Utilizing Synchrotron-Based X-ray Micro-Computed Tomography to Visualize the Microscopic Structure of Starch Hydrogels In Situ.

This study aimed to visualize the microstructures of starch hydrogels using synchrotron-based X-ray micro-computed tomography (µCT). Waxy maize starch (WMS, 3.3% amylose, db), pea starch (PS, 40.3% amylose), and high-amylose maize starch (HMS, 63.6% amylose) were cooked at 95 and 140 °C to prepare starch hydrogels. WMS and HMS failed to form a gel after 95 °C cooking and storage, while PS developed a firm gel. At 140 °C cooking, HMS of a high amylose nature was fully gelatinized and generated a rigid gel with the highest strength. Both scanning electron microscopy (SEM) and µCT revealed the unique structural features of various starch hydrogels/pastes prepared at different temperatures, which were greatly affected by the degree of swelling and dispersity of the starches. As a nondestructive method, µCT showed certain advantages over SEM, including minimal shrinkage of the hydrogels, relatively simple sample preparation, and allowing for three-dimensional reconstruction of the hydrogel microstructure. This study indicated that synchrotron-based µCT could be a useful technique in visualizing biopolymer-based hydrogels.

Important roles of coarse particles in pasting and gelling performance of different pulse flours under high-temperature heating.

Dehulled pea, lentil, and faba bean grains were milled into flours with 0.5- to 2.5-mm sieves. As the particle size decreased, damaged-starch contents of the flours from the same pulse crop increased. At a holding temperature of 95 °C in RVA, peak and final viscosities and gelling ability of the flours generally increased as the particle size decreased. When the holding temperature increased from 95 to 140 °C, pasting viscosities of pea and lentil flours and gel hardness of lentil flours gradually decreased. In contrast, pasting viscosities and gel hardness of faba bean flours reached the highest values at 120 °C. The comparison of the pulse flours varying in particle size across the three market classes revealed that coarse particles comprising agglomerated starch, protein, and dietary fiber (i.e., particles of the second peak in the bimodal particle-size distribution curves) showed significant correlations with certain important functional properties of pulse flours.

Clustering and Beamwidth Optimization for UAV-Assisted Wireless Communication.

With the development of wireless communication technology, unmanned aerial vehicles (UAV) are now widely used in many complex communication scenarios. When a UAV serves as an aerial base station for urban and rural ground users or marine users, it is necessary to consider the clustering of ground users and the energy efficiency of the UAV since the users are usually randomly distributed. For the scenario with randomly distributed ground users and different densities of ground users in urban and rural areas, a clustering and beamwidth optimization method for UAV-assisted wireless communication is proposed. Firstly, the energy efficiency expression of a UAV serving ground users was derived in a downlink wireless communication system assisted by a UAV. Secondly, based on the geographical location information of non-uniformly distributed users, an improved k-means method is proposed to cluster ground users, ensuring that the number of users in each cluster is within an appropriate range. Then, based on the clustering results, a fixed-point iteration (FPI) algorithm was proposed to design the optimal beamwidth of UAVs and improve their energy efficiency. Finally, the superiority of the proposed algorithm in improving energy efficiency was verified through simulation analysis, and the impact of parameters such as the cluster number and transmission power on system energy efficiency was also analyzed.

Effect of Impact Velocity and Angle on Impact Wear Behavior of Zr-4 Alloy Cladding Tube.

In the pressurized water reactor nuclear power plant, 316L SS chips were captured by the support grid and continued to affect the Zr-4 cladding tube, causing the fuel rods to wear and perforate. In this work, a 60° acute angle cone of 316L SS was used to simulate the cyclic impact of debris on a Zr-4 alloy tube with different initial impact velocities and impact angles. Results showed that increasing the initial impact velocity will generate a wear debris accumulation layer with a wear-reducing effect, but also promote the extension and expansion of fatigue cracks, resulting in the delamination of Zr-4 alloy tubes. The inclination of the impact angle increases the energy loss. The energy loss rate of the 45° impact is as high as 69.68%, of which 78% is generated by the impact-sliding stage. The normal force is mainly responsible for the wear removal and plastic deformation of Zr-4 alloy tubes. Tangential forces cause severe cutting in Zr-4 alloys and pushes the resulting wear debris away from the contact surfaces.

