bluuebunny/crossref_metadata_2025 huggingface dataset:
Plastisisation of polyvinilchloride biofilms with palm oil oleine and methylmethacrylate as comonomer
Authors: Wirjosentono Basuki , Nasution Darwin Yunus , Nasution Diana Adnanda
Published: June 2022

Polyvinylchloride (PVC) is the second largest thermoplastics produced after polyethylene (PE), polypropylene (PP) and polystyrene (PS), especially for packaging, households, toys, and other commodity products. However when used for food packaging, PVC has to be plastisised using plastisisers (added upto 30%), which may not comply with safety requirements for food biofilms. Palm oil oleine (POO) is a nontoxic and edible triglyceride containing double bond and can be bounded onto PVC backbone in the presence of methylmethacrylate (MMA) as comonomer and benzylperoxide (BPO) as initiator. The PVC resin was dissolved in tetrahydrofurane (THF), added with POO, MMA and BPO, (in various compositions), under constant stirring in a reflux reactor. The reaction mixtures were then refluxed for 3 hours under nitrogen atmosphere at constant pressure 1 atm. Plastisised PVC films were obtained after casting the reaction mixtures on a glass plates, and dried under vacuum at constant temperature 40°C. Mechanical properties of the films were tested and their morphology were analysed under scanning electron microscope (SEM) and FTIR spectoscopy. Optimum clear and flexible PVC films was obtained when weight composition of the reaction mixture: PVC/MMA/POO/BPO: 2/0.5/0.5/0.35. Elongation at break of the optimum film was more than 95% higher, whereas the tensile strength was 60% lower when compare to those of pure casted PVC film. SEM analysis of the film surface also showed good homogenous morphology, whereas analysis of FTIR spectra of the films before and after exhausted washing in n-hexane, indicating 48.5% binding of MMA and POO in the PVC films.
Thermal study of Ca(OH)2 coated OPEFB fibers from limestone through the calcination-hydration process
Authors: Nikmatin Siti , Irmansyah  , Indro Muhammad Nur , Heryan Gito , Sholikhah Mirna Mariani
Published: June 2022

Limestone is one of the main mineral sources in the form of CaCO3, which is very abundant in nature. Limestone can be converted into other forms of calcium for special needs in various fields. The purpose of this research was to convert limestone as a source of CaCO3 to Ca(OH)2 as a temporary flame-retardant material that can be applied to OPEFB fibers to improve their thermal properties. The manufacturing process used calcination-hydration, namely the process of converting from CaCO3 to Ca(OH)2. The testing method used was the hanging test technique and the flammability test. Both of these techniques were used to deter mine the best sample as an instantaneous flame-retardant material in OPEFB fibers. The results showed that the best sample with a calcination temperature of 800 °C with a concentration of 1 M and immersion time of 10 minutes achieved the optimum thermal properties which were able to increase its thermal properties with a flame retaining time of more than 45 seconds. This was evidenced by the increase in the value of onset x and the tip point of x samples using TGA, as well as an increase in the intensity of the alkanes and alkenes functional groups through FTIR.
Thermal hydrolysate of coconut trunk, coir, and shell as bioherbicide
Authors: Agusta H , Guntoro D , Yunindanova M B , Sari M N
Published: June 2022

Biomass of coconut trunk, coir, and shell as lignocellulosic waste was partially hydrolyzed in sub-critical temperature for a relatively short time. The process was implemented in an anaerobic condition which produced predominantly phenolics compounds and other complexes’ organic constituents. Base on previous findings, in which allelopathic effects of growing vegetation were sourced by phenolics compounds, the filtrates of the hydrolysates were tested as bioherbicide on Borreria alata as a broadleaf weed. The testing of the weed growth covered the weed response at pre-emergence, early post-emergence, and post-emergence stages. The hydrolysate solution contained phenolic, carboxylic, and ketone groups with a yield of less than 12 mg/kg feedstock after undergoing the thermal hydrolyzation process at subcritical temperature. At the post-emergence stage, coconut shell hydrolysates were capable to suppress the growth of Borreria alata by 13-40% and cause leaf damage at the level of 43-63%. However, its effectivity was higher at the pre-emergence and the early post-emergence stages, where the suppression capacity of shell hydrolysate on the weed growth reached 84-100%.
Equilibrium Behavior of CO2 Adsorption from Biogas onto Zeolites
Authors: Kindi Hablinur Al , Tambunan Armansyah H , Hartulistiyoso Edy , Salundik  , Fadillah Achmad Kemal , Yuliana Iyan
Published: June 2022

