The antenna array LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from extensive air ...showers. The coincident measurements allow us to reconstruct the electric field strength at observation level in dependence of general EAS parameters. In the present work, the lateral distribution of the radio signal in air showers is studied in detail. It is found that the lateral distributions of the electric field strengths in individual EAS can be described by an exponential function. For about 20% of the events a flattening towards the shower axis is observed, preferentially for showers with large inclination angle. The estimated scale parameters
R
0
, describing the slope of the lateral profiles range between 100 and 200
m. No evidence for a direct correlation of
R
0
with shower parameters like azimuth angle, geomagnetic angle, or primary energy can be found. This indicates that the lateral profile is an intrinsic property of the radio emission during the shower development which makes the radio detection technique suitable for large scale applications.
The evolution of the cosmic ray primary composition in the energy range 106–107 GeV (i.e. the “knee” region) is studied by means of the e.m. and muon data of the Extensive Air Shower EAS-TOP array ...(Campo Imperatore, National Gran Sasso Laboratories). The measurement is performed through: (a) the correlated muon number (Nμ) and shower size (Ne) spectra, and (b) the evolution of the average muon numbers and their distributions as a function of the shower size. From analysis (a) the dominance of helium primaries at the knee, and therefore the possibility that the knee itself is due to a break in their energy spectrum (at EkHe=(3.5±0.3)×106 GeV) are deduced. Concerning analysis (b), the measurement accuracies allow the classification in terms of three mass groups: light (p,He), intermediate (CNO), and heavy (Fe). At primary energies E0≈106 GeV the results are consistent with the extrapolations of the data from direct experiments. In the knee region the obtained evolution of the energy spectra leads to: (i) an average steep spectrum of the light mass group (γp,He>3.1), (ii) a spectrum of the intermediate mass group harder than the one of the light component (γCNO≃2.75, possibly bending at EkCNO≈(6–7)×106 GeV), (iii) a constant slope for the spectrum of the heavy primaries (γFe≃2.3–2.7) consistent with the direct measurements. In the investigated energy range, the average primary mass increases from 〈lnA〉=1.6–1.9 at E0≃1.5×106 GeV to 〈lnA〉=2.8–3.1 at E0≃1.5×107 GeV. The result supports the standard acceleration and propagation models of galactic cosmic rays that predict rigidity dependent cut-offs for the primary spectra of the different nuclei. The uncertainties connected to the hadronic interaction model (QGSJET in CORSIKA) used for the interpretation are discussed.
Bleeding and staple line leak are the most common postoperative complications of LSG. To prevent and/or to promptly identify such complications, conventional peri-operative protocols imply ...post-operative gastric decompression (NGT) and staple line drain (IAD). Our aim was to evaluate the role of naso-gastric tube (NGT) and intra-abdominal drain (IAD) in preventing and/or facilitating identification and treatment of post-operative complications after sleeve gastrectomy.
A retrospective observational study on two consecutive series has been undertaken to evaluate the real utility of routine placement of NGT and IAD at the end of a LSG to prevent (primary end-point), promptly identify (secondary end-point) and manage (tertiary end-point) bleeding and staple line leakage. Collected outcome data of all consecutive cases, which underwent primary LSG at our Department, were analyzed. The first 100 consecutive patients (group A) received the standard perioperative protocol and the other consecutive 100 (group B) received a fast track protocol (no NGT neither IAD).
The two groups were not different in their outcome. Two bleeding occurred in Group A and were conservatively treated. One abscess developed in group B soon after surgery. It was diagnosed by an abdominal CT performed because patients presented fever, leucocitosis and tachycardia. It was successfully treated by percutaneous ultrasound-guided drainage. One fistula occurred in group B after discharge on 30th post-operative day. Fistula was suspected based on fever and tachycardia in absence of any abdominal discomfort and was confirmed by an abdominal CT. The patient was successfully treated in 40 days by endoscopic positioning of a gastric tube-prosthesis and percutaneous ultrasound-guided drainage of abdominal collection. A third patient in group B experienced bleeding suspected due to hemoglobin drop and confirmed by abdominal CT. He also was conservatively treated.
In conclusion, placement of drains does not facilitate detection of leak, abscess, or bleeding after primary LSG.
Bipolar disorder (BD) is characterized by episodic mood dysregulation, although a significant portion of patients suffer persistent cognitive impairment during euthymia. Previous magnetic resonance ...imaging (MRI) research suggests BD patients may have accelerated brain aging, observed as lower grey matter volumes. How these neurostructural alterations are related to the cognitive profile of BD is unclear.
We aim to explore this relationship in euthymic BD patients with multimodal structural neuroimaging. A sample of 27 euthymic BD patients and 24 healthy controls (HC) underwent structural grey matter MRI and diffusion-weighted imaging (DWI). BD patient's cognition was also assessed. FreeSurfer algorithms were used to obtain estimations of regional grey matter volumes. White matter pathways were reconstructed using TRACULA, and four diffusion metrics were extracted. ANCOVA models were performed to compare BD patients and HC values of regional grey matter volume and diffusion metrics. Global brain measures were also compared. Bivariate Pearson correlations were explored between significant brain results and five cognitive domains.
Euthymic BD patients showed higher ventricular volume (F(1, 46) = 6.04; p = 0.018) and regional grey matter volumes in the left fusiform (F(1, 46) = 15.03; pFDR = 0.015) and bilateral parahippocampal gyri compared to HC (L: F(1, 46) = 12.79, pFDR = 0.025/ R: F(1, 46) = 15.25, pFDR = 0.015). Higher grey matter volumes were correlated with greater executive function (r = 0.53, p = 0.008).
We evaluated a modest sample size with concurrent pharmacological treatment.
