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Diagnostic efficiency of breast cancer screening remains one of the most important issues in oncology and radiology. Artificial intelligence technologies are widely used in clinical medicine to effectively solve a number of technological and diagnostic problems. The aim. To develop segmentation neural network model for breast plain radiographs analysis with subsequent study of its clinical effectiveness. Materials and methods. The artificial intelligence-based system was developed to analyze X-ray mammography, аnd included a segmentation neural network with the U-Net architecture, a classification neural architecture ResNet50 with outputting the result using gradient boosting. 15486 X-ray cases were used for training, estimation of diagnostic accuracy and validation of the developed segmental model. All cases were labeled in specially developed software environment LabelCMAITech. The segmentation accuracy was determined by Intersection over Union (IoU) similarity coefficient, the probability of malignancy was calculated using the binary classification metrics. Results. The developed system is represented by a segmentation model based on neural network architecture. The model allows, with high accuracy of 0.8176 and higher, at threshold values on the output neurons of the network of 0.1 and 0.15, to localize X-ray findings that have diagnostic value for determining the likelihood of the presence of breast cancer signs in an X-ray mammographic study — focus, architecture distortion, local asymmetry, calcifications. When comparing the results of machine segmentation and marking of images by a radiologist, it was found that the model is not inferior to the doctor in the accuracy of determining the formations, extra-focal calcifications and intraglandular lymph nodes. Conclusion. The results of this study allow considering the model as an intelligent assistant to a radiologist in the analysis of screening mammographic cases.

Avicennia dominated mangrove forests occur from seaward to landward sites and hence are subject to different dynamics within estuarine ecosystems. Regeneration of mangrove forests primarily depends on the extent of propagule spread and subsequent establishment in suitable habitats. The complex nature of estuarine systems induces a wide variety of local conditions for within-site propagule retention and settlement thereby allowing spontaneous regeneration of mangroves. In this study, we estimated the fine-scale spatial genetic structure (FSGS) of Avicennia populations and examined whether their position relative to the seaside or the size of mangrove patches could have influenced the extant local population genetic structure. A kinship-based FSGS was performed using microsatellite markers in 523 A. marina, 189 A. rumphiana and 60 A. alba adult trees of 24 sites in The Philippines. Transects within each estuary were taken both parallel and perpendicular to the coastline or tidal river edge. The extent of local mangrove areas and various human-induced encroachments as such did not show any trend in allele diversity, heterozygosity values or inbreeding levels. However, farther inland situated mangrove patches showed a larger FSGS extent across the neighborhood (up to 75 m) though less diversity along with inbreeding, most likely due to retention of related propagules and lowered chance of external propagule input. Estimation of connectivity along a same coastline stretch supported a unidirectional steppingstone or adjacent migration model for populations of either A. marina, A. alba or A. rumphiana. These were congruent with ocean currents across mangrove estuaries of the Tablas Strait and along Western Leyte, thereby emphasizing the relevance of coastal connectivity for long term persistence. From this study, we conclude that both proximity to open water and narrowness of mangrove patches may affect their captured diversity, inbreeding and fine-scale structure caused by propagule movement within or beyond a local mangrove fragment during recent generations. Higher levels of allele diversity for seaward sites and highest likelihood of migration for adjacent mangroves both add to the importance of coastal connectivity that is the only natural cohesive force on longer term and necessary to counteract short term effects of increasingly encroached mangrove environments.

The CEIPA Business School is a Colombian higher education institution, characterized by providing different education models in the country since its inception. For this reason, CEIPA became the first university institution that created and offered virtual programs in the City of Medellin, and today, it has the largest ratio of the number of high-quality virtual programs in the country. From its first steps in virtual education, since 1996, CEIPA recognized the importance of developing together the virtual education and its own pedagogical model based on problem solving, which allow achieving the learning objectives of its students, understanding the educational process as a whole, in which didactics and teaching methodology cannot be separated. This chapter is aimed to show the case study of CEIPA in the transformation of its graduate and postgraduate programs into digital environments, which shows the changes that were necessary to develop in its academic and administrative process to respond to this new education model, which was a pioneer not only in its beginnings but also in times of the COVID-19 pandemic, spotlighting its success and positioning CEIPA as a leading institution in high educational Colombian´s sector.

