Validation of a histology e-book for the teaching-learning process at the university level.

Histology is a science fundamental for life and health undergraduate courses. During its teaching and learning process, digital books (e-books) stand out by offering students more contact time with theoretical-practical content; however, the reliability of these must be examined. Therefore, this study aimed to validate an e-book, Histologia interativa: roteiros de estudos (interactive histology: study guide) for teaching and learning histology at the university level. A methodological validation study was performed, in which the data were collected by filling out an online form regarding the qualities from experts and about the review of the e-book's content. Seven experts participated in the study, the majority of them working as professors at universities in the morphofunction field. The content validity indices for item (I-CVI) and scale (S-CVI) were calculated. Values≥0.78 for I-CVI and≥0.90 for S-CVI/AVE were considered to have excellent content validity. Only two (6.06%) of 33 items did not achieve acceptable I-CVI values. Overall, S-CVI/AVE obtained a value of 0.955. In conclusion, the e-book evaluation has sufficient structural- and criterion-related validity. Furthermore, despite the experts' suggestions, they favored the use of the e-book in the teaching and learning of histology at the university level.

Factors associated with perceived performance drops and musculoskeletal injuries in Brazilian recreational triathletes.

OBJECTIVE: The aim of the study was to investigate sleep characteristics, use of supplements, and training volume of recreational triathletes, and to verify possible associations with perceived performance drops and occurrence of injuries. MATERIALS AND METHODS: Recreational triathletes (n=942) answered a questionnaire inquiring about their demographic characteristics, performance, injuries and training volume. RESULTS: When comparing athletes who slept more (9-10 hours) with those who slept less, less sleep was associated with a higher prevalence of perceived performance drops. Regarding difficulties in initiating sleep, the absence of initiating difficulties (p<0.001) was a protective factor against perceived performance drops. Regarding weekly training volume, compared to those who trained more than 20 hours, training less than 3 hours (p<0.001), 3-5 hours (p<0.001), or 12-14 hours (p<0.001) were protective factors against perceived performance drops. Concerning training volume and injuries, we found that compared to those who trained more than 20 hours, training 18-20 hours (p<0.001), 15-17 hours (p<0.001), 12-14 hours (p<0.001), 6-8 hours (p<0.001), or 3-5 hours (p<0.001) were protective factors against injuries. CONCLUSIONS: Triathletes with a lower sleep quantity and those who have difficulties initiating sleep frequently experience drops in performance. Training volumes can influence both performance and the likelihood of injuries.

Effects of aerobic and strength training on depression, anxiety, and health self-perception levels during the COVID-19 pandemic.

OBJECTIVE: This study aimed at comparing the depression and anxiety levels, and health self-perception during the coronavirus disease 2019 pandemic among subjects who practice aerobic, strength, and mixed (aerobic and strength) exercises and nonsports participants. MATERIALS AND METHODS: We included 304 Brazilians of both sexes in this cross-sectional study. All participants were recruited through online advertisement and completed a self-administered questionnaire regarding the personal information, level of restriction adopted, physical activity, and mood state screening (Patient Health Questionnaire-9 and General Anxiety Disorder-7). We divided the participants into four groups: strength sports group (CrossFit or strength training), aerobic/endurance sports groups (running, cycling, triathlon, or swimming), mixed sports groups (individuals who practice endurance and strength sports), and nonsports group. RESULTS: The Kruskal-Wallis test showed a significant effect of the group on the depression and anxiety levels. Meanwhile, the post-hoc comparisons showed a significantly lower depression level in the mixed and aerobic sports groups than in the strength sports and nonsports groups, and a significantly lower anxiety level in the mixed and aerobic sports groups than in the nonsports group. Furthermore, participants in the mixed, strength, and aerobic sports groups presented a better level of health self-assessment than the nonsports group, and those in the mixed sports group had a better level of health self-assessment than the strength or aerobic sports groups. CONCLUSIONS: Individuals practicing aerobic exercises present lower depression and anxiety levels than those practicing strength training and are inactive. However, individuals who practice strength exercises and aerobics have the best levels of health perception.

The aspects of sex, age and nationality in winter swimming performance.

