Pattern formation in drying blood drops

Patterns in dried droplets are commonly observed as rings left after spills of dirty water or coffee have evaporated. Patterns are also seen in dried blood droplets and the patterns have been shown to differ from patients afflicted with different medical conditions. This has been proposed as the basis for a new generation of low-cost blood diagnostics. Before these diagnostics can be widely used, the underlying mechanisms leading to pattern formation in these systems must be understood. We analyse the height profile and appearance of dispersions prepared with red blood cells (RBCs) from healthy donors. The red cell concentrations and diluent were varied and compared with simple polystyrene particle systems to identify the dominant mechanistic variables. Typically, a high concentration of non-volatile components suppresses ring formation. However, RBC suspensions display a greater volume of edge deposition when the red cell concentration is higher. This discrepancy is caused by the consolidation front halting during drying for most blood suspensions. This prevents the standard horizontal drying mechanism and leads to two clearly defined regions in final crack patterns and height profile. This article is part of a discussion meeting issue ‘A cracking approach to inventing new tough materials: fracture stranger than friction’.

Download Full-text

Improved photocatalytic conversion of high−concentration ammonia in water by low−cost Cu/TiO2 and its mechanism study

Chemosphere ◽

10.1016/j.chemosphere.2021.129689 ◽

2021 ◽

Vol 274 ◽

pp. 129689

Author(s):

Jianpei Feng ◽

Xiaolei Zhang ◽

Guan Zhang ◽

Ji Li ◽

Wei Song ◽

...

Keyword(s):

Low Cost ◽

Mechanism Study ◽

High Concentration

Download Full-text

Synthesis of poly (n-butyl acrylate) with tempo by nitroxide mediated polymerization method

Polymers and Polymer Composites ◽

10.1177/09673911211024577 ◽

2021 ◽

pp. 096739112110245

Author(s):

Amrita Sharma ◽

PP Pande

Keyword(s):

Butyl Acrylate ◽

Low Cost ◽

Polymerization Process ◽

Polymerization Reaction ◽

High Concentration ◽

Acrylate Monomer ◽

Controlled Polymerization ◽

Acrylate Monomers ◽

Nitroxide Mediated Polymerization ◽

Polymerization Method

It has been observed that acrylate monomers are very difficult to polymerize with the low cost nitroxide catalyst 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Therefore, costly acyclic nitroxides such as N-tert-butyl-N-(1-diethylphosphono-2,2-dimethyl)-N-oxyl, (SG1), 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and TIPNO derivatives have to be used for the polymerization of the acrylic acid derivatives. There are very few reports on the use of TEMPO-derivatives toward the polymerization of n-butyl acrylate. Generally different reducing agents viz. glucose, ascorbic acid, hydroxyacetone etc. have been used to destroy excess TEMPO during the polymerization reaction. The acrylate polymerizations fail in the presence of TEMPO due to the strong C–O bond formed between the acrylate chain end and nitroxide. To the best of our knowledge, no literature report is available on the use of TEMPO without reducing agent or high temperature initiators, toward the polymerization of n-butyl acrylate. The present study has been carried out with a view to re-examine the application of low cost nitroxide TEMPO, so that it can be utilized towards the polymerization of acrylate monomers (e.g. n-butyl acrylate). We have been able to polymerize n-butyl acrylate using the nitroxide TEMPO as initiator (via a macroinitiator). In this synthesis, a polystyrene macroinitiator was synthesized in the first step from TEMPO, after this TEMPO end-capped styrene macroinitiator (PSt-TEMPO) is used to polymerize n-butyl acrylate monomer. The amount of macroinitiator taken was varied from 0.05% to 50% by weight of n-butyl acrylate monomer. The polymerization was carried out at 120°C by bulk polymerization method. The experimental findings showed a gradual increase in molecular weight of the polymer formed and decrease in the polydispersity index (PDI) with increase in amount of PSt-TEMPO macroinitiator taken. In all experiments conversion was more than 80%. These results indicate that the polymerization takes place through controlled polymerization process. Effect of different solvents on polymerization has also been investigated. In the following experiments TEMPO capped styrene has been used as macroinitiator leading to the successful synthesis of poly n-Butyl acrylate. It has been found that styrene macroinitiator is highly efficient for the nitroxide mediated polymerization, even in very small concentration for the synthesis of poly n-butyl acrylate. High concentration of macroinitiator results in the formation of block copolymers of polystyrene and poly ( n-butyl acrylate) viz. polystyrene-block-poly-( n-butyl acrylate). The use of TEMPO toward controlled polymerization is of much importance, because it is the nitroxide commercially available at the lowest cost.

