We analyze the time series of hashtag numbers of social media data. We observe that the usage distribution of hashtags is characterized by a fat-tailed distribution with a size-dependent power law ...exponent and we find that there is a clear dependency between the growth rate distributions of hashtags and size of hashtags usage. We propose a generalized random multiplicative process model with a theory that explains the size dependency of the fat-tailed distribution. Numerical simulations show that our model reproduces these size-dependent properties nicely. We expect that our model is useful for understanding the mechanism of fat-tailed distributions in various fields of science and technology.
The aim of this study was to elucidate the different effects and difference mechanism of gelling properties among egg white (EW) treated with different heating intensities and the composite addition ...of rhamnolipid and soybean lecithin. Particle size analyzer, potentiometric analyzer, surface hydrophobicity method, and Fourier transform infrared spectroscopy techniques were used to determine the physicochemical properties and molecular structure, respectively. Low-field nuclear magnetic resonance, magnetic resonance imaging, texture profile analysis, and scanning electron microscopy techniques were used to analyze the gelling properties and gel structure, respectively. And we illuminate the different mechanisms in the gelling properties of the EW with various treatments and key internal factors that play important roles in improving gelling properties by establishing the link between the gelling properties and relevant characteristics by mixed effects model and visual network analysis. The results indicate raising the content of rhamnolipid decreased the migration of immobilized water in the EW gel and the free water content. At the heating intensities of 55 °C/3.5, 65 °C/2.5, and 67 °C/1.5 min, with an increase in rhamnolipid, the gel's cohesiveness, gumminess, and chewiness gradually increased. The mixed effects model indicated that heating intensities and composite ratios have a 2-way interaction on zeta potential, the relaxation time of bound water (T21), the content of bound water (P21), the content of immobilized water (P22), and fractal dimension (df) attributes (P < 0.05). The visual network analysis showed that the protein solubility, the relaxation time of immobilized water (T22), surface hydrophobicity, zeta potential, average particle size (d43) and the relaxation time of free water (T23) are critical contributors to the different gelling properties of EW subjected to various treatments and the improvement of gelling properties. This study will provide theoretical guidance for the development of egg white products and the expansion of egg white's application scope in the egg product processing industry.
Several recent studies have reported subacute combined degeneration (SCD) induced by nitrous oxide (N
O) abuse. However, the association between the evolution of dynamic neuroimaging and clinical ...manifestations has not been reported in patients with N
O-induced SCD.
We described the case of a 24-year-old man who developed SCD with inverted V-sign hyperintensities over the posterior aspect of the spinal cord caused by frequent, excessive N
O inhalation. One month after treatment, his weakness and paresthesia resolved and serum vitamin B
levels exceeded the normal levels. However, the hyperintensities had extended horizontally and longitudinally on T2-weighted magnetic resonance imaging (MRI), compared to those on the initial scan. Two months after treatment, the patient experienced some residual numbness in the distal limbs, and his serum homocysteine levels were normal, but the abnormal signals seen on cervical T2-weighted MRI had decreased only slightly compared to those seen on the one-month follow-up MRI. The evolution of conventional MRI findings lagged compared to the clinical manifestation, which was suggestive of a clinical-radiological dissociation.
Clinical-radiological dissociation might have occurred in this case because T2-weighted imaging was not sensitive enough to reveal cytotoxic edema. Moreover, the serum vitamin B
level is not a good indicator of cellular vitamin B
. Thus, clinicians should recognize this phenomenon, comprehensively assess the condition of patients with N
O-induced SCD, and avoid terminating treatment based on the resolution of clinical symptoms and serological results.
Inspired by the swarming behavior of various bacteria in nature, light-driven micromotor with collective behavior has attracted a great deal of attention, which will be a valuable tool to understand ...the cooperation and communication between bacterial populations and will contribute to the creation of reconfigurable microrobots and the cooperative transportation of large cargoes. However, it is still challenging to modulate the micromotors’ collective behavior based on local interaction and communication. Herein, we develop a light-powered BiVO
4
-based micromotor with self-propulsion and dynamic ‘predator-bait’ collective behavior, which is based on the photocatalytic reaction of BiVO
4
. The BiVO
4
-based micromotor has great potential in the field of organic pollutant degradation with enhanced apparent rate constant (0.076 min
−1
) which originates from the dynamic ‘predator-bait’ behavior.
