Covalent Organic Frameworks (COFs) are an exciting new class of microporous polymers with unprecedented properties in organic material chemistry. They are generally built from rigid, geometrically ...defined organic building blocks resulting in robust, covalently bonded crystalline networks that extend in two or three dimensions. By strategically combining monomers with specific structures and properties, synthesized COF materials can be fine-tuned and controlled at the atomic level, with unparalleled precision on intrapore chemical environment; moreover, the unusually high pore accessibility allows for easy post-synthetic pore wall modification after the COF is synthesized. Overall, COFs combine high, permanent porosity and surface area with high thermal and chemical stability, crystallinity and customizability, making them ideal candidates for a myriad of promising new solutions in a vast number of scientific fields, with widely varying applications such as gas adsorption and storage, pollutant removal, degradation and separation, advanced filtration, heterogeneous catalysis, chemical sensing, biomedical applications, energy storage and production and a vast array of optoelectronic solutions. This review attempts to give a brief insight on COF history, the overall strategies and techniques for rational COF synthesis and post-synthetic functionalization, as well as a glance at the exponentially growing field of COF research, summarizing their main properties and introducing the numerous technological and industrial state of the art applications, with noteworthy examples found in the literature.
In this work, we propose a comprehensive experimental study of the diffusion of nickel ions in combination with different cyclodextrins as carrier molecules for enhanced solubility and facilitated ...transport. For this, ternary mutual diffusion coefficients measured by Taylor dispersion method are reported for aqueous solutions containing nickel salts and different cyclodextrins (that is, α-CD, β-CD, and γ-CD) at 298.15 K. A combination of Taylor dispersion and other methods, such as UV-vis spectroscopy, will be used to obtain complementary information on these systems. The determination of the physicochemical properties of these salts with CDs in aqueous solution provides information that allows us to understand solute-solvent interactions, and gives a significant contribution to understanding the mechanisms underlying diffusional transport in aqueous solutions, and, consequently, to mitigating the potential toxicity associated with these metal ions. For example, using mutual diffusion data, it is possible to estimate the number of moles of each ion transported per mole of the cyclodextrin driven by its own concentration gradient.
Complexes of lanthanide ions, such as Eu(III) (red light emission) and Tb(III) (green light emission), with proper ligands can be highly luminescent and color-tunable, also attaining yellow and ...orange emission under UV radiation. The ligands employed in this work were poly(sodium acrylate), working as polymeric matrix, and 1,10-phenanthroline, taking advantage of its antenna effect. Possibilities of color display were further enhanced by incorporating a cationic polyfluorene with blue emission. This strategy allowed for obtaining cyan and magenta, besides the aforementioned colors. Uncoated cellulose paper was impregnated with the resulting luminescent inks, observing a strong hypsochromic shift in excitation wavelength upon drying. Hence, while a cheap UV-A lamp sufficed to reveal the polyfluorene’s blue emission, shorter wavelengths were necessary to visualize the emission due to lanthanide ions as well. The capacity to reveal, with UV-C radiation, a full-color image that remains invisible under natural light is undoubtedly useful for anti-counterfeiting applications. Furthermore, both lanthanide ion complexes and polyfluorenes were shown to have their luminescence quenched by Cu(II) ions and nitroarenes, respectively.
Cette recherche a pour objectif l’étude des interactions mère-bébé à 3 mois, au cours du Still-Face, en comparant des dyades au sein desquelles la mère présente un trouble de la personnalité ...borderline (TPB) à des dyades témoins. Nous émettons l’hypothèse que les interactions entre une mère et son bébé présentent des différences dès 3 mois selon que la mère présente un trouble de la personnalité borderline ou non, et que ces différences prennent une forme différente selon que le bébé est une fille ou un garçon.
Les interactions de 19 dyades mères borderline-bébé et de 41 dyades témoins sont filmées dans le cadre de la situation du paradigme du Still-Face. Les comportements des deux partenaires sont étudiés à l’aide d’une micro-analyse basée sur deux grilles : le Maternal et l’Infant Regulation Scoring System (Weinberg et Tronick, 1994).
Aucune différence significative ne ressort en fonction du genre du bébé ou du TPB maternel si l’on ne prend pas en compte les temps du Still-Face dans l’analyse, autrement dit de la perturbation induite. Relativement au groupe témoin, les bébés du groupe TPB manifestent moins d’attention visuelle, les filles se régulent plus tandis que c’est l’inverse pour les garçons, et les mères TPB présentent davantage de stimulations tactiles.
