Risk stratification of patients with medically treated unstable angina using exercise echocardiography

The effect of high-dose irradiation on the migration of dioctyl adipate (DOA) and acetyl tributyl citrate (ATBC) plasticizers from food-grade poly (vinyl chloride) (PVC) and poly (vinylidene chloride/vinyl chloride) (PVDC/PVC) copolymer (Saran) films, respectively, into olive oil was studied. The results showed a significantly higher amount of DOA migrated into olive oil from irradiated versus nonirradiated samples. This difference was more noticeable in oil samples collected during initial periods of contact. The amount of DOA migrating into olive oil was lower for samples irradiated at a dose of 20 kGy in comparison with samples irradiated at a dose of 50 kGy. At a sampling time of 1 h the amount of DOA that migrated into olive oil was 93.9 mg/liter, 141.5 mg/liter, and 183.4 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. After 288 hr (12 days) of oil-film contact the respective amounts were 390.8 mg/liter, 409.2 mg/liter, and 430.1 mg/liter. There were no statistically significant differences in migrating amount of ATBC between nonirradiated samples and samples irradiated at a dose of 20 kGy, while in samples irradiated at a dose of 50 kGy the migration of ATBC was increased. After 1 h of oil-film contact no detectable amounts of ATBC had migrated. After 288 h of contact the amounts of ATBC that migrated into olive oil were 3.59 mg/liter, 3.56 mg/liter, and 4.12 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. It is suggested that plasticized PVC should not be used in direct contact with high-fat foodstuffs with or without irradiation treatment.     

反差增强材料最大吸收波长的经验估算

本文分析了二芳基硝酮、二芳基乙烯、二芳基偶氮化合物以及芳族重氮化合物的最大吸收波长(λmax)与环上取代基的Hammett σ系数之间的关系。发现λmax的红移量与Σ|σ|之间有强相关性。并提出一种经验估算法,用于判断某些反差增强材料的λmax。列出了若干估算实例,说明本方法有一定准确性和实用意义。     

An enriched reaction center preparation from green photosynthetic bacteria

Bacteriochlorophyll a reaction-center complex I from Chlorobium limicola f. thiosulfatophilum 6230 (Tassajara) was incubated in 2 M guanidine - HCl and then chromatographed on cross-linked dextran or agarose gel. Two principal components were separated: a larger component with photochemical activity (bacteriochlorophyll a reaction-center complex II) and a smaller component without activity (bacteriochlorophyll a protein). Complex II contains carotenoid, bacteriochlorophyll a, reaction center(s), and cytochromes b and c, but lacks the well characterized bacteriochlorophyll a protein contained in Complex I. Complex II carries out a light-induced reduction of cytochrome b along with an oxidation of cytochrome c.     

Josephson junctions with 1 ?m dimensions and with picosecond switching times

Josephson junctions with 1 × 3 ?m dimensions have no resonances. For a current density of about 1000 A/cm2, the risetime of the switching transient from zero to the gap voltage is below 38 ps.     

Urinary morphine excretion during and after morphine anaesthesia for open-heart surgery in children

The urine of 20 children undergoing complete correction of atrial septal defect (ASD) or tetralogy of Fallot (TF) were analyzed for morphine and its glucuronide conjugation product before and after induction of morphine anaesthesia, throughout the operation and for two hours post-operatively. Children with ASD had a higher, mean urine flow rate during anesthetic induction and during the entire operation than those with TF (P less than 0.01). ASD children excreted a greater percentage of the administered morphine by the time they reached the recovery room and after two hours in the recovery room than those with TF. Urinary morphine in the glucuronide form increased progressively from anaesthetic induction until the post-operative period in both groups and was more than 93% after two hours in the recovery room. Fifty-five per cent of ASD patients had respiratory dynamics that enabled them to be extubated within six hours of the end of their operation. Those that could be extubated after six hours had excreted a significantly greater percentage of morphine than those that couldn't (P less than 0.025). None of the children with TF could be extubated until the day after operation. These data demonstrate that the ability to maintain adequate spontaneous respiration after morphine anaesthesia is directly related to urinary output during anaesthesia and operation.