The distribution of the azimuthal angle of charged and neutral hadrons relative to the lepton plane has been studied for neutral current deep inelastic ep scattering using an integrated luminosity of ...45 pb-1 taken with the ZEUS detector. The kinematic range is 100<Q2<8000 GeV2, 0.2<y<0.8 and 0.01<x<0.1 where Q2 is the virtuality of the exchanged boson, y is the inelasticity and x is the Bjorken variable. The measurements were made in the hadronic centre-of-mass system. The analysis exploits the energy-flow method, which allows the measurement to be made over a larger range of pseudorapidity compared to previous results. The dependence of the moments of the azimuthal distributions on the pseudorapidity and minimum transverse energy of the final-state hadrons are presented. Although the predictions from next-to-leading-order QCD describe the data better than do the Monte Carlo models incorporating leading-logarithm parton showers, they still fail to describe the magnitude of the asymmetries. This suggests that higher-order calculations may be necessary to describe these data.
There is an increasing incidence of type 2 diabetes mellitus (DM) among adolescents (especially females), and the serum glucose concentrations in pregnant women <25 years during a 3-h oral glucose ...tolerance test (3-h OGTT) seem to be lower than those of pregnant women >25 years. Among 115 Mexican pregnant adolescents (<18 years) we analyzed their serum glucose concentrations during: a) 1-h 50-g glucose challenge test (GCT) performed at 24-28 weeks of gestation (n = 103) or at 29-35 weeks of gestation (n = 12); b) A standard 3-h OGTT performed 3-5 days later. Eight adolescents had an abnormal GCT, three of whom also had an abnormal 3-h OGTT. Sixteen adolescents (13 with previously normal GCT) had an abnormal 3-h OGTT, 15 classified as GGI and one as gestational DM (GDM). Serum glucose concentrations in adolescents with GGI were higher than in adolescents with normal 3-h OGTT: a) at 60 and 120 min during the 3-h OGTT (p < 0.001); and b) when expressed as the area under the glucose curve (p < 0.001). Adolescents with GGI had serum glucose concentrations during the 3-h OGTT similar to adult, non-diabetic pregnant Mexican women. It is suggested that GGI in pregnant adolescents may represent an early sign of a future deterioration in glucose metabolism, leading to a higher risk for GDM in future pregnancies and/or type 2 DM in adulthood. Thus, the current criteria to diagnose GDM in adults may not completely apply to adolescents, especially in ethnic groups with high risk for glucose abnormalities and considering the frequency of multiparous adolescents, especially in developing countries.
Management of locally advanced rectal cancer (RC) consists of neoadjuvant chemoradiotherapy (CRT) with fluoropyrimidines, followed by total mesorectal excision. We sought to evaluate the expression ...of selected genes, some of which were derived from a previous undirected SAGE (serial analysis of gene expression)-based approach, before and after CRT, to identify mechanisms of resistance.
This retrospective cohort study included 129 consecutive patients. Quantitative polymerase chain reaction of 53 candidate genes was performed on the biopsy specimen before treatment and on the surgical specimen after CRT. A paired-samples t test was performed to determine genes that were significantly changed after CRT. The result was correlated with patients' disease-free survival.
Twenty-two genes were significantly upregulated, and two were significantly downregulated. Several of the upregulated genes have roles in cell cycle control; these include CCNB1IP1, RCC1, EEF2, CDKN1, TFF3, and BCL2. The upregulation of TFF3 was associated with worse disease-free survival on multivariate analyses (hazard ratio, 2.64; P=.027). Patients whose surgical specimens immunohistochemically showed secretion of TFF3 into the lumen of the tumoral microglands had a higher risk of relapse (hazard ratio, 2.51; P=.014). In vitro experiments showed that DLD-1 cells stably transfected with TFF3 were significantly less sensitive to 5-fluorouracil and showed upregulation of genes involved in the transcriptional machinery and in resistance to apoptosis.
Upregulation of TFF3 after CRT for RC is associated with a higher risk of relapse. The physiological role of TFF3 in restoring the mucosa during CRT could be interfering with treatment efficacy. Our results could reveal not only a novel RC prognostic marker but also a therapeutic target.
The production of D super(c)- and D super(0)-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb super(-1). The measurements cover the kinematic range ...5<Q super(2)<1000 GeV super(2), 0.02<y<0.7, 1.5<p sub(T) super(D )<15 GeV and
Measurements of the neutral current cross sections for deep inelastic scattering in e−p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential ...cross-sections dσ/dQ2, dσ/dx and dσ/dy and the double-differential cross sections in Q2 and x are measured in the kinematic region y<0.9 and Q2>185 GeV2 for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9 pb−1 taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318 GeV. The structure functions \(x\tilde{F_{3}}\) and xF3γZ are determined by combining the e−p results presented in this paper with previously measured e+p neutral current data. The asymmetry parameter A− is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model.
The photoproduction of dijet events, where the two jets with the highest transverse energy are separated by a large gap in pseudorapidity, have been studied with the ZEUS detector using an integrated ...luminosity of 39 pb-1. Rapidity-gap events are defined in terms of the energy flow between the jets, such that the total summed transverse energy in this region is less than some value ETCUT. The data show a clear excess over the predictions of standard photoproduction models. This is interpreted as evidence for a strongly interacting exchange of a color-singlet object. Monte Carlo models which include such a color-singlet exchange are able to describe the data.
Bose–Einstein correlations in one and two dimensions have been studied in deep inelastic ep scattering events measured with the ZEUS detector at HERA using an integrated luminosity of 121 pb−1. The ...correlations are independent of the virtuality of the exchanged photon, Q2, in the range 0.1<Q2<8000 GeV2. There is no significant difference between the correlations in the current and target regions of the Breit frame for Q2>100 GeV2. The two-dimensional shape of the particle-production source was investigated, and a significant difference between the transverse and the longitudinal dimensions of the source is observed. This difference also shows no Q2 dependence. The results demonstrate that Bose–Einstein interference, and hence the size of the particle-production source, is insensitive to the hard subprocess.
A new method is employed to measure the neutral current cross section up to Bjorken-x values of one with the ZEUS detector at HERA using an integrated luminosity of 65.1 pb-1 for e+p collisions and ...16.7 pb-1 for e-p collisions at \(\sqrt{s}=318\,\mathrm{GeV}\) and 38.6 pb-1 for e+p collisions at \(\sqrt{s}=300\,\mathrm{GeV}\). Cross sections have been extracted for Q2≥648 GeV2 and are compared to predictions using different parton density functions. For the highest x bins, the data have a tendency to lie above the expectations using recent parton density function parametrizations.
A search for QCD-instanton-induced events in deep inelastic ep scattering has been performed with the ZEUS detector at the HERA collider, using data corresponding to an integrated luminosity of 38 ...pb-1. A kinematic range defined by cuts on the photon virtuality, Q2 > 120 GeV2, and on the Bjorken scaling variable, x > 10-3, has been investigated. The QCD-instanton induced events were modelled by the Monte Carlo generator QCDINS. A background-independent, conservative 95% confidence level upper limit for the instanton cross section of 26 pb is obtained, to be compared with the theoretically expected value of 8.9 pb.
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