25 results on '"Zongyuan Chen"'
Search Results
2. Multi-scenario renewable energy absorption capacity assessment method based on the attention-enhanced time convolutional network
- Author
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Yang Wu, Han Zhou, Congtong Zhang, Shuangquan Liu, and Zongyuan Chen
- Subjects
renewable energy absorption capacity ,attention-enhanced ,time convolutional network ,uncertainty ,multi-scenario ,General Works - Abstract
As the penetration rate of renewable energy in modern power grids continues to increase, the assessment of renewable energy absorption capacity plays an increasingly important role in the planning and operation of power and energy systems. However, traditional methods for assessing renewable energy absorption capacity rely on complex mathematical modeling, resulting in low assessment efficiency. Assessment in a single scenario determined by the source-load curve is difficult because it fails to reflect the random fluctuation characteristics of the source-load, resulting in inaccurate assessment results. To address and solve the above challenges, this paper proposes a multi-scenario renewable energy absorption capacity assessment method based on an attention-enhanced time convolutional network (ATCN). First, a source-load scene set is generated based on a generative adversarial network (GAN) to accurately characterize the uncertainty on both sides of the source and load. Then, the dependence of historical time series information in multiple scenarios is fully mined using the attention mechanism and temporal convolution network (TCN). Finally, simulation and experimental verification are carried out using a provincial power grid located in southwest China. The results show that the method proposed in this article has higher evaluation accuracy and speed than the traditional model.
- Published
- 2024
- Full Text
- View/download PDF
3. Polymeric concentrated electrolyte enables simultaneous stabilization of electrode/electrolyte interphases for quasi‐solid‐state lithium metal batteries
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Guanming Yang, Wangshu Hou, Yanfang Zhai, Zongyuan Chen, Chengyong Liu, Chuying Ouyang, Xiao Liang, Peerasak Paoprasert, Ning Hu, and Shufeng Song
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cathode electrolyte interphase ,concentrated quasi‐solid electrolyte ,lithium metal batteries ,ring‐opening polymerization ,solid electrolyte interphase ,Renewable energy sources ,TJ807-830 ,Environmental sciences ,GE1-350 - Abstract
Abstract To achieve next‐generation lithium metal batteries (LMBs) with desirable specific energy and reliability, the electrolyte shown simultaneously high reductive stability toward lithium metal anode and oxidative stability toward high‐voltage cathode is of great importance. Here, we report for the first time that high‐concentration lithium bis(fluorosulfonyl)imide (LiFSI) initiates ring‐opening polymerization of 1,3‐dioxolane in presence of ethylene carbonate and ethylmethyl carbonate to produce in‐situ a novel polymeric concentrated quasi‐solid electrolyte (poly‐CQSE). The unique poly‐CQSE with 10 M LiFSI forms a mixed‐lithiophobic‐conductive LiF‐Li3N solid electrolyte interphase on lithium metal anode, and a F‐rich conformal cathode electrolyte interphase on LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode simultaneously. As a result, the poly‐CQSE not only enables stable Li plating/stripping of metallic Li anode at a sound Coulombic efficiency of 95.3% without dendrite growth, but also enables a stable cycling of the Li||NCM523 quasi‐solid‐state LMB at a capacity retention of 94% over 100 cycles.
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- 2023
- Full Text
- View/download PDF
4. A modifiable microarray-based universal sensor: providing sample-to-results automation
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Rubina Yasmin, Hui Zhu, Zongyuan Chen, and Richard A. Montagna
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Bioengineering ,Biotechnology ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
A microfluidic system consisting of generic single use cartridges which interface with a workstation allows the automatic performance of all necessary sample preparation, PCR analysis and interpretation of multiplex PCR assays. The cartridges contain a DNA array with 20 different 16mer DNA “universal” probes immobilized at defined locations. PCR amplicons can be detected via hybridization of user-defined “reporter” probes that are complementary at their 3′ termini to one or more of the universal probes and complementary to the target amplicons at their 5′ termini. The system was able to detect single-plex and multiplex PCR amplicons from various infectious agents as well as wild type and mutant alleles of single nucleotide polymorphisms. The system's ease of use was further demonstrated by converting a published PCR assay for the detection of Mycobacterium genitalium in a fully automated manner. Excellent correlation between traditional manual methods and the automated analysis performed by the workstation suggests that the system can provide a means to easily design and implement a variety of customized PCR-based assays. The system will be useful to researchers or clinical investigators seeking to develop their own user defined assays. As the U.S. FDA continues to pursue regulatory oversight of LDTs, the system would also allow labs to continue to develop compliant assays.
- Published
- 2016
- Full Text
- View/download PDF
5. The influence of psychological control in parenting on children
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Zongyuan Chen
- Abstract
A large amount of literature suggests that all aspects of children’s live will be impacted by excessive parental psychological control, and this paper finds that excessive parental psychological control has an impact on children's peer relationships, family relationships, and adolescent maladjustment. In particular, when parents do not exert psychological control over their adolescents, the adolescents may become involved in drugs and substance abuse as a result of low-quality peer relationships. In addition, this paper focuses on the fact that Chinese families have stronger psychological control than Western families, and that there are bidirectional effects of psychological control in the Chinese family samples. The results discussed in this paper may provide direction for future research, as psychological control is stronger in the Chinese sample and has bidirectional effects.
