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排序方式: 共有78条查询结果,搜索用时 15 毫秒
1.
Simonetta Pazzaglia Barbara Tanno Francesca Antonelli Paola Giardullo Gabriele Babini Prabal Subedi Omid Azimzadeh Zohaib N. Khan Kateryna Oleksenko Fabian Metzger Christine von Toerne Damien Traynor Dinesh Medipally Aidan D. Meade Munira Kadhim Fiona M. Lyng Soile Tapio Anna Saran Mariateresa Mancuso 《International journal of molecular sciences》2021,22(8)
The brain undergoes ionizing radiation exposure in many clinical situations, particularly during radiotherapy for brain tumors. The critical role of the hippocampus in the pathogenesis of radiation-induced neurocognitive dysfunction is well recognized. The goal of this study is to test the potential contribution of non-targeted effects in the detrimental response of the hippocampus to irradiation and to elucidate the mechanisms involved. C57Bl/6 mice were whole body (WBI) or partial body (PBI) irradiated with 0.1 or 2.0 Gy of X-rays or sham irradiated. PBI consisted of the exposure of the lower third of the mouse body, whilst the upper two thirds were shielded. Hippocampi were collected 15 days or 6 months post-irradiation and a multi-omics approach was adopted to assess the molecular changes in non-coding RNAs, proteins and metabolic levels, as well as histological changes in the rate of hippocampal neurogenesis. Notably, at 2.0 Gy the pattern of early molecular and histopathological changes induced in the hippocampus at 15 days following PBI were similar in quality and quantity to the effects induced by WBI, thus providing a proof of principle of the existence of out-of-target radiation response in the hippocampus of conventional mice. We detected major alterations in DAG/IP3 and TGF-β signaling pathways as well as in the expression of proteins involved in the regulation of long-term neuronal synaptic plasticity and synapse organization, coupled with defects in neural stem cells self-renewal in the hippocampal dentate gyrus. However, compared to the persistence of the WBI effects, most of the PBI effects were only transient and tended to decrease at 6 months post-irradiation, indicating important mechanistic difference. On the contrary, at low dose we identified a progressive accumulation of molecular defects that tended to manifest at later post-irradiation times. These data, indicating that both targeted and non-targeted radiation effects might contribute to the pathogenesis of hippocampal radiation-damage, have general implications for human health. 相似文献
2.
Due to the fast development in data communication systems and computer networks in recent years, the necessity to protect the secret data has become extremely imperative. Several methods have been proposed to protect the secret data; one of them is the secret sharing scheme. It is a method of distributing a secret K among a finite set of participants, in such a way that only predefined subset of participant is enabled to reconstruct a secret from their shares. A secret sharing scheme realizing uniform access structure described by a graph has received a considerable attention. In this scheme, each vertex represents a participant and each edge represents a minimum authorized subset. In this paper, an independent dominating set of vertices in a graph G is introduced and applied as a novel idea to construct a secret sharing scheme such that the vertices of the graph represent the participants and the dominating set of vertices in G represents the minimal authorized set. While most of the previous schemes were based on the principle of adjacent vertices, the proposed scheme is based upon the principle of non-adjacent vertices. We prove that the scheme is perfect, and the lower bound of the information rate of this new construction is improved when compared to some well-known previous constructions. We include an experiment involving security threats to demonstrate the effectiveness of the proposed scheme. 相似文献
3.
M.A. Abbas M.A. Lajis D.R. Abbas O.M. Merzah M.H. Kadhim A.A. Shamran 《Materialwissenschaft und Werkstofftechnik》2020,51(6):719-724
The quality of the machined surface resulted from the electrical discharge machining (EDM) environment is not efficient according to the previous studies. One of the significant problems is the impedance of dielectric fluid, where it is contributing to focusing the plasma channel in a limited area. Hence, this behavior leads to appearing deep craters on the machined zone. The researchers have attempted to enhance the average of surface roughness by employing powder particles or surfactant as the additive materials in the dielectric fluid. Unfortunately, these studies did not present a comparison between these additive materials in this environment. Therefore, the present study aims to compare the performance of the average of surface roughness (Ra) for AISI D2 steel by utilizing Nano chromium powder (NCP) and Span-20. The present work has proved that the behavior of the average of surface roughness for this steel is dropping at the maximum level of Nano chromium powder concentration and pulse duration as compared to the behavior with the Span-20. Moreover, the best roughness was produced by this steel with Nano chromium powder at 2 g/L and 20 μs for this powder and the pulse duration. 相似文献
4.
