were used to detect the change in white matter fibers using voxel-based analysis of DTI in comitant extropia patients. VBM analysis showed that in adult strabismus, white matter volumes were smaller in the right middle occipital gyrus, right occipital lobe/cuneus, right supramarginal gyrus, right cingulate gyrus, right frontal lobe/sub-gyral, right inferior temporal gyrus, left parahippocampa gyrus, left cingulate gyrus, left occipital lobe/cuneus, left middle frontal gyrus, left inferior parietal lobule, and left postcentral gyrus, while no brain region with greater white matter volume was found. Voxel-based analysis of DTI showed lower fractional anisotropy (FA) values in the right middle occipital gyrus and right supramarginal gyrus in strabismus patients, while brain region with increased FA value was found in the right inferior frontal gyrus. CONCLUSION: By combining VBM and voxel-based analysis of DTI results, the study suggests that the dorsal visual pathway was abnormal or impaired in patients with comitant exotropia.

This research delves into the transfer and loss of energy in a discrete mass when subjected to forced vibration. Using discrete element method (DEM), we analyzed the dynamic behavior of regular spherical granular assemblies and the energy distribution characteristics under different excitation frequencies and reduced accelerations. Moreover, the energy transfer and dissipation process of granular assemblies under different vibration states are studied using an experimental method. The results show that the granular assemblies will produce collision energy dissipation, thermal energy dissipation, acoustic energy dissipation and other forms of energy dissipation in the forced vibration state and the proportion of different energy dissipation under different excitation is given. The collision and friction of granular assemblies are the key to affecting other forms of energy dissipation. When the excitation increases, the energy dissipation forms are generated inside the granular assemblies, and the proportion of collision energy dissipation of the granular assemblies increases. The acoustic energy above 20 kHz occupies the main part of the acoustic energy dissipation. Thermal energy consumption always exists, which takes a long time to play a role. The granular also have other forms of energy loss, which is hard to be measured, including Rayleigh waves generated by granular collision. In this study, the relationship between the forced vibration state of the granular assemblies and the energy loss distribution is established. Various types of energy transfer and conversion distribution which further enriches the energy dissipation of discrete element calculation of the granular assemblies is discussed and provides a reference for the energy loss analysis of the granular assemblies. [ABSTRACT FROM AUTHOR]

During underground resource extraction and deep underground engineering development, the engineering rock body frequently encounters elevated temperatures and water cooling, leading to alterations in the mechanical properties of the rock. These changes will have an impact on the safety and stability of the project. This study aimed to investigate the changes in mechanical properties of rocks following treatment with high temperatures and water cooling. The experiment involved subjecting layered sandstone samples to heating and water cooling, followed by conducting uniaxial compression tests using a high-temperature furnace and a WA-1000 universal testing machine. The effects of temperature and inclination angles on the uniaxial mechanical properties of layered sandstone were then analyzed. Furthermore, the utilization of the scanning electron microscope and various other microscopic testing devices allowed for the examination of the micro-mechanism behind rock damage and rupture subsequent to undergoing heating and water-cooling treatment. The findings from the experiment suggest that: 1) the relationship between the changes in sandstones' mechanical properties and temperature and bedding inclinations can be attributed to the uneven deformation of minerals caused by heating and water-cooling treatment, leading to the distribution of microcracks within the rock. 2) The stress-strain curve of the specimen can be divided as four-stages. With the increase of bedding inclination, the compaction stage of the specimen is more prominent. 3) As the bedding inclination increases, the specimens exhibit a pattern of initially decreasing and then increasing in terms of peak strength and strain. With the increase of temperature, the peak axial strain gradually increases, while it first increases and then decreases with the increasing dip angles. [ABSTRACT FROM AUTHOR]