Hierarchical Network-Based Tracklets Data Association for Multiple Extended Target Tracking with Intermittent Measurements.

The key issue of multiple extended target tracking is to differentiate the origins of the measurements. The association of measurements with the possible origins within the target's extent is difficult, especially for occlusions or detection blind zones, which cause intermittent measurements. To solve this problem, a hierarchical network-based tracklet data association algorithm (ET-HT) is proposed. At the low association level, a min-cost network flow model based on the divided measurement sets is built to extract the possible tracklets. At the high association level, these tracklets are further associated with the final trajectories. The association is formulated as an integral programming problem for finding the maximum a posterior probability in the network flow model based on the tracklets. Moreover, the state of the extended target is calculated using the in-coordinate interval Kalman smoother. Simulation and experimental results show the superiority of the proposed ET-HT algorithm over JPDA- and RFS-based methods when measurements are intermittently unavailable.

Adjustable Removable Traction Appliance With Surgically Assisted Eruption for Impacted Maxillary Central Incisors.

Context: Impacted maxillary central incisors (MCIs) can seriously affect children's appearance, verbal abilities, and maxillofacial development. Clinically, a combination of surgically assisted eruption and orthodontic traction is the treatment modality most acceptable to dentists and children's families. However, previously used traction methods have been complex and required a long treatment time. Objective: The study intended to evaluate the clinical effects of the use of the research team's adjustable removable traction appliance combined with a surgically assisted eruption of impacted MCIs. Design: The research team performed a controlled prospective study. Setting: The study took place at Department of Orthodontics, Hefei Stomatological, Hospital. Participants: 10 patients with impacted MCIs, aged 7-10 years, who had visited the hospital between September 2017 and December 2018. Intervention: The research team assigned the impacted MCIs to the intervent ion group and contral ateral normal MCIs to thecontrol group. For the intervention group, the research team performed a surgical eruption and inserted the adjustable removable traction appliance. The control group received no treatments. Outcome Measures: Postintervention, the research team determined the mobility of both groups' teeth. At baseline and immediately postintervention for both groups, the team performed cone-beam computed tomography (CBCT) and measured root length, apical-foramen width, volume, surface area, and root-canal wall thickness for the labial and palatal sides. For both groups, after the intervention group's treatments, the team: (1) performed electric pulp testing and periodontal probing on the participants' teeth; (2) measured and documented pulp vitality, gingival index, periodontal probing depth, and gingival height (GH)for the labial and palatal sides; and (3) measured labial-and-palatal, alveolar bone level and alveolar bone thickness. Results: At baseline, the intervention group showed delayed root development, and that group's root length was significantly shorter (P < .05) and apical-foramen width (P < .05) was significantly greater than those of the control group. The intervention group's treatment success rate was 100%. And the intervention group did not have any adverse reactions, such as tooth loosening, gingival redness and swelling, or bleeding. Postintervention, the intervention group's labial GH was significantly higher than that of the control group, at 10.58 ± 0.45 mm and 9.47 ± 0.31 mm, respectively (P = .000). The increase in the intervention group's root length postintervention was significantly greater than that of the control group, at 2.80 ± 1.09 mm and 1.84 ± 0.97 mm, respectively (P < .05). The intervention group also had significantly greater decrease in the apical-foramen width than the control group did, at 1.79 ± 0.59 mm and 0.96 ± 0.40 mm, respectively (P < .05). At the end of traction, the intervention group had significantly higher labial-and-palatal alveolar-bone levels, at 1.77 ± 0.37 mm and 1.23 ± 0.21 mm, respectively, than the control group did, at 1.25 ± 0.26 mm (P = .002) and 1.05 ± 0.15 mm (P = .036), respectively. The labial alveolar-bone thickness in the intervention group was thinner than that of the control group, at 1.49 ± 0.31 mm and 1.80 ± 0.11 mm, respectively (P = .008). The volume and surface area (P < .01) of the intervention group's impacted teeth had increased significantly postintervention (both P < .01), but both were significantly smaller than those of the control group, both at baseline and postintervention. Conclusions: An adjustable removable traction appliance combined with a surgically assisted eruption can be a reliable treatment for impacted MCIs and can provide root development and a good periodontal-pulp condition postintervention.

Whole genome sequencing and analysis of Armillaria gallica Jzi34 symbiotic with Gastrodia elata.

