Variations in activation energy and nuclei size during nucleation explain chiral symmetry breaking.

We show that variations in enantiomer nuclei size and activation energy during the nucleation stage of crystallization are responsible for the chiral symmetry breaking resulting in excess of one of the possible enantiomers with respect to the other. By understanding the crystallisation process as a non-equilibrium self-assembly process, we quantify the enantiomeric excess through the probability distribution of the nuclei size and activation energy variations which are obtained from the free energy involved in the nucleation stage of crystallisation. We validate our theory by comparing it to Kondepudi et al. previous experimental work on sodium chlorate crystallisation. The results demonstrate that the self-assembly of enantiomeric crystals provides an explanation for chiral symmetry breaking. These findings could have practical applications for improving the production of enantiopure drugs in the pharmaceutical industry, as well as for enhancing our understanding of the origins of life since enantiomeric amino acids and monosaccharides are the building blocks of life.

Predicting cancer stages from tissue energy dissipation.

Understanding cancer staging in order to predict its progression is vital to determine its severity and to plan the most appropriate therapies. This task has attracted interest from different fields of science and engineering. We propose a computational model that predicts the evolution of cancer in terms of the intimate structure of the tissue, considering that this is a self-organised structure that undergoes transformations governed by non-equilibrium thermodynamics laws. Based on experimental data on the dependence of tissue configurations on their elasticity and porosity, we relate the cancerous tissue stages with the energy dissipated, showing quantitatively that tissues in more advanced stages dissipate more energy. The knowledge of this energy allows us to know the probability of observing the tissue in its different stages and the probability of transition from one stage to another. We validate our results with experimental data and statistics from the World Health Organisation. Our quantitative approach provides insights into the evolution of cancer through its different stages, important as a starting point for new and integrative research to defeat cancer.

Optimal transport of active particles induced by substrate concentration oscillations.

We show the existence of a stochastic resonant regime in the transport of active colloidal particles under confinement. The periodic addition of substrate to the system causes the spectral amplification to exhibit a maximum for an optimal noise level value. The consequence of this is that particles can travel longer distances with lower fuel consumption. The stochastic resonance phenomenon found allows the identification of optimal scenarios for the transport of active particles, enabling them to reach regions that are otherwise difficult to access, and may therefore find applications in transport in cell membranes and tissues for medical treatments and soil remediation.

Chiral symmetry breaking induced by energy dissipation.

Spontaneous chiral symmetry breaking is observed in a wide variety of systems on very different scales, from the subatomic to the cosmological. Despite its generality and importance for a large number of applications, its origin is still a matter of debate. It has been shown that the existence of a difference between the energies of the intermediate states of optical enantiomers leads to disparate production rates and thus to symmetry breaking. However, it is still unclear why this occurs. We measured for the first time the optical rotation angle of NaClO3 enantiomeric crystals in solution during their formation and found that the amount of energy needed to induce the enantiomeric excess is exactly the same as the energy dissipated per mole of solid salt calculated from the entropy production obtained from the proposed model. The irreversible nature of the process leading to entropy production thus explains the chiral symmetry breaking in the salt crystals studied. The proposed method could be used to explain the formation of self-organised structures generated by self-assembly of enantiomers arising from chiral symmetry breaking, such as those emerging in the production of advanced materials and synthetic biological tissues.

Nonequilibrium thermodynamics of Janus particle self-assembly.

We compute the energetic cost of formation of Janus particle structures. Using an approach that couples particle dynamics to the evolution of fuel concentration in the medium, which we consider to be initially inhomogeneous, we show the different types of emerging structures. The energy dissipated in the formation of such structures is obtained from the entropy production rate, which is a non-monotonic function of the fraction of assembled particles and, thus, different in each self-assembly regime. An analysis of the free energy of these particles allows us to establish a thermodynamic criterion of structure formation based on the behavior of chemical potential as a function of the fraction of assembled particles.

