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Background: Nasopharyngeal carcinoma (NPC) is an assertive malignancy with partially understood underlying mechanisms, urging further study into its diverse and dynamic tumor microenvironment (TME) to bolster diagnosis, treatment, and prognostic accuracy. Aims: To track the evolutionary route of metastasis, here we perform a yielding scRNA-seq data from 24 primary carcinoma, 7 peripheral blood mononuclear cell (PBMC) nasopharyngeal carcinoma, and 7 metastatic carcinoma patients’ sample. Materials and methods: Following high quality control and filtration, a total of 292,298 cells from these tumors were classified into 10 clusters: T cells, B cells, Macrophages/Monocytes, Natural Killer (NK) cells, Plasma cells, plasmacytoid Dendritic Cells, Migratory Dendritic Cells, Mast cells, Cancer-Associated Fibroblasts, and Epithelial cells. Results: By comparing and analyzing the different functional capacities of cellular entities within primary and metastatic nasopharyngeal carcinoma, coupled with a detailed investigation into the heterogeneity and differential fate trajectories of T cells, B cells, and myeloid cells, as well as assessing the interactions of cell–cell communicative heterogeneity between these carcinogenic states, we established single-cell atlases for primary and metastatic tumors and identified a large number of potential therapeutic targets. Conclusion: This comprehensive analysis significantly advances our understanding of nasopharyngeal carcinoma (NPC) metastasis by detailing the evolutionary dynamics and the impact of the tumor microenvironment at a single-cell resolution, thereby laying a crucial foundation for future metastatic tumor research and providing new insights into immune heterogeneity, molecular interactions, and potential therapeutic strategies for NPC. [ABSTRACT FROM AUTHOR]

LEO augmentation systems are attracting worldwide attention. However, their performance in real-world environments has not yet been reported, although several systems have already launched experimental satellites, such as the CENTISPACE™ system developed by Beijing Future Navigation Tech Co., Ltd. By using real observations from two experimental CENTISPACE™ satellites recorded by a regional network, we present the results of LEO-enhanced precise point positioning (PPP) performance. Based on a proposed three-step approach for LEO orbit determination and time synchronization, a framework for LEO augmentation data processing is established and validated. Two stations are selected for LEO augmentation evaluation, and static PPP is performed by combining the LEO augmentation observations with different GNSS systems, including GPS, BDS-3, and Galileo. The static PPP precision shows a few improvements attributed to LEO observations; the positioning errors with one, two, and three GNSS systems are 6.1, 4.6, and 4.6 cm, respectively, while they are reduced to 5.2, 3.9, and 3.8 cm by adding the LEO satellites, respectively, revealing improvements of 13.9, 16.4, and 18.8%, respectively. Moreover, PPP convergence is significantly enhanced. The average convergence times with one, two, and three GNSS systems are 32.7, 17.9, and 14.2 min, respectively, which are reduced to 16.7, 8.9, and 5.7 min, respectively, by adding LEO observations. This indicates that the convergence time is significantly shortened by approximately 53% with the augmentations from only two LEO satellites. Such results show the potential of LEO augmentation, and larger improvements can be expected with more LEO satellites to be deployed in the future. [ABSTRACT FROM AUTHOR]

In the current work, the microstructure evolution and mechanical properties of (Ce + Yb) modified in situ TiB2/Al-Si matrix composite were systematically investigated by thermal deformation at strain rates of 0.0005–0.0125 s− 1 and temperatures of 250–450 °C. The enhanced strength and plasticity of the composite have a good correlation with the microstructure evolution under different thermal deformation parameters. The obtained results indicated that under the hot deformation parameters of strain rate of 0.0025 s− 1 and deformation temperature of 250 °C, the defects of micropores can be reduced or even eliminated and improved the density of the composite. The coarse α-Al grains, eutectic Si and Fe-rich phases and undissolved primary (Ce + Yb)-containing intermetallics were significantly refined under high shear stress. At the same time, the distribution of in-situ synthesized submicron TiB2 particles in the Al matrix tends to be more uniform. The substructures such as high density dislocations and low angle grain boundaries were introduced under the thermal deformation of 250 °C/0.0025 s− 1, which provided the necessary conditions for the formation of recrystallized grains that are less likely to overgrow and further promoted the aging precipitation of nano-strengthening precipitates. Finally, the UTS, YS and elongation of the composite reached the maximum values of 385 MPa, 316 MPa and 9.6% respectively, which were 60.4%, 85.9% and 45.5% higher than the as-cast and undeformed composite. [ABSTRACT FROM AUTHOR]

