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Abstract The lymphatic circulation plays a crucial role in maintaining fluid balance and supporting immune responses by returning serum proteins and lipids to the systemic circulation. Lymphatic leaks, though rare, pose significant challenges post-radical neck surgery, oesophagectomy, and thoracic or retroperitoneal oncological resections, leading to heightened morbidity and mortality. Managing lymphatic leaks necessitates consideration of aetiology, severity, and volume of leakage. Traditionally, treatment involved conservative measures such as dietary restrictions, drainage, and medical management, with surgical intervention reserved for severe cases, albeit with variable outcomes and extended recovery periods. Lymphography, introduced in the 1950s, initially served as a diagnostic tool for lymphoedema, lymphoma, tumour staging, and monitoring chemotherapy response. However, its widespread adoption was impeded by alternative techniques like Computed Tomography, learning curves, and its associated complications. Contemporary lymphatic interventions have evolved, favouring nodal lymphangiography over pedal lymphangiography for its technical simplicity and reduced complexity. Effective management of chylous leaks mandates a multimodal approach encompassing clinical evaluation and imaging techniques. In cases where conservative management proves ineffective, embolization through conventional lymphangiography by bipedal dissection or intranodal injection emerges as a viable option. This review underscores the importance of a comprehensive approach to diagnosing and treating lymphatic leaks, highlighting advancements in imaging and therapeutic interventions that enhance patient outcomes.

Assessing muscle mass in critically ill patients remains challenging. This retrospective cohort study explores the potential of phase angle (PA°) derived from bioelectrical impedance analysis (BIA) as a surrogate marker for muscle mass monitoring by associating it with daily creatinine excretion (DCE), a structural and metabolic muscle mass marker. In 20 ICU patients, we observed a linear relationship between PA° and DCE at initial (S1) and follow-up (S2) points, with Rho values of 0.78 and 0.65, respectively, as well as between their percentage changes (Rho = 0.80). Multivariate analysis confirmed a strong association between changes in PA° and DCE (adjusted R2 of 0.73), while changes in the extracellular water to total body water (ECW/TBW) ratio showed no significant association. This study establishes a relationship between a BIA-derived independent-weight parameter and DCE, highlighting the potential of PA° for muscle mass monitoring during acute changes, such as those seen in ICU settings. Integrating PA° into clinical practice could provide a non-invasive and reliable tool to enhance muscle assessment and support targeted interventions in critically ill patients.

Injection moulding is a very popular technology for shaping plastics. Its history stretches back to the nineteenth century, and, as a consequence, it has developed outside the framework of digitisation. In order to fully implement the concepts of Industry 4.0, we need to update these legacy technologies so that they can fully benefit from the developments inherent in the “Internet of Things” and allow the process of injection moulding to take full advantage of digital optimisation so that it can fit effectively in the digital factory. In this work, we explore the quantitative use of X-ray scattering as a technology that can provide dynamic and multiscale feedback during the injection moulding cycle to be able to exploit digital twin technology as a means to optimise the operational parameters involved in injection moulding and to enable digital design of moulds in the fullest sense. This manuscript provides a way to mark future work and draw these possibilities to a wider audience.

In this work, we study the magnetocaloric effect (MCE) in a working substance corresponding to a square lattice of spins with Q possible orientations, known as the “Q-state clock model”. When the Q-state clock model has Q≥5 possible configurations, it presents the famous Berezinskii–Kosterlitz–Thouless (BKT) phase associated with vortex states. We calculate the thermodynamic quantities using Monte Carlo simulations for even Q numbers, ranging from Q=2 to Q=8 spin orientations per site in a lattice. We use lattices of different sizes with N=L×L=82,162,322,642,and1282 sites, considering free boundary conditions and an external magnetic field varying between B=0 and B=1.0 in natural units of the system. By obtaining the entropy, it is possible to quantify the MCE through an isothermal process in which the external magnetic field on the spin system is varied. In particular, we find the values of Q that maximize the MCE depending on the lattice size and the magnetic phase transitions linked with the process. Given the broader relevance of the Q-state clock model in areas such as percolation theory, neural networks, and biological systems, where multi-state interactions are essential, our study provides a robust framework in applied quantum mechanics, statistical physics, and related fields.

We propose a quasistatic magnon-based Otto thermal machine in two-dimensional (2D) magnetic insulators. The thermodynamical cycles are engineered by exposing a magnon spin system to thermal baths at different temperatures and tuning the Dzyaloshinskii-Moriya (DM) interaction. We find that a thermal gas of magnons converts a fraction of heat into energy in the form of work, where the efficiency is maximized for specific values of DM, reaching the corresponding Carnot efficiency. We witness a positive to negative net work transition during the cycle that marks the onset of a refrigeratorlike behavior. The work produced by the magnonic Otto engine enhances the magnon chemical potential. The last enables a spin accumulation that might result in the pumping of spin currents at the interfaces of metal-magnet heterostructures. Our work opens possibilities for the efficient leverage of conventional two-dimensional magnets.

