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Abstract The existence of flaws seriously weakens the rock strength, directly affects the crack expansion morphology, and indirectly affects the slope stability. In this study, uniaxial compression tests were carried out on double-flawed granite to investigate the effects of flaw angle on its compressive strength and crack coalescence based on DIC technology and PFC2D numerical simulation. The result indicates that the UCS values of flawed specimens at angles of 15°, 30°, 45°, and 60° are approximately 25.5–51.7% lower than that of the intact specimen. The failure strength of the double-flawed sample increases with the increase of flaw inclination angle, and the fracture morphology shifts from no expansion to split expansion. When the flaw tip strain of each flaw sample exceeded 0.6%, the stress concentration was generated at the flaw tip, and the sample began to appear macroscopic large cracks. DIC technique can well observe the crack initiation and propagation process, recording inclined shear strain bands at flaw tips, tensile strain bands in the middle of flaws, and tensile shear O-shaped strain ring in rock bridge areas. Numerical simulations using PFC2D software were carried out and showed a good agreement with the physical results. In addition, the effect of structural inclination on specimen failure strength is clearly explained by the theory of compressive damage based on the projected size of flaws. The deformation of rock mass is not a simple material deformation but is composed of material deformation and structural deformation. These experimental and numerical results enhance our understanding of crack initiation and coalescence characteristics, aiding in the analysis of rock structure stability in scenarios such as excavated underground openings, slopes, and tunneling construction, where pre-existing cracks or step-path fractures are pivotal to structural integrity.

ObjectivesPyrophyllite, as a sealed pressure medium, has been widely used in high-pressure research for laboratories and industrial synthesis. A highly efficient pressure transfer medium can generate higher cell pressure at the same loading force. The use of a highly efficient pressure transfer medium reduces the risk of anvil rupture and production costs. Therefore, it is important to develop a suitable and efficient pressure-transmitting pyrophyllite.MethodsThe pressure calibration of four pyrophyllites from different localities at room temperature was conducted in a 6 × 8 MN multi-anvil large-volume press. The relationship between loading force and cell pressure at room temperature was established. The influence of mineral composition changes in pyrophyllite on pressure-transmitting efficiency was studied using X-ray diffraction.ResultsBy investigating the influence of mineral composition changes in pyrophyllite on pressure-transmitting efficiency, the results are as follows: (1) When achieving the same cell pressure, the required loading force for Pyrophyllite 4 is 10% lower than those for the other three pyrophyllites, indicating that Pyrophyllite 4 has the best pressure-transmitting efficiency. (2) As cell pressure increases, the relationship between cell pressure and loading force begins to deviate from linearity, and the pressure-transmitting efficiency of pyrophyllite gradually decreases. When the cell pressure exceeds 5.00 GPa, applying higher loading force does not significantly increase the cell pressure. (3) Higher hardness minerals (such as Diaspore, Boehmite) in pyrophyllite can effectively improve pressure-transmitting efficiency in the low-pressure stage (cell pressure 2.55-3.68 GPa). When the minerals in pyrophyllite undergo phase transformation to form new minerals with higher hardness (such as Muscovite and Kaolinite) in the high-pressure stage (cell pressure of 5.50 GPa), pressure-transmitting efficiency can be effectively improved.ConclusionsPyrophyllite 4 has better pressure-transmitting efficiency than Pyrophyllite 2 does in the high-pressure stage, but it is prone to failure in sealing due to the changes in mineral composition. However, Pyrophyllite 2 shows good elastic recovery effect and sealing performance and can stably complete compression and decompression work. Considering both pressure-transmitting efficiency and sealing effect, Pyrophyllite 2 has better application value and economic benefits.

The empirical relationships between tensile strength, mode I and mode II fracture toughness obtained by previous studies have the problem of a small amount of data for fitting, and more data are needed for further study. There is a discrepancy between the theoretical prediction and the experimental results of the relationship between mode II and mode I fracture toughness. Because of this, a review is conducted to determine the relationships among tensile strength, mode I fracture toughness, and mode II fracture toughness from the data gathered from the available literature. The results indicate that the mode I and mode II fracture toughness have linear relationships with tensile strength with the linear coefficient of 0.141 and 0.219, respectively. The linear coefficient between mode II and mode I fracture toughness is 2.389, indicating that the classical mixed mode criteria are mistaken the empirical relationship between mode II and mode I fracture toughness. The microcracking mechanism and failure model are quantified and compared in detail among tensile test, mode I and mode II fracture toughness tests based on moment tensor. It found that the nature of the source can be related to each other, which gives some light on the reason for the existence of certain relationships between these macroscopic parameters from a microcracking perspective.

Abstract Conventional material processing approaches often achieve strengthening of materials at the cost of reduced ductility. Here, we show that high-pressure and high-temperature (HPHT) treatment can help overcome the strength-ductility trade-off in structural materials. We report an initially strong-yet-brittle eutectic high entropy alloy simultaneously doubling its strength to 1150 MPa and its tensile ductility to 36% after the HPHT treatment. Such strength-ductility synergy is attributed to the HPHT-induced formation of a hierarchically patterned microstructure with coherent interfaces, which promotes multiple deformation mechanisms, including dislocations, stacking faults, microbands and deformation twins, at multiple length scales. More importantly, the HPHT-induced microstructure helps relieve stress concentration at the interfaces, thereby arresting interfacial cracking commonly observed in traditional eutectic high entropy alloys. These findings suggest a new direction of research in employing HPHT techniques to help develop next generation structural materials.

