Mortality in employees of a Scottish paper mill

The complexity of the monitored data available in modern intensive care units suggests that they may be best processed, for presentation to medical staff, by expert system techniques. However, standard expert system shells are ill-fitted to either the basic sequential monitoring tasks of data acquisition and storage, or to handling the temporal considerations inherent in monitoring and in the recognition and processing of sporadic alarm signals. A solution to this dilemma is described: an expert system that has an appropriately designed inference engine and manages data acquisition via a medical information bus (MIB). Use of this MIB standard allows great flexibility as regards the monitoring apparatuses employed; in particular, the connection or disconnection of any apparatus is recognised and triggers the automatic reconfiguration of the network.     

Risk of death from malignant neoplasms among paper mill workers

A cohort study was designed to evaluate the risk of death from malignant neoplasms among pulp and paper workers. This paper presents the evaluation of death risk among workers engaged only in the production of paper, paperboard and paper products. The cohort study covered 1,322 males and 1,914 females employed for, at least, one year in a big pulp and paper mill during the period 1968-90. The study of exposure to harmful factors revealed that concentrations of paper and paperboard dusts in this mill exceeded hygienic standards. The analysis of death risk by causes and gender of those under study was based on standardized mortality rate (SMR) calculated using the method of person-year observation. The general population of Poland was used as reference. The results do not confirm excess mortality from lung, stomach and hematopoietic cancers in paper mill workers reported by other authors. However, an elevated risk of bladder cancer in males (SMR = 491, two deaths) and brain cancer in females (SMR = 353, two deaths) was observed. Both SMR values were not statistically significant. Because of small number of deaths, risk according to exposure and latency was not evaluated.     

Purification and properties of a xylan-binding endoxylanase from Alkaliphilic bacillus sp. strain K-1

An alkaliphilic bacterium, Bacillus sp. strain K-1, produces extracellular xylanolytic enzymes such as xylanases, beta-xylosidase, arabinofuranosidase, and acetyl esterase when grown in xylan medium. One of the extracellular xylanases that is stable in an alkaline state was purified to homogeneity by affinity adsorption-desorption on insoluble xylan. The enzyme bound to insoluble xylan but not to crystalline cellulose. The molecular mass of the purified xylan-binding xylanase was estimated to be approximately 23 kDa. The enzyme was stable at alkaline pHs up to 12. The optimum temperature and optimum pH of the enzyme activity were 60 degrees C and 5.5, respectively. Metal ions such as Fe2+, Ca2+, and Mg2+ greatly increased the xylanase activity, whereas Mn2+ strongly inhibited it. We also demonstrated that the enzyme could hydrolyze the raw lignocellulosic substances effectively. The enzymatic products of xylan hydrolysis were a series of short-chain xylooligosaccharides, indicating that the enzyme was an endoxylanase.     

Extraction of selenium from copper anode slimes in a sealed leaching system

A new method was proposed for extracting selenium from copper anode slimes with a low concentration of nitric acid in a sealed sulfuric acid leaching system. It is performed under an atmosphere of oxygen which allowed for a cyclic utilization of nitric acid. The effects of main parameters on selenium leaching were studied. The mineralogical characterizations of the typical samples were investigated by XRD and SEM. The results showed that the optimal conditions of the process are considered to be total gas pressure of 0.1 MPa, leaching temperature of 388 K, solid-liquid ratio of 0.20 g mL^–1, H₂SO₄ concentration of 2 mol L^–1, HNO₃ concentration of 0.07 mol L^–1 and leaching time of 2 h. The high selenium leaching efficiency of 99.23% was obtained under these conditions. According to the results of XRD and SEM-EDS, Cu–Ag selenide in the raw anode slimes is difficult to be leached with sulfuric acid alone; copper can be leached more easily from Cu-Ag selenide than silver; selenide is oxidized into the solution, undergoing the intermediate product of elemental selenium.     

Morphological and biochemical characterization and analysis of apoptosis

Apoptosis is a form of programmed cell death serving physiologic and homeostatic functions. However, recent evidence implicating apoptosis in the etiology and pathophysiology of known human diseases, such as heart diseases, cancer, AIDS, and neurodegenerative and autoimmune diseases are continually surfacing. This has spawned the need for identifying which methods are the most effective and well accepted to decipher its presence in a variety of research settings. We have therefore detailed the morphology and biochemical features of apoptotic cell death, with an emphasis on discriminating it from necrosis. In addition, we describe specific and selective techniques which are optimal to target hallmark apoptotic features, such as microscopy, Annexin V labeling, in situ nick-end labeling (TUNEL), and DNA fragmentation analysis by gel electrophoresis and ELISA for oligonucleosome-sized DNA. The advantages and disadvantages of each technique are discussed, as well as their experimental importance relative to one another. The methods have been described in a stepwise fashion, and can readily be applied in the majority of cell systems. Whether working on the tissue or single cell level, these methods are highly effective in qualifying and quantifying apoptosis. The application of these methods in conjunction with molecular techniques can further delineate the underlying mechanisms of apoptosis.     

