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BACKGROUND: Cerebral hyperperfusion syndrome is a rare but potentially severe complication of carotid artery revascularisation that develops under conditions of resistant postoperative hypertension and impaired cerebrovascular autoregulation. OBJECTIVE: Was to determine which preoperative and operative factors affect the development of cerebral hyperperfusion syndrome after carotid endarterectomy. METHODS: This prospective observational study enrolled 93 asymptomatic patients who underwent carotid endarterectomy. Cerebral hyperperfusion was registered in patients who had 100% postoperative increase in mean flow in middle cerebral artery registered by Transcranial Doppler ultrasound. Cerebral hyperperfusion syndrome was diagnosed in patients with cerebral hyperperfusion who postoperatively developed at least one of the symptoms. Pre-operative and operative risk factors for cerebral hyperperfusion syndrome were analysed by multivariate binary logistic regression. RESULTS: Out of 93 operated patients, cerebral hyperperfusion was registered in 23 and cerebral hyperperfusion syndrome in 18 patients. Risk factors for cerebral hyperperfusion syndrome were included in the binary logistic regression model. Incomplete Circle of Willis morphology on 3D TOF magnetic resonance image (pâ¯=â¯0.002), Breath holding index below the 0.69 cut-off (pâ¯=â¯0.006), positive criteria for insufficient collateral flow through circle of Willis registered by TCD (pâ¯=â¯0.03), and poorly controlled hypertension (pâ¯=â¯0.023) showed statistically significant independent predictive value for cerebral hyperperfusion syndrome. The model was statistically significant (pâ¯=â¯0.012) and correctly classified 90.3 % of patients. CONCLUSIONS: Incomplete circle of Willis and insufficient collateral flow, low cerebrovascular reserve, and poorly regulated hypertension are significant predictors of post- carotid endarterectomy hyperperfusion development.
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Estenosis Carotídea/cirugía , Circulación Cerebrovascular , Trastornos Cerebrovasculares/etiología , Endarterectomía Carotidea/efectos adversos , Arteria Cerebral Media/fisiopatología , Anciano , Velocidad del Flujo Sanguíneo , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/fisiopatología , Trastornos Cerebrovasculares/diagnóstico por imagen , Trastornos Cerebrovasculares/fisiopatología , Círculo Arterial Cerebral/anomalías , Círculo Arterial Cerebral/fisiopatología , Circulación Colateral , Femenino , Humanos , Hipertensión/complicaciones , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Arteria Cerebral Media/diagnóstico por imagen , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Resultado del Tratamiento , Ultrasonografía Doppler TranscranealRESUMEN
Background and Objectives: People employed in emergency medical services represent a professional group which encounters events beyond ordinary human experience, great work demands, the risk of professional disputes, and stressful situations. The goal of this study is to examine the presence of mobbing and violence at work, as well as their influence on work ability of emergency medical doctors. Materials and Methods: The survey is conducted in Emergency Medical Service (EMS) in Nis in the period between December 2017 and January 2018. Using standardized questionnaires on psychosocial conditions in work environment (COPSOQ II) and work ability index (WAI) this study encompasses 79 doctors. For estimation of the examined factors' influence on WAI linear regression analysis was used. Results: EMS doctors were exposed to abuse in 30.4% of the cases. The decline in WAI is significantly related with exposure to violence by patients (ß = 0.727), exposure to physical violence (ß = 0.896), exposure to abuse several times (ß = 0.691) and exposure to ill-treatment by patients (ß = 0.750). Conclusion: The results indicate that in the examined doctors mobbing and workplace violence are very much present and have a negative impact on their work, and therefore on the quality of health care.
