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El objetivo de esta tesis es investigar, en la población general adulta sin aparente enfermedad inflamatoria, la influencia de factores comunes en los marcadores de inflamación como VSG, PCR, IL-6 y sIL2-r séricas así como la la discordancia entre la VSG y la PCR séricas. Para ello realizamos un estudio observacional, transversal, de 1499 sujetos seleccionados aleatoriamente. Encontramos que la edad se asocia con un incremento de la VSG y de la IL-6, mientras que el efecto de la edad en la PCR es menor. El sexo se asocia de forma no uniforme con diferentes niveles de marcadores de inflamación: el sexo femenino se asocia con mayores niveles de VSG, el sexo masculino se asocia con mayores niveles de IL-6 y no se demuestra efecto independiente del sexo en los niveles de PCR. El consumo regular de alcohol ligero o moderado se asocia con unos menores niveles de VSG, PCR e IL-6, en comparación con los bebedores ocasionales y abstemios. El tabaquismo activo se asocia con unos mayores niveles de VSG, PCR e IL-6. El ejercicio físico regular moderado y alto se asocia con unos menores niveles de VSG. La obesidad y los trastornos metabólicos con ella relacionados se asocian con unos mayores niveles de VSG, de IL-6 y de PCR, de la que es el principal determinante. El aumento de PCR con VSG normal se asocia con un mayor IMC, mientras que el aumento de VSG con cifras normales de PCR se asocia con la edad. En lo que respecta a la sIL-2R, sus niveles séricos aumentan con la edad, son mayores en varones, fumadores y sujetos con obesidad, al igual que son menores en bebedores ligeros.

Virtual synchronous generators (VSGs) with inertia characteristics are generally adopted for the control of distributed generators (DGs) in order to mimic a synchronous generator. However, since the amount of virtual inertia in VSG control is usually constant and given by trial and error, the real power and frequency oscillations of a battery energy storage system (BESS) occurring under load variation result in the degradation of the control performance of the DG. Thus, in this study, a novel virtual inertia estimation methodology is proposed to estimate suitable values of virtual inertia for VSGs and to suppress the real power output and frequency oscillations of the DG under load variation. In addition, to improve the function of the proposed virtual inertia estimator and the transient responses of the real power output and frequency of the DG, an online-trained Petri probabilistic wavelet fuzzy neural network (PPWFNN) controller is proposed to replace the proportional integral (PI) controller. The network structure and the online learning algorithm using backpropagation (BP) of the proposed PPWFNN are represented in detail. Finally, on the basis of the experimental results, it can be concluded that superior performance in terms of real power output and frequency response under load variation can be achieved by using the proposed virtual inertia estimator and the intelligent PPWFNN controller.

African trypanosomes are bloodstream protozoan parasites that infect mammals including humans, where they cause sleeping sickness. Long-lasting infection is required to favor parasite transmission between hosts. Therefore, trypanosomes have developed strategies to continuously escape innate and adaptive responses of the immune system, while also preventing premature death of the host. The pathology linked to infection mainly results from inflammation and includes anemia and brain dysfunction in addition to loss of specificity and memory of the antibody response. The serum of humans contains an efficient trypanolytic factor, the membrane pore-forming protein apolipoprotein L1 (APOL1). In the two human-infective trypanosomes, specific parasite resistance factors inhibit APOL1 activity. In turn, many African individuals express APOL1 variants that counteract these resistance factors, enabling them to avoid sleeping sickness. However, these variants are associated with chronic kidney disease, particularly in the context of virus-induced inflammation such as coronavirus disease 2019. Vaccination perspectives are discussed. Expected final online publication date for the

Electrical energy storage (EES) with a virtual synchronous generator (VSG) method is used widely for power fluctuation compensation in renewable energy microgrid systems. In the traditional VSG method, the inertia moment and damping coefficients usually remain constant. When dealing with large load variations, this method may cause obvious system frequency deviations and exceed the standard limit (e.g., IEEE Std 1547-2018). This paper proposes a novel control method combining fuzzy control with a model predictive controller (MPC) to solve this problem. The new method was applied to VSG. The virtual inertia and damping coefficient of VSG are on-line adjusted by a fuzzy controller, so that the regulation capability of the swing equation can be substantially utilized. The optimal rated power of VSG was modified using the MPC method, which further strengthens the EES support for power needs. The system frequency performance can be enhanced effectively under joint control. The simulation and experimental results further demonstrated the effectiveness of the proposed method.

For the pre-synchronization method of the virtual synchronous generator (VSG), only the case of a single VSG pre-synchronization and grid connection has been studied and analyzed. If the phase synchronization of multiparallel VSGs in a decentralized microgrid is realized by controlling a VSG, power circulation exists in the pre-synchronization process. Firstly, the structure and control mode of the microgrid are introduced. For the decentralized structure, a control mode switching mechanism under distributed communication is designed, and a pre-synchronization method of parallel VSGs based on control mode switching is proposed. Secondly, a theoretical analysis of the active power circulation problem is performed by an equivalent frequency model for parallel VSGs in the pre-synchronization process. Finally, the simulation results show that the proposed pre-synchronization method can reduce the dynamic power circulation of parallel VSGs by 83%, and improve the pre-synchronization speed by 75%.

In recent years, virtual synchronous generator (VSG) control algorithm has been widely studied in distributed grid-connected power inverters to deal with active and reactive power adjustment by simulating the operation principle of the actual synchronous generator. Nevertheless, once the current sensor fails, the grid-connected power inverter will lose its stability. To enhance the fault-tolerant operation ability of the grid-connected power inverter, a new inverter side current sensor-less model predictive control method based on sliding mode observer (SMO) is proposed. The stability of the SMO is analyzed by using the Lyapunov stability criterion. The gains of the SMO are then designed by analyzing their influences on the current and voltage observation based on the closed-loop transfer functions. Besides, to show the influences of the capacitance changes on the current observation, a detailed parameter sensitivity analysis is also carried out. Then, by using the estimated inductance current from the SMO, a current sensor-less model predictive control method is finally proposed. The main novelty of the proposed method is that both the output voltage of the inverter and the inverter side inductance are not required in the proposed SMO. So, the accuracy of current sensor-less control is improved. To verify the effectiveness of the proposed method, detailed experimental studies are carried out based on a Typhoon and PE-Expert 4 based experimental platform.

African trypanosomes are early divergent protozoan parasites responsible for high mortality and morbidity as well as a great economic burden among the world's poorest populations. Trypanosomes undergo antigenic variation in their mammalian hosts, a highly sophisticated immune evasion mechanism. Their nuclear organization and mechanisms for gene expression control present several conventional features but also a number of striking differences to the mammalian counterparts. Some of these unorthodox characteristics, such as lack of controlled transcription initiation or enhancer sequences, render their monogenic antigen transcription, which is critical for successful antigenic variation, even more enigmatic. Recent technological developments have advanced our understanding of nuclear organization and gene expression control in trypanosomes, opening novel research avenues. This review is focused on Trypanosoma brucei nuclear organization and how it impacts gene expression, with an emphasis on antigen expression. It highlights several dedicated sub-nuclear bodies that compartmentalize specific functions, whilst outlining similarities and differences to more complex eukaryotes. Notably, understanding the mechanisms underpinning antigen as well as general gene expression control is of great importance, as it might help designing effective control strategies against these organisms.

This paper researched on the pre-synchronization grid connection method of a virtual synchronous generator (VSG), and proposed a fast pre-synchronization method based on the virtual power loop. According to the self-synchronization characteristics of the VSG power loop, the double power loop design was adopted in this paper. The two power loops had the same structure, which the power loop 1 was used to implement the basic VSG function, and the power loop 2 was used to achieve rapid pre-synchronous control. Therefore, the mathematical model of the VSG was similar to the synchronous generator in the pre-synchronization control. This method did not require a phase-locked loop and VSG has a good inertia and Damping performance. Moreover, this method was suitable for the networking of multiple VSGs.

The single-cell parasite Trypanosoma brucei causes the fatal disease human African trypanosomiasis and is able to colonize the blood, fat, skin, and central nervous system. Trypanosomes survive in the mammalian host owing to a dense protective protein coat that consists of a single-variant surface glycoprotein species.