Efficacy of cement restrictors: Experimental study and development of a classification. / Eficacia de los restrictores de cemento: estudio experimental y desarrollo de una clasificación.

INTRODUCTION: Cement restrictors (CRs) are devices that allow occlusion of the femoral canal in order to obtain greater interdigitation of the cement between the bone and a better pressurization, which generates an increase in the survival of cemented stems. The aim of this study was to evaluate the efficacy of the different CRs used and propose a classification of this device. MATERIALS AND METHODS: An experimental study was carried out, where 7 CR references of different designs and manufacturers were taken. Later, tests were carried out on 9 chlorinated polyvinyl chloride tubes for each reference, to achieve a total of 63 tests. RESULTS: In our study, 34.9% of the CRs in ultra high molecular weight polyethylene failed, presenting migration and allowing cement to leak while none of the gelatin RC failed. CONCLUSION: The RC with an umbrella design proved to be the less effective, presented a higher incidence of migration and cement leakage, while the gelatin CRs were the best performers. Based on the results of this study, an analysis of the CR design was carried out and a classification was proposed that divides these devices into 2 types.

Efficacy of cement restrictors: Experimental study and development of a classification / Eficacia de los restrictores de cemento: estudio experimental y desarrollo de una clasificación

Introduction: Cement restrictors (CRs) are devices that allow occlusion of the femoral canal in order to obtain greater interdigitation of the cement between the bone and a better pressurization, which generates an increase in the survival of cemented stems. The aim of this study was to evaluate the efficacy of the different CRs used and propose a classification of this device. Materials and methods: An experimental study was carried out, where 7 CR references of different designs and manufacturers were taken. Later, tests were carried out on 9 chlorinated polyvinyl chloride tubes for each reference, to achieve a total of 63 tests. Results: In our study, 34.9% of the CRs in ultra high molecular weight polyethylene failed, presenting migration and allowing cement to leak while none of the gelatin RC failed. Conclusion: The RC with an umbrella design proved to be the less effective, presented a higher incidence of migration and cement leakage, while the gelatin CRs were the best performers. Based on the results of this study, an analysis of the CR design was carried out and a classification was proposed that divides these devices into 2 types.(AU)

Introducción: Los restrictores de cemento (RC) son dispositivos que permiten la oclusión del canal femoral con el fin de obtener una mayor interdigitación del cemento en el hueso y una mejor presurización, lo que genera un incremento en la supervivencia de los vástagos cementados. El objetivo de este estudio fue evaluar la eficacia de los diferentes RC utilizados y proponer una clasificación de este dispositivo. Materiales y métodos: Se realizó un estudio experimental, donde se tomaron 7 referencias de RC de diferentes diseños y fabricantes. Posteriormente se hicieron pruebas en 9 tubos de policloruro de vinilo clorado por cada referencia para conseguir un total de 63 pruebas. Resultados: El 34,9% de los RC de nuestro estudio presentaron migración y permitieron la fuga de cemento; todos estos RC eran de polietileno de ultra alto peso molecular (PUAPM), mientras que ninguno de los RC de gelatina falló. Conclusión: Los RC con diseño en paraguas demostraron ser los menos eficaces, presentando una mayor incidencia de migración y fuga de cemento, mientras que los RC de gelatina fueron los de mejor desempeño. Basado en los resultados de este estudio, se realizó un análisis del diseño de los RC y se propuso una clasificación que divide estos dispositivos en 2 tipos.(AU)

Eficacia de los restrictores de cemento: estudio experimental y desarrollo de una clasificación / Efficacy of cement restrictors: Experimental study and development of a classification

