Does solar structure vary with solar magnetic activity?

We present evidence that solar structure changes with changes in solar activity. We find that the adiabatic index, Gamma_1, changes near the second helium ionization, i.e., at a depth of about 0.98 R_sun. We believe that this change is a result of the change in the effective equation of state caused by magnetic fields. Inversions should be able to detect the changes in Gamma_1 if mode sets with reliable and precise high-degree modes are available.Comment: To appear in ApJ Letter

Abolished adherence alters signaling pathways in phorbol ester-induced human U937 cells

Phorbol ester (TPA) treatment of human U937 myeloid leukemia cells is associated with increasing adherence and monocyte-like maturation whereby the role of β2 integrin-mediated attachment for subsequent growth properties and the differentiation program remains unclear. Here, stably-transfected U937 cells with a pMTH1 vector containing the β2 integrin gene of CD11b in antisense orientation (asCD11b-U937) demonstrated a significantly reduced proliferative capacity in contrast to control vector transfectants (pMTH1-U937) or wild-type U937 cells. Phorbol ester exposure induced adherence and growth arrest in more than 90% of pMTH1-U937 and wild-type U937 cells after 72 h. In contrast, TPA-treated asCD11b-U937 failed to attach and the proliferation continued in more than 30% of the cells. Moreover, increased apoptosis appeared in asCD11b-U937 after TPA induction in contrast to pMTH1-U937 cells. In addition, non-specific inhibition of adherence on an agarose surface demonstrated internucleosomal DNA fragmentation in both, pMTH1-U937 and asCD11b-U937 after TPA treatment indicating a functional relationship between abolished adherence, regulation of proliferation and induction of apoptosis. Western blot analysis revealed differences in the expression levels and altered phosphorylation patterns of Pyk-2, pp60src and p42/p44 MAP kinases between pMTH1-U937 and asCD11b-U937 following TPA exposure which was also substantiated by Pyk-2 immunoprecipitation. These findings suggested that induced adherence predominantly mediated by a functional CD11b/CD18 integrin in U937 cells is involved in the activation of downstream signaling kinases and contributes to cell cycle regulation and apoptosis during monocytic maturation

Few-photons model of the optical emission of semiconductor quantum dots

The Jaynes-Cummings model provides a well established theoretical framework for single electron two level systems in a radiation field. Similar exactly solvable models for semiconductor light emitters such as quantum dots dominated by many particle interactions are not known. We access these systems by a generalized cluster expansion, the photon-probability-cluster-expansion: a reliable approach for few photon dynamics in many body electron systems. As a first application, we discuss vacuum Rabi flopping and show that their amplitude determines the number of electrons in the quantum dot.Comment: Paper slightly shortened. Accepted for publication in Physical Review Letter

The burden of Clostridium difficile infection between 2010 and 2013: trends and outcomes from an academic center in Eastern Europe

Modeling is now an essential ingredient in business process management and information systems development. The general usefulness of models in these areas is therefore generally accepted. It is also undisputed that the quality of the models has a significant impact on their usefulness. In the literature we can find any number of quality metrics, but hardly any study that investigates their relation with (perceived) usefulness and none that considers their relative impact on usefulness. We take a look at some of the most frequent quality dimensions and their relative impact on the perceived usefulness of models

Una storia di lesioni bollose di lunga durata

Si presenta il caso di una paziente di 33 anni di origine marocchina che riferiva fin dall’età infantile la comparsa al minimo traumatismo di multiple piccole lesioni bollose prevalentemente agli arti inferiori con saltuario coinvolgimento del cavo orale. In anamnesi ipertensione arteriosa in terapia farmacologica, un fratello di 47 anni con manifestazioni analoghe ed una sorella di 28 anni affetta da vitiligine, entrambi residenti nel paese di origine. All’esame obiettivo si osservavano molteplici esiti ipo- ed iper-pigmentati ed alcune aree disepitelizzate frammiste a lesioni crostose prevalentemente agli arti inferiori. Erano presenti, inoltre, alcune piccole bolle flaccide a contenuto siero-ematico alla pianta dei piedi ed un marcato diradamento dei capelli. Non era documentabile un interessamento delle mucose. Le indagini biochimiche, istologiche, immunologiche ed ultrastrutturali hanno portato ad una inconsueta diagnosi

Un raro caso di flogosi granulomatosa non necrotizzante in paziente sieropositivo