The Trypanosoma (T) brucei life cycle alternates between the tsetse fly vector and the mammalian host. In the insect, T. brucei undergoes several developmental stages until it reaches the salivary gland and differentiates into the metacyclic form, which is capable of infecting the next mammalian host. Mammalian infectivity is dependent on expression of the metacyclic variant surface glycoprotein genes as the cells develop into mature metacyclics. The VEX complex is essential for monoallelic variant surface glycoprotein expression in T. brucei bloodstream form, however, initiation of expression of the surface proteins genes during metacyclic differentiation is poorly understood. To better understand the transition to mature metacyclics and the control of metacyclic variant surface glycoprotein expression we examined the role of VEX1 in this process. We show that modulating VEX1 expression leads to a dysregulation of variant surface glycoprotein expression during metacyclogenesis, and that following both in vivo and in vitro metacyclic differentiation VEX1 relocalises from multiple nuclear foci in procyclic cells to one to two distinct nuclear foci in metacyclic cells - a pattern like the one seen in mammalian infective bloodstream forms. Our data suggest a role for VEX1 in the metacyclic differentiation process and their capacity to become infectious to the mammalian host.

In older centralized power systems, power is often generated by massive synchronous generators (SGs), with the grid frequency defined by the prime mover's rotational frequency. The rotor inertia attribute prevents the frequency from shifting and keeps the system stable if the load changes quickly. During transient times, the rotor kinetic energy is delivered into the grid to balance power supply between generating and load. Because of the recent high penetration of renewable energy sources, the power grid is undergoing structural changes because of more inverter-based distributed generation (RES). Because inverter-based power sources lack the inertia of classic synchronous machines (SM), a high level of inverter penetration in the grid could generate grid instability and significant voltage variations. This paper looks at themathematical modeling and control of VSGs to replicate the inertia and damping properties of SMs. &nbsp

In islanded ac microgrids, conventional primary control uses innerloop cascaded linear controller and outerloop droop to realize local voltage regulation and power sharing. However, it has a poor dynamic performance and fast rate of frequency change following disturbances. This paper addresses these issues by proposing a modified virtual synchronous generator (VSG) control. A Laguerre functionsbased discretetime model predictive control (LFDMPC) with a multiobjective cost function is incorporated as the inner loop; yielding large prediction horizon, improved dynamic response, and inherent overcurrent protection in the case of faults. The swingbased and the reactive power droop controllers also form the outer loop aimed at inertia emulation and power sharing. The merits of proposed approach are verified by comparisons with conventional droop and VSG controls. Detailed model simulations are conducted on a 2converter ac microgrid in MATLABSimulink to show the efficacy of the proposed controller.

Glas ist ein Material, dass die Menschen seit Jahrhunderten mit seiner Schönheit und Eleganz fasziniert. Mit seiner Transparenz bereichert es den Innenraum, verleiht ihm Licht und Wärme und schafft eine Verbindung zwischen der Außenumgebung und dem Interieur. Heutzutage spielt Glas in der modernen Architektur nicht nur eine ästhetische Rolle, sondern auch eine konstruktive, daher werden Glasträger, Glaswände oder Glassäulen oft als primäre und sekundäre tragende Elemente verwendet.Im Lauf des Studiums wird wenig über diesen interessanten Baustoff unterrichtet. Während Beton-, Stahl- und Holzkonstruktionen meist im Detail behandelt werden, tritt Glas zu Unrecht in den Hintergrund. Aus diesem Grund wurde diese Masterarbeit verfasst, die einen jungen Bauingenieur oder Architekt in die Welt des Glases einführen und ihm einen Einblick in dessen Grundlagen und die Möglichkeiten seines Einsatzes geben soll. Das einleitende Kapitel befasst sich mit den grundlegenden Eigenschaften von Glas, seinen chemischen und physikalischen Eigenschaften, seiner Herkunft und Geschichte. Das nächste Kapitel befasst sich mit den Grundtypen von Glasscheiben, die in der Bauindustrie verwendet werden. Das Grundprodukt Floatglas und andere Isolier- und Sicherheitsgläser wie ESG oder VSG, welches durch das Laminieren von Glasschichten gewonnen wird, werden näher beschrieben.Der Hauptkapitel befasst sich mit konstruktiven Elementen aus Glas und deren Einsatzgebieten in Architektur und Bauwesen. Elemente wie Glasträger, Glassäulen oder Glaswände werden näher erläutert, ebenso deren Anwendungsbereiche, Lagerungsarten, typische Querschnitte usw.Besonderes Augenmerk werde auf das Thema kaltgebogene Glasscheiben gelegt, die zunehmend für die Herstellung gebogener Glasfassaden und -paneele eingesetzt werden. Im Gegensatz zu klassischen heißgebogenen Glasscheiben haben kaltgeformte Scheiben deutlich bessere ästhetische und optische Eigenschaften, sind deutlich günstiger und wirtschaftlicher, da für ihre Gewinnung keine energieintensiv hohen Temperaturen eingesetzt werden müssen. Relativ wenig bekannte Instabilitätsphänomene des kaltgebogenen Glases, die durch übermäßiges Biegen auftreten können, werden ebenfalls behandelt, und es werden Richtlinien gegeben, um deren Auftreten zu verhindern., Glass is a material that has fascinated people with its beauty and elegance for centuries. With its transparency, it enriches the interior, giving it light and warmth, creating a link between the outside environment and the interior. Today in modern architecture glass plays not only an aesthetic role, but also a constructive one, so glass beams, glass walls or glass columns are often used as primary and secondary load-bearing elements.Little is taught about this interesting building material during the course of study. While concrete, steel and wood constructions are usually processed in detail, glass, wrongly, takes a back seat. For this reason, this master's thesis was written, to introduce a young civil engineer or an architect to the world of glass and give an insight into its basics and the possibilities of its use. The introductory chapter deals with the basic properties of glass, its chemical and physical properties, its origin and history. The next chapter deals with the basic types of glass panes used in the construction industry. The basic product float glass and other insulating and safety glass such as ESG or VSG, which is obtained by laminating glass layers, are described in more detail.The main chapter deals with structural elements made of glass and their implementation in architecture and construction. Elements such as glass beams, glass columns or glass walls are explained in more detail, as well their areas of application, types of support, typical cross-sections, etc.Particular attention was paid to the topic of cold-bent glass panels, which are increasingly used to produce curved glass facades and panels. In contrast to classic hot-bent glass panels, cold-formed panels have significantly better aesthetic and optical properties, are significantly cheaper and more economical, since no energy-intensive high temperatures need be used for their production. Relatively little-known instability phenomena of cold-bent glass, which can occur from excessive bending, are also addressed and guidelines are provided to prevent their occurrence.

