ABSTRACT
Hemicellulose lean pulps are a raw material source for numerous high value products. We have previously presented the IONCELL-P(ulp) process, a hemicellulose extraction method, based on a binary mixture of ionic liquid and water. The IONCELL-P process does not suffer from yield losses or polymer degradation and retains the Cellulose I crystalline form. In this paper, a selection of cellulose dissolving ionic liquids is tested, in order to compare their applicability in the process. We demonstrate that the extraction selectivity towards low molar mass polymers is related to the anion's ability to accept hydrogen bonds (Kamlet-Taft ß-value), if divided by the water molar fraction of the solvent system. Pulp consistency, solvent system viscosity and pH are investigated in order to identify the factors affecting the extraction efficiency. The results show that all the tested ionic liquid-water mixtures were able to dissolve hemicelluloses, but there were differences in their efficiency, selectivity and the ability to process high pulp consistencies.
ABSTRACT
IONCELL-P is a solvent fractionation process, which can separate pulps almost quantitatively into pure cellulose and hemicellulose fractions using IL-water mixtures. In this work the role of the molecular weight of cellulose on its solubility in ionic liquid-water mixtures is studied. The aim of this study was to understand and identify the determining factors of this IONCELL-P fractionation. Cotton linters (CL) served as model cellulose substrate and was degraded by ozone treatment to adjust the molecular weight to that of hemicelluloses and low molar mass cellulose in commercial pulps. The ozone treated CLs were subjected to the IONCELL-P process using 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) and water mixtures with a water content between 13.5 and 19wt%. Based on the molar mass distributions of dissolved and undissolved cellulose the effect of the molecular weight of cellulose in IL-water mixture appears to be a key factor in the fractionation process.
Subject(s)
Cellulose/isolation & purification , Chemical Fractionation/methods , Solvents/chemistry , Cellulose/chemistry , ViscosityABSTRACT
Atypical antipsychotics, the first line therapy for schizophrenia, have already been reported as causing rhabdomyolysis or isolated elevation in serum creatine kinase (SCK). This case report dealing with rhabdomyolysis in a 25-year-old man treated with antipsychotics is particularly unusual, due to the extremely high elevation in SCK and the ensuing acute renal failure. He was treated with loxapine 400 mg/day and risperidone 4 mg/day for 4 days and then loxapine was replaced by levomepromazine 300 mg/day. A series of laboratory examinations showed: SCK 43 650 UI/L, creatinine 392 µmol/L. An acute renal failure (acute tubular necrosis) after iatrogenic rhabdomyolysis was diagnosed, requiring hemodialysis. Furthermore, the patient also developed a deep vein thrombosis (DVT) attributed to his antipsychotic treatment. This case underlines the importance of taking rhabdomyolysis and DVT risk factors into account in patients treated with antipsychotics. Indeed, in this case we note that rhabdomyolysis was probably promoted by the interruption and the reintroduction of the treatment more than by possible dehydration, because no other risk factor could be identified.
Subject(s)
Acute Kidney Injury/chemically induced , Antipsychotic Agents/adverse effects , Loxapine/adverse effects , Rhabdomyolysis/chemically induced , Risperidone/adverse effects , Venous Thrombosis/chemically induced , Antipsychotic Agents/therapeutic use , Humans , Loxapine/therapeutic use , Male , Psychotic Disorders/drug therapy , Risperidone/therapeutic useABSTRACT
BACKGROUND: The assessment of medical trainees is becoming an increasingly prominent issue, with current methods having varying degrees of inherent subjectivity and bias. Cusum analysis is a technique used in quality control systems, and is starting to be employed in medical training. Endobronchial ultrasound (EBUS) is an established tool in the diagnosis and staging of lung cancer, although its use in the UK is currently restricted. As it becomes more widespread, there will be a need to assess trainees' competence accurately to ensure that those performing EBUS at new centres are appropriately skilled. METHODS: A retrospective review of clinical practice in tertiary referral centres in England, Scotland and Spain was carried out. The study group comprised 500 patients undergoing EBUS for the diagnosis and staging of lung cancer as part of a clinical service. Using cusum analysis, the first 100 cases from each of the five centres are presented. Each centre has one consultant physician as the primary EBUS operator, and all operators began using EBUS at their current centre (ie, no learning from prior experience). The data are presented as learning curves. RESULTS: It is evident that there is a wide range of time over which EBUS-guided transbronchial needle aspiration (TBNA) competence is attained. The pooled sensitivity was 67.4% (individual sensitivities 66.7, 70.7, 61.2, 80.3 and 59.7%). CONCLUSION: Cusum analysis is well suited to the assessment of procedures with a binary outcome, but accurate and appropriate standards of practice must be determined prior to assessment to ensure correct identification of underperformance. This report suggests that the learning curve for EBUS is greater than previously reported using different methods, and that even experienced bronchoscopists vary in their speed of learning.
