Photothermal deflection determination of iron(II) with ferrozine with sorption preconcentration on silufol plates

Photothermal deflection spectroscopy was applied to the selective detection of iron(II) chelate with ferrozine by its sorption preconcentration on Silufol plates. The linearity range was 1 × 10-11-6 × 10 -8 mol cm-2 of chelate at the plate surface, which corresponded to 1 × 10-9 × 10-6 M of chelate in solution. The limits of detection and quantification are 8 × 10 -12 and 2.5 × 10-11 mol cm-2 at the plate from 15 μL of test solution (0.5 nM and 1.5 nM in solution, respectively), and the absolute detection limit is 8 fmol in the whole spot applied to a plate. Characteristics and features of photothermal deflection detection are discussed. © 2008 Society for Applied Spectroscopy

Determination of Thermal Diffusivity of Ceramics by Means of Photothermal Beam Deflection

The non-contact and non-destructive photothermal beam deflection (PBD) method has been used for the characterization of the thermal properties of Alumina (Al2O3), Mullite (3Al2O3·2SiO2) and Oxidic-Bonded Silicon Carbide (OBSiC) samples often used in chemical engineering. Measurements of thermal diffusivity κ have been performed. One obtains κ = 7.96 ⋅10$^{-6}$ m²/s for Alumina, κ =1.94 ⋅10$^{-6}$(m² )/s for Mullite and κ = 3.91⋅10$^{-6}$(m² )/s for OBSiC

Local-scale nutrient regeneration facilitates seaweed growth on wave-exposed rocky shores in an upwelling system

Abstract This study shows that, even on exposed, wave-swept, rocky shores in a nutrient-replete upwelling ecosystem, mussels (Mytilus californianus) facilitate the growth of the seaweed Porphyra perforata by enhancing nutrient concentrations in the nearby water column. In field surveys on emergent substrate in the mid-intertidal zone, we found ten times greater abundance of P. perforata on mussels than on adjacent rock. In field experiments, P. perforata accumulated and grew more quickly on mussels than on bare rock or on mussel mimics, suggesting that nutrients excreted by mussels might be responsible for greater P. perforata cover. At high tide, water column ammonium concentrations over mussel beds were nearly double those found over bare rock. Correspondingly, tissue nitrogen concentrations were higher, and carbon-to-nitrogen ratios were lower in P. perforata growing on mussels compared to bare rock. Given the dominance of mussels in mid-intertidal regions of temperate coasts worldwide, ammonium regeneration could be a general contributor to local-scale nutrient availability, even in high-flow systems characterized by high nutrient concentrations

Artrodesis subtalar primaria como tratamiento de fracturas conminutas de calcáneo Sanders tipo IV

Las fracturas conminutas Sanders IV de calcáneo dan lugar, en la mayoría de los casos, a una artrosis subtalar postraumática dolorosa e incapacitante, que en muchas ocasiones, requiere una artrodesis subtalar secundaria. Esta artrodesis puede ser técnicamente compleja, ya que no se trata de una fijación in situ, sino que requiere la realización de osteotomías de corrección a nivel del cuerpo del calcáneo en la misma cirugía.Material y métodos. Presentamos 4 pacientes con fracturas conminutas de calcáneo Sanders tipo IV que fueron tratadas mediante una artrodesis subtalar primaria con reconstrucción concomitante del cuerpo del calcáneo. El seguimiento medio fue de 15 meses. Resultados. Obtuvimos la consolidación ósea, tanto de la artrodesis como de la fractura, alrededor de los 4 meses, sin existir signos de artrosis en otras articulaciones. No hubo ninguna complicación de herida quirúrgica, ni aparecieron otras complicaciones típicas de estas lesiones, como impingement de peroneos, problemas con el calzado o bloqueo o degeneración de la articulación tibio talar durante el seguimiento. La puntuación AOFAS media a los 12 meses fue de 78. Conclusiones. La artrodesis subtalar primaria con la corrección inicial de las deformidades asociadas en el cuerpo del calcáneo (acortamiento, ensanchamiento y varo) evita complicaciones posteriores y obtiene buenos resultados

