200 research outputs found
Cell migration on material-driven fibronectin microenvironments
Cell migration is a fundamental process involved in a wide range of biological phenomena. However, how the underlying mechanisms that control migration are orchestrated is not fully understood. In this work, we explore the migratory characteristics of human fibroblasts using different organisations of fibronectin (FN) triggered by two chemically similar surfaces, poly(ethyl acrylate) (PEA) and poly(methyl acrylate) (PMA); cell migration is mediated via an intermediate layer of fibronectin (FN). FN is organised into nanonetworks upon simple adsorption on PEA whereas a globular conformation is observed on PMA. We studied cell speed over the course of 24 h and the morphology of focal adhesions in terms of area and length. Additionally, we analysed the amount of cell-secreted FN as well as FN remodelling. Velocity of human fibroblasts was found to exhibit a biphasic behaviour on PEA, whereas it remained fairly constant on PMA. FA analysis revealed more mature focal adhesions on PEA over time contrary to smaller FAs found on PMA. Finally, human fibroblasts seemed to remodel adsorbed FN more on PMA than on PEA. Overall, these results indicate that the cellâproteinâmaterial interface affects cell migratory behaviour. Analysis of FAs together with FN secretion and remodelling were associated with differences in cell velocity providing insights into the factors that can modulate cell motility
TRAINING HIGHER EDUCATION BIOSCIENCE STUDENTS WITH VIRTUAL REALITY SIMULATOR
Laboratory training is the cornerstone of science education in higher education. However, in several cases hands-on experimental procedures are not possible, and therefore technology provide alternative educational methods. One of the rapidly evolving technologies, namely Virtual Reality (VR) can offer multiple benefits in laboratory training through the development of simulations and virtual laboratories that support, facilitate, and promote an effective their learning experience. We present an empirical research carried out at the Department of Molecular Biology and Genetics of the Democritus University of Thrace during the winter semester of the academic year 2020-2021. 51 undergraduate students carried out a Virtual Reality activity aiming to train them to the use of a Class II Biosafety Cabinet (BSC) in an immersive virtual environment. Our results show that VR approach was highly and enthusiastically accepted by the students; they reported that they had an authentic learning experience which enabled them to better achieve the learning objectives. However, in some cases symptoms like dizziness and blurry image were reported most likely due to equipment, showing that improvement of the equipment used in VR is needed.
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An SDN-approach for QoE management of multimedia services using resource allocation
Future networks will be accompanied by new heterogeneous requirements in terms of end-users Quality of Experience (QoE) due to the increasing number of application scenarios being deployed. Network softwarization technologies such as Software Defined Networks (SDNs) and Network Function Virtualization (NFV) promise to provide these capabilities. In this paper, a novel QoE-driven resource allocation mechanism is proposed to dynamically assign tasks to virtual network nodes in order to achieve an optimized end-to-end quality. The aim is to find the best combination of network node functions that can provide an optimized level of QoE to the end users though node cooperation. The service in question is divided in tasks and the neighbor nodes negotiate the assignment of these considering the final quality. In the paper we specifically focus on the video streaming service. We also show that the agility provided by SDN/NFV is a key factor for enhancing video quality, resource allocation and QoE management in future networks. Preliminary results based on the Mininet network emulator and the OpenDaylight controller have shown that our approach can significantly improve the quality of a transmitted video by selecting the best path with normalized QoS values
Intermittent Atrioventricular Block following Fingolimod Initiation
A 47-year-old female patient with multiple sclerosis (MS) developed symptomatic intermittent 2nd degree atrioventricular block (AVB) of five-hour duration, five hours after the first two doses of fingolimod, that resolved completely. Frequency domain analysis of heart rate variability (HRV) revealed increased parasympathetic activity and decreased sympathetic tone, while modified Ewing tests were suggestive of impaired cardiac sympathetic function. We hypothesize that expression of this particular arrhythmia might be related to autonomic nervous system (ANS) dysfunction due to demyelinating lesions in the upper thoracic spinal cord, possibly augmented by the parasympathetic effect of the drug
Email is Evil! Behavioural Responses towards Permission-based Direct Email Marketing and Gender Differences
Purpose
This study aims to assess consumersâ beliefs in three Middle Eastern Arab countries regarding attitudinal and behavioural responses towards permission-based direct email marketing (hereafter DEM) and the moderating role of gender in the hypothesised path model.
