Acidogenic fermentation of blended food‐waste in combination with primary sludge for the production of volatile fatty acids

The performance of a laboratory‐scale anaerobic acidogenic fermenter fed with a mixture of blended kitchen food‐waste and primary sludge from a sewage treatment plant was investigated for the production of volatile fatty acids (VFA). The operating variables for acidogenic fermentation were kitchen food‐waste content (10 and 25 wt %), hydraulic retention time (HRT: 1, 3 and 5 days), temperature (ambient: 18 ± 2 °C, and mesophilic: 35 ± 2 °C) and pH (varied from 5.2 to 6.7). The experimental results indicated that effluent VFA concentrations and VFA production rates were higher at ambient temperature than at mesophilic conditions. The net amount of VFA with 10 wt % food‐waste increased up to 920 mg dm^?3 with an increase of HRT, but contrasting results (a decrease of 2610 mg dm^?3) were found due to the conversion of VFA into biogas in the case of 25 wt % food‐waste, which increased significantly at HRT of 3–5 days. In terms of biogas composition (CO₂ and CH₄), the organic matter was converted into CO₂ through the oxidative pathway by facultative species at low temperature while mesophilic temperature and optimum pH (6.3–7.8) played a pivotal role in increasing rate of conversion of VFA into biogas by methanogenesis. Rates of VFA production and their conversion are dependent on the food‐waste content in the mixture. Yet, the higher concentration of food‐waste (25% compared with 10%) did not produce VFA proportionally due to the increased rate of conversion of VFA into gaseous products. The maximum VFA production rate (0.318 g VFA_produced g^?1 VS_fed day^?1) was achieved in the 10 wt % food‐waste at ambient temperature and at a 5‐day HRT. Copyright © 2005 Society of Chemical Industry     

Clinical investigation of traumatic injuries of permanent incisors in Izmir, Turkey

470 injured teeth of 370 patients who consulted the Dental Clinic of Ege University, Izmir, Turkey for examination or treatment between 1981-1993 were evaluated. Information concerning sex, age of patients at the time of injury, cause of trauma, number of injured teeth, type of tooth and type of trauma were recorded. More boys suffered traumatic injuries (64.8%) than girls (35.2%). Patients aged 11-15 years old exhibited the highest number of injuries (34.4%) followed by the 6-10 years old group (24.5%). Most injuries involved one tooth (60%) and maxillary central incisors were the most often affected teeth (66.2%). The leading cause of injury was undefined falls (45.1%). At the initial examination, cases seen after a long posttraumatic period showed more complications than those presented within a short time period. Educational programs about the importance of dental trauma, the benefits of immediate attendance and conservation of avulsed and fractured teeth would be very helpful for patients. Additionally improving the knowledge of the dental practitioner about trauma would be another important point in solving the problem.     

Further studies of the mixed acetals of nucleosides

We reported in 1988 on a new nucleoside modification reaction: the exocyclic amino groups of (d)adenosine and (d)cytidine react rapidly at ambient temperature with acetaldehyde and alcohols to give stable mixed acetals (N-ethylethoxy-acetal). NH2 + O = CH(CH3) + ROH-->NH-CH(CH3)-O-R + H2O. Here we report in detail on the occurrence of this reaction in very dilute aqueous solution (ie under biological conditions), on its mechanism and kinetics, on the mixed acetal formation with other aldehydes and other nucleic acid components, and on the question of whether these adducts are mutagenic.     

Controlling bacterial contamination of an enteral formula through the use of a unique closed system: contamination, enteral formulas, closed system

Contamination of enteral diets may play an essential role in formula tolerance and safety for patients. Contaminated enteral formula commonly support microbiological growth. Commercially sterile liquid formulas received from the manufacturer are required by the Food & Drug Administration (FDA) to be shelf-stable and free from enteric pathogens. This study examined the use of large volume, closed system containers in a typical nursing home. Large volume (1500 mL) containers with unique pierceable caps and piercing spikes were studied to determine their ability to reduce the incidence of microbiological contamination due to their design and ability to decrease handling requirements. This study took place in a room of a typical nursing home. In this clinical setting, 211 containers and administration spike sets were evaluated following a 36-h hangtime. Contamination was virtually nondetectable. Nursing staff in a clinical facility can effectively utilize a large volume, prefilled, ready-to-use feeding system to achieve delivery of noncontaminated product for up to 36 h hangtime.     