BACKGROUND: Armillaria species are plant pathogens, but a few Armillaria species can establish a symbiotic relationship with Gastrodia elata, a rootless and leafless orchid, that is used as a Chinese herbal medicine. Armillaria is a nutrient source for the growth of G. elata. However, there are few reports on the molecular mechanism of symbiosis between Armillaria species and G. elata. The genome sequencing and analysis of Armillaria symbiotic with G. elata would provide genomic information for further studying the molecular mechanism of symbiosis. RESULTS: The de novo genome assembly was performed with the PacBio Sequel platform and Illumina NovaSeq PE150 for the A. gallica Jzi34 strain, which was symbiotic with G. elata. Its genome assembly contained ~ 79.9 Mbp and consisted of 60 contigs with an N50 of 2,535,910 bp. There were only 4.1% repetitive sequences in the genome assembly. Functional annotation analysis revealed a total of 16,280 protein coding genes. Compared with the other five genomes of Armillaria, the carbohydrate enzyme gene family of the genome was significantly contracted, while it had the largest set of glycosyl transferase (GT) genes. It also had an expansion of auxiliary activity enzymes AA3-2 gene subfamily and cytochrome P450 genes. The synteny analysis result of P450 genes reveals that the evolutionary relationship of P450 proteins between A. gallica Jzi34 and other four Armillaria was complex. CONCLUSIONS: These characteristics may be beneficial for establishing a symbiotic relationship with G. elata. These results explore the characteristics of A. gallica Jzi34 from a genomic perspective and provide an important genomic resource for further detailed study of Armillaria. This will help to further study the symbiotic mechanism between A. gallica and G. elata.

Structural Evolution of Polyglycolide and Poly(glycolide-co-lactide) Fibers during In Vitro Degradation with Different Heat-Setting Temperatures.

The structural evolution of polyglycolide (PGA) and poly(glycolide-co-lactide) (P(GA-co-LA)) with 8% LA content fibers with different heat-setting temperatures was investigated during in vitro degradation using WAXD, SAXS, and mechanical property tests. It was found that the PGA fiber was more susceptible to the degradation process than the P(GA-co-LA) fiber and a higher heat-setting temperature reduced the degradation rate of the two samples. The weight and mechanical properties of the samples showed a gradual decrease during degradation. We proposed that the degradation of PGA and P(GA-co-LA) fibers proceeded in four stages. A continuous increase in crystallinity during the early stage of degradation and a gradual decline during the later period indicated that preferential hydrolytic degradation occurred in the amorphous regions, followed by a further degradation in the crystalline regions. The cleavage-induced crystallization occurred during the later stage of degradation, contributing to an appreciable decrease in the long period and lamellar thickness of both PGA and P(GA-co-LA) samples. The introduction of LA units into the PGA skeleton reduced the difference in the degradation rate between the crystalline and amorphous regions, and they were simultaneously degraded in the early stage of degradation, leading to a degradation mechanism different from that of the PGA fiber.

Structural Evolution of Polyglycolide and Poly(glycolide-co-lactide) Fibers during the Heat-Setting Process.

PGA and P(GA-co-LA) fibers applied as surgical sutures strongly depend on their microstructure. The structural evolution in both the relaxed and tensioned states during heat-setting after hot stretching, which included heating and postannealing, was investigated using in situ WAXD/SAXS and DSC techniques. We found that the fibers of both PGA and P(GA-co-LA) with 8% LA content under the relaxed state were more advantageous than the fibers under the tensioned state indicated by the larger crystallite sizes and unit cell parameters and the higher crystallinity. The mechanical properties of the samples increased after heat-setting. Heat-setting at 120 °C was more suitable for promoting the fiber properties, which can be ascribed to crystal formation and perfection. During the heating, the thermal expansion increased the unit cell parameters and the long period of PGA linearly, whereas the unit cell parameters of P(GA-co-LA) had an obvious turning point at 60-80 °C, and the long period showed a sudden decline in the temperature range of 60-80 °C, which was mainly the result of the discharge of LA units. The unit cell parameters and the long period of both PGA and P(GA-co-LA) decreased during the isotherm process due to crystal perfection. However, the P(GA-co-LA) decrease was more prominent than PGA because of the inclusion of LA monomers in the crystal structure of GAs.

De novo RNA sequencing and analysis reveal the putative genes involved in diterpenoid biosynthesis in Aconitum vilmorinianum roots.

In this study, the putative genes involved in diterpenoid alkaloids biosynthesis in A. vilmorinianum roots were revealed by transcriptome sequencing. 59.39 GB of clean bases and 119,660 unigenes were assembled, of which 69,978 unigenes (58.48%) were annotated. We identified 27 classes of genes (139 candidate genes) involved in the synthesis of diterpenoid alkaloids, including the mevalonate (MVA) pathway, the methylerythritol 4-phosphate (MEP) pathway, the farnesyl diphosphate regulatory pathway, and the diterpenoid scaffold synthetic pathway. 12 CYP450 genes were identified. We found that hydroxymethylglutaryl-CoA reductase was the key enzyme in MVA metabolism, which was regulated by miR6300. Transcription factors, such as bHLH, AP2/EREBP, and MYB, used to synthesize the diterpenes were analyzed. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02646-6.