Morphological and biochemical features affecting the antithrombotic properties of the aorta in adult rabbits and rabbit pups

We hypothesised that there are important physiologic differences in arterial wall structure and function with respect to antithrombotic activity in the very young (pre-puberty) compared to adults. Electron microscopy, gel electrophoresis, and activity assays were used to examine differences in aorta structure and function comparing prepubertal rabbits (pups) to adult rabbits. Differences in endothelial function, extracellular matrix structure, proteoglycan (PG) distribution and glycosaminoglycan (GAG) content and function were shown. In both intima and media, total PG, chondroitin sulfate (CS) PG and heparan sulfate (HS) PG content were significantly increased in pups compared to adult rabbits. These findings corresponded to increased concentrations by mass analyses of CS GAG and DS GAG in aortas from pups. There was also a significant increase in antithrombin activity in pups due to HS GAG. In conclusion, differences in both structure and antithrombin activity of aortas from pups compared to adult rabbits suggest that young arteries may have greater antithrombotic potential that is, at least in part, related to increased HS GAG.     

Morphological and biochemical changes in the myocardium after sudden death from ischemic heart disease

The myocardium was examined in 44 persons who had suddenly died of ischemic heart disease, in 37 who had died of injury, and in 28 who had died of alcohol poisoning. Those with ischemic heart disease had foci of necrosis of the muscle fibers, severe disturbances in microcirculation, changes in the activity of certain myocardial enzymes and in the content of lipids in the myocardium. Biochemical changes similar to these in many respects were revealed in individuals who had died of alcohol poisoning, in view of which alcohol poisoning may be a factor conducive to sudden death in ischemic heart disease.     

Respiratory survey of workers in a pulp and paper mill in Powell River, British Columbia

Researchers in applied behavior analysis have been charged to provide large-scale demonstration of the outcomes of evaluations. In this research, three experiences were conducted to examine the relative efficacy of three methods of presenting stimuli in object naming tasks. Stimuli were introduced successively, simultaneously, or using a combination of the two procedures. College adults, mentally retarded children and adolescents, and preschool children were taught to produce the names of five Hebrew letters, English words, or American coins, respectively. Presentation method was a between-subjects treatment in a factorial design. Results from the series of systematic replications were consistent showing better posttest for subjects in the Simultaneous and Combined conditions. Further, follow-up data in Experiment III showed that retention was also superior for subjects trained by the Simultaneous or Combined methods. Although the acquisition criterion was met in fewer trials by subjects in the Successive condition, only several minutes more training time was required by the Simultaneous and Combined conditions. From a cost-effectiveness point of view, either of the latter two techniques should be favored over the Successive procedure for testing verbal naming skills.     

Crushing properties of silicon and titanium carbides in a vertical vibratory mill

The vibratory mill type as well as the correlation between the grinding bodies' weight and size and the materials being ground have been examined to determine their influence on the particle size and the grinding factor when silicon and titanium carbides were ground in a vertical vibratory mill. It has been shown that the grinding efficiency increases when smaller grinding spheres are used, and that a single sphere impact energy and the probability of particles' segregation reduce the grinding time.Dnepropetrovsk Mining Institute. Translated from Poroshkovaya Metallurgiya, No. 2(362), pp. 5–7, February, 1993.     

Strelkovimermis arkansensis n. sp. and Hydromermis welchi n. sp. from chironomid imagos