Download Full-text

Modelling of new generation plasma optical devices

Nukleonika ◽

10.1515/nuka-2016-0035 ◽

2016 ◽

Vol 61 (2) ◽

pp. 207-212 ◽

Cited By ~ 2

Author(s):

Irina V. Litovko ◽

Alexy A. Goncharov ◽

Andrew N. Dobrovolskiy ◽

Lily V. Naiko ◽

Irina V. Naiko

Keyword(s):

Low Cost ◽

Rocket Engine ◽

Cost Effective ◽

Optical Devices ◽

High Tech ◽

Practical Applications ◽

Plasma Accelerators ◽

New Generation ◽

Closed Electron ◽

Positive Space

Abstract The paper presents new generation plasma optical devices based on the electrostatic plasma lens configuration that opens a novel attractive possibility for effective high-tech practical applications. Original approaches to use of plasma accelerators with closed electron drift and open walls for the creation of a cost-effective low-maintenance plasma lens with positive space charge and possible application for low-cost, low-energy rocket engine are described. The preliminary experimental, theoretical and simulation results are presented. It is noted that the presented plasma devices are attractive for many different applications in the state-of-the-art vacuum-plasma processing.

Download Full-text

Ultra-high-risk paradigm: lessons learnt and new directions

Evidence-Based Mental Health ◽

10.1136/ebmental-2018-300061 ◽

2018 ◽

Vol 21 (4) ◽

pp. 131-133 ◽

Cited By ~ 17

Author(s):

Patrick D McGorry ◽

Cristina Mei

Keyword(s):

High Risk ◽

Mental Disorders ◽

Psychotic Disorder ◽

Psychotic Disorders ◽

Evidence Base ◽

Ultra High Risk ◽

Underlying Mechanisms ◽

Staging Model ◽

Definition Of ◽

New Generation

Within the embryonic early psychosis field in the early 1990s, the conceptualisation and definition of an at-risk or ultra-high-risk (UHR) mental state for psychosis was a breakthrough which transformed the clinical and research landscape in psychiatry. Twenty-five years later, we have a new evidence base that has illuminated the neurobiology of the onset phase of psychotic disorder, delivered Cochrane level 1 evidence showing that the onset of full-threshold sustained psychotic disorder can be at least delayed, and is paving the way to a new generation of transdiagnostic research. Here, we document the contribution of the UHR approach to understanding the underlying mechanisms of psychosis onset as well as the long-term outcomes. Particularly, we highlight that psychosis onset can be delayed in those meeting UHR criteria and that these criteria have a higher valence for subsequent psychotic disorders and some valence for persistent non-psychotic syndromes. Critiques have helped to identify some of the limitations of this paradigm, which are acknowledged. These include evidence that psychotic disorders can emerge more acutely and from other, as yet undefined, precursor states. Rather than defending, or alternatively questioning the value of, the UHR approach, we propose a broader, transdiagnostic staging model that is consistent with the pluripotent and variably comorbid trajectories for mental disorders. This approach moves beyond psychosis to capture a wider range of subthreshold symptoms and full-threshold disorders, thus enhancing prediction for the emergence and progression of a range of mental disorders, as well as providing new avenues for early intervention and prevention.

Download Full-text

A haemagglutination test for rapid detection of antibodies to SARS-CoV-2

10.1101/2020.10.02.20205831 ◽

2020 ◽

Author(s):

Alain Townsend ◽

Pramila Rijal ◽

Julie Xiao ◽

Tiong Kit Tan ◽

Kuan-Ying A Huang ◽

...

