Publications by authors named "Zahra Nemati"

9 Publications

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An ultra-high bandwidth nano-electronic interface to the interior of living cells with integrated fluorescence readout of metabolic activity.

Sci Rep 2020 07 1;10(1):10756. Epub 2020 Jul 1.

Department of Electrical Engineering and Computer Science, University of California, Irvine, CA, 92697, USA.

We present the first ever broadband, calibrated electrical connection to the inside of a cell. The interior of a vital, living cell contains multiple dynamic and electrically active organelles such as mitochondria, chloroplasts, lysosomes, and the endoplasmic reticulum. However, little is known about the detailed electrical activity inside the cell. Here we show an ultra-high bandwidth nano-electronic interface to the interior of living cells with integrated fluorescence readout of metabolic activity. On-chip/on-petri dish nanoscale capacitance calibration standards are used to quantify the electronic coupling from bench to cell from DC to 26 GHz (with cell images at 22 GHz). The interaction of static to high frequency electromagnetic fields with the cell constituents induce currents of free charges and local reorganization of linked charges. As such, this enables a direct, calibrated, quantitative, nanoscale electronic interface to the interior of living cells. The interface could have a variety of applications in interfacing life sciences to nano-electronics, including electronic assays of membrane potential dynamics, nano-electronic actuation of cellular activity, and tomographic, nano-radar imaging of the morphology of vital organelles in the cytoplasm, during all phases of the cell life cycle (from development to senescence), under a variety of physiological environments, and under a broad suite of pharmacological manipulations.
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http://dx.doi.org/10.1038/s41598-020-67408-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7329815PMC
July 2020

Virulence of Leaf Rust Physiological Races in Iran From 2010 to 2017.

Plant Dis 2020 Feb 18;104(2):363-372. Epub 2019 Dec 18.

Department of Plant Pathology, University of Minnesota, Minneapolis, MN, U.S.A.

The wheat leaf rust fungus, , has widespread geographical distribution in Iran within the Fertile Crescent region of the Middle East where wheat was domesticated and originated. Therefore, it is of great importance to identify the prevalence and distribution of pathotypes in this area. From 2010 to 2017, 241 single-uredinium isolates of . were purified from 175 collections of made from various hosts in 14 provinces of Iran, and they were tested on 20 Thatcher near-isogenic lines carrying single-leaf rust resistance genes. In total, 86 pathotypes were identified, of which the pathotypes FDTTQ, FDKPQ, FDKTQ, and FDTNQ were most prevalent. No virulence for was detected, whereas virulence for was found only on bread wheat in a few provinces in 2016. Only isolates from durum wheat and wild barley were virulent to . Although virulence for , , and was observed in some years, the virulence frequency for these genes was lower than that of the other genes. collections from host plants with different ploidy levels or genetically dissimilar backgrounds were grouped individually according to genetic distance. Based on these results, collections from barley, durum wheat, oat, triticale, and wild barley were different from those of bread wheat.
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http://dx.doi.org/10.1094/PDIS-06-19-1340-REDOI Listing
February 2020

Scanning Microwave Microscopy of Vital Mitochondria in Respiration Buffer.

IEEE MTTS Int Microw Symp 2018 Jun 20;2018:115-118. Epub 2018 Aug 20.

Integrated Nanosystems Research Facility, University of California, Irvine, Irvine, CA 92697, USA.

We demonstrate imaging using scanning microwave microscopy (SMM) of vital mitochondria in respiration buffer. The mitochondria are isolated from cultured HeLa cells and tethered to a solid graphene support. The mitochondria are kept vital (alive) using a respiration buffer, which provides nutrients to sustain the Krebs cycle. We verify that the mitochondria are "alive" by measuring the membrane potential using a voltage sensitive fluorescent dye (TMRE). The organelles are measured capacitively at 7 GHz. Several technical advances are demonstrated which enable this work: 1) The SMM operates in an electrophysiologically relevant liquid (hence conducting) environment; 2) The SMM operates in tapping mode, averaging the microwave reflection measurement over many tapping periods; 3) A tuned reflectometer enables increased sensitivity; 4) Variable frequencies up to 18 GHz are used; 5) In contrast with traditional matching/resonant methods that exhibit high quality factor that fail in the presence of liquids, interferometric/tuned reflectometer gives the possibility to adjust the quality factor or sensitivity even in the presence of the liquid.
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http://dx.doi.org/10.1109/MWSYM.2018.8439645DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469850PMC
June 2018

Saffron (Crocus sativus) is an autotriploid that evolved in Attica (Greece) from wild Crocus cartwrightianus.