An Improved Transformer-Based Neural Machine Translation Strategy: Interacting-Head Attention.

Transformer-based models have gained significant advances in neural machine translation (NMT). The main component of the transformer is the multihead attention layer. In theory, more heads enhance the expressive power of the NMT model. But this is not always the case in practice. On the one hand, the computations of each head attention are conducted in the same subspace, without considering the different subspaces of all the tokens. On the other hand, the low-rank bottleneck may occur, when the number of heads surpasses a threshold. To address the low-rank bottleneck, the two mainstream methods make the head size equal to the sequence length and complicate the distribution of self-attention heads. However, these methods are challenged by the variable sequence length in the corpus and the sheer number of parameters to be learned. Therefore, this paper proposes the interacting-head attention mechanism, which induces deeper and wider interactions across the attention heads by low-dimension computations in different subspaces of all the tokens, and chooses the appropriate number of heads to avoid low-rank bottleneck. The proposed model was tested on machine translation tasks of IWSLT2016 DE-EN, WMT17 EN-DE, and WMT17 EN-CS. Compared to the original multihead attention, our model improved the performance by 2.78 BLEU/0.85 WER/2.90 METEOR/2.65 ROUGE_L/0.29 CIDEr/2.97 YiSi and 2.43 BLEU/1.38 WER/3.05 METEOR/2.70 ROUGE_L/0.30 CIDEr/3.59 YiSi on the evaluation set and the test set, respectively, for IWSLT2016 DE-EN, 2.31 BLEU/5.94 WER/1.46 METEOR/1.35 ROUGE_L/0.07 CIDEr/0.33 YiSi and 1.62 BLEU/6.04 WER/1.39 METEOR/0.11 CIDEr/0.87 YiSi on the evaluation set and newstest2014, respectively, for WMT17 EN-DE, and 3.87 BLEU/3.05 WER/9.22 METEOR/3.81 ROUGE_L/0.36 CIDEr/4.14 YiSi and 4.62 BLEU/2.41 WER/9.82 METEOR/4.82 ROUGE_L/0.44 CIDEr/5.25 YiSi on the evaluation set and newstest2014, respectively, for WMT17 EN-CS.

DAN-SuperPoint: Self-Supervised Feature Point Detection Algorithm with Dual Attention Network.

In view of the poor performance of traditional feature point detection methods in low-texture situations, we design a new self-supervised feature extraction network that can be applied to the visual odometer (VO) front-end feature extraction module based on the deep learning method. First, the network uses the feature pyramid structure to perform multi-scale feature fusion to obtain a feature map containing multi-scale information. Then, the feature map is passed through the position attention module and the channel attention module to obtain the feature dependency relationship of the spatial dimension and the channel dimension, respectively, and the weighted spatial feature map and the channel feature map are added element by element to enhance the feature representation. Finally, the weighted feature maps are trained for detectors and descriptors respectively. In addition, in order to improve the prediction accuracy of feature point locations and speed up the network convergence, we add a confidence loss term and a tolerance loss term to the loss functions of the detector and descriptor, respectively. The experiments show that our network achieves satisfactory performance under the Hpatches dataset and KITTI dataset, indicating the reliability of the network.

Comparative Transcriptome Analysis Revealed Candidate Genes Potentially Related to Desiccation Sensitivity of Recalcitrant Quercus variabilis Seeds.

