Kinetics of Thermal Decomposition of Particulate Samples of MgCO3: Experiments and Models

In this work, we study the kinetics of thermal decomposition of MgCO3 in the form of particles of known size. In the experiments, the material is heated to a known temperature in a vacuum oven, and it is characterized, both before and after heating, by infrared spectroscopy and gravimetry. The agreement between the results of the two techniques is excellent. These results are rationalized by means of a model based on Languir's law, and the comparison with the experiments allows us to estimate the activation energy of the process. The reabsorption of atmospheric water by the oxide is shown spectroscopically, finding that is strongly influenced by the temperature of the process

Síndrome de Gorlin-Goltz - Relato de Dois Casos

Gorlin-Goltz syndrome is a rare autosomal dominant disorder caused by mutation in the gene PTCH1 (patched homolog 1 (Drosophila)), a tumor suppressor gene. The classic triad described by Gorlin and Goltz in 1960 is composed of multiple basal cell carcinomas, odontogenic keratocysts and bifid ribs, but many other changes may be present, such as palmoplantar pits, calcification of the falx cerebri, rare tumours such as medulloblastoma, congenital malformations, macrocephaly and various skeletal changes. Diagnosis is based on clinical, radiological and presence of first-degree relative with the syndrome. We describe two cases that illustrate the need for a rigorous clinical examination, radiological investigation and multidisciplinary follow-up after clinical suspicion, because life expectancy is not usually affected, but the potential morbidity can be considerable.A síndrome de Gorlin-Goltz é uma rara desordem hereditária autossômica dominante, causada pela mutação no gene PTCH1 (patched homolog 1 da Drosophila), um gene supressor tumoral. A tríade clássica descrita por Gorlin e Goltz em 1960 é composta por múltiplos carcinomas basocelulares, queratocistos odontogénicos e costela bífida, porém várias outras alterações podem estar presentes, como depressões palmoplantares, calcificações da foice cerebral, neoplasias raras como o meduloblastoma, malformações congénitas, macrocefalia e diversas alterações esqueléticas. O diagnóstico é baseado em critérios clínicos, radiológicos e presença de parente de primeiro grau com a síndrome. Relatamos dois casos que ilustram a necessidade de exame clínico rigoroso, investigação radiológica e acompanhamento multidisciplinar após a suspeita clínica, já que a expectativa de vida geralmente não é afetada, porém o potencial de morbidade pode ser considerável

CUBES : the Cassegrain U-band Efficient Spectrograph

In the era of Extremely Large Telescopes, the current generation of 8-10m facilities are likely to remain competitive at ground-UV wavelengths for the foreseeable future. The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high-efficiency (> 40%) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R >20, 000 (with a lower-resolution, sky-limited mode of R ~7, 000). With the design focusing on maximizing the instrument throughput (ensuring a Signal to Noise Ratio (SNR) ~20 per high-resolution element at 313 nm for U ~18.5 mag objects in 1h of observations), it will offer new possibilities in many fields of astrophysics, providing access to key lines of stellar spectra: a tremendous diversity of iron-peak and heavy elements, lighter elements (in particular Beryllium) and light-element molecules (CO, CN, OH), as well as Balmer lines and the Balmer jump (particularly important for young stellar objects). The UV range is also critical in extragalactic studies: the circumgalactic medium of distant galaxies, the contribution of different types of sources to the cosmic UV background, the measurement of H2 and primordial Deuterium in a regime of relatively transparent intergalactic medium, and follow-up of explosive transients. The CUBES project completed a Phase A conceptual design in June 2021 and has now entered the detailed design and construction phase. First science operations are planned for 2028

Acral Myxoinflammatory Fibroblastic Sarcoma: Report of a Case and Treatment with Mohs Micrographic Surgery

Acral myxoinflammatory fibroblastic sarcoma (AMFS) represents a low-grade sarcoma with a high rate of local recurrence that commonly affects the distal extremities. The lesion often presents as a painless mass in the hands or feet. There is no formal standardized treatment protocol for this tumor, but wide surgical excision, with or without adjuvant radiation therapy, is the conventional treatment. We report a case of a patient with an AMFS treated with Mohs micrographic surgery (MMS) without recurrence. Because of the propensity of this tumor to involve acral sites where tissue conservation is important, MMS might be an alternative treatment modality for this rare entity

A simple strategy based on ATR-FTIR difference spectroscopy to monitor substrate intake and metabolite release by growing bacteria

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) difference spectroscopy has been employed for a variety of applications spanning from reaction mechanisms analysis to interface phenomena assessment. This technique is based on the detection of spectral changes induced by the chemical modification of the original sample. In the present study, we highlight the potential of the ATR-FTIR difference approach in the field of microbial biochemistry and biotechnology, reporting on the identification of main soluble species consumed and released by growing bacteria during the biohydrogen production process. Specifically, the mid-infrared spectrum of a model culture broth, composed of glucose, malt extract and yeast extract, was used as background to acquire the FTIR difference spectrum of the same broth as modified by Enterobacter aerogenes metabolism. The analysis of difference signals revealed that only glucose is degraded during hydrogen evolution in anaerobic conditions, while ethanol and 2,3-butanediol are the main soluble metabolites released with H2. This fast and easy analytical approach can therefore represent a sustainable strategy to screen different bacterial strains and to select raw and waste materials to be employed in the field of biofuel production

Update of the Human MitBASE database

Human MitBASE is a database collecting human mtDNA variants. This database is part of a greater mitochondrial genome database (MitBASE) funded within the EU Biotech Program. The present paper reports the recent improvements in data structure, data quality and data quantity. As far as the database structure is concerned it is now fully designed and implemented. Based on the previously described structure some changes have been made to optimise both data input and data quality. Cross-references with other bio-databases (EMBL, OMIM, MEDLINE) have been implemented. Human MitBASE data can be queried with the MitBASE Simple Query System (http://www.ebi.ac.uk/htbin/Mitbase/mit base.pl) and with SRS at the EBI under the 'Mutation' section (http://srs.ebi.ac.uk/srs5/). At present the HumanMitBASE node contains approximately 5000 variants related to studies investigating population polymorphisms and pathologies