Granulation of Activated Sludge in a Continuous Flow Airlift Reactor by Strong Drag Force

Dandan Zhou,Mengyuan Liu,Jun Wang,Shuangshi Dong,Ning Cui,Linlin Gao 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

Most aerobic granule cultivation has been based on the sequencing batch reactor (SBR) and then the factors that affect aerobic granulations were developed in the SBR. However, little work has been done to cultivate aerobic granules in a continuous-flow bioreactor with simple structure that is realistic for engineering. This work is the first to cultivate aerobic granules in a continuous flow airlift fluidized bed reactor (CAFB) possesses a very simple structure and without settling time and starvation time controlling. The configuration of CAFB was the simplest continuous-flow aerobic granular bioreactor reported by now. The majority of granules could be formatted in the CAFB after 12 days cultivation. The effluent COD concentration maintained at 50 ± 10 mg/L for the variable COD loading rate of 3.5 g COD/L/d and 4.8 g COD/L/d, which confirmed that the CAFB performed good anti-shock abilities. CAFB performed good nitrification ability, however, little denitrification was found under the operating conditions of this study. The shear stress acting on the solid phase were hundreds of times stronger in the CAFB than in the SBR at the same aeration strength. It seems CAFB is very efficient for granulation due to the strong shear-force exertion,which is promising for continuous-flow aerobic granular bioreactor. Protein, positive to the hydrophobicity, was predominant in extracellular polymeric substances in the granules, and favored the granules formation in the CAFB combined with the polysaccharides. However, filamentous bulking always happened in 35 days operation of the CAFB, thus further study on the stability of this bioreactor is urgently necessary.

The Impacts of Childhood Trauma on Psychosocial Features in a Chinese Sample of Young Adults

Dandan Wang,Shaojia Lu,Weijia Gao,Zhaoguo Wei,Jinfeng Duan,Shaohua Hu,Manli Huang,Yi Xu,Lingjiang Li 대한신경정신의학회 2018 PSYCHIATRY INVESTIGATION Vol.15 No.11

Objective The aims of the present study were to explore the occurrence of childhood trauma and importantly to determine the impacts of childhood trauma on psychosocial features in a Chinese sample of young adults. Methods A survey was carried out in a group of 555 university students by using Childhood Trauma Questionnaire (CTQ), Self-rating Depression Scale (SDS), Self-rating Anxiety Scale (SAS), Dysfunctional Attitudes Questionnaire (DAS), Eysenck Personality Questionnaire (EPQ), and Social Support Rating Scale (SSRS). The moderate-severe cut-off scores for CTQ were used to calculate the prevalence of childhood trauma, and then psychosocial features were compared between individuals with and without childhood trauma. Results A proportion of 18.6% of university students had self-reported childhood trauma exposures. Subjects with childhood trauma reported higher scores of SDS, SAS, DAS, and psychoticism and neuroticism dimensions of EPQ (t=4.311–5.551, p<0.001); while lower scores of SSRS and extraversion dimension of EPQ (t=-4.061– -3.039, p<0.01). Regression analyses further revealed that scores of SAS and DAS were positively (Adjusted B=0.211–0.230, p<0.05), while scores of SSRS were negatively (Adjusted B=-0.273– -0.240, p<0.05) associated with specific CTQ scores. Conclusion Childhood trauma is still a common social and psychological problem. Individuals with childhood trauma show much more depression, anxiety, distorted cognition, personality deficits, and lower levels of social support, which may represent the social and psychological vulnerability for developing psychiatric disorders after childhood trauma experiences.

