282 research outputs found

    Thermal analysis applied to estimation of solidification kinetics of Al–Si aluminium alloys

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    Evaluation of solidification kinetics by thermal analysis is a useful tool for quality control of Al–Si melts before pouring provided it is rapid and highly reproducible. Series of thermal analysis records made with standard cups are presented that show good reproducibility. They are evaluated using a Newton’s like approach to get the instantaneous heat evolution and from it solidification kinetics. An alternative way of calculating the zero line is proposed which is validated by the fact that the latent heat of solidification thus evaluated is within 5% of the value calculated from thermodynamic data. Solidification kinetics was found highly reproducible provided appropriate experimental conditions were achieved: high enough casting temperature for the cup to heat up to the metal temperature well before solidification starts; and equal and homogeneous temperatures of the metal and of the cup at any time in the temperature range used for integration

    The false memory syndrome: Experimental studies and comparison to confabulations

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    a b s t r a c t False memories, or recollections that are factually incorrect but strongly believed, remain a source of confusion for both psychiatrists and neurologists. We propose model for false memories based on recent experimental investigations, particularly when analyzed in comparison to confabulations, which are the equivalent of false memories from neurological disease. Studies using the Deese/Roedinger-McDermott experimental paradigm indicate that false memories are associated with the need for complete and integrated memories, self-relevancy, imagination and wish fulfillment, familiarity, emotional facilitation, suggestibility, and sexual content. In comparison, confabulations are associated with the same factors except for emotional facilitation, suggestibility, and sexual content. Both false memories and confabulations have an abnormal sense of certainty for their recollections, and neuroanatomical findings implicate decreased activity in the ventromedial frontal lobe in this certainty. In summary, recent studies of false memories in comparison to confabulations support a model of false memories as internally-generated but suggestible and emotionally-facilitated fantasies or impulses, rather than repressed memories of real events. Furthermore, like confabulations, in order for false memories to occur there must be an attenuation of the normal, nonconscious, right frontal ''doubt tag'' regarding their certainty. Published by Elsevier Ltd

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    Pancreatic cancer and depression: myth and truth

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    <p>Abstract</p> <p>Background</p> <p>Various studies reported remarkable high incidence rates of depression in cancer patients compared with the general population. Pancreatic cancer is still one of the malignancies with the worst prognosis and therefore it seems quite logical that it is one of the malignancies with the highest incidence rates of major depression.</p> <p>However, what about the scientific background of this relationship? Is depression in patients suffering from pancreatic cancer just due to the confrontation with a life threatening disease and its somatic symptoms or is depression in this particular group of patients a feature of pancreatic cancer per se?</p> <p>Discussion</p> <p>Several studies provide evidence of depression to precede the diagnosis of pancreatic cancer and some studies even blame it for its detrimental influence on survival. The immense impact of emotional distress on quality of life of cancer patients enhances the need for its early diagnosis and adequate treatment. Knowledge about underlying pathophysiological mechanisms is required to provide the optimal therapy.</p> <p>Summary</p> <p>A review of the literature on this issue should reveal which are the facts and what is myth.</p

    2024 Recommendations on the Optimal Use of Lipid-Lowering Therapy in Established Atherosclerotic Cardiovascular Disease and Following Acute Coronary Syndromes: A Position Paper of the International Lipid Expert Panel (ILEP)

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    Atherosclerotic cardiovascular disease (ASCVD) and consequent acute coronary syndromes (ACS) are substantial contributors to morbidity and mortality across Europe. Fortunately, as much as two thirds of this disease’s burden is modifiable, in particular by lipid-lowering therapy (LLT). Current guidelines are based on the sound premise that, with respect to low-density lipoprotein cholesterol (LDL-C), “lower is better for longer”, and recent data have strongly emphasised the need for also “the earlier the better”. In addition to statins, which have been available for several decades, ezetimibe, bempedoic acid (also as fixed dose combinations), and modulators of proprotein convertase subtilisin/kexin type 9 (PCSK9 inhibitors and inclisiran) are additionally very effective approaches to LLT, especially for those at very high and extremely high cardiovascular risk. In real life, however, clinical practice goals are still not met in a substantial proportion of patients (even in 70%). However, with the options we have available, we should render lipid disorders a rare disease. In April 2021, the International Lipid Expert Panel (ILEP) published its first position paper on the optimal use of LLT in post-ACS patients, which complemented the existing guidelines on the management of lipids in patients following ACS, which defined a group of “extremely high-risk” individuals and outlined scenarios where upfront combination therapy should be considered to improve access and adherence to LLT and, consequently, the therapy’s effectiveness. These updated recommendations build on the previous work, considering developments in the evidential underpinning of combination LLT, ongoing education on the role of lipid disorder therapy, and changes in the availability of lipid-lowering drugs. Our aim is to provide a guide to address this unmet clinical need, to provide clear practical advice, whilst acknowledging the need for patient-centred care, and accounting for often large differences in the availability of LLTs between countries

