Spectrum Usage for 5G Mobile Communication Systems and Electromagnetic Compatibility with Existent Technologies

The increased demand of consumers on services in the mobile broadband environment with high data rate and developed mobile broadband communication systems will require more spectrum to be available in the future. New technologies as well as the existing services require frequencies for their development. In this chapter, we investigate the available and potential future mobile terrestrial radio frequency bands (5G)—worldwide and in Europe. An insight into the mobile spectrum estimate is provided. Characteristics and requirements of IMT-2020, future possible IMT frequency bands, and examples of 5G usage scenarios are also addressed in the chapter. Electromagnetic compatibility evaluation methods are provided mainly focusing on existent mobile technologies below 1 GHz where also 5G technologies will be developed in the future. It is stressed that the radio frequency spectrum is a limited national resource that will become increasingly precious in the future

Pneumonia and hypercapnic respiratory failure

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Activation of melanogenesis by vacuolar type H+-ATPase inhibitors in amelanotic, tyrosinase positive human and mouse melanoma cells

AbstractIn this study, we describe the activation of melanogenesis by selective vacuolar type H+-ATPase inhibitors (bafilomycin A1 and concanamycin A) in amelanotic human and mouse melanoma cells which express tyrosinase but show no melanogenesis. Addition of the inhibitors activated tyrosinase within 4 h, and by 24 h the cells contained measurable amounts of melanin. These effects were not inhibited by cycloheximide (2 μg/ml) which is consistent with a post-translational mechanism of activation. Our findings suggest that melanosomal pH could be an important and dynamic factor in the control of melanogenesis in mammalian cells

Insufficient assessment of sexual dysfunction : A problem in gynecological practice

Background and Objective: Sexual health is an important part of a woman's life and well-being. Female sexual dysfunction is a complicated problem, it is often underestimated in the healthcare process, and its management is complex. Giving women the opportunity to talk about sexual problems is a fundamental part of healthcare and may improve their quality of life. The aim of this study was to find out patients' experience and attitudes toward the involvement of gynecologists addressing sexual issues, to disclose the main barriers to initiate a conversation, and to assess the prevalence of sexual disorders among patients in a gynecological clinic. Material and Methods: A questionnaire-based approach was used to survey 18- to 50-year-old voluntary patients in the gynecological clinic. The study population comprised 300 different gynecological (except oncologic) patients independently of reasons for being in the clinic. The duration of the study was 6 months. Results: Only one-third of the patients had ever been asked about their sexual life by a gynecologist, whilst the majority (80%) of the respondents reported they would like to be asked and discuss sexual issues. The patients mostly did not complain because of psychoemotional barriers, and shame was the main barrier for patients to talk about their problems. Sexual dysfunction was a frequent disorder among gynecological patients, reaching especially high levels in the arousal (46.41%) and lubrication (40.67%) domains. Conclusions: The assessment of sexual health is insufficient in gynecological care, and sexual history-taking and evaluation of sexual functions should be included in routine gynecological health assessments.publishersversionPeer reviewe

Symptoms of depression and anxiety among health care workers during COVID-19 pandemia in Latvia : A cohort study

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Primary culture of avian embryonic heart forming region cells to study the regulation of vertebrate early heart morphogenesis by vitamin A

Copyright: Copyright 2014 Elsevier B.V., All rights reserved.Background: Important knowledge about the role of vitamin A in vertebrate heart development has been obtained using the vitamin A-deficient avian in ovo model which enables the in vivo examination of very early stages of vertebrate heart morphogenesis. These studies have revealed the critical role of the vitamin A-active form, retinoic acid (RA) in the regulation of several developmental genes, including the important growth regulatory factor, transforming growth factor-beta2 (TGFβ2), involved in early events of heart morphogenesis. However, this in ovo model is not readily available for elucidating details of molecular mechanisms determining RA activity, thus limiting further examination of RA-regulated early heart morphogenesis. In order to obtain insights into RA-regulated gene expression during these early events, a reliable in vitro model is needed. Here we describe a cell culture that closely reproduces the in ovo observed regulatory effects of RA on TGFβ2 and on several developmental genes linked to TGFβ signaling during heart morphogenesis. Results: We have developed an avian heart forming region (HFR) cell based in vitro model that displays the characteristics associated with vertebrate early heart morphogenesis, i.e. the expression of Nkx2.5 and GATA4, the cardiogenesis genes, of vascular endothelial growth factor (VEGF-A), the vasculogenesis gene and of fibronectin (FN1), an essential component in building the heart, and the expression of the multifunctional genes TGFβ2 and neogenin (NEO). Importantly, we established that the HFR cell culture is a valid model to study RA-regulated molecular events during heart morphogenesis and that the expression of TGFβ2 as well as the expression of several TGFβ2-linked developmental genes is regulated by RA. Conclusions: Our findings reported here offer a biologically relevant experimental in vitro system for the elucidation of RA-regulated expression of TGFβ2 and other genes involved in vertebrate early cardiovascular morphogenesis.publishersversionPeer reviewe

