Ionic conductivity in dehydrated zeolites

The ionic conductivity of pressed pellets of dehydrated synthetic offretite, cancrinite and zeolite A, with various alkali metal ions, was determined by low-frequency impedance spectroscopy. Experiments were carried out in the frequency range 10 Hz–10 MHz at temperatures from 100–600°C. The conduction activation energies range between 55 kJ mol^?1 (Na-zeolite A) and 108 kJ mol^?1 (Li-cancrinite). The best conductivity value obtained was that of Na-zeolite A with 2.9×10^?3Ω^?1cm^?1 at 600°C.     

Ionic conductivity of synthetic analcime,sodalite and offretite

The ionic conductivity of pressed pellets of dehydrated synthetic analcime, sodalite and offretite was determined by a.c. measurements within the range 10 Hz to 10 MHz. The ionic conductivity values of those zeolites exchanged with various monovalent cations were determined by the complex impedance plane method. The conduction activation energies range between 63 and 101 kJ mol^–1. Sodium analcime shows the best ionic conductivity, namely 1.8×10^–4–1 cm^–1 at 400° C. A comparison with the conductivity of other ion-conducting solids was made.     

Smoothed Particle Hydrodynamics (SPH) simulation of a high-pressure homogenization process

High-pressure homogenization is a widely used process in the food, pharmaceutical, and cosmetic industry for producing emulsions. Because of small dimensions and high velocities, the experimental and numerical investigation of such a process is challenging. Hence, the development of products is mostly based on trial and error. In this paper, simulations of a generic high-pressure homogenization process using the Lagrangian, mesh-free smoothed particle hydrodynamics (SPH) method are presented and compared to experimental findings using Micro-Particle Image Velocimetry (μ-PIV). The SPH code has been developed and validated with the scope of simulating technical relevant multi-phase problems (Höfler et al. 2012). The present simulations cover the investigation of two different dynamic viscosities of the dispersed phase as well as different droplet trajectories. The comparison between the simulations and the experiments focusses on the velocity distribution of the continuous phase and the droplet deformation and breakup. In both cases a qualitatively good agreement is observed, demonstrating the ability of our SPH implementation for simulating technical relevant two-phase flows.     

Why are rocks pointy? Children's preference for teleological explanations of th natural world.

Teleological explanations are based on the assumption that an object or behavior exists for a purpose. Two studies explored the tendency of adults and first-, second-, and fourth-grade elementary-school children to explain the properties of living and nonliving natural kinds in teleological terms. Consistent with the hypothesis that young children possess a promiscuous teleological tendency, Study 1 found that children were more likely than adults to broadly examine the properties of both living and nonliving natural kinds in teleological terms, although the kinds of functions that they endorsed varied with age. Study 2 was an attempt to reduce children's broad teleological bias by introducing a pretrial that described, in nonteleological terms, the physical process by which nonliving natural kinds form. In spite of this attempt, Study 2 replicated the effects of Study 1, with only fourth graders showing any shift in preference for teleological explanation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of diagnostic peritoneal lavage in stable patients with gunshot wounds to the abdomen

BACKGROUND: Diagnostic peritoneal lavage (DPL) is used to diagnose intra-abdominal injury in patients with stab wounds and blunt trauma. Because exploratory celiotomy is routinely performed on patients with gunshot wounds to the abdomen, DPL is rarely employed. However, several studies have questioned routine exploration and have drawn attention to the associated morbidity of negative celiotomy. Diagnostic peritoneal lavage is an easily performed and inexpensive test that may be useful in this situation. OBJECTIVE: To evaluate the performance of DPL in the diagnosis of intra-abdominal injury in hemodynamically stable patients with gunshot wounds to the abdomen. DESIGN: A prospective clinical trial. SETTING: Two urban trauma centers. PATIENTS: Patients with gunshot wounds to the abdomen and a systolic blood pressure of at least 90 mm Hg. INTERVENTIONS: Clinical predication of intra-abdominal injury in the emergency department and DPL performed in the operating room before the initiation of celiotomy. Injuries found during the celiotomy were recorded. MAIN OUTCOME MEASURES: The results of the clinical evaluation and DPL were compared with the findings of the celiotomy. RESULTS: Forty-four patients were enrolled into the study. Intra-abdominal injury was present in 32 (73%) of these patients. The senior surgery resident correctly predicted the presence of intra-abdominal injury in 36 (82%) of the patients (sensitivity = 90.0%, specificity = 58.3%, positive predictive value = 85.3%, negative predictive value = 63.6%, phi = 0.52, P < .01) in the emergency department before DPL and celiotomy were performed. Diagnostic peritoneal lavage correctly identified the presence or absence of intra-abdominal injury in 40 (91%) of the patients (positive predictive value = 96.7%, negative predictive value = 78.6%, phi = 0.79, P < .01). CONCLUSIONS: Clinical judgment is highly accurate in separating patients with tangential gunshot wounds to the abdomen from those with intra-abdominal injury but may miss patients with intra-abdominal hemorrhage. Diagnostic peritoneal lavage is highly predictive of the presence of intra-abdominal injury. The return of gross blood on aspiration or a lavage red blood cell count greater than 10 x 10(9)/L should prompt an urgent celiotomy. Missed injuries are rare and most likely to be bowel perforations. Diagnostic peritoneal lavage is an objective test that may augment clinical judgment in selecting hemodynamically stable patients with potential tangential gunshot wounds for observation and is especially useful in identifying intra-abdominal hemorrhage.     

