42 results on '"Zhibing Zhan"'
Search Results
2. Manipulation of charge transfer and transport in plasmonic-ferroelectric hybrids for photoelectrochemical applications
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Zhijie Wang, Dawei Cao, Liaoyong Wen, Rui Xu, Manuel Obergfell, Yan Mi, Zhibing Zhan, Nasori Nasori, Jure Demsar, and Yong Lei
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Science - Abstract
Photoelectrochemical systems based on plasmonics require control of band bending at the interface as well as transport of hot carriers. Here, Wang et al. employ a ferroelectric material, Pb(Zr,Ti)O3, with gold on ITO to capture hot electrons from the metal and manipulate the photoexcited charges for energy conversion.
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- 2016
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3. Robust mold fabricated by femtosecond laser pulses for continuous thermal imprinting of superhydrophobic surfaces
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Zhibing Zhan, Erik M Garcell, and Chunlei Guo
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superhydrophobic ,thermoplastic imprinting ,polymer ,pulsed-laser ablation ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Chemical technology ,TP1-1185 - Abstract
Superhydrophobic surfaces rely on a large number of surface micro/nano structures to increase the roughness of a material. Producing such structures is possible through a multitude of relatively slow methods; however, economic and large scale production of superhydrophobic surfaces require using a fast process on a cheap substrate. Here, we used femtosecond laser processing to fabricate micro and nanostructures on tungsten carbide that we use as a mold to thermally imprint polypropylene sheets. The fabricated tungsten carbide mold was used to imprint more than twenty superhydrophobic polypropylene sheets before mold contamination reduces the surface contact angle below 150°. Using Toluene solution, the mold is subsequently capable of being cleaned of contamination from polypropylene residue and reused for further imprinting. Ninety thermoplastic imprints were conducted using a single tungsten carbide mold with only minimal structural degradation apparent on the micro/nano structured surface.
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- 2019
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4. Eco-Friendly Fungal Chitosan-Silica Dual-Shell Microcapsules with Tailored Mechanical and Barrier Properties for Potential Consumer Product Applications
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Daniele Baiocco, Mohammed Al-Sharabi, Benjamin T. Lobel, Olivier J. Cayre, Alexander F. Routh, and Zhibing Zhang
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Chemistry ,QD1-999 - Published
- 2024
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5. Research on and Application of Feature Recognition and Intelligent Retrieval Method for Multi-Component Alloy Powder Injection Molding Gear Based on Partition Templates
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Yan Kong, Xiaoyi Cui, Zhibing Zhang, and Yuqi Liu
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multi-alloy gear ,MIM ,forming process ,automatic identification ,intelligent retrieval ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The forming process of multi-alloy gears by metal powder injection molding is tedious, and the current design process mainly depends on the experience of designers, which seriously affects the product development cycle and forming quality. In order to solve the problem of the gear feature expression being missing, which hinders the automatic retrieval of similar parts in the analogical design process, a feature recognition and intelligent retrieval method for a multi-alloy powder injection molding gear based on partition templates is proposed in this paper. The partition templates of the gear are defined, and gear digitization is completed by using the automatic recognition algorithm. Searching for similar gear parts in the knowledge base, designers can analogically design the forming process for new parts according to the mature process of the parts in the knowledge base. The automatic identification and intelligent retrieval system developed according to this method has been implemented in two MIM (metal injection molding) product manufacturing enterprises. Case studies and industrial applications have proved the effectiveness of the system, the efficiency of identification and retrieval has been improved by more than 97%, and the number of mold tests has been reduced by 60%.
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- 2024
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6. Debiased ambient vibrations optical coherence elastography to profile cell, organoid and tissue mechanical properties
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Jonathan H. Mason, Lu Luo, Yvonne Reinwald, Matteo Taffetani, Amelia Hallas-Potts, C. Simon Herrington, Vlastimil Srsen, Chih-Jen Lin, Inês A. Barroso, Zhihua Zhang, Zhibing Zhang, Anita K. Ghag, Ying Yang, Sarah Waters, Alicia J. El Haj, and Pierre O. Bagnaninchi
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Biology (General) ,QH301-705.5 - Abstract
Abstract The role of the mechanical environment in defining tissue function, development and growth has been shown to be fundamental. Assessment of the changes in stiffness of tissue matrices at multiple scales has relied mostly on invasive and often specialist equipment such as AFM or mechanical testing devices poorly suited to the cell culture workflow.In this paper, we have developed a unbiased passive optical coherence elastography method, exploiting ambient vibrations in the sample that enables real-time noninvasive quantitative profiling of cells and tissues. We demonstrate a robust method that decouples optical scattering and mechanical properties by actively compensating for scattering associated noise bias and reducing variance. The efficiency for the method to retrieve ground truth is validated in silico and in vitro, and exemplified for key applications such as time course mechanical profiling of bone and cartilage spheroids, tissue engineering cancer models, tissue repair models and single cell. Our method is readily implementable with any commercial optical coherence tomography system without any hardware modifications, and thus offers a breakthrough in on-line tissue mechanical assessment of spatial mechanical properties for organoids, soft tissues and tissue engineering.
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- 2023
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7. Femtosecond-Laser-Produced Underwater "Superpolymphobic" Nanorippled Surfaces: Repelling Liquid Polymers in Water for Applications of Controlling Polymer Shape and Adhesion.
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Jiale Yong, Singh, Subhash C., Zhibing Zhan, Mohamed EIKabbash, Feng Chen, and Chunlei Guo
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- 2019
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8. DNALI1 interacts with the MEIG1/PACRG complex within the manchette and is required for proper sperm flagellum assembly in mice
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Yi Tian Yap, Wei Li, Qian Huang, Qi Zhou, David Zhang, Yi Sheng, Ljljiana Mladenovic-Lucas, Siu-Pok Yee, Kyle E Orwig, James G Granneman, David C Williams Jr, Rex A Hess, Aminata Toure, and Zhibing Zhang
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DNALI1 ,manchette ,cargo transport ,spermatogenesis ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
The manchette is a transient and unique structure present in elongating spermatids and required for proper differentiation of the germ cells during spermatogenesis. Previous work indicated that the MEIG1/PACRG complex locates in the manchette and is involved in the transport of cargos, such as SPAG16L, to build the sperm flagellum. Here, using co-immunoprecipitation and pull-down approaches in various cell systems, we established that DNALI1, an axonemal component originally cloned from Chlamydomonas reinhardtii, recruits and stabilizes PACRG and we confirm in vivo, the co-localization of DNALI1 and PACRG in the manchette by immunofluorescence of elongating murine spermatids. We next generated mice with a specific deficiency of DNALI1 in male germ cells, and observed a dramatic reduction of the sperm cells, which results in male infertility. In addition, we observed that the majority of the sperm cells exhibited abnormal morphology including misshapen heads, bent tails, enlarged midpiece, discontinuous accessory structure, emphasizing the importance of DNALI1 in sperm differentiation. Examination of testis histology confirmed impaired spermiogenesis in the mutant mice. Importantly, while testicular levels of MEIG1, PACRG, and SPAG16L proteins were unchanged in the Dnali1 mutant mice, their localization within the manchette was greatly affected, indicating that DNALI1 is required for the formation of the MEIG1/PACRG complex within the manchette. Interestingly, in contrast to MEIG1 and PACRG-deficient mice, the DNALI1-deficient mice also showed impaired sperm spermiation/individualization, suggesting additional functions beyond its involvement in the manchette structure. Overall, our work identifies DNALI1 as a protein required for sperm development.
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- 2023
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9. Fluorescence enhanced lab-on-a-chip patterned using a hybrid technique of femtosecond laser direct writing and anodized aluminum oxide porous nanostructuring.