Chinese cork oak (Quercus variabilis) is a widely distributed and highly valuable deciduous broadleaf tree from both ecological and economic perspectives. Seeds of this species are recalcitrant, i.e., sensitive to desiccation, which affects their storage and long-term preservation of germplasm. However, little is known about the underlying molecular mechanism of desiccation sensitivity of Q. variabilis seeds. In this study, the seeds were desiccated with silica gel for certain days as different treatments from 0 (Control) to 15 days (T15) with a gradient of 1 day. According to the seed germination percentage, four key stages (Control, T2, T4, and T11) were found. Then the transcriptomic profiles of these four stages were compared. A total of 4,405, 4,441, and 5,907 differentially expressed genes (DEGs) were identified in T2 vs. Control, T4 vs. Control, and T11 vs. Control, respectively. Among them, 2,219 DEGs were overlapped in the three comparison groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that these DEGs were enriched into 124 pathways, such as "Plant hormone signal transduction" and "Glycerophospholipid metabolism". DEGs related to hormone biosynthesis and signal transduction (ZEP, YUC, PYR, ABI5, ERF1B, etc.), stress response proteins (LEA D-29, HSP70, etc.), and phospholipase D (PLD1) were detected during desiccation. These genes and their interactions may determine the desiccation sensitivity of seeds. In addition, group specific DEGs were also identified in T2 vs. Control (PP2C62, UNE12, etc.), T4 vs. Control (WRKY1-like, WAK10, etc.), and T11 vs. Control (IBH1, bZIP44, etc.), respectively. Finally, a possible work model was proposed to show the molecular regulation mechanism of desiccation sensitivity in Q. variabilis seeds. This is the first report on the molecular regulation mechanism of desiccation sensitivity of Q. variabilis seeds using RNA-Seq. The findings could make a great contribution to seed storage and long-term conservation of recalcitrant seeds in the future.

[Analysis of Heavy Metal Pollution and Ecological Risk Assessment on Vegetation Leaves in Baoji City].

Using seven types of vegetation and seven heavy metals (Cr, Cu, Ni, Mn, Pb, Cd, and As), the present study explored the ability of accumulation and degree of contamination in the leaves of vegetation in Binhe Road. The results demonstrated a negative trend between vegetation height and heavy metal content of vegetation leaves, i.e., as plant height increased, heavy metal contamination decreased. Leaves varied in the accumulation of heavy metals depending on the heavy metal and vegetation type. Cr, Mn, and Pb content were the most abundant in vegetation leaves. The highest values for Cr, Cu, Ni, and Mn were observed in the vegetative leaves of Hybrida vicary privet and were 217.33, 58.61, 36.79, 1676.14 mg·kg-1, respectively. The highest Pb content was 1295.64 mg·kg-1 in Ligustrun lucidum, the highest Cd content was 110.19 mg·kg-1 in Cedrus deodara, and the highest As content was 139.42 mg·kg-1in Prunus cerasifera. The degree of pollution in vegetation leaves was evaluated using the comprehensive index method Single-factor pollution index method and the Nemero Composite Index Method. The Single-factor pollution index of vegetation leaves with Prunus cerasifera, Platanus acerifolia, Cercis chinensis were between 0.02-1.23, and the Nemero Composite Index values were 1.01, 0.82, 0.4, respectively, with light pollution. The Single-factor pollution index of vegetation leaves by Cedrus deodara, Platycladus orientalis, Hybrida vicary privet and Ligustrun lucidum were much higher than 1, and the Nemero Composite Index was 16.53, 140.64, 98.80, and 37.52, respectively, with high levels of pollution. The potential ecological risk of heavy metals in vegetation leaves was determined using the Hakanson potential ecological risk assessment method. The order of the average potential ecological risk degree of the seven examined heavy metals was as follows:Cd > Ni > Cr > As > Pb > Cu > Mn, and the RI value range was 19.04-4020.29, with high levels of pollution.

Complete mitochondrial genome of Quercus variabilis (Fagales, Fagaceae).

