Publications by authors named "Abbas Karami"

6 Publications

  • Page 1 of 1

Hairpin-Spherical Nucleic Acids for Diagnosing COVID-19: a Simple Method to Generalize the Conventional PCR for Molecular Assays.

Anal Chem 2021 07 22;93(26):9250-9257. Epub 2021 Jun 22.

Department of Molecular Diagnosis, Farzan Molecular and Pathobiology Laboratory, Hamedan 6515638377, Iran.

The COVID-19 pandemic revealed during the first global wave of this infectious disease that mass diagnostic testing was necessary to more rapidly detect infection in patients and control the pandemic. Therefore, extra research efforts to develop reliable and more accessible techniques for disease diagnosis are of supreme importance. Here, a target-responsive assembly of gold nanoparticle-core hairpin-spherical nucleic acids (AuNP-core H-SNAs) was implemented to modify the conventional polymerase chain reaction (PCR) assay for the "naked-eye" colorimetric detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. Two hairpin DNA ligands are designed based on the two highly conserved regions within N and E genes of SARS-CoV-2 RNA by positioning two short palindromic arms (stem) on either side of a recognition sequence (loop). In the presence of a sequence-specific probe (activator), hairpin DNAs anchored to the surface of AuNPs unfold and expose the palindromic ends to the DNA-directed assembly of AuNPs. The sequence of the activator probes was chosen to be identical to the TaqMan probe in a real-time reverse transcription PCR (RT-PCR) assay for specifically targeting the N and E genes of SARS-CoV-2 RNA. They may either be degraded by the 5'-exonuclease activity of DNA polymerase during PCR cycles or stay intact depending on the presence or absence of the target template in the sample, respectively. Post-addition of H-SNA solutions to the final PCR products of some preconfirmed clinical samples for COVID-19 generated naked-eye-observable red and blue colors for positive and negative cases, respectively, with similar sensitivity to that of the real-time RT-PCR method.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.analchem.1c01515DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8247783PMC
July 2021

Conventional PCR assisted single-component assembly of spherical nucleic acids for simple colorimetric detection of SARS-CoV-2.

Sens Actuators B Chem 2021 Feb 28;328:128971. Epub 2020 Sep 28.

Department of Molecular Diagnosis, Farzan Molecular and Pathobiology Laboratory, Hamedan, Iran.

Continuous identification of suspected infectious cases is crucial to control the recent pandemic caused by the novel human coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Real-time polymerase chain reaction (real-time PCR) technology cannot be implemented easily and in large scale in some communities due to lack of resources and infrastructures. Here, we report a simple colorimetric strategy derived from linker-based single-component assembly of gold nanoparticle-core spherical nucleic acids (AuNP-core SNAs) for visual detection of PCR products of SARS-CoV-2 ribonucleic acid (RNA) template. A palindromic linker is designed based on SARS-CoV-2 specific E gene to program the identical colloidal SNAs into large assemblies along with a distinct red-to-purple color change. The linker acts as a probe of SARS-CoV-2 RNA in conventional PCR reaction. In the presence of the correct template the palindromic linker, which is complementary to a short region within the target amplicon, is cleaved by 5'-exonuclease activity of deoxyribonucleic acid (DNA) polymerase. Cleavage of the palindromic linker during the amplification process inhibits the single-component assembly formation of SNAs. So, positive and negative viral samples produce simply red and purple colors in the post PCR colorimetric test, respectively. Evaluation of the samples obtained from cases with laboratory-confirmed SARS-CoV-2 infection revealed that our assay can rival with real-time PCR method in sensitivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.snb.2020.128971DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7521892PMC
February 2021

A palindromic-based strategy for colorimetric detection of HIV-1 nucleic acid: Single-component assembly of gold nanoparticle-core spherical nucleic acids.

Anal Chim Acta 2020 Mar 19;1102:119-129. Epub 2019 Dec 19.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, 65174, Iran. Electronic address:

Gold nanoparticle-core spherical nucleic acids (AuNP core-SNAs), by virtue of the programmable nature of oligonucleotides, have yielded access to the innovative strategies for targeted biodiagnostics. Here, DNA-directed self-assembly of AuNP core-SNAs has been used to design a colorimetric method to sense HIV-1 viral nucleic acid. This strategy utilizes an oligonucleotide with sequence of 5'-untranslated region (5' UTR) of the HIV-1 RNA genome anchored on the surface of AuNPs and a complementary linker strand with a palindromic sequence tail. In the absence of HIV-1 target nucleic acid the complementary linker induces self-assembly of SNAs based on sequence symmetry in the free palindromic tail which can bridge two DNA double helices. While in the presence of the target DNA, due to linker-target duplex formation, the colloidal stability and the red color of the SNAs solution are preserved. Picomole amounts of target DNA can easily be detected with the naked eyes. A 95-mer synthetic DNA strand with the same sequence of HIV-1 viral RNA was utilized for positive control of HIV-1 RNA. The selectivity of the selected linker was satisfactory up to 90% match.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.aca.2019.12.050DOI Listing
March 2020

Health-promoting behaviors in nursing students: is it related to self-efficacy for health practices and academic achievement?

