Polyglycolide/polylactide-coated platinum coils for patients with ruptured and unruptured cerebral aneurysms: a single-center experience

BACKGROUND AND PURPOSE: Recanalization of cerebral aneurysm is a limitation of bare platinum coils (BPCs). In a swine aneurysm model, polyglycolide/polylactide (a polymer)-coated platinum coils (Matrix) accelerated clot fibrosis and reduced recanalization rate and aneurysmal volume. We aimed to evaluate the safety of Matrix coils in patients with intracranial aneurysm. METHODS: This is a single-center, prospective study of patients with intracranial aneurysms treated with Matrix alone or in combination with BPCs. Follow-up evaluation included a 1-month clinical evaluation and a 6- and 12-month clinical and angiographic examination. Primary adverse events included death, stroke, and permanent neurological deficits. RESULTS: Between May 2002 and January 2004, 52 patients (range 34 to 79 years of age; 38 females) were treated for 54 aneurysms (size 7.9+/-4.6 mm; neck 3.9+/-1.5 mm; 26 ruptured). Matrix alone was used in 13 aneurysms. In 39, we used a combination of Matrix and BPCs. Twenty-one aneurysms had a 6-month follow-up examination (11 Matrix; 10 Matrix combined with bare platinum), and 11 completed the 12-month follow-up evaluation (Matrix only). Adverse events not related to the procedure were 2 deaths (ruptured basilar aneurysms) and 1 stroke at day 10 postcoiling secondary to vasospasm. Procedure-related adverse events were 2 strokes. At 6-month follow-up (n=21) evaluation, 2 of 3 recanalizations needed retreatment. At 12-month follow-up (n=11), there was no recanalization in patients treated with Matrix alone and no significant reduction in aneurysmal size. CONCLUSIONS: Polyglycolide/polylactide-coated coils had a satisfactory safety profile. Significant aneurysmal size reduction after coiling was not observed

Waveguide Characterization of S-Band Microwave Mantle Cloaks for Dielectric and Conducting Objects

We present the experimental characterization of mantle cloaks designed so as to minimize the electromagnetic scattering of moderately-sized dielectric and conducting cylinders at S-band microwave frequencies. Our experimental setup is based on a parallel-plate waveguide system, which emulates a two-dimensional plane-wave scattering scenario, and allows the collection of near-field maps as well as more quantitative assessments in terms of global scattering observables (e.g., total scattering width). Our results, in fairly good agreement with full-wave numerical simulations, provide a further illustration of the mantle- cloak mechanism, including its frequency-sensitivity, and confirm its effectiveness both in restoring the near-field impinging wavefront around the scatterer, and in significantly reducing the overall scattering

Experimental evidence of cut-wire-induced enhanced transmission of transverse-electric fields through sub-wavelength slits in a thin metallic screen

Recent numerical studies have demonstrated the possibility of achieving substantial enhancements in the transmission of transverse-electric-polarized electromagnetic fields through subwavelength slits in a thin metallic screen by placing single or paired metallic cut-wire arrays at a close distance from the screen. In this Letter, we report on the first experimental evidence of such extraordinary transmission phenomena, via microwave (X/Ku-band) measurements on printed-circuit-board prototypes. Experimental results agree very well with full-wave numerical predictions, and indicate an intrinsic robustness of the enhanced transmission phenomena with respect to fabrication tolerances and experimental imperfections.Comment: 6 pages, 4 figures (slight revision

Validation and refinement of PROSASH model using the neutrophil‐to‐lymphocyte ratio in patients with HCC receiving sorafenib

AbstractThe recently developed PROSASH model is proving to be a useful tool in risk‐group discrimination in hepatocellular carcinoma (HCC) patients treated with sorafenib. Several studies highlighted that the neutrophil‐to‐lymphocyte ratio (NLR) is one of the most important predictors of survival in HCC patients treated with sorafenib. The aims of the present study were to validate the PROSASH model and determine whether the incorporation of inflammatory markers can improve risk stratification. This study included 438 patients. According to the four categories of the PROSASH model, median overall survival (OS) was 20.0, 14.9, 8.5 and 3.0 months respectively (P < .001). The Harrell's c for this categorized model was 0.621. NLR (cut‐off 3) stratified OS in each of the PROSASH categories. After reclassification, median OS was 21.0, 15.1, 8.2 and 4.1 months (P < .001). The Harrell's c increased from 0.621 to 0.673 (P = .001). Integrating NLR into the PROSASH model allowed a more accurate classification of the patients in the risk groups

Italian natural history museums on the verge of collapse?