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Acoso Escolar/psicología , Exposición a la Violencia/psicología , Estrés Laboral/psicología , Médicos/psicología , Lugar de Trabajo/psicología , Adulto , Servicio de Urgencia en Hospital , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estrés Laboral/epidemiología , Serbia/epidemiologíaRESUMEN
Persistent homology captures the evolution of topological features of a model as a parameter changes. The most commonly used summary statistics of persistent homology are the barcode and the persistence diagram. Another summary statistic, the persistence landscape, was recently introduced by Bubenik. It is a functional summary, so it is easy to calculate sample means and variances, and it is straightforward to construct various test statistics. Implementing a permutation test we detect conformational changes between closed and open forms of the maltose-binding protein, a large biomolecule consisting of 370 amino acid residues. Furthermore, persistence landscapes can be applied to machine learning methods. A hyperplane from a support vector machine shows the clear separation between the closed and open proteins conformations. Moreover, because our approach captures dynamical properties of the protein our results may help in identifying residues susceptible to ligand binding; we show that the majority of active site residues and allosteric pathway residues are located in the vicinity of the most persistent loop in the corresponding filtered Vietoris-Rips complex. This finding was not observed in the classical anisotropic network model.
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Modelos Moleculares , Proteínas/química , Algoritmos , Sitios de Unión , Dominio Catalítico , Modelos Estadísticos , Simulación de Dinámica Molecular , Unión Proteica , Conformación Proteica , Proteínas/metabolismoRESUMEN
There is limited evidence showing that elevated arterial blood pressure in surgical patients may be associated with increased perioperative risk; however, cardiovascular instability frequently occurs during anesthesia. The most commonly used anesthetic agents, both intravenous and inhalation ones, produce a decrease in arterial blood pressure. Magnesium, acting as a natural calcium-channel blocker, induces direct and indirect vasodilatation, thus playing a role in the treatment of arterial hypertension. In this research, we assessed the effects of magnesium sulfate on cardiovascular stability in patients undergoing diverse planned surgical procedures (abdominal, orthopedic, urology) under general balanced anesthesia, who were diagnosed with arterial hypertension grade 1 and 2. The research encompassed 100 patients of both sexes, aged from 20 to 65. Immediately before induction of anesthesia with propofol, the patients in the experimental group (50 study subjects) received 30 mg/ kg bolus dose and magnesium sulfate infusion at 10 mg/kg/h, whereas the subjects in the control group (50 patients) were administered normal saline. Anesthesia was achieved and maintained with sevoflurane, fentanyl and rocuronium. The hemodynamic variables of mean arterial pressure and heart rate were measured every five minutes, starting immediately before magnesium infusion. Statistical analysis of the categorized values of mean arterial pressure and heart rate revealed a statistically significant between-group difference at 60th and 90th minute of anesthesia. In conclusion, magnesium sulfate as an adjuvant to anesthesia in patients with arterial hypertension reduces hemodynamic changes during anesthesia.
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Anestesia/métodos , Anestésicos Combinados/administración & dosificación , Hemodinámica/efectos de los fármacos , Hipertensión/fisiopatología , Sulfato de Magnesio/administración & dosificación , Adulto , Anestesiología , Presión Sanguínea , Método Doble Ciego , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos OperativosRESUMEN
Large amounts of fruit seeds, especially peach, are discarded annually in juice or conserve producing industries which is a potential waste of valuable resource and serious disposal problem. Regarding the fact that peach seeds can be obtained as a byproduct from processing companies their exploitation should be greater and, consequently more information of cultivars' kernels and their composition is required. A total of 25 samples of kernels from various peach germplasm (including commercial cultivars, perspective hybrids and vineyard peach accessions) differing in origin and ripening time were characterized by evaluation of their sugar composition. Twenty characteristic carbohydrates and sugar alcohols were determined and quantified using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC/PAD). Sucrose, glucose and fructose are the most important sugars in peach kernels similar to other representatives of the Rosaceae family. Also, high amounts of sugars in seeds of promising hybrids implies that through conventional breeding programs peach kernels with high sugar content can be obtained. In addition, by the means of several pattern recognition methods the variables that discriminate peach kernels arising from diverse germplasm and different stage of maturity were identified and successful models for further prediction were developed. Sugars such as ribose, trehalose, arabinose, galactitol, fructose, maltose, sorbitol, sucrose, iso-maltotriose were marked as most important for such discrimination.