    Radiographic Outcomes and Subsidence Rate in Hyperlordotic Versus Standard Lordotic Interbody Spacers in Patients Undergoing Anterior Cervical Discectomy and Fusion

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    Background: Anterior cervical discectomy and fusion (ACDF) is a common surgery for patients with degenerative cervical disease and current interbody spacers utilized vary based on material composition, structure, and angle of lordosis. Currently, there is a lack of literature comparing subsidence rates or long-term radiographic outcomes with hyperlordotic and standard lordotic spacers. This study compares long-term radiographic outcomes, subsidence rate, and rate of fusion in patients who underwent ACDF with hyperlordotic or standard interbody placement. Materials and Methods: Patients who underwent 1-3-level ACDF with either a standard lordosis or hyperlordotic interbody were included. Standard radiographs were evaluated for C2-7 lordosis (CL), sagittal vertical axis, C2 slope (C2S), T1 slope (T1S), subsidence rate, and fusion. Results: Forty-five patients underwent ACDF with hyperlordotic interbody placement and after a 1:1 propensity match with standard lordotic patients, 90 patients were included. 1-year postoperative radiographs demonstrated the hyperlordotic cohort achieved higher CL (15.3° ± 10.6° vs. 9.58° ± 8.88°; P = 0.007). The change in CL (8.42° ± 9.42° vs. 0.94° ± 8.67°; P \u3c 0.001), change in C2S (-4.02° ± 6.68° vs. -1.11° ± 5.42°; P = 0.026), and change in T1S (3.49° ± 7.30° vs. 0.04° ± 6.86°, P = 0.008) between pre- and postoperative imaging were larger in the hyperlordotic cohort. There was no difference in overall subsidence (P = 0.183) and rate of fusion (P = 0.353) between the cohorts. Conclusion: Hyperlordotic spacer placement in ACDF can provide increased CL compared to standard lordosis spacers, which can be considered for patients requiring restoration or maintenance of CL following ACDF

    Pancreatic carcinoma

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44375/1/10620_2005_Article_BF02235997.pd

    The impact of type of dietary protein, animal versus vegetable, in modifying cardiometabolic risk factors: A position paper from the International Lipid Expert Panel (ILEP)

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    Proteins play a crucial role in metabolism, in maintaining fluid and acid-base balance and antibody synthesis. Dietary proteins are important nutrients and are classified into: 1) animal proteins (meat, fish, poultry, eggs and dairy), and, 2) plant proteins (legumes, nuts and soy). Dietary modification is one of the most important lifestyle changes that has been shown to significantly decrease the risk of cardiovascular (CV) disease (CVD) by attenuating related risk factors. The CVD burden is reduced by optimum diet through replacement of unprocessed meat with low saturated fat, animal proteins and plant proteins. In view of the available evidence, it has become acceptable to emphasize the role of optimum nutrition to maintain arterial and CV health. Such healthy diets are thought to increase satiety, facilitate weight loss, and improve CV risk. Different studies have compared the benefits of omnivorous and vegetarian diets. Animal protein related risk has been suggested to be greater with red or processed meat over and above poultry, fish and nuts, which carry a lower risk for CVD. In contrast, others have shown no association of red meat intake with CVD. The aim of this expert opinion recommendation was to elucidate the different impact of animal vs vegetable protein on modifying cardiometabolic risk factors. Many observational and interventional studies confirmed that increasing protein intake, especially plant-based proteins and certain animal-based proteins (poultry, fish, unprocessed red meat low in saturated fats and low-fat dairy products) have a positive effect in modifying cardiometabolic risk factors. Red meat intake correlates with increased CVD risk, mainly because of its non-protein ingredients (saturated fats). However, the way red meat is cooked and preserved matters. Thus, it is recommended to substitute red meat with poultry or fish in order to lower CVD risk. Specific amino acids have favourable results in modifying major risk factors for CVD, such as hypertension. Apart from meat, other animal-source proteins, like those found in dairy products (especially whey protein) are inversely correlated to hypertension, obesity and insulin resistance
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