Hot dry rock (HDR) is a kind of clean, renewable energy and has received widespread attention worldwide in recent years. It is significant to explore the dynamic tensile properties of thermal-treated ...granite using different cooling methods for mining HDR. In the current work, a series of tests were performed containing ultrasonic testing and Split Hopkinson Pressure Bar (SHPB) tests on granite at different temperatures (25, 200, 400, 500, 600, and 800 °C) after different cooling methods (including natural, water, and liquid nitrogen cooling). Then the dynamic tensile properties, thermal shock damage, and energy evolution process of granite using different cooling methods were compared and analyzed. The high-speed camera and Digital Image Correlation (DIC) technology were used to analyze the tensile failure mode and the failure mechanism under different thermal treatment and cooling conditions. According to the experimental results, with the increasing thermal treatment temperature by adopting the three cooling methods, the P-wave velocity, dynamic tensile strength, and final absorbed energy of granite decreased, and thermal shock damage increased. In addition, the effect of liquid nitrogen cooling on thermal-treated granite was the most obvious among the three methods, followed by water cooling and natural cooling. Moreover, with the increasing treatment temperature, the time for the occurrence of central cracks in the specimen after impact was prolonged, and the areas of the shear failure zone and tensile failure zone increased; the influence of different cooling methods was also evident (natural cooling < water cooling < liquid nitrogen cooling). The experimental findings were expected to offer a reference for understanding the dynamic tensile properties and failure mechanism of thermal-treated granite after rapid cooling. By studying the degree of deterioration of rock dynamic properties by different cooling methods, the exploitation efficiency of geothermal wells can be improved.
Shear deformation often occurs during multistage fracturing of shale gas worldwide, increasing the operation cost of gas well completion and lowering the well’s productivity; strike-slip fault ...slippage is thought to be a crucial underlying factor. This paper presents a detailed analysis of the influence of strike-slip fault slippage on casing inner diameter and establishes a technique for predicting casing inner diameter after fault slippage. Numerical simulation models were developed to simulate the process of fault slippage and calculate changes in the inner diameters of the casing, considering different engineering and geological conditions. The influential factors, including the fault strike angle, slip distance, radius-thickness ratio, and mechanical properties of the formation, were analyzed in engineering practice; the simulation results were shown to be consistent. Four methods, including adjusting the wellbore trajectory of shale gas horizontal wells, avoiding perforation at the formation interface, decreasing the fracturing parameters including the fracturing pressure, discharge capacity, volume of injecting fracturing fluid, and prediction of casing inner diameter after casing shear deformation, were proposed and verified through engineering application and theoretical calculation, respectively.
•Analysis of the influence of strike-slip fault slippage on casing inner diameter was conducted.•A prediction technique of casing inner diameter after fault slippage was established.•Four mitigating methods of casing shear deformation were verified by engineering application or theory calculation.
AbstractLimited by the particle size requirements of testing apparatus, little true triaxial test (TTT) research on rockfill has been conducted. Using a large true triaxial apparatus (TTA) developed ...independently by the Changjiang River Scientific Research Institute (CRSRI), tests with different intermediate principal stress ratios {Ratio b=(σ2−σ3)/(σ1−σ3)} and plane strain tests were carried out on sandstone rockfill. The results show that, with the same Ratio b, the initial slope in stress-strain curves and peak stress increased with rising σ3; with low σ3, volumetric strain first contracted and then transitioned to dilatancy; with high σ3, it continued to contract throughout the deformation process. With stable σ3 but increasing Ratio b, softening and brittle failure after peak stress were obvious and the strain corresponding to peak stress slightly lagged behind the strain bending point in the ε1–εv curves, which reflected deformation and failure of the specimen force chain. The effect of Ratio b in increasing strength was significant, especially in the range 0–0.25, where strength showed significant growth. The Lade–Duncan failure criterion was more suited to revealing strength evolution than were other criteria, but both σ3 and Ratio b induced significant particle breakage. The actual tested strength was always lower than the estimated strength obtained by the Lade–Duncan failure criterion. Under plane strain, when deviatoric stress approached its peak value, Ratio b was around 0.17–0.19 in all tested specimens. The contribution of σ2 in increasing specimen strength was basically reflected. This means that, when test conditions are limited, the plane strain test can be used to make a rough estimate of the strength index of rockfill under complex three-directional stress.