This historical review of the development of the Oregonator model of the Belousov–Zhabotinsky reaction is based on a lecture Dick Field presented during IrvFest2015—Celebrating a founding father of chaos!, a meeting in commemoration of Irving R. Epstein’s [Formula: see text] birthday. For Dick’s [Formula: see text] birthday festschrift, we focus here on the five papers in the series named “ Oscillations in chemical systems,” published in 1972 [Noyes et al., J. Am. Chem. Soc. 94, 1394–1395 (1972); Field et al., J. Am. Chem. Soc. 94, 8649–8664 (1972); Field and Noyes, Nature 237, 390–392 (1972)] and 1974 [Field and Noyes, J. Chem. Phys. 60, 1877–1884 (1974); Field and Noyes, J. Am. Chem. Soc. 96, 2001–2006 (1974)].

The microwave propagation in a 3D dielectric photonic crystal at the frequency range from 8.5 to 12GHz has been investigated. A frequency range where effective refractive index nef of the crystal approaches zero is found. In the frequency range where nef

Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease.

Hydrogels are promising materials for mimicking the extra-cellular environment. Here, we present a simple methodology for the formation of a free-standing viscoelastic hydrogel from the abundant and low cost protein serum albumin. We show that the mechanical properties of the hydrogel exhibit a complicated behaviour as a function of the weight fraction of the protein component. We further use X-ray scattering to shed light on the mechanism of gelation from the formation of a fibrillary network at low weight fractions to interconnected aggregates at higher weight fractions. Given the match between our hydrogel elasticity and that of the myocardium, we investigated its potential for supporting cardiac cells in vitro. Interestingly, these hydrogels support the formation of several layers of myocytes and significantly promote the maintenance of a native-like gene expression profile compared to those cultured on glass. When confronted with a multicellular ventricular cell preparation, the hydrogels can support macroscopically contracting cardiac-like tissues with a distinct cell arrangement, and form mm-long vascular-like structures. We envisage that our simple approach for the formation of an elastic substrate from an abundant protein makes the hydrogel a compelling biomedical material candidate for a wide range of cell types.

The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell–material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy., Advances in chemical imaging capability can add to our understanding of complex cellular systems. Here the authors develop a framework for label-free quantitative volumetric Raman spectroscopic imaging and use it to visualize and quantify biomolecules in various 3D cellular systems.

Matrix metalloproteinases (MMPs) contribute to the breakdown of tissue structures such as the basement membrane, promoting tissue fibrosis. Here we developed an electrospun membrane biofunctionalized with a fragment of the laminin β1-chain to modulate the expression of MMP2 in this context. We demonstrate that interfacing of the β1-fragment with the mesothelium of the peritoneal membrane via a biomaterial abrogates the release of active MMP2 in response to transforming growth factor β1 and rescues tissue integrity ex vivo and in vivo in a mouse model of peritoneal fibrosis. Importantly, our data demonstrate that the membrane inhibits MMP2 expression. Changes in the expression of epithelial-to-mesenchymal transition (EMT)-related molecules further point towards a contribution of the modulation of EMT. Biomaterial-based presentation of regulatory basement membrane signals directly addresses limitations of current therapeutic approaches by enabling a localized and specific method to counteract MMP2 release applicable to a broad range of therapeutic targets., Matrix metalloproteinase enzymes are widely known to contribute to the breakdown of tissues. Here, the authors utilise a biomaterial substrate functionalised with a laminin fragment to modulate the expression of these enzymes, subsequently controlling the integrity of tissue.