In this work, the effects of combined addition of Ce and Yb on the microstructure and mechanical properties of Al6Si/5TiB2 MMC were systematically investigated by using optical microscopy (OM), x-ray diffraction (XRD), scanning electron microscopy (SEM) configured with energy diffraction spectrum (EDS), electron probe micro-analysis (EPMA), transmission electron microscopy (TEM) and mechanical tests. The results show that the combined addition of Ce and Yb can simultaneously refine α-Al grains and modify eutectic Si as well as suppress the agglomeration of TiB2 particles to a certain extent. The ultimate tensile strength (UTS), yield strength (YS) and elongation (El) of the composites reached the maximum values of 367.5, 271.3 MPa and 6.1% when the content of Ce and Yb was 0.4 wt.%, which were 14.4, 17.1 and 38.6% higher than that the situation without Ce and Yb addition, respectively. The tensile fracture mode of Al6Si/5TiB2 MMC belongs to a typical mixed brittle–ductile fracture, but when the Ce and Yb were added, it can change part of the brittle fracture into ductile fracture. [ABSTRACT FROM AUTHOR]

Various testing techniques established the association between precipitates and the mechanical characteristics of IN783 alloy at high temperatures. The results show that the β phase is coarser at the grain boundary and that the Ni5Al3 phase precipitates inside the β phase as service time increases, which destroys the structure of the β phase, weakening the strength of the grain boundary and reducing the ductility of the alloy at high temperatures. Meanwhile, increasing the size of the γ′ phase coarser from 53 to about 74 nm enhances the yield strength of the alloy. Following the recovery heat treatment, the grain boundary β phase is precipitated again with a smaller size and no Ni5Al3, and the size of the γ′ phase is refined to the unused level. The alloy material's high-temperature ductility is restored, which extends the material's service life. [ABSTRACT FROM AUTHOR]

To achieve timeliness and accuracy when conducting a performance analysis of a complex product assembly process, we consider the performance analysis of an array antenna assembly process, and investigate the measurability of the assembly process' performance. In this study, a digital twin modeling method is proposed for the assembly performance analysis of an array antenna. This method integrates finite elements, mesh model simplification, and surrogate models. To achieve real-time prediction and rapid visualization of the assembly performance of the assembly process, a mesh simplification algorithm for a finite element mesh model based on edge collapse is proposed and a Gaussian process regression surrogate model for product assembly performance is constructed to complete the construction of a digital twin model for assembly performance analysis. Finally, the proposed method is verified by an example of the assembly performance analysis of a typical array antenna. Results show that the digital twin model proposed achieves a high response speed and fidelity in the analysis of assembly performance and provides a valuable reference to application of digital twin technology in product assembly processes. [ABSTRACT FROM AUTHOR]

In the present work, the effects of combined addition of (Ce + Yb) on the heat treatment microstructure and mechanical properties of Al-6Si-0.6 Mg-0.6Cu-0.2Cr casting alloy were investigated. The results indicated that the α-Al grains, eutectic Si and β-Al5FeSi phases were refined and modified simultaneously by (Ce + Yb), which transformed the coarse plate-like eutectic Si into short rod–like and/or granular shape. Furthermore, the heat treatment process facilitated the spheroidization of eutectic Si and the optimum combined addition of (Ce + Yb) was 0.4 wt%. The 0.4 wt% (Ce + Yb) modified alloy was compared with the unmodified alloy, and it was found that the average grain size and SADS of the α-Al grains were reduced by 62.9 and 60.6%, and the average aspect ratio and area of eutectic Si decreased by 182.0 and 91.3%, respectively. Most importantly, the combined addition of (Ce + Yb) greatly enhanced the tensile properties of the alloy, especially due to the significant improvement of the microstructure, which resulted in a remarkable increase in the ultimate tensile strength (UTS), yield strength (YS) and elongation (El) of the alloy. Finally, the combined addition of (Ce + Yb) transformed the fracture patterns of the modified alloy from brittle fracture to ductile fracture. [ABSTRACT FROM AUTHOR]

This study enhances the strength and ductility of (Ce + Yb)-modified Al-Si-Mg-Cu-Cr casting alloy by integrating hot deformation and heat treatment. In addition, the synergistic effects of hot deformation and heat treatment on the microstructure and mechanical behavior were thoroughly investigated. As-solutionized alloys were subjected to hot deformation examinations at temperatures ranging from 250 to 450 °C and strain rates varying between 0.0005-0.0125 s−1. The results revealed that the flow stress increased as the temperature decreased, and the strain rate increased. The maximum ultimate tensile strength (UTS), yield strength (YS) and elongation (El) of as-solutionized, hot deformed at 250 °C, strain rate of 0.0025 s−1 and aged alloy were 353, 296 MPa and 11.4%, respectively, higher by 79.1, 193.1 and 96.6% than the as-cast alloy. The interactions between Ce- and/or Yb-rich precipitates, the high-density dislocations induced by hot deformation and the creation of substructures such as subgrains are primarily responsible for the increase in strength. Finally, the high strength of the (Ce + Yb)-modified alloy after hot deformation and heat treatment is primarily attributed to the synergistic strengthening of several factors through solid solution strengthening, precipitation strengthening, substructural strengthening and work hardening. [ABSTRACT FROM AUTHOR]

