A single-mode Yb-doped fiber laser producing 2 W CW at 978 nm is demonstrated with a high slope efficiency of 72%. Thanks to its narrow bandwidth, lower than 0.02 nm, and its tunability of 6 nm, it ...has been efficiently frequency doubled in a periodically poled MgO:LiNbO3 waveguide, leading to a power of 83 mW at 489 nm and an internal conversion efficiency of 26 %.
In this paper, we present a back-end method for biofunctionalizing a large-scale array of nanocantilevers. Our method relies on the use of a modified microcontact printing process where molecules are ...delivered onto the fragile structures from the grooves of the stamp while its base sits on the chip, thus providing mechanical stability. We have used this method to print antibodies onto fabricated chips containing up to 10
5 nanostructures/cm
2and the presence of antibodies was validated by fluorescent microscopy. Furthermore, measurement of the nanocantilever resonant frequency shifts provoked by a mean added mass of ∼140
fg/cantilever demonstrated that the cantilevers retained their mechanical integrity. Hence, the method presented here aims at providing an answer to the biofunctionalization of freestanding nanostructures for their use as biosensors.
We present an amplified spontaneous emission (ASE) source based on a single-mode ytterbium-doped fiber pumped by a Nd : YVO/sub 4/ laser emitting at 914 nm. The ASE is centered on 977 nm with a ...bandwidth of 3 nm. With a spectrally filtered reflection of the copropagating ASE, we have obtained a source of ASE with a bandwidth of 0.4 nm and a tunability of 7 nm. This source delivers an output power of 340 for 700 mW of pump power, with a slope efficiency of 50%.
Land use and land cover change (LULCC) dynamics have been particularly strong in the Mediterranean region, due to its historical development and to agro-pedoclimatic conditions favorable to human ...settlement. This area has undergone in the 1950s and the 1980s intense urbanization processes that has followed different trajectories. Urban expansion commonly occurs at the expense of agricultural land, leading to the fragmentation of natural areas and conflicts over access to land resources. These dynamics mainly concern the fringe between urban and agricultural land, e.g. the peri-urban areas usually included within functional urban regions. Here, to identify common features of LULCC in Western Mediterranean urban regions, we investigated two main features: direct changes due to urbanization and indirect changes affecting non-artificial land uses. We compared LULCC dynamics in 6 case studies from the north and south of the Western Mediterranean region: the urban regions of Montpellier and Avignon (France), Pisa (Italy), Madrid (Spain), Meknes (Morocco), and Constantine (Algeria), using a 30-year multitemporal spatial analysis (1980–2010). Two series of Landsat TM images were acquired for each case study and land cover data were analyzed both for dynamics and for land patterns, using landscape and class metrics. We found no significant north-south differences in LULCC dynamics between the investigated Western Mediterranean urban regions. Differences are more pronounced between small–medium cities and large metropolitan areas in type of urban diffusion, which is more sprawled in small–medium cities and more compact in large metropolitan areas. Rather, differences occur in LULCC not directly affected by urbanization, since in Northern Mediterranean urban regions afforestation and abandonment of agricultural areas are prevalent and closer to the urban areas, whereas transformation of natural areas into agricultural ones occurs mainly in Southern Mediterranean urban regions at a similar distance from urban areas than it happens for afforested or abandoned areas. In attempting for the first time to assess LULCC in these Mediterranean urban regions, we provide a preliminary comprehensive analysis that can contribute to the active LULCC research in the Mediterranean basin and that can be easily applied to other Mediterranean urban regions.
•LULCC of 6 Mediterranean urban regions were compared.•No significant north-south differences in urbanization were found.•Differences appeared for urban growths patterns in metropolitan and medium cities.•Agricultural abandonment occurs nearest to urban areas in the northern regions.
An acute increase in portal pressure is associated with an immediate reduction in renal blood flow. It has been suggested that this supports the presence of an hepatorenal reflex. In this study, we ...used TIPSS placement as a model to investigate the effect of an acute reduction in portal pressure on renal blood flow and cardiopulmonary hemodynamic parameters.