Abstract It is known that the heterogeneity caused by thermally induced micro-cracks and thermal stress can affect the mechanical behavior of granite. The laboratory-scale tests have the intrinsic limitation of non-repeatability and lack of effective methods to characterize the interaction effect between thermal micro-cracks and thermal stresses. In this study, we demonstrate how advancements in particle bonded model and moment tensor can help better understand the roles of high temperature in weakening granite and thermally induced cracking process in Brazilian test. Our results show that the types of micro-cracks (intergranular, intragranular, and transcrystalline ones) are related to their thermal expansion coefficients of mineralogical compositions. The intergranular tensile micro-cracks are predominant during the heating and heating–cooling processes. An obvious weakening of granite and non-central initiation is associated with the heterogeneity caused by the thermal damage and thermal stress. We also quantitatively evaluate the thermal damage based on orientation distribution, b-value, and nature of the sources, which gives a new microcracking perspective on tensile characteristics subjected to high temperature.

This paper systematically investigated the impact mechanisms of proton irradiation, atomic oxygen irradiation and space debris collision, both individually and in combination, on the laser damage threshold and damage evolution characteristics of HfO2/SiO2 triple-band high-reflection films and fused silica substrates using a simulated near-Earth space radiation experimental system. For the high-reflection film samples, the damage thresholds decreased by 15.38%, 13.12% and 46.80% after proton, atomic oxygen and simulated space debris (penetration) irradiation, respectively. The coupling irradiation of the first two factors resulted in a decrease of 26.93%, while the combined effect of all the three factors led to a reduction of 63.19%. Similarly, the fused silica substrates exhibited the same pattern of laser damage performance degradation. Notably, the study employed high-precision fixed-point in situ measurement techniques to track in detail the microstructural changes, surface roughness and optical-thermal absorption intensity before and after proton and atomic oxygen irradiation at the same location, thus providing a more accurate and comprehensive analysis of the damage mechanisms. In addition, simulations were conducted to quantitatively analyze the transmission trajectories and concentration distribution lines of protons and atomic oxygen incident at specific angles into the target material. The research findings contribute to elucidating the laser damage performance degradation mechanism of transmissive elements in near-Earth space environments and provide technical support for the development of high-damage-threshold optical components resistant to space radiation.

Carbon, the fourth most abundant element in the Universe, possesses numerous allotropes with diverse bonding character (sp1-, sp2- and sp3-hybridized bonds) and structural motif of the constituting atoms. In particular, the carbon materials with a fully or nearly 100% sp3-hybridized strong C-C bonds often lead to excellent mechanical properties, chemical stability, thermal and optical properties, such as crystalline diamond and diamond-like amorphous carbon (DLC). In this review, we systematically summarize the synthesis, microstructure, mechanical properties, thermal and optical properties of ultrahard carbon materials with current experimental results on nano-polycrystalline diamond (NPD), nanotwinned diamond (NTD), micro-grained polycrystalline diamond (MPD), and amorphous diamond/carbon. In addition, we discuss the difference of spectra of XRD, Raman and EELS between various nanocrystalline diamond powder and ultrahard carbon materials. Finally, we provide our insights into the future development and applications in the research of ultrahard carbon bulk materials by high-pressure and high-temperature techniques according to the current advantages, limitations and challenges in the experiment.

In this study, the structural and in vitro fermentation characterizations of Rosa sterilis S.D.Shi polysaccharides (RSP), extracted by hot water (HW), acid (AA), alkali (AK) and enzyme (EM) were investigated for the first time. The results indicated that extraction methods exhibited significant effects on the structure of RSPs, thus resulting in different probiotic effects. HW-RSP and AA-RSP had high contents of Gal, Glc and GalA, while AK-RSP and EM-RSP mainly contained Ara, Gal and GalA. EM-RSP was rich in RG-I and its size of average side chain were the largest. Moreover, HW-RSP and AK-RSP exhibited the smallest (57.55 kDa) and largest (922.20 kDa) molecular weights, respectively. All RSPs promoted the production of total SCFAs and the growth of beneficial bacteria like Bifidobacterium, Bacteroides, Faecalibacterium and Paraclostrium to varying degrees, but inhibited the growth of pathogenic bacteria such as Escherichia-shigella, thereby regulating the composition of gut microbiota. Furthermore, the function prediction results showed that EM-RSP had the most special metabolic pathways. Collectively, our findings provide new insights into the relationship between the structure and probiotic function of RSPs, and offer theoretical basis for the development of functional products of Rosa sterilis S.D.Shi.