- Published
- 2022
6. Strengthened erosion resistance of compacted bentonite by layered double hydroxide: A new electrostatic interaction-based approach
- Author
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Zhen Zhang, Pengyuan Gao, Gilles Montavon, Zongyuan Chen, Dongqi Wang, Zhaoyi Tan, Qiang Jin, Wangsuo Wu, Ju Wang, and Zhijun Guo
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Radioactive Waste ,Static Electricity ,Public Health, Environmental and Occupational Health ,Bentonite ,Hydroxides ,Environmental Chemistry ,Clay ,General Medicine ,General Chemistry ,Pollution - Abstract
For the geological repository of high-level radioactive waste (HLW) built in granitic host rock,the control of buffer material (compacted bentonite) erosion and subsequent loss caused by groundwater in granite fissures is an unresolved problem of major concern. We propose here new insight into enhancing the erosion resistance of compacted bentonite by means of its electrostatic interaction with oppositely-charged layered double hydroxide (LDH). The interaction between bentonite and LDH was studied by dropwise addition of colloidal LDH into colloidal bentonite suspension, during which the variation in electrical conductivity, zeta potential and particle size proved a strong interaction between these two materials. Interestingly, in addition to their aggregation, intercalated structures of LDH and montmorillonite were found in the composite (BEN@LDH) by a combined characterization of X-ray diffraction (XRD) and high resolution transmission electron microscopy (HR-TEM), and were confirmed by density functional theory (DFT) calculation. Colloid generation of compacted BEN@LDH under ultrasonic conditions is negligible comparing with that of compacted bentonite, indicating a significantly higher erosion resistance. Besides, a small amount of LDH by mechanically mixing with bentonite (mass ratio 1:99) can also effectively improve the erosion resistance of compacted bentonite. Moreover, BEN@LDH displayed stronger retention performance towards U(VI) and Se(IV) than bentonite under near-neutral/weakly alkaline conditions. Our results indicate that LDH is a promising additive in compacted bentonite, and this approach may be extended to common geotechnical structures built with clays and soils.
- Published
- 2021
7. Co-transport of U(VI), humic acid and colloidal gibbsite in water-saturated porous media
- Author
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Zhijun Guo, Junwei Yang, Qiang Jin, Mengtuan Ge, and Zongyuan Chen
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Water Pollutants, Radioactive ,endocrine system ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Context (language use) ,02 engineering and technology ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,chemistry.chemical_compound ,Colloid ,Zeta potential ,Environmental Chemistry ,Humic acid ,Colloids ,Groundwater ,Gibbsite ,Humic Substances ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Symporters ,Chemistry ,Osmolar Concentration ,digestive, oral, and skin physiology ,Public Health, Environmental and Occupational Health ,Water ,Quartz ,General Medicine ,General Chemistry ,Silicon Dioxide ,Acid mine drainage ,Uranyl ,Pollution ,020801 environmental engineering ,Models, Chemical ,Ionic strength ,Environmental chemistry ,Uranium ,Adsorption ,Porosity - Abstract
The release of uranyl from uranium tailing sites is a widely concerned environmental issue, with limited investigations on the effect of coexistence of various colloids. Gibbsite colloids extensively exist, together with ubiquitous humic substances, in uranium polluted waters at tailing sites, due to high concentration of dissolved Al in acid mine drainage. In this context, we investigated the co-transport of U(VI), gibbsite colloids and humic acid (HA) as a function of pH and ionic strength at a U(VI) concentration (5.0 × 10−5 M) relevant within mine tailings and related waste. It was found that, owing to electrostatic attraction, gibbsite colloids and HA associated with each other and transported simultaneously regardless of U(VI) presence. Besides the impact of pH and ionic strength, whether gibbsite colloids facilitated U(VI) transport depended on HA concentration. Gibbsite colloids impeded U(VI) transport at relatively low HA concentration (≤5 mg L−1), because associated colloids loaded with U(VI) were positively charged which favored colloid retention on negatively charged quartz sand in the column. U(VI) together with gibbsite colloids and low concentration HA was completely blocked at natural pH and/or high ionic strength. At relatively high HA concentration (20 mg L−1), however, the associated colloids showed negative zeta potential which facilitated U(VI) transport because of repulsion between negatively charged colloids and quartz sand. Meanwhile, high concentration of HA dramatically accelerated the transport of gibbsite colloids. These results implied that gibbsite colloids might imped U(VI) migration at uranium tailing sites unless the aquifers are enriched with abundant humic substances.
- Published
- 2019
8. Interaction of environmental colloids and radionuclides: a brief review
- Author
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Wangsuo Wu, Zhen Xu, Zongyuan Chen, Zhiwei Niu, Duoqiang Pan, Zhijun Guo, Yalou Sun, Xiaoyan Wei, and Qiang Jin
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endocrine system ,Radionuclide ,General Chemical Engineering ,digestive, oral, and skin physiology ,Radioactive waste ,General Chemistry ,complex mixtures ,Biochemistry ,Nuclear environment ,body regions ,Environmental chemistry ,Materials Chemistry ,Related research ,Environmental science - Abstract
Environmental colloids exist widely in nature media, due to the strong reactivity and mobility. They can act as a carrier for radionuclides and play an important role in the transport of radionuclides in environment. The interaction between environmental colloids and radionuclides is of great significance to nuclear environment safety as well as nuclear emergency. In recent years, the colloids related issues have attracted much attention in the field of environmental radiochemistry. This review targeted on the typical environmental colloids in disposal environment of radioactive waste. Besides, the progress on interaction between environmental colloids and radionuclides was reviewed, the source, stability and transport of environmental colloids were discussed, common approaches for conducting colloidal related research were summarized, and the influence of environmental colloids on radionuclides migration was analyzed. The points in this review are expected to be referable for a comprehensive and in-depth understanding on the geochemical behavior of environmental colloids and radionuclides.
