Magnetization of a two-dimensional electron gas with a second filled subband

We have measured the magnetization of a dual-subband two-dimensional electron gas, confined in a GaAs/AlGaAs heterojunction. In contrast to two-dimensional electron gases with a single subband, we observe non-1/B-periodic, triangularly shaped oscillations of the magnetization with an amplitude significantly less than $1 \mu_{\mathrm{B}}^*$ per electron. All three effects are explained by a field dependent self-consistent model, demonstrating the shape of the magnetization is dominated by oscillations in the confining potential. Additionally, at 1 K, we observe small oscillations at magnetic fields where Landau-levels of the two different subbands cross.Comment: 4 pages, 4 figure

Precision planar drift chambers and cradle for the TWIST muon decay spectrometer

To measure the muon decay parameters with high accuracy, we require an array of precision drift detector layers whose relative position is known with very high accuracy. This article describes the design, construction and performance of these detectors in the TWIST (TRIUMF Weak Interaction Symmetry Test) spectrometer.Comment: 44 pages, 16 Postscript figures, LaTeX2e, uses Elsevier class elsart.cls, package graphicx, submitted to Nuclear Instruments & Methods in Physics Researc

The PREDICT study uncovers three clinical courses of acutely decompensated cirrhosis that have distinct pathophysiology

Background & Aims: Acute decompensation (AD) of cirrhosis is defined as the acute development of ascites, gastrointestinal hemorrhage, hepatic encephalopathy, infection or any combination thereof, requiring hospitalization. The presence of organ failure(s) in patients with AD defines acute-on-chronic liver failure (ACLF). The PREDICT study is a European, prospective, observational study, designed to characterize the clinical course of AD and to identify predictors of ACLF. Methods: A total of 1,071 patients with AD were enrolled. We collected detailed pre-specified information on the 3-month period prior to enrollment, and clinical and laboratory data at enrollment. Patients were then closely followed up for 3 months. Outcomes (liver transplantation and death) at 1 year were also recorded. Results: Three groups of patients were identified. Pre-ACLF patients (n = 218) developed ACLF and had 3-month and 1-year mortality rates of 53.7% and 67.4%, respectively. Unstable decompensated cirrhosis (UDC) patients (n = 233) required ≥1 readmission but did not develop ACLF and had mortality rates of 21.0% and 35.6%, respectively. Stable decompensated cirrhosis (SDC) patients (n = 620) were not readmitted, did not develop ACLF and had a 1-year mortality rate of only 9.5%. The 3 groups differed significantly regarding the grade and course of systemic inflammation (high-grade at enrollment with aggravation during follow-up in pre-ACLF; low-grade at enrollment with subsequent steady-course in UDC; and low-grade at enrollment with subsequent improvement in SDC) and the prevalence of surrogates of severe portal hypertension throughout the study (high in UDC vs. low in pre-ACLF and SDC). Conclusions: Acute decompensation without ACLF is a heterogeneous condition with 3 different clinical courses and 2 major pathophysiological mechanisms: systemic inflammation and portal hypertension. Predicting the development of ACLF remains a major future challenge. ClinicalTrials.gov number: NCT03056612. Lay summary: Herein, we describe, for the first time, 3 different clinical courses of acute decompensation (AD) of cirrhosis after hospital admission. The first clinical course includes patients who develop acute-on-chronic liver failure (ACLF) and have a high short-term risk of death – termed pre-ACLF. The second clinical course (unstable decompensated cirrhosis) includes patients requiring frequent hospitalizations unrelated to ACLF and is associated with a lower mortality risk than pre-ACLF. Finally, the third clinical course (stable decompensated cirrhosis), includes two-thirds of all patients admitted to hospital with AD – patients in this group rarely require hospital admission and have a much lower 1-year mortality risk

Thin-layer chromatography under tropical conditions: Impact of high temperatures and high humidities on screening systems for analytical toxicology

The impact of high temperatures (33-38 degrees C) and high relative humidities (80-100%) on the applicability of TLC systems for drug identification was studied during a six month climatologic cycle in Jakarta, Indonesia. In general, the R(F) values as observed on the plates were substantially affected in comparison to values obtained at moderate climates: most substances gave higher R(F) values under the tropical conditions, although exceptions may occur as well. The deviations tended to increase with increasing humidities and could amount easily to 20-30 R(F) units. On the other hand, some TLC systems were more affected than others. Tropical conditions also had a negative effect on the reproducibility of the R(F) values. However, when an R(F) correction procedure was applied, using reference mixtures of standard drugs on each plate, accuracies as well as reproducibilities of the resulting R(F)(c) values were drastically improved and data thus corrected were found to be compatible with existing TLC data bases developed under moderate climatic conditions. These results are in line with earlier studies carried out in a relatively dry tropical climate. In the latter the observed R(F) values tended to be lower than the ones published in the literature, but the R(F) correction procedure was able to correct for this phenomenon

Thermal ablation combined with transarterial chemoembolization for hepatocellular carcinoma: What is the right treatment sequence?

Background: The combination treatment regimen of thermal ablation (TA) and transarterial chemoembolization (TACE) has gained a place in treatment of hepatocellular carcinoma (HCC) lesions > 3 cm unsuitable for surgery. Despite a high heterogeneity in the currently used treatment protocols, the pooled results of combined treatments seem to outperform those of TA or TACE alone. TACE preceding TA has been studied extensively, while results of the reverse treatment sequence are lacking. In this retrospective cohort study we compared the two treatment sequences. Patients and methods: 38 patients (median age: 68.5 yrs (range 40–84), male: 34, liver cirrhosis: 33, early stage HCC: 21, intermediate stage HCC: 17) were included in two tertiary referral centers, of whom 27 were treated with TA and adjuvant TACE (TA + TACE). The other 11 patients received TA with neoadjuvant TACE (TACE + TA). Overall survival (OS), time to progression (TTP) and local tumor progression (LTP) free survival were determined for the entire cohort and compared between the two treatment sequences. Results: The median OS of all patients was 52.7 months and the median time to LTP was 11.5 months (censored for liver transplantation). No differences were found with respect to OS between the two treatment sequences. Median time to LTP for TACE + TA was 23.6 months and 8.1 months for TA + TACE (p = 0.19). Discussion: No statistical differences were found for OS, TTP and time to LTP between patients treated with TA combined with neoadjuvant or adjuvant TACE