Design/methodology/approach
Structural equation modelling was used to test the hypothesised path model by using data collected from 829 respondents.
Findings
The findings show that attitude was found to fully mediate the relationship between beliefs and behavioural responses towards permission-based DEM. Gender moderates the relationship between beliefs and attitudes and responses to permission-based DEM. Notably, female respondents were found to react more actively when exposed to permission-based DEM.
Research limitations/implications
Further qualitative research is needed to learn more about how and why individuals develop behavioural intentions in certain ways towards opt-in DEM. In addition, neuropsychology approaches such as eye-tracking are endorsed for future research to gain more insights and conquer biases associated with self-reporting procedures in countries where such technologies are deemed as legal and ethical to be used with human subjects.
Practical implications
Advertisers promoting products and services in the Middle Eastern Arab context should take further steps to enhance the quality of information (including cultural sensitiveness) and the perceived entertainment value that could be delivered to consumers through permission-based DEM, especially for female internet users. Additionally, this study highly recommends the double opt-in approach to permission-based DEM.
Originality/value
To the best of the authorsâ knowledge, this is the first attempt to address the gender role as a moderator of the path depicting the effectiveness of permission-based DEM approach in the Middle East (Arab counties) from beliefs to behavioural responses via attitudes
of Research in Interactive Marketing Email is Evil! Behavioural Responses towards Permission based Direct Email Marketing and Gender Differences
Purpose â This study assesses consumersâ beliefs in three Middle Eastern Arab countries regarding attitudinal and behavioural responses towards permission-based Direct Email Marketing (hereafter DEM) and the moderating role of gender in the hypothesized path model.
Design/methodology/approach â Structural equation modelling was used to test our hypothesized path model, utilizing data collected from 829 respondents.
Findings â Our findings show that attitude was found to fully mediate the relationship between beliefs and behavioural responses towards permission-based DEM. Gender moderates the relationship between beliefs and attitudes, and responses to permission-based DEM. Notably, female respondents were found to react more actively when exposed to permission-based DEM.
Research limitations/implications â Further qualitative research is needed to learn more about how and why individuals develop behavioural intentions in certain ways towards opt-in DEM. Also, neuropsychology approaches such eye-tracking are endorsed for future research to gain more insights and conquer biases associated with self-reporting procedures in countries where such technologies are deemed as legal and ethical to be used with human subjects.
Practical implications â Advertisers promoting products and services in the Middle Eastern Arab context should take further steps to enhance the quality of information [including cultural sensitiveness] and the perceived entertainment value that could be delivered to consumers through permission-based DEM, especially for female internet users. Additionally, this study highly recommends the double opt-in approach to permission-based DEM.
