Use of recirculation reactor to study biodegradation of Aroclor 1242, a polychlorinated biphenyl

The performance of immobilized microorganisms in the detoxification of hazardous waste was investigated using a recirculation flow reactor, run in a batch mode. A mixed microbial population from a wastewater treatment plant was immobilized in calcium alginate gel. The bio-oxidation ability of these microbes towards a model toxin Aroclor 1242 (R) (PCB 1242) was studied. A non-ionic surfactant (Triton X-405 (R)) was used as a medium in the enhancement of the solubility of Aroclor 1242 in aqueous phase. Dissolved oxygen concentration was monitored using a flow Clark-type dissolved oxygen probe. Oxygen consumption was compared to the biodegradation of Aroclor 1242. Physical removal of Aroclor 1242 by adhering to the system without microorganisms was also determined and was compared with the biodegradation value obtained. It was found that biodegradation was the primary removal mechanism. Total removal of Aroclor 1242 was 96, 98.6 and 98% for three consecutive spikes of which physical removal accounted for up to 25%

Endoscopy in the Diagnosis of Small Intestinal Tumors

The importance of endoscopy in the diagnosis of small intestinal tumors was evaluated in 15 patients with small intestinal tumors treated in our hospital. Two tumors were benign, and 13 were malignant (carcinoma in 5 patients, malignant lymphoma in 5 and leiomyosarcoma in 3). The presence of lesions could be determined by X-rays before surgery, but definitive diagnoses were difficult. When preoperative endoscopy of the small intestine was possible accurate preoperative diagnoses could be made based on the endoscopic findings and biopsies taken under direct vision. Endoscopy is therefore very important for the diagnosis of small intestinal tumors. It is necessary to develop small intestinal endoscopes that are easier to insert

A comparison of MITS counseling and informed consent processes in Pakistan, India, Bangladesh, Kenya, and Ethiopia

Globally, more than 5 million stillbirths and neonatal deaths occur annually. For many, the cause of death (CoD) is unknown. Minimally invasive tissue sampling (MITS) has been increasingly used in postmortem examinations for ascertaining the CoD in stillbirths and neonates. Our study compared the counseling and consent methods used in MITS projects in five countries in Africa and south Asia. Key informant interviews were conducted with researchers to describe the characteristics and backgrounds of counselors, the environment and timing of consent and perceived facilitators and barriers encountered during the consent process. Counselors at all sites had backgrounds in social science, psychology and counseling or clinical expertise in obstetrics/gynecology or pediatrics. All counsellors received training about techniques for building rapport and offering emotional support to families; training duration and methods differed across sites. Counselling environments varied significantly; some sites allocated a separate room, others counselled families at the bedside or nursing stations. All counsellors had a central role in explaining the MITS procedure to families in their local languages. Most sites did not use visual aids during the process, relying solely on verbal descriptions. In most sites, parents were approached within one hour of death. The time needed for decision making by families varied from a few minutes to 24 h. In most sites, extended family took part in the decision making. Because many parents wanted burial as soon as possible, counsellors ensured that MITS would be conducted promptly after receiving consent. Barriers to consent included decreased comprehension of information due to the emotional and psychological impact of grief. Moreover, having more family members engaged in decision-making increased the complexity of counselling and achieving consensus to consent for the procedure. While each site adapted their approach to fit the context, consistencies and similarities across sites were observed

Burnout and fear of COVID-19 among medical students in Japan: impact of infection history, gender, and social support

The COVID-19 pandemic caused significant changes in medical students' lives and study methods, with online learning replacing in-person classes and limited opportunities for clinical practice. However, there are few studies about burnout and fear of COVID-19 among medical students, especially in East Asia, and a need for research investigating the impact of gender, a history of COVID-19 infection, and social support. In March 2022, we conducted a cross-sectional web-based survey of 4th/5th year medical students who completed a clinical clerkship in Japan. Our survey included the Japan Burnout Scale (JBS, range 5-85, comprising of emotional exhaustion, depersonalization and reduced personal accomplishment), fear of COVID-19 scale (range, 1-4), gender, school year, COVID-19 history, household composition, online education use, and financial burden. There were 343 respondents and 42.4% were women. Multivariable adjusted linear regression analyses showed that students with a COVID-19 infection history had significantly higher overall burnout, depersonalization, reduced personal accomplishment, and lower fear of COVID�19. Students with low social support (living alone and greater financial burden) had higher overall burnout, emotional exhaustion, and depersonalization. Gender had no significant effect on burnout (mean JBS among women was 38.6 versus 39.3 among men). Gender significantly predicted fear of COVID-19, with women scoring higher (1.60 versus 1.50). The findings of the present study have implications that medical schools should provide pastoral care for their students according to students’ circumstances, especially those who live alone, have a high financial burden, and/or were infected with COVID-19

High-level production of violacein by the newly isolated Duganella violaceinigra str. NI28 and its impact on Staphylococcus aureus

A violacein-producing bacterial strain was isolated and identified as a relative of Duganella violaceinigra YIM 31327 based upon phylogenetic analyses using the 16S rRNA, gyrB and vioA gene sequences and a fatty acid methyl ester (FAME) analysis. This new strain was designated D. violaceinigra str. NI28. Although these two strains appear related based upon these analyses, the new isolate was phenotypically different from the type strain as it grew 25% faster on nutrient media and produced 45-fold more violacein. When compared with several other violacein producing strains, including Janthinobacterium lividum, D. violaceinigra str. NI28 was the best violacein producer. For instance, the crude violacein yield with D. violaceinigra str. NI28 was 6.0 mg/OD at 24 hours, a value that was more than two-fold higher than all the other strains. Finally, the antibacterial activity of D. violaceinigra str. NI28 crude violacein was assayed using several multidrug resistant Staphylococcus aureus. Addition of 30 mu M crude violacein led to a 96% loss in the initial S. aureus population while the minimum inhibitory concentration was 1.8 mu M. Consequently, this novel isolate represents a phenotypic variant of D. violaceinigra capable of producing much greater quantities of crude violacein, an antibiotic effective against multidrug resistant S. aureusopen

The Synthesis, Self-Assembly and Self-Organisation of Polysilane Block Copolymers

Block copolymers containing polysilane blocks are unique in that the polysilane components possess electro-active properties and are readily photodegradable. This review will discuss and assess the two major approaches to the synthesis of polysilane block copolymers via pre-formed polymer chain coupling and living polymerisation techniques. The self-organisation of polysilane block copolymers and the morphologies adopted in thin films are reviewed. Amphiphilic polysilane-containing block copolymers self-assemble in solvents selective for one block and a number of examples are highlighted. The versatility of these materials is highlighted by recent significant applications including the preparation of hollow crosslinked micellar aggregates in aqueous solutions and in patterned thin film generation subsequently employed as templates for the growth of cell cultures and CaCO (3.