Search

Robotic systems have the potential to improve the accuracy and efficiency of percutaneous interventions. However, their widespread adoption is hindered by challenges such as high costs and usability deficiencies. To address these challenges, we designed a novel semi-automated robotic system that combines manual and robotic degrees of freedom for needle guidance. Since the initial presentation of the system, we have implemented hardware and software improvements. The objective of this study is to evaluate the accuracy of the system. To achieve this, experiments were conducted that involved the entire process from CT scanning to lesion targeting with a needle, using a phantom that replicated abdominal lesions of varying sizes. A total of 36 needle insertions were performed, and a control scan was conducted each time to evaluate the needle tip position. The results demonstrate promising accuracy, with a mean Euclidean error of 5.8 ± 1.7 mm. Qualitative analysis showed that lesion targeting was successful across different sizes, with a total success rate of 27 out of 36 attempts. Although our prototype shows promising accuracy, there is still room for improvement compared to existing systems. Future efforts will prioritize enhancing accuracy, exploring usability aspects, and validating the system's performance with medical professionals.

Nanotomography with hard X-rays is a widely used technique for high-resolution imaging, providing insights into the structure and composition of various materials. In recent years, tomographic approaches based on simultaneous illuminations of the same sample region from different angles by multiple beams have been developed at micrometre image resolution. Transferring these techniques to the nanoscale is challenging due to the loss in photon flux by focusing the X-ray beam. We present an approach for multi-beam nanotomography using a dual-beam Fresnel zone plate (dFZP) in a near-field holography setup. The dFZP generates two nano-focused beams that overlap in the sample plane, enabling the simultaneous acquisition of two projections from slightly different angles. This first proof-of-principle implementation of the dual-beam setup allows for the efficient removal of ring artifacts and noise using machine-learning approaches. The results open new possibilities for full-field multi-beam nanotomography and pave the way for future advancements in fast holotomography and artifact-reduction techniques.

Currently, it is necessary to reduce CO2 emissions into the atmosphere. The oil industry in Colombia can contribute through CO2 injection processes in depleted fields. To achieve this, it is essential to have knowledge of the physicochemical interactions of CO2 with reservoir fluids. To integrate CO2, water and hydrocarbon phases, advanced models are required that capture the phenomenology of thermodynamic equilibrium. The CPA (Cubic-Plus-Association) equation of state is an equation that adds an associative term to model the interaction of water with the hydrocarbon and CO2 phase. In this work, the CO2 injection process is thermodynamically modeled in a depleted Colombian reservoir case study. There is a compositional fluid with a gradient of PVT properties in a vertical relief of 10,000 ft at a depletion condition of 2,000 psi @ 15,374 ft and an oil-water contact (OWC) at 17,000 ft. CO2 injections between 10 and 80 mol% were carried out, and through the CPA equation of state, the swelling conditions of the crude oil, the solubility of CO2 in the formation water and the pressurization of the system were evaluated. The associative parameters of the equation were taken from literature and estimated through molecular dynamics simulations of water-CO2-Hydrocarbon interactions. This thermodynamic modeling with an advanced equation of state and use of molecular dynamics simulations allowed us to simulate different CO2 injection scenarios in a compositional fluid. The development of these types of studies is key to carrying out successful CO2 injection processes focused on enhanced recovery (EOR) and CO2 storage in the porous medium in a Colombian-depleted compositional reservoir.

Existe en Colombia un aval constitucional para llevar a cabo la muerte digna. Sin embargo, a pesar de que fue desarrollado por varias resoluciones expedidas por el Ministerio de Salud y Protección Social (Minsalud), su práctica puede ser compleja debido a la intervención de diversos actores frente a los cuales puede incluso darse una colisión de derechos. En este artículo se plantean preguntas como: ¿qué hacer cuando se solicita la práctica de un procedimiento eutanásico y entran en conflicto derechos fundamentales de los actores involucrados?, ¿es clara, completa, precisa y efectiva la regulación frente al tema?, ¿los actores que intervienen en estos conflictos como prestadores de servicios, pacientes, médicos, ven sus derechos en conflicto en el procedimiento eutanásico en Colombia? Para dar respuestas a estos interrogantes, se abordó un estudio de los conceptos de derecho a la muerte digna, objeción de conciencia, eutanasia activa y pasiva, suicidio asistido y homicidio por piedad, así como la prueba de razonabilidad y principio de proporcionalidad, en aras de dar respuesta a estos interrogantes.

As the number of English Learners (EL) increases, U.S. schools must understand and meet their unique needs. Employing qualitative methodology, the authors sought to understand the academic experience of twelve, 10th grade ELs. Three themes of academic success, perception of the student/teacher relationship, and perception of self, along with multiple subthemes emerged. Key concepts from the themes included the importance of relationship, influence teacher expectations had on participants experiencing academic success or engaging a cycle of failure, and value placed on a sense of agency related to academic experiences. Suggestions for how schools can meet ELs' unique needs are provided.

