scholarly journals An Immunosensor for the Determination of Cathepsin S in Blood Plasma by Array SPRi—A Comparison of Analytical Properties of Silver–Gold and Pure Gold Chips

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 298
Author(s):  
Pawel Falkowski ◽  
Piotr Mrozek ◽  
Zenon Lukaszewski ◽  
Lukasz Oldak ◽  
Ewa Gorodkiewicz

The array SPR imaging (SPRi) technique is well suited to the determination of biomarkers in body fluids, called liquid biopsy. No signal enhancement or analyte preconcentration is required. With the aim of achieving signal enhancement and lowering the cost of a single determination, the replacement of gold-covered chips by silver–gold chips was investigated. The aim of this work was to investigate the analytical characteristics of a biosensor formed on a Ag/Au chip and to compare them with those of a biosensor formed on a gold chip. A biosensor for the determination of cathepsin S (Cath S) was chosen as an example. The biosensor consisted of the linker cysteamine and an immobilized rat monoclonal antibody specific for cathepsin S. Both biosensors exhibited a Langmuirian response to Cath S concentration, with linear response ranging from LOQ to 1.5 ng mL−1. The LOQ is 0.1 ng mL−1 for the biosensor formed on the Ag/Au chip, and 0.22 ng mL−1 for that formed on the gold chip. Recoveries and precision for medium and high Cath S concentrations were acceptable for both biosensors, i.e., precision better than 10% and recoveries within the range 102–105%. However, the results for the lowest Cath S concentration were better for the biosensor formed on the Ag/Au chip (9.4 and 106% for precision and recovery, respectively). Generally, no significant differences in analytical characteristics were observed between the Ag/Au and Au chips. The two biosensors were also compared in the determination of Cath S in real samples. Nine plasma samples from healthy donors and nine from patients with ovarian cancer were analyzed for Cath S concentration with the biosensors formed on Ag/Au and Au chips. The results obtained with the two biosensors were very similar and show no significant differences on the Bland–Altman plot. The Cath S concentration in the blood plasma of ovarian cancer patients was elevated by one order of magnitude as compared with the control (12.6 ± 3.6 vs. 1.6 ± 1.2 ng mL−1).

Talanta ◽  
2021 ◽  
Vol 225 ◽  
pp. 121900
Author(s):  
Lukasz Oldak ◽  
Anna Sankiewicz ◽  
Beata Żelazowska-Rutkowska ◽  
Bogdan Cylwik ◽  
Zenon Lukaszewski ◽  
...  

2021 ◽  
Author(s):  
Mahboobe Moazampour ◽  
Hamid R. Zare ◽  
Zahra Shekari

Schematic representation of the label free electrochemical genosensor fabrication for detecting miRNA (miR-200a).


Biosensors ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
Pawel Falkowski ◽  
Piotr Mrozek ◽  
Piotr Miluski ◽  
Zenon Lukaszewski ◽  
Ewa Gorodkiewicz

Non-fluidic array SPR imaging (SPRi) with appropriate biosensors is a new tool for the determination of various biomarkers in body fluids. Numerous biomarkers can be determined without signal enhancement or preliminarily preconcentration. The introduction of a new material solution of the chip may increase the scope of the application of this technique. Solutions with adhesive separating foil and an Ag/Au chip were compared with the previously used two-paint separating polymer and pure gold chip. These solutions were tested using the example of a biosensor for cathepsin D (Cath D), which consisted of pepstatin A (a Cath D inhibitor) immobilized via a cysteamine linker using the NHS/EDC protocol. Four material versions of the Cath D biosensor proved adequate in terms of range of linearity, LOQ, precision and recovery. All four versions of the biosensor were used for the determination of Cath D in the blood serum patients with glioblastoma and control samples, producing very similar results and showing an elevated biomarker concentration in the case of cancer. Therefore, the problem of determining the correct level of Cath D in the serum of healthy individuals has been resolved, correcting literature data which ranged over three orders of magnitude.


2021 ◽  
Vol 66 (2) ◽  
pp. 80-86
Author(s):  
O. V. Kovaleva ◽  
T. P. Belova ◽  
D. N. Kushlinsky ◽  
E. A. Korotkova ◽  
P. A. Podlesnaya ◽  
...  