[Resumen] La obesidad es una patología multifactorial definida como una acumulación anormal de tejido adiposo en el cuerpo, que incrementa el riesgo de padecer patologías secundarias y cuya prevalencia está en aumento. Entre los tratamientos de la obesidad están los cambios en el estilo de vida (de difícil cumplimiento), fármacos (de escasa eficacia) y la cirugía bariátrica (CB), siendo esta el tratamiento más efectivo. La CB permite cambios metabólicos y fisiológicos que conducen a la pérdida de peso y, en muchos casos, a la remisión de las patologías secundarias asociadas. Entre los factores que se han sugerido que contribuyen al éxito de la CB están los cambios en el patrón y concentración de ácidos biliares (ABs). Sin embargo, cómo cambia lo concentración de ABs con la obesidad y a lo largo del tiempo tras la CB es un tema escasamente estudiado, especialmente con perspectiva de género. En este trabajo demostramos que la concentración total de ABs circulantes son mayores en varones normopeso con respecto a mujeres, y que su concentración disminuye con la obesidad mórbida en ambos sexos desapareciendo el dimorfismo sexual. Tras la CB los niveles de ABs circulantes aumentan significativamente al cabo de tres meses. Doce meses después de la CB la concentración de ABs es superior en los pacientes operados con baipás gástrico en Y de Roux (RYGB) con respecto a los pacientes operados con gastrectomía vertical en manga (VSG) y no hay asociaciones claras con los parámetros antropométricos y bioquímicos analizados, lo que conlleva a la necesidad de profundizar el tema en el futuro. [Resumo] A obesidade é unha patoloxía multifactorial definida como unha acumulación anormal de tecido adiposo no corpo, que incrementa o risco de padecer patoloxías secundarias e cuxa prevalencia está en aumento. Entre os tratamentos da obesidade están os cambios no estilo de vida (de difícil cumprimento), fármacos (de escasa eficacia) e a cirurxía bariátrica (CB), sendo esta o tratamento máis efectivo. A CB permite cambios metabólicos e fisiolóxicos que conducen á perda de peso e, en moitos casos, á remisión das patoloxías secundarias asociadas. Entre os factores que se suxeriron que contribúen ao éxito da CB están os cambios no patrón e concentración de ácidos biliares (ABs). Con todo, como cambia o concentración de ABs coa obesidade e ao longo do tempo tras a CB é un tema escasamente estudado, especialmente con perspectiva de xénero. Neste traballo demostramos que a concentración total de ABs circulantes son maiores en homes normopeso con respecto a mulleres, e que a súa concentración diminúe coa obesidade mórbida en ambos os sexos desaparecendo o dimorfismo sexual. Tras a CB os niveis de ABs circulantes aumentan significativamente ao cabo de tres meses. Doce meses despois da CB a concentración de ABs é superior nos pacientes operados con baipás gástrico en Y de Roux (RYGB) con respecto aos pacientes operados con gastrectomía vertical en manga (VSG) e non hai asociacións claras cos parámetros antropométricos e bioquímicos analizados, o que leva á necesidade de afondar o tema no futuro. [Abstract] Obesity is a multifactorial pathology defined as an abnormal accumulation of adipose tissue in the body, which increases the risk of secondary pathologies and whose prevalence is rising. Among the treatments of obesity there are lifestyle changes (difficult to comply), medicines (of little efficacy) and bariatric surgery (BC), this being the most effective treatment. BC allows metabolic and physiological changes that lead to weight loss and, in many cases, remission of associated secondary pathologies. Among the factors that have been suggested to contribute to the success of CB there are changes in the pattern and concentration of bile acids (BAs). However, how the concentration of BAs changes and evolves with obesity and after BC is little studied, especially depending on gender. In this work we show that the total concentration of circulating BAs is higher in normal weighted men with respect to women, and that this concentration decreases with morbid obesity in both sexes, disappearing sexual dimorphism. After BC, circulating BAs levels increase significantly after three months. Twelve months after BC the concentration of BAs is higher in patients operated with Roux's Y gastric bypass (RYGB) compared to patients operated with vertical sleeve gastrectomy (VSG) and there are no clear associations with the nthropometric and biochemical parameters analysed, which leads to the need to study in more detail the topic in the future. Traballo fin de mestrado (UDC.CIE). Bioloxía molecular, celular e xenética. Curso 2021/2022

This paper proposes an inductor current sensorless control strategy based on modified virtual synchronous generator (VSG) method for single-phase inverter-interfaced microgrid application. Firstly, the outer power loop with Q-U integral term is presented for output reactive power enhancement, and an inner voltage regulation loop based on luenberger state observer is proposed to reduce the inductor current sensor. Meanwhile, in order to improve the response speed of the observer, the luenberger observer is designed based on the optimal pole assignment method. Secondly, a seamless switching strategy based on the modified VSG method is proposed, which can realize the seamless transition between the island mode and grid-connected mode. Finally, a single-phase 3kW VSG prototype is built, and the effectiveness and correctness of the proposed control strategy is verified by the simulation and experimental results.

Obese patients are at risk of dental erosion due to micronutrient deficiency, consumption of soft drinks, gastric reflux disease and vomiting. The present study evaluates the presence of dental erosion in obese patients before and after bariatric surgery using the BEWE (basic erosive wear examination) scoring system. A total of 62 patients with severe obesity were included in the analysis, 31 in the control group (without bariatric surgery) and 31 in the surgery group (after bariatric surgery). BEWE scores did not vary between groups. Vitamin D deficiency was detected in 19 patients in the control group and three in the surgery group (p &lt, 0.001). The serum calcium and vitamin D values were significantly higher in the surgery group (p = 0.003, p &lt, 0.001 consecutively). All patients after bariatric surgery showed compliance with supplements, including vitamin D and calcium daily. Patients after bariatric surgery were less likely to drink soft drinks regularly (p = 0.026). Obese patients, before or after bariatric surgery, are at risk for erosive dental wear. However, with sufficient education prior to surgery and consistent intake of vitamin and mineral supplements, significant erosive dental wear after bariatric surgery could be avoided. Regular dental examination should be included in the check-up and follow-up program.

ObjectiveTo determine whether vertical sleeve gastrectomy (VSG) attenuates fibrosis in mice on a high-fat high-cholesterol (HFHC) diet.BackgroundBariatric surgery mitigates non-alcoholic steatohepatitis in 85-90% of obese patients. While animal models demonstrate similar results on a high-fat diet, none have observed the effects of bariatric surgery on a combined HFHC diet.MethodsMice on a HFHC diet were used to confirm the development of hepatic fibrosis at 8 (n = 15) and 24 (n = 15) weeks. A separate cohort of mice on a HFHC diet for 12weeks was subjected to either VSG (n = 18) or sham (n = 12) operations and remained on a HFHC diet for an additional 20weeks. Changes in weight, dyslipidemia, and the development of steatosis and fibrosis were documented. Serum was obtained for bile acid analysis by liquid chromatography and mass spectrometry, while hepatic gene expression by RT-PCR was performed to evaluate intrahepatic lipid metabolism.ResultsHepatic steatosis and fibrosis developed after 8weeks on the HFHC diet. After VSG, mice demonstrated a sustained decrease in weight with a significant decrease in fibrosis compared to sham mice. Serum total cholesterol, HDL, and LDL were significantly reduced following surgery, while serum bile acids were significantly elevated. Intra-hepatic cholesterol excretion was not upregulated based on hepatic gene expression of CYP7A1 and ABCG5/8.ConclusionsVSG attenuates the development of hepatic fibrosis in diet-induced obese mice, presumably through enhancement of cholesterol elimination at the intestinal level.

Trypanosoma brucei is the causative agent of human sleeping sickness. The parasites’ variant surface glycoprotein (VSG) enables them to evade adaptive immunity via antigenic variation. VSG comprises 10% of total cell protein and the high stability of VSG mRNA is essential for trypanosome survival. To determine how VSG mRNA stability is maintained, we used mRNA affinity purification to identify all its associated proteins. CFB2 (cyclin F-box protein 2), an unconventional RNA-binding protein with an F-box domain, was specifically enriched with VSG mRNA. We demonstrate that CFB2 is essential for VSG mRNA stability, describe cis acting elements within the VSG 3'-untranslated region that regulate the interaction, identify trans-acting factors that are present in the VSG messenger ribonucleoprotein particle, and mechanistically explain how CFB2 stabilizes the mRNA of this key pathogenicity factor. Beyond T. brucei, the mRNP purification approach has the potential to supply detailed biological insight into metabolism of relatively abundant mRNAs in any eukaryote.

