Risk factors of early mortality in COVID-19 patients in Indonesia: A retrospective cohort study in a provincial referral hospital of Aceh.

Some of coronavirus disease 2019 (COVID-19) patients died after being hospitalized and early mortality is a matter of concern during the pandemic; therefore, it is critical to determine which patients are the most vulnerable of having early mortality. The aim of this study was to determine the risk factors for early mortality among hospitalized COVID-19 patients in Indonesia. A retrospective cohort study was conducted on hospitalized COVID-19 patients from July 2020 to September 2021 at Dr. Zainoel Abidin Hospital, Banda Aceh, Indonesia. Demographic data, clinical characteristics, laboratory findings, and mortality were collected. Early mortality was defined as a death before seven days of the hospitalization. Multivariate regression analysis was employed to determine the risk factors associated with early mortality. We included the data of 624 COVID-19 patients who died during the study period. More than half of the patients were male and aged over 50 years old. The average hospitalization period was 10 days and most patients had more than two comorbidities. Chronic lung disease was the most common comorbidity (46.0%) followed by respiratory disease (26.8%) and heart disease (14.3%). Multiple comorbidities and elevated D-dimers exceeding 3376.92 ng/mL were associated with early mortality with OR: 7.029; 95%CI: 2.02-24.43 and OR: 1.000085, 95%CI: 1.000028-1.000142, respectively. In conclusion, early mortality in COVID-19 patients was associated with having multiple comorbidities and elevated D-dimer level. Therefore, it is crucial to assess the presence of comorbidities and routine laboratory test while managing COVID-19 patients in order to prevent the early mortality.

Correlation between high sensitivity C reactive protein (Hs-CRP) and neutrophil-to- lymphocyte ratio (NLR) with functional capacity in post COVID-19 syndrome patients.

Post coronavirus disease 2019 (COVID-19) syndrome is one of the causes of reduced functional capacity and work productivity, in particular for healthcare workers. The pathophysiology of the post COVID-19 syndrome is related to complex and multisystem inflammatory mechanisms, and cardiopulmonary exercise rehabilitation program is one of the efforts to improve the recovery process for patients with post COVID-19 syndrome. The aim of this study was to determine the correlation between the level of high sensitivity C-reactive protein (Hs-CRP) and neutrophil-to-lymphocyte ratio (NLR) with functional capacity (VO2max) in individuals with post-COVID-19 syndrome who received moderate- and high-intensity supervised cardiopulmonary exercise. A prospective cohort study was conducted at the Integrated Cardiac Rehabilitation Center of Dr. Zainoel Abidin Hospital, Banda Aceh, Indonesia. The supervised cardiopulmonary exercise was conducted for six weeks according to the participant's baseline VO2max. Spearman's and Pearson's correlation tests were used to assess the correlations. A total of 30 individuals (19 and 11 had moderate and high intensity exercise, respectively) were involved in this study. At moderate intensity exercise, the average Hs-CRP and NLR were 3.3 mg/L and 1.99, respectively; while at high intensity, the values were 3.8 mg/L and 1.79, respectively. No significant correlation between Hs-CRP level and functional capacity in both moderate-intensity and high intensity groups. In contrast, NLR was negatively correlated with functional capacity (r=-0.545, p=0.016) in moderate intensity exercise group. In conclusion, NLR value was negatively correlated with functional capacity in individuals with post-COVID-19 syndrome after receiving moderate intensity supervised cardiopulmonary exercise program. Therefore, moderate intensity of cardiopulmonary exercise maybe be used as a program to accelerate the recovery for those with post COVID-19 syndrome.

KI and TEDA influences towards the retention of radiotoxic CH3I by activated carbons.