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Zhi Yu, Yuhao Lei, Weili Yu, Jinluo Cheng, Jun Xing, Xin Zheng, Zhibing Zhan, Bin Wang, and Chunlei Guo
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- 2019
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10. Whole-Exome Sequencing Identifies the VHL Mutation (c.262T > C, p.Try88Arg) in Non-Obstructive Azoospermia-Associated Cystic Renal Cell Carcinoma
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Yonghong Man, Xuejun Shang, Chunyu Liu, Wei Zhang, Qian Huang, Suheng Ma, Rita Shiang, Feng Zhang, Ling Zhang, and Zhibing Zhang
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renal cell carcinoma ,von Hippel-Lindau syndrome ,non-obstructive azoospermia ,VHL ,pVHL ,microtubule ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Von Hippel-Lindau (VHL) genes are intimately involved in renal cell carcinoma (RCC), including clear cell RCC (ccRCC) pathogenesis. However, the contribution of pathogenic VHL mutations to ccRCC remains poorly understood. We report a xanthoderm with non-obstructive azoospermia (NOA)-associated cystic ccRCC, and the missense VHL mutation (c.262T > C, p.Try88Arg). In a 34-year-old patient, a urologic physical examination identified hard epididymis, and imaging tests revealed deferens-associated NOA, as well as multi-organ hydatid cysts, including bilateral epididymal cysts, bilateral testicular cysts, bilateral renal cysts, and pancreatic cysts. Five years later, ccRCC was developed based on clinical and radiologic evidence. Two different prediction models of protein structure and multiple sequence alignment across species were applied to assess the pathological effects of the VHL mutation. The reliability of the assessment in silico was determined by both the cellular location and protein levels of the mutant products, using IF and Western blot, respectively. Our study shows that the missense VHL mutation (c.262T > C, p.Try88Arg) plays a deleterious role in pVHL functions, as predicted by multiple sequence alignment across species. While a structural analysis identified no significant structural alterations in pVHL, the detrimental effects of this mutation were determined by exogenous expression, evidenced by a markedly different spatial distribution and reduced expression of mutant pVHL. This is the first report of the VHL gene mutation (c.475T > C, p.Try88Arg) in a xanthoderm.
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- 2022
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11. Exposure to dithiocarbamate fungicide maneb in vitro and in vivo: Neuronal apoptosis and underlying mechanisms
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Chaoyang Liu, Zehua Liu, Yanyan Fang, Zizhuo Liao, Zhibing Zhang, Xin Yuan, Ting Yu, Yunying Yang, Min Xiong, Xingyu Zhang, Guoxin Zhang, Lanxia Meng, and Zhentao Zhang
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Maneb ,Neurotoxicity ,Mitochondrial dysfunction ,Apoptosis ,Parkinson’s disease ,Environmental sciences ,GE1-350 - Abstract
Maneb, a widely-used dithiocarbamate fungicide, remains in the environment and exerts adverse health effects. Epidemiological evidence shows that maneb exposure is associated with a higher risk of Parkinson’s disease (PD), one of the most common neurodegenerative diseases. However, the molecular mechanisms underlying maneb-induced neurotoxicity remain unclear. Here we investigated the toxic effects and the underlying mechanisms of maneb on the degeneration of dopaminergic cells and α-synuclein in A53T transgenic mice. In SH-SY5Y cells, exposure to maneb reduces cell viability, triggers neuronal apoptosis, induces mitochondrial dysfunction, and generates reactive oxidative species (ROS) in a dose-dependent manner. Furthermore, Western blot analysis found that the mitochondrial apoptosis pathway (Bcl-2, Bax, cytochrome c, activated caspase-3) and the PKA/CREB signaling pathway (PKA, PDE10A, CREB, p-CREB) were changed by maneb both in vitro and in vivo. In addition, the activation of the mitochondrial apoptosis pathway induced by maneb was attenuated by activating PKA. Therefore, these results suggest that the PKA/CREB signaling pathway is involved in maneb-induced apoptosis. This study provides novel insights into maneb-induced neurotoxicity and the underlying mechanisms, which may serve as a guide for further toxicological assessment and standard application of maneb.
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- 2023
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12. Sperm-associated antigen 6 (Spag6) mutation leads to vestibular dysfunction in mice
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Xiaofei Li, Daogong Zhang, Lei Xu, Wenwen Liu, Na Zhang, Jerome F. Strauss, III, Zhibing Zhang, and Haibo Wang
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Sperm-associated antigen 6 ,Vestibular dysfunction ,Apoptosis ,Hair cells ,Scarpa's ganglion cells ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Spag6 encodes an axoneme central apparatus protein that is required for normal flagellar and cilia motility. Recent findings suggest that Spag6 plays a role in hearing and planar cell polarity (PCP) in the cochlea of the inner ear. However, a role for Spag6 in the vestibule has not yet been explored. In the present study, the function of Spag6 in the vestibule of the inner ear was examined using Spag6-deficient mice. Our results demonstrate a vestibular disorder in the Spag6 mutants, associated with abnormal ultrastructures of vestibular hair cells and Scarpa's ganglion cells, including swollen stereocilia, decreased crista in mitochondria and swollen Scarpa's ganglion cells. Immunostaining data suggests existence of caspase-dependent apoptosis in vestibular sensory epithelium and Scarpa's ganglion cells. Our observations reveal new functions for Spag6 in vestibular function and apoptosis in the mouse vestibule.
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- 2021
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13. Concurrent production of glycyrrhetic acid 3-O-mono-β-d-glucuronide and lignocellulolytic enzymes by solid-state fermentation of a plant endophytic Chaetomium globosum
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Boliang Gao, Yiwen Xiao, Qian Zhang, Junru Sun, Zhibing Zhang, and Du Zhu
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Glycyrrhetic acid 3-O-mono-β-d-glucuronide ,Chaetomium globosum DX-THS3 ,Solid-state fermentation ,Lignocelluloses-degrading enzymes ,Technology ,Chemical technology ,TP1-1185 ,Biotechnology ,TP248.13-248.65 - Abstract
Abstract Glycyrrhetic acid 3-O-mono-β-d-glucuronide (GAMG) as an important derivative of glycyrrhizin (GL) shows stronger biological activities and higher sweetness than GL. The biotransformation process is considered as an efficient strategy for GAMG production, due to its mild reaction, high production efficiency and environmentally friendly status. In this study, licorice straw was used for the first time as a medium for GAMG and lignocellulosic enzyme production via solid-state fermentation (SSF) of endophytic fungus Chaetomium globosum DX-THS3. The fermentation conditions including particle size, temperature, seed age, inoculum size, and moisture of substrate were optimized. Furthermore, additional nitrogen sources and carbon sources were screened for GAMG production by C. globosum DX-THS3 of SSF. Under optimal fermentation conditions, the percent conversion of glycyrrhizin reached 90% in 15 days, whereas the control needed 35 days to achieve the same result. The productivity of optimization (P = 2.1 mg/g/day) was 2.33-fold that of non-optimization (P = 0.9 mg/g/day). Meanwhile, high activities of filter paper enzyme (FPase) (245.80 U/g), carboxymethyl cellulase (CMCase) (33.67 U/g), xylanase (83.44 U/g), and β-glucuronidase activity (271.42 U/g) were obtained faster than those in the control during SSF. Our study provides a novel and efficient strategy for GAMG production and indicates C. globosum DX-THS3 as a potential producer of lignocellulolytic enzymes.