OBJECTIVE: Winter swimming is a new sport discipline. Very little is known, however, about the sex differences, origin, participation and performance of the world's best winter swimmers. Therefore, the study aimed to investigate sex differences in performance and age. Furthermore, it should be determined which country has the fastest swimmers, the highest numbers of participants and the most successful age group athletes in winter swimming. SUBJECTS AND METHODS: A total of 6,477 results from the 25 m events of the IWSA (International Winter Swimming Association) World Cups from 2016-2020 was collected from the official website of IWSA. Data were analyzed using a generalized linear model (GLM) with a gamma probability distribution and identity link function. The 25 m events were carried out in head-up breaststroke style, freestyle and butterfly. The nationalities were grouped into six groups, the five nationalities with the highest number of participants in the 25 m competitions and one group with the other nationalities. The mean time of 25 m races by sex and country of the total sample was compared. For the top 10 comparisons, the best ten athletes from the six groups were selected. The mean time of each top 10 groups was compared by sex and nationality. RESULTS: Men were faster than women for all categories. Swimmers in age group 15-29 years were the fastest, where females were the fastest in age group 15-19 years and males in age group 20-29 years. Women from both Russia and Estonia and men from both Russia and China were the fastest. Both Russian and Chinese males were the fastest in all water categories in the top 10 section in the 25 m events. CONCLUSIONS: In summary, males were faster than females in the IWSA World Cups between 2016 and 2020. The age group of 15-29 years old athletes was the most successful while females had their age of peak performance earlier than males. Russian and Estonian males and Russian females were the overall fastest in the 25 m events in all water categories. Future studies should investigate the optimal anthropometric characteristics of male and female winter swimming sprint athletes and whether there are distinct areas in Russia, Estonia and China, where many international winter swimming athletes originate.

Comparison of the levels of depression and anxiety during the first and fourth waves of coronavirus disease-2019 pandemic in Brazil.

OBJECTIVE: To compare the levels of depression, anxiety, physical activity, and mobility restrictions between the first wave in June 2020 and the fourth wave in January 2022 of the coronavirus disease-2019 (COVID-19) pandemic in Brazil. PATIENTS AND METHODS: Brazilian citizens answered a self-administered questionnaire that included questions related to personal information, mobility restriction levels, physical activity levels, and the status of mood disorders in June 2020 (n=1853) and January 2022 (n=728). RESULTS: The levels of mobility restrictions (p<0.001), anxiety (p<0.001), and depression (p<0.001) significantly decreased from 2020 to 2022. In June 2020, 23.2% of the participants presented moderate to severe anxiety, and in January 2022, this percentage decreased to 14.8%. In June 2020, 29.6% of the participants presented moderate to severe depressive symptoms, and in January 2022 this percentage decreased to 19.3%. On the contrary, physical activity levels significantly increased between 2020 and 2022 (p<0.001). CONCLUSIONS: During the fourth wave of the COVID-19 pandemic, participants were less restricted and more physically active than in the first wave. Furthermore, anxiety and depression levels were significantly lower in the fourth wave than in the first wave. Despite this reduction, levels of anxiety and depression remain high; therefore, the authors suggest measures to encourage physical activity and promote mental health.

Association between lowering restriction levels during the coronavirus outbreak and physical activity among adults: a longitudinal observational study in Brazil.

OBJECTIVE: The COVID-19 pandemic has had significant consequences on public health and lifestyle and has negatively affected mental health and the level of physical activity worldwide. This study examined the impact of reopening fitness centers and nonessential services and introducing flexible measures to ensure social distancing on physical activity and mental health. MATERIALS AND METHODS: This was a longitudinal study. A self-administered questionnaire, including personal, behavioral, physical activity, perception of health, and mood state disorder information, was answered by 128 Brazilians in June 2020 (during severe restrictive measures) and again in April 2021 (after fitness centers and nonessential services were reopened). RESULTS: The restriction level adopted in April 2021 was significantly lower than that in June 2020 (p<0.001). The level of physical activity (p<0.001) and health status perception (p<0.001) decreased from June 2020 to April 2021. The median values for depression and anxiety did not differ across the study period. CONCLUSIONS: The level of physical activity was reduced during the COVID-19 pandemic, and anxiety and depression were not improved following less restrictive social distancing measures and the reopening of fitness centers. Thus, the return to a prepandemic level of physical activity and mental health status may not be automatic. The results presented herein suggest that the decrease in physical activity observed in the population may be challenging in the postpandemic period.