- Published
- 2018
9. Effects of iron oxide coatings on the mobility and retardation of U(VI) in water saturated media
- Author
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Chao Gao, Qiang Jin, Zhijun Guo, Zongyuan Chen, and Yufeng Sun
- Subjects
chemistry.chemical_compound ,Colloid and Surface Chemistry ,Adsorption ,Kinetic model ,Chemistry ,Inorganic chemistry ,Aqueous two-phase system ,Iron oxide ,Surface complexation ,Porous medium ,Quartz ,Transport system - Abstract
Iron oxide coatings occur commonly in the environment and affect significantly the fate of heavy metals. However, U(VI) transport in water saturated iron oxide-coating porous media has been seldom investigated. In this study, the adsorption and retardation of U(VI) on iron oxide-coated sand were comparatively investigated over a wide range of experimental conditions by batch and column experiments combined with modelling. The presence of iron oxide coatings significantly enhanced U(VI) adsorption which could be described by a two-site surface complexation model. The breakthrough curves of U(VI) in iron oxide coated quartz sand column show a two-plateau profile, which could not be directly reproduced by the commonly used two-site kinetic model. More sites for U(VI) have to be considered, implying that the heterogeneity of surface sites might be more significant in the non-equilibrium transport system than that in the equilibrium adsorption system. In addition, the presence of salicylic acid (SA) facilitated the transport of U(VI) at acidic pH, due to the competition between surface complexation of U(VI) and the complexation of U(VI) with SA in aqueous phase. Overall, this study provides a comprehensive understanding of the migration behavior of U(VI) in water saturated iron oxide-coated sand system.
- Published
- 2021
10. Surface complexation modeling of Eu(III) and phosphate on Na-bentonite: Binary and ternary adsorption systems
- Author
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Wangsuo Wu, Gilles Montavon, Zongyuan Chen, Qiang Jin, and Zhijun Guo
- Subjects
Denticity ,Ternary numeral system ,General Chemical Engineering ,Inorganic chemistry ,General Chemistry ,Surface complexation ,Phosphate ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,Adsorption ,chemistry ,X-ray photoelectron spectroscopy ,Bentonite ,Environmental Chemistry ,Ternary operation - Abstract
This study aims to investigate and model the adsorption of Eu(III) on bentonite in the presence of phosphate. Binary (phosphate/bentonite) and ternary (Eu(III)/phosphate/bentonite) systems were studied as a function of contact time, pH, solid-to-liquid ratio and Eu(III)/phosphate concentration by using a batch experimental method. The adsorption of phosphate on bentonite slightly increased in the pH range of 2.5–6.5, and decreased in the pH range of 6.5–9.4. This adsorption can be quantitatively interpreted by a model considering the formation of three monodentate surface complexes. In the ternary system, a synergistic adsorption was observed in the presence of both phosphate and Eu(III). In addition to the two sub-models describing Eu(III) and phosphate adsorption, the formation of ternary surface complexes had to be considered in order to explain the synergistic effect experimentally observed. The experimental data could be quantitatively explained when Eu(III) ( SOEuH2PO4+ and SOEuHPO4) or phosphate ( SPO4Eu+) are the bridged atoms. Complementary experiments carried out by X-ray photoelectron spectroscopy suggested that the second case is the most probable. The proposed model can be used in order to predict Eu(III) adsorption on buffer/backfilling material in the presence of phosphate.
- Published
- 2014
11. A modifiable microarray-based universal sensor: providing sample-to-results automation
- Author
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Richard A. Montagna, Hui Zhu, Rubina Yasmin, and Zongyuan Chen
- Subjects
0301 basic medicine ,Multidisciplinary ,Microarray ,business.industry ,Interface (computing) ,Sample (material) ,030106 microbiology ,Microfluidics ,Bioengineering ,Computational biology ,Biology ,Amplicon ,Automation ,Molecular biology ,Article ,03 medical and health sciences ,030104 developmental biology ,Multiplex polymerase chain reaction ,lcsh:H1-99 ,lcsh:Social sciences (General) ,business ,lcsh:Science (General) ,Pcr analysis ,Biotechnology ,lcsh:Q1-390 - Abstract
A microfluidic system consisting of generic single use cartridges which interface with a workstation allows the automatic performance of all necessary sample preparation, PCR analysis and interpretation of multiplex PCR assays. The cartridges contain a DNA array with 20 different 16mer DNA "universal" probes immobilized at defined locations. PCR amplicons can be detected via hybridization of user-defined "reporter" probes that are complementary at their 3′ termini to one or more of the universal probes and complementary to the target amplicons at their 5′ termini. The system was able to detect single-plex and multiplex PCR amplicons from various infectious agents as well as wild type and mutant alleles of single nucleotide polymorphisms. The system's ease of use was further demonstrated by converting a published PCR assay for the detection of Mycobacterium genitalium in a fully automated manner. Excellent correlation between traditional manual methods and the automated analysis performed by the workstation suggests that the system can provide a means to easily design and implement a variety of customized PCR-based assays. The system will be useful to researchers or clinical investigators seeking to develop their own user defined assays. As the U.S. FDA continues to pursue regulatory oversight of LDTs, the system would also allow labs to continue to develop compliant assays.