In the present work, the in situ TiB2 particle-reinforced Al–Si matrix composites with or without (Ce + Yb) were fabricated by mixed salt–metal reaction, and the effect of TiB2 and (Ce + Yb) on microstructure and mechanical properties were investigated. The results showed that the combined addition of 0.4 wt% (Ce + Yb) and 3 wt% TiB2 further facilitated the uniform microstructure and modified the eutectic Si of composites. Meanwhile, the combined addition of (Ce + Yb) promoted the nucleation and inhibited the growth of TiB2 particles. The mechanical properties of the composites with 0.4 wt% (Ce + Yb) and 3 wt% TiB2 reached maximum values with ultimate tensile strength, yield strength and elongation of 240.5 MPa, 169.8 MPa and 6.6%, which were 53.8%, 116.1% and 164.0% higher compared to the Al–Si matrix alloy. The fractography observations indicated that the fracture mode of the composites belongs to a typical of mixed brittle–ductile fracture. But the combined addition of (Ce + Yb) is beneficial to improve the plasticity of the composites. [ABSTRACT FROM AUTHOR]

Thanks to its single-atomic-layer structure, high carrier transport, and low power dissipation, carbon nanotube electronics is a leading candidate towards beyond-silicon technologies. Its low temperature fabrication processes enable three-dimensional (3D) integration with logic and memory (static random access memory (SRAM), magnetic random access memory (MRAM), resistive random access memory (RRAM), etc.) to realize efficient near-memory computing. Importantly, carbon nanotube transistors require good thermal stability up to 400 °C processing temperature to be compatible with back-end-of-line (BEOL) process, which has not been previously addressed. In this work, we developed a robust wafer-scale process to build complementary carbon nanotube transistors with high thermal stability and good uniformity, where AIN was employed as electrostatic doping layer. The gate stack and passivation layer were optimized to realize high-quality interfaces. Specifically, we demonstrate 1-bit carbon nanotube full adders working under 250 °C with rail-to-rail outputs. [ABSTRACT FROM AUTHOR]

Zinc-modified hypoeutectic Al–Si–Cu–Mg–Cr–B alloy underwent a two-stage solution treatment at 520 °C for two hours and 550 °C for half an hour, followed by a two-stage aging treatment at 100 °C for three hours and 180 °C for eight hours. The impact of heat treatment and Zn addition on the eutectic Si phase, alloy compounds, and mechanical properties of the hypoeutectic Al–Si–Cu–Mg–Cr–B alloy was systematically investigated using an optical microscope, X-ray diffractometer, scanning electron microscope, energy spectrum analysis, and mechanical properties test. The findings revealed that heat treatment and Zn addition improved the size, morphology, quantity, and types of eutectic silicon phases and alloy compounds, as well as their mechanical properties. After heat treatment, the alloy displayed optimal characteristics with the addition of 0.3 wt% Zn. The eutectic Si phase of the alloy exhibited the most favorable morphology, the greatest variety of alloy compounds, the most favorable morphology and size, and the largest Q index, which is utilized to evaluate the overall tensile properties of the alloy. This indicates superior mechanical properties. [ABSTRACT FROM AUTHOR]

By varying the tempering temperature, the effects of various tempering temperatures on the microstructure and properties of the coating were investigated. The results show that after heat treatment, eutectic carbides of the original coating disappear and spherical granular carbides resurface. The form and size of alloy carbide alter as the tempering temperature changes. The alloy carbide microstructure size is more rounded when the tempering temperature is 500 °C, and the average hardness is 658 HV, which is 4.9% greater than the original coating. The wear loss is least at a tempering temperature of 500 °C. The abrasion loss is 0.46 and 0.76 times that of the original coating when the load is 50 N and 75 N, respectively. The corrosion current density after tempering at 700 °C is the lowest in the electrochemical experiment, but the self-corrosion potential is the largest. [ABSTRACT FROM AUTHOR]

The C1q protein, which contains the globular C1q (gC1q) domain, is involved in the innate immune response, and is found abundantly in the shell, and it participates in the shell formation. In this study, a novel gC1q domain-containing gene was identified from Pinctada fucata martensii (P. f. martensii) and designated as PmC1qDC-1. The full-length sequence of PmC1qDC-1 was 902 bp with a 534 bp open reading frame (ORF), encoding a polypeptide of 177 amino acids. Quantitative real-time PCR (qRT-PCR) result showed that PmC1qDC-1 was widely expressed in all tested tissues, including shell formation-associated tissue and immune-related tissue. PmC1qDC-1 expression was significantly high in the blastula and gastrula and especially among the juvenile stage, which is the most important stage of dissoconch shell formation. PmC1qDC-1 expression was located in the outer epithelial cells of mantle pallial and mantle edge and irregular crystal tablets were observed in the nacre upon knockdown of PmC1qDC-1 expression at mantle pallial. Moreover, the recombined protein PmC1qDC-1 increased the rate of calcium carbonate precipitation. Besides, PmC1qDC-1 expression was significantly up-regulated in the mantle pallial at 6 h and was significantly up-regulated in the mantle edge at 12 h and 24 h after shell notching. The expression level of PmC1qDC-1 in mantle edge was significantly up-regulated at 48 h after LPS stimulation and was significantly up-regulated at 12 h, 24 h and 48 h after poly I:C stimulation. Moreover, PmC1qDC-1 expression was significantly up-regulated in hemocytes at 6 h after lipopolysaccharide (LPS) and poly I:C challenge. These findings suggest that PmC1qDC-1 plays a crucial role both in the shell formation and the innate immune response in pearl oysters, providing new clues for understanding the shell formation and defense mechanism in mollusk. [ABSTRACT FROM AUTHOR]

