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Summary At high salinities and high temperatures, the growth rate of Pterocladia was high, the tips of branch initials were dilated and holdfasts broadened. By the end of the fourth week bleaching of the whole plant was complete.Under low salinities and low temperatures, the rate of vegetative growth was decreased, the cuticle was thin and food reserve was centrally accumulated in the cells.Under high salinities and low temperatures, the rate of growth was greatly reduced and cells were devoid of food reserve. Defoliation of lateral branches was frequent.Under low salinities and high temperatures, the rate of growht was rather high and cells were relatively large. 相似文献
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Hamid Shafaei Douk Mahmoud Reza Aghamiri Mahdi Ghorbani Bagher Farhood Mohsen Bakhshandeh Hamid Reza Hemmati 《Reports of Practical Oncology and Radiotherapy》2018,23(2):105-113
Aim
The aim of this study is to evaluate the accuracy of the inverse square law (ISL) method for determining location of virtual electron source (SVir) in Siemens Primus linac.Background
So far, different experimental methods have presented for determining virtual and effective electron source location such as Full Width at Half Maximum (FWHM), Multiple Coulomb Scattering (MCS), and Multi Pinhole Camera (MPC) and Inverse Square Law (ISL) methods. Among these methods, Inverse Square Law is the most common used method.Materials and methods
Firstly, Siemens Primus linac was simulated using MCNPX Monte Carlo code. Then, by using dose profiles obtained from the Monte Carlo simulations, the location of SVir was calculated for 5, 7, 8, 10, 12 and 14 MeV electron energies and 10 cm × 10 cm, 15 cm × 15 cm, 20 cm × 20 cm and 25 cm × 25 cm field sizes. Additionally, the location of SVir was obtained by the ISL method for the mentioned electron energies and field sizes. Finally, the values obtained by the ISL method were compared to the values resulted from Monte Carlo simulation.Results
The findings indicate that the calculated SVir values depend on beam energy and field size. For a specific energy, with increase of field size, the distance of SVir increases for most cases. Furthermore, for a special applicator, with increase of electron energy, the distance of SVir increases for most cases. The variation of SVir values versus change of field size in a certain energy is more than the variation of SVir values versus change of electron energy in a certain field size.Conclusion
According to the results, it is concluded that the ISL method can be considered as a good method for calculation of SVir location in higher electron energies (14 MeV). 相似文献116.
Maryam Amiri Mohsen Basiri Hossein Eskandary Zeinab Akbarnejad Marzie Esmaeeli Yaser Masoumi-Ardakani 《Electromagnetic biology and medicine》2018,37(3):138-145
Glioblastoma multiforme (GBM) is a malignant brain cancer that causes high mortality in patients. GBM responds weakly to the common cancer treatments such as chemotherapy and radiotherapy and even surgery. Carboplatin is an alkylating agent widely used to treat cancer. However, resistance to this drug is a common problem in its use in cancer treatment. Concomitant exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) and carboplatin is one unexplored possibility for overcoming this resistance. Indeed, many lines of evidence show that EMF affects cancer cells and drug action. In this study, we evaluated the effect of concomitant administration of carboplatin and EMF (50 Hz, 70 G) and also concomitant administration of carboplatin and static magnetic field (SMF) (70 G) on human glioma cell line (U-87). The results showed that cotreatment reduced the efficiency of carboplatin in U-87 cells, by decreasing caspase-3 in comparison to drug groups. Overall, EMF reduced the apoptotic effect of carboplatin, possibly through a redox regulation mechanism. Therefore, we have to avoid coadministration of magnetic field (MF) and carboplatin in tumor area, because the MF decreased the toxicity of the drug. However, further studies are needed to reveal the action mechanism of this combination therapeutic method. 相似文献
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Javad Zamani Mohammad Ali Hajabbasi Mohammad Reza Mosaddeghi Mohsen Soleimani Mehran Shirvani Rainer Schulin 《Soil & Sediment Contamination》2018,27(1):13-30
