Fast clustering algorithm based on MST of representative points.

Minimum spanning tree (MST)-based clustering algorithms are widely used to detect clusters with diverse densities and irregular shapes. However, most algorithms require the entire dataset to construct an MST, which leads to significant computational overhead. To alleviate this issue, our proposed algorithm R-MST utilizes representative points instead of all sample points for constructing MST. Additionally, based on the density and nearest neighbor distance, we improved the representative point selection strategy to enhance the uniform distribution of representative points in sparse areas, enabling the algorithm to perform well on datasets with varying densities. Furthermore, traditional methods for eliminating inconsistent edges generally require prior knowledge about the number of clusters, which is not always readily available in practical applications. Therefore, we propose an adaptive method that employs mutual neighbors to identify inconsistent edges and determine the optimal number of clusters automatically. The experimental results indicate that the R-MST algorithm not only improves the efficiency of clustering but also enhances its accuracy.

A novel density peaks clustering algorithm for automatic selection of clustering centers based on K-nearest neighbors.

The density peak clustering algorithm (DPC) requires manual determination of cluster centers, and poor performance on complex datasets with varying densities or non-convexity. Hence, a novel density peak clustering algorithm is proposed for the automatic selection of clustering centers based on K-nearest neighbors (AKDPC). First, the AKDPC classifies samples according to their mutual K-nearest neighbor values into core and non-core points. Second, the AKDPC uses the average distance of K nearest neighbors of a sample as its density. The smaller the average distance is, the higher the density. Subsequently, it selects the highest density sample among all unclassified core points as a center of the new cluster, and the core points that satisfy the merging condition are added to the cluster until no core points satisfy the condition. Afterwards, the above steps are repeated to complete the clustering of all core points. Lastly, the AKDPC labels the unclassified non-core points similar to the nearest points that have been classified. In addition, to prove the validity of AKDPC, experiments on manual and real datasets are conducted. By comparing the AKDPC with classical clustering algorithms and excellent DPC-variants, this paper demonstrates that AKDPC presents higher accuracy.

Physicochemical and microstructural mechanisms for quality changes in lightly salted tilapia (Oreochromis niloticus) fillets during frozen storage.

BACKGROUND: Frozen tilapia fillet has become a leading aquatic product. High drip loss, dry and fibrous mouthfeel, and an unappealing appearance are its main problems. It was hypothesized that light salting could improve the quality, and that the preparation conditions would affect the storage stability of frozen tilapia fillets. RESULTS: The quality changes of lightly salted tilapia fillets were evaluated during frozen storage, and the underlying mechanisms were studied from the physicochemicaland microstructural perspectives. Though the salt content was 1.5% in all samples,the amount of ice crystals in frozen tissues decreased with the descending water content and freezing point (P < 0.05). No intracellular voids were observed in the samples prepared under proper salting conditions, and the myofibers were plump and smooth after freezing-thawing, which contributed to the high water-holding capacity of lightly salted fillets. After 28 days,the water-binding capacity of the salted groups was 14.69%-18.62% higher than that of their unsalted counterparts (P < 0.05). The reduced protein solubility in the salted fillets was likely to have occurred because the solubilized and unfolded proteins interacted more easily during frozen storage. The oxidation degree of myofibrillar proteins was also affected by salting condition, and the fillets with less oxidized sulfhydryl groups maintained high springiness after 28 days of frozen storage. CONCLUSION: The salting condition of 9% NaCl solution for 1 h was recommended for the preparation of lightly salted fillets from freshwater fish, taking into account quality, processing efficiency, and storage stability. The enhanced water-holding capacity and texture of lightly salted tilapia fillets were attributed to modified physicochemical and microstructural properties. These results could provide a scientific basis for the processing and storage of high-quality, frozen, lightly salted fillets from freshwater fish. © 2022 Society of Chemical Industry.

Fast and Low-GPU-memory abdomen CT organ segmentation: The FLARE challenge.