Image captioning has become a hot topic in artificial intelligence research and sits at the intersection of computer vision and natural language processing. Most recent imaging captioning models have adopted an “encoder + decoder” architecture, in which the encoder is employed generally to extract the visual feature, while the decoder generates the descriptive sentence word by word. However, the visual features need to be flattened into sequence form before being forwarded to the decoder, and this results in the loss of the 2D spatial position information of the image. This limitation is particularly pronounced in the Transformer architecture since it is inherently not position-aware. Therefore, in this paper, we propose a simple coordinate-based spatial position encoding method (CSPE) to remedy this deficiency. CSPE firstly creates the 2D position coordinates for each feature pixel, and then encodes them by row and by column separately via trainable or hard encoding, effectively strengthening the position representation of visual features and enriching the generated description sentences. In addition, in order to reduce the time cost, we also explore a diagonal-based spatial position encoding (DSPE) approach. Compared with CSPE, DSPE is slightly inferior in performance but has a faster calculation speed. Extensive experiments on the MS COCO 2014 dataset demonstrate that CSPE and DSPE can significantly enhance the spatial position representation of visual features. CSPE, in particular, demonstrates BLEU-4 and CIDEr metrics improved by 1.6% and 5.7%, respectively, compared with a baseline model without sequence-based position encoding, and also outperforms current sequence-based position encoding approaches by a significant margin. In addition, the robustness and plug-and-play ability of the proposed method are validated based on a medical captioning generation model.

The inner ear has a rich population of pericytes, a multi-functional mural cell essential for sensory hair cell heath and normal hearing. However, the mechanics of how pericytes contribute to the homeostasis of the auditory vascular-neuronal complex in the spiral ganglion are not yet known. In this study, using an inducible and conditional pericyte depletion mouse (PDGFRB-CreERT2; ROSA26iDTR) model, we demonstrate, for the first time, that pericyte depletion causes loss of vascular volume and spiral ganglion neurons (SGNs) and adversely affects hearing sensitivity. Using an in vitro trans-well co-culture system, we show pericytes markedly promote neurite and vascular branch growth in neonatal SGN explants and adult SGNs. The pericyte-controlled neural growth is strongly mediated by pericyte-released exosomes containing vascular endothelial growth factor-A (VEGF-A). Treatment of neonatal SGN explants or adult SGNs with pericyte-derived exosomes significantly enhances angiogenesis, SGN survival, and neurite growth, all of which were inhibited by a selective blocker of VEGF receptor 2 (Flk1). Our study demonstrates that pericytes in the adult ear are critical for vascular stability and SGN health. Cross-talk between pericytes and SGNs via exosomes is essential for neuronal and vascular health and normal hearing.

Protein binding by the Hsp70/J-domain protein (JDP) chaperones prevents aggregation of the client protein. Here, the authors show that DnaJC7 binds preferentially to natively folded wild-type tau, via a β-turn element in tau that contains the known amyloid motif, while aggregation-prone tau mutants are recognized with reduced affinity.

Abstract Pathogenesis of tauopathies involves conversion of tau monomer into pathological tau conformers that serve as templates to recruit native tau into growing assemblies. Small soluble tau seeds have been proposed to drive pathological tau assembly in vitro, in cells and in vivo. We have previously described the isolation of monomeric pathogenic tau seeds derived from recombinant samples and tauopathy tissues but in-depth biophysical characterization of these species has not been done. Here we describe a chromatographic method to isolate recombinant soluble tau seeds derived from heparin treatment. We used biochemical and biophysical approaches to show that the seeds are predominantly monomeric and have the capacity to nucleate aggregation of inert forms of tau in vitro and in cells. Finally, we used crosslinking mass spectrometry to identify the topological changes in tau as it converts from an inert state to a pathogenic seed. Future studies will reveal the relationship between soluble seeds and structural polymorphs derived from tauopathies to help diagnose and develop therapeutics targeting specific tauopathies.

There are a few dependent multivariate relationships among high dimensional data sets. Then how to identify these dependent variables from high dimensional data sets is an important issue for data analysis. Now, the most frequently used method is the enumeration method, that is all multivariate relationships in the high dimensional data sets are examined. However, the time complexity of the enumeration method is exponential (2n) and the calculation load is very heavy when the dimension is high. Aiming at solving this problem, the matrix iteration algorithm with pruning (MIP) is proposed for pinpointing multivariate dependent relationships in high dimensional data sets without examining all multivariate relationships. Some not dependent relationships are ignored without examined by the pruning process of the proposed MIP and the computing burden is reduced. The maximal information coefficient (MIC) is adopted as the measure of correlations in the proposed MIP algorithm due to the excellent properties, generality and equitability, of MIC. In the case of the data set with 5 variables, more than 50% multivariate relationships are pruned without examining. Numerical experiments also show that the calculating burden is greatly reduced. Compared to the enumeration method, 82.5% calculating time and 98.5% calculating times of multivariate relationships are saved for the data set with two dependent multivariate relationships among 30 variables in the experiment. The proposed MIP algorithm is effective for pinpointing multivariate dependent relationships from data sets with high dimensions.

