Regular Chip Research Articles

Current Advances and Applications of Diagnostic Microfluidic Chip: A Review

Background: As a developed technology, microfluidics now offers a great toolkit for handling and manipulating suspended samples, fluid samples, and particles. A regular chip is different from a microfluidic chip. A microfluidic chip is made of a series of grooves or microchannels carved on various materials. This arrangement of microchannels contained within the microfluidic chip is connected to the outside by inputs and outputs passing through the chip. Objective: This review includes the current progress in the field of microfluidic chips, their advantages and their biomedical applications in diagnosis. Methods: The various manuscripts were collected in the field of microfluidic chip that have biomedical applications from the different sources like Pubmed,Science direct and Google Scholar, out of which some were relevant and considered for the present manuscript. Results: Microfluidic channels inside the chip allow for the processing of the fluid, such as blending and physicochemical reactions. Aside from its practical, technological, and physical benefits, microscale fluidic circuits also improve researchers' capacity to do more accurate quantitative measurements while researching biological systems. Microfluidic chips, a developing type of biochip, were primarily focused on miniaturising analytical procedures, especially to enhance analyte separation. Since then, the procedures for device construction and operation have gotten much simpler. Conclusion: For bioanalytical operations, microfluidic technology has many advantages. As originally intended, a micro total analysis system might be built using microfluidic devices to integrate various functional modules (or operational units) onto a single platform. More researchers were able to design, produce, and use microfluidic devices because of increased accessibility, which quickly demonstrated the probability of wide-ranging applicability in all branches of biology.

High-Efficiency Inertial Separation of Microparticles Using Elevated Columned Reservoirs and Vortex Technique for Lab-on-a-Chip Applications.

The discovery of circulating tumor cells (CTCs) has envisioned an excellent outlook for cancer diagnosis and prognosis. Among numerous efforts proposed for CTCs isolation, vortex separation is a well-known method for capturing CTCs from blood due to its applicability, low sample volume requirement, and ability to retain cell viability. It is a label-free, passive, low-cost, and automated method, making it an ideal solution for lab-on-a-chip applications. The previous designs that employed vortex technology have shown reaching high throughput and 70% separation efficiency although it was after three processing cycles which are not desired. Inspired by our earlier design, in this work, we redesigned the chip geometry by elevating the columned reservoir height to capture more particles and consequently reduce particle-particle collision, eventually improving efficiency. So, a height-variable chip with fewer elevated columned reservoirs (ECRs) was employed to isolate 20 μm microparticles representing CTCs from 8 μm microparticles. Also, numerical simulations were conducted to investigate the third axis contribution to the separation mechanism. The new design with ECRs resulted in a 14% increase in average efficiency, reaching ∼80% ± 8.3% in microparticle separation and 61% purity. Moreover, the proposed chip geometry demonstrated more than three times higher capacity in retaining orbiting particles up to 1300 in peak performance without sacrificing efficiency compared to earlier single-layer designs. We came up with an upgraded injection system to facilitate this chip characterization. We also presented an effortless and straightforward approach for purging air bubbles trapped inside the reservoirs to preserve regular chip operation, especially where there is a mismatch between channel and reservoir heights.

34 Dimensionality of Genomic Information and Its Impact on GWA and Variant Selection: A Simulation Study

Abstract The ability to identify true-positive variants increases as more genotyped animals are available. Although thousands of animals can be genotyped, the dimensionality of the genomic information is limited. Therefore, there is a certain number of animals that represent all chromosome segments (Me) segregating in the population. The number of Me can be approximated from the eigenvalue decomposition of the genomic relationship matrix (G). Thus, the limited dimensionality may help to identify the number of animals to be used in genome-wide association (GWA). The first objective of this study was to examine different discovery set sizes for GWA, with set sizes based on the number of largest eigenvalues explaining a certain proportion of variance in G. Additionally, we investigated the impact of incorporating variants selected from different set sizes to regular SNP chip used for genomic prediction. Sequence data were simulated that contained 500k SNP and 2k QTL, where the genetic variance was fully explained by QTL. The GWA was conducted using the number of genotyped animals equal to the number of largest eigenvalues of G (EIG) explaining 50, 60, 70, 80, 90, 95, 98, and 99 percent of the variance in G. Significant SNP had a p-value lower than 0.05 with Bonferroni correction. Further, SNP with the largest effect size (top10, 100, 500, 1k, 2k, and 4k) were also selected to be incorporated into the 50k regular chip. Genomic predictions using the 50k combined with selected SNP were conducted using single-step GBLUP (ssGBLUP). Using the number of animals corresponding to at least EIG98 enabled the identification of the largest effect size QTL. The greatest accuracy of prediction was obtained when the top 2k SNP was combined to the 50k chip. The dimensionality of genomic information should be taken into account for variant selection in GWAS.