Automatic segmentation of abdominal organs in CT scans plays an important role in clinical practice. However, most existing benchmarks and datasets only focus on segmentation accuracy, while the model efficiency and its accuracy on the testing cases from different medical centers have not been evaluated. To comprehensively benchmark abdominal organ segmentation methods, we organized the first Fast and Low GPU memory Abdominal oRgan sEgmentation (FLARE) challenge, where the segmentation methods were encouraged to achieve high accuracy on the testing cases from different medical centers, fast inference speed, and low GPU memory consumption, simultaneously. The winning method surpassed the existing state-of-the-art method, achieving a 19× faster inference speed and reducing the GPU memory consumption by 60% with comparable accuracy. We provide a summary of the top methods, make their code and Docker containers publicly available, and give practical suggestions on building accurate and efficient abdominal organ segmentation models. The FLARE challenge remains open for future submissions through a live platform for benchmarking further methodology developments at https://flare.grand-challenge.org/.

NbN films on flexible and thickness controllable dielectric substrates.

A simple method for preparing superconducting NbN thin films on flexible dielectric substrates with controllable thickness was developed. The structure and surface characteristics and superconducting properties of the flexible film were studied by X-ray diffraction (XRD), atomic force microscopy (AFM) and physical property measurement system (PPMS). We found that NbN films on the flexible substrate show certain preferred orientations through the self-buffering effect of the amorphous NbN layer. The zero resistance superconducting transition temperature (TC0) for 10 nm thick NbN films is 8.3 K, and the TC0 for 30 nm thick NbN films in a magnetic field of 9 T remains above 7 K. This flexible film can be transferred to any substrate and adapted to different shape applications. It can also be further processed into single-layer or multilayer flexible superconducting devices.

Effects of Te- and Fe-doping on the superconducting properties in FeySe1-xTex thin films.

High quality FeySe1-xTex epitaxial thin films have been fabricated on TiO2-buffered SrTiO3 substrates by pulsed laser deposition technology. There is a significant composition deviation between the nominal target and the thin film. Te doping can affect the Se/Te ratio and Fe content in chemical composition. The superconducting transition temperature Tc is closely related to the chemical composition. Fe vacancies are beneficial for the FeySe1-xTex films to exhibit the higher Tc. A 3D phase diagram is given that the optimize range is x = 0.13-0.15 and y = 0.73-0.78 for FeySe1-xTex films. The anisotropic, effective pining energy, and critical current density for the Fe0.72Se0.94Te0.06, Fe0.76Se0.87Te0.13 and Fe0.91Se0.77Te0.23 films were studied in detail. The scanning transmission electron microscopy images display a regular atomic arrangement at the interfacial structure.

Interaction of interregional O3 pollution using complex network analysis.

In order to improve the accuracy of air pollution management and promote the efficiency of coordinated inter-regional prevention and control, this study analyzes the interaction of O3 in Qilihe District, Lanzhou City, China. Data used for analysis was obtained from 63 air quality monitoring stations between November 2017 and October 2018. This paper uses complex network theory to describe the network structure characteristics of O3 pollution spatial correlation. On this basis, the node importance method is used to mine the sub-network with the highest spatial correlation in the O3 network, and use transfer entropy theory to analyse the interaction of pollutants between regions. The results show that the O3 area of Qilihe District, Lanzhou City can be divided into three parts: the urban street community type areas in urban areas, the township and village type areas in mountain areas and the scattered areas represented by isolated nodes. An analysis of the mutual influence of O3 between each area revealed that the impact of O3 on each monitoring station in adjacent areas will vary considerably. Therefore these areas cannot be governed as a whole, and the traditional extensive management measures based on administrative divisions cannot be used to replace all other regional governance measures. There is the need to develop a joint prevention and control mechanism tailored to local conditions in order to improve the accuracy and efficiency of O3 governance.

Insight into Physicochemical, Rheological, and Antibacterial Properties of Chitosan Extracted from Antarctic krill: A Comparative Study.