Al2O3-based self-lubricating ceramics are cutting tool materials that meet the extreme working conditions of dry cutting. However, due to the soft lubricating components, the mechanical properties of composites are dramatically reduced. In this paper, Al2O3-cBN-hBN self-lubricating material was designed. High density, fine grain ceramics were synthesized by high-pressure technology. The influence of thermodynamic condition, cBN/hBN addition on mechanical and thermal properties of sintered composites was analyzed. Friction and wear tests were carried out. It is found that the addition of cBN particles can significantly improve the mechanical and thermal properties of the composites. However, the truss effect caused by excessive volume fraction of cBN can reduce the pressure transfer efficiency, and then affect the properties of sintered composites. The different hBN content can change the wear mechanism of the composites. The release efficiency of hBN particles in composites was enhanced due to the large modulus difference between cBN and hBN. The well-sintered Al2O3-cBN-hBN bulks present an excellent mechanical property. The hardness of the composites is improved at least by 54% compared with the traditional self-lubricating material on the premise of ensuring fracture toughness and lubrication performance.

BackgroundPostauricular injection as a local therapy has been confirmed to be effective for inner ear diseases. However, the mechanism for the drugs entering the inner ears remains unknown. This study aims to compare the distribution of dexamethasone by intramuscular injection with that by postauricular injection, and explore the pathway of the drugs entering the inner ears.MethodsAn in vivo optical imaging system was used to conduct a time course observation to compare the distribution of dexamethasone by intramuscular injection with that by postauricular injection in male guinea pigs. The drug availability in the tympanic mucosa, tympanum, endolymphatic sac, and cochlea was observed by a confocal laser scanning microscope.ResultsThe local fluorescent intensity by postauricular injection was significantly higher in the inner ears, and lower in partial peripheral organs, than that by the intramuscular injection. The drug metabolism by postauricular injection exhibited an obviously sustained release effect in the inner ears. Drugs by postauricular injection might enter the endolymphatic sac through the posterior auricular artery and occipital artery, as well as the connections of the mastoid emissary vein, sigmoid sinus and endolymphatic sac.ConclusionMore drugs concentrated in the inner ear for longer therapeutic time and less systemic delivery implied more effective and less risk of side effects through postauricular injection than intramuscular injection safer for the treatment of inner ear diseases.

ObjectiveThis study aimed to analyze the hearing improvement and prognosis factors of idiopathic sudden sensorineural hearing loss (ISSNHL) in different ages with initial total hearing loss.MethodsWe reviewed the medical records of 5,711 hospitalized patients with ISSNHL from 2016 to 2021 in our center. All of the patients had been treated with uniform combination drug therapy. After excluding the patients with initial partial hearing loss and those diagnosed with clear etiology, 188 patients were enrolled in this study and divided into six age groups (18–30, 31–40, 41–50, 51–60, 61–70, ≥ 71 years). In all groups, decreases in pure-tone average (PTA) 1 month posttreatment, effective rate, and clinical characteristics (vertigo, tinnitus, hospital stay, comorbidity, and inner ear magnetic resonance imaging) were analyzed.ResultsAmong the 188 enrolled patients, 86% had vertigo. Complete recovery was seen in 0.5% of patients, and marked recovery was seen in 43% of patients. The mean 1 month posttreatment PTAs were as follows: 18–30 years: 80 ± 7.5 dB; 31–40 years: 100 ± 9.0 dB; 41–50 years: 99 ± 8.3 dB; 51–60 years: 101 ± 8.6 dB; 61–70 years: 96 ± 9.6 dB; and ≥ 71 years: 88 ± 13.0 dB. Compared with the other groups, the 18–30- years group showed better recovery of hearing threshold in five frequencies (0.25, 0.5, 1, 2, and 4 kHz, respectively, at octave or semioctave frequencies under air conduction), and the recovery of hearing threshold at 0.25 and 0.5 Hz was better than the recovery at 1, 2, and 4 kHz. According to the results of the chi-square test statistical analysis, vertigo and comorbidities were associated with a poor prognosis of ISSNHL.ConclusionIn summary, the treatment outcomes of patients with ISSNHL with initial total hearing loss were poor. There was a significant age-related difference with respect to marked recovery 1 month posttreatment, and the 18–30- years group showed better recovery than the other age groups.

Correlation filter is a simple yet efficient method to deal with the visual tracking task. However, the unwanted boundary effects hinder further performance improvement. Spatially Regularized DCF (SRDCF) has been proposed to address this problem with a pre-computed spatial penalty matrix, which improves the tracking performance greatly. In this paper, aiming to achieve more accurate spatial regularization, we present our spatial adaptive regularized correlation filter (SARCF). A coarse-to-fine scale estimation approach is proposed to change the spatial penalty area, which can efficiently deal with large scale variation. Moreover, temporal regularization is introduced for long-term tracking. Experimental results show that the proposed algorithm outperforms most advanced algorithms in tracking accuracy and success rate.

The seaworthiness of a ship plays a critical role in ensuring the safety of life and property and the prevention of marine pollution. One meaning of seaworthiness is the fundamental ability to sail safely to a destination, as well as being fit and ready for cargo. The parameters of seaworthiness have been expanded with the introduction of new maritime regulations. The entry of the 2019 amendments to the IMSBC Code into force has brought significant changes to bulk carriers with cargo that may liquefy at sea. Using examples from history, as well as an understanding of the environmental conditions of the oceans that ships are subject to, the seaworthiness of bauxite carriers was examined critically. First, the concept and doctrine of seaworthiness were clarified considering the existing transportation technology. Then, the spirit of the 2019 amendments to the IMSBC Code was applied to the seaworthiness of a bauxite carrier, showing that it demonstrated dynamic instability. Beyond that, from a transportability performance perspective, an extensive discussion was provided concerning the major correlation related to seaworthiness. Finally, practical recommendations were given on keeping a ship seaworthy before and during the process of bauxite transportation.

