Operando sulfur speciation during sulfur poisoning-regeneration of Ru/SiO2 and Ru/Al2O3 using non-resonant sulfur Kα1,2 emission

A periodic oxidative regeneration of a sulfur-poisoned methanation catalyst is an alternative to the expensive state-of-the-art process of syngas cleaning using wet scrubbers. Here we have employed operando X-ray emission spectroscopy (XES) to study sulfur speciation on Ru/SiO₂ and Ru/Al₂O₃ during methanation in the presence of H₂S and subsequent regeneration in dilute O₂ at 360 °C. XES allowed us to obtain semi-quantitative sulfur speciation and to monitor changes in the absolute sulfur concentration. It was established that Al₂O₃, in contrast to SiO₂, forms sulfite/sulfate species by reacting with SO₂, which is released from the poisoned Ru surface upon oxidative treatment. The concentration of sulfite/sulfate species is reduced upon switching the feed to H₂/CO while no simultaneous increase in sulfide concentration is observed. For both catalysts, the regenerative treatment removes adsorbed sulfur as SO₂ only partially, which we propose is the main reason for the incomplete activity recovery of the poisoned catalyst after regeneration.

Operando S Kα X-ray emission spectroscopy allows for a quantitative understanding of the sulfur poisoning and regeneration mechanism of state-of-the-art methanation catalysts used for the wood to synthetic natural gas process.     

Nonfunctional Pancreatic Neuroendocrine Tumors <2 cm on Preoperative Imaging are Associated with a Low Incidence of Nodal Metastasis and an Excellent Overall Survival

Background

The optimal surgical management of small nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) remains controversial. We sought to identify (1) clinicopathologic factors associated with survival in NF-PNETs and (2) preoperative tumor characteristics that can be used to determine which lesions require resection and lymph node (LN) harvest.

Methods

The records of all 116 patients who underwent resection for NF-PNETs between 1989 and 2012 were reviewed retrospectively. Preoperative factors, operative data, pathology, surgical morbidity, and survival were analyzed.

Results

The overall 5- and 10-year survival rates were 83.9 and 72.8 %, respectively. Negative LNs (p?=?0.005), G1 or G2 histology (p?=?0.033), and age <60 years (p?=?0.002) correlated with better survival on multivariate analysis. The 10-year survival rate was 86.6 % for LN-negative patients (n?=?73) and 34.1 % for LN-positive patients (n?=?32). Tumor size ≥2 cm on preoperative imaging predicted nodal positivity with a sensitivity of 93.8 %. Positive LNs were found in 38.5 % of tumors ≥2 cm compared to only 7.4 % of tumors <2 cm.

Conclusions

LN status, a marker of systemic disease, was a highly significant predictor of survival in this series. Tumor size on preoperative imaging was predictive of nodal disease. Thus, it is reasonable to consider parenchyma-sparing resection or even close observation for NF-PNETs <2 cm.     

Distinct medial temporal contributions to different forms of recognition in amnestic mild cognitive impairment and Alzheimer's disease

The simplest expression of episodic memory is the experience of familiarity, the isolated recognition that something has been encountered previously. Brain structures of the medial temporal lobe (MTL) make essential contributions to episodic memory, but the distinct contributions from each MTL structure to familiarity are debatable. Here we used specialized tests to assess recognition impairments and their relationship to MTL integrity in people with amnestic mild cognitive impairment (aMCI, n=19), people with probable Alzheimer's disease (AD; n=10), and age-matched individuals without any neurological disorder (n=20). Recognition of previously presented silhouette objects was tested in two formats—forced-choice recognition with four concurrent choices (one target and three foils) and yes/no recognition with individually presented targets and foils. Every foil was extremely similar to a corresponding target, such that forced-choice recognition could be based on differential familiarity among the choices, whereas yes/no recognition necessitated additional memory and decision factors. Only yes/no recognition was impaired in the aMCI group, whereas both forced-choice and yes/no recognition were impaired in the AD group. Magnetic resonance imaging showed differential brain atrophy, as MTL volume was reduced in the AD group but not in the aMCI group. Pulsed arterial spin-labeled scans demonstrated that MTL blood flow was abnormally increased in aMCI, which could indicate physiological dysfunction prior to the emergence of significant atrophy. Regression analyses with data from all patients revealed that regional patterns of MTL integrity were differentially related to forced-choice and yes/no recognition. Smaller perirhinal cortex volume was associated with lower forced-choice recognition accuracy, but not with lower yes/no recognition accuracy. Instead, smaller hippocampal volumes were associated with lower yes/no recognition accuracy. In sum, familiarity memory can be specifically assessed using the forced-choice recognition test, it declines later than other MTL-dependent memory functions as AD progresses, and it has distinct anatomical substrates.     

The prognostic role of pre-cystectomy hemoglobin levels in patients with invasive bladder cancer

Purpose

To determine whether pre-treatment hemoglobin (Hb) levels in patients with bladder cancer impact on oncological outcomes after radical cystectomy (RC).

