Performance and Strength Characteristics of Suture Knots in Periodontal Microsurgery: An In Vitro Study.

This study is aimed to investigate the types of knot failure (untying or breaking) and the tension required to break different suture diameters. A total of 150 knots were fabricated using polyamide sutures with diameters of 6/0, 7/0, and 8/0. The studied knots were either squared or slipped with different numbers of throws (2, 3, 4, 5, and 6), and the following data were recorded: type of failure (untied or broken), number of throws, the tension required to untie or break each knot, slippage, and elongation of the knot.

Nutrient dynamics in water resources of productive flatland territories in the Pampean region of Argentina: evaluation at a watershed scale.

The Pampean plains in South America are well-known for their livestock and agricultural productivity. The peri-urban watershed of El Pescado Creek (Central-Eastern Argentina) has been significantly modified in the last few years due to local land-use changes. This work aims to analyze the dynamics of nutrient content associated with the surface water-groundwater relationship in this watershed and to define the trophic state of the watercourse.

Preclinical Testing of Living Tissue-Engineered Heart Valves for Pediatric Patients, Challenges and Opportunities.

Pediatric patients with cardiac congenital diseases require heart valve implants that can grow with their natural somatic increase in size. Current artificial valves perform poorly in children and cannot grow; thus, living-tissue-engineered valves capable of sustaining matrix homeostasis could overcome the current drawbacks of artificial prostheses and minimize the need for repeat surgeries. To prepare living-tissue-engineered valves, we produced completely acellular ovine pulmonary valves by perfusion.

Chemical stabilization of the extracellular matrix attenuates growth of experimentally induced abdominal aorta aneurysms in a large animal model.

Objective: The goal of the present study was to test the safety and efficacy of chemical stabilization of the arterial extracellular matrix as a novel nonoperative treatment of abdominal aortic aneurysms (AAAs) in a clinically relevant large animal model.

Methods: To achieve matrix stabilization, we used 1,2,3,4,6-pentagalloylglucose (PGG), a noncytotoxic polyphenolic agent capable of binding to and stabilizing elastin and collagen against the action of degrading enzymes. We first optimized the therapeutic PGG formulation and time of exposure by in vitro testing on porcine aortas using phenol histologic staining with iron chloride, elastic recoil assays, and PGG quantification as a function of tissue thickness.

Land-use changes in the periurban interface: Hydrologic consequences on a flatland-watershed scale.

The aim of this work was to analyze the hydrologic effects on surface runoff and infiltration of changes in land use and land coverage. The periurban-flatland watershed of El Pescado Creek (Argentina) was the study site investigated. We used Geographic-Information-System techniques together with the curve-number method (CN) to estimate the surface runoff in five land-use scenarios having increasing levels of anthropic impact (years 1986, 1996, 2006, 2016, and 2026) considering two rainfalls and the antecedent-runoff conditions (ARC) defined by that methodology.

Mechanochemical synthesis of N-doped porous carbon at room temperature.

We report the one-pot mechanochemical synthesis of N-doped porous carbons at room temperature using a planetary ball mill. The fast reaction (5 minutes) between calcium carbide and cyanuric chloride proceeds in absence of any solvent and displays a facile bottom-up strategy that completely avoids typical thermal carbonization steps and directly yields a N-doped porous carbon containing 16 wt% of nitrogen and exhibiting a surface area of 1080 m2 g-1.

Surgical safety in catheterization laboratory.

Objective: To describe the process of implanting the surgical safety checklist in a catheterization laboratory (CL).

Method: Descriptive case report study about the safety strategies developed in the last six years in a university hospital in the southern region of Brazil.

Results: The six international patient safety goals (IPSG) were incorporated into the care practice in accordance with the hospital's Joint Comission International (JCI) accreditation program, through a continuous process of educational nature.

Methane Hydrate in Confined Spaces: An Alternative Storage System.

Methane hydrate inheres the great potential to be a nature-inspired alternative for chemical energy storage, as it allows to store large amounts of methane in a dense solid phase. The embedment of methane hydrate in the confined environment of porous materials can be capitalized for potential applications as its physicochemical properties, such as the formation kinetics or pressure and temperature stability, are significantly changed compared to the bulk system. We review this topic from a materials scientific perspective by considering porous carbons, silica, clays, zeolites, and polymers as host structures for methane hydrate formation.

A sol-gel monolithic metal-organic framework with enhanced methane uptake.

