A novel biodegradable polyurethane based on hydroxylated polylactic acid and tung oil mixtures. I. Synthesis,physicochemical and biodegradability characterization     

Hossein Izadi-Vasafi  Gity Mir Mohamad Sadeghi  Amir Babaei  Faezeh Ghayoumi 《Fibers and Polymers》2016,17(3):311-323

A novel biodegradable polylactic acid-based polyurethane (PU) was synthesized via a chain extension reaction between hydroxylated polylactic acid (PLA-OH) and hydroxylated tung oil (HTO) using 1,6-hexamethylene diisocyanate (HDI) to link the two polyols and dibutyltin dilaurate (DBTDL) as a catalyst. Both PLA-OH and HTO, as polyols, were separately synthesized in our laboratory. Three different molecular weights of PLA-OH prepolymers were used, and the molar ratio of PLA-OH to HTO was also changed to investigate the effect of these two parameters on the structure and properties of the final PUs. Chemical structures of PLA-OH, HTO, and final PUs were investigated by Fourier transform infrared (FTIR) and Hydrogen-1 nuclear magnetic resonance (¹HNMR) spectroscopies. Thermal transitions and thermal stability of the final PUs were, respectively, studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR and ¹HNMR results showed that the chain-extension reaction of the two polyols with HDI was sufficiently achieved. The TGA results showed that the polyurethanes based on the lower molecular weight PLA segments were more thermally stable; it was not degraded up to 270 °C. DSC results showed that incorporating HTO in the PU chains led to formation of more flexible PU chains, while the glass transition temperatures of the PUs of higher PLA-OH molecular weights were higher than those of lower ones.  相似文献   

The effect of pod elimination on water stress in relation to antioxidant enzymes activity and proline in three annual medics species     

Farzaneh Fakhari  Hossein Sadeghi 《Journal of Crop Science and Biotechnology》2016,19(1):109-115

Despite the importance of pod removal in the seeds of annual medics, there have been few studies carried out in this area. In this research, the role of pod removal in growth and biochemical enzyme activities was examined in three annual medic species during drought stress and subsequent recovery. This study was carried out as a factorial experiment based on a completely randomized design. The treatments were carried out on annual medic species of three levels: Medicago rigidula, M. scutellata, M. polymorpha, presence or removal of the pod and water stress. Water stress was split into the following four levels: 100%, 80%, 60%, and 40% field capacity (FC) during the stress period. The results showed that drought stress and subsequent recovery increased proline content and antioxidant enzyme activity. The highest proline content and antioxidant enzyme activity was observed in M. Scutellata. However, the rate at which proline increased, decreased at 40% FC whereas the antioxidant enzyme reached their highest activity at 40% FC. The antioxidant enzymes’ activity and proline content without the pod experiment were significantly higher than with the pod experiment. Since the activation of an antioxidant system and the increasing of the proline content helps the plants with stress induced damages, our results indicated that elimination of pods of annual medics before sowing helps seedlings to perform better under drought stress. This data is useful to gain a better understanding of the physiological basis of the changes in drought resistance as well as the crop breeding projects.  相似文献   

Study the Effects of Siderophore-Producing Bacteria on Zinc and Phosphorous Nutrition of Canola and Maize Plants     

Nazanin Ghavami  Hossein Ali Alikhani  Ahmad Ali Pourbabaee  Hossein Besharati 《Communications in Soil Science and Plant Analysis》2016,47(12):1517-1527

Plant growth-promoting rhizobacteria (PGPR) are soil bacteria that are able to colonize rhizosphere and to enhance plant growth by means of a wide variety of mechanisms. In the present study, Myristica yunnanensis and Stenotrophomonas chelatiphaga strains were recognized as new records in Iran flora. According to the results, these strains significantly affected plants’ zinc and phosphorous contents which could be due to the production of phytosiderophore. Siderophore-producing bacteria increased canola zinc (Zn) content as strategy-I plant, while in maize, it can be said that probably the effect of phytosiderophore produced by plant on increasing root and shoot Zn content was more than siderophore produced by bacteria. These isolates could be used as bio-input for improving the plant productivity as a substitute to chemical fertilizers and also to correct the nutrient deficiencies in canola and maize for sustainable agriculture.  相似文献   

Suppression of the fungal pathogen Magnaporthe grisea by Stenotrophomonas maltophilia,a seed-borne rice (Oryza sativa L.) endophytic bacterium     

Hassan Etesami  Hossein Ali Alikhani 《Archives of Agronomy and Soil Science》2016,62(9):1271-1284

