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Phlebia radiata is a widespread white-rot basidiomycete fungus with significance in diverse biotechnological applications due to its ability to degrade aromatic compounds, xenobiotics, and lignin using an assortment of oxidative enzymes including laccase. In this work, a chemical screen with 480 conditions was conducted to identify chemical inducers of laccase expression in P. radiata. Among the chemicals tested, phenothiazines were observed to induce laccase activity in P. radiata, with promethazine being the strongest laccase inducer of the phenothiazine-derived compounds examined. Secretomes produced by promethazine-treated P. radiata exhibited increased laccase protein abundance, increased enzymatic activity, and an enhanced ability to degrade phenolic model lignin compounds. Transcriptomics analyses revealed that promethazine rapidly induced the expression of genes encoding lignin-degrading enzymes, including laccase and various oxidoreductases, showing that the increased laccase activity was due to increased laccase gene expression. Finally, the generality of promethazine as an inducer of laccases in fungi was demonstrated by showing that promethazine treatment also increased laccase activity in other relevant fungal species with known lignin conversion capabilities including Trametes versicolor and Pleurotus ostreatus. [ABSTRACT FROM AUTHOR]

The range of applications for industrial hemp has consistently increased in various sectors over the years. For example, hemp hurd can be used as a resource to produce biodegradable packaging materials when incorporated into a fungal mycelium composite, a process that has been commercialized. Although these packaging materials can be composted after usage, they may present an opportunity for valorization in a biorefinery setting. Here, we demonstrate the potential of using this type of discarded packaging composite as a feedstock for biofuel production. A one-pot ionic liquid-based biomass deconstruction and conversion process was implemented, and the results from the packaging material were compared with those obtained from untreated hemp hurd. At a 120 °C reaction temperature, 7.5% ionic liquid loading, and 2 h reaction time, the packaging materials showed a higher lignocellulosic sugar yield and sugar concentrations than hemp hurd. Hydrolysates prepared from packaging materials also promoted production of higher titers (1400 mg/L) of the jet-fuel precursor bisabolene when used to cultivate an engineered strain of the yeast Rhodosporidium toruloides. Box–Behnken experiments revealed that pretreatment parameters affected the hemp hurd and packaging materials differently, evidencing different degrees of recalcitrance. This study demonstrated that a hemp hurd-based packaging material can be valorized a second time once it reaches the end of its primary use by supplying it as a feedstock to produce biofuels. [ABSTRACT FROM AUTHOR]

Objective: To evaluate which parameters of a sonographic cervical length measurement are associated with preterm birth in women with ultrasound- or exam-indicated cerclage. Methods: This was a retrospective cohort study of women with singleton pregnancies who underwent ultrasound- or exam-indicated Shirodkar cerclage by a single maternal–fetal medicine practice between 2011 and 2019. All patients underwent sonographic cervical length measurement 2–3 weeks after cerclage placement, and then every 2–4 weeks up to 32 weeks. The images from the first and second post-cerclage cervical lengths were reviewed. Total cervical length, upper cervical length (from the internal cervical os to the cerclage), and lower cervical length (from the cerclage to the external os) were measured. The primary outcome for this study was gestational age at delivery. Results: A total of 114 women with cerclage were included (85 (74.6%) ultrasound-indicated and 29 (25.4%) exam-indicated). The first and second total cervical lengths correlated with gestational age at delivery (r = 0.26, p=.005; r = 0.33, p<.001, respectively), and the change from first to second was inversely correlated with gestational age at delivery (r = 0.20, p=.032). The first and second upper cervical lengths also correlated with gestational age at delivery (r = 0.22, p = .019; r = 0.33, p<.001, respectively), and the change from first to second upper cervical length was inversely correlated with gestational age at delivery (r= 0.20, r = 0.029). Neither the first nor the second lower cervical lengths were significantly associated with gestational age at delivery. On regression analysis, total cervical length and upper cervical length were not independently associated with gestational age at delivery (p = .108 and p=.806, respectively, for the first scan; p = .153 and p=.166, respectively, for the second scan). Conclusions: Postcerclage total cervical length and upper cervical length are both associated with gestational age at delivery and risk of preterm birth, but not independently. After ultrasound- or exam-indicated cerclage, sonographic monitoring of either the total cervical length or the upper cervical length might be predictive of gestational age at delivery and the risk of preterm birth. [ABSTRACT FROM AUTHOR]

We present a transformative professional development project with a focus on equity, diversity and social justice (EDSJ) to raise cultural awareness among faculty, increase agency, and promote positive change through transformative projects. Twenty-three faculty members from nine different colleges located at a Research I university were provided with critical cultural awareness workshops and then supported to develop transformative projects related to EDSJ. Based on focus group interviews and pre-post surveys, we identified four themes and five categories: two outcome-related (Building Community and Transformative Actions) and two operational themes (Barriers and Facilitators). We conclude that faculty-centered and transformative professional development projects could significantly benefit all those interested in establishing a culturally inclusive, positive and responsive climate. Our study also contributes to the emerging research on scholar activism and provides a practical model for implementation. [ABSTRACT FROM AUTHOR]

Generating value from lignin through depolymerization and biological conversion to valuable fuels, chemicals, or intermediates has great promise but is limited by several factors including lack of cost-effective depolymerization methods, toxicity within the breakdown products, and low bioconversion of the breakdown products. High yield depolymerization of natural lignins requires cleaving carbon–carbon bonds in addition to ether bonds. To address that need, we report that a chelator-mediated Fenton reaction can efficiently cleave C–C bonds in sulfonated polymers at or near room temperature, and that unwanted repolymerization can be minimized through optimizing reaction conditions. This method was used to depolymerize lignosulfonate from Mw = 28 000 g mol−1 to Mw = 800 g mol−1. The breakdown products were characterized by SEC, FTIR and NMR and evaluated for bioavailability. The breakdown products are rich in acid, aldehyde, and alcohol functionalities but are largely devoid of aromatics and aliphatic dienes. A panel of nine organisms were tested for the ability to grow on the breakdown products. Growth at a low level was observed for several monocultures on the depolymerized lignosulfonate in the absence of glucose. Much stronger growth was observed in the presence of 0.2% glucose and for one organism we demonstrate doubling of melanin production in the presence of depolymerized lignosulfonate. The results suggest that this chelator-mediated Fenton method is a promising new approach for biological conversion of lignin into higher value chemicals or intermediates. [ABSTRACT FROM AUTHOR]

