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1.
The complex nature of spinal cord injuries has provided much inspiration for the design of novel biomaterials and scaffolds which are capable of stimulating neural tissue repair strategies. Recently, conductive polymers have gained much attention for improving the nerve regeneration. In our previous study, a three-dimensional (3D) structure with reliable performance was achieved for electrospun scaffolds. The main purpose in the current study is formation of electrical excitable 3D scaffolds by appending polyaniline (PANI) to biocompatible polymers. In this paper, an attempt was made to develop conductive nanofibrous scaffolds, which can simultaneously present both electrical and topographical cues to cells. By using a proper 3D structure, two kinds of conductive scaffolds are compared with a non-conductive scaffold. The 3D nanofibrous core-sheath scaffolds, which are conductive, were prepared with nanorough sheath and aligned core. Two different sheath polymers, including poly(lactic-co-glycolic acid) PLGA and PLGA/PANI, with identical PCL/PANI cores were fabricated. Nanofibers of PCL and PLGA blends with PANI have fiber diameters of 234±60.8 nm and 770±166.6 nm, and conductivity of 3.17×10-5 S/cm and 4.29×10-5 S/cm, respectively. The cell proliferation evaluation of nerve cells on these two conductive scaffolds and previous non-conductive scaffolds (PLGA) indicate that the first conductive scaffold (PCL/ PANI-PLGA) could be more effective for nerve tissue regeneration. Locomotor scores of grafted animals by developed scaffolds showed significant performance of non-conductive 3D scaffolds. Moreover, the animal studies indicated the ability of two new types of conductive scaffolds as spinal cord regeneration candidates.  相似文献   
2.
Tropical Animal Health and Production - Avian influenza virus (AIV) H9N2 subtype is endemic in Iran and causes substantial economic loss to the growing poultry industry within the country. In this...  相似文献   
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A single nucleotide polymorphism (SNP) in the cytochrome b gene confers resistance to strobilurin fungicides for several fungal pathogens. Therefore, on the basis of a change at amino acid position 143 from glycine to alanine, a real-time PCR assay was established for the quantitative detection of the analogous SNP in the cytochrome b sequence of Pyrenophora teres Drechsler, which causes barley net blotch. Allelic discrimination was achieved by using allele specific primers with artificially mismatched nucleic acid bases and minor groove binding probes. Validation parameters for the lower limits of the working range, namely limits of detection (LOD) and limits of quantification (LOQ), were statistically determined by the variance of calibration data, as well as by the variance of the 100% non-strobilurin-resistant allele DNA sample (blank values). It was found that the detection was limited by the variance of blank values (five in 801 458 copies; 0.0006%), whereas the quantification was limited by the variance of calibration data (37 in 801 458 copies; 0.0046%). The real-time PCR assay was finally used to monitor strobilurin-resistant cytochrome b alleles in barley net blotch field samples, which were already classified in in vivo biotests to be fully sensitive to strobilurins. All signals for strobilurin-resistant cytochrome b alleles were below the LOD, and therefore the results are in total agreement with the phenotypes revealed by biotests.  相似文献   
5.
Conventional lung cancer therapies are associated with poor survival rates; therefore, new approaches such as gene therapy are required for treating cancer. Gene therapies for treating lung cancer patients can involve several approaches. Among these, aerosol gene delivery is a potentially more effective approach. In this study, Akt1 kinase-deficient (KD) and wild-type (WT) Akt1 were delivered to the lungs of CMV-LucR-cMyc-IRES-LucF dual reporter mice through a nose only inhalation system using glucosylated polyethylenimine and naphthalene was administrated to the mice via intraperitoneal injection. Aerosol delivery of Akt1 WT and naphthalene treatment increased protein levels of downstream substrates of Akt signaling pathway while aerosol delivery of Akt1 KD did not. Our results showed that naphthalene affected extracellular signal-regulated kinase (ERK) protein levels, ERK-related signaling, and induced Clara cell injury. However, Clara cell injury induced by naphthalene was considerably attenuated in mice exposed to Akt1 KD. Furthermore, a dual luciferase activity assay showed that aerosol delivery of Akt1 WT and naphthalene treatment enhanced cap-dependent protein translation, while reduced cap-dependent protein translation was observed after delivering Akt1 KD. These studies demonstrated that our aerosol delivery is compatible for in vivo gene delivery.  相似文献   
6.
