Problemas cuantitativos y comprensión de conceptos

Los docentes de química a nivel universitario usamos «problemas», habitualmente de tipo cuantitativo, para enseñar y para evaluar. En este trabajo ponemos en duda de que lo hagamos en forma eficaz. Se muestra, a partir de pruebas diagnósticas de pares de problemas (uno cuantitativo y otro cualitativo similar), que muchos estudiantes pueden resolver los problemas cuantitativos sin una adecuada comprensión conceptual.Chemistry professors at university level make use of «problems», usually of a quantitative type, to teach and evaluate. In this article we question the fact of whether they do it in an efficient way. From diagnostic test of pairs of problems (a quantitative and a similar qualitative one) it is shown that many students can solve quantitative problems without an appropriate conceptual comprehension

A defect-in-continuity in the canine femur: and in-vivo experimental model for the study of bone graft incorporation.

The in-vivo study of bone graft incorporation has traditionally used a segmental diaphyseal bone defect. This model reliably produces a nonunion, but is complicated by graft instability and altered limb loading stresses. The authors discuss the advantages of a defect-in-continuity canine femur model which produces a more consistent union with fewer mechanical complications despite the absence of fixation. This proposed model permits analysis of radiographic, histologic and biomechanical data which are more applicable to the usual clinical setting in which bone graft is required

Dementia caregiving in spousal relationships: a dyadic perspective

Objectives: The number of couples facing a dementia diagnosis for one partner of the spousal dyad increases. Spousal caregiving can be a highly stressful experience associated with negative caregiver outcomes such as depression and poorer immune function. However, surprisingly little is known about how the illness and the required care effects patient’s well-being and relational changes experienced by afflicted couples. The aim of this study was to provide a literature review on how the dyadic perspective is taken into account and on how dementia effects both parts of the dyad. Methods: In order to outline findings about individual and dyadic well-being of affected couples, we conducted a literature search to review the three types of studies. First, studies focusing on one partner’s perspective, usually the perspective of the caregiver; second, studies including the caregiver’s and partially the care receiver’s view; third, studies directly referring to both partners’ perspectives. Results: The majority of studies neglect the individual with dementia by exclusively assessing caregiver variables or only indirectly including patients’ characteristics. Very few studies embrace dyadic and relational variables to execute how both partners experience the illness, spousal caregiving, and changes in the relationship. Despite the arguable validity of self reports of individuals with dementia, some studies demonstrated the usefulness of including both partners’ perspectives. Discussion: Results indicate the urgent need of integrating the perspective of the individual with dementia to improve the understanding of the effects of dementia caregiving

An analysis of the most distant catalogued open clusters -- Re-assessing fundamental parameters with Gaia EDR3 and ASteCA\texttt{ASteCA}

Several studies have been presented in the last few years applying some kind of automatic processing of data to estimate the fundamental parameters of open clusters. These parameters are later on employed in larger scale analyses, for example the structure of the Galaxy's spiral arms. The distance is one of the more straightforward parameters to estimate, yet enormous differences can still be found among published data. This is particularly true for open clusters located more than a few kpc away. We cross-matched several published catalogues and selected the twenty-five most distant open clusters ($>$9000 pc). We then performed a detailed analysis of their fundamental parameters, with emphasis on their distances, to determine the agreement between catalogues and our estimates.} Photometric and astrometric data from the Gaia EDR3 survey was employed. The data was processed with our own membership analysis code (pyUPMASK), and our package for automatic fundamental cluster's parameters estimation ($\texttt{ASteCA}$). We find differences in the estimated distances of up to several kpc between our results and those catalogued, even for the catalogues that show the best matches with $\texttt{ASteCA}$ values. Large differences are also found for the age estimates. As a by-product of the analysis we find that vd Bergh-Hagen 176 could be the open cluster with the largest heliocentric distance catalogued to date. Caution is thus strongly recommended when using catalogued parameters of open clusters to infer large-scale properties of the Galaxy, particularly for those located more than a few kpc away.Comment: Accepted for publication in A&

Etoposide and adriamycin containing combination chemotherapy (HOPE-Bleo) for relapsed Hodgkin's disease.

Forty-four patients with relapsed or resistant Hodgkin's disease were treated with adriamycin 40 mg m-2 i.v. on day 1, vincristine 1.4 mg m-2 i.v. on days 1 and 8, prednisolone 40 mg m-2 orally daily for 8 days, etoposide 200 mg m-2 orally daily for 4 days according to the nadir white cell count, and bleomycin 10 mg m-2 i.v. days 1 and 8 (HOPE-Bleo). Median age was 27 (range 12-71). When stage was considered according to all sites currently or previously involved by Hodgkin's disease (cumulative stage) 26 patients (59%) had stage IV, 13 (29%) stage III and five (11%) stage II disease; 33 (75%) had B symptoms. All patients had received previous chemotherapy and 18 (41%) had received two or more regimens. Twenty-six patients (59%) achieved CR and 10 (23%) PR; the median duration of CR was 22 months and median survival for all patients was 48 months. Eight patients remain in continuous CR; none of these had received extensive previous chemotherapy. Among the 19 patients who had relapsed from CR achieved by a single previous chemotherapy regimen, six (32%) achieved long CR on HOPE-Bleo. The regimen was generally well tolerated but the principal toxicity was myelosuppression. There were two toxic deaths, one due to neutropenic sepsis and the other due to acute peritonitis. The HOPE-Bleo regimen is an effective treatment for relapsed or resistant Hodgkin's disease, with a low probability of carcinogenesis and infertility. These factors suggest that HOPE-Bleo deserves further evaluation as primary treatment for Hodgkin's disease and very careful selection of relapsed patients for high dose salvage chemotherapy with bone marrow transplants must be exercised

Cribriform Morular Thyroid Carcinoma - Ultimobranchial Pouch-Related? Deep Molecular Insights of a Unique Case.

A 44-year-old female patient with a familial adenomatous polyposis (FAP) was diagnosed with a cribriform morular thyroid carcinoma (CMTC). We observed within the very necrotic tumor a small but distinct poorly differentiated carcinomatous component. As expected, next generation sequencing of both components revealed a homozygous APC mutation and in addition, a TERT promoter mutation. A TP53 mutation was found exclusively in the CMTC part, while the poorly differentiated component showed a clonal evolution, harboring an activating PIK3CA mutation and copy number gains of BRCA2, FGF23, FGFR1, and PIK3CB-alterations which are typically seen in squamous cell carcinoma. The mutational burden in both components was low, and there was no evidence for microsatellite instability. No mutations involving the mitogen-activated protein kinase (MAPK) pathway, typically seen in papillary thyroid carcinomas, were detected. Immunohistochemically, all tumor parts were negative for thyroglobulin, providing further evidence that this entity does not belong to the follicular epithelial cell-derived thyroid carcinoma group. CD5 was negative in the poorly differentiated component, making a relation to intrathyroidal thymic carcinoma rather unlikely. However, since this marker was seen in the morules, a loss in the poorly differentiated component and a relation to the ultimobranchial body cannot be excluded either. After total thyroidectomy and radioiodine ablation, the patient was disease-free with no residual tumor burden on 2-year follow-up