Objective: To assess the association of first-trimester subchorionic hematomas with pregnancy outcomes after 20 weeks of gestation in women with singleton pregnancies.Methods: We conducted a retrospective cohort study of all women with singleton pregnancies presenting for prenatal care before 14 weeks of gestation over a 3-year period at a single obstetric practice. All patients underwent routine first-trimester ultrasound examinations. We compared rates of adverse pregnancy outcomes at more than 20 weeks of gestation in women with and without a subchorionic hematoma on the initial ultrasound examination, excluding women with pregnancy loss before 20 weeks of gestation.Results: From January 2015 to December 2017, a total of 2,172 women met the inclusion criteria for the study, 389 (17.9%) of whom had a subchorionic hematoma (mean largest diameter 2.1±1.4 cm). Women with subchorionic hematomas had their first ultrasound examination at earlier gestational ages (8 5/7 vs 9 6/7 weeks, P<.001) and were more likely to have vaginal bleeding at the time of the ultrasound examination (31.9% vs 7.9%, P<.001). Maternal age, race, use of in vitro fertilization, body mass index, and medical comorbidities did not differ between the groups. On univariable analysis, subchorionic hematoma was not associated with any pregnancy outcomes at more than 20 weeks of gestation, including gestational age at delivery, preterm birth, birth weight, birth weight less than the 10th percentile for gestational age, gestational hypertension, preeclampsia, placental abruption, intrauterine fetal death at more than 20 weeks of gestation, cesarean delivery, blood transfusion, and antepartum admissions. On regression analysis including subchorionic hematoma, vaginal bleeding, and gestational age at ultrasound examination, vaginal bleeding was independently associated with preterm birth at less than 37 weeks of gestation and birth weight less than the 10th percentile. Subchorionic hematoma was not independently associated with pregnancy outcomes. This study had 80% power to detect a 5% absolute difference in the frequency of preterm birth; that is, from 10% to 15%.Conclusion: In singleton pregnancies, a first-trimester subchorionic hematoma is not associated with adverse pregnancy outcomes at more than 20 weeks of gestation. [ABSTRACT FROM AUTHOR]

Even though significant progress has been made on raising awareness about equity and diversity issues in science education in the last two decades, the current push to address the Next Generation Science Standards' (NGSS) emphasis on integrating engineering and scientific practices has opened up new pitfalls. Here, I describe seven of the most salient pitfalls we should all seek to avoid if we are committed to making STEM education more culturally and socially relevant. Suggestions are provided to encourage educators, researchers, and curriculum developers to distinguish and stress the importance of engaging children in STEM instead of teaching STEM to students. [ABSTRACT FROM AUTHOR]

Hydroxycinnamic acids such as p-coumaric acid (CA) are chemically linked to lignin in grassy biomass with fairly labile ester bonds and therefore represent a straightforward opportunity to extract and valorize lignin components. In this work, we investigated the enzymatic conversion of CA extracted from lignocellulose to 4-vinylphenol (4VP) by expressing a microbial phenolic acid decarboxylase in Corynebacterium glutamicum, Escherichia coli, and Bacillus subtilis. The performance of the recombinant strains was evaluated in response to the substrate concentration in rich medium or a lignin liquor and the addition of an organic overlay to perform a continuous product extraction in batch cultures. We found that using undecanol as an overlay enhanced the 4VP titers under high substrate concentrations, while extracting > 97% of the product from the aqueous phase. C. glutamicum showed the highest tolerance to CA and resulted in the accumulation of up to 187 g/L of 4VP from pure CA in the overlay with a 90% yield when using rich media, or 17 g/L of 4VP with a 73% yield from CA extracted from lignin. These results indicate that C. glutamicum is a suitable host for the high-level production of 4VP and that further bioprocess engineering strategies should be explored to optimize the production, extraction, and purification of 4VP from lignin with this organism. [ABSTRACT FROM AUTHOR]

Objective  The aim of this study was to estimate if preterm premature rupture of membranes in women with cerclage is due to the cerclage itself or rather the underlying risk factors for preterm birth in this population. Study Design  This was a retrospective cohort study of singleton pregnancies who underwent Shirodkar cerclage by a single maternal–fetal medicine practice between 2005 and 2019. The control group was an equal number of randomly selected women with a singleton gestation who had a prior preterm birth and were treated with 17-OH-progesterone but no cerclage. Patients with major uterine anomalies or fetal anomalies were excluded. The primary outcome was preterm premature rupture of membranes prior to 34 weeks. Chi-square and logistic regression were used. Results  A total of 350 women with cerclage (154 [44%] history-indicated, 137 [39%] ultrasound-indicated, and 59 [17%] exam-indicated) and 350 controls were included. Preterm premature rupture of membranes prior to 34 weeks did not differ between the groups (8.9% in cerclage vs. 6.0% in controls, p  = 0.149, adjusted odds ratio 0.62, 95% confidence interval: 0.24–1.64) nor between the different cerclage indications (9.1% of history-indicated, 7.3% of ultrasound-indicated, and 11.9% of exam-indicated, p  = 0.582). This study had 80% power with an α error of 0.05 to detect an increase in preterm premature rupture of membranes prior to 34 weeks from 6.0% in the control group to 12.0% in the cerclage group. Conclusion  Cerclage does not increase the risk of preterm premature rupture of membranes prior to 34 weeks compared with other women at increased risk of preterm birth. The observed association between cerclage and preterm premature rupture of membranes is likely due to underlying risk factors and not the cerclage itself. The risk of preterm premature rupture of membranes prior to 34 weeks in women with cerclage is 10% or less and does not appear to differ based on cerclage indication. Key Points Cerclage does not increase the risk of PPROM. Risk of PPROM with cerclage is approximately 10%. Risk does not appear to vary by indication. [ABSTRACT FROM AUTHOR]

The article discusses the history of professional and semi-professional baseball in Lower Rio Grande Valley region of Texas from the 1920s to the 1970s. Teams considered include the Brownsville Tigers, San Benito Nine, and the Mission 30-30s. Topics explored include the social and community building aspects of baseball, racial interactions through baseball, and Mexican and Mexican-American baseball players.