Introducción: Los restrictores de cemento (RC) son dispositivos que permiten la oclusión del canal femoral con el fin de obtener una mayor interdigitación del cemento en el hueso y una mejor presurización, lo que genera un incremento en la supervivencia de los vástagos cementados. El objetivo de este estudio fue evaluar la eficacia de los diferentes RC utilizados y proponer una clasificación de este dispositivo. Materiales y métodos: Se realizó un estudio experimental, donde se tomaron 7 referencias de RC de diferentes diseños y fabricantes. Posteriormente se hicieron pruebas en 9 tubos de policloruro de vinilo clorado por cada referencia para conseguir un total de 63 pruebas. Resultados: El 34,9% de los RC de nuestro estudio presentaron migración y permitieron la fuga de cemento; todos estos RC eran de polietileno de ultra alto peso molecular (PUAPM), mientras que ninguno de los RC de gelatina falló. Conclusión: Los RC con diseño en paraguas demostraron ser los menos eficaces, presentando una mayor incidencia de migración y fuga de cemento, mientras que los RC de gelatina fueron los de mejor desempeño. Basado en los resultados de este estudio, se realizó un análisis del diseño de los RC y se propuso una clasificación que divide estos dispositivos en 2 tipos.(AU)

Introduction: Cement restrictors (CRs) are devices that allow occlusion of the femoral canal in order to obtain greater interdigitation of the cement between the bone and a better pressurization, which generates an increase in the survival of cemented stems. The aim of this study was to evaluate the efficacy of the different CRs used and propose a classification of this device. Materials and methods: An experimental study was carried out, where 7 CR references of different designs and manufacturers were taken. Later, tests were carried out on 9 chlorinated polyvinyl chloride tubes for each reference, to achieve a total of 63 tests. Results: In our study, 34.9% of the CRs in ultra high molecular weight polyethylene failed, presenting migration and allowing cement to leak while none of the gelatin RC failed. Conclusion: The RC with an umbrella design proved to be the less effective, presented a higher incidence of migration and cement leakage, while the gelatin CRs were the best performers. Based on the results of this study, an analysis of the CR design was carried out and a classification was proposed that divides these devices into 2 types.(AU)

Enhancing particle transport in deformable micro-channels.

It is shown that the action of an oscillating force on particles moving through a deformable-walled channel causes them to travel greater distances than in the case of a rigid channel. This increase in the transport efficiency is due to an intensification of the stochastic resonance effect observed in corrugated rigid channels, for which the response to the force is maximal for an optimal value of the thermal noise. The distances traveled by the particles are even larger when the oscillation of the micro-channel is synchronized with that of an applied transverse force and also when a constant external force is considered. The phenomenon found could be observed in the transport of particles through elastic porous media, in drug delivery to cancerous tissues, and in the passage of substrates through transporters in biological membranes. Our results indicate that an appropriate channel design and a suitable choice of applied forces lead to optimal scenarios for particle transport.

Utility of the combination of hederagenin glucoside saponins and chromane hydrazone in the topical treatment of canine cutaneous leishmaniasis. An observational study.

Canine cutaneous leishmaniasis (CCL) is an emerging zoonotic infection endemic in several countries of the world. Due to variable response to therapy and frequency of relapses, a more effective, safer, and inexpensive treatment is needed. Recently, it was reported that the hederagenin glucoside saponins (SS) and chromane-derived hydrazone (TC2) combined in a 1:1 ratio has high potential in antileishmanial therapy since both compounds alter the survival of Leishmania and the ability to infect adjacent macrophage. Not only the skin permeation and the absorption of an ointment containing 2% TC2 and 2% SS (w/w) was determined in this work, but also the acute dermal toxicity in both in vitro and in vivo assays. Last, the effectiveness and safety of the topical therapy with 2% TC2-2% SS ointment was evaluated in an observational study in dogs with diagnosis of cutaneous leishmaniasis (CL). Both TC2 and SS diffused through pig ear skin and traces of TC2 (but not SS) were detected in the stratum corneum of mice at 6-24 h. Neither TC2 nor SS was detected in plasma. The acute dermal toxicity was negative. Treatment with 2% TC2-2% SS ointment produced a complete long-term clinical cure in 56 dogs (24 females and 32 males) from the Orinoco and Amazonas regions in southeastern Colombia without adverse effects. All dogs have remained disease-free for the last 24 months. In conclusion, these results support the use of this topical therapy as a safer and new first-line local treatment of CCL that could help limit the spread of CL from dogs to humans.

