72 research outputs found

    Molecular Diversity of Antagonistic Streptomyces spp. against Botrytis allii, the agent of onion gray mold using Random Amplified Polymorphic DNA (RAPD) Markers

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    As an aim in sustainable agriculture, biological control of plant diseases has received intensive attention mainly as a response to public concern about the use of chemical fungicides in the environment. Soil Actinomycetes particularly Streptomyces spp. enhance soil fertility and have antagonistic activity against wide range of plant pathogens. To investigate for biocontrol means against the pathogen, 30 isolates of Actinomycetes have been isolated from agricultural soils of Kerman province of Iran and assayed for antagonistic activity against Botrytis allii, the agent of onion gray mold. RAPD DNA analysis has been used to determine the relatedness of active and non-active isolates based on their RAPD-PCR fingerprints. PCR amplifiable DNA samples have been isolated using the CTAB method and amplified fragments have been obtained from 5 random 10-mer primers. Different DNA fingerprinting patterns have been obtained for all of the isolates. Electrophoretic and cluster analysis of the amplification products has revealed incidence of polymorphism among the isolates. A total of 138 bands, ranging in size from 150-2800 bp, have been amplified from primers which 63.7% of the observed bands have been polymorphic. Genetic distances among different varieties have been analyzed with a UPGMA (Unweighted pair-group method, arithmetic average)-derived dendrogram. Resulting dendrogram has showed from 0.65 to 0.91 similarities among varieties and divided the isolates into five major groups. Isolates which haven’t had any antagonistic activity against B. allii have been separated into a group and other isolates classified into four groups. The results indicate that RAPD is an efficient method for discriminating and studying genetic diversity of Streptomyces isolates

    Epitaxial Ge-rich silicon layers after dry oxidation of Ge implanted silicon

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    We report on formation of epi-layer of SixGe1-x by taking standard procedure in CMOS technology. The competitive process of solid solubility of Ge dopant into Si and SiO2 is the key to engineer atomically sharp, low defect very thin epitaxial layer at the interface of oxide-Si. Oxidation time process was used to control the distribution of the doped Ge ions at the interface of Si with oxide and in the oxide layer. Implanted samples (35 keV and 1 × 1016 Ge+/cm2) were oxidized at 1050 °C for 30–90 min. RBS-Channeling analysis shows two separate peaks of Ge corresponds to different depths after oxidation. Corroborate with high resolution microscopy and elemental analysis, we determined the first peak as enriched layer of SixGe1-x at the interface of SiO2single bondSi. Less than 10 nm epitaxially grown interfacial layer is very low in defects, and Ge ions are fully substituted into the host lattice. The second peak originated from diffusion of Ge into SiO2 resulted in a segregated layer containing Ge in oxide film. Technological demand on forming SixGe1-x layer for CMOS application through standard routes is what we address in this research.publishe

    Development of ferroelectric domains and topological defects in vacancy doped ceramics of h-LuMnO<sub>3</sub>

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    Self-doping of the h-LuMnxO3±δ (0.92 ≤ x ≤ 1.12) phase and changes in the sintering time are applied to investigate the formation and annihilation of antiphase ferroelectric (FE) domains in bulk ceramics. The increase in the annealing time in sintering results in growth of FE domains, which depends on the type of vacancy, 6-fold vortices with dimensions of the order of 20 μm being observed. Interference of planar defects of the lattice with the growth of topological defects shows breaking of 6-fold symmetry in the self-doped ceramics. The role of grain boundaries in the development of topological defects has been studied. Dominance of the atypical FE domain network in very defective h-LuMnxO3±δ lattices saturated with Mn vacancies (x < 1) was also identified in the current study. After a long annealing time, scattered closed-loops of nano-dimensions are often observed isolated inside large FE domains with opposite polarization. Restoring of the polarization after alternative poling with opposite electrical fields is observed in FE domains. Stress/strain in the lattice driven by either planar defects or chemical inhomogeneity results in FE polarization switching on the nanoscale and further formation of nano-vortices, with detailed investigation being carried out by electron microscopy. Pinning of FE domains to planar defects is explored in the present microscopy analysis, and nano-scale observation of lattices is used to explain features of the ferroelectricity revealed in Piezo Force Microscopy images of the ceramics

    Analysis of bovine growth hormone gene polymorphism of local and Holstein cattle breeds in Kerman province of Iran using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP)