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- 2021
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14. Taguchi and ANOVA analysis for the optimization of the microencapsulation of a volatile phase change material
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Abdullah Naseer Mustapha, Yan Zhang, Zhibing Zhang, Yulong Ding, Qingchun Yuan, and Yongliang Li
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ANOVA analysis ,Taguchi ,Microencapsulation ,Volatile organic compounds ,Phase change materials ,Process optimization ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The microencapsulation of volatile phase change materials is an important and challenging area for low-temperature thermal energy storage. Our previous studies have effectively addressed the challenge of long-term volatile core retention and also indicated that the quality of the obtained poly(urea-formaldehyde) microcapsules is highly affected by various process parameters, including reaction temperature, initial pH, reaction time, and homogenization speed. In this paper, the Taguchi orthogonal array has been employed to optimise controllable process parameters to identify the most synergistic combination, in order to maximise the payload, yield, and encapsulation efficiency. The Taguchi signal-to-noise ratio results substantiated that the most efficient combination of parameters was 3 h reaction time, pH 3.5, 55 °C reaction temperature, and 1200 rpm homogenization speed. With this combination of parameters, microcapsules with superbly high payload of 95.2%, as well as a yield of 30.5% and encapsulation efficiency of 71.1% were amalgamated. In addition, Analysis of Variance (ANOVA) was also utilised to demonstrate the mean response magnitudes (% contribution) of each of the four controllable process parameters, in terms of contribution for the payload, yield, and encapsulation efficiency. Overall, it was indicated that the temperature is the most influential parameter at 83.1% contribution, followed by pH at 6.8%, reaction time at 5.2%, and homogenization speed at 4.9%. Such findings in this work postulate the fundamental insights into maximising the output of the formulation conditions, which in turn is aimed to minimise the time and cost of production of the microcapsules.
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- 2021
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15. Assisting scalable diagnosis automatically via CT images in the combat against COVID-19
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Bohan Liu, Pan Liu, Lutao Dai, Yanlin Yang, Peng Xie, Yiqing Tan, Jicheng Du, Wei Shan, Chenghui Zhao, Qin Zhong, Xixiang Lin, Xizhou Guan, Ning Xing, Yuhui Sun, Wenjun Wang, Zhibing Zhang, Xia Fu, Yanqing Fan, Meifang Li, Na Zhang, Lin Li, Yaou Liu, Lin Xu, Jingbo Du, Zhenhua Zhao, Xuelong Hu, Weipeng Fan, Rongpin Wang, Chongchong Wu, Yongkang Nie, Liuquan Cheng, Lin Ma, Zongren Li, Qian Jia, Minchao Liu, Huayuan Guo, Gao Huang, Haipeng Shen, Liang Zhang, Peifang Zhang, Gang Guo, Hao Li, Weimin An, Jianxin Zhou, and Kunlun He
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Medicine ,Science - Abstract
Abstract The pandemic of Coronavirus Disease 2019 (COVID-19) is causing enormous loss of life globally. Prompt case identification is critical. The reference method is the real-time reverse transcription PCR (RT-PCR) assay, whose limitations may curb its prompt large-scale application. COVID-19 manifests with chest computed tomography (CT) abnormalities, some even before the onset of symptoms. We tested the hypothesis that the application of deep learning (DL) to 3D CT images could help identify COVID-19 infections. Using data from 920 COVID-19 and 1,073 non-COVID-19 pneumonia patients, we developed a modified DenseNet-264 model, COVIDNet, to classify CT images to either class. When tested on an independent set of 233 COVID-19 and 289 non-COVID-19 pneumonia patients, COVIDNet achieved an accuracy rate of 94.3% and an area under the curve of 0.98. As of March 23, 2020, the COVIDNet system had been used 11,966 times with a sensitivity of 91.12% and a specificity of 88.50% in six hospitals with PCR confirmation. Application of DL to CT images may improve both efficiency and capacity of case detection and long-term surveillance.
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- 2021
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16. Viscoelastic Properties of Polymeric Microneedles Determined by Micromanipulation Measurements and Mathematical Modelling
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Zhihua Zhang, Guangsheng Du, Xun Sun, and Zhibing Zhang
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single microneedles ,micromanipulation ,mechanical strength ,viscoelastic analysis ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Microneedles, including dissolvable ones made from biocompatible and biodegradable materials, have been widely studied and can potentially be used for transdermal drug delivery, disease diagnosis (sampling), skin care, etc. Characterizing their mechanical properties is essential, as being mechanically strong enough to pierce the skin barrier is one of the most fundamental and crucial requirements for them. The micromanipulation technique was based on compressing single microparticles between two flat surfaces to obtain force and displacement data simultaneously. Two mathematical models had already been developed to calculate the rupture stress and apparent Young’s modulus, which can identify variations of these parameters in single microneedles within a microneedle patch. In this study, a new model has been developed to determine the viscoelasticity of single microneedles made of hyaluronic acid (HA) with a molecular weight of 300 kDa loaded with lidocaine by using the micromanipulation technique to gather experimental data. The modelling results from the micromanipulation measurements suggest that the microneedles were viscoelastic and their mechanical behaviour was strain-rate dependent, which implies that the penetration efficiency of viscoelastic microneedles can be improved by increasing their piercing speed into the skin.
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- 2023
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17. Salt Effect on the Isobaric Vapor–Liquid Equilibrium Study of Binary Mixtures H2O–NMP (N‑Methyl-2-pyrrolidone)
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Baorong Wang, Hongliang Qian, Ziya Gao, Xiankun Wu, Guoqiang Yang, Zheng Zhou, Feng Zhang, and Zhibing Zhang
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Chemistry ,QD1-999 - Published
- 2020
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18. Computed tomography colonography versus colonoscopy for detection of colorectal cancer: a diagnostic performance study
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Junping sha, Jun chen, Xuguang lv, Shaoxin liu, Ruihong chen, and Zhibing zhang
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Colonoscopy ,Colorectal cancer ,Computed tomographic colonography ,Surgical pathology ,Suspicious polyps ,Medical technology ,R855-855.5 - Abstract
Abstract Background Colonoscopy is the reference standard for the detection of colorectal cancer but it is an invasive technique and has the risk of bowel perforation and bleeding. Unlike colonoscopy, sedation is not required in computed tomography colonography and requires additional reassurance endoscopy. The objectives of the study were to compare the diagnostic performance of computed tomography colonography against colonoscopy for a diagnosis of colorectal cancer. Methods Data regarding any polyp ≥10 mm diameter (ø) and
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- 2020
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19. Relationship between the Young’s Moduli of Whole Microcapsules and Their Shell Material Established by Micromanipulation Measurements Based on Diametric Compression between Two Parallel Surfaces and Numerical Modelling
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Daniele Baiocco, Zhihua Zhang, Yanping He, and Zhibing Zhang
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plant-based ,non-synthetic ,microcapsules ,micromanipulation ,intrinsic mechanical properties ,apparent elastic modulus ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Micromanipulation is a powerful technique to measure the mechanical properties of microparticles including microcapsules. For microparticles with a homogenous structure, their apparent Young’s modulus can be determined from the force versus displacement data fitted by the classical Hertz model. Microcapsules can consist of a liquid core surrounded by a solid shell. Two Young’s modulus values can be defined, i.e., the one is that determined using the Hertz model and another is the intrinsic Young’s modulus of the shell material, which can be calculated from finite element analysis (FEA). In this study, the two Young’s modulus values of microplastic-free plant-based microcapsules with a core of perfume oil (hexyl salicylate) were calculated using the aforementioned approaches. The apparent Young’s modulus value of the whole microcapsules determined by the classical Hertz model was found to be EA = 0.095 ± 0.014 GPa by treating each individual microcapsule as a homogeneous solid spherical particle. The previously obtained simulation results from FEA were utilised to fit the micromanipulation data of individual core–shell microcapsules, enabling to determine their unique shell thickness to radius ratio (h/r)FEA = 0.132 ± 0.009 and the intrinsic Young’s modulus of their shell (EFEA = 1.02 ± 0.13 GPa). Moreover, a novel theoretical relationship between the two Young’s modulus values has been derived. It is found that the ratio of the two Young’s module values (EA/EFEA) is only a function on the ratio of the shell thickness to radius (h/r) of the individual microcapsule, which can be fitted by a third-degree polynomial function of h/r. Such relationship has proven applicable to a broad spectrum of microcapsules (i.e., non-synthetic, synthetic, and double coated shells) regardless of their shell chemistry.