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Carbohidratos/análisis , Prunus persica , Semillas/química , Cromatografía Líquida de Alta Presión , Manipulación de Alimentos , Fructosa/análisis , Frutas/química , Glucosa/análisis , Prunus persica/química , Prunus persica/clasificación , Prunus persica/crecimiento & desarrollo , Sacarosa/análisis , Edulcorantes , ResiduosRESUMEN
BACKGROUND: Nutrition recommendations in patients with type 2 diabetes mellitus (T2DM) are to consume rye or integral bread instead of white bread. A positive effect on glucoregulation has been achieved by enriching food with various biologically active substances of herbal origin, so we formulated an herbal mixture that can be used as a supplement for a special type of bread (STB) to achieve better effects on postprandial glucose and insulin levels in patients with T2DM. AIM: To compare organoleptic characteristics and effects of two types of bread on postprandial glucose and insulin levels in T2DM patients. METHODS: This trial included 97 patients with T2DM. A parallel group of 16 healthy subjects was also investigated. All participants were given 50 g of rye bread and the same amount of a STB with an herbal mixture on 2 consecutive days. Postprandial blood glucose and insulin levels were compared at the 30th, 60th, 90th and 120th min. A questionnaire was used for subjective estimation of the organoleptic and satiety features of the two types of bread. RESULTS: Compared to patients who consumed rye bread, significantly lower postprandial blood glucose and insulin concentrations were found in T2DM patients who consumed STB. No relevant differences were found among the healthy subjects. Subjectively estimated organoleptic and satiety characteristics are better for STB than for rye bread. CONCLUSION: STB have better effects than rye bread on postprandial glucoregulation in T2DM patients. Subjectively estimated organoleptic and satiety characteristics are better for STB than for rye bread. Therefore, STB can be recommended for nutrition in T2DM patients.
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Simulations of microphase separation are carried out using the dissipative particle dynamics (DPD). By varying the concentration and temperature of resin solutions we explore mesomorphologies supported by the all-atom models. We found that for a low degree of functionalization the homogeneously distributed ionomers self-assemble into spherical micelles at solid loads below 31 wt%, subject to the activation energy barrier for the gradual growth of pre-micellar aggregates. Computed optimum aggregation numbers exhibit sensitivity to both the temperature-dependent interfacial tension and the ionic content and compare well with the experimental observations.
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OBJECTIVES: The paper analyses the impact of socio-demographic characteristics of the employees in conditions of uncertainty in the organizations. MATERIAL AND METHODS: The study was conducted on a sample of 210 employees using the Mental Health Inventory - 38 (MHI-38), Satisfaction with life scale (SWLS), and the Center for Epidemiological Studies - Depression (CES-D). RESULTS: The results showed that female respondents had significantly higher scores on ANX (t = 2,278, p < 0.05), while male employees had higher scores on life satisfaction (t = 2.103, p < 0.05). Older employees have a higher tendency for loss of emotional-behavioral control (F = 4.427, p < 0.05). Respondents who have satisfying living standards have also higher scores on SWLS (t = 2.257, p < 0.05). Respondents who have dissatisfying living standard have higher scores on generally positive affect (t = 3.152, p < 0.01), life satisfaction (t = 3.571, p < 0.01), psychological distress (t = 2.929, p < 0.01) and loss of emotional- behavioral control (t = 2.361, p < 0.05). Employees with different levels of educational background have similar tendencies in life satisfaction, mental health, and depressive symptoms (p > 0.05). CONCLUSIONS: The study showed that the specific socio-demographic profile of the employees is related to higher levels of mental health issues. Specifically, the mental health of female and older employees have been especially affected and disturbed by uncertain conditions. The results can be potentially used both in the terms of designing activities that support the mental health of the population, as well as in relation to the mental health of employees. Int J Occup Med Environ Health. 2023;36(2):250-62.