Activated carbons (AC) are widely used within the ventilation networks of nuclear facilities to trap volatile iodine species. In this paper, the performances of various commercial activated carbons towards the trapping of γ-labelled methyl iodide were evaluated in semi-pilot scale under different R.H. according to normalized procedures. A combination between the retention performances and the physico-chemical properties as deduced from several techniques was performed to gain insights about the AC influencing parameters on γ-CH3I capture. Different trends were obtained depending on the impregnant nature and the studied conditions. A high sensitivity of KI/AC towards water vapor was outlined. At R.H. = 40%. The enhancement of water uptake by KI/AC as deduced from water adsorption experiments, leads to decrease the available microporosity for CH3I physisorption, inducing therefore the reduction of performances as a function of KI content at these conditions. At R.H. = 90%, the adsorption mechanism was found to be governed by isotopic exchange reaction since 90% of the microporosity was occupied by water molecules. Therefore, a slight increase of DF was obtained in these conditions. This sensitivity was found to be of a lesser extent for TEDA/AC displaying the highest retention performances whatever the studied condition.

Biomarker analyses of second-line ramucirumab in patients with advanced gastric cancer from RAINBOW, a global, randomized, double-blind, phase 3 study.

BACKGROUND: The RAINBOW trial showed that second-line ramucirumab with paclitaxel prolongs overall survival (OS) and progression-free survival (PFS) compared with placebo plus paclitaxel for treatment of advanced gastric/gastroesophageal junction cancer. Plasma samples were collected from patients during the trial and tested to identify predictive and prognostic biomarkers. PATIENTS AND METHODS: Circulating factors in plasma samples from mutually exclusive subsets of RAINBOW patients were assayed using: Intertek assays (24 markers, 380 samples, 57% of patients) and Lilly-developed assay (LDA) platform (5 markers, 257 samples, 39% of patients). Time-trend plots were generated for each marker from the Intertek assays. Baseline patient data were dichotomized into low- and high-marker subgroups. Markers were analyzed for predictive effects using interaction models and for prognostic effects using main-effects models. RESULTS: The Intertek and LDA populations were representative of the full trial population. Plasma levels of VEGF-D and PlGF increased from baseline levels during treatment, then declined after treatment discontinued. Angiopoietin-2 exhibited a decrease during treatment, then increased after treatment discontinuation. No clear time trend was evident with the other markers. Analyses of baseline biomarker expression and its relationship with efficacy variables found no biomarker was predictive for efficacy outcomes, including VEGF-D. However, CRP, HGF, ICAM-3, IL-8, SAA, and VCAM-1 were identified as potential prognostic markers with low baseline levels corresponding to longer OS and PFS. CONCLUSIONS: Pharmacodynamic and prognostic relationships were found from the exploratory biomarker analyses in RAINBOW; however, no predictive markers for ramucirumab in gastric cancer were identified in this trial.

Analysis of angiogenesis biomarkers for ramucirumab efficacy in patients with metastatic colorectal cancer from RAISE, a global, randomized, double-blind, phase III study.

Background: The phase III RAISE trial (NCT01183780) demonstrated that the vascular endothelial growth factor (VEGF) receptor (VEGFR)-2 binding monoclonal antibody ramucirumab plus 5-fluororuracil, leucovorin, and irinotecan (FOLFIRI) significantly improved overall survival (OS) and progression-free survival (PFS) compared with placebo + FOLFIRI as second-line metastatic colorectal cancer (mCRC) treatment. To identify patients who benefit the most from VEGFR-2 blockade, the RAISE trial design included a prospective and comprehensive biomarker program that assessed the association of biomarkers with ramucirumab efficacy outcomes. Patients and methods: Plasma and tumor tissue collection was mandatory. Overall, 1072 patients were randomized 1 : 1 to the addition of ramucirumab or placebo to FOLFIRI chemotherapy. Patients were then randomized 1 : 2, for the biomarker program, to marker exploratory (ME) and marker confirmatory (MC) groups. Analyses were carried out using exploratory assays to assess the correlations of baseline marker levels [VEGF-C, VEGF-D, sVEGFR-1, sVEGFR-2, sVEGFR-3 (plasma), and VEGFR-2 (tumor tissue)] with clinical outcomes. Cox regression analyses were carried out for each candidate biomarker with stratification factor adjustment. Results: Biomarker results were available from >80% (n = 894) of patients. Analysis of the ME subset determined a VEGF-D level of 115 pg/ml was appropriate for high/low subgroup analyses. Evaluation of the combined ME + MC populations found that the median OS in the ramucirumab + FOLFIRI arm compared with placebo + FOLFIRI showed an improvement of 2.4 months in the high VEGF-D subgroup [13.9 months (95% CI 12.5-15.6) versus 11.5 months (95% CI 10.1-12.4), respectively], and a decrease of 0.5 month in the low VEGF-D subgroup [12.6 months (95% CI 10.7-14.0) versus 13.1 months (95% CI 11.8-17.0), respectively]. PFS results were consistent with OS. No trends were evident with the other antiangiogenic candidate biomarkers. Conclusions: The RAISE biomarker program identified VEGF-D as a potential predictive biomarker for ramucirumab efficacy in second-line mCRC. Development of an assay appropriate for testing in clinical practice is currently ongoing. Clinical trials registration: NCT01183780.