- Published
- 2016
- Full Text
- View/download PDF
12. A Rapid, Self-confirming Assay for HIV: Simultaneous Detection of Anti-HIV Antibodies and Viral RNA
- Author
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Daniel Malamud, Sayli S. Modak, Zongyuan Chen, Cheryl A. Barber, William R. Abrams, Malvin N. Janal, Rubina Yasmin, Hui Zhu, Yhombi Yvon Serge Ongagna, and Richard A. Montagna
- Subjects
0301 basic medicine ,Immunology ,Loop-mediated isothermal amplification ,Dermatology ,Article ,Serology ,03 medical and health sciences ,Virology ,medicine ,Molecular diagnostics ,Seroconversion ,biology ,medicine.diagnostic_test ,business.industry ,HIV diagnostics ,Rapid diagnostics ,Reverse transcriptase ,3. Good health ,AIDS ,030104 developmental biology ,Infectious Diseases ,Immunoassay ,biology.protein ,Antibody ,business ,Viral load ,Loop Mediated Isothermal Amplification (LAMP) - Abstract
Objective: We developed a microfluidic system to simultaneously detect host anti-HIV antibodies and viral RNA in the same specimen in order to satisfy two important diagnostic criteria, especially within resource-limited settings. First, the system can detect acute HIV infection and allow immediate confirmation of a seropositive screening result by detection of HIV RNA. It also addresses the well-known "seroconversion window" during early HIV infection when antibodies are not yet detectable and viral loads are at their highest. Methods: We first developed and optimized two separate manual assays for the detection of host anti-HIV antibodies and viral RNA and then converted them to the microfluidic system. We optimized a commercially available serologic assay to run within the microfluidic device while we incorporated the isothermal LAMP assay to detect the presence of viral RNA. The microfluidic device and instrumentation were developed to simultaneously perform both assays without any user intervention. Results: The finalized system consists of a disposable injection molded and film-laminated microfluidic CARD disposable device and a portable, software controlled instrument, which together can automatically perform all steps of both assays without any user intervention after the initial loading of samples and reagents. The microfluidic CARD cartridge has multiple microchannels, valves, pumps and reservoirs, which perform the immunoassay, isolates viral RNA for detection by magnetic bead based purification, and Reverse Transcriptase loop-mediated isothermal amplification (RT-LAMP). The microfluidic system was able to detect host anti-HIV antibodies and viral RNA in either a blood or saliva sample. Conclusion: The ability to detect antibodies and simultaneously confirm a seropositive HIV-RNA result provides healthcare workers with a complete and accurate appraisal of a patient's infection status in the earliest stages of the disease and represents an important tool for the "Test and Treat" and "Treatment as Prevention" approaches for controlling the HIV epidemic.
- Published
- 2016
13. Rheonix CARD® Technology
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Whitney Honey, Deborah Mahoney, Lincoln C. Young, Travis Lee, Gwendolyn Spizz, Peng Zhou, Richard A. Montagna, Rubina Yasmin, Benjamin W. Thomas, Todd Roswech, Zongyuan Chen, I. Cristina McGuire, Greg Mouchka, and Xun Zhang
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Pathology ,medicine.medical_specialty ,Buccal swab ,Nucleic acid methods ,Computational biology ,Amplicon ,Molecular diagnostics ,Article ,Primer extension ,Multiplex polymerase chain reaction ,medicine ,Multiplex ,Genotyping ,General Nursing - Abstract
A versatile microfluidic platform for the evolving molecular diagnostics industry is described. It incorporates low cost Rheonix CARD(®) (Chemistry and Reagent Device) technology to analyze a variety of clinical specimens. A patented lamination process incorporates all pumps, valves, microchannels and reaction compartments into an inexpensive disposable plastic device. Once an untreated clinical specimen is introduced, all assay steps, including cell lysis, nucleic acid purification, multiplex PCR, and end-point analysis, are automatically performed. Three distinct CARD assays are described which utilize either a low density microarray for multiplex detection of amplicons or an integrated primer extension assay to detect single nucleotide polymorphisms of interest. The STI (Sexually Transmitted Infections) CARD(®) is able to simultaneously detect four sexually transmitted infectious agents (N. gonorrhoeae, C.trachomatis, T. pallidum and T. vaginalis). Human C33A cervical epithelial cells were spiked with different levels of genomic DNA from the four species of interest, singly or in combination, and applied to the CARD device. Using multiplex PCR amplification of the targets followed by microarray detection, the CARD device was able to correctly detect a minimum of 10 copies of each of the four pathogens. The HPV (Human Papillomavirus) CARD(®) was able to detect and distinguish 20 different clinically relevant HPV types using cloned HPV DNA. In addition, the HPV CARD could identify HPV types in vaginal specimens previously demonstrated to contain high or low risk HPV using a currently commercially available testing method. Finally, the detection of specific single nucleotide polymorphisms (SNP) associated with warfarin dosing sensitivity was achieved on the Warfarin Genotyping CARD(®) by analyzing human buccal swabs. Once multiplex PCR was completed, the SNPs were detected using a primer extension assay.
