Occupational hygiene problems in a plant for biological gas production

The production of biological gas from biological material is an alternative resource of energy and an important method of the future. Moreover there is a possibility for destruction of liquid dung of animal production. An experimental biological gas-producer was built in the district of Suhl. Technical and individual means of health protection are described.     

Intestinal glucose absorption but not endogenous glucose production differs between colostrum- and formula-fed neonatal calves

Glucose supply markedly changes during the transition to extrauterine life. In this study, we investigated diet effects on glucose metabolism in neonatal calves. Calves were fed colostrum (C; n = 7) or milk-based formula (F; n = 7) with similar nutrient content up to d 4 of life. Blood plasma samples were taken daily before feeding and 2 h after feeding on d 4 to measure glucose, lactate, nonesterified fatty acids, protein, urea, insulin, glucagon, and cortisol concentrations. On d 2, additional blood samples were taken to measure glucose first-pass uptake (FPU) and turnover by oral [U-(13)C]-glucose and i.v. [6,6-(2)H(2)]-glucose infusion. On d 3, endogenous glucose production and gluconeogenesis were determined by i.v. [U-(13)C]-glucose and oral deuterated water administration after overnight feed deprivation. Liver tissue was obtained 2 h after feeding on d 4 and glycogen concentration and activities and mRNA abundance of gluconeogenic enzymes were measured. Plasma glucose and protein concentrations and hepatic glycogen concentration were higher (P < 0.05), whereas plasma urea, glucagon, and cortisol (d 2) concentrations as well as hepatic pyruvate carboxylase mRNA level and activity were lower (P < 0.05) in group C than in group F. Orally administered [U-(13)C]-glucose in blood was higher (P < 0.05) but FPU tended to be lower (P < 0.1) in group C than in group F. The improved glucose status in group C resulted from enhanced oral glucose absorption. Metabolic and endocrine changes pointed to elevated amino acid degradation in group F, presumably to provide substrates to meet energy requirements and to compensate for impaired oral glucose uptake.     

Hygienic effects and gas production of plastic bio-digesters under tropical conditions

Plastic plug-flow bio-digesters have been promoted as a good option for improved treatment of manure and wastewater in developing countries although minimal information has been published on their hygienic status. This bench-scale study replicates bio-digester conditions to evaluate the reduction of pathogen and indicator microorganisms at three different hydraulic retention times (HRT) in the anaerobic treatment of pig manures at 30°C for 50 days. Results showed that physicochemical values differed between HRTs. Gas production efficiency was better for longer HRTs. The accumulated sludge at the reactor's base increased with longer HRT. Phages and bacteria examined were reduced, but none was completely eliminated. Log₁₀ reduction of bacteria ranged from 0.54 to 2.47. Phages ranged from 1.60 to 3.42. The reduction of organisms at HRT = 30 days was about one log₁₀ unit higher than HRT = 15 days and about two log₁₀ units higher than HRT = 3 days. The results indicate that the reduction of tested organisms increases with HRT. However the hygienic quality of the liquid effluent does not meet required quality values for surface and irrigation water. Longer HRTs are recommended to increase gas yield and achieve higher pathogen reduction. More barriers should be applied while handling bio-digester outputs to minimise risks to environmental and human health.     

Carbohydrates blended with polydextrose lower gas production and short-chain fatty acid production in an in vitro system

Maximizing health benefits of prebiotics, while limiting negative side effects, is of importance to the food industry. This study examined several oligosaccharides and their blends in an in vitro fermentation model. Substrates included medium- and long-chain fructooligosaccharides (FOS), oligofructose-enriched inulin, galactooligosaccharide, polydextrose (POL), and 50:50 substrate blends. Substrates and blends were fermented in vitro using human fecal inoculum, and fermentation characteristics were quantified at 0, 4, 8, and 12 hours. We hypothesized that mixtures of short- and long-chain oligosaccharides would generate less gas than do short-chain oligosaccharides and modulate gut microflora to a greater extent than do long-chain oligosaccharides. Carbohydrates blended with POL had decreased (P < .01) total gas volume and H₂ produced after 4, 8, and 12 hours of fermentation compared with individual carbohydrates. Mixing of 2 oligofructose-enriched inulin products led to less (P < .05) gas produced and a slower (P < .05) rate of production. When mixed with POL, all carbohydrates tested in the present study produced less total short-chain fatty acids (P < .04) and butyrate (P < .0001) after 12 hours of in vitro fermentation, compared with individual carbohydrates. The bifidogenic effect of medium-chain FOS and oligofructose-enriched inulin after 12 hours of in vitro fermentation was lower (P < .05) when mixed with POL. Mixing the pure carbohydrates with galactooligosaccharide increased (P < .05) bifidobacteria counts measured after 12 hours of in vitro fermentation, except when mixed with medium-chain FOS. In general, when mixed with POL, all carbohydrates had lower gas production, gas production rates, butyrate and total short-chain fatty acid production, and bifidobacteria counts than when fermented alone for 12 hours.     

Intestinal motility

This review covers the recent advances that have been made in intestinal motility. Failure to stimulate the cephalic response when enteral tube feeding via the nasogastric route is important in contributing to enteral tube feeding related diarrhoea, which cannot be initially overcome by the use of fibre containing feeds. Dysfunction of the nervous system and visceral hypersensitivity appear to be important in contributing to the symptoms associated with irritable bowel syndrome.     

Intestinal endometriosis

Endometriosis is a chronic, benign gynaecological disorder that is frequent in women of a child-bearing age. It is estimated that there is some degree of endometriosis in as many as 15% of pre-menopausal women, associated with a history of infertility, caesarean antecedents, dysmenorrhoea and abnormality in uterine bleeding. It is believed to be due to the rise of menstrual contents through the Fallopian tubes (retrograde menstruation). In the intestinal affectation, the colon is the segment most frequently affected, above all at the rectosigmoidal level. The clinical features are unspecific, with abdominal pain the most frequent and/or pelvic pain of a cholic type that coincides with, or is exacerbated by, menstruation. Differential diagnosis includes intestinal inflammatory disease, diverticulitis, ischemic colitis and neoplastic processes, with the definitive diagnosis being anatomopathological. With respect to treatment, this will depend on the clinical features and the age of the patient, as well as her wishes with regard to pregnancy.     

Intestinal ischaemia

Over the past three decades major advances have been made in the diagnosis and management of mesenteric ischaemia. Early identification and treatment of this condition has reduced its mortality and morbidity. This review discusses the causes, preliminary and definitive investigations, and treatment protocols relating to gut ischaemia.     

Intestinal transplantation

Increasing experience with intestinal transplantation has led to the refinement of techniques to detect and treat rejection and infectious complications. Improved outcome has led to a broadening of the indications for intestinal transplantation, particularly solitary intestinal transplantation.     

新型材料在防尘口罩和防毒面具制作中的应用

随着新材料和新技术的不断出现,呼吸防护用品也在不断地改良和完善。根据新材料的特点,可分为高滤过新型材料（新型活性炭材料、聚四氯乙烯材料、金属-有机骨架材料）、高分子纳米材料（纳米纤维膜材料,气凝胶合成材料）、光分解材料（二氧化钛材料）、新型橡胶材料、可降解材料、智能材料等。结合国内外的研究报道,对各种新型材料在防尘口罩和防毒面具中的应用现状、优缺点、前景做了综述。