Biogas is one of the types of renewable energy that has a major gas content of CH4 and CO2. One of the methods for upgrading biogas is adsorption. The principle of adsorption’s work is to deliver biogas into a column with containing adsorbent, so that a CO2 gas is bound to zeolite, causing the CH4 to increase in the result product. The biogas used in research came from a cow feces that was dumped into a 10bar pressure vessel. Adsorbent used zeolite 13X that was activated. The biogas tube has a height 0.3 m and diameter 3 cm. It was made of stainless steel and there was a cartridge heater inside. Biogas was channeled into adsorbent column with pressure variations 0.8, 1.2, 1.6 and 2 bars and temperature variations 30, 50 and 100°C. The flow rate of biogas used 4 L/minute with a 4-minute data retrieval. Data retrieval was continuous, so that the composition of CO2 gas from beginning to end recorded on the Gas analyzer. The research aims to identify the balance of adsorption with variations in pressure and temperature by Langmuir equation which has been developed. The results show if the higher the pressure, then CO2 that was absorbed is inversely proportional to the temperature where the higher the temperature, the less CO2 was adsorbed. This research succeeded in getting the Langmuir constant, maximum amount adsorbed of CO2, and heat of adsorption.
Refining of Fish Oil from Fish Meal Processing By-product Using Zeolite and Bleaching Earth
Authors: Tandewi Sang Ayu Made Sri , Hambali Erliza
Published: June 2022

As a by-product of the fish meal processing by-product industry, fish oil is a material that has the potential to be reused if it undergoes further processing. What can be done is the bleaching process. This study aims to determine the quality of fish oil before and after the addition of adsorbent, obtain information on the best bleaching process conditions, determine the effect of the best type and concentration of adsorbent on the quality of fish oil, obtain the best adsorbent and concentration. Crude fish oil is weighed and heated. Then, when the temperature has reached 55-60 °C, adsorbents with various concentrations are added. The oil was then reheated and stirred at 80 °C for 30 minutes. After that, the oil was centrifuged at 6500 rpm for 20 minutes. The best type and adsorbent for the bleaching process was obtained using zeolite adsorbent with a concentration of 5%. The interaction of adsorbent type and concentration significantly affected each test parameter of yield, density, viscosity, free fatty acid content, acid number, peroxide number, total oxidation number, and p-anisidine number on the quality of fish oil.
Phytotoxicity of chromium-containing wastewater on germination and growth of Oryza sativa L
Authors: Taufikurahman Taufik , Rizkyani Raden Roro Deby A. , Rahmawati Andira
Published: June 2022

Leather tanning industries in Sukaregang area, Garut district-West Java, have been using chromium since 1980s. Since that time chromium containing wastewater has been polluting river water in the area since there has not been effective waste water treatment available until today. The polluted river water spread bad smell to the environment and the water also has been used by local farmers to irrigate their paddy field. This research was conducted to examine the effect of chromium containing wastewater to growth of paddy, including the physiology stress in plant organs. For examination of the effect of chromium to plant growth, Ciherang variety (Cvar) of paddy was grown in soil and treated with chemical solutions of K2Cr2O7 with concentrations of 50, 100, 200 mg/L, polluted river water (PRW) and distilled water as a control. Direct exposure of chromium 100-200 mg/L killed the plants a week after treatment. Exposure of the plant to wastewater and chromium 50 mg/L reduced plants growth. In Cr 50 mg/L treatment, chlorophyll content in paddy decreased to 60.82%, while the proline concentration in leaves increased by 18.47%. The activity of CAT and APX enzymes also increased, especially in paddy leaves after treated with Cr 50 mg/L, with the highest CAT activity value reached 1990.31 units/mg (an increase of 76.76%) and APX activity of 59.91 units/mg (an increase of 81.02%). The effect of chromium-containing wastewater to paddy was similar to the effect when the plant was exposed to 50 mg/L of chromium.
LCA analysis and quantification of adsorption performance of Kanuma clay by simultaneous adsorption of H2S and NH3
Authors: Torii Kento , Dowaki Kiyoshi
Published: June 2022

