Isolation and characterization of a crude extracellular phenol oxidase from a recirculation bioreactor

The study of phenol biodegradation has been performed using calcium alginate entrapped activated sludge in a recirculation reactor. An effective recirculation reactor system may be used on the laboratory scale to produce phenol oxidase, Phenol oxidase was isolated and concentrated from the degradation solution of phenol by ultrafiltration and freeze-drying respectively, The effects of various concentrations of phenol, pH, temperature, ionic strength, cations, anions and 2- chlorophenol were studied on the oxidation reaction of enzyme. The optimal conditions of activated sludge phenol oxidase are [phenol] = 100 ppm; pH = 6.0; temperature 37°C; ionic strength equivalent to 0.1 M Na2HPO4-NaH2PO4 ; The enzyme activity was increased by Cu2+, inhibited by Ag+, Cl-, and unsignificantly changed by Zn2+, Fe2+, NO3 , and SO42-; other substrates such as 2-chlorophenol, styrene, and methylene chloride, have also been shown to be oxidized by this enzyme; the enzyme activity was inhibited by beta-hydroxybutyric acid as a substract. Preliminary studies indicate that phenol stimulates the activated sludge to release phenol oxidase at low concentrations of phenol and inhibit at high concentrations of phenol

Overburdened Chinese Compulsory Education Teachers

The universalization of “nine-year compulsory education” in China has significantly augmented the teaching force at this level. Compulsory education teachers are the most crucial human resource for the development of this system. However, they have been under disproportionately heavy work burdens, which are detrimental to their mental and physical health and compromise the quality of education. This article focuses on presenting the signs of overburden among compulsory education teachers and pinpointing its causes, with the purpose of contributing to alleviating the job strain of this group and developing a sustainable compulsory education

Daoist Freedom, Psychological Hygiene, and Social Criticism

The article explores the inner logic and defining features of Daoist freedom. It argues that Daoist freedom can be meaningfully understood as psychological hygiene, and it suggests that Daoist xuan-jie (懸解) can be rendered possible only if one can rid oneself of intensional suffering—an idea ultimately inspired by Friedrich Nietzsche. This comparative approach enables the article contribute to the received way of understanding Daoist freedom by stressing its dialectics: by being at ease with one’s social and political environment, Daoist freedom demands social criticism, calling for room for people to be able to act spontaneously so that all can nurture their distinctive natures and have a full and free exercise of their natural abilities. The article aims to achieve two objectives at once: it aims to argue for the understanding of Daoist freedom as psychological hygiene, and it defends this reading by bringing two dimensions of Daoist freedom into a consistent whole. In a constantly changing and increasingly pluralistic world, psychological hygiene and social criticism are both necessary for leading a robust and healthy human life

Characteristics of Postural Muscle Activity in Response to A Motor-Motor Task in Elderly

The purpose of the current study was to evaluate postural muscle performance of older adults in response to a combination of two motor tasks perturbations. Fifteen older participants were instructed to perform a pushing task as an upper limb perturbation while standing on a fixed or sliding board as a lower limb perturbation. Postural responses were characterized by onsets and magnitudes of muscle activities as well as onsets of segment movements. (Please see full abstract article