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1.
Environ Res ; 222: 115369, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36706903

RESUMO

The currently promulgated RF exposure guidelines and standards cover the entire range of RF radiation and apply predominantly to restrict RF-induced short-term heating and in guarding against raising tissue temperatures, including the 5G frequencies. There are substantial abnormalities in these putative health safety protection guidelines and standards. Some of the safety limits are irrelevant, debatable, and absent of scientific justification from the standpoint of safety and public health protection. Also, the cellular mobile 5G technology is hailed as a speedier and more secure wireless communication technology than its predecessor systems. The key supporting architecture uses millimeter-wave (mm-wave) and antenna array technology to achieve better directivity, lower latency, and elevated data transmission rates. For radiation protection, it is not obvious whether the health effects of 5G mm-wave radiations would be analogous or not to radiations from previous generations (which was classified as possibly carcinogenic in humans by IARC). The interaction of mm-waves with the structure and function of pertinent cellular elements and cutaneous neuroreceptors in the skin are of special concern. The current scientific database is inadequate at mm wavelengths to render a trustworthy appraisal or to reach a judgment with confidence.


Assuntos
Ondas de Rádio , Tecnologia sem Fio , Humanos , Pele , Temperatura , Comunicação
2.
Front Public Health ; 10: 1042478, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36388374

RESUMO

The past two decades have seen exponential growth in demand for wireless access that has been projected to continue for years to come. Meeting the demand would necessarily bring about greater human exposure to microwave and radiofrequency (RF) radiation. Our knowledge regarding its health effects has increased. Nevertheless, they have become a focal point of current interest and concern. The cellphone and allied wireless communication technologies have demonstrated their direct benefit to people in modern society. However, as for their impact on the radiation health and safety of humans who are unnecessarily subjected to various levels of RF exposure over prolonged durations or even over their lifetime, the jury is still out. Furthermore, there are consistent indications from epidemiological studies and animal investigations that RF exposure is probably carcinogenic to humans. The principle of ALARA-as low as reasonably achievable-ought to be adopted as a strategy for RF health and safety protection.


Assuntos
Telefone Celular , Ondas de Rádio , Animais , Humanos , Ondas de Rádio/efeitos adversos , Carcinogênese , Previsões
3.
Bioelectromagnetics ; 43(4): 217, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35445747
4.
Bioelectromagnetics ; 42(8): 659-663, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34719051
5.
Phys Med Biol ; 66(10)2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33873175

RESUMO

Microwave thermoacoustic tomography (MTT) uses microwave pulse-induced thermoelastic pressure waves to form planar or tomographic images. Since the generation and detection of thermoelastic pressure waves depends on dielectric permittivity, specific heat, thermal expansion, and acoustic properties of tissue, microwave thermoacoustic imaging possesses the characteristic features of a dual-modality imaging system. The unique attributes of the high contrast offered by microwave absorption and the fine spatial resolution furnished by ultrasound are being explored to provide a nonionizing and noninvasive imaging modality for characterization of tissues, especially for early detection of breast cancer. This paper reviews the research being conducted in developing MTT imaging for medical diagnosis. It discusses the science of thermoelastic wave generation and propagation in biological tissues, the design of prototype MTT systems, the reconstruction of tomographic images, and the application and accomplishment of prototype MTT systems in phantom models and experimental subjects.