Intercostal celiotomy for removal of proventriculus foreign body in muscovy duck (Cairina moschata): case report / Celiotomia intercostal para remoção de corpo estranho do proventrículo de pato-do-mato (Cairina Moschata): relato de caso]

Ducks, geese and swans are included in the Anatidae family, Anseriformes order. The leading injuries causes to waterfowl are tangling in fishing materials and foreign bodies ingestion. A muscovy duck (Cairina moschata) was referred for treatment at Veterinary Teaching Hospital and a radiographic examination showed the presence of a hook in the coelom. Surgical exposure and incision of the proventriculus was made through left intercostal access and the hook along with a fishing line were gently removed. The animal began to feed voluntarily at the fourth post-operative day and two weeks after the procedure the patient was clinically well and was released to wild. This surgical approach differs in some aspects from the listed techniques in the known literature. It proved to be a viable and appropriate alternative to treat this affection since it did not cause any trans- or post-operative complications and enabled rapid recovery and subsequent patient release.(AU)

Patos, gansos e cisnes estão incluídos na família Anatidae, ordem Anseriformes. Entre as principais causas de ferimentos em aves aquáticas, o embaraço com materiais de pesca e a ingestão de corpos estranhos são os mais citados. Um pato-do-mato (Cairina moschata) foi encaminhado para tratamento no Hospital Veterinário e, mediante exame radiográfico, verificou-se a presença de um anzol na cavidade celomática, provavelmente no proventrículo. Utilizando-se o acesso intercostal esquerdo, foi feita a exposição e a incisão do proventrículo. Por meio dessa incisão, o anzol com um segmento de linha de pesca foi delicadamente retirado. O animal começou a se alimentar voluntariamente no quarto dia pós-operatório e duas semanas após o procedimento o paciente se encontrava clinicamente bem e apto à soltura. Esta abordagem cirúrgica difere, em alguns aspectos, das técnicas listadas na literatura e provou ser uma alternativa viável e adequada ao caso, não causando complicações e permitindo recuperação rápida, com posterior soltura do animal.(AU)

Fungal Planet description sheets: 558-624.