Feature pyramid networks and attention mechanisms are the mainstream methods to improve the detection performance of many current models. However, when they are learned jointly, there is a lack of information association between multi-level features. Therefore, this paper proposes a feature pyramid of the multi-level local attention method, dubbed as MLA-Net (Feature Pyramid Network with Multi-Level Local Attention for Object Detection), which aims to establish a correlation mechanism for multi-level local information. First, the original multi-level features are deformed and rectified using the local pixel-rectification module, and global semantic enhancement is achieved through the multi-level spatial-attention module. After that, the original features are further fused through the residual connection to achieve the fusion of contextual features to enhance the feature representation. Extensive ablation experiments were conducted on the MS COCO (Microsoft Common Objects in Context) dataset, and the results demonstrate the effectiveness of the proposed method with a 0.5% enhancement. An improvement of 1.2% was obtained on the PASCAL VOC (Pattern Analysis Statistical Modelling and Computational Learning, Visual Object Classes) dataset, reaching 81.8%, thereby, indicating that the proposed method is robust and can compete with other advanced detection models.

Medicago archiducis-nicolai Sirj. is a well-known high-quality forage as its good palatability and strong tolerance to drought, cold and saline-alkali stress. Here, the complete chloroplast genome sequence of M. archiducis-nicolai was reported. The size of the complete chloroplast genome is 127,072 bp in length. The chloroplast genome has no inverted repeat (IR) regions, which is very common in the family Fabaceae. The M. archiducis-nicolai chloroplast genome encodes 106 genes: 72 protein-coding genes, 30 tRNAs, and 4 rRNAs. The phylogenetic analysis result strongly suggested that M. archiducis-nicolai is a distinct lineage in Medicago, being sister to highly supported clade composed of three species (M. hybrida, M. papillosa and M. sativa).

The biophysical mechanisms of how disease-associated tau mutations drive amyloid formation are not well understood. Here the authors use biophysical approaches, cell models and MD simulations and find that the intrinsically disordered repeat domain of tau encodes a metastable local structure and perturbations through mutations and proline isomerization cause an aggregation phenotype in vitro and in cells.

Abstract Background Cataract patients were always excluded from studies on ageing of colour vision; thus, effect of age-related cataracts on deterioration of colour perception has not been analysed. In present study, impacts of age-related cataracts on colour discrimination, postoperative recovery and related spectra were investigated. Methods In this cohort study, thirty age-related cataract patients scheduled for binocular surgery and 30 elderly volunteers were enrolled. Colour discrimination under photopic (1000 lx) and mesopic (40 lx) conditions was evaluated with Farnsworth-Munsell 100-hue test. The total error score (TES) and partial error score (PES) were calculated. Results Preoperatively, the TES in the patient group was 129.7 ± 59.5 at 1000 lx and 194.6 ± 74.5 at 40 lx, exhibiting worse discrimination than the volunteer group (TES1000lux = 71.5 ± 37.5 and TES40lux = 113.1 ± 38.8, p ≤ 0.001). Inferior perception were detected in the yellow to green-yellow (Y-GY), green-yellow to green (GY-G), green to blue-green (G-BG) and blue-green to blue (BG-B) colour bands (p ≤ 0.003), corresponding to the 470 nm–580 nm range of the visible light spectrum. Under mesopic conditions, the impact expanded to all colour bands except for yellow-red to yellow (YR-Y). Postoperatively, the TES in the patient group were 80.4 ± 62.4 at 1000 lx and 112.0 ± 85.2 at 40 lx, which were lower than those of the preoperative phase (p ≤ 0.001) but similar to those of the volunteer group (p ≥ 0.505). Postoperative improvement occurred in the Y-GY, GY-G and G-BG colour bands (490 nm to 580 nm) at 1000 lx (p ≤ 0.001) and shifted to the Y-GY, GY-G, G-BG and BG-B colour bands (470 nm to 580 nm) at 40 lx (p ≤ 0.001). Deterioration of hue perception for decrement of illumination was detected in the red to yellow-red (R-YR), Y-GY, G-BG, BG-B, blue to purple-blue (B-PB) and red-purple to red (RP-R) colour bands (450 nm to 500 nm) in the volunteer group (p ≤ 0.002) and the R-YR, G-BG, BG-B, B-PB, PB-P and red-purple to red (RP-R) colour bands (from the short-wavelength end to 500 nm) in the patient group preoperatively (p ≤ 0.001). Conclusions Phacoemulsification could effectively rebuild colour perception in patients with age-related cataract. The postoperative benefits were most significant in colour bands corresponding with spectrum from 470 nm to 580 nm.