A methodology for the assessment of cell concentration, in the range 5–100 cells/μL, suitable for in vivo analysis of serous body fluids is presented in this work. This methodology is based on the quantitative analysis of ultrasound images obtained from cell suspensions and considers applicability criteria, such as short analysis times, moderate frequency, and absolute concentration estimation, all necessary to deal with the variability of tissues among different patients. Numerical simulations provided the framework to analyze the impact of echo overlapping and the polydispersion of scatterer sizes on the cell concentration estimation. The cell concentration range that can be analyzed as a function of the transducer and emitted waveform used was also discussed. Experiments were conducted to evaluate the performance of the method using 7-μm and 12-μm polystyrene particles in water suspensions in the 5–100 particles/μL range. A single scanning focused transducer working at a central frequency of 20 MHz was used to obtain ultrasound images. The method proposed to estimate the concentration proved to be robust for different particle sizes and variations of gain acquisition settings. The effect of tissues placed in the ultrasound path between the probe and the sample was also investigated using 3-mm-thick tissue mimics. Under this situation, the algorithm was robust for the concentration analysis of 12 μm particle suspensions, yet significant deviations were obtained for the smallest particles. [ABSTRACT FROM AUTHOR]

This article presents an offline solution and online approximation to the hybrid control problem of planar non-prehensile manipulation. Hybrid dynamics and underactuation are key characteristics of this task that complicate the design of feedback controllers. We show that a model predictive control approach used in tandem with integer programming offers a powerful solution to capture the dynamic constraints associated with the friction cone as well as the hybrid nature of contact. We introduce the Model Predictive Controller with Learned Mode Scheduling (MPC-LMS), which leverages integer programming and machine learning techniques to effectively deal with the combinatorial complexity associated with determining sequences of contact modes. We validate the controller design through a numerical simulation study and with experiments on a planar manipulation setup using an industrial ABB IRB 120 robotic arm. Results show that the proposed algorithm achieves closed-loop tracking of a nominal trajectory by reasoning in real-time across multiple contact modalities. [ABSTRACT FROM AUTHOR]

This article is focused on the design of a high-voltage (800 V) bidirectional boost converter with high efficiency at medium-low power levels. Triangular current mode (TCM) enhances the efficiency of the converter at low power, thanks to soft-switching operation, but it requires variable switching frequency and large current ripple through the inductor. The former can be implemented by using silicon carbide (SiC) mosfets and the latter can be minimized by using interleaved modules. At low power, TCM requires high switching frequency, a minimum negative inductor current, and a minimum deadtime to obtain zero voltage switching. These values vary for different input/output voltage ratios and must be properly selected to reduce deadtime losses, normally neglected in the literature since it is assumed that they have low impact. However, it can be relevant at high frequencies (especially for devices with high reverse conduction voltage drop, such as SiC mosfets). In this article, deadtime losses are included in the proposed losses models and the selection of optimum values of deadtime and minimum inductor current to minimize these deadtime losses are analytically evaluated and experimentally validated. [ABSTRACT FROM AUTHOR]

The combined use of 3D-fluorescence spectroscopy and independent component analysis using a differential fingerprinting approach has been applied with success to detect physiological effects of dimethoate in honeybees. Biochemical determinations combined with the identification of fluorescence zones that may correspond to proteins, NADH or neurotransmitters/neurohormones (octopamine, dopamine and serotonin) related to the physiological stress caused by the pesticide enabled phenomenological modeling of the physiological response in the honeybee using a simple and rapid method. The signals associated with the fluorophores involved in the response to stress were extracted from the fluorescence spectra using an unsupervised algorithm such as independent component analysis. The signals of different neurotransmitters were isolated on separated factorial components, thus facilitating their biochemical interpretation. [ABSTRACT FROM AUTHOR]

Multi-step forceful manipulation tasks, such as opening a push-and-twist childproof bottle, require a robot to make various planning choices that are substantially impacted by the requirement to exert force during the task. The robot must reason over discrete and continuous choices relating to the sequence of actions, such as whether to pick up an object, and the parameters of each of those actions, such how to grasp the object. To enable planning and executing forceful manipulation, we augment an existing task and motion planner with constraints that explicitly consider torque and frictional limits, captured through the proposed forceful kinematic chain constraint. In three domains, opening a childproof bottle, twisting a nut and cutting a vegetable, we demonstrate how the system selects from among a combinatorial set of strategies. We also show how cost-sensitive planning can be used to find strategies and parameters that are robust to uncertainty in the physical parameters. [ABSTRACT FROM AUTHOR]

Abstract A significant proportion of neonatal and childhood seizures are poorly controlled by existing anti-seizure drugs (ASDs), likely due to prominent differences in ionic homeostasis and network connectivity between the immature and mature brain. In addition to the poor efficacy of current ASDs, many induce apoptosis, impair synaptic development, and produce behavioral deficits when given during early postnatal development. There is growing interest in new targets, such as cannabidiol (CBD) and its propyl analog cannabidivarin (CBDV) for early life indications. While CBD was recently approved for treatment of refractory childhood epilepsies, little is known about the efficacy or safety of CBDV. Here, we addressed this gap through a systematic evaluation of CBDV against multiple seizure models in postnatal day (P) 10 and 20 animals. We also evaluated the impact of CBDV on acute neurotoxicity in immature rats. CBDV (50–200 mg/kg) displayed an age and model-specific profile of anticonvulsant action. In P10 rats, CBDV suppressed seizures only in the pentylenetetrazole model. In P20 rats, CBDV suppressed seizures in the pentylenetetrazole, DMCM, and maximal electroshock models. Between P10 and P20, we identified significant increases in mRNA expression of TRPV1 in multiple brain regions; when CBDV was tested in P20 TRPV1 knockout mice, anticonvulsant effects were attenuated. Finally, CBDV treatment generally avoided induction of neuronal degeneration in immature rats. Together, the efficacy and safety profile of CBDV suggest it may have therapeutic value for early life seizures. Highlights • Cannabidiol (CBD) was recently approved for early life refractory seizures. • The efficacy and safety profile of the CBD analog, cannabidivarin (CBDV) is unknown. • CBDV displayed age- and model-specific efficacy against seizures in developing animals. • CBDV effects are mediated in part by TRPV1 expression. • CBDV has a favorable safety profile for use during development. [ABSTRACT FROM AUTHOR]

