Ultrahigh-frequency, wireless mems qcm biosensor for direct, label-free detection of biomarkers in a large amount of contaminants

Label-free biosensors, including conventional quartz-crystal-microbalance (QCM) biosensors, are seriously affected by nonspecific adsorption of contaminants involved in analyte solution, and it is exceptionally difficult to extract the sensor responses caused only by the targets. In this study, we reveal that this difficulty can be overcome with an ultrahigh-frequency, wireless QCM biosensor. The sensitivity of a QCM biosensor dramatically improves when the quartz resonator is thinned, which also makes the resonance frequency higher, causing high-speed surface movement. Contaminants weakly (nonspecifically) interact with the quartz surface, but they fail to follow the fast surface movement and cannot be detected as the loaded mass. The targets are, however, tightly captured by the receptor proteins immobilized on the surface, and they can move with the surface, contributing to the loaded mass and decreasing the resonant frequency. We have developed a MEMS QCM biosensor in which an AT-cut quartz resonator, 26 μm thick, is packaged without fixing, and we demonstrate this phenomenon by comparing the frequency changes of the fundamental (∼64 MHz) and ninth (∼576 MHz) modes. At ultrahigh-frequency operation with the ninth mode, the sensor response is independent of the amount of impurity proteins, and the binding affinity is unchanged. We then applied this method to the label-free and sandwich-free, direct detection of C-reactive protein (CRP) in serum and confirmed its applicability.Kentaro Noi, Arihiro Iwata, Fumihito Kato, and Hirotsugu Ogi. Ultrahigh-frequency, wireless mems qcm biosensor for direct, label-free detection of biomarkers in a large amount of contaminants. Analytical Chemistry, 2019, 91(15), 9398-9402. ©2019 American Chemical Society. https://doi.org/10.1021/acs.analchem.9b01414

Design and synthesis of strong root gravitropism inhibitors with no concomitant growth inhibition

Abstract Herein, we describe a highly potent gravitropic bending inhibitor with no concomitant growth inhibition. Previously, we reported that (2Z,4E)-5-phenylpenta-2,4-dienoic acid (ku-76) selectively inhibits root gravitropic bending of lettuce radicles at 5 μM. Based on the structure–activity relationship study of ku-76 as a lead compound, we designed and synthesized various C4-substituted analogs of ku-76. Among the analogs, 4-phenylethynyl analog exhibited the highest potency for gravitropic bending inhibition, which was effective at only 0.01 μM. Remarkably, 4-phenylethynyl analog is much more potent than the known inhibitor, NPA. Substitution in the para position on the aromatic ring of 4-phenylethynyl group was tolerated without diminished activity. In addition, evaluation using Arabidopsis indicated that 4-phenylethynyl analog inhibits gravitropism by affecting auxin distribution in the root tips. Based on the effects on Arabidopsis phenotypes, 4-phenylethynyl analog may be a novel inhibitor that differs in action from the previously reported auxin transport inhibitors

Impact of the Distance from the Stent Edge to the Residual Plaque on Edge Restenosis following Everolimus-Eluting Stent Implantation

<div><p>Objectives</p><p>This study aimed to assess the relation between stent edge restenosis (SER) and the distance from the stent edge to the residual plaque using quantitative intravascular ultrasound.</p><p>Background</p><p>Although percutaneous coronary intervention with drug-eluting stents has improved SER rates, determining an appropriate stent edge landing zone can be challenging in cases of diffuse plaque lesions. It is known that edge vascular response can occur within 2 mm from the edge of a bare metal stent, but the distance to the adjacent plaque has not been evaluated for drug-eluting stents.</p><p>Methods</p><p>A total of 97 proximal residual plaque lesions (plaque burden [PB] >40%) treated with everolimus-eluting stents were retrospectively evaluated to determine the distance from the stent edge to the residual plaque.</p><p>Results</p><p>The SER group had significantly higher PB (59.1 ± 6.1% vs. 51.9 ± 9.1% for non-SER; P = 0.04). Higher PB was associated with SER, with the cutoff value of 54.74% determined using receiver operating characteristic (ROC) curve analysis. At this cutoff value of PB, the distance from the stent edge to the lesion was significantly associated with SER (odds ratio = 2.05, P = 0.035). The corresponding area under the ROC curve was 0.725, and the cutoff distance value for predicting SER was 1.0 mm.</p><p>Conclusion</p><p>An interval less than 1 mm from the proximal stent edge to the nearest point with the determined PB cutoff value of 54.74% was significantly associated with SER in patients with residual plaque lesions.</p></div

Privacy: An Issue of Priority

This note highlights the competing stakes in the online privacy debate. It provides an overview of the U.S. business model of companies that participate in data gathering and analysis, and why they do so (namely because of the emergence of Big Data technologies), and discusses examples of how online privacy has eroded in recent years, in turn highlighting the need for federal action. This note also discusses the current status quo of online privacy in America, and why current legislation is inadequate to address online privacy issues. It further includes a discussion of why the U.S. should let the new EU Directive be a guide for establishing its own comprehensive privacy protection framework, and concludes with an analysis of the most important principles that can be taken from the EU Directive. Additionally, strategies are discussed on how to incentivize companies to engage in beneficial research for the entire industry that could make the transition of complying with the new online privacy regulations more manageable

Study flow chart.

<p>EES: everolimus-eluting stent; IVUS: Intravascular ultrasound; LMT: left main trunk; SER: stent edge restenosis;</p

Procedural characteristics and post-stenting intravascular ultrasound (IVUS) findings.

<p>SER: stent edge restenosis.</p><p>Data are presented as mean ± SD.</p><p>Stent/Lumen ratio is the ratio of stent area to mean lumen area of the proximal reference.</p><p>Stent/Vessel ratio is the ratio of stent area to mean vessel area of the proximal reference.</p><p>P values suggesting statistical significance are shown in italics.</p><p>Procedural characteristics and post-stenting intravascular ultrasound (IVUS) findings.</p