A critical bottleneck for the use of natural gas as a transportation fuel has been the development of materials capable of storing it in a sufficiently compact form at ambient temperature. Here we report the synthesis of a porous monolithic metal-organic framework (MOF), which after successful packing and densification reaches 259 cm (STP) cm capacity. This is the highest value reported to date for conformed shape porous solids, and represents a greater than 50% improvement over any previously reported experimental value.

Longitudinal Stretching for Maturation of Vascular Tissues Using Magnetic Forces.

Cellular spheroids were studied to determine their use as "bioinks" in the biofabrication of tissue engineered constructs. Specifically, magnetic forces were used to mediate the cyclic longitudinal stretching of tissues composed of Janus magnetic cellular spheroids (JMCSs), as part of a post-processing method for enhancing the deposition and mechanical properties of an extracellular matrix (ECM). The purpose was to accelerate the conventional tissue maturation process via novel post-processing techniques that accelerate the functional, structural, and mechanical mimicking of native tissues.

Iron Oxide Nanoparticles Stimulates Extra-Cellular Matrix Production in Cellular Spheroids.

Nanotechnologies have been integrated into drug delivery, and non-invasive imaging applications, into nanostructured scaffolds for the manipulation of cells. The objective of this work was to determine how the physico-chemical properties of magnetic nanoparticles (MNPs) and their spatial distribution into cellular spheroids stimulated cells to produce an extracellular matrix (ECM). The MNP concentration (0.

Pain assessment and management in patients undergoing endovascular procedures in the catheterization laboratory.

Objective: To describe how pain is assessed (characteristic, location, and intensity) and managed in clinical practice in patients undergoing endovascular procedures in the catheterization laboratory setting.

Method: Cross-sectional study with retrospective data collection.

Results: Overall, 345 patients were included; 116 (34%) experienced post-procedural pain; in 107 (92%), pain characteristics were not recorded; the location of pain was reported in 100% of patients, and its intensity in 111 (96%); management was largely pharmacologic; of the patients who received some type of management (n=71), 42 (59%) underwent reassessment of pain.

Illuminating solid gas storage in confined spaces - methane hydrate formation in porous model carbons.

Methane hydrate nucleation and growth in porous model carbon materials illuminates the way towards the design of an optimized solid-based methane storage technology. High-pressure methane adsorption studies on pre-humidified carbons with well-defined and uniform porosity show that methane hydrate formation in confined nanospace can take place at relatively low pressures, even below 3 MPa CH4, depending on the pore size and the adsorption temperature. The methane hydrate nucleation and growth is highly promoted at temperatures below the water freezing point, due to the lower activation energy in ice vs.

High-Performance of Gas Hydrates in Confined Nanospace for Reversible CH4 /CO2 Storage.

The molecular exchange of CH4 for CO2 in gas hydrates grown in confined nanospace has been evaluated for the first time using activated carbons as a host structure. The nano-confinement effects taking place inside the carbon cavities and the exceptional physicochemical properties of the carbon structure allows us to accelerate the formation and decomposition process of the gas hydrates from the conventional timescale of hours/days in artificial bulk systems to minutes in confined nanospace. The CH4 /CO2 exchange process is fully reversible with high efficiency at practical temperature and pressure conditions.

Paving the way for methane hydrate formation on metal-organic frameworks (MOFs).

The presence of a highly tunable porous structure and surface chemistry makes metal-organic framework (MOF) materials excellent candidates for artificial methane hydrate formation under mild temperature and pressure conditions (2 °C and 3-5 MPa). Experimental results using MOFs with a different pore structure and chemical nature (MIL-100 (Fe) and ZIF-8) clearly show that the water-framework interactions play a crucial role in defining the extent and nature of the gas hydrates formed. Whereas the hydrophobic MOF promotes methane hydrate formation with a high yield, the hydrophilic one does not.

[Management of avoidable acute transfers from an intermediate care geriatric facility to acute hospitals: critical aspects of an intervention protocol].

Objective: The unplanned transfers (UT) from post-acute intermediate care facilities, are associated with adverse outcomes for patients, and a significant cost to the system. We present a practical protocol and the design of an intervention study aimed at reducing avoidable UT from a geriatric post-acute rehabilitation setting to acute care hospitals.

Patients And Methods: A quasi-experimental non randomized study.

Gate-opening effect in ZIF-8: the first experimental proof using inelastic neutron scattering.