Role of Interfacial Entropy in the Particle-Size Dependence of Thermophoretic Mobility.

We show that changes in the surface tension of a particle due to the presence of nonionic surfactants and impurities, which alter the interfacial entropy, have an impact on the value of the thermophoretic mobility. We have found the existence of different behaviors of this quantity in terms of particle size which can be summarized through a power law. For particles that are small enough, the thermophoretic mobility is a constant, whereas for larger particles it is linear in the particle radius. These results show the important role of the interfacial entropic effects on the behavior of the thermophoretic mobility.

Entropic transport in a crowded medium.

To know how liquid matter moves through a crowded medium due to the action of a force constitutes currently a problem of great practical importance, present in cases as diverse as the transport of particles through a cell membrane and through a particulate porous medium. To calculate the mass flow through the system, we present an approach that emulates the texture of the medium by using entropic barriers that the particles must overcome in order to move. The model reproduces the scaling behavior of the velocity with the force found in many systems in order to show how the scaling exponent depends on the micro-structure of the medium. Our model offers a new perspective that is able to characterize the flow of matter through the medium and may be useful in studies of nano-fluids, oil recovery, soil drainage, tissue engineering, and drug delivery.

Tumor glómico en mucosa bucal: reporte de caso / Tumor in oral mucosa: case report

El tumor glómico es una neoplasia vascular originada de las células del músculo liso del componente neuromioarterial, responsable del control del flujo sanguíneo microvascular. Representa el 1,6% de todos los tumores de tejidos blandos, localizándose principalmente en la zona subungüeal y clínicamente muy doloroso. Su diagnóstico puede ser tardío debido a su pequeño tamaño, manifestaciones clínicas inespecíficas y localizaciones anatómicas inusuales. El tratamiento principalmente es quirúrgico, el cual es curativo, permitiendo además la confirmación histopatológica. Se presenta el reporte de caso de una paciente de 13 años de edad con un tumor glómico de localización inusual en mucosa bucal.

The glomus tumor is a vascular neoplasm originating from smooth muscle cells of neuromyoarterial component, responsible for the control of microvascular blood flow. It represents 1.6% of all soft tissue tumors, being located mainly in the subungual area and clinically very painful. Diagnosis may be delayed because of their small size, nonspecific clinical manifestations and unusual anatomical locations. Treatment is primarily surgical, which is healing, also allowing the histopathologic confirmation. The case report of a 13-year-old patient with an unusual-located glomus tumor in the oral mucosa is presented.

Self-assembling outside equilibrium: emergence of structures mediated by dissipation.

A set of disordered interacting building blocks may form ordered structures by means of a self-assembling process. An external intervention in the system by adding a chemical species or by applying forces leads to different self-assembly scenarios with the appearance of new structures. For instance, the formation of microtubules, gels, virus capsides, cells and living beings among others takes place by self-assembly under nonequilibrium conditions. A general evolution criterion able to account for why nature selects some structures outside equilibrium and not others is lacking. Nevertheless, progress in the understanding of nonequilibrium self-assembly (NESA) mechanisms has been made thanks to the formulation of models that take particular situations into consideration. We review recent efforts devoted to describing self-assembly out of equilibrium and we provide a reference linking several current concepts in order to help in the development of new models and experimental studies. We hope that the knowledge of the intimate mechanisms leading to the formation of structures will make the implementation of re-configurable and bio-inspired materials possible and give a simpler perspective on the understanding of the emergence of life.

Clinical and Health Care Utilization Outcomes of Kidney Transplantation in HIV-Positive Recipients: A Nationwide Analysis From 2008-2013.