With the increasing amount of HD or even UHD video, the video streaming transmission over the mobile network is confronted with various quality of experience issues. To facilitate the delivery of compressed video over the network, it is extremely helpful to further compress the coded video bit stream without any information loss, so-called lossless recompression. However, the existing lossless video/image compression algorithms aim to remove the pixel-domain (e.g., lossless coding mode of HEVC) or the coefficient-domain (e.g., entropy coding) redundancy rather than the bit-stream-domain redundancy. To this end, we propose a novel lossless recompression approach to eliminate statistical redundancy in the coded video bit stream. The core idea is to increase the probability of this repetitive pattern of continuous “0” or “1” symbol strings in the binary symbol sequence by rearranging the sequence, including value mapping and position aggregation. In particular, Fibonacci-based mapping rule is used to convert the original sequence (those binary symbols in Fibonacci positions) into a new one with more continuous “0” or “1.” Besides, we aggregate as many identical symbols as possible together to further increase the probability of the occurrence of repetitive patterns. Finally, the lossless compression algorithm and the asymptotic lossless compression scheme are designed to achieve a compact representation of the rearranged symbol sequence. We also regulate formal syntactic structures for the proposed mapping rule, aggregation algorithm, and recompression scheme so as to deterministically revert from the recoded version to the original bit stream. The experimental results on compressed H.264/AVC and H.265/HEVC video data show that our approach can considerably reduce the bit rate of streaming video.

Correlation filters have achieved appealing performance with high speed in recent years. The advantage of correlation filter-based tracking methods is mainly attributed to powerful features and effective online filter learning. However, the periodic assumption of the training data would introduce unwanted boundary effects, which severely degrade the discrimination power of the correlation filter. In this paper, we construct the spatial reliable map with deep features from Convolutional Neural Network, then the map is used to adjust the filter support to the part of the object suitable for tracking. In order to further improve the long-term tracking ability, we introduce temporal regularization to DCF training, which can deal with occlusion and deformation situations. The experimental results show that the proposed algorithm achieves high tracking success rate and accuracy.

Millions of people are affected by hearing loss. Hearing loss is frequently caused by noise or aging and often associated with loss of pericytes. Pericytes populate the small vessels in the adult cochlea. However, their role in different types of hearing loss is largely unknown. Using an inducible and conditional pericyte depletion mouse model and noise-exposed mouse model, we show that loss of pericytes leads to marked changes in vascular structure, in turn leading to vascular degeneration and hearing loss. In vitro, using advanced tissue explants from pericyte fluorescence reporter models combined with exogenous donor pericytes, we show that pericytes, signaled by VEGF isoform A165 (VEGFA165), vigorously drive new vessel growth in both adult and neonatal mouse inner ear tissue. In vivo, the delivery of an adeno-associated virus serotype 1–mediated (AAV1–mediated) VEGFA165 viral vector to pericyte-depleted or noise-exposed animals prevented and regenerated lost pericytes, improved blood supply, and attenuated hearing loss. These studies provide the first clear-cut evidence that pericytes are critical for vascular regeneration, vascular stability, and hearing in adults. The restoration of vascular function in the damaged cochlea, including in noise-exposed animals, suggests that VEGFA165 gene therapy could be a new strategy for ameliorating vascular associated hearing disorders.

Rock joints have obvious acoustic emission (AE) Kaiser effect and Felicity effect under multilevel cyclic shear conditions. The TFD-20H/50J rock shear apparatus was used to carry out cyclic loading and unloading joint shear tests, and the acoustic emission parameters and frequency spectrum characteristics of the whole shearing process were analyzed. The results show that, under the cyclic loading, the shear stress-displacement curve forms several cyclic hysteresis loops, and the number of loops increases with the increase of normal stress. With the cycles increase, the shear damage gradually increases, and the Felicity ratio gradually decreases. The Felicity ratio at the final shear failure moment is about 0.94~0.99. The ratio of the RA value (rise time/amplitude) and the average frequency value (RA-AF) is used to classify the cracking mode of the joint sample. There are two AE crack signal types (tensile type and shear type) during shear damage. The peak frequency is displayed as high, medium, and low three frequency bands, which are distributed in the range of 0~35 kHz, 35~122 kHz, and 122~300 kHz, respectively. Both low-frequency and high-frequency signals account for less than 10%, and medium-frequency signals account for more than 90%. The research of the AE monitoring signals of multilevel shear behaviors can help understand the shear-friction mechanisms of rock joints.

Objective: Connexin 43 (Cx43) is a protein constituent of gap junctions (GJs) in various barrier cells, especially astrocytes and microglia of the blood-brain-barrier (BBB), where it plays an important role in intercellular communication and regulation of the barrier. Despite the importance of Cx43 in other blood barriers, not much attention has been paid to expression and function of Cx43 in the blood-labyrinth-barrier (BLB) of the stria vascularis in the cochlea.Methods: We used multiple research approaches, including immunocytochemical staining, patch-clamp dye loading technique, real-time quantitative reverse transcription (RT)-PCR, western blot, measurement of endocochlear potential (EP) with an electrode through the scala media, and auditory brainstem response to test hearing function.Results: We found Cx43 expressed in vascular endothelial cells (ECs) and perivascular resident macrophages (PVMs) in the stria vascularis of adult C57BL/6 mouse cochleae. In particular, we found Cx43 expressed in foot processes of PVMs at points of contact with the endothelium. Consistent with Cx43 expression in vivo, we also found Cx43 expressed in EC-EC and EC-PVM interfaces in a co-cultured cell line model. Using a patch-clamp dye loading technique, we demonstrated that Alexa Fluor® 568 dye injected into PVMs diffuses to connected neighboring ECs. The functional coupling between the ECs and PVMs is blocked by 18α-Glycyrrhetinic acid (18α-GA), a GJ blocker. Suppression of Cx43 with small interfering RNA (siRNA) in vivo significantly elevated hearing threshold and caused the EP to drop and the blood barrier to become more permeable. In further study, using in vitro primary EC cell line models, we demonstrated that suppression of Cx43 disrupts intercellular tight junctions (TJs) in the EC monolayer and increases endothelial monolayer permeability.Conculsion: Taken together, these findings underscore the importance of Cx43 expression in the normal ear for maintaining BLB integrity, normal EP, and hearing function.