TEOA, a triterpenoid from Actinidia eriantha, induces autophagy in SW620 cells via endoplasmic reticulum stress and ROS-dependent mitophagy

Dandan Zhang,Cuixia Gao,Ruyi Li,Lin Zhang,Jingkui Tian 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.5

2a,3a,24-Thrihydroxyurs-12-en-28-oicacid (TEOA),a pentacyclic triterpenoid, isolated from the roots of Actinidiaeriantha, exhibits significant cytotoxicity against SW620, BGC-823, HepG-2, A549 and PC-3 cancer cells. In this study, weinvestigated the underlying molecular mechanism of the anticanceractivity of TEOA in SW620 cells.We demonstrated thatTEOA induced apoptosis through cleavage of caspase-9 andPARP in SW620 cells. In addition, evidence of TEOA-mediatedautophagy included the induction of autophagolysosomesand activation of autophagic markers LC-3B and p62. Furtheranalysis illustrated that TEOA promoted the phosphorylation ofPERK and elF2a, followed by up-regulation of the downstreamprotein CHOP, suggesting the involvement of PERK/eIF2a/CHOP pathway and ER stress in TEOA-induced autophagy inSW620 cells. Meanwhile, TEOA-mediated PINK1, Parkin,ubiquitin and p62 activation revealed that TEOA inducedspecific autophagy-mitophagy in SW620 cells. Additionally, anantioxidant NAC attenuated the TEOA-induced mitophagy,indicating that TEOA triggers mitophagy via a ROS-dependentpathway. Collectively, our findings revealed a novel cellularmechanism of TEOA in the colon cancer cell line SW620, thusproviding a molecular basis for developing TEOA into an antitumorcandidate.

Mean-square Exponential Stability of Impulsive Stochastic Time-delay Systems with Delayed Impulse Effects

Lijun Gao,Dandan Wang,Yingying Cai 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.3

This paper is concerned with the mean-square exponential stability problem for a class of impulsivestochastic systems with delayed impulses. The delays exhibit in both continuous subsystem and discrete subsystem. By constructing piecewise time-varying Lyapunov functions and Razumikhin technique, sufficient conditions arederived which guarantee the mean-square exponential stability for impulsive stochastic delay system. It is shownthat the obtained stability conditions depend both on the lower bound and the upper bound of impulsive intervals,and the stability of system is robust with regard to sufficiently small impulse input delays. Finally, two examplesare proposed to verify the efficiency of the proposed results.

Hearing Improvement in A/J Mice via the Mouse Nerve Growth Factor

Lixiang Gao,Ruli Ge,Gang Xie,Dandan Yao,Ping Li,Oumei Wang,Xiufang Ma,Fengchan Han 대한이비인후과학회 2017 Clinical and Experimental Otorhinolaryngology Vol.10 No.4

Objectives. To investigate the otoprotective effects of mouse nerve growth factor (mNGF) in A/J mice. Methods. The mice at postnatal day 7 (P7) were randomly separated into a mNGF treated group (mNGF group) and a distilled water (for injection) treated group (control group). The mNGF dissolved in distilled water or distilled water alone was given to the mice once every other day from P7 by intramuscular injection in the hips. The otoprotective effects of mNGF in A/J mice were observed in a time course manner. The thresholds of auditory-evoked brainstem response (ABR) were tested from the age of the 3rd to the 8th week. Sections of the inner ears were stained by hematoxylin and eosin, and spiral ganglion neurons (SGNs) were observed at the age of the 3rd, the 6th, and the 8th week. Counts of whole mount outer hair cells (OHCs) in the cochleae were made at the age of 8 weeks. Expression of apoptosis related genes was determined by quantitative real-time polymerase chain reaction and Western blotting. Results. ABR thresholds of the mNGF group were significantly lower than those of the control group at the age of the 6th and the 8th week. Moreover, the mNGF preserved OHC and SGN in the mouse cochleae in this period. Further experiments showed that the expression of caspase genes (including caspase-3) was inhibited in the mouse inner ears in the mNGF group. Conclusion. The mNGF improves hearing in A/J mice by preserving SGN and OHC in the cochleae.