Novel species of fungi described in this study include those from various countries as follows: Australia: Banksiophoma australiensis (incl. Banksiophoma gen. nov.) on Banksia coccinea, Davidiellomycesaustraliensis (incl. Davidiellomyces gen. nov.) on Cyperaceae, Didymocyrtis banksiae on Banksia sessilis var. cygnorum, Disculoides calophyllae on Corymbia calophylla, Harknessia banksiae on Banksia sessilis, Harknessia banksiae-repens on Banksia repens, Harknessia banksiigena on Banksia sessilis var. cygnorum, Harknessia communis on Podocarpus sp., Harknessia platyphyllae on Eucalyptus platyphylla, Myrtacremonium eucalypti (incl. Myrtacremonium gen. nov.) on Eucalyptus globulus, Myrtapenidiella balenae on Eucalyptus sp., Myrtapenidiella eucalyptigena on Eucalyptus sp., Myrtapenidiella pleurocarpae on Eucalyptuspleurocarpa, Paraconiothyrium hakeae on Hakea sp., Paraphaeosphaeria xanthorrhoeae on Xanthorrhoea sp., Parateratosphaeria stirlingiae on Stirlingia sp., Perthomyces podocarpi (incl. Perthomyces gen. nov.) on Podocarpus sp., Readeriella ellipsoidea on Eucalyptus sp., Rosellinia australiensis on Banksia grandis, Tiarosporella corymbiae on Corymbia calophylla, Verrucoconiothyriumeucalyptigenum on Eucalyptus sp., Zasmidium commune on Xanthorrhoea sp., and Zasmidium podocarpi on Podocarpus sp. Brazil: Cyathus aurantogriseocarpus on decaying wood, Perenniporia brasiliensis on decayed wood, Perenniporia paraguyanensis on decayed wood, and Pseudocercospora leandrae-fragilis on Leandrafragilis.Chile: Phialocephala cladophialophoroides on human toe nail. Costa Rica: Psathyrella striatoannulata from soil. Czech Republic: Myotisia cremea (incl. Myotisia gen. nov.) on bat droppings. Ecuador: Humidicutis dictiocephala from soil, Hygrocybe macrosiparia from soil, Hygrocybe sangayensis from soil, and Polycephalomyces onorei on stem of Etlingera sp. France: Westerdykella centenaria from soil. Hungary: Tuber magentipunctatum from soil. India: Ganoderma mizoramense on decaying wood, Hodophilus indicus from soil, Keratinophyton turgidum in soil, and Russula arunii on Pterigota alata.Italy: Rhodocybe matesina from soil. Malaysia: Apoharknessia eucalyptorum, Harknessia malayensis, Harknessia pellitae, and Peyronellaea eucalypti on Eucalyptus pellita, Lectera capsici on Capsicum annuum, and Wallrothiella gmelinae on Gmelina arborea.Morocco: Neocordana musigena on Musa sp. New Zealand: Candida rongomai-pounamu on agaric mushroom surface, Candida vespimorsuum on cup fungus surface, Cylindrocladiella vitis on Vitis vinifera, Foliocryphia eucalyptorum on Eucalyptus sp., Ramularia vacciniicola on Vaccinium sp., and Rhodotorula ngohengohe on bird feather surface. Poland: Tolypocladium fumosum on a caterpillar case of unidentified Lepidoptera.Russia: Pholiotina longistipitata among moss. Spain: Coprinopsis pseudomarcescibilis from soil, Eremiomyces innocentii from soil, Gyroporus pseudocyanescens in humus, Inocybe parvicystis in humus, and Penicillium parvofructum from soil. Unknown origin: Paraphoma rhaphiolepidis on Rhaphiolepsis indica.USA: Acidiella americana from wall of a cooling tower, Neodactylaria obpyriformis (incl. Neodactylaria gen. nov.) from human bronchoalveolar lavage, and Saksenaea loutrophoriformis from human eye. Vietnam: Phytophthora mekongensis from Citrus grandis, and Phytophthora prodigiosa from Citrus grandis. Morphological and culture characteristics along with DNA barcodes are provided.

Impacto de la hipertensión arterial como factor de riesgo cardiovascular / Burden of hypertension as a cardiovascular risk factor

La Hipertensión Arterial (HTA) continúa siendo un problema de Salud Pública relevante a nivel mundial. En Chile es la principal causa de morbimortalidad y el factor de riesgo de mayor carga atribuible para la patología cardiovascular isquèc)mica y el accidente cerebrovascular. En este artículo se revisa su prevalencia, el grado de conocimiento, el logro de su control y tratamiento, así como su riesgo atribuible analizando la carga de enfermedad y la pèc)rdida de años por discapacidad. Se presentan estudios del impacto de su inclusión en el AUGE, resultados de la intervención multidisciplinaria, su interacción con otros factores de riesgo cardiovascular y se comentan algunos aspectos de las actualizaciones de las guías internacionales para su manejo.

Hypertension (HT) remains as an important public health problem worldwide. In Chile constitutes the leading cause of morbidity and mortality and the risk factor with the highest attributable risk burden for ischemic heart disease and stroke. This article reviews HT??s prevalence, degree of knowledge, achievement of its control and treatment. Also the risk burden of disease and disability loss years due to this pathology is analyzed. The results of studies after the inclusion of HT as explicit guaranteed health problem, multidisciplinary approach and its interaction with other cardiovascular risk factors is presented. Finally, some aspects of international updates guidelines for its management are discussed.

Strength field tests performance are correlated with isokinetic strength of shoulder rotator muscles in female handball players.