La gestión empresarial exitosa se refiere a la rentabilidad organizacional, sin descuidar otros aspectos importantes, como lo social y ambiental. Este tipo de gestión se logra con el desarrollo de habilidades, que permiten establecer relaciones duraderas y rentables con los distintos grupos de interés. Esta investigación tuvo como objetivo analizar la gestión de Responsabilidad Social Empresarial (GRSE) en el sector de los medios de comunicación en Manabí, Ecuador. A partir de ese referente, y con la aplicación de técnicas de encuestas procesadas estadísticamente, se analizó si las entidades vinculadas con los medios de comunicación ofrecen información sobre la gestión socialmente responsable que realizan. Los resultados establecieron que no hay un procedimiento estandarizado para medir la GRSE. Sin embargo, es relevante ya que, además de su gestión rentable, en su carácter de comunicación pública, constituye un elemento básico de la vida económica, política y social.

Computations and experiments leading to new chiral phosphoric acids (CPAs) for epoxide thionations are reported. Density functional theory calculations reveal the mechanism and origin of the enantioselectivity of such CPA-catalyzed epoxide thionations. The calculated mechanistic information was used to design new efficient CPAs that were tested experimentally and found to be highly effective. Bulky ortho-substituents on the 3,3'-aryl groups of the CPA are important to restrict the position of the epoxide in the key transition states for the enantioselectivity-determining step. Larger para-substituents significantly improve the enantioselectivity of the reaction.

The complex electronic structure of metallic ferromagnets is determined by a balance between exchange interaction, electron hopping leading to band formation, and local Coulomb repulsion. By combining high energy and temporal resolution in femtosecond time-resolved X-ray absorption spectroscopy with ab initio time-dependent density functional theory we analyze the electronic structure in fcc Ni on the time scale of these interactions in a pump-probe experiment. We distinguish transient broadening and energy shifts in the absorption spectra, which we demonstrate to be captured by electron repopulation respectively correlation-induced modifications of the electronic structure, requiring to take the local Coulomb interaction into account.

Abstract Achromatic doublets are combinations of two individual lenses designed to focus different wavelengths of light in the same position. Apochromatic optics are improved versions of the achromatic schemes which extend the wavelength range significantly. Both achromatic and apochromatic optics are well-established for visible light. However, X-ray achromatic lenses did not exist until very recently, and X-ray apochromatic lenses have never been experimentally demonstrated. Here, we create an X-ray apochromatic lens system using an appropriate combination of a Fresnel zone plate and a diverging compound refractive lens with a tuned separation distance. The energy-dependent performance of this apochromat was characterized at photon energies between 6.5 and 13.0 keV by ptychographic reconstruction of the focal spot and scanning transmission X-ray microscopy of a resolution test sample. The apochromat delivered a reconstructed focal spot size of 940 × 740 nm2. The apochromatic combination shows a four-fold improvement in the chromatic aberration correction range compared to an achromatic doublet configuration. Thus, apochromatic X-ray optics have the potential to increase the focal spot intensity for a wide variety of X-ray applications.

RESUMEN El vólvulo total de intestino medio es una complicación infrecuente que pueden sufrir algunos pacientes con anomalías de rotación intestinal. Afecta la totalidad del intestino que está irrigada por la arteria mesentérica superior, causa obstrucción intestinal y se presenta generalmente en pacientes mayores de 15 años. La presentación y el diagnóstico del cuadro clínico en adolescentes y adultos puede ser inespecífica, por lo cual el objetivo del presente trabajo es describir una modalidad de obstrucción intestinal infrecuente denominada vólvulo total de intestino medio mediante la presentación de un caso. Se trata de un adolescente con antecedentes de dolor abdominal tipo cólico de más de 5 años de evolución. Al momento de la atención se quejó de dolor intenso, localizado en epigastrio e hipocondrio derecho, acompañado de vómitos. Al examen físico presentó ruidos hidroaéreos aumentados en tono y frecuencia. En la tomografía computarizada de abdomen se visualizó el signo del «remolino». Se realizó el abordaje inicial por vía laparoscópica, pero las características del vólvulo no permitieron continuar con el procedimiento, por lo que se realizó la conversión a cirugía abierta y se utilizó el procedimiento Ladd convencional. La paciente evolucionó favorablemente y fue dada de alta a los 7 días del acto quirúrgico. Palabras clave: vólvulo intestinal, obstrucción intestinal, malrotación intestinal