The inflammatory process involves several vascular changes controlled by inflammation mediators. Vascular changes are increased vasodilation, increased vascular permeability, decreased local blood flow. The inflammatory process also induces leukocyte mobilization and migration from its storage sites to the site of action. During the process there is an increase in hepatic metabolism that leads to increased levels of acute phase proteins: fibrinogen, C-reactive protein, among others. In this work, parameters in the blood count were measured, such as total plasma protein, fibrinogen and ESR to measure the degree of inflammation, the red series was evaluated taking into account the presence of anemia and its type and the white series classifying leukocytosis and why the appearance of each of them. To obtain these results, a complete blood count, total plasma protein and erythrocyte sedimentation rate were performed using the Westergren method. The main objective of this work is to measure the erythrocyte sedimentation rate, making a comparison between animals with high ESR and animals with ESR within the reference values, observing the recovery time and degree of inflammation of the patient. In the results, we were able to perceive simple changes in the ESR with animals with inflammatory processes, making that, in the near future, this parameter also be used as a complementary exam to assist in the diagnosis of diseases that involve the inflammatory process itself. It is concluded that the ESR is a valid test in inflammatory processes, even with its low specificity. El proceso inflamatorio implica varios cambios vasculares controlados por mediadores de la inflamación. Los cambios vasculares son aumento de la vasodilatación, aumento de la permeabilidad vascular, disminución del flujo sanguíneo local. El proceso inflamatorio también induce la movilización y migración de leucocitos desde sus sitios de almacenamiento al sitio de acción. Durante el proceso se produce un aumento del metabolismo hepático que conduce a niveles elevados de proteínas de fase aguda: fibrinógeno, proteína C reactiva, entre otras. En este trabajo se midieron parámetros en el hemograma, como proteína plasmática total, fibrinógeno y VSG para medir el grado de inflamación, se evaluó la serie roja teniendo en cuenta la presencia de anemia y su tipo y la serie blanca clasificando la leucocitosis y por qué la aparición de cada uno de ellos. Para obtener estos resultados, se realizó un hemograma completo, proteínas plasmáticas totales y velocidad de sedimentación globular mediante el método de Westergren. El objetivo principal de este trabajo es medir la velocidad de sedimentación globular, realizando una comparación entre animales con VSG alta y animales con VSG dentro de los valores de referencia, observando el tiempo de recuperación y grado de inflamación del paciente. En los resultados, pudimos percibir cambios simples en la VSG con animales con procesos inflamatorios, haciendo que, en un futuro próximo, este parámetro también sea utilizado como examen complementario para ayudar en el diagnóstico de enfermedades que involucran al propio proceso inflamatorio. Se concluye que la VSG es una prueba válida en procesos inflamatorios, aún con su baja especificidad. O processo inflamatório envolve várias mudanças vasculares controladas por mediadores da inflamação. Dentre elas, são aumento vasodilatação, aumento da permeabilidade vascular, diminuição do fluxo sanguíneo local. O processo inflamatório também induz a mobilização e a migração de leucócitos dos seus sítios de armazenamento para o local de ação. Durante o processo ocorre aumento do metabolismo hepático que leva a aumento dos níveis de proteínas de fase aguda: fibrinogênio, proteína C reativa, entre outros. Neste trabalho foram medidos parâmetros no hemograma como proteína plasmática total, fibrinogênio e VHS para mensurar o grau de inflamação, a série vermelha foi avaliada levando em consideração a presença de anemia e qual o seu tipo e a série branca classificando as leucocitoses e porque o surgimento de cada uma delas. Para chegar em tais resultados foi realizado hemograma, proteína plasmática total e a velocidade de hemossedimentação pelo método Westergren. O objetivo principal deste trabalho é mensurar a velocidade de hemossedimentação, fazendo uma comparação entre animais com VHS elevado e animais com VHS dentro dos valores de referência, observando o tempo de recuperação e grau de inflamação do paciente. Nos resultados, pudemos perceber singelas alterações no VHS com animais portadores de processos inflamatórios, fazendo que, num futuro próximo, este parâmetro também seja utilizado como exame complementar para auxiliar no diagnóstico de enfermidades que envolvem o processo inflamatório em si. Conclui-se que o VHS é um exame valido em processos inflamatórios, mesmo com sua baixa especificidade.

In this study, virtual excitation emulation (VEE) is proposed along with the virtual inertia emulation (VIE) for a virtual synchronous generator (VSG) in a standalone microgrid to improve the AC voltage and frequency profile through the control of power electronic DC–AC converter in the microgrid. The VIE emulates the inertia and damping characteristics of a synchronous generator by mimicking the swing equation. The VEE is proposed to emulate the behaviour of the field circuit and exciter system of a synchronous generator. In addition, a restoration control is also added with the inertia and excitation emulation to restore the magnitude and frequency of the output voltage at the rated value and achieve isochronous control. A linearised small-signal model of the VSG with the proposed control technique is also presented to analyse the system stability and design the control parameters. The standalone microgrid is simulated in MATLAB/Simulink environment to show the effectiveness of the proposed control technique. From the simulation results, it is reflected that the proposed control technique improves the voltage and frequency response during transient and steady-state including the frequency nadir of the microgrid.

In this research study, a multiterminal voltage source converter (VSC) medium voltage DC (MVDC) distribution network hierarchical control scheme is proposed for renewable energy (RE) integration in a co-simulation environment of MATLAB and PSCAD/EMTDC. A DC optimal power flow (DC OPF) secondary controller is created in MATLAB. In PSCAD/EMTDC, the main circuit containing the adaptive DC voltage droop with a dead band and virtual synchronous generator (VSG) based primary controller for the VSCs is implemented. The simulation of the MVDC network under the proposed hierarchical control scheme is investigated considering variations in wind and solar photovoltaic (PV) power. The network is also connected to the standard IEEE-39 bus system and the hierarchical scheme tested by assessing the effect of tripping as well as restoration of the REs. The results show that during random variations in active power such as increasing wind and PV power generation, a sudden reduction or tripping of wind and PV power, the primary controller ensures accurate active power sharing amongst the droop-based VSCs as well as regulates DC voltage deviations within the set range of 0.98–1.02 pu with an enhanced dynamic response. The DC OPF secondary control optimizes the system’s losses by 38% regularly giving optimal droop settings to the primary controllers to ensure proper active power balance and DC voltage stability. This study demonstrates that the hierarchical control strategy is effective for RE integration in the MVDC distribution network.

The increasing utilisation of renewable energy sources (RESs) plays an important role in the modern power system. The high penetration of the RESs in the electrical power network leads to challenges to the system’s stability. Therefore, the microgrid concept is proposed to solve such problems due to its flexibility and practicality. The hybrid AC/DC microgrid configuration is compatible with AC power supplies, DC power supplies, AC loads and DC loads which is viewed as the most practical choice in the power system application. The microgrid utilises an interlinking converter for the system’s control and grid connection. In this case, the microgrid implementation provides the possibility to achieve the other power electronic device functions such as a static compensator (STATCOM) or an active power filter (APF) in addition to dealing with the RES problems. In this PhD thesis, a grid-connected-mode-based control strategy for the microgrid is proposed to regulate the power generation as well as to reduce the grid current harmonics and neutral current. A virtual synchronous generator (VSG) based control strategy is introduced for microgrid’s smooth transient performance purpose. The first contribution of this research is the combination of the notch filter and traditional grid-connected microgrid control strategy. The notch filter is introduced into a three-phase system for current harmonics detection. The obtained harmonics signals are converted into reference signals for a revised constant power control strategy so that the microgrid is able to achieve the power regulation and harmonics reduction simultaneously. The interlinking converter is designed with three transistor-based bridges and a split-capacitor-based bridge so that the system is decoupled from hardware without any internal signals interference. The second contribution of this research is the design for grid neutral current compensation. The interlinking converter is designed with another independent neutral module bridge for the neutral current compensation purpose and a controller is developed based on this. In the context, the microgrid is implemented as a traditional microgrid with STATCOM-APF functions embedded. The third contribution of this research is the introduction of an improved VSG controller with its specific pre-synchronisation module. The designed method conducts smooth transient performances for a microgrid under different scenarios. An exclusive pre-synchronisation block is designed for the improved VSG controller for the microgrid to reconnect to the utility network smoothly when there is a requirement. The final contribution of this research is the establishment of the microgrid system benchtop. The hardware setup achieves the traditional power regulation function as well as the power-sharing between two microgrids. The proposed STATCOM-APF-based grid-connected microgrid controller is also tested under different scenarios. The effectiveness is validated through experiment. Various case studies are conducted in this research to investigate the microgrid possibilities. The proposed methods are validated through simulation first. The hardware prototype also verifies the correctness of the proposed grid-connected microgrid control method. The microgrid setup finally realises the power regulation, the harmonics reduction, the neutral current compensation and the cooperative operation functions.

In this paper, the implementation of virtual inertia in a dual two-level voltage source inverter (DTL VSI) configuration is investigated. The derivative control method is employed to provide virtual inertia. The virtual synchronous generator (VSG) topology is presented, and its elements are introduced. According to the frequency changes, the active power reference is generated. Moreover, the control structure is designed and presented to control the DTL VSI properly. By means of the derivative control method, the DTL VSI participates in the frequency regulation, and the frequency oscillations during contingencies are confined. The results show that the controller follows its reference in all cases. The potentiality of the proposed controller is confirmed through MATLAB simulations. Compared to the conventional DTL VSI, the rate of change of frequency (ROCOF) and frequency nadir are reduced during disturbances.

Background Gold standard microscopic examination of Plasmodium falciparum intraerythrocytic stage remains an important process for staging and enumerating parasitized erythrocytes in culture; however, microscopy is laborious and its accuracy is dependent upon the skill of the examiner. Methods In this study, ViSafe Green (VSG), which is a nucleic acid-binding fluorescent dye, was used for assessing in vitro development of P. falciparum using flow cytometry. Results Fluorescence intensity of VSG was found to depend on the developmental stage of parasites. Specifically, multiple-nuclei-containing schizonts were observed in the VSGhigh population, and growing trophozoites and ring-shaped forms were observed in the VSGintermediate and VSGlow populations. The efficacy of VSG-based assay was found to be comparable to the microscopic examination method, and it demonstrated an ability to detect as low as 0.001% of the parasitaemia estimated by Giemsa staining. Moreover, when applying VSG for anti-malarial drug test, it was able to observe the growth inhibitory effect of dihydroartemisinin, the front-line drug for malaria therapy. Conclusions Taken together, the results of this study suggest the VSG-based flow cytometric assay to be a simple and reliable assay for assessing P. falciparum malaria development in vitro.

