123 research outputs found

    Novi aktivni leap-frog filtar trećeg reda

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    This paper presents the realization of third-order low-pass active-RC filters using a new Leap-Frog (LF) topology. New structure is a simplified LF structure with the elements calculated directly from the transfer function coefficients. Several versions of the circuits are presented and compared. The comparison to other common thirdorder filter sections is done, as well. The new LF filter has the reduced number of components, reduced complexity and straightforward design procedure compared to classical filters. As an illustration of the efficiency of the proposed new LF filter, the sensitivity analysis using Schoeffler sensitivity measure as well as output thermal noise analysis was performed on examples with Butterworth and Chebyshev 0.5dB pass-band ripple transfer functions. Using PSpice with a TL081 opamp model, the filter performance is simulated and the results compared and verified by measurements on a discrete-component breadboard filter. All equations needed for the step-by-step design are given.U radu je predstavljena realizacija nisko-propusnog aktivnog-RC filtra trećeg reda koji upotrebljava novu "leap-frog" (LF) topologiju. Nova struktura je pojednostavljena LF struktura s elementima koji se računaju direktno iz koeficijenata prijenosne funkcije. Nekoliko inačica krugova je prikazano i obavljena je usporedba. Napravljena je usporedba tako.er i s drugim uobičajenim filtarskim sekcijama trećeg reda. Novi LF filtar ima smanjeni broj komponenata, smanjenu kompleksnost i jednostavniji postupak projektiranja u usporedbi s klasičnim filtrima. Za ilustraciju učinkovitosti predstavljenog novog LF filtra, provedena je analiza osjetljivosti pomoću Schoefflerove mjere osjetljivosti i analiza termičkog šuma na izlazu na primjerima s prijenosnim funkcijama po Butterworthu i Chebyshevu s valovitošću u području propuštanja od 0.5 dB. Pomoću PSpice-a s modelom pojačala TL081, filtarska svojstva su simulirana, uspore.ena i potvr.ena mjerenjima na filtrima realiziranim pomoću diskretnih elemenata na štampanoj pločici. U radu su dane sve potrebne jednadžbe u postupku projektiranja korak po korak

    Doppler ultrasound study of portal hemodynamics in patients with Gaucher disease

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    Gaucher disease is a lysosomal storage disorder caused by a deficiency of the enzyme glucocerebrosidase and characterized by the presence of pathological macrophages laden with glucosylceramide. Hepatosplenomegaly is a common manifestation of Gaucher disease, but symptomatic portal hypertension is rarely seen. The study included 20 untreated adult patients with Gaucher disease (non-neuronopathic type 1) diagnosed with the presence of Gaucher cells in the bone marrow, and 20 healthy subjects as controls. The examination of patients included color Doppler ultrasonography (pulsed Doppler mode), resistive index (RI) and Doppler perfusion index (DPI) using a Toshiba Xario ultrasound machine and a convex array probe PVT-375AX (1.9-6 MHz) with the objective of analyzing portal hemodynamics. Results showed that all patients had enlarged liver and spleen, and their average sizes were significantly larger than those in the healthy controls (liver: 17.04 vs.14.02 cm; spleen: 22.2 vs. 10.74 cm). DPI values were significantly different between patients and controls (0.15 vs. 0.21). Considering DPI <0.15 indicates arterial liver hypoperfusion and hypoxia, it can be concluded that a number of patients had a problem with liver oxygenation, which may be linked to the high angiotensin-converting enzyme (ACE) levels obtained in the patients (339.42 U/L), 10 times greater than in control subjects. Since ACE is a potent vasoconstrictor produced by spleen macrophages in Gaucher disease, we can suppose that elevated ACE is associated with effects on the blood vessels of the liver and spleen

    Prospective analysis of the influence of sport and educational factors on the prevalence and initiation of smoking in older adolescents from Croatia

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    The prevalence of smoking among Croatian adolescents is alarmingly high, but no previous study has prospectively examined the sport- and academic-factors associated with smoking and smoking initiation. This study aimed to prospectively examine the associations between scholastic (educational) achievement and sport factors and smoking in 16- to 18-year-old adolescents. This twoyear prospective cohort study included 644 adolescents who were 16 years of age at baseline (46% females). Baseline testing was implemented at the beginning of the 3rd year of high school (September 2014) when participants were 16 years old. Follow-up testing was completed at the end of the fourth year of high school, which occurred 20 months later. The evaluated predictor variables were educational-achievement- and sport-related-factors. The outcome variables were (i) smoking at baseline; (ii) smoking at follow-up; and (iii) smoking initiation over the course of the study. We assessed the associations between predictors and outcomes using logistic regression models adjusted for age, gender, socioeconomic status, and conflict with parents. The educational variables were consistently associated with smoking, with lower grade-point-average (Baseline: odd ratio (OR): 2.01, 95% confidence interval (CI): 1.61\u20132.55; Follow-up: 1.59, 1.31\u20131.94), more frequent absence from school (Baseline: OR: 1.40, 95% CI: 1.19\u20131.69; Follow-up: 1.30, 1.08\u20131.58), and lower behavioral grades (Baseline: OR: 1.80, 95% CI: 1.10\u20132.89; Follow-up: 1.57, 1.03\u20132.41) in children who smoke. Adolescents who reported quitting sports were at greater odds of being smokers (Baseline: 2.07, 1.31\u20133.32; Followup: 1.66, 1.09\u20132.56). Sport competitive achievement at baseline was protective against smoking initiation during following two-year period (0.45, 0.21\u20130.91). While the influence of the educational variables on smoking initiation has been found to be established earlier; sport achievement was identified as a significant protective factor against initiating smoking in older adolescents. Results should be used in development of an anti-smoking preventive campaign in older adolescents

