HPMBP与伯胺N_(1923)对希土元素(Ⅲ)的协同萃取

本文研究了HPMBP与伯胺N_(1923)的二甲苯溶液,从盐酸介质中协同萃取希土(Ⅲ)的机理。用斜率法、恒摩尔法确定了协萃配合物的组成为:RNH_3Ln(PMBP)_4。求得关于Pr(Ⅲ)协萃反应的平衡常数及协萃配合物的生成常数分别为:logK_(12)=-1.95;logβ_(12)=3.94。实验发现,协萃系数(R)随希土元素的原子序数(Z)递变而呈现“双峰效应”。还研究了协萃配合物的IR,NMR谱。     

Ultrasound‐activated Knoevenagel condensation of malononitrile with carbonylic compounds catalysed by alkaline‐doped saponites

α,β‐Unsaturated nitriles have been synthesized by Knoevenagel condensation of a carbonylic compound with malononitrile, assisted by sonochemical irradiation. Two alkaline‐promoted clays (Li⁺‐ and Cs⁺‐exchanged saponites) have been employed as catalysts. The influence of the carbonylic compound (benzaldehyde or cyclohexanone) and the use of a solvent on the catalytic activity have been studied. Remarkable increase in the conversion values has been found when the reaction is activated by ultrasound, as compared with the thermal activation. In this green, solvent‐free procedure, α,β‐unsaturated nitriles have been produced in very high yields (97%) when the Cs⁺‐saponite is used as catalyst. Copyright © 2004 Society of Chemical Industry     

Respective importance of the different risk factors for osteoporosis

Among the factors which influence accumulation of bone mass, genetic factors related to race and family are preponderant: they account for approximately 80% of the variance observed in adulthood. At puberty, nutritional factors and physical activity modulate the accumulation of bone and determine whether or not optimal bone mass is achieved. In women, estrogen deprivation following menopause, and also more minor disorders of gonad function, are the main causes of decreased bone mass; their respective contributions are analyzed.     

A genomic map of infectious laryngotracheitis virus and the sequence and organization of genes present in the unique short and flanking regions

The involvement of the intermediate area and B?tzinger complex (BOT) of the rostral ventral respiratory group (r-VRG) in laryngeal control and generation of the expiration reflex were studied in anaesthetized non-paralyzed cats Focal cooling (to 20 degrees C) of the nucleus paraambigualis (NPA) caused changes in the frequency and timing of breathing with the concomitant rise in laryngeal resistance. Cooling of the nucleus ambiguus resulted in a consistent drop in laryngeal resistance. Alterations in timing and intensity of breathing but no changes in laryngeal patency were found during cooling of the BOT. The expiration reflex was inhibited by cooling of either the NPA or BOT. The role of these medullary regions in the control of laryngeal patency and central integration of the expiration reflex is discussed.     

Simple method for determination of dietary fiber in frozen foods

A simple method was developed for the determination of dietary fiber in multicomponent foods. The method involves dispersing the sample into pH 7.4 phosphate buffer and adding bile and pancreatic enzyme as described. Results were comparable to AOAC methods with correlation coefficients of 86% for multicomponent dinners and 89% for breakfast foods. Coefficients of variation ranged from 7.4 to 20.0% for multicomponent foods and 1.0 to 3.6% for single component foods. In addition, blind duplicate samples had a correlation of 0.99. The described method required less time, labor, and manipulation than AOAC methods.     

Phase II study of vinorelbine (Navelbine) in previously treated small cell lung cancer patients. EORTC Lung Cancer Cooperative Group

26 previously treated patients with progressive recurrent small cell lung cancer (SCLC) were given vinorelbine (Navelbine), 30 mg/m2 weekly. All patients had responded to first-line chemotherapy and were off therapy for at least 3 months. Partial response was observed in 4 out of 25 eligible patients (16%; 95% confidence interval 4-36%), stable disease in 7 patients and progression in 12 patients. The limiting toxicity was a non-cumulative leucopenia (80%, 32% WHO grade 3-4). Reaction at the site of injection was observed in 5 patients, causing treatment discontinuation in 2 cases. Other non-haematological toxicities were moderate. These results suggest acceptable toxicity and some antitumour activity of vinorelbine in pretreated SCLC patients.     

Attitudes and beliefs of Canadian infection control decision-makers towards 'borderline' methicillin-resistant Staphylococcus aureus

'Borderline' methicillin-resistant Staphylococcus aureus (MRSA) strains are inhibited by drug concentrations of 2 to 8 micrograms/mL. This type of resistance is usually mediated by 'hyper beta-lactamase' production which is detectable in vitro by susceptibility to combinations of a beta-lactam and a beta-lactamase inhibitor (ie, amoxicillin and clavulanic acid). A survey of Canadian infection control experts was performed to assess the knowledge, attitudes and beliefs regarding the containment requirements for borderline MRSA strains in acute health care facilities. Twenty-three of 38 Canadian infection control experts (61%) (members of the Canadian Hospital Epidemiology Committee [CHEC] or the Society for Healthcare Epidemiology of American [SHEA]) returned a questionnaire about a fictional patient with a postoperative wound infection with such a strain. Eleven respondents (48%) considered the isolate as an MRSA, 11 did not and one was unsure. All who did not believe the strain to be MRSA would not have isolated or cohorted the patient. Four in the latter group would have isolated the patient if he or she were on a neurosurgery or cardiovascular surgery unit, indicating a desire to restrict spread of this isolate on those units. Seven of the 12 individuals who had managed at least one patient with a borderline MRSA did not advocate patient isolation or cohorting, and five did. This survey has supported the belief that there are discrepancies among infection control decision-makers in Canada regarding the approach, precautions and therapy of patients infected with borderline strains of MRSA. Further data on virulence of and effective therapy for these isolates are needed to assess whether the additional cost is warranted in controlling the nosocomial spread of these isolates.