Si presenta il caso di un paziente di 54 anni HIV-positivo in terapia antiretrovirale dal 1996, giunto alla nostra osservazione nel 2011 per la comparsa di maculo-papule eritematose degli arti superiori. Il paziente ha contratto negli ultimi 20 anni diverse infezioni opportunistiche, epatite A, B, D e C ed ha sviluppato un’invalidante polineuropatia sensitivo-motoria di tipo assonale. L’esame istologico delle lesioni cutanee ha evidenziato una flogosi granulomatosa non necrotizzante di tipo interstiziale. Dopo un inefficace trattamento con steroidi topici si è osservata una trasformazione del quadro clinico con marcata estensione delle lesioni maculo-papulari a tutto l’ambito cutaneo con risparmio del volto e con comparsa di noduli deturpanti dei gomiti. Nel sospetto di una grave patologia sistemica con interessamento cutaneo, sono stati eseguiti accertamenti strumentali, valutazioni multidisciplinari ed una biopsia di una delle lesioni nodulari che ha portato a diagnosticare un raro quadro di flogosi granulomatosa non necrotizzante del derma superficiale e profondo con aspetti peculiari. È stato quindi iniziato trattamento con idrossiclorochina e successivamente con metotrexato, quest’ultimo sospeso dopo 1 mese per la comparsa di importanti effetti collaterali, da cui il paziente non ha tratto alcun beneficio. Attualmente è in corso di valutazione terapia con farmaco biologico anti-TNF alfa

Uno strano caso di pemfigo seborroico

Riportiamo il caso di un uomo di 74 anni che all’esame obiettivo presentava una lesione eritemato-squamo-crostosa del dorso del naso, di cui riferiva la comparsa e persistenza da 4 mesi. Clinicamente la lesione aveva l’aspetto di un epitelioma. Il paziente nel resto del corpo non presentava altre lesioni, non assumeva farmaci e non riferiva patologie di rilievo. Per un migliore inquadramento diagnostico e per valutare l’estensione della lesione venivano eseguite 5 biopsie (parte superiore, centrale, inferiore, destra e sinistra della lesione). Il referto istologico deponeva per un quadro di cheratosi attinica acantolitica. In considerazione dell’aspetto clinico della lesione si inviava la documentazione fotografica della lesione all’anatomopatologo e si chiedeva una sua rivalutazione. Veniva posta, quindi, diagnosi di pemfigo seborroico con aspetti anche di pemfigo volgare, successivamente confermata con l’immunofluorescenza diretta ed indiretta. Veniva impostata una terapia sistemica steroidea con risoluzione del quadro cutaneo. Il pemfigo seborroico è caratterizzato da piccole bolle a tetto flaccido dalla cui rottura si hanno lesioni squamo-crostose localizzate al centro del viso, cuoio capelluto, regioni medio-toraciche, con decorso lungo e benigno. Il nostro caso è particolare perché il pemfigo seborroico si presentava clinicamente in maniera atipica e per la sovrapposizione di aspetti istologici da pemfigo volgare

Is early limited surgery associated with a more benign disease course in Crohn’s disease?

AIM: To analyze the difference in disease course and need for surgery in patients with Crohn's disease (CD). METHODS: Data of 506 patients with incident CD were analyzed (age at diagnosis: 31.5 ± 13.8 years). Both hospital and outpatient records were collected prospectively with a complete clinical follow-up and comprehensively reviewed in the population-based Veszprem province database, which includes incident CD patients diagnosed between January 1, 1977 and December 31, 2008. Follow-up data were collected until December 31, 2009. All patients included had at least 1 year of follow-up available. Patients with indeterminate colitis at diagnosis were excluded from the analysis. RESULTS: Overall, 73 patients (14.4%) required resective surgery within 1 year of diagnosis. Steroid exposure and need for biological therapy were lower in patients with early limited surgery (P < 0.001 and P = 0.09). In addition, surgery rates during follow-up in patients with and without early surgery differed significantly after matching on propensity scores (P < 0.001, HR = 0.23). The need for reoperation was also lower in patients with early limited resective surgery (P = 0.038, HR = 0.42) in a Kaplan-Meier and multivariate Cox regression (P = 0.04) analysis. However, this advantage was not observed after matching on propensity scores (P(Logrank) = 0.656, P(Breslow) = 0.498). CONCLUSION: Long-term surgery rates and overall exposure to steroids and biological agents were lower in patients with early limited resective surgery, but reoperation rates did not differ