A new radiation-free conditioning in bone marrow transplantation and dibromo-mannitol therapy in chronic myeloid leukemia

A new, radiation-free, conditioning protocol, containing the original Hungarian mitobronitol (DBM) (DBM/ cytosine arabinoside/cyclosphosphamide) has been applied to 36 chronic myeloid leukemia (CML) patients followed by bone marrow transplantation (BMT) from HLA identical sibling donors between 1990-1997. In spite of some prognostically disadvantageous factors (half of them were above 40 years, 10 out of 36 patients were in accelerated phase, the disease history was longer than 2 years in average) the overall survival (30/36) and the leukemia free survival rate (26/36) were in accordance with the best international results. Transplantation-related toxicity was remarkably reduced in comparison to bone marrow transplantation performed by total body irradiation/cyclophosphamide (TBI/Cy) or busulphan/cyclophosphamide (Bu/Cy) conditioning protocols. Acute graft versus host disease was present in lower percentage (9/36) and the number of serious cases was only 2/36. Chronic GVH disease, generally known to be associated with antileukemic effect (GVL), occurred in 25 of cases. Early haematological relapse among the 34 patients with functioning graft occurred in 6 patients which rate is slightly higher than reported after TBI/Cy or Bu/Cy conditioning treatment. There was no relapse among patients transplanted within one year post-diagnosis and patients having CML with accelerated phase. The leukemia free post-transplant period was in association with the chronic GVH disease and full chimeric state.     

Occurrence, causes and clinical characteristics of status epilepsy in adults

INTRODUCTION: Status epilepticus, particularly grand mal, is one of the gravest and most dramatic conditions in neurology requiring immediate attention. Status epilepticus can occur in epileptic patients, often with higher mortality rates in symptomatic than idiopathic, but also as an initial symptom of a number of neurological and systemic diseases. No data are available on the exact incidence rates of status epilepticus. According to some assessments, 10% of patients have at least one status epilepticus in their lifetime (3,6). The prognosis mostly depends on the main cause, time in which seizures are stopped and age of patients. Latest data available in literature suggest the mortality rate of 2-8%. MATERIALS AND METHODS: We analyzed frequency of hospital admissions, causes and clinical characteristics of status epilepticus in adults. The study was retrospective, based on case histories of epileptic patients from the Intensive Care Unit of the Neurology Clinic in Novi Sad in 1990, 1993 and 1995. Special emphasis was placed on differences in studied parameters between cases confirmed earlier and those with status epilepticus occurring as an initial symptom of some other illness or condition. RESULTS: Number of hospital admissions rose slightly in the interval observed in comparison with total admissions (0.68% in 1990, 1.24% in 1993, and 1.73% in 1995) (Tabs 1 and 2). During 1993, status epilepticus was more frequent in cases confirmed earlier (69%) compared with the years 1990 (56%) and 1995 (43%) (Graf.1). Epileptic patients were younger on the average than nonepileptic ones (Tab. 3). Status epilepticus occurred more often in male patients (Tab. 4). Irregular treatment was the prevailing cause in epileptic patients (Tab 5). Symptomatic status epilepticus was reported higher in 1990 and 1995, and stroke was definitely the predominant cause (Tab 6). Convulsive grand mal status prevailed in all patients (Graf 2). Focal status was a more frequent finding in nonepileptic patients (Graf 3). Every third in 16 patients died in 1993 and every fifth in 23 in 1995 probably due to the acute destructive brain damage rather than the status itself. No deaths occurred in 1990. DISCUSSION: According to research carried out by other authors, half of grand mal status cases occurred in confirmed epileptics (4). In our study the grand mal status was reported in 70.4% cases of epilepsy. Primary cause was abrupt withdrawal of antiepileptic treatment, infections, alcohol abuse and use of convulsive drugs. This is compatible with our results which confirm that grand mal status either primary or with secondary generalization prevail in both groups of patients (7,8,9). In terms of causes of status epilepticus in nonepileptic patients, literature data mainly suggest cerebral trauma, frontal brain tumors, cerebral arteriosclerosis or other vascular disorders and anaphylaxis (4). Our results point to stroke as the major cause of status epilepticus in nonepileptic patients, similar with data presented by Towne (10). There is no data in literature concerning the relation between sex of patients and occurrence of status. In our study status epilepticus occurred more frequently in male patients. CONCLUSION: The grand mal status was the major clinical type of status in all patients and was primarily caused by discontinued or irregular antiepileptic treatment in patients with confirmed epilepsy, and by stroke in nonepileptic patients.