Design of FPGA-Implemented Reed-Solomon Erasure Code (RS-EC) Decoders With Fault Detection and Location on User Memory

Reed–Solomon erasure codes (RS-ECs) are widely used in packet communication and storage systems to recover erasures. When the RS-EC decoder is implemented on a field-programmable gate array (FPGA) in a space platform, it will suffer single-event upsets (SEUs) that can cause failures. In this article, the reliability of an RS-EC decoder implemented on an FPGA when there are errors in the user memory is first studied. Then, a fault detection and location scheme is proposed based on partial reencoding for the faults in the user memory of the RS-EC decoder. Furthermore, check bits are added in the generator matrix to improve the fault location performance. The theoretical analysis shows that the scheme could detect most faults with small missing and false detection probability. Experimental results on a case study show that more than 90% of the faults on user memory could be tolerated by the decoder, and all the other faults can be detected by the fault detection scheme when the number of erasures is smaller than the correction capability of the code. Although false alarms exist (with probability smaller than 4%), they can be used to avoid fault accumulation. Finally, the fault location scheme could accurately locate all the faults. The theoretical estimates are very close to the experiment results, which verifies the correctness of the analysis done.This work was supported in part by the National Natural Science Foundation of China under Grant 61501321, in part by the China Postdoctoral Science Foundation and Luoyang Newvid Technology Company, Ltd., and in part by the ACHILLES Project PID2019-104207RB-I00 funded by the Spanish Ministry of Science and Innovation

Synthesis of Biotin-Modified Galactosylated Chitosan Nanoparticles and Their Characteristics in Vitro and in Vivo

Background/Aims: Our previous study found that a nanoparticle drug delivery system that operates as a drug carrier and controlled release system not only improves the efficacy of the drugs but also reduces their side effects. However, this system could not efficiently target hepatoma cells. The aim of this study was to synthesize biotin-modified galactosylated chitosan nanoparticles (Bio-GC) and evaluate their characteristics in vitro and in vivo. Methods: Bio-GC nanomaterials were synthesized, and confirmed by fourier transform infrared spectroscopy (FT-IR) and hydrogen-1 nuclear magnetic resonance (1H-NMR). The liver position and cancer target property of Bio-GC nanoparticles in vitro and in vivo was tested by confocal laser and small animal imaging system. The characteristics of Bio-GC/5-fluorouracil (5-FU) nanoparticles in vitro and in vivo were explored by cell proliferation, migration and cytotoxicity test, or by animal experiment. Results: Bio-GC nanoparticles were synthesized with biodegradable chitosan as the nanomaterial skeleton with biotin and galactose grafts. Bio-GC was confirmed by FT-IR and 1H-NMR. Bio-GC/5-FU nanoparticles were synthesized according to the optimal mass ratio for Bio-GC/5-FU (1: 4) and had a mean particle size of 81.1 nm, zeta potential of +39.2 mV, and drug loading capacity of 8.98%. Bio-GC/5-FU nanoparticles had sustained release properties (rapid, steady, and slow release phases). Bio-GC nanoparticles targeted liver and liver cancer cell in vitro and in vivo, and this was confirmed by confocal laser scanning and small animal imaging system. Compared with GC/5-FU nanoparticles, Bio-GC/5-FU nanoparticles showed more specific cytotoxic activity in a dose- and time-dependent manner and a more obvious inhibitory effect on the migration of liver cancer cells. In addition, Bio-GC/5-FU nanoparticles significantly prolonged the survival time of mice in orthotopic liver cancer transplantation model compared with other 5-FU nanoparticles or 5-FU alone. Bio-GC (0.64%) nanomaterial had no obvious cytotoxic effects on cells; thus, the concentration of Bio-GC/5-FU nanoparticles used was only 0.04% and showed no toxic effects on the cells. Conclusion: Bio-GC is a liver- and cancer-targeting nanomaterial. Bio-GC/5-FU nanoparticles as drug carriers have stronger inhibitory effects on the proliferation and migration of liver cancer cells compared with 5-FU in vitro and in vivo

Impaired large-scale cortico–hippocampal network connectivity, including the anterior temporal and posterior medial systems, and its associations with cognition in patients with first-episode schizophrenia