BACKGROUND: The aim of this study was to analyze the relationship between the isokinetic shoulder strength of the athletes and their performance on strength field tests. Data on the balance and functional strength ratios of the internal and external rotator muscles of shoulders of handball players was also investigated. METHODS: Twenty-seven female athletes (23±3.4 years, 71±10.6 kg and 173.3±7.1 cm) underwent an isokinetic assessment of the strength of the shoulder rotator muscles. Athletes also performed the following strength field tests: bench press test, lying bench barbell row test, handgrip test, and medicine ball throwing. RESULTS: The bench press test results and the lying bench barbell row test results were significantly correlated with the concentric internal and external rotator peak torques at 1.05 rad.s-1 and 5.23 rad.s-1, with total work at 1.05 rad.s-1 and with average power at 5.23 rad.s-1 (r=0.51 to 0.81). CONCLUSION: We suggested the use of field test to infer about internal and external rotator muscular strength, but not to infer about isokinetic muscular strength ratios. These findings could be useful to coaches and trainers.

Development of newborn and 1-year-old reference phantoms based on polygon mesh surfaces.

The purpose of this study is the development of paediatric reference phantoms for newborn and 1-year-old infants to be used for the calculation of organ and tissue equivalent doses in radiation protection. The study proposes a method for developing anatomically highly sophisticated paediatric phantoms without using medical images. The newborn and 1-year-old hermaphrodite phantoms presented here were developed using three-dimensional (3D) modelling software applied to anatomical information taken from atlases, textbooks and images provided by the Department of Anatomy of the Federal University of Pernambuco, Brazil. The method uses polygon mesh surfaces to model body contours, the shape of organs as well as their positions and orientations in the human body. Organ and tissue masses agree with corresponding data given by the International Commission on Radiological Protection for newborn and 1-year-old reference children. Bones were segmented into cortical bone, spongiosa, medullary marrow and cartilage to allow for the use of µCT images of trabecular bone for skeletal dosimetry. Anatomical results show 3D images of the phantoms' surfaces, organs and skeletons, as well as tables with organ and tissue masses or skeletal tissue volumes. Dosimetric results present comparisons of organ and tissue absorbed doses or specific absorbed fractions between the newborn and 1-year-old phantoms and corresponding data for other paediatric stylised or voxel phantoms. Most differences were found to be below 10%.

The enigmatic life history of the symbiotic crab Tunicotheres moseri (Crustacea, Brachyura, Pinnotheridae): implications for its mating system and population structure.

Resource-monopolization theory predicts the adoption of a solitary habit in species using scarce, discrete, and small refuges. Life-history theory suggests that temporarily stable parental dwellings favor extended parental care in species that brood embryos. We tested these two predictions with the symbiotic crab Tunicotheres moseri. This species exhibits abbreviated development and inhabits the atrial chamber of the scarce, structurally simple, long-lived, and relatively small ascidian Phalusia nigra in the Caribbean. These host characteristics should favor a solitary habit and extended parental care (EPC) in T. moseri. As predicted, males and females of T. moseri inhabited ascidians solitarily with greater frequency than expected by chance alone. The male-female association pattern and reverse sexual dimorphism (males < females) additionally suggests a promiscuous "pure-search" mating system in T. moseri. Also in agreement with theoretical considerations, T. moseri displays EPC; in addition to embryos, females naturally retain larval stages, megalopae, and juveniles within their brooding pouches. This is the first record of EPC in a symbiotic crab and the second confirmed record of EPC in a marine brachyuran crab. This study supports predictions central to resource-monopolization and life-history theories.

Skeletal dosimetry based on µCT images of trabecular bone: update and comparisons.