Lack of Association between Rs2067474 Polymorphism in the Histamine Receptor H2 Gene and Gastric Cancer in Latvian Population

Funding Information: The study was partly supported by the Latvian Government Research Programme BIOMEDICINE 2014–2017 Project Nr. 4 “Study of gastric cancer mortality reduction capability in Latvia”. Publisher Copyright: © 2018 Georgijs Moisejevs et al.Histamine has an important role in the process of the gastric mucosa inflammation acting via histamine receptor H2 (encoded by the gene HRH2). Single nucleotide polymorphism of the enhancer element of HRH2 gene promoter rs2067474 (1018G>A)may be associated with changes of expression of the receptor. We attempted to clarify the association of this polymorphism with gastric cancer and/or atrophic gastritis in the Latvian (Caucasian) population. The study group consisted of 121 gastric cancer patients and 650 patients with no evidence of gastric neoplasia on upper gastrointestinal endoscopy. Genotyping for rs2067474 was performed with the TaqMan probe-based system using a commercially available probe for RT-PCR. The frequency of the A allele in the gastric cancer group was 0.41% and in the control group - 1.54% (p = 0.231). No significant differences were found comparing genotypes between gastric cancer versus control patients (OR = 0.236, CI95% = 0.030-1.896), patients with (n = 165) versus without (n = 485) gastric metaplastic lesions (OR = 0.854, CI95% = 0.288-2.540) and patients with (n = 297) and without (n = 353) gastric atrophic lesions (OR = 1.145, CI95% = 0.451-2.906). Our findings suggest that the HRH2 -1018G>A polymorphism (rs2067474) is neither associated with gastric cancer nor the grade of atrophic gastritis in the Latvian (Caucasian) population.Peer reviewe

Oxidative stress parameters in Posttraumatic Stress Disorder risk group patients

Funding Information: The research is supported by European Social Foundation co-financing: Project for Doctoral students support, at Rîga Stradiòð University (No. 2009/0147/1DP/1.1.2.1.2/09/IPIA/ VIAA/009). The views expressed in this article are those of the authors and do not reflect the official policy or position of the Latvian government, Latvian National Armed Forces, Medical Support Centre of Latvian National Armed Forces or any of the institutions with which the authors are affiliated. The authors state no conflict of interest. All authors read and approved the final manuscript.Increased excitotoxity in response to stressors leads to oxidative stress (OS) due to accumulation of excess reactive oxygen/nitrogen species. Neuronal membrane phospholipids are especially susceptible to oxidative damage, which alters signal transduction mechanisms. The Contingent of International Operations (CIO) has been subjected to various extreme stressors that could cause Posttraumatic Stress Disorder (PTSD). Former studies suggest that heterogeneity due to gender, race, age, nutritional condition and variable deployment factors and stressors produce challenges in studying these processes. The research aim was to assess OS levels in the PTSD risk group in CIO. In a prospective study, 143 participants who were Latvian CIO, regular personnel, males, Europeans, average age of 27.4, with the same tasks during the mission, were examined two months before and immediately after a six-month Peace Support Mission (PSM) in Afghanistan. PCL-M questionnaire, valid Latvian language "Military" version was used for PTSD evaluation. Glutathione peroxidase (GPx), superoxide dismutase (SOD) and lipid peroxidation intensity and malondialdehyde (MDA) as OS indicators in blood were determined. Data were processed using SPSS 20.0. The MDA baseline was 2.5582 μM, which after PSM increased by 24.36% (3.1815 μM). The GPx baseline was 8061.98 U/L, which after PSM decreased by 9.35% (7308.31 U/L). The SOD baseline was 1449.20 U/gHB, which after PSM increased by 2.89% (1491.03 U/gHB). The PTSD symptom severity (total PCL-M score) baseline was 22.90 points, which after PSM increased by 14.45% (26.21 points). The PTSD Prevalence rate (PR) baseline was 0.0357, which after PSM increased by 147.06% (0.0882). We conclude that there is positive correlation between increase of OS, PTSD symptoms severity level, and PTSD PR in a group of patients with risk of PTSD - CIO. PTSD PR depends on MDA intensity and OS severity. OS and increased free radical level beyond excitotoxity, is a possible causal factor for clinical manifestation of PTSD.publishersversionPeer reviewe

Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?

The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a) maintaining endothelial and suppression of inflammatory markers; b) protection from sepsis in animal models; and c) direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis

Regulatory evaluation of Glybera in Europe-two committees, one mission

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