Using a generic model of how active array imaging systems operate, a formal definition of the image as a projection of the reflected wave field onto the wave field emitted to probe the medium is proposed. This definition is applied to the case of imaging in homogeneous and isotropic media to which, by using the frequency-domain solution of the wave equation, the relationship between the calculated image, the emitted and received signals, the positions of the transducers, the speed of the waves used, and the reflectivity of the medium is shown at each point. Then, a general algorithm for the formation of images of a region in this kind of media is derived. Finally, using real and simulated ultrasound signals, images obtained with the proposed signal projection method are compared with those produced by the “de facto” standard delay and sum-based algorithms. [ABSTRACT FROM AUTHOR]

In this paper, we present Tac2Pose, an object-specific approach to tactile pose estimation from the first touch for known objects. Given the object geometry, we learn a tailored perception model in simulation that estimates a probability distribution over possible object poses given a tactile observation. To do so, we simulate the contact shapes that a dense set of object poses would produce on the sensor. Then, given a new contact shape obtained from the sensor, we match it against the pre-computed set using an object-specific embedding learned using contrastive learning. We obtain contact shapes from the sensor with an object-agnostic calibration step that maps RGB (red, green, blue) tactile observations to binary contact shapes. This mapping, which can be reused across object and sensor instances, is the only step trained with real sensor data. This results in a perception model that localizes objects from the first real tactile observation. Importantly, it produces pose distributions and can incorporate additional pose constraints coming from other perception systems, multiple contacts, or priors. We provide quantitative results for 20 objects. Tac2Pose provides high accuracy pose estimations from distinctive tactile observations while regressing meaningful pose distributions to account for those contact shapes that could result from different object poses. We extend and test Tac2Pose in multi-contact scenarios where two tactile sensors are simultaneously in contact with the object, as during a grasp with a parallel jaw gripper. We further show that when the output pose distribution is filtered with a prior on the object pose, Tac2Pose is often able to improve significantly on the prior. This suggests synergistic use of Tac2Pose with additional sensing modalities (e.g., vision) even in cases where the tactile observation from a grasp is not sufficiently discriminative. Given a coarse estimate of an object's pose, even ambiguous contacts can be used to determine an object's pose precisely. We also test Tac2Pose on object models reconstructed from a 3D scanner, to evaluate the robustness to uncertainty in the object model. We show that even in the presence of model uncertainty, Tac2Pose is able to achieve fine accuracy comparable to when the object model is the manufacturer's CAD (computer-aided design) model. Finally, we demonstrate the advantages of Tac2Pose compared with three baseline methods for tactile pose estimation: directly regressing the object pose with a neural network, matching an observed contact to a set of possible contacts using a standard classification neural network, and direct pixel comparison of an observed contact with a set of possible contacts. Website: mcube.mit.edu/research/tac2pose.html [ABSTRACT FROM AUTHOR]

Vibrio parahaemolyticus and Vibrio harveyi are commonly associated with brine shrimp, where they proliferate at the time of hatching and colonize nauplius surfaces, becoming a potential risk to organisms feeding on them. Among the strategies to prevent their occurrence, the use of chemotherapeutic agents and disinfectants could be considered; however, these strategies have side effects on the quality of brine shrimp and the environment. As a consequence, the use of bacteriophages (phages) is gaining interest in aquaculture. In this study, we investigated the effect of phage therapy (single phages and cocktails) on hatching and survival of brine shrimp ( Artemia franciscana ) cysts and nauplii exposed to pathogenic strains of V. parahaemolyticus and V. harveyi. The results revealed that application of single phages enhanced significantly ( p  < 0.05) the hatching success and survival rate, even at low multiplicity of infection (MOI). Subsequently, these promising phages were mixed (cocktails) and administered to brine shrimp cysts and nauplii exposed to both pathogenic Vibrio species. The results also revealed an enhanced hatching success (100% in both cases) and survival rate (from 85 to 89%) in groups treated with phage cocktails, whereas control groups had a hatching success of around 50% and survival rate from 40 to 50%. Given this, phage cocktails offer an alternative to chemotherapeutic agents routinely used in brine shrimp production. [ABSTRACT FROM AUTHOR]

Summary: Objective: Phenobarbital is the most commonly utilized drug for the treatment of neonatal seizures. The use of phenobarbital continues despite growing evidence that it exerts suboptimal seizure control and is associated with long‐term alterations in brain structure, function, and behavior. Alterations following neonatal phenobarbital exposure include acute induction of neuronal apoptosis, disruption of synaptic development in the striatum, and a host of behavioral deficits. These behavioral deficits include those in learning and memory mediated by the hippocampus. However, the synaptic changes caused by acute exposure to phenobarbital that lead to lasting effects on brain function and behavior remain understudied. Methods: Postnatal day (P)7 rat pups were treated with phenobarbital (75 mg/kg) or saline. On P13‐14 or P29‐37, acute slices were prepared and whole‐cell patch‐clamp recordings were made from CA1 pyramidal neurons. Results: At P14 we found an increase in miniature inhibitory postsynaptic current (mIPSC) frequency in the phenobarbital‐exposed as compared to the saline‐exposed group. In addition to this change in mIPSC frequency, the phenobarbital group displayed larger bicuculline‐sensitive tonic currents, decreased capacitance and membrane time constant, and a surprising persistence of giant depolarizing potentials. At P29+, the frequency of mIPSCs in the saline‐exposed group had increased significantly from the frequency at P14, typical of normal synaptic development; at this age the phenobarbital‐exposed group displayed a lower mIPSC frequency than did the control group. Spontaneous inhibitory postsynaptic current (sIPSC) frequency was unaffected at either P14 or P29+. Significance: These neurophysiological alterations following phenobarbital exposure provide a potential mechanism by which acute phenobarbital exposure can have a long‐lasting impact on brain development and behavior. [ABSTRACT FROM AUTHOR]

