Optimizing biodegradable plastics: Molecular dynamics insights into starch plasticization with glycerol and oleic acid.

Petroleum-based plastics dominate everyday life, necessitating the exploration of natural polymers as alternatives. Starch, abundant and biodegradable, is a promising raw material. However, understanding the molecular mechanisms underlying starch plasticization has proven challenging. To address this, we employ molecular dynamics simulations, focusing on amylose as a model. Our comprehensive evaluation revealed that chain size affects solubility, temperature influenced diffusivity and elastic properties, and oleic acid expressed potential as an alternative plasticizer. Furthermore, blending glycerol or oleic acid with water suggested the enhancement amylose's elasticity. These findings contribute to the design of sustainable and improved biodegradable plastics.

Can psychopathy be prevented? Clinical, neuroimaging, and genetic data: an exploratory study.

The aim of the study was to explore the relationship among brain functional activations elicited by an emotional paradigm, clinical scores (PTSD, anxiety, and depression), psychopathic traits, and genetic characteristics (5-HTTLPR) in a group of severely maltreated children compared to a healthy control group before and after the implementation of a Trauma Focused-Cognitive Behavioral Therapy. The final sample consisted of an experimental group of 14 maltreated children (mean age = 8.77 years old, S.D. = 1.83) recruited from a non-governmental shelter in Mexico City for children who had experienced child abuse and a control group of 10 children from the general population (mean age = 9.57 years old, S.D. = 1.91). Both groups were matched according to age and gender and were assessed before and after the implementation of the aforementioned therapy by means of clinical scales and an emotional paradigm that elicited brain activations which were recorded through functional magnetic resonance imaging. Genotyping of the 5-HTTLPR polymorphism was made at first assessment. A region of interest analysis showed amygdala hyperactivation during exposure to fear and anger stimuli in the maltreated children before treatment. Following therapy, a decrease in brain activity as well as a decrease in clinical symptoms were also observed. 5-HTTLPR polymorphism did not show any effect on the severity of clinical symptoms in maltreated children. Trauma-Focused Behavioral Therapy may help reorganize the brain's processing of emotional stimuli. These observations reveal the importance of an early intervention when the mechanisms of neuroplasticity may be still recruited.

Denervación artroscópica de la rótula / Arthroscopic patellar denervation

Fundamento: el síndrome doloroso anterior de la rodilla es muy frecuente en la actualidad, para su tratamiento se combinan medidas conservadoras y quirúrgicas, dentro de las quirúrgicas la denervación de la rótula por vía artroscópica puede ser una de estas modalidades.Objetivo: profundizar en esta técnica basado en el conocimiento de la anatomía y peculiaridades de esta forma de tratamiento quirúrgico.Métodos: la búsqueda de la información se realizó en un periodo de tres meses (primero de septiembre de 2017 al 30 de noviembre de 2017) y se emplearon las siguientes palabras: denervation of the patella, patellar denervation y anterior knee pain, a partir de la información obtenida se realizó una revisión bibliográfica de un total de 150 artículos publicados en las bases de datos PubMed, Hinari, SciELO y Medline mediante el gestor de búsqueda y administrador de referencias EndNote, de ellos se utilizaron 51 citas seleccionadas para realizar la revisión, de ellas 34 de los últimos cinco años y se consultaron 13 libros.Desarrollo: se abordaron los factores relacionados con la anatomía de la región anterior de la rodilla. Se hizo referencia a la exploración física de la articulación. Las modalidades de tratamiento se mencionaron al igual que las indicaciones quirúrgicas y ventajas de la denervación por la vía artroscópica. En relación a la técnica se muestran imágenes ilustrativas sobre el procedimiento. Para culminar se hace referencia a las principales complicaciones.Conclusiones: la denervación artroscópica es una técnica factible y segura, para su realización se necesita del conocimiento de la anatomía(AU)

Background: anterior knee pain syndrome is a frequent disease, conservative and surgical modalities are useful for treatment. In regards to surgical treatment, denervation of the patella could be one of the ways.Objective: to deep about the denervation techniques taking into account anatomy and surgical steps.Methods: a search in the databases PubMed, Hinari, SciELO and Medline was done through the information locator EndNote by using the words denervation of the patella, patellar denervation and anterior knee pain, resulting in a total of 150 articles which 51 of them selected for review, all of them in the last three years, including 13 books.Development: important aspects related to biomechanics and anatomy of the anterior knee was pointed out. Physical examination was described. Surgical modalities and indications were stated as well as its advantages. In regards to surgical techniques, illustrative images were shown.Conclusions: denervation of the patella is a safe and practical technique, to perform the technique is important to know about anatomy and arthroscopic surgery(AU)

Crystal structure of (±)-[trans-cyclo-hexane-1,2-diylbis(aza-nedi-yl)]di-phospho-nium dibromide dichloro-methane disolvate.

