96 research outputs found

    Synthetic Turing protocells: vesicle self-reproduction through symmetry-breaking instabilities

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    The reproduction of a living cell requires a repeatable set of chemical events to be properly coordinated. Such events define a replication cycle, coupling the growth and shape change of the cell membrane with internal metabolic reactions. Although the logic of such process is determined by potentially simple physico-chemical laws, the modeling of a full, self-maintained cell cycle is not trivial. Here we present a novel approach to the problem which makes use of so called symmetry breaking instabilities as the engine of cell growth and division. It is shown that the process occurs as a consequence of the breaking of spatial symmetry and provides a reliable mechanism of vesicle growth and reproduction. Our model opens the possibility of a synthetic protocell lacking information but displaying self-reproduction under a very simple set of chemical reactions

    Modelling of Resistive Type Superconducting Fault Current Limiter for HVDC Grids

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    The protection of high voltage direct current (HVDC) grids is a challenge considering that the protection system must detect, locate, and interrupt large fault currents in a few milliseconds. Resistive type superconducting fault current limiters (R-SFCL) can help solve that difficult task, reducing the extremely demanding ratings of HVDC circuit breakers. This paper presents different approaches to model R-SFCLs in order to analyze their suitability for assessing the performance of HVDC grid protection, including the step model, the exponential model, the RQ model, and the magneto-thermal model. In the first instance, the R-SFCL models are evaluated in a test grid to analyze their parameterisation and select the most adequate model for the study of HVDC grids. The RQ model is finally chosen for its simplicity but closer behavior to the magneto thermal model in terms of fault resistance dependency and resistance evolution curve. Then, the performance of an RQ type R-SFCL model in conjunction with a mechanical circuit breaker is evaluated in a multiterminal HVDC grid with different fault cases. This way, fault currents are greatly decreased as well as circuit breaker requirements. Hence, the R-SFCL under study enables a reliable protection of the HVDC grid

    Students’ Speaking Skill Trough Storytelling Technique At Smp Negeri 4 Tanjung Morawa

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    Abstract   A speaking talent is the ability to say or recite an idea that a person has, and it includes features of pronunciation, vocabulary, and syntax. The objective of speaking is to express a thought or sensation that has arisen in the individual as a result of listening to music or learningcontent. The storytelling technique is one way to help pupils enhance their speaking abilities. Storytelling is a fascinating practice that encourages children to use their imaginations.Storytelling can assist them improve their language abilities while also deepening and broadening their comprehension of the story's characters. A qualitative research design is used in this study. The goal of this study is to help researchers and readers understand what media and approaches teachers use in the classroom to help students, particularly junior high school students, enhance their vocabulary.     Keywords : Storytelling, Effect, Speaking skil

    The Value of Paratracheal Lymphadenectomy in Esophagectomy for Adenocarcinoma of the Esophagus or Gastroesophageal Junction: A Systematic Review of the Literature

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    Esophageal adenocarcinoma; Nodal metastases; Upper mediastinal lymphadenectomyAdenocarcinoma esofágico; Metástasis ganglionares; Linfadenectomía del mediastino superiorAdenocarcinoma esofàgic; Metàstasis ganglionars; Limfadenectomia del mediastí superiorBackground The role of upper mediastinal lymphadenectomy for distal esophageal or gastroesophageal junction (GEJ) adenocarcinomas remains a matter of debate. This systematic review aims to provide a comprehensive overview of evidence on the incidence of nodal metastases in the upper mediastinum following transthoracic esophagectomy for distal esophageal or GEJ adenocarcinoma. Methods A literature search was performed using Medline, Embase and Cochrane databases up to November 2020 to include studies on patients who underwent transthoracic esophagectomy with upper mediastinal lymphadenectomy for distal esophageal and/or GEJ adenocarcinoma. The primary endpoint was the incidence of metastatic nodes in the upper mediastinum based on pathological examination. Secondary endpoints were the definition of upper mediastinal lymphadenectomy, recurrent laryngeal nerve (RLN) palsy rate and survival. Results A total of 17 studies were included and the sample sizes ranged from 10-634 patients. Overall, the median incidence of upper mediastinal lymph node metastases was 10.0% (IQR 4.7-16.7). The incidences of upper mediastinal lymph node metastases were 8.3% in the 7 studies that included patients undergoing primary resection (IQR 2.0-16.6), 4,4% in the 1 study that provided neoadjuvant therapy to the full cohort, and 10.6% in the 9 studies that included patients undergoing esophagectomy either with or without neoadjuvant therapy (IQR 8.9-15.8%). Data on survival and RLN palsy rates were scarce and inconclusive. Conclusions The incidence of upper mediastinal lymph node metastases in distal esophageal adenocarcinoma is up to 10%. Morbidity should be weighed against potential impact on survival