Epitaxial Crystallization of Poly(ε-caprolactone) on Reduced Graphene Oxide at a Low Shear Rate by In Situ SAXS/WAXD Methods.

The interfacial interaction between polymers and reinforcements has a positive effect on the properties of polymer nanocomposites, and a further study on the evolution of this interfacial interaction under a shear field is conducive to reasonable regulation of the properties of polymer nanocomposites. For this purpose, epitaxial crystallization of poly(ε-caprolactone) (PCL) on reduced graphene oxide (RGO) is investigated by shearing at the shear rate of 3 s-1 by in situ synchrotron radiation. In situ two-dimensional small-angle X-ray scattering (2D SAXS) results suggest that the imposed shear field promotes the orientation of the polymer chains, resulting in the formation of a large periodic structure of PCL on the RGO surface. In addition, higher shear temperatures facilitate the conformational adjustment of the PCL molecular chain on RGO at the shear rate of 3 s-1, resulting in the formation of thicker lamellae. In situ two-dimensional wide-angle X-ray diffraction (2D WAXD) results show that shear enhances the crystallinity of the PCL/RGO nanocomposite and promotes the oriented growth of epitaxial and bulk crystals. The current findings can improve the understanding of the structural evolution behavior of PCL/RGO nanocomposites after shear and especially enhance dramatically our understanding of the underlying mechanism of influence of shear on interfacial epitaxial crystallization in polymer/graphene nanocomposite systems.

Preparation of Prussian Blue Containing Polymeric Nanocapsule via Interfacial Confined Coordination in Crosslinked Inverse Miniemulsion.

This work presents a simple and facile strategy for the creation of Prussian blue containing polymeric nanocapsules. An crosslinked inverse miniemulsion with a formula of water/ K4Fe(CN)6/1,2-bis-(-2-iodoethyl) ethane(BIEE)/ toluene/ PDMAEMA-b-PS stabilizer mixture was prepared as soft template firstly. A crosslinking nanocapsule structure with K4Fe(CN)6 in water core could be achieved by a crosslinking reaction between PDMAEMA-b-PS stabilizers and BIEE. Upon the following addition of FeCl3 ether solution into the oil phase of this inverse miniemulsion, a coordination reaction between two iron salts occurred immediately to form a Prussian blue complex. Due to the solubility limitation of FeCl3 in the oil phase of the miniemulsion, forcing the coordination reaction of K4Fe(CN)6 and FeCl3 mainly occurred at the oil-water interface of the nanocapsules, resulting in a soft polymer/Prussian blue(PB) hybrid nanocapsule.

Microbeam two-dimensional small-angle X-ray scattering investigating the effects of reduced graphene oxide on local microstructures of high-density polyethylene/reduced graphene oxide nanocomposite bars.

It has been reported that the introduction of reduced graphene oxide (RGO) can enhance the crystallization and orientation of high-density polyethylene (HDPE) matrix and thus improve the mechanical properties of HDPE/RGO nanocomposites. In this study, the local microstructures and orientations in different regions of HDPE/RGO bars with varied RGO contents were further explored by two-dimensional small-angle X-ray scattering using a microbeam technique. It is unveiled that the orientation orderings of each position is intensified with increasing RGO amount, and of particular interest is the observation of the slight change of the ordering degrees in diverse zones of HDPE/RGO nanocomposite bars, indicating that RGO imposes a uniform enhancing effect upon HDPE matrix within different areas and consequently induces an effective increase of the mechanical properties of HDPE/RGO nanocomposites.

Preference adjustable multi-objective NMPC: An unreachable prioritized point tracking method.

This paper proposes a new preference adjustable multi-objective model predictive control (PA-MOMPC) law for constrained nonlinear systems. With this control law, a reasonable prioritized optimal solution can be directly derived without constructing the Pareto front by solving a minimal optimization problem, which is a novel development of recently proposed utopia tracking approaches by additionally considering objective preferences with more flexible terminal and stability constraints. The tracking point of the proposed PA-MOMPC law is represented by a parametric vector with the parameters adjustable on the basis of objective preferences. The main result of this paper is that the solution obtained through the proposed PA-MOMPC law is demonstrated to have two important properties. One is the inherent Pareto optimality, and the other is the priority consistency between the solution and the tuning parametric vector. This combination makes the objective priorities tuning process transparent and efficient. The proposed PA-MOMPC law is supported by feasibility analyses, proof of nominal stability, and a numerical case study.

