Research on capacitance-coupled electrical impedance imaging fusion algorithm based on wavelet transform.

Capacitively Coupled Electrical Impedance Tomography (CCEIT), as a new electrical tomography method, effectively overcomes the drawbacks of traditional electrical resistance tomography that requires direct contact with liquids, so as to achieve non-contact measurement. In order to make full use of the complete electrical impedance information (real and imaginary) obtained by CCEIT and further improve the quality of image reconstruction, an image fusion algorithm based on wavelet transform was proposed. First, the Landweber algorithm is used to image the real part information and the imaginary part information, and the wavelet transform algorithm is used to decompose the two images at multiple scales, in which the low-frequency coefficient is fused by the improved logic filter algorithm based on the adaptive threshold, the high-frequency coefficient is selected based on the absolute value maximum method for fusion, and finally, the fused image is obtained by wavelet reconstruction. Numerical simulations and experiments verify the feasibility of the proposed method, and the results show that the relative error is reduced by up to 17% and the correlation coefficient is increased by up to 10%.

Oriented Growth of Neural Stem Cell-Derived Neurons Regulated by Magnetic Nanochains.

Neural stem cell therapy has become a promising cure in the treatment of neurodegenerative disorders. Owing to the anisotropy of the nervous system, the newly derived neurons need not only the functional integrity but also the oriented growth to contact with the partner cells to establish functional connections. So the oriented growth of the newly derived neurons is a key factor in neural stem cell-based nerve regeneration. Nowadays, various biomaterials have been applied to assist in the oriented growth of neural stem cell-derived neurons. However, among these biomaterials, the magnetic materials applied in guiding the neuronal growth are still fewer than the other materials, such as the fibers. So in this work, we developed the magnetic nanochains to guide the oriented growth of neural stem cell-derived neurons. With the guidance of the magnetic nanochains, the seeded neural stem cells exhibited a good arrangement, and the neural stem cell-derived neurons showed well-oriented growth with the orientation of the nanochains. We anticipated that the magnetic nanochains would have huge potential in stem cell-based nerve regeneration.

Tetrandrine Prevents Neomycin-Induced Ototoxicity by Promoting Steroid Biosynthesis.

Aminoglycoside antibiotics are widely used for the treatment of serious acute infections, life-threatening sepsis, and tuberculosis, but all aminoglycosides cause side effects, especially irreversible ototoxicity. The mechanisms underlying the ototoxicity of aminoglycosides need further investigation, and there are no effective drugs in the clinic. Here we showed that tetrandrine (TET), a bioactive bisbenzylisoquinoline alkaloid derived from Stephania tetrandra, ameliorated neomycin-induced cochlear hair cell injury. In both in vitro and in vivo experiments we found that TET administration significantly improved auditory function and reduced hair cell damage after neomycin exposure. In addition, we observed that TET could significantly decrease oxidative stress and apoptosis in hair cells after neomycin exposure. Finally, RNA-seq analysis suggested that TET protected against neomycin-induced ototoxicity mainly by promoting steroid biosynthesis. Collectively, our results provide pharmacological evidence showing that TET may be a promising agent in preventing aminoglycosides-induced ototoxicity.

Autophagy Regulates the Survival of Hair Cells and Spiral Ganglion Neurons in Cases of Noise, Ototoxic Drug, and Age-Induced Sensorineural Hearing Loss.

Inner ear hair cells (HCs) and spiral ganglion neurons (SGNs) are the core components of the auditory system. However, they are vulnerable to genetic defects, noise exposure, ototoxic drugs and aging, and loss or damage of HCs and SGNs results in permanent hearing loss due to their limited capacity for spontaneous regeneration in mammals. Many efforts have been made to combat hearing loss including cochlear implants, HC regeneration, gene therapy, and antioxidant drugs. Here we review the role of autophagy in sensorineural hearing loss and the potential targets related to autophagy for the treatment of hearing loss.

Genome-wide association study of COVID-19 severity among the Chinese population.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a broad clinical spectrum of coronavirus disease 2019 (COVID-19). The development of COVID-19 may be the result of a complex interaction between the microbial, environmental, and host genetic components. To reveal genetic determinants of susceptibility to COVID-19 severity in the Chinese population, we performed a genome-wide association study on 885 severe or critical COVID-19 patients (cases) and 546 mild or moderate patients (controls) from two hospitals, Huoshenshan and Union hospitals at Wuhan city in China. We identified two loci on chromosome 11q23.3 and 11q14.2, which are significantly associated with the COVID-19 severity in the meta-analyses of the two cohorts (index rs1712779: odds ratio [OR] = 0.49; 95% confidence interval [CI], 0.38-0.63 for T allele; P = 1.38 × 10-8; and index rs10831496: OR = 1.66; 95% CI, 1.38-1.98 for A allele; P = 4.04 × 10-8, respectively). The results for rs1712779 were validated in other two small COVID-19 cohorts in the Asian populations (P = 0.029 and 0.031, respectively). Furthermore, we identified significant eQTL associations for REXO2, C11orf71, NNMT, and CADM1 at 11q23.3, and CTSC at 11q14.2, respectively. In conclusion, our findings highlight two loci at 11q23.3 and 11q14.2 conferring susceptibility to the severity of COVID-19, which might provide novel insights into the pathogenesis and clinical treatment of this disease.

