Effects of aspect ratio on laboratory simulation of tornado-like vortices

Zhuo Tang,Delong Zuo,Darryl James,Yuzuru Eguchi,Yasuo Hattori 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.27 No.2

Experiments were conducted in a large-scale Ward-type tornado simulator to study tornado-like vortices. Both flow velocities and the pressures at the surface beneath the vortices were measured. An interpretation of these measurements enabled an assessment of the mean flow field as well as the mean and fluctuating characteristics of the surface pressure deficit, which is a manifestation of the flow fluctuation aloft. An emphasis was placed on the effect of the aspect ratio of the tornado simulator on the characteristics of the simulated flow and the corresponding surface pressure deficit, especially the evolution of these characteristics due to the transition of the flow from a single-celled vortex to a two-celled vortex with increasing swirl ratio.

Bisphenol A and the related alkylphenol contaminants in crustaceans and their potential bioeffects

Zuo, Yuegang,Zhu, Zhuo,Alshanqiti, Mohammed,Michael, Joseph,Deng, Yiwei Techno-Press 2015 Advances in environmental research Vol.4 No.1

Bisphenol A is widely used in plastic and other industrial consumer products. Release of bisphenol A and its analogues into the aquatic environment during manufacture, use and disposal has been a great scientific and public concern due to their toxicity and endocrine disrupting effects on aquatic wildlife and even human beings. More recent studies have shown that these alkylphenols may affect the molting processes and survival of crustacean species such as American lobster, crab and shrimp. In this study, we have developed gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometric (GC-MS) methods for the determination of bisphenol A and its analogues in shrimp Macrobrachium rosenbergii, blue crab Callinectes sapidus and American lobster Homarus americanus samples. Bisphenol A, 2,4-bis-(dimethylbenzyl)phenol and 4-cumylphenol were found in shrimp in the concentration ranges of 0.67-5.51, 0.36-1.61, and < LOD (the limit of detection)-1.96 ng/g (wet weight), and in crab of 0.10-0.44, 0.13-0.62, and 0.26-0.58 ng/g (wet weight), respectively. In lobster tissue samples, bisphenol A, 2-t-butyl-4-(dimethylbenzyl)phenol, 2,6-bis-(t-butyl)-4-(dimethylbenzyl)phenol, 2,4-bis-(dimethybenzyl)phenol, 2,4-bis-(dimethylbenzyl)-6-t-butylphenol and 4-cumylphenol were determined at the concentration ranges of 4.48-7.01, 1.23-2.63, 2.71-9.10, 0.35-0.91, 0.64-3.25, and 0.44-1.00 ng/g (wet weight), respectively. At these concentration levels, BPA and its analogs may interfere the reproduction and development of crustaceans, such as larval survival, molting, metamorphosis and shell hardening.

Effects of aspect ratio on laboratory simulation of tornado-like vortices

Tang, Zhuo,Zuo, Delong,James, Darryl,Eguch, Yuzuru,Hattori, Yasuo Techno-Press 2018 Wind and Structures, An International Journal (WAS Vol.27 No.2

Experiments were conducted in a large-scale Ward-type tornado simulator to study tornado-like vortices. Both flow velocities and the pressures at the surface beneath the vortices were measured. An interpretation of these measurements enabled an assessment of the mean flow field as well as the mean and fluctuating characteristics of the surface pressure deficit, which is a manifestation of the flow fluctuation aloft. An emphasis was placed on the effect of the aspect ratio of the tornado simulator on the characteristics of the simulated flow and the corresponding surface pressure deficit, especially the evolution of these characteristics due to the transition of the flow from a single-celled vortex to a two-celled vortex with increasing swirl ratio.

Bisphenol A and other alkylphenols in the environment - occurrence, fate, health effects and analytical techniques

Zhu, Zhuo,Zuo, Yuegang Techno-Press 2013 Advances in environmental research Vol.2 No.3

Bisphenol A and other alkylphenols are widely used in plastic and other industrial consumer products. Release of these compounds into the aquatic environment during their manufacture, use and disposal has been a great scientific and public concern due to their toxicity at high concentrations and endocrine disrupting effects at low concentration on aquatic wildlife and human beings. This paper reviews the published data and researches on the environmental occurrence, distribution, health effects and analytical techniques of bisphenol A and alkylphenols. The aim is to provide an overview of the current understanding about bisphenol A and alkylphenols in the environment and the difficulties faced today in order to establish standard and systematic environmental analysis and assessment process for these endocrine disruptor compounds.

