Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

This paper presents a comparative analysis of the propagation models Hata Extended, SUI with a frequency correction factor, and Ericsson 9999 in mobile telephony systems operating in the 1900 MHz band (LTE). The study is carried out by measuring the electric field to establish a recommendation for an existing propagation model that fits the characteristics of the urban area of Ambato City. First, five base stations were located. Then, two base stations working in the band and technology mentioned above are chosen. Subsequently, four radial limits were drawn in the surroundings of the base stations, and four electric field measurement campaigns were carried out with the Narda SRM-3006 equipment for a total of 48 points for 6 minutes per point. In addition, the coordinates of the measurement points were determined using the Spectra Precision Mobile Mapper 50 equipment, obtaining the distances and heights of the terrain with great precision. With the data collected, the propagation losses are calculated to bring the theoretical electric field of each propagation model. Next, comparing the measured electric field values concerning each model's theoretical electric field values is performed to evaluate which model best fits the measurements. Also, a comparison of the RMSE is made. Finally, it is concluded that the SUI model with frequency correction factor is the best fit for the urban environment of the city of Ambato.

By using a triple machine learning approach, we conduct a content analysis on dos million bites of Mexican government information, and 28, 127 news and opinion columns published in 2020, relating to COVID pandemia. Findings report similarity in news and polarization in opinion columns. This means that news covered accurately Health General Council recommendations, but comments in media tended to distort what this group of professionals in Medicine provided with the objective of protect Mexicans’ lives. Those findings bring media social responsibility and right to information to the further discussions of COVID-19, the most serious health crisis in Mexico history.

Virtual reality in Pediatric Dentistry has enormous potential, in the treatment of phobia of dental treatments, this technology is also promising, since it shows satisfactory results and in the surgical area it has a high potential for complex treatments, allowing predictable and safe results. However, future studies should have to establish technological standards with high data quality and in the development of applications approved for clinical routine. Distraction is a non-pharmacological pain management technique commonly used by Pediatric Dentists to control pain and anxiety. There are some new techniques that use audio and video stimulation and distract the patient by exposing him to three-dimensional videos. These techniques are called virtual reality audiovisual systems. The objective of this case was to evaluate the effectiveness of virtual reality glasses as a distraction aid to reduce anxiety in a 7-year-old girl who attends the pediatric dentistry office to perform a dental extraction procedure.

Sialolithiasis is one of the most common pathologies of the major salivary glands and occurs more frequently in the submandibular glands. Between 80 and 95% of sialoliths develop in the submandibular glands, between 5 and 20% in the parotid gland, and only 1% in the sublingual gland. Sialoliths form within the parenchyma and associated duct systems. In Wharton's duct (80- 90%) and only 15% in the gland. Sialolithiasis is the cause of pain and inflammation of the salivary gland by obstructing the duct and preventing salivary secretion, before, during and after food. The objective of this article was to review the different diagnostic imaging methods used for the study of calcifications of the submandibular gland, based on different studies reported in contemporary scientific literature, in order to establish the correct diagnosis. A search of the literature was carried out in the main information sources including Medline (via PubMed), ELSEVIER, SCIELO, and LILACS, using the search terms with a date limitation of the last 5 years on average. The selected articles included information regarding the calcifications of the salivary glands. Imaging studies of salivary gland calcifications can be obtained with conventional radiographs, Sialography, Ultrasonography (US), Computed Tomography (CT) and Magnetic Resonance Imaging (MR).

Aim: To describe the oral finding, physical features and medical features with the genetic diagnosis of a Pentasomy X. Case report: A 6-year-old female patient was referred for oral evaluation presenting acute pain related to ulcers in the attached gingival and dorsum of tongue mucosa. Medical history revealed Pentasomy X associated with interatrial communication, convergent strabismus, recurrent seizures, dysautonomia, episodes of thrombosis and cognitive delay with limited oral communication skills. A palliative oral treatment was applied. Oral hygiene improvement and surveillance were decided considering the absence of dental hypersensitivity, post eruptive enamel breakdowns or dental caries. Less than 30 cases had been reported in the literature, reflecting the rare nature of this genetic disorder and with great difficulties to perform dental treatment. As regards the oral health status of these patients, with an emphasis on dental care, information is totally lacking. Conclusion: Oral care in patients with genetic syndromes must consider the status in general health to prevent medical complications associated with oral disease or dental treatment. Minimal intervention and surveillance are appropriate options in customized therapy.  

In dental practice, the use of imaging has increased over the years, generating an increase in the radiation dose for the dental patient. One factor under discussion is the amount of dose used in patients, men, women and children, at different stages of their life, due to the scientific evidence of the harmful effects of ionizing radiation. This review of the literature analyzed the characteristics of radiation and its effects in relation to the doses administered, and its equivalences in dental practice in panoramic periapical radiographs and cone beam tomographies. A search of the literature was carried out in the main information sources such as Medline (via PubMed), ELSEVIER, SCIELO,　and LILACS, using the search terms with a date limitation of the last 10 years. The selected articles　had to include information regarding the keywords used, including "Dental Offices, Radiation Dose, X-Rays, Ambulatory Care".

The implementation of the right to be forgotten in Mexico has generated controversies derived from its denomination, its little regulation, the ignorance of the figure or its conflict with other rights such as the one related to freedom of expression or access to information. The objective of this work is to carry out the current thinking on the aforementioned right for which, we will take a look at the way in which this topic has been addressed in the European Union progresses on the matter, and the backgrounds in our country as well. As a conclusion, we will refer to the outstanding issues that Mexico has in this discipline and we will propose some alternatives to facilitate its exercise.