Background and objectiveThe cortico–hippocampal network is an emerging neural framework with striking evidence that it supports cognition in humans, especially memory; this network includes the anterior temporal (AT) system, the posterior medial (PM) system, the anterior hippocampus (aHIPPO), and the posterior hippocampus (pHIPPO). This study aimed to detect aberrant patterns of functional connectivity within and between large-scale cortico–hippocampal networks in first-episode schizophrenia patients compared with a healthy control group via resting-state functional magnetic resonance imaging (rs-fMRI) and to explore the correlations of these aberrant patterns with cognition.MethodsA total of 86 first-episode, drug-naïve schizophrenia patients and 102 healthy controls (HC) were recruited to undergo rs-fMRI examinations and clinical evaluations. We conducted large-scale edge-based network analysis to characterize the functional architecture of the cortico–hippocampus network and investigate between-group differences in within/between-network functional connectivity. Additionally, we explored the associations of functional connectivity (FC) abnormalities with clinical characteristics, including scores on the Positive and Negative Syndrome Scale (PANSS) and cognitive scores.ResultsCompared with the HC group, schizophrenia patients exhibited widespread alterations to within-network FC of the cortico–hippocampal network, with decreases in FC involving the precuneus (PREC), amygdala (AMYG), parahippocampal cortex (PHC), orbitofrontal cortex (OFC), perirhinal cortex (PRC), retrosplenial cortex (RSC), posterior cingulate cortex (PCC), angular gyrus (ANG), aHIPPO, and pHIPPO. Schizophrenia patients also showed abnormalities in large-scale between-network FC of the cortico–hippocampal network, in the form of significantly decreased FC between the AT and the PM, the AT and the aHIPPO, the PM and the aHIPPO, and the aHIPPO and the pHIPPO. A number of these signatures of aberrant FC were correlated with PANSS score (positive, negative, and total score) and with scores on cognitive test battery items, including attention/vigilance (AV), working memory (WM), verbal learning and memory (Verb_Lrng), visual learning and memory (Vis_Lrng), reasoning and problem-solving (RPS), and social cognition (SC).ConclusionSchizophrenia patients show distinct patterns of functional integration and separation both within and between large-scale cortico–hippocampal networks, reflecting a network imbalance of the hippocampal long axis with the AT and PM systems, which regulate cognitive domains (mainly Vis_Lrng, Verb_Lrng, WM, and RPS), and particularly involving alterations to FC of the AT system and the aHIPPO. These findings provide new insights into the neurofunctional markers of schizophrenia

Cancer-associated fibroblasts are positively correlated with metastatic potential of human gastric cancers

<p>Abstract</p> <p>Background</p> <p>The prognosis of gastric cancer patients is difficult to predict because of defects in establishing the surgical-pathological features. Cancer-associated fibroblasts (CAFs) have been found to play prominent role in promoting tumor growth, invasion and metastasis. Thus raises the hypothesis that the extent of CAFs prevalence may help to establish the prognosis of gastric cancer patients.</p> <p>Methods</p> <p>Immunochemistry and realtime-PCR experiments were carried out to compare the expression of proteins which are specific markers of CAFs or secreted by CAFs in the tumor and normal tissue specimens. The extent of CAFs' prevalence was graded according to immunochemical staining, and correlation was further analyzed between CAFs' prevalence and other tumor characteristics which may influence the prognosis of gastric cancer patients.</p> <p>Results</p> <p>Nearly 80 percent of normal gastric tissues were negative or weak positive for CAFs staining, while more than 60 percent of gastric cancer tissues were moderate or strong positive for CAFs staining. Realtime-PCR results also showed significant elevated expression of FAP, SDF-1 and TGF-β1 in gastric cancer tissues compared to normal gastric tissues. Further analysis showed that CAFs' prevalence was correlated with tumor size, depth of the tumor, lymph node metastasis, liver metastasis or peritoneum metastasis.</p> <p>Conclusions</p> <p>Reactive cancer associated fibroblasts (CAFs) were frequently accumulated in gastric cancer tissues, and the prevalence of CAFs was correlated with tumor size, depth of the tumor and tumor metastasis, thus give some supports for establishing the prognosis of the gastric cancer patients.</p

Formation mechanism of financial vulnerability in rural China based on Markov model and countermeasures

As an important part of the national economy, finance plays a leading role in the configuration of the daily production life of urban and rural enterprises and residents. In order to promote the further development of China’s rural economy, deepen rural financial reform, and seek the formation mechanism and countermeasures of China’s rural financial vulnerability, this paper proposes a research method based on Markov model for analyzing the formation mechanism and countermeasures of China’s rural financial vulnerability. The results of the study show that the method effectively reveals an overall decreasing trend of rural financial vulnerability in China in recent years. In response, more reasonable rural financial institutions should be established to optimize the rural industrial structure and improve the ability to prevent rural financial risks, while conducting dynamic organizational management to ensure that the organizational structure and organizational management of rural finance must be compatible with the coordinated development of the rural economy and finance