Abstract Background Prone positioning is currently applied in time-limited daily sessions up to 24 h which determines that most patients require several sessions. Although longer prone sessions have been reported, there is scarce evidence about the feasibility and safety of such approach. We analyzed feasibility and safety of a continuous prolonged prone positioning strategy implemented nationwide, in a large cohort of COVID-19 patients in Chile. Methods Retrospective cohort study of mechanically ventilated COVID-19 patients with moderate-to-severe acute respiratory distress syndrome (ARDS), conducted in 15 Intensive Care Units, which adhered to a national protocol of continuous prone sessions ≥ 48 h and until PaO2:FiO2 increased above 200 mm Hg. The number and extension of prone sessions were registered, along with relevant physiologic data and adverse events related to prone positioning. The cohort was stratified according to the first prone session duration: Group A, 2–3 days; Group B, 4–5 days; and Group C, > 5 days. Multivariable regression analyses were performed to assess whether the duration of prone sessions could impact safety. Results We included 417 patients who required a first prone session of 4 (3–5) days, of whom 318 (76.3%) received only one session. During the first prone session the main adverse event was grade 1–2 pressure sores in 97 (23.9%) patients; severe adverse events were infrequent with 17 non-scheduled extubations (4.2%). 90-day mortality was 36.2%. Ninety-eight patients (24%) were classified as group C; they exhibited a more severe ARDS at baseline, as reflected by lower PaO2:FiO2 ratio and higher ventilatory ratio, and had a higher rate of pressure sores (44%) and higher 90-day mortality (48%). However, after adjustment for severity and several relevant confounders, prone session duration was not associated with mortality or pressure sores. Conclusions Nationwide implementation of a continuous prolonged prone positioning strategy for COVID-19 ARDS patients was feasible. Minor pressure sores were frequent but within the ranges previously described, while severe adverse events were infrequent. The duration of prone session did not have an adverse effect on safety.

We studied the performance of a quantum magnetic Stirling cycle that uses a working substance composed of two entangled antiferromagnetic qubits (J) under the influence of an external magnetic field (Bz) and an uniaxial anisotropy field (K) along the total spin in the y-direction. The efficiency and work were calculated as a function of Bz and for different values of the anisotropy constant K given hot and cold reservoir temperatures. The anisotropy has been shown to extend the region of the external magnetic field in which the Stirling cycle is more efficient compared to the ideal case.

Abstract The electrocaloric (EC) effect is the change in temperature and entropy of a material driven by the application of an electric field. Our tight-binding calculations linked to Fermi statistics, show that the EC effect can be produced in trilayer graphene (TLG) structures connected to a heat source, triggered by changes in the electronic density of states (DOS) at the Fermi level when external gate fields are applied on the outer graphene layers. We demonstrate that entropy changes are sensitive to the stacking arrangement in TLG systems. The AAA-stacked TLG presents an inverse EC response (cooling) regardless of the temperature value and gate field potential strength, whereas the EC effect in ABC-stacked TLG remains direct (heating) above room temperature. We reveal otherwise the TLG with Bernal-ABA stacking generates both the direct and inverse EC response within the same sample, associated with gate-dependent electronic transitions of thermally excited charge carriers from the valence band to the conduction band in the band structure. The novel charge carrier electrocaloric effect we propose in quantum layered systems may bring a wide variety of prototype van der Waals materials that could be used as versatile platforms to controlling the thermal response in nanodevices.

In this work, we report the caloric effect for an electronic system of the antidot type, modeled by combining a repulsive and attractive potential (parabolic confinement). In this system, we consider the action of a perpendicular external magnetic field and the possibility of having an Aharonov–Bohm flux (AB-flux) generated by a current passing through a solenoid placed inside the forbidden zone for the electron. The energy levels are obtained analytically, and the model is known as the Bogachek and Landman model. We propose to control the caloric response of the system by varying only the AB-flux, finding that, in the absence of an external magnetic field, the maximization of the effect always occurs at the same AB-flux intensity, independently of the temperature, while fixing the external magnetic field at a non-zero value breaks this symmetry and changes the point where the caloric phenomenon is maximized and is different depending on the temperature to which the process is carried. Our calculations indicate that using an effective electron mass of GaAs heterostructures and a trap intensity of the order of 2.896 meV, the modification of the AB-flux achieves a variation in temperature of the order of 1 K. Our analysis suggests that increasing the parabolic confinement twofold increases the effect threefold, while increasing the antidot size generates the reverse effect, i.e., a strong decrease in the caloric phenomenon under study. Due to the great diversity in technological applications that have antidots in electronics, the possibility of controlling their thermal response simply by varying the intensity of the internal current inside the solenoid (i.e., the intensity of AB-flux) can be a platform of interest for experimental studies.

