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.

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 Electrochemistry/Photoelectrochemistry-Based Immunosensing and Aptasensing of Carcinoembryonic Antigen

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7742
Author(s):  
Jingjing Jiang ◽  
Jili Xia ◽  
Yang Zang ◽  
Guowang Diao
Keyword(s):  
Carcinoembryonic Antigen ◽  
Early Cancer ◽  
Low Cost ◽  
High Sensitivity ◽  
Advanced Materials ◽  
Current Trends ◽  
Signaling Strategies ◽  
Development Prospects ◽  
Screening And Diagnosis ◽  
Excellent Selectivity

Recently, electrochemistry- and photoelectrochemistry-based biosensors have been regarded as powerful tools for trace monitoring of carcinoembryonic antigen (CEA) due to the fact of their intrinsic advantages (e.g., high sensitivity, excellent selectivity, small background, and low cost), which play an important role in early cancer screening and diagnosis and benefit people’s increasing demands for medical and health services. Thus, this mini-review will introduce the current trends in electrochemical and photoelectrochemical biosensors for CEA assay and classify them into two main categories according to the interactions between target and biorecognition elements: immunosensors and aptasensors. Some recent illustrative examples are summarized for interested readers, accompanied by simple descriptions of the related signaling strategies, advanced materials, and detection modes. Finally, the development prospects and challenges of future electrochemical and photoelectrochemical biosensors are considered.

scholarly journals A Review of Carbon Dots Produced from Biomass Wastes

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2316
Author(s):  
Chao Kang ◽  
Ying Huang ◽  
Hui Yang ◽  
Xiu Fang Yan ◽  
Zeng Ping Chen
Keyword(s):  
Carbon Dots ◽  
Raw Materials ◽  
Low Cost ◽  
Disease Diagnosis ◽  
Good Choice ◽  
Biomass Waste ◽  
Renewable Raw Materials ◽  
Wide Availability ◽  
Low Cytotoxicity ◽  
Synthetic Approaches

The fluorescent carbon dot is a novel type of carbon nanomaterial. In comparison with semiconductor quantum dots and fluorescence organic agents, it possesses significant advantages such as excellent photostability and biocompatibility, low cytotoxicity and easy surface functionalization, which endow it a wide application prospect in fields of bioimaging, chemical sensing, environmental monitoring, disease diagnosis and photocatalysis as well. Biomass waste is a good choice for the production of carbon dots owing to its abundance, wide availability, eco-friendly nature and a source of low cost renewable raw materials such as cellulose, hemicellulose, lignin, carbohydrates and proteins, etc. This paper reviews the main sources of biomass waste, the feasibility and superiority of adopting biomass waste as a carbon source for the synthesis of carbon dots, the synthetic approaches of carbon dots from biomass waste and their applications. The advantages and deficiencies of carbon dots from biomass waste and the major influencing factors on their photoluminescence characteristics are summarized and discussed. The challenges and perspectives in the synthesis of carbon dots from biomass wastes are also briefly outlined.

scholarly journals Sonography of the iliotibial band: spectrum of findings

2014 ◽  
Vol 47 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Carlos Frederico Arend
Keyword(s):  
Imaging Modality ◽  
Low Cost ◽  
Iliotibial Band ◽  
Band Spectrum ◽  
Correct Identification ◽  
First Line ◽  
Potential Source ◽  
Wide Availability ◽  
Line Imaging ◽  
Clinical Complaint

Iliotibial band lesions constitute a potential source of discomfort and are frequently confounded with other conditions which cause pain on the lateral aspect of the hip, thigh and knee. Ultrasonography is usually regarded as a first-line imaging modality in the assessment of such conditions because of its excellent diagnostic accuracy, low cost and wide availability. The correct identification of the structure involved in the production of symptoms leads to an appropriate management and to a higher probability of resolution of the clinical complaint. The present article is aimed at reviewing the different sonographic presentations of iliotibial band syndromes.

scholarly journals Adapting the MgO-CO2 Working Pair for Thermochemical Energy Storage by Doping with Salts: Effect of the (LiK)NO3 Content

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2262
Author(s):  
Seon Tae Kim ◽  
Haruka Miura ◽  
Hiroki Takasu ◽  
Yukitaka Kato ◽  
Alexandr Shkatulov ◽  
...  
Keyword(s):  
Energy Storage ◽  
Heat Storage ◽  
Low Cost ◽  
Salt Content ◽  
Eutectic Mixture ◽  
High Heat ◽  
High Conversion ◽  
Wide Availability ◽  
Good Potential ◽  
Useful Heat

The MgO-CO2 working pair has been regarded as prospective for thermochemical energy storage (TCES) due to its relatively high heat storage capacity, low cost, and wide availability. This study is aimed at the optimization of the molar salt content, α, for the MgO modified with the eutectic mixture of LiNO3 and KNO3 (Li0.42K0.58NO3) which was earlier shown to provide high conversion, Δx, in heat-storage/release processes at 300–400 °C. The composites that have different salt content were prepared and carbonation kinetics was investigated under various conditions (carbonation temperature, Tcarb., is 290–360 °C and CO2 pressure, P(CO2), is 50–101 kPa). Significant accelerating effect was revealed at α ≥ 0.05, and the Δx value was maximized at α = 0.10–0.20. The largest conversion of 0.70 was detected at α = 0.10 and Tcarb. = 350 °C that corresponds to the specific useful heat (Qcomp.) is 1.63 MJ/kg-composite. However, the salt content of 0.20 ensures the high conversion, Δx = 0.63–0.67 and Qcomp. = 1.18–1.25 MJ/kg-composite in the whole temperature range between 290 and 350 °C. The (LiK)NO3/MgO composite with an optimal salt content of 0.20 exhibits reasonable durability through cyclic experiment at 330 °C, namely, the stabilized reacted conversion Δx = 0.34 (Qcomp. = 0.64 MJ/kg-composite). The studied (Li0.42K0.58)NO3 promoted MgO-CO2 working pair has good potential as thermochemical storage material of middle temperature heat (300–400 °C).

Intelligent Monitoring and Control of Industrial Processes Through the Internet

2002 ◽  
Author(s):  
Poi Loon Tang ◽  
Clarence W. de Silva ◽  
George Wang
Keyword(s):  
Low Cost ◽  
Web Server ◽  
Internet Technology ◽  
Industrial Processes ◽  
Main Element ◽  
Monitoring And Control ◽  
Process Scheduling ◽  
Multiple Control ◽  
Wide Availability ◽  
And Control

This paper presents a framework for developing a universal network infrastructure that would allow web-based monitoring and control of industrial processes, research facilities, and academic experiments. Internet technology is used here for its versatility, wide availability, and relative low cost. The main element of the infrastructure is a web-server, which connects to multiple control-servers, which in turn are connected to various processing modules within a local industrial facility, Since the web-server is the system centerpiece, which provides smooth information flow, a robust, intelligent, and autonomous scheduling scheme is required. Once such infrastructure is established, remote users in an academic or research environment, or in an industrial environment will be able to carry out a variety of tasks including experiments, monitoring and supervision, process scheduling and reconfiguration, using a web-browser. The flexibility and modularity of the developed networked infrastructure provide the rationale for implementing a multi-level hierarchical monitoring and control structure for a process. The usefulness of such a hierarchical structure is demonstrated through an application example on an industrial fish processing machine, which incorporates intelligent adaptive control.

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