The cation of the title solvated salt, C42H42N2P2 (2+)·2Br(-)·2CH2Cl2, lies on a crystallographic twofold rotation axis. The 1,2-di-amino-cyclo-hexane fragment has a chair conformation with two N atoms in a transoid conformation [N-C-C-N = 163.4 (2)°]. In the crystal, the cations are linked to the anions by N-H⋯Br and C-H⋯Br hydrogen bonds, forming a chain structure along the c axis. The di-chloro-methane mol-ecule takes part in the hydrogen-bond network through C-H⋯π and C-H⋯Br inter-actions.

Irregular Liesegang-type patterns in gas phase revisited. I. Experimental setup, data processing, and test of the spacing law.

Since the early work on Liesegang rings in gels, they have been a reference point for the study of pattern formation in chemical physics. Here we present a variant of the Liesegang experiment in gas phase, where ammonia and hydrochloric acid react within a glass tube producing a precipitate, which deposits along the tube wall producing a spatial pattern. With this apparently simple experiment a wide range of rich phenomenon can be observed due to the presence of convective flows and irregular dynamics reminiscent of turbulent behavior, for which precise measurements are scarce. In this first part of our work, we describe in detail the experimental setup, the method of data acquisition, the image processing, and the procedure used to obtain an intensity profile, which is representative of the amount of precipitate deposited at the tube walls. Special attention is devoted to the techniques rendering a data series reliable for statistical studies and model building, which may contribute to a characterization and understanding of the pattern formation phenomenon under consideration. As a first step in this direction, based on our data, we are able to show that the observed band pattern follows, with slight deviations, the spacing law encountered in common Liesegang rings, despite that the experimental conditions are very different. A further statistical correlation analysis of the data constitutes Paper II of this research.

Assessment of the nature interactions of ß-amyloid protein by a nanoprobe method.

We present a method based on atomic force microscopy (AFM) to assess the work of adhesion between the interfaces of gold AFM tips functionalized with three peptides derived from ß-sheet breaker LPFFD [CLPFFD-NH2 (i0) and their isomers CDLPFF-NH2 (i1) and CLPDFF-NH2 (i2)], and the beta-amyloid protein (Aß1-42). ß-Amyloid protein was deposited onto a highly oriented graphite (HOPG) surface as protofibrils and fibrils. The presence of the residues Leu (L), Phe (F), and Phe (F), which are also present in the native sequence, confirm that the peptides are able to bind to the aggregates of Aß1-42 fibrils and protofibrils. Force of adhesion data were directly obtained from the maximum force on retraction, and the work of adhesion was calculated from the Jhonson-Kendall-Roberts model (JKR-Model). Both the polar and dispersive contributions to the surface energy of the peptides i0, i1, and i2, as well as Aß1-42 fibrils and protofibrils, were determined by means of measuring the contact angle and using the two-fluid method. The macroscopic energies of the functionalized gold surfaces do not differ significantly between isomers, which confirms the similar nature of the peptides i0, i1, and i2 but suggests that the macroscopic measurements are not able to distinguish specific sequences. The nanoprobe reveals a typical adhesion work value associated with the interaction of protofibrils with i0 and i2; this value is three times higher than that of i1. The difference is attributed to the hydrophobic nature of protofibrils, the predominant exposition of hydrophobic residues of the peptides i0 and i2, with respect to i1, and the degree of functionalization. i0 and i2 presented a slight adhesion with Aß fibrils, which is associated with the exposed hydrophilic groups of these fibrils (onto HOPG) compared to the protofibrils. However, i1 showed interaction with both Aß fibrils and protofibrils. For this, we propose an explanation based on the fact that the peptide i1 locates itself adjacent to the gold surface of the probe, concealing their hydrophobic groups and therefore decreasing the probability of interaction with Aß fibrils and protofibrils. The peptide-gold nano probe represents a useful tool to study the nanobiointeractions of functionalized nanoparticles with amyloid aggregates.