Subject(s)
Clinical Competence , Education, Medical, Graduate/methods , Educational Measurement/methods , Lung Neoplasms/pathology , Ultrasonography, Interventional/standards , Biopsy, Fine-Needle/methods , Biopsy, Fine-Needle/standards , Endosonography/methods , Endosonography/standards , Humans , Lung Neoplasms/diagnostic imaging , Neoplasm Metastasis , Neoplasm Staging , Quality Control , Radiology/education , Retrospective Studies , Sensitivity and Specificity , Ultrasonography, Interventional/methodsABSTRACT
AIM: Power spectral analysis of heart rate variability has been used to assess the time course of neurovegetative adaptations to training. This study was undertaken: 1) to evaluate whether and which indicator(s) of autonomic cardiac regulation and psychophysical stress can identify successful athletes during a training season culminating with the Olympic Games and 2) to evaluate the feasibility of a quasi-on-line assessment of autonomic cardiac regulation from training field, by a telematic approach. METHODS: This study was conducted on the group of male athletes composing the Italian national team of rowing (n=34), in the season preceding the 2004 Olympic Games. Complete results are from 18 subjects (age 25.3+/-0.5 years), who were selected to participate to the Athens' Olympic games. Athletes were studied while partially detrained, at mid-training season and close to the games. The RR interval was obtained through a miniature transtelephonic-ECG recorder in the supine and standing posture, thus allowing the evaluation of cardiovascular responses to a sympathetic challenge. Data were downloaded through a telephone line, to the referral center where RR-interval variability data were analyzed with the autoregressive method. Also, in each study sessions, athletes filled a self-administered questionnaire of stress perception and somatic symptoms (4S-Q). RESULTS: All ECG recordings were transmitted successfully by phone to the referral center. No significant difference was detected in any marker of autonomic cardiac regulation between athletes who won a medal at the Olympic Games and those who did not. However, respiratory rate was faster in medal winners (P=0.02), while the questionnaire addressing stress (4S-Q) provided greater scores in the group that did not win a medal (F=5.55, P<0.022) at mid-training season and close to the Olympic Games. CONCLUSIONS: The results of this study would suggest the possibility of an early detection of psychosomatic symptoms resulting from long duration and elevated stress of preparing for top level competitions, whose better handling might identify the most successful athletes. In addition, it indicates the feasibility of a quasi-on-line assessment of autonomic cardiac adaptations to strenuous training directly from field to be possibly used for improving individual training programs, allowing athletes evaluation in their natural environment.
Subject(s)
Adaptation, Physiological/physiology , Adaptation, Psychological/physiology , Autonomic Nervous System/physiology , Heart Rate/physiology , Sports/physiology , Adult , Blood Pressure/physiology , Electrocardiography , Humans , Male , Physical Fitness/physiology , Stress, Psychological , TelecommunicationsSubject(s)
Diabetes Mellitus, Type 2/drug therapy , Glyburide/administration & dosage , Hypoglycemic Agents/administration & dosage , Metformin/administration & dosage , Patient Compliance , Patient Education as Topic/methods , Sulfonylurea Compounds/administration & dosage , Counseling , Drug Combinations , Drug Therapy, Combination , Humans , United StatesABSTRACT
An Hippocratic aphorism from Epidemics VI 4.18 quoted in two byzantine scholarly works testify the wide influence of alexandrian commentaries on this difficult treatise in Byzantine cultivated society.