Two skeletal dosimetry methods using µCT images of human bone have recently been developed: the paired-image radiation transport (PIRT) model introduced by researchers at the University of Florida (UF) in the US and the systematic­periodic cluster (SPC) method developed by researchers at the Federal University of Pernambuco in Brazil. Both methods use µCT images of trabecular bone (TB) to model spongiosa regions of human bones containing marrow cavities segmented into soft tissue volumes of active marrow (AM), trabecular inactive marrow and the bone endosteum (BE), which is a 50 µm thick layer of marrow on all TB surfaces and on cortical bone surfaces next to TB as well as inside the medullary cavities. With respect to the radiation absorbed dose, the AM and the BE are sensitive soft tissues for the induction of leukaemia and bone cancer, respectively. The two methods differ mainly with respect to the number of bone sites and the size of the µCT images used in Monte Carlo calculations and they apply different methods to simulate exposure from radiation sources located outside the skeleton. The PIRT method calculates dosimetric quantities in isolated human bones while the SPC method uses human bones embedded in the body of a phantom which contains all relevant organs and soft tissues. Consequently, the SPC method calculates absorbed dose to the AM and to the BE from particles emitted by radionuclides concentrated in organs or from radiation sources located outside the human body in one calculation step. In order to allow for similar calculations of AM and BE absorbed doses using the PIRT method, the so-called dose response functions (DRFs) have been developed based on absorbed fractions (AFs) of energy for electrons isotropically emitted in skeletal tissues. The DRFs can be used to transform the photon fluence in homogeneous spongiosa regions into absorbed dose to AM and BE. This paper will compare AM and BE AFs of energy from electrons emitted in skeletal tissues calculated with the SPC and the PIRT method and AM and BE absorbed doses and AFs calculated with PIRT-based DRFs and with the SPC method. The results calculated with the two skeletal dosimetry methods agree well if one takes the differences between the two models properly into account. Additionally, the SPC method will be updated with larger µCT images of TB.

Development of 5- and 10-year-old pediatric phantoms based on polygon mesh surfaces.

PURPOSE: The purpose of this study is the development of reference pediatric phantoms for 5- and 10-year-old children to be used for the calculation of organ and tissue equivalent doses in radiation protection. METHODS: The study proposes a method for developing anatomically highly sophisticated pediatric phantoms without using medical images. The 5- and 10-year-old male and female phantoms presented here were developed using 3D modeling software applied to anatomical information taken from atlases and textbooks. The method uses polygon mesh surfaces to model body contours, the shape of organs as well as their positions, and orientations in the human body. Organ and tissue masses comply with the corresponding data given by the International Commission on Radiological Protection (ICRP) for the 5- and 10-year-old reference children. Bones were segmented into cortical bone, spongiosa, medullary marrow, and cartilage to allow for the use of micro computer tomographic (microCT) images of trabecular bone for skeletal dosimetry. RESULTS: The four phantoms, a male and a female for each age, and their organs are presented in 3D images and their organ and tissue masses in tables which show the compliance of the ICRP reference values. Dosimetric data, calculated for the reference pediatric phantoms by Monte Carlo methods were compared with corresponding data from adult mesh phantoms and pediatric stylized phantoms. The comparisons show reasonable agreement if the anatomical differences between the phantoms are properly taken into account. CONCLUSIONS: Pediatric phantoms were developed without using medical images of patients or volunteers for the first time. The models are reference phantoms, suitable for regulatory dosimetry, however, the 3D modeling method can also be applied to medical images to develop patient-specific phantoms.

Sir2-Related Protein 1 from Leishmania amazonensis is a glycosylated NAD+-dependent deacetylase.

Sirtuin proteins form a family of NAD+-dependent protein deacetylases that are considered potential drug targets against parasites. Here, we present the first characterization of a sirtuin orthologue from Leishmania amazonensis, an aetiological agent of American tegumentary leishmaniasis that has been the subject of many studies focused in the development of therapeutic approaches. The protein has high sequence identity with other Kinetoplastid Silent information regulator 2 Related Protein 1 (Sir2RP1) and was named LaSir2RP1. The gene exists as a single copy, encoding a monomeric protein (LaSir2RP1) of approximately 41 kDa that has NAD+-dependent deacetylase activity. LaSir2RP1 was immunodetected in total protein extracts, in cytoplasmic granules, and in the secreted material of both promastigotes and lesion-derived amastigotes. Analysis of both lectin­affinity purified promastigote and amastigote extracts revealed the presence of a major enriched protein of approximately 66 kDa that was recognized by an anti-LaSir2RP1 serum, suggesting that a parasite sirtuin could be glycosylated in vivo.

Analytical linear theory for the interaction of a planar shock wave with a two- or three-dimensional random isotropic density field.