    NEW TERMS OF THE EDUCATIONAL ACTIVITY SPHERE IN THE RUSSIAN AND OSSETIAN LANGUAGES

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    The changes that have occurred in the Russian education system in the XXI century have entailed an influx of new words and expressions related to the provision of this type of activity. The traditions existing in Russian lexicography on the representation of the emerging nomenclature of terms can also be projected into the languages of the peoples of the Russian Federation. However, at the present stage, the corpus of special words showing certain aspects of education reform has not been reflected in the dictionaries of the Russian language and requires further research. This includes a wide range of new terms, as well as those related to the documentation support of the unified state exam, as well as the procedure for its conduct. Background. A significant number of neologisms that have entered the field of education in recent years require reflection in special dictionaries of the Russian and Ossetian languages, since this terminology is used in the professional activities of a large number of people, and its significant part is used in the educational activities of the young, being a social group. Purpose. Analysis and classification of the nomenclature of terms related to the field of education, to the procedure for organizing and conducting the unified state exam, for their inclusion in special and bilingual dictionaries. Materials and methods. The material for the study was regulatory legal acts concerning the procedures governing the organization and conduct of the unified state exam. The main research methods are content analysis and continuous sampling. Results. The nomenclature of terms covering a significant part of society is determined for inclusion in both dictionaries and national corpus of the Russian and Ossetian languages. The thematic classification of special vocabulary is carried out taking into account the logical and semantic connections and the technological process of the state final certification. Practical implications. The research materials can be used for inclusion in the national corpus of the Russian and Ossetian languages, preparation of dictionaries and in the practice of documentation support of management activities in the Ossetian language

    Energy Efficiency of Transport and Logistics Infrastructure: The Example of the Republic of Kazakhstan

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    The study investigates existing approaches of assessing energy efficiency of the transport and logistics infrastructure. It also shows the methodology for placing logistics facilities and analyzes the influence of market environment factors on the placement of logistics centers. The paper considers the problem of locating elements of the transport and logistics infrastructure as objects of energy and resource saving of cargo traffic. On the basis of taking into account the identified factors, a method of forming an energy efficient transport and logistics infrastructure is proposed. Keywords: transport and logistics infrastructure, efficiency, energy consumption, logistic approach. JEL Classifications: L91, Q40, R40 DOI: https://doi.org/10.32479/ijeep.820

    Risk Factors for Failure of Direct Oral Feeding Following a Totally Minimally Invasive Esophagectomy

