Nationwide population-based surveys of Iranian COVID-19 Serological Surveillance (ICS) program: The surveys protocol.

Background: Serological surveillance of COVID-19 through conducting repetitive population-based surveys can be useful in estimating and monitoring changes in the prevalence of infection across the country. This paper presents the protocol of nationwide population-based surveys of the Iranian COVID-19 Serological Surveillance (ICS) program. Methods: The target population of the surveys is all individuals ≥6 years in Iran. Stratified random sampling will be used to select participants from those registered in the primary health care electronic record systems in Iran. The strata are the 31 provinces of the country, in which sampling will be done through simple random sampling. The sample size is estimated 858 individuals for each province (except for Tehran province, which is 2574) at the first survey. It will be recalculated for the next surveys based on the findings of the first survey. The participants will be invited by the community health workers to the safe blood sampling centers at the district level. After obtaining written informed consent, 10 mL of venous blood will be taken from the participants. The blood samples will be transferred to selected reference laboratories in order to test IgG and IgM antibodies against COVID-19 using an Iranian SARS-CoV-2 ELISA Kit (Pishtaz Teb). A serologically positive test is defined as a positive IgG, IgM, or both. After adjusting for the measurement error of the laboratory test, nonresponse bias, and sampling design, the prevalence of COVID-19 will be estimated at the provincial and national levels. Also, the approximate incidence rate of infection will be calculated based on the data of both consecutive surveys. Conclusion: The implementation of these surveys will provide a comprehensive and clear picture of the magnitude of COVID-19 infection and its trend over time for health policymakers at the national and subnational levels.

RHD genotyping of serological weak D phenotypes in the Iranian blood donors and patients.

BACKGROUND: Most prevalent weak D types in the Caucasians molecularly defined weak D types 1, 2 or 3 and can be managed safely as RhD-positive, conserving limited supplies of RhD-negative RBCs. Therefore, identification of RHD alleles prevalence in each population could improve the policies related to accuracy of RhD typing. The aim of this study was to determine the frequency of RHD variant alleles among donors and patients for the first time in Iran. MATERIALS AND METHODS: RHD genotyping was performed on 100 blood donor and patient samples with weak D phenotype. PCR-SSP and DNA sequencing were used to identify the RHD alleles. RESULTS: Molecular analysis showed only 15 samples were RHD*weak D 1(n = 13) and RHD*weak D 3(n = 2), and no cases of RHD*weak D 2 were detected. RHD*weak 15 (n = 43) was determined as the most prevalent D variants in our population and the other weak D types follows: RHD*weak 4, 5, 80 and one case of each one: RHD*weak 8, 11, 14, 100 and 105. Partial D variants also was identified in 18 samples as follows: RHD*partial DLO, DBT1, DV2, DHK and DAU-1. CONCLUSION: The results of this study highlight the specific pattern of RHD status in the Iranian population. The weak D types 15 was the most common weak D type in the Iranian population. However, the screening for weak D types 1, 2 and 3 with 15 % frequency is also necessary for accurate RhD typing and developing clinical strategy of blood transfusion in weak D patients.

Three-Dimensional Surface Stereometric Analysis of Ni-Cu Films with Different Cu Contents.

The purpose of this work is a stereometric analysis of Ni-Cu thin films to obtain the three-dimensional (3D) microtexture surface based on atomic force microscopy (AFM). Four Ni-Cu thin films on glass and silicon substrates were prepared by a capacitively coupled RF-PECVD system with a 13.56 MHz power supply. The AFM data of the samples were stereometrically analyzed, and the surface microtexture was determined according to the definition of relevant parameters in the standards ISO 25178-2:2012 and ASME B46.1-2009. All microtexture features can be implemented in numerical programs to simulate advanced microtexture models under specific microstructure and composition conditions. The results can be used to validate theoretical models for predicting or correlating the surface parameters of nanostructures. The Ni-Cu films with 40% Cu have a more irregular surface; hence, the maximum Sq value of the as-deposited Ni-Cu films is about 81.24 µm. The core roughness height Sk is calculated as a difference between two extreme levels (maximal and minimal) of the surface core, for which Ni-Cu films with 40% Cu have a maximum value of 183.4 µm. Since the surface kurtosis (Sku) of all sample films was lower than 7, there are very small peaks or valleys on the film surface and for Ni-Cu films with 5% Cu with a value of 3.568. With increasing Cu content, the height distribution histograms of films show more uniform distributions.

The optical density and topography characterizations of MWCNTs on Ni-Cu/ a-C:H substrates with different copper percentage.

In this article, the Ni-Cu nanoparticles (NPs) in the amorphous carbon hydrogenated thin films with different copper percentage by co-deposition of RF-plasma enhanced chemical vapor deposition were prepared using acetylene gas and Ni and Cu targets. The films deposited with 5% Cu have minimum value of the average diameter of Multi-walled Carbon Nanotubes, MWCNTs, in about of 100 nm. It can be seen that the lateral size values of the nanoparticles for films with 5% Cu have minimum value of 5.34 nm. Films deposited with 75% Cu have maximum value of optical density specially in high energy. The spectral density power of all films indicated the presence of fractal components in prominent topographies. Films deposited without Cu NPs have minimum value of fractal dimension in about of 2.96. The diagram of the bearing area versus the nanoparticles height has shown the percentage of cavities and single-layers. The single-layer contents of all films were about 95%.