scholarly journals Improved yield of AAV2 and rAAV2-retro serotypes following sugar supplementation during the viral production phase

2018 ◽  
Author(s):  
Meghan Rego ◽  
Luke Makana Hanley ◽  
Ina Ersing ◽  
Karen Guerin ◽  
Meron Tasissa ◽  
...  
Keyword(s):  
Antibody Production ◽  
Production Systems ◽  
Low Cost ◽  
Gradient Centrifugation ◽  
Ease Of Use ◽  
Hybridoma Cells ◽  
Viral Production ◽  
Adeno Associated Virus ◽  
Wide Availability ◽  
Viral Preparation

Hyperosmolarity has been used as a means to improve yields in various processes such as antibody production in hybridoma cells and retroviral and adenoviral production systems. In this study we demonstrate that treatment of AAVpro 293T packaging cells with the sugars sucrose or sorbitol during adeno-associated virus (AAV) production improves the yields of AAV2 and rAAV2-retro serotypes 1.8-fold and 1.5-fold, respectively. Using an iodixanol gradient centrifugation strategy followed by a column-based buffer exchange, we show that the sugar supplements are not carried over to the final viral preparation and have no effect on the purity or infectivity of the virus. Given the wide availability, low cost, and ease of use of these sugars, we believe that this strategy can be easily adopted by vector cores and laboratories to improve yields of their AAV preparations.

Causes of gear pump fails and methods for their elimination

2020 ◽  
pp. 98-107
Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev
Keyword(s):  
Adhesion Strength ◽  
Production Systems ◽  
Low Cost ◽  
High Strength ◽  
Strength Properties ◽  
Research Purpose ◽  
Working Fluid ◽  
Gear Pump ◽  
Repair Service ◽  
Recovery Method

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.

scholarly journals Imaging in Propeller Flap Surgery

2020 ◽  
Vol 34 (03) ◽  
pp. 145-151
Author(s):  
Shimpei Ono ◽  
Hiroyuki Ohi ◽  
Rei Ogawa
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Duplex Sonography ◽  
Computed Tomographic Angiography ◽  
Ease Of Use ◽  
Computed Tomographic ◽  
Imaging Tool ◽  
Preoperative Mapping ◽  
Flap Design ◽  
Tomographic Angiography

AbstractSince propeller flaps are elevated as island flaps and most often nourished by a single perforator nearby the defect, it is challenging to change the flap design intraoperatively when a reliable perforator cannot be found where expected to exist. Thus, accurate preoperative mapping of perforators is essential in the safe planning of propeller flaps. Various methods have been reported so far: (1) handheld acoustic Doppler sonography (ADS), (2) color duplex sonography (CDS), (3) perforator computed tomographic angiography (P-CTA), and (4) magnetic resonance angiography (MRA). To facilitate the preoperative perforator assessment, P-CTA is currently considered as the gold standard imaging tool in revealing the three-dimensional anatomical details of perforators precisely. Nevertheless, ADS remains the most widely used tool due to its low cost, faster learning, and ease of use despite an undesirable number of false-positive results. CDS can provide hemodynamic characteristics of the perforator and is a valid and safer alternative particularly in patients in whom ionizing radiation and/or contrast exposure should be limited. Although MRA is less accurate in detecting smaller perforators of caliber less than 1.0 mm and the intramuscular course of perforators at the present time, MRA is expected to improve in the future due to the recent developments in technology, making it as accurate as P-CTA. Moreover, it provides the advantage of being radiation-free with fewer contrast reactions.

scholarly journals Liquid marble based digital microfluidics – fundamentals and applications

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Chin Hong Ooi ◽  
Raja Vadivelu ◽  
Jing Jin ◽  
Sreejith Kamalalayam Rajan ◽  
Pradip Singha ◽  
...  
Keyword(s):  
Low Cost ◽  
Digital Microfluidics ◽  
Ease Of Use ◽  
Liquid Marbles ◽  
Liquid Marble

Liquid marbles are droplets with volume typically on the order of microliters coated with hydrophobic powder. The versatility, ease of use and low cost make liquid marbles an attractive platform...

scholarly journals Molecularly Imprinted Polymers Combined with Electrochemical Sensors for Food Contaminants Analysis

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4607
Author(s):  
Dounia Elfadil ◽  
Abderrahman Lamaoui ◽  
Flavio Della Pelle ◽  
Aziz Amine ◽  
Dario Compagnone
Keyword(s):  
Food Safety ◽  
Molecularly Imprinted Polymers ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Electrochemical Analysis ◽  
Ease Of Use ◽  
Electrochemical Sensing ◽  
Food Contaminants ◽  
Molecularly Imprinted ◽  
Imprinted Polymers

