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Karimi A, Zarifkar A, Miri M. Design of ultracompact tunable fractional-order temporal differentiators based on hybrid-plasmonic phase-shifted Bragg gratings. APPLIED OPTICS 2018; 57:7402-7409. [PMID: 30182963 DOI: 10.1364/ao.57.007402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/25/2018] [Indexed: 06/08/2023]
Abstract
The design and the simulation of tunable fractional-order temporal differentiators based on Si-hybrid plasmonic phase-shifted Bragg gratings are proposed in this paper, where strong light confinement in the hybrid plasmonic waveguide is employed to significantly reduce the overall length of the differentiators. According to 2D- and 3D-FDTD simulation results, the proposed structures with overall lengths of less than 8 μm can provide arbitrary differentiation order and differentiation bandwidths as high as 1.6 THz. The differentiation order and the bandwidth of the proposed structures can be tuned in relatively wide ranges by changing the geometrical parameters of the structures. For example, the differentiation order can be changed from 0.57 to 0.97 by changing the number of the Bragg grating periods in a 3D differentiator structure. Furthermore, it is shown that using an electro-optical polymer as the low-index material of the hybrid plasmonic waveguide, the differentiation order and the central frequency of the proposed differentiators can be actively tuned through applying a proper actuating electrical field (voltage) to the structure. This property, along with the ultracompact footprint and wide bandwidth of the proposed differentiators, suggest their application in ultrafast all-optical signal-processing systems.
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Gitoee A, Sadeghi G, Karimi A. Combination Effects of Organic and Inorganic Chromium on Production Performance, Reproductive Response, Immune Status, and Maternal Antibody Transmission in Breeder Quails Under Heat Stress. Biol Trace Elem Res 2018; 184:508-516. [PMID: 29181821 DOI: 10.1007/s12011-017-1205-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 11/15/2017] [Indexed: 01/02/2023]
Abstract
This experiment was carried out to investigate the combination effects of organic and inorganic chromium (Cr) on egg production, egg quality, reproductive response, and immune status of breeder quails and their offspring under heat stress. A total of 140 7-week-old Japanese breeder quails (120 females and 20 males) according to a completely randomized design were used in four treatment groups (five replicate and seven birds per each) lasted for 8 weeks. Quails exposed to 35 °C for 8 h/day for induction of cyclic heat stress treatments consisted of diets supplemented with (1) 1 mg CrCl3 per kilogram of diet as control (CNT); (2) 1 mg Cr-L-Met per kilogram of diet as organic Cr (OCr); (3) 0.5 mg CrCl3 plus 0.5 mg Cr-L-Met per kilogram of diet (ISO); (4) 1 mg CrCl3 plus 0.5 mg Cr-L-Met per kilogram of diet (On-top). Productive performance and egg quality parameters were determined weekly. Fertility, hatchability, and embryonic mortality were measured at the end of experiment. Humoral immunity was assessed by primary and secondary antibody titer in sheep red blood cells (SRBC) and Newcastle disease (ND) tests. Cell-mediated immunity was assessed by the cutaneous basophil hypersensitivity (CBH) test to phytohemagglutinin (PHA) at days 20 and 45 of age. White blood cell count and immunoglobulin Y (IgY) content in serum and yolk of breeders and in serum and yolk residues of offspring were also measured. Results showed that maximum egg production, egg shell thickness, and Haugh unit were observed in birds fed ISO and On-top diets (P ≤ 0.05). The highest (P ≤ 0.05) antibody levels in ND test were observed in birds fed with OCr, ISO, and On-top diets. The highest cellular response (P ≤ 0.05) was in 12 h after primary PHA injection and 12 and 24 h after secondary PHA injection in birds fed with On-top diets. The highest count of heterophil and (H/L) were gained in breeder quails fed with CNT diet, and the lowest of them were reached with On-top diet (P ≤ 0.05). Results showed that the highest IgY level in serum of breeder and their offspring and that of yolk suck and egg yolk were observed in birds fed with On-top diet (P ≤ 0.05). These results suggest that extra supplemental organic Cr in combination with CrCl3 could lead to higher egg production, egg quality, and immune status of breeder quails and their offspring.
