排序方式: 共有311条查询结果,搜索用时 15 毫秒
91.
Abbas Nasehi Jugah Bin Kadir Farnaz Abed Ashtiani Mehdi Nasr-Esfahani Mui Yun Wong Siti Khadijah Rambe Hajar Ghadirian Farshid Mahmodi Elham Golkhandan 《Mycological Progress》2014,13(4):1041-1048
A new species of Alternaria causing leaf spot of pepper (Capsicum annuum) obtained from the Cameron highlands, Pahang, Malaysia, was determined based on phylogenetic analyses, morphological characteristics, and pathogenicity assays. Phylogenetic analyses of combined dataset of the glyceraldehyde-3-phosphate dehydrogenase (gpd), Alternaria allergen a 1 (Alt a1) and calmodulin genes revealed that the new isolates clustered into a subclade distinct from the closely related Alternaria species A. tomato and A. burnsii. The solitary or short chains of conidia resemble those of A. burnsii. However, conidia with long beaks are morphologically similar to A. tomato. Hence, the pathogenic fungus is proposed as Alternaria capsicicola sp. nov. Pathogenicity assays indicated that A. capsicicola causes leaf spot on pepper. 相似文献
92.
Mohammad Taghi Bahreyni Toossi Maliheh Abdollahi Mahdi Ghorbani 《Reports of Practical Oncology and Radiotherapy》2013,18(2):112-116
Aim
Stepping source in brachytherapy systems is used to treat a target lesion longer than the effective treatment length of the source. Cancerous lesions in the cervix, esophagus and rectum are examples of such a target lesion.Background
In this study, the stepping source of a GZP6 afterloading intracavitary brachytherapy unit was simulated using Monte Carlo (MC) simulation and the results were used for the validation of the GZP6 treatment planning system (TPS).Materials and methods
The stepping source was simulated using MCNPX Monte Carlo code. Dose distributions in the longitudinal plane were obtained by using a matrix shift method for esophageal tumor lengths of 8 and 10 cm. A mesh tally has been employed for the absorbed dose calculation in a cylindrical water phantom. A total of 5 × 108 photon histories were scored and the MC statistical error obtained was at the range of 0.008–3.5%, an average of 0.2%.Results
The acquired MC and TPS isodose curves were compared and it was shown that the dose distributions in the longitudinal plane were relatively coincidental. In the transverse direction, a maximum dose difference of 7% and 5% was observed for tumor lengths of 8 and 10 cm, respectively.Conclusion
Considering that the certified source activity is given with ±10% uncertainty, the obtained difference is reasonable. It can be concluded that the accuracy of the dose distributions produced by GZP6 TPS for the stepping source is acceptable for its clinical applications. 相似文献93.
Farshid Ghezelbash Aboulfazl Shirazi-Adl 《Computer methods in biomechanics and biomedical engineering》2013,16(16):1760-1767
Due to the complexity of the human spinal motion segments, the intervertebral joints are often simulated in the musculoskeletal trunk models as pivots thus allowing no translational degrees of freedom (DOFs). This work aims to investigate, for the first time, the effect of such widely used assumption on trunk muscle forces, spinal loads, kinematics, and stability during a number of static activities. To address this, the shear deformable beam elements used in our nonlinear finite element (OFE) musculoskeletal model of the trunk were either substantially stiffened in translational directions (SFE model) or replaced by hinge joints interconnected through rotational springs (HFE model). Results indicated that ignoring intervertebral translational DOFs had in general low to moderate impact on model predictions. Compared with the OFE model, the SFE and HFE models predicted generally larger L4–L5 and L5–S1 compression and shear loads, especially for tasks with greater trunk angles; differences reached ~15% for the L4–L5 compression, ~36% for the L4–L5 shear and ~18% for the L5–S1 shear loads. Such differences increased, as location of the hinge joints in the HFE model moved from the mid-disc height to either the lower or upper endplates. Stability analyses of these models for some select activities revealed small changes in predicted margin of stability. Model studies dealing exclusively with the estimation of spinal loads and/or stability may, hence with small loss of accuracy, neglect intervertebral translational DOFs at smaller trunk flexion angles for the sake of computational simplicity. 相似文献
94.