Quercus variabilis (Chinese cork oak) is an economically valuable oak as the source of industrial cork, which was widely distributed in eastern Asia. In this study, the complete mitochondrial genome of Q. variabilis was sequenced using the Illumina Hiseq and PacBio Sequel technique. The mitogenome is 412,886 bp in length and the GC content is 45.76%. The genome consists of 36 protein-coding genes, 3 ribosomal-RNA genes, and 21 transfer-RNA genes. Phylogenetic analysis based on protein-coding genes showed that Q. variabilis was close to the species in the Cucurbitaceae family.

Partitioning beta diversity in a tropical karst seasonal rainforest in Southern China.

Both deterministic and stochastic processes have been linked to forest community assembly; however, their contribution to beta diversity has not been properly explored, and no studies to date have investigated their impacts on sparse depleted soils in forests that contain widespread exposed limestone karst. We found that the pairwise differences in species composition between quadrates was determined by a balanced variation in abundance, whereby the individuals of some species at one site were substituted by an equivalent number of individuals of different species at another site. Both the total beta diversity and its balanced variation in abundance declined with increasing sampling grain size. Our research indicated that environmental differences exert a strong influence on beta diversity, particularly total beta diversity and its balanced abundance variation in larger grain sizes. It was evident that deterministic and stochastic processes worked together, and that deterministic processes were more important than stochastic processes in the regulation of beta diversity in this heterogeneous tropical karst seasonal rainforest of Southern China. However, in future research a functional trait based approach will be required to tease out the relative degree of deterministic and stochastic processes toward an assessment of the temporal changes in species composition.

Starch structure in developing kiwifruit.

Starch is the major component of kiwifruit at the time of commercial harvesting. The structural changes of starches from 2 kiwifruit varieties (Hayward and Gold3) at different growing stages up to commercial harvesting time were studied. During the fruit growth, the starch content (dry weight basis) increased from ~2% to 46% (Hayward) and 58% (Gold3) and the starch granules enlarged from 4 to 10 µm. The polymorph type of the starches remained as B-type and the amylose contents (AC) levelled off (~10-12%, Hayward) or increased (~15 to 19%, Gold3) throughout the fruit developing. The external and internal structures of amylopectins remained similar as the starch granules enlarged in expanding kiwifruit, suggesting a homogeneous molecular structure from the centre towards the periphery of a kiwifruit starch granule. This is the first report to provide the structural information on B-type starch granules in developing fruit. The results of the structural changes shared similarity as well as differences with other types of the starches in developing crops including kidney bean and various cereals. The comparative analysis suggests that the evolution of amylopectin structure in developing crops largely depends on the botanical source, and the dynamics of AC appeared to be independent of that of amylopectin structure.

Characterization of polymer chain fractions of kiwifruit starch.

In this report, the amylose composition and molecular structure of starches from the core and outer pericarp of 3 golden kiwifruit varieties were characterised, using enzymatic and chromatographic techniques. Starches from the core tissues of kiwifruit tend to have higher amylose contents (by ∼3-5%) and longer unit chains of both amylopectins and their φ, ß-limit dextrins (LDs) than those of the outer pericarp starches. The contents of short B-chains of the φ, ß-LDs of amylopectins from the outer pericarp were higher (by ∼3%) than those of φ, ß-LDs of the core amylopectins. Overall, the composition and structure of starches from the outer pericarp and core tissues of a golden kiwifruit were different. This study provides a structural basis to further investigate the starch degradation in kiwifruit, which may be of importance for the storage and eating quality of the fruit.

Physicochemical properties of kiwifruit starch.