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    Bovine growth hormone (bGH) gene is a part of the multiple gene family that contains prolactin and placental lactogens. Also, variations in introns have potential usefulness as genetic markers and could help in the genetic improvement of populations. Genomic DNA was isolated from blood samples of two local herds (53 animals) and two Holstein herds (50 animals). Genomic DNA samples were genotyped for the GHI-AluI polymorphism by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). A 211 bp (bGH) gene exon 5 segment was amplified by PCR using bovine specific primers. RFLPs in this segment were studied using AluI restriction enzyme. The frequencies of V and L alleles in the local and Holstein herds were 0.2 and 0.65, respectively. For both herds, significant difference from the Hardy-Weinberg equilibrium was observed.Key words: Growth hormone, polymorphism, polymerase chain reaction restriction fragment length polymorphism, local herds, Holstein herds

    Giant Strain and Induced Ferroelectricity in Amorphous BaTiO3 Films under Poling

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    We report an effect of giant surface modification of a 5.6 nm thick BaTiO3 film grown on Si (100) substrate under poling by conductive tip of a scanning probe microscope (SPM). The surface can be locally elevated by about 9 nm under −20 V applied during scanning, resulting in the maximum strain of 160%. The threshold voltage for the surface modification is about 12 V. The modified topography is stable enough with time and slowly decays after poling with the rate ~0.02 nm/min. Strong vertical piezoresponse after poling is observed, too. Combined measurements by SPM and piezoresponse force microscopy (PFM) prove that the poled material develops high ferroelectric polarization that cannot be switched back even under an oppositely oriented electric field. The topography modification is hypothesized to be due to a strong Joule heating and concomitant interface reaction between underlying Si and BaTiO3. The top layer is supposed to become ferroelectric as a result of local crystallization of amorphous BaTiO3. This work opens up new possibilities to form nanoscale ferroelectric structures useful for various applications

    Effect of Intermediate-Dose vs Standard-Dose Prophylactic Anticoagulation on Thrombotic Events, Extracorporeal Membrane Oxygenation Treatment, or Mortality among Patients with COVID-19 Admitted to the Intensive Care Unit: The INSPIRATION Randomized Clinical Trial

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    Importance: Thrombotic events are commonly reported in critically ill patients with COVID-19. Limited data exist to guide the intensity of antithrombotic prophylaxis. Objective: To evaluate the effects of intermediate-dose vs standard-dose prophylactic anticoagulation among patients with COVID-19 admitted to the intensive care unit (ICU). Design, Setting, and Participants: Multicenter randomized trial with a 2 � 2 factorial design performed in 10 academic centers in Iran comparing intermediate-dose vs standard-dose prophylactic anticoagulation (first hypothesis) and statin therapy vs matching placebo (second hypothesis; not reported in this article) among adult patients admitted to the ICU with COVID-19. Patients were recruited between July 29, 2020, and November 19, 2020. The final follow-up date for the 30-day primary outcome was December 19, 2020. Interventions: Intermediate-dose (enoxaparin, 1 mg/kg daily) (n = 276) vs standard prophylactic anticoagulation (enoxaparin, 40 mg daily) (n = 286), with modification according to body weight and creatinine clearance. The assigned treatments were planned to be continued until completion of 30-day follow-up. Main Outcomes and Measures: The primary efficacy outcome was a composite of venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days, assessed in randomized patients who met the eligibility criteria and received at least 1 dose of the assigned treatment. Prespecified safety outcomes included major bleeding according to the Bleeding Academic Research Consortium (type 3 or 5 definition), powered for noninferiority (a noninferiority margin of 1.8 based on odds ratio), and severe thrombocytopenia (platelet count &lt;20 �103/µL). All outcomes were blindly adjudicated. Results: Among 600 randomized patients, 562 (93.7) were included in the primary analysis (median interquartile range age, 62 50-71 years; 237 42.2% women). The primary efficacy outcome occurred in 126 patients (45.7%) in the intermediate-dose group and 126 patients (44.1%) in the standard-dose prophylaxis group (absolute risk difference, 1.5% 95% CI,-6.6% to 9.8%; odds ratio, 1.06 95% CI, 0.76-1.48; P =.70). Major bleeding occurred in 7 patients (2.5%) in the intermediate-dose group and 4 patients (1.4%) in the standard-dose prophylaxis group (risk difference, 1.1% 1-sided 97.5% CI,-� to 3.4%; odds ratio, 1.83 1-sided 97.5% CI, 0.00-5.93), not meeting the noninferiority criteria (P for noninferiority &gt;.99). Severe thrombocytopenia occurred only in patients assigned to the intermediate-dose group (6 vs 0 patients; risk difference, 2.2% 95% CI, 0.4%-3.8%; P =.01). Conclusions and Relevance: Among patients admitted to the ICU with COVID-19, intermediate-dose prophylactic anticoagulation, compared with standard-dose prophylactic anticoagulation, did not result in a significant difference in the primary outcome of a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days. These results do not support the routine empirical use of intermediate-dose prophylactic anticoagulation in unselected patients admitted to the ICU with COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04486508. © 2021 American Medical Association. All rights reserved