- Published
- 2012
14. The adsorption of Eu(III) on Beishan granite
- Author
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WenYu Tian, ZhiJun Guo, Tao Chen, ZongYuan Chen, Chunli Liu, Chun Li, and WangSuo Wu
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Titration curve ,General Chemical Engineering ,Inorganic chemistry ,Potentiometric titration ,Ionic bonding ,General Chemistry ,Surface complexation ,Biochemistry ,Partition coefficient ,chemistry.chemical_compound ,Adsorption ,Montmorillonite ,chemistry ,Ionic strength ,Materials Chemistry - Abstract
The acid-base chemistry of Beishan (Gansu, China) granite (BS03, 600 m) was studied by potentiometric titration, and the adsorption of Eu(III) on the granite was investigated using a batch technique. It was found that the pHPZNPC of the granite is 9.4 at I = 0.1 M NaCl and decreases to 9.0 at I = 0.4 M NaCl. The profile of parallel titration curves of the granite at variable ionic strengths is roughly comparable to that of montmorillonite under similar conditions. The distribution coefficient ( K d) of Eu(III) on the granite varies with pH, ionic strength and Eu(III) concentration. The K d values of Eu(III) decrease significantly with increasing ionic strength in the low pH range, whereas the effect of ionic strength on the K d values is very weak in the high pH range. The experimental results of Eu(III) adsorption on the granite as a function of pH, ionic strength and Eu(III) concentration were quantitatively interpreted by a model with a cation exchange reaction of Eu3+ on the granite and two inner-sphere surface complexation reactions of Eu(III) on the surface hydroxyl sites. The adsorption of Eu(III) on the granite at I = 0.1 M was predicted by the proposed model, which was compared with the results of Am(III) adsorption on the granite under similar conditions reported by other groups.
- Published
- 2011
15. Lab-on-a-chip for oral cancer screening and diagnosis
- Author
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Haim H. Bau, Michael G. Mauk, Erica M. Falls, Zongyuan Chen, Amy Ziober, and Barry L. Ziober
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Poor prognosis ,medicine.medical_specialty ,Transcription, Genetic ,Early detection ,Disease ,Antigens, Neoplasm ,Biomarkers, Tumor ,medicine ,Humans ,Mass Screening ,RNA, Messenger ,Intensive care medicine ,Mass screening ,Glycoproteins ,Oral cancer screening ,Reverse Transcriptase Polymerase Chain Reaction ,business.industry ,Gene Expression Profiling ,Advanced stage ,Cancer ,Microfluidic Analytical Techniques ,Epithelial Cell Adhesion Molecule ,medicine.disease ,Surgery ,stomatognathic diseases ,Otorhinolaryngology ,Carcinoma, Squamous Cell ,Biomarker (medicine) ,Mouth Neoplasms ,Carrier Proteins ,business ,Cell Adhesion Molecules ,Software - Abstract
Oral squamous cell carcinoma (OSCC) is a disfiguring and deadly cancer. Despite advances in therapy, many patients continue to face a poor prognosis. Early detection is an important factor in determining the survival of patients with OSCC. No accurate, cost-efficient, and reproducible method exists to screen patients for OSCC. As a result, many patients are diagnosed at advanced stages of the disease. Early detection would identify patients, facilitating timely treatment and close monitoring. Mass screening requires a rapid oral cancer diagnostic test that can be used in a clinical setting. Current diagnostic techniques for OSCC require modern laboratory facilities, sophisticated equipment, and elaborate and lengthy processing by skilled personnel. The lab-on-chip technology holds the promise of replacing these techniques with miniaturized, integrated, automated, inexpensive diagnostic devices. This article describes lab-on-chip devices for biomarker-based identification of oral cancer. Similar methods can be employed for the screening of other types of cancers.
- Published
- 2007
16. Determination of genotypes using a fully automated molecular detection system
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Gregory Mouchka, Paulina Klimkiewicz, Peng Zhou, I. Cristina McGuire, Gregory Wilding, Zongyuan Chen, Peng Li, Benjamin W. Thomas, Lincoln C. Young, Rubina Yasmin, Whitney Hungerford, Richard A. Montagna, Devin Zysling, and Gwendolyn Spizz
- Subjects
Genotype ,Genotyping Techniques ,Computer science ,User analysis ,Machine learning ,computer.software_genre ,Polymerase Chain Reaction ,Polymorphism, Single Nucleotide ,DNA sequencing ,Pathology and Forensic Medicine ,Software ,Vitamin K Epoxide Reductases ,Humans ,Genotyping ,Cytochrome P-450 CYP2C9 ,business.industry ,Reproducibility of Results ,General Medicine ,Sequence Analysis, DNA ,Biotechnology ,Isoenzymes ,Medical Laboratory Technology ,Fully automated ,Private practice ,Pharmacogenomics ,Artificial intelligence ,business ,computer - Abstract
ContextAlthough the value of pharmacogenomics to improve patient outcomes has become increasingly clear, adoption in medical practice has been slow, which can be attributed to several factors, including complicated and expensive testing procedures and required equipment, lack of training by private practice physicians, and reluctance of both private and commercial payers to reimburse for such testing.ObjectivesTo evaluate a fully automated molecular detection system for human genotyping assays, starting with anticoagulated whole blood samples, and to perform all sample preparation, assay, and analysis steps automatically with actionable results reported by the system's software.DesignThe genotypes of 254 random individuals were determined by performing bidirectional DNA sequencing, and that information was used to statistically train the imaging software of the automated molecular detection system to distinguish the 3 possible genotypes (ie, homozygous wild type, heterozygous, and homozygous mutant) at each of 3 different loci (CYP2C9*2, CYP2C9*3, and VKORC1).Results—The resulting software algorithm was able to correctly identify the genotypes of all 254 individuals (100%) evaluated without any further user analysis.ConclusionsThe EncompassMDx workstation (Rheonix, Inc, Ithaca, New York) is a molecular detection system that can automatically determine the genotypes of individuals in an unattended manner. Considerably less technical expertise was required to achieve results identical to those obtained using more complex, time-consuming, and expensive bidirectional DNA sequencing. This optimized system may dramatically simplify and reduce the costs of pharmacogenomics testing, thus leading to more-widespread use.
