Suggestions for interdisciplinary teaching in mathematics education: The case of the history of the concept of group

The role of the history of mathematics in mathematics education, as a support in teaching, is widely acknowledged. It can serve to arouse students’ interest in mathematics as well as to stimulate reflection on mathematical concepts and methods. This work focuses on the group as “cross-concept”, in relation to its history from its origins in algebra to its applications in other areas. Given its very nature, the group should be adequately re-evaluated in an interdisciplinary approach, which may prove particularly captivating in linking the history of mathematics to the history of the psychology of perception. This historical interdisciplinary perspective may be useful in the context of university mathematics teaching, particularly teacher training

A Career in Catalysis: Laura Prati

This account celebrates the long and successful scientific career of Laura Prati, recalling her most important scientific achievements since the beginning of her work as a researcher in inorganic chemistry. Laura went through many aspects of liquid-phase heterogeneous catalysis, taking her first steps in the field of catalysts synthesis, where she pursued the development of innovative strategies for preparing catalysts until laying the foundations of the colloidal synthesis of metal nanoparticles, with particular interest in gold. Her investigations in colloids for catalysis had a natural outcome on catalysts synthesis and optimization. In her career, she dealt with liquidphase oxidation reactions, with particular attention to biomass valorization processes. According to this, she could not help to deal also with hydrogenation and hydrogenolysis reactions, to which she dedicated herself, especially in the more recent years. Her discoveries have influenced many researchers in the area of heterogeneous catalysis and design of materials

Yeasts and moulds contaminants of food ice cubes and their survival in different drinks

Aims: To evaluate the levels of unicellular and filamentous fungi in ice cubes produced at different levels and to determine their survival in alcoholic beverages and soft drinks. Methods and Results: Sixty samples of ice cubes collected from home level (HL) productions, bars and pubs (BP) and industrial manufacturing plants (MP) were investigated for the presence and cell density of yeasts and moulds. Moulds were detected in almost all samples, while yeasts developed from the majority of HL and MP samples. Representative colonies of microfungi were subjected to phenotypic and genotypic characterization. The identification was carried out by restriction fragment length polymorphism (RFLP) analysis of the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5·8S rRNA gene. The process of yeast identification was concluded by sequencing the D1/D2 region of the 26S rRNA gene. The fungal biodiversity associated with food ice was represented by nine yeast and nine mould species. Strains belonging to Candida parapsilosis and Cryptococcus curvatus, both opportunistic human pathogens, and Penicillium glabrum, an ubiquitous mould in the ice samples analysed, were selected to evaluate the effectiveness of the ice cubes to transfer pathogenic microfungi to consumers, after addition to alcoholic beverages and soft drinks. All strains retained their viability. Conclusions: The survival test indicated that the most common mode of consumption of ice cubes, through its direct addition to drinks and beverages, did not reduce the viability of microfungi. Significance and Impact of the Study: This study evidenced the presence of microfungi in food ice and ascertained their survival in soft drinks and alcoholic beverages

Treatment of Hepatitis C virus genotype 3 infection with direct-acting antiviral agents

Hepatitis C virus (HCV) genotype 3 is responsible for 30.1% of chronic hepatitis C infection cases worldwide. In the era of directacting antivirals, these patients have become one of the most challenging to treat, due to fewer effective drug options, higher risk of developing cirrhosis and hepatocellular carcinoma and lower sustained virological response (SVR) rates. Currently there are 4 recommended drugs for the treatment of HCV genotype 3: pegylated interferon (PegIFN), sofosbuvir (SOF), daclatasvir (DCV) and ribavirin (RBV). Treatment with PegIFN, SOF and RBV for 12 weeks has an overall SVR rate of 83-100%, without significant differences among cirrhotic and non-cirrhotic patients. However, this therapeutic regimen has several contra-indications and can cause significant adverse events, which can reduce adherence and impair SVR rates. SOF plus RBV for 24 weeks is another treatment option, with SVR rates of 82-96% among patients without cirrhosis and 62-92% among those with cirrhosis. Finally, SOF plus DCV provides 94-97% SVR rates in non-cirrhotic patients, but 59-69% in those with cirrhosis. The addition of RBV to the regimen of SOF plus DCV increases the SVR rates in cirrhotic patients above 80%, and extending treatment to 24 weeks raises SVR to 90%. The ideal duration of therapy is still under investigation. For cirrhotic patients, the optimal duration, or even the best regimen, is still uncertain. Further studies are necessary to clarify the best regimen to treat HCV genotype 3 infection491