In recent years, fuel cell (FC) applications have shown promise in contributing to the abatement of greenhouse gas (GHG) emissions, thereby expanding the demand for hydrogen fuel. Currently, non-renewable sources such as fossil fuels are the primary source of hydrogen. Therefore, for mitigating the GHG emissions during the hydrogen production phase, the focus has been directed toward biomass-derived hydrogen (Bio-H2) production processes. In this study, the environmental impact of Bio-H2 production from sewage sludge has been discussed. The bio-syngas contain various impurities, such as H2S, HCl, and NH3. These impurities could damage the performance of the FC operation. Our previous experimental studies have proposed the use of hydroxyl aluminum silicate clay (HAS-Clay) as an adsorbent in the impurity removal process. HAS-Clay can adsorb a significant amount of H2S by physisorption and is an environment-friendly adsorbent. However, it was found that NH3 decreased the adsorption performance of HAS-Clay. The life cycle assessment revealed that any reduction of eco-burden would be less obtained. Therefore, in this study, Kanuma clay (Kc), which is a natural resource, was used to first adsorb NH3 and aim for maintaining the adsorption performance of HAS-Clay. Kc adsorption capacities of H2S and NH3 have been obtained. However, the adsorption capacity in the simultaneous adsorption of H2S and NH3 has never been investigated. Thus, in this study, the simultaneous adsorption of H2S and NH3 was conducted using an adsorption column with the adsorbents as Kc and HAS-Clay. Finally, the environmental burden of the system was assessed.
EXPERIMENTAL AND CFD SIMULATION VALIDATION PERFORMANCE ANALYSIS OF FRANCIS TURBINE
Authors: Umar Baig Mirza , Cao Jingwei , Wang Zhengwei
Published: June 2022

Francis Turbines are designed to Extract hydraulic power as much as possible in hydro power plant stations. Performance analysis and selecting design of hydraulic turbines are two very essential aspects of any hydro power project which ensure the economical and efficient functioning of these hydro power plants.CFD simulation can provide us insight into field flow characteristics which will help us understand the design parameter and development of Francis turbine. The performance analyzed in different operating conditions with the help of numerical simulation and experimental testing. The various visualization techniques in numerically and Physically model testing for hydraulic performance with maximum-minimum and rated head and different flow rate analyses of the turbines are briefly discussed. These techniques can be provided efficiency and insight flow characteristics with different operating conditions of the Francis turbine. Efficiency is calculated 94% with Computational fluid dynamics simulation with an error of less than 0.7% compared with physical model testing. The numerically simulation and physical model testing are shown that feasibility for the optimal design of the hydraulic Francis turbine.
Modeling of the Blade Leading-Edge Pressure Drop of Centrifugal Impeller Based on Machine-Learning
Authors: Wu Yanzhao , Li Na , Tao Ran , Li Puxi , Xiao Ruofu
Published: June 2022

