Grasp planning with a soft reconfigurable gripper exploiting embedded and environmental constraints

Grasping in unstructured environments requires highly adaptable and versatile hands together with strategies to exploit their features to get robust grasps. This paper presents a method to grasp objects using a novel reconfigurable soft gripper with embodied constraints, the Soft ScoopGripper (SSG). The considered grasp strategy, called scoop grasp, exploits the SSG features to perform robust grasps. The embodied constraint, i.e., a scoop, is used to slide between the object and a flat surface (e.g., a table or a wall) in contact with it. The fingers are first configured according to object geometry and then used to establish reliable contact with it. Given the object to be grasped, the proposed grasp planner chooses the best configuration of the fingers and the scoop based on the object point cloud and then suitably aligns the gripper to it

Comparative analysis of 23-, 25-, and 27-gauge forceps stiffness and related displacement

Purpose: To test the stiffness and displacement of different vitreous forceps. Physical features and deformation after multiple procedures were also measured. Methods: Eleven different 23-, 25-, and 27-gauge vitreous forceps were studied. The measurements were repeated loading the probe at different distances from the tip: at the top of the tip and 10 and 20 mm from the tip, respectively. For each probe, 10 successive identical bending tests were performed. The total length and the internal and external diameters of each forceps were also measured. Results: A total of 330 successive identical bending tests were performed. No progression in deformation after the repeated measurements was recorded (p > 0.05). In each gauge group, displacement differences were detected according to the manufacturing metal properties, the total length, and the thickness of the shaft wall. A minimal adequate model to describes forceps displacements in terms of their significant predictors, such as gauge, model, and load distance from the tip, was created. Conclusion: We provided a precise assessment of the stiffness and displacement of different vitreous forceps to enable surgeons to select the optimal instrument according to the benefits and limitations of each forceps

Fibrin clot adhesion to conditioned root surfaces: an in vitro study with scanning electron microscopy analysis

Aim: Periodontal regeneration is contingent on the adhesion and maturation of fibrin clot to a root surface exposed to periodontal disease. Root surface demineralization in vitro improves the formation of a stable union between the fibrin clot and the root surface. In scientific literature there are not studies of comparison that stand which demineralizing agent is the best in promoting fibrin clot adhesion. The aim of this study was to evaluate and compare the efficacy of six root conditionings in removing the smear layer and developing the fibrin clot in static and dynamic conditions. Methods: 36 single-root teeth extracted for periodontal disease were cut with a microtome in order to obtain 72 specimens that were divided in three groups: 24 samples not covered with blood, 24 covered with fresh human whole blood, 24 covered with blood and rinsed in a rotary shaker table (Vortex\uae). 4 specimens from each group were conditioned for 3 minutes with: physiological saline solution (FISIO) as the control group, saturated solution of citric acid 25% (AC), ethylenediaminetetraacetic acid 24% (EDTA), a solution of tetracycline 200mg/mL (TETRA), a solution of tetracycline and citric acid (TETRA+AC), Prefgel\uae and successively Emdogain\uae (EMD). Then the 48 samples from group 2 and 3 were covered with blood, which was allowed to coagulate for 20 minutes in a 37\ub0C chamber. The blocks were rinsed and dehydrated under standardized conditions; specimens of group 3 were vortexed (100rpm). All the blocks were then sputtered with gold and analyzed with SEM. SEM images were evaluated by two blinded examiners, starting from the cementoenamel junction (CEJ), at 5 standardized points 2 mm distant from each other. A statistical analysis was performed. Results: EMD samples showed a more disorganized smear layer, in which is probably present the residual vehicle (propylene glycol alginate). However, in the 90% of all the specimens smear layer was found. AC treated samples showed a firmly adherent fibrin clot that covered the surfaces for the 70% of the specimens (the data was statistically relevant). Same results were found in TETRA+AC samples. The conditioning with EDTA, TETRA and EMD resulted in a sparsely organized clot worsened by the application of tensile forces, especially in TETRA samples. Only few blood cells without any clot organization were found in the control group, confirming that conditioning root surfaces improves the fibrin clot adhesion. Conclusion: The best formation of fibrin clot was observed for AC treated samples; this is probably due to the increase of root surface wettability caused by AC. The other root conditioning agents, even if lead to results better than the control group, are more susceptible to external forces and do not promote a stable fibrin clot adhesion

Inter-annual and decadal changes in teleconnections drive continental-scale synchronization of tree reproduction