Hepatitis C virus in monozygotic twins

É relatado o caso de paciente grávida, com hepatite C crônica que deu à luz dois gêmeos monozigóticos. Um recém-nascido apresentou positividade para o RNA do vírus da hepatite C (RNA-VHC), no sangue venoso, coletado de veia periférica doze horas após o parto. O outro recém-nascido apresentou-se negativo para o RNA-VHC logo após o nascimento, porém tornou-se RNA-VHC positivo na amostra coletada aos três meses de idade. Os resultados permitem supor que um dos gêmeos provavelmente foi contaminado no período intra-uterino, enquanto o outro adquiriu a infecção no período perinatal. Ambos foram negativos para a presença do RNA-VHC e para os anticorpos anti-HCV em todas as amostras séricas coletadas após os nove meses de idade. Os exames laboratoriais dos gêmeos não mostraram a presença de infecção crônica pelo VHC durante o acompanhamento de 29 meses .A case of a pregnant patient with chronic hepatitis C who gave birth to monozygotic twins that were infected with HCV is reported. One of the newborns was positive for HCV-RNA in blood sample collected 12 hours after delivery. The other newborn was negative for HCV-RNA at birth, but was detected HCV viremia at three months of age. The results have led to the conclusion that one of the twins was probably contaminated in the intrauterine period, while the other acquired the infection in the perinatal period. Both were negative for HCV-RNA and for anti-HCV in the serum samples collected at nine months of age. The report describes the changes in the laboratory tests conducted in mother and twins until 29 months after delivery

A Clinical, Epidemological, Laboratorial, Histological And Ultrasonographical Evaluation Of Anti-hcv Eia-2 Positive Blood Donors.

Between 1992 and 1997, 790 blood donors with anti-HCV EIA-2 strongly reagent (relationship between the sample optical density/cut-off > 3) detected at the blood bank serological screening, were evaluated in ambulatory environment. They were all negative for Chagas disease, syphilis, hepatitis B (HBsAg) and AIDS. Blood samples were collected at the first ambulatorial evaluation, for hemogram, biochemical tests and new serological tests for HCV (anti-HCV EIA-2). In blood samples of 226 repeatedly reagent anti-HCV EIA-2 blood donors, supplementary immunoblot test for HCV (RIBA-2) was used. In 209 donors, the presence of HCV-RNA was investigated by the PCR test. The abdominal ultrasonography was realized in 366 donors. In 269 patients liver biopsy was performed for the histopathological study. The follow-up of blood donors showed that 95.6% were repeatedly EIA-2 reagent, 94% were symptomless and denied any hepatitis history, with only 2% mentioning previous jaundice. In 47% of this population at least one risk factor has been detected for the HCV transmission, the use of intravenous drugs being the main one (27.8%). Blood transfusion was the second factor for HCV transmission (27.2%). Hepatomegaly was detected in 54% of the cases. Splenomegaly and signs of portal hypertension have seldom been found in the physical examination, indicating a low degree of hepatic compromising in HCV. Abdominal ultrasound showed alterations in 65% of the subjects, being the steatosis the most frequent (50%). In 83. 5% of the donors submitted to the liver biopsy, the histopathological exam showed the presence of chronic hepatitis, usually classified as active (89%) with mild or moderate grade in most of the cases (99.5%). The histopathological exam of the liver was normal in 1.5% of blood donors. The RIBA-2 test and the HCV-RNA investigation by PCR were positive in respectively 91.6 and 75% of the anti-HCV EIA-2 reagent donors. The HCV-RNA research was positive in 82% of the RIBA-2 positive subjects, in 37.5% of the indeterminate RIBA-2 donors and in 9% of the negative RIBA-2 donors. Chronic hepatitis has also been observed in 50% of the histopathological exams of the anti-HCV EIA-2 reagent donors which were indeterminate RIBA-2. Among 18 blood donors with minimal changes histopathological exam 11 (61%) were HCV-RNA positive. Our blood donors anti-HCV reagent generally had clinical, laboratorial and histopathological features observed in patients with chronic HCV hepatitis and a high proportion could be identified in interviews and medical evaluation realized in blood blanks. Generally, these HCV infected donors are identified and discharged only by the serological tests results.42147-5

Using HoloLens Mixed Reality to research correlations between language and movement: a case study

Communication can be defined as the understanding and exchanging of meaningful messages. The role of communication is central to the lives of human beings as, everyday, we use language to interact with the world around us. Linguistic skills play a fundamental role in this scenario and Language Disorders (LD) are impairments that limit the processing of linguistic information. Early and accurate identification of LD is thus essential to promote lifelong learning and well-being. From an evolutionary perspective, some human language constructs evolved from an ancestral motor system and share the same neural pathways in the Broca’s area of the brain. This suggests a correlation between action and language. If such a relationship is well established and reliable, it would be possible to use the former as a marker of the latter. The hypothesis of our work, in a nutshell, is that movement can be a predictor of language. To study this correlation, we developed C(H)o(L)ordination, a Mixed Reality (MR) application for HoloLens 2. The application offers several activities based on visual stimuli involving motor movements, which tap on the same skills needed to perform some language tasks. We performed an exploratory study with N=22 users to test the application usability and user experience. The results suggest that C(H)o(L)ordination is a usable and powerful tool to gather insights on the ongoing debate about language evolution and language disorders