We examine the performance of a finite-time, endoreversible Otto heat engine with a working medium of monolayer or multilayered graphene subjected to an external magnetic field. As the energy spectrum of multilayer graphene under an external magnetic field depends strongly on the number of layers, so too does its thermodynamic behavior. We show that this leads to a simple relationship between the engine efficiency and the number of layers of graphene in the working medium. Furthermore, we find that the efficiency at maximum power for bilayer and trilayer working mediums can exceed that of a classical endoreversible Otto cycle. Conversely, a working medium of monolayer graphene displays identical efficiency at maximum power to a classical working medium. These results demonstrate that layered graphene can be a useful material for the construction of efficient thermal machines for diverse quantum device applications.

We study the performance of an endoreversible magnetic Otto cycle with a working substance composed of a single quantum dot described using the well-known Fock–Darwin model. We find that tuning the intensity of the parabolic trap (geometrical confinement) impacts the proposed cycle’s performance, quantified by the power, work, efficiency, and parameter region where the cycle operates as an engine. We demonstrate that a parameter region exists where the efficiency at maximum output power exceeds the Curzon–Ahlborn efficiency, the efficiency at maximum power achieved by a classical working substance.

Chylous ascites is an uncommon complication after surgery that can result in malnutrition and immunodeficiency. Therefore, surgical interventions are reserved for refractory patients, and the primary success factor for these interventions is locating the point of leakage, which is often tricky. We describe a case of a 56-year-old male with chylous ascites after laparoscopic radical nephrectomy and lumbo-aortic lymphadenectomy for kidney cancer. The patient was initially managed with dietary modifications and drainage placement. Afterward, lymphography with Lipiodol, percutaneous embolization of the leakage point, and total parenteral nutrition were established. Finally, the patient underwent laparoscopic repair after identifying the leakage point by injecting methylene blue through an inguinal node. Complete resolution was achieved, and no complications related to the procedure were recorded. Intranodal methylene blue injection can be an invaluable tool to identify the point of leakage in selected patients to improve the outcomes of surgical repair of refractory chylous ascites.

Dexmedetomidine (DEX) is a highly selective α2-adrenergic agonist with sedative and analgesic properties, with minimal respiratory effects. It is used as a sedative in the intensive care unit and the operating room. The opioid-sparing effect and the absence of respiratory effects make dexmedetomidine an attractive adjuvant drug for anesthesia in obese patients who are at an increased risk for postoperative respiratory complications. The pharmacodynamic effects on the cardiovascular system are known; however the mechanisms that induce cardioprotection are still under study. Regarding the pharmacokinetics properties, this drug is extensively metabolized in the liver by the uridine diphosphate glucuronosyltransferases. It has a relatively high hepatic extraction ratio, and therefore, its metabolism is dependent on liver blood flow. This review shows, from a basic clinical approach, the evidence supporting the use of dexmedetomidine in different settings, from its use in animal models of ischemia-reperfusion, and cardioprotective signaling pathways. In addition, pharmacokinetics and pharmacodynamics studies in obese subjects and the management of patients subjected to mechanical ventilation are described. Moreover, the clinical efficacy of delirium incidence in patients with indication of non-invasive ventilation is shown. Finally, the available evidence from DEX is described by a group of Chilean pharmacologists and clinicians who have worked for more than 10 years on DEX.

This present work explores the performance of a thermal–magnetic engine of Otto type, considering as a working substance an effective interacting spin model corresponding to the q− state clock model. We obtain all the thermodynamic quantities for the q = 2, 4, 6, and 8 cases in a small lattice size (3×3 with free boundary conditions) by using the exact partition function calculated from the energies of all the accessible microstates of the system. The extension to bigger lattices was performed using the mean-field approximation. Our results indicate that the total work extraction of the cycle is highest for the q=4 case, while the performance for the Ising model (q=2) is the lowest of all cases studied. These results are strongly linked with the phase diagram of the working substance and the location of the cycle in the different magnetic phases present, where we find that the transition from a ferromagnetic to a paramagnetic phase extracts more work than one of the Berezinskii–Kosterlitz–Thouless to paramagnetic type. Additionally, as the size of the lattice increases, the extraction work is lower than smaller lattices for all values of q presented in this study.

At low-temperatures a gas of bosons will undergo a phase transition into a quantum state of matter known as a Bose–Einstein condensate (BEC), in which a large fraction of the particles will occupy the ground state simultaneously. Here we explore the performance of an endoreversible Otto cycle operating with a harmonically confined Bose gas as the working medium. We analyze the engine operation in three regimes, with the working medium in the BEC phase, in the gas phase, and driven across the BEC transition during each cycle. We find that the unique properties of the BEC phase allow for enhanced engine performance, including increased power output and higher efficiency at maximum power.