Flat-field postobjective polygon scanner

A general two-dimensional ray-trace analysis is presented for the motion of a geometric focal point over a flat surface provided by a postobjective rotating polygon laser beam scanner. The exact defocus equation is derived for any value of the neutral scan position deflection angle and the polygon rotation angle. The scan nonlinearity is derived for the special case of a zero neutral scan deflection angle. Geometric parameters were found that reduce the peak-to-peak defocus by more than an order of magnitude from that found in previous design approaches. Conditions were also found that reduce scan nonlinearity to less than 2 × 10(-4). Practical limitations, such as large polygons and beam obscurations, encountered in the implementation of postobjective scanning are discussed.     

From research to practice: the effects of the jointly sponsored dissemination of an arthritis self-care nursing intervention

Various educational programs have been developed and found to be effective in the self-management of arthritis. This study reexamined the effectiveness of one such program, "Bone Up On Arthritis" (BUOA), when the program was delivered by a community-based service organization to a sample of persons (N = 154) who differed widely in disease type and demographic characteristics. Arthritis Foundation staff implemented BUOA at four national sites; data were collected and analyzed by University of Michigan nurse researchers. Investigators found improved scores on all outcome measures (self-care behavior, helplessness, pain, dysfunction, and depression). These findings suggest that "Bone Up" is an effective nursing intervention in multiple organizational and community environments and for diverse patient populations.     

The effect of antioxidants on the production, of volatile nitrosamines during the frying of bacon

Summary In model system studies simulating the frying of bacon a considerable variation in the production of N-nitrosopyrrolidine (NOPyr) has been observed, as occurs in sliced bacon fried conventionally. The inclusion of ascorbate or erythorbate (isoascorbate) has led consistently to a fall in or an elimination of NOPyr production up to an addition of 300 ppm (1,5 mM). Above this concentration of ascorbate, the elimination of NOPyr formation persisted in some instances but in others an increased production of the nitrosamine occurred. Using-tocopherol, a fall of NOPyr production during the simulated frying of bacon was obtained with increase of concentration of the antioxidant, there being a consistent elimination of the volatile nitrosamine following an addition of 500 ppm (1.16 mM). Whilst ascorbyl palmitate had a similar action in reducing or eliminating NOPyr production, no synergistic effect between it and a-tocopherol was noted in an experiment combining the two antioxidants. When bacon was fried in fat containing 400 or 800 ppm-tocopherol, the total production of NOPyr and DMN in the fried bacon, cooked out fat and condensate was markedly reduced but not completely eliminated as in the model system studies. Similarly, the curing of bacon with a brine containing a mixture of-tocopherol, ascorbyl palmitate and citric acid has led to considerable reductions in NOPyr and DMN output on frying when the combined concentrations of the two anti-oxidants were calculated to be 800 ppm.

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Der Einfluß von Antioxydantien auf die Entwicklung flüchtiger Nitrosamine während des Bratens von Speck

Zusammenfassung Bei Untersuchungen in Modell-Systemen, in denen das Braten von Speck simuliert wurde, stellte man eine nennenswerte Variation in der Entstehung von N-Nitrosopyrrolidin (NOPyr) fest, wie sie auch bei konventionell gebratenem Scheibenspeck auftritt. Der Zusatz von Ascorbat oder Isoascorbat hat bei einem Zusatz bis zu 300 ppm (1,5 mmol) regelmäßig zur Abnahme der NOPyr-Produktion geführt. Bei größerer Ascorbatkonzentration nahm die NOPyr-Bildung in einigen Fällen ab, in anderen setzte dagegen eine erhöhte Nitrosaminbildung ein. Bei Anwendung von-Tokopherol wurde eine Abnahme in der NOPyr-Bildung während des simulierten Bratens von Speck bei zunehmender Antioxydantien-Konzentration erreicht, wobei ein gleichbleibendes Verschwinden des flüchtigen Nitrosamins eine Folge des Zusatzes von 500 ppm (1,16 mmol) war. Während Ascorbylpalmitat eine ähnliche Wirkung in der Reduzierung der NOPyr-Bildung hatte, konnte bei einem Experiment, bei dem die beiden Antioxydantien zugegen waren, keine synergistische Wirkung festgestellt werden. Wenn Speck in 400 oder 800 ppm-Tokopherol enthaltendem Fett gebraten wude, war die Gesamtbildung von NOPyr und DMN in dem gebratenen Speck, dem ausgekochten Fett und im Kondensat wesentlich reduziert, aber nicht wie bei den Modell-System-Versuchen vollständig eliminiert. Ähnlich führte auch das Pökeln von Speck in Lake, die eine Mischung von-Tokopherol, Ascorbylpalmitat und Citronensäure enthielt, zu wesentlicher Reduzierung in NOPyr- und DMN-Produktion beim Braten, wenn die Konzentration der beiden Antioxydatien zusammen auf 800 ppm berechnet wurden.