Subject(s)
Disease Outbreaks/history , Manuscripts, Medical as Topic/history , Byzantium , Greece , History, Ancient , History, MedievalABSTRACT
To get insight into the potential risk of myopathy associated with therapy involving 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, we evaluated in vivo and in vitro the effects of a daily 2 to 3-month treatment with pravastatin (100 mg/kg) and with simvastatin (5, 10 and 50 mg/kg) on the electrical properties of rat skeletal muscle fibers. The electromyographic activity revealed no sign of myopathy during treatment with pravastatin and with simvastatin. At the end of the treatment, the passive and active membrane electrical parameters of the extensor digitorum longus muscles were measured in vitro by computerized two-intracellular-microelectrode technique. A dose-dependent reduction of membrane chloride conductance was recorded in extensor digitorum longus fibers of simvastatin-treated groups, and at 50 mg/kg the reduction of chloride conductance was significant in 6 out of the 7 treated rats. By contrast, none of the pravastatin-treated rats showed significant alteration of chloride conductance. Consequently, the excitability parameters were modified by simvastatin but not by pravastatin treatment, whereas the resting membrane potential was not affected. An increase in potassium conductance, reduced by in vitro application of glybenclamide, was recorded in 30% of the simvastatin-treated rats (50 mg/kg) and in only 15% of the pravastatin-treated rats. Our results suggest that the risk of myopathy is much higher with the lipophilic simvastatin than with the hydrophilic pravastatin and support the hypothesis that the muscle toxicity of HMG-CoA reductase inhibitors is due to an intracellular action mediated by the inhibition of muscle cholesterol synthesis.
Subject(s)
Enzyme Inhibitors/pharmacology , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Lovastatin/analogs & derivatives , Muscle, Skeletal/drug effects , Pravastatin/pharmacology , Animals , In Vitro Techniques , Lovastatin/pharmacology , Male , Membrane Potentials/drug effects , Muscle, Skeletal/physiology , Rats , Rats, Wistar , SimvastatinSubject(s)
Hemoperitoneum/surgery , Pregnancy, Ectopic/surgery , Adult , Female , Hemoperitoneum/etiology , Humans , Liver , Pregnancy , Pregnancy, Ectopic/pathologyABSTRACT
Among 267 surgical specimens of histologically proved cancer of the stomach during the last 20 years (1957 to 1976), 25 were classified as early gastric cancer. Of these early gastric cancers, 16 were found during the last 5 year period. The increasing number of early gastric cancers found in the recent years may be attributed to the more aggressive diagnostic approaches in patients who have symptoms suggestive of peptic ulcer disease. Another factor which may contribute to the increased incidence of early detection of gastric cancer is a more aggressive surgical treatment in patients with a gastric ulcer. Some patients with early gastric cancer will remain undetected if the surgical treatment was vagotomy and pyloroplasty. Lymph node metastases were present in six patients in this series. Of these 25 patients who had gastric resection for early cancer, follow-up was available in 20. Two patients were noted to have local recurrence at 3 and 8 years, respectively, after the initial operation. One of these two patients died after reoperation and the other still is living. One other patient died of cerebral hemorrhage 12 years following the initial operation of gastric resection. The remaining 17 patients all are living, with no evidence of recurrence. From these results it is concluded that (1) routine gastroscopy should be done in patients with radiological gastric abnormalities and in patients with symptoms suggestive of peptic ulcer disease, even though the upper gastrointestinal series is normal; (2) multiple biopsies should be taken from gastric lesions seen on gastroscopy; and (3) gastrectomy is the treatment of choice, since some of the early gastric cancers in this series would have remained undetected if vagotomy and pyloroplasty had been performed.