Lucy Glover’s research focuses on the role of DNA repair and recombination in antigenic variation in the parasite Trypanosoma brucei, the causative agent of both human and animal African trypanosomiasis. In this mSphere of Influence article, she reflects on how “A CRISPR-based approach for proteomic analysis of a single genomic locus” by Z. J. Waldrip, S. D. Byrum, A. J. Storey, J., Lucy Glover’s research focuses on the role of DNA repair and recombination in antigenic variation in the parasite Trypanosoma brucei, the causative agent of both human and animal African trypanosomiasis. In this mSphere of Influence article, she reflects on how “A CRISPR-based approach for proteomic analysis of a single genomic locus” by Z. J. Waldrip, S. D. Byrum, A. J. Storey, J. Gao, et al. (Epigenetics 9:1207–1211, 2014, https://doi.org/10.4161/epi.29919) made an impact on her research by taking the precision of CRISPR-Cas9 and repurposing it to look at single-locus proteomics. By using this technology in trypanosomes, Dr. Glover and her colleagues could study the dynamic accumulation of repair proteins after specific damage and gain insight into how the location of a double-strand break (DSB) dictates repair pathway choice and how this may influence immune evasion in these parasites.

Die Schlauchgastrektomie ist derzeit zusammen mit anderen bariatrischen Eingriffen die wirksamste Therapie für die Behandlung von Fettleibigkeit und damit assoziierten Komorbiditäten wie beispielsweise Typ-2 Diabetes Mellitus. Sowohl die Anzahl der gesamt zirkulierenden Gallensäuren als auch die Zusammensetzung der Darmflora scheint nach einer Schlauchgastrektomie verändert zu sein. Zusammen mit FXR-Signaling könnten diese Veränderungen potenzielle Treiber für Stoffwechselverbesserungen nach der bariatrischen Operation sein. Um den FXR der Leber oder des Darms als molekulares Target in der Schlauchgastrektomie zu identifizieren, wurden gewebsspezifische FXR KO Mäuse eingesetzt. Darm- oder Leber-FXR KO Mäuse und deren Wurfgeschwister wurden maximal 15 Wochen mit einer westlichen Diät zur Induktion von Fettleibigkeit gefüttert und anschließend einer Schlauchgastrektomie oder Scheinoperation unterzogen. Stuhlproben wurden vor der Operation (0, 4 und 12 Wochen nach der westlichen Diät) und nach der Operation (0, 5, 8, 9 und 10 Wochen) gesammelt und metabolische Tests durchgeführt. Ebenfalls 10 Wochen nach der Operation wurde den Versuchstieren das Cecum entnommen, worauf basierend der Einfluss des gewebsspezifischen FXR-Knockouts und der Schlauchgastrektomie auf die Ökologie der Darmflora mittels 16S rRNA Gene Profiling untersucht wurde. Bereits 4 Wochen nach der Schlauchgastrektomie zeigen unseren Daten eine anhaltende Verringerung der Körpergewichtszunahme, eine verringerte Masse des Körperfetts und eine niedrigere zirkulierende Nüchternglukose, sofern FXR sowohl in der Leber als auch im Darm aktiviert wird. Durch Abwesenheit von FXR im Darm ist die Fähigkeit der Schlauchgastrektomie das Körpergewicht und den Nüchternglukosespiegel zu reduzieren, signifikant verringert. Gleichzeitig wird beobachtet, dass die Zusammensetzung der Gallensäuren und die mikrobiellen Gemeinschaften des Darms durch die Schlauchgastrektomie und das Fehlen des intestinalen FXR moduliert werden. Diese Ergebnisse deuten darauf hin, dass der Zusammenhang zwischen intestinalem FXR-Signaling und der Komposition der Darmflora für die vorteilhaften Wirkungen der Schlauchgastrektomie entscheidend sein könnte. Daher ist zukünftig der Einsatz einer fäkalen Mikrobiota-Transplantation (FMT) oder die Entwicklung von Darm-spezifischen FXR-Agonisten zur Vorbeugung oder sogar Behandlung von Fettleibigkeit und damit verbundenen Komorbiditäten denkbar. Vertical sleeve gastrectomy (VSG) is one of the most effective bariatric surgeries for the treatment of obesity and related comorbidities like type-2 diabetes mellitus. Circulating total bile acids and gut microbiota composition seems to be altered after VSG intervention and together with FXR-signaling, they might be potential drivers for the beneficial effects after surgery. In order to identify intestinal or hepatic FXR as a molecular target in VSG surgery, tissue-specific FXR KO mice were used. Intestine or liver FXR KO mice and their littermates were feed western diet for a maximum of 15 weeks and then they underwent VSG or sham surgery. Fecal samples were collected and metabolic tests were assessed before surgery (0, 4, 12 weeks post-diet) and after surgery (0, 5, 8, 9 and 10 weeks). Cecum contents were used to assess the impact of tissue-specific FXR deficiency and VSG surgery on gut microbial ecology by using 16S rRNA gene profiling. Our data shows sustained reduction in body weight gain, decreased body fat mass and lower circulating fasting glucose already 4 weeks after surgery when FXR is activated in both liver and intestine. Here we show that only in absence of FXR in the intestine, the ability of VSG surgery to reduce body weight and fasting glucose levels is significantly diminished. In the same direction we observe that bile acid composition and gut microbiota communities are modulated by VSG surgery and by the absence of intestinal FXR. These results suggest that the association between intestinal FXR signaling and gut microbiota composition might be crucial for the beneficial effects of VSG surgery. Thus, undertaking fecal microbiota transplant (FMT) or developing drugs that function as intestine-specific FXR agonists could lead to prevention or even treatment of obesity and associated comorbidities in a less-invasive manner.

Since the concept that inverters can be controlled to behave like a synchronous generator has been proposed, the virtual synchronous generator (VSG) started to become the mainstream control of distributed energy resources connected distributed system. This concept simulates the frequency and voltage regulation of synchronous generator to improve the overall stability of the medium- and low-voltage power system. Although significant research works have considered the application of VSGs in active and reactive power sharing, it seems to be that the issue of the proportional power sharing of VSGs of different capacities has not considered much in the previous works, especially when the distribution lines have increased resistive components. Such resistive disturbs the power flow and causes the power coupling. When focusing eyes on the parallel operation, VSGs need to coordinate parallel operation to increase the microgrid power quality, reliability, and for easy maintenance. Based on an improved droop control and virtual complex impedance, this study adjusts PI controller parameters to implement the proportional power sharing and decoupling for VSGs of different capacities. Simulation results are shown to verify the feasibility and validity of the control method.

The grid-connected inverter with virtual synchronous generator (VSG) control technology can improve the friendliness of a distributed power supply to the power grid. However, its low-voltage ride-through (LVRT) capability is insufficient, which results in difficulties in limiting the current and provide reactive power support. A new LVRT control strategy based on the smooth switching is proposed in this paper. In this strategy, the voltage source mode of VSG is transformed into current source mode to limit the output current and provide reactive power support through the proportional resonance current control algorithm under grid fault. Furthermore, the feedback tracking synchronization strategy of the phase angle is employed to realize the smooth switching between two modes. When the grid fault recovers, it can directly switch back to grid-connected operation mode through a delay module without an additional algorithm. The simulation results verify the correctness and feasibility of the proposed control strategy.

Trypanosoma brucei causes human African trypanosomiasis and regularly switches its major surface antigen, Variant Surface Glycoprotein (VSG), to evade the host immune response. Such antigenic variation is a key pathogenesis mechanism that enables T. brucei to establish long-term infections. VSG is expressed exclusively from subtelomere loci in a strictly monoallelic manner, and DNA recombination is an important VSG switching pathway. The integrity of telomere and subtelomere structure, maintained by multiple telomere proteins, is essential for T. brucei viability and for regulating the monoallelic VSG expression and VSG switching. Here we will focus on T. brucei TRF and RAP1, two telomere proteins with unique nucleic acid binding activities, and summarize their functions in telomere integrity and stability, VSG switching, and monoallelic VSG expression. Targeting the unique features of TbTRF and TbRAP1′s nucleic acid binding activities to perturb the integrity of telomere structure and disrupt VSG monoallelic expression may serve as potential therapeutic strategy against T. brucei.