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- 2023
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20. Research on the Prediction Problem of Satellite Mission Schedulability Based on Bi-LSTM Model
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Guohui Zhang, Xinhong Li, Xun Wang, Zhibing Zhang, Gangxuan Hu, Yanyan Li, and Rui Zhang
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satellite intelligent mission planning ,schedulability prediction ,recurrent neural network ,Bi-LSTM ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 - Abstract
The realization of microsatellite intelligent mission planning is the current research focus in the field of satellite planning, and mission schedulability prediction is the basis of this research. Aiming at the influence of the sequence tasks before and after the task sequence to be predicted, we propose an online schedulability prediction model of satellite tasks based on bidirectional long short-term memory (Bi-LSTM) on the basis of describing and establishing the satellite task planning and solving model. The model is trained using satellite offline mission planning data as learning samples. In the experiment, the prediction effect of the model is excellent, with a recall rate of 93.17% and a precision rate of 92.59%, which proves that the model can be effectively applied to predict the schedulability of satellite tasks.
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- 2022
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21. Microplastic-Free Microcapsules to Encapsulate Health-Promoting Limonene Oil
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Daniele Baiocco and Zhibing Zhang
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microencapsulation ,microplastic-free ,plant-based ,coacervation ,micromanipulation ,Organic chemistry ,QD241-441 - Abstract
Fast-moving consumer goods (FMCG) industry has long included many appealing essential oils in products to meet consumers’ needs. Among all, the demand for limonene (LM) has recently surged due to its broad-spectrum health benefits, with applications in cosmetic, detergent, and food products. However, LM is extremely volatile, hence has often been encapsulated for a longer shelf-life. To date, mostly non-biodegradable synthetic polymers have been exploited to fabricate the microcapsule shells, and the resulting microcapsules contribute to the accumulation of microplastic in the environment. So far, information on LM-entrapping microcapsules with a natural microplastic-free shell and their mechanism of formation is limited, and there is lack of an in-depth characterisation of their mechanical and adhesive properties, which are crucial for understanding their potential performance at end-use applications. The present research aims towards developing safe microcapsules with a core of LM fabricated via complex coacervation (CC) using gum Arabic (GA) and fungally sourced chitosan (fCh) as shell precursors. The encapsulation efficiency (EE) for LM was quantified by gas chromatography (GC) separation method. The morphology of microcapsules was investigated via bright-field optical microscopy and scanning electron microscopy, and their mechanical properties were characterised using a micromanipulation technique. Moreover, the adhesive properties of the resulting microcapsules were studied via a bespoke microfluidic device fitted with a polyethylene-terephthalate (PET) substrate and operating at increasingly hydrodynamic shear stress (HSS). Spherical core-shell microcapsules (EE ~45%) with a mean size of 38 ± 2 μm and a relatively smooth surface were obtained. Their mean rupture force and nominal rupture stress were 0.9 ± 0.1 mN and 2.1 ± 0.2 MPa, respectively, which are comparable to those of other microcapsules with synthetic shells, e.g., urea- and melamine-formaldehyde. It was also found that the fCh-GA complexed shell provided promising adhesive properties onto PET films, leading to a microcapsule retention of ~85% and ~60% at low (≤50 mPa) and high shear stress (0.9 Pa), respectively. Interestingly, these values are similar to the adhesion data available in literature for microplastic-based microcapsules, such as melamine-formaldehyde (50–90%). Overall, these findings suggest that microplastics-free microcapsules with a core of oil have been successfully fabricated, and can offer a potential for more sustainable, consumer- and environmentally friendly applications in FMCGs.
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- 2022
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22. Micromanipulation and Automatic Data Analysis to Determine the Mechanical Strength of Microparticles
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Zhihua Zhang, Yanping He, and Zhibing Zhang
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micromanipulation ,automatic data analysis ,mechanical strength ,microparticles ,algorithms ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Microparticles are widely used in many industrial sectors. A micromanipulation technique has been widely used to quantify the mechanical properties of individual microparticles, which is crucial to the optimization of their functionality and performance in end-use applications. The principle of this technique is to compress single particles between two parallel surfaces, and the force versus displacement data are obtained simultaneously. Previously, analysis of the experimental data had to be done manually to calculate the rupture strength parameters of each individual particle, which is time-consuming. The aim of this study is to develop a software package that enables automatic analysis of the rupture strength parameters from the experimental data to enhance the capability of the micromanipulation technique. Three algorithms based on the combination of the “three-sigma rule”, a moving window, and the Hertz model were developed to locate the starting point where onset of compression occurs, and one algorithm based on the maximum deceleration was developed to identify the rupture point where a single particle is ruptured. Fifty microcapsules each with a liquid core and fifty porous polystyrene (PS) microspheres were tested in order to produce statistically representative results of each sample, and the experimental data were analysed using the developed software package. It is found that the results obtained from the combination of the “3σ + window” algorithm or the “3σ + window + Hertz” algorithm with the “maximum-deceleration” algorithm do not show any significant difference from the manual results. The data analysis time for each sample has been shortened from 2 to 3 h manually to within 20 min automatically.
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- 2022
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23. Microcapsules with a fungal chitosan-gum Arabic-maltodextrin shell to encapsulate health-beneficial peppermint oil
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Daniele Baiocco, Jon A. Preece, and Zhibing Zhang
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Vegan ,Eco-friendly ,Complex coacervation ,Spray drying ,Micromanipulation ,Fluorescence ,Nutrition. Foods and food supply ,TX341-641 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
Microcapsules encapsulating peppermint oil (L-Carvone) were fabricated via two-stage encapsulation processes (complex coacervation followed by spray drying) using three plant-based biopolymers (fungal chitosan, gum Arabic, and maltodextrin). Transglutaminase was introduced to the formulation to crosslink the coacervate formed during microcapsule wall development. The microcapsules were assayed for their physical, structural, morphological, mechanical, and barrier properties, using several analytical techniques, including light scattering, spectrophotometry, SEM, TEM, and a micromanipulation technique. The size of the microcapsules ranged from 10–125 µm, with a Sauter mean diameter of 37.8 ± 1.4 µm and shell thickness of 0.91 ± 0.15 μm. The microcapsules were spherical with a relatively smooth surface. Nile red was employed as a fluorescent dye dopant in the peppermint oil to assess the presence of oil in microcapsules after spray drying. A micromanipulation technique was used to quantify the mechanical properties of microcapsules, such as rupture force (0.6 ± 0.1 mN) and nominal rupture stress (2.1 ± 0.3 MPa). Static oil leakage from dry microcapsules was negligible after storage for 50 days. The release rates of the oil from the microcapsules to aqueous ethanol solutions (5–20% w/w) were measured, and the effective diffusivity was quantified (Deff = 4.210−12 m2 s–1). These results show that the two-stage encapsulation processes could be an eco-friendly and sustainable methodology for the manufacture of active oil containing microcapsules, with potential applications in food, personal care, and cosmetics products. Furthermore, the use of plant based materials will overcome the growing issues associated with the consumer turning away from animal based products in favour of vegan alternatives.