Comparative study on the cutting performance of self-propelled rotary cutters and indexable cutters in milling TC11 titanium alloy

Titanium alloy, with superior mechanical properties, is widely used to manufacture key parts in the aerospace industry. Nonetheless, there exist some problems in machining titanium alloy, such as low machining efficiency, serious tool wear, and difficulty to guarantee the surface quality. In this paper, the comparative experimental study is conducted on milling the titanium alloy TC11 with indexable milling cutters and self-propelled rotary milling ones, and the wear process of the two types of cutters is explored to have found how the milling force, chip micro-morphology, and machined surface quality of theirs vary according to milling length. The experimental results indicate that compared with indexable milling cutters, self-propelled rotary milling cutters show relatively minor and slowly increasing cutting forces. Moreover, self-propelled rotary milling cutters show better wear resistance; that is, the flank wear is more evenly distributed along the cutting edge and the wear rate is slower. The two types of cutters both produce serrated chips, but the curling degree of the chips produced by self-propelled rotary milling cutters is comparatively larger than that by indexable milling cutters, and with the increase of milling length, the former produces more regular chip morphology and evener sawtooth distribution. When the cutting edge wear is slight, the machined surface quality by the two types of cutters does not differ a lot. However, with the increase of the milling length, the wear of indexable milling cutters becomes increasingly serious, and the machined surface quality by it becomes a lot worse as some defects occur such as holes and tearing on the workpiece surface. In comparison, the surface roughness of self-propelled rotary milling cutters get worsen slowly.

Spoofing Attack Results Determination in Code Domain Using a Spoofing Process Equation.

When a user receiver is tracking an authentic signal, a spoofing signal can be transmitted to the user antenna. The question is under what conditions does the tracking point of the receiver move from the authentic signal to the spoofing signal? In this study, we develop a spoofing process equation (SPE) that can be used to calculate the tracking point of the delay lock loop (DLL) at regular chip intervals for the entire spoofing process. The condition for a successful spoofing signal is analyzed using the SPE. To derive the SPE, parameters, such as the signal strength, sweep velocity, loop filter order, and DLL bandwidth are considered. The success or failure of a spoofing attack is determined for a specific spoofing signal using the SPE. In addition, a correlation between each parameter for a successful spoofing attack could be obtained through the SPE. The simulation results show that the SPE performance is largely consistent with that of general DLL methods, even though the computational load of SPE is very low.

Combined immunomagnetic capture coupled with ultrasensitive plasmonic detection of circulating tumor cells in blood.

We demonstrate enhanced on-chip circulating tumor cell (CTC) detection through the incorporation of plasmonic-enhanced near-infrared (NIR) fluorescence screening. Specifically, the performance of plasmonic gold coated chips was evaluated on our previously reported immunomagnetic CTC capture system and compared to the performance of a regular chip. Three main performance metrics were evaluated: capture efficiency, capture reproducibility, and clinical efficacy. Use of the plasmonic chip to capture SK-BR-3 cells in PBS, resulted in a capture efficiency of 82%, compared to 76% with a regular chip. Both chips showed excellent capture reproducibility for all three cells lines evaluated (MCF-7, SK-BR-3, Colo 205) in both PBS and peripheral blood, with R2 values ranging from 0.983 to 0.996. Finally, performance of the plasmonic chip was evaluated on thirteen peripheral blood samples in patients with both breast and prostate cancer. The regular chip detected 2-8 cells per 5mL of blood, while the plasmonic chip detected 8-85 cells per 5mL of blood in parallel samples. In summary, we successfully demonstrate improved CTC capture and detection capabilities through use of plasmonic-enhanced near-infrared (NIR) fluorescence screening in both in vitro and ex vivo experiments. This work not only has the potential to improve clinical outcomes though improved CTC analysis, but also demonstrates successful interface design between plasmonic materials and cell capture for bioanalytical applications.