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    Càncer d'esòfag; Jejunostomia; NutricióCáncer de esófago; Yeyunostomía; NutriciónEsophageal cancer; Jejunostomy; NutritionRecently, it has been shown that directly starting oral feeding (DOF) from postoperative day one (POD1) after a totally minimally invasive Ivor-Lewis esophagectomy (MIE-IL) can further improve postoperative outcomes. However, in some patients, tube feeding by a preemptively placed jejunostomy is necessary. This single-center cohort study investigated risk factors associated with failure of DOF in patients that underwent a MIE-IL between October 2015 and April 2021. A total of 165 patients underwent a MIE-IL, in which DOF was implemented in the enhanced recovery after surgery program. Of these, 70.3% (n = 116) successfully followed the nutritional protocol. In patients in which tube feeding was needed (29.7%; n = 49), female sex (compared to male) (OR 3.5 (95% CI 1.5–8.1)) and higher ASA scores (III + IV versus II) (OR 2.2 (95% CI 1.0–4.8)) were independently associated with failure of DOF for any cause. In case of failure, this was either due to a postoperative complication (n = 31, 18.8%) or insufficient caloric intake on POD5 (n = 18, 10.9%). In the subgroup of patients with complications, higher ASA scores (OR 2.8 (95% CI 1.2–6.8)) and histological subtypes (squamous-cell carcinoma versus adenocarcinoma and undifferentiated) (OR 5.2 (95% CI 1.8–15.1)) were identified as independent risk factors. In the subgroup of patients with insufficient caloric intake, female sex was identified as a risk factor (OR 5.8 (95% CI 2.0–16.8)). Jejunostomy-related complications occurred in 17 patients (10.3%). In patients with preoperative risk factors, preemptively placing a jejunostomy may be considered to ensure that nutritional goals are met.The previous NUTRIENT II trial was funded by KWF Kankerbestrijding (Dutch Cancer Society, grant number 10495) and Medtronic (20130529)

    Segregation of Mn, Si, Al, and oxygen during the friction stir welding of DH36 steel

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    This work investigates the role of welding speed in elemental segregation of Mn, Si, Al, and oxygen during friction stir welding (FSW) in DH36 steel. The experimental work undertaken showed that when the speed of the FSW process exceeds 500 RPM with a traverse speed of 400 mm/min, then elemental segregation of Mn, Si, Al, and O occurred. The mechanism of this segregation is not fully understood; additionally, the presence of oxygen within these segregated elements needs investigation. This work examines the elemental segregation within DH36 steel by conducting heat treatment experiments on unwelded samples incrementally in the range of 1200–1500 °C and at cooling rates similar to that in FSW process. The results of heat treatments were compared with samples welded under two extremes of weld tool speeds, namely W1 low tool speeds (200 RPM with traverse speed of 100 mm/min) and W2 high tool speeds (550 RPM with traverse speed of 400 mm/min). The results from the heat treatment trials showed that segregation commences when the temperature exceeds 1400 °C and Mn, Si, Al, and oxygen segregation progress occurs at 1450 °C and at a cooling rate associated with acicular ferrite formation. It was also found that high rotational speeds exceeding 500 RPM caused localized melting at the advancing-trailing side of the friction stir-welded samples. The study aims to estimate peak temperature limits at which elemental segregation does not occur and hence prevent their occurrence in practice by applying the findings to the tool’s rotational and traverse speed that correspond to the defined temperature

    Assessing copy number abnormalities and copy-neutral loss-of-heterozygosity across the genome as best practice in diagnostic evaluation of acute myeloid leukemia: An evidence-based review from the cancer genomics consortium (CGC) myeloid neoplasms working group

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    Structural genomic abnormalities, including balanced chromosomal rearrangements, copy number gains and losses and copy-neutral loss-of-heterozygosity (CN-LOH) represent an important category of diagnostic, prognostic and therapeutic markers in acute myeloid leukemia (AML). Genome-wide evaluation for copy number abnormalities (CNAs) is at present performed by karyotype analysis which has low resolution and is unobtainable in a subset of cases. Furthermore, examination for possible CN-LOH in leukemia cells is at present not routinely performed in the clinical setting. Chromosomal microarray (CMA) analysis is a widely available assay for CNAs and CN-LOH in diagnostic laboratories, but there are currently no guidelines how to best incorporate this technology into clinical testing algorithms for neoplastic diseases including AML. The Cancer Genomics Consortium Working Group for Myeloid Neoplasms performed an extensive review of peer-reviewed publications focused on CMA analysis in AML. Here we summarize evidence regarding clinical utility of CMA analysis in AML extracted from published data, and provide recommendations for optimal utilization of CMA testing in the diagnostic workup. In addition, we provide a list of CNAs and CN-LOH regions which have documented clinical significance in diagnosis, prognosis and treatment decisions in AML
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