排序方式: 共有107条查询结果,搜索用时 15 毫秒
91.
Ehsan Zamani Hanieh Shaki Mehdi Rafizadeh Alireza Khosravi Milad Pilehkouhi 《Fibers and Polymers》2017,18(8):1431-1437
A novel self-colored polyethylene terephthalate (PET) was synthesized using a synthesized dye, 4-amino-N-propanoic acid-1,8-naphthalimide. For this purpose, the prepared naphthalimide dye was added upon the polycondensation step and then a self-colored PET was prepared by step-growth polymerization. The characterization of synthesized self-colored PET and naphthalimide dye were carried out using TLC, FTIR, 1HNMR, DSC, UV-visible and Fluorometery. Results indicated that, the novel fluorescent yellow-green PET with appropriate properties was obtained. The glass transition temperature of self-colored PET was 70 °C and it was measured by differential scanning calorimeter, which revealed that addition of dye to the chains of polymer did not affect the context of glass transition of polymer. UV-visible spectrum indicated that, 99 percent of dye was incorporated in polymer chains chemically. Furthermore, the intrinsic viscosity of self-colored PET was 0.556 dl/g and molecular weight of polymer was around 35000 (g/mol) and measured using the viscometer technique. 相似文献
92.
Dr. Abolghasem Bahrami was among the generation of Iranian scientists in the early twentieth century who gained most of their knowledge through resources available inside the country. Educated at Dar-ul-Funun Medical School, he was a physician with a great talent in learning, especially self-teaching natural sciences and European languages. He joined the Pasteur Institute of Iran (IPI) at the early days of its foundation and became an integral contributor to this institution during the first twenty-five years of its mission. One of his first assignments at IPI was to help initiating an anti-rabies department by bringing back the rabies vaccine and its manufacturing equipment from Institut Pasteur of Paris. During his IPI years, aside from managerial tasks, he actively participated in upgrading the medical treatments and protocols used for controlling many infectious diseases. He functioned twice as the provisional director of IPI (1925-1926 and 1937-1946) and is considered as the first Iranian director of the Institute. Meanwhile, Dr. Bahrami was a significant contributor to the public health system and assumed several responsibilities such as Chief Quarantine Medical Officer, Chief of Public Health, and the Head of Public Health Administration, in order to improve public health planning throughout the country.Key Words: History of medicine, Iran, Microbiology, Pasteur Institute of Iran, Public health 相似文献
93.
Complementary conservation strategies for the genus Coffea: A case study of Mascarene Coffea species
Mohammad Ehsan Dulloo Luigi Guarino Florent Engelmann Nigel Maxted John H. Newbury Frank Attere Brian V. Ford-Lloyd 《Genetic Resources and Crop Evolution》1998,45(6):565-579
No single conservation technique can adequately conserve the full range of genetic diversity of a target species or genepool. To optimize the efficiency of germplasm conservation, a range of conservation techniques needs to be applied simultaneously. In this paper we review the progress made in the application of both in situ and ex situ complementary conservation strategies and techniques to the conservation of the genus Coffea and identify areas where more research work is required. Traditionally, Coffea species have been conserved ex situ as living plants in field genebanks due to their intermediate seed storage behaviour. However, progress made in the field of biotechnology in recent years have made it possible to envisage the use of in vitro, slow growth and cryopreservation for medium- and long-term conservation of Coffea germplasm, respectively. In situ conservation is also an important option for long-term conservation, but there are no genetic reserves specifically set up for conserving Coffea. Protected areas and managed reserves offer the best opportunities for conserving Coffea. A case study for Mascarene Coffea in Mauritius is presented and a strategy for their conservation is discussed. 相似文献
94.
