Closed-cell stent for coil embolization of intracranial aneurysms: clinical and angiographic results

BACKGROUND AND PURPOSE: Recanalization is observed in 20-40% of endovascularly treated intracranial aneurysms. To further reduce the recanalization and expand endovascular treatment, we evaluated the safety and efficacy of closed-cell SACE. MATERIALS AND METHODS: Between 2007 and 2010, 147 consecutive patients (110 women; mean age, 54 years) presenting at 2 centers with 161 wide-neck ruptured and unruptured aneurysms were treated by using SACE. Inclusion criteria were wide-neck aneurysms ( \u3e 4 mm or a dome/neck ratio RESULTS: Eighteen aneurysms (11%) were treated following rupture. Procedure-related mortality and permanent neurologic deficits occurred in 2 (1.4%) and 5 patients (3.4%), respectively. In total, 7 patients (4.8%) died, including 2 with reruptures. Of the 140 surviving patients, 113 (80.7%) patients with 120 aneurysms were available for follow-up neurologic examination at a mean of 11.8 months. An increase in mRS score from admission to follow-up by 1, 2, or 3 points was seen in 7 (6.9%), 1 (1%), and 2 (2%) patients, respectively. Follow-up angiography was performed in 120 aneurysms at a mean of 11.9 months. Recanalization occurred in 12 aneurysms (10%), requiring retreatment in 7 (5.8%). Moderate in-stent stenosis was seen in 1 (0.8%), which remained asymptomatic. CONCLUSIONS: This series adds to the evidence demonstrating the safety and effectiveness of SACE in the treatment of intracranial aneurysms. However, SACE of ruptured aneurysms and premature termination of antiplatelet treatment are associated with increased morbidity and mortality

Evaluation of Plant Nitrogen Use Efficiency in Different Crop Rotations

IntroductionThere is an urgent need to increase per capita food production to compete with high population growth while maintaining environmental sustainability. Because nitrogen plays a vital role in food production for humans and livestock, nitrogen management is essential in food production. In most cropping systems, nitrogen management seems to be a major challenge due to its high mobility and natural tendency for losses from the soil-plant system to the environment. Soil organic carbon plays a key role in improving soil ecological conditions. Adding organic matter to the soil is an excellent tool for improving physical, chemical and biological conditions and is almost always desirable. Soil organic carbon stock of crop ecosystems may be increased by improving farming practices. The application of green manure, fertilizer and the return of crop straw into the soil are known as management operations to increase soil organic carbon. Fertilizers, especially nitrogen, increase crop yield, and organic carbon is returned to the soil through roots and debris, which in most cases leads to increased soil organic carbon.Materials and MethodsThis study was conducted with the aim of utilizing a set of improving farming practices in diverse cropping systems to improve nitrogen efficiency during two crop years. Farming practices including removal of summer fallow were used by importing three crops of mung bean, corn and wild rocket in rotation plus nitrogen supply levels factor. The crop rotation factor was applied in four levels of Fallow-wheat, mung bean-wheat, corn-wheat and wild rocket-wheat and the factor of nitrogen fertilizer (0, 180 and 360 kg.ha-1) in a randomized complete block design as factorial. Soil mineral nitrogen (nitrate and ammonium) were measured before sowing wheat and grain, straw and total plant nitrogen after harvest. Uptake efficiency, utilization efficiency, agronomic efficiency and nitrogen harvest index were calculated.Results and DiscussionThe results of combined analysis of variance showed that the crop rotation and nitrogen were significantly effective (ρ ≤ 0.01) on plant nitrogen, harvest index and nitrogen efficiency. Increasing nitrogen fertilizer up to 360 kg.ha-1 increased grain nitrogen, straw nitrogen, total plant nitrogen and also nitrogen harvest index. While the best uptake, utilization and agronomic efficiency of nitrogen was observed on the treatment without nitrogen fertilizer. Comparison of the means showed that the wild rocket-wheat crop rotation had the best result among all measured traits except utilization efficiency, while the utilization efficiency in the corn-wheat crop rotation showed the best performance. The results clearly show the effect of increasing organic carbon on nitrogen availability and grain nitrogen concentration as well as the role of cover crops and legume, in increasing access to nitrogen. The amount of grain nitrogen was directly affected by the amount of nitrogen fertilizer. The highest correlation coefficient was seen between agronomic and uptake efficiency (r = 0.96**). There was also a significant inverse relationship between nitrogen harvest index and the types of calculated efficiencies. The amount of uptake efficiency and agronomic efficiency in all crop rotations except corn-wheat in the second year improved compared to the first year. The highest increase in efficiency in the second year was related to the wild rocket-wheat crop rotation. In the conditions of 360 and 180 kg.ha-1 nitrogen fertilizer, the nitrogen harvest index increased in the second year compared to the first year. While in conditions without nitrogen fertilizer, nitrogen harvest index has a significant decrease. Therefore, at least in the short term, to increase the nitrogen harvest index, the minimum supply of nitrogen fertilizer should be used, even under improving crop management conditions such as green manure, removal of fallow and introduction of legumes in rotation and return of crop residues.ConclusionContinuous cropping, removal of fallow, use of cover crops and legume and preservation of residues led to increased carbon and nitrogen sequestration in soil and consequently increase biomass and nitrogen concentration in plant tissue. On the other hand, crop rotations that increased soil organic carbon and improved soil fertility quickly improved nitrogen efficiency and nitrogen harvest index

Hybrid Metal-Dielectric Metasurfaces for Refractive Index Sensing

Hybrid metal-dielectric nanostructures have recently gained prominence because they combine strong field enhancement of plasmonic metals and the several low-loss radiation channels of dielectric resonators, which are qualities pertaining to the best of both worlds. In this work, an array of such hybrid nanoantennas is successfully fabricated over a large area and utilized for bulk refractive index sensing with a sensitivity of 208 nm/RIU. Each nanoantenna combines a Si cylinder with an Al disk, separated by a SiO2 spacer. Its optical response is analyzed in detail using the multipoles supported by its subparts and their mutual coupling. The nanoantenna is further modified experimentally with an undercut in the SiO2 region to increase the interaction of the electric field with the background medium, which augments the sensitivity to 245 nm/RIU. A detailed multipole analysis of the hybrid nanoantenna supports our experimental findings

Chemical-specific biosensing through mid-infrared graphene plasmons

Infrared spectroscopy provides chemical information of biomolecules by detecting their vibrational fingerprints. Here, we use graphene plasmons to enhance infrared absorption and to demonstrate a tunable biosensor with high sensitivity for label-free and chemically-specific detection of protein monolayers. We show that the tunability and extreme light confinement of graphene offer great possibilities for biosensing

Graphene as enabling material for infrared plasmonic biosensors

We demonstrate a graphene infrared biosensor for chemical-specific label-free protein detection. Graphene plasmon resonances are dynamically tuned to enhance protein vibrational bands. We show that the extreme light confinement makes graphene plasmons extremely sensitive to nanometric molecules