Hybrid tracking detector based on semiconductor and gas technologies

New Silicon-Gas Pixel Detector (SiGPD) is the result of the further development already proposed Gas-Pixel Detector (GPD). The only disadvantage of GPD was the uncertainty of the particle arriving time. The problem can be solved by additional silicon pixels implementation inside existed electronic chip epitaxial layer during regular chip production. The cost of new Si-Gas Pixel Detector remains practically the same. The new detectors have self-triggering properties and can be used for a first level trigger generation in the particle physics experiments and for many other applications.

SURFACE ROUGHNESS AND CUTTING FORCES IN TURNING OF TOOL STEEL WITH MIXED CERAMIC AND CUBIC BORON NITRIDE CUTTING TOOLS

Tool steel has been widely used, especially to manufacture forming dies and molds by machining processes. Generally, cubic boron nitride (CBN) and ceramic tools are recommended for finish machining a specific steel. This study contributes to filling the research gap for the selection of low- content CBN tools or mixed ceramic tools for turning of hard tool steel. The turning tests were conducted to determine the performance of CBN and the mixed ceramic tools in turning soft (HRC22) and hard (HRC52) H13 tool steel with different cutting speeds, feed rates and depths of cut. ANOVA was used to determine the interaction of the cutting parameters on the surface roughness and cutting forces obtained from turning tests. The results indicate that the surface roughness in hard turning was lower with the CBN tool than with the ceramic tool. On the other hand, the cutting forces in turning with the ceramic tool were lower. Acceptable regular chip formation increases with the cutting speed for each tool.

Nursing Research Across a Large Health Care System

In our journey to achieve Magnet designation, we sought to increase staff nurses' research participation and teach them about the research process by conducting a corporate-wide study, a blind taste test, using potato chips. To compare 3 varieties of the same-brand potato chips for overall preference and perception of healthiness. We hypothesized that the potato chip the nurses liked the best would not be the chip they perceived as the healthiest. For this institutional review board-approved study, nurses were recruited via (1) randomly selected units and (2) a convenience sample during cafeteria lunch hours. After informed consent was obtained, nurses rated each potato chip in a blinded manner, based on appearance, crispiness, flavor, saltiness, and greasiness. They indicated which potato chip they perceived to be the healthiest and which they preferred overall, and they completed an anonymous demographic questionnaire. A total of 263 nurses participated, with 78% being staff nurses. Regular (full fat) was most preferred (37.6%), whereas fat free was least preferred (16%) and also considered the healthiest (45.2%) (P < .0001). Nurses preferred the regular chip and chose the fat-free chip as the healthiest, proving our hypothesis that the preferred chip would not be considered the healthiest. This study was easy, feasible, and helped promote systemwide nursing research.

Research on Chip Breaking Feature of the Micro Hole Vibration Drilling

It is often one of the most important issues for chip breaking and chip removal problems in the hole machining process, especially for micro hole. The chip breaking mechanism of the vibration drilling is researched, and its chip breaking conditions is analyzed. The micro drilling experiments are carried to contrast the chip shape of common drilling and vibration one. It can be draw that the vibration drilling can realize the regular chip breaking, which is beneficial to chip removal in hole machining, the chip breaking feature is one of the fine process effects. This work further enriches the vibration drilling technology.

Recruitment of SWI/SNF Complex Is Required for Transcriptional Activation of the SLC11A1 Gene during Macrophage Differentiation of HL-60 Cells

The solute carrier family 11 member 1 (SLC11A1) gene is strictly regulated and exclusively expressed in myeloid lineage cells. However, little is known about the transcriptional regulation of the SLC11A1 gene during myeloid development. In this study, we used HL-60 cells as a model to investigate the regulatory elements/factors involved in the transactivation of the SLC11A1 gene during phorbol 12-myristate 13-acetate (PMA)-induced macrophage differentiation of HL-60 cells. Promoter deletion analysis showed that a 7-base AP-1-like element (TGACTCT) was critical for the responsiveness of the SLC11A1 promoter to PMA. Stimulation by PMA induced the binding of ATF-3 and the recruitment of two components of the SWI/SNF complex, BRG1 and β-actin, to this element in an ATF-3-dependent manner. RNAi-mediated depletion of ATF-3 or BRG1 markedly decreased SLC11A1 gene expression and its promoter activity induced by PMA. Luciferase reporter experiments demonstrated that ATF-3 cooperated with BRG1 and β-actin to activate the SLC11A1 promoter. Furthermore, we showed that PMA can induce the proximal (GT/AC)(n) repeat sequence to convert to the Z-DNA structure in the SLC11A1 gene promoter, and depletion of BRG1 resulted in a significant decrease of Z-DNA formation. Our results demonstrated that recruitment of the SWI/SNF complex initiated Z-DNA formation and subsequently helped to transactivate the SLC11A1 gene.