The present work was carried out to study the potential of bacteria isolated from the seeds of rice plant for the biocontrol of five rice pathogenic fungi. Eleven endophytic bacteria isolated from rice seeds were evaluated for their antagonistic potential. Of five pathogens studied, only the growth of Magnaporthe grisea was inhibited by one bacterial isolate in an in vitro dual culture assay. Based on 16S rDNA sequence analysis, and biochemical and morphological characteristics, this strain was closely related to Stenotrophomonas maltophilia. We named this new isolate to be S. maltophilia SEN₁ (seed endophyte). This isolate was further tested for the production of volatile and diffusible antibiotics against M. grisea, for plant growth-promoting (PGP) traits and colonization of some rice cultivars. In addition, S. maltophilia SEN₁ was tested for its ability to promote plant growth and reduce the incidence of rice blast disease under greenhouse conditions. When applied to the soil, this isolate increased seedling growth and suppressed blast disease in plants of three studied cultivars. This study also showed this isolate could colonize the root interior of other rice cultivars. This study indicates that the S. maltophilia isolate studied has an excellent potential to be used as biocontrol agents of M. grisea or biofertilizer under in vitro and in vivo conditions.  相似文献   

Neuronal Cell Reconstruction with Umbilical Cord Blood Cells in the Brain Hypoxia-Ischemia     

Hossein Ali Ghaffaripour  Mehdi Jalali  Mohammad Reza Nikravesh  Masoumeh Seghatoleslam  Javad Sanchooli 《Iranian Biomedical Journal》2015,19(1):29-34

Background: Brain hypoxia-ischemia is a human neonatal injury that is considered a candidate for stem cell therapy. Methods: The possible therapeutic potential of human umbilical cord blood (HUCB) stem cells was evaluated in 14-day-old rats subjected to the right common carotid occlusion, a model of neonatal brain hypoxia-ischemia. Seven days after hypoxia-ischemia, rats received either saline solution or 4 × 10⁵ HUCB cells i.v. Rats in control group did not receive any injection. After two weeks, rats were assessed using two motor tests. Subsequently, rats were scarified for histological and immunohistochemical analyses. Results: Our immunohistochemical findings demonstrated selective migration of the injected HUCB cells to the ischemic area as well as reduction in infarct volume. Seven days after surgery, we found significant recovery in the behavioral performance in the test group (12.7 +/- 0.3) compared to the sham group (10.0 +/-0.05), a trend which continued to day 14 (15.3 ± 0.3 vs. 11.9 ± 0.5, P<0.05). Postural and motor asymmetries at days 7 and 14 in the test group showed a significant decrease in the percentage of right turns in comparison to the sham group (75% and 59% vs. 97% and 96%, P<0.05). Conclusion: The results show the potential of HUCB stem cells in reduction of neurologic deficits associated with neonatal hypoxia-ischemia. Key Words: Hypoxia-Ischemia, Nerve cell, Umbilical Cord Blood  相似文献   

Association between p53?Codon 72 (Arg72Pro) Polymorphism and Primary Open-Angle Glaucoma in Iranian Patients     

Hossein Neamatzadeh  Reza Soleimanizad  Masoud Zare-Shehneh  Saba Gharibi  Abolfazl Shekari  Amir Bahman Rahimzadeh 《Iranian Biomedical Journal》2015,19(1):51-56

Background: Glaucomatous neuropathy is a type of cell death due to apoptosis. The p53 gene is one of the regulatory genes of apoptosis. Recently, the association between the p53 gene encoding for proline at codon 72 and primary open-angle glaucoma (POAG) has been studied in some ethnic groups. This study is the first association analysis of POAG and p53 codon 72 polymorphism in Iranian patients. Methods: A cohort of 65 unrelated patients with POAG (age range from 12-62 years, mean ± SD of 40.16 ± 17.51 years) and 65 unrelated control subjects (without glaucoma, age range of 14-63 years, mean ± SD of 35.64 ± 13.61 years) were selected. In Iranian POAG patients and normal healthy controls, the p53 codon 72 polymorphism in exon 4 was amplified using polymerase chain reaction. The amplified DNA fragments were digested with the BstUI restriction enzyme, and the digestion patterns were used to identify the alleles for the polymorphic site. Results: Comparisons revealed significant differences in allele and genotype frequencies of Pro72Arg between POAG patients and control group. A higher risk of POAG was associated with allele Pro (OR = 2.1, 95% CI = 1.2–3.4) and genotype Pro/Pro (OR = 3.9, 95% CI = 0.13-12.7). Conclusion: The p53 Pro72 allele was more frequent in Iranian POAG patients than in the control group (P<0.05). The present findings show that the individuals with the Pro/Pro genotype may be more likely to develop POAG. However, additional studies are necessary to confirm this association. Key Words: Primary open-angle glaucoma (POAG), Glaucoma, p53, Codon 72, Iran  相似文献   

Simultaneous Analysis of Multidrug Resistance 1(MDR1) C3435T,G2677T/A,and C1236T Genotypes in Hamadan City Population,West of Iran     