The Italian natural history museums are facing a critical situation, due to the progressive loss of scientific relevance, decreasing economic investments, and scarcity of personnel. This is extremely alarming, especially for ensuring the long-term preservation of the precious collections they host. Moreover, a commitment in fieldwork to increase scientific collections and concurrent taxonomic research are rarely considered priorities, while most of the activities are addressed to public events with political payoffs, such as exhibits, didactic meetings, expositions, and talks. This is possibly due to the absence of a national museum that would have better steered research activities and overall concepts for collection management. We here propose that Italian natural history museums collaborate to instate a “metamuseum”, by establishing a reciprocal interaction network aimed at sharing budgetary and technical resources, which would assure better coordination of common long-term goals and scientific activities

Egg numbers and fecundity traits in nine species of Mantella poison frogs from arid grasslands and rainforests of Madagascar (Anura: Mantellidae)

The body size and number of eggs in dissected females were analysed in nine species of the Malagasy frog genus Mantella basing upon preserved specimens. These species were distinguished in terms of habitat and grouped as ‘grassland species’ (included M. betsileo, M. expectata, M. viridis), and ‘rainforest species’ (M. baroni, M. crocea, M. cowani, M. laevigata, M. nigricans, M. pulchra). The species with the lowest egg - number was M. cowani with a mean egg number of 37 ± 15, while the species with the highest egg-number was M. viridis with 115 ± 21 eggs. In general, the grassland species are characterised by a higher number of relatively small eggs. Moreover, their fecundity was positively and significantly correlated to female body size. Rainforest species were smaller in size and with a lower number of eggs. We interpreted these differences as possible consequences of habitat adaptations. Among the studied species, the Critically Endangered Mantella cowani is also featured by a low number and large size of eggs. This is likely correlated with the high elevation site of the central highlands where this species occurs. RÉSUMÉDans cet article, nous présentons des informations portant sur la taille et le nombre d’oeufs de neuf espèces de grenouilles de Madagascar appartenant au genre Mantella, en nous basant sur l’analyse de spécimens muséologiques. Ces espèces ont été classées selon l’habitat dans lequel elles ont été récoltées en deux groupes qui sont les «Mantella de zones herbeuses», originaires de l’Ouest et du Sud (arides) de Madagascar (M. betsileo, M. expectata, M. viridis), et les ‘Mantella de forêt pluviale’ (M. baroni, M. crocea, M. cowani, M. laevigata, M. nigricans, M. pulchra). L’espèce présentant le taux de fécondité le plus bas est M. cowani, avec un nombre moyen d’oeufs par ponte de 37 ± 15, tandis que l’espèce avec le taux le plus élevé est M. viridis avec 115 ± 21 oeufs par ponte. Nous avons également testé si la fécondité observée chez les espèces étudiées était différente entre le groupe des espèces de zones herbeuses (appartenant toutes au groupe Mantella betsileo) et celui des espèces de forêt pluviale (appartenant à plusieurs lignées phylogénétiques). Il apparaît clairement que les espèces de zones herbeuses produisent un plus grand nombre d’oeufs par ponte et que les oeufs sont plus grands que ceux pondus par les espèces de forêt pluviale. De plus, il existe dans le groupe des espèces de zones herbeuses une corrélation significative entre le taux de fécondité et la taille corporelle des femelles. Par contre, les résultats sont plus hétérogènes pour les espèces de forêt. Les femelles de ce groupe présentent une taille corporelle plus réduite et il n’y a pas de corrélation claire entre le nombre d’oeufs et la taille corporelle des femelles. Les différences constatées ont été interprétées et expliquées par les modes de vie distincts que présentent les espèces considérées, avec la production d’un plus grand nombre d’oeufs lorsque leur taille est réduite. En outre, les femelles de ces espèces présentent une taille corporelle plus importante; il a d’ailleurs été prouvé que le taux de fécondité des amphibiens est directement proportionnel à la taille des femelles. Nous pouvons formuler l’hypothèse qu’il est plus avantageux pour les Mantella de zones herbeuses de produire le maximum d’oeufs dans un nombre limité d’événements reproductifs, qui seraient rares et localisés. Ces résultats confirment également que les Mantella de forêts pluviales sont probablement plus sensibles aux altérations de l’habitat, qui est plus stable que celui des espèces de zones herbeuses. Dans ce contexte, nous considérons que l’espèce M. cowani peut être classée comme espèce en danger critique d’extinction. Cette espèce particulière de grenouille se présente comme la plus menacée parmi les espèces de la forêt pluviale du fait qu’elle produit un nombre limité d’oeufs de taille relativement importante. L’espèce est ainsi probablement plus sensible que les autres Mantella aux altérations environnementales et à la collecte d’individus pour le commerce d’animaux