A randomized, open-label study of the efficacy and safety of AZD4547 monotherapy versus paclitaxel for the treatment of advanced gastric adenocarcinoma with FGFR2 polysomy or gene amplification.

BACKGROUND: Approximately 5%-10% of gastric cancers have a fibroblast growth factor receptor-2 (FGFR2) gene amplification. AZD4547 is a selective FGFR-1, 2, 3 tyrosine kinase inhibitor with potent preclinical activity in FGFR2 amplified gastric adenocarcinoma SNU16 and SGC083 xenograft models. The randomized phase II SHINE study (NCT01457846) investigated whether AZD4547 improves clinical outcome versus paclitaxel as second-line treatment in patients with advanced gastric adenocarcinoma displaying FGFR2 polysomy or gene amplification detected by fluorescence in situ hybridization. PATIENTS AND METHODS: Patients were randomized 3:2 (FGFR2 gene amplification) or 1:1 (FGFR2 polysomy) to AZD4547 or paclitaxel. Patients received AZD4547 80 mg twice daily, orally, on a 2 weeks on/1 week off schedule of a 21-day cycle or intravenous paclitaxel 80 mg/m2 administered weekly on days 1, 8, and 15 of a 28-day cycle. The primary end point was progression-free survival (PFS). Safety outcomes were assessed and an exploratory biomarker analysis was undertaken. RESULTS: Of 71 patients randomized (AZD4547 n = 41, paclitaxel n = 30), 67 received study treatment (AZD4547 n = 40, paclitaxel n = 27). Among all randomized patients, median PFS was 1.8 months with AZD4547 and 3.5 months with paclitaxel (one-sided P = 0.9581); median follow-up duration for PFS was 1.77 and 2.12 months, respectively. The incidence of adverse events was similar in both treatment arms. Exploratory biomarker analyses revealed marked intratumor heterogeneity of FGFR2 amplification and poor concordance between amplification/polysomy and FGFR2 mRNA expression. CONCLUSIONS: AZD4547 did not significantly improve PFS versus paclitaxel in gastric cancer FGFR2 amplification/polysomy patients. Considerable intratumor heterogeneity for FGFR2 gene amplification and poor concordance between FGFR2 amplification/polysomy and FGFR2 expression indicates the need for alternative predictive biomarker testing. AZD4547 was generally well tolerated.

Negative Differential Conductance & Hot-Carrier Avalanching in Monolayer WS2 FETs.

The high field phenomena of inter-valley transfer and avalanching breakdown have long been exploited in devices based on conventional semiconductors. In this Article, we demonstrate the manifestation of these effects in atomically-thin WS2 field-effect transistors. The negative differential conductance exhibits all of the features familiar from discussions of this phenomenon in bulk semiconductors, including hysteresis in the transistor characteristics and increased noise that is indicative of travelling high-field domains. It is also found to be sensitive to thermal annealing, a result that we attribute to the influence of strain on the energy separation of the different valleys involved in hot-electron transfer. This idea is supported by the results of ensemble Monte Carlo simulations, which highlight the sensitivity of the negative differential conductance to the equilibrium populations of the different valleys. At high drain currents (>10 µA/µm) avalanching breakdown is also observed, and is attributed to trap-assisted inverse Auger scattering. This mechanism is not normally relevant in conventional semiconductors, but is possible in WS2 due to the narrow width of its energy bands. The various results presented here suggest that WS2 exhibits strong potential for use in hot-electron devices, including compact high-frequency sources and photonic detectors.