Genome-wide association study identifies new loci associated with noise-induced tinnitus in Chinese populations.

BACKGROUND: Tinnitus is an auditory phantom sensation in the absence of an acoustic stimulus, which affects nearly 15% of the population. Excessive noise exposure is one of the main causes of tinnitus. To now, the knowledge of the genetic determinants of susceptibility to tinnitus remains limited. RESULTS: We performed a two-stage genome-wide association study (GWAS) and identified that two single nucleotide polymorphisms (SNPs), rs2846071 located in the intergenic region at 11q13.5 (odds ratio [OR] = 2.14, 95% confidence interval [CI] = 1.96-3.40, combined P = 4.89 × 10- 6) and rs4149577 located in the intron of TNFRSF1A gene at 12p13.31 (OR = 2.05, 95% CI = 1.89-2.51, combined P = 6.88 × 10- 6), are significantly associated with the susceptibility to noise-induced tinnitus. Furthermore, the expression quantitative trait loci (eQTL) analyses revealed that rs2846071 is significantly correlated with the expression of WNT11 gene, and rs4149577 with the expression of TNFRSF1A gene in multiple brain tissues (all P < 0.05). The newly identified candidate gene WNT11 is involved in Wnt pathway, and TNFRSF1A in the tumor necrosis factor pathway, respectively. Pathway enrichment analyses also showed that these two pathways are closely relevant to tinnitus. CONCLUSIONS: Our findings highlight two novel loci at 11q13.5 and 12p13.31 conferring susceptibility to noise-induced tinnitus. and suggest that the WNT11 and TNFRSF1A genes might be the candidate causal targets of 11q13.5 and 12p13.31 loci, respectively.

Genome-wide association study identifies 7q11.22 and 7q36.3 associated with noise-induced hearing loss among Chinese population.

Noise-induced hearing loss (NIHL) seriously affects the life quality of humans and causes huge economic losses to society. To identify novel genetic loci involved in NIHL, we conducted a genome-wide association study (GWAS) for this symptom in Chinese populations. GWAS scan was performed in 89 NIHL subjects (cases) and 209 subjects with normal hearing who have been exposed to a similar noise environment (controls), followed by a replication study consisting of 53 cases and 360 controls. We identified that four candidate pathways were nominally significantly associated with NIHL, including the Erbb, Wnt, hedgehog and intraflagellar transport pathways. In addition, two novel index single-nucleotide polymorphisms, rs35075890 in the intron of AUTS2 gene at 7q11.22 (combined P = 1.3 × 10-6 ) and rs10081191 in the intron of PTPRN2 gene at 7q36.3 (combined P = 2.1 × 10-6 ), were significantly associated with NIHL. Furthermore, the expression quantitative trait loci analyses revealed that in brain tissues, the genotypes of rs35075890 are significantly associated with the expression levels of AUTS2, and the genotypes of rs10081191 are significantly associated with the expressions of PTPRN2 and WDR60. In conclusion, our findings highlight two novel loci at 7q11.22 and 7q36.3 conferring susceptibility to NIHL.

Case-based reasoning based on grey-relational theory for the optimization of boiler combustion systems.

Boiler combustion optimization is an important method to improve the flexibility of thermal power units and ensures the stability of unit operation. However, time-variability of boiler combustion systems and time-consuming optimization methods pose great challenges for the use of boiler combustion optimization techniques because many optimization methods cannot be used online in practical engineering due to time constraints. In this paper, we propose a case-based reasoning optimization method based on grey-relational theory (GR-CBR) for online optimization of a boiler combustion system. After the introduction of the proposed algorithm, we discuss the potential of applying the proposed GR-CBR optimization method to a boiler combustion system; a case study of an existing fossil fuel power plant is conducted to demonstrate the feasibility of the proposed method. A least-squares support vector machine (LS-SVM) model of the boiler combustion process is established by using the real-time operation data of a 350-MW coal-based power plant. Based on the model, a non-linear global optimization algorithm is proposed to obtain the optimal case base and real-time data mining and online optimization are used to achieve efficient and stable boiler combustion optimization. The results of combining offline optimization with online querying show that this approach is suitable for online real-time combustion optimization, and provides support for power plant operators for optimization and condition monitoring to improve boiler efficiency, reduce NOx emissions, and ensure stable and efficient operation of the power system.