Blade leading-edge pressure drop is an important parameter that strongly influences the safe and stable operation of centrifugal pump. It is sensitive to blade leading-edge geometry. To understand the inlet flow state of centrifugal pump, it is necessary to evaluate the location and the minimum value of blade leading-edge pressure drop. However, the operation condition is complex. A large amount of experiments and numerical simulations should be conducted for a fully understanding of the local pressure field. With the development of artificial intelligence, machine learning can be used for accelerating the evaluations with potential laws of fluid mechanism. Therefore, neural network is used in this case to fit the solution space of condition, leading-edge geometry and local pressure drop. The influence of different factors can be well analyzed. The conditions which is not directly tested will be predicted by well-trained neural network. With the increasing of the leading-edge elliptic ratio of the blade inlet, the minimum pressure position of the blade moves from the impeller hub to the impeller shroud. This study provides a preliminary study and a good reference of the evaluation of blade inlet leading edge flow state in the future researches.
Measurements for Condition Monitoring of Hydropower plants: A Review
Authors: Sapkota P , Chitrakar S , Neopane H P , Thapa B
Published: June 2022

Condition monitoring is an extension of the predictive maintenance or proactive maintenance process for detecting faults in a machine component with the help of pre identified measuring parameters to identify a significant change which is indicative of a developing fault. The fault developed due to various factors in the hydropower plants can damage or halt the operation of power plants. The literatures on the measurement process for condition monitoring of power plants has been reviewed and discussed. Since condition monitoring is a newer and a broader topic, few literatures were available and they were review on the basis of measurement and faults detection processes.
Coating technology in hydro-turbines for sediment affected power plants: A review
Authors: Aryal Shekhar , Chitrakar Sailesh , Shrestha Rajendra , Jha Ajay kumar
Published: June 2022

The sediment loads originated from Run-off-river reaches to the turbines as suspended particles, causing wear and tear of the mechanical components. In the case of power plants under Himalayan Rivers, the turbines need to undergo repair and maintenance in a regular basis, due to a substantial loss of material from the turbine components. Past research works have focused on minimizing the erosion in turbines by changing the design of runner and guide vanes, strategically operation of the power plant during the monsoon season, as well as application of the coating materials over the susceptible regions. This paper studies the suitable coating technologies that could be implemented for hydro turbines, in the context of hydro power plants exposed to sediment particles. The review has shown numerous materials and approaches of applying the coating, their performance evaluation using experiments and important findings. This paper also discusses on different methods of characterizing the coating, mechanical integrity as well as the tribological behavior of the coated material.
Clearance flow field characteristics of Kaplan turbine under different flange clearance
Authors: Zhang Y L , Wu Y B , Wei J W , Wang Z W , Zhou L J
Published: June 2022

Flange clearance flow is a complex flow phenomenon in axial flow units. Clearance vortex and vortex cavitation caused by it have always been the focus of research at home and abroad. In this paper, the steady cavitation calculation of Kaplan turbine with blade tip clearance width of 0.5mm, 1mm and 2mm is carried out under four working conditions. The energy characteristics, clearance flow characteristics and cavitation characteristics of the runner under different clearances are analyzed. Results show that: The energy characteristics of the runner domain are greatly affected by the tip clearance width. When ω/D increases by 1%, the power coefficient P
* decreases by 0.83%~1.45%, and the efficiency η decreases by 0.3%~0.5%. With the increase of the clearance width, the diameter of the clearance leakage vortex band becomes thicker, and the vortex length gradually extends to the outflow edge of the blade, and the included Angle with the blade suction surface gradually increases. The cavitation type of the tip area is mostly leaking vortex cavitation when there is a tiny clearance. Clearance cavitation and leakage vortex cavitation grow as tip clearance rises, and the interaction between them is reinforced.
Pressure fluctuation measurement in pressure vessels
Authors: Kapali A , Neopane H P , Chitrakar S , Shrestha K P , Sapkota P
Published: June 2022

Pressure vessels are mechanical devices that act as a reservoir of fluids at pressure more or less than atmospheric pressure. This research focuses on the application of the pressure vessel for hydraulic testing of hydro turbines to maintain uniform velocity profile and to suppress the pressure surge in the pipeline. An initial assumption for the design of a thin-walled horizontal type pressure vessel with the ellipsoidal type of head is based on the mathematical relations as per ASME code, Section VIII, Division I, for an operating pressure of 0.3 MPa and design pressure of 0.6 MPa. The pressure vessel has been placed, close to outlet of the main pump to prevent the water hammering in the pipeline. The measurement of the pressure fluctuations at the inlet, outlet, and inside of the vessel, due to the dynamic action of fluid forced by the pump are recorded. The study attempts to relate the use of pressure vessels to generate stable flow and pressure at the outlet for hydraulic testing of turbines.
Turbine blade strike tests for evaluation and optimization of fish-friendly turbine
Authors: Meng L , Chen R , Wang X , Zhang C Y , Zheng Y , Tian Y J
Published: June 2022