    The Percent of Extract and Glycyrrhizin Content of Glycyrrhia glabra Root Grown in Kerman Province and Some Samples from Fars Province by HPLC Method

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    Abstract: Background & Aims: Licorice (Glycyrrhia glabra L.) is an important herbal medicine that its root extract has long been used for the treatment of various diseases. The essential component of its root is glycyrrhizin. This study was performed to determine the percentage of the extract and glycyrrhizin content of the roots of Glycyrrhiz glabra grown in different areas of Kerman province and some samples in Fars province. Methods: Twenty six samples from the roots of Glycyrrhia glabra grown in various areas of Kerman province and 2 samples from Fars Province (a total of 28 samples from 8 regions) were collected and extracted by using ethanol and distilled water (for 5 samples). The percentage of glycyrrhizin in the extracts was determined by High Performance Liquid Chromatography (HPLC) technique. Results: Mean percent of extracts from the samples of Fasa and Shiraz in Fars province (18.25 ± 1.06%), Sirjan (17.29 ± 0.90%) and Bardsir (16.33 ± 5.62%) were higher than other areas (P<0.05). Glycyrrhizin contents of samples of Bardsir (5.09 ± 0.02%), Sirjan (4.94 ± 0.75%), Zarand (4.46 ± 3.34%) were non significantly higher than Glycyrrhizin content of Fars samples (3.65 ± 0.59%). The percentage of the extract and glycyrrhizin were higher in ethanol extract compared to the aqueous extract (P<0.05). Samples with yellow root color had higher percentage of glycyrrhizin than those with brown color and samples of relatively cold and high altitude areas had higher glycyrrhizin content (P<0.001, P<0.05 respectively). Conclusion: Overall, it is concluded that the percent of extract and glycyrrhizin content of licorice root in the most areas of Kerman is relatively high. Appropriate measures for using this root in the country and for exporting purposes and also industrial growing in potential areas of the Province are recommended. Keywords: Glycyrrhia glabra, Extract, Glycyrrhizin, HPLC, Kerman province, Fars provinc

    Biological control of Sclerotinia sclerotiorum, causal agent of sunflower head and stem rot disease, by use of soil borne Actinomycetes isolates

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    Problem statement: High level of biosafety and non adverse effects on the environment of biocontrol strategies of pest management, are priorities of tomorrow's world agriculture. Actinomycetes are active biocontrol agents due to their antagonistic properties against wide range of plant pathogens particularly fungi. Fungal pathogens are liable for a big part of damages in agriculture economy. Approach: In the present research antifungal bioactivity of 50 isolates of Actinomycetes collected from soils of Kerman province of Iran was investigated against Sclerotinia sclerotiorum (Lib.), the causal agent of stem rot in sunflower, through agar disc method and dual culture bioassays. The Streptomyces isolate No. 363 was propagated in submerged cultures and active crude was prepared upon which several biological characterizations performed. Greenhouse studies were achieved to confirm laboratory results. Results: Among the tested Streptomyces isolates, 10 isolates revealed antagonistic properties in dual culture procedure from which isolate No. 363 showed highest bioactivity. The active metabolite of Streptomyces isolate No. 363 was polar and well soluble in H2O. Using agar-disc method, progressive growth of the pathogen was highly reduced by the antagonist through exhibiting ability to constitute fungus-free zones of inhibitions. The results indicated that isolate No. 363 was a proper candidate for field biocontrol studies. Conclusion: Results may open a horizon for production of resistant transgenic plants having antifungal properties originated from biologically active Streptomyces spp. recognition and production of effective metabolite(s) of Streptomyces spp. which was responsible for antifungal activities will be our commercial goal due to rich reserves of soil borne Actinomycetes in Iran
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