A converter intended to be used for the interconnection of battery-based energy storage systems with the cells of a multilevel converter is addressed in this paper. High efficiency at light and medium loads is important in these applications and it can be achieved using soft switching techniques. Two control techniques with fixed and variable switching frequency are proposed and compared. The use of silicon carbide (SiC) mosfets provides a higher attainable switching frequency, which is especially interesting in variable frequency control techniques, allowing the operation at high voltages and high switching frequencies, with high efficiencies over a wide power range. A synchronous boost DC/DC converter rated for 400 to 800 V and 10 kW is designed and developed with SiC mosfets obtaining efficiencies higher than 97% from 100% to 3.5% of full load using a variable switching frequency (up to 200 kHz) control. Significant efficiency improvement is achieved at medium and light loads. [ABSTRACT FROM PUBLISHER]

Quasi-square wave mode with zero voltage switching (QSW-ZVS) is an operation mode in which the switching losses can be minimized. However, a large inductance current ripple is needed in this mode, which limits the maximum attainable power of the topology. A possible way to increase the power managed by a QSW-ZVS mode converter is to use a modular converter. An input parallel output parallel (IPOP) arrangement, in which the current can be shared among the modules, can increase the total power proportionally to the number of modules. This paper addresses two main proposals. The first one is a master–slave technique to extend the QSW-ZVS mode to an IPOP modular converter, achieving an interleaved solution which minimizes the total input current ripple and assures the current balance among the modules. The second one is a comparison of four different control techniques applied to the IPOP modular converter to improve the overall efficiency at light to medium load: balanced master–slave technique, master–slave with phase-shedding, asymmetrical master–slave, and burst mode (or hysteretic control). These four strategies are theoretically analyzed, experimentally validated and compared using a 150–400 V 2 kW modular IPOP prototype made up of four synchronous boost converter operating in QSW-ZVS mode. [ABSTRACT FROM PUBLISHER]

This paper is focused on a high-voltage (400 to 800 V) bidirectional converter, which is intended to be used for the interconnection of battery-based energy-storage systems with the cells of a modular multilevel converter, providing distributed energy-storage capability to a solid-state transformer. This converter must have a high efficiency at medium and light load and also a low current ripple due to the charging and discharging processes. This work takes advantage of the use of SiC MOSFETs into a synchronous boost converter to accomplish the previous requirements. First, the adoption of a variable-switching frequency control to keep the efficiency high is analyzed, and second, the use of a modular converter with different control techniques to provide a current ripple reduction is also addressed in this study. An input-parallel–output-parallel synchronous boost converter, made up with three modules (3 kW per module), is used to validate experimentally the advantages of the use of SiC MOSFETs and to compare different control techniques. [ABSTRACT FROM PUBLISHER]

Making engineering and science culturally and socially relevant requires teachers to have broader content knowledge and an increased repertoire of pedagogical skills. One aspect of being an effective and culturally inclusive teacher that is seldom discussed is the ability to engage with the emotions associated with working for social justice. In other words, teachers need to be prepared to address the mixed emotions and desire to effect social change that students (children or adults) often experience when exposed to the very real social inequalities present in their own communities or in the world. This issue is particularly important now that the Next Generation Science Education Standards, and its emphasis on engineering practices, calls for students to engage in more problem solving of real world issues. This article seeks to raise awareness aboutcritical emotional pedagogyandcritical emotional literacyas 2 additional tools that are likely to augment teachers and researchers’ professional tool kit when interested in building a culturally inclusive and socially relevant learning environment. [ABSTRACT FROM PUBLISHER]

The aim of this study was to determine whether markers of inflammation and coagulation are associated with short-term particulate matter exposure and predict major adverse cardiovascular events at 360 d in patients with acute coronary syndrome (ACS). We included 307 consecutive patients, and assessed the average concentrations of data on atmospheric pollution in ambient air and meteorological variables from 1 d up to 7 d prior to admission. In patients with ACS, the markers of endothelial activation and coagulation, but not black carbon exposure, are associated with major adverse cardiovascular events at one-year follow-up. [ABSTRACT FROM AUTHOR]

1,3-propanediol (PDO) production from raw glycerol using Shimwellia blattae ATCC 33430 has been studied. Batch cultures of S. blattae under anaerobic conditions have been carried out changing the initial substrate concentration. A kinetic model is proposed to describe the evolution of experimental glycerol, biomass, PDO and by-products concentrations, achieved at different times. The model is able to simulate adequately the experimental data of runs conducted at six different initial raw glycerol concentrations and the parameter values describe the influence of initial substrate concentration on the metabolism of the bacteria. The process was clearly inhibited by initial glycerol concentration from 57.8 g/L, affecting the biomass growth, the PDO production and the by-products metabolic flux, that winded up to lactic acid and ethanol synthesis. The best PDO production results were obtained when using around 30 g/L of initial glycerol concentration, reaching 13.6 g PDO/L, with a yield of 0.49 g/g and a productivity of 1.36 g/(L h). [ABSTRACT FROM AUTHOR]

The MARIA randomized trial evaluated the efficacy and safety of melatonin for the reduction of reperfusion injury in patients undergoing revascularization for ST-elevation myocardial infarction ( STEMI). This was a prespecified interim analysis. A total of 146 patients presenting with STEMI within 6 hours of chest pain onset were randomized to receive intravenous and intracoronary melatonin (n=73) or placebo (n=73) during primary percutaneous coronary intervention ( PPCI). Primary endpoint was myocardial infarct size as assessed by magnetic resonance imaging ( MRI) at 6 ± 2 days. Secondary endpoints were changes in left ventricular volumes and ejection fraction ( LVEF) at 130 ± 10 days post- PPCI and adverse events during the first year. No significant differences in baseline characteristics were observed between groups. MRI was performed in 108 patients (86.4%). Myocardial infarct size by MRI evaluated 6 ± 2 days post- PPCI, did not differ between melatonin and placebo groups ( P=.63). Infarct size assessed by MRI at 130 ± 10 days post- PPCI, performed in 91 patients (72.8%), did not show statistically significant differences between groups ( P=.27). The recovery of LVEF from 6 ± 2 to 130 ± 10 days post- PPCI was greater in the placebo group (60.0 ± 10.4% vs 53.1 ± 12.5%, P=.008). Both left ventricular end-diastolic and end-systolic volumes were lower in the placebo group ( P=.01). The incidence of adverse events at 1 year was comparable in both groups ( P=.150). Thus, in a nonrestricted STEMI population, intravenous and intracoronary melatonin was not associated with a reduction in infarct size and has an unfavourable effect on the ventricular volumes and LVEF evolution. Likewise, there is lack of toxicity of melatonin with the doses used. [ABSTRACT FROM AUTHOR]