IgY antibodies anti-Tityus caripitensis venom: purification and neutralization efficacy.

Tityus caripitensis is responsible for most of scorpion stings related to human incidents in Northeastern Venezuela. The only treatment for scorpion envenomation is immunotherapy based on administration of scorpion anti-venom produced in horses. Avian antibodies (IgY) isolated from chicken egg yolks represent a new alternative to be applied as anti-venom therapy. For this reason, we produced IgY antibodies against T. caripitensis scorpion venom and evaluated its neutralizing capacity. The anti-scorpion venom antibodies were purified by precipitation techniques with polyethylene glycol and evaluated by Multiple Antigen Blot Assay (MABA), an indirect ELISA, and Western blot assays. The lethality neutralization was evaluated by preincubating the venom together with the anti-venom prior to testing. The IgY immunoreactivity was demonstrated by a dose-dependent inhibition in Western blot assays where antibodies pre-absorbed with the venom did not recognize the venom proteins from T. caripitensis. The anti-venom was effective in neutralizing 2LD50 doses of T. caripitensis venom (97.8 mg of IgY neutralized 1 mg of T. caripitensis venom). Our results support the future use of avian anti-scorpion venom as an alternative to conventional equine anti-venom therapy in our country.

Influence of examiner experience on the reproducibility of retinal nerve fiber thickness values using Cirrus and Stratus OCTs.

PURPOSE: The purpose of the study was to evaluate the influence of the examiner's experience on the reproducibility of retinal nerve fiber layer (RNFL) measurements obtained with Cirrus optical coherence tomography (OCT) and Stratus. METHODS: Fifty-one normal and glaucomatous eyes of 51 participants were included. Two examiners (1 novice, 1 experienced) obtained 2 scans using both OCTs. For quantitative measurements, Bland and Altman limits of agreement were evaluated. For qualitative classifications, κ coefficients were calculated. RESULTS: Signal strength was higher with Cirrus than with Stratus (P<0.05). Signal strength was higher in scans performed by the experienced examiner than in those carried out by the inexperienced examiner in Stratus but not in Cirrus. RNFL measurement differences between Cirrus and Stratus were influenced by the examiner for the inferior (P=0.02), superior (P<0.001), and temporal quadrants (P=0.009). The RNFL quantitative agreement of examiners was higher in Cirrus than in Stratus. The qualitative agreement (κ coefficients) of both examiners in the RNFL classification were almost perfect with Cirrus (in the average, superior, and inferior quadrants), and moderate with Stratus (only in average and inferior quadrant). CONCLUSIONS: The signal strength is independent of the examiner's experience in Cirrus but not in Stratus. RNFL measurements obtained by both examiners were more reproducible with Cirrus than with Stratus. The differences in RNFL measurements between both OCTs were related to the examiner's experience in all 3 quadrants. Agreement between operators in the RNFL classification was higher with Cirrus than Stratus.

Misalignments in the retinal nerve fiber layer evaluation using cirrus high-definition optical coherence tomography.

PURPOSE: To evaluate the frequency and characteristics of misalignments (MAs) in the retinal nerve fiber layer (RNFL) analysis protocol of spectral-domain optical coherence tomography (Cirrus) and determine factors associated with MAs. METHODS: Three hundred eyes (162 normal and 138 glaucomatous eyes) were included in this cross-sectional study. The MAs were considered limited when they affected only part of the scan line, and complete (CMA) when they were observed in the entire scan line. A subgroup (153 cases) with repeated scans was analyzed to compare the RNFL thicknesses in the scans with and without CMAs. RESULTS: Two hundred ninety-nine limited MAs were found in 140 eyes (46.7%) and 151 CMAs were found in 91 eyes (30.3%). The frequency and number of CMAs were significantly related to age (P<0.05). Seventy-two CMAs were in the measurement ring in 48 eyes, more frequently in the 3 and 9-o'clock positions (P=0.001) and the horizontal quadrants (P=0.001). Among the repeated scans, the number of cases with CMAs was similar to the first scan (P=0.32). No significant differences were found in global or quadrant RNFL thickness between scans with and without CMAs. CONCLUSIONS: CMAs were present in the first or second scans in about 30% of cases and were related to older age. CMAs were more frequently in horizontal meridians and quadrants. No differences in RNFL thickness were found between scans with and without CMAs in the same patients. Scans with CMAs in the measurement ring can be considered in the RNFL evaluation.