The gate-opening phenomenon in ZIFs is of paramount importance to understand their behavior in industrial molecular separations. Here we show for the first time using in situ inelastic neutron scattering (INS) the swinging of the -CH3 groups and the imidazolate linkers in the prototypical ZIF-8 and ZIF-8@AC hybrid materials upon exposure to mild N2 pressure.

Improved mechanical stability of HKUST-1 in confined nanospace.

One of the main concerns in the technological application of several metal-organic frameworks (MOFs) relates to their structural instability under pressure (after a conforming step). Here we report for the first time that mechanical instability can be highly improved via nucleation and growth of MOF nanocrystals in the confined nanospace of activated carbons.

Methane hydrate formation in confined nanospace can surpass nature.

Natural methane hydrates are believed to be the largest source of hydrocarbons on Earth. These structures are formed in specific locations such as deep-sea sediments and the permafrost based on demanding conditions of high pressure and low temperature. Here we report that, by taking advantage of the confinement effects on nanopore space, synthetic methane hydrates grow under mild conditions (3.

Manipulation of cellular spheroid composition and the effects on vascular tissue fusion.

Cellular spheroids were investigated as tissue-engineered building blocks that can be fused to form functional tissue constructs. While spheroids can be assembled using passive contacts for the fusion of complex tissues, physical forces can be used to promote active contacts to improve tissue homogeneity and accelerate tissue fusion. Understanding the mechanisms affecting the fusion of spheroids is critical to fabricating tissues.

Phytoplankton chlorophyte structure as related to ENSO events in a saline lowland river (Salado River, Buenos Aires, Argentina).

We analyzed the phytoplankton present in the lower sector of the Salado River (Buenos Aires, Argentina) for 10 years (1995-2005) and detected significant changes occurring in chlorophyte abundance and species richness during La Niña event (1998-1999), which period was analyzed throughout the entire basin (main stream and tributaries). We compared the physicochemical and biologic variables between two El Niño-La Niña-Southern Oscillation (ENSO) periods - El Niño (March 1997-January 1998) and La Niña (May 1998-May 1999) - to identify possible indicators of a relationship between climatic anomalies and chlorophyte performance. Chlorophyte density increased during the La Niña.

Janus magnetic cellular spheroids for vascular tissue engineering.

Cell aggregates, or spheroids, have been used as building blocks to fabricate scaffold-free tissues that can closely mimic the native three-dimensional in vivo environment for broad applications including regenerative medicine and high throughput testing of drugs. The incorporation of magnetic nanoparticles (MNPs) into spheroids permits the manipulation of spheroids into desired shapes, patterns, and tissues using magnetic forces. Current strategies incorporating MNPs often involve cellular uptake, and should therefore be avoided because it induces adverse effects on cell activity, viability, and phenotype.

Biological magnetic cellular spheroids as building blocks for tissue engineering.

Magnetic nanoparticles (MNPs), primarily iron oxide nanoparticles, have been incorporated into cellular spheroids to allow for magnetic manipulation into desired shapes, patterns and 3-D tissue constructs using magnetic forces. However, the direct and long-term interaction of iron oxide nanoparticles with cells and biological systems can induce adverse effects on cell viability, phenotype and function, and remain a critical concern. Here we report the preparation of biological magnetic cellular spheroids containing magnetoferritin, a biological MNP, capable of serving as a biological alternative to iron oxide magnetic cellular spheroids as tissue engineered building blocks.

Diffusion-barrier-free porous carbon monoliths as a new form of activated carbon.

For the practical use of activated carbon (AC) as an adsorbent of CH(4) , tightly packed monoliths with high microporosity are supposed to be one of the best morphologies in terms of storage capacity per apparent volume of the adsorbent material. However, monolith-type ACs may cause diffusion obstacles in adsorption processes owing to their necked pore structures among the densely packed particles, which result in a lower adsorption performance than that of the corresponding powder ACs. To clarify the relationship between the pore structure and CH₄ adsorptivity, microscopic observations, structural studies on the nanoscale, and conductivity measurements (thermal and electrical) were performed on recently developed binder-free, self-sinterable ACs in both powder and monolithic forms.

[Tubal pregnancy after vaginal hysterectomy].

We report a case of woman who was admitted to the hospital for evaluation of abdominal pain, five years after a vaginal hysterectomy. Exploratory laparotomy was performed and tubal pregnancy found. A review of the literature reveals similar complications following supracervical and total or vaginal hysterectomy: it is a rare event and the common aspect of all cases is the inability to accurately diagnose before laparotomy.