- Published
- 2021
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24. Editorial: Sperm Differentiation and Spermatozoa Function: Mechanisms, Diagnostics, and Treatment
- Author
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Tomer Avidor-Reiss, Zhibing Zhang, and Xin Zhiguo Li
- Subjects
spermatogenesis ,sperm ,capacitation ,manchette ,centriole ,cilia ,Biology (General) ,QH301-705.5 - Published
- 2020
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25. The Ancient and Evolved Mouse Sperm-Associated Antigen 6 Genes Have Different Biologic Functions In Vivo
- Author
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Yi Tian Yap, Wei Li, Qi Zhou, Sarah Haj-Diab, Dipanwita Dutta Chowdhury, Asmita Vaishnav, Pamela Harding, David C. Williams, Brian F. Edwards, Jerome F. Strauss, and Zhibing Zhang
- Subjects
cilia ,flagella ,axoneme ,central apparatus ,spermatogenesis ,Spag6 ,Cytology ,QH573-671 - Abstract
Sperm-associated antigen 6 (SPAG6) is the mammalian orthologue of Chlamydomonas PF16, an axonemal central pair protein involved in flagellar motility. In mice, two Spag6 genes have been identified. The ancestral gene, on mouse chromosome 2, is named Spag6. A related gene originally called Spag6, localized on mouse chromosome 16, evolved from the ancient Spag6 gene. It has been renamed Spag6-like (Spag6l). Spag6 encodes a 1.6 kb transcript consisting of 11 exons, while Spag6l encodes a 2.4 kb transcript which contains an additional non-coding exon in the 3′-end as well as the 11 exons found in Spag6. The two Spag6 genes share high similarities in their nucleotide and amino acid sequences. Unlike Spag6l mRNA, which is widely expressed, Spag6 mRNA expression is limited to a smaller number of tissues, including the testis and brain. In transfected mammalian cells, SPAG6/GFP is localized on microtubules, a similar localization as SPAG6L. A global Spag6l knockout mouse model was generated previously. In addition to a role in modulating the ciliary beat, SPAG6L has many unexpected functions, including roles in the regulation of ciliogenesis/spermatogenesis, hearing, and the immunological synapse, among others. To investigate the role of the ancient Spag6 gene, we phenotyped global Spag6 knockout mice. All homozygous mutant mice were grossly normal, and fertility was not affected in both males and females. The homozygous males had normal sperm parameters, including sperm number, motility, and morphology. Examination of testis histology revealed normal spermatogenesis. Testicular protein expression levels of selected SPAG6L binding partners, including SPAG16L, were not changed in the Spag6 knockout mice, even though the SPAG16L level was significantly reduced in the Spag6l knockout mice. Structural analysis of the two SPAG6 proteins shows that both adopt very similar folds, with differences in a few amino acids, many of which are solvent-exposed. These differences endow the two proteins with different functional characteristics, even though both have eight armadillo repeats that mediate protein–protein interaction. Our studies suggest that SPAG6 and SPAG6L have different functions in vivo, with the evolved SPAG6L protein being more important. Since the two proteins have some overlapping binding partners, SPAG6 could have functions that are yet to be identified.
- Published
- 2022
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26. Mammalian Cell-Free System Recapitulates the Early Events of Post-Fertilization Sperm Mitophagy
- Author
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Won-Hee Song, Dalen Zuidema, Young-Joo Yi, Michal Zigo, Zhibing Zhang, Miriam Sutovsky, and Peter Sutovsky
- Subjects
mitochondria ,mtDNA ,cell-free system ,ubiquitin-proteasome system ,autophagy ,SQSTM1 ,Cytology ,QH573-671 - Abstract
Propagation of paternal sperm-contributed mitochondrial genes, resulting in heteroplasmy, is seldom observed in mammals due to post-fertilization degradation of sperm mitochondria, referred to as sperm mitophagy. Whole organelle sperm mitochondrion degradation is thought to be mediated by the interplay between the ubiquitin-proteasome system (UPS) and the autophagic pathway (Song et al., Proc. Natl. Acad. Sci. USA, 2016). Both porcine and primate post-fertilization sperm mitophagy rely on the ubiquitin-binding autophagy receptor, sequestosome 1 (SQSTM1), and the proteasome-interacting ubiquitinated protein dislocase, valosin-containing protein (VCP). Consequently, we anticipated that sperm mitophagy could be reconstituted in a cell-free system consisting of permeabilized mammalian spermatozoa co-incubated with porcine oocyte extracts. We found that SQSTM1 was detected in the midpiece/mitochondrial sheath of the sperm tail after, but not before, co-incubation with oocyte extracts. VCP was prominent in the sperm mitochondrial sheath both before and after the extract co-incubation and was also detected in the acrosome and postacrosomal sheath and the subacrosomal layer of the spermatozoa co-incubated with extraction buffer as control. Such patterns are consistent with our previous observation of SQSTM1 and VCP associating with sperm mitochondria inside the porcine zygote. In addition, it was observed that sperm head expansion mimicked the early stages of paternal pronucleus development in a zygote during prolonged sperm-oocyte extract co-incubation. Treatment with anti-SQSTM1 antibody during extract co-incubation prevented ooplasmic SQSTM1 binding to sperm mitochondria. Even in an interspecific cellular environment encompassing bull spermatozoa and porcine oocyte extract, ooplasmic SQSTM1 was recruited to heterospecific sperm mitochondria. Complementary with the binding of SQSTM1 and VCP to sperm mitochondria, two sperm-borne pro-mitophagy proteins, parkin co-regulated gene product (PACRG) and spermatogenesis associated 18 (SPATA18), underwent localization changes after extract coincubation, which were consistent with their degradation observed inside fertilized porcine oocytes. These results demonstrate that the early developmental events of post-fertilization sperm mitophagy observed in porcine zygote can be reconstituted in a cell-free system, which could become a useful tool for identifying additional molecules that regulate mitochondrial inheritance in mammals.
- Published
- 2021
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27. Strategy for Preparing Al-Doped ZnO Thin Film with High Mobility and High Stability.
- Author
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Zhibing Zhan, Jiye Zhang, Qinghong Zheng, Danmei Pan, Jin Huang, Feng Huang, and Zhang Lin
- Subjects
- *
ZINC oxide thin films , *DOPED semiconductors , *ALUMINUM , *MOLECULAR structure , *CRYSTAL lattices , *CHEMICAL vapor deposition , *ELECTRIC conductivity , *CHEMICAL processes - Abstract
Ideal Al-doped ZnO (AZO) thin films should have high carrier mobility and carrier concentration, as well as high thermal and chemical stability. To achieve these properties, ZnO should be heavily doped with Al and perfectly crystallized. Through analyzing the possible valence state of the elements and local lattice structures of AZO films during the gas-phase deposition process, we find that the current gas-phase deposition method may encounter an intrinsic obstacle that heavy doping of Al, high thermal stability, and high mobility (perfect crystallinity) cannot be achieved simultaneously. However, based on the understanding that an AZO thin film prepared in oxidizing atmosphere is actually accompanied with a high concentration of zinc vacancy, we propose a strategy to obtain an AZO film with ideal characteristics. Under an oxidizing atmosphere, a heavily doped AZO film with a high concentration of zinc vacancy is prepared using a gas-phase deposition method. Then a zinc vapor annealing treatment is employed to improve the crystallinity and conductivity of the film by filling the zinc vacancies with zinc atoms. The prepared AZO films possess the highest mobility (36.8 cm2Vâ1sâ1) ever reported. Moreover, the films also show remarkable stability in carrier concentration, mobility, and resistivity under damp heat treatment (85 °C) over months. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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28. A Dynamic Risk Appraisal Model and Its Application in VTS Based on a Cellular Automata Simulation Prediction
- Author
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Yongfeng Suo, Zhihong Sun, Christophe Claramunt, Shenhua Yang, and Zhibing Zhang
- Subjects
cellular automata ,risk appraisal ,traffic simulation ,traffic prediction ,VTS ,Chemical technology ,TP1-1185 - Abstract
The successful implementation of Vessel Traffic Services (VTS) relies heavily on human decisions. With the increasing development of maritime traffic, there is an urgent need to provide a sound support for dynamic risk appraisals and decision support. This research introduces a cellular automata (CA) simulation-based modelling approach the objective of which is to analyze and evaluate real-time maritime traffic risks in port environments. The first component is the design of a CA model to monitor ships’ behavior and maritime fairway traffic. The second component is the refinement of the modelling approach by combining a cloud model with expert knowledge. The third component establishes a risk assessment model based on a fuzzy comprehensive evaluation. A typical scenario was experimentally implemented to validate the model’s efficiency and operationality.
