Multiplex metal-detection based assay (MMDA) for COVID-19 diagnosis and identification of disease severity biomarkers

The ongoing COVID-19 pandemic caused by SARS-CoV-2 highlights the urgent need to develop sensitive methods for diagnosis and prognosis. To achieve this, multidimensional detection of SARS-CoV-2 related parameters including virus loads, immune response, and inflammation factors is crucial. Herein, by using metal-tagged antibodies as reporting probes, we developed a multiplex metal-detection based assay (MMDA) method as a general multiplex assay strategy for biofluids. This strategy provides extremely high multiplexing capability (theoretically over 100) compared with other reported biofluid assay methods. As a proof-of-concept, MMDA was used for serologic profiling of anti-SARS-CoV-2 antibodies. The MMDA exhibits significantly higher sensitivity and specificity than ELISA for the detection of anti-SARS-CoV-2 antibodies. By integrating the high dimensional data exploration/visualization tool (tSNE) and machine learning algorithms with in-depth analysis of multiplex data, we classified COVID-19 patients into different subgroups based on their distinct antibody landscape. We unbiasedly identified anti-SARS-CoV-2-nucleocapsid IgG and IgA as the most potently induced types of antibodies for COVID-19 diagnosis, and anti-SARS-CoV-2-spike IgA as a biomarker for disease severity stratification. MMDA represents a more accurate method for the diagnosis and disease severity stratification of the ongoing COVID-19 pandemic, as well as for biomarker discovery of other diseases.

A MMDA platform is developed by using metal-tagged antibodies as reporting probes combined with machine learning algorithms, as a general strategy for highly multiplexed biofluid assay.     

AROMATIZATION OF C_6 PARAFFIN OVER Pt/ML(M=K,Rb)AND Pt/AlPO_4-5 CATALYSTS AT DIFFERENT TEMPERATURE

The reaction product distributions from the reactions of n-C6 and MCP over different Pt-catalysts at different temperatures were studied. It is shown that the product distributions depended on the reaction temperatures The influences of the zeolite channel functioned only at high temperature. The activity and selectivity of aromatization of n-C6 over Pt/AIPO4-5 were lower than those over Pt/L zeolite catalysts. A1PO4-5 is a non-basic support and its product distribution and reaction mechanism were different from that of basic-support catalysts such as Pt/KL and Pt/RbL.     

Correction of a coherent image during KrF excimer laser ablation using a mask projection

Using masks for laser ablation has proven useful in the fabrication of prototypes for the manufacturing of micro-fluidic devices. In this work, an excimer laser was used to engrave microscopic channels on the surface of polyethylene terephthalate (PET), which showed a high absorption ratio for an excimer laser beam with a wavelength of 248 nm. When 50 μm wide rectangular microscopic channels were made using a 500×500 μm square mask and a magnification ratio of 1/10, ditch-shaped defects were found at both corners. The calculation of the laser beam intensity showed that a coherent image in the PET specimen caused the defects. An analysis based on the Fourier diffraction theory enabled the prediction of a coherent shape at the image plane, as well as a diffracted beam between the mask and the image plane. The analysis also showed that the diameter of the aperture was a predominant factor toward the elimination of ditch-shaped defects in the rectangular microscopic channels on the PET produced by an excimer laser ablation.     

A new approach to the discretization of chaplygin’s method

5. Conclusion Chaplygin’s method is not convenient for the application in analytical form. However, the discretization of this method can be made successfully. The method of discretization described in this work is easy for the program-ming and, in some cases, gives better results than the Runge—Kutta method. Specifically, this happens when the steph is relatively small. It is highly un-likely that more than 6 iterations are necessary to achieve full accuracy, with 3 iterations being the most usual case. The fact that the upper and lower Chaplygin’s boundary functions be-come almost identical after several iterations (in the sense of the floating point representation of their values on the grid) did not produce noticeable problems, even though it means evident departure from the assumptions of Chaplygin’s Theorem (specifically, the solution of the differential equation ceases to be bounded by the lower and upper functions). Nevertheless, the definite conclusion on this subject requires further theoretical investigation.     

A STUDY OF METHANE OXIDATIVE COUPLING OVER La-Me-O(Me=Mg,Ca,Sr,Ba)CATALYSTS BY MEANS OF TPD

CO2TPD was used to study the surface basicity of La-Me-O mixed oxides and O2-TPD was employed to study the surface active oxygen species. Among numerous catalysts studied , La Ba O (La/Ba=7/3) catalyst had the strongest basicity, and gave the highest CH4 conversion and C2 selectivity.     

Number of Kekulé structures of hexagon-shaped benzenoids

An explicit combinatorial formula for the number of Kekulé structures of a hexagon-shaped benzencid system is deduced. Thus, the validity of the previously proposed, but hitherto unproved formulas of Everett (from 195'1), Woodger (from 1951), and Cyvin from 1986) is confirmed. The proof is based on the application of the John-Sachs theorem.     

Emergence of the genuine Johari-Goldstein secondary relaxation in m-fluoroaniline after suppression of hydrogen-bond-induced clusters by elevating temperature and pressure

The dielectric spectra of the glass former, m-fluoroaniline (m-FA), at ambient pressure show the presence of a secondary relaxation, which was identified in the literature as the universal Johari-Goldstein (JG) beta relaxation. However, published elastic neutron scattering and simulation data [D. Morineau, C. Alba-Simionesco, M. C. Bellisent-Funel, and M. F. Lauthie, Europhys. Lett. 43, 195 (1998); D. Morineau and C. Alba-Simionesco, J. Chem. Phys. 109, 8494 (1998)] showed the presence of hydrogen-bond-induced clusters of limited size in m-FA at ambient pressure and temperature of the dielectric measurements. The observed secondary relaxation may originate from the hydrogen-bond-induced clusters. If so, it should not be identified with the JG beta relaxation that involves essentially all parts of the molecule and has certain characteristics [K. L. Ngai and M. Paluch, J. Chem. Phys. 120, 857 (2004)], but then arises the question of where is the supposedly universal JG beta relaxation in m-FA. To gain a better understanding and resolving the problem, we perform dielectric measurements at elevated pressures and temperatures to suppress the hydrogen-bond-induced clusters and find significant changes in the dielectric spectra. The secondary relaxation observed at ambient pressure in m-FA is suppressed, indicating that indeed it originates from the hydrogen-bond-induced clusters. The spectra of m-FA are transformed at high temperature and pressure to become similar to that of toluene. The new secondary relaxation that emerges in the spectra has properties of a genuine JG relaxation like in toluene.