Keyword(s):

High Performance ◽

Point Of Care ◽

Low Cost ◽

Glycophorin A ◽

Red Cell ◽

Special Equipment ◽

Cell Agglutination ◽

Haemagglutination Test ◽

Point Of Care Test ◽

Laboratory Facilities

ABSTRACTSerological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, detection of seroconversion after vaccination, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests have a long history in blood typing, and general serology through linkage of reporter molecules to the red cell surface. They do not require special equipment, are read by eye, have short development times, low cost and can be applied as a Point of Care Test (POCT). We describe a red cell agglutination test for the detection of antibodies to the SARS-CoV-2 receptor binding domain (RBD). We show that the Haemagglutination Test (“HAT”) has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. The HAT can be titrated, detects rising titres in the first five days of hospital admission, correlates well with a commercial test that detects antibodies to the RBD, and can be applied as a point of care test. The developing reagent is composed of a previously described nanobody to a conserved glycophorin A epitope on red cells, linked to the RBD from SARS-CoV-2. It can be lyophilised for ease of shipping. We have scaled up production of this reagent to one gram, which is sufficient for ten million tests, at a cost of ∼0.27 UK pence per test well. Aliquots of this reagent are ready to be supplied to qualified groups anywhere in the world that need to detect antibodies to SARS-CoV-2, but do not have the facilities for high throughput commercial tests.

Download Full-text

Extending the lymphoblastoid cell line model for drug combination pharmacogenomics

Pharmacogenomics ◽

10.2217/pgs-2020-0160 ◽

2021 ◽

Author(s):

Adrian J Green ◽

Benedict Anchang ◽

Farida S Akhtari ◽

David M Reif ◽

Alison Motsinger-Reif

Keyword(s):

Molecular Mechanisms ◽

Cost Model ◽

Low Cost ◽

Clinical Effectiveness ◽

Precision Oncology ◽

Combination Drug ◽

Human Lymphoblastoid Cell ◽

Drug Classes ◽

Integrated Omics ◽

Underlying Mechanisms

Combination drug therapies have become an integral part of precision oncology, and while evidence of clinical effectiveness continues to grow, the underlying mechanisms supporting synergy are poorly understood. Immortalized human lymphoblastoid cell lines (LCLs) have been proven as a particularly useful, scalable and low-cost model in pharmacogenetics research, and are suitable for elucidating the molecular mechanisms of synergistic combination therapies. In this review, we cover the advantages of LCLs in synergy pharmacogenomics and consider recent studies providing initial evidence of the utility of LCLs in synergy research. We also discuss several opportunities for LCL-based systems to address gaps in the research through the expansion of testing regimens, assessment of new drug classes and higher-order combinations, and utilization of integrated omics technologies.

Download Full-text

Compartments, wingless and engrailed: patterning the ventral epidermis of Drosophila embryos

Development ◽

10.1242/dev.122.12.4095 ◽

1996 ◽

Vol 122 (12) ◽

pp. 4095-4103 ◽

Cited By ~ 14

Author(s):

P.A. Lawrence ◽

B. Sanson ◽

J.P. Vincent

Keyword(s):