Assuntos
Imageamento de Micro-Ondas , Micro-Ondas , Acústica , Humanos , Imagens de Fantasmas , Tomografia , Tomografia Computadorizada por Raios X
6.
Bioelectromagnetics ; 41(8): 656-660, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33164214
7.
IEEE Trans Biomed Eng ; 66(8): 2253-2258, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30561338

RESUMO

OBJECTIVE: This study investigated the influence of absorption metrics and averaging schemes on correlation between RF/microwave energy and induced temperature elevation for plane wave exposures. METHODS: A voxel-based, anatomically realistic model of the human body was considered. Correlation of electromagnetic fields and temperature increases were evaluated at several frequencies. Both specific absorption rate (SAR) and volume absorption rate (VAR) were considered. RESULTS: The best correlation with temperature increase occurs for exposure durations between 1 and 2 min both for SAR and VAR for most of the 700 to 2700 MHz frequencies considered. In this case, a 1 g mass or 1 cm3 volume appears to be optimal. However, for VAR, as frequency increases to above 900 MHz, a better correlation is achieved at slightly increased exposure times and volumes. For longer exposures, the maximum correlation coefficient is reduced, and the correlation favors larger averaging mass or volume. At steady-state (30 min), correlation of temperature increase with SAR is maximum for a mass of 9 g for all frequencies considered, whereas the volume for VAR maximum correlation is 15 cm3 for higher frequencies and 20 cm3 for lower frequencies. CONCLUSIONS: In general, SAR provides a better correlation with temperature compared to VAR for short exposures, while VAR renders better correlations for higher frequencies and longer exposures. SIGNIFICANCE: The correlation between electromagnetic absorption and temperature increases has implications in guidelines for limiting human exposure to electromagnetic fields and in biomedical applications such as imaging, sensing, and hyperthermia.


Assuntos
Temperatura Corporal , Micro-Ondas , Modelos Biológicos , Adulto , Temperatura Corporal/fisiologia , Temperatura Corporal/efeitos da radiação , Campos Eletromagnéticos , Humanos , Masculino , Segurança do Paciente/normas , Doses de Radiação , Termografia/métodos , Imagem Corporal Total/métodos
9.
Cardiol J ; 24(2): 195-205, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27734460

RESUMO

BACKGROUND: Beta-catenin has been implicated in cell-cell communication in a wide variety of developmental and physiological processes. Defective Wnt signaling could result in various cardiac and vascular abnormalities. Little is known regarding Wnt/frizzled pathway in cardiomyocyte apoptosis. METHODS: In this study, the role of b-catenin in apoptosis was investigated in H9c2 cardiomyocytes and primary cardiomyocytes isolated in diabetic Wistar rats. The cardiomyocytes were transfected with porcine cytomegalovirus (pCMV)-b-catenin plasmid in order to overexpress b-catenin. RESULTS: The transcription factor displayed a significant nuclear localization in Wistar rats with cardiac hypertension. Transfection of b-catenin plasmid induced apoptosis and reduced expression of survival pathway markers in cardiomyocytes in a dose-dependent manner. Furthermore, expression of fibrosis protein markers was upregulated by the overexpression. CONCLUSIONS: Taken together, these results revealed that altered Wnt/b-catenin signaling might provoke heart failure. (Cardiol J 2017; 24, 2: 195-205).


Assuntos
Apoptose , Cardiomiopatias/genética , Regulação da Expressão Gênica no Desenvolvimento , Miócitos Cardíacos/metabolismo , beta Catenina/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Animais Recém-Nascidos , Western Blotting , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Sobrevivência Celular , Células Cultivadas , Diabetes Mellitus Experimental , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos/patologia , Ratos , Ratos Wistar , Transdução de Sinais , Suínos , beta Catenina/biossíntese
10.
13.
Gait Posture ; 39(1): 272-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23973352

RESUMO

UNLABELLED: This study investigates the kinematic variability of the head, lumbar spine and knee during the various walk and turn to sit phases in older and young adults. Sixteen older adults and eighteen young adults were recruited for this study. Each subject performed the "Walk and turn to sit down" test. A 16-channel telemetry system with electrogoniometers and an inclinometer was used to record the kinematic data. The turning step was divided into braking, mid-stance, swing and terminal load phases for kinematic analysis. The results showed that the older adults had a lower displacement angle and velocity of the lumbar spine, head and knee during different turning phases than the young adults. However, older adults performed turning with a higher variability in angular velocity of head flexion than the young adults during the turning step. The onset of lumbar movement and lateral flexion of the head occurred significantly earlier in older adults than in the young adults during turning. CONCLUSION: Older adults more cautiously control their motion by changing their trunk movement amplitude, velocity and timing in relation to their lower extremity movements during turning. The larger variability in angular velocity of head flexion may imply that older adults cannot precisely estimate the required movement for smooth turning.