Widening the knowledge for fish injury and mortality mechanism caused by pressure, shear stress and blade strikes inside turbine was constructive for optimizing fish-friendly turbine design and turbine operation regime. A special designed test equipment was applied for simulating the rotating blade inside turbine passage, anesthetized fish (crucian carp) was placed on the route of the blade for strike tests. The fish length, blade thickness, strike angle, and strike speed were independent variables during the tests, the injury rate, degree of injury and mortality rate were analysed according to observation or anatomical examination after repeated tests. The injury types were classified into: imbalance, ribs broken, gill cover broken, internal hemorrhage and death. The injury severity was directly affected by strike speed under same blade thickness and fish length. The ratio of blade thickness and fish length also affect the injury rate. Multiple injuries can be observed on one fish after tests, and combined injuries are more likely to lead to death. In the fish-friendly turbine design, blade thickness in the leading edge and blade numbers shall be carefully considered and the rotational speed shall be calculated.
Analysis and research on sluice gate flow of a hydropower station under different working conditions
Authors: Xu Yang , Li Zheng gui , Gong Chengyong , Guan Zhijun , Ma Biao
Published: June 2022

The rationality design of the sluice gate directly influences the flood control capacity of hydropower stations. To demonstrate the rationality of the creation of the spillway gate of a hydropower station in the Yellow River Basin, this paper adopts the method of combining model test with a mathematical model to study the pressure, flow velocity, and water level changes of the spillway gate of the hydropower station under the working conditions of check flood and design flood. The research results show that there is no negative pressure in the whole flood discharge sluice dam section under check flood and desert flood conditions. The pressure characteristics of each area of the sluice floor are good, and the velocity distribution is uniform. However, the outflow velocity of the reinforced cage section is greater than the anti-scour velocity of the river under the two working conditions, which impacts the downstream river, so it is necessary to increase the length of the reinforced cage section appropriately. The water flow falls twice in the spillway dam section. The initial position of the first fall is the same under two working conditions. However, the falling depth decreases with the decrease of reservoir water level. The second fall position moves backward with the reduction of the water level. This paper provides a theoretical reference for the demonstration of flood discharge capacity of other hydropower stations through the analysis and research of the flood discharge sluice state of this hydropower station.
Green Ammonia as a flexible hydro-electricity carrier for Nepal
Authors: Neupane B , Bhattarai S , Shah A K , Thapa B S
Published: June 2022

An increase in the installed capacity of Hydroelectricity in Nepal in 2022 by 122% compared to that in 2021 is a major milestone in power production in the country. This increase in electricity production will make the country self-sufficient in electricity for the first time in the last three decades. The future growth of hydropower installations in Nepal is expected to rise much beyond the local consumption and is forecasted to reach as much as 3500 MW surplus energy by 2028. Most of the hydropower projects built and under construction are run-off -river type, due to which the power generation is highly seasonal and results in the poor load factor. There is a need for Nepal to plan the effective use of surplus power and the seasonality variation of hydro-energy. Producing green ammonia from hydroelectricity and its utilization in industries and commercial sectors can be one of the options for the storage and transportation of surplus hydroelectricity in Nepal in the future. With the flexibility of usage, and given the fact that the required technologies and infrastructures for safer transportation, distribution, and ammonia application are already in place; ammonia can be a viable option to be a hydro-electricity carrier of the future in Nepal. This paper studies the potentials of ammonia as a hydroelectricity carrier and its application as a chemical commodity in the industries and transportation sector. The different chemical attributes of ammonia along with the production technologies, economies of ammonia production, storage, transportation, and its subsequent application are studied. This study concludes that utilization of ammonia as a hydro-energy carrier and its usage as a chemical commodity in the industries, green fuel in the transportation sector can be a good opportunity to lead the country towards sustainable and renewable energy economy.
Time-domain model and optimization for single-axis kinetic energy harvesters driven by arbitrary non-harmonic excitation
Authors: Struwig Michael N , Niesler Thomas , Wolhuter Riaan , Strauss Johann
Published: June 2022