Femtosecond transient soft X-ray absorption spectroscopy (XAS) is a very promising technique that can be employed at X-ray free-electron lasers (FELs) to investigate out-of-equilibrium dynamics for material and energy research. Here, a dedicated setup for soft X-rays available at the Spectroscopy and Coherent Scattering (SCS) instrument at the European X-ray Free-Electron Laser (European XFEL) is presented. It consists of a beam-splitting off-axis zone plate (BOZ) used in transmission to create three copies of the incoming beam, which are used to measure the transmitted intensity through the excited and unexcited sample, as well as to monitor the incoming intensity. Since these three intensity signals are detected shot by shot and simultaneously, this setup allows normalized shot-by-shot analysis of the transmission. For photon detection, an imaging detector capable of recording up to 800 images at 4.5 MHz frame rate during the FEL burst is employed, and allows a photon-shot-noise-limited sensitivity to be approached. The setup and its capabilities are reviewed as well as the online and offline analysis tools provided to users.

Full-field X-ray nanoimaging is a widely used tool in a broad range of scientific areas. In particular, for low-absorbing biological or medical samples, phase contrast methods have to be considered. Three well established phase contrast methods at the nanoscale are transmission X-ray microscopy with Zernike phase contrast, near-field holography and near-field ptychography. The high spatial resolution, however, often comes with the drawback of a lower signal-to-noise ratio and significantly longer scan times, compared with microimaging. In order to tackle these challenges a single-photon-counting detector has been implemented at the nanoimaging endstation of the beamline P05 at PETRA III (DESY, Hamburg) operated by Helmholtz-Zentrum Hereon. Thanks to the long sample-to-detector distance available, spatial resolutions of below 100 nm were reached in all three presented nanoimaging techniques. This work shows that a single-photon-counting detector in combination with a long sample-to-detector distance allows one to increase the time resolution for in situ nanoimaging, while keeping a high signal-to-noise level.

A mountain bike program was designed and adapted for the school setting with middle school-aged students during 2020, amid the COVID-19 pandemic. Two mountain bike groups were offered to facilitate training and development of mountain bike knowledge and skills: one group with integrated Adventure Therapy components to facilitate a therapeutic process and the other group without a therapeutic debriefing process. Forty-one students participated in the program after being randomly assigned to one of two groups. An exploratory qualitative analysis revealed that the pandemic negatively impacted participants' wellbeing and academics, leading to increased isolation and decreased motivation, while the mountain bike program increased their focus, competency, physical and mental wellbeing, and connection to the environment. It appears the mountain bike program served as a protective factor for participants. Implications for professionals and researchers are discussed.

Free-electron lasers provide bright, ultrashort, and monochromatic x-ray pulses, enabling novel spectroscopic measurements not only with femtosecond temporal resolution: The high fluence of their x-ray pulses can also easily enter the regime of the non-linear x-ray–matter interaction. Entering this regime necessitates a rigorous analysis and reliable prediction of the relevant non-linear processes for future experiment designs. Here, we show non-linear changes in the L 3-edge absorption of metallic nickel thin films, measured with fluences up to 60 J/cm2. We present a simple but predictive rate model that quantitatively describes spectral changes based on the evolution of electronic populations within the pulse duration. Despite its simplicity, the model reaches good agreement with experimental results over more than three orders of magnitude in fluence, while providing a straightforward understanding of the interplay of physical processes driving the non-linear changes. Our findings provide important insights for the design and evaluation of future high-fluence free-electron laser experiments and contribute to the understanding of non-linear electron dynamics in x-ray absorption processes in solids at the femtosecond timescale.

Cervical cancer is primarily caused by Human Papillomavirus (HPV) infection and remains a significant public health concern, particularly in Latin American regions. This comprehensive narrative review addresses the relationship between Human Papillomavirus (HPV) and cervical cancer, focusing on Latin American women. It explores molecular and immunological aspects of HPV infection, its role in cervical cancer development, and the epidemiology in this region, highlighting the prevalence and diversity of HPV genotypes. The impact of vaccination initiatives on cervical cancer rates in Latin America is critically evaluated. The advent of HPV vaccines has presented a significant tool in combating the burden of this malignancy, with notable successes observed in various countries, the latter due to their impact on immune responses. The review synthesizes current knowledge, emphasizes the importance of continued research and strategies for cervical cancer prevention, and underscores the need for ongoing efforts in this field.