- Published
- 2021
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29. Spag6 Mutant Mice Have Defects in Development and Function of Spiral Ganglion Neurons, Apoptosis, and Higher Sensitivity to Paclitaxel
- Author
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Xiaofei Li, Lei Xu, Gaoying Sun, Xianmin Wu, Xiaohui Bai, Jianfeng Li, Jerome F. Strauss, Zhibing Zhang, and Haibo Wang
- Subjects
Medicine ,Science - Abstract
Abstract Mammalian Sperm Associated Antigen 6 (SPAG6) is the orthologue of Chlamydomonas PF16, a protein localized in the axoneme central apparatus. Recent studies showed that Spag6 has a role in brain neuronal proliferation and differentiation. The mammalian spiral ganglion neurons (SGNs) are specialzed bipolar neurons in the inner ear. However, the role of SPAG6 in SGN has not been elucidated. Therefore, We hypothesized that a Spag6 knockout would affect the development and function of SGNs. We utilized Spag6-deficient mice and SGN explants to define the role of SPAG6. On postnatal day 30 (P30) mutant mice had lower SGN density compared to their wild-type littermates, and more apoptosis was evident in the mutants. Increased Bax expression, a disturbed distribution of cytochrome c, and cleaved caspase-3 positive staining indicated that increased apoptosis involved a mitochondrial pathway. Transmission electron microscopy revealed abnormalities in the ultrastructure of mutant SGNs as early as P7. In vitro, lack of SPAG6 affected the growth of neurites and growth cones. Additionally, SPAG6 deficiency decreased synapse density in SGN explants. Finally, Spag6 mutant SGNs were more sensitive to the microtubule stabilizing agent, paclitaxel. These findings suggest that Spag6 plays a crucial role in SGN development and function.
- Published
- 2017
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30. Designing Microfluidic Devices to Sort Haematopoietic Stem Cells Based on Their Mechanical Properties
- Author
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Mingming Du, Dean Kavanagh, Zhibing Zhang, and Neena Kalia
- Subjects
Internal medicine ,RC31-1245 - Abstract
Aim. Few haematopoietic stem cells (HSCs) injected systemically for therapeutic purposes actually reach sites of injury as the vast majority become entrapped within pulmonary capillaries. One promising approach to maintain circulating HSC numbers would be to separate subpopulations with smaller size and/or greater deformability from a heterogeneous population. This study tested whether this could be achieved using label-free microfluidic devices. Methods. 2 straight (A-B) and 3 spiral (C-E) devices were fabricated with different dimensions. Cell sorting was performed at different flow rates after which cell diameter and stiffness were determined using micromanipulation. Cells isolated using the most efficient device were tested intravitally for their ability to home to the mouse injured gut. Results. Only straight Device B at a high flow rate separated HSCs with different mechanical properties. Side outlets collected mostly deformable cells (nominal rupture stress/σR=6.81 kPa; coefficient of variation/CV=0.31) at a throughput of 2.3×105 cells/min. All spiral devices at high flow rates separated HSCs with different stiffness and size. Inner outlets collected mostly deformable cells in Devices C (σR=25.06 kPa; CV=0.26), D (σR=22.21 kPa; CV=0.41), and E (σR=29.26 kPa; CV=0.27) at throughputs of 2.3×105 cells/min, 1.5×105 cells/min, and 1.6×105 cells/min, respectively. Since Device C separated cells with higher efficiency and throughput, it was utilized to test the homing ability of separated cells in vivo. Significantly more deformable cells were observed trafficking through the injured gut—interestingly, increased retention was not observed. Conclusion. This study applied microfluidics to separate subpopulations from one stem cell type based on their intrinsic mechanical heterogeneity. Fluid dynamics within curved devices most effectively separated HSCs. Such devices may benefit cellular therapy.
- Published
- 2019
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31. Robust observability for regular linear systems under nonlinear perturbation
- Author
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Weisheng Jiang, Bin Liu, and Zhibing Zhang
- Subjects
Admissible observation operator ,exact observability ,nonlinear semigroup ,regular linear system ,Mathematics ,QA1-939 - Abstract
In this article, we consider the admissibility and exact observability of a class of semilinear systems obtained by nonlinear perturbation for regular linear systems. We obtain the well-posedness of the semilinear system and the admissibility of the observation operator for the nonlinear semigroup, the solution semigroup of the semilinear system. Further, we obtain the robustness of the exact observability with respect to nonlinear perturbations when the Lipschitz constant is small enough. Finally, we give two examples to illustrate the obtained results.
- Published
- 2015
32. Coating of sodium percarbonate particles using water soluble materials in a fluidised bed to achieve delayed release in aqueous environment
- Author
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Lei Xing, Bingyu Zhuo, Serafim Bakalis, Jerome Castro, and Zhibing Zhang
- Subjects
sodium percarbonate ,controlled release ,thermal stability ,sodium sulphate ,sodium silicate ,fluidised bed coating ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Three coating materials, namely sodium sulphate, 1.6R and 2.35R sodium silicate, were respectively used to coat sodium percarbonate (SPC) particles in a fluidised bed coater to achieve its delayed release in aqueous environment. The size of SPC particles was measured using image analysis. The thickness and porosity of the shell materials were analysed using scanning electron microscopy (SEM) and helium pycnometry respectively. The rates of SPC release from uncoated and the coated particles were measured using an iodide molybdate titration method coupled with UV-vis spectrometry. The results indicate that sodium sulphate coating with an average thickness of 53 ± 9 μm only reduced the release rate of SPC as no delayed release was observed. In contrast, sodium silicate coating generated a significant delayed release. 1.6R sodium silicate coating with a thickness of 109 ± 8 μm delayed the release of SPC by approximate 60 s under a static condition. At the same condition, 2.35R sodium silicate coating with a thickness of 71 ± 10 μm delayed the release by approximately 7 min. When the coated SPC particles immersed in water were shaken using an orbital shaker at 150 rpm, the delayed time was reduced by 50% in comparison with the static condition. The 1.6R sodium silicate shell in solid phase transformed to gel-like structure during dissolution and the hydrodynamic forces generated in the shaker accelerated its dissolution. However, there was no significant change of 2.35R sodium silicate shell when the capsules were immersed in water under the static condition, and they broke into pieces in the shaker. For both 1.6R and 2.35R sodium silicate, the further increase in shell thickness increased their shell porosity, which facilitated the water penetration and thus resulted in no significant benefit to additional delay. Moreover, the thermal stability of SPC after coating was slightly improved and the flowability did not change significantly. This study demonstrates that a significant delay in release of SPC can be achieved using 2.35R sodium silicate as a coating material.
- Published
- 2017
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33. MgZnO-based metal-semiconductor-metal solar-blind photodetectors on ZnO substrates.