Meta-analysis of individual patient safety data from six randomized, placebo-controlled trials with the antiangiogenic VEGFR2-binding monoclonal antibody ramucirumab.

BACKGROUND: Ramucirumab, the human immunoglobulin G1 monoclonal antibody receptor antagonist of vascular endothelial growth factor receptor 2, has been approved for treating gastric/gastroesophageal junction, non-small-cell lung, and metastatic colorectal cancers. With the completion of six global, randomized, double-blind, placebo-controlled, phase III trials across multiple tumor types, an opportunity now exists to further establish the safety parameters of ramucirumab across a large patient population. MATERIALS AND METHODS: An individual patient meta-analysis across the six completed phase III trials was conducted and the relative risk (RR) and associated 95% confidence intervals (CIs) were derived using fixed-effects or mixed-effects models for all-grade and high-grade adverse events (AEs) possibly related to vascular endothelial growth factor pathway inhibition. The number needed to harm was also calculable due to the placebo-controlled nature of all six registration standard trials. RESULTS: A total of 4996 treated patients (N = 2748 in the ramucirumab arm and N = 2248 in the control, placebo arm) were included in this meta-analysis. Arterial thromboembolic events [ATE; all-grade, RR: 0.8, 95% CI 0.5-1.3; high-grade (grade ≥3), RR: 0.9, 95% CI 0.5-1.7], venous thromboembolic events (VTE; all-grade, RR: 0.7, 95% CI 0.5-1.1; high-grade, RR: 0.7, 95% CI 0.4-1.2), high-grade bleeding (RR: 1.1, 95% CI 0.8-1.5), and high-grade gastrointestinal (GI) bleeding (RR: 1.1, 95% CI 0.7-1.7) did not demonstrate a definite increased risk with ramucirumab. A higher percentage of hypertension, proteinuria, low-grade (grade 1-2) bleeding, GI perforation, infusion-related reaction, and wound-healing complications were observed in the ramucirumab arm compared with the control arm. CONCLUSIONS: Ramucirumab may be distinct among antiangiogenic agents in terms of ATE, VTE, high-grade bleeding, or high-grade GI bleeding by showing no clear evidence for an increased risk of these AEs in this meta-analysis of a large and diverse patient population. Ramucirumab is consistent with other angiogenic inhibitors in the risk of developing certain AEs. Clinical Trial Numbers: NCT00917384 (REGARD), NCT01170663 (RAINBOW), NCT01168973 (REVEL), NCT01183780 (RAISE), NCT01140347 (REACH), and NCT00703326 (ROSE).

First in-flight synchrotron X-ray absorption and photoemission study of carbon soot nanoparticles.

Many studies have been conducted on the environmental impacts of combustion generated aerosols. Due to their complex composition and morphology, their chemical reactivity is not well understood and new developments of analysis methods are needed. We report the first demonstration of in-flight X-ray based characterizations of freshly emitted soot particles, which is of paramount importance for understanding the role of one of the main anthropogenic particulate contributors to global climate change. Soot particles, produced by a burner for several air-to-fuel ratios, were injected through an aerodynamic lens, focusing them to a region where they interacted with synchrotron radiation. X-ray photoelectron spectroscopy and carbon K-edge near-edge X-ray absorption spectroscopy were performed and compared to those obtained for supported samples. A good agreement is found between these samples, although slight oxidation is observed for supported samples. Our experiments demonstrate that NEXAFS characterization of supported samples provides relevant information on soot composition, with limited effects of contamination or ageing under ambient storage conditions. The highly surface sensitive XPS experiments of airborne soot indicate that the oxidation is different at the surface as compared to the bulk probed by NEXAFS. We also report changes in soot's work function obtained at different combustion conditions.

Ramucirumab combined with FOLFOX as front-line therapy for advanced esophageal, gastroesophageal junction, or gastric adenocarcinoma: a randomized, double-blind, multicenter Phase II trial.