BACKGROUND: Kidney transplantation (KTxp) provides dialysis independence, improved quality of life, and prolonged life expectancy for patients with end-stage renal disease. Before and during the early antiretroviral therapy era, KTxp was not a consideration for patients with end-stage renal disease who were HIV-positive (HIV+ve) given their short life expectancy and prevailing organ procurement constraints. Recent advancements in antiretroviral therapy and HIV care have overhauled this paradigm and KTxp has now been performed for several years, however, pragmatic studies documenting outcomes are lacking. We herein document the effectiveness of KTxp in patients who are HIV+ve by reporting clinical and health care utilization outcomes in the United States. METHODS: Utilizing the Inpatient Databases of the Healthcare Cost & Utilization Project spanning 2008-2013, we identified all adult recipients of KTxp by procedural codes and recipients who are HIV+ve by ICD-9 codes. We extracted demographic, clinical, and resource utilization variables and compared recipients who are HIV+ve with those who are HIV-negative (HIV-ve). We then performed descriptive statistics and multivariate analysis using logistic regression to assess the effect of HIV on clinical and utilization outcomes. RESULTS: A total of 104,137 patients had kidney transplants during the study period. Of the total, 605 patients were HIV+ve. Infections rates were similar among patients who were HIV+ve and HIV-ve (odds ratio [OR] 1.18, confidence interval [CI] 0.58-2.40; P = .652). In-hospital mortality rates were also similar (OR 0.83, CI 0.18-3.69; P = .80). Hospital charges for patients who were HIV+ve were no different from patients who were HIV-ve ($195,099 ± 1074 vs $186,567 ± 9558; P = .38). CONCLUSION: Clinical and fiscal outcomes are comparable among patients who are HIV+ve and HIV-ve during transplant hospitalization.

[Predictors of seizure related injuries in adult patients with epilepsy in Colombia: a case-control study]. / Predictores de lesiones asociadas a crisis epilepticas en pacientes adultos con epilepsia en Colombia: estudio de casos y controles.

AIM: To identify predictors of seizure related injuries in adult patients with epilepsy in Colombia. SUBJECTS AND METHODS: Case-control study. Patients with a diagnosis of epilepsy aged 16 years and older who attended the Neurocentro epilepsy center between 2013-2016 and were attended by a specialist in epilepsy were included. Patients with seizure related injuries were defined as the case. The control group was conformed by those without seizure related injuries. Odds ratios and 95% confidence intervals were calculated. A logistic regression was performed. RESULTS: A total of 101 (28.5%) patients were cases and 253 (71.5%) were controls. Patients with seizure related injuries were significantly younger than controls at the age of onset of epilepsy (9 vs 12 years; p = 0.017). The significant variables in the bivariate analysis were: some degree of cognitive impairment, drug resistant epilepsy, abnormal neurological examination, and seizures related with changes in the lunar phases. No protective factors were identified. In the multivariate analysis, two variables remained significant: drug resistant epilepsy and some degree of cognitive impairment. CONCLUSION: Drug-resistant epilepsy and cognitive impairment were predictors of seizure related injuries in adult patients with epilepsy. Adequate pharmacological control of epileptic seizures and prevention recommendations may reduce the risk of seizure related injuries in these patients.