Aiming at an efficient feature match and similarity search in visual tracking, this study proposes a tracking algorithm based on quantum genetic algorithm. Therein, the global optimisation ability of quantum genetic algorithm is utilised. In the framework of quantum genetic algorithm, the positions of pixels are taken as individuals in population, while scale‐invariant feature transform and colour features are taken as target model. Via defining the objective function, individual's fitness values can be measured. Visual tracking is realised when the pixel point with the biggest fitness value is searched and its corresponding position is returned. The experiment results show that the tracking algorithm the authors proposed performs more efficiently when it is compared with the state‐of‐the‐art tracking algorithms.

Image segmentation is of great significance to a variety of tasks in image processing and computer vision. Since fully unsupervised image segmentation is usually very hard in most cases, a task-oriented interactive segmentation approach becomes a popular solution. This paper proposes a weakly supervised image segmentation algorithm to extract foreground from a complex background relying only on a roughly predefined bounding-box. The algorithm integrates the Watershed algorithm and Mean-shift clustering algorithm to obtain reliable initial foreground and background labels for simple linear iterative clustering (SLIC) superpixels. Then, a synthetic superpixel grouping mechanism is proposed to group the remainder SLIC superpixels into foreground or background until the whole superpixels are completely grouped. The proposed algorithm reliefs the interactive information from users while maintaining the segmentation precision. Extensive experiments are performed, and the results indicate that the proposed algorithm can reliably segment the image foreground from the complex background with only a weakly supervision.

The chloroplast genome and evolutionary relationship analysis of Tulipa gesneriana L. could provide fundamental genetic reference for its molecular breeding and biological research. The complete chloroplast genome of Tulipa iliensis was sequenced and reported here. Its chloroplast genome was 151,744 bp in length, containing a pair of inverted repeated regions (26,354 bp) which were separated by a large single copy region of 81,794 bp, and a small single copy region of 17,242 bp. Moreover, a total of 133 functional genes were annotated, including 87 mRNA, 38 tRNA genes, and 8 rRNA genes.The phylogenetic relationships of 16 species indicated that T. iliensis was closely related to T. altaica.

The complete chloroplast genome of Tulipa buhseana was sequenced and reported here. The circular genome of T. buhseana is 152,062 bp in length and contains 133 functional genes consisting of 87 coding sequences, 38 tRNA genes, and 8 rRNA genes. With 1 species from Smilacaceae and 1 species from Alstroemeriaceae as outgroup, phylogenetic relationships of 8 Liliaceae species based on their chloroplast genomes indicated that T. buhseana is closest to T. altaica.

In this study, a three‐dimensional mean shift tracking algorithm, which combines the multi‐scale model and background weighted spatial histogram, is proposed to address the problem of scale estimation under the framework of mean shift tracking. The target template is modelled with multi‐scale model and described with three‐dimensional spatial histogram. The tracking algorithm is implemented by three‐dimensional mean shift iteration, which translates the problem of scale estimation in two‐dimensional image plane into the localisation in three‐dimensional image space. To enhance the robustness, the background weighted histogram is employed to suppress the background information in the target candidate model. Firstly, the multi‐scale model and three‐dimensional spatial histogram are introduced to represent the target template. Then, the three‐dimensional mean shift iteration formulation is derived based on the similarity measure between the target model and the target candidate model. Finally, a multi‐scale mean shift tracking algorithm combining multi‐scale model and background weighted spatial histogram is proposed. The proposed algorithm is evaluated on some challenging sequences which contain scale changed targets and other complex appearance variations in comparison with three representative mean shift based tracking algorithms. Both the qualitative results and quantitative analysis indicate that the proposed algorithm outperforms the referenced algorithms in both tracking precision and scale estimation.

Robust visual tracking is a very challenging problem especially when the target undergoes large appearance variation. In this study, the authors propose an efficient and effective tracker based on watershed regions. As middle‐level visual cues, watershed regions contain more semantics information than low‐level features, and reflect more structure information than high‐level model. First, the authors manually select the target template in initial frame, and predict the target candidate in the next frame using motion prediction. Then, the authors utilise marker‐based watershed algorithm to obtain the watershed regions of target template and candidate template, and describe each region with multiple features. Next, the authors calculate the nearest neighbour in feature space to match the watershed regions and construct an affine relation from target template to candidate template. Finally, the authors resolve the affine relation to calculate the final tracking result, and update the template for the following tracking. The authors test their tracker on some challenging sequences with appearance variation range from illumination change, partial occlusion, pose change to background clutters and compare it with some state‐of‐the‐art works. Experiment results indicate that the proposed tracker is robust to the large appearance variation and exceeds the state‐of‐the‐art trackers in most situations.