In this work, physicochemical, rheological, and antibacterial properties of chitosan (CS) extracted from white shrimp (WS), giant river prawn (GP), and Antarctic krill (AK) were investigated. The results demonstrated that molecular weight (MW) of commercial chitosan (CCS), WSCS, GPCS, and AKCS were 1175.8, 2130.4, 1293.3, and 1109.3 kDa with the degree of deacetylation (DDA) of 73.5, 74.1, 82.1, and 75.9%, respectively. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscope (SEM) were employed to study the structural differences of CS. Moreover, storage modulus (G') and loss modulus (G″) of AKCS were lower than that of WSCS and GPCS, respectively, but higher than that of CCS. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) of CS against Escherichia coli and Staphylococcus aureus were investigated at concentration between 0.0125 and 1 mg/mL. These results highlighted that AKCS with low viscoelastic properties had a potential application in food and pharmaceutical application.

Effects of microwave time on quality of grass carp fillets processed through microwave combined with hot-air drying.

In this study, the quality changes of grass carp fillets dried by microwave-hot-air combined drying under different microwave time were investigated. The salted fillets were dried at 385 W microwave with different time (0, 2, 4, 6, 8, and 10 min), followed by 65℃ hot air to the end. The quality of fillets was evaluated by drying time, color, hardness, rehydration ratio, and taste characteristics (ATP-related compounds, free amino acids, E-tongue taste profile, EUC, and TAV). Results showed that grass carp fillets dried by microwave-hot-air combined drying had better qualities compared with single hot-air drying. Besides, microwave time had obvious effects on the quality changes of grass carp fillets, and 6 min was considered as the optimal drying time.

Research on the quality changes of grass carp during brine salting.

The research on the quality changes of grass carp during brine salting with 6%, 8%, and 10% salt additions was evaluated by chemical and physical indicators, as well as a sensory assessment and microbiological analysis. The NaCl content was proportional to salt addition and salting time. The increase of salt addition could lead to the increase of hardness and chewiness in which change trends were contrary to the pH within 24 hr. All K values were less than 10% during brine salting. The effect of 8% salt additions on free amino acids was relatively smaller. Higher levels of salt additions could inhibit bacterial growth. Combined with sensory assessment, equivalent umami concentration (EUC), and taste activity value (TAV) to analysis comprehensively, it was suggested that grass carp meat should be eaten at 4-8 hr of brine salting with 8% salt additions or processed for the next step, in which the grass carp meat had a better taste and quality.

Research on quality changes of grass carp (Ctenopharyngodon idellus) during short-term starvation.

This study was aimed at to investigate the quality changes of grass carp during short-term starvation. The pH, lactic acid, free amino acid, and adenosine triphosphate-related compounds of dorsal meat, belly meat and red meat in grass carp were measured during starvation for 6 days, and the quality of grass carp was evaluated by K value, equivalent umami concentration (EUC), taste activity value (TAV), and electronic tongue. The pH of three parts meat reached the maximum value on the fourth day, which was closely related to the lactic acid content. Concurrently, the contents of fresh sweet amino acids were higher on the fourth day in all parts. The K values in dorsal meat and belly meat were below 10% during starvation. Considering the overall results of electronic tongue, EUC, and TAV analysis, it is suggested that grass carp should be marketed and eaten with a starvation period of 2-4 days for best taste and quality.

Effects of different proteases enzymatic extraction on the lipid yield and quality of Antarctic krill oil.

This study was investigated the effects of six proteases (papain, compound proteinase, acidic protease, neutrase, pancreatin, and alcalase) on the lipid yield and quality of krill oil. The result shown that the krill oil extracted by alcalase and compound proteinase led to comparatively higher lipid yields (5.29% and 4.90%, respectively), Content of tocopherols and vitamin A, the content of omega-3 polyunsaturated fatty acids (PUFAs) and phospholipids extracted by alcalase was relatively higher. Control and alcalase had comparatively higher concentration of astaxanthin. On the whole, compared with the extraction of solvent, enzymatic hydrolysis could improve the quality and the lipid yield of krill oil. Therefore, enzymatic hydrolysis could be used as a better method to extract krill oil.