Feasibility of recycled newspaper as cellulose source for regenerated cellulose membrane fabrication
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Mohamad Azuwa Mohamed W. N. W. Salleh Juhana Jaafar A. F. Ismail Muhazri Abd. Mutalib Siti Munira Jamil 《应用聚合物科学杂志》2015,132(43)
An environmental friendly regenerated cellulose membrane (RCM) was successfully prepared via NaOH/urea aqueous solution system by utilizing recycled newspaper (RNP) as the cellulose source. The morphological and chemical structure of resulting membrane were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD) spectroscopy, and thermogravimetric analysis (TGA). Results from FTIR and XRD verified that the transparent RCM possesses cellulose II structure. SEM observation revealed that the transparent RCM consist of homogeneous dense symmetric membrane structure and composed of a skin layer with mean roughness parameter Ra, obtained from AFM analysis of 29.53 nm. Pure water flux, water content, water contact angle, porosity, and pore size of the resulting membrane were also measured. This study promotes the potential of the cellulose‐based membrane obtained from low cost cellulose source for application in filtration and separation system. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42684. 相似文献
5.
Simonetta Pazzaglia Barbara Tanno Ilaria De Stefano Paola Giardullo Simona Leonardi Caterina Merla Gabriele Babini Seda Tuncay Cagatay Ammar Mayah Munira Kadhim Fiona M. Lyng Christine von Toerne Zohaib N. Khan Prabal Subedi Soile Tapio Anna Saran Mariateresa Mancuso 《International journal of molecular sciences》2022,23(4)
Cell communication via exosomes is capable of influencing cell fate in stress situations such as exposure to ionizing radiation. In vitro and in vivo studies have shown that exosomes might play a role in out-of-target radiation effects by carrying molecular signaling mediators of radiation damage, as well as opposite protective functions resulting in resistance to radiotherapy. However, a global understanding of exosomes and their radiation-induced regulation, especially within the context of an intact mammalian organism, has been lacking. In this in vivo study, we demonstrate that, compared to sham-irradiated (SI) mice, a distinct pattern of proteins and miRNAs is found packaged into circulating plasma exosomes after whole-body and partial-body irradiation (WBI and PBI) with 2 Gy X-rays. A high number of deregulated proteins (59% of WBI and 67% of PBI) was found in the exosomes of irradiated mice. In total, 57 and 13 miRNAs were deregulated in WBI and PBI groups, respectively, suggesting that the miRNA cargo is influenced by the tissue volume exposed to radiation. In addition, five miRNAs (miR-99b-3p, miR-200a-3p, miR-200a, miR-182-5p, miR-182) were commonly overexpressed in the exosomes from the WBI and PBI groups. In this study, particular emphasis was also given to the determination of the in vivo effect of exosome transfer by intracranial injection in the highly radiosensitive neonatal cerebellum at postnatal day 3. In accordance with a major overall anti-apoptotic function of the commonly deregulated miRNAs, here, we report that exosomes from the plasma of irradiated mice, especially in the case of WBI, prevent radiation-induced apoptosis, thus holding promise for exosome-based future therapeutic applications against radiation injury. 相似文献
6.
Kadhim Mustafa M. Rheima Ahmed Mahdi Shadhar Mohanad Hatem Abdulnabi Shuaib M. Saleh Zuhra Muter Al Mashhadani Zuhair I. Najm Zainab Mohsen Sarkar A. 《SILICON》2023,15(1):417-424
Silicon - A theoretical research study was conducted into the possibility of using a two-dimensional graphene-like material silicon carbide nano-sheet (2D-SiCNS) as an anode in rechargeable Ca-ion... 相似文献
7.
Physical properties of Bi2 (Te,Se)3 and Bi2Se1.2Te1.8 prepared using solid-state microwave synthesis
Bi2(Te, Se)3 and Bi2Se1.2Te1.8 bulk products were synthesised using standard solid-state microwave synthesis. The Bi2(Te, Se)3 and Bi2Se1.2Te1.8 were then deposited thermally onto glass substrates at a pressure of 10? 6 Torr. The structure of the samples was analysed using X-ray diffraction (XRD), and the powders and thin films were observed to be polycrystalline and rhombohedral in structure. The surface morphology of the samples was determined using scanning electron microscopy (SEM). From the measurements of optical properties, the energy gap values for the Bi2Te3, Bi2Se3, and Bi2Se1.2Te1.8 thin films were 0.43, 0.73, and 0.65 eV, respectively. 相似文献
8.
9.
A number of workers investigating diffusion in semiconductors using radio-tracer techniques have reported a type of profile which is not easily explained by current theories of diffusion. This anomalous profile is usually found in experiments in which the solute concentration is high and has often been associated with the substitutional-interstitial diffusion mechanism. The profile shape is considered in this paper, taking the diffusion of zinc in GaAs at 1000° C as an example. The use of the Boltzman-Matano technique for analysing complex diffusion profiles is considered and experiments are described which suggest that the technique is not appropriate for this type of profile. An adaptation of the substitutional-interstitial diffusion theory is presented in which allowance is made for the possibility of the gallium vacancy concentration falling below the thermal equilibrium value. Theoretical profiles are computed and compared to experiments. Reasonable agreement is found. 相似文献
10.