Una sesión innovadora de trabajo de laboratorio para enseñar proceso de datos : segundo curso de estudios de física a nivel universitario

An innovative reflection about measurement is proposed through Franck and Hertz experiment for second year University students. We present a sequence of laboratory work during which the students have the opportunity of deepening notions like dispersion, error and uncertainty, accuracy and precision, and some concepts of statistics. We describe how students are led to develop personal comments on their own results

Seven exercises planned to stimulate the flow of ideas in creative composition

Thesis (Ed.M.)--Boston Universit

Higgs bosons at 98 and 125 GeV at LEP and the LHC

We discuss NMSSM scenarios in which the lightest Higgs boson h 1 is consistent with the small LEP excess at ~ 98 GeV in e^+ e^− → Zh with h→bb and the heavier Higgs boson h 2 has the primary features of the LHC Higgs-like signals at 125 GeV, including an enhanced γγ rate. Verification or falsification of the 98 GeV h_1 may be possible at the LHC during the 14 TeV run. The detection of the other NMSSM Higgs bosons at the LHC and future colliders is also discussed, as well as dark matter properties of the scenario under consideration

Učinkovitost natrijevih soli hidroksiflavona kao hvatača slobodnih radikala u usporedbi s aktivnošću samih hidroksiflavona

Different studies have demonstrated that the bioactivity of hydroxyflavones is due to their antioxidant and free radical scavenging activity. Recently, most interest has been devoted to structure- activity relationships; however, the main problems encountered in these studies are the low solubility of some hydroxyflavones in aqueous solution and the pro-oxidant character of the hydroxyl group at the 3 position. In the present investigation, these problems have been resolved by preparing the corresponding hydroxyflavone sodium salts. In this way, the hydroxyl free radical (OH)• scavenging activity of different hydroxyflavone salts were studied using the Fenton reaction model, and the superoxide (O2)• – scavenging activity was studied using the xanthine oxidase model. The results obtained show clearly that the (OH)• scavenging activity of the hydroxyflavone salt form is at least two times that of the corresponding hydroxyflavone itself. Considering the (O2)• – scavenging activity, the salt form of hydroxyflavone is as good as the corresponding hydroxyflavone. Moreover, it was observed that for a good scavenging activity the hydroxyl at the 3\u27 position must be free, and only the hydroxyl groups of 3 and 4\u27 have to be substituted by sodium when the sodium salt of hydroxyflavone at position 7 does not have an important role in radical scavenging. The salt forms of hydroxyflavones are interesting free radical scavenger compounds showing a hydrophilic character.Različita istraživanja pokazala su da je bioaktivnost hidroksiflavona posljedica njihove antioksidacijske aktivnosti i sposobnosti hvatanja slobodnih radikala. Do sada je mnogo zanimanja iskazano za odnos između strukture i aktivnosti; međutim, osnovni problemi na koje se naišlo u tim istraživanjima slaba je topljivost nekih hidroksiflavona u vodenoj otopini i prooksidacijski karakter hidroksilne skupine u položaju 3. U ovom istraživanju ti problemi razriješeni su pripremom odgovarajućih natrijevih soli hidroksiflavona. Tako su proučavani učinkovitost soli raznih hidroksiflavona kao hvatača slobodnih hidroksilnih radikala (OH)• modelom Fentonove reakcije te kao hvatača superoksid radikala (O2)• – modelom ksantin oksidaze. Dobiveni rezultati jasno pokazuju da soli hidroksiflavona najmanje dva puta učinkovitije hvataju hidroksilne radikale (OH)• nego što to čine odgovarajući hidroksiflavoni. Učinkovitost hvatanja superoksid radikala (O2)• – jednaka je kako za soli hidroksiflavona tako i za same hidroksiflavone. Osim toga opaženo je da za dobar učinak hvatanja radikala, OH skupina u položaju 3\u27 treba biti slobodna, da samo hidroksilne skupine 3 i 4\u27 trebaju biti supstituirane natrijem, dok natrijeva sol hidroksiflavona u položaju 7 nema znatnijega utjecaja na hvatanje radikala. Soli hidroksiflavona, spojevi koji pokazuju hidrofilni karakter, zanimljivi su hvatači slobodnih radikala

Use of Sysmex XE-2100 and XE-5000 hematology analyzers for the diagnosis of malaria in a nonendemic country (France).

INTRODUCTION: Most studies dealing with automated hematology analyzers (HAs) and malaria diagnosis are conducted in endemic countries. METHODS: We retrospectively studied cell blood counts (CBCs) performed with Sysmex XE-2100 and XE-5000 HAs in our center (Angers, France) regarding 67 patients returning from endemic areas and infected with various Plasmodium species. RESULTS: In 83% of infected samples with Plasmodium vivax (Pv), ovale (Po), or malariae (Pm), extra clouds of dots were present in neutrophil and/or eosinophil area(s) on routine differential (DIFF) scattergrams. In contrast, samples infected with Plasmodium falciparum (Pf) failed to show such DIFF scattergrams, or any other suggesting malaria infection (0/ 49 pts). Abnormal areas from DIFF scattergrams were related to the presence of mature schizonts and gametocytes, undestroyed by lysis agent, the latter not observed in Pf-infected patients from our series. The internal parameter WBC[DIFF] - WBC[BASO] raised in parallel to parasitemia in Pv, Po, and Pm samples but could not be used as a surrogate for parasitemia. In Pf infection, reticulocyte/ immature reticulocyte fraction (IRF) ratio showed a significant correlation with parasitemia (P < 0.05). A diagnostic model developed for Pf in endemic countries showed sensitivity of 77%. CONCLUSION: Using SYSMEX analyzers, Pv, Po, and Pm infections are easy to ascertain as DIFF scattergrams are almost specific (specificity = 99.9%). Pf infection diagnosis by CBC may be a more promising tool