Research on the changes of water-soluble flavor substances in grass carp during steaming.

In this study, adenosine triphosphate (ATP)-related compounds and free amino acids were determined to study the changes of water-soluble flavor substances in grass carp meat during steaming for 18 min. Sensory assessment, electronic tongue, equivalent umami concentration (EUC) value, and taste active value (TAV) were also performed to obtain the best quality of steamed grass carp meat. The results showed that the flavor presented by nucleotides in three parts meat was better within 9 min. The bitter amino acids in the dorsal meat and red meat significantly decreased at 6 min (101.33 mg/100 g and 44.64 mg/100 g, respectively). From the sensory analysis, EUC value, and TAV, it can be found that the quality of grass carp meat was the best when steamed for 6-9 min. The electronic tongue indicated that the taste differences were significantly between 6 and 9 min. Therefore, this study suggested that grass carp should be eaten during 6-9 min of steaming. PRACTICAL APPLICATIONS: As the main way of meat processing and eating, heating not only endows the product with good color, but also kill microorganisms and improve the product quality. The reasonable heating will make the protein denaturation of the food, so that the protein digestion and absorption rate can be improved, which is conducive to people to obtain more abundant nutrition. The quality changes of grass carp meat during 18 min of steaming were studied by measuring ATP-related compounds and free amino acids, combining with sensory assessment, electronic tongue analysis, EUC value, and TAV. These results not only provide useful information for the quality control of grass carp in the heating process, but also provide theoretical reference for the improvement of the nutritional value of grass carp. In addition, the mechanism of flavor change in the heating process of grass carp will be further improved, and effective suggestions will be provided for consumers to reasonably eat grass carp.

Light Element Doping and Introducing Spin Entropy: An Effective Strategy for Enhancement of Thermoelectric Properties in BiCuSeO.

The Seebeck coefficient and carrier mobility in reported doped BiCuSeO system are too small, which limits the improvement of thermoelectric performance. Here, we proposed a novel strategy for optimizing thermoelectric performance by increasing Seebeck coefficient and boosting carrier mobility. We demonstrate that light element Li doping boosts carrier mobility (7.39 cm2 V-1 s-1) due to largely reduced carrier scattering, which results in about 2-fold increase in carrier mobility as compared with reported Bi0.875Ba0.125CuSeO through modulation doping or microstructure texturing. Moreover, the Seebeck coefficient remarkably increases by contribution of spin entropy induced by magnetic ions Mn incorporation. The enhancement of Seebeck coefficient coupled with enhanced electrical conductivity result in high power factor. Furthermore, nanoprecipitates and dual-atom point defect leads to a significant reduction of lattice thermal conductivity. Therefore, a high ZT value of 0.9 was achieved at 873 K through optimizing power factor while maintaining low thermal conductivity. Our findings provide a new perspective for designing prospective thermoelectric materials.

Effect of ice water pretreatment on the quality of Pacific White Shrimps (Litopenaeus vannamei).

Pacific White Shrimps (Litopenaeus vannamei) are an aquaculture species with global importance. For the purpose of this paper, the quality shelling process of Pacific White Shrimps, freshly harvested from farms and stored in a mixture ice water up to 24 hr, was investigated. Both the differences and correlations between the indexes such as peeling time, shrimp yield, chromatic aberration, texture, K value, TBA value, and microstructure were compared and analyzed. The optimal shell peeling time of Pacific White Shrimps was determined by ice water treatment for 8 hr. The shell peeling time was 1.77 min, the elasticity of the shrimp was 0.51 mm, the hardness was 2,124.58 g, K value was 1.33%, and TBA value was 0.004 mg/100 g. Both the smell and color of the shelled shrimp were normal. This study aims to endorse the mechanical shelling of Pacific White Shrimps.

Realizing High Figure of Merit in Phase-Separated Polycrystalline Sn1-xPbxSe.