Massoud Saidijam  Hossein Mahjub  Nooshin Shabab  Reza Yadegarazari 《Iranian Biomedical Journal》2015,19(1):57-62

Background: One of the limitations in the treatment of common diseases such as cancer chemotherapy is development of multidrug resistance (MDR). Polymorphisms could alter the expression level of MDR1 gene, which plays an important role in MDR. In this research, the frequency of C3435T, C1236T, and G2677T/A polymorphisms of MDR1 gene was investigated in a large group of population from Hamadan city to provide a sample data resource. Methods: Peripheral blood (2 ml) was taken, and DNA extraction was carried out. Multiplexed mutagenically separated PCR, which was followed by polyacrylamide gel electrophoresis and silver staining, was applied to detect the mentioned polymorphisms in 935 individuals. Sequencing performed for confirmation of gel electrophoresis resulted in 10 random cases. In total, alleles and genotypes of 933 persons (776 women and 157 men) were determined. Results: The most frequent alleles of the polymorphisms were: 3435T, C1236, and G2677. The most frequent genotypes were: 3435C/T, 1236C/T, and 2677G/A, and their concurrent presence was also found as the most frequent simultaneous genotypes. There was not any meaningful difference among the prevalence of these genotypes in groups of men and women. Conclusion: Our results were close to those of other studies performed in Iran and compared to the other ethnic groups, which showed more similarity to Asian peoples than Europeans. As an aspect of personalized medicine, it could be used by chemotherapists to improve the routine methods of cancer treatment.Key Words: Gene polymorphism, Multi-drug resistance, Neoplasm  相似文献   

Role of GABAB Receptor and L-Arg in GABA-Induced Vasorelaxation in Non-diabetic and Streptozotocin-Induced Diabetic Rat Vessels     

Fatemah Kharazmi  Nepton Soltani  Sana Rezaei  Mansoor Keshavarz  Leila Farsi 《Iranian Biomedical Journal》2015,19(2):91-95

Background:

Hypertension is considered an independent risk factor for cardiovascular mortality in diabetic patients. The present study was designed to determine the role of gamma amino butyric acid B (GABA_B) receptor and L-arginine (L-Arg) in GABA-induced vasorelaxation in normal and streptozotocin-induced diabetic rat vessels.

Methods:

Diabetes was induced by a single i.p. injection of streptozotocin (STZ, 60 mg/kg). Eight weeks later, superior mesenteric arteries of all groups were isolated and perfused according to the McGregor method.

Results:

Baseline perfusion pressure of STZ diabetic rats was significantly higher than non-diabetic rats in both intact and denuded endothelium. In the presence of faclofen, a selective GABA_B receptor blocker, GABA-induced relaxation in intact and denuded endothelium mesenteric beds of STZ diabetic rats was suppressed, but this response in non-diabetic rats was not suppressed. Our results showed that in the presence of L-Arg, a nitric oxide precursor, GABA induced vasorelaxation in both diabetic and non-diabetic vessels.

Conclusion:

From the results of this study, it may be concluded that the vasorelaxatory effect of GABA in diabetic vessel is mediated by the GABA_B receptor and nitric oxide, but it seems that in non-diabetic vessel GABA_B receptor does not play any role in GABA-induced vasorelaxation, but nitric oxide induced GABA relaxation in non-diabetic vessel. Key Words: Gamma amino butyric acid (GABA), Diabetes, GABA_B receptor  相似文献   

Mechanisms of glyphosate resistance in two perennial ryegrass (Lolium perenne) populations          下载免费PDF全文

Hossein Ghanizadeh  Kerry C Harrington  Trevor K James  David J Woolley  Nicholas W Ellison 《Pest management science》2015,71(12):1617-1622

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Sex steroids in the seminal fluid and milt quality indices in the endangered Caspian brown trout,Salmo trutta caspius     

Hamid Reza Jamalzadeh  Maryam Akhundian  Milad Kabir  Hossein Khara  Saeed Hajirezaee 《Aquaculture Research》2014,45(6):1090-1095

In this study, the relationships between the seminal fluid sex steroids sperm quality parameters (i.e. sperm motility and sperm production were investigated in the endangered Caspian brown trout. According to results, the variation of sex steroid concentrations was comparatively high. The seminal fluid levels of 17α‐Hydroxyprogesterone (OHP) had positive correlation with percentage and duration of sperm motility. Similar correlation was found between the seminal fluid concentration of testosterone (T) and estradiol‐17β (E2) with sperm concentration. As well as, there was no significant correlation between progesterone (P) with sperm quality indices. The significant correlation of some steroids i.e. OHP, T and E2 and sperm quality parameters of Caspian brown trout confirms the key role of these steroids in acquisition of the potential of motility during final stage of the maturation.  相似文献