Nrf2 in adipocytes

Zhendi Wang,Zhuo Zuo,Lu Li,Suping Ren,Tianchang Gao,Jingqi Fu,Yongyong Hou,Yanyan Chen,Jingbo Pi 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.3

White adipocytes play a key role in maintainingwhole body energy homeostasis by forming white adiposetissue (WAT). The impairment of WAT formation or WATdysfunction is clearly associated with severe metabolic disorders. Mature adipocytes are derived from differentiatedpreadipocytes and are pivotal in energy storage and metabolism. Nuclear factor erythroid 2-related factor 2 (Nrf2) isa member of a family of CNC-bZIP proteins which exerttheir transcriptional control on genes harboring antioxidantresponse elements (ARE) in partnership with smallmusculoaponeurotic fibrosarcoma proteins. The activationof Nrf2-ARE coordinated by specific repressor Kelch-likeECH-associated protein 1 (Keap1) regulates networks ofgenes controlling diverse homeostatic processes involvingadaptive antioxidant response and detoxification amongmany other adaptive responses. Interestingly, accumulatingevidence indicates that Nrf2 may act as a transcription factorin regulating the formation and function of adipose tissues,including adipogenesis, lipid metabolism and insulin sensitivity. In this mini-review, an overview on the distinct rolesof Nrf2 in adipocytes is provided. While highlighting the regulatory role of Nrf2 in adipogenesis, recent key findingson Nrf2 in insulin signal transduction and energy metabolismof adipocytes are also summarized.

Ursolic Acid-induced Apoptosis in K562 Cells Involving Upregulation of PTEN Gene Expression and Inactivation of the PI3K/Akt Pathway

Bin Wu,Zhuo-gang Liu,Xu Wang,Zuo-fei Chi,Rong Hu,Rong Zhang,Wei Yang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.3

Ursolic acid (UA), a pentacyclic triterpenoid derived from a variety of medicinal plants, exhibits potent anticancer activity against many types of cancer cells. However, the anticancer mechanism of UA is not clearly understood. Suppression of phosphatase and a tensin homolog deleted on chromosome 10 (PTEN) gene expression leading to activation of the phosphatidylinositol-3-OH kinase (PI3K)/Akt pathway has been observed in many cancers including leukemia, making the PTEN gene and PI3K/Akt pathway a central target for cancer therapy. Here, we demonstrated that UA was able to inhibit growth, induce apoptosis in a human chronic myelogenous leukemia cell line (K562 cells) via upregulation of PTEN gene expression, inhibit Akt kinase activity, change mitochondrial transmembrane potential and reduce the release of cytochrome c and the activity of caspases. These results suggest that UA may elicit its strong antitumor effects via upregulation of the PTEN gene and inhibition of the PI3K/Akt pathway.

Discrimination of neutrons and gamma-rays in plastic scintillator based on spiking cortical model

Liu Bing-Qi,Liu Hao-Ran,Chang Lan,Cheng Yu-Xin,Zuo Zhuo,Li Peng 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.9

In this study, a spiking cortical model (SCM) based n-g discrimination method is proposed. The SCMbased algorithm is compared with three other methods, namely: (i) the pulse-coupled neural network (PCNN), (ii) the charge comparison, and (iii) the zero-crossing. The objective evaluation criteria used for the comparison are the FoM-value and the time consumption of discrimination. Experimental results demonstrated that our proposed method outperforms the other methods significantly with the highest FoM-value. Specifically, the proposed method exhibits a 34.81% improvement compared with the PCNN, a 50.29% improvement compared with the charge comparison, and a 110.02% improvement compared with the zero-crossing. Additionally, the proposed method features the second-fastest discrimination time, where it is 75.67% faster than the PCNN, 70.65% faster than the charge comparison and 38.4% slower than the zero-crossing. Our study also discusses the role and change pattern of each parameter of the SCM to guide the selection process. It concludes that the SCM's outstanding ability to recognize the dynamic information in the pulse signal, improved accuracy when compared to the PCNN, and better computational complexity enables the SCM to exhibit excellent n-g discrimination performance while consuming less time.