Cirrus high-definition optical coherence tomography compared with Stratus optical coherence tomography in glaucoma diagnosis.

PURPOSE: To compare the retinal nerve fiber layer (RNFL) evaluation using Cirrus optical coherence tomography (OCT) and Stratus OCT in glaucoma diagnosis. METHODS: One hundred thirty normal and 86 patients with glaucoma were included in this prospective study. The signal strengths of the OCTs were evaluated. The sensitivities and specificities of global RNFL average thickness were compared in the four quadrants and in each clock hour sector. Receiver operating characteristic (ROC) curves, areas under the ROC (AUC), and the likelihood ratio (LR) were plotted for RNFL thickness. Agreement between the OCTs was calculated by using the Bland-Altman method and kappa (kappa) coefficient. RESULTS: Twenty-three percent of all cases examined with Stratus OCT and 1.9% examined with Cirrus OCT had a signal strength below 6 (P = 0.01). In cases with signal strengths > or =6, the mean signal strength was higher with Cirrus OCT than with Stratus OCT (P = 0.01). The RNFL measurements by Cirrus were thicker than those of Stratus OCT (P < 0.05). The AUCs were 0.829 for Stratus and 0.837 for Cirrus OCT (P = 0.706) for global RNFL average. LRs were similar in both OCTs in global RNFL classification but varied in quadrants. The widths of the limits of agreement varied between 42.16 and 97.79 microm. There was almost perfect agreement (kappa = 0.82) in the average RNFL classification. CONCLUSIONS: Cirrus OCT has better scan quality than Stratus OCT, especially in glaucomatous eyes. In cases with good-quality scans, the sensitivity and specificity, and AUCs were similar. The best agreement was in the global average RNFL classification. The widths of limits of agreements exceed the limits of resolution of the OCTs.

Optical coherence tomography evaluation of posterior capsule opacification related to intraocular lens design.

PURPOSE: To evaluate posterior capsule opacification (PCO) and the impact of different intraocular lens (IOL) models on PCO characteristics using optical coherence tomography (OCT). METHODS: Eighty-three eyes with PCO (fibrosis or pearl type) and 32 pseudophakic eyes without PCO were included. Horizontal 3.0 mm long OCT scans of the posterior capsule were obtained. Measurements and means of the peak posterior capsule intensity (PCI) and posterior capsule thickness (PCT) (distance between 2 spikes at posterior capsule) at 3 scan points were recorded. The PCI and PCT were compared with best corrected visual acuity (BCVA) and IOL data. RESULTS: The PCT was high for IOLs with a rounded edge (P = .001) and with poly(methyl methacrylate) (PMMA) IOLs (P<.001). If the IOL optic was concave-convex, the PCT was higher than if the optic was biconvex (P = .001). The PCT of hydrophilic acrylic IOLs was higher than of hydrophobic acrylic IOLs (P = .04). Multivariate analysis of PCT showed that PMMA was the only factor statistically associated with PCT (P = .02). The worse logMAR BCVA correlated significantly with a higher PCT value (P<.001) but not with PCI (P = .42). An IOL size of 12.5 mm was related to fibrosis-type PCO (odds ratio, 3.14; P = .04). CONCLUSIONS: The PCT was most affected by IOL characteristics. Poly(methyl methacrylate) IOLs and IOLs with rounded edges were associated with higher PCT. Hydrophilic acrylic IOLs were associated with greater PCT than hydrophobic IOLs. Posterior capsule thickness was a factor in decreased BCVA.

Usefulness of optical coherence tomography parameters of the optic disc and the retinal nerve fiber layer to differentiate glaucomatous, ocular hypertensive, and normal eyes.