Acute kidney injury is associated with subsequent infection in neonates after the Norwood procedure: a retrospective chart review

Background: Acute kidney injury (AKI) and infection are common complications after pediatric cardiac surgery. No pediatric study has evaluated for an association between postoperative AKI and infection. The objective of this study was to determine if AKI in neonates after cardiopulmonary bypass was associated with the development of a postoperative infection. Methods: We performed a single center retrospective chart review from January 2009 to December 2015 of neonates (age ≤ 30 days) undergoing the Norwood procedure. AKI was defined by the modified neonatal Kidney Disease Improving Global outcomes serum creatinine criteria using (1) measured serum creatinine and (2) creatinine corrected for fluid balance on postoperative days 1-4. Infection, (culture positive or presumed), must have occurred after a diagnosis of AKI and within 60 days of surgery. Results: Ninety-five patients were included, of which postoperative infection occurred in 42 (44%). AKI occurred in 38 (40%) and 42 (44%) patients by measured serum creatinine and fluid overload corrected creatinine, respectively, and was most commonly diagnosed on postoperative day 2. The median time to infection from the time of surgery and AKI was 7 days (IQR 5-14 days) and 6 days (IQR 3-13 days), respectively. After adjusting for confounders, the odds of a postoperative infection were 3.64 times greater in patients with fluid corrected AKI (95% CI, 1.36-9.75; p = 0.01). Conclusions: Fluid corrected AKI was independently associated with the development of a postoperative infection. These findings support the notion that AKI is an immunosuppressed state that increases the risk of infection

Cytokine production increases and cytokine clearance decreases in mice with bilateral nephrectomy

BackgroundSerum cytokines are increased in patients with acute kidney injury (AKI) and predict increased mortality. It is widely assumed that increased renal production of cytokines is the source of increased serum cytokines; the role of extra-renal cytokine production and impaired renal cytokine clearance is less well studied. We hypothesized that cytokine production in AKI was mononuclear phagocyte dependent, independent of production by the kidneys, and that serum cytokine clearance would be impaired in AKI.MethodsBilateral nephrectomy was used as a model of AKI to assess cytokine production independent of kidney cytokine production. Mononuclear phagocytes were depleted utilizing intravenous (IV) administration of liposome-encapsulated clodronate (LEC). Twenty-three serum cytokines were determined utilizing a multiplex cytokine kit. Proteins for cytokines were determined in the spleen and liver by enzyme-linked immunosorbent assay. Recombinant cytokines were injected by IV into mice with bilateral nephrectomy to determine the effect of absent kidney function on serum cytokine clearance.ResultsSerum interleukin (IL)-6, chemokine (C-X-C motif) ligand 1 (CXCL1), IL-10, IL-1β, monocyte chemotactic protein 1 (MCP-1), IL-5 and eotaxin were increased in the serum of mice after bilateral nephrectomy and were reduced with LEC. Serum IL-12p40 and regulated upon activation, normal T-cell expressed, and secreted (RANTES) were increased after bilateral nephrectomy and were further increased with LEC. Spleen IL-6, CXCL1, IL-10 and IL-1β and liver IL-6 and IL-10 were increased after bilateral nephrectomy. After IV injection, IL-6, CXCL1, IL-10 and IL-1β had a prolonged serum cytokine appearance in mice with bilateral nephrectomy versus sham operation.ConclusionsIncreased mononuclear phagocyte production and impaired renal clearance contribute to serum cytokine accumulation in AKI, independent of kidney injury. The effect of AKI on cytokine production and clearance may contribute to the increased mortality of patients with AKI. © 2012 The Author

The validity of the EQ-5D-3L items: An investigation with type 2 diabetes patients from six European countries

Background: Most previous studies concerning the validity of the EQ-5D-3L items refer to applications of only a single language version of the EQ-5D-3L in only one country. Therefore, there is little information concerning the extent to which the results can be generalised across different language versions and