753 research outputs found
A VISCOELASTOPLASTIC MODEL TO INTERPRET DENTAL CEMENTS RESPONSE TO A NANOINDENTATION TEST
Nowadays employment of dental resins of different types has become a standard procedure. Providing a complete characterization of their mechanical behaviour is mandatory to improve their characteristics, design, and usage. In this study, we applied the nanoindentation technique to obtain experimental data to be fitted. Then, a genetic algorithm combined with a gradient algorithm were applied to find the best set of the mechanical
parameters that characterize the Burger model in series with a frictional element, able to predict the nanoindentation process. Furthermore, with this approach one type of test permits to obtain mechanical parameters useful to characterize the viscoelastoplastic response of these materials
Healthcare workers training courses on vaccinations: A flexible format easily adaptable to different healthcare settings.
Since 2017, Italy has expanded the compulsory vaccination from 4 to 10 for those aged 0 to 16 years. Because of the great organizational effort required for the immunization services, minor attention was given to the vaccinations not included among the mandatory ones. This situation led to a real difficulty in harmonizing the vaccination procedures even inside a single region. In the Lazio region, the Laboratory of Vaccinology of the University of Rome Tor Vergata established a working group to create a new training model for healthcare professionals. The course program proposed an update of three vaccinations which are not mandatory but actively offered. It included the same part of scientific updating and a variable part based on local experiences. A specific anonymous questionnaire on knowledge and attitude was administered. The study aimed to propose a general format of training courses for vaccination centers adaptable to the individual local health units (ASLs) and to evaluate through questionnaires. The results show differences in knowledge and attitudes toward non‐mandatory vaccinations among the ASLs of Lazio, confirming the usefulness of a support to make knowledge and procedures homogeneous. This model could be adapted to any healthcare setting and exported to other services
COVID-19 and individual genetic susceptibility/receptivity: Role of ACE1/ACE2 genes, immunity, inflammation and coagulation. might the double x-chromosome in females be protective against SARS-COV-2 compared to the single x-chromosome in males?
In December 2019, a novel severe acute respiratory syndrome (SARS) from a new coronavirus (SARS-CoV-2) was recognized in the city of Wuhan, China. Rapidly, it became an epidemic in China and has now spread throughout the world reaching pandemic proportions. High mortality rates characterize SARS-CoV-2 disease (COVID-19), which mainly affects the elderly, causing unrestrained cytokines-storm and subsequent pulmonary shutdown, also suspected micro thromboembolism events. At the present time, no specific and dedicated treatments, nor approved vaccines, are available, though very promising data come from the use of anti-inflammatory, anti-malaria, and anti-coagulant drugs. In addition, it seems that males are more susceptible to SARS-CoV-2 than females, with males 65% more likely to die from the infection than females. Data from the World Health Organization (WHO) and Chinese scientists show that of all cases about 1.7% of women who contract the virus will die compared with 2.8% of men, and data from Hong Kong hospitals state that 32% of male and 15% of female COVID-19 patients required intensive care or died. On the other hand, the long-term fallout of coronavirus may be worse for women than for men due to social and psychosocial reasons. Regardless of sex-or gender-biased data obtained from WHO and those gathered from sometimes controversial scientific journals, some central points should be considered. Firstly, SARS-CoV-2 has a strong interaction with the human ACE2 receptor, which plays an essential role in cell entry together with transmembrane serine protease 2 (TMPRSS2); it is interesting to note that the ACE2 gene lays on the X-chromosome, thus allowing females to be potentially heterozygous and differently assorted compared to men who are definitely hemizygous. Secondly, the higher ACE2 expression rate in females, though controversial, might ascribe them the worst prognosis, in contrast with worldwide epidemiological data. Finally, several genes involved in inflammation are located on the X-chromosome, which also contains high number of immune-related genes responsible for innate and adaptive immune responses to infection. Other genes, out from the RAS-pathway, might directly or indirectly impact on the ACE1/ACE2 balance by influencing its main actors (e.g., ABO locus, SRY, SOX3, ADAM17). Unexpectedly, the higher levels of ACE2 or ACE1/ACE2 rebalancing might improve the outcome of COVID-19 in both sexes by reducing inflammation, thrombosis, and death. Moreover, X-heterozygous females might also activate a mosaic advantage and show more pronounced sex-related differences resulting in a sex dimorphism, further favoring them in counteracting the progression of the SARS-CoV-2 infection
MILIARY TUBERCULOSIS IN THE XXI CENTURY – A CASE REPORT
Introdução: Atualmente, a tuberculose ainda representa um sério problema de saúde pública. A idade precoce e a infeção VIH constituem importantes fatores de risco para doença grave ou disseminada.
