scholarly journals Formation of uniform reaction volumes using concentric amphiphilic microparticles

2020 ◽  
Author(s):  
Ghulam Destgeer ◽  
Mengxing Ouyang ◽  
Chueh-Yu Wu ◽  
Dino Di Carlo
Keyword(s):  
Dynamic Range ◽  
Uv Light ◽  
Sample Volume ◽  
Cross Sectional ◽  
Shape Coding ◽  
Large Numbers ◽  
Mask Design ◽  
3D Printed ◽  
Reaction Volumes ◽  
Rate Ratios

Reactions performed in uniform microscale volumes have enabled numerous applications in the analysis of rare entities (e.g. cells and molecules), however, sophisticated instruments are usually required to form large numbers of uniform compartments. Here, uniform aqueous droplets are formed by simply mixing microscale multi-material particles, consisting of concentric hydrophobic outer and hydrophilic inner layers, with oil and water. The particles are manufactured in batch using a 3D printed device to co-flow four concentric streams of polymer precursors which are polymerized with UV light. The size of the particles is readily controlled by adjusting the fluid flow rate ratios and mask design; whereas the cross-sectional shapes are altered by microfluidic nozzle design in the 3D printed device. Once a particle encapsulates an aqueous volume, each “dropicle” provides uniform compartmentalization and customizable shape-coding for each sample volume to enable multiplexing of uniform reactions in a scalable manner. We implement an enzymatically-amplified affinity assay using the dropicle system, yielding a detection limit of <1 pM with a dynamic range of at least 3 orders of magnitude. Moreover, multiplexing using two types of shape-coded particles was demonstrated without cross talk, laying a foundation for democratized single-entity assays.

scholarly journals Multi-Scale Studies of 3D Printed Mn–Na–W/SiO2 Catalyst for Oxidative Coupling of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 290
Author(s):  
Tim Karsten ◽  
Vesna Middelkoop ◽  
Dorota Matras ◽  
Antonis Vamvakeros ◽  
Stephen Poulston ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Oxidative Coupling Of Methane ◽  
Operating Conditions ◽  
Homogeneous Distribution ◽  
Silica Support ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Multi Scale ◽  
3D Printed

This work presents multi-scale approaches to investigate 3D printed structured Mn–Na–W/SiO2 catalysts used for the oxidative coupling of methane (OCM) reaction. The performance of the 3D printed catalysts has been compared to their conventional analogues, packed beds of pellets and powder. The physicochemical properties of the 3D printed catalysts were investigated using scanning electron microscopy, nitrogen adsorption and X-ray diffraction (XRD). Performance and durability tests of the 3D printed catalysts were conducted in the laboratory and in a miniplant under real reaction conditions. In addition, synchrotron-based X-ray diffraction computed tomography technique (XRD-CT) was employed to obtain cross sectional maps at three different positions selected within the 3D printed catalyst body during the OCM reaction. The maps revealed the evolution of catalyst active phases and silica support on spatial and temporal scales within the interiors of the 3D printed catalyst under operating conditions. These results were accompanied with SEM-EDS analysis that indicated a homogeneous distribution of the active catalyst particles across the silica support.

scholarly journals A tandem giant magnetoresistance assay for one-shot quantification of clinically relevant concentrations of N-terminal pro-B-type natriuretic peptide in human blood

2021 ◽  
Author(s):  
Fanda Meng ◽  
Weisong Huo ◽  
Jie Lian ◽  
Lei Zhang ◽  
Xizeng Shi ◽  
...  
Keyword(s):  
Detection Limit ◽  
Giant Magnetoresistance ◽  
Dynamic Range ◽  
Point Of Care ◽  
Sample Volume ◽  
Small Sample ◽  
Broad Dynamic Range ◽  
Gmr Sensors ◽  
Gmr Sensor ◽  
Sample Volume Requirement

AbstractWe report a microfluidic sandwich immunoassay constructed around a dual-giant magnetoresistance (GMR) sensor array to quantify the heart failure biomarker NT-proBNP in human plasma at the clinically relevant concentration levels between 15 pg/mL and 40 ng/mL. The broad dynamic range was achieved by differential coating of two identical GMR sensors operated in tandem, and combining two standard curves. The detection limit was determined as 5 pg/mL. The assay, involving 53 plasma samples from patients with different cardiovascular diseases, was validated against the Roche Cobas e411 analyzer. The salient features of this system are its wide concentration range, low detection limit, small sample volume requirement (50 μL), and the need for a short measurement time of 15 min, making it a prospective candidate for practical use in point of care analysis.