Background Cardiac resynchronization therapy (CRT) is an effective treatment for left ventricular reverse remodeling (LVRR) in patients with congestive heart failure (HF) and ventricular dyssynchrony. Melatonin is a secretory product of the pineal gland with highly beneficial effects from any tissues including the heart. Herein, we investigated whether the response to CRT is associated with levels of melatonin before CRT implantation in patients with HF and ventricular dyssynchrony. Methods Diurnal melatonin levels were performed in serum from 93 patients with HF and ventricular dyssynchrony before CRT implantation. Moreover, we calculated the MADIT-CRT score. Evaluation of patients at 1-year follow-up included an echocardiographic study since the patients were categorized as responders if they presented both a reduction in left ventricular end-systolic volume index > 10% and an increase in left ventricular ejection fraction > 10%. Results At 1-year, 34 patients (36.5%) were considered responders to CRT according to the predefined criteria. The diurnal melatonin levels were significantly lower in the non-responder group (9.9 ± 2.84 vs 14.7 ± 2.32 pg/mL). After adjustment by multivariate analysis, diurnal serum melatonin levels ( P < 0.001) and diabetes mellitus ( P = 0.03) were predictors of LVRR. On Cox regression analysis, diurnal serum melatonin levels ( P < 0.001) and left atrial volume < 40 mL/m 2 ( P = 0.04) remained independent predictors of the adverse clinical events. The area under of curve for the prediction LVRR of melatonin (0.91, 95%CI 0.85–0.97; P < 0.001) was significantly higher compared to MADIT-CRT score (0.69, 95%CI 0.58–0.80; P = 0.002). Conclusion Diurnal levels of melatonin before CRT implantation are associated with LVRR at 12 month follow-up. [ABSTRACT FROM AUTHOR]

Growth differentiation factor-15 (GDF-15) is produced by cardiomyocytes and atherosclerotic lesions under stress conditions, but little is known about its relation with severity and complexity of coronary lesions. The aim of this study was to investigate the association between GDF-15 and the syntax score for risk prediction of major adverse cardiovascular events (MACE) at 2-year follow-up in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). This is a prospective cohort study of 502 patients with NSTEACS. The syntax score was calculated from baseline coronary angiography. Blood samples were obtained at study entry for the assessment of GDF-15 and high-sensitivity C reactive protein. One hundred and three patients (20.5%) showed MACE at 2-year follow-up. Patients who developed MACE had greater GDF-15 concentrations and syntax score (p <0.001) compared to patients who did not. There was a positive, but moderate, correlation between GDF-15 and syntax score (ρ = 0.45, p <0.0001). On Cox regression analysis, only GDF-15 levels (p <0.001), body mass index (p = 0.04), and syntax score (p <0.001) remained independent predictors of the MACE. The area under the curve of GDF-15 (0.912, 95% confidence interval 0.894 to 0.944) was significantly greater compared to high-sensitivity C reactive protein and syntax score. In conclusion, in patients with NSTEACS, levels of GDF-15 at admission were correlated with the syntax score and independently associated with an increased risk of MACE during 2-year follow-up. [ABSTRACT FROM AUTHOR]

Shimwellia blattae ATCC 33430 as biocatalyst in the conversion of 1,3-propanediol from glycerol is herein evaluated. Several operational conditions in batch cultivations, employing pure and raw glycerol as sole carbon source, were studied. Temperature was studied at shaken bottle scale, while pH control strategy, together with the influence of raw glycerol and its impurities during fermentation were studied employing a 2 L STBR. Thereafter, fluid dynamic conditions were considered by changing the stirring speed and the gas supply (air or nitrogen) in the same scale-up experiments. The best results were obtained at a temperature of 37 °C, an agitation rate of 200 rpm, with free pH evolution from 6.9 and subsequent control at 6.5 and no gas supply during the fermentation, employing an initial concentration of 30 g/L of raw glycerol. Under these conditions, the biocatalyst is competitive, leading to results in line with other previous works in the literature in batch conditions, reaching a final concentration of 1,3-propanediol of 13.84 g/L, with a yield of 0.45 g/g and a productivity of 1.19 g/(L h) from raw glycerol. [ABSTRACT FROM AUTHOR]

Envelope tracking (ET) is a technique designed to enhance the efficiency of radio frequency power amplifiers (RF PA). It is based on providing the voltage to the RF PA with variations that mimic the shape of the envelope of the communication signal that the RF PA is processing. As the bandwidth of these signals can be around several megahertz, the switching frequency of the switching mode power supply designed for ET applications has to be very high. The good switching characteristics of Gallium Nitride devices makes them suitable for this application. This paper presents two multiphase converters to be used as envelope modulators in envelope tracking applications. [ABSTRACT FROM AUTHOR]

This paper addresses the performance of the bidirectional dual active bridge (DAB) converter. One of the advantages of the DAB is the possibility to achieve the zero-voltage switching (ZVS) operation in all the switches of this converter. However, the ZVS operation range can be lost for light loads, especially if high voltage is required in at least one of the DAB ports and the phase-shift control is used to regulate the power processed by the converter. Theoretically simple averaged and small-signal models are presented for the DAB converter. Using the study presented in this paper, the boundaries of the ZVS operation can be easily evaluated. The proposed models and analysis of the ZVS boundaries allow the proposal and evaluation of two different design strategies with different purposes: on the one hand, increasing the ZVS operation range and, on the other, improving efficiency at full load. Moreover, some techniques are presented for increasing the ZVS operation range and improving the efficiency of the DAB at full load (both using phase-shift control) employing the aforementioned analysis to obtain certain design criteria and conclusions. Finally, the proposed models, design strategies, and techniques to improve the performance of the DAB are experimentally tested using a 1-kW prototype with input and output voltages of 48 and 400 V, respectively. [ABSTRACT FROM AUTHOR]