BACKGROUND: We report the first randomized, Phase II trial of ramucirumab, an anti-vascular endothelial growth factor receptor-2 monoclonal antibody, as front-line therapy in patients with advanced adenocarcinoma of the esophagus or gastric/gastroesophageal junction (GEJ). PATIENTS AND METHODS: Patients from the USA with advanced esophageal, gastric, or GEJ adenocarcinoma randomly received (1:1) mFOLFOX6 plus ramucirumab (8 mg/kg) or mFOLFOX6 plus placebo every 2 weeks. The primary end point was progression-free survival (PFS) with 80% power to detect a hazard ratio (HR) of 0.71 (one-sided α = 0.15). Secondary end points included evaluation of response and overall survival (OS); an exploratory ramucirumab exposure-response analysis was undertaken. RESULTS: Of 168 randomized patients, 52% of tumors were located in the stomach/GEJ and 48% in the esophagus. The trial did not meet the primary end point of PFS [6.4 versus 6.7 months, HR 0.98 (95% confidence interval 0.69-1.37)] or the secondary end point of OS (11.7 versus 11.5 months) in the intent-to-treat (ITT) population. Objective response rates (45.2% versus 46.4%) were similar between arms. Most Grade ≥3 toxicities did not differ significantly between arms, yet premature discontinuation of FOLFOX and ramucirumab (for reasons other than progressive disease) was more common among ramucirumab- versus placebo-treated patients. In an exploratory analysis that censored for premature discontinuation, the HR for PFS favored the ramucirumab arm (HR 0.76), particularly in patients with gastric/GEJ cancer. An exploratory exposure-response analysis indicated that patients with higher ramucirumab exposure had longer OS. CONCLUSION: The addition of ramucirumab to front-line mFOLFOX6 did not improve PFS in the ITT population. CLINICALTRIALSGOV IDENTIFIER: NCT01246960.

Conductance fluctuations in high mobility monolayer graphene: Nonergodicity, lack of determinism and chaotic behavior.

We have fabricated a high mobility device, composed of a monolayer graphene flake sandwiched between two sheets of hexagonal boron nitride. Conductance fluctuations as functions of a back gate voltage and magnetic field were obtained to check for ergodicity. Non-linear dynamics concepts were used to study the nature of these fluctuations. The distribution of eigenvalues was estimated from the conductance fluctuations with Gaussian kernels and it indicates that the carrier motion is chaotic at low temperatures. We argue that a two-phase dynamical fluid model best describes the transport in this system and can be used to explain the violation of the so-called ergodic hypothesis found in graphene.

Cisplatin in the modern era: The backbone of first-line chemotherapy for non-small cell lung cancer.

The treatment of advanced non-small cell lung cancer (NSCLC) may be changing, but the cisplatin-based doublet remains the foundation of treatment for the majority of patients with advanced NSCLC. In this respect, changes in practice to various aspects of cisplatin use, such as administration schedules and the choice of methods and frequency of monitoring for toxicities, have contributed to an incremental improvement in patient management and experience. Chemoresistance, however, limits the clinical utility of this drug in patients with advanced NSCLC. Better understanding of the molecular mechanisms of cisplatin resistance, identification of predictive markers and the development of newer, more effective and less toxic platinum agents is required. In addition to maximising potential benefits from advances in molecular biology and associated therapeutics, modification of existing cisplatin-based treatments can still lead to improvements in patient outcomes and experiences.

Physicochemical properties of aerosol released in the case of a fire involving materials used in the nuclear industry.

For industrial concerns, and more especially for nuclear applications, the characterization of soot is essential for predicting the behaviour of containment barriers in fire conditions. This study deals with the characterization (emission factor, composition, size, morphology, microstructure) of particles produced during thermal degradation of materials found in nuclear facilities (electrical cables, polymers, oil and solvents). Small-scale experiments have been conducted for oxygen concentrations [O2] ranging from 15% to 21% in order to imitate the oxygen depletion encountered during a confined fire. Particles denote distinct shapes, from aggregates composed of monomers with diameters ranging from 31.2 nm to 52.8 nm, to compact nanoparticles with diameters ranging from 15 nm to 400 nm, and their composition strongly depends on fuel type. Despite the organic to total carbon ratio (OC/TC), their properties are poorly influenced by the decrease in [O2]. Finally, two empirical correlations are proposed for predicting the OC/TC ratio and the monomer diameter, respectively, as a function of the fuel's carbon to hydrogen ratio and the emission factor.