Association of MCP-1 promoter polymorphism with susceptibility to nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is prevalent among populations from southern China and is influenced by both genetic and environmental risk factors. The monocyte chemoattractant protein-1 (MCP-1), a member of cysteine-cysteine chemokine family, plays critical roles in cancers. A polymorphism within the MCP-1 promoter, rs1024611, has been shown to be significantly associated with the risk of several cancers. Our purpose was to assess the role of rs1024611 in NPC susceptibility. By polymerase chain reaction-restriction fragment length polymorphism method, we genotyped rs1024611 in 593 patients with NPC (cases) and 480 cancer-free subjects (controls) among Guangxi population from southern China. We observed that the G allele of rs1024611 was significantly associated with the increased risk of NPC in an additive model and dominant model, respectively (P = 0.018 and 0.010, odds ratio = 1.25 and 1.41, respectively). No appreciable variation of the effects was found across the subgroups stratified by age, sex, nationality, smoking and drinking status, and smoking level. In addition, significantly higher messenger RNA (mRNA) expression level of MCP-1 was observed in NPC tissues than that in normal nasopharyngeal tissues, and the G allele of rs1024611 was significantly associated with elevated mRNA expression level of MCP-1 in Epstein-Barr virus-transformed lymphocytes. In conclusion, our findings suggested that rs1024611 at the MCP-1 promoter may be a risk factor for NPC. Further studies with larger sample size are necessary to confirm these findings.

Synthesis and self-assembly behavior of POSS-embedded hyperbranched polymers.

Here we demonstrate a simple and straightforward approach to prepare POSS-embedded hyperbranched (HB-POSS) polymers with customized molecular weights and sizes just by controlling the polymerization time. The polymers can be further used for building amphiphilic polymers, presenting morphological transition from micelle to vesicle in aqueous solution.

A biomimetic 3D microtubule-orientated poly(lactide-co-glycolide) scaffold with interconnected pores for tissue engineering.

An ideal tissue engineering scaffold should imitate physical and biochemical cues of natural extracellular matrix and have interconnected porous structures with high porosity to provide adequate space for cell seeding, growth and proliferation, as well as nutrient delivery and metabolized product elimination. In this study, we examined the feasibility of fabricating microtubule-orientated poly(lactide-co-glycolide) (PLGA) scaffolds with interconnected pores (denoted as MOIP-PLGA) by an improved thermal-induced phase separation technique. We successfully constructed MOIP-PLGA using 1,4-dioxane as the first solvent and benzene or water with lower freezing point as the second solvent. Especially, when water was used, the MOIP-PLGA had higher porosity and it could guide rabbit aortic smooth muscle cells (SMCs) to better grow along the microtubule direction of the scaffold. Comparing with microtubule-orientated scaffold without interconnected pores (denoted as MONIP-PLGA), the proliferation and viability of SMCs cultured on MOIP-PLGA were higher. Moreover, basic fibroblast growth factor could be effectively bound on MOIP-PLGA by a plasma treatment technique and the growth factor could be slowly released in vitro, maintaining bioactivity.

Hyperexcitability of inferior colliculus neurons caused by acute noise exposure.

Noise exposure is one of the most common causes of hearing loss. Recent studies found that noise exposure-induced cochlear damage may change the excitability and tonotopic organization of the central auditory system (CAS). This plasticity was suspected to be related to tinnitus and hyperacusis. However, how cochlear damage affects CAS function and causes these neurologic diseases is still not clear. CAS function is activity dependent, so we hypothesize that a restricted cochlear lesion might disrupt the balance of excitation and inhibition in the CAS and thereby affect its neural activity. To test this hypothesis, we studied the effects of narrow-band noise exposure on the firing properties of neurons in the inferior colliculus (IC), which has complex neural circuits and plays an important role in sound processing. We found that noise exposure (20 kHz, 105 dB SPL, 30 min) caused a dramatic decrease of the characteristic frequency in about two-thirds of high-frequency neurons with/without causing a significant threshold shift. The noise exposure also caused an increase in firing rate of the low-frequency neurons at suprathreshold levels, whereas it dramatically decreased the firing rate of the high-frequency neurons. Our results suggest that acute high-frequency noise exposure may increase low-frequency responsiveness by causing hyperexcitability of low-frequency neurons. The functional change of the low-frequency neurons may be related to the disruption of side-band inhibition at the noise exposure frequencies caused by cochlear damage.

Interaction of a calcium channel blocker with noise in cochlear function in guinea pig.

CONCLUSIONS: Both nifedipine and noise exposure had damaging effects on cochlear function. These damaging effects were subtractive rather than additive, suggesting that calcium channel blockers may have a protective role in noise-induced hearing loss. OBJECTIVE: We assessed the interaction of nifedipine, a calcium channel blocker, with noise in cochlear function by evaluating changes in the compound action potential (CAP) threshold after the administration of nifedipine with or without noise exposure. METHODS: Eighty guinea pigs were randomly assigned to eight groups based on those with cochlear perfusion with nifedipine only (0, 0.15, 0.5, and 3 µM, groups 1-4) and noise exposure (groups 5-8). CAP thresholds were recorded using a round window electrode before and 120 min after cochlear perfusion. RESULTS: Cochlear perfusion of different concentrations of nifedipine caused 2.5, 5.5, 28, and 21.5 dB SPL threshold shift, respectively, at 0, 0.15, 0.5, and 3 µM concentrations (groups 1-4). In comparison, the CAP thresholds after nifedipine perfusion with noise exposure were 43.5, 46.5, 20, and 21.5 dB SPL, respectively, in groups 5-8.