Deceptive reviews on Web are a common phenomenon and how to detect them has a very important impact on products, services, and even business policies. In order to filter out deceptive reviews more accurately, a new model called Sentence Joint Topic Sentiment Model (SJTSM) is presented in this paper, which incorporates the sentence structure of reviews and the sentiment label information of words based on Latent Dirichlet Allocation (LDA) model to extract the review features. The proposed model employs Gibbs algorithm to estimate the maximum likelihood parameters and takes the vector of topic-sentiment distribution as the review features. Then a voting system of multiple-classifier, which takes the extracted review feature vector as its input is designed to realize the classification of deceptive review detection. The comparative experiments on different public datasets with other existing methods based on LDA model show that the new classifying system based on SJTSM model can achieve more satisfying classification results on deceptive review detection. [ABSTRACT FROM AUTHOR]

The effects of Nb addition on the microstructure and corrosion resistance of the as-rolled Ti-stabilized Fe-17Cr ferritic stainless steels were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction, pitting tests, and electrochemical measurements. TiN precipitate tends to form in the microstructure of Ti-stabilized Fe-17Cr ferritic stainless steel. After 0.1 wt. % Nb addition, (Ti, Nb) (C, N) composite precipitates with MgO and Al2O3 core form in the microstructure. After adding 0.1 wt. % Nb, the corrosion rate of the Ti-stabilized Fe-17Cr ferritic stainless steel in FeCl3 solution is decreased significantly. The corrosion current densities decrease in HNO3, NaOH, and NaCl solutions, and the pitting corrosion potentials can be improved in NaCl solution for the Fe-17Cr ferritic stainless steel with 0.1 wt. % Nb addition. [ABSTRACT FROM AUTHOR]

Rice in cold region is threatened by cold stress frequently, resulting in severe losses of rice production. In the present study, two rice varieties with contrast cold tolerance in the reproductive stage (Longjing25, cold tolerant; Longjing11 cold sensitive) were compared using RNA-seq technique. A total of 14,861 and 12,148 differentially expressed genes (DEGs) were obtained by comparison of LJ25 and LJ11 after 2 days and 4 days of cold stress challenge. Subsequent Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that five significant pathways were specifically enriched in LJ11. Starch and sucrose metabolism was the only one significant pathway (containing 47 DEGs) annotated in both of varieties during two cold treatment periods. By weighted gene co-expression network analysis (WGCNA), 14 co-expression gene modules were calculated, among which turquoise, cyan, and dark green were the most concerned modules, containing 4807, 2682, and 1174 DEGs, respectively. Finally, we analyzed the transcriptional factors (TFs), and TF families of MYB, zinc finger, AP2/ERF-AP2, bHLH, NAC, bZIP, and WRKY were the biggest seven subfamilies. Collectively, our findings provided valuable insights into the molecular and genetic mechanisms responsible for rice's response to cold stress. [ABSTRACT FROM AUTHOR]

The Eastern Guangxi area locates in the southwestern part of the transition zone between Yangtze and Cathaysia blocks, which is an important region because the boundary between two blocks probablycrosses there. We determined LA-ICPMS U-Pb ages for detrital zircons extracted from three sandstone samples in the Sinian-Cambrian strata in this region. The resulting ages are in the range of the Archeozoic and Neoproterozoic, with three notable concentrates at 991 Ma, 974 Ma, and 964 Ma, all of which are coeval to the Grenvillian magmatic activity. The new age distribution is similar to the data reported in the Precambrian strata of the adjacent southwestern Cathaysia Block, suggesting that most of our detrital zircons are likely derived from the Cathaysia Block. Combined with others' research, we are more inclined to accept the opinion that there was not an ocean basin between the two blocks during the Sinian-Cambrian period in Eastern Guangxi area if the timing of collision is the Early Neopro-terzoic. But if the timing of collision is the Early Paleozoic, we conclude that Luzhai uplift (i.e., the uplift between Guilin-Yongfu faultand Lipu fault) beyond the west of Dayaoshan regoin might be one part of southwestern sedimentation boundary of Cathaysia Block and Yangtze Block. We also get a few of detrital zircons with ages of ~590 Ma which probably sourced from northeastern Gondwana and 13 detrital zircons with over 3 000 Ma U-Pb ages which record the early formation of the earth. [ABSTRACT FROM AUTHOR]