The production of aromatic amino acids using fermentation processes with recombinant microorganisms can be an advantageous approach to reach their global demands. In addition, a large array of compounds with alimentary and pharmaceutical applications can potentially be synthesized from intermediates of this metabolic pathway. However, contrary to other amino acids and primary metabolites, the artificial channelling of building blocks from central metabolism towards the aromatic amino acid pathway is complicated to achieve in an efficient manner. The length and complex regulation of this pathway have progressively called for the employment of more integral approaches, promoting the merge of complementary tools and techniques in order to surpass metabolic and regulatory bottlenecks. As a result, relevant insights on the subject have been obtained during the last years, especially with genetically modified strains of Escherichia coli. By combining metabolic engineering strategies with developments in synthetic biology, systems biology and bioprocess engineering, notable advances were achieved regarding the generation, characterization and optimization of E. coli strains for the overproduction of aromatic amino acids, some of their precursors and related compounds. In this paper we review and compare recent successful reports dealing with the modification of metabolic traits to attain these objectives. [ABSTRACT FROM AUTHOR]

Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine that increased in patients with established type 2 diabetes mellitus (DM). Diabetic cardiomyopathy (DC), defined as left ventricular diastolic dysfunction (LVDD) in patients with type 2 DM in the absence of arterial hypertension, heart disease, or other heart disease, was assessed by GDF-15 levels in type 2 DM patients with and without DC. A total of 213 DM outpatients had blood samples drawn and on the same day (basal) underwent echocardiography and treadmill exercise testing. Plasma GDF-15 concentrations were measured by an enzymelinked immunosorbent assay (ELISA) at baseline. DC was diagnosed in the presence of LVDD, defined when early mitral valve flow velocity (E) and early diastolic lengthening velocity (E') ratio was E/E' ⩾15. The prevalence of DC was 21.13%. GDF-15 levels were higher in patients with DC compared with those without DC (5,273 [8,708.4] vs 2,812.66 [7,662.1] pg/ml, respectively, p <0.001). We assessed predictors of DC using multivariate regression analysis. GDF-15 (odds ratio 9.9; 95% confidence interval [3.9 to 24.5], p <0.001) was the unique independent predictor of DC. The results of receiver operating characteristic curve show that the cut-off point of 3,812 pg/ml of GDF-15 was indicative for DC (AUC = 0.83, sensitivity = 82.2% and specificity = 70.2%, p <0.0001). In conclusion, GDF-15 represents a useful and novel tool to screen DC in patients with type 2 DM. [ABSTRACT FROM AUTHOR]

This paper studies the robustness of grasping in the frictionless plane from a geometric perspective. By treating grasping as a process that shapes the free-space object over time, we define three types of certificates to guarantee success of a grasp: (a) invariance under an initial set, (b) convergence toward a goal grasp, and (c) observability over the final object pose. We develop convex-combinatorial models for each of these certificates, which can be expressed as simple semi-algebraic relations under mild-modeling assumptions, such as point-fingers and frictionless contact. By leveraging these models to synthesize certificates, we optimize certifiable grasps of planar objects composed as a union of convex polygons, using manipulators described as point-fingers. We validate this approach in simulations by grasping random polygons, and with real sensorless grasps of several objects. [ABSTRACT FROM AUTHOR]

The new wide band-gap semiconductor devices provide new properties to be explored. Normally on silicon carbide (SiC) JFET power devices have several advantages, in particular low switching losses and the potential capabilities of high temperature and high reverse blocking voltage. Looking for improving the overall efficiency in power converters, new structures based on these power devices might be studied. In this paper, a cascode rectifier based on normally on SiC JFET is presented and analyzed. This rectification structure can be applied as front-end rectifier stage for ac-dc power converters, increasing the overall efficiency of these topologies. A second cascode rectifier based on silicon (Si) MOSFET is also studied, as a low-cost alternative. A simple static forward characterization and a brief dynamic behavior analysis of the proposed cascode rectifier structure are made. Both cascode structures are compared with traditional Si rectifier diodes and front-end rectifiers, using an active power factor corrector (PFC) interleaved boost converter. As a result of this comparison, an efficiency improvement as high as two points is obtained. An additional OR gate based on a diode is also used as second test circuit to compare the proposed structures to the traditional Si rectifiers. A reduction between 75% and 55% of the total loss are obtained in this second experimental test. [ABSTRACT FROM AUTHOR]

Grasping an object is usually only an intermediate goal for a robotic manipulator. To finish the task, the robot needs to know where the object is in its hand and what action to execute. This paper presents a general statistical framework to address these problems. Given a novel object, the robot learns a statistical model of grasp state conditioned on sensor values. The robot also builds a statistical model of the requirements for a successful execution of the task in terms of uncertainty in the state of the grasp. Both of these models are constructed by offline experiments. The online process then grasps objects and chooses actions to maximize likelihood of success. This paper describes the framework in detail, and demonstrates its effectiveness experimentally in placing, dropping, and insertion tasks. To construct statistical models, the robot performed over 8,000 grasp trials, and over 1,000 trials each of placing, dropping, and insertion. [ABSTRACT FROM AUTHOR]

Among the numerous emerging biomarkers, high-sensitivity C-reactive protein (hsCRP) and growth-differentiation factor-15 (GDF-15) have received widespread interest, with their potential role as predictors of cardiovascular risk. The concentrations of inflammatory biomarkers, however, are influenced, among others, by physiological variations, which are the natural, with in individual variation occurring over time. The aims of our study are: (a) to describe the changes in hsCRP and GDF-15 levels over a period of time and after an episode of non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and (b) to examine whether the rate of change in hsCRP and GDF-15 after the acute event is associated with long-term major cardiovascular adverse events (MACE). Two hundred and Fifty five NSTE-ACS patients were included in the study. We measured hsCRP and GDF-15 concentrations, at admission and again 36 months after admission (end of the follow-up period). The present study shows that the change of hsCRP levels, measured after 36 months, does not predict MACE in NSTEACS-patients. However, the level of GDF-15 measured, after 36 months, was a stronger predictor of MACE, in comparison to the acute unstable phase. [ABSTRACT FROM AUTHOR]