Beyond the usual ferromagnetic and paramagnetic phases present in spin systems, the usual q-state clock model presents an intermediate vortex state when the number of possible orientations q for the system is greater than or equal to 5. Such vortex states give rise to the Berezinskii-Kosterlitz-Thouless (BKT) phase present up to the XY model in the limit q→∞. Based on information theory, we present here an analysis of the classical order parameters plus new short-range parameters defined here. Thus, we show that even using the first nearest neighbors spin-spin correlations only, it is possible to distinguish the two transitions presented by this system for q greater than or equal to 5. Moreover, the appearance at relatively low temperature and disappearance of the BKT phase at a rather fix higher temperature is univocally determined by the short-range interactions recognized by the information content of classical and new parameters.

In this paper, we analyze the total work extracted and the efficiency of the magnetic Otto cycle in its classic and quantum versions. As a general result, we found that the work and efficiency of the classical engine is always greater than or equal to its quantum counterpart, independent of the working substance. In the classical case, this is due to the fact that the working substance is always in thermodynamic equilibrium at each point of the cycle, maximizing the energy extracted in the adiabatic paths. We apply this analysis to the case of a two-level system, finding that the work and efficiency in both the Otto’s quantum and classical cycles are identical, regardless of the working substance, and we obtain similar results for a multilevel system where a linear relationship between the spectrum of energies of the working substance and the external magnetic field is fulfilled. Finally, we show an example of a three-level system in which we compare two zones in the entropy diagram as a function of temperature and magnetic field to find which is the most efficient region when performing a thermodynamic cycle. This work provides a practical way to look for temperature and magnetic field zones in the entropy diagram that can maximize the power extracted from an Otto magnetic engine.

We studied the performance of classical and quantum magnetic Otto cycle with a working substance composed of a single quantum dot using the Fock−Darwin model with the inclusion of the Zeeman interaction. Modulating an external/perpendicular magnetic field, in the classical approach, we found an oscillating behavior in the total work extracted that was not present in the quantum formulation.We found that, in the classical approach, the engine yielded a greater performance in terms of total work extracted and efficiency than when compared with the quantum approach. This is because, in the classical case, the working substance can be in thermal equilibrium at each point of the cycle, which maximizes the energy extracted in the adiabatic strokes.

Antecedentes: La embolización de arterias uterinas es un procedimiento que permite manejar patologías hemorrágicas ginecológicas y obstétricas de manera conservadora y mínimamente invasiva. Métodos: Revisión retrospectiva de casos tratados con embolización selectiva en nuestro Servicio desde su inicio en octubre de 2007. Objetivo: Conocer las indicaciones y resultados de esta técnica. Resultados: Seis casos por patología ginecológica y 7 de causa obstétrica fueron tratados con este procedimiento. El procedimiento fue factible y libre de complicaciones en todos los casos, siendo terapéutico en primera instancia en 12 de los 13 casos. En ningún caso se requirió un tratamiento complementario quirúrgico para cumplir el objetivo terapéutico planificado. Conclusiones: La embolización de arterias uterinas representa una excelente herramienta para tratar cuadros hemorrágicos graves del puerperio, deteniendo hemorragias activas con manejo conservador del útero. En casos de patología ginecológica, el resultado inmediato resulta adecuado, consiguiendo buen control de la hemorragia. Este procedimiento debe ser considerado como alternativa posible en el manejo de la patología hemorrágica obstétrica y ginecológica.Background: The uterine artery embolization is a procedure that can manage haemorrhagic obstretrics and gynecologic pathologies, in a conservative fashion and minimally invasive. Method: Retrospective review of cases that had been treated in our institution since October 2007. Objectives: To know the indication and results of this technique. Results: Six cases were done for gynecologic indications and seven for obstetrics cases. The procedure was feasible and without complications in all cases, being therapeutic in 12 of 13 patients. There was no need of a surgical procedure in order to achieve the therapeutic objective. Conclusions: The uterine artery embolization can be used as an excellent tool in the management of postpartum haemorrhage, reducing the necessity to perform an hysterectomy. In gynecology cases, the results in bleeding response are good as well. This procedure should be considerate as an acceptable alternative in the management of obstetric and gynecologic haemorragic pathology.