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Momeneh T, Karimi A, Sadeghi G, Vaziry A, Bedford M. Evaluation of dietary calcium level and source and phytase on growth performance, serum metabolites, and ileum mineral contents in broiler chicks fed adequate phosphorus diets from one to 28 days of age. Poult Sci 2018; 97:1283-1289. [DOI: 10.3382/ps/pex432] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 12/23/2017] [Indexed: 11/20/2022] Open
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Samimi A, Tajik J, Aghamiri S, Karimi A. A serial evaluation of electrocardiographic indices and cardiac arrhythmias during pregnancy, lactation and dry periods in Saanen goats. BULGARIAN JOURNAL OF VETERINARY MEDICINE 2018. [DOI: 10.15547/bjvm.1010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Fallahi S, Moosavi SF, Karimi A, Chegeni AS, Saki M, Namdari P, Rashno MM, Varzi AM, Tarrahi MJ, Almasian M. An advanced uracil DNA glycosylase-supplemented loop-mediated isothermal amplification (UDG-LAMP) technique used in the sensitive and specific detection of Cryptosporidium parvum, Cryptosporidium hominis, and Cryptosporidium meleagridis in AIDS patients. Diagn Microbiol Infect Dis 2017; 91:6-12. [PMID: 29366630 DOI: 10.1016/j.diagmicrobio.2017.12.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 12/15/2017] [Accepted: 12/16/2017] [Indexed: 11/18/2022]
Abstract
The rapid and accurate detection of Cryptosporidium spp. is critically important for the prevention and timely treatment of cryptosporidiosis in AIDS patients (APs). This study was conducted to examine a UDG-LAMP technique for the first time to diagnose cryptosporidiosis in APs. After collecting demographic and clinical data, three stool samples were collected from the participants (120 volunteering APs). The microscopic examination of stained smears using the acid-fast method and the UDG-LAMP assay were performed for each sample. 10% of APs were infected with Cryptosporidium spp. The number of detected cryptosporidiosis cases using the acid-fast staining and UDG-LAMP methods were significantly different (P < 0.001). Diarrhea and weight loss were found to be significantly associated with cryptosporidiosis in patients (P < 0.05). The pretreatment of LAMP reagents with UDG successfully eliminated the likelihood of product re-amplification remaining from previous reactions. The UDG-LAMP technique could detect cryptosporidiosis in APs with high sensitivity and rapidity without carryover contamination.
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Karimi A, Tulloch AIT, Brown G, Hockings M. Understanding the effects of different social data on selecting priority conservation areas. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2017; 31:1439-1449. [PMID: 28425128 DOI: 10.1111/cobi.12947] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 02/21/2017] [Accepted: 04/13/2017] [Indexed: 06/07/2023]
Abstract
Conservation success is contingent on assessing social and environmental factors so that cost-effective implementation of strategies and actions can be placed in a broad social-ecological context. Until now, the focus has been on how to include spatially explicit social data in conservation planning, whereas the value of different kinds of social data has received limited attention. In a regional systematic conservation planning case study in Australia, we examined the spatial concurrence of a range of spatially explicit social values and land-use preferences collected using a public participation geographic information system and biological data. We used Zonation to integrate the social data with the biological data in a series of spatial-prioritization scenarios to determine the effect of the different types of social data on spatial prioritization compared with biological data alone. The type of social data (i.e., conservation opportunities or constraints) significantly affected spatial prioritization outcomes. The integration of social values and land-use preferences under different scenarios was highly variable and generated spatial prioritizations 1.2-51% different from those based on biological data alone. The inclusion of conservation-compatible values and preferences added relatively few new areas to conservation priorities, whereas including noncompatible economic values and development preferences as costs significantly changed conservation priority areas (48.2% and 47.4%, respectively). Based on our results, a multifaceted conservation prioritization approach that combines spatially explicit social data with biological data can help conservation planners identify the type of social data to collect for more effective and feasible conservation actions.
