LSMR Iterative Method for General Coupled Matrix Equations

By extending the idea of LSMR method, we present an iterative method to solve the general coupled matrix equations ∑k=1qAikXkBik=Ci, i=1,2,…,p, (including the generalized (coupled) Lyapunov and Sylvester matrix equations as special cases) over some constrained matrix groups (X1,X2,…,Xq), such as symmetric, generalized bisymmetric, and (R,S)-symmetric matrix groups. By this iterative method, for any initial matrix group (X1(0),X2(0),…,Xq(0)), a solution group (X1*,X2*,…,Xq*) can be obtained within finite iteration steps in absence of round-off errors, and the minimum Frobenius norm solution or the minimum Frobenius norm least-squares solution group can be derived when an appropriate initial iterative matrix group is chosen. In addition, the optimal approximation solution group to a given matrix group (X¯1,X¯2,…,X¯q) in the Frobenius norm can be obtained by finding the least Frobenius norm solution group of new general coupled matrix equations. Finally, numerical examples are given to illustrate the effectiveness of the presented method

The first inherited retinal disease registry in Iran: Research protocol and results of a pilot study

Background: To describe the protocol for developing a national inherited retinal disease (IRD) registry in Iran and present its initial report. Methods: This community-based participatory research was approved by the Ministry of Health and Medical Education of Iran in 2016. To provide the minimum data set (MDS), several focus group meetings were held. The final MDS was handed over to an engineering team to develop a web-based software. In the pilot phase, the software was set up in two referral centers in Iran. Final IRD diagnosis was made based on clinical manifestations and genetic findings. Ultimately, patient registration was done based on all clinical and non-clinical manifestations. Results: Initially, a total of 151 data elements were approved with Delphi technique. The registry software went live at www.IRDReg.org based on DHIS2 open source license agreement since February 2016. So far, a total of 1001 patients have been registered with a mean age of 32.41±15.60 years (range, 3 months to 74 years). The majority of the registered patients had retinitis pigmentosa (42, 95 CI: 38.9 to 45). Genetic testing was done for approximately 20 of the registered individuals. Conclusion: Our study shows successful web-based software design and data collection as a proof of concept for the first IRD registry in Iran. Multicenter integration of the IRD registry in medical centers throughout the country is well underway as planned. These data will assist researchers to rapidly access information about the distribution and genetic patterns of this disease. © 2020 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons. org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Evaluation of antioxidant activity and identification of main compounds of various extracts of Artemisia turanica aerial parts

Background and objectives: Artemisia turanica Krash. grows wildly in north-eastern Iran. The aim of the present work was to undertake an investigation of the antioxidant activity as well as identification of main compound of different extracts and fractions of A. turanica. Methods: Total phenolic contents (TPC) and antioxidant activity of five different extracts (petroleum ether, dichloromethane, ethyl acetate, ethanol and ethanol-water) and seven fraction of hydroethanolic extract was investigated by Folin-Ciocalteu assay and three different methods: β-catotene bleaching (BCB) test, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and ferrous ion chelating (FIC) assays, respectively. Purification of the major constituents of the most active fraction was done by preparative and semi preparative HPLC. Structure elucidation of isolated compounds was achieved using spectroscopic techniques including ESIMS, 1D and 2D NMR experiments. Results: Among the extracts analyzed, the hydroethanolic extract exhibited the highest phenolic content. Fraction D (40% MeOH in water) showed the highest total phenolics content and free radical scavenging activity but the only statistically significant correlation between TPC and EC50 values was observed for BCB. There were no significant differences (

Evaluation of antioxidant activity and phenolic contents and identification of main compounds of various extracts from Artemisia aucheri aerial parts

Background and objectives: Artemisia aucheri Boiss. is regarded as one of 34 Artemisia species growing in Iran. The aim of this study was to undertake an investigation of the antioxidant activity as well as identification of main compound of different extracts and fractions of A. aucheri. Methods: Antioxidant activity and total phenolics content of five different extracts (petroleum ether, dichloromethane, ethyl acetate, ethanol and ethanol-water) and five fraction of ethanol extract was investigated by three different methods (2,2-diphenyl-1-picrylhydrazyl radical scavenging method, ferrous ion chelating assay and β-catotene bleaching test) and Folin-Ciocalteu method, respectively. Purification of major constituents of the most active fraction was done by preparative and semi preparative HPLC. For one of the isolated compounds, structure elucidation was achieved using spectroscopic techniques (ESIMS, 1D NMR, 2D NMR) experiments. Results: Hydroethanolic extract exhibited the strongest inhibitory activity in BCB assay in comparison with other extracts. The ethanol extract was the most active one in DPPH assay while none of the extracts showed notable ferrous ion chelating activity. Fraction 40% MeOH in water showed both the highest total phenolics content and the most potent DPPH radical scavenging activity. Statistical analysis did not show any significant difference between the two aforementioned assays in screening the samples for the antioxidant ability. One known caffeic acid derivative, ethyl caffeate, was isolated from the most active fraction of ethanolic extract. Conclusion: The findings of present study suggested that A. aucheri may be regarded as a potential source of natural antioxidants