La velocidad de sedimentación globular (VSG) es una de las pruebas más realizadas en el laboratorio clínico, pues es económica y de fácil ejecución. Existen varios métodos para medir la VSG que han sido estandarizados como Westergren y el de Wintrobe. Sin embargo, existen otros que si bien son empleados en la actualidad, no presentan estandarización alguna como el Dispette y el Micrométodo. Es por ello que el objetivo de esta investigación fue realizar un estudio comparativo entre cinco métodos para la determinación de la VSG en estudiantes de la Universidad de Carabobo, Sede Aragua. Este estudio fue de tipo descriptivo con diseño comparativo; se procesaron 50 muestras a las cuales se les determinó la VSG por los métodos Westergren, Wintrobe, Micrométodo, Dispette 90º y Dispette 60º a diferentes tiempos. Se obtuvo como resultado que no hubo diferencia estadísticamente significativa en el valor promedio de las técnicas de Wintrobe, Micrométodo, Dispette 90º y Dispette inclinado a 60º (6 y 10 minutos, 8 y 12 minutos) al compararse con la técnica estándar Westergren (p > 0,05). En el Dispette inclinado a 60º (4 y 8 minutos, 10 y 14 minutos y 12 y 16 minutos), se obtuvo diferencias estadísticamente significativas (p < 0,01). Los resultados entre la comparación de los métodos reflejan que las técnicas de Wintrobe, Micrométodo, Dispette a 90º, Dispette inclinado a 60º ensayado a los 6 y 10 minutos y a los 8 y 12 minutos, son reproducibles.

Background Glucagon-like peptide-1 (GLP-1) level was significantly increased post Vertical Sleeve Gastrectomy (VSG), an effect believed to contribute to its beneficial cardiometabolic effects. Objective To validate the beneficial GLP-1 mediated cardiometabolic effects post VSG using GLP-1 antagonist (exendin 9-39) in Zucker diabetic fatty rats. Methods Animals were divided into three (n = 5) groups: (i) sham, (ii) VSG, and (iii) VSG received exendin 9–39 (GLP-1 receptor antagonist). The study was performed over 12 weeks and parameters were measured 12 weeks post-surgery. Results and discussion As expected, fasting blood glucose and insulin levels were improved post VSG due to enhanced GLP-1 secretion. However, both fasting glucose and insulin levels were impaired in the presence of GLP-1 antagonist. Baseline total cholesterol level pre-surgery was 100±1 mg/dl which remained unchanged in the VSG group but significantly increased to 140±8 mg/dl in the presence of antagonist. Interestingly, post-surgery there was a nearly 70% reduction in triglyceride level in the VSG group compared to sham which was overcome in the presence of antagonist. Myographic studies using aortic rings showed no significant change between groups. Additionally, blood pressure and heart rate also remained unchanged in all groups. Serum bile acid and L-PGDS levels increased post VSG but significantly decreased in the presence of antagonist, suggesting a strong association with GLP-1 and a novel mechanism of action. Conclusion Enhanced GLP-1 secretion post VSG imparted beneficial cardiometabolic effects on blood glucose, insulin, total cholesterol, triglyceride, bile acids and L-PGDS levels which were abated in the presence of GLP-1 antagonist., Highlights • GLP-1 increases post-VSG 30 min after glucose load. • Post-VSG GLP-1 secretion is associatged with lower cholesterol and triglycerides. • Bile acids and L-PGDS increase post-VSG and are inhibited in the presence of GLP-1 antagonist. • Heart rate, blood pressure and myograph profile remain unchanged.

Islanded microgrids (IMGs) are more likely to be perturbed by renewable generation and load demand fluctuation, thus leading to system instability. The virtual synchronous generator (VSG) control has become a promising method in the microgrids stability control area for its inertia-support capability. However, the improper power sharing and inaccurate voltage control problems of the distributed generations (DGs) in microgrids still has not been solved with a unified method. This paper proposes a novel VSG equivalent control method named Imitation Excitation Control (IEC). In this method, a multi-objective control strategy for voltage and reactive power in a low voltage grid that considers a non-negligible resistance to reactance ratio (R/X) is proposed. With the IEC method, the voltage drop across feeders is compensated, thus the terminal voltage of each inverter will be regulated, which will effectively stabilize the PCC (point of common coupling) voltage and inhibit the circular current. Meanwhile, this method can realize accurate reactive power tracking the reference value, making it accessible for reactive power scheduling. What is more, the reasonability of the IEC model, namely the equivalent mechanical characteristic and transient process inertia support between VSGs and conventional synchronous generators (SG), is illustrated in this paper. Moreover, steady-state stability is proved by the small-signal modeling method, and the energy required by inertia support is given. Finally, the simulation result validates the effectiveness of the proposed method, and it is also demonstrated that the proposed method outperforms the conventional droop control method.

The power quality of new energy resources has received tremendous attention recently. The control approach for the inverter, an interface between the new energy resources, and the infinite bus system is of vital importance. For the virtual synchronous generator (VSG), one of the research hotspots in the inverter control field, there are some challenges remaining to be dealt with. First is the contradiction between the rapid response and overshoot of active power output if VSG is connected to the grid. Secondly, the active power is deeply influenced by the fluctuation of gird frequency and this may bring power oscillation to VSG in weak grids. In this article, an active power controller for power tracking of grid-connected VSG is designed based on linear active disturbance rejection control (LADRC) by compensating for the lumped disturbance in a feedforward fashion. The parameters of the controller are analyzed and tuned in the frequency domain to acquire a desirable control performance. Moreover, the robustness of the control system is also considered. Simulation results show that the designed control system can transmit active power to the grid in a timely manner with no overshoot, as demanded. Additionally, it can output active power steadily according to the power reference without using a phase-locked loop (PLL) when the grid frequency has different features of fluctuation. In addition, the simulation results demonstrate that the improved VSG has strong robustness to the model parameter perturbation and mismatch.

Suramin was introduced into the clinic a century ago and is still used to treat the first stage of acute human sleeping sickness. Due to its size and sixfold negative charge, uptake is mediated through endocytosis and the suramin receptor in trypanosomes is thought to be the invariant surface glycoprotein 75 (ISG75). Nevertheless, we recently identified a variant surface glycoprotein (VSGSur) that confers strong in vitro resistance to suramin in a Trypanosoma brucei rhodesiense line. In this study, we introduced VSGSur into the active bloodstream expression site of a T. b. brucei line. This caused suramin resistance and cross resistance to trypan blue. We quantified the endocytosis of different substrates by flow cytometry and showed that the expression of VSGSur strongly impairs the uptake of low‐density lipoprotein (LDL) and transferrin, both imported by receptor‐mediated endocytosis. However, bulk endocytosis and endocytosis of the trypanolytic factor were not affected, and the VSGSur‐expressors did not exhibit a growth phenotype in the absence of suramin. Knockdown of ISG75 was synergistic with VSGSur expression, indicating that these two proteins are mediating distinct suramin resistance pathways. In conclusion, VSGSur causes suramin resistance in T. brucei bloodstream forms by decreasing specific, receptor‐mediated endocytosis pathways.

Recently, the virtual synchronous generator (VSG) has drawn considerable attention for its function of simulating the electromechanical transient of SG to make converters equip with the characters of inertia, damping, voltage regulating, and frequency regulating. Energy storage systems (ESSs), which are connected to the converter by a DC/DC circuit, are the basis of VSG. The output active power of VSG is restricted by the capacity margin of the grid-side converter and DC/DC circuit, and the output energy is bounded by the energy margin of ESS, which means that VSG is restrained by treble constraints: DC side power, DC-side energy, and AC-side power. A small signal model of VSG is built, and the method of getting the treble constraints is proposed. Through the analysis of the dynamic response characteristics of the VSG, the operating zone of VSG under constraints is confirmed. Simulations in power system computer aided design (PSCAD)/electromagnetic transient including DC (EMTDC) verified the theoretical analysis and the transient characteristics of VSG when the constraints are broken and simulated.