Ehsan Khodapasand Narges Jafarzadeh Farid Farrokhi Behnam Kamalidehghan Massoud Houshmand 《Iranian Biomedical Journal》2015,19(2):69-75
Background:
Bax and Bcl-2 are the major members of Bcl-2 family whose play a key role in tumor progression or inhibition of intrinsic apoptotic pathway triggered by mitochondrial dysfunction. Therefore, the balance between pro- and anti-apoptotic members of this family can determine the cellular fate.Methods:
In this study, the relative level of mRNA expression of Bax and Bcl-2 genes was determined using RNA extraction, cDNA synthesis and RT-qPCR technique from 22 tumoral tissues and adjacent non-tumoral tissues from adenocarcinoma colorectal cancer.Results:
The potential prognostic and predictive significance of Bax and Bcl-2 gene expression and Bax/Bcl-2 ratio were demonstrated in colorectal cancer. The significant correlation between qPCR data and different clinicopathologic parameters of colorectal carcinoma, including age, gender, tumor size, tumor stage, tumor location, and tumor differentiation was also examined. Interestingly, no significant correlation was seen between Bax and Bcl-2 expressions and clinicopathological parameters of colorectal cancer. However, Bax/Bcl-2 ratio was statistically correlated with age and tumor location. Patients with age above 50 showed decreased levels of Bax/Bcl-2 ratio. Moreover, the Bax/Bcl-2 ratio was significantly lower in tumors resected from colon compared to sigmoid colon, rectosigmoid and rectum tumors.Conclusion:
This study indicates a significant correlation between age and tumor location with Bax/Bcl-2 expression ratio, suggesting predictive value as a potential molecular marker of colorectal cancer.Key Words: Colorectal cancer, Bax/Bcl-2 ratio, Bax expression, Bcl-2 expression 相似文献95.
Soheil Zorofchian Moghadamtousi Sonia Nikzad Habsah Abdul Kadir Sazaly Abubakar Keivan Zandi 《Marine drugs》2015,13(7):4520-4538
Biodiversity of the marine world is only partially subjected to detailed scientific scrutiny in comparison to terrestrial life. Life in the marine world depends heavily on marine fungi scavenging the oceans of lifeless plants and animals and entering them into the nutrient cycle by. Approximately 150 to 200 new compounds, including alkaloids, sesquiterpenes, polyketides, and aromatic compounds, are identified from marine fungi annually. In recent years, numerous investigations demonstrated the tremendous potential of marine fungi as a promising source to develop new antivirals against different important viruses, including herpes simplex viruses, the human immunodeficiency virus, and the influenza virus. Various genera of marine fungi such as Aspergillus, Penicillium, Cladosporium, and Fusarium were subjected to compound isolation and antiviral studies, which led to an illustration of the strong antiviral activity of a variety of marine fungi-derived compounds. The present review strives to summarize all available knowledge on active compounds isolated from marine fungi with antiviral activity. 相似文献
96.
Ehsan Borzoui Bahram Naseri Mozhgan Mohammadzadeh-Bidarani 《Journal of insect science (Online)》2016,16(1)
Food characteristics strongly regulate digestive enzymatic activity of insects through direct influences on their midgut mechanisms. Insect performance is better on diets that contain nutrients in proportions that fit its digestive enzymes. Little is known about the influences of rearing history on parasitism success of Habrobracon hebetor Say. This research focused on the effect of nutrient regulation on survival, development, and parasitism of H. hebetor. Life history and digestive enzyme activity of fourth-stage larvae of H. hebetor were studied when reared on Ephestia kuehniella Zeller. This parasitoid was then introduced to Helicoverpa armigera (Hübner), and above-mentioned parameters were also studied in the first and fourth generations after transfer. In term of parasitism success, H. hebetor preferred E. kuehniella over He. armigera. When the first and fourth generations of He. armigera-reared H. hebetor were compared, the rearing history affected the life history and enzymatic activity of the parasitoid. A better performance of H. hebetor was achieved after it was reared on He. armigera for the four generations. Because, digestive α-amylase and general protease of the parasitoid were matched with the new host, it used reserve energy for a better performance. Thus, a better performance of H. hebetor could be obtained when the parasitoid was reared on its original host for at least four generations. 相似文献
97.
Journal of Plant Diseases and Protection - Two experiments were established in the laboratory of the Department of Organic Farming and Cropping Systems and the greenhouse of the University of... 相似文献
98.