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Salud Laboral , Humanos , Masculino , Femenino , Salud Mental , Depresión/epidemiología , Depresión/psicología , Factores Socioeconómicos , Demografía , Encuestas y CuestionariosRESUMEN
Background: Surgical stress and pain result in activation of hypothalamus-pituitary-adrenal axis. The aim of this study was to establish the effects of postoperative pain and various modalities of analgesic administration on salivary and serum cortisol levels, as well as to establish the validity of salivary cortisol as a stress indicator in surgical patients. Methods: A randomized controlled trial involved 60 patients scheduled for elective abdominal aortic aneurysm surgery. Patients were randomly divided into two groups depending on the model of postoperative analgesia. The first group (MI - morphine intermittently) included patients given morphine doses 0.1 mg/kg/6h s.c. intermittently. The second group (MPCA - morphine patient-controlled analgesia) included patients who received morphine via the PCA system - intravenous administration of morphine adjusted to a dose of 1 mg per shot and a lockout interval of 6 minutes.
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We present a systematic analysis of a large number of mass spectra accumulated as the number of ion fragments recorded in unit mass-to-charge detector channels. The method retrieves the abundances of detected species using an efficient deconvolution algorithm, which relies on fragment pattern recognition, mass calibration, and background correction. The abundance analysis identifies target species, amino acids, and mycotoxins through their characteristic fragmentation patterns in the presence of an increasing number of interfering species. The method offered robust and efficient retrieval of abundances of metabolic molecules in complex mixtures obscured by a wide range of toxic compounds.
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Wild grapevine (Vitis vinifera subsp. sylvestris Gmel Hegi) is dioecious with male and female plants, whereas domesticated grapevine is mostly hermaphrodite with self-fertile hermaphrodite flowers. The pollen morphology of wild grapevine has been poorly studied. There is no detailed palynological study of V. sylvestris in Croatia and neighboring countries. Here, scanning electron microscopy (SEM) was used to analyze the pollen of V. sylvestris from male and female individuals growing at two natural sites in Croatia. The selective APT3 marker was used to confirm the flower phenotype with the genetic background. SEM analysis showed that the pollen grains of V. sylvestris were isopolar and radially symmetrical, with foveolate perforated ornamentation, regardless of the flower type of the individuals. All male flowers were 3-colporate and prolate in shape, whereas female individuals varied from subprolate to spheroidal and had inaperturate pollen grains. Pollen shape, dimensions and exine ornamentation proved very informative, and here we address the most polymorphic traits in the analyzed V. sylvestris individuals. Principal component analysis (PCA) and clustering based on pollen morphology variables clearly differentiated individuals by their flower type, and no grouping specific to population was observed, pointing to the conserved pollen structure of V. sylvestris. The results indicate the need to continue the palynological study of V. sylvestris and serve as a good phenotypic basis for functional genetic studies on genes involved in pollen morphology and function.
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The study aimed to test the hypothesis that homeostatic microbiome (HM) disorders lead to the increased indirect influence of certain microorganisms (MO) in the gastrointestinal tract, causing a disorder of insulin secretion, insulin resistance, and diabetes. We highlighted Candida and certain types of bacteria since previous in vitro research showed they significantly affect insulin secretion and can cause insulin resistance in obese patients with metabolic syndrome. After determining the type of MO present in the throat swab and the stool, the oral glucose tolerance test (OGTT) test, and analysis of glucose and insulin secretion were performed in patients (n = 38) who were positive for certain types of MO compared to negative patients. Finally, all patients were divided into two groups: overweight patients (body mass index [BMI] < 30) and obese patients (BMI > 30). These two groups were compared for the percentage of certain types of MO to determine which MO can affect an increase in obesity and BMI. The presence of Diphtheroids in the throat (60.5%) reduces insulin secretion in patients compared with the negative group (194.5: 332.4) and the difference was statistically significant (P = .030). The presence of Candida in the throat (10%) increases insulin secretion, but the difference was statistically insignificant. The presence of Candida in the stool (28.9%) also increases insulin secretion and the difference was statistically significant (P = .038). Cumulative results (throat + stool) were similar (180: 332, P = .022). Analysis of BMI showed that the percentage of Diphtheroids in the throat decreases with increased body weight (53.8: 75%) while the percentage of Candida (38.5: 8.3%) and Enterobacter (61.5: 25%) increases, but these differences were statistically insignificant (P > .05). Diphtheroids in the throat can reduce insulin secretion by synthesizing their metabolites. Candida albicans is a conditional pathogen and as a significant indirect factor induces increased insulin secretion and insulin resistance. There are indications that elevated levels of Candida in the intestinal system can cause increased body weight of patients. C albicans should be considered a new factor in the pathogenesis of diabetes.