The effects of three artificial diets (S1, S2 and S3) on survival, growth and biochemical composition of one-year-old pearl oyster Pinctada martensii were investigated. Six experimental groups (EG1, EG2, EG3, EG4, EG5 and EG6) and one control group (CG) were set up. EG1, EG2 and EG3 were solely fed on S1, S2 and S3, respectively. EG4, EG5 and EG6 were fed on mixed diets, as follows: S1 and Platymonas subcordiformis; S2 and P. subcordiformis; and S3 and P. subcordiformis, respectively. CG was fed on only P. subcordiformis. All groups were continuously fed for 60 days. Survival, growth and biochemical composition of soft tissues were compared across the groups. Results showed that survival rate, the absolute growth rate (AGR) and relative growth rate (RGR) of shell length did not differ significantly across the groups ( p > 0.05). The AGR and RGR of total weight differed significantly among the groups ( p < 0.05). AGR and RGR of shell length and total weight were the highest in EG5 and the lowest in EG1. Gross fat content showed insignificant differences among the groups ( p > 0.05). However, gross protein content and ash content showed significant differences across the groups ( p < 0.05). The gross protein of the groups solely fed on artificial diets was lower than those of the groups fed on mixtures of artificial diets and microalgae or single microalgae. The contents of other amino acids, total amino acids (TAAs) and essential amino acids (EAAs) showed significant differences across the groups ( p < 0.05). TAA, EAA and delicious amino acids of the groups fed solely on artificial diets were lower than those of the groups fed on mixtures of artificial diets and microalgae or single microalgae. Results indicated that the artificial diet (S2) can serve as substitutes of microalgal diets for P. martensii. [ABSTRACT FROM AUTHOR]

Under the intraday microstructure framework, we analyze the impact of traders' responses to market information on daily futures price and trading activity by utilizing the unique features of the Class III milk futures contract. The cash settlement and classified pricing scheme distinguish milk futures from those of other commodities. We construct two variables, days to maturity and price deviates, to capture the distinctive features. While the number of days to maturity indicates the length of time before cash settlement in the maturity month, price deviates reflects traders' aggregate responses to weekly announced information on milk prices. A structural price volatility-trading volume model is specified and estimated using the Bayesian Markov chain Monte Carlo method. The results confirm that (1) the closer to cash settlement, the lower milk price volatility, which is different from the typical 'Samuelson effect' for other commodity futures, and (2) both price variability and trading volume increase with traders' responses to market information and therefore are positively associated. [ABSTRACT FROM AUTHOR]

In this study, Al–Si matrix composites containing different contents of in situ TiB2 particles and (Ce+Yb) were fabricated via a mixed salt–metal reaction of KBF4 and K2TiF6 and the effects of the reinforcement particles on the microstructure and mechanical properties of the composites were investigated. Results revealed that the addition of TiB2 particles and (Ce+Yb) further refined the α-Al grains and modified the eutectic Si phase of the composite. Moreover, the combined addition of (Ce+Yb) resulted in the suppression of TiB2 agglomeration, causing a notable modification in the distribution and morphology of TiB2 particles as well as a significant reduction in their size compared with the condition without the addition of (Ce+Yb). The mechanical properties of 3 wt.% TiB2/Al–Si matrix composites with the combined addition of 0.4 wt.% (Ce+Yb) reached the maximum values with the ultimate tensile strength, yield strength, and elongation of 372.4 MPa, 268.7 MPa, and 4.5%, respectively, which increased by 30.1%, 40.1%, and 9.8%, respectively, compared with those of Al–Si matrix alloy. Optical microscopy, scanning electron microscopy with energy-dispersive spectroscopy, and X-ray diffraction were used to demonstrate the presence of (Ce+Yb)-containing precipitates, other precipitates, and in situ TiB2 particles. [ABSTRACT FROM AUTHOR]