We present an analytical linear model describing the interaction of a planar shock wave with an isotropic random pattern of density nonuniformities. This kind of interaction is important in inertial confinement fusion where shocks travel into weakly inhomogeneous cryogenic deuterium-wicked foams, and also in astrophysics, where shocks interact with interstellar density clumps. The model presented here is based on the exact theory of space and time evolution of the perturbed quantities generated by a corrugated shock wave traveling into a small-amplitude single-mode density field. Corresponding averages in both two and three dimensions are obtained as closed analytical expressions for the turbulent kinetic energy, acoustic energy flux, density amplification, and vorticity generation downstream. They are given as explicit functions of the two parameters (adiabatic exponent γ and shock strength M(1)) that govern the dynamics of the problem. In addition, these explicit formulas are simplified in the important asymptotic limits of weak and strong shocks and highly compressible fluids.

Standing adult human phantoms based on 10th, 50th and 90th mass and height percentiles of male and female Caucasian populations.

Computational anthropomorphic human phantoms are useful tools developed for the calculation of absorbed or equivalent dose to radiosensitive organs and tissues of the human body. The problem is, however, that, strictly speaking, the results can be applied only to a person who has the same anatomy as the phantom, while for a person with different body mass and/or standing height the data could be wrong. In order to improve this situation for many areas in radiological protection, this study developed 18 anthropometric standing adult human phantoms, nine models per gender, as a function of the 10th, 50th and 90th mass and height percentiles of Caucasian populations. The anthropometric target parameters for body mass, standing height and other body measures were extracted from PeopleSize, a well-known software package used in the area of ergonomics. The phantoms were developed based on the assumption of a constant body-mass index for a given mass percentile and for different heights. For a given height, increase or decrease of body mass was considered to reflect mainly the change of subcutaneous adipose tissue mass, i.e. that organ masses were not changed. Organ mass scaling as a function of height was based on information extracted from autopsy data. The methods used here were compared with those used in other studies, anatomically as well as dosimetrically. For external exposure, the results show that equivalent dose decreases with increasing body mass for organs and tissues located below the subcutaneous adipose tissue layer, such as liver, colon, stomach, etc, while for organs located at the surface, such as breasts, testes and skin, the equivalent dose increases or remains constant with increasing body mass due to weak attenuation and more scatter radiation caused by the increasing adipose tissue mass. Changes of standing height have little influence on the equivalent dose to organs and tissues from external exposure. Specific absorbed fractions (SAFs) have also been calculated with the 18 anthropometric phantoms. The results show that SAFs decrease with increasing height and increase with increasing body mass. The calculated data suggest that changes of the body mass may have a significant effect on equivalent doses, primarily for external exposure to organs and tissue located below the adipose tissue layer, while for superficial organs, for changes of height and for internal exposures the effects on equivalent dose are small to moderate.

Electron absorbed fractions of energy and S-values in an adult human skeleton based on µCT images of trabecular bone.

When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on µCT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 µm thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters (14)C, (59)Fe, (131)I, (89)Sr, (32)P and (90)Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 µm endosteum and the previously recommended 10 µm endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by ∼20% when the beta emitters are in marrow.

Leishmania amazonensis: partial purification and study of the biochemical properties of the telomerase reverse transcriptase activity from promastigote-stage.

Telomeres are protein-DNA complexes that protect chromosome ends from degradation and fusion. In Leishmania spp., telomeric DNA comprises a conserved TTAGGG repeat and is maintained by telomerase. Telomerase is a multisubunit enzymatic complex that ensures the complete DNA replication by adding new telomeric repeats to the G-rich strand. In this report we aimed to purify and study the biochemical properties of Leishmania amazonensis telomerase. In a first trial we used affinity chromatography with antisense 2'-O-methyl oligonucleotide without success since the Leishmania telomerase, similarly to Trypanosoma cruzi enzyme, was not eluted by competition, but instead, it remained bound to the column. Partially purified L. amazonensis telomerase activity was achieved by fractionation of extracts on complementary ion exchange and Heparin columns. Further purification of these fractions on a G-rich telomeric DNA affinity chromatography enriched for telomerase activity. The knowledge of telomerase characteristics in Leishmania could help to develop new strategies to overcome leishmaniasis.