Usefulness of seroconversion rates for comparing infection pressures between countries

2010 ◽  
Vol 139 (4) ◽  
pp. 636-643 ◽  
Author(s):  
J. SIMONSEN ◽  
P. TEUNIS ◽  
W. VAN PELT ◽  
Y. VAN DUYNHOVEN ◽  
K. A. KROGFELT ◽  
...  
Keyword(s):  
Bayesian Method ◽  
Healthy Population ◽  
Surveillance Systems ◽  
National Surveillance ◽  
Serum Samples ◽  
Cross Sectional ◽  
Infection Pressure ◽  
Control Programmes ◽  
True Infection ◽  
Rate Ratios

SUMMARYSalmonella is a frequent cause of foodborne illness. However, since most symptomatic cases are not diagnosed, the true infection pressure is unknown. Furthermore, national surveillance systems have different sensitivities that limit inter-country comparisons. We have used recently developed methods for translating measurements of Salmonella antibodies into estimates of seroincidence: the frequency of infections including asymptomatic cases. This methodology was applied to cross-sectional collections of serum samples obtained from the general healthy population in three European countries. Denmark and The Netherlands had the lowest seroincidence (84169 infections/1000 person-years), whereas Poland had the highest seroincidence (547/1000 person-years). A Bayesian method for obtaining incidence rate ratios was developed; this showed a 6·3 (95% credibility interval 3·3–12·5) higher incidence in Poland than in Denmark which demonstrates that this methodology has a wider applicability for studies of surveillance systems and evaluation of control programmes.

scholarly journals Polydopamine/Transferrin Hybrid Nanoparticles for Targeted Cell-Killing

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1065 ◽  
Author(s):  
Daniel Hauser ◽  
Manuela Estermann ◽  
Ana Milosevic ◽  
Lukas Steinmetz ◽  
Dimitri Vanhecke ◽  
...  
Keyword(s):  
Cell Death ◽  
Biological Function ◽  
Uv Light ◽  
Melanoma Cells ◽  
Hybrid Nanoparticles ◽  
Apoptosis Induction ◽  
Uv Laser ◽  
Lysosomal Membrane Permeabilization ◽  
Mouse Melanoma ◽  
3D Printed

Polydopamine can form biocompatible particles that convert light into heat. Recently, a protocol has been optimized to synthesize polydopamine/protein hybrid nanoparticles that retain the biological function of proteins, and combine it with the stimuli-induced heat generation of polydopamine. We have utilized this novel system to form polydopamine particles, containing transferrin (PDA/Tf). Mouse melanoma cells, which strongly express the transferrin receptor, were exposed to PDA/Tf nanoparticles (NPs) and, subsequently, were irradiated with a UV laser. The cell death rate was monitored in real-time. When irradiated, the melanoma cells exposed to PDA/Tf NPs underwent apoptosis, faster than the control cells, pointing towards the ability of PDA/Tf to mediate UV-light-induced cell death. The system was also validated in an organotypic, 3D-printed tumor spheroid model, comprising mouse melanoma cells, and the exposure and subsequent irradiation with UV-light, yielded similar results to the 2D cell culture. The process of apoptosis was found to be targeted and mediated by the lysosomal membrane permeabilization. Therefore, the herein presented polydopamine/protein NPs constitute a versatile and stable system for cancer cell-targeting and photothermal apoptosis induction.

scholarly journals Analysis of the Role of Parent’s Lifestyle by the Authoritative Parenting Style in Girls of Grade Three of High School in Zahedan: A Cross Sectional Study

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Azam Akbarizadeh ◽  
Khadijeh Khoeini
Keyword(s):  
High School ◽  
Parenting Style ◽  
Field Studies ◽  
Cross Sectional Study ◽  
Sample Volume ◽  
Authoritative Parenting ◽  
Cross Sectional ◽  
Authoritative Parenting Style ◽  
Political Economic