Eleven cirrhotic patients were studied during elective TIPSS placement for variceal hemorrhage (n = 9) or refractory ascites (n = 2). Unilateral renal blood flow (RBF) was measured before and at 5, 15, 30, 45, and 60 min after shunt insertion. Heart rate (HR), mean arterial pressure (MAP), right atrial pressure (RAP), mean pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), and systemic vascular resistance (SVR) were also measured before and 30 min after TIPSS placement.
Despite significant increases in CO (p = 0.001), RAP (p < 0.001), PAP (p < 0.001), and PCWP (p = 0.001), and a fall in SVR (p = 0.003), no change was observed in RBF, HR, or MAP after TIPSS placement. The fall in the portoatrial pressure gradient correlated only with the rise in CO (p < 0.05) and the drop in SVR (p < 0.05).
Despite the fall in portal pressure and the systemic hemodynamic changes caused by TIPSS placement, there is no immediate effect on RBF. Any improvement in renal function after TIPSS procedure does not appear to be due to an acute increase in RBF.
Background: Transjugular intrahepatic portosystemic stent‐shunts (TIPSS) are becoming widely used in the management of oesophageal variceal haemorrhage (OVH). Their place in the treatment of gastric ...variceal haemorrhage (GVH), a condition with a traditionally poor prognosis, remains unclear. The aims of our study were to compare portal haemodynamics and patient outcome in patients undergoing TIPSS for either GVH or OVH.
Patients and Methods: 106 consecutive patients undergoing TIPSS at our institution for either GVH (32 patients) or OVH (74 patients) were studied. The groups were similar with regard to patient age, aetiology and severity of liver disease and number of procedures carried out as an emergency (34.4% vs. 36.5%). Episodes of shunt insufficiency, rebleeding, encephalopathy and other clinical sequela were recorded. Mean follow‐up was similar in both patient groups (14.2 vs. 12.1 months).
Results: Baseline portocaval pressure gradient was lower in patients with GVH compared with those with OVH (13.0±0.9 mmHg vs. 19.0±0.6 mmHg) (P< 0.001). Rates of variceal rebleeding, encephalopathy and shunt insufficiency during follow‐up were similar in both groups and there was no difference in survival.
Conclusion: Patients with GVH had markedly lower portocaval pressure gradients than those with OVH, but shunt and clinical complications and survival were similar during follow‐up. TIPSS appears to be an effective treatment for GVH and should be compared with endoscopic or surgical techniques in controlled trials.
This study evaluated the effect of varying the synthesis of nitric oxide with sodium nitroprusside or N-nitro-L-arginine methyl ester (L-NAME) in a pancreatitis-lung injury model. Rats (n = 45) were ...randomized to control or caerulein-induced pancreatitis groups, treated with saline, sodium nitroprusside (0.4 micrograms/kg) or L-NAME (10 mg/kg). Myeloperoxidase activity was used as a measure of neutrophil infiltration. Wet to dry (W:D) lung weight and bronchoalveolar lavage (BAL) protein concentrations were used to assess vascular leakage. Pancreatitis was shown to induce pulmonary neutrophil influx: mean(s.e.m.) myeloperoxidase activity 6.79(0.5) units/g in caerulein-treated animals versus 2.08(0.5) units/g in controls (P < 0.001). Animals with pancreatitis showed increased microvascular leakage compared with controls (mean(s.e.m.) W:D lung weight 7.01(0.5) versus 2.85(0.2), P < 0.001; BAL protein concentration 2539(222) versus 347(32) micrograms/ml, P < 0.001). Compared with the saline-treated pancreatitis group, these changes were reduced by sodium nitroprusside (mean(s.e.m.) myeloperoxidase activity to 2.5(0.4) units/g, P < 0.001; W:D lung weight to 3.8(0.37), P < 0.001; BAL protein concentration 1389(182) micrograms/ml, P < 0.05). L-NAME exacerbated the pancreatitis-induced pulmonary oedema (W:D lung weight increased to 11.96(0.6), P < 0.001), protein leakage (BAL protein concentration rose to 3707(309) micrograms/ml, P < 0.05) and neutrophil infiltration (myeloperoxidase activity increased to 9.01(0.3) units/g, P < 0.05). These data suggest that, in vivo, nitric oxide inhibits pancreatitis-induced lung injury, possibly in part by inhibiting pulmonary neutrophil influx.
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