507 research outputs found

    Dispersions of Nanoclays of Different Shapes into Aqueous and Solid Biopolymeric Matrices. Extended Physicochemical Study

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    Dispersions of nanofillers into aqueous and solid biopolymeric matrices were studied from the physicochemical viewpoint. This work was carried out based on the idea that the combination of biopolymers, derived from renewable resources, and nanofiller, environmentally friendly, may form a new generation of nanomaterials with excellent and unique properties at low cost. To this purpose, two pectins with different degrees of methyl esterification and nanoclays like halloysite and laponite RD were selected. The thermodynamic and structural studies on the aqueous mixtures of pectin and nanoclay were able to discriminate the interactions, which control the adsorption of pectin onto the filler and the aggregation of both pectin and clay particles. The gained insights were useful to interpret the mesoscopic structure of the nanocomposites (prepared from the aqueous mixtures by means of the casting method) evidenced by SEM, thermal stability, tensile properties, and transparency investigations. The attained knowledge represents a basic point for designing new hybrid nanostructures in both the aqueous and the solid phase for specific purposes

    Sustainable nanocomposites based on halloysite nanotubes and pectin/polyethylene glycol blend

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    This study was focused on the preparation and characterization of biofilms based on pectin/polyethylene glycol 20000 (PEG) blend and halloysite nanotubes (HNTs). The obtained blends loaded with a natural nanoclay are proposed as sustainable alternative to the polymers produced from non-renewable resources such as fossil fuels. Properties of technological interest have been monitored and they were correlated to the structural features of the nanocomposites. It turned out that the wettability of the films can be tuned by changing the composition and the distribution of HNTs into the material as well as the surface roughness. The tensile properties of the blend are enhanced by the presence of the nanoclays. The PEG crystallinity is reduced by the nanoparticles and preserved if a certain amount of pectin is added. This work represents a starting point to develop new green composite material, which can be used for purposes such as in packaging, by employing the strategy of adding plasticizers and fillers within a full biocompatible approach

    Titanium versus absorbable tacks comparative study (TACS): a multicenter, non-inferiority prospective evaluation during laparoscopic repair of ventral and incisional hernia: study protocol for randomized controlled trial

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    BACKGROUND: Laparoscopic repair of ventral and incisional hernias has gained popularity since many studies have reported encouraging results in terms of outcomee and recurrence. Choice of mesh and fixation methods are considered crucial issues in preventing recurrences and complications. Lightweight meshes are considered the first choice due to their biomechanical properties and the ability to integrate into the abdominal wall. Titanium helicoidal tacks still represent the "gold standard" for mesh fixation, even if they have been suggested to be involved in the genesis of post-operative pain and complications. Recently, absorbable tacks have been introduced, under the hypothesis that there will be no need to maintain a permanent fixation device after mesh integration. Nevertheless, there is no evidence that absorbable tacks may guarantee the same results as titanium tacks in terms of strength of fixation and recurrence rates. The primary end point of the present trial is to test the hypothesis that absorbable tacks are non-inferior to titanium tacks in laparoscopic incisional and ventral hernia repair (LIVHR) by lightweight polypropylene mesh, in terms of recurrence rates at 3-year follow-up. Surgical complications, post-operative stay, comfort and pain are secondary end points to be assessed. METHODS/DESIGN: Two hundred and twenty patients with ventral hernia will be randomized into 2 groups: Group A (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by titanium tacks; Group B (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by absorbable tacks. DISCUSSION: A few retrospective studies have reported similar results when comparing absorbable versus non-absorbable tacks in terms of intraoperative and early post-operative outcomes. These studies have the pitfalls to be retrospective evaluation of small series of patients, and the reported results still need to be validated by larger series and prospective studies. The aim of the present trial is to investigate and test the non-inferiority of absorbable versus non-absorbable tacks in terms of hernia recurrence rates, in order to assess whether the use of absorbable tacks may achieve the same results as non-absorbable tacks in mid-term and long-term settings

    Modified Halloysite Nanotubes: Nanoarchitectures for Enhancing the Capture of Oils from Vapor and Liquid Phases

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    We prepared hybrid halloysite nanotubes (HNT/sodium alkanoates) in which the inner cavity of the nanoclay was selectively modified. Physicochemical studies evidenced the interactions between HNT and sodium alkanoates, ruled out clay exfoliation, quantified the amount of the loaded substance, and showed an increase of the total net negative charge, allowing us to obtain rather stable aqueous nanoclay dispersions. These dispersions were exploited as inorganic micelles to capture hydrocarbon and aromatic oils in the vapor and liquid states and were revealed to be nonfoaming but very efficient in encapsulating oils. Here, we have fabricated biocompatibile and low-cost inorganic micelles that can be exploited for industrial applications on a large scale

    A prospective evaluation on external jugular vein cut-down approach for TIVAD implantation

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    BACKGROUND: Totally implantable venous access devices can be implanted both by percutaneous approaches and by surgical approaches with cephalic vein or external jugular vein cut-down techniques that are related to low intraoperative complication rates. The authors report a prospective evaluation of 83 consecutive external jugular vein cut-down approaches for totally implantable venous access devices implantation. METHODS: Eighty three consecutive patients (28 M, 55 F, mean age 54.2) suffering from solid tumors (58) or hematologic diseases (25) were consecutively submitted to totally implantable venous access devices insertion through external jugular vein cut-down approach (75 on right side, 8 on left side). RESULTS: All devices were surgically implanted; no instances of intraoperative complications were detected. After a minimum follow-up of 150 days, only one case of wound hematoma and one case of device malfunction due to incorrect catheter angulation were noted. Postoperative patient satisfaction was evaluated by the use of specific questionnaire that demonstrated a good satisfaction and compliance (92.8 %) of patients with implanted devices. CONCLUSIONS: Despite the lack of controlled studies comparing external jugular vein cut-down approach vs other approaches, this approach should be considered as a tool for long-term central vein catheters positioning, both as an alternative and for primary approach
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