It is shown that direct group cosubjection of symmetries of neighboring crystalline phases of water along the melting and sublimation curves in the pT phase diagram is observed only for ices V and VI. Those relationships between numbers NV of independent variable parameters and numbers NC of unequal constants in the parametric description of neighboring phases at their interfaces, which are needed for transitions to take place, are fulfilled inmost cases. Correlation is established between the absolute values of entropy variation |ΔS| and the absolute values |ΔNC| and |ΔNV| at the transitions through the boundaries of phase regions.

It is shown that the cages in water frameworks of clathrate structures of crystalline gas hydrates are characterized by averaged values of the numbers NV (polyhedron vertices), NE (polyhedron edges), NF (polyhedron faces) and NVF (vertices per face), close to the values calculated for the unit cell of a 3D random Voronoi mosaic.

The method of Kikuchi, Hijmans, and de Boer for the calculation of order-disorder phenomena on lattices is extended to the case when not all lattice sites are equivalent. The nonequivalence results from there being more than one kind of basic figure. The modifications of the theory caused by this circumstance are worked out for the Hijmans-de Boer formulation.

A series of equations are developed for the study of the effects of cosolvents on the solubility of a solute in mixed solutions where the solute displays a finite solubility. The equations differ depending on the scale used for the solute (and cosolvent) concentrations. The expressions use Kirkwood-Buff integrals to relate the changes in solubility to changes in the local solution composition around the solute and can be applied to study any type of ternary system including electrolyte cosolvents. The expressions provided here differ from previous approaches because of the use of a semi-open ensemble and the extension to finite solute solubilities.

To construct a physical model of water vapor condensation with the formation of dew water, a geometrically based Monte Carlo method was developed. The hit and geometrical density functions of random space filling with identical spheres were determined. The parameters of these functions is the minimum allowable approach OO min of spheres and their excess in comparison with the space capacity. The specificity of dew-water molecules and hydrogen bonds (HBs) between them appears at 2/3L b < OO min < 2L b, where L b is the HB length. As the approach OO min = L b, the random filling density does not exceed the packing density in the sphere models of I h and I c ices. The densities characteristic of the sphere model of water molecule packing in these ices are achievable at OO min ≈ 0.8L b and/or a significant HB kink, as well as at vapor supersaturation (excess of molecules over the space capacity).

The Baker technique for visualizing fluid flows consists of generating hydroxyl ions (OH−) in situ in a flowing fluid by electrochemical means. An acid–base indicator is added to the solution, which has been adjusted to an appropriate pH. The local generation of hydroxyl will change the pH locally and hence the color of the indicator will change locally. This technique was introduced in 1966 by D. James Baker. One immediate advantage of this technique is that the tracer is neutrally buoyant. This paper explores the workings of this method in a manner which should give considerable confidence in exactly what is being observed.

An analysis of the salting-out, or Sechenow, effect is given in terms of Kirkwood-Buff, or fluctuation, integrals. The analysis is formally exact but cannot easily be applied in its original form. When the solute that is being salted out is sparingly soluble, simplifications arise and the theory can be used to compute one of the Kirkwood-Buff integrals which is otherwise difficult to obtain.

The pT phase diagram topology of water, including textures, is established, assuming that structural phase transitions do not change the molecule intrinsic symmetry and local symmetry in Wyckoff positions, but correspond to a group-subgroup cosubjection.

The salting out of solid solutes near the critical point of the solvent is investigated using the results of a previous paper (J. Phys. Chem. B 2006, 110, 24077) on the fluctuation theory of salting out. It is found that the salting out coefficient at infinite dilution of cosolvent is approximately proportional to the compressibility of the solvent and is consequently quite large near the critical point. No estimate is given for the range of cosolvent concentrations over which the infinite dilution slope might be a good approximation. Far from the critical point, it is known to be a good approximation over a considerable cosolvent concentration range.