A phase II randomized study evaluating the addition of iniparib to gemcitabine plus cisplatin as first-line therapy for metastatic non-small-cell lung cancer.

BACKGROUND: Iniparib is a novel anticancer agent initially considered a poly (ADP-ribose) polymerase (PARP) inhibitor, but subsequently shown to act via non-selective protein modification through cysteine adducts. This randomized phase II study investigated the addition of iniparib to gemcitabine-cisplatin in metastatic non-small-cell lung cancer (NSCLC) patients. PATIENTS AND METHODS: Patients with histologically confirmed stage IV NSCLC were randomized 2 : 1 to receive gemcitabine (1250 mg/m(2), days 1/8) and cisplatin (75 mg/m(2), day 1) with [gemcitabine/cisplatin/iniparib (GCI)] or without [gemcitabine/cisplatin (GC)] iniparib (5.6 mg/kg, days 1/4/8/11) every 3 weeks for six cycles. The primary end point was the overall response rate (ORR). Secondary objectives included progression-free survival (PFS), overall survival (OS), and safety. The study was not designed for formal efficacy comparison, the control arm being to benchmark results against the literature. RESULTS: One hundred and nineteen patients were randomized (39 GC and 80 GCI). More GCI patients were male (80% GCI and 67% GC) and had PS 0 (61% GCI and 49% GC). The ORR was 25.6% [95% confidence interval (CI) 13.0%-42.1%] with GC versus 20.0% (95% CI 11.9%-30.4%) with GCI, which did not allow rejection of the null hypothesis (ORR with GCI ≤20%; P = 0.545). Median PFS was 4.3 (95% CI 2.8-5.6) months with GC and 5.7 (95% CI 4.6-6.6) months with GCI (hazard ratio 0.89, 95% CI 0.56-1.40). Median OS was 8.5 (95% CI 5.5 to not reached) months with GC, and 12.0 (95% CI 8.9-17.1) months with GCI (hazard ratio 0.78, 95% CI 0.48-1.27). More GCI patients received second-line treatment (51% GC and 68% GCI). Toxicity was similar in the two arms. Grade 3-4 toxicities included asthenia (28% GC and 8% GCI), nausea (3% GC and 14% GCI), and decreased appetite (10% in each). CONCLUSIONS: Addition of iniparib to GC did not improve ORR over GC alone. The GCI safety profile was comparable to GC alone. Imbalances in PS and gender distribution may have impacted study results regarding PFS and OS. TRIAL REGISTRATION: ClinicalTrial.gov Identifier NCT01086254.

Assessing health-state utility values in patients with metastatic colorectal cancer: a utility study in the United Kingdom and the Netherlands.

PURPOSE: This study aimed to elicit EuroQol Quality of Life 5-Dimensions (EQ-5D) utility values from patients with second-line metastatic colorectal cancer (mCRC) pre- and post-progression. METHODS: A cross-sectional study was conducted in five hospitals in the Netherlands and the UK. Patients with mCRC were eligible if prescribed a second or subsequent line of therapy or best supportive care (BSC), received prior oxaliplatin in first-line therapy, and had Eastern Cooperative Oncology Group (ECOG) performance status scores of 0-2 at second-line initiation. Patients completed the EuroQol Quality of Life 5-Dimensions 3-levels (EQ-5D-3L) questionnaire and were categorized as pre- or post-progression. Chart data including patient demographics, clinical history, prior/current treatments and serious adverse events (SAEs) were collected. Mean utilities were estimated; uni- and multivariate analyses were conducted. RESULTS: Seventy-five patients were enrolled; 42 were pre-progression defined as second line or third line following an AE on second line and 33 were post-progression defined as third or subsequent therapy lines or BSC. Patient/disease characteristics and number of SAEs were similar between cohorts. Mean utility scores were 0.741 (SD = 0.230) and 0.731 (SD = 0.292) for pre- and post-progression cohorts, respectively. Compared to pre-progression, more patients reported increased anxiety/depression (36 vs. 12 %) and fewer problems with daily activities (64 vs. 38 %) post-progression. More patients pre-progression were on active treatment at enrolment (83 vs. 42 %) compared to post-progression. CONCLUSIONS: This is the first real-world study to collect utilities for patients with second-line mCRC pre- and post-disease progression. Utility values were similar pre- and post-progression. To further explore the effect of radiological progression on utilities, longitudinal research is required that includes patients in palliative care centres.