Cemented waste rock backfill (CWRB), which is a mixture of tailings, waste rock, cement, and water, is subjected to combination actions in underground mining operations and has been widely used in deep resource mining. While the strength requirement and macroscopic deformation behaviors of CWRB have been well studied, the mesoscopic damage evolution mechanisms are still not well understood. In this work, a CWRB sample with a waste rock proportion of 30% was studied with a uniaxial compression test under tomographic monitoring, using a 450 kV industrial X-ray computed tomography (CT). Clear CT images, CT value analysis, crack identification, and extraction reveal that CWRB damage evolution is extremely inhomogeneous and affected by the waste rock size, shape, and distribution. Furthermore, the crack initiation, propagation, and coalescence behaviors are limited to the existing waste rocks. When deformation grows to a certain extent, the cracks demonstrate an interlocking phenomenon and their propagation paths are affected by the waste rocks, which may improve the ability to resist compressive deformation. Volumetric dilatancy caused by the damage and cracking behavior has closed a link with the meso-structural changes, which are controlled by the interactions between the waste rocks and the cemented tailing paste.

Middle ear infection (or inflammation) is the most common pathological condition that causes fluid to accumulate in the middle ear, disrupting cochlear homeostasis. Lipopolysaccharide, a product of bacteriolysis, activates macrophages and causes release of inflammatory cytokines. Many studies have shown that lipopolysaccharides cause functional and structural changes in the inner ear similar to that of inflammation. However, it is specifically not known how lipopolysaccharides affect the blood-labyrinth barrier in the stria vascularis (intra-strial fluid-blood barrier), nor what the underlying mechanisms are. In this study, we used a cell culture-based in vitro model and animal-based in vivo model, combined with immunohistochemistry and a vascular leakage assay, to investigate lipopolysaccharide effects on the integrity of the mouse intra-strial fluid-blood barrier. Our results show lipopolysaccharide-induced local infection significantly affects intra-strial fluid-blood barrier component cells. Pericytes and perivascular-resident macrophage-like melanocytes are particularly affected, and the morphological and functional changes in these cells are accompanied by substantial changes in barrier integrity. Significant vascular leakage is found in the lipopolysaccharide treated-animals. Consistent with the findings from the in vivo animal model, the permeability of the endothelial cell monolayer to FITC-albumin was significantly higher in the lipopolysaccharide-treated monolayer than in an untreated endothelial cell monolayer. Further study has shown the lipopolysaccharide-induced inflammation to have a major effect on the expression of tight junctions in the blood barrier. Lipopolysaccharide was also shown to cause high frequency hearing loss, corroborated by previous reports from other laboratories. Our findings show lipopolysaccharide-evoked middle ear infection disrupts inner ear fluid balance, and its particular effects on the intra-strial fluid-blood barrier, essential for cochlear homeostasis. The barrier is degraded as the expression of tight junction-associated proteins such as zona occludens 1, occludin, and vascular endothelial cadherin are down-regulated.

A series of experimental flow tests for artificial block-in-matrix-soils (bimsoils) samples with various slenderness ratios were performed to study the Non-Darcy groundwater flow characteristics. The variations of seepage velocity, permeability coefficient, critical sample height, and non-Darcy flow factor for samples against slenderness ratios were investigated. A servo-controlled flow testing system that was developed by the authors was adopted to conduct the flow test. Cylindrical bimsoil samples (50 mm diameter and various heights) with staggered rock block percentages (RBPs) (30, 40, 50, and 60%, by mass) were prepared by compaction tests to roughly insure the same porosity of the soil matrix. The testing results show that flow the distance has a strong influence on the flow characteristics of bimsoil, and the relationship between the permeability coefficient and slenderness ratio is proposed. In addition, the critical sample height to eliminate the slenderness effect was determined, and the relationship between the critical sample height and RBP was established. Moreover, the responses of non-Darcy flow were studied by using an index of non-Darcy βfactor, which reveals the internal mechanism of the effect of flow distance on groundwater flow characteristics. The research results can be useful to the prediction of flow piping disaster for geological body made up of bimsoils.

PURPOSE: Dynamic visual acuity (DVA) is a relatively independent parameter for evaluating the ability to distinguish details of a moving target. The present study has been designed to discuss the extent to which age-related cataract impacts DVA in elderly individuals and to determine whether it could be restored after bilateral phacoemulsification combined with intraocular lens implantation surgery. METHODS: Twenty-six elderly cataract patients scheduled for binocular cataract surgery and 30 elderly volunteers without cataract were enrolled in the study. DVA at 15, 30, 60 and 90 degree per second (dps) was assessed, and velocity-dependent visual acuity decreases between consecutive speed levels were calculated. RESULTS: Compared with the control group, the patient group exhibited significantly worse DVA performance at all speed levels (p