On the global time evolution of the Covid-19 pandemic: Logistic modeling.

In this article it is presented a multi-logistic model to describe the time evolution of the Covid-19 pandemics. The model is not intended as paragon for the accurate prediction of the future number of people infected, but instead as a useful phenomenological approach for a comprehensive understanding of the pandemic development, able to uncover some hidden aspects of its unfolding. Our results, using OWID data of total cases and daily cases of Covid-19 from March 12, 2020, up to September 27, 2021, brought to light that the pandemic has unfolded globally as a multi-step logistic, namely six logistic phases, each with its own characteristic duration and intensity. Moreover, it is demonstrated how differently the pandemics spread among different countries and continents. The methodology is tested regarding its ability of forecasting, and is demonstrated that it works well in the range of circa 30 days within a margin of less than 3% error while a given phase is still in development. The case study of Portugal demonstrates the benefit of preventive sanitary measures, as well as shows how disastrous it may be the absence of such measures due to hesitations and/or political positions. Completing the article, a qualitative analysis is presented to scrutinize the possible causes of the asymmetry observed in the diffusion of Covid-19 among the different continents and countries.

Endothelium-dependent and -independent hepatic artery vasodilatation is not impaired in a canine model of liver ischemia-reperfusion injury.

We investigated whether hepatic artery endothelium may be the earliest site of injury consequent to liver ischemia and reperfusion. Twenty-four heartworm-free mongrel dogs of either sex exposed to liver ischemia/reperfusion in vivo were randomized into four experimental groups (N = 6): a) control, sham-operated dogs, b) dogs subjected to 60 min of ischemia, c) dogs subjected to 30 min of ischemia and 60 min of reperfusion, and d) animals subjected to 45 min of ischemia and 120 min of reperfusion. The nitric oxide endothelium-dependent relaxation of hepatic artery rings contracted with prostaglandin F2a and exposed to increasing concentrations of acetylcholine, calcium ionophore A23187, sodium fluoride, phospholipase-C, poly-L-arginine, isoproterenol, and sodium nitroprusside was evaluated in organ-chamber experiments. Lipid peroxidation was estimated by malondialdehyde activity in liver tissue samples and by blood lactic dehydrogenase (LDH), serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) activities. No changes were observed in hepatic artery relaxation for any agonist tested. The group subjected to 45 min of ischemia and 120 min of reperfusion presented marked increases of serum aminotransferases (ALT = 2989 +/- 1056 U/L and AST = 1268 +/- 371 U/L; P < 0.01), LDH = 2887 +/- 1213 IU/L; P < 0.01) and malondialdehyde in liver samples (0.360 +/- 0.020 nmol/mgPT; P < 0.05). Under the experimental conditions utilized, no abnormal changes in hepatic arterial vasoreactivity were observed: endothelium-dependent and independent hepatic artery vasodilation were not impaired in this canine model of ischemia/reperfusion injury. In contrast to other vital organs and in the ischemia/reperfusion injury environment, dysfunction of the main artery endothelium is not the first site of reperfusion injury.

Endothelium-dependent and -independent hepatic artery vasodilatation is not impaired in a canine model of liver ischemia-reperfusion injury

We investigated whether hepatic artery endothelium may be the earliest site of injury consequent to liver ischemia and reperfusion. Twenty-four heartworm-free mongrel dogs of either sex exposed to liver ischemia/reperfusion in vivo were randomized into four experimental groups (N = 6): a) control, sham-operated dogs, b) dogs subjected to 60 min of ischemia, c) dogs subjected to 30 min of ischemia and 60 min of reperfusion, and d) animals subjected to 45 min of ischemia and 120 min of reperfusion. The nitric oxide endothelium-dependent relaxation of hepatic artery rings contracted with prostaglandin F2a and exposed to increasing concentrations of acetylcholine, calcium ionophore A23187, sodium fluoride, phospholipase-C, poly-L-arginine, isoproterenol, and sodium nitroprusside was evaluated in organ-chamber experiments. Lipid peroxidation was estimated by malondialdehyde activity in liver tissue samples and by blood lactic dehydrogenase (LDH), serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) activities. No changes were observed in hepatic artery relaxation for any agonist tested. The group subjected to 45 min of ischemia and 120 min of reperfusion presented marked increases of serum aminotransferases (ALT = 2989 ± 1056 U/L and AST = 1268 ± 371 U/L; P < 0.01), LDH = 2887 ± 1213 IU/L; P < 0.01) and malondialdehyde in liver samples (0.360 ± 0.020 nmol/mgPT; P < 0.05). Under the experimental conditions utilized, no abnormal changes in hepatic arterial vasoreactivity were observed: endothelium-dependent and independent hepatic artery vasodilation were not impaired in this canine model of ischemia/reperfusion injury. In contrast to other vital organs and in the ischemia/reperfusion injury environment, dysfunction of the main artery endothelium is not the first site of reperfusion injury.