Flavonoids from the aerial parts of Artemisia biennis Willd

Background and objectives: The genus Artemisia contains over 250 species all over the world. A. biennis Willd is one of the species which grows wildly in Iran. Camphor and (E)-beta-farnesene have been reported as the major components of the essential oil from A. biennis. In spite of the presence of a rather wide range of reported bioactivities there is no previous phytochemical study on  A. biennis. Methods: The plant was collected from Zoshk (Khorasan Razavi province, Iran). Extraction was done by maceration method using petroleum ether, dichloromethane, ethyl acetate, ethanol and equal amounts of water and ethanol (hydroethanolic extract), respectively. A combination of solid phase extraction (SPE) and high pressure liquid chromatography (HPLC) of the hydroethanolic extract was used to purify the compounds. Structures of the isolated compounds were elucidated by spectroscopic means, including MS and 1HNMR. Results: Three known flavonoids, luteolin, kaempferol and apigenin were isolated and identified from the hydroethanolic extract. Conclusion: Our results are in good agreement with dominant presence of derivatives of the flavones luteolin and apigenin in the genus Artemisia which has been previously reported

Evaluation of anti-malarial activity of Artemisia turcomanica and A. kopetdaghensis by cell-free β-hematin formation assay

Background and objectives:The plants of genus Artemisia (Asteraceae) have been conventionally used for prevention and medication of a number of ailments. In the present research, ten extracts with different polarities from aerial parts of two Artemisia species, A. kopetdaghensis and A. turcomanica were evaluated for their potential anti-malarial properties. Methods: The plant materials were extracted successively with petroleum ether (PE), dichloromethane (DCM), ethyl acetate (EtOAC), ethanol, and ethanol-water (1:1 v/v)  by cold maceration method. Cell free β-hematin formation assay were used for assessing anti-malarial activity of obtained extracts. Results: DCM extract of A. kopetdaghensis and PE extract of A. turcomanica showed remarkable anti-malarial activity with IC50 values of 1.04±0.02 mg/mL and 0.90±0.27 mg/mL, respectively, compared to positive control (chloroquine, IC50 0.04±0.01 mg/mL). Conclusion:  It seems that the anti-malarial activity of these extracts might be bound up with the presence of compounds with low or medium polarity; hence, this preliminary test indicated that these potent extracts could be considered for further investigations to find new sources of anti-malarial phytochemicals

The effects simultaneous inhibition of dipeptidyl peptidase-4 and P2X7 purinoceptors in an in vivo Parkinson�s disease model

Loss of dopaminergic neurons following Parkinson�s disease (PD) diminishes quality of life in patients. The present study was carried out to investigate the protective effects of simultaneous inhibition of dipeptidyl peptidase-4 (DPP-4) and P2X7 purinoceptors in a PD model and explore possible mechanisms. The 6-hydroxydopamine (6-OHDA) was used as a tool to establish PD model in male Wister rats. The expressions of SIRT1, SIRT3, mTOR, PGC-1α, PTEN, P53 and DNA fragmentation were evaluated by ELISA assay. Behavioral impairments were determined using apomorphine-induced rotational and narrow beam tests. Dopamine synthesis and TH-positive neurons were detected by tyrosine hydroxylase (TH) immunohistochemistry. Neuronal density was determined by Nissl staining. OHDA-lesioned rats exhibited behavioral impairments that reversed by BBG, lin and lin + BBG. We found significant reduced levels of SIRT1, SIRT3, PGC-1α and mTOR in both mid brain and striatum from OHDA-lesioned rats that reversed by BBG, lin and lin + BBG. Likewise, significant increased levels of PTEN and P53 were found in both mid brain and striatum from OHDA-lesioned rats that was reversed by BBG, lin and lin + BBG. TH-positive neurons and neuronal density were markedly reduced OHDA-lesioned rats that reversed by BBG, lin and lin + BBG. Collectively, our results showed protective effects of simultaneous inhibition of DPP-4 and P2X7 purinoceptors in a rat model of PD can be linked to targeting SIRT1/SIRT3, PTEN-mTOR pathways. Moreover, our findings demonstrated that simultaneous inhibition of DPP-4 and P2X7 purinoceptors might have stronger effect on mitochondrial biogenesis compared to only one. © 2020, Springer Science+Business Media, LLC, part of Springer Nature