Introducción: Las anomalías vasculares son una patología frecuente en la población general, y son causa de deterioro de la calidad de vida de los pacientes que las padecen. En los últimos años, las técnicas mínimamente invasivas de radiología intervencional se han convertido en una alternativa eficaz para el tratamiento de estos pacientes. El objetivo del presente estudio es mostrar nuestra experiencia en el manejo de malformaciones vasculares con estas técnicas en la Clínica Alemana de Santiago y evaluar la satisfacción de los pacientes con este manejo. Material y Métodos: Evaluación del seguimiento de todos los pacientes con malformaciones vasculares tratados en la Unidad de Radiología Intervencional desde el año 2006 hasta junio del año 2009. Los pacientes fueron clasificados en base a la hemodinamia de la malformación vascular (alto flujo vs. bajo flujo). Se evaluaron las complicaciones, y se realizó una encuesta sobre la satisfacción de los pacientes con el tratamiento. Resultados: Ochenta y siete pacientes (253 procedimientos) fueron incluidos en el estudio, 36 hombres y 51 mujeres, todos con seguimiento completo en este periodo. La edad promedio de ellos fue de 20,6 años. En más del 50% de los pacientes la anomalía vascular se ubicó en la cara o extremidades inferiores. Un 28% (25 pacientes) presentó malformación de alto flujo (pura o mixta) y 72% (62 pacientes) de bajo flujo (malformaciones vasculares, linfangiomas o mixtas). En promedio, cada paciente se realizó 2,9 procedimientos (1-10). Del total de procedimientos realizados, hubo 4 complicaciones mayores (1,65%), una de ellas con secuelas estéticas producto de necrosis de la zona. El promedio de satisfacción fue de un 7,95 en una escala de 1 a 10, siendo significativamente mayor en pacientes con malformaciones de bajo flujo (8,27) que en los de alto flujo (7,16) (p < 0.05). Discusión: El tratamiento de las malformaciones vasculares mediante técnicas de radiología intervencional es una alternativa eficaz, con buenas expectativas de mejoría clínica, satisfacción de los pacientes y baja tasa de complicaciones.Background: Vascular anomalies are prevalent in the general population and may produce significant impairment in quality of life. In recent years, minimally invasive interventional radiology techniques have become an efficient alternative for the treatment of these patients. The aim of this study was to present our experience in the management of vascular malformations with such techniques at Clínica Alemana in Santiago, Chile, and assess the satisfaction of patients with this management. Material and Methods: Evaluation of the follow-up of patients with vascular malformations treated in the Interventional Radiology Unit at our center since June - 2006 to June - 2009. Patients were classified according to the hemodynamics of the lesions (high vs low-flow). Complications and patient satisfaction with the treatment were assessed. Results: Eighty-seven patients (253 procedures) were included in the study, 36 men and 51 women, all with complete follow-up during the period of the study. Their average age was 20.6 years. In over 50% of the patients the vascular anomaly was located on the face or the lower extremities. Twenty-eight percent (25 patients) had a high-flow malformation (pure or mixed) and 62 (72%) had a low-flow lesion (vascular malformation, lymphangioma or mixed). On average, each patient underwent 2.9 procedures (1-10). There were 4 major complications (1.65%), one of which was predominantly cosmetic with necrosis in the area of the lesion. The average satisfaction rate was 7.95 (on a rating scale of 1 to 10). Satisfaction was significantly higher in patients with low-flow malformations (8.27) than in those with high-flow lesions (7.16). (p < 0.05) Discussion: Treatment of vascular malformations using interventional radiology techniques is an effective alternative, with good prospects of clinical improvement, patient satisfaction and low complication rates.

In this paper, we revisit the q-state clock model for small systems. We present results for the thermodynamics of the q-state clock model for values from q = 2 to q = 20 for small square lattices of L × L , with L ranging from L = 3 to L = 64 with free-boundary conditions. Energy, specific heat, entropy, and magnetization were measured. We found that the Berezinskii⁻Kosterlitz⁻Thouless (BKT)-like transition appears for q > 5, regardless of lattice size, while this transition at q = 5 is lost for L < 10; for q ≤ 4, the BKT transition is never present. We present the phase diagram in terms of q that shows the transition from the ferromagnetic (FM) to the paramagnetic (PM) phases at the critical temperature T 1 for small systems, and the transition changes such that it is from the FM to the BKT phase for larger systems, while a second phase transition between the BKT and the PM phases occurs at T 2. We also show that the magnetic phases are well characterized by the two-dimensional (2D) distribution of the magnetization values. We made use of this opportunity to carry out an information theory analysis of the time series obtained from Monte Carlo simulations. In particular, we calculated the phenomenological mutability and diversity functions. Diversity characterizes the phase transitions, but the phases are less detectable as q increases. Free boundary conditions were used to better mimic the reality of small systems (far from any thermodynamic limit). The role of size is discussed.

In this work, we report the magnetocaloric effect (MCE) for an electron interacting with an antidot, under the effect of an Aharonov-Bohm flux (AB-flux) subjected to a parabolic confinement potential. We use the Bogachek and Landman model, which additionally allows the study of quantum dots with Fock-Darwin energy levels for vanishing antidot radius and AB-flux. We find that AB-flux strongly controls the oscillatory behaviour of the MCE, thus acting as a control parameter for the cooling or heating of the magnetocaloric effect. We propose a way to detect AB-flux by measuring temperature differences.