Objective: Calculate the risk of miscarriage in women with a viable (defined as presence of fetal heart rate on ultrasound) first trimester singleton pregnancy and to create a model for stratified risk-assessment for pregnancy loss based on significant risk factors. Study Design: Retrospective cohort study of unselected women with singleton pregnancies in a large obstetrical practice who presented for prenatal care prior to 14 weeks over a three-year period. All women underwent a formal first-trimester ultrasound, and we only included women with viable pregnancies with fetal heart activity seen on that ultrasound. Our primary outcome was pregnancy loss prior to 20 weeks. Statistical modeling was used to create a risk-assessment tool from adjusted likelihood ratios of pregnancy loss based on risk factors independently associated with this outcome. Results: From January 2015-December 2017, 2,446 women met the inclusion criteria for the study and 132 (5.4%) had a pregnancy loss <20 weeks. On regression analysis, the independent risk factors for pregnancy loss were earlier gestational age (aOR 0.72, 95% CI 0.65-0.80) and increasing number of prior miscarriages (aOR 1.56, 95% CI 1.32-1.83). Using these risk factors, we calculated the stratified risk of pregnancy loss, which ranged from 0.8% in women at 13 weeks of gestation with no prior miscarriages to 33.7% in women at six weeks of gestation with three or more prior miscarriages. Conclusion: In first trimester singleton pregnancies, the overall risk of pregnancy loss <20 weeks after confirmation of fetal heart activity is 5.4%, but can be stratified for each woman and ranges from 0.8% to 33.7% based on the gestational age and number of prior pregnancy losses. [ABSTRACT FROM AUTHOR]

Low circulating melatonin levels predict poor outcome in patients with ST-segment elevation myocardial infarction (STEMI). In the present study, we investigated whether a relationship between myocardial deformation in parameters measured by echocardiography and circulating melatonin level exists. We prospectively included 112 patients with STEMI who performed echocardiography and simultaneous measurement of serum melatonin, during the light period within 72 h of admission. We found a negative correlation between circulating melatonin levels and global longitudinal strain ( p = 0.006, r = −0.33). In conclusion, melatonin levels have a correlation with two-dimensional speckle tracking in patients with STEMI. [ABSTRACT FROM AUTHOR]

The mechanism of coronary thrombus formation is a complex phenomenon that involves different cellular components. ARTERIA is a prospective, multicenter study that will include patients presenting with a diagnosis of ST-elevation acute coronary syndrome undergoing thrombus aspiration during an emergency primary percutaneous coronary revascularization. The purpose of the ARTERIA study is to try to clarify whether there is an association between inflammatory markers measured in blood and in intracoronary thrombi and, if any, what set of molecules provides better prognostic information in these patients. Our study will help to elucidate the complex relationship between thrombus and circulating blood. [ABSTRACT FROM AUTHOR]

This article describes a prospective study of 1,200 participants, half of whom were offspring of trauma survivors, and their emotional symptom levels before and after the Corralito, an economic crisis that occurred in Argentina at the end of 2001. The authors report pre- and postcrisis data on anxiety and depression in a group of adult offspring of victims of the Dirty War (1976–1983) in an attempt to ascertain whether they are at greater risk than a control group for developing anxiety and depression in response to an economic crisis. The results indicated the offspring of war victims experienced greater emotional distress than the control subjects before, but not after the imposition of the Corralito. [ABSTRACT FROM AUTHOR]

As experimental studies suggest that melatonin is cardioprotective after myocardial infarction (MI), this study sought to investigate the relationships between circulating levels of melatonin and left ventricular (LV) remodelling in patients after acute MI. This prospective study included 161 patients (age 61 ± 3 yr; 78% men) undergoing primary percutaneous coronary intervention who were assessed echocardiographically at hospital discharge (day 3-7) and at 12 months. LV remodelling was defined as >20% increase in LV end-diastolic volume at 12-month follow-up compared with baseline. Serum melatonin concentrations were measured at admission, during the light period. Twenty-four patients showed LV remodelling, and 137 had no evidence of LV remodelling. Patients with LV remodelling had lower levels of melatonin at study entry [9.96 (8.28-11.03) versus 16.74 (13.77-19.59) pg/mL, respectively; P < 0.0001]. Multivariate analysis showed that melatonin levels (OR = 2.10, CI 95% 1.547-2.870, P < 0.001) were an independent predictor of LV remodelling at 12-month follow-up. Receiver operating characteristic (ROC) analysis showed an area under the curve of 0.959 (CI 95% 0.93-0.98; P < 0.0001). To our knowledge, this is the first study to show the relationship between melatonin and LV remodelling during the chronic phase post-MI. [ABSTRACT FROM AUTHOR]

This paper revisits the notion of free configuration space and reviews some of its path-connectivity-related properties. The literature on motion planning reveals at least three different definitions for the free configuration space of a robot in the presence of obstacles. This paper shows that, assuming regularity of both object and obstacles, those three definitions are equivalent. We show that the three definitions regularize the free space and therefore prevent the existence of “thin bits,” or low-dimensional strata. The paper concludes by discussing a series of properties regarding the existence and smoothability of contact-free paths between pairs of configurations. [ABSTRACT FROM AUTHOR]

This paper digs into the relationship between cages and grasps of a rigid body. In particular, it considers the use of cages as waypoints to grasp an object. We introduce the concept of pregrasping cages, caging configurations from which an object can be grasped without first breaking the cage. For two-fingered manipulators, all cages are pregrasping cages and, consequently, useful waypoints to grasp an object. A contribution of this paper is to show that the same does not hold for more than two fingers. A second contribution is to show how to overcome that limitation. We explore the natural generalization of the well-understood squeezing/stretching characterization of two-finger cages to arbitrary workspace dimension, arbitrary object shapes without holes, and arbitrary number of point fingers, and exploit it to give sufficient conditions for a cage to be a pregrasping cage. As a product of that generalization, we introduce grasping functions: scalar functions defined on the finger formation that control the process of going from a cage to a grasp. We finish the paper by establishing an analogy between the role of grasping functions in grasping and that of Lyapunov functions in stability theory. [ABSTRACT FROM PUBLISHER]