Ehsan Ramezani-Fard Aziz Arshad Yong-Meng Goh Mahdi Ebrahimi 《Journal Of Aquatic Food Product Technology》2013,22(6):824-834
ABSTRACTHarpiosquilla harpax and Miyakea nepa are two out of 400 marine crustaceans commonly known as mantis shrimp. Mantis shrimp are commercially valuable and can be found in fish markets of some Mediterranean and many Asian countries. This study focused on a comparative analysis of variation throughout the year in regards to proximate and total fatty acid composition in the muscle of male and female H. harpax and M. nepa. The most abundant fatty acids identified in the muscle of both species were C16:0, C18:0, docosahexaenoic acid (DHA; C22:6n-3), eicosapentaenoic acid (EPA; C20:5n-3), and C20:4n-6. Results of this study revealed that the muscle fatty acid profiles of H. harpax and M. nepa were not significantly different (p > 0.05), except for C14:0, C16:0, C22:0, and DHA amounts, and were mostly influenced by sex within each sampling month. Generally, the muscle of H. harpax contained higher (p < 0.05) levels of DHA than the muscle of M. nepa. The male mantis shrimp, within each species and most of the sampling months, appeared to have higher (p < 0.05) DHA, total n-3 polyunsaturated fatty acid (PUFA), and PUFA/saturated fatty acid ratio compared to the females. Both species could be considered as a good source of n-3 PUFA in the human diet. 相似文献
99.
Ehsan Bari Hamed Aghajani Katie M. Ohno Roya Shahi Mike D. C. Hale Mohsen Bahmani 《Forest Pathology》2019,49(2)
Wood‐decay fungi are important in forest ecosystems and play an important role in nutrient and carbon recycling. The scope of this research was to identify wood‐inhabiting and wood‐decay macrofungi and determine their ecology. We sampled standing trees and dead wood of oak and hornbeam in the northern forests of Iran, specifically in Mazandaran and Golestan provinces. We assessed the influence of field slope, elevation, site direction and the height of fungal sporocarp position on the tree. The species of wood‐inhabiting and wood‐decay fungi belonged to 11 families: Polyporaceae; Stereaceae; Ganodermataceae; Physalacriaceae; Agaricaceae; Xylariaceae; Pluteaceae; Coprinaceae; Strophariaceae; Pleurotaceae; and Hydnaceae. The most common fungal species identified belonged to the Polyporaceae and Ganodermataceae and predominantly grew on trees growing on a slope of 20%, at an altitude of 700–900 m, 0–3 m from the ground a southwesterly site direction and the northern sides of both tree species. These results indicated that field slope was the most important factor in determining fungal sporocarp abundance. 相似文献
100.
Ehsan Abdi Baris Majnounian Hassan Rahimi Mahmud Zobeiri Zahra Mashayekhi Hamed Yosefzadeh 《Journal of Forest Research》2010,15(2):99-107
Slope is a complex environmental factor that can subject plants to a number of mechanical stresses. The anchorage of roots
and improvement of slope stability mainly depend on specific properties of root systems, such as root distribution. In the
present study, 24 trees (from three species) growing on gentle slopes (10–20°) were randomly chosen for root distribution
analysis. The profile trenching method was used to obtain root characteristics. The findings indicated that root area ratio
(RAR) decreased with depth and that maximum RAR values were observed in the upper layers; RAR values were between 0.0004%
and 6.6444%. Average RAR values were not statistically different in upslope and downslope layers except in one case. The dot
grid method (100 × 150 mm) usually overestimated the RAR values. The amount of roots decreased with depth following a power
law. About 50% and 90% of roots were located in the first 30 and 60 cm depths, respectively. Results of analysis of covariance
(ANCOVA) showed a significant effect of diameter at breast height (DBH) on total RAR but not on the total number of roots.
About 70% of roots had diameter of less than 10 mm. Spearman’s correlation showed significant negative correlation between
the total number of roots and the amount of N, P, and K elements, and a positive correlation between DBH and RAR. The results
serve to develop understanding of the biotechnical characteristics of root systems of Caspian species. 相似文献