Background: Every family applies a certain educational style in individual and social education of their children. These styles are influenced by many factors, including cultural, social, political, economic styles, etc. The parents’ lifestyle is one of styles that have a great impact on parenting. In this regard, the goal of present research is analysis of the role of parent’s lifestyle by the authoritative parenting style. Methods: The research method is descriptive-analytic based on library, documentary and field studies. Statistical Society of the research is all intelligent girls of grade three in high school of Zahedan during 2015-2016 school years. Cochran formula has been used to determine the sample volume which 311 people were estimated. Spearman statistical methods and multiple regressions have been used to analyze the data. Results: The results of the research show that the lifestyle and its components have a significant correlation with authoritative parenting style and can predict it. Conclusion: The findings of this study, while having applicable aspects in this domain, can be helpful in planning supplementary remedial procedures.

Environment Influence on the Properties of Functional Parts Made of HIPS Material

2021 ◽  
Vol 105 (1) ◽  
pp. 431-440
Author(s):  
Pavel Šafl ◽  
Jana Zimáková ◽  
Tomáš Binar
Keyword(s):  
Electron Microscope ◽  
3D Printing ◽  
Tensile Test ◽  
Uv Light ◽  
Starting Material ◽  
Climatic Chamber ◽  
3D Printed ◽  
Formation Of Cracks ◽  
Printed Materials ◽  
Degree Of Degradation

The aim of this work is to study the climatic influences on 3D printed materials. This study focuses on the HIPS material, which was chosen as the starting material for further studies. The material in the field of 3D printing is known for its rapid photooxidation, which results in the formation of cracks in the final product. A climatic chamber was used for degradation, in which UV light, heat and increased humidity were applied to the material. The degree of degradation was then checked by tensile test and electron microscope.

Methods of plasma catecholamine measurement including radioimmunoassay

1984 ◽  
Vol 247 (1) ◽  
pp. E4-E12 ◽  
Author(s):  
W. J. Raum
Keyword(s):  
Reference Method ◽  
Sample Volume ◽  
Plasma Catecholamine ◽  
Methyl Transferase ◽  
Radioenzymatic Assay ◽  
Specificity And Sensitivity ◽  
Large Numbers ◽  
Sensitivity Specificity ◽  
Layer Chromatography ◽  
Radioenzymatic Assays

Fluorometric and radioenzymatic assays are presently the most widely used techniques for the estimation of plasma, urine, and tissue catecholamines. The fluorometric assay lacks specificity and sensitivity. The radioenzymatic assay is significantly more sensitive and specific but is technically very complex, time consuming, and expensive. A newer methodology has been developed by modification of a 125I radioimmunoassay for metanephrine. The assay utilizes an antibody that specifically binds metanephrine. Plasma and urinary epinephrine and norepinephrine are detected by conversion to metanephrine with the enzymes catechol-O-methyl-transferase (COMT) and phenylethanolamine-N-methyltransferase (PNMT). The major advantages of the radioimmunoassay are the savings in cost and time. The radioenzymatic assay utilizes an expensive tritium-labeled compound, S-adenosylmethionine, and requires multiple organic solvent-extraction steps, thin-layer chromatography, and liquid scintillation counting. The radioimmunoassay requires only one extraction with alumina to aid in specificity and to concentrate the catecholamines. Sample detection is by gamma counting. The radioenzymatic assay is presently the reference method for catecholamines and is best suited for small numbers of samples where sample volume is limited and exquisite sensitivity is required. The radioimmunoassay is rapid, has sufficient sensitivity, specificity, and precision for most applications and is best applied to the analysis of large numbers of samples.

scholarly journals Automated 3D-printed unibody immunoarray for chemiluminescence detection of cancer biomarker proteins

Lab on a Chip ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 484-489 ◽  
Author(s):  
C. K. Tang ◽  
A. Vaze ◽  
J. F. Rusling
Keyword(s):  
Dynamic Range ◽  
Low Cost ◽  
Protein Detection ◽  
Cancer Biomarker ◽  
Chemiluminescence Detection ◽  
Large Dynamic Range ◽  
3D Printed