Mol Phylogenet Evol 2019 07 1;136:14-20. Epub 2019 Apr 1.

Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany. Electronic address:

Crocus sativus, the saffron crocus, is the source of saffron, which is made from the dried stigmas of the plant. It is a male-sterile triploid lineage that ever since its origin has been propagated vegetatively. Its mode of evolution and area of origin are matters of long-lasting debates. Here we analyzed chloroplast genomes and genome-wide DNA polymorphisms obtained through genotyping-by-sequencing (GBS) to infer the parent and area of origin of C. sativus. These data were complemented by genome size measurements and analyses of nuclear single-copy genes. We could place 99.3% of saffron GBS alleles in Crocus cartwrightianus, a species occurring in southeastern mainland Greece and on Aegean islands, identifying it as the sole progenitor of the saffron crocus. Phylogenetic and population assignment analyses together with chloroplast polymorphisms indicated the C. cartwrightianus population in the vicinity of Athens as most similar to C. sativus. We conclude that the crop is an autotriploid that evolved in Attica by combining two different genotypes of C. cartwrightianus. Triploid sterility and vegetative propagation prevented afterwards segregation of the favorable traits of saffron, resulting in worldwide cultivation of a unique clonal lineage.
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http://dx.doi.org/10.1016/j.ympev.2019.03.022DOI Listing
July 2019

Phylogeny of the saffron-crocus species group, Crocus series Crocus (Iridaceae).

Mol Phylogenet Evol 2018 10 21;127:891-897. Epub 2018 Jun 21.

Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany. Electronic address:

Phylogenetic relationships among the taxa of Crocus series Crocus are still unclear, preventing the understanding of species diversity and the evolution of the important spice saffron (Crocus sativus). Therefore, we analyzed sequences of two chloroplast (trnL-trnF, matK-trnK) and three nuclear (TOPO6, ribosomal DNA ETS and ITS) marker regions to infer phylogenetic relationships among all species belonging to series Crocus. Our phylogenetic analyses resolved the relationships among all taxa of the series. Crocus hadriaticus and the former C. pallasii subspecies appeared polyphyletic. The latter deserve elevating the subspecies to species rank, while for C. hadriaticus a detailed study of species boundaries is necessary. Multi-locus and also genome-wide single nucleotide polymorphism data obtained through genotyping-by-sequencing placed C. sativus within C. cartwrightianus with no indication that other Crocus species contributed to the evolution of the triploid. Our analyses thus made an autotriploid origin of C. sativus from C. cartwrightianus very likely.
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http://dx.doi.org/10.1016/j.ympev.2018.06.036DOI Listing
October 2018

Effects of unstable footwear on gait characteristic: A systematic review.

Foot (Edinb) 2017 Jun 24;31:72-76. Epub 2017 Apr 24.

Department of Management, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.

Background: Over the last three decades, several designs of unstable footwear have been developed in the forms of shoes, sandals and boots. There are marketing claims related to the positive effects of these shoes on the training of lower limb muscles and improving gait. Many studies have been performed on the effects of unstable footwear on muscle activity, balance, posture, energy expenditure, lower extremity disorders, and biomechanical changes. The analysis of the kinetics and kinematics characteristics of gait would provide objective representation of body movement.

Objective: To systematically review available evidence on the use of unstable footwear on kinetic and kinematic parameters to make specific recommendation for practice and future studies.

Method: A computer-based search was undertaken through PubMed, Cochrane Library, Embase, PEDro, Web of Science and Google Scholar from 2005 to 2015. The included studies were appraised using McMaster Critical Review Form for Quantitative Studies.

Result: Ten studies (quasi-experimental design) were included.

Conclusion: Considering kinetic and kinematic interaction of variables in the included studies revealed that confounding factors may have high impact on biomechanical findings of unstable footwear. Then, more homogeneous studies, considering these factors, should be implemented in future studies to inform the best clinical practice.
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http://dx.doi.org/10.1016/j.foot.2017.04.005DOI Listing
June 2017

Metabolic and Growth Rate Alterations in Lymphoblastic Cell Lines Discriminate Between Down Syndrome and Alzheimer's Disease.

J Alzheimers Dis 2017 ;55(2):737-748

Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), and Center for the Neurobiology of Learning and Memory (CNLM), University of California, Irvine, CA, USA.

Background: Deficits in mitochondrial function and oxidative stress play pivotal roles in Down syndrome (DS) and Alzheimer's disease (AD) and these alterations in mitochondria occur systemically in both conditions.

