Synthesis of a Mn-6 cluster and its self-assembly of an azido-bridged polymer

A rare mu(6)-oxo-centered Mn-6 mixed-valent cluster (1) is prepared and used as a secondary building unit for the self-assembly of its azido-bridged polymeric analogue (2) in a systematic way with the retention of the Mn-6 core of (1). Both complexes are characterized by X-ray single-crystal structure determination. The complex 1 was crystallized in a monoclinic system, space group P2(1), a = 11.252(5) A, b = 20.893(9) A, c = 12.301(6) A, and beta = 115.853(7)degrees, whereas the polymeric analogue was crystallized in an orthorhombic system, space group P2(1)2(1)2(1), a = 13.1941(8) A, b = 14.9897(9) A, and c = 27.8746(14) A. Variable-temperature magnetic behavior showed the presence of strong antiferromagnetic interaction in both cases.

Impacto funcional con el uso de clavo telescopico tipo Fassier Duval en pacientes con osteogénesis imperfecta

Introducción: la osteogénesis es una patología de origen genético caracterizada por fragilidad ósea, en su curso natural los pacientes que la padecen se enfrentan a múltiples fracturas y múltiples intervenciones quirúrgicas, este tipo de pacientes por ser de alto riesgo necesitan técnicas quirúrgicas que aumenten el tiempo entre cada intervención y que demuestren un mayor impacto en el estado funcional. Objetivo: Determinar el impacto en el estado funcional de los pacientes con osteogénesis imperfecta llevados a tratamiento quirúrgico con clavos telescopados tipo Fassier Duval. Diseño: Estudio descriptivo prospectivo en el que se incluyeron 8 pacientes con diagnóstico de osteogénesis imperfecta, llevados a tratamiento quirúrgico con clavos telescopados tipo Fassier Duval desde el 2009 al 2013 a los cuales se les realizó seguimiento menor de 1 año del post operatorio. Resultados: La respuesta encontrada fue satisfactoria en la mayoría de los pacientes analizados 6 de 8, con cercanía a un estado funcional normal; un riesgo de caída bajo, incorporación y deambulación adecuada y una valoración funcional motora gruesa con valores cercanos al 100% identificando un buen nivel de independencia funcional. Se pudo demostrar que existieron cambios en los valores de la escala y que estos fueron estadísticamente significativos con p=0,028 indicando que el aumento dichos valores en el posoperatorio están relacionados con el procedimiento quirúrgico al utilizado en este grupo de pacientes. Conclusión: El tratamiento quirúrgico con el clavo telescopado de Fassier Duval en nuestra experiencia demostró tener una mejoría en el estado funcional de los pacientes del presente estudio, por lo tanto se sugiere la posibilidad de implementar su uso según este indicado con el fin de obtener un mejor resultado quirúrgico y funcional. Palabras clave: Osteogénesis Imperfecta, Clavo de Fassier Duval, Valoración Funcional Motora

Effect of acute hypoxia on maximal oxygen uptake and maximal performance during leg and upper-body exercise in Nordic combined skiers

We examined the effect of normobaric hypoxia (3200 m) on maximal oxygen uptake (VO2max) and maximal power output (Pmax) during leg and upper-body exercise to identify functional and structural correlates of the variability in the decrement of VO2max (DeltaVO2max) and of maximal power output (DeltaPmax). Seven well trained male Nordic combined skiers performed incremental exercise tests to exhaustion on a cycle ergometer (leg exercise) and on a custom built doublepoling ergometer for cross-country skiing (upper-body exercise). Tests were carried out in normoxia (560 m) and normobaric hypoxia (3200 m); biopsies were taken from m. deltoideus. DeltaVO2max was not significantly different between leg (-9.1+/-4.9%) and upper-body exercise (-7.9+/-5.8%). By contrast, Pmax was significantly more reduced during leg exercise (-17.3+/-3.3%) than during upper-body exercise (-9.6+/-6.4%, p<0.05). Correlation analysis did not reveal any significant relationship between leg and upper-body exercise neither for DeltaVO2max nor for DeltaPmax. Furthermore, no relationship was observed between individual DeltaVO2max and DeltaPmax. Analysis of structural data of m. deltoideus revealed a significant correlation between capillary density and DeltaPmax (R=-0.80, p=0.03), as well as between volume density of mitochondria and DeltaPmax (R=-0.75, p=0.05). In conclusion, it seems that VO2max and Pmax are differently affected by hypoxia. The ability to tolerate hypoxia is a characteristic of the individual depending in part on the exercise mode. We present evidence that athletes with a high capillarity and a high muscular oxidative capacity are more sensitive to hypoxia.