We consider a purely mechanical quantum cycle comprised of adiabatic and isoenergetic processes. In the latter, the system interacts with an energy bath keeping constant the expectation value of the Hamiltonian. In this work, we study the performance of the quantum cycle for a system described by the quantum Rabi model for the case of controlling the coupling strength parameter, the resonator frequency, and the two-level system frequency. For the cases of controlling either the coupling strength parameter or the resonator frequency, we find that it is possible to closely approach to maximal unit efficiency when the parameter is sufficiently increased in the first adiabatic stage. In addition, for the first two cases the maximal work extracted is obtained at parameter values corresponding to high efficiency, which constitutes an improvement over current proposals of this cycle.

In this work, we report the magnetocaloric effect (MCE) in two systems of non-interactive particles: the first corresponds to the Landau problem case and the second the case of an electron in a quantum dot subjected to a parabolic confinement potential. In the first scenario, we realize that the effect is totally different from what happens when the degeneracy of a single electron confined in a magnetic field is not taken into account. In particular, when the degeneracy of the system is negligible, the magnetocaloric effect cools the system, while in the other case, when the degeneracy is strong, the system heats up. For the second case, we study the competition between the characteristic frequency of the potential trap and the cyclotron frequency to find the optimal region that maximizes the ΔT of the magnetocaloric effect, and due to the strong degeneracy of this problem, the results are in coherence with those obtained for the Landau problem. Finally, we consider the case of a transition from a normal MCE to an inverse one and back to normal as a function of temperature. This is due to the competition between the diamagnetic and paramagnetic response when the electron spin in the formulation is included.

El estudio taxonómico y sistemático de ejemplares de moluscos terrestres recolectados bajo hojarasca en fragmentos aislados de bosque nativo secundario, Parque Botánico Hualpén, (36º45´-36º49´ S, 73º9´-73º13´ W), Universidad de Concepción, Chile, permitió describir dos géneros nuevos Pichikadi gen.n. de la familia Punctidae, y Chellius gen.n. de la familia Charopidae, con las siguientes especies nuevas para la ciencia: Pichikadi hualpensis sp.n. y Chellius piramidalis sp.n. Para facilitar interpretaciones y estudios posteriores, se sigue a diversos autores en describir las características de la concha, que como otros caracteres filogenéticos han dado origen a la aparente estabilidad sistemática de los micromoluscos terrestres en el ámbito mundial. Las descripciones y observaciones de cada género y especies se complementan con una clave para las especies de estas familias encontradas en Chile continental.Two new genera of land snails (Stylommatophora: Arionacea) from Chile. We describe two new genera of land molluscs found under wet leaf litter in isolated fragments of a secondary native forest at the Hualpén Botanical Park (36º45´-36º49´ S, 73º9´-73º13´ W), University of Concepción, Chile. The new taxa are Pichikadi gen.n., of Punctidae, and Chellius gen.n., of Charopidae, with the following new species: Pichikadi hualpensis sp.n., and Chellius piramidalis sp.n. English diagnosis are presented for all taxa, together with an English identification key and English versions of figure captions and table headings. To facilitate subsequent studies and interpretations, we follow recent authors in using mainly shell characters, an approach that has favored the present taxonomic stability of the world’s land micromollusca. The diagnosis and observations are complemented with a key for the species of these families inhabiting continental Chile. Rev. Biol. Trop. 55 (2): 693-708. Epub 2007 June, 29.

La resección percutánea del osteoma osteoide es una técnica de radiología intervencional que ha empezado a ser utilizada en forma más frecuente. Reportamos nuestra experiencia en 9 casos evaluando los resultados obtenidosPercutaneous resection of osteoid osteomas is a technique of interventional radiology that is becoming more commonly used. We reported our experience with this technique in 9 patients to evaluate the medium-term outcome of this technique of percutaneous resection

We study the effect of the degeneracy factor in the energy levels of the well-known Landau problem for a magnetic engine. The scheme of the cycle is composed of two adiabatic processes and two isomagnetic processes, driven by a quasi-static modulation of external magnetic field intensity. We derive the analytical expression of the relation between the magnetic field and temperature along the adiabatic process and, in particular, reproduce the expression for the efficiency as a function of the compression ratio.