Objective: We hypothesized that peripheral cells of elder subjects with DS exhibit disease-specific and dementia-specific metabolic features. To test this, we performed a comprehensive analysis of energy metabolism in lymphoblastic-cell-lines (LCLs) derived from subjects belonging to four groups: DS-with-dementia (DSAD), DS-without-dementia (DS), sporadic AD, and age-matched controls.

Methods: LCLs were studied under regular or minimal feeding regimes with galactose or glucose as primary carbohydrate sources. We assessed metabolism under glycolysis or oxidative phosphorylation by quantifying cell viability, oxidative stress, ATP levels, mitochondrial membrane potential (MMP), mitochondrial calcium uptake, and autophagy.

Results: DS and DSAD LCLs showed slower growth rates under minimal feeding. DS LCLs mainly dependent on mitochondrial respiration exhibited significantly slower growth and higher levels of oxidative stress compared to other groups. While ATP levels (under mitochondrial inhibitors) and mitochondrial calcium uptake were significantly reduced in DSAD and AD cells, MMP was decreased in DS, DSAD, and AD LCLs. Finally, DS LCLs showed markedly reduced levels of the autophagy marker LC3-II, underscoring the close association between metabolic dysfunction and impaired autophagy in DS.

Conclusion: There are significant mitochondrial functional changes in LCLs derived from DS, DSAD, and AD patients. Several parameters analyzed were consistently different between DS, DSAD, and AD lines suggesting that metabolic indicators between LCL groups may be utilized as biomarkers of disease progression and/or treatment outcomes.
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http://dx.doi.org/10.3233/JAD-160278DOI Listing
February 2018

The effect of new dynamic splint in pinch strength in De Quervain syndrome: a comparative study.

Disabil Rehabil Assist Technol 2017 07 17;12(5):457-461. Epub 2016 Feb 17.

a Department of Orthotics and Prosthetics, School of Rehabilitation Sciences , Iran University of Medical Sciences , Tehran , Iran.

Objective For patients with De Quervain syndrome using thumb spica orthosis is restricting, so many patient are dissatisfied with using static model. The aim of this study is to compare the effect of modified dynamic and conventional static orthoses on pinch power and functional abilities of hand in De Quervain syndrome. Method In this quasi-experimental study, palmar and lateral pinch strength of the thumb, pain and functional abilities of hand, patient's satisfaction of orthoses, were evaluated after using modified dynamic and conventional static orthosis in two groups. Results Both orthoses improved palmar and lateral pinch strength of the thumb, pain level and functional abilities. In comparison of mentioned variables, there was no significant difference between two groups regarding to pain recovery and abilities improvement (p > 0.05). However, the satisfaction level of the patients who had used dynamic orthosis was higher (p < 0.05). Conclusion It seems, adding a joint to the static thumb spica leads to patient's relief and consequently to their satisfaction. Implications for Rehabilitation The dynamic thumb spica, is easier to use and patients satisfaction is higher than static thumb spica. Therefore, it can be used for conservative treatment of De Quervain syndrome.
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http://dx.doi.org/10.3109/17483107.2016.1139635DOI Listing
July 2017

Isolation and characterization of a first set of polymorphic microsatellite markers in saffron, Crocus sativus (Iridaceae).

Am J Bot 2012 Sep 30;99(9):e340-3. Epub 2012 Aug 30.

Department of Genomics, Agricultural Biotechnology Research Institute of Iran (ABRII), Seed and Plant Improvement Institutes Campus, Mahdasht Road, P.O. Box 31535-1897, Karaj, Iran.

Premise Of The Study: Twelve novel polymorphic microsatellite loci were developed and characterized from a repeat-enriched genomic library of Crocus sativus to study population and conservation genetics of this economically and medically important species.

Methods And Results: The microsatellite loci were isolated using a modified Fast Isolation by AFLP of Sequences COntaining repeats (FIASCO) method. The average number of alleles per locus was 2.6. The observed and expected heterozygosities varied from 0.07 to 0.92 and 0.1 to 0.58, respectively. Polymorphic information content value ranged from 0.09 to 0.55 with an average of 0.34. Four out of twelve loci showed significant departures from Hardy-Weinberg equilibrium.

Conclusions: The microsatellite markers reported here will be useful for evaluating genetic diversity and will likely serve as an ideal resource for use in marker-assisted breeding programs, germplasm analysis, and varietal identification.
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http://dx.doi.org/10.3732/ajb.1100531DOI Listing
September 2012