Landslides located beside reservoirs tend to be unstable or are characterized by large deformation during the drawdown process. This has been accepted by many experts. In this paper, we use Qiaotou ...Landslide, which is located beside the Three Gorges Reservoir (TGR), as a typical case study to investigate and predict the deformation mechanism during the drawdown process of TGR in detail. According to field investigation, the landslide mass is mainly composed of thick, loose silt and clay mixed with fragments of rock. Bedrock is mainly composed of silty sandstone. Field and laboratory tests indicate that the landslide mass has a high permeability coefficient. If the water level declines fast, intense seepage force may result. Based on these data, we establish a three-dimensional geological model of Qiaotou Landslide by FLAC
3D
and perform a numerical simulation using the saturated–unsaturated fluid–solid coupling theory. For the simulation, we assume that the drawdown from 175 to 145 m takes place with a speed of 25 cm/day, which is based on the extreme water level regulation program of TGR. The simulation shows that this causes a significant deformation in the landslide mass and that the maximum displacement within the landslide is 24.2 cm. During the drawdown process, the maximum displacement zone is shifting from the upper part of the landslide where bedrock surface is steeper and thickness of loose deposits is less to the middle part of the landslide where bedrock surface is less steep and thickness of loose deposits is higher. The deformation mechanism indicates that in the early stage of the drawdown the deformation of the landslide mass is mainly caused by seepage and in the later stage mainly by consolidation.
Background
Recreational N2O abuse is an important etiology of neurological impairment in young patients, which may easily be ignored clinically. Few current studies have investigated the ...characteristics or the effects experienced by its users. We aimed to explore any correlation between the clinical severity and biomarkers and spinal magnetic resonance imaging (MRI) abnormalities, identify independent factors associated with spinal MRI abnormalities, and ascertain factors affecting depression/anxiety in patients with N2O‐related neurological disorders.
Methods
Patients with N2O‐related neurological disorders were enrolled retrospectively between February 2017 and July 2020. Their demographic, clinical, laboratory, neuroimaging, electrophysiological, and neuropsychological findings were analyzed. Correlation analyses were conducted using Spearman's or Pearson's correlation and linear regression analysis. Independent factors associated with spinal MRI abnormalities were identified using univariate and multivariate analyses.
Results
The principal clinical manifestations of N2O‐related neurological disorders (n = 63; 38 men, 25 women; mean age ± SD: 22.60 ± 4.46 years) were sensory disturbance, followed by gait disturbance and pyramidal tract damage. A significant negative correlation existed between serum vitamin B12 levels and clinical severity (r = −0.309, p = .014), which disappeared after linear regression. An interval of less than 6 months between initial N2O abuse and hospitalization was independently associated with spinal MRI abnormalities (39.47% vs. 72.00%, respectively; χ2 = 6.40, p = .01). Thirty‐eight (60.32%) and 40 (63.49%) patients experienced anxiety and depression, respectively. Moreover, the higher the clinical scores/serum homocysteine levels, the greater the severity of anxiety/depression (r = 0.442, p < .01; r = 0.346, p < .01; r = 0.477, p < .01; r = 0.324, p < .01).
Conclusions
The significant inverse correlation between initial vitamin B12 levels and clinical severity could aid prognosis prediction in patients with N2O‐related neurological disorders. Spinal MRI abnormalities were not related to clinical severity but depended on the time interval between initial N2O abuse and hospitalization. Anxiety and depression were common comorbidity in these patients, and their severity increased with the intensity of clinical impairment and/or serum homocysteine levels.
We develop a research to explore any correlation between clinical severity and biomarkers and spinal magnetic resonance imaging (MRI) abnormalities, identify independent factors associated with spinal‐MRI abnormalities, and ascertain factors affecting depression/anxiety in patients with N2O‐related neurological disorders.
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