Energy harvesting is employed to extend the life of battery-powered devices, however, demanding applications such as wildlife tracking collars, the operating conditions impose size and weight constraints. They also only provide non-harmonic mechanical motion, which renders much of the existing literature inapplicable, which focuses on harvesting energy from harmonic mechanical sources. As a solution, we propose an energy harvesting architecture that consists of variable number of evenly-spaced magnets, forming a fixed assembly that is free to move through a series of evenly-spaced coils, and is supported by a magnetic spring. We present an electromechanical model for this architecture, and evolutionary optimization process that finds the model parameters which describe the time-domain behaviour observed in ground truth measurements. The resulting model can predict the time-domain behaviour of the energy harvester for any configuration of the proposed architecture and for any mechanical excitation. We also propose an optimization process that, using the electromechanical model, optimizes the energy harvester configuration to maximize the power delivered to a resistive load. The resulting optimized harvester design is specific to the particular kind of non-harmonic mechanical excitation to which it will be exposed. To demonstrate the effectiveness of our proposed model and optimization procedure, we constructed four energy harvesters, each with different configurations, and compared their measured behaviour with that predicted by the model, given an excitation that approximates footstep-like motion. We show that the model predictions were consistently within 25% of the RMS load voltage. We then synthesize an optimal energy harvester using the proposed optimization process. The resulting optimal design was constructed and tested using the same footstep-like excitation, and delivered an average power of 1.526 mW to a 30Ωload. This is a 2.8-fold improvement over an unoptimized reference design. We conclude that our proposed behavioural model and optimization process allows the determination of energy harvester designs that are optimized for a non-harmonic and specific input excitation.
A Multicenter, Randomized, Double-Blind, Split-Body Clinical Trial Evaluating the Efficacy and Outcomes of a Topical Product Pre and Post Aesthetic Surgical Body Procedures
Authors: Casas Laurie A , Claytor R Brannon , Zeidler Kamakshi R , Shridharani Sachin M , Cohen Steven R , Khanna Julie J , Gould Daniel J , Yates Essie K , Lultschik Shantel , Bell Michaela , Widgerow Alan D
Published: June 2022

Background

Skin preconditioning prior to and following procedures, has previously been demonstrated to hasten and optimize healing, and decrease the symptoms and signs associated with invasive surgery. These trials involved the use of multiple topical products. In an effort to control costs and to increase patient compliance, a single surgical product was developed, with actives aimed at decreasing swelling, bruising, induration, and internal fibrous banding.

Objectives

This multi-center trial was designed to measure the efficacy of this single product in these mentioned parameters.

Methods

A double-blind, randomized, split body, clinical study was undertaken in 29 patients involving 38 surgical procedures. Assessments included photography, biopsies, ultrasound imaging, and blinded investigator and participant assessments.

Results

Differentiated results between test comparator sides became apparent at postop day 10-14 (as previously observed). Thus, blinded investigator and participant assessment scores demonstrated statistical significance exclusive to the test product side at postop day 10-14 for ecchymoses and then extending to skin discoloration, edema, induration and subcutaneous fibrous banding, at weeks 3, 4, 6, and 12. Ultrasound evaluation confirmed the earlier dissolution of fibrous banding on the test side in the subcutaneous tissue at the 3-6-week postop period. In addition, biopsies assessing the pre-conditioned period prior to surgery confirmed that the topical test product stimulated a remodeled extracellular matrix without comparative changes on the opposite side.