Originality/value â To the best of our knowledge, this is the first attempt to address the gender role as a moderator of the path depicting the effectiveness of permission-based DEM approach in the Middle East (Arab counties), from beliefs to behavioural responses via attitudes
MSC-Regulated MicroRNAs Converge on the Transcription Factor FOXP2 and Promote Breast Cancer Metastasis
SummaryMesenchymal stem/stromal cells (MSCs) are progenitor cells shown to participate in breast tumor stroma formation and to promote metastasis. Despite expanding knowledge of their contributions to breast malignancy, the underlying molecular responses of breast cancer cells (BCCs) to MSC influences remain incompletely understood. Here, we show that MSCs cause aberrant expression of microRNAs, which, led by microRNA-199a, provide BCCs with enhanced cancer stem cell (CSC) properties. We demonstrate that such MSC-deregulated microRNAs constitute a network that converges on and represses the expression of FOXP2, a forkhead transcription factor tightly associated with speech and language development. FOXP2 knockdown in BCCs was sufficient in promoting CSC propagation, tumor initiation, and metastasis. Importantly, elevated microRNA-199a and depressed FOXP2 expression levels are prominent features of malignant clinical breast cancer and are associated significantly with poor survival. Our results identify molecular determinants of cancer progression of potential utility in the prognosis and therapy of breast cancer
Transperitoneal laparoscopic right radical nephrectomy for renal cell carcinoma and end-stage renal disease: a case report
Nephron-sparing surgery (partial nephrectomy) results are similar to those of radical nephrectomy for small (<4 cm) renal tumors. However, in patients with end-stage renal disease, radical nephrectomy emerges as a more efficient treatment for localized renal cell cancer. Laparoscopic radical nephrectomy (LRN) increasingly is being performed. The objective of the present study was to present a case of a patient under hemodialysis who was submitted to LRN for a small renal mass and discuss the current issues concerning this approach. It appears that radical nephrectomy should be the standard treatment in dialysis patients even for small tumors. The laparoscopic technique is associated with acceptable cancer-specific survival and recurrence rate along with shorter hospital stay, less postoperative pain and earlier return to normal activities
Nine Months of Hybrid Intradialytic Exercise Training Improves Ejection Fraction and Cardiac Autonomic Nervous System Activity.
Cardiovascular disease is the most common cause of death in hemodialysis (HD) patients. Intradialytic aerobic exercise training has a beneficial effect on cardiovascular system function and reduces mortality in HD patients. However, the impact of other forms of exercise on the cardiovascular system, such as hybrid exercise, is not clear. Briefly, hybrid exercise combines aerobic and strength training in the same session. The present study examined whether hybrid intradialytic exercise has long-term benefits on left ventricular function and structure and the autonomous nervous system in HD patients. In this single-group design, efficacy-based intervention, twelve stable HD patients (10M/2F, 56 ± 19 years) participated in a nine-month-long hybrid intradialytic training program. Both echocardiographic assessments of left ventricular function and structure and heart rate variability (HRV) were assessed pre, during and after the end of the HD session at baseline and after the nine-month intervention. Ejection Fraction (EF), both assessed before and at the end of the HD session, appeared to be significantly improved after the intervention period compared to the baseline values (48.7 ± 11.1 vs. 58.8 ± 6.5, p = 0.046 and 50.0 ± 13.4 vs. 56.1 ± 3.4, p = 0.054 respectively). Regarding HRV assessment, hybrid exercise training increased LF and decreased HF (p p > 0.05). In conclusion, long-term intradialytic hybrid exercise training was an effective non-pharmacological approach to improving EF and the cardiac autonomous nervous system in HD patients. Such exercise training programs could be incorporated into HD units to improve the patients' cardiovascular health
Kaposi's sarcoma of the hand mimicking squamous cell carcinoma in a woman with no evidence of HIV infection: a case report
<p>Abstract</p> <p>Introduction</p> <p>Kaposi's sarcoma is a vascular neoplasm mainly affecting the skin of the lower extremities. Although it is the most common neoplasm affecting patients with AIDS, sporadic cases in HIV-negative people have been reported. It is a lesion mainly affecting men and its clinical presentation presents a challenge, as it can resemble other benign or malignant skin lesions.</p> <p>Case presentation</p> <p>We report a rare case of Kaposi's sarcoma presenting in a 68-year-old Mediterranean woman with no evidence of HIV infection. The patient had a 6-month history of a slowly progressing pigmented lesion on the dorsum of her left hand. The lesion clinically resembled a squamous cell carcinoma. The patient was treated with a wide excision of the lesion and primary reconstruction with a full thickness skin graft. Histopathological and immunohistochemical analysis of the excised lesion revealed the presence of Kaposi's sarcoma. Serologic investigation for HIV was negative but polymerase chain reaction for human herpes virus type 8 infection was positive. Thorough clinical and imaging investigation of the abdomen and chest were both negative for loci of disease.</p> <p>Conclusion</p> <p>Kaposi's sarcoma, although rare in its sporadic form, should be considered in the differential diagnosis of indeterminate skin lesions, especially those affecting the extremities.</p
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