Mandragora turcomanica Mizg. is reported from gardens of Dahaneh village c.7 km north of Kalaleh in Golestan Province (NE Iran). The plants were transplanted from wild populations by the local people many years ago, because of their highly aromatic leaves and fruits. Current information suggests the species is extinct or extremely rare in natural habitats in Iran and protection of extant stands in this village is urgently recommended. It is already known to be endangered in Turkmenistan. The detailed morphological characteristics are discussed and compared with the Mediterranean M. officinarum L., and photographs of the plant are provided. 相似文献
95.
Keramati Arezoo Azizi Soroush Hashemi Ali Pajoum Shariati Farshid 《Journal of applied phycology》2021,33(3):1513-1524
Journal of Applied Phycology - Light is one of the most critical factors for the growth of microalgae; therefore, optimization and accessibility of light improve productivity and wastewater... 相似文献
96.
Ghorbani Atosa Hashemzadeh Mohammad Amin Mansour Moosavian Mojtaba Nashibi Rohangiz Mehraban Zahra 《Molecular biology reports》2021,48(11):7141-7146
Molecular Biology Reports - This study aimed to investigate the occurrence of Legionella species in the respiratory samples of patients with pneumonia symptoms from Ahvaz, Iran by culture and the... 相似文献
97.
Fathi Farshid Zamani Batool Piroozmand Ahmad Mozafarpoor Samaneh Seyedhashemi Effat ArefNezhad Reza Motedayyen Hossein 《Molecular biology reports》2021,48(3):2047-2052
Molecular Biology Reports - Programmed death-1 (PD-1), as an immunoinhibitory receptor encoded by programmed cell death-1 (PDCD1) gene, has a pivotal role in tolerance to self-antigens. Mutations... 相似文献
98.
Sepideh Ghorbani Fatemeh Tabandeh Bagher Yakhchali Mohammad Reza Mehrnia 《Biotechnology and Bioprocess Engineering》2011,16(5):1019-1026
A cell surface display system with metalbinding properties was previously developed using CS3 fimbriae, which are hollow tubes
20 nm-thick and 2 nm in diameter. In this study, hybrid CS3 pili were separated from recombinant Escherichia coli and entrapped in calcium alginate gel beads in order to improve their stabilization and also adsorption of heavy metals.
The surface morphology of the gel beads containing pili was investigated by scanning electron microscopy (SEM). Immunofluorescence
microscopy was employed to confirm the attachment of nanobiofibers to the alginate beads. The effects of three variables (sodium
alginate concentration, protein to alginate mass ratio, and bead size) at two levels each on Cd2+ biosorption efficiency were investigated by full factorial experimental design. A second-order polynomial equation modeled
the design space for the process response of cadmium removal capacity. The optimal values of the factors were obtained as
follows: 1% sodium alginate concentration, 0.25 protein to alginate mass ratio, and a 6 mm bead size. Under these conditions,
Cd2+ was adsorbed at 45.45 mg/g to the nanobiofiber. The results indicate that the immobilized recombinant hybrid CS3 pili may
be an appropriate biosorbent for removal of heavy metals from polluted aquatic environments. 相似文献
99.
An autocrine TGF-beta/ZEB/miR-200 signaling network regulates establishment and maintenance of epithelial-mesenchymal transition 总被引:1,自引:0,他引:1
100.
Nucleus pulposus (NP) cells of the intervertebral disk (IVD) have unique morphological characteristics and biologic responses
to mechanical stimuli that may regulate maintenance and health of the IVD. NP cells reside as single cell, paired or multiple
cells in a contiguous pericellular matrix (PCM), whose structure and properties may significantly influence cell and extracellular
matrix mechanics. In this study, a computational model was developed to predict the stress–strain, fluid pressure and flow
fields for cells and their surrounding PCM in the NP using three-dimensional (3D) finite element models based on the in situ
morphology of cell–PCM regions of the mature rat NP, measured using confocal microscopy. Three-dimensional geometries of the
extracellular matrix and representative cell–matrix units were used to construct 3D finite element models of the structures
as isotropic and biphasic materials. In response to compressive strain of the extracellular matrix, NP cells and PCM regions
were predicted to experience volumetric strains that were 1.9–3.7 and 1.4–2.1 times greater than the extracellular matrix,
respectively. Volumetric and deviatoric strain concentrations were generally found at the cell/PCM interface, while von Mises
stress concentrations were associated with the PCM/extracellular matrix interface. Cell–matrix units containing greater cell
numbers were associated with higher peak cell strains and lower rates of fluid pressurization upon loading. These studies
provide new model predictions for micromechanics of NP cells that can contribute to an understanding of mechanotransduction
in the IVD and its changes with aging and degeneration. 相似文献