Caso clínico: Apresentamos o caso de uma menina de três anos de idade observada por febre prolongada sem foco infecioso evidente ao exame físico. O estudo analítico inicial foi sugestivo
de infeção urinária, pelo que iniciou antibioticoterapia empírica. A urocultura confirmou esse diagnóstico, mas a febre persistiu. Na investigação complementar, a radiografia torácica revelou um infiltrado pulmonar com padrão miliar. O Mycobacterium tuberculosis foi isolado no aspirado gástrico, líquor e urina. Iniciou tratamento com antituberculosos e corticóide, com melhoria clínica significativa.
Conclusões: Nesta era de tecnologia médica avançada, a tuberculose ainda é um desafio diagnóstico, especialmente quando a apresentação clínica é atípica e extrapulmonar. Um elevado índice de suspeição clínica é fundamental, pois a instituição precoce do tratamento é decisiva para o prognóstico
X-ray Reflection and An Exceptionally Long Thermonuclear Helium Burst from IGR J17062-6143
Thermonuclear X-ray bursts from accreting neutron stars power brief but strong irradiation of their surroundings, providing a unique way to study accretion physics. We analyze MAXI/Gas Slit Camera and Swift/XRT spectra of a day-long flash observed from IGR J17062-6143 in 2015. It is a rare case of recurring bursts at a low accretion luminosity of 0.15% Eddington. Spectra from MAXI, Chandra, and NuSTAR observations taken between the 2015 burst and the previous one in 2012 are used to determine the accretion column. We find it to be consistent with the burst ignition column of 5 × 10^(10) g cm^(−2), which indicates that it is likely powered by burning in a deep helium layer. The burst flux is observed for over a day, and decays as a straight power law: F ∝ t^(-1.15). The burst and persistent spectra are well described by thermal emission from the neutron star, Comptonization of this emission in a hot optically thin medium surrounding the star, and reflection off the photoionized accretion disk. At the burst peak, the Comptonized component disappears, when the burst may dissipate the Comptonizing gas, and it returns in the burst tail. The reflection signal suggests that the inner disk is truncated at ~102 gravitational radii before the burst, but may move closer to the star during the burst. At the end of the burst, the flux drops below the burst cooling trend for 2 days, before returning to the pre-burst level
Source/load-pull noise measurements at ka band
This paper is focused on the extraction of the noise parameters of a linear active device by exploiting both forward and reverse noise power measurements associated with different termina-tions. In order for load-pull measurements to yield a significant marginal improvement (as compared to forward measurements only) it is expected that the device under test should appreciably deviate from unidirectionality. For this reason, the source/load-pull technique is applied to frequencies at which the considered devices are still usable but their reverse noise factor exhibits a measurable dependence on the output terminations. Details on the test bench set up to the purpose, covering the 20–40 GHz frequency range, are provided. A characterization campaign on a 60 nm gate length, 4 × 35 µm GaN-on-Si HEMT fabricated by OMMIC is illustrated
Floristic Inventory of The Proposed Site for Tarsier Tourism Center in Villa Aurora, Bilar, Bohol, Philippines