- Published
- 2015
17. Electrochemical reaction with RedOx electrolyte in toroidal conduits in the presence of natural convection
- Author
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Haim H. Bau, Jing Wang, Shizhi Qian, and Zongyuan Chen
- Subjects
Fluid Flow and Transfer Processes ,Convection ,Natural convection ,Materials science ,Mechanical Engineering ,Diffusion ,Thermodynamics ,Electrolyte ,Condensed Matter Physics ,Electrochemistry ,Redox ,Reaction rate ,Electrode ,Physics::Chemical Physics - Abstract
Transport processes in an upright, concentric, annular, electrochemical reactor filled with RedOx electrolyte solution are studied experimentally and theoretically. The electrodes form the two vertical surfaces of the reactor. The theoretical calculations consist of the solution of the Navier–Stokes and the Nernst–Planck equations accounting for species’ diffusion, migration, convection, and electrochemical reactions on the electrodes’ surfaces as a function of the difference in electrodes’ potentials and the average concentration of the electrolyte. Since the convection is driven by density gradients, the momentum and mass transport equations are coupled. The current transmitted through the electrolyte is significantly enhanced by natural convection. The current is measured as a function of the difference in the electrodes’ potentials. To obtain the reaction rate constants, an inverse problem is solved and the reaction rate constants are determined by minimizing the discrepancy between theoretical predictions and experimental observations. As an example, we study the reversible electrochemical reaction Fe +++ + e − = Fe ++ on platinum electrodes.
- Published
- 2006
18. A disposable microfluidic cassette for DNA amplification and detection
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Zongyuan Chen, Michael G. Mauk, Paul L. A. M. Corstjens, Jing Wang, and Haim H. Bau
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Materials science ,Thermal cycler ,business.industry ,Microfluidics ,Ir laser ,Biomedical Engineering ,Analytical chemistry ,Bioengineering ,Phosphor ,General Chemistry ,Microfluidic Analytical Techniques ,Amplicon ,Dna amplification ,Biochemistry ,Hydrogel, Polyethylene Glycol Dimethacrylate ,Flow control (fluid) ,Optoelectronics ,business ,Nucleic Acid Amplification Techniques ,Oligonucleotide Array Sequence Analysis ,Rapid testing - Abstract
A pneumatically driven, disposable, microfluidic cassette comprised of a polymerase chain reaction (PCR) thermal cycler, an incubation chamber to label PCR amplicons with up-converting phosphor (UPT) reporter particles, conduits, temperature-activated, normally closed hydrogel valves, and a lateral flow strip, was constructed and tested. The hydrogel valves, which were opened and closed with the aid of electrically controlled thermoelectric units, provided a simple means to seal the PCR reactor and suppress bubble formation. The hydrogel-based flow control was electronically addressable, leakage-free, and biocompatible. To test the device, a solution laden with genomic DNA isolated from B. cereus was introduced into the microfluidic cassette and a specific 305 bp fragment was amplified. The PCR amplicons were labelled with the phosphor (UPT) reporter particles, applied to the lateral flow strip, bound to pre-immobilized ligands, and detected with an IR laser that scanned the lateral flow strip and excited the phosphor (UPT) particles that, in turn, emitted light in the visible spectrum. The UPT particles do not bleach, they provide a permanent record, and they readily facilitate the filtering of background noise. The cassette described herein will be used for rapid testing at the point of care.
- Published
- 2006
19. Self-Actuated, Thermo-Responsive Hydrogel Valves for Lab on a Chip
- Author
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Jing Wang, Zongyuan Chen, Shu Yang, Haim H. Bau, Mengyan Li, Kuang-Sheng Hong, and Michael G. Mauk
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Materials science ,Microfluidics ,Acrylic Resins ,Biomedical Engineering ,Biocompatible Materials ,Nanotechnology ,Polymerase Chain Reaction ,law.invention ,law ,Materials Testing ,Computer Simulation ,Metering mode ,Molecular Biology ,Leakage (electronics) ,Temperature ,technology, industry, and agriculture ,Hydrogels ,Equipment Design ,Microfluidic Analytical Techniques ,Lab-on-a-chip ,Equipment Failure Analysis ,Flow control (fluid) ,Models, Chemical ,Reagent ,Flow Injection Analysis ,Computer-Aided Design ,Sample collection ,Liquid bubble - Abstract
An easy to fabricate, thermally-actuated, self-regulated hydrogel valve for flow control in pneumatically driven, microfluidic systems is described. This microvalve takes advantage of the properties of the hydrogel, poly(N-isopropylacrylamide), as well as the aqueous fluid itself to realize flow control. The valve was designed for use in a diagnostic system fabricated with polycarbonate and aimed at the detection of pathogens in oral fluids at the location of the sample collection. The paper describes the construction and characterization of the hydrogel valves and their application for flow control, sample and reagent metering, sample distribution into multiple analysis paths, and the sealing of a polymerase chain reaction (PCR) reactor to suppress bubble formation. The hydrogel-based flow control is electronically addressable, does not require any moving parts, introduces minimal dead volume, is leakage and contaminant free, and is biocompatible.