Protein-folding intermediates have been implicated in amyloid fibril formation involved in neurodegenerative disorders. However, the structural mechanisms by which intermediates initiate fibrillar aggregation have remained largely elusive. To gain insight, we used relaxation dispersion nuclear magnetic resonance spectroscopy to determine the structure of a low-populated, on-pathway folding intermediate of the A39V/N53P/V55L (A, Ala; V, Val; N, Asn; P, Pro; L, Leu) Fyn SH3 domain. The carboxyl terminus remains disordered in this intermediate, thereby exposing the aggregation-prone amino-terminal β strand. Accordingly, mutants lacking the carboxyl terminus and thus mimicking the intermediate fail to safeguard the folding route and spontaneously form fibrillar aggregates. The structure provides a detailed characterization of the non-native interactions stabilizing an aggregation-prone intermediate under native conditions and insight into how such an intermediate can derail folding and initiate fibrillation.  相似文献   
7.
Background: Spinal cord has a limited capacity to repair; therefore, medical interventions are necessary for treatment of injuries. Transplantation of Schwann cells has shown a great promising result for spinal cord injury (SCI). However, harvesting Schwann cell has been limited due to donor morbidity and limited expansion capacity. Furthermore, accessible sources such as bone marrow stem cells have drawn attentions to themselves. Therefore, this study was designed to evaluate the effect of bone marrow-derived Schwann cell on functional recovery in adult rats after injury. Methods: Mesenchymal stem cells were cultured from adult rats’ bone marrow and induced into Schwann cells in vitro. Differentiation was confirmed by immunocytochemistry and RT-PCR. Next, Schwann cells were seeded into collagen scaffolds and engrafted in 3 mm lateral hemisection defects. For 8 weeks, motor and sensory improvements were assessed by open field locomotor scale, narrow beam, and tail flick tests. Afterwards, lesioned spinal cord was evaluated by conventional histology and immunohistochemistry. Results: In vitro observations showed that differentiated cells had Schwann cell morphology and markers. In this study, we had four groups (n = 10 each): laminectomy, control, scaffold and scaffold + Schwann cells. Locomotor and sensory scores of cell grafted group were significantly better than control and scaffold groups. In histology, axonal regeneration and remyelination were better than control and scaffold groups. Conclusion: This study demonstrates that bone marrow-derived Schwann cells can be considered as a cell source for Schwann cells in SCI treatment. Key Words: Rats, Spinal cord injuries (SCI), Bone marrow, Schwann cells, Cell transdifferentiation  相似文献   
8.
Ten blue-neck male ostriches (Struthio camelus) were fed Prosopis farcta beans throughout a 30-day experiment. Blood samples were collected from ostriches on days 0 and 30 to measure levels of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride, total serum protein, albumin, globulin, cholesterol, calcium, inorganic phosphorus, the activity of aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transferase (γ-GT). From days 0 to 30, HDL cholesterol, total protein, and globulins levels increased significantly whereas LDL cholesterol, inorganic phosphorus, and γ-GT activity decreased significantly.  相似文献   
9.
Today, due to the rapid spoilage of fish, the use of natural preservatives is a priority over those of synthetic varieties. Also, the natural antimicrobial effects of essential oils can help to increase shelf life. There are very few studies concerning the use of essential oils in this regard. In the present study, the antibacterial effect of chitosan coated with Heracleum persicum oil was investigated on the quality of rainbow trout. The control and the coated fish samples were analyzed periodically by generalized estimating equation (GEE) for total viable count (TVC), psychrophilic bacteria, total volatile base nitrogen (TVB-N), polyunsaturated fatty acids (PUFA), texture, taste, odor, and overall acceptance parameters. The results showed that by increasing the amount of chitosan, TVC, psychrophilic bacteria, and TVB-N decreased while PUFA, texture, taste, odor, and overall acceptance parameters increased.  相似文献   
10.
Loss of canopy cover by forest harvesting generally increases the average surface runoff volume and sediment. Selective cutting (single and group selection method) is the most usual forest harvesting method in the Hyrcanian forests in the north of Iran. The purpose of this study is to find the effect of selective logging technique on the hydrological behavior of runoff and sediment in the Kheyrud forests located in northern Iran over 1 year. Four treatments were implemented: natural forest without harvesting (C), forest with selective harvesting (H) and area without canopy cover (WC) and skid trail (S). Three types of data were measured in each plot including soil chemical and physical properties, runoff and sediment load after each rainfall. The results indicate significant differences (P ≤ 0.05) in runoff generation and sediment production with respect to the treatments cover. The runoff in all treatments showed relatively similar response to rainfall, while the highest runoff and sediment were observed in skid trails, and the area without canopy cover (1.13 and 0.62 mm, and 1.2 and 0.51 g m?2), averagely. In contrast, the natural forest without harvesting and the forest with selective harvesting treatments exhibited the lowest amounts of runoff (0.2 and 0.44 mm) and sediment (0.1 and 0.17 g m?2), averagely. Implementation of low logging technique was useful to control the effects of logging on the runoff and sediment yield.  相似文献   
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