1,337 research outputs found
Assessing QT prolongation and electrocardiography restitution using a beat-to-beat method
Historically, the heart rate corrected QT (QTc) interval has been the standard method to assess
for impaired ventricular repolarization, particularly for drug development. However, QTc does
not reflect changes in autonomic state or QT-RR hysteresis which can also affect the interpretation
of arrhythmogenic risk. With the advent of more accurate algorithms to automatically
measure the QT interval from continuously collected digital ECG data, usage of heart rate
corrected functions is no longer necessary. The dynamic beat-to-beat QT interval method
compares the QT interval to individual cardiac cycles from all normal autonomic states at
similar RR intervals, thus eliminating the need for correction functions. The upper 97.5%
reference boundary of these beat-to-beat QT interval values is defined across the entire 24-hour
RR interval range. Beats with QT intervals exceeding this limit are flagged as outlier beats for
further arrhythmia vulnerability assessment. The same beat-to-beat technique can also be used
to assess the QT-TQ interval relationship known as ECG restitution. This analysis potentially
provides an additional means to quantify cardiac stress or arrhythmia vulnerability as the
heart works more in relationship to each rest cycle. (Cardiol J 2010; 17, 3: 230-243
Estudio comparativo de la estabilización de un suelo plastico con cal y/o cemento portland
En este trabajo se comentan las determinaciones practicadas en la estabilización de un suelo plástico con cemento portland y con cal hidratada en polvo, asà como la estabilización de dicho suelo con cemento portland, previa corrección con cal, Los gráficos muestran los resultados obtenidos en dicha estabilización.
Se comentan los posibles procesos fÃsico-quÃmicos que tendrÃan lugar entre el suelo y los estabilizantes, para dar lugar a la mencionada estabilización.The present repot refers to the determinations made over one plastic soil, estahilized with portlandcement and with hidrated lime, as soon as the stabilization of the same soil with Portland cement, foregoing corrected with hidrated lime.
The graphs includes the results obtained in these determinations.
The work contains some ideas on the physicochemical proccesses that would explains the mentioned stabilization
APLICAÇÃO DO TRIÂNGULO DE PASCAL
O presente artigo objetiva, através de uma análise linguÃstica e matemática, fazer uma breve explanação de certos aspetos do Triângulo Aritmético (Triângulo de Pascal), conforme a abordagem de Blaise Pascal (1623-1662) no seu Tratado sobre o Triângulo Aritmético. Especificamente, investiga-se uma das várias aplicações do referido Triângulo, a saber, como dividir a aposta de um jogo de soma zero, caso for necessário interromper o mesmo antes de chegar à sua conclusão. Apresenta-se um método para fazer a divisão sem usar o Triângulo (como apresentado por Pascal) e, então, o método de Pascal por fazer a mencionada divisão usando o Triângulo, pois a demonstração deste método depende daquele. Finalmente, analisa-se a demonstração dada por Pascal de que o seu método usando o Triângulo é válido, pois a referida demonstração é uma das primeiras na história em que a Indução Matemática foi formulada corretamente. ConcluÃmos que a formulação do argumento por Indução Matemática é, de fato, correta e que a base da indução é bem-feita. O passo da indução, ou seja, a passagem do n-ésimo caso para o n+1-ésimo caso, porém, não é válido pelos padrões lógicos modernos porque não é feito com a generalidade necessária. Também concluÃmos, porém, que Pascal certamente considerava sua demonstração válida, pois considerava o caso abordado como um template que é aplicável a todos os casos da demonstração
A principle-based approach to AI: the case for European Union and Italy
As Artificial Intelligence (AI) becomes more and more pervasive in our everyday life, new questions arise about its ethical and social impacts. Such issues concern all stakeholders involved in or committed to the design, implementation, deployment, and use of the technology. The present document addresses these preoccupations by introducing and discussing a set of practical obligations and recommendations for the development of applications and systems based on AI techniques. With this work we hope to contribute to spreading awareness on the many social challenges posed by AI and encouraging the establishment of good practices throughout the relevant social areas. As points of novelty, the paper elaborates on an integrated view that combines both human rights and ethical concepts to reap the benefits of the two approaches. Moreover, it proposes innovative recommendations, such as those on redress and governance, which add further insight to the debate. Finally, it incorporates a specific focus on the Italian Constitution, thus offering an example of how core legislations of Member States might contribute to further specify and enrich the EU normative framework on AI
Investigação sistemática e propriedades dos triângulos retângulos em números inteiros
A obra de Bahier é uma investigação de um dos assuntos mais antigos da matemática, triângulos pitagóricos, ou seja, triângulos retângulos cujos lados são medidos por números inteiros (positivos). Alguns desses triângulos, como o (3, 4, 5), foram conhecidos pelos antigos babilônios e egÃpcios. Era entre os pitagóricos, especialmente com Platão, porém, que os referidos triângulos foram investigados mais intensivamente, pois se tornaram fundamentais para o desenvolvimento das suas filosofias. [Trecho retirado da apresentação da obra
Risk of cancer in relatives of testicular cancer patients.