Fuzzy modeling and predictive control of superheater steam temperature for power plant.

This paper develops a stable fuzzy model predictive controller (SFMPC) to solve the superheater steam temperature (SST) control problem in a power plant. First, a data-driven Takagi-Sugeno (TS) fuzzy model is developed to approximate the behavior of the SST control system using the subspace identification (SID) method. Then, an SFMPC for output regulation is designed based on the TS-fuzzy model to regulate the SST while guaranteeing the input-to-state stability under the input constraints. The effect of modeling mismatches and unknown plant behavior variations are overcome by the use of a disturbance term and steady-state target calculator (SSTC). Simulation results for a 600 MW power plant show that an offset-free tracking of SST can be achieved over a wide range of load variation.

Data-driven modeling and predictive control for boiler-turbine unit using fuzzy clustering and subspace methods.

This paper develops a novel data-driven fuzzy modeling strategy and predictive controller for boiler-turbine unit using fuzzy clustering and subspace identification (SID) methods. To deal with the nonlinear behavior of boiler-turbine unit, fuzzy clustering is used to provide an appropriate division of the operation region and develop the structure of the fuzzy model. Then by combining the input data with the corresponding fuzzy membership functions, the SID method is extended to extract the local state-space model parameters. Owing to the advantages of the both methods, the resulting fuzzy model can represent the boiler-turbine unit very closely, and a fuzzy model predictive controller is designed based on this model. As an alternative approach, a direct data-driven fuzzy predictive control is also developed following the same clustering and subspace methods, where intermediate subspace matrices developed during the identification procedure are utilized directly as the predictor. Simulation results show the advantages and effectiveness of the proposed approach.

Rhythmic Growth Combined with Lamellar Twisting Induces Poly(ethylene adipate) Nested Ring-Banded Structures.

Previously, poly(ε-caprolactone) (PCL) classical ring-banded spherulites with periodic twisted lamellae and nonclassical concentric ringed structures induced by rhythmic growth were obtained by modulating the competition between diffusion flux and spherulitic growth. In this study, the modulation of diffusion flux and spherulitic growth on ring-banded structures is further studied, and hierarchical nested ring-banded patterns with a banded structure nested in the ridge rings of the other concentric ringed structure are prepared during slow solvent evaporation in poly(ethylene adipate) (PEA) solution films. The structural characterizations reveal that the big concentric ringed structure derives from periodic variation of thicknesses and that the small inner banded structure consists of periodic twisted lamellae. A diffusion-induced rhythmic growth mechanism and an unbalanced surface stress induced lamellar twisting model are proposed to illustrate the formation of the big concentric and the inner banded structures, respectively.

Band-to-Nonband Transition into Unique Poly(ε-caprolactone) Crystals by Modulating the Interplay of Diffusion and Growth.

Previously, by modulating the interplay of chain diffusion and crystal growth rate in evaporating solution-cast poly(ε-caprolactone) (PCL) thin films, discrete banded crystals were obtained when diffusion and growth are competitive. In this study, we further investigated the effect of diffusion and growth, here mainly the growth rate on the crystallization of PCL. We found that there is a threshold (or range of) growth rate above which the banding cannot develop, and thus a band-to-nonband transition leads to the emergence of a novel crystal pattern. Accompanied by the band-to-nonband transition, the lamellar orientation also changes from flat-on to mainly tilted or even edge-on. The result reveals the significant impact of the diffusion and growth, especially the growth rate on the crystal construction and then the crystal morphology.

The study of physics and thermal characteristics for in-hospital neutron irradiator (IHNI).

The IHNI is designed for boron neutron capture therapy (BNCT) based on miniature neutron source reactor (MNSR). The reactor with thermal power 30 kW is an undermoderated reactor of pool-tank type, and UO(2) as fuel, light water as coolant and moderator, and metallic beryllium as reflector. The fission heat produced by the reactor is removed by the natural convection. The paper gives the calculating results of critical mass and the worths of central control rod, auxiliary control rod, reactivity regulator and neutron beam equipments. The parameters at thermal and small thermal ports and at epithermal port were calculated by optimizing combination of kinds of material by MCNP code. The dynamic feature research was done by RELAP5 code when the reactivities of 3, 4.5 and 6 mK were inserted, respectively. The results show that the reactor power can be limited to safe level by itself owing to the Doppler effect of fuel element and moderator negative temperature effect when the 6 mK reactivity was inserted into the reactor.