Nanoimprint lithography for high-efficiency thin-film silicon solar cells.

We demonstrate high-efficiency thin-film silicon solar cells with transparent nanotextured front electrodes fabricated via ultraviolet nanoimprint lithography on glass substrates. By replicating the morphology of state-of-the-art nanotextured zinc oxide front electrodes known for their exceptional light trapping properties, conversion efficiencies of up to 12.0% are achieved for micromorph tandem junction cells. Excellent light incoupling results in a remarkable summed short-circuit current density of 25.9 mA/cm(2) for amorphous top cell and microcrystalline bottom cell thicknesses of only 250 and 1100 nm, respectively. As efforts to maximize light harvesting continue, our study validates nanoimprinting as a versatile tool to investigate nanophotonic effects of a large variety of nanostructures directly on device performance.

Rosuvastatin given during reperfusion decreases infarct size and inhibits matrix metalloproteinase-2 activity in normocholesterolemic and hypercholesterolemic rabbits.

There is evidence that statin treatment before ischemia protects myocardium from ischemia/reperfusion injury. The objective is to determine whether rosuvastatin administered during reperfusion modifies infarct size and the recovery of postischemic ventricular dysfunction in normocholesterolemic and hypercholesterolemic rabbits. In addition, we also evaluated the role of matrix metalloproteinase type 2 (MMP)-2 activation. Langendorff-perfused rabbit hearts were subjected to 30 minutes of ischemia and 120 minutes of reperfusion. In group 2, we added rosuvastatin after 30 minutes of ischemia and from the beginning of reperfusion. In group 3, an MMP inhibitor (doxycycline) was administered during the first 2 minutes of reperfusion. Finally, we repeated these groups but in hypercholesterolemic rabbits (groups 4, 5, and 6). The infarct size was 16.6% +/- 3.9% in group 1 and 25.6% +/- 2.7% in group 4. Rosuvastatin reduced infarct size to 4.5% +/- 1.1% and 6.1% +/- 1.5% in groups 2 and 5, respectively (P < 0.05). Rosuvastatin significantly decreased MMP-2 activity during reperfusion, and doxycycline induced an inhibition of MMP-2 activity and a reduction of infarct size in normocholesterolemic (4.9% +/- 0.9%) and hypercholesterolemic animals (8.3% +/- 1.6%) (P < 0.05). Rosuvastatin reduces infarct size and attenuates MMP-2 activity. These data and the correlation between MMP-2 and infarct size suggest that MMP-2 plays an important role in the mechanisms of cardioprotection afforded by rosuvastatin.

Influence of thoracic epidural analgesia on postoperative pain relief and ileus after laparoscopic colorectal resection : Benefit with epidural analgesia.

BACKGROUND: Thoracic epidural analgesia (TEA) provides superior analgesia with a lower incidence of postoperative ileus when compared with systemic opiate analgesia in open colorectal surgery. However, in laparoscopic colorectal surgery the role of TEA is not well defined. This prospective observational study investigates the influence of TEA in laparoscopic colorectal resections. METHODS: All patients undergoing colorectal resection between November 2004 and February 2007 were assessed for inclusion into a prospective randomized trial investigating the influence of bisacodyl on postoperative ileus. All patients treated by laparoscopic resection from this collective were eligible for the present study. Primary endpoints were use of analgesics and visual analogue scale (VAS) pain scores. Secondary endpoint concerned full gastrointestinal recovery, defined as the mean time to the occurrence of the following three events (GI-3): first flatus passed, first defecation, and first solid food tolerated. RESULTS: 75 patients underwent laparoscopic colorectal resection, 39 in the TEA group and 36 in the non-TEA group. Patients with TEA required significantly less analgesics (metamizol median 3.0 g [0-32 g] versus 13.8 g [0-28 g] (p < 0.001); opioids mean 12 mg [+/-2.8 mg standard error of mean, SEM] versus 103 mg [+/-18.2 mg SEM] (p < 0.001). VAS scores were significantly lower in the TEA group (overall mean 1.67 [+/- 0.2 SEM] versus 2.58 [+/-0.2 SEM]; p = 0.004). Mean time to gastrointestinal recovery (GI-3) was significantly shorter (2.96 [+/-0.2 SEM] days versus 3.81 [+/-0.3 SEM] days; p = 0.025). Analysis of the subgroup of patients with laparoscopically completed resections showed corresponding results. CONCLUSION: TEA provides a significant benefit in terms of less analgesic consumption, better postoperative pain relief, and faster recovery of gastrointestinal function in patients undergoing laparoscopic colorectal resection.