[Rumenocentesis: a suitable technique for analysis of rumen juice pH in cattle?]

In the United States, rumenocentesis has been recommended especially for early diagnosis of subacute rumen acidosis (SARA). The objective of the current study was to evaluate health risks due to the technique ofrumenocentesis and to measure pH in ruminal juice using a commercial indicator paper (Pehanon) and a pH electrode (reference method). After 11 dairy cows underwent rumenocentesis, the clinical status of those animals was evaluated daily, and cows were slaughtered as well as pathologically--anatomically examined on day 7. During the observation period, the following pathological clinical signs were evident: forced inspiration (3 cows), transient episode of hyperthermia (2 cows), increased tension of the abdominal wall (8 cows) and positive foreign body tests (3 cows). One cow had to be culled on day 7 because of severe generalised septic peritonitis spreading from the site of rumenocentesis. At slaughter, hematoma formation in the area of the puncture site was found in 9 out of 10 cows. It was concluded that the severe complications encountered with this technique do not legitimate rumenocentesis as a routine procedure for collection of rumen juice samples in cows under Swiss conditions. The correlation between the pH reference method and the commercial indicator paper was the high (r = 0.926).

[Treatment after drug-eluting stent placement]

The use of drug-eluting stents (DES) in percutaneous coronary interventions (PCI) decreased the rate of restenosis and hence the need for repeat revascularization by 50-71%. DES have changed PCI. DES allow successful revascularization of anatomically challenging lesions, such as long, thin vessels, bifurcation lesions, and chronic total occlusions. A rare, but severe complication of coronary stenting is stent thrombosis, a partial or total thrombotic occlusion of the stent. The use of DES for increasingly more complex lesions, the prothrombotic effect of the antiproliferative substances, and a delayed endothelialization of DES all potentially prolong and increase the risk of stent thrombosis. Dual antiplatelet therapy for 1 year is therefore recommended after DES placement. There is currently no evidence for the efficacy and safety of routine dual antiplatelet therapy beyond 1 year. It is also recommended postponing elective surgery for 1 year and, if surgery cannot be deferred, considering continuation of acetylsalicylic acid during the perioperative period in high-risk patients with DES.

The influence of zero value subtraction on the performance of a new laser fluorescence device for approximal caries detection

The aim of this study was to assess the influence of the zero value subtraction on the performance of laser fluorescence (LFpen) for approximal caries detection. Three areas (cuspal, middle and cervical) of both mesial and distal buccal surfaces of 78 permanent molars were assessed using both wedge-shaped (WDG) and tapered wedge-shaped (TWDG) tips. With the addition of the average, one cut-off value for each area was obtained and the performance was assessed. The areas under the receiver operating characteristics (ROC) curve, specificity, sensitivity and accuracy with and without the zero value subtraction were calculated. The McNemar test revealed a statistically significant difference for specificity at thresholds D(1), D(2) and D(3) (WDG) and D(1) and D(2) (TWDG) when the zero value subtraction was not performed. Influence of the zero value subtraction on the LFpen performance was observed for approximal caries detection. However, when modified cut-off values were used, the zero value subtraction could be eliminated.

Non-Hodgkin lymphoma incidence in the Swiss HIV Cohort Study before and after highly active antiretroviral therapy