- Author
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Qinghong Zheng, Feng Huang, Kai Ding, Jin Huang, Dagui Chen, Zhibing Zhan, and Zhang Lin
- Subjects
OPTOELECTRONIC devices ,SEMICONDUCTOR-metal boundaries ,WURTZITE ,ZINC oxide ,MAGNETRONS ,HETEROSTRUCTURES - Abstract
Using lattice matched ZnO substrates, wurtzite single crystalline Mg
0.49 Zn0.51 O films were obtained by reactive magnetron cosputtering method, and the heterostructures of MgZnO/ZnO were fabricated into metal-semiconductor-metal solar-blind photodetectors (SBPDs). Calculated and experimental results demonstrate that the response of the ZnO substrate can be suppressed by adopting a thick MgZnO epilayer. The SBPD with a 2 μm thick MgZnO epilayer shows a peak responsivity of 304 mA/W at 260 nm under 10 V bias, which is comparable to the highest value ever reported in MgZnO-based SBPDs. A rejection ratio (R260 nm/R365 nm) over 5×102 is also observed, indicating fully suppression of the signal from ZnO substrate. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
34. SPAG17 Is Required for Male Germ Cell Differentiation and Fertility
- Author
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Elizabeth Kazarian, HyunYoung Son, Paulene Sapao, Wei Li, Zhibing Zhang, Jerome F. Strauss III, and Maria E. Teves
- Subjects
manchette ,central pair complex protein ,spermatogenesis ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Spag17 encodes a protein present in the axoneme central pair complex of motile cilia and flagella. A mutation in this gene has been reported to be associated with infertility caused by defects in sperm motility. Here, we report that Spag17 knockout mice are infertile because of a severe defect in spermatogenesis. The histological evaluation of testis sections from mutant mice revealed seminiferous tubules with spermatogenesis arrested at the spermatid stage and cell debris in the cauda epididymis. The few sperm collected from the cauda epididymis were immotile and displayed abnormal tail and head morphology. Immunofluorescence analysis of Spag17 knockout germ cells showed spermatids with abnormally long manchette structures and morphological defects in the head. Electron microscopy showed altered manchette microtubules, reduced chromatin condensation, irregular nuclear shape, and detached acrosomes. Additionally, the transport of proteins (Pcdp1 and IFT20) along the manchette microtubules was disrupted in the knockout elongating spermatids. Our results show for the first time that Spag17 is essential for normal manchette structure, protein transport, and formation of the sperm head and flagellum, in addition to its role in sperm motility.
- Published
- 2018
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35. Spag17 deficiency results in skeletal malformations and bone abnormalities.
- Author
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Maria Eugenia Teves, Gobalakrishnan Sundaresan, David J Cohen, Sharon L Hyzy, Illya Kajan, Melissa Maczis, Zhibing Zhang, Richard M Costanzo, Jamal Zweit, Zvi Schwartz, Barbara D Boyan, and Jerome F Strauss
- Subjects
Medicine ,Science - Abstract
Height is the result of many growth and development processes. Most of the genes associated with height are known to play a role in skeletal development. Single-nucleotide polymorphisms in the SPAG17 gene have been associated with human height. However, it is not clear how this gene influences linear growth. Here we show that a targeted mutation in Spag17 leads to skeletal malformations. Hind limb length in mutants was significantly shorter than in wild-type mice. Studies revealed differences in maturation of femur and tibia suggesting alterations in limb patterning. Morphometric studies showed increased bone formation evidenced by increased trabecular bone area and the ratio of bone area to total area, leading to reductions in the ratio of marrow area/total area in the femur. Micro-CTs and von Kossa staining demonstrated increased mineral in the femur. Moreover, osteocalcin and osterix were more highly expressed in mutant mice than in wild-type mice femurs. These data suggest that femur bone shortening may be due to premature ossification. On the other hand, tibias appear to be shorter due to a delay in cartilage and bone development. Morphometric studies showed reduction in growth plate and bone formation. These defects did not affect bone mineralization, although the volume of primary bone and levels of osteocalcin and osterix were higher. Other skeletal malformations were observed including fused sternebrae, reduced mineralization in the skull, medial and metacarpal phalanges. Primary cilia from chondrocytes, osteoblasts, and embryonic fibroblasts (MEFs) isolated from knockout mice were shorter and fewer cells had primary cilia in comparison to cells from wild-type mice. In addition, Spag17 knockdown in wild-type MEFs by Spag17 siRNA duplex reproduced the shorter primary cilia phenotype. Our findings disclosed unexpected functions for Spag17 in the regulation of skeletal growth and mineralization, perhaps because of its role in primary cilia of chondrocytes and osteoblasts.
- Published
- 2015
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36. Mechanical characterization of calcium pectinate hydrogel for controlled drug delivery
- Author
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Chung Jin Thau and Zhibing Zhang
- Subjects
Calcium pectinate ,Hydrogel ,Controlled drug delivery ,Mechanical property ,Permeability ,Micromanipulation ,Chemical technology ,TP1-1185 - Abstract
Calcium pectinate beads, a paniculate hydrogel system, is an attractive drug carrier for oral delivery. In this study, a poorly water-soluble model drug indomethacin was incorporated into calcium pectinate beads made of different pectin concentrations, which were produced by an extrusion method. The effect of pectin concentration on bead size, circularity, swelling behavior, and mechanical properties, as well as in vitro drug release profile was investigated. The mechanical properties of calcium pectinate beads were determined by a micromanipulation technique. The drug release profile was measured using a standard British Pharmacopoeia method. It was found that the beads made of higher pectin concentration in general had a less permeable matrix structure and greater mechanical rigidity, although they swelled more after hydration. However, such an effect was not significant when the pectin concentration was increased to above 8%. Micromanipulation measurements showed that there was significant relaxation of the force being imposed on single hydrated beads when they were held, but this phenomenon did not occur on dry beads, which means that the force relaxation was dominated by liquid loss from the beads. The rate of the force relaxation was determined, and has been related to the release rate of the model drug entrapped in the calcium pectinate beads.
- Published
- 2003
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- View/download PDF
37. Sperm-associated antigen 6 (SPAG6) deficiency and defects in ciliogenesis and cilia function: polarity, density, and beat.
- Author
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Maria E Teves, Patrick R Sears, Wei Li, Zhengang Zhang, Waixing Tang, Lauren van Reesema, Richard M Costanzo, C William Davis, Michael R Knowles, Jerome F Strauss, and Zhibing Zhang
- Subjects
Medicine ,Science - Abstract
SPAG6, an axoneme central apparatus protein, is essential for function of ependymal cell cilia and sperm flagella. A significant number of Spag6-deficient mice die with hydrocephalus, and surviving males are sterile because of sperm motility defects. In further exploring the ciliary dysfunction in Spag6-null mice, we discovered that cilia beat frequency was significantly reduced in tracheal epithelial cells, and that the beat was not synchronized. There was also a significant reduction in cilia density in both brain ependymal and trachea epithelial cells, and cilia arrays were disorganized. The orientation of basal feet, which determines the direction of axoneme orientation, was apparently random in Spag6-deficient mice, and there were reduced numbers of basal feet, consistent with reduced cilia density. The polarized epithelial cell morphology and distribution of intracellular mucin, α-tubulin, and the planar cell polarity protein, Vangl2, were lost in Spag6-deficient tracheal epithelial cells. Polarized epithelial cell morphology and polarized distribution of α-tubulin in tracheal epithelial cells was observed in one-week old wild-type mice, but not in the Spag6-deficient mice of the same age. Thus, the cilia and polarity defects appear prior to 7 days post-partum. These findings suggest that SPAG6 not only regulates cilia/flagellar motility, but that in its absence, ciliogenesis, axoneme orientation, and tracheal epithelial cell polarity are altered.
- Published
- 2014
- Full Text
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38. High levels of SOX5 decrease proliferative capacity of human B cells, but permit plasmablast differentiation.
- Author
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Mirzokhid Rakhmanov, Heiko Sic, Anne-Kathrin Kienzler, Beate Fischer, Marta Rizzi, Maximilian Seidl, Kerstina Melkaoui, Susanne Unger, Luisa Moehle, Nadine E Schmit, Sachin D Deshmukh, Cemil Korcan Ayata, Wolfgang Schuh, Zhibing Zhang, François-Loic Cosset, Els Verhoeyen, Hans-Hartmut Peter, Reinhard E Voll, Ulrich Salzer, Hermann Eibel, and Klaus Warnatz
- Subjects
Medicine ,Science - Abstract
Currently very little is known about the differential expression and function of the transcription factor SOX5 during B cell maturation. We identified two new splice variants of SOX5 in human B cells, encoding the known L-SOX5B isoform and a new shorter isoform L-SOX5F. The SOX5 transcripts are highly expressed during late stages of B-cell differentiation, including atypical memory B cells, activated CD21low B cells and germinal center B cells of tonsils. In tonsillar sections SOX5 expression was predominantly polarized to centrocytes within the light zone. After in vitro stimulation, SOX5 expression was down-regulated during proliferation while high expression levels were permissible for plasmablast differentiation. Overexpression of L-SOX5F in human primary B lymphocytes resulted in reduced proliferation, less survival of CD138neg B cells, but comparable numbers of CD138+CD38hi plasmablasts compared to control cells. Thus, our findings describe for the first time a functional role of SOX5 during late B cell development reducing the proliferative capacity and thus potentially affecting the differentiation of B cells during the germinal center response.