Pernicious placenta previa is an obstetric complication that results in a crisis situation for many patients. Most existing options deal with the problems after delivery leading to unfavorable outcomes. To circumvent this situation, a few preventive simple surgical options have been discussed in this paper. The highlight of the approach is the application of ascending uterine artery suture that drastically reduced the amount of bleeding as compared to that observed in regular surgeries. Combined with the placenta accrete location, wedge resection and 'patch' homeostasis of the serous membrane, the surgical modifications adopted effectively reduced the need for hysterectomy thus preserving the fertility of the patients for the future. Since fetuses were safely removed within 1-2 min, the Apgar scores of the neonates were also largely unaffected. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are short-nucleotide RNA molecules that function as negative regulators of gene expression in various organisms. However, miRNAs of Pinctada martensii have not been reported yet. P. martensii is one of the main species cultured for marine pearl production in China and Japan. In order to obtain the repertoire of miRNAs in P. martensii, we constructed and sequenced small RNA libraries prepared from P. martensii by Solexa deep sequencing technology and got a total of 27,479,838 reads representing 3,176,630 distinct sequences. After removing tRNAs, rRNAs, snRNAs, and snoRNAs, 10,596,306 miRNA reads representing 18,050 distinct miRNA reads were obtained. Based on sequence similarity and hairpin structure prediction, 258 P. martensii miRNAs (pm-miRNA) were identified. Among these pm-miRNAs, 205 were conserved across the species, whereas 53 were specific for P. martensii. The 3′ end sequence of U6 snRNA was obtained from P. martensii by 3′ rapid amplification of cDNA end PCR reaction and sequence-directed cloning. Eight conserved pm-miRNAs and two novel pm-miRNAs were validated by stem-loop quantitative real-time PCR with U6 snRNA as an internal reference gene. pm-miRNAs and the reported biomineralization-related genes were subjected to target analysis by using target prediction tools. Some of the pm-miRNAs, such as miR-2305 and miR-0046, were predicted to participate in biomineralization by regulating the biomineralization-related genes. Thus, this study demonstrated a large-scale characterization of pm-miRNAs and their potential function in biomineralization, providing a foundation to understand shell formation. [ABSTRACT FROM AUTHOR]

Pearl oyster Pinctada martensii is cultured for production of pearl in China. It needs to implant a mantle graft cut from a donor oyster and a seed nucleus into the gonad of the host oyster to produce a pearl. Pearl sac surrounding the nucleus is formed by the proliferation of the implanted mantle graft from the outer mantle epithelial cells in the host oyster. The pearl sac is responsible for production of a cultured pearl. A comprehensive transcriptome analysis on pearl sac will help to understand the mechanism on pearl formation and immune response of host oyster after nucleus implantation. In the present study, 39,400,004 reads were produced from the pearl sac using RNA-sequence technology and then assembled into 102,762 unigenes. More than 22.4% of these unigenes were possibly involved in approximately 219 known signaling pathways. A total of 37,188 unigenes were annotated based on sequences similarities with known proteins. Fifty-one biomineralization-related unigenes and 268 immune-related unigenes were not previously detected in P. martensii. The un-annotated unigenes may be some genes specifically existed in P. martensii. These annotated or un-annotated unigenes in the present studies were valuable for the future investigation on molecular mechanism of pearl formation and immune response of the species. [ABSTRACT FROM AUTHOR]

Characterization of biodegradable stent vein graft thickening. Polydioxanone vascular sutures (PDSs) were used in a biodegradable arteriovenous bypass model. Twenty-four rabbits underwent carotid interposition bypass via ipsilateral jugular vein. One half received the stent (PDS group) and the remaining half a simple vein graft (controls). Group subsets received external stent removal or sham-control exploration at 4 and 12 weeks. At 4 and 12 weeks, the PDS group had significantly less medial and intimal thickening than the control group ( P < 0.05), and there were fewer proliferating smooth muscle cells and extra cellular matrix formation than the control group at every interval. At 12 weeks, partial stent degradation occurred without deleterious effects. Furthermore proliferating cell nuclear antigen (PCNA), angiotensin type 1 receptor (AT1R), and transforming growth factor beta 1 (TGF-β1) levels were significantly lower than the control group. The external stent inhibited medial and intimal hyperplasia, an effect that remains after the material has completely degraded. This PDS stent is feasible option for vein grafts. [ABSTRACT FROM AUTHOR]

In May of 2007, the second generation selected (SS) and control (SC) groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length, respectively, from the first generation selected group. Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8, 18, 60, 95, 195 and 365. On Day 365, 100 individuals (60.0-75.0 mm at shell length) were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate, oxygen consumption and ammonia excretion were measured at 15, 20, 25 and 30 °C. The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8, 18, 60, 95, 195 and 365 ( P <0.05). The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height, respectively. At 15, 20, 25 and 30 °C, the SS groups had significantly larger filtrate rate than the SC group ( P <0.05). At 15 and 25 °C, the differences in oxygen consumption rate between the SS and SC groups were not significant ( P >0.05). At 20 and 30 °C, however, the oxygen consumption rate of the SS group was significantly larger than the SC group ( P <0.05). At 15, 20, 25 and 30 °C, there were no significant differences in ammonia excretion rate between the SS and SC groups ( P >0.05). The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful. Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior. [ABSTRACT FROM AUTHOR]