Anemia and acute coronary syndrome: current perspectives

Reference hemoglobin (Hb) values for the definition of anemia are still largely based on the 1968 WHO Scientific Group report, which established a cutoff value of <13 g/dL for adult men and <12 g/dL for adult nonpregnant women. Subsequent studies identified different normal values according to race and age. Estimated prevalence of anemia on admission in the setting of an acute coronary syndrome (ACS) is between 10% and 43% of the patients depending upon the specific population under investigation. Furthermore, up to 57% of ACS patients may develop hospital-acquired anemia (HAA). Both anemia on admission and HAA are associated with worse short- and long-term mortality, even if different mechanisms contribute to their prognostic impact. Baseline anemia can usually be traced back to preexisting disease that should be specifically investigated and corrected whenever possible. HAA is associated with clinical characteristics, medical therapy and interventional procedures, all eliciting cardiovascular adaptive response that can potentially worsen myocardial ischemia. The intrinsic fragility of anemic patients may limit aggressive medical and interventional therapy due to an increased risk of bleeding, and could independently contribute to worse outcome. However, primary angioplasty for ST elevation ACS should not be delayed because of preexisting (and often not diagnosed) anemia; delaying revascularization to allow fast-track anemia diagnosis is usually feasible and justified in non-ST-elevation ACS. Besides identification and treatment of the underlying causes of anemia, the only readily available means to reverse anemia is red blood cell transfusion. The adequate transfusion threshold is still being debated, although solid evidence suggests reserving red blood cell transfusions for patients with Hb level <8 g/dL and considering it in selected cases with Hb levels of between 8 and 10 g/dL. No evidence supports the use of iron supplements and erythropoiesis-stimulating agents in the setting of ACS

Predictors of early treatment discontinuation and severe anemia in a Brazilian cohort of hepatitis C patients treated with first-generation protease inhibitors

The aim of this study was to determine risk factors for adverse events (AE)-related treatment discontinuation and severe anemia among patients with chronic hepatitis C virus (HCV) genotype 1 infection, treated with first-generation protease inhibitor (PI)-based therapy. We included all patients who initiated treatment with PI-based therapy at a Brazilian university hospital between November 2013 and December 2014. We prospectively collected data from medical records using standardized questionnaires and used Epi Info 6.0 for analysis. Severe anemia was defined as hemoglobin ≤8.5 mg/dL. We included 203 patients: 132 treated with telaprevir (TVR) and 71 treated with boceprevir (BOC). AE-related treatment discontinuation rate was 19.2% and anemia was the main reason (38.5%). Risk factors for treatment discontinuation were higher comorbidity index (OR=1.85, CI=1.05-3.25) for BOC, and higher bilirubin count (OR=1.02, CI=1.01-1.04) and lower BMI (OR=0.98, CI=0.96-0.99) for TVR. Severe anemia occurred in 35 (17.2%) patients. Risk factors for this outcome were lower estimated glomerular filtration rate (eGFR; OR=0.95, CI=0.91-0.98) for patients treated with TVR, and higher comorbidity index (OR=2.21, CI=1.04-4.67) and ribavirin dosage (OR=0.84, CI=0.72-0.99) for those treated with BOC. Fifty-five (57.3%) patients treated with TVR and 15 (27.3%) patients treated with BOC achieved sustained virological response (SVR). Among patients who received TVR and interrupted treatment due to AE (n=19), only 26.3% (n=5) achieved SVR (P=0.003). Higher number of comorbidities, lower eGFR and advanced liver disease are associated with severe anemia and early treatment cessation, which may compromise SVR achievement4971

Transient elastography and APRI score: looking at false positives and false negatives. Diagnostic performance and association to fibrosis staging in chronic hepatitis C

Although long regarded as the gold standard for liver fibrosis staging in chronic hepatitis C (CHC), liver biopsy (LB) implies both the risk of an invasive procedure and significant variability. The aim of this study was to evaluate the diagnostic performance for transient elastography (TE) and aspartate aminotransferase to platelet index (APRI) used alone and in combination compared to liver biopsy and to analyze false positive/negative results. Patients with CHC, and no previous clinical diagnosis of cirrhosis were enrolled to undergo liver biopsy, TE and APRI. A total of 182 adult patients with a median age of 55 years and median body mass index of 26.71 kg/m2 were analyzed. On LB, 56% of patients had significant levels of fibrosis (METAVIR F≥2) and 28% had advanced fibrosis (F3/F4). The strongest performance for both tests was observed for exclusion of advanced fibrosis with good negative predictive values (89 and 86%, respectively). Low necroinflammatory activity on LB was associated with false negative TE. False positives were associated with NASH and smaller LB fragments. Correlation between APRI and Fibroscan for F≥2 was 100% and 84% for F≥3 and remained high in both false negative and false positive instances, correctly identifying F<2 in 71% of cases and F<3 in 78% (and potentially foregoing up to 84% of LB). We concluded that low individual performance indicators could be attributable to limitations of LB. Poorer differentiation of lower levels of fibrosis is a known issue for LB and remains so for noninvasive tests. Good predictability is possible, however, for advanced fibrosis4991