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Tajbakhsh M, Karimi A, Fallah F, Akhavan MM. Overview of ribosomal and non-ribosomal antimicrobial peptides produced by Gram positive bacteria. ACTA ACUST UNITED AC 2017; 63:20-32. [PMID: 29096754 DOI: 10.14715/cmb/2017.63.10.4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Indexed: 11/18/2022]
Abstract
The increasing incidence of antimicrobial resistance bacterial infection and decreasing effectiveness of conventional antibiotics to treatment have caused serious problems worldwide. The demand for new generationantibiotics to combat microbial pathogens is imperative. Cationic antimicrobial peptides (AMPs) with different sources from prokaryotic to complex eukaryotic organisms, with variable length, amino acid composition and secondary structure, have been consideredduring the past decades. The advantages of large number of AMPs are related to broad spectrum and morphogenetic activities, low resistance rate among microorganismswithout side effect on human cells, rapid killing of bacteria via membrane damage and intracellular targets,and their critical roles in anti-inflammatory. Ribosomal synthesized peptides of Gram positive bacteria with various post translational modificationsrepresent extended types of antimicrobial peptide with different structural and functional diversity. These types of peptides have been considered as new therapeutic agents for pharmaceutical development .In addition, non- ribosomal synthesized peptides are a wide range of peptides , an extremely extensive range of biological activities and pharmacological properties that are not synthesized by ribosomes, show interesting biological properties ranging from antibiotic to bio surfactants. This review focused on genetics, mechanism of action and modifications, resistance mode of Gram positive bacteria to AMPs and the biotechnological application of ribosomally and non-ribosomally synthesized peptides derived from Gram positive bacteria.
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Mirkeshavarz M, Ganjibakhsh M, Aminishakib P, Farzaneh P, Mahdavi N, Vakhshiteh F, Karimi A, Gohari NS, Kamali F, Kharazifard MJ, Shahzadeh Fazeli SA, Nasimian A. Interleukin-6 secreted by oral cancer- associated fibroblast accelerated VEGF expression in tumor and stroma cells. Cell Mol Biol (Noisy-le-grand) 2017; 63:131-136. [DOI: 10.14715/cmb/2017.63.10.21] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/20/2017] [Accepted: 09/25/2017] [Indexed: 11/18/2022]
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Farhadi D, Karimi A, Sadeghi G, Rostamzadeh J, Bedford M. Effects of a high dose of microbial phytase and myo-inositol supplementation on growth performance, tibia mineralization, nutrient digestibility, litter moisture content, and foot problems in broiler chickens fed phosphorus-deficient diets. Poult Sci 2017; 96:3664-3675. [DOI: 10.3382/ps/pex186] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 06/14/2017] [Indexed: 11/20/2022] Open
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Karimi A, Joukar S, Najafipour H, Masoumi-Ardakani Y, Shahouzehi B. Low-intensity endurance exercise plus nandrolone decanoate modulates cardiac adiponectin and its receptors. ACTA ACUST UNITED AC 2017; 37:29-33. [PMID: 28544314 DOI: 10.1111/aap.12056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/17/2017] [Accepted: 03/07/2017] [Indexed: 12/12/2022]
Abstract
Vast adverse effects of anabolic-androgenic steroids (AASs) on athletes' cardiovascular systems have been reported. However, there is still a lack of adequate information regarding the pathways and mechanisms involved. We tested the hypothesis that adiponectin and its receptors in the heart may be affected by long-term use of AASs alongside exercising. Male Wistar rats were randomized into the control (CTL), exercise (EX), nandrolone (Nan), arachis (Arach) group which treated with arachis as vehicle, trained vehicle (EX+Arach) and trained nandrolone (EX+Nan) groups that were treated for 8 weeks. One day after the end of the protocol, animals were sacrificed and their hearts were frozen. TNF-α and adiponectin proteins of hearts were evaluated quantitatively by ELISA kits, and Western blot analysis was used for measuring adiponectin receptor protein expression. TNF-α protein increased significantly in the EX+Nan group (P<.05 vs CTL group). The AdipoR1 protein was significantly higher in the presence of nandrolone alongside exercise (P<.05 vs Nan and EX+Arach groups, P<.01 vs CTL and Arach groups). In addition, AdipoR2 protein enhanced in the EX+Nan group when compared with the other groups (P<.05 vs EX and EX+Arach groups, P<.01 vs CTL, Arach and Nan groups). Chronic nandrolone plus mild endurance exercise may be associated with imbalance in pro-/anti-inflammatory cytokines and may induce a positive modulatory effect on cardiac adiporeceptors in rat. Further studies are required before these findings can be generalized to humans.