OBJECTIVE: To assess the long-term effect of HAART on non-Hodgkin lymphoma (NHL) incidence in people with HIV (PHIV). DESIGN: Follow-up of the Swiss HIV Cohort Study (SHCS). METHODS: Between 1984 and 2006, 12 959 PHIV contributed a total of 75 222 person-years (py), of which 36 787 were spent under HAART. Among these PHIV, 429 NHL cases were identified from the SHCS dataset and/or by record linkage with Swiss Cantonal Cancer Registries. Age- and gender-standardized incidence was calculated and Cox regression was used to estimate hazard ratios (HR). RESULTS: NHL incidence reached 13.6 per 1000 py in 1993-1995 and declined to 1.8 in 2002-2006. HAART use was associated with a decline in NHL incidence [HR = 0.26; 95% confidence interval (CI), 0.20-0.33], and this decline was greater for primary brain lymphomas than other NHL. Among non-HAART users, being a man having sex with men, being 35 years of age or older, or, most notably, having low CD4 cell counts at study enrollment (HR = 12.26 for < 50 versus >or= 350 cells/microl; 95% CI, 8.31-18.07) were significant predictors of NHL onset. Among HAART users, only age was significantly associated with NHL risk. The HR for NHL declined steeply in the first months after HAART initiation (HR = 0.46; 95% CI, 0.27-0.77) and was 0.12 (95% CI, 0.05-0.25) 7 to10 years afterwards. CONCLUSIONS: HAART greatly reduced the incidence of NHL in PHIV, and the influence of CD4 cell count on NHL risk. The beneficial effect remained strong up to 10 years after HAART initiation.

ATPase activity, proton gradients and proton secretion inhibition during experiments with Sepia officinalis and Sepioteuthis lessoniana

The constraints of an active life in a pelagic habitat led to numerous convergent morphological and physiological adaptations that enable cephalopod molluscs and teleost fishes to compete for similar resources. Here, we show for the first time that such convergent developments are also found in the ontogenetic progression of ion regulatory tissues; as in teleost fish, epidermal ionocytes scattered on skin and yolk sac of cephalopod embryos appear to be responsible for ionic and acid-base regulation before gill epithelia become functional. Ion and acid-base regulation is crucial in cephalopod embryos, as they are surrounded by a hypercapnic egg fluid with a Pco2 between 0.2 and 0.4 kPa. Epidermal ionocytes were characterized via immunohistochemistry, in situ hybridization, and vital dye-staining techniques. We found one group of cells that is recognized by concavalin A and MitoTracker, which also expresses Na+/H+ exchangers (NHE3) and Na+-K+-ATPase. Similar to findings obtained in teleosts, these NHE3-rich cells take up sodium in exchange for protons, illustrating the energetic superiority of NHE-based proton excretion in marine systems. In vivo electrophysiological techniques demonstrated that acid equivalents are secreted by the yolk and skin integument. Intriguingly, epidermal ionocytes of cephalopod embryos are ciliated as demonstrated by scanning electron microscopy, suggesting a dual function of epithelial cells in water convection and ion regulation. These findings add significant knowledge to our mechanistic understanding of hypercapnia tolerance in marine organisms, as it demonstrates that marine taxa, which were identified as powerful acid-base regulators during hypercapnic challenges, already exhibit strong acid-base regulatory abilities during embryogenesis.

地域研究とディシプリン -- アフリカ研究の立場から (特集 発展途上国研究の方法)

地域研究の方法論的特徴やディシプリンとの関係は，これまで繰り返し議論されてきた。本稿では，日本における地域研究の受容と展開を跡づけたうえで，アフリカ研究の立場からこの問題を検討する。第２次世界大戦後に欧米で誕生した地域研究に比べ，日本の地域研究は，社会科学や人文科学のみならず自然科学も含むなど，研究対象領域や方法論の幅が広い。地域研究を既存のディシプリンから独立した研究領域とみなす主張もあるものの，筆者を含め研究者の多くはそれがディシプリン上の基礎をもつべきだと考えている。社会科学に依拠しつつ特定地域を長期的，継続的に調査する地域研究は，(1)現地情勢の迅速，的確な分析，(2)データ解析の質的向上，(3)研究に値する「問い」の発見，といった優位性をもつ。地域研究は他の研究分野から独立した自律的研究領域とはいえないが，ディシプリンとの間に構築される緊張関係を通じて社会科学を豊かにする可能性をもつ。

比較地域研究試論 (特集 発展途上国研究の方法)

本稿では比較の視点から地域理解を目指す研究手法，比較地域研究を提案する。それは，同じ目的をもった行為や同じ衝撃によって生じた現象が，国・地域によって異なった現れ方をしたとき，その違いをもたらした要因を地域の文脈に求め，その分析を通して地域の特色を知ろうとする方法である。理解できる地域の特色は部分的，限定的であるから，包括的・総合的理解を目指す従来の地域研究とは異なっている。比較地域研究は地域理解を第一義的な目的とするものの，社会的現象の生じる場の構造的特色が，行為や衝撃と結果の関係にどう作用するのかという，理論的，実践的な含意をもたらしうるものである。