Pattern Formation ◽

Wing Disc ◽

High Concentration ◽

Good Region ◽

Steep Slopes ◽

Cuticular Structures ◽

Different Levels ◽

Promote Cell Death ◽

Drosophila Embryos

Recent experiments on the wing disc of Drosophila have shown that cells at the interface between the anterior and posterior compartments drive pattern formation by becoming the source of a morphogen. Here we ask whether this model applies to the ventral embryonic epidermis. First, we show that interfaces between posterior (engrailed ON) and anterior (engrailed OFF) cells are required for pattern formation. Second, we provide evidence that Wingless could play the role of the morphogen, at least within part of the segmental pattern. We looked at the cuticular structures that develop after different levels of uniform Wingless activity are added back to unsegmented embryos (wingless- engrailed-). Because it is rich in landmarks, the T1 segment is a good region to analyse. There, we find that the cuticle formed depends on the amount of added Wingless activity. For example, a high concentration of Wingless gives the cuticle elements normally found near the top of the presumed gradient. Unsegmented embryos are much shorter than wild type. If Wingless activity is added in stripes, the embryos are longer than if it is added uniformly. We suggest that the Wingless gradient landscape affects the size of the embryo, so that steep slopes would allow cells to survive and divide, while an even distribution of morphogen would promote cell death. Supporting the hypothesis that Wingless acts as a morphogen, we find that these stripes affect, at a distance, the type of cuticle formed and the planar polarity of the cells.

Download Full-text

Reconstruction of high frequency methane peaks from measurements of metal oxide low-cost sensors using machine learning

10.5194/egusphere-egu21-16027 ◽

2021 ◽

Author(s):

Rodrigo Rivera Martinez ◽

Diego Santaren ◽

Olivier Laurent ◽

Ford Cropley ◽

Cecile Mallet ◽

...

Keyword(s):

Machine Learning ◽

Random Forest ◽

Metal Oxide ◽

High Frequency ◽

Polynomial Regression ◽

Low Cost ◽

Point Sources ◽

Baseline Correction ◽

High Concentration ◽

Industrial Facilities

Deploying a dense network of sensors around emitting industrial facilities allows to detect and quantify possible CH4&#160;leaks and monitor the emissions continuously. Designing such a monitoring network with highly precise instruments is limited by the elevated cost of instruments, requirements of power consumption and maintenance. Low cost and low power metal oxide sensor could come handy to be an alternative to deploy this kind of network at a fraction of the cost with satisfactory quality of measurements for such applications.Recent studies have tested Metal Oxide Sensors (MOx) on natural and controlled conditions to measure atmospheric methane concentrations and showed a fair agreement with high precision instruments, such as those from Cavity Ring Down Spectrometers (CRDS). Such results open perspectives regarding the potential of MOx to be employed as an alternative to measure and quantify CH4 emissions on industrial facilities. However, such sensors are known to drift with time, to be highly sensitive to water vapor mole fraction, have a poor selectivity with several known cross-sensitivities to other species and present significant sensitivity environmental factors like temperature and pressure. Different approaches for the derivation of CH4 mole fractions from the MOx signal and ancillary parameter measurements have been employed to overcome these problems, from traditional approaches like linear or multilinear regressions to machine learning (ANN, SVM or Random Forest).Most studies were focused on the derivation of ambient CH4 concentrations under different conditions, but few tests assessed the performance of these sensors to capture CH4 variations at high frequency, with peaks of elevated concentrations, which corresponds well with the signal observed from point sources in industrial sites presenting leakage and isolated methane emission. We conducted a continuous controlled experiment over four months (from November 2019 to February 2020) in which three types of MOx Sensors from Figaro&#174; measured high frequency CH4 peaks with concentrations varying between atmospheric background levels up to 24 ppm at LSCE, Saclay, France. We develop a calibration strategy including a two-step baseline correction and compared different approaches to reconstruct CH4 spikes such as linear, multilinear and polynomial regression, and ANN and random forest algorithms. We found that baseline correction in the pre-processing stage improved the reconstruction of CH4 concentrations in the spikes. The random forest models performed better than other methods achieving a mean RMSE = 0.25 ppm when reconstructing peaks amplitude over windows of 4 days. In addition, we conducted tests to determine the minimum amount of data required to train successful models for predicting CH4 spikes, and the needed frequency of re-calibration / re-training under these controlled circumstances. We concluded that for a target RMSE <= 0.3 ppm at a measurement frequency of 5s, 4 days of training are required, and a recalibration / re-training is recommended every 30 days.Our study presents a new approach to process and reconstruct observations from low cost CH4 sensors and highlights its potential to quantify high concentration releases in industrial facilities.