Three varieties of golden kiwifruit (Actinidia chinensis) (Gold3, Gold9 and Hort16A) were collected at the commercial harvesting time, and physicochemical properties of starches from core and outer pericarp were studied. Starch contents (dry weight basis) in outer pericarp and core tissues ranged from 38.6 to 51.8% and 34.6 to 40.7%, respectively. All the kiwifruit starches showed B-type polymorph. Compared to the outer pericarp starches, amylose content and enzyme susceptibility of core starches were higher, and the degree of crystallinity, granule size and gelatinization parameters of core starches were somewhat lower. This suggests different biosynthetic properties between these two starches. The enthalpy changes of gelatinization of outer pericarp starches were high (∼21J/g). Rheological properties of outer pericarp starches were compared with normal maize and potato starches showed high yield stress of flow properties. This study revealed the unique properties of kiwifruit starch among various types of starches.

The Suppressive Effects of Cinnamomi Cortex and Its Phytocompound Coumarin on Oxaliplatin-Induced Neuropathic Cold Allodynia in Rats.

Oxaliplatin, a chemotherapy drug, induces acute peripheral neuropathy characterized by cold allodynia, spinal glial activation and increased levels of pro-inflammatory cytokines. Herein, we determined whether Cinnamomi Cortex (C. Cortex), a widely used medicinal herb in East Asia for cold-related diseases, could attenuate oxaliplatin-induced cold allodynia in rats and the mechanisms involved. A single oxaliplatin injection (6 mg/kg, i.p.) induced significant cold allodynia signs based on tail immersion tests using cold water (4 °C). Daily oral administration of water extract of C. Cortex (WECC) (100, 200, and 400 mg/kg) for five consecutive days following an oxaliplatin injection dose-dependently alleviated cold allodynia with only a slight difference in efficacies between the middle dose at 200 mg/kg and the highest dose at 400 mg/kg. WECC at 200 mg/kg significantly suppressed the activation of astrocytes and microglia and decreased the expression levels of IL-1ß and TNF in the spinal cord after injection with oxaliplatin. Furthermore, oral administration of coumarin (10 mg/kg), a major phytocompound of C. Cortex, markedly reduced cold allodynia. These results indicate that C. Cortex has a potent anti-allodynic effect in oxaliplatin-injected rats through inhibiting spinal glial cells and pro-inflammatory cytokines. We also suggest that coumarin might play a role in the anti-allodynic effect of C. Cortex.

Preventive Effects of Bee Venom Derived Phospholipase A2 on Oxaliplatin-Induced Neuropathic Pain in Mice.

Oxaliplatin, a chemotherapy drug used to treat colorectal cancer, induces specific sensory neurotoxicity signs that are aggravated by cold and mechanical stimuli. Here we examined the preventive effects of Bee Venom (BV) derived phospholipase A2 (bvPLA2) on oxaliplatin-induced neuropathic pain in mice and its immunological mechanism. The cold and mechanical allodynia signs were evaluated by acetone and von Frey hair test on the hind paw, respectively. The most significant allodynia signs were observed at three days after an injection of oxaliplatin (6 mg/kg, i.p.) and then decreased gradually to a normal level on days 7-9. The oxaliplatin injection also induced infiltration of macrophages and upregulated levels of the pro-inflammatory cytokine interleukin (IL)-1ß in the lumbar dorsal root ganglia (DRG). Daily treatment with bvPLA2 (0.2 mg/kg, i.p.) for five consecutive days prior to the oxaliplatin injection markedly inhibited the development of cold and mechanical allodynia, and suppressed infiltration of macrophages and the increase of IL-1ß level in the DRG. Such preventive effects of bvPLA2 were completely blocked by depleting regulatory T cells (Tregs) with CD25 antibody pre-treatments. These results suggest that bvPLA2 may prevent oxaliplatin-induced neuropathic pain by suppressing immune responses in the DRG by Tregs.

Analgesic Effects of Bee Venom Derived Phospholipase A(2) in a Mouse Model of Oxaliplatin-Induced Neuropathic Pain.