Assuntos
Movimentos da Cabeça/fisiologia , Articulação do Joelho/fisiologia , Vértebras Lombares/fisiologia , Movimento/fisiologia , Amplitude de Movimento Articular/fisiologia , Tronco/fisiologia , Caminhada/fisiologia , Adulto , Idoso , Fenômenos Biomecânicos , Humanos , Masculino , Adulto Jovem
14.
Am J Geriatr Psychiatry ; 22(11): 1356-63, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24021218

RESUMO

OBJECTIVE: To examine associations of alcohol and tobacco use disorders and psychiatric conditions among older U.S. adults. METHODS: Sample was individuals aged at least 65 years (N = 8,205) who participated in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions. Measurements included lifetime and past 12-month Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition alcohol use disorders (AUDs), tobacco use disorders (TUDs), and psychiatric conditions. RESULTS: Among older adults, prevalence of lifetime and past 12-month AUDs were 16.1% and 1.5% and lifetime and past 12-month TUDs were 8.7% and 4.0%, respectively. Lifetime TUD was associated with increased odds of both lifetime (odds ratio [OR]: 4.17; 95% confidence interval [CI]: 3.30-5.26) and past 12-month (OR: 2.52; 95% CI: 1.50-4.24) AUDs, and lifetime AUD was associated with increased odds of both lifetime (OR: 4.13; 95% CI: 3.28-5.210 and past 12-month (OR: 3.51; 95% CI: 2.47-4.96) TUDs. Any lifetime mood, anxiety, or personality disorder among older adults was associated with increased odds of lifetime AUD and TUD, any lifetime mood disorder was associated with increased odds of past 12-month AUD and TUD, and any personality disorder was associated with past 12-month TUD. CONCLUSION: There is a strong association between AUD and TUD among older U.S. adults as well as associations between AUD and TUD with mood, anxiety, and personality disorders. Understanding the psychiatric conditions associated with AUDs and TUDs, especially past 12-month use disorders involving alcohol or tobacco, will enable healthcare providers to target screening and be more aware of symptoms and signs of potential AUDs and TUDs among those at higher risk.


Assuntos
Alcoolismo/epidemiologia , Transtornos Mentais/epidemiologia , Tabagismo/epidemiologia , Idoso , Alcoolismo/psicologia , Transtornos de Ansiedade/epidemiologia , Comorbidade , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Transtornos do Humor/epidemiologia , Transtornos da Personalidade/epidemiologia , Tabagismo/psicologia , Estados Unidos/epidemiologia
15.
J Am Geriatr Soc ; 61(8): 1296-302, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23889690

RESUMO

OBJECTIVES: To understand characteristics of older at-risk drinkers and reasons why they decide to change or maintain their alcohol consumption. DESIGN: Secondary analysis of data from a randomized controlled trial to reduce drinking in at-risk drinkers. SETTING: Three primary care sites in southern California. PARTICIPANTS: Six hundred thirty-one adults aged 55 and older who were at-risk drinkers at baseline, 521 of whom who completed a 12-month assessment. MEASUREMENTS: Sociodemographic and alcohol-related characteristics of 12-month assessment completers and noncompleters and among those completing the 12-month assessment by telephone or mail were compared using descriptive statistics. Reasons why respondents maintained or changed average alcohol consumption were asked of those who completed a 12-month assessment by telephone. Factors that might motivate at-risk drinkers to reduce drinking were asked about, and frequencies were calculated for these responses. RESULTS: Participants were primarily male, white, highly educated, and in good health. Those who responded to the 12-month assessment by mail were more likely to be working, to be in the intervention arm, and to drink more. Most who reduced alcohol consumption and heavy drinking did so because they thought it would benefit them. Those who did not thought that drinking was not a problem for them. Both groups cited their environment and circumstances as influencing their drinking. Remaining at-risk drinkers reported that medical evidence that alcohol was harming them would motivate them to reduce drinking. CONCLUSION: Older adults report that they reduce their drinking when they recognize that their drinking habits may be causing them harm; one's environment can hinder or help one to reduce drinking.


