STRUCTURAL AND STEREOSPECIFIC REQUIREMENTS FOR THE NUCLEOSIDE-TRIGGERED GERMINATION OF BACILLUS-CEREUS SPORES

A selection of adenosine analogues was tested for their ability to trigger germination of Bacillus cereus NCIB 8122 spores. The germination-inducing activity was governed by the structural properties of the sugar rather than the base moieties of the nucleosides. Among the sugar-modified analogues, only those containing a 2'-deoxy-D-ribose moiety promoted spore germination. Requirements for a specific molecular structure of the base were not clearly identified, although the highest activity was observed when substituents were inserted at position 6 of the purine ring. All the base-modified analogues, even those such as coformycin and 2'-deoxycoformycin with an expanded base ring, retained the germination-inducing activity of adenosine. However, of the two 2'-deoxycoformycin diastereoisomers characterized by an asymmetric carbon atom at position 8 of the homopurine ring, only the 8S-isomer induced germination, thus indicating that stereospecific configuration of the inducer, at least in the case of 2'-deoxycoformycin, appears to be essential for the initiation of spore germination. The differences in the germination-inducing activity of the various analogues tested were not affected significantly by spore activation at different temperatures, although the higher the activation temperature, the lower was the concentration of each analogue required for maximum germination

Depth profile investigations of surface modifications of limestone artifacts by laser-induced breakdown spectroscopy.

Made available in DSpace on 2017-11-01T23:23:05Z (GMT). No. of bitstreams: 1 PROCI17Depthprofileinvestigations....pdf: 1977315 bytes, checksum: f46ba065d28554ead651738267cea5a4 (MD5) Previous issue date: 2017-10-30bitstream/item/165807/1/PROCI-17-Depth-profile-investigations....pd

Adapting and implementing training, guidelines and treatment cards to improve primary care-based hypertension and diabetes management in a fragile context: results of a feasibility study in Sierra Leone

Background Sierra Leone, a fragile country, is facing an increasingly significant burden of non-communicable diseases (NCDs). Facilitated by an international partnership, a project was developed to adapt and pilot desktop guidelines and other clinical support tools to strengthen primary care-based hypertension and diabetes diagnosis and management in Bombali district, Sierra Leone between 2018 and 2019. This study assesses the feasibility of the project through analysis of the processes of intervention adaptation and development, delivery of training and implementation of a care improvement package and preliminary outcomes of the intervention. Methods A mixed-method approach was used for the assessment, including 51 semi-structured interviews, review of routine treatment cards (retrieved for newly registered hypertensive and diabetic patients from June 2018 to March 2019 followed up for three months) and mentoring data, and observation of training. Thematic analysis was used for qualitative data and descriptive trend analysis and t-test was used for quantitative data, wherever appropriate. Results A Technical Working Group, established at district and national level, helped to adapt and develop the context-specific desktop guidelines for clinical management and lifestyle interventions and associated training curriculum and modules for community health officers (CHOs). Following a four-day training of CHOs, focusing on communication skills, diagnosis and management of hypertension and diabetes, and thanks to a CHO-based mentorship strategy, there was observed improvement of NCD knowledge and care processes regarding diagnosis, treatment, lifestyle education and follow up. The intervention significantly improved the average diastolic blood pressure of hypertensive patients (n = 50) three months into treatment (98 mmHg at baseline vs. 86 mmHg in Month 3, P = 0.001). However, health systems barriers typical of fragile settings, such as cost of transport and medication for patients and lack of supply of medications and treatment equipment in facilities, hindered the optimal delivery of care for hypertensive and diabetic patients. Conclusion Our study suggests the potential feasibility of this approach to strengthening primary care delivery of NCDs in fragile contexts. However, the approach needs to be built into routine supervision and pre-service training to be sustained. Key barriers in the health system and at community level also need to be addressed

L-Carnitine counteracts in vitro fructose-induced hepatic steatosis through targeting oxidative stress markers

Purpose: Nonalcoholic fatty liver disease (NAFLD) is defined by excessive lipid accumulation in the liver and involves an ample spectrum of liver diseases, ranging from simple uncomplicated steatosis to cirrhosis and hepatocellular carcinoma. Accumulating evidence demonstrates that high fructose intake enhances NAFLD development and progression promoting inhibition of mitochondrial \u3b2-oxidation of long-chain fatty acids and oxidative damages. l-Carnitine (LC), involved in \u3b2-oxidation, has been used to reduce obesity caused by high-fat diet, which is beneficial to ameliorating fatty liver diseases. Moreover, in the recent years, various studies have established LC anti-oxidative proprieties. The objective of this study was to elucidate primarily the underlying anti-oxidative mechanisms of LC in an in vitro model of fructose-induced liver steatosis. Methods: Human hepatoma HepG2 cells were maintained in medium supplemented with LC (5 mM LC) with or without 5 mM fructose (F) for 48 h and 72 h. In control cells, LC or F was not added to medium. Fat deposition, anti-oxidative, and mitochondrial homeostasis were investigated. Results: LC supplementation decreased the intracellular lipid deposition enhancing AMPK activation. However, compound C (AMPK inhibitor-10 \u3bcM), significantly abolished LC benefits in F condition. Moreover, LC, increasing PGC1 \u3b1 expression, ameliorates mitochondrial damage-F induced. Above all, LC reduced ROS production and simultaneously increased protein content of antioxidant factors, SOD2 and Nrf2. Conclusion: Our data seemed to show that LC attenuate fructose-mediated lipid accumulation through AMPK activation. Moreover, LC counteracts mitochondrial damages and reactive oxygen species production restoring antioxidant cellular machine. These findings provide new insights into LC role as an AMPK activator and anti-oxidative molecule in NAFLD

Laser-induced breakdown spectroscopy associated with multivariate analysis applied to discriminate fertilizers of different nature.

Made available in DSpace on 2017-11-24T23:20:19Z (GMT). No. of bitstreams: 1 PLaserinducedbreakdown....pdf: 277933 bytes, checksum: cfd2c91da7bb377fd7e089171b43d4b1 (MD5) Previous issue date: 2017-11-24bitstream/item/167439/1/P-Laser-induced-breakdown....pd

More than one dynamic crossover in protein hydration water

Studies of liquid water in its supercooled region have led to many insights into the structure and behavior of water. While bulk water freezes at its homogeneous nucleation temperature of approximately 235 K, for protein hydration water, the binding of water molecules to the protein avoids crystallization. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules, comparing measurements of a hydrated globular protein with the results of a coarse-grained model that has been shown to successfully reproduce the properties of hydration water. With dielectric spectroscopy we measure the temperature dependence of the relaxation time of protons charge fluctuations. These fluctuations are associated to the dynamics of the HB network of water molecules adsorbed on the protein surface. With Monte Carlo (MC) simulations and mean--field (MF) calculations we study the dynamics and thermodynamics of the model. In both experimental and model analyses we find two dynamic crossovers: (i) one at about 252 K, and (ii) one at about 181 K. The agreement of the experiments with the model allows us to relate the two crossovers to the presence of two specific heat maxima at ambient pressure. The first is due to fluctuations in the HB formation, and the second, at lower temperature, is due to the cooperative reordering of the HB network