In the present paper, we discuss the interpretation of some of the results of the thermodynamics in the case of very small systems. Most of the usual statistical physics is done for systems with a huge number of elements in what is called the thermodynamic limit, but not all of the approximations done for those conditions can be extended to all properties in the case of objects with less than a thousand elements. The starting point is the Ising model in two dimensions (2D) where an analytic solution exits, which allows validating the numerical techniques used in the present article. From there on, we introduce several variations bearing in mind the small systems such as the nanoscopic or even subnanoscopic particles, which are nowadays produced for several applications. Magnetization is the main property investigated aimed for two singular possible devices. The size of the systems (number of magnetic sites) is decreased so as to appreciate the departure from the results valid in the thermodynamic limit; periodic boundary conditions are eliminated to approach the reality of small particles; 1D, 2D and 3D systems are examined to appreciate the differences established by dimensionality is this small world; upon diluting the lattices, the effect of coordination number (bonding) is also explored; since the 2D Ising model is equivalent to the clock model with q = 2 degrees of freedom, we combine previous results with the supplementary degrees of freedom coming from the variation of q up to q = 20 . Most of the previous results are numeric; however, for the case of a very small system, we obtain the exact partition function to compare with the conclusions coming from our numerical results. Conclusions can be summarized in the following way: the laws of thermodynamics remain the same, but the interpretation of the results, averages and numerical treatments need special care for systems with less than about a thousand constituents, and this might need to be adapted for different properties or devices.

Se examina el status taxonómico de las especies chilenas de las familias Veronicellidae, Pupillidae y Achatinellidae, como parte de una serie de análisis taxonómicos sobre los moluscos terrestres de Chile que se elabora como seguimiento a la sinopsis del grupo publicada con anterioridad (Stuardo & Vega 1985). Son pocos los trabajos trascendentes publicados después de la sinopsis. En la actualidad hay descritas dos especies de Veronicellidae, dos de Pupillidae y 21 especies de Achatinellidae. De éstas, el único registro de Chile para Heterovaginina limayana Lesson es cuestionable y la subespecie Pupoides (Ischnopupoides) minimus costatus Biese, es considerada inválida. Se presenta una exhaustiva compilación de la sinonimia, junto a una discusión morfológica de los caracteres de la concha y de la distribución topotípica de cada una de las especies conocidas. Sin embargo, es ya necesario realizar estudios genéticos de especiación en los morfos del único veronicélido ampliamente distribuido en Chile central y sur, y en las especies de Orthurethra encontrados en Chile continental y sus islas oceánicas.The content of this paper, part of a series of taxonomic analysis of the land mollusca of Chile being written as a follow up to a synopsis published earlier (Stuardo & Vega 1985), examines the status of the Veronicellidae, Pupillidae and Achatinellidae. Only a few meaningful contributions have been published after the synopsis. So far, two species of Veronicellidae, two species of Pupillidae and 21 species of Achatinellidae have been recorded. Of these, Heterovaginina limayana Lesson with only one record from Chile continues being questioned and the subspecies Pupoides (Ischnopupoides) minimus costatus Biese, is here considered invalid. A full synonymic compilation, with a discussion of morphological distinctive shell traits and topotypic geographical distributions is given for each of these species. However, much needed taxonomic work on the genetic of speciation becomes necessary for the understanding of the morphs of the only widely distributed veronicellid species in central and south Chile and the species of Orthurethra found in continental Chile and the Oceanic Islands

The aim of this study was to prepare a novel targeting drug delivery system for 2-Methoxyestradiol (2ME) in order to improve the clinical application of this antitumor drug. It is based in nanoparticles (NPs) of titanium dioxide (TiO2) coated with polyethylene glycol (PEG) and loaded with 2ME. A complete IR and Raman characterization have been made to confirm the formation of TiO2–PEG–2ME composite. Vibrational modes have been assigned for TiO2, PEG, and 2ME and functionalized TiO2–PEG and TiO2–PEG–2ME. The observed variation in peak position of FTIR and Raman of each for these composites has been elucidated in terms of intermolecular interactions between PEG–2ME and TiO2, obtaining step-by-step the modification processes that were attributed to the conjugation of PEG and 2ME to TiO2 NPs. Modifying TiO2 NPs with PEG loaded with the 2ME drug revealed that the titanium dioxide nanocarrier possesses an effective adsorption capability, and we discuss their potential application as a system of drug delivery.