Assuntos
Alcoolismo/psicologia , Alcoolismo/reabilitação , Comportamentos Relacionados com a Saúde , Motivação , Idoso , Alcoolismo/epidemiologia , Atitude Frente a Saúde , California , Comorbidade , Negação em Psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Meio Social
19.
J Aging Health ; 23(5): 806-21, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21311049

RESUMO

OBJECTIVE: To examine whether consistent low-risk drinking is associated with lower risk of developing functional limitations among older adults. METHOD: Data were obtained from five waves of the Health and Retirement Study. Function was assessed by questions measuring four physical abilities and five instrumental activities of daily living. Five different drinking patterns were determined using data over two consecutive survey periods. RESULTS: Over the follow-up periods, 38.6% of older adults developed functional limitations. Consistent low-risk drinkers had lower odds of developing functional limitations compared with consistent abstainers, and the effect of consistent low-risk drinking was greater among those aged 50 to 64 years compared with those aged ≥65 years. Other drinking patterns were not associated with lower odds of incident functional limitation. DISCUSSION: Consistent low-risk drinking was associated with lower odds of developing functional limitations, and this association was greater among older middle-aged adults aged 50 to 64 years.


Assuntos
Atividades Cotidianas , Consumo de Bebidas Alcoólicas , Fatores Etários , Idoso , Consumo de Bebidas Alcoólicas/epidemiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Aposentadoria
20.
Am J Geriatr Psychiatry ; 19(3): 292-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20808122

RESUMO

OBJECTIVES: To examine the prevalence, sociodemographic, and health-related correlates of substance use disorders, including alcohol, tobacco, and nonmedical drug use among adults aged 65 years and older. DESIGN: The 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions, a cross-sectional survey of a population-based sample. SETTING: The United States. PARTICIPANTS: Eight thousand two hundred five adults aged 65 years and older. MEASUREMENTS: Prevalence of lifetime and past 12-month Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, determined alcohol, tobacco, and nonmedical drug use disorders. RESULTS: Prevalence of any substance use disorder was 21.1% during the lifetime and 5.4% in the past 12 months. Lifetime and past 12-month alcohol use disorders were 16.1% and 1.5%; tobacco use disorders were 8.7% and 4.0%; and nonmedical drug use disorders were 0.6% and 0.2%, respectively. Younger age was associated with greater odds of any lifetime or past 12-month substance use disorders. Men and those who were divorced or separated had greater odds of both lifetime alcohol and tobacco use disorders. Very good or excellent self-rated health was associated with lower odds of lifetime and past 12-month tobacco use disorders. Younger age and being divorced or separated were associated with greater odds of lifetime nonmedical drug use disorder. CONCLUSIONS: More than one in five older adults ever had a substance use disorder, and more than 1 in 20 had a disorder in the past 12 months, primarily involving alcohol or tobacco. Older adults have increased comorbidities and use of medications, which can increase risks associated with substance use.


Assuntos
Alcoolismo/epidemiologia , Inquéritos Epidemiológicos/estatística & dados numéricos , Automedicação/estatística & dados numéricos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Tabagismo/epidemiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Demografia , Divórcio , Feminino , Nível de Saúde , Humanos , Masculino , Prevalência , Fatores Sexuais , Estados Unidos/epidemiologia
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