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Karami N, Karimi A, Aliahmadi A, Mirzajan F, Rezadoost H, Ghassempour A, Fallah F. Identification of bacteria using volatile organic compounds. Cell Mol Biol (Noisy-le-grand) 2017; 63:112-121. [DOI: 10.14715/cmb/2017.63.2.18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 03/19/2017] [Indexed: 11/18/2022]
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Fallah F, Karimi A, Abdolghafoorian H, Mohammadzadeh A, Zahraei SM, Goudarzi H, Fallah M. Molecular analysis of the bacille Calmette-Guérin vaccine strain currently being used in Iran. Int J Tuberc Lung Dis 2017; 20:223-7. [PMID: 26792475 DOI: 10.5588/ijtld.15.0434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In developing countries, tuberculosis (TB) infection control remains a challenge. The bacille Calmette-Guérin (BCG) vaccine is the only effective vaccine available for TB control. Iran uses a local BCG vaccine strain with an unknown substrain. OBJECTIVE To investigate the molecular characteristics of the current BCG strain being used in Iran using comparative genomics of the evolutionarily late strains, including BCG vaccines Pasteur, BCG-Danish, BCG-Glaxo, BCG-Prague, BCG-Frappier, BCG-Connaught and BCG-Moreau. METHODS A total of 67 different vials of BCG vaccine were cultured. DNA was extracted using the modified cetrimonium bromide (CTAB) method, and multiplex polymerase chain reaction (PCR) was performed to determine four target genomic regions of difference (RD) 1, RD8, RD16 and SenX3-RegX3, and to see whether RD2 and RD14 were present. RESULTS Our results showed that all studied batches were Mycobacterium bovis; molecular analysis revealed that the Iranian vaccine strains possess RD8, RD16 and SenX3-RegX3 regions but not RD1, RD2 and RD14. All of the vaccine batches analysed were compatible with BCG-Pasteur 1173p2, the original strain. CONCLUSION All of the BCG strains studied were recognised as the BCG-Pasteur 1173p2 strain. No genetic diversity among stocks and ready-for-use vaccine vials were detected.
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Farhadi D, Karimi A, Sadeghi G, Sheikhahmadi A, Habibian M, Raei A, Sobhani K. Effects of using eucalyptus ( Eucalyptusglobulus L.) leaf powder and its essential oil on growth performance and immune response of broiler chickens. IRANIAN JOURNAL OF VETERINARY RESEARCH 2017; 18:60-62. [PMID: 28588635 PMCID: PMC5454581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 06/07/2023]
Abstract
The aim of this study was to evaluate the effects of eucalyptus leaf powder (ELP) and eucalyptus essential oil (EEO) on growth performance and immune response of broiler chickens. A total of 160 broiler chicks were assigned randomly into five dietary treatments from 7-42 days of age. Dietary treatments included: a control diet, control diets plus 1,000 or 3,000 mg/kg of ELP, and control diets plus 250 or 500 mg/kg of EEO. Dietary inclusion of ELP decreased body weight gain (BWG) during 7-28 days of age. Broilers fed diet containing 3,000 mg/kg of ELP had lower feed intake (FI) during 7-28 days compared to the other treatments. Broilers fed ELP or EEO had greater primary antibody response to sheep red blood cells (SRBC) compared to the control, but differences in secondary antibody response were not significant. In conclusion, dietary EEO has the potential to enhance immune response of broiler chickens.
