662 research outputs found
Gamma radiation-induced impairment of hippocampal neurogenesis, comparison of single and fractionated dose regimens Deterioro de la neurogénesis en el hipocampo inducida por radiación gamma, comparación de los regímenes de dosis única y fraccionada
Radiation therapy of the brain is associated with many consequences, including cognitive disorders. Pathogenesis of radiation induced cognitive disorder is not clear, but reduction of neurogenesis in hippocampus may be an underlying reason. 24 adult male rats entered to study. Radiation absorbed dose to midbrain was 10 Gy, delivered by routine cobalt radiotherapy machine which its output was measured 115.24 cGy/min. The rats were divided in four groups of sixes, including groups of control, single fraction 10 Gy, fractionated 10 Gy and finally anaesthesia sham group. Number of pyramidal nerve cells was counted in two regions of hippocampus formation (CA1 and CA3). The radiation could reduce the number of cells in two regions of hippocampus significantly (p=0.000). It seems fractionated 10 Gy irradiation to more efficient than single fraction, while role of anaesthesia drug should be cautiously assessed. Moreover the rate of neurogenesis reduction was determined the same in these regions of hippocampus meaning the same radiosensitivity of cells
Power spectrum characterization of systematic coded UW-OFDM systems
Unique word (UW)-OFDM is a newly proposed multicarrier technique that has shown to outperform cyclic prefix (CP)-OFDM in fading channels. Until now, the spectrum of UW-OFDM is not thoroughly investigated. In this paper, we derive an analytical expression for the spectrum taking into account the DFT based implementation of the system. Simulations show that the proposed analytical results are very accurate. Compared to CP-OFDM, we show that UW-OFDM has much lower out-of-band (OOB) radiation, which makes it suitable for systems with strict spectral masks, as e. g. cognitive radios. Further, in this paper, we evaluate the effect of the redundant carrier placement on the spectrum
Quality assurance program for prototype stereotactic system developed for Neptun 10 PC linac
Background: A prototype stereotactic radiosurgery set was designed and constructed for a Neptun 10 PC linac that is currently being used at Imam Reza hospital in Mashhad. Materials and Methods: A complete qualit y assurance program was designed and performed for the constructed system including isocentric accuracy test, localization accuracy test, dose delivery accuracy test and leakage radiation test. Target simulator, control alignment device and plexiglass phantom which were parts of the developed hardware were used to fulfill quality assurance program. Results: The average isocentric shift resulted from the gantry rotation and couch turning were respectively obtained to be 1.4 and 2 mm. The average localization error in the three coordinates was found to be 2.2 mm. The total treatment uncertainty due to all of the probable errors in the system was equal to 4.32 mm. The dose delivery accuracy test was carried out, the result indicated a 3-7% difference between the given and measured dose. Conclusion: The quality assurance tests showed consistent performance of the constructed system within the accepted limits; however, some inconsistency might exist in certain cases. The safety of SRS method is increased when the overall uncertainty is minimized and the treatment of the lesions adjacent to critical organs is avoided
Attribution of ghrelin to cancer; Attempts to unravel an apparent controversy
Ghrelin is an endogenous peptide hormone mainly produced in the stomach. It has been known to regulate energy homeostasis, stimulate secretion of growth hormone, and mediate many other physiologic effects. Various effects attributed to ghrelin contribute to many aspects of cancer development and progression. Accordingly, a large body of evidence has emerged about the association of ghrelin with several types of cancer in scales of cell-line, animal, and human studies. However, existing data are controversial. This controversy occurs in two main domains: one is the controversial results in local effects of ghrelin on different types of human cancer cell-lines; the second is the apparent disagreement in the results o
The effect of radiotherapy and chemotherapy on osmotic fragility of red blood cells and plasma levels of malondialdehyde in patients with breast cancer
Background: Gamma radiation effects on the erythrocyte membrane from three different functional parts, lipid bilayer, cytoskeleton and protein components. When the red cell membrane is exposed to radiation, it loses its integrity and hemoglobin leaks out. In addition, irradiation leads to lipid peroxidation and the products of this process, leading to hemolysis. The aim of the present study was to measure osmotic fragility (OF) of red blood cells and malondialdehyde (MDA) levels as a marker of oxidative injury in breast cancer patients treated with radiation and chemotherapy. Materials and Methods: The OF test was performed using different concentrations of a salt solution. The measurement of MDA was done with chemical methods.11 The sampling was taken during three stages of treatment: first sample was taken before starting chemotherapy, the second sample was taken before radiation therapy and the third sample was taken after radiotherapy. Results: No statistically significant differences between levels of MDA in these three stages of treatment were observed. However, the comparison of mean levels of MDA showed an increase after radiotherapy. The OF rate did not show significant difference (P > 0.05) during the stages of treatment. Conclusion: In a standard treatment program of radiotherapy and chemotherapy lipid peroxidation level and OF do not significantly increase. © 2014 Greater Poland Cancer Centre
Development of group method of data handling based on genetic algorithm to predict incipient motion in rigid rectangular storm water channel
Sediment transport is a prevalent vital process in uvial and coastalenvironments, and \incipient motion" is an issue inseparably bound to this topic. Thisstudy utilizes a novel hybrid method based on Group Method of Data Handling (GMDH)and Genetic Algorithm (GA) to design GMDH structural (GMDH-GA). Also, SingularValue Decomposition (SVD) was utilized to compute the linear coefficient vectors. Inorder to predict the densimetric Froude number (Fr), the ratio of median diameter ofparticle size to hydraulic radius (d=R) and the ratio of sediment deposit thickness tohydraulic radius (ts=R) are utilized as e ective parameters. Using three di erent sources ofexperimental data and GMDH-GA model, a new equation is proposed to predict incipientmotion. The performance of development equation is compared using GMDH-GA andtraditional equations . The results indicate that the presented equation is more accurate(RMSE= 0:18 andMAPE= 6:48%) than traditional methods. Also, a sensitivityanalysis is presented to study the performance of each input combination in predictingincipient motion (15) Development of Group Method of Data Handling based on Genetic Algorithm to predict incipient motion in rigid rectangular storm water channel