Higher medial temporal volumes in euthymic BD patients may be a potential signature of brain resilience and cognitive adaptation to a putative illness neuroprogression. This knowledge should be integrated into further efforts to implement imaging into BD clinical management.
•Euthymic bipolar patients show higher grey matter volumes in the temporal lobe.•Higher grey matter volumes correlate with better executive function.•White matter metrics did not discriminate between patients and healthy participants.
The effects of β-irradiation on the OH-related infrared (IR) absorption band in synthetic wet silica samples have been investigated by Fourier transform infrared spectroscopy. Depending on the ...accumulated doses, β-irradiation affects different zones of the IR composite band at about 3670
cm
−1, assigned to the OH stretching modes of silanol groups. These modifications are independent of the original OH content. The results are discussed considering possible radiation-induced changes of the silanol bonding configuration and of the glass network. These are monitored by revealing the IR band a 2260
cm
−1, which is related to the distribution of Si–O–Si bond angle. We have identified the existence of two regimes as a function of radiation dose; low radiation doses produce the reduction of the
Si-OH hydrogen-bonded states in favor of the isolated ones, while the opposite effect is observed at higher doses, where the formation of H-bonded pairs seems to be favored.
Patients with bipolar disorder (BD) frequently suffer from neurocognitive deficits that can persist during periods of clinical stability. Specifically, impairments in executive functioning such as ...working memory and in self-processing have been identified as the main components of the neurocognitive profile observed in euthymic BD patients. The study of the neurobiological correlates of these state-independent alterations may be a prerequisite to develop reliable biomarkers in BD.
A sample of 27 euthymic BD patients and 25 healthy participants (HC) completed working memory and self-referential functional Magnetic Resonance Imaging (fMRI) tasks. Activation maps obtained for each group and contrast images (i.e., 2-back > 1-back/self > control) were used for comparisons between patients and HC.
Euthymic BD patients, in comparison to HC, showed a higher ventromedial prefrontal cortex activation during working memory, a result driven by the lack of deactivation in BD patients. In addition, euthymic BD patients displayed a greater dorsomedial and dorsolateral prefrontal cortex activation during self-reference processing.
Pharmacotherapy was described but not included as a confounder in our models. Sample size was modest.
Our findings revealed a lack of deactivation in the anterior default mode network (aDMN) during a working memory task, a finding consistent with prior research in BD patients, but also a higher activation in frontal regions within the central executive network (CEN) during self-processing. These results suggest that an imbalance of neural network dynamics underlying external/internal oriented cognition (the CEN and the aDMN, respectively) may be one of the first reliable biomarkers in euthymic bipolar patients.
•Euthymic bipolar patients show state-independent neurobiological alterations.•Bipolar patients failed to deactivate the DMN during working memory processing.•Higher CEN activations during self-processing were detected in bipolar patients.
We present a study on the vacuum-ultraviolet (VUV) and infrared (IR) absorption of silanol groups in amorphous silicon dioxide (a- SiO sub(2)) in the range of temperature from 4 to 300 K. The ...observed temperature induced modifications of IR and VUV absorption spectra are interpreted as due to a process of conversion of free into H-bonded silanol groups. The changes of the amplitude of the VUV absorption spectra are shown to be linearly correlated to the changes of the IR absorption of free Si-OH groups. This point together with the evidence that the shape of the Si-OH VUV absorption does not depend on temperature demonstrates that the different silanol group sub-species have different VUV absorption properties, being only the free Si-OH groups responsible for the near-edge VUV absorption. A rough estimation of the percentage of free Si-OH groups (43%) converted into H-bonded ones by cooling a- SiO sub(2) down to 4 K is provided as well. A possible model for the interpretation of the observed experimental evidences is proposed: we suggest silanol groups to be arranged in clusters in the amorphous SiO sub(2) network.
Passive control introducing energy absorbing devices into the structure has received considerable attention in recent years. Unfortunately the constitutive law of viscous fluid dampers is highly ...nonlinear, and even supposing that the structure behaves linearly, the whole system has inherent nonlinear properties. Usually the analysis is performed by a stochastic linearization technique (SLT) determining a linear system equivalent to the nonlinear one, in a statistical sense. In this paper the effect of the non-Gaussianity of the response due to the inherent nonlinearity of the damper device will be studied in detail via the Path Integral Solution (PIS) method. A systematic study is conducted showing that for a very wide range of parameters the SLT gives satisfactory results in terms of variance of displacement and velocity but not in terms of joint Probability Density Function (PDF). It has also been shown that at steady state the two processes, displacement and velocity, may be considered as independent ones.
Abstract Background Recent studies have shown that the cyclooxygenase (COX) and the inducible nitric oxide synthase (iNOS) pathways are involved in the development of tumor angiogenesis in human ...cancers. Aims To investigate whether a different pattern of COX-2 and iNOS expression/activity exists within different areas of colorectal tumors and to analyze the relationship between these two enzymes and tumor angiogenesis. Methods Microvessel density (MVD) and COX-2, iNOS, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein expression were evaluated at both the invasive front (IF) and the tumor center (TC) in 46 human colorectal cancer specimens. We also investigated the concentration of PGE2 and NO at the same sites. Results COX-2 and iNOS protein expression and activity were significantly higher within the IF than the TC of the tumor specimens. Similarly, MVD and VEGF/VEGFR-2 expression significantly increased from the TC to the IF. Only COX-2 expression was significantly correlated with MVD and VEGF/VEGFR-2 expression at both the TC and the IF. Conclusion Our study shows a heterogeneous expression of COX-2 and iNOS in colorectal cancer. The up-regulation of COX-2 at the IF parallels an increase in vessel density and VEGF/VEGFR-2 expression, thus supporting the hypothesis that the tumor periphery is the most aggressive portion of a colorectal tumor.
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