The definition of the solvation Gibbs energy of a solute A in any solvent is repeated in exactly the same way as was done almost 20 years ago. Some recent publications that challenged this definiti...

Hand hygiene is the most cost-effective and simple measure of preventing healthcare associated infections (HAI). The approach to improve low compliance must be through multimodal interventions such as the "Clean Care is Safer Care" strategy (WHO).To estimate the efficacy of a multimodal strategy in improving hand hygiene in five wards of a tertiary care hospital in Medellín, Colombia (2008-2010).Quasi-experimental before-after study.Hand hygiene compliance significantly increased after the intervention (82 to 89%, p = 0.007). The knowledge score increased from a median of 26 (IQR=22-28) to 30 (IQR=26-32, p = 0.001). Alcohol-based hand rub consumption increased significantly from 10.5 liters to 58.1 liters per 1000 patient-days [incidence ratio (IR) = 2.39, 95% CI = 1.99; 2.88]. Monthly HAI rates showed no significant variations during the same period [IR = 0.90, 95% CI = 0.71; 1.13].This and other recent studies demonstrate that implementing a multimodal strategy for hand hygiene significantly increases compliance with this measure, irrespective of type of health worker or hospital department.Implementing a multimodal strategy we achieved significant increases in hand hygiene compliance but mild or no significant variations in monthly HAI rates.

We study Taylor diffusion for the case when the diffusion transverse to the bulk motion is a persistent random walk on a one-dimensional lattice. This is mapped onto a Markovian walk where each lattice site has two internal states. For such a model we find the effective diffusion coefficient which depends on the rate of transition among internal states of the lattice. The Markovian limit is recovered in the limit of infinite rate of transitions among internal states; the initial conditions have no role in the leading-order time-dependent term of the effective dispersion, but a strong effect on the constant term. We derive a continuum limit of the problem presented and study the asymptotic behavior of such limit.

The dispersion of particles in a stratified medium with a flow normal to the stratification is studied for the case when the transition rates between the various strata are random variables. One‐ and two‐dimensional stratified systems are considered. The effective diffusion coefficient in the flow direction is computed numerically. The numerical results are compared with the predictions of a mean‐field theory known as the effective (or coherent) medium approximation.

This paper presents a new computerized control system for a dual-beam photostimulator. Electronic hardware and software were developed to set the optical filters and shutters for light stimulation of recorded retinal cells. Filters were set into stepper-motor-driven wheels which were controlled by specific boards and commanded through a new specially designed personal computer interface, all controlled by specially designed software. Each motor-controlling board was equipped with an electronic control system allowing command transduction and sequential generation of protocols. The electromagnetic shutters were controlled through a different board. The personal computer interface was set with a decodification system based on programmable logic devices. All electronic systems were organized in modular structures. The design performance was tested by measurement of the spectral and absolute sensitivity of retinal horizontal cells.

The solvation Gibbs free energy of linear molecules is shown to be a linear function of the length, or number of units, of the molecule when this length exceeds the correlation length of the solute due to the solvent. For large molecules in simple solvents, the solvation Gibbs energy, in leading order, scales as the solute volume, not the solute surface area, as might be expected. The solvation Gibbs energy, as determined from experimental measurements on solute concentrations in coexisting phases, needs no correction due to solute-solvent size ratio. A critique of a recent assertion to the contrary is presented

This paper presents a sensor system used to measure the height variations of the overhead contact wire feeding electric traction trains when a pantograph is passing. These measures are used to determine the occurrence of defects in the catenary-pantograph interaction. The non-contact sensor for monitoring catenary-pantograph interaction (NCCPI) system consists of a line-scan camera focused to an infrared screen, so that the contact wire is within the viewing plane of the line-scan. The screen is comprised of a light illuminated area and four black areas, which are used as a reference for determining the height of the wire. The measures are taken in differential form, diminishing the effect of vibrations and changes in lighting. The paper shows the mathematical model of the sensor system and the practical results obtained.