Current approaches and future perspectives on strategies for the development of personalized tissue engineering therapies
Personalized tissue engineering and regenerative medicine (TERM) therapies propose patient-oriented effective solutions, considering individual needs. Cell-based therapies, for example, may benefit from cell sources that enable easier autologous set-ups or from recent developments on IPS cells technologies towards effective personalized therapeutics. Furthermore, the customization of scaffold materials to perfectly fit a patientâ s tissue defect through rapid prototyping technologies, also known as 3D printing, is now a reality. Nevertheless, the timing to expand cells or to obtain functional in vitrotissue substitutes prior to implantation prevents advancements towards routine use upon patient´s needs. Thus, personalized therapies also anticipate the importance of creating off-the-shelf solutions to enable immediately available tissue engineered products. This paper reviews the main recent developments and future challenges to enable personalized TERM approaches and to bring these technologies closer to clinical applications.The authors wish to acknowledge the financial support of
the Portuguese Foundation for Science and Technology for
the post-doctoral grant (SFRH/BPD/111729/2015) and
Recognize (UTAP-ICDT/CTM-BIO/0023/2014), and the project
RL3 -TECT -NORTE-07-0124-FEDER-000020 co-financed by
ON.2 (NSRF), through ERDF
Investigating the Effect of the Relationship between Brand Visual Identities, Focus on Employees and Customers and Brand Personality on Organizational Commitment
Corporate brand identity is a key issue for any organization. Accordingly, its study is a profitable field of research. As a result, companies should pay special attention to brand identity management because it affects employees' commitment to the organization, their job satisfaction, and brand performance. The present study aimed to investigate the role of organizational commitment in the relationship between organizational brand identity, brand performance and job satisfaction of Shahr Bank employees. The present research is applied in terms of purpose and descriptive-correlational in terms of data collection. The statistical population of the study was the employees of Shahr Bank which was estimated to be 120 samples through Morgan table, and then the data were collected using cluster sampling method. A questionnaire was used to collect information, which was distributed among the sample after confirming its validity and reliability (Cronbach's alpha coefficient of 0.94%). Finally, after collecting data, the data were analyzed using structural equations (Smart PLS). To analyze the research data, two methods of descriptive statistics and inferential statistics have been used. The results show that brand identity has a positive effect on employee commitment, as well as sub-hypotheses of positive effect of focus on customer and employee, brand personality and having consistent relationships on the formation of brand identity were confirmed. Also positive effect of brand visual identity and human resource planning on the formation of brand identity was not confirmed according to the results. Finally, the hypotheses of a positive effect of employee commitment on brand performance and employee job satisfaction were confirmed
The Hidden War: Injustice in the Wake of the Philippine-American War
This thesis describes the United States’ campaign in the Philippines and the atrocities that occurred there and tells the story of how those atrocities were hidden, marginalized, and forgotten in the years after the war. I will show how this was not a natural process, that the Philippine-American war was not passively misunderstood or forgotten. Instead, I will show how misinformation and the suppression of the truth was an orchestrated effort by imperialist politicians and military officials to control the narrative, justify their decisions and protect their policies. Specifically, this thesis will analyze the hearings before the Committee on the Philippines, which was tasked with investigating the reports of atrocities, as well as the military courts-martial after the war. Analysis of that bias and partisanship reveals that the hearings were more of a vindication than an investigation, and the courts-martial were more of a search for an excuse than a search for justice. This thesis will explain the precedents of military misconduct and political manipulation that were established by how United States politicians and military officials dealt with the atrocities that occurred during one of the United States’ first overseas imperialist occupations.Ope
Patient perception of pain versus observed pain behavior during a standardized electrodiagnostic test
Introduction: Clinicians often assume that observations of pain behavior are adequate for assessment of patient pain perception during procedures. This has not been tested during a standardized electrodiagnostic experience. Methods: During a prospective trial including extensive, standardized electrodiagnostic testing on persons with lumbar stenosis, vascular claudication, and asymptomatic volunteers, the subjects and an observer rated levels of pain. Results: In 60 subjects, observers significantly under‐rated pain (Visual Analog Scale 3.17 ± 2.23 vs. 4.38 ± 2.01, t = −4.577, df = 59, P < 0.001). Perceived pain during testing related to bodily pain as measured by the visual analog, McGill, Pain Disability, and Quebec scales, but not age, duration of symptoms, Tampa kinesiphobia, Center for Epidemiological Studies Depression scale, or SF‐36 health quality of life. Conclusions: Persons with worse pain syndromes may perceive more pain during testing than others. Clinicians and researchers should understand that patients may have more pain than they recognize. Muscle Nerve 51: 185–191, 2015Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110539/1/mus24308.pd
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