Intensidad lumínica de las lámparas de fotocurado LED en los consultorios odontológicos de Piura, Perú / Output intensity of LED light curing units in dental offices of Piura, Peru

Introducción: La lámpara de fotocurado, que utiliza diodos emisores de luz (LED), se emplea en odontología para la conversión polimérica de los materiales de restauración dental. Se ha comunicado que una intensidad lumínica inadecuada de la lámpara no aseguraría la correcta polimerización del material de restauración. Objetivo: Determinar la intensidad lumínica de las lámparas de fotocurado LED en consultorios odontológicos de la ciudad de Piura, Perú, 2020. Métodos: Estudio observacional, descriptivo. Se midió la intensidad lumínica en 70 lámparas de fotocurado LED, usando un radiómetro con una longitud de onda de 400-500 nm, con capacidad de medida de la intensidad lumínica de hasta 3500 mw/cm2. Por debajo de los 400 mw/cm2 indica intensidad baja, de 400 a 800 mw/cm2 intensidad media, de 800 a 1200 mw/cm2 intensidad alta y por encima de los 1200 mw/cm2 indica intensidad muy alta. Resultados: El 48,5 por ciento de las lámparas analizadas presentaban intensidad media, el 22,86 por ciento intensidad alta, mientras que el 15,71 por ciento intensidad baja y finalmente el 12,86 por ciento de las lámparas presentaban intensidad muy alta. Se reportó menor frecuencia de lámparas con mayor uso clínico. Conclusiones: Las lámparas de fotocurado LED, utilizadas en los consultorios dentales de la provincia de Piura durante el 2020, emiten una intensidad lumínica promedio de 778,14 mW/cm2, equivalente a la intensidad media(AU)

Introduction: Light curing lamps that use light-emitting diodes (LED) are used in dentistry for the polymeric conversion of dental restorative materials. It has been reported that inadequate light intensity in the lamp would not ensure the appropriate polymerization of restorative materials. Objective: Determine the output intensity of LED light curing units used in dental offices of the city of Piura, Peru, in the year 2020. Methods: An observational descriptive study was conducted. Measurements were taken of the light output of 70 LED light curing lamps using a radiometer with a wavelength of 400-500 nm and a light intensity measurement capacity of up to 3 500 mw/cm2. Intensity below 400 mw/cm2 was recorded as low, from 400 to 800 mw/cm2 as medium, from 800 a 1 200 mw/cm2 as high and above 1 200 mw/cm2 as very high. Results: Intensity was medium in 48.5 percent of the lamps analyzed, high in 22.86 percent, low in 15.71 percent and very high in 12.86 percent. A lower frequency of lamps with greater clinical use was reported. Conclusions: The LED light curing lamps used in dental offices of the province of Piura during the year 2020 emit an average output intensity of 778.14 mW/cm2, which corresponds to medium intensity(AU)

Study of the Pattern of Cell Phone Usage Associated With Side Effects Among University Students: Case Study in a Malaysian University

@#Introduction: Cell phone is a device that has been used almost every day for all age groups. It connects everyone and everything around the world as it provides various social platforms. However, not many people realized that cell phone is a source of non-ionizing electromagnetic waves that can be associated with various physical effects. Therefore, the aim of this research is to identify the physical side effects associated with exposure to the electromagnetic waves emitted by cell phone use and to detect if these effects are associated with specific pattern of use. Methods: A cross-sectional study was conducted on 166 participants randomly selected from university students. Results: showed that those suffering side effects associated with cell phone usage are usually using more than one cell phone (79%) since about 5 – 10 years (41.9%) for more than 5 hours daily (65.7%) for entertainment (34.3%) and making about 1-5 calls daily (41%) with average call duration 1 – 30 min (56.2%). 66.7% of them started using cell phone at age 7 – 12 years old, mostly handheld (61%), at their right side (40%), at all times of the day (64.8%). Most common side effects associated with cell phone usage include ear pain (52.4%), headache (79.5%), fatigue, anxiety or insomnia (57.8%), tremors and eye pain beside statistically significant (P<0.05) complain of dry mouth (56.6%) and/or bad odor mouth (46.4%). Conclusion: There is a specific pattern associated with occurrence of side effects due to cell phone use.

Fundamentos Neurobiológicos Del Sueño / Neurobiological Basis Of Sleep

Resumen El sueño es una de las conductas más importantes para la cognición del ser humano. Tiene entre 4 a 6 ciclos que se caracterizan por presentar diferente actividad electromagnética que hace que se presente una determinada actividad cerebral en cada una de ellas. Cuando el patrón del sueño se afecta, se presentan alteraciones en la vida diaria del sujeto que lo padece, generando un impacto negativo en las actividades que realiza en el medio personal, familiar y social. En este artículo se reporta una revisión teórica del sueño, su actividad eléctrica durante cada una de sus fases, los trastornos del sueño y el impacto de los trastornos del sueño en la vida del individuo. Se concluye resaltando el rol de mantener un equilibrio en el patrón de sueño como un beneficio para la vida diaria del sujeto.

Abstract Sleep is one of the most important behaviors for the cognition of the human being. It has between 4 to 6 cycles that are characterized by presenting different electromagnetic activity that causes a certain brain activity to occur in each of them. When the sleep pattern is affected, there are alterations in the daily life of the subject who suffers it, generating a negative impact on the activities carried out in the personal, family and social environment. In this article we report a theoretical review of the dream, its electrical activity during each of its phases, sleep disorders and the impact of sleep disorders on the individual's life. It is concluded by emphasizing the role of maintaining a balance in the sleep pattern as a benefit for the daily life of the subject.