A valve-free, low cost 3D-printed device was designed for fast, low cost automated protein detection of PSA and PF-4 with a LOD of 0.5 pg mL−1 and a large dynamic range.

scholarly journals Prevalence study of dermatoses referred to the phototherapy unit at the Dermatology Service of the Clinics Hospital of Porto Alegre, RS, Brazil

2013 ◽  
Vol 88 (2) ◽  
pp. 211-215 ◽  
Author(s):  
Carolina Casara ◽  
Leticia Eidt ◽  
Vivian Cunha
Keyword(s):  
Skin Diseases ◽  
Uv Light ◽  
Secondary Data ◽  
Cross Sectional Study ◽  
Study Data ◽  
Porto Alegre ◽  
Cross Sectional ◽  
Number Of Patients ◽  
Long Time ◽  
Official Data

BACKGROUND: Phototherapy consists of exposure to ultraviolet radiation for therapeutic reasons. Radiation is already used in dermatological practice, and many studies have already proved the beneficial effect of UV light treatment for chronic inflammatory or lymphoproliferative skin diseases. The Dermatology Service of the Clinics Hospital of Porto Alegre (Hospital de Clínicas de Porto Alegre) has been using phototherapy for a long time, and no official data have been described so far. OBJECTIVES: To study the prevalence of dermatoses referred to the phototherapy unit at the Clinics Hospital of Porto Alegre and describe the total number of patients who have already been referred to this sector and their phototype. METHODS: This is a descriptive cross-sectional study. Data were collected through a review of the phototherapy patients' records (secondary data), which are available on a database of the Dermatology Service of the Clinics Hospital of Porto Alegre, from August 1997 to July 2011. RESULTS: A total of 653 records were analyzed. Phototype 3 was the most prevalent (n=313). Distribution of the prevalence of dermatoses referred to the phototherapy unit was as follows: vitiligo (279), psoriasis (255), cutaneous T-cell lymphoma/mycosis fungoides (29), graftversus-host disease (15), scleroderma (11), atopic dermatitis (10), alopecia areata (6), parapsoriasis (5), eczema (4), granuloma annulare (4), and others (35). As vitiligo and psoriasis were the two most prevalent dermatoses, they were analyzed separately, with no statistical difference in prevalence between them (P=0,177). CONCLUSIONS: Our findings are in accordance with the literature, showing that although phototherapy is still mostly indicated to treat psoriasis, it has been used to treat other dermatoses, since the results are promising.

scholarly journals An Optical Filter-Less CMOS Image Sensor with Differential Spectral Response Pixels for Simultaneous UV-Selective and Visible Imaging

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 13
Author(s):  
Yhang Ricardo Sipauba Carvalho da Silva ◽  
Rihito Kuroda ◽  
Shigetoshi Sugawa
Keyword(s):  
Visible Light ◽  
Spectral Sensitivity ◽  
Dynamic Range ◽  
Uv Light ◽  
Spectral Response ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Conversion Gain ◽  
Uv Sensitivity

This paper presents a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) capable of capturing UV-selective and visible light images simultaneously by a single exposure and without employing optical filters, suitable for applications that require simultaneous UV and visible light imaging, or UV imaging in variable light environment. The developed CIS is composed by high and low UV sensitivity pixel types, arranged alternately in a checker pattern. Both pixel types were designed to have matching sensitivities for non-UV light. The UV-selective image is captured by extracting the differential spectral response between adjacent pixels, while the visible light image is captured simultaneously by the low UV sensitivity pixels. Also, to achieve high conversion gain and wide dynamic range simultaneously, the lateral overflow integration capacitor (LOFIC) technology was introduced in both pixel types. The developed CIS has a pixel pitch of 5.6 µm and exhibits 172 µV/e− conversion gain, 131 ke− full well capacity (FWC), and 92.3 dB dynamic range. The spectral sensitivity ranges of the high and low UV sensitivity pixels are of 200–750 nm and 390–750 nm, respectively. The resulting sensitivity range after the differential spectral response extraction is of 200–480 nm. This paper presents details regarding the CIS pixels structures, doping profiles, device simulations, and the measurement results for photoelectric response and spectral sensitivity for both pixel types. Also, sample images of UV-selective and visible spectral imaging using the developed CIS are presented.

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