Índice• Contenidos • Estudios, trabajos e investigaciones aplicadas• Identidad local y cultural Lafkenche • Diversificación productiva como base de desarrollo para la auracanía costera • Descripción de la zona auracanía costera • Propuesta de ordenación territorial• Complementareidad territorial • Jerarquía de los centros poblados • Propuesta de desarrollo productivo• Tendencias de uso de suelo rural • Identificación de productos con potencial para el desarrollo territorial • Temática de recursos marítimos • Temática silvo-agropecuaria • Temática silvo-agrícola • Producción silvícola • Temática ganadera • Temática de desarrollo turístico • Conclusiones • Programas de fortalecimiento de capital humano en la araucanía• Programa de fortalecimiento para la Araucanía Costera. Universidad autónoma de Chile y Sercotec • Momento I. Fortalecimiento social y de redes • Momento II. Enfoque de desarrollo territorial sustentable • Momento III. Fortalecimiento de competencias • Integración de conocimientos en el territorio y fortalecimiento social y de redes • Referencias bibliográficas Resumen El Instituto de Estudios del Hábitat dependiente de la Universidad Autónoma de Chile, ha desarrollado desde su creación en el año 2007 una propuesta de investigación aplicada basada en el concepto de Desarrollo Integral del Territorio. Esto implica experiencias mixtas en términos de Ordenamiento Territorial, que albergan propuestas de desarrollo productivo incorporando temáticas de mejoramiento de capital humano, social y fortalecimiento de Redes, asociadas a los resguardos medio-ambientales y el rescate de los valores identitarios de las zonas donde se trabaja. Los proyectos realizados han buscado vincular las realidades socioculturales presentes en La Araucanía, a partir del reconocimiento de las características Sociales, Culturales y Naturales propias y únicas de la Región. Abstract The Habitat Studies Institute attached to the Autonomous University of Chile, has developed since its creation in 2007 applied a research proposal based on the concept of Integral Development of the Territory. This implies mixed experiences in terms of Zoning, housing development proposals incorporating themes of improving productive human capital and strengthening social networks, combined with halfenvironmental safeguards and the rescue of identity values of the areas where work. The projects have sought to link the socio-cultural realities present in Araucanía, upon recognition of the social, cultural and Natural own unique of the Region.

Trends and last advances in science and technology require the application of modern tools and techniques to generate structured and useful knowledge. The present status and the dynamics of the information in the actual field can be accessed through processes of technological survey, capture, processing, analysis and visualization of information. With this purpose, we performed a scientometric study of the Chilean scientific production. Another Latin American countries and other three countries overseas were also taken into account as a reference to Chilean scientific reality. The study was lead by Dr. Patricio Vargas from the Physics department of the Universidad Tecnica Federico Santa Maria. The study included the scientific productivity in indexed journals throughout the last 10 years. The searched areas were nanoscience and nanotechnology, constituting the knowledge-corpus that were analyzed and mapped with data mining tools. The main conclusion of this work is that the actual quantity of scientist working in nanoscience is insufficient to reach technological development in the near future. In order to design scientific policies in areas such as nanoscience and nanotechnology, as well as in other technological areas, one of the main recommendations that emerge from this work is that this kind of survey techniques have to be applied in a systematic and continuous way by the people involved in science and technology policy.

Introducción: Las anomalías vasculares son una patología frecuente en la población general, y son causa de deterioro de la calidad de vida de los pacientes que las padecen. En los últimos años, las técnicas mínimamente invasivas de radiología intervencional se han convertido en una alternativa eficaz para el tratamiento de estos pacientes. El objetivo del presente estudio es mostrar nuestra experiencia en el manejo de malformaciones vasculares con estas técnicas en la Clínica Alemana de Santiago y evaluar la satisfacción de los pacientes con este manejo. Material y Métodos: Evaluación del seguimiento de todos los pacientes con malformaciones vasculares tratados en la Unidad de Radiología Intervencional desde el año 2006 hasta junio del año 2009. Los pacientes fueron clasificados en base a la hemodinamia de la malformación vascular (alto flujo vs. bajo flujo). Se evaluaron las complicaciones, y se realizó una encuesta sobre la satisfacción de los pacientes con el tratamiento. Resultados: Ochenta y siete pacientes (253 procedimientos) fueron incluidos en el estudio, 36 hombres y 51 mujeres, todos con seguimiento completo en este periodo. La edad promedio de ellos fue de 20,6 años. En más del 50% de los pacientes la anomalía vascular se ubicó en la cara o extremidades inferiores. Un 28% (25 pacientes) presentó malformación de alto flujo (pura o mixta) y 72% (62 pacientes) de bajo flujo (malformaciones vasculares, linfangiomas o mixtas). En promedio, cada paciente se realizó 2,9 procedimientos (1-10). Del total de procedimientos realizados, hubo 4 complicaciones mayores (1,65%), una de ellas con secuelas estéticas producto de necrosis de la zona. El promedio de satisfacción fue de un 7,95 en una escala de 1 a 10, siendo significativamente mayor en pacientes con malformaciones de bajo flujo (8,27) que en los de alto flujo (7,16) (p < 0.05). Discusión: El tratamiento de las malformaciones vasculares mediante técnicas de radiología intervencional es una alternativa eficaz, con buenas expectativas de mejoría clínica, satisfacción de los pacientes y baja tasa de complicaciones.

La resección percutánea del osteoma osteoide es una técnica de radiología intervencional que ha empezado a ser utilizada en forma más frecuente. Reportamos nuestra experiencia en 9 casos evaluando los resultados obtenidos