Study The Pattern Of Mobile Phone Usage In Medical Students

Objective: Mobile technology has influenced the way of living across all segments of society and has raisedconcern about its electromagnetic waves. Hence, the present study gives emphasis on investigating the pattern ofmobile phone usage among undergraduate medical students and their perception and awareness regardingnegative health effects due to excessive exposure of electromagnetic waves.Methods: A cross sectional study was conducted among 170 UG students of PDU Govt. Medical College, Rajkot,Gujarat, India. Data were collected by pre-tested questionnaire in Google form and analysed using MS Excelsoftware.Results: Out of total students participated in the study, 103 were males and 67 were females; Average time spentusing mobile phones was 3.75 hours/day; 51.2% students kept their mobile phone ON during lecture; 75.9% alsostated that they were aware of health hazards due to exposure to electromagnetic waves; 27.6% students agreedthat their sleep is suffered due to use of mobile phone.Conclusion: the outcomes of this study confirms that there is excessive use of mobile phone among medicalstudents. Regulatory bodies should form some specific regulations and guidelines regarding mobile phoneusage in classroom. Further, it is also required to anticipate long term health hazards considering its overuseamong young adults

Effects of electromagnetic waves from cell phone on the hip abduction strength / 体力科学

No consensus exists regarding the effects of electromagnetic waves from cell phones on the human body, and no studies have investigated effects on the locomotor system. To elucidate the effects on muscle strength during cell phone use, the present study investigated changes in hip abduction strength, visual analog scale (VAS) scores, surface electromyogram (EMG), and Root Mean Square (RMS) value. Hip abduction strength did not differ from the NORMAL when the cell phone was powered off, but significantly decreased when it was powered on. Moreover, no differences were observed in RMS and VAS during muscle exertion between states in which the cell phone was powered on or off. Even if there had been a placebo effect or effects of pressure on the temporal bone, the finding that some form of environmental change associated with reproducing the state in which one talks on a cell phone affects the human body is unable to be dismissed. The findings in this case were attributed to reduced function of the central nervous system rather than peripheral muscles or the peripheral nervous system. However, the cause of these findings cannot be identified from the present study. In view of the facts that “muscle strength decreases under conditions in which electromagnetic waves, however small, are emitted from cell phones” and “there are no changes in ease of exerting strength in the subjects themselves”, it was considered necessary both to investigate the causes of these findings and to implement measures in response to these facts.

Application of the special electromagnetic acupoint irradiation in the treatment of acute exacerbation of chronic obstructive pulmonary disease of Hantanzufei type / 中国基层医药

Objective To explore the application value of the special electromagnetic(TDP) acupoint irradiation in the treatment of acute exacerbation of chronic obstructive pulmonary disease of Hantanzufei type.Methods According to the digital table,43 patients with acute exacerbation of chronic obstructive pulmonary disease of Hantanzufei type were randomly divided into the control group (17 cases) and the observation group(26 cases).The control group was given the anti-infective symptomatic and supportive as well as traditional Chinese medicine decoction oral treatment,and the observation group was given TDP acupoint irradiation(Dazhuixue,lefi and right Dingchuanxue) on the basis of the control group.The treatment course of the two groups was 5 to 10 days.The efficacy,symptom score,duration of hospitalization,medical costs and adverse reactions of the two groups were observed.Results The total effective rate of the observation group was 88.5 ％,which was significantly higher than that of the control group(76.5％)(x2 =4.54,P ＜ 0.05).After treatment,the symptom scores,length of hospital stay in the observation group were better than those of the control group(all P ＜ 0.05).But the difference of medical expenses between the two groups was not statistically significant(P ＜0.05).The two groups showed no significant adverse reactions.Conclusion Application of TDP acupoint irradiation in the treatment of acute exacerbation of chronic obstruc-tive pulmonary disease of Hantanzufei type can improve the efficacy,and it has the value of clinical promotion.

Dielectric studies of wheat in powder form at microwave frequencies.

Dielectric constant and loss factor of Raj-4120 variety of Indian wheat were determined in powder form (grain size 125 to 150 ) at room temperature. Microwaves at three different frequencies were employed in C-band, X-band and Ku-band respectively for investigating frequency dependence of dielectric parameters of the sample. Bulk dielectric values of the sample were determined by employing the dielectric mixture relations, such as, half power mixture equation, Landau and Lifshitz, Looyenga equation etc.

Mechanism of Biological Effects of ELF Pulsed Electromagnetic Wave on Cells / 航天医学与医学工程

Objective To observe changes of cytosolic Ca2+ levels before and after irradiation by ELF pulsed electromagnetic waves and to study the mechanism of these changes.Methods Basing on the result from experiment,time-frequency analysis was applied to analyze the bio-effects of ELF pulsed electromagnetic field on cytosolic Ca2+ levels.Results The PHMx(t,?)isoline of cytosolic Ca2+ levels of the cells before(a)and after(b)irradiation by ELF pulsed electromagnetic field was given.Electrohydrodynamic instability and a crystalline liquid biomembrane were applied to explain the mechanism of biological effects on the cells.Conclusion The cytosolic Ca2+ concentration represents a well-defined pattern of spectrum in time-frequency domain,containing continuous and dispersive spectral components.The circs which was considered to induce bio-effects in time-frequency domain presented two unique properties:the continuous spectrum of cellular Ca2+ fluctuations in time-frequency domain was narrowed by the high-energy spectrum component restrained,and the distribution and the frequencies of the dispersive spectra were changed.Furthermore,the pulse frequencies and intensities producing the bio-effects are discrete and distant.