OBJECTIVES: We analyzed the possible relation between the presence of a hospital admission delay (> or =24 h), undue physical effort or recurrence of anginal pain, alone or in combination, with the development of free wall rupture (FWR), septal rupture (SR) or papillary muscle rupture (PMR) in patients with an acute myocardial infarction (AMI). BACKGROUND: Physical activity as a trigger of FWR in AMI remains controversial, and its contribution to SR or PMR remains unknown. Moreover, the role of ischemia or reinfarction as an additional cause of rupture has not been explored. METHODS: The incidence of hospital admission delay > or =24 h with maintenance of some ambulatory activity and the incidence of postinfarction angina were analyzed in consecutive patients with a first AMI with (n = 225) or without rupture (n = 1,012 [control group]) over different time periods. RESULTS: An admission delay > or =24 h occurred in 27 (27.6%) of 98 patients with FWR, 47 (47.0%) of 100 with SR and 14 (51.9%) of 27 with PMR but in only 81 (8%) of 1,012 control patients (p < 0.0001). Information on undue in-hospital effort preceding rupture was available for 111 patients and was present in 17 (32.7%) of 52 with FWR, 9 (18.4%) of 49 with SR and 3 (30%) of 10 with PMR versus only 76 (7.5%) of 1,012 control patients (p < 0.001). Information on postinfarction anginal pain was available for 114 patients with rupture and occurred in 30 (56.6%) of 53 with FWR, 30 (60%) of 50 with SR and 4 (36.4%) of 11 with PMR versus 120 (11.9%) of 1,012 control patients (p < 0.0001). Mean age and incidence of male gender, hypertension, absence of heart failure, single-vessel disease or occlusion of the infarct-related artery were comparable among the groups with FWR, SR or PMR. CONCLUSIONS: Delayed hospital admission or undue in-hospital physical activity appears to increase the risk of rupture in patients prone to this complication (i.e., a first transmural AMI, absence of overt heart failure and advanced age); recurrence of ischemia/infarction emerges as a potential additional trigger in a proportion of these patients.     

Leptolstatin from Streptomyces sp. SAM1595, a new gap phase-specific inhibitor of the mammalian cell cycle. II. Physico-chemical properties and structure

Leptolstatin, a product from Streptomyces sp. SAM1595, is a gap phase-specific inhibitor of the mammalian cell cycle. Physico-chemical properties and spectrometric analyses showed that the structure of leptolstatin is (2Z,6E,8Z,12E,14E,22E)-19,24-dihydro xy-8,10,14,16,18,20,22-heptamethyl-17-oxo-2 , 6,8,12,14,22-tetracosahexaen-5-olide.     

New species of Actinomadura coeruleoviolacea sp. nov. and its antagonistic properties

Eight strains of actinomycetes isolated from soil samples were described as representatives of Actinomadura coeruleoviolacea sp.nov. The species was characterized by straight and sometimes branching short chains of spores, smooth spores, blue aerial mycellium and violet soluble pigment. All the strains showed antibacterial activity when cultivated in liquid media. The pigment differed from all known pigments. It is probably a new natural compound.     

从铜阳极泥高压釜浸出液中回收碲和硒的新工艺

在铜阳极泥加压氧化浸出过程中,超过65％的碲在脱铜过程中同时析出.在浸出条件恶劣的情况下,大约10％ ～15％的硒也会同时溶解.目前对浸出液的处理方式是让浸出液通过一层铜屑进行循环.浸出液经沉积形成碲化铜和硒化铜,溶液再经过滤进行分离.为了提高反应效率,降低工艺成本,尽量减少铜的加入量,缩短停留时间,降低能耗,在实验室中研究了一种化学还原剂,并进行了沉积工艺试验.本文给出了试验结果,并对工艺化学进行了探讨.     

Mineralogical characterization of a copper anode and the anode slimes from the la caridad copper refinery of mexicana de cobre

A detailed mineralogical study was carried out to characterize a copper anode, the anode-face slimes, the slimes on the bottom of the refining cell, and the autoclave-leached slimes from the La Caridad refinery of Mexicana de Cobre. The objective was to identify possible Pb-Sb-Bi and As-Sb-Bi interactions that could control the Sb and Bi concentrations of the electrolyte. Although some Pb, As, Sb, and Bi can be found in solid solution in the copper crystals of the anode, these elements are mostly present as Cu-Pb-As oxide and Cu-Pb-As-Sb-Bi oxide inclusions at the grain boundaries. During electrorefining, the Pb, As, Sb, and Bi in solid solution dissolve. Part of the Pb, As, Sb, and Bi in the oxide inclusions also dissolves, but part reacts in situ to form PbSO₄ and Pb₅(AsO₄)₃(OH,Cl). Some of the dissolved elements reprecipitate as PbSO₄, SbAsO₄, Sb-As oxide, Sb-As-Bi oxide, Pb₅(AsO₄)₃(OH,Cl), and an oxidate phase of mainly Cu-Ag-AsO₄-SO₄ composition. Thus, high As contents facilitate the precipitation of Sb and Bi from the electrolyte. Although Pb-Sb oxide and Pb-Bi oxide species were only rarely detected, a high Pb content in the anode may retard the dissolution of the Cu-Pb-As-Sb-Bi oxide inclusions, thereby retaining some Sb and Bi in the raw anode slimes. Autoclave leaching dissolves part of As, Sb, and Bi, but the SbAsO₄ and Sb-As-Bi oxide species remain in the leach residue. The Pb is converted almost entirely to PbSO₄, which is present as subhedral crystals in the autoclave leach residue.