- Published
- 2005
20. Development of a Generic Microfluidic Device for Simultaneous Detection of Antibodies and Nucleic Acids in Oral Fluids
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Zongyuan Chen, Jesus M. Gonzalez, R. Sam Niedbala, Daniel Malamud, Paul L. A. M. Corstjens, Claudia J. de Dood, Peng Zhou, Hans J. Tanke, Eran Geva, and William R. Abrams
- Subjects
Nucleic acid quantitation ,Article Subject ,030231 tropical medicine ,Microfluidics ,Sample processing ,lcsh:Medicine ,HIV Infections ,Computational biology ,Antibodies, Viral ,Polymerase Chain Reaction ,Antibodies ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Nucleic Acids ,Humans ,Viral rna ,Saliva ,030304 developmental biology ,0303 health sciences ,General Immunology and Microbiology ,biology ,lcsh:R ,RNA ,Phosphorus ,Equipment Design ,General Medicine ,Microfluidic Analytical Techniques ,Molecular biology ,3. Good health ,biology.protein ,Nucleic acid ,RNA, Viral ,Antibody ,Research Article - Abstract
A prototype dual-path microfluidic device (Rheonix CARD) capable of performing simultaneously screening (antigen or antibody) and confirmatory (nucleic acid) detection of pathogens is described. The device fully integrates sample processing, antigen or antibody detection, and nucleic acid amplification and detection, demonstrating rapid and inexpensive “sample-to-result” diagnosis with performance comparable to benchtop analysis. For the chip design, a modular approach was followed allowing the optimization of individual steps in the sample processing process. This modular design provides great versatility accommodating different disease targets independently of the production method. In the detection module, a lateral flow (LF) protocol utilizing upconverting phosphor (UCP) reporters was employed. The nucleic acid (NA) module incorporates a generic microtube containing dry reagents. Lateral flow strips and PCR primers determine the target or disease that is diagnosed. Diagnosis of HIV infection was used as a model to investigate the simultaneous detection of both human antibodies against the virus and viral RNA. The serological result is available in less than 30 min, and the confirmation by RNA amplification takes another 60 min. This approach combines a core serological portable diagnostic with a nucleic acid-based confirmatory test.
- Published
- 2013
21. Finger-Actuated, Self-Contained Immunoassay Cassettes
- Author
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Michael G. Mauk, Changchun Liu, Jason A. Thompson, Cheryl A. Barber, Dafeng Chen, Paul L. A. M. Corstjens, Serge Ongagna, Sudhir Ramprasad, Xianbo Qiu, Daniel Malamud, Haim H. Bau, Zongyuan Chen, and William R. Abrams
- Subjects
Immunoassay ,Chromatography ,Materials science ,medicine.diagnostic_test ,Microfluidics ,Interleukin-8 ,Biomedical Engineering ,Human immunodeficiency virus (HIV) ,medicine.disease_cause ,Diagnostic system ,Article ,Microspheres ,Needles ,medicine ,Immobilized proteins ,Fluid motion ,Molecular Biology ,Mixing chamber ,Process operation - Abstract
The building blocks for an inexpensive, disposable, luminescence-based microfluidic immunoassay cassette are described, and their integration in a point-of-care diagnostic system is demonstrated. Fluid motion in the cassette is driven by depressing finger-actuated pouches. All reagents needed for the immunoassay can be stored in the cassette in liquid form. Prior to use, the cassette consists of two separate parts. A top storage component contains pouches, sealed storage chambers, a metering chamber, and needle seats. The bottom processing component contains connection needles, a mixing chamber, and a detection chamber with immobilized proteins. Subsequent to sample introduction, the storage and processing components are mated. The needles form hydraulic connections between the two parts and, in some cases, close valves. The pouches are then actuated sequentially to induce flow of various reagents and facilitate process operations. The cassette is compatible with different detection modalities. Both a cassette with immunochromatographic-based detection and a cassette with microbead-based detection were constructed and evaluated. The immunochromatographic cassette was used to detect antibodies to HIV in saliva samples. The bead-based cassette was used to detect the proinflammatory chemokine IL-8. The experimental data demonstrates good repeatability and reasonable sensitivity.
- Published
- 2009
22. A timer-actuated immunoassay cassette for detecting molecular markers in oral fluids
- Author
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Serge Ongagna, William R. Abrams, Dafeng Chen, Haim H. Bau, Paul L. A. M. Corstjens, Xianbo Qiu, Zongyuan Chen, Changchun Liu, and Daniel Malamud
- Subjects
Immunoassay ,medicine.diagnostic_test ,Computer science ,Biomedical Engineering ,Analytical chemistry ,Human immunodeficiency virus (HIV) ,Bioengineering ,HIV Infections ,General Chemistry ,medicine.disease_cause ,Biochemistry ,Article ,medicine ,Humans ,Timer ,Reagent Kits, Diagnostic ,Saliva ,Biomarkers ,Biomedical engineering ,Point of care - Abstract
An inexpensive, hand-held, point-of-care, disposable, self-contained, immunoassay cassette comprised of air pouches for pumping, a metering chamber, reagents storage chambers, a mixer, and a lateral flow strip was designed, constructed, and tested. The assay was carried out in a consecutive flow format. The detection was facilitated with up-converting, phosphor (UCP) reporter particles. The automated, timely pumping of the various reagents was driven by a spring-loaded timer. The utility of the cassette was demonstrated by detecting antibodies to HIV in saliva samples and further evaluated with a non-contagious, haptenized DNA assay. The cassette has several advantages over dip sticks such as sample preprocessing, integrated storage of reagents, and automated operation that reduces operator errors and training. The cassette and actuator described herein can readily be extended to detect biomarkers of other diseases in body fluids and other fluids at the point of care. The system is particularly suitable for resource poor countries, where funds and trained personnel are in short supply.