Int J Adolesc Med Health 2018 Jun 28;32(3). Epub 2018 Jun 28.

School of Nursing and Midwifery, Nursing Research Center, Department of Medical-Surgical Nursing, Kerman University of Medical Sciences, PO Box: 7716913555 Haft-bagh Highway, Kerman, Iran.

Background Nursing students play a role in promotion of public health as health promoters and professional care providers. Therefore, health-promoting behaviors in nursing students and their self-efficacy for health practices are important in providing better services to patients and clients. With regard to the importance of these factors in the academic progress of students, this study was conducted to examine the level of health-promoting behaviors among nursing students and its relationship with self-efficacy for health practices and academic achievement. Methods This descriptive and correlational study was conducted on 217 nursing students of a large university of medical sciences in the south of Iran in 2016. Data were collected using the Persian version of the health promotion lifestyle profile (HPLP II), self-rated abilities for health practices scale (SRAHPS) and the grade point average of the students (levels A, B, C). Results The mean health-promoting behaviors (2.48 ± 0.35) and self-efficacy for health practices of the students (2.55 ± 0.62) were moderate. The mean score of the students' academic achievement was at level B (16.02 ± 1.85). The health-promoting behaviors were significantly correlated with self-efficacy for health practices (r = 0.623, p < 0.0001) and academic achievement (r = 0.285, p < 0.0001). Moreover, self-efficacy for health practices was significantly correlated with academic achievement (r = 0.282, p < 0.0001). Conclusion The correlation between the health-promoting behaviors and health self-efficacy with academic achievement can be a good basis in devising health and educational programs for students. In planning for promoting academic achievement and health-promoting behaviors of students, it is essential to pay special attention to enhancement of self-efficacy for health practices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/ijamh-2017-0148DOI Listing
June 2018

Nurses' professional competency and organizational commitment: Is it important for human resource management?

PLoS One 2017 8;12(11):e0187863. Epub 2017 Nov 8.

Nursing Research Center, Kerman University of Medical Sciences, Kerman, Iran.

Background: Professional competency is a fundamental concept in nursing, which has a direct relationship with quality improvement of patient care and public health. Organizational commitment as a kind of affective attachment or sense of loyalty to the organization is an effective factor for professional competency.

Objective: This study was conducted to evaluate the nurses´ professional competency and their organizational commitment as well as the relationship between these two concepts.

Methods And Materials: This descriptive-analytic study was conducted at the hospitals affiliated with a University of Medical Sciences, in the southeast of Iran in 2016. The sample included 230 nurses who were selected using stratified random sampling. Data were gathered by three questionnaires including socio-demographic information, competency inventory for registered nurse (CIRN) and Allen Meyer's organizational commitment.

Results: Results showed that professional competency (Mean±SD: 2.82±0.53, range: 1.56-4.00) and organizational commitment (Mean±SD: 72.80±4.95, range: 58-81) of the nurses were at moderate levels. There was no statistically significant correlation between professional competency and organizational commitment (ρ = 0.02; p = 0.74). There were significant differences in professional competency based on marital status (p = 0.03) and work experience (p<0.001).

Conclusion: The results highlighted that the nurses needed to be more competent and committed to their organizations. Developing professional competency and organizational commitment is vital, but not easy. This study suggests that human resource managers should pursue appropriate strategies to enhance the professional competency and organizational commitment of their nursing staff. It is necessary to conduct more comprehensive studies for exploring the status and gaps in the human resource management of healthcare in different cultures and contexts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0187863PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5678726PMC
November 2017

Prediction of muscle activation for an eye movement with finite element modeling.

Comput Biol Med 2017 10 24;89:368-378. Epub 2017 Aug 24.

School of Mechanical Eng., Shiraz Univ., Shiraz, Fars, 71348-51154, Iran.

In this paper, a 3D finite element (FE) modeling is employed in order to predict extraocular muscles' activation and investigate force coordination in various motions of the eye orbit. A continuum constitutive hyperelastic model is employed for material description in dynamic modeling of the extraocular muscles (EOMs). Two significant features of this model are accurate mass modeling with FE method and stimulating EOMs for motion through muscle activation parameter. In order to validate the eye model, a forward dynamics simulation of the eye motion is carried out by variation of the muscle activation. Furthermore, to realize muscle activation prediction in various eye motions, two different tracking-based inverse controllers are proposed. The performance of these two inverse controllers is investigated according to their resulted muscle force magnitude and muscle force coordination. The simulation results are compared with the available experimental data and the well-known existing neurological laws. The comparison authenticates both the validation and the prediction results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.compbiomed.2017.08.018DOI Listing
October 2017
-->