Scanning gate imaging of a disordered quantum point contact.

Scanning gate microscopy (SGM) is a novel technique that has been used to image characteristic features related to the coherent electron flow in mesoscopic structures. For instance, SGM has successfully been applied to study peculiar electron transport properties that arise due to small levels of disorder in a system. The particular case of an InGaAs quantum well layer in a heterostructure, which is dominated by a quasi-ballistic regime, was analyzed. A quantum point contact fabricated onto this material exhibits conduction fluctuations that are not expected in typical high-mobility heterostructures such as AlGaAs/GaAs. SGM revealed not only interference patterns corresponding to specific conductance fluctuations but also mode-dependent resistance peaks corresponding to the first and second quantum levels of conductance (2e(2)/h) at zero magnetic field. On the other hand, clear conductance plateaus originating from the integer quantum Hall effect were observed at high magnetic fields. The physical size of incompressible edge channels was estimated from cross-sectional analysis of these images.

Final results of Australasian Gastrointestinal Trials Group ARCTIC study: an audit of raltitrexed for patients with cardiac toxicity induced by fluoropyrimidines.

BACKGROUND: Cardiac toxicity an uncommon but serious side-effect of some fluoropyrimides. Cardiac toxicity from raltitrexed is rarely reported. With this background, we initiated this study to investigate the incidence of cardiac events in patients who had switched to raltitrexed following cardiac toxicity from fluoropyrimidines (5-fluorouracil or capecitabine). PATIENTS AND METHODS: Pharmacy records were used to identify patients receiving raltitrexed from January 2004 till March 2012. Medical records were then reviewed to confirm the use of raltitrexed after cardiac toxicity from 5-fluorouracil or capecitabine. The primary end point was the rate of further cardiac events after commencing raltitrexed. RESULTS: Forty-two patients were identified and the majority had colorectal cancer. Prior regimens included 5-fluorouracil ± leucovorin, capecitabine alone, FOLFOX, FOLFIRI, epirubicin/cisplatin/5-fluorouracil, and capecitabine/oxaliplatin. Seven patients (17%) had bolus 5-fluorouracil regimens, 26 patients (62%) had infusion 5-fluorouracil regimens, and 9 patients (21%) had capecitabine alone or in combination. Angina was the most common cardiac toxicity from 5-fluorouracil or capecitabine and usually occurred in the first or the second cycle. Four patients after their first cardiac event continued with the same 5-fluorouracil or capecitabine regimen with the addition of nitrates and calcium antagonists but still had further cardiac events. After changing to raltitrexed, either as a single agent or a continuing combination regimen, no patients experienced further cardiac toxicity. CONCLUSION: Raltitrexed is associated with no significant cardiac toxicity in patients who have experienced prior cardiac toxicity from 5-fluorouracil or capecitabine. Raltitrexed, alone or in combination with oxaliplatin or irinotecan, provides a safe option in terms of cardiac toxicity for such patients.

Conductance fluctuations in semiconductor nanostructures.

Conductance fluctuations have been seen in semiconductors and graphene for quite some time. It has generally been believed that a universality existed in which the conductance variance was the same for variations in energy and magnetic field, although some experiments have questioned this view. Here, we use numerical simulations to show that fluctuations in magneto-conductance are typically smaller than those in energy by as much as a factor of 3. Moreover, the amplitude of the fluctuations in each case varies with the strength of the random potential.

Fast energy relaxation of hot carriers near the Dirac point of graphene.

We investigate energy relaxation of hot carriers in monolayer and bilayer graphene devices, demonstrating that the relaxation rate increases significantly as the Dirac point is approached from either the conduction or valence band. This counterintuitive behavior appears consistent with ideas of charge puddling under disorder, suggesting that it becomes very difficult to excite carriers out of these localized regions. These results therefore demonstrate how the peculiar properties of graphene extend also to the behavior of its nonequilibrium carriers.