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Diabetes Mellitus , Resistencia a la Insulina , Microbiota , Humanos , Secreción de Insulina , Estudios Transversales , Candida albicans , Insulina/metabolismo , Obesidad/patología , Aumento de Peso , CandidaRESUMEN
Acute pelvic pain (APP) requires urgent medical evaluation and treatment. Differential diagnosis of APP is broad, including a variety of gynecologic and non-gynecologic/ urinary, gastrointestinal, vascular and other entities. Close anatomical and physiological relations of pelvic structures, together with similar clinical presentation of different disorders and overlapping of symptoms, especially in the emergency background, make the proper diagnosis of APP challenging. Imaging plays a crucial role in the fast and precise diagnosis of APP. Ultrasonography is the first-line imaging modality, often accompanied by CT, while MRI is utilized in specific cases, using short, tailored protocols. Recognizing the cause of APP in females is a challenging task, due to the wide spectrum of possible origin and overlap of their imaging features. Therefore, the radiologist has to be familiar with the possible causes of APP, and, relying on clinical presentation, together with laboratory findings, choose the best imaging strategy in order to establish a fast and accurate diagnosis.
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Diagnóstico por Imagen/métodos , Enfermedades Gastrointestinales/complicaciones , Enfermedades de los Genitales Femeninos/complicaciones , Dolor Pélvico/etiología , Enfermedades Urológicas/complicaciones , Enfermedades Vasculares/complicaciones , Dolor Agudo/etiología , Femenino , Enfermedades Gastrointestinales/diagnóstico por imagen , Enfermedades de los Genitales Femeninos/diagnóstico por imagen , Humanos , Masculino , Enfermedades Urológicas/diagnóstico por imagen , Enfermedades Vasculares/diagnóstico por imagenRESUMEN
The Enceladus plume is a target of astrobiological interest in planetary science since it may carry signs of extraterrestrial life entrapped in ice grains formed from the subsurface ocean of this moon of Saturn. Fly-by mission concepts have been proposed to perform close investigations of the plume, including detailed in situ measurements of chemical composition with a new generation of mass spectrometer instrumentation. Such a scenario involves high-velocity collisions (typically around 5 km/s or higher) of the instrument with the encountered ice grains. Postimpact processes may include molecular fragmentation, impact ionization, and various subsequent chemical reactions that could alter the original material prior to analysis. In order to simulate Enceladus plume fly through conditions, we are developing an ice grain accelerator and have coupled it to the quadrupole ion trap mass spectrometer (QITMS) developed for flight applications. Our experimental setup enables the creation and acceleration of ice particles with well-defined size, charge, and velocity, which are subsequently directed into the QITMS, where they impact the surface of the mass analyzer and the analysis of postimpact, volatilized molecules takes place. In this work, we performed mass spectral analysis of ice grains of ca. 1.3 µm in diameter, accelerated and impacted at velocities up to 1000 m/s, with an upgrade of the accelerator in progress that will enable velocities up to 5000 m/s. We report the first observations of ice grain impacts measured by the QITMS, which were recorded as brief increases in the abundance of water molecules detected within the instrument.