Download Full-text

New Generation Transparent Conducting Electrode Materials for Solar Cell Technologies

Materials for Solar Cell Technologies I - Materials Research Foundations ◽

10.21741/9781644901090-4 ◽

2021 ◽

pp. 86-128

Keyword(s):

Electrical Conductivity ◽

Solar Cell ◽

Indium Tin Oxide ◽

Carbon Nanomaterials ◽

Electrode Materials ◽

Low Cost ◽

Optical Transparency ◽

Metal Mesh ◽

Transparent Conducting ◽

New Generation

Transparent conducting electrodes (TCEs) play a vital role for the fabrication of solar cells and pivoted almost 50% of the total cost. Recently several materials have been identified as TCEs in solar cell applications. Still, indium tin oxide (ITO) based TCEs have dominated the market due to their outstanding optical transparency and electrical conductivity. However, inadequate availability of indium has increased the price of ITO based TCEs, which attracts the researchers to find alternative materials to make solar technology economical. In this regard, various kinds of conducting materials are available and synthesized worldwide with high electrical conductivity and optical transparency in order to find alternative to ITO based electrodes. Especially, new generation nanomaterials have opened a new window for the fabrication of cost effective TCEs. Carbon nanomaterials such as graphene, carbon nanotubes (CNTs), metal nanowires (MNWs) and metal mesh (MMs) based electrodes especially attracted the scientific community for fabrication of low cost photovoltaic devices. In addition to it, various conducting polymers such as poly (3, 4-ethylene dioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) based TCEs have also showed their candidacy as an alternative to ITO based TCEs. Thus, the present chapter gives an overview on materials available for the TCEs and their possible use in the field of solar cell technology

Download Full-text

Importance of grass ecosystems for milk and meat production

Кормопроизводство ◽

10.25685/krm.2019.2019.43407 ◽

2019 ◽

Author(s):

Г. Благовещенский ◽

В. Конончук ◽

С. Тимошенко

Keyword(s):

Low Cost ◽

Model Development ◽

General Meeting ◽

Meat Production ◽

Product Price ◽

Animal Products ◽

Model Modification ◽

Maize Cultivation ◽

New Generation ◽

Farmer Income

Данные материалы представляют оценку эффективности распространённых в Европе, основанных на травяных агроэкосистемах технологий производства молочной и мясной продукции, представленных на 27-м Генеральном собрании ЕФЛ 1721 июня 2018 года в Ирландии. В докладах отражается существенное сокращение травяных систем, активизация возделывания кукурузы и использования зернофуражных кормов в рационе, перевода скота на стойловое содержание. Вместе с тем значительная часть материалов отражает возможность пастбищного содержания скота, базирующегося на основе низкозатратного производства животноводческой продукции. Отражается положительное влияние качественной полноценности этой продукции на здоровье человека. Оценивается нетто пищевого протеина человека в зависимости от диеты. Показывается необходимость изменения экономической модели, при которой доход фермеров определяется функцией цены за продаваемую продукцию, субсидий/прямых оплат, ассоциированных стоимостью продукции. Выгоды использования травяных агроэкосистем в производстве ведут к обещающим новым моделям, в которых фермеры финансово вознаграждаются за их добавочный вклад в экосистемное обслуживание. Особое внимание должно уделяться молодым фермерам, представляющим следующую генерацию фермерства. This article reviews the grass ecosystem-based technologies of milk and meat production widespread in Europe and presented at the 27th European Grassland Federation General Meeting (1721 of June 2018, Ireland). The reports showed significant decrease in grass ecosystems, increase in maize cultivation area, grain forage use and indoor livestock maintenance. Most works reported the possibility of low-cost production of animal products based on cattle grazing. Influence of such products was described to be positive on human health. Net protein was evaluated for humans as affected by a diet. The necessity of economic model modification was shown determining farmer income through the product price function, subsidies and direct payments associated with product price. Using grass mixtures in production results in new model development, providing farmers with additional income as a result of their role in ecosystem cultivation. New generation of farmers should be paid special attention.

Download Full-text