Modular multilevel converter-battery energy storage system (MMC-BESS) has a good engineering application. When MMC-BESS is connected to the grid, the real-time phase angle of grid is an important parameter. When MMC-BESS is connected to the grid, a simulation model based on virtual synchronous generator (VSG) is built in MATLAB. The results show the control algorithm based on VSG can improve the dynamic response of the system and stably detect the phase angle of the grid.

Suramin was introduced into the clinic a century ago and is still used to treat the first stage of acute human sleeping sickness. Due to its size and sixfold negative charge, uptake is mediated through endocytosis and the suramin receptor in trypanosomes is thought to be the invariant surface glycoprotein 75 (ISG75). Nevertheless, we recently identified a variant surface glycoprotein (VSG; Sur; ) that confers strong in vitro resistance to suramin in a; Trypanosoma brucei rhodesiense; line. In this study, we introduced; VSG; Sur; into the active bloodstream expression site of a; T. b. brucei; line. This caused suramin resistance and cross resistance to trypan blue. We quantified the endocytosis of different substrates by flow cytometry and showed that the expression of VSG; Sur; strongly impairs the uptake of low-density lipoprotein (LDL) and transferrin, both imported by receptor-mediated endocytosis. However, bulk endocytosis and endocytosis of the trypanolytic factor were not affected, and the; VSG; Sur; -expressors did not exhibit a growth phenotype in the absence of suramin. Knockdown of ISG75 was synergistic with; VSG; Sur; expression, indicating that these two proteins are mediating distinct suramin resistance pathways. In conclusion, VSG; Sur; causes suramin resistance in; T. brucei; bloodstream forms by decreasing specific, receptor-mediated endocytosis pathways.

This paper presents a methodology that aims at identifying virtual inertia (VI) gain limitations from virtual synchronous generators (VSGs) while maintaining the frequency stability considering the delay associated with the frequency measurement process. The phase-locked loop (PLL) is typically used for frequency estimation that is used to calculate the rate of change of frequency (RoCoF) and it drives the VI loop. The PLL is generally accompanied by a low-pass filter that aims to suppress the impact of harmonics. This filter introduces a delay that when used with the VI control loop causes stability issues for high values of VI gain. A comparison of various PLL approaches suggests that certain variants tend to permit higher value of cut-off frequencies which can be utilized to increase the VI gain limit from VSG. This study presents a method by which the upper limit on VI gain can be quantified and related to the cut-off frequency of the PLL low pass filter that is indirectly representing the delay. It is performed using small signal frequency stability analysis on the frequency domain model of the grid with virtual inertia emulating VSG. The effective maximum VI gain from VSG is explored while satisfying the frequency measurement accuracy specification considering harmonics. The results show that the requirements of reaching a stable operation with sufficient stability margins can still be met with a faster PLL-based system and the potential increases in VI support from VSG can be quantified using the proposed method. The study has been first performed on a single machine single inverter bus (SMSIB) system and is generalized to the multi-machine and multi-inverter system.

Background Trypanosoma cruzi and Trypanosoma brucei are protozoan parasites causing Chagas disease and African sleeping sickness, displaying unique features of cellular and molecular biology. Remarkably, no canonical signals for RNA polymerase II promoters, which drive protein coding genes transcription, have been identified so far. The secondary structure of DNA has long been recognized as a signal in biological processes and more recently, its involvement in transcription initiation in Leishmania was proposed. In order to study whether this feature is conserved in trypanosomatids, we undertook a genome wide search for intrinsic DNA curvature in T. cruzi and T. brucei. Results Using a region integrated intrinsic curvature (RIIC) scoring that we previously developed, a non-random distribution of sequence-dependent curvature was observed. High RIIC scores were found to be significantly correlated with transcription start sites in T. cruzi, which have been mapped in divergent switch regions, whereas in T. brucei, the high RIIC scores correlated with sites that have been involved not only in RNA polymerase II initiation but also in termination. In addition, we observed regions with high RIIC score presenting in-phase tracts of Adenines, in the subtelomeric regions of the T. brucei chromosomes that harbor the variable surface glycoproteins genes. Conclusions In both T. cruzi and T. brucei genomes, a link between DNA conformational signals and gene expression was found. High sequence dependent curvature is associated with transcriptional regulation regions. High intrinsic curvature also occurs at the T. brucei chromosome subtelomeric regions where the recombination processes involved in the evasion of the immune host system take place. These findings underscore the relevance of indirect DNA readout in these ancient eukaryotes. Electronic supplementary material The online version of this article (10.1186/s13104-017-2908-y) contains supplementary material, which is available to authorized users.

Background The compaction of DNA in chromatin in eukaryotes allowed the expansion of genome size and coincided with significant evolutionary diversification. However, chromatin generally represses DNA function, and mechanisms coevolved to regulate chromatin structure and its impact on DNA. This included the selection of specific nucleosome positions to modulate accessibility to the DNA molecule. Trypanosoma brucei, a member of the Excavates supergroup, falls in an ancient evolutionary branch of eukaryotes and provides valuable insight into the organization of chromatin in early genomes. Results We have mapped nucleosome positions in T. brucei and identified important differences compared to other eukaryotes: The RNA polymerase II initiation regions in T. brucei do not exhibit pronounced nucleosome depletion, and show little evidence for defined −1 and +1 nucleosomes. In contrast, a well-positioned nucleosome is present directly on the splice acceptor sites within the polycistronic transcription units. The RNA polyadenylation sites were depleted of nucleosomes, with a single well-positioned nucleosome present immediately downstream of the predicted sites. The regions flanking the silent variant surface glycoprotein (VSG) gene cassettes showed extensive arrays of well-positioned nucleosomes, which may repress cryptic transcription initiation. The silent VSG genes themselves exhibited a less regular nucleosomal pattern in both bloodstream and procyclic form trypanosomes. The DNA replication origins, when present within silent VSG gene cassettes, displayed a defined nucleosomal organization compared with replication origins in other chromosomal core regions. Conclusions Our results indicate that some organizational features of chromatin are evolutionarily ancient, and may already have been present in the last eukaryotic common ancestor. Electronic supplementary material The online version of this article (doi:10.1186/s13072-017-0121-9) contains supplementary material, which is available to authorized users.

Objective In addition to adipocytes, adipose tissue contains large numbers of immune cells. A wide range of evidence links the activity of these cells to regulation of adipocyte and systemic metabolic function. Bariatric surgery improves several aspects of metabolic derangements and at least some of these effects occur in a weight-loss independent manner. We sought to investigate the impact of vertical sleeve gastrectomy (VSG) on adipose immune cell frequencies. Methods We analyzed the frequencies of immune cells within distinct adipose tissue depots in obese mice that had VSG or sham surgery with a portion of the latter group pair-fed such that their body mass was matched to the VSG animals. Results We demonstrate that VSG induced a shift in the epididymal adipose tissue leukocyte profile including increased frequencies of CD11c− macrophages, increased frequencies of T cells (CD4+, CD8+, and CD4−/CD8− T cells all increased), but a significantly decreased frequency of adipose tissue dendritic cells (ATDC) that, despite the continued high fat feeding of the VSG group, dropped below control diet levels. Conclusions These results indicate that VSG induces substantial changes in the immune populations residing in the adipose depots independent of weight loss., Highlights • Sleeve gastrectomy in mice altered the adipose leukocyte populations. • CD11c− macrophages were selectively upregulated independent from weight loss. • All identified T cell populations increased manifold independent from weight loss. • The dendritic cell fraction was decreased below lean control levels with surgery.

RESUMEN Objetivo Establecer la correlación entre los métodos de Wintrobe y de micro-hematocrito Métodos Se tomaron 407 pacientes asistentes a un laboratorio de tercer nivel a quienes en forma simultánea se les realizó las dos pruebas en estudio. Resultados Mediante el un método estadístico de regresión lineal se encontró un coeficiente de correlación de 0,99. Conclusión Ambos métodos pueden contribuir al análisis clínico de los pacientes a quienes se les solicitó la prueba con fines de diagnóstico, control y seguimiento de diferentes patologías. ABSTRACT Objective To establish the correlation between the methods of Wintrobe and micro-hematocrit Methods 407 patients attendees were taken laboratory to third level simultaneo usly tests were performed in the study. Results Using a statistical method of linear regression correlation coefficient of 0,99 was found. Conclusion Both methods can contribute to the clinical analysis of patients who were asked to test for diagnosis or control of different pathologies.

