2,983 research outputs found
Petrographical and geochemical signatures of the Granja paragneisses (NW CearĂĄ, Brasil)
The Granja Granulitic Complex
(GCC) constitutes a NEâSW
trending high-grade
metamorphic belt occupying the
western sector of the MĂ©dio
CoreaĂș Domain (NW CearĂĄ,
Brasil) (Figs. 1 and 2).
According to the published data,
the GCC represents a segment
of the Paleoproterozoic
basement intensely reworked
during the Brasiliano Orogeny.
Lithologically, the GCC is mainly
composed of garnet-sillimanite
migmatitic paragneisses,
enclosing discontinuous lenses
of mafic granulites and
enderbites.
At outcrop scale, the GCC
gneisses are well-foliated fineto
medium-grained grey rocks
showing a stromatic layering
parallel to the main regional
fabric (Fig. 3). The occurrence of
lenses of leucocratic quartzfeldspathic
material interlayered
with the host paragneisses
indicates that these rocks
reached partial melting
conditions during the Brasiliano
orogenic event (â 600 Ma).
Petrographically, the gneisses
are characterized by the
presence of mineral
assemblages dominated by
garnet, sillimanite and biotite
with moderate amounts of
quartz, plagioclase, cordierite
and K-feldspar (Figs. 4a-b).
Twelve whole-rock samples
were analyzed for major and
trace elements. As shown in
Graph 1, all the analyzed
samples plot in the sedimentary
field. Their REE patterns closely
resemble those of PAAS (PostArchean
average Australian
Shale) confirming the
sedimentary origin of the
paragneiss protoliths (Graph 2).
Geochemical data also suggest
that these sediments derived
from source areas of felsic to
intermediate composition and
were deposited in a tectonically
active continental margin
(Graphs 3 and 4)
School Evasion in the Brazilian trends: analyzing the vectors that influence studentsâ decision to interrupt their formative process
Research data demonstrate that the analyzes built around School Evasion considers, primarily, the quantitative metrics of studentsrsquo; entry and exit and also the monetary losses, especially because it would be incoherent not to take as reference the goals and objectives outlined for education school system. However, analyzing the vectors that influence studentsrsquo; decision to interrupt their formative process, according to purely numerical criteria, would imply in ignoring the function of educational institutions and the real causes/reasons stemming from the social and relational demand of students' passage on educational institutions. For this reason, problematizing some of the recurring issues and incidents generated by certain investigations seems instigating and challenging. If in on the one hand, the attitude of understanding the conceptualization, the investigative tendencies and the characteristics of the studies give rise to certain criticisms that put in check the complexity of the object in question, on the other, it can stimulate the construction of other tendencies, new pathways, other possible ways of overcoming the gaps identified in the studies about School Evasion in Brazil
Portuguese consensus document statement in diagnostic and management of atypical hemolytic uremic syndrome
Among thrombotic microangiopathies (TMA), the hemolytic uremic syndrome associated with dysregulation of the alternative complement pathway (aHUS) is one of the most challenging diseases a nephrologist can face. By the end of the XXth century, the complementâs role was unraveled with the discovery that mutations in the factor H coding gene were responsible for aHUS. But it was the acknowledgment that pharmacological C5-9 blockage provided a cure for aHUS that fostered the interest of the nephrology community in the genetics, pathophysiology and therapeutics of, not only of aHUS, but TMA in general. The molecular genetics of aHUS is technically demanding and, as such, in Portugal (alike many other European countries) a single laboratory emerged as a national reference center. The fact that all samples are evaluated in a single center provides a unique opportunity for data collection and a forum for discussion for all those interested in the field: immunologists, molecular geneticists, pathologists and nephrologists. The current consensus document emerged from such a discussion forum and was sponsored by the Portuguese Society of Nephrology. The goal is more to portray the Portuguese picture regarding the diagnostic approach and therapeutic options than to extensively review the state of the art of the subject. The accompanying documents that are published as supplementary data are in line with that goal. They range from the informed consent and clinical form to be sent together with the biological samples for genetic testing, to the appendix regarding the actual sampling and storing conditions. The document is also intended to set an example for future documents and independente discussion forums on other kidney diseases for which emerging diagnostic and/or therapeutic strategies are reaching clinical practice.info:eu-repo/semantics/publishedVersio
Malignancy risk of thyroid nodules: quality assessment of the thyroid ultrasound report
Background
Thyroid nodules are a challenge in clinical practice and thyroid ultrasonography is essential for assessing the risk of malignancy. The use of ultrasound-based malignancy risk classification systems has been recommended by several scientific societies but radiologistâs adherence to these guidelines may vary. The authors aimed to analyze the quality of the information provided by the thyroid ultrasound report, to assess the malignancy risk of thyroid nodules, in Portugal.
Methods
Multicenter and retrospective study, conducted in three of the five Portuguese NUTS2 corresponding to about 88.3% of the mainland population. We included 344 consecutive unselected participants agedââ„â18 years who underwent thyroid ultrasonography in 2019. The description of six features of the dominant thyroid nodule was analyzed: maximum size, shape, margins, composition, echogenicity and echogenic foci. A utility score, including these six features, was used as an indicator of the reportâs quality. A score of 4 was considered as a minimum value.
Results
Maximum diameter was reported for all nodules. Shape, margins, composition, echogenicity and echogenic foci were reported in 8.1%, 25.0%, 76.5%, 53.2% and 20.9%, respectively. Only 21.8% of the nodules had a scoreââ„â4. At least one of four suspicious features, including marked hypoechogenicity, microcalcifications, irregular margins and non-oval shape, was identified in 8.7% of the nodules. Cervical lymph nodesâ status was reported in 93% of the exams. The risk category was only reported in 7.8% of the participants.
Conclusion
The adherence of Portuguese radiologists to a standardized reporting model and to an ultrasound-based malignancy risk stratification system is still low and has implications for the correct characterization of the malignancy risk of nodules and the decision to perform fine-needle aspiration biopsy
Structural changes in intestinal enteroendocrine cells after ileal interposition in normal rats
INTRODUCTION: No therapeutic approach has significantly impacted the progression of diabetes. As early improvement of glicaemic control is observed after bariatric surgeries, there is currently a search for surgical procedures that can promote euglycemia also in non-obese patients. Glicaemic control can be achieved by increasing the blood concentration of GLP-1, a hormone produced by L cells that are more densely concentrated in the terminal ileum. The interposition of ileal segment to a more anterior region (proximal jejunum) can promote a greater stimulation of the L cells by poorly digested food, increasing the production of GLP-1 and reflecting on glicaemic control.
AIMS: To investigate long-term histological modifications of intestinal mucosa of rats submitted to interposition of ileum segment to a proximal region (jejunum).
METHODS: Forty 8-week old male Wistar-EPM1 rats (Rattus norvegicus albinus) were randomly distributed into 3 groups: the Interposition Group (IG) was subjected to ileal interposition, the Sham Group (SG) was subjected to sham operations, and the Control Group (CG) was not subjected to surgery. All animals were followed until the 60th postoperative day (8 postoperative week) when they were euthanized. Segments of jejunum and ileum from all groups were collected and analyzed by optical microscopy and immunohistochemistry.
RESULTS: No structural nor histological changes in intestinal L cells in the interposed intestinal segment and other intestinal segments were noted after ileal interposition surgery. 
CONCLUSION: As L cells endocrine characteristics were likely maintained, the use of metabolic surgical techniques for the treatment of metabolic diseases, especially diabetes, seems to be justified
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