Methods

A consecutive, contemporary series of 246 patients undergoing RC and pelvic lymph node dissection for bladder cancer. Decreased Hb level was defined as ≤12 g/dL. The Kaplan–Meier method was used to estimate recurrence-free (RFS), cancer-specific (CSS) and overall survival (OS). The Fisher exact/Chi-square test was used to investigate differences between both groups. Uni- and multivariable Cox regression analysis addressed risk factors for recurrence, cancer-specific death and overall death. The median follow-up was 30 months (2–116).

Results

Of the 246 patients, 182 (74 %) had normal (>12 g/dL) and 64 decreased (≤12 g/dL) preoperative Hb (26 %). In univariable analysis, decreased Hb was associated with increased age, extravesical disease, hydronephrosis (all p < 0.001), node-positive disease and positive resection margins (both p = 0.01). Subanalyzed for patients with organ-confined disease (defined as ≤pT2bN0R0; N = 109), the 3-year RFS, CSS and OS was significantly lower in patients with decreased (34.9, 35.5 and 19.8 %) compared to normal Hb level (69.7, 86.3 and 77.6 %; p = 0.01/p = 0.002/p < 0.001). In multivariable analysis, RFS, CSS and OS were significantly lower in patients with decreased Hb (p = 0.007, p = 0.001 and p = 0.002), pathologically locally advanced tumor (≥pT3a; p = 0.023, p = 0.036 and p = 0.065) and nodal stage (p < 0.001, p = 0.006 and p = 0.001) and positive soft tissue surgical margins (p = 0.040, p = 0.004 and 0.012).

Conclusions

Pre-cystectomy Hb levels are associated with adverse histopathologic characteristics and provide additional prognostic information especially for patients with pathologically localized bladder cancer.

     

CA19-9 Normalization During Pre-operative Treatment Predicts Longer Survival for Patients with Locally Progressed Pancreatic Cancer

Background

Compared to the widely adopted 2–4 months of pre-operative therapy for patients with borderline resectable (BR) or locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC), our institution tends to administer a longer duration before considering surgical resection. Using this unique approach, the aim of this study was to determine pre-operative variables associated with survival.

Methods

Records from patients with BR/LA PDAC who underwent attempt at surgical resection from 1992–2014 were reviewed.

Results

After a median duration of 6 months of pre-operative treatment, 109 patients with BR/LA PDAC (BR 63, LA 46) were explored; 93 (85.3 %) underwent pancreatectomy. Those who received at least 6 months of pre-operative treatment had longer median overall survival (OS) than those who received less (52.8 vs. 32.1 months, P?=?0.044). On multivariate analysis, pre-operative treatment duration was the strongest predictor of survival (hazard ratio (HR) 4.79, P?=?0.043). However, OS was similar in those whose CA19-9 normalized regardless of whether they received more or less than 6 months of chemotherapy (71.4 vs. 101.8 months, P?=?0.930).

Conclusions

Pre-operative CA19-9 decline can guide treatment duration in patients with BR/LA PDAC. We endorse 6 months of therapy except in those patients whose values normalize, where surgery can be considered after a shorter course.

     

An electrophysiological endophenotype of hypomanic and hyperthymic personality

BACKGROUND: Hyperthymic Temperament (HYT) and a closely related trait, Hypomanic Personality (HYP), have both been related to bipolar affective disorder (BAD). Intensity dependence of auditory evoked potentials (IAEP) is a suggested inverse indicator of serotonergic neurotransmission and has been found to be elevated in BAD. Therefore the present study explored for the first time whether subclinical variance of HYT/HYP is also associated with IAEP in a healthy sample. As several traits from biological personality research are correlated with HYT/HYP and also with BAD, the specificity of results against these traits was further analyzed by calculating multiple regression analyses. METHODS: Evoked potentials were recorded from a sample (N=87) homogenous for confounding variables influencing IAEP. For this reason, only 19 to 27-year-old non-smoker psychiatrically healthy male students were included. RESULTS: Significant correlations were found between IAEP and both HYP and HYT. Including Sensation or Novelty Seeking and Extraversion in Regression Analyses did not weaken the associations of HYP with IAEP much, but did affect those of HYT. However, these competing biological personality traits were hardly able to predict IAEP themselves. Impulsivity, though, was able to reduce the predictive power of HYP and HYT and to explain unique IAEP-variance. This was even more the case for Behavioral-Activation-System-Sensitivity (BAS) subscale Fun Seeking clearly dominating all regression analyses. LIMITATIONS: Homogeneity of sample. CONCLUSIONS: The impact of BAS is in agreement with the assumption that heightened BAS-sensitivity is an underlying biological cause for HYP/HYT and for BAD. Future studies on BAD should include BAS and Impulsivity besides HYP/HYT to further explore uniqueness of the latter and to develop questionnaires based on those items of a hyperthymic-hypomanic-impulsive-funseeking item pool, which possess the most external validity.