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Rib internal anatomy and its cross-sectional morphology inform about important biomechanical or even evolutionary aspects. Classic histological studies require destructive techniques that are reprehensible depending on the case (e.g., fossils). In the last years, non-destructive CT-based methods are contributing to complementing previous knowledge without damaging the bone. Even though these methods have been proved to be useful to understand adult variation, we do not know whether these methods are useful to cover ontogenetic variation. This work compares classical histological methods with medical- and micro-CT to quantify the amount of mineral area at the rib midshaft (% Min. Ar.), a proxy for bone density. We compared cross-sections from an ontogenetic sample of 14 human first ribs ranging from perinates to adults using a) classical histology, b) HD (9–17 microns) and SD micro-CT (90 microns), and c) standard medical-CT (0.66 mm). We found that all the CT-based methods provide a larger % Min. Ar. compared to the histological techniques, but the HD micro-CT resolution is the only capable of producing results comparable to classical histology (p > 0.01), with the SD micro-CT and the medical-CT producing statistically larger results compared to classical histology (p < 0.01). In addition, it is important to state that the resolution of a standard medical-CT is not high enough to differentiate between mineral and non-mineral areas of the cross-sections for perinates and infants. These results could have important implications to avoid (when necessary) destructive techniques that are not appropriate in the case of highly valuable specimens such as fossils.

Background and Aims Due to COVID-19 pandemic we must continue attending in our hospital consultations and, at the same time, avoid transfers and visit that involve risks to our patients. For this reason, we implemented new forms of care. Mainly electronic consultation (eConsult) using institutional email as way of contact between Primary Care Providers (PCPs) and nephrologist, trying to decrease in-person visit. Objective To analyze the results of the creation in June 2020 of a Nephrology electronic consultation in our hospital. Method Retrospective observational study of eConsults made to our department, which serves a population of 200.000 people, with total of 9 primary care centers. The study period was June 10, 2020 to December 31, 2020. We have studied the number of eConsults, response time, type of consult made, problem resolution and subsequent follow up. Results Of 141 workdays, in 61 days (43%) there was eConsult, total 80 eConsults, mean 1.3 and median 1 daily (range 1 to 3). All primary care centers used this communication way, as well as 50 PCPs. Median response time for eConsult was 1 day (range 1-4). 55% patient was male, mean age 70.8 years (SD 13.9) (range 16-95 years). 64% it was his first assessment for Nephrology. The most frequent causes of eConsult: increase of creatinine (41.3%), uncontrolled blood pressure (12.5%), sodium and potassium disturbances (11.3%), treatment adjustment (11.3%) and changes in previous appointment (8.8%). After assessment eConsult, to 55% of patients was treatment adjustment, 22.5% were converted to an in-person visit, 11% they didn´t need any action but only 1 patient was referred to the emergency room. 44% patient is subsequent follow up by PCPs, 39% by nephrologist, 15% joint assessment PCP and nephrologist and 2% by other specialists. Only 2 patients (2.5%) made second eConsult. Conclusion The eConsult is an important help to PCPs to solve doubts quickly, avoid unnecessary the travels to hospital the patients, treatment adjustment above all in control of hypertension an ionic disturbance, and guide in handling of chronic kidney disease. The diffusion and empowerment of this type of consultation in a next future may decrease, partly, the usual saturation of face-to-face visit and optimize the patient population being seen by nephrologist.

19 páginas, 4 figuras, 2 tablas, 4 esquemas., The dipolar cycloaddition of (Z)-N-benzyl-(3-O-benzyl-1,2-O-isopropylidene-α-d-ribofuranos-5-ylidene)amine N-oxide to methyl acrylate gives a 53:16:26:5 diastereomeric mixture of isoxazolidine derivatives. The dipolar cycloaddition of the xylo analogue to methyl acrylate is more diastereoselective, producing a 44:13:43 mixture of only three diastereomers. The ribo-configured adducts have been converted (4 steps only) into the new (2R,6S,7S,8R,8aR)-, (2S,6S,7S,8R,8aR)-, (2S,6S,7S,8R,8aS)- and (2R,6S,7S,8R,8aS)-2,6,7,8-tetrahydroxyindolizidines. Similarly, the two xylo-configured major isoxazolidine derivatives were converted into the known derivatives (2R,6S,7R,8R,8aS)- and (2S,6S,7R,8R,8aR)-2,6,7,8-tetrahydroxyindolizidines. The six isomeric indolizidine derivatives obtained have been evaluated for their inhibiting activities towards 15 glycosidases. Only the (2R,6S,7S,8R,8aR)-configured isomer is a selective inhibitor of amyloglucosidases from Aspergillus niger (IC50 = 350 μM) and from Rhizopus mold (IC50 = 90 μM, Ki = 195 μM, non-competitive), the other indolizidines show very little inhibitory activity at 1 mM concentration., We thank the ‘Dirección General de Investigación, Ministerio de Ciencia y Tecnología’ of Spain (Grant No. BQU2000-1155), the ‘Dirección General de Universidades e Investigación, Consejería de Educación y Ciencia’ of Andalusia (FQM 142) and the Swiss Federal Science Foundation for financial support. We also thank Miss Catherine Schuetz for her technical assistance.