229 research outputs found
Enriched Satellite Cells with Pre-plate Technique Differentiate Strongly on Electrospun Polyacrylonitril Membrane
Introduction: Satellite cells known as the main regenerating cell types in skeletal muscle which can be isolated using pre-plate technique due to weak or slow adhesive interactions with satellite cells. Although, there are some issues about digestion of muscle tissue and isolation of satellite cells, which highlight need for an efficient procedure. Also, the employment of a nanofibrous surface can facilitate the attachment of satellite cells to reach matured muscle tissue. On the other hand, polyacrylonitrile (PAN) has been reported as a biocompatible polymer that can be electrospun into a nonwoven membrane. Materials and Methods: Herein, a modified digestion and pre-plate protocol was established for the enrichment of satellite cells. Also, a PAN electrospun scaffold was used to provide a higher surface area for cell attachment compared to tissue culture polystyrene (TCPS). However, the surface of prepared scaffold was modified with plasma treatment to progress cell adhesion. Results: The corresponding scaffold was examined with scanning electron microscopy (SEM) and tensile examination. The enriched cells, which exhibited a close gene expression pattern with satellite cells, seeded on this electrospun PAN membrane. The cultured satellite cells showed a good tendency to surface of PAN scaffold and also a higher rate of cell proliferation. Subsequently, the cells were induced to more expression of specific muscle genes compared to TCPS group. Conclusion: As a whole, satellite cells could mature to multinuclear cells using PAN scaffold as a function of efficient mechanical property and also higher surface area.
Using differential evolution and Moth–Flame optimization for scientific workflow scheduling in fog computing
Finding the existence of of Helicobacter pylori in springs of Chaharmahal and Bakhtiari Province, Iran by polymerase chain reaction
Background and aims: Helicobacter pylori is the primary cause of various diseases. This study was conducted to determine the existence of H. pylori in springs and surface water in Chaharmahal and Bakhtiari province. Methods: In this study, 29 water samples were collected from three different locations of Zayanderud River, 24 springs, and two subterranean from June 2014 to August 2014 in Chaharmahal and Bakhtiari province. Samples were filtered and DNAs were extracted. Then, the existence of H. pylori DNA was tested by polymerase chain reaction (PCR) for 16S rRNA, glm and Cag genes. Results: In the present study, the total infection rate of samples by H. pylori was 24.13. H. pylori and DNA was detected in 100 of samples of Zayanderud River, 12.5 in springs of Dehcheshmeh in Farsan and Baram in Lordegan, and 50 in aqueducts. Conclusion: These findings show the existence of H. pylori in springs and surface water in Chaharmahal and Bakhtiari province and additional evidence for waterborne transmission of H. pylori in some environments
The effect of dietary intake changes on nutritional status in acute leukemia patients after first induction chemotherapy
This study aimed to evaluate how changes in dietary intake among acute lymphoblastic and acute myeloid leukaemia (ALL and AML) patients affect nutritional status after the first induction chemotherapy. Dietary intake was assessed using 24-h recall and a 136-item food frequency questionnaire. Nutritional status was assessed by Patients Subjective Global Assessment questionnaire before starting induction therapy and again after 1 month. All newly diagnosed acute leukaemia patients aged 15 years old and older who attended three referral hospitals for initiation of their induction chemotherapy were included in the sample selection provided that they gave informed consent. A total of 30 AML and 33 ALL patients participated in the study. Dietary intake and nutritional status worsened after the chemotherapy treatment. Dietary intake in terms of macronutrients, micronutrients, food variety and diet diversity score changed significantly after the induction chemotherapy. No significant relationship was found between the changes in dietary indices and nutritional status. Chemotherapy-related side effects as an additional factor to cancer itself could affect dietary intake of leukaemia patients. The effectiveness of an early assessment of nutritional status and dietary intake should be further investigated in order to deter further deterioration
Active immunization using exotoxin A confers protection against Pseudomonas aeruginosa infection in a mouse burn model
<p>Abstract</p> <p>Background</p> <p><it>Pseudomonas aeruginosa </it>is an important cause of nosocomial infection and may lead to septicemia and death. We evaluated the immunogenicity of semi-purified exotoxin A from the bacterium in a mouse burn model.</p> <p>Methods</p> <p>The toxoid was prepared from exotoxin A taken from toxigenic strains of <it>P. aeruginosa </it>(PA 103). 50 mice were immunized with the toxoid, burned with hot metal and infected with 1 × 10<sup>8 </sup>CFU of toxigenic strains of <it>P. aeruginosa </it>(experimental group); 25 non-immunized mice were also burned and infected (control group). The mortality rate and presence of any exotoxin and <it>P. aeruginosa </it>in the sera, liver and spleen were determined.</p> <p>Results</p> <p>In the experimental group, 2 mice died before the burns were administered and were excluded from the study. The remainder (48 mice) were challenged with a lethal dose of <it>P. aeruginosa </it>and followed for 70 days. 3 of these mice died. Neither <it>P. aeruginosa </it>nor exotoxin A was not detected in the liver, spleen or sera of the surviving mice. The protective efficacy of toxoid vaccination was therefore 93.8%. In the control group, all mice died from bacteremia and septicemia, most (80%) within 6 days, and <it>P. aeruginosa </it>and exotoxin A were isolated from sera, spleen and liver.</p> <p>Conclusion</p> <p>Active immunization of mice using a semi-purified exotoxin A derived from <it>P. aeruginosa </it>was 93.8% effective at protecting mice from subsequent <it>P. aeruginosa </it>infections in a mouse burn model.</p