Parameter Optimization Based on Evolutionary Algorithms for Green Cognitive Radio

Hongyuan Gao,Dandan Liu,Yanan Du 한국산학기술학회 2015 SmartCR Vol.5 No.5

In this paper, we study parameter adjustments that maximize the energy efficiency of green cognitive radio. Because the problem of parameter adjustments for green cognitive radio can be looked at as a complex discrete optimization problem, evolutionary algorithms can be applied to solve it. Parameter optimization methods based on quantum genetic algorithm (QGA), particle swarm optimization (PSO), and chaotic quantum particle swarm optimization (CQPSO) are designed. In particular, CQPSO integrates the characteristics of chaos with quantum particle swarm optimization (QPSO), which gives it strong global search abilities. Chaotic mutation is introduced into the proposed CQPSO to avoid premature convergence and keep diversity in populations. Quantum computing has excellent features used to increase optimization speed and enhance the search abilities of the algorithm. The proposed CQPSO method provides good performance in terms of convergence rate and convergence accuracy, and can search for an optimal solution to parameter adjustments in green cognitive radio networks. Through simulations comparing it to QGA and PSO, we conclude that the proposed CQPSO can improve energy efficiency and meet users’ quality of service needs.

SYNTHESIS AND ORGANIZATION OF PLATINUM NANOPARTICLES AND NANOSHELLS ON A NATIVE VIRUS BIOSCAFFOLD

LI HOU,FAMING GAO,DANDAN TONG,YANG JIANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.6

A wild type virion, bacteriophage T4, was used as an organic template for the controlled synthesisand organization of Pt nanoparticles and nanoshells on its capsid. A long incubation of T4 virionswith the metalchloride solution is necessary to the speci¯c binding of the external surface of T4capsid with Pt IV by means of interactions between Pt IV and the chemical functionality foundinherently on the surface of the proteinaceous viral capsid. After chemical reduction with dime-thylaminoborane (DMAB), the highly dispersive Pt nanoparticles with a uniform size of 3 – 4 nmwere synthesized and covered the whole viral capsid. The packing density of Pt nanoparticles wasenhanced by increasing the incubation cycles of the virions in metal salt solution. Moreover,Pt@T4 shell/core structures could be achieved by increasing the amount of metal ions aroundvirons. UV/vis spectroscopy was used to follow the course of the reaction, and the formationmechanism was discussed. Both the small Pt nanoparticles and Pt@T4 shell/core structures showhigh electrocatalytic activity in electrochemical measurement, and therefore are expected to havepotential applications in electrocatalysis.

Expression profile and estrogenic regulation of Amh during gonadal sex differentiation in northern snakehead (Channa argus)

Qing Luo,Mi Ou,Jian Zhao,Haiyang Liu,Dandan Gao,Yanduo Wu,Lanlan Zhang,Kunci Chen 한국유전학회 2020 Genes & Genomics Vol.42 No.7

Background Anti-Müllerian hormone (Amh) plays a critical role in both early sex determination and later gonad development in vertebrate species. However, it remains unknown in northern snakehead (Channa argus), which is economically important freshwater fish with sexual dimorphism. Objective This study aimed to identify the expression profiles and estrogenic regulation of CaAmh during gonadal sex differentiation in C. argus. Methods The cDNA and genomic DNA sequences of CaAmh were identified by PCR and RACE techniques. The expression patterns of CaAmh were detected by qRT-PCR during the gonadal sex differentiation and after 17α-ethinyloestradiol (EE2) treatments. Results CaAmh is composed of seven exons and six introns, and its full-length cDNA is 2413 bp in length, with 1635 bp open reading frame (ORF) that encodes a 544 amino acid protein. Tissues expression patterns revealed that CaAmh display the highest expression in testis of XY males (40.36 folds, p < 0.01). The spatio-temporal expression patterns during gonadal sex differentiation indicated that CaAmh expression differed between XX females and XY males at 30 day after hatching (dah), and reached to the peak (36.03 folds, p < 0.01) at 90 dah in XY gonads. However, CaAmh expression in XX gonads remained low throughout the sampling period. Furthermore, CaAmh expression in the gonads (ovaries) of the sex-reversed XY fish (XY-F) by the administration of estrogen EE2 was downregulated to low level, similar to that in ovaries of normal XX females (XX-F). Conclusions These results show that Amh plays a critical role in testicular differentiation of C. argus and it is apparently modulated by estrogens in this species.