Plant-based methods such as rhizodegradation are very promising for the remediation of petroleum-contaminated soils. Associations of plants with endophytes can further enhance their phytoremediation potential. In this study, a rhizobox experiment was conducted to investigate whether inoculation with the root-colonizing fungus Piriformospora indica could further enhance the degradation of petroleum hydrocarbons in the root zone of maize (Zea mays L.). The rhizoboxes were subdivided into compartments in accordance with distance from the plants. After filling the boxes with soil from a petroleum-contaminated site, seedlings that had either been inoculated with P. indica or not were grown in the middle compartments of the rhizoboxes and grown for 64 days. A plant-free treatment was included for control. The presence of roots strongly increased the counts of total and petroleum-degrading soil bacteria, respiration, dehydrogenase activity, water-soluble phenols and petroleum degradation. All these effects were also found in the soil adjacent to the middle compartments of the rhizoboxes, but strongly decreased further away from it. Inoculation with P. indica further enhanced all the recorded parameters without changing the spatial pattern of the effects. Inoculated plants also produced around 40% more root and shoot biomass than noninoculated plants and had greener leaves. Together, the results indicate that the treatment effects on the recorded soil microbial and biochemical parameters including petroleum hydrocarbon degradation were primarily due to increased root exudation. Irrespectively of this, they show that maize can be used to accelerate the rhizodegradation of petroleum hydrocarbons in soil and that inoculation with P. indica can substantially enhance the phytoremediation performance of maize. 相似文献
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Afsaneh Sadremomtaz Kamran Mansouri Golnaz Alemzadeh Majid Safa Ahmadreza Esmaeili Rastaghi S. Mohsen Asghari 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(12):2688-2700
Background
Neutralization of vascular endothelial growth factor receptor 1 (VEGFR1) and/or VEGFR2 is a widely used means of inhibiting tumor angiogenesis.Methods
Based on the complex X-ray structures of VEGFA/VEGFR1, VEGFA/VEGFR2, and VEGFB/VEGFR1, a peptide (referred to as VGB) was designed to simultaneously bind to VEGFR1 and VEGFR2, and binding, antiangiogenic and antitumor properties of the peptide was investigated in vitro.Results
VGB bound to both VEGFR1 and VEGFR2 in human umbilical vein endothelial cells (HUVECs) and 4?T1 mammary carcinoma tumor (MCT) cells, and inhibited the proliferation of HUVE, 4?T1 MCT, and U87 glioblastoma cells. Through abrogation of AKT and ERK1/2 phosphorylation, VEGFA-stimulated proliferation, migration, and two- and three-dimensional tube formation in HUVECs were inhibited more potently by VGB than by bevacizumab. In a murine 4?T1 MCT model, VGB strongly inhibited tumor growth without causing weight loss, accompanied by inhibition of AKT and ERK1/2 phosphorylation, a significant decrease in tumor cell proliferation (Ki-67 expression), angiogenesis (CD31 and CD34 expression), an increase in apoptosis index (increased TUNEL staining and p53 expression and decreased Bcl-2 expression), and the suppression of systematic spreading of the tumor (reduced NF-κB and MMP-9 and increased E-cadherin expression).Conclusion
The dual specificity of VGB for VEGFR1 and VEGFR2, through which the PI3K/AKT and MAPK/ERK1/2 signaling pathways can be abrogated and, subsequently, angiogenesis, tumor growth, and metastasis are inhibited.General significance
This study demonstrated that simultaneous blockade of VEGFR1 and VEGFR2 downstream cascades is an effective means for treatment of various angiogenic disorders, especially cancer. 相似文献119.
Mohsen Hesami Mohammad Hosein Daneshvar Mohsen Yoosefzadeh-Najafabadi Milad Alizadeh 《Journal of Genetic Engineering and Biotechnology》2018,16(1):175-180
Ficus religiosa is known as a long-lived multipurpose forest tree. The tree plays an important role for religious, medicinal, and ornamental purposes. However, the propagation rate of Ficus religiosa is low in natural habitat so the plant tissue culture techniques are an applicable method for multiplication of this valuable medicinal plants. Thus, the aim of this study is to understand the effect of different auxin/cytokinin ratios on indirect shoot organogenesis of this plant. According to our results, the maximum callus induction frequency (100%) was obtained on Murashige and Skoog (MS) medium supplemented with 0.5?mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) plus 0.05?mg/l 6-benzylaminopurine (BAP) from petiole segments. For shoot induction purpose, the yellow-brownish, friable, organogenic calli were inoculated on shoot induction medium. On MS medium supplemented with 1.5?mg/l BAP and 0.15?mg/l Indole-3-butyric acid (IBA), 96.66% of the petiole-derived calli responded with an average number of 3.56 shoots per culture. The highest root formation frequency (96.66%), root number (5.5), and root length (4.83?cm) were achieved on MS medium containing 2.0?mg/l IBA plus 0.1?mg/l Naphthaleneacetic acid (NAA). The rooted shoots were successfully transferred to field condition and the substrate with the mixture of cocopeat and perlite (1:1) had the highest survival rate (96.66%). This is the first report of an effective in vitro organogenesis protocol for F. religiosa by indirect shoot organogenesis through axenic seedling derived petiole explants, which can be efficiently employed for conservation of this important medicinal plant species as well as the utilization of active biomolecules. 相似文献
120.
Arshid Yousefi-Avarvand Mohsen Tafaghodi Saman Soleimanpour Farzad Khademi 《生物学前沿》2018,13(4):293-296