- Published
- 2009
23. Thermally-actuated, phase change flow control for microfluidic systems
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Zongyuan Chen, Jing Wang, Haim H. Bau, and Shizhi Qian
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Engineering ,business.industry ,Microfluidics ,Biomedical Engineering ,Temperature ,Mechanical engineering ,Bioengineering ,Control engineering ,General Chemistry ,Microfluidic Analytical Techniques ,Models, Theoretical ,Open flow ,Biocompatible material ,Biochemistry ,Polymerase Chain Reaction ,Phase change ,Flow control (fluid) ,Metering mode ,business ,Closed loop ,Leakage (electronics) - Abstract
An easy to implement, thermally-actuated, noninvasive method for flow control in microfluidic devices is described. This technique takes advantage of the phase change of the working liquid itself—the freezing and melting of a portion of a liquid slug—to noninvasively close and open flow passages (referred to as a phase change valve). The valve was designed for use in a miniature diagnostic system for detecting pathogens in oral fluids at the point of care. The paper describes the modeling, construction, and characteristics of the valve. The experimental results favorably agree with theoretical predictions. In addition, the paper demonstrates the use of the phase change valves for flow control, sample metering and distribution into multiple analysis paths, sealing of a polymerase chain reaction (PCR) chamber, and sample introduction into and withdrawal from a closed loop. The phase change valve is electronically addressable, does not require any moving parts, introduces only minimal dead volume, is leakage and contamination free, and is biocompatible.
- Published
- 2005
24. Determination of Genotypes Using a Fully Automated Molecular Detection System.
- Author
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Spizz, Gwendolyn, Zongyuan Chen, Peng Li, McGuire, I. Cristina, Klimkiewicz, Paulina, Zysling, Devin, Yasmin, Rubina, Hungerford, Whitney, Thomas, Benjamin, Wilding, Gregory, Mouchka, Gregory, Young, Lincoln, Peng Zhou, and Montagna, Richard A.
- Subjects
- *
ALGORITHMS , *AUTOMATION , *COMPUTER software , *LABORATORIES , *MOLECULAR diagnosis , *PHARMACOGENOMICS , *RESEARCH funding , *STATISTICAL sampling , *EVALUATION research , *RECEIVER operating characteristic curves , *DATA analysis software , *SEQUENCE analysis , *GENOTYPES - Abstract
Context.—Although the value of pharmacogenomics to improve patient outcomes has become increasingly clear, adoption in medical practice has been slow, which can be attributed to several factors, including complicated and expensive testing procedures and required equipment, lack of training by private practice physicians, and reluctance of both private and commercial payers to reimburse for such testing. Objectives.—To evaluate a fully automated molecular detection system for human genotyping assays, starting with anticoagulated whole blood samples, and to perform all sample preparation, assay, and analysis steps automatically with actionable results reported by the system's software. Design.—The genotypes of 254 random individuals were determined by performing bidirectional DNA sequencing, and that information was used to statistically train the imaging software of the automated molecular detection system to distinguish the 3 possible genotypes (ie, homozygous wild type, heterozygous, and homozygous mutant) at each of 3 different loci (CYP2C9*2, CYP2C9*3, and VKORC1). Results.—The resulting software algorithm was able to correctly identify the genotypes of all 254 individuals (100%) evaluated without any further user analysis. Conclusions.—The EncompassMDx workstation (Rheonix, Inc, Ithaca, New York) is a molecular detection system that can automatically determine the genotypes of individuals in an unattended manner. Considerably less technical expertise was required to achieve results identical to those obtained using more complex, timeconsuming, and expensive bidirectional DNA sequencing. This optimized system may dramatically simplify and reduce the costs of pharmacogenomics testing, thus leading to more-widespread use. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
25. Surface complexation modeling of Eu(III) and phosphate on Na-bentonite: Binary and ternary adsorption systems.
- Author
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Zongyuan Chen, Qiang Jin, Zhijun Guo, Montavon, Gilles, and Wangsuo Wu
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- *
EUROPIUM compounds , *SODIUM compounds , *ADSORPTION (Chemistry) , *BENTONITE , *PH effect , *PHOSPHATES , *SURFACE chemistry - Abstract
This study aims to investigate and model the adsorption of Eu(III) on bentonite in the presence of phosphate. Binary (phosphate/bentonite) and ternary (Eu(III)/phosphate/bentonite) systems were studied as a function of contact time, pH, solid-to-liquid ratio and Eu(III)/phosphate concentration by using a batch experimental method. The adsorption of phosphate on bentonite slightly increased in the pH range of 2.5-6.5, and decreased in the pH range of 6.5-9.4. This adsorption can be quantitatively interpreted by a model considering the formation of three monodentate surface complexes. In the ternary system, a synergistic adsorption was observed in the presence of both phosphate and Eu(III). In addition to the two sub-models describing Eu(III) and phosphate adsorption, the formation of ternary surface complexes had to be considered in order to explain the synergistic effect experimentally observed. The experimental data could be quantitatively explained when Eu(III) (SOEuH2PO4+ and SOEuHPO4) or phosphate (SPO4Eu+) are the bridged atoms. Complementary experiments carried out by X-ray photoelectron spectroscopy suggested that the second case is the most probable. The proposed model can be used in order to predict Eu(III) adsorption on buffer/backfilling material in the presence of phosphate. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
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