Climate teleconnections drive highly variable and synchronous seed production (masting) over large scales. Disentangling the effect of high-frequency (inter-annual variation) from low-frequency (decadal trends) components of climate oscillations will improve our understanding of masting as an ecosystem process. Using century-long observations on masting (the MASTREE database) and data on the Northern Atlantic Oscillation (NAO), we show that in the last 60 years both high-frequency summer and spring NAO, and low-frequency winter NAO components are highly correlated to continent-wide masting in European beech and Norway spruce. Relationships are weaker (non-stationary) in the early twentieth century. This finding improves our understanding on how climate variation affects large-scale synchronization of tree masting. Moreover, it supports the connection between proximate and ultimate causes of masting: indeed, large-scale features of atmospheric circulation coherently drive cues and resources for masting, as well as its evolutionary drivers, such as pollination efficiency, abundance of seed dispersers, and natural disturbance regimes

Peripheral giant cell granuloma: immunohistochemical analysis of different markers. Study of three cases

El granuloma periférico de células gigantes (GPCG) es una lesión de tejido blando no neoplásica ocasionada por una reacción hiperplásica a consecuencia de un traumatismo o inflamación. Es una lesión reactiva del tejido blando que se desarrolla exclusivamente en la cavidad oral y con una ligera predilección en el sexo femenino. La localización habitual de GPCG es en la región de los premolares y la mucosa de la cresta alveolar edéntula. Se presentan tres casos con GPCG (dos hombres y una mujer) con una edad comprendida entre los 25 y 35 años. Todos los pacientes se trataron con resección quirúrgica y ninguno sufrió recidivas. Con el propósito de determinar el posible origen de las células estromales mononucleares y de las células gigantes multinucleares, las muestras de cada caso se estudiaron mediante inmunohistoquímica (marcadores CD-68, CD-34 y α-1 antitripsina) con el fin de evaluar la expresión del linaje endotelial y del linaje monocito/macrófago. Los resultados inmunohistoquímicos mostraron una marcada positividad difusa de CD-68 en las células estromales mononucleares y en las células gigantes multinucleadas. Estas últimas resultaron ser inmunonegativas para CD-34 y sólo puntualmente positivas para α-1 antitripsina. Estos resultados sugieren que las cιlulas gigantes multinucleares poseen un fenotipo osteoclαstico, proviniendo del linaje monocito/macrσfago, y que no derivan del linaje de las células endoteliales de los capilares. Se establece la importancia de un exhaustivo diagnóstico y de una exéresis quirúrgica completa de la lesión (curetaje óseo) con el propósito de evitar la reabsorción del diente y hueso adyacente

Rifampicin-loaded electrospun polycaprolactone membranes: Characterization of stability, antibacterial effects and urotheliocytes proliferation

Pathological conditions such as infections, cancer, inflammation, or iatrogenic lesions, can hinder the cor-rect functionality of the ureter and its structural integrity. Several strategies for the regeneration of the ureter and the restoration of its functionality are available but the best strategy has not been reached yet. Among the proposed strategies, a promising one is the development of tubular scaffolds, in particular exploiting electrospinning technique. In this work, antibacterial electrospun polycaprolactone/rifampicin (PCL/Rif) membranes were prepared and characterized. The membranes are characterized by randomly oriented nanofibers with a homogeneous diameter, as determined by scanning electron microscopy. The mechanical characterization, performed with uniaxial tensile tests, showed a suitable stability over time and a proper deformability. The rifampicin release, investigated by UV spectrophotometry, showed a burst release in the first part of the experiment and a sustained release over time. The membranes are biocompatible and able to support the adhesion and proliferation of urotheliocytes. Moreover, PCL/Rif membranes showed an antibacterial activity against Escherichia coli and other bacterial strains belonging to the "ESKAPE" group. Considering the possibility to use the electrospinning for the production of tubu-lar scaffolds, the described membranes represent a promising starting point for the preparation of uret-eral scaffolds with antibacterial properties.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Multiple interannual records of young-of-the-year identify an important area for the protection of the shortfin mako, Isurus oxyrinchus

The shortfin mako (Isurus oxyrinchus) is the second most fishery-exploited pelagic shark in the Mediterranean Sea, thus its conservation status is a cause for concern. Despite the species has been listed in fishery and trade regulations to hinder its population decline, the lack of knowledge on its distribution patterns and habitats essential for its persistence still hampers the implementation of sound conservation actions. Combining data from local expert knowledge, opportunistic catch records, and Baited Remote Underwater Videos, we show evidence of the interannual presence of young-of-the-year (YOY) I. oxyrinchus in the Pelagie Archipelago (Central Mediterranean Sea). A total of twenty-one individuals ranging 71–92.5 cm FL were incidentally caught (on average 2.3 YOY/1000 hooks) or documented on BRUVS in July and August over three consecutive years. These data coupled with questionnaires administered to longline fishers identify one specific area used by YOY in the summer months. Our study presents the most abundant record of YOY shortfin makos in the Mediterranean Sea within such a restricted time and limited area providing important information for improving the protection of this critically endangered species