Engineering the internal cavity of neuroglobin demonstrates the role of the haem-sliding mechanism.

Neuroglobin is a member of the globin family involved in neuroprotection; it is primarily expressed in the brain and retina of vertebrates. Neuroglobin belongs to the heterogeneous group of hexacoordinate globins that have evolved in animals, plants and bacteria, endowed with the capability of reversible intramolecular coordination, allowing the binding of small gaseous ligands (O2, NO and CO). In a unique fashion among haemoproteins, ligand-binding events in neuroglobin are dependent on the sliding of the haem itself within a preformed internal cavity, as revealed by the crystal structure of its CO-bound derivative. Point mutants of the neuroglobin internal cavity have been engineered and their functional and structural characterization shows that hindering the haem displacement leads to a decrease in CO affinity, whereas reducing the cavity volume without interfering with haem sliding has negligible functional effects.

Dispersion and treatment performance analysis of an UASB reactor under different hydraulic loading rates.

Mixing and transport phenomena affect the efficiency of all bioreactor configurations. An even mixing pattern at the macro-level is desirable to provide good conditions for substrate transport to, and from, the microbial aggregates. The state of segregation of particulate material in the reactor is also important. The production of biogas in anaerobic reactors is another factor that affects mixing intensity and hence the interactions between the liquid, solid and gaseous phases. The CSTR model with some degree of short-circuiting, dead zones and bypassing flows seems to describe the overall hydrodynamics of UASBs. However, few data are available in the literature for full-scale reactors that relate process performance to mixing characteristics. Dispersion studies using LiCl were done for four hydraulic loading rates on a full-scale UASB treating domestic wastewater in Ginebra, Valle del Cauca, southwest Colombia. COD, TSS, and Settleable Solids were used to evaluate the performance of organic matter removal. The UASB showed a complete mixing pattern for hydraulic loading rates close to the design value (i.e. Q = 10-13l s(-1) and HRT=8-6 h). Gross mixing distortions and localised stagnant zones, short-circuiting and bypass flows were found in the sludge bed and blanket zones for both extreme conditions (underloading and overloading). The liquid volume contained below the gas-liquid-solid separator was found to contribute to the overall stagnant volume, particularly when the reactor was underloaded. The removal of organic matter showed a log-linear correlation with the dispersion number.

Meningocele sacro anterior. Caso clinico y revision de la literatura / Anterior sacral meningocele. Clinical case and literature review

Objective: to describe the surgical treatment of an anterior sacral meningocele (ASM). Description: a 67 year-old woman presented with pelvic mass symptoms, and had a previous history of four surgeries with mistaken diagnosis, consulted to the neurosurgery departament for pain treatment. MRI revealed a cystic sacral mass connected with the spinal subarachnoid space, with low density structures in the pedicle. MyeloCT showed no neural elements in the sac. Intervention: an anterior transabdominal approach with wall cyst dissection, excision of the sac and simple ligation of the neck was performed. Conclusion: we presented an uncommon case of ASM in an adult woman, with the transabdominal surgical approach was the treatment of choice in anterior sacral meningocele (AU)

Meningocele sacro anterior. Caso clinico y revision de la literatura / Anterior sacral meningocele. Clinical case and literature review

Objective: to describe the surgical treatment of an anterior sacral meningocele (ASM). Description: a 67 year-old woman presented with pelvic mass symptoms, and had a previous history of four surgeries with mistaken diagnosis, consulted to the neurosurgery departament for pain treatment. MRI revealed a cystic sacral mass connected with the spinal subarachnoid space, with low density structures in the pedicle. MyeloCT showed no neural elements in the sac. Intervention: an anterior transabdominal approach with wall cyst dissection, excision of the sac and simple ligation of the neck was performed. Conclusion: we presented an uncommon case of ASM in an adult woman, with the transabdominal surgical approach was the treatment of choice in anterior sacral meningocele

Mineral contents of some southern Italian wines. II. Determination of Li, Na, Mg, K, Ca, Co, As, Rb, Sr, Ag, Sb, Ba.

Following our study of the mineral contents of some Southern Italian wines, this work reports on the detection of 12 elemental components. The elements were determined using ICP-AES, flame atomic emission or absorption spectroscopy. The values determined for Li, Na, Mg, K, Ca, Rb, Sr and Ba were within the usual ranges for wines (average values for these elements were: 0.010, 26.2; 94.4; 888; 94.0; 3.30, 0.82 and 0.11 mg/l respectively). All the wines contained low levels of As, the concentrations of which were always under 0.20 mg/l, the maximum level permitted by E.E.C. standards. The measuring of Co, Ag, and Sb led us to ascertain, in all the wines, concentrations lower than 0.01 mg/l for Co and Ag and below the instrumental detection level for Sb (0.06 mg/l). In a previous study wines from D.O.C. areas of Southern Italy were analysed by the technique of inductively coupled plasma atomic emission spectroscopy (ICP-AES), for 14 minerals. This paper deals with further investigation of the mineral composition of the same wines for different metal constituents, analysed by ICP-AES, flame atomic emission, or atomic-absorption spectroscopy (two techniques). The first technique was applied to the detection of Co, As, Sr, Ag, Sb, and Ba. The alkaline metals Li, Na, K, and Rb were determined by flame atomic emission, a technique which possesses better detection limits for these elements. For Mg and Ca the atomic absorption methods were applied.