EFFECT OF CRYPTOTANSHINONE ON APOPTOSIS OF LIVER CANCER CELLS AND ITS MECHANISM OF ACTION

Objective To investigate the effect of cryptotanshinone (CPT) on the apoptosis of HepG2 cells and the underlying mechanism. Methods The MTT assay was used to measure the effects of CPT at final concentrations of 0, 1, 5, 10, 20, 40, and 100 μmol/L on the viability of HepG2 cells. The median lethal concentration (IC50) of CPT for HepG2 cells was calculated. HepG2 cells were divided into groups A to D for 48 h culture with CPT at final concentrations of 0, 1, 5, and 10 μmol/L, respectively. The migration ability, mitochondrial membrane potential, and apoptosis rate of HepG2 cells were determined by wound healing assay, JC-1 staining, and flow cytometry, respectively. HepG2 cells were divided into groups E to H for culture with 0 μmol/L CPT+20 μmol/L Spautin-1, 1 μmol/L CPT+20 μmol/L Spautin-1, 5 μmol/L CPT+20 μmol/L Spautin-1, 10 μmol/L CPT+20 μmol/L Spautin-1, respectively. After 48 h culture, cell viability in groups E to H was measured by the MTT assay; LC3B-Ⅱ protein expression in groups A, D, and H was determined by Western blot; the mitochondrial membrane potential in groups A, D, E, and H was measured with JC-1 staining; and cell apoptosis in groups A, D, E, and H was measured by flow cytometry. Results With the increase of CPT concentrations, the viability of HepG2 cells was decreased significantly, with the IC50 value being 3.9 μmol/L after 48 h culture. As CPT concentrations increased, the migration ability of HepG2 cells was decreased significantly (t=5.96-29.63,P&lt;0.05); the green/red fluorescence ratio was increased significantly (t=4.24-23.36,P&lt;0.05); the apoptosis rate of HepG2 cells was increased significantly (t=7.30-18.15,P&lt;0.05). There was a significant difference in cell viability between groups A to H (F=231.15,P&lt;0.05), with higher cell viability in groups E-H than in groups A-D (t=3.96-18.80,P&lt;0.05). Group H showed significantly lower expression of the autophagy-related protein LC3B-Ⅱ than group D (t=3.51,P&lt;0.05). The JC-1 staining results showed that groups E and H significantly differed from group D in the green/red fluorescence ratio (t=3.58,14.76,P&lt;0.05). The results of apoptosis by flow cytometry showed significant differences between group E and group D as well as between group H and group D (t=12.38,4.99,P&lt;0.05). Conclusion CPT can effectively inhi-bit the viability of HepG2 cells through autophagy-mediated apoptosis

Chemokine CX3CL1 has potential anti-fibrosis effect in mouse liver fibrosis

Objective To explore the effect and mechanism of chemokine CX3CL1 on mouse liver fibrosis model. Methods C57BL/6 mice were randomly divided into CCl-4 model group and normal control group with 8 animals in each group. The model group was injected with 10% CCl-4 intra peritoneally for 6 weeks. After 6 weeks, the mice were sacrificed, and the pathological changes of the mouse liver were observed by HE staining. The level of CX3CL1 in peripheral blood of the mice was measured, and the expression level of CX3CL1 mRNA in the liver tissue of the mice was detected. In addition, in order to explore the mechanism of CX3CL1, the level of IFN-γ in mouse serum was detected as well. Results After the 6-week modeling, the liver pathology microscopy showed a successful modeling of liver fibrosis. The serum CX3CL1 level and liver tissue CX3CL1 expression in the model group were found to be significantly up-regulated, which suggested a potential impact on the pathogenesis of liver fibrosis. In addition, the level of IFN-γ in the serum of mice in the model group increased significantly. Conclusions CX3CL1 is related to liver fibrosis in mice, and its mechanism might be explained by promoting the production of IFN-γ so to prevent liver fibrosis

Microstructure and property of Ti2AlNb alloy by selective electron beam melting

Ti2AlNb based alloys is considered to be the most potential material material to replace the traditional Ni-based superalloys, because of its excellent high-temperature specific strength, creep resistance and high fracture toughness. Ti-22Al-25Nb alloy was fabricated by selective electron beam melting(SEBM), and the density of as-built samples reached 5.42-5.43 g/cm3through process optimization. The microstructure, phase evolution and mechanical property of the as-built and HIPed Ti2AlNb alloy samples were investigated. The results show that the microstructure of the as-built and HIPed samples both show the columnar crystalline structures along the deposition direction, which are all composed of B2, O and α2 phases, and the amount of O/α2 phase gradually increases from top to bottom. After HIP, the width and amount of the O/α2 phase are reduced and relatively uniform when compared with that of the as-built samples. In the bottom area, the microhardness of the as-built sample exhibits higher value of about (345.87±5.09)HV, while the hardness increases to 388.91-390.48HV after HIP. The ultimate tensile strength and elongation of the as-built sample at room temperature are (1061±23.71) MPa and (3.67±1.15)% respectively, and the ultimate tensile strength increases to (1101±23.07) MPa and the elongation reduces to 3.5% after HIP