Microstructural Evolution in Chips during Machining of Commercially Pure (Grade 2) Titanium

Development of microstructure in chips during machining of Grade 2 titanium at different cutting speeds has been investigated. The morphology of the chip changes from continuous chip to irregular and regular segmented chip with increasing cutting speed. The deformation in continuous and segmented chips is characterized as continuous and localized shear respectively. The deformation mechanism in the irregular segmented chip is the dislocation slip in the continuous region and twinning around the localized shear. Deformation twinning was observed inside the segment between the shear bands in the regular segmented chip. These deformation twins are responsible for the hardening inside the segment.

Influence of Surface Topography on Corrosion of Stainless Steel AISI 304 Turned Surfaces with Different Cutting Conditions

In this study, the correlation between corrosion behaviour and formations, and topographic characteristics of machined surfaces of stainless steel AISI 304 is investigated. Face turning was performed for combinations of cutting conditions, leading to four differing surface patterns owing to regular chip formation, very small chip thickness effect and built-up-edge formation. To simulate industrial and environmental corrosion two corrosion tests were applied i.e. alternate immersion method and exposure to FeCl3 solution. Different corrosion behaviour was revealed through stereoscopic examination of the surfaces with regard to machining conditions and the best global anti-corrosive performance was exhibited by the surfaces generated under regular chip formation.

Multi-parameter identification and control of turned surface textures

A method for characterizing turned surface textures corresponding to varying cutting variables leading to differing profile shape is presented with emphasis on a global view of turning machinability parameters. Through a multi-parameter experimental analysis of turned steel specimens, several standardized parameters are developed. The ability of these parameters are tested to distinguish between different profiles in shape or to identify some particular features with respect to cutting factors. It is indicated that texture statistical functions and parameters are the most effective for relative discrimination and control. Based on the results of this study, new maps for turned surface control are developed. With regards to the variability of some of the parameters at different surface measuring sites, it is evident that the amount of scatter is lower when cutting factors offer regular chip formation.

598 The cancer therapy evaluation program, National Cancer Institute initiative to enhance combination investigational agent clinical trials

We have designed microfluidic devices with the aim of coupling isotachophoresis (ITP) with zone electrophoresis (ZE) as a method to increase the concentration limit of detection in microfluidic devices. We used plastic multi-channel chips, designed with long sample injection channel segments, to increase the sample loading. The chip was designed to allow stacking of the sample into a narrow band by discontinuous ITP buffers and subsequent separation in the ZE mode. In the ITP–ZE mode, with a 2-cm long sample injection plug, sensitivity was increased by 400-fold over chip ZE and we found that the separation performance after the ITP stacking was comparable to that of regular chip ZE. We report sub-picomolar limits of detection of fluorescently labeled ACLARA eTag reporter molecules electrokinetically injected from cell lysate sample matrixes containing moderate salt concentrations. We evaluated sample injections from buffers with varied ionic strengths and found that efficient stacking and separations were obtained in both low and high conductivity buffers, including physiological buffer with at least 140 mM salt. We applied ITP–ZE to the analysis of a cell surface protease (ADAM 17) which used live intact cells in physiological buffers with detection limits below 10 cells/assay.

Sample pre-concentration by isotachophoresis in microfluidic devices.

We have designed microfluidic devices with the aim of coupling isotachophoresis (ITP) with zone electrophoresis (ZE) as a method to increase the concentration limit of detection in microfluidic devices. We used plastic multi-channel chips, designed with long sample injection channel segments, to increase the sample loading. The chip was designed to allow stacking of the sample into a narrow band by discontinuous ITP buffers and subsequent separation in the ZE mode. In the ITP-ZE mode, with a 2-cm long sample injection plug, sensitivity was increased by 400-fold over chip ZE and we found that the separation performance after the ITP stacking was comparable to that of regular chip ZE. We report sub-picomolar limits of detection of fluorescently labeled ACLARA eTag reporter molecules electrokinetically injected from cell lysate sample matrixes containing moderate salt concentrations. We evaluated sample injections from buffers with varied ionic strengths and found that efficient stacking and separations were obtained in both low and high conductivity buffers, including physiological buffer with at least 140 mM salt. We applied ITP-ZE to the analysis of a cell surface protease (ADAM 17) which used live intact cells in physiological buffers with detection limits below 10 cells/assay.