Objective of this article is to construct and characterize a three-layered small-caliber, artificial vascular stent. The outer layer of the stent consisted of small intestine submucosa (SIS), the middle layer was the polydioxanone (PDS) vascular stents, and the inner layer. The SIS and PDS were attached with 8-0 PDS thread. Crosslinking with a 10% collagen/chondroitin sulfate solution and 0.020% glutaraldehyde secured the structure. The stent was implanted into the muscles on both sides of the canines’ spine at 2, 4, 12, and 24 weeks. A MTT assay using L-929 cells measured the cytotoxicity of the implant. Histological and microscopy analyses were employed to examine the degradation characteristics of the PDS stent. Biomechanical properties of the stent were tested and compared to those of normal physiological blood vessels. The PDS stent burst pressure (43.5 ± 8.3) kPa, rupture intensity (19.1 ± 1.56) N, strain ratio (42.88 ± 3.16)%, and radial compliance (5.96 ± 0.87)%/100 mmHg were similar to that of physiological vessels. The cytotoxicity test showed that the PDS stent complied with specifications for biological materials for medical applications, with a cell toxicity ranging from 0 to 1. After 12 weeks, SIS and collagen sponge were completely replaced by fibrous connective tissue. Although there was some degradation of PDS, inflammatory cell infiltration subsided. After 24 weeks, the scaffold material began to absorb the new fibers and became filled with inflammatory cells and macrophages. This artificial vascular stent met the requirements of transplant experiments and should be further investigated for future clinical applications. [ABSTRACT FROM AUTHOR]

The impact corrosion-abrasion properties and mechanism of high manganese steel were investigated under different impact energies. The result shows that the wearability of the steel decreases with the increase of the impact energy. The dominant failure mechanism at a lower impact energy is the rupture of extrusion edge along root and a slight shallow-layer spalling. It transforms to shallow-layer fatigue flaking along with serious corrosion-abrasion when the impact energy is increased, and finally changes to bulk flaking of hardened layer caused by deep work-hardening and heavy corrosion-abrasion. [ABSTRACT FROM AUTHOR]

An Al–8Si–1Cu–0.35Mg casting alloy with (Mn + B) composite addition was prepared via traditional ingot metallurgy. The effects of (Mn + B) composite addition on the α-Al dendrites, AlB2 phase, Fe-rich phase, fluidity, and mechanical properties of the hypoeutectic Al–8Si–1Cu–0.35Mg casting alloy were systematically studied via optical microscopy, scanning electron microscopy, energy–dispersive spectroscopy analysis, and fluidity and mechanical property tests. Results show that (Mn + B) addition refines the α-Al dendrites. The α-Al phase and AlB2 particles function as heterogeneous nucleation particles to promote alloy nucleation, and the coarse dendrites are transformed into fine equiaxed crystals. The best effect is observed when 0.6 wt% Mn and 0.1 wt% B are added. (Mn + B) composite addition improves the morphology of the Fe-rich phase in the alloy and transforms the needle-like β-Fe phase into a dendritic Fe-rich phase and α-Fe phase. Furthermore, the grain refinement of the alloy and the improvement of the Fe-rich phase enhance the fluidity of the alloy. When 0.6 wt% Mn and 0.3 wt% B are added, the fluidity is the best, which is 77.5% higher than that without addition. (Mn + B) composite addition has minimal effect on the hardness of the alloy. The best mechanical properties are obtained upon the addition of 0.6 wt% Mn and 0.2 wt% B. In particular, the tensile strength and elongation are 235 MPa and 8.6%, respectively. These values are 40.1% and 100% higher than those obtained without addition, respectively. The fracture mode of the alloy also changes from ductile–brittle mixed fracture to ductile fracture. [ABSTRACT FROM AUTHOR]

Previously, wastewaters containing organic matter such as sulfur and other nitrogenous compounds were treated by employing separate biotechnologies. The current investigation investigated simultaneous carbon, nitrogen, and sulfur removal in single bioreactor under oxygen and oxygen deficient experimental conditions. Two separate bioreactors (aerobic and anaerobic) were operated under similar mesophilic conditions. It was revealed that the products of COD, nitrate, and sulfate mainly depended on the medium pH which was the main determining factor. The substrates ratios like C:N, C:S, and N:S could result in the diverse end products. Under aerobic conditions, COD completely degraded into CO2 and H2O, nitrate was anticipated to be converted as ammonium through dissimilatory nitrate reduction to ammonium which could become part of cellular metabolism. The bulk of sulfate was converted to elemental sulfur. While the results of anaerobic digestion showed that COD mainly contributed to methanogenesis, the COD conversion was lower as compared with the aerobic conversion. Nitrate was anticipated to be converted to nitrogen gas via denitrification. However, mass balance suggested lower amount of elemental sulfur formed as compared with aerobic treatment. Such information may help to understand complex nature of bacterial interactions employed in aerobic and anaerobic wastewater treatments. [ABSTRACT FROM AUTHOR]