The incidence of cancer at sites other than the testis has been investigated in the families of 797 Norwegian and 178 Swedish patients diagnosed with testicular cancer during 1981-91. In the families of the Norwegian patients, the total number of cancers in the relatives was significantly lower than the expected number derived from national incidence rates [observed number of cancers 250, expected number of cancers 281.92, standardised incidence ratio (SIR) 0.89, 95% confidence interval (CI) 0.78-1.00]. This finding can be accounted for almost entirely by the finding of fewer than expected prostate and gastrointestinal cancers in the parents of cases. The other common cancers were found at slightly lower than or near the expected levels in the relatives. In the Swedish cohort, which accounts for less than 20% of cases, the observed number of cancers was very close to the expected number. Fourteen fathers of cases had prostate cancer compared with 27.57 prostate cancers expected, giving a SIR of 0.51 (P=0.006). Mothers had more lung cancers (ten cases observed, SIR=2.11, P=0.04) and cancers of the endometrium than expected (13 cases observed, SIR=1.73, P=0.09). These findings may be interpreted as support for theories proposing hormonal dysfunction as causing testicular cancer. Fifty-four gastrointestinal cancers were observed in the parents compared with 68.48 expected (SIR=0.78, P=0.082). Furthermore, testicular cancer was not found to be associated with the known dominantly inherited cancer syndromes [Familial breast (-ovarian) cancer, hereditary no-polyposis colon cancer]. However, one patient belonged to a Li-Fraumeni family, raising the possibility that testicular cancer may be an infrequent component of this rare cancer syndrome. This study supports the hypothesis that families of testicular cancer patients are not prone to cancer
Familial testicular cancer in Norway and southern Sweden.
Information about occurrence of testicular cancer (TC) in relatives of TC patients has been collected using questionnaires from 797 out of 922 consecutive Norwegian and 178 out of 237 Swedish patients with TC seen at the Norwegian Radium Hospital and the University Hospital Lund in Sweden during 1981-91. Fifty-one Norwegian and five Swedish patients had a relative with confirmed TC. Thus, 51/922 (5.5%) of the Norwegian and 5/237 (2.1%) of the Swedish patients treated during the time interval investigated were considered to have familial TC. Thirty-two of the patients had an affected first-degree relative. Expected numbers of cancers in the relatives were computed from data in the Norwegian and Swedish Cancer Registries. Standardised incidence ratios (SIRs) were taken as observed numbers of TC/expected numbers of TC in the relatives. The SIR for brothers was 10.2 (95% confidence interval 6.22-15.77). SIR for fathers was 4.3 (1.6-9.3) and for sons 5.7 (0.7-23.2). The point estimate for the risk to brothers in the Norwegian part of the sample to develop TC by the age of 60 was 4.1% (95% CI 1.7-6.6%). This study indicates that genetic factors may be of greater importance in TC than previously assumed. Patients with familial testicular cancer had bilateral tumours more often than sporadic cases (9.8% bilaterality in familial vs 2.8% in sporadic cases, P=0.02). For patients with seminoma age of onset was lower in familial than in sporadic cases (32.9 vs 37.6 years, P=0.06). In father-son pairs, there was a statistically significant earlier age of diagnosis in the generation of sons (28.8 years vs 44.9 years, P=0.04). The prevalence of undescended testis (UDT) did not seem to be higher in familial than in sporadic TC (8.2% in familial TC and 13.3% in sporadic cases). This may indicate that different factors are of importance for the development of familial TC and UDT
173. Does the correlation between chemotherapy-induced leukopenia with response in locally advanced breast cancer exist?
PurposeThe correlation between chemotherapy-induced toxicity and treatment outcome in cancer patients has not been thoroughly studied. Our aim was to evaluate whether leukopenia following primary chemotherapy may be predictive for response in patients with locally advanced breast cancer.Patients and MethodsThe records of 164 breast cancer patients administered primary chemotherapy between 1985 and 1995 were analysed. Most of the patients presented with locally advanced disease, however included were also patients with large operable tumours. Chemotherapy included one of the three combinations: CMF; modified Cooper regimen (CMFVP); 31 patients (19%), anthracycline-based regimens (FAC and FEC); 16 patients (10%) and 118 patients (71%).ResultsThe objective response rate in the entire group was 58%; 75% in patients who developed grade 2–3 leukopenia during induction chemotherapy, and 52% in those who had no or grade 1 leukopenia (p < 0.01, multivariate analysis). No other patient- or treatment-related factor including age, performance status, T stage, N stage, supraclavicular Iymph node involvement, inflammatory carcinoma or chemotherapy regimen correlated with response to chemotherapy. There was no correlation between treatment-induced leukopenia and overall survival.ConclusionsThese findings suggest a relationship between chemotherapy induced leukopenia and tumour response in patients with locally advanced breast cancer. The prognostic impact of leukopenia is negliglble
- …