- Published
- 2014
- Full Text
- View/download PDF
39. Otitis media in sperm-associated antigen 6 (Spag6)-deficient mice.
- Author
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Xiaofei Li, Lei Xu, Jianfeng Li, Boqin Li, Xiaohui Bai, Jerome F Strauss, Zhibing Zhang, and Haibo Wang
- Subjects
Medicine ,Science - Abstract
Mammalian SPAG6 protein is localized to the axoneme central apparatus, and it is required for normal flagella and cilia motility. Recent studies demonstrated that the protein also regulates ciliogenesis and cilia polarity in the epithelial cells of brain ventricles and trachea. Motile cilia are also present in the epithelial cells of the middle ear and Eustachian tubes, where the ciliary system participates in the movement of serous fluid and mucus in the middle ear. Cilia defects are associated with otitis media (OM), presumably due to an inability to efficiently transport fluid, mucus and particles including microorganisms. We investigated the potential role of SPAG6 in the middle ear and Eustachian tubes by studying mice with a targeted mutation in the Spag6 gene. SPAG6 is expressed in the ciliated cells of middle ear epithelial cells. The orientation of the ciliary basal feet was random in the middle ear epithelial cells of Spag6-deficient mice, and there was an associated disrupted localization of the planar cell polarity (PCP) protein, FZD6. These features are associated with disordered cilia orientation, confirmed by scanning electron microscopy, which leads to uncoordinated cilia beating. The Spag6 mutant mice were also prone to develop OM. However, there were no significant differences in bacterial populations, epithelial goblet cell density, mucin expression and Eustachian tube angle between the mutant and wild-type mice, suggesting that OM was due to accumulation of fluid and mucus secondary to the ciliary dysfunction. Our studies demonstrate a role for Spag6 in the pathogenesis of OM in mice, possibly through its role in the regulation of cilia/basal body polarity through the PCP-dependent mechanisms in the middle ear and Eustachian tubes.
- Published
- 2014
- Full Text
- View/download PDF
40. Mouse RC/BTB2, a member of the RCC1 superfamily, localizes to spermatid acrosomal vesicles.
- Author
-
Jiannan Wang, Maria E Teves, Xuening Shen, David R Nagarkatti-Gude, Rex A Hess, Scott C Henderson, Jerome F Strauss, and Zhibing Zhang
- Subjects
Medicine ,Science - Abstract
Mouse RC/BTB2 is an unstudied protein of the RCC1 (Regulator of Chromosome Condensation) superfamily. Because of the significant remodeling of chromatin that occurs during spermiogenesis, we characterized the expression and localization of mouse RC/BTB2 in the testis and male germ cells. The Rc/btb2 gene yields two major transcripts: 2.3 kb Rc/btb2-s, present in most somatic tissues examined; and 2.5 kb Rc/btb2-t, which contains a unique non-translated exon in its 5'-UTR that is only detected in the testis. During the first wave of spermatogenesis, Rc/btb2-t mRNA is expressed from day 8 after birth, reaching highest levels of expression at day 30 after birth. The full-length protein contains three RCC1 domains in the N-terminus, and a BTB domain in the C-terminus. In the testis, the protein is detectable from day 12, but is progressively up-regulated to day 30 and day 42 after birth. In spermatids, some of the protein co-localizes with acrosomal markers sp56 and peanut lectin, indicating that it is an acrosomal protein. A GFP-tagged RCC1 domain is present throughout the cytoplasm of transfected CHO cells. However, both GFP-tagged, full-length RC/BTB2 and a GFP-tagged BTB domain localize to vesicles in close proximity to the nuclear membrane, suggesting that the BTB domain might play a role in mediating full-length RC/BTB2 localization. Since RCC1 domains associate with Ran, a small GTPase that regulates molecular trafficking, it is possible that RC/BTB2 plays a role in transporting proteins during acrosome formation.
- Published
- 2012
- Full Text
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41. Spag16, an axonemal central apparatus gene, encodes a male germ cell nuclear speckle protein that regulates SPAG16 mRNA expression.
- Author
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David R Nagarkatti-Gude, Ruth Jaimez, Scott C Henderson, Maria E Teves, Zhibing Zhang, and Jerome F Strauss
- Subjects
Medicine ,Science - Abstract
Spag16 is the murine orthologue of Chlamydomonas reinhardtii PF20, a protein known to be essential to the structure and function of the "9+2" axoneme. In Chlamydomonas, the PF20 gene encodes a single protein present in the central pair of the axoneme. Loss of PF20 prevents central pair assembly/integrity and results in flagellar paralysis. Here we demonstrate that the murine Spag16 gene encodes two proteins: 71 kDa SPAG16L, which is found in all murine cells with motile cilia or flagella, and 35 kDa SPAG16S, representing the C terminus of SPAG16L, which is expressed only in male germ cells, and is predominantly found in specific regions within the nucleus that also contain SC35, a known marker of nuclear speckles enriched in pre-mRNA splicing factors. SPAG16S expression precedes expression of SPAG16L. Mice homozygous for a knockout of SPAG16L alone are infertile, but show no abnormalities in spermatogenesis. Mice chimeric for a mutation deleting the transcripts for both SPAG16L and SPAG16S have a profound defect in spermatogenesis. We show here that transduction of SPAG16S into cultured dispersed mouse male germ cells and BEAS-2B human bronchial epithelial cells increases SPAG16L expression, but has no effect on the expression of several other axoneme components. We also demonstrate that the Spag16L promoter shows increased activity in the presence of SPAG16S. The distinct nuclear localization of SPAG16S and its ability to modulate Spag16L mRNA expression suggest that SPAG16S plays an important role in the gene expression machinery of male germ cells. This is a unique example of a highly conserved axonemal protein gene that encodes two protein products with different functions.
- Published
- 2011
- Full Text
- View/download PDF
42. Effective approach to strengthen plasmon resonance localized on top surfaces of Ag nanoparticles and application in surface-enhanced Raman spectroscopy.
- Author
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Zhibing Zhan, Rui Xu, Xianzheng Zheng, Qun Fu, Minghong Wu, and Yong Lei
- Subjects
- *
SURFACE plasmon resonance , *RAMAN spectroscopy , *SILVER nanoparticles , *SPATIAL distribution (Quantum optics) , *THERMAL stability , *SYMMETRY breaking , *FINITE difference time domain method , *ELECTROMAGNETIC fields - Abstract
The spatial distribution of localized surface plasmon resonance (LSPR) plays a key role in many plasmonic applications. Based on the thermal stability of alumina templates, this work reports a novel approach to manipulate the distribution of LSPR and exhibits its significance for an important plasmonic application, the surface-enhanced Raman spectroscopy (SERS). A suitable thermal annealing sharpens the edges in top surfaces (far from the substrates) of Ag nanoparticles, which significantly strengthens the distal mode (DM) with the LSPR excited on the top surfaces. Because the top surface is the major place to adsorb probe molecules, this manipulation greatly improves the detection sensitivity of SERS. Our research provides a new way to improve the sensitivity of SERS, which also indicates that great care has to be taken on special LSPR mode which is largely responsible for a certain plasmonic application (e.g., the DM for SERS although it is not the major mode). [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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