Abstract Autologous matrix induced chondrogenesis (AMIC) is a bone marrow stimulating technique used for the surgical management of chondral defects of the talus. The present study evaluated the clinical outcomes and imaging of AMIC as revision procedure for failed AMIC surgery for osteochondral defects of the talus. Forty-eight patients with symptomatic osteochondral defects who received a revision AMIC were evaluated after a minimum of two years follow-up. Patients with previous procedures rather than AMIC, those who required additional surgical procedures (e.g. ligament repair or deformity correction), or those who had evidence of kissing, bilateral, or multiple lesions were excluded. Outcome parameters included the Visual Analogic Scale (VAS), Tegner Activity Scale, the American Orthopedic Foot and Ankle Score (AOFAS), and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. All patients were followed by an assessor who was not involved in the clinical management. 27 patients were enrolled in the present study. The mean age of the patient was 34.9 ± 3.1 years, and the mean BMI 27.2 ± 5.1 kg/m2. The mean defect surface area was 2.8 ± 1.9 cm2. The mean follow-up was 44.3 ± 21.4 months. The mean hospital length of stay was 4.4 ± 1.4 days. At final follow-up, the mean VAS score was 4.1 ± 3.1, the mean Tegner 3.5 ± 1.6, the mean AOFAS 58.8 ± 20.6. The preoperative MOCART score was 22.1 ± 13.7 points, the postoperative MOCART score was 42.3 ± 27.9 points (+ 20.2%; P = 0.04), respectively. 30% (8 of 27 patients) experienced persistent pain and underwent a further chondral procedure. Concluding, AMIC could be a viable option as revision procedure for failed AMIC in recurrent symptomatic osteochondral defects of the talus. The PROMs indicated that patients were moderately satisfied with the procedure, and the MOCART score demonstrated a significant improvement from baseline to the last follow-up. A deeper understanding in prognostic factors and patient selection is critical to prevent failures.

Ralstonia solanacearum, the causal agent of bacterial wilt, is one of the most devastating bacterial diseases worldwide. In potatoes and many other commercial species such as tomato, banana, plantain, and eggplant, among others, there is a lack of efficient strategies to control this pathogen. Therefore, using resistant cultivars might be the best strategy to prevent this disease. However, breeding for bacterial wilt resistance is challenging since latent infections pose a significant limitation when evaluating resistance to this disease in plant germplasm. Part of the diversity of potato genetic resources is maintained in the Colombian Central Collection (CCC) of potatoes, Corporación Colombiana de Investigación Agropecuaria (Agrosavia). With its 2069 accessions, the CCC is a good source for plant breeding programs. As a first attempt to identify bacterial wilt resistant/tolerant potato sources, 11 commercially available potato varieties were evaluated, representing Andigena and Phureja materials from the CCC. To this end, plants were drench-inoculated with R. solanacearum. This strain was able to cause severe disease in six of the 11 accessions tested. Thus, five highly R. solanacearum-resistant accessions were identified. These results represent a preliminary assessment for identifying bacterial wilt resistance sources that will contribute to establishing a potato breeding program to face this devasting pathogen before it arrives 70 Colombia.

Abstract Materials with insulator-metal transitions promise advanced functionalities for future information technology. Patterning on the microscale is key for miniaturized functional devices, but material properties may vary spatially across microstructures. Characterization of these miniaturized devices requires electronic structure probes with sufficient spatial resolution to understand the influence of structure size and shape on functional properties. The present study demonstrates the use of imaging soft X-ray absorption spectroscopy with a spatial resolution better than 2 $$\upmu$$ μ m to study the insulator-metal transition in vanadium dioxide thin-film microstructures. This novel technique reveals that the transition temperature for the conversion from insulating to metallic vanadium dioxide is lowered by 1.2 K ± 0.4 K close to the structure edges compared to the center. Facilitated strain release during the phase transition is discussed as origin of the observed behavior. The experimental approach enables a detailed understanding of how the electronic properties of quantum materials depend on their patterning at the micrometer scale.

Tattoos are one way that people can construct their narrative identity. This study used a Consensual Qualitative Research design to explore if and how life-story constructs are evident in participants' tattoo narratives. Seven previously identified life-story constructs were adapted, using 17 core ideas to specify how the constructs were evident in the narratives participants shared about their tattoos. The tattoo narratives revealed interactive dynamics between life-story constructs. [ABSTRACT FROM AUTHOR]

The objective of this systematic review was to identify and classify, from the available literature, non-conventional feed ingredients from terrestrial plants, animals, algae, and fungi which have been evaluated for their potential use for tilapia (Oreochromis spp.) production. For this purpose, 795 papers published in the Scopus and Web of Science databases between 2011 and 2021 were analyzed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Data on the growth rate (GR) and effects on weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR); digestibility; fatty acid profile (FAP) of the fish carcass; and the survival rate (SR) were compiled in databases and summary tables. The results were refined according to different criteria, obtaining 144 documents that were pertinent for an in-depth analysis. From those, we found that 50.7% evaluated terrestrial plants, 22.2% animals, 13.9% algae, 9% fungi, and the remaining, combinations of some of the above categories. From the summarized results we concluded that most of the non-conventional sources analyzed have a positive potential impact as alternatives for producing tilapia. Survival was the most evaluated parameter, while digestibility was the least evaluated parameter.