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A lightweight, low-power instrument package to measure, in situ, both (1) the local gaseous environment and (2) the composition and microphysical properties of attendant venusian aerosols is presented. This Aerosol-Sampling Instrument Package (ASIP) would be used to explore cloud chemical and possibly biotic processes on future aerial missions such as multiweek balloon missions and on short-duration (<1 h) probes on Venus and potentially on other cloudy worlds such as Titan, the Ice Giants, and Saturn. A quadrupole ion-trap mass spectrometer (QITMS; Madzunkov and Nikolic, J Am Soc Mass Spectrom 25:1841-1852, 2014) fed alternately by (1) an aerosol separator that injects only aerosols into a vaporizer and mass spectrometer and (2) the pure aerosol-filtered atmosphere, achieves the compositional measurements. Aerosols vaporized <600°C are measured over atomic mass ranges from 2 to 300 AMU at <0.02 AMU resolution, sufficient to measure trace materials, their isotopic ratios, and potential biogenic materials embedded within H2SO4 aerosols, to better than 20% in <300 s for H2SO4 -relative abundances of 2 × 10-9. An integrated lightweight, compact nephelometer/particle-counter determines the number density and particle sizes of the sampled aerosols.
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Saturno , Venus , Aerosoles , Atmósfera/análisis , Gases/análisisRESUMEN
BACKGROUNDS/AIMS: The aim of this study was to compare efficacy of two enzymes, Liberase HI and Collagenase XI in human adult pancreatic islet isolation. METHODOLOGY: Pancreatic tissue samples were digested either with Liberase HI or Collagenase XI, using a non-automated method. We investigated the effect of both enzymes on yield, function and percent viability of the islets. RESULTS: No significant differences were found regarding islet yield when comparing Liberase HI to Collagenase XI. Viability of Collagenase-isolated islets was initially lower, but following 3 days of culture they attained a higher viability than the Liberase treated islets. Although the stimulation index tended to be higher in the Liberase-isolated islets no significant differences were observed between the two enzymes, except on the first day of cultivation; SI values for all Liberase concentrations were significantly higher than for Collagenase (p < 0.05). CONCLUSIONS: We conclude that during the isolation procedure using Collagenase XI, the functional capacity of the isolated islets decline, but this is restored during a subsequent cultivation. On the other hand, during digestion with Liberase HI, the islets suffer less functional damage, resulting in better preservation of their functional capacity immediately after the isolation, as well as the subsequent 7 days of cultivation.
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Separación Celular/métodos , Colagenasas/metabolismo , Islotes Pancreáticos/citología , Islotes Pancreáticos/enzimología , Termolisina/metabolismo , Adulto , Técnicas de Cultivo , Humanos , Estadísticas no ParamétricasRESUMEN
A new technique that has applications for the detection of nonvolatile organics on Ocean Worlds has been developed. Here, liquid mixtures of fatty acids (FAs) and/or amino acids (AAs) are introduced directly into a miniature quadrupole ion trap mass spectrometer (QITMS) developed at Jet Propulsion Laboratory and analyzed. Two ionization methods, electron impact and chemical ionization (EI and CI, respectively), are compared and contrasted. Further, multiple CI reagents are tested to explore their potential to "soften" ionization of FAs and AAs. Both EI and CI yield mass spectra that bear signatures of FAs or AAs; however, soft CI yields significantly cleaner mass spectra that are easier to interpret. The combination of soft CI with tandem mass spectrometry (MS/MS) has also been demonstrated for AAs, generating "fingerprint" mass spectra of fragments from protonated parent ions. To mimic potential Ocean World conditions, water is used as the primary collision gas in MS/MS experiments. This technique has the potential for the in situ analysis of molecules in the cryogenic plumes of Ocean Worlds (e.g., Enceladus) and comets with the ultimate goal of detecting potential biosignatures.