The study assessed the present vegetation composition of the Proposed Site for the Tarsier Tourism Center (PTTC) at Villa Aurora, Bilar, Bohol and performed a comparative analysis with the existing Tarsier Sanctuary (TS) at Canapnapan, Corella, Bohol. The basis for comparison was the computed importance values, species richness, species dominance, and percent distribution of plants according to self-defined DBH classes. Results showed that both sites had very high species richness and evenness values. Common overstorey and understorey plant species found in both areas were katagpo (Psychotria sp.), sagimsim (Syzygium brevistylum [C. B. Rob]Merr.) and bagauak (Clerodendrum minahassae Teijsm. & Binn.). Apart from sagimsim (Syzygium brevistylum [C.B.Rob.] Merr.), selaginella (Selaginella cuppresina Lin.), and lunas (Lunasia amara Blanco) were also common in the ground vegetation of both areas. Percent distribution of trees according to self-defined DBH classes revealed that PTTC had 87.55% of the total recorded plants with DBH measurements of 20 cm. Percent distribution of trees on these DBH ranges (especially on DBH class >20 cm) indicated the presence of medium and large trees. The largest DBH measured in the PTTC was 70 cm while in TS was only 22 cm. The proposed 10-ha site in Villa Aurora, Bilar, is suited to be utilized as Tarsier Tourism Center. In case the proposed project is to be pursued, enclosure similar to what has been constructed in Canapnapan, Corella, Bohol, Philippines should also be established to prevent stray animals from predating the captive tarsiers.Keywords: floristic inventory, Philippine tarsier, Bohol, primate conservation, tourism. Inventarisasi flora dari Situs Usulan untuk Sentra Wisata Tarsier di Villa Aurora, Bilar, Bohol, FilipinaAbstractPenelitian ini ditujukan untuk melakukan penilaian komposisi vegetasi dari Usulan Lokasi Pusat Wisata Tarsius (ULPWT) di Villa Aurora, Bilar, Bohol dan melakukan analisis perbandingan antara Tarsier Sanctuary (TS) yang ada di Canapnapan, Corella, Bohol. Dasar perbandingan yang digunakan yaitu dengan menghitung nilai penting, kekayaan spesies, dominansi spesies, dan prosentase distribusi dari tumbuhan berdasarkan kelas diameter yang telah ditentukan. Hasil penelitian menunjukkan bahwa kedua tempat memiliki kekayaan spesies dan nilai evenness/ kemerataan yang sangat tinggi. Spesies tumbuhan yang umum ditemukan di overstorey dan understorey di kedua area adalah katagpo (Psychotria sp.), sagimsim (Syzygium brevistylum [C. B. Rob]Merr.), dan bagauak (Clerodendrum minahassae Teijsm. & Binn.). Selain itu, sagimsim (Syzygium brevistylum [C.B.Rob.] Merr.), selaginella (Selaginella cuppresina Lin.), dan lunas (Lunasia amara Blanco) juga umum ditemukan di lantai hutan di kedua tempat. Prosentase distribusi dari tumbuhan berdasarkan kelas diameter yang telah ditentukan menunjukkan bahwa ULPWT memiliki 87.55% dari keseluruhan tumbuhan yang tercatat dengan ukuran diameter 20 cm. Prosentase distribusi dari pohon pada kisaran ini (khususnya pada diameter >20 cm) menunjukkan adanya kehadiran pohon berukuran medium dan besar. Diameter terbesar yang terukur di ULPWT adalah 70 cm sementara di TS hanya sebesar 22 cm. Lokasi seluas 10 ha di Villa Aurora, Bilar, sesuai untuk digunakan sebagai Pusat Wisata Tarsius. Apabila akan didirikan, maka kandang yang dibangun diharapkan mirip dengan yang telah dibangun di Canapnapan, Corella, Bohol, Pilipina, agar mencegah pemangsaan oleh satwa yang lepas.
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