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Shabani S, Karimi A, Rashki A, Meshkinkhood N, Niknam F, Poursharif A, Mahboudi F, Djadid ND. Identification and evaluation expression level of arrestin 1 gene during the development stage of Anopheles stephensi. GENE REPORTS 2016. [DOI: 10.1016/j.genrep.2016.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Najafi M, Jahangiry L, Mortazavi H, Jalali A, Karimi A, Bozorgi A. Outcomes and long-term survival of patients undergoing coronary artery bypass graft surgery; the controversial role of opium as a risk marker. J Cardiothorac Vasc Anesth 2016. [DOI: 10.1053/j.jvca.2016.03.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fallah S, Karimi A, Panahi G, Gerayesh Nejad S, Fadaei R, Seifi M. Human colon cancer HT-29 cell death responses to doxorubicin and Morus Alba leaves flavonoid extract. Cell Mol Biol (Noisy-le-grand) 2016; 62:72-77. [PMID: 27064876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/24/2016] [Indexed: 06/05/2023]
Abstract
The mechanistic basis for the biological properties of Morus alba flavonoid extract (MFE) and chemotherapy drug of doxorubicin on human colon cancer HT-29 cell line death are unknown. The effect of doxorubicin and flavonoid extract on colon cancer HT-29 cell line death and identification of APC gene expression and PARP concentration of HT-29 cell line were investigated. The results showed that flavonoid extract and doxorubicin induce a dose dependent cell death in HT-29 cell line. MFE and doxorubicin exert a cytotoxic effect on human colon cancer HT-29 cell line by probably promoting or induction of apoptosis.
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Kakavand T, Mirzaii M, Eslami M, Karimi A. Nuclear model calculation and targetry recipe for production of 110mIn. Appl Radiat Isot 2015; 104:60-6. [DOI: 10.1016/j.apradiso.2015.06.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 05/31/2015] [Accepted: 06/16/2015] [Indexed: 11/26/2022]
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Ghanaie R, Sadeghi H, Esteghamati A, Fallah F, Armin S, Fahimzad S, Ghanaie M, Shamshiri A, Shiva F, Karimi A. Frequency of pertussis in iranian school-age children. J PEDIAT INF DIS-GER 2015. [DOI: 10.3233/jpi-130380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Hanafi-Bojd AA, Rassi Y, Yaghoobi-Ershadi MR, Haghdoost AA, Akhavan AA, Charrahy Z, Karimi A. Predicted Distribution of Visceral Leishmaniasis Vectors (Diptera: Psychodidae; Phlebotominae) in Iran: A Niche Model Study. Zoonoses Public Health 2015; 62:644-54. [DOI: 10.1111/zph.12202] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Indexed: 01/30/2023]
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Fatemeh F, Karimi A, Abbassion M, Rad PK, Yazdi MK. Extraction of Rosa damascena as an antibacterial agent. Int J Mycobacteriol 2015. [DOI: 10.1016/j.ijmyco.2014.11.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Ali Moghaddam K, Vaezi M, Karimi A, Jahani M, Namroud N, Ghavamzadeh A. Post-HSCT Fertility in Patients Receiving Non-TBI-Based Conditioning Regimen: A 23-Year of Iranian Experience. Biol Blood Marrow Transplant 2015. [DOI: 10.1016/j.bbmt.2014.11.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Karimi A, Karig D, Kumar A, Ardekani AM. Interplay of physical mechanisms and biofilm processes: review of microfluidic methods. LAB ON A CHIP 2015; 15:23-42. [PMID: 25385289 PMCID: PMC4261921 DOI: 10.1039/c4lc01095g] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Bacteria in natural and artificial environments often reside in self-organized, integrated communities known as biofilms. Biofilms are highly structured entities consisting of bacterial cells embedded in a matrix of self-produced extracellular polymeric substances (EPS). The EPS matrix acts like a biological 'glue' enabling microbes to adhere to and colonize a wide range of surfaces. Once integrated into biofilms, bacterial cells can withstand various forms of stress such as antibiotics, hydrodynamic shear and other environmental challenges. Because of this, biofilms of pathogenic bacteria can be a significant health hazard often leading to recurrent infections. Biofilms can also lead to clogging and material degradation; on the other hand they are an integral part of various environmental processes such as carbon sequestration and nitrogen cycles. There are several determinants of biofilm morphology and dynamics, including the genotypic and phenotypic states of constituent cells and various environmental conditions. Here, we present an overview of the role of relevant physical processes in biofilm formation, including propulsion mechanisms, hydrodynamic effects, and transport of quorum sensing signals. We also provide a survey of microfluidic techniques utilized to unravel the associated physical mechanisms. Further, we discuss the future research areas for exploring new ways to extend the scope of the microfluidic approach in biofilm studies.