Protective effect of thymoquinone, the active constituent of Nigella sativa fixed oil, against ethanol toxicity in rats
Objective(s): Long term consumption of ethanol may induce damage to many organs. Ethanol induces its noxious effects through reactive oxygen species production, and lipid peroxidation and apoptosis induction in different tissues and cell types. Previous experiments have indicated the antioxidant characteristics of thymoquinone, the active constituent of Nigella sativa fixed oil, against biologically dangerous reactive oxygen species. This experiment was planned to evaluate the protective effect of thymoquinone against subchronic ethanol toxicity in rats. Materials and Methods: Experiments were performed on six groups. Each group consisted of six animals, including control group (saline, gavage), ethanol-receiving group (3 g/kg/day, gavage), thymoquinone (2.5, 5, 10 mg/Kg/day, intraperitoneally (IP)) plus ethanol and thymoquinone (10 mg/Kg/day, IP) groups. Treatments were carried out in four weeks. Results: Thymoquinone reduced the ethanol-induced increase in the lipid peroxidation and severity of histopathological alteration in liver and kidney tissues. In addition it improved the levels of proinflammatory cytokines in liver tissue. Furthermore, thymoquinone corrected the liver enzymes level including alanine transaminase, aspartate transaminase and alkaline phosphatase in serum and glutathione content in liver and kidney tissues. Other experiments such as Western blot analysis and quantitative real-time RT-PCR revealed that thymoquinone suppressed the expression of Bax/Bcl-2 ratio (both protein and mRNA level), and caspases activation pursuant to ethanol toxicity. Conclusion: This study indicates that thymoquinone may have preventive effects against ethanol toxicity in the liver and kidney tissue through reduction in lipid peroxidation and inflammation, and also interrupting apoptosis
Development of a lightweight centralized authentication mechanism for the internet of things driven by fog
The rapid development of technology has made the Internet of Things an integral element of modern society. Modern Internet of Things’ implementations often use Fog computing, an offshoot of the Cloud computing that offers localized processing power at the network’s periphery. The Internet of Things serves as the inspiration for the decentralized solution known as Fog computing. Features such as distributed computing, low latency, location awareness, on-premise installation, and support for heterogeneous hardware are all facilitated by Fog computing. End-to-end security in the Internet of Things is challenging due to the wide variety of use cases and the disparate resource availability of participating entities. Due to their limited resources, it is out of the question to use complex cryptographic algorithms for this class of devices. All Internet of Things devices, even those connected to servers online, have constrained resources such as power and processing speed, so they would rather not deal with strict security measures. This paper initially examines distributed Fog computing and creates a new authentication framework to support the Internet of Things environment. The following authentication architecture is recommended for various Internet of Things applications, such as healthcare systems, transportation systems, smart buildings, smart energy, etc. The total effectiveness of the method is measured by considering factors such as the cost of communication and the storage overhead incurred by the offered integrated authentication protocol. It has been proven that the proposed technique will reduce communication costs by at least 11%
A New Strong Adversary Model for RFID Authentication Protocols
Radio Frequency Identification (RFID) systems represent a key technology for ubiquitous
computing and for the deployment of the Internet of Things (IoT). In RFID technology, authentication protocols are often necessary in order to confirm the identity of the parties involved (i.e. RFID readers, RFID tags
and/or database servers). In this article, we analyze the security of a mutual authentication protocol proposed
by Wang and Ma. Our security analysis clearly shows major security pitfalls in this protocol. Firstly, we show
two approaches that an adversary may use to mislead an honest reader into thinking that it is communicating
with a legitimate database. Secondly, we show how an adversary that has compromised some tags can
impersonate an RFID reader to a legitimate database. Furthermore, we present a new adversary model, which
pays heed on cases missed by previous proposals. In contrast to previous models where the communication
between an RFID reader and a back-end server is through a secure channel, our model facilitates the security
analysis of more general schemes where this communication channel (RFID reader-to-server) is insecure.
This model determines whether the compromise of RFID tags has any impact on the security of the readerto-server communication or vice versa. In a secure protocol, the possible compromise of RFID tags should
not affect the RFID reader-server communication. In this paper, we show that compromising of RFID tags
in Wang and Ma protocol has a direct impact on the reader-server security. Finally, we propose a new
authentication protocol that offers an adequate security level and is resistant against the mentioned security
risks. The security proofs of the proposed protocol are supported with Gong-Needham-Yahalom (GNY)
logic and Scyther tool, which are formal methods to evaluate the security of a cryptographic protocol
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