Notre recherche met en évidence qu’il existe dans notre échantillon des mécanismes d’adaptation différents en fonction de la pathologie maternelle et le genre du bébé. Ces différences suggèrent que, dès 3 mois postpartum, les bébés sont déjà en train de s’adapter par le biais de mécanismes de régulation aux dysfonctionnements maternels, et invitent à explorer plus finement et longitudinalement les échanges précoces tout au long de la petite enfance.
This research aims to study mother-infant interactions at 3months postpartum using the Still Face Face-to-Face Paradigm comparing two groups, mothers with borderline personality disorder and controls. We hypothesized that dyadic interactions with mothers afflicted with the disorder would be significantly different from those without psychopathology, and that these differences would vary according to infant gender.
Nineteen dyads of mothers with Borderline Personality Disorder and 41 with control mothers were filmed using the Still Face Paradigm. Behaviors of both partners were studied using microanalytic coding with the Maternal and Infant Regulation Scoring System.
Our analysis shows that both partners react to the stress induced by the Still Face episode (the paradigm is divided in three phases, 2minutes of spontaneous interaction face-to-face, 2minutes of maternal Still Face per se, and 2minutes of reuniting interactive play). Infants of mothers with Borderline Personality Disorder show less gaze focused on mother than their control counterparts; infant girls regulate themselves more than boys and mothers with psychopathology demonstrate more tactile stimulation of their infants (touch, tickle, etc.). Our research illustrates how different dyadic adaptive mechanisms exist according to maternal psychopathology and infant gender, and suggests that as early as 3months postpartum, infants are already trying to adapt to maternal functioning and dysfunctional interactions through self-regulatory mechanisms. This begs for further research exploring as precisely as possible interactive mechanisms both early in life and in longitudinal studies.
Previous experiments with Senegalese sole (Solea senegalensis) have demonstrated that dietary lipid levels above 8% impaired growth and did not promote protein retention. We hypothesised that this ...low ability to use high-lipid diets may depend on the dietary protein level. In the present study, a 2 × 2 factorial design was applied where two dietary lipid (4-17% DM) and two dietary protein (below and above the requirement levels, 48 and 54% DM) levels were tested in juveniles for 114 d. Growth performance was not improved by the increase in dietary fat, irrespectively of the dietary protein levels. Protein retention was similar among the diets, although fish fed the diets with high lipid content resulted in significantly lower protein gain. Among the enzymes involved in amino acid catabolism, only aspartate aminotransferase activity in the liver was affected by the dietary lipid levels, being stimulated in fish fed high-lipid diets. Moreover, phosphofructokinase 1 activity was significantly elevated in the muscle of Senegalese sole fed 4% lipid diets, suggesting enhanced glycolysis in the muscle when the dietary lipid supply was limited and dietary starch increased. The results confirmed that high-lipid diets do not enhance growth, and data from the selected enzymes support the assumption that lipids are not efficiently used for energy production and protein sparing, even when dietary protein is below the protein requirement of the species. Furthermore, data suggest a significant role of glucose as the energy source in Senegalese sole.
Aim
Fistula laser closure (FiLaC™) is a novel sphincter‐saving procedure for the treatment of anal fistula. Primary closure of the track is achieved using laser energy emitted by a radial fibre ...connected to a diode laser. The energy causes shrinkage of the tissue around the radial fibre with the aim being to close the track. This pilot study was designed to investigate the safety and effectiveness of this new technique in the treatment of anal fistula.
Method
Thirty‐five patients with anal fistula underwent the FiLaC™ procedure. They had either a primary or a recurrent trans‐sphincteric anal fistula, a previously placed seton or a fistula involving a significant portion of the sphincter with a potential risk of postoperative incontinence on fistulotomy. The surgical procedure consisted of ‘sealing’ the fistula by laser energy. The primary end‐point was cure of the disease and evaluation of morbidity. The secondary end‐point was an assessment of the degree of postoperative continence using the Cleveland Clinic Florida (CCF) Fecal Incontinence Score.
Results
The median operation time was 20 (6–35) min. No intra‐operative complications were reported. Median duration of follow up was 20 (3–36) months. Primary healing was observed in 25 (71.4%) patients. There were eight (23%) failures and two recurrences at 3 and 6 months after the operation. No patient reported incontinence postoperatively.