PURPOSE: To assess Stratus optical coherence tomography (OCT) original parameters for identifying glaucomatous damage and to evaluate differences among glaucomatous, ocular hypertensive, and normal eyes. DESIGN: Cross-sectional prospective study. SUBJECTS AND METHODS: The study was conducted at 2 centers. The study population consisted of 55 normal individuals, 95 patients with ocular hypertension (OHT), and 79 patients with glaucoma. Retinal nerve fiber layer (RNFL) and optic nerve head OCT protocols were used to evaluate all study participants. Measurements taken were RNFL thickness, several ratios, RNFL asymmetry between both eyes, rim volume, rim width, disc area, cup area, rim area, cup/disc (C/D) area ratio, and horizontal and vertical C/D ratios. The main outcome measures were the differences in OCT parameters among groups and the areas under the receiver operating characteristic curves (AROC). RESULTS: Mean RNFL thickness around the disc, and superior and inferior RNFL thickness, were significantly thinner in glaucomatous eyes than in OHT or normal eyes (P<0.001). Rim parameters were significantly smaller in glaucomatous eyes than in normal (P<0.001) and OHT eyes (P=0.01). C/D ratios were significantly greater in glaucomatous eyes than in OHT (P<0.001) and normal (P<0.001) eyes. Significant differences were found between normal and OHT eyes in 7 disc parameters. No difference was found among groups in parameters describing RNFL asymmetry between both eyes. The AROC curves of the other RNFL and disk parameters ranged from 0.741 to 0.85. CONCLUSIONS: Almost all RNFL and disc parameters showed significant differences and discriminated between glaucomatous and normal eyes. There were significant differences in some optic nerve parameters, but no RNFL parameters, between normal and OHT eyes.

Objective quantification of posterior capsule opacification after cataract surgery, with optical coherence tomography.

PURPOSE: To evaluate posterior capsule opacification (PCO) in humans after cataract surgery with intraocular lens (IOL) implantation, by using optical coherence tomography (OCT-1). METHODS: Sixty-six eyes with PCO and 20 eyes with a normal posterior capsule were analyzed. A 3-mm-long horizontal scan of the posterior capsule was obtained. Measurements at three points and their average were recorded. Intraoperator and interoperator reliabilities were assessed. Investigated was peak intensity (PI) and posterior capsule thickening (PCT), with PCT indicating the distance between two reflectivity spikes, with an approximate axial resolution of 10 microm. Results were compared with visual acuity (VA) and PCO type. RESULTS: Intraoperator reliability was 0.59 and 0.97 for average PI and PCT, respectively. The interoperator concordance correlation coefficient was 0.70 and 0.82 for average PI and PCT, respectively. Median (interquartile range) intensities of the reflectivity spike were 16.88 (dB) (range, 12.88-20.41) and 11.9 (8.58-14.28), respectively, in the PCO and control eyes (P = 0.001). PCT was found in PCO eyes (median: 86.13 microm; range, 46.33-115.33), whereas no second spike appeared in control eyes (P = 0.001). The area under the receiver operating characteristic curve of the average PCT for differentiating pearl-type from fibrosis-type PCO was 0.87 (P = 0.001). For a cutoff point of 55.3 microm, the sensitivity was 97.5%, and the specificity was 69%. Worse VA correlated significantly only with larger PCT (r(o) = 0.66; P = 0.01). CONCLUSIONS: OCT-1 appears useful to quantitate PCO. In addition, this system seems to discriminate between different types of PCO. PCT may be a previously unrecognized factor in VA degradation.

Clinical factors related to the frequency and intensity of glistenings in AcrySof intraocular lenses.

PURPOSE: To assess the frequency of glistenings in eyes that had phacoemulsification and implantation of AcrySof intraocular lenses (IOLs) (Alcon) and to evaluate the clinical factors related to the glistenings. SETTING: Departamento de Oftalmología, Clínica Universitaria, Universidad de Navarra, Pamplona, Spain. METHODS: A consecutive series of 129 eyes of 94 patients was prospectively evaluated. All patients had cataract surgery and implantation of an MA30BA AcrySof IOL by the same surgeon using the same technique. The operating surgeon examined patients for the presence of glistenings. The frequency and intensity of glistenings were assessed in relation to 14 clinical factors. The effect of glistenings on postoperative Snellen best corrected visual acuity (BCVA) was also evaluated. RESULTS: Glistenings, which occurred in 38 cases (29.5%), were slight in 15 eyes, moderate in 18, and intense in 5. The frequency of the glistenings was related to the time between surgery and evaluation (P =.0001), the IOL dioptric power (P =.01), postoperative inflammation (P =.01), and phacotrabeculectomy (P =.01). The intensity of the glistenings was related to the time after surgery (P =.01) and presence of postoperative inflammation (P =.004). No relation between glistenings and Snellen BCVA was found. CONCLUSIONS: The frequency and intensity of glistenings in AcrySof IOLs increased with time after surgery and were higher when postoperative inflammation was present. Glistenings developed more frequently in cases of phacotrabeculectomy but not after combined phacoemulsification and deep sclerectomy. Glistenings did not result in decreased Snellen BCVA.