Solid-state thermoelectric technology, interconverting heat to electrical energy, offers a promising solution for relaxing global energy problems. A high dimensionless figure of merit ZT is desirable for high-efficiency thermoelectric power generation. To date, thermoelectric materials research has focused on increasing the material's ZT. Here we first fabricated phase-separated Sn1-xPbxSe materials by hydrothermal synthesis. We demonstrate that the simultaneous optimization of the power factor and significant reduction in thermal conductivity can be achieved in the phase-separated Sn1-xPbxSe material. The introduction of the PbSe phase contributes to improvement of the electrical conductivity and power factor of the SnSe phase. Meanwhile, nanoscale precipitates and mesoscale grains define all-scale hierarchical architectures to scattering phonons, leading to low lattice thermal conductivity. These two favorable factors lead to remarkably high thermoelectric performance with ZT ∼ 1.7 at 873 K in polycrystalline SnSe + 1% PbSe along the pressing direction, which is a record-high ZT for SnSe polycrystals. These findings highlight the prospects of realizing highly effective solid-state thermoelectric devices.

Oriented Mn-doped CuO nanowire arrays.

Using anodic aluminum oxide membranes as the nanoreactors and controller, oriented nanowire arrays of the diluted magnetic semiconductor Mn-doped CuO have been successfully fabricated using Mn(NO3)2 · 4H2O and Cu(NO3)2 · 3H2O as the starting materials. X-ray diffraction measurements showed that the as-prepared oriented nanowire arrays are of high purity. Scanning electron microscope and transmission electron microscope studies showed the nanowires are oriented, continuous and uniform with a diameter and length of about 170 nm and several tens of micrometers, respectively, and thus of a high aspect ratio. Low-temperature magnetic measurements showed the ferromagnetic property of the oriented Mn-doped CuO nanowire arrays with the critical temperature at around 80 K, which will endow them with great potential applications in spintronics in the future.

Functional characterization of an invertase inhibitor gene involved in sucrose metabolism in tomato fruit.

In this study, we produced tomato plants overexpressing an invertase inhibitor gene (Sly-INH) from tomato, using a simple and efficient transient transformation system. Compared with control plants, the expression of Sly-INH was highly upregulated in Sly-INH overexpressing plants, as indicated by real-time polymerase chain reaction (PCR). Physiological analysis revealed that Sly-INH inhibited the activity of cell wall invertase (CWIN), which increased sugar accumulation in tomato fruit. Furthermore, Sly-INH mediated sucrose metabolism by regulating CWIN activity. Our results suggest that invertase activity is potentially regulated by the Sly-INH inhibitor at the post-translational level, and they demonstrate that the transient transformation system is an effective method for determining the functions of genes in tomato.

Association between genetic polymorphisms in the ADAM33 gene and asthma risk: a meta-analysis.

The aim of this study was to evaluate the associations between the rs3918396 G>A and rs528557 C>G polymorphisms in the disinterring and metalloproteinase domain 33 (ADAM33) gene and asthma risk. We searched CISCOM, CINAHL, Web of Science, PubMed, Google Scholar, EBSCO, Cochrane Library, and CBM databases from inception through August 1st, 2013 without language restrictions. Meta-analysis was performed using the STATA 12.0 software. Crude odds ratios (ORs) with their 95% confidence intervals (95% CI) were calculated. Thirteen case-control studies were included with a total of 7104 asthma patients and 8172 healthy controls. Our meta-analysis results revealed that ADAM33 rs528557 C>G polymorphism was associated with an increased risk of asthma (all p<0.05). However, we found no correlation between the ADAM33 rs3918396 G>A polymorphism and asthma risk (all p>0.05). Subgroup analysis by ethnicity indicated that the ADAM33 rs528557 C>G polymorphism might be strongly associated with an increased risk of asthma among both Caucasian and Asian populations (All p<0.05). No significant association was found between the ADAM33 rs3918396 G>A polymorphism and the risk of asthma among the studied ethnicities (All p>0.05). The present meta-analysis suggests that the ADAM33 rs528557 C>G polymorphism may contribute to susceptibility to asthma. Thus, the ADAM33 rs528557 C>G polymorphism may be utilized as a biomarker for early diagnosis of asthma.