Conclusion
The laser FiLaC™ procedure for fistula‐in‐ano is a safe, relatively simple, minimally invasive, sphincter‐saving procedure with a high chance of success.
In microwave heating, the energy is directly introduced into the material resulting in a rapid and volumetric heating process with reduced thermal gradients, when the electromagnetic field is ...homogeneous. From those reasons, the microwave technology has been widely used in the industry to process dielectric materials. The capacity to heat with microwave radiation is related with the dielectric properties of the materials and the electromagnetic field distribution. The knowledge of the permittivity dependence with the temperature is essential to understand the thermal distribution and to minimize the non-homogeneity of the electromagnetic field. To analyse the history of the heating process, the evolution of the electromagnetic field, the temperature and the skin depth, were simulated dynamically in a ceramic sample. The evaluation of the thermal runaway has also been made. This is the most critical phenomenon observed in the sintering of ceramic materials because it causes deformations, or even melting on certain points in the material, originating the destruction of it. In our study we show that during the heating process the hot spot’s have some dynamic, and at high temperatures most of the microwave energy is absorbed at the surface of the material. We also show the existence of a time-delay of the thermal response with the electromagnetic changes.
► Electromagnetic field, the temperature and the skin depth were simulated dynamically. ► The evaluation of the thermal runaway has been made. ► A time-delay of the thermal response with the electromagnetic changes exists.
A straightforward and versatile methodology for the extraction of volatile metabolites in biological samples from ruminants for gas chromatography analysis is proposed. The methodology was applied in ...the determination of multiclass metabolites (short-chain fatty acids, aldehydes, alcohols, ketones, esters, phenols, and sulfides) in different analytical matrices (rumen fluid, urine, and feces) collected from Holstein cows. The 24 multiclass volatile metabolites reported in the different biological samples and their respective concentrations were critically discussed in the context of digestive physiology. Most detected compounds are derived from the rumen and lower gut fermentation of carbohydrates, proteins, and lipids or their metabolism, being consistent with the prior state of the art. The proposed method also takes advantage of the already existing tools in animal nutrition laboratories, providing a novel methodological ground that can generate relevant bioanalytical information with a significant impact on ruminant's nutritional studies.
In this work the use of coffee endocarp as precursor for the production of activated carbons by steam and CO2 was studied. Activation by both methods produces activated carbons with small external ...areas and microporous structures having very similar mean pore widths. The activation produces mainly primary micropores and only a small volume of larger micropores. The CO2 activation leads to samples with higher BET surface areas and pore volumes when compared with samples produced by steam activation and with similar burn-off value. All the activated carbons produced have basic characteristics with point of zero charge between 10 and 12. By FTIR it was possible to identify the formation on the activated carbon's surface of several functional groups, namely ether, quinones, lactones, ketones, hydroxyls (free and phenol); pyrones and Si-H bonds.
The effects of island ontogeny on species diversity and phylogeny Valente, Luis M.; Etienne, Rampal S.; Phillimore, Albert B.
Proceedings - Royal Society. Biological sciences/Proceedings - Royal Society. Biological Sciences,
06/2014, Letnik:
281, Številka:
1784
Journal Article
Recenzirano
Odprti dostop
A major goal of island biogeography is to understand how island communities are assembled over time. However, we know little about the influence of variable area and ecological opportunity on island ...biotas over geological timescales. Islands have limited life spans, and it has been posited that insular diversity patterns should rise and fall with an island's ontogeny. The potential of phylogenies to inform us of island ontogenetic stage remains unclear, as we lack a phylogenetic framework that focuses on islands rather than clades. Here, we present a parsimonious island-centric model that integrates phylogeny and ontogeny into island biogeography and can incorporate a negative feedback of diversity on species origination. This framework allows us to generate predictions about species richness and phylogenies on islands of different ages. We find that peak richness lags behind peak island area, and that endemic species age increases with island age on volcanic islands. When diversity negatively affects rates of immigration and cladogenesis, our model predicts speciation slowdowns on old islands. Importantly, we find that branching times of in situ radiations can be informative of an island's ontogenetic stage. This novel framework provides a quantitative means of uncovering processes responsible for island biogeography patterns using phylogenies.
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