The data of a complex immunoassay comparative study of the content of soluble forms of sPD-1, sPD-L1, sNKG2D, sNKG2DL1, sB7-H3 and sHLA-G in the blood plasma of 75 patients with epithelial ovarian cancer and 20 healthy donors of the control group are presented. The diagnostic significance of the studied proteins was determined. The study showed that the profile of soluble immunity checkpoints differs when malignant ovarian pathology occurs. There was a statistically significant decrease in the content of sPD-L1, sNKG2DL1, sB7-H3, and sHLA-G in the blood plasma of patients compared with the control group. Differences were found in the content of the studied markers depending on the histological type of tumors. Correlations between the soluble forms of some of the studied proteins are shown, indicating the presence of independent mechanisms of immune regulation in ovarian cancer, which may explain the insufficient effectiveness of the existing immunotherapy for this type of tumor. The results obtained will undoubtedly facilitate the development of new effective methods for the diagnostics and therapy of ovarian cancer.


Liquidity ◽  
2017 ◽  
Vol 6 (2) ◽  
pp. 103-109
Author(s):  
Yuri Nanda Larasati ◽  
Jafril Khalil

Regulation of the financial services authority (OJK) No. 31/POJK.05/2016 on Venture had arranged that the financial services agency on the basis of the law of pledge is in coaching and supervision OJK. Yet the existence of laws – invitation to Governing Enterprise pawn shops causing business activities conducted by the above parties are not yet regulated. The condition is feared could cause harm to the consumer society. The purpose of this research is to know the procedures, mechanisms, protection of goods and guarantee the consumer on an informal pledge financing, methods of determination of the cost of maintenance of the goods and the goods of the execution mechanism of the pledge as well as protection for the collateral items are viewed from the side of the consumer by looking at laws-invitations and Sharia. To find out whether the pledge have gotten permission from OJK. This research uses qualitative research methods with the study of library research, field data and simulations. The approach used in this study is the empirical juridical approach. Elaboration upon the results is discussed further in this article.


2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).


2017 ◽  
Vol 3 (1) ◽  
pp. 42
Author(s):  
Roshanira Che Mohd Noor ◽  
Nur Atiqah Rochin Demong

Providing a safe and healthy workplace is one of the most effective strategies in for holding down the cost of doing construction business. It was a part of the overall management system to facilitate themanagement of the occupational health and safety risk that are associated with the business of the organization. Factors affected the awareness level inclusive of safety and health conditions, dangerous working area, long wait care and services and lack of emergency communication werethe contributed factors to the awareness level for the operational level. Total of 122 incidents happened at Telekom Malaysia Berhad as compared to year 2015 only 86 cases. Thus, the main objective of this study was to determine the relationship between safety and health factors and the awareness level among operational workers.The determination of this research was to increase the awareness level among the operational level workerswho committing to safety and health environment.


2016 ◽  
Vol 1 (2) ◽  
pp. 183-190
Author(s):  
Dwi Urip Wardoyo

This study aims to determine the determination of the cost of production for products produced by PT. DWA. The Company is engaged in the manufacturing industry specialized in automotive components. Its activity is carried out through a series of production processes, so that expenses spent in the production will be calculated into the cost of the production sold. The population in this study were all manufacturing companies in Jakarta. Convenience sampling method selected one of the companies that get the confidence to assemble three national car project in Indonesia, namely Timor, Bakrie and Maleo. Test analysis used in this study is to test the calculation of full costing with job order costing. This study shows that (a) determination of the cost elements associated with the cost of production and (b) determining the cost of production on a product-based job costing with full costing approach. Keywords: cost of production, full costing


2020 ◽  
pp. 73-75
Author(s):  
B.M. Bazrov ◽  
T.M. Gaynutdinov

The selection of technological bases is considered before the choice of the type of billet and the development of the route of the technological process. A technique is proposed for selecting the minimum number of sets of technological bases according to the criterion of equality in the cost price of manufacturing the part according to the principle of unity and combination of bases at this stage. Keywords: part, surface, coordinating size, accuracy, design and technological base, labor input, cost price. [email protected]


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