Detection of relevant contaminants using screening approaches is a key issue to ensure food safety and respect for the regulatory limits established. Electrochemical sensors present several advantages such as rapidity; ease of use; possibility of on-site analysis and low cost. The lack of selectivity for electrochemical sensors working in complex samples as food may be overcome by coupling them with molecularly imprinted polymers (MIPs). MIPs are synthetic materials that mimic biological receptors and are produced by the polymerization of functional monomers in presence of a target analyte. This paper critically reviews and discusses the recent progress in MIP-based electrochemical sensors for food safety. A brief introduction on MIPs and electrochemical sensors is given; followed by a discussion of the recent achievements for various MIPs-based electrochemical sensors for food contaminants analysis. Both electropolymerization and chemical synthesis of MIP-based electrochemical sensing are discussed as well as the relevant applications of MIPs used in sample preparation and then coupled to electrochemical analysis. Future perspectives and challenges have been eventually given.

scholarly journals Review of Electrochemical DNA Biosensors for Detecting Food Borne Pathogens

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4916 ◽  
Author(s):  
Qiaoyun Wu ◽  
Yunzhe Zhang ◽  
Qian Yang ◽  
Ning Yuan ◽  
Wei Zhang
Keyword(s):  
Pathogen Detection ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
Ease Of Use ◽  
Detection Methods ◽  
Future Research ◽  
Dna Biosensors ◽  
Food Borne Pathogens ◽  
Chip Technology ◽  
Food Borne

The vital importance of rapid and accurate detection of food borne pathogens has driven the development of biosensor to prevent food borne illness outbreaks. Electrochemical DNA biosensors offer such merits as rapid response, high sensitivity, low cost, and ease of use. This review covers the following three aspects: food borne pathogens and conventional detection methods, the design and fabrication of electrochemical DNA biosensors and several techniques for improving sensitivity of biosensors. We highlight the main bioreceptors and immobilizing methods on sensing interface, electrochemical techniques, electrochemical indicators, nanotechnology, and nucleic acid-based amplification. Finally, in view of the existing shortcomings of electrochemical DNA biosensors in the field of food borne pathogen detection, we also predict and prospect future research focuses from the following five aspects: specific bioreceptors (improving specificity), nanomaterials (enhancing sensitivity), microfluidic chip technology (realizing automate operation), paper-based biosensors (reducing detection cost), and smartphones or other mobile devices (simplifying signal reading devices).

Face recognition in an intelligent door lock with ResNet model based on deep learning

2021 ◽  
pp. 1-11
Author(s):  
Suphawimon Phawinee ◽  
Jing-Fang Cai ◽  
Zhe-Yu Guo ◽  
Hao-Ze Zheng ◽  
Guan-Chen Chen
Keyword(s):  
Face Recognition ◽  
Detection System ◽  
Low Cost ◽  
Ease Of Use ◽  
Raspberry Pi ◽  
Training Methods ◽  
Graphics Recognition ◽  
Face Images ◽  
The Face ◽  
Door Lock

Internet of Things is considerably increasing the levels of convenience at homes. The smart door lock is an entry product for smart homes. This work used Raspberry Pi, because of its low cost, as the main control board to apply face recognition technology to a door lock. The installation of the control sensing module with the GPIO expansion function of Raspberry Pi also improved the antitheft mechanism of the door lock. For ease of use, a mobile application (hereafter, app) was developed for users to upload their face images for processing. The app sends the images to Firebase and then the program downloads the images and captures the face as a training set. The face detection system was designed on the basis of machine learning and equipped with a Haar built-in OpenCV graphics recognition program. The system used four training methods: convolutional neural network, VGG-16, VGG-19, and ResNet50. After the training process, the program could recognize the user’s face to open the door lock. A prototype was constructed that could control the door lock and the antitheft system and stream real-time images from the camera to the app.

scholarly journals A Person-to-Person and Person-to-Place COVID-19 Contact Tracing System Based on OGC IndoorGML

2020 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Soroush Ojagh ◽  
Sara Saeedi ◽  
Steve H. L. Liang
Keyword(s):  
Data Model ◽  
Low Cost ◽  
Large Body ◽  
Contact Tracing ◽  
Trajectory Data ◽  
Sequential Order ◽  
Human Contact ◽  
Wide Availability ◽  
Data Points ◽  
The Impact

With the wide availability of low-cost proximity sensors, a large body of research focuses on digital person-to-person contact tracing applications that use proximity sensors. In most contact tracing applications, the impact of SARS-CoV-2 spread through touching contaminated surfaces in enclosed places is overlooked. This study is focused on tracing human contact within indoor places using the open OGC IndoorGML standard. This paper proposes a graph-based data model that considers the semantics of indoor locations, time, and users’ contexts in a hierarchical structure. The functionality of the proposed data model is evaluated for a COVID-19 contact tracing application with scalable system architecture. Indoor trajectory preprocessing is enabled by spatial topology to detect and remove semantically invalid real-world trajectory points. Results show that 91.18% percent of semantically invalid indoor trajectory data points are filtered out. Moreover, indoor trajectory data analysis is innovatively empowered by semantic user contexts (e.g., disinfecting activities) extracted from user profiles. In an enhanced contact tracing scenario, considering the disinfecting activities and sequential order of visiting common places outperformed contact tracing results by filtering out unnecessary potential contacts by 44.98 percent. However, the average execution time of person-to-place contact tracing is increased by 58.3%.