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Cromatografía de Gases y Espectrometría de Masas/métodos , Océanos y Mares , Compuestos Orgánicos/análisis , Presión , Protones , VolatilizaciónRESUMEN
Numerical solutions of equation-based simulations require computationally intensive tasks such as evaluation of model equations, linear algebra operations and solution of systems of linear equations. The focus in this work is on parallel evaluation of model equations on shared memory systems such as general purpose processors (multi-core CPUs and manycore devices), streaming processors (Graphics Processing Units and Field Programmable Gate Arrays) and heterogeneous systems. The current approaches for evaluation of model equations are reviewed and their capabilities and shortcomings analysed. Since stream computing differs from traditional computing in that the system processes a sequential stream of elements, equations must be transformed into a data structure suitable for both types. The postfix notation expression stacks are recognised as a platform and programming language independent method to describe, store in computer memory and evaluate general systems of differential and algebraic equations of any size. Each mathematical operation and its operands are described by a specially designed data structure, and every equation is transformed into an array of these structures (a Compute Stack). Compute Stacks are evaluated by a stack machine using a Last In First Out queue. The stack machine is implemented in the DAE Tools modelling software in the C99 language using two Application Programming Interface (APIs)/frameworks for parallelism. The Open Multi-Processing (OpenMP) API is used for parallelisation on general purpose processors, and the Open Computing Language (OpenCL) framework is used for parallelisation on streaming processors and heterogeneous systems. The performance of the sequential Compute Stack approach is compared to the direct C++ implementation and to the previous approach that uses evaluation trees. The new approach is 45% slower than the C++ implementation and more than five times faster than the previous one. The OpenMP and OpenCL implementations are tested on three medium-scale models using a multi-core CPU, a discrete GPU, an integrated GPU and heterogeneous computing setups. Execution times are compared and analysed and the advantages of the OpenCL implementation running on a discrete GPU and heterogeneous systems are discussed. It is found that the evaluation of model equations using the parallel OpenCL implementation running on a discrete GPU is up to twelve times faster than the sequential version while the overall simulation speed-up gained is more than three times.
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This study identifies dynamical properties of maltose-binding protein (MBP) useful in unveiling active site residues susceptible to ligand binding. The described methodology has been previously used in support of novel topological techniques of persistent homology and statistical inference in complex, multi-scale, high-dimensional data often encountered in computational biophysics. Here we outline a computational protocol that is based on the anisotropic elastic network models of 14 all-atom three-dimensional protein structures. We introduce the notion of dynamical distance matrices as a measure of correlated interactions among 370 amino acid residues that constitute a single protein. The dynamical distance matrices serve as an input for a persistent homology suite of codes to further distinguish a small subset of residues with high affinity for ligand binding and allosteric activity. In addition, we show that ligand-free closed MBP structures require lower deformation energies than open MBP structures, which may be used in categorization of time-evolving molecular dynamics structures. Analysis of the most probable allosteric coupling pathways between active site residues and the protein exterior is also presented.
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Proteínas Portadoras/química , Proteínas de Unión a Maltosa/química , Modelos Moleculares , Sitios de Unión , Proteínas Portadoras/genética , Dominio Catalítico/genética , Biología Computacional , Ligandos , Maltosa/química , Proteínas de Unión a Maltosa/genética , Simulación de Dinámica Molecular , Unión Proteica/genética , Conformación ProteicaRESUMEN
INTRODUCTION: The rupture of infrarenal abdominal aortic aneurysm is a surgical emergency condition with a high rate of mortality before the patients arrive at hospital. The signs and symptoms of abdominal aortic aneurysm rupture into the retroperitoneal cavity are pulsatile mass, abdominal pain, hypotension and shock, but sometimes silent symptoms also hide a dangerous and life threatening condition, such as chronic aneurysm rupture of abdominal aorta into the retroperitoneal cavity. CASE REPORT: We present a patient having had the lower back pain for 4 months, which had been recognized and treated as lumbar ischialgia but which was eventually diagnosed to be chronic infrarenal abdominal aortic aneurysm rupture by computed tomography angiography. The surgical intervention was successful and the patient was discharged from hospital after 6 days without any clinical complications. Preoperative imaging by computed tomography angiography of ruptured abdominal aortic aneurysm is highly sensitive for detection of several specific signs for rupture. This condition leads to urgent vascular surgery.