TITLE: Predictores de lesiones asociadas a crisis epilepticas en pacientes adultos con epilepsia en Colombia: estudio de casos y controles.Objetivo. Identificar los predictores de lesiones asociadas con crisis epilepticas en adultos con epilepsia en Colombia. Sujetos y metodos. Estudio de casos y controles. Se incluyo a los pacientes con diagnostico de epilepsia mayores de 16 anos que fueron atendidos por una especialista en epilepsia que acudieron a Neurocentro en el periodo comprendido entre 2013 y 2016. Se definio como caso a los pacientes que habian presentado lesiones asociadas con crisis epilepticas, y como grupo control, a los que no las habian presentado. Se calcularon odds ratios e intervalos de confianza al 95%. Se realizo una regresion logistica. Resultados. Se identificaron 101 (28,5%) casos y 253 (71,5%) controles. Los pacientes con lesiones asociadas con crisis epilepticas fueron significativamente mas jovenes que los controles a la edad de inicio de la epilepsia (9 frente a 12 anos; p = 0,017). Las variables significativas en el analisis bivariado fueron: algun grado de deterioro cognitivo, epilepsia resistente a medicamentos, examen neurologico anormal y crisis asociadas a cambios en las fases lunares. No se identificaron factores protectores. En el analisis multivariado, dos variables permanecieron significativas: epilepsia resistente a medicamentos y algun grado de deterioro cognitivo. Conclusion. Se observo que la epilepsia resistente a medicamentos y el deterioro cognitivo son predictores de lesiones asociadas con crisis epilepticas en pacientes adultos con epilepsia. Un adecuado control farmacologico de las crisis epilepticas y unas recomendaciones de prevencion pueden disminuir el riesgo de dichas lesiones en estos pacientes.

Successful eradication of invasive Scopulariopsis brumptii in a liver transplant recipient.

Ten months after orthotopic liver transplant, a 53-year-old male patient developed cough and fever. Imaging revealed diffuse ground-glass opacities involving all lobes, and subsequent bronchoscopic washings revealed Scopulariopsis brumptii infection. The patient initially had significant clinical deterioration requiring intubation and extracorporeal membrane oxygenation. However, combination antifungal therapy, including posaconazole and terbinafine, eventually proved successful in eradicating the infection.

Effects of extremely low frequency electromagnetic fields on in-vitro cellular cultures HeLa and CHO.

This paper presents the cellular proliferation effects of the exposure to extremely low frequency electromagnetic fields (ELF-EMF) on in-vitro cellular cultures HeLa and CHO. Through the magnetic stimulation system (MSS) the cells were exposed to magnetic fields with sinusoidal waveform at 50 Hz; initially for 40 minutes at intensities of 0.4 mT, 1.4 mT, 2.13 mT, 2.49 mT and 2.53 mT in parallel and perpendicular directions to the culture plates. Subsequently, the repetitive electromagnetic field (rEMF) was applied to 2.49 mT in parallel direction (for 40 minutes every twelve hours during 4 days) with which the highest cellular proliferation rate was obtained at 66.6 %. The results show a greater effect on proliferation in radiated cell lines, particularly in the application of rEMF a greater effect of ELF-EMF was observed in the proliferation rate of HeLa cells than in CHO cells, in contrast to the respective control cells. These results supported by other studies serve as a reference in the search for alternatives for the treatment of cervical cancer and the maintenance and preservation of cell lines.

Liver X Receptor Agonist Modifies the DNA Methylation Profile of Synapse and Neurogenesis-Related Genes in the Triple Transgenic Mouse Model of Alzheimer's Disease.

The liver X receptor agonist, GW3965, improves cognition in Alzheimer's disease (AD) mouse models. Here, we determined if short-term GW3965 treatment induces changes in the DNA methylation state of the hippocampus, which are associated with cognitive improvement. Twenty-four-month-old triple-transgenic AD (3xTg-AD) mice were treated with GW3965 (50 mg/kg/day for 6 days). DNA methylation state was examined by modified bisulfite conversion and hybridization on Illumina Infinium Methylation BeadChip 450 k arrays. The Morris water maze was used for behavioral analysis. Our results show in addition to improvement in cognition methylation changes in 39 of 13,715 interrogated probes in treated 3xTg-AD mice compared with untreated 3xTg-AD mice. These changes in methylation probes include 29 gene loci. Importantly, changes in methylation status were mainly from synapse-related genes (SYP, SYN1, and DLG3) and neurogenesis-associated genes (HMGB3 and RBBP7). Thus, our results indicate that liver X receptors (LXR) agonist treatment induces rapid changes in DNA methylation, particularly in loci associated with genes involved in neurogenesis and synaptic function. Our results suggest a new potential mechanism to explain the beneficial effect of GW3965.