Efecto de la rosuvastatina sobre el infarto experimental en conejos normales e hipercolesterolémicos / Effects of Rosuvastatin on Experimental Infarction on Normal and in Hypercholesterolemic Rabbits

Es conocido que el pretratamiento con rosuvastatina disminuye el tamaño del infarto y mejora la disfunción ventricular. Sin embargo, no existe evidencia experimental que demuestre su efecto cuando se administra durante la reperfusión. El objetivo del presente estudio fue evaluar si la rosuvastatina administrada durante la reperfusión modifica el tamaño del infarto y la recuperación de la función ventricular posisquémica en corazones de conejos normocolesterolémicos e hipercolesterolémicos. Corazones aislados e isovolúmicos de conejo fueron perfundidos según la técnica de Langendorff. En el grupo 1 (G1) se realizó una isquemia global de 30 minutos seguidos por 120 minutos de reperfusión. En el grupo 2 (G2) se administró rosuvastatina (50 µM) durante toda la reperfusión. En los grupos 3 y 4 (G3 y G4) se repitieron los protocolos de G1 y G2, respectivamente, pero en conejos alimentados durante un mes con una dieta rica en colesterol al 1%. El colesterol total antes de iniciar la dieta fue de 59,6 ± 9,3 mg/dl y luego de la alimentación durante 4 semanas con una dieta rica en colesterol se incrementó hasta un valor de 185,4 ± 21,4 (p < 0,05). No hubo diferencias en la recuperación de la presión desarrollada (PDVI) ni en la presión diastólica final del ventrículo izquierdo (PDFVI) en los animales normocolesterolémicos. Sin embargo, en G3 y G4 la administración de rosuvastatina atenuó la disfunción ventricular posisquémica sistólica y diastólica. El tamaño del infarto de G1 y G3 fue de 16,6 ± 2,6 y 25,6 ± 2,7, respectivamente (p < 0,05). La administración de rosuvastatina redujo el tamaño del infarto en G2 y G4 a un valor de 4,5 ± 1,1 y 5,5 ± 1,6 (p < 0,05), respectivamente. La rosuvastatina administrada desde el inicio de la reperfusión disminuye el tamaño del infarto en conejos normales e hipercolesterolémicos y mejora la recuperación de la función ventricular sólo en los animales hipercolesterolémicos.

It is well accepted that previous treatment with rosuvastatin may reduce infarct size and improve ventricular dysfunction. Nevertheless, there is no experimental evidence of this action when administered during reperfusion. The objective of the present study was to assess if the administration of rosuvastatin during reperfusion might modify not only the infarct size but also ventricular function recovery after an ischemic episode in normocholesterolemic and hypercholesterolemic rabbits. Isolated and isovolumetric rabbit hearts were perfused according to Langendorff technique. Rabbits in group 1 (G1) underwent a 30-minute global ischemia followed by a reperfusion lasting for 120 minutes. Rosuvastatin (50 µM) was administered to rabbits in group 2 (G2) throughout the whole reperfusion. Protocols G1 and G2 were repeated in groups 3 and 4 (G3 and G4), respectively, but in rabbits previously fed for a month with a 1% cholesterol-rich diet. Total cholesterol levels were 59.6±9.3 mf/dl before treatment with the diet, and after a cholesterol-rich diet for 4 weeks, cholesterol levels increased to 185.4±21.4 (p<0.05). No differences among recovery in left ventricle developed pressure (LVDP) or in end-diastolic left ventricle pressure (EDLVP) were reported in normocholesterolemic animals. Nevertheless, the administration of rosuvastatin mitigated systolic and diastolic post-ischemic left ventricular dysfunction. Infarct size in G1 and G3 was 16.6±2.6 and 25.6 ± 2.7, respectively (p < 0.05). Administration of rosuvastatin reduced the infarct size in G2 and G4 to 4.5±1.1 y 5.5±1.6 (p<0.05), respectively. The administration of rosuvastatin since the beginning of reperfusion reduces the infarct size in normocholesterolemic and hypercholesterolemic rabbits, and improves ventricular function only in hypercholesterolemic animals.