Bone mineral density in familial amyloid polyneuropathy and in other neuromuscular disorders.

Neuromuscular diseases are a known risk factor for immobilization-induced osteoporosis. The aim of the study was to analyse bone mineral density (BMD) in patients with familial amyloid polyneuropathy (FAP) type I (Val30 Met) and to compare them with a population of patients with other neuromuscular disorders. We studied 24, ambulatory, neuromuscular patients, all men and premenopausal women. We included 12 FAP patients (GI) and 12 patients with other disorders (GII). Clinical data included age, sex, height, weight, alcohol intake, smoking, calcium intake, physical activity and history of fractures. Serum and urinary calcium, osteocalcin, bone alkaline phosphatase, parathyroid hormone, thyroid stimulating hormone and urinary N-telopeptide cross-linked type 1 collagen were determined in all patients. Bone mineral density of lumbar spine, hip and wrist were determined by dual energy X-ray absorptiometry scan. No statistical differences were found in clinical or analytic data between the two groups, except for body mass index and calciuria, which were lower in GI. In GI, 54.5% were osteoporotic, against 23.1% in GII (P = 0.04). Bone mineral density was lower in GI when compared with GII, and tended to decrease with disease duration. Decreased BMI and the early autonomic involvement in GI probably explain the results. The prevention and early treatment of osteoporosis, in FAP patients should be considered a priority.

[Nutritional evaluation of protein quality of cassava leaf combined with casein by plastein reaction]. / Avaliação da qualidade nutricional da proteína da folha de mandioca combinada com a caseína pela reação de plasteína.

The present work was conducted to obtain a proteic product and to evaluate its biological value in order to be used for human and/or domestic animal consumption. Thus, it were used cassava leaves as a non conventional source of protein. It was produced a freeze-dried, fat-free and colourless proteic isolated from those leaves (CLPI). This was mixed with casein and after the mixture as enzymatically hydrolyzed and resynthesized (Plastein reaction) to obtain a precipitated (PP) and a soluble plastein (SP) fractions. The protein contents observed were 64.39% (PS), 61.36% (PP) and 51.97% (CLPI). Trypsin inhibitor activities values showed a 41% reduction in the PP fraction suggesting that the heat treatment used to inactivated the enzyme also inactiveted partially the inhibitor or the reduction was due to the casein dilution. The amino acid composition of the frations obtained showed values close to the standards established. It can be concluded:--the utilization of non-conventional source should be stimulated when the proteins from those sources have an amino acidic profile that allow them to be used as an amino acid supplementation in food with low level of essential amino acids;--the fractions obtained by the plastein reaction showed satisfactory protein contents and their amino acid profiles were comparable with the FAO/OMS/UNU (1985) recommendations;--the plastein reaction can be utilized in food processing, after industrial scale adaptation remove compounds responsible to bitter taste, fetidness and to discolour protein products.

Vascularizacao das paredes intestinais subsequentes aos diversos tipos de sutura. Estudo experimental em caes. / Vascularization of the intestinal walls subsequent to the suture types. Experimental study in dogs

Em trabalho experimental os autores estudam a vascularizacao dos tecidos envolvidos em anastomoses intestinais realizadas em dois planos de sutura, variando os tipos de sutura do primeiro plano (pontos simples, pontos em U e sutura continua em guarda grega) e anastomoses em plano unico extramucoso. Os resultados encontrados levaram-nos a deduzir que os diversos tipos de sutura seromuscular nao interferem significativamente na vascularizacao das anastomoses, o mesmo nao ocorrendo em relacao a sutura em plano total. Em termos comparativos, as anastomoses em plano unico extramucoso mostraram vascularizacao significativamente melhor que as anastomoses em dois planos

Theory of the photoacoustic effect in semiconductors influence of carrier diffusion and recombination.

A quantitative derivation is presented for the production of the photoacoustic signal in semiconductors, taking into account finite carrier diffusion and recombination times in the solid.

Photoacoustic effect in solids: influence of heat loss.

The effects of taking into account the heat loss on the production of the photoacoustic signal are presented. A comparison with the previous results is also made.

[Influence of lactose rate on calcium fixation in bones. Study in rats]. / Influência da taxa de lactose na fixação óssea do cálcio.--Estudo em ratos.

This investigation was performed to study the effect of lactose on the fixation of calcium in bones of rats. Lactose 3% and 10% concentration was used and the action was compared to that obtained by 67 U.I. of vitamin D in 100 g diet. The data obtained indicated very definitely that the presence of lactose in the diet favorably influences the fixation of Ca in bone, when the amount is 10%; at 3% concentration lactose don't seem influence Ca fixation in bone.