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Bazyar J, Daliri S, Sayehmiri K, Karimi A, Delpisheh A. Assessing the relationship between maternal and neonatal factors and low birth weight in Iran; a systematic review and meta-analysis. J Med Life 2015; 8:23-31. [PMID: 28316702 PMCID: PMC5319292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 12/17/2015] [Indexed: 11/25/2022] Open
Abstract
Introduction. Low birth weight is an important indicator of the health of babies. A low birth weight is a leading health problem and a major reason for death in newborns. This study targeted to assess the relationship between maternal and infant factors and low birth weight in Iran through a systematic review and meta-analysis. Materials and Methods. This paper was a systematic review and meta-analysis of the relationship between maternal/ infant factors and low birth weight based on the published research papers conducted in Iran. To achieve this goal, two trained researchers independently elicited all the relevant articles by using the appropriate keywords and their combinations in SID, Madlib, Iranmedex, Irandoc, Google Scholar, Pubmed, ISI, Scopus and Magiran databases. The results of the study were combined with SPSS 20 and STATA software. Results. In the initial stage, 25 more relevant articles out of 46 papers were selected. The gestational age with less than 37 weeks and prenatal care had the most (CI: 27- 14. 53, OR: 19.81) and the least (CI: 1.86, OR: 1.5) effect on the low birth weight in newborns, respectively. Conclusion. This study showed that there is a significant relationship between the low birth weight and multiple births, pre-eclampsia, maternal weight gaining during pregnancy, baby's gender, and pregnancy age. Hence, controlling the factors above in mothers during pregnancy by the health authorities could lead to the birth of infants with a healthy weight and consequently the number of infants with low birth weight will decrease.
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Li GJ, Karimi A, Ardekani AM. Effect of solid boundaries on swimming dynamics of microorganisms in a viscoelastic fluid. RHEOLOGICA ACTA 2014; 53:911-926. [PMID: 26855446 PMCID: PMC4743766 DOI: 10.1007/s00397-014-0796-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We numerically study the effect of solid boundaries on the swimming behavior of a motile microorganism in viscoelastic media. Understanding the swimmer-wall hydrodynamic interactions is crucial to elucidate the adhesion of bacterial cells to nearby substrates which is precursor to the formation of the microbial biofilms. The microorganism is simulated using a squirmer model that captures the major swimming mechanisms of potential, extensile, and contractile types of swimmers, while neglecting the biological complexities. A Giesekus constitutive equation is utilized to describe both viscoelasticity and shear-thinning behavior of the background fluid. We found that the viscoelasticity strongly affects the near-wall motion of a squirmer by generating an opposing polymeric torque which impedes the rotation of the swimmer away from the wall. In particular, the time a neutral squirmer spends at the close proximity of the wall is shown to increase with polymer relaxation time and reaches a maximum at Weissenberg number of unity. The shear-thinning effect is found to weaken the solvent stress and therefore, increases the swimmer-wall contact time. For a puller swimmer, the polymer stretching mainly occurs around its lateral sides, leading to reduced elastic resistance against its locomotion. The neutral and puller swimmers eventually escape the wall attraction effect due to a releasing force generated by the Newtonian viscous stress. In contrast, the pusher is found to be perpetually trapped near the wall as a result of the formation of a highly stretched region behind its body. It is shown that the shear-thinning property of the fluid weakens the wall-trapping effect for the pusher squirmer.
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