Objetivo Establecer la correlación entre los métodos de Wintrobe y de micro-hematocritoMétodos Se tomaron 407 pacientes asistentes a un laboratorio de tercer nivel a quienes en forma simultánea se les realizó las dos pruebas en estudio.Resultados Mediante el un método estadístico de regresión lineal se encontró un coeficiente de correlación de 0,99.Conclusión Ambos métodos pueden contribuir al análisis clínico de los pacientes a quienes se les solicitó la prueba con fines de diagnóstico, control y seguimiento de diferentes patologías.

This paper introduces a new control strategy to realize a virtual synchronous generator. The proposed control strategy is based on virtual impedance and band-pass damping algorithms to achieve the electro-mechanical characteristics of synchronous generator for the grid converter. Differences between new and traditional method on impedance emulation, and differences between traditional pure proportional damping algorithm and new band-pass damping algorithm are discussed as well. Additionally, detailed analysis of the components of synchronous generator is given, also the roles of the various parts of synchronous generator in the power system stability control are explained. The behavior of designed control strategy is validated by both simulations and experiments made on a 2kW grid-connected inverter.

Background African trypanosomes cause lethal diseases in humans and animals and escape host immune attack by switching the expression of Variant Surface Glycoprotein (VSG) genes. The expressed VSGs are located at the ends of telomeric, polycistronic transcription units known as VSG expression sites (VSG-ESs). Each cell has many VSG-ESs but only one is transcribed in bloodstream-form parasites and all of them are inactive upon transmission to the insect vector mid-gut; a subset of monocistronic metacyclic VSG-ESs are then activated in the insect salivary gland. Deep-sequence analyses have been informative but assigning sequences to individual VSG-ESs has been challenging because they each contain closely related expression-site associated genes, or ESAGs, thought to contribute to virulence. Results We utilised ART, an in silico short read simulator to demonstrate the feasibility of accurately aligning reads to VSG-ESs. Then, using high-resolution transcriptomes from isogenic bloodstream and insect-stage Lister 427 Trypanosoma brucei, we uncover increased abundance in the insect mid-gut stage of mRNAs from metacyclic VSG-ESs and of mRNAs from the unusual ESAG, ESAG10. Further, we show that the silencing associated with allelic exclusion involves repression focussed at the ends of the VSG-ESs. We also use the approach to report relative fitness costs following ESAG RNAi from a genome-scale screen. Conclusions By assigning sequences to individual VSG-ESs we provide new insights into VSG-ES transcription control, allelic exclusion and impacts on fitness. Thus, deeper insights into the expression and function of regulated multi-gene families are more accessible than previously anticipated. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3154-8) contains supplementary material, which is available to authorized users.

A large scale of renewable energy employing grid connected electronic inverters fail to contribute inertia or damping to power systems, and, therefore, may bring negative effects to the stability of power system. As a solution, an advanced Virtual Synchronous Generator (VSG) control technology based on Hamilton approach is introduced in this paper firstly to support the frequency and enhance the suitability and robustness of the system. The charge and discharge process of power storage devices forms the virtual inertia and damping of VSG, and, therefore, limits on storage capacity may change the coefficients of VSG. To provide a method in keeping system output in an acceptable level with the capacity restriction in a transient period, an energy control algorithm is designed for VSG adaptive control. Finally, simulations are conducted in DIgSILENT to demonstrate the correctness of the algorithm. The demonstration shows: (1) the proposed control model aims at better system robustness and stability; and (2) the model performs in the environment closer to practical engineering by fitting the operation state of storage system.

African Trypanosomiasis is an excellent model system to study immune escape by invading extracellular pathogens. Being under continuous attack of the host humoral response, trypano-somes developed a system of antigenic variation of their surface coat in order to evade anti-body-mediated immune destruction. In-depth studies on the mechanisms of antigenic varia-tion have resulted in the understanding of both structural and genetic aspects of the surface coat organization of trypanosomes, and the variant-specific glycoproteins (VSG) itself, i.e. the protein that provides the interface between the parasite and the host immune system (see chapters 1 and 3). To date, the current hypothesis of VSG-mediated antibody escape implies that during infection the host is capable of mounting an ever changing antibody repertoire, which allows to target in a specific manner each new trypanosome wave. In this chapter, a number of recent insights will be discussed, that highlight the complexity of this system. In-deed, experimental data obtained in rodent T. brucei models suggest that anti-VSG responses are very short lived, and no memory is mounted during infection against the successive waves of occurring VATs. In addition, active destruction of the host B-cell compartment occurs dur-ing infection, affecting both trypanosome specific and non-specific B-cell memory. These finding will be discussed in the context of the long string of vaccine failure results that have hampered the initiation of an effective vaccine program for trypanosomiasis. Finally, this chapter will also provide new insights into antibody engineering that allow interfering with trypanosome biology in ways that are not part of the natural evolutionary pressure. Hence, possible new tools can be developed that can help in a sustainable long term battle against both human and animal trypanosomiasis.

Trypanosoma and Plasmodium species are unicellular, eukaryotic pathogens that have evolved the capacity to survive and proliferate within a human host, causing sleeping sickness and malaria, respectively. They have very different survival strategies. African trypanosomes divide in blood and extracellular spaces, whereas Plasmodium species invade and proliferate within host cells. Interaction with host macromolecules is central to establishment and maintenance of an infection by both parasites. Proteins that mediate these interactions are under selection pressure to bind host ligands without compromising immune avoidance strategies. In both parasites, the expansion of genes encoding a small number of protein folds has established large protein families. This has permitted both diversification to form novel ligand binding sites and variation in sequence that contributes to avoidance of immune recognition. In this review we consider two such parasite surface protein families, one from each species. In each case, known structures demonstrate how extensive sequence variation around a conserved molecular architecture provides an adaptable protein scaffold that the parasites can mobilise to mediate interactions with their hosts.

BACKGROUND AND PURPOSE: Nanobodies are promising antigen-binding moieties for molecular imaging and therapeutic purposes due to their favorable pharmacological and pharmacokinetic properties. However, the capability of monovalent nanobodies to reach targets in the central nervous system (CNS) remains to be demonstrated. EXPERIMENTAL APROACH: We have assessed the blood-brain barrier permeability of Nb_An33, a nanobody against the Trypanosoma brucei brucei Variant-specific Surface Glycoprotein (VSG). This analysis was performed in healthy rats and in rats that were in the encephalitic stage of African trypanosomiasis using intracerebral microdialysis, Single Photon Emission Computed Tomography (SPECT), or a combination of both methodologies. This enabled the quantification of unlabeled and (99m) Tc-labeled nanobodies using respectively a sensitive VSG-based nanobody-detection ELISA, radioactivity measurement in collected microdialysates, and SPECT image analysis. KEY RESULTS: The combined read-out methodologies demonstrate that disposition of Nb_An33 can be detected in the brain of healthy rats following intravenous injection and that inflammation-induced damage to the blood-brain barrier significantly increases the nanobody perfusion efficiency. We also illustrate the advantage of complementing SPECT analyses with intracerebral microdialysis in brain disposition studies and suggest that it is of interest to evaluate the blood-brain barrier penetrating potential of monovalent nanobodies in models of CNS-inflammation. The presented data also suggest that fast blood clearance might hamper efficient targeting of specific nanobodies to the CNS. CONCLUSIONS AND IMPLICATIONS: Nanobodies can perfuse into the brain parenchyma, especially in pathological conditions where the blood-brain barrier integrity is compromised.

Graphical abstract The VSG coat of Trypanosoma brucei prevents access of antibodies to the VSG C-terminal domain. Research highlights ▶ Antisera raised against recombinant VSG C-terminal domains. ▶ Anti-VSG C-terminal domain sera recognise fixed but not live cells. ▶ Support for model where diffusion barrier is at the base of the VSG N-terminal domain., In the mammalian host, the Trypanosoma brucei cell surface is covered with a densely packed protein coat of a single protein, the variant surface glycoprotein (VSG). The VSG is believed to shield invariant surface proteins from host antibodies but there is limited information on how far antibodies can penetrate into the VSG monolayer. Here, the VSG surface coat was probed to determine whether it acts as a barrier to binding of antibodies to the membrane proximal VSG C-terminal domain. The binding of C-terminal domain antibodies to VSG221 or VSG118 was compared with antibodies recognising the cognate whole VSGs. The C-terminal VSG domain was inaccessible to antibodies on live cells but not on fixed cells. This provides further evidence that the VSG coat acts as a barrier and protects the cell from antibodies that would otherwise bind to some of the other externally disposed proteins.