Herein, six types of Al–7Si–xCu–0.35Mg–0.12Ti–0.24Zr–0.05Sr alloys were prepared with different Cu contents (x = 0, 1.8, 2.1, 2.4, 2.7, and 3.0). The effects of Cu addition and spheroidization treatment on the microstructure and mechanical properties of the alloys were examined. The findings demonstrated that the θ-Al2Cu phase tended to concentrate near the β-Al5FeSi phase. Furthermore, Cu could refine the grain and passivate the eutectic Si. Among the as-cast alloys, the mechanical properties were found to be optimal when the Cu content was 2.7 wt%, with ultimate tensile strength (UTS), yield strength (YS), and elongation (El) values measuring 251.1 MPa, 159.5 MPa, and 5.7%, respectively. Despite the decrease in El, the UTS and YS improved by 23.6% and 23.5%, respectively, compared to the C0 alloy. However, excessive Cu content aggregated and adhered to the massive θ-Al2Cu phases, weakening the mechanical characteristics of the alloy. In addition, the spheroidization treatment caused significant spheroidization in the eutectic Si and promoted a more uniform size distribution. This treatment also facilitated the transition of the solid solution of numerous θ-Al2Cu phase into a matrix, leading to a uniformly dispersed precipitation of Al–Si–Cu and Al–Cu phases. Consequently, the mechanical properties of the alloys were considerably enhanced. When the Cu content was 2.7 wt%, the UTS, YS, and El of the alloy were 301.9 MPa, 174.4 MPa, and 9.1%, respectively, representing increases of 20.2%, 9.3%, and 59.7% compared with those of the as-cast alloy. [ABSTRACT FROM AUTHOR]

In the present study, the effects of Mg, Cu, Sc and Zr combined additions on the microstructure and mechanical properties of hypoeutectic Al-Si cast alloy were systematically investigated. Characterization techniques such as optical microscopy (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), electron back-scatter diffraction (EBSD), atomic force microscopy (AFM), transmission electron microscope (TEM), Brinell hardness tester and universal testing machine were employed to analyze the microstructure and mechanical properties. The results showed that Sc served as modifier on the microstructure of Al-3Si-0.45Mg-0.45Cu-0.2Zr alloys, including modification of eutectic Si and grains. Extraordinarily, grain refinement was found to be related to the primary particles, which exhibited a close orientation to matrix. After T6 heat treatment, the grain structures were composed of nano-scaled secondary Al3(Sc, Zr) precipitates and spherical eutectic Si. Combined with T6 heat treatment, the highest hardness, yield strength, ultimate tensile strength and elongation were achieved in 0.56 wt.% Sc-modified alloy. Interestingly, the strength and ductility had a similar tendency. This paper demonstrated that combined additions of Mg, Cu, Sc and Zr could significantly improve the microstructure and performance of the hypoeutectic Al-Si cast alloy. [ABSTRACT FROM AUTHOR]

In this study, Al-6Si-0.6Mg-0.6Cu-0.2Cr alloys were prepared with the combined addition of (Ce+Yb) using the traditional ingot metallurgy method. The synergistic effects of (Ce+Yb) modification on the microstructure, including α-Al dendrites and eutectic Si phases, as well as the mechanical properties of Al-6Si-0.6Mg-0.6Cu-0.2Cr cast alloys were systematically investigated using differential scanning calorimetry (DSC), optical microscopy (OM), scanning electron microscopy (SEM), energy diffraction spectrum (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and mechanical tests. The results showed that the combined addition of (Ce+Yb) refined the α-Al grains and modified eutectic Si phases, with the combined addition of 0.6 wt% (Ce+Yb) exhibiting the best impacts on them. The Al11Ce3 and Al3Yb intermetallics were also obtained from the modification. Moreover, the Al11Ce3 and Al3Yb intermetallics functioned as strengthening precipitates and the eutectic Si phases were further spheroidized in the alloy during heat-treatment processing with the combined addition of (Ce+Yb). Coupled with heat treatment, the alloy with 0.6 wt% (Ce+Yb) exhibited enhanced mechanical properties with microhardness, ultimate tensile strength, yield strength and elongation of 89.4%, 114.1%, 183.9% and 208.0%, respectively, which were higher than those of the alloy without (Ce+Yb) modification and heat treatment. Notably, when the alloy was modified with the combined addition of (Ce+Yb), its strength significantly improved, whereas the elongation was not reduced and inversely was increased. [ABSTRACT FROM AUTHOR]

A new process for preparing fiber-reinforced silica sol shells for investment casting is proposed. The influence of fiber length on bending strength of shell is studied under the condition that fibers are not agglomerated or clustered. Polypropylene fibers were suspended under the action of air currents and adhered to the surface of shell with back-up slurry in the fiber placement device. Three millimeter and six millimeter lengths of fiber were used as reinforcing agents for the investment shell. The results showed that fibers could be placed uniformly on the surface of shell with slurry by air flowing in the fiber placement device, thereby enhancing the strength of the fiber-reinforced shell. Green bending strength of shell with additive of 6-mm-length fiber was higher than that of 3-mm-length fiber. This was due to the fact that the fibers were scattered into a reticular formation and the action of bridge connection between the longer fiber and matrix was stronger. Compared with the fiber of 3 mm length, the scanning electron microscope morphology of 6-mm-length fiber had typical characteristics on the fracture section of shell, which meant that fiber was pulled out from the shell with large mechanical force. [ABSTRACT FROM AUTHOR]