scholarly journals Environmental Attitudes and Willingness to Purchase Online—Classification Approach

2021 ◽  
Vol 13 (15) ◽  
pp. 8592
Author(s):  
Marcin Gąsior
Keyword(s):  
Information Search ◽  
Environmental Attitudes ◽  
Low Cost ◽  
Ease Of Use ◽  
Internet Users ◽  
Research Procedure ◽  
Willingness To Purchase ◽  
Willingness To Use ◽  
Competitive Pricing ◽  
Self Reporting Questionnaire

During the last several years, a tremendous increase in the popularity of online shopping has been observed. There are several possible reasons behind it, some of them, like competitive pricing, convenience or low cost of information search, considered to be extrinsic, others—like ease of use of this channel, pleasure related to it or willingness to reduce social interactions—intrinsic. The purpose of this research is to evaluate another factor, i.e., consumers’ environmental attitudes, in the perspective of their possible relation with the perception and willingness to use online and conventional shopping channels. In order to achieve this, a self-reporting questionnaire was developed and the data from a representative sample of 1000 Polish Internet users was gathered. The research procedure included cluster analysis, whose objective was to identify groups of customers with similar composition of environmental attitudes and next, a set of Kruskal–Wallis tests, aimed at identifying differences in opinions on channels between these clusters. The research proved that large groups of consumers with consistent sets of environmental attitudes exist and the scope of differences between such clusters is not reduced to a unidimensional, “positive–negative” continuum. Furthermore, there are significant differences between clusters in the declared willingness to use online and conventional shopping channels—groups more environmentally-oriented are more willing to purchase online and trust online shops, although they neither perceive conventional retail in a more negative way nor directly prefer online over conventional channels. The nature of such a phenomenon is open to explanation and interpretation, nevertheless, the research proves that environmental attitudes should be included in future models of consumers’ channel choice.

scholarly journals Plant-Produced Antigen Displaying Virus-Like Particles Evokes Potent Antibody Responses against West Nile Virus in Mice

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 60
Author(s):  
Junyun He ◽  
Huafang Lai ◽  
Adrian Esqueda ◽  
Qiang Chen
Keyword(s):  
West Nile Virus ◽  
Fusion Protein ◽  
Nicotiana Benthamiana ◽  
Specific Binding ◽  
Low Cost ◽  
Gradient Centrifugation ◽  
Conformational Epitope ◽  
Protein Domain ◽  
Core Antigen ◽  
West Nile

In this study, we developed a hepatitis B core antigen (HBcAg)-based virus-like particle (VLP) that displays the West Nile virus (WNV) Envelope protein domain III (wDIII) as a vaccine candidate for WNV. The HBcAg-wDIII fusion protein was quickly produced in Nicotiana benthamiana plants and reached a high expression level of approximately 1.2 mg of fusion protein per gram of leaf fresh weight within six days post gene infiltration. Electron microscopy and gradient centrifugation analysis indicated that the introduction of wDIII did not interfere with VLP formation and HBcAg-wDIII successfully assembled into VLPs. HBcAg-wDIII VLPs can be easily purified in large quantities from Nicotiana benthamiana leaves to >95% homogeneity. Further analysis revealed that the wDIII was displayed properly and demonstrated specific binding to an anti-wDIII monoclonal antibody that recognizes a conformational epitope of wDIII. Notably, HBcAg-wDIII VLPs were shown to be highly immunogenic and elicited potent humoral responses in mice with antigen-specific IgG titers equivalent to that of protective wDIII antigens in previous studies. Thus, our wDIII-based VLP vaccine offers an attractive option for developing effective, safe, and low-cost vaccines against WNV.

scholarly journals Exploring and Exploiting the Symmetry-Breaking Effect of Cyclodextrins in Mechanomolecules

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1249 ◽  
Author(s):  
Bruns
Keyword(s):  
Symmetry Breaking ◽  
Chemical Synthesis ◽  
Low Cost ◽  
Molecular Machine ◽  
Advanced Materials ◽  
Breaking Effect ◽  
Planar Chirality ◽  
Conical Shape ◽  
Wide Availability ◽  
Molecular Rings

Cyclodextrins (CDs) are cone-shaped molecular rings that have been widely employed in supramolecular/host–guest chemistry because of their low cost, high biocompatibility, stability, wide availability in multiple sizes, and their promiscuity for binding a range of molecular guests in water. Consequently, CD-based host–guest complexes are often employed as templates for the synthesis of mechanically bonded molecules (mechanomolecules) such as catenanes, rotaxanes, and polyrotaxanes in particular. The conical shape and cyclodirectionality of the CD “bead” gives rise to a symmetry-breaking effect when it is threaded onto a molecular “string”; even symmetrical guests are rendered asymmetric by the presence of an encircling CD host. This review focuses on the stereochemical implications of this symmetry-breaking effect in mechanomolecules, including orientational isomerism, mechanically planar chirality, and topological chirality, as well as how they support applications in regioselective and stereoselective chemical synthesis, the design of molecular machine prototypes, and the development of advanced materials.

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