    The envelope protein of Usutu virus attenuates West Nile virus virulence in immunocompetent mice

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    West Nile virus (WNV) and Usutu virus (USUV) are the two most widespread mosquito-borne flaviviruses in Europe causing severe neuroinvasive disease in humans. Here, following standardization of the murine model with wild type (wt) viruses, we engineered WNV and USUV genome by reverse genetics. A recombinant virus carrying the 5′ UTR of WNV within the USUV genome backbone (r-USUV5′-UTR WNV) was rescued; when administered to mice this virus did not cause signs or disease as wt USUV suggesting that 5′ UTR of a marked neurotropic parental WNV was not per se a virulence factor. Interestingly, a chimeric virus carrying the envelope (E) protein of USUV in the WNV genome backbone (r-WNVE-USUV) showed an attenuated profile in mice compared to wt WNV but significantly more virulent than wt USUV. Moreover, except when tested against serum samples originating from a live WNV infection, r-WNVE-USUV showed an identical antigenic profile to wt USUV confirming that E is also the major immunodominant protein of USUV

    Adenocarcinoma of the third and fourth portion of the duodenum: a case report and review of the literature

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    A 65-year-old woman presented with abdominal pain, weight loss, fatigue, and microcytic anemia. Esophagogastroduodenoscopy, until the second part of duodenum, was normal. Ultrasound and computed tomography demonstrated a solid mass in the distal duodenum. A repeat endoscopy confirmed an ulcerative, intraluminar mass in the third and fourth part of the duodenum. Segmental resection of the third and fourth portion of the duodenum was performed. Histology revealed an adenocarcinoma. On the 4th postoperative day, the patient developed severe acute pancreatitis leading to multiple organ failure and died on the 30th postoperative day

    Genome sequences of three SARS-CoV-2 P.1 strains identified from patients returning from Brazil to Italy

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the current coronavirus disease 2019 (COVID-19) pandemic. We report the complete sequences of three SARS-CoV-2 P.1 strains obtained from nasopharyngeal swab specimens from three patients returning from Brazil to Italy

    The impact of generation Y’s customer experience on emotions: online banking sector

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    Recently, banking sector focused on attracting Generation Y (individuals born between 1980 and 2000) because they have emerged as a huge force with growing spending power which will unavoidably rival with Baby Boomers’ market dominance. They try to attract them through a unique customer experience, especially the ability of differentiation. Using the Mehrabian & Russell’s model of stimulus (S) - organism (O) - response (R), this study developed the Generation Y customer experience framework that intends to explain their consumer emotional responses toward customer experience attributes in a bank through three aspects: pleasure, dominance, and arousal toward online banks. Empirical evidence, based on data from a survey suggests that the overall customer experience attributes in the bank had a positive relation with emotional responses in different ways. “Value for money”, “Getting things right the first time” and “Put the consumer first” emerged as the most important attributes for Generation Y in experiencing a bank.info:eu-repo/semantics/acceptedVersio

    Trend of suicide by self-immolation in a 13-year timeline: was the COVID-19 pandemic a potentially important stressor?

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    IntroductionSelf-immolation is an uncommon way of attempting and committing a suicide, with a fatality rate of 80%. The risk factors in self-immolation victims vary depending on demographic characteristics, socio-economic and cultural factors as well as religious beliefs. Whether the COVID-19 pandemic was a potentially important stressor for self-immolation is still unknown, with insufficient studies examining this issue. Therefore, in this study, we aimed to examine the trend of self-immolation in a 13-year timeline, and the potential association of COVID-19 pandemic with the increase in the incidence and severity of self-immolation injuries in Serbia in 2021.Materials and methodsThe study included hospitalized patients due to intentional burns caused by self-immolation in the period from January 1, 2008 to December 31, 2021. Joinpoint regression analysis was used for the analysis of continuous linear trends of self-immolation cases with change points.ResultsWhile a rising trend was observed in the 2008–2013 time segment, followed by a decline in the upcoming 2013–2016 time segment, a significant increase reached its maximum during COVID-19 pandemic (2021), with annual percent change of 37.1% (p = 0.001). A significant increase in the median number of cases per year was observed during 2021 compared to the previous periods (7.5 vs. 2). Frequency of patients with a psychiatric diagnosis vs. those without a psychiatric diagnosis was significantly higher during than before the COVID-19 period (66.7 vs. 36.1%, p = 0.046).ConclusionIn our study, a significant increase in the frequency of suicide attempts by self-immolation during COVID-19 pandemic was noticed. There was also an increased frequency of pre-existing psychiatric illness among patients during the pandemic period. With limited high-quality data available, the study adds to a rising body of evidence for assessment of outcomes of the pandemic on mental health and recognition of stressors for self-immolation
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