scholarly journals Detection of Non-nitro Compounds by Amplified Fluorescence Polymer (AFP): An Opportunity for Breath-Based Disease Diagnosis

2021 ◽  
Vol 33 (9) ◽  
pp. 2229-2236
Author(s):  
D. Sharath Kumar ◽  
H.S. Pallavi ◽  
Phani Kumar Pullela

Amplified fluorescence polymers (AFP) are a set of unique polymers known for their ability to detect trace nitro explosives. The prior knowledge in the AFP field indicates that the functional group variation on the polymer backbone is responsible for the selectivity of an analyte. The mechanism of analyte detection is believed that only compounds with nitro functional groups are detected by AFP. Usually, AFP functional groups varied to detect nitro compounds and the non-nitro compound detection and the mechanism of the AFP were not completely understood. In this work, the AFP polymer was kept constant and studied with 136 analytes with different functional groups for analyzing few non-nitro compounds. Among the 136 compounds analyzed, about fourteen have been detected by AFP. It was observed that most of the fourteen compounds were non-nitro compounds. The mechanism proposed originally for nitro compounds and associated hypothesises the existence of a parking space on the polymer backbone. Present study suggested that the possibility of only nitro compounds interacting with AFP due to the three-dimensional shape of the analyte as the detrimental factor. The discovery of non-nitro compound detection by AFP opens up the use of AFP for gas-phase disease volatile organic compound detection. Future studies of functional group variation on the AFP backbone in relation to the analyte detection could provide insights into the relation of analyte detection by AFP and the parameters to optimize for obtaining the selectivity and specificity.

2021 ◽  
Vol 288 (1943) ◽  
pp. 20202604
Author(s):  
Karen L. Baab

Homo erectus is the first hominin species with a truly cosmopolitan distribution and resembles recent humans in its broad spatial distribution. The microevolutionary events associated with dispersal and local adaptation may have produced similar population structure in both species. Understanding the evolutionary population dynamics of H. erectus has larger implications for the emergence of later Homo lineages in the Middle Pleistocene. Quantitative genetics models provide a means of interrogating aspects of long-standing H. erectus population history narratives. For the current study, cranial fossils were sorted into six major palaeodemes from sites across Africa and Asia spanning 1.8–0.1 Ma. Three-dimensional shape data from the occipital and frontal bones were used to compare intraspecific variation and test evolutionary hypotheses. Results indicate that H. erectus had higher individual and group variation than Homo sapiens , probably reflecting different levels of genetic diversity and population history in these spatially disperse species. This study also revealed distinct evolutionary histories for frontal and occipital bone shape in H. erectus , with a larger role for natural selection in the former. One scenario consistent with these findings is climate-driven facial adaptation in H. erectus , which is reflected in the frontal bone through integration with the orbits.


2016 ◽  
Vol 19 (2) ◽  
pp. 93-100
Author(s):  
Lalita El Milla

Scaffolds is three dimensional structure that serves as a framework for bone growth. Natural materials are often used in synthesis of bone tissue engineering scaffolds with respect to compliance with the content of the human body. Among the materials used to make scafffold was hydroxyapatite, alginate and chitosan. Hydroxyapatite powder obtained by mixing phosphoric acid and calcium hydroxide, alginate powders extracted from brown algae and chitosan powder acetylated from crab. The purpose of this study was to examine the functional groups of hydroxyapatite, alginate and chitosan. The method used in this study was laboratory experimental using Fourier Transform Infrared (FTIR) spectroscopy for hydroxyapatite, alginate and chitosan powders. The results indicated the presence of functional groups PO43-, O-H and CO32- in hydroxyapatite. In alginate there were O-H, C=O, COOH and C-O-C functional groups, whereas in chitosan there were O-H, N-H, C=O, C-N, and C-O-C. It was concluded that the third material containing functional groups as found in humans that correspond to the scaffolds material in bone tissue engineering.


2006 ◽  
Vol 37 (4) ◽  
pp. 583
Author(s):  
Michael McGowan

This article examines the relatively new fields of colour and shape trade marks. It was initially feared by some academics that the new marks would encroach on the realms of patent and copyright.  However, the traditional requirements of trade mark law, such as functionality and descriptiveness, have meant that trade marks in colour and shape are extremely hard to acquire if they do not have factual distinctiveness. As colour and shape trade marks have no special restrictions, it is proposed that the combination trade mark theory and analysis from the Diamond T case should be used as a way to make them more accessible. The combination analysis can be easily applied because every product has a three dimensional shape and a fourth dimension of colour.


2017 ◽  
Author(s):  
Tatsuya Kitamura ◽  
Hironori Takemoto ◽  
Hisanori Makinae ◽  
Tetsutaro Yamaguchi ◽  
Kotaro Maki

i-Perception ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 204166952098231
Author(s):  
Masakazu Ohara ◽  
Juno Kim ◽  
Kowa Koida

Perceiving the shape of three-dimensional objects is essential for interacting with them in daily life. If objects are constructed from different materials, can the human visual system accurately estimate their three-dimensional shape? We varied the thickness, motion, opacity, and specularity of globally convex objects rendered in a photorealistic environment. These objects were presented under either dynamic or static viewing condition. Observers rated the overall convexity of these objects along the depth axis. Our results show that observers perceived solid transparent objects as flatter than the same objects rendered with opaque reflectance properties. Regional variation in local root-mean-square image contrast was shown to provide information that is predictive of perceived surface convexity.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1109
Author(s):  
Varnakavi. Naresh ◽  
Nohyun Lee

A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal. The design and development of biosensors have taken a center stage for researchers or scientists in the recent decade owing to the wide range of biosensor applications, such as health care and disease diagnosis, environmental monitoring, water and food quality monitoring, and drug delivery. The main challenges involved in the biosensor progress are (i) the efficient capturing of biorecognition signals and the transformation of these signals into electrochemical, electrical, optical, gravimetric, or acoustic signals (transduction process), (ii) enhancing transducer performance i.e., increasing sensitivity, shorter response time, reproducibility, and low detection limits even to detect individual molecules, and (iii) miniaturization of the biosensing devices using micro-and nano-fabrication technologies. Those challenges can be met through the integration of sensing technology with nanomaterials, which range from zero- to three-dimensional, possessing a high surface-to-volume ratio, good conductivities, shock-bearing abilities, and color tunability. Nanomaterials (NMs) employed in the fabrication and nanobiosensors include nanoparticles (NPs) (high stability and high carrier capacity), nanowires (NWs) and nanorods (NRs) (capable of high detection sensitivity), carbon nanotubes (CNTs) (large surface area, high electrical and thermal conductivity), and quantum dots (QDs) (color tunability). Furthermore, these nanomaterials can themselves act as transduction elements. This review summarizes the evolution of biosensors, the types of biosensors based on their receptors, transducers, and modern approaches employed in biosensors using nanomaterials such as NPs (e.g., noble metal NPs and metal oxide NPs), NWs, NRs, CNTs, QDs, and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.


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