A single infusion of oxaliplatin, which is widely used to treat metastatic colorectal cancer, induces specific sensory neurotoxicity signs that are triggered or aggravated when exposed to cold or mechanical stimuli. Bee Venom (BV) has been traditionally used in Korea to treat various pain symptoms. Our recent study demonstrated that BV alleviates oxaliplatin-induced cold allodynia in rats, via noradrenergic and serotonergic analgesic pathways. In this study, we have further investigated whether BV derived phospholipase A2 (bvPLA2) attenuates oxaliplatin-induced cold and mechanical allodynia in mice and its mechanism. The behavioral signs of cold and mechanical allodynia were evaluated by acetone and a von Frey hair test on the hind paw, respectively. The significant allodynia signs were observed from one day after an oxaliplatin injection (6 mg/kg, i.p.). Daily administration of bvPLA2 (0.2 mg/kg, i.p.) for five consecutive days markedly attenuated cold and mechanical allodynia, which was more potent than the effect of BV (1 mg/kg, i.p.). The depletion of noradrenaline by an injection of N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride (DSP4, 50 mg/kg, i.p.) blocked the analgesic effect of bvPLA2, whereas the depletion of serotonin by injecting DL-p-chlorophenylalanine (PCPA, 150 mg/kg, i.p.) for three successive days did not. Furthermore, idazoxan (α2-adrenegic receptor antagonist, 1 mg/kg, i.p.) completely blocked bvPLA2-induced anti-allodynic action, whereas prazosin (α1-adrenegic antagonist, 10 mg/kg, i.p.) did not. These results suggest that bvPLA2 treatment strongly alleviates oxaliplatin-induced acute cold and mechanical allodynia in mice through the activation of the noradrenergic system, via α2-adrenegic receptors, but not via the serotonergic system.

Oxygen consumption by bovine granulosa cells with prediction of oxygen transport in preantral follicles.

The rate of oxygen consumption by granulosa cells is a key parameter in mathematical models that describe oxygen transport across ovarian follicles. This work measured the oxygen consumption rate of bovine granulosa cells in vitro to be in the range 2.1-3.3×10⁻¹6 mol cell⁻¹ s⁻¹ (0.16-0.25 mol m⁻³ s⁻¹). The implications of the rates for oxygen transport in large bovine preantral follicles were examined using a mathematical model. The results indicate that oocyte oxygenation becomes increasingly constrained as preantral follicles grow, reaching hypoxic levels near the point of antrum formation. Beyond a preantral follicle radius of 134 µm, oxygen cannot reach the oocyte surface at typical values of model parameters. Since reported sizes of large bovine preantral follicles range from 58 to 145 µm in radius, this suggests that oocyte oxygenation is possible in all but the largest preantral follicles, which are on the verge of antrum formation. In preantral bovine follicles, the oxygen consumption rate of granulosa cells and fluid voidage will be the key determinants of oxygen levels across the follicle.

A novel method for modifying AFM probe to investigate the interaction between biomaterial polymers (chitosan-coated PLGA) and mucin film.

A new method for modifying atomic force microscope (AFM) probe with polymer was proposed to estimate the interaction between Chitosan (CS)-coated poly (lactic-co-glycolic acid) (PLGA) polymer and mucin film. In this method, the mixture of polymers and its suitable volatile dissolvent were deposited on the AFM probe tip through a micropipette controlled by micromanipulator. After being dried, the polymer film forms on the probe tip. Several evaluation experiments show that using the new method, the AFM probe tip can be smoothly and uniformly coated with PLGA and CS with approximately same curvature radius as that of probe tip less than 500 nm. As a preliminary application of the proposed method, the interaction force between PLGA/CS and mucin film in air was investigated. It was revealed that when a PLGA probe is retracting from the mucin film, a repulsive force appeared; however, after the PLGA probe was further overcoated with CS, the force became attractive if the amount of CS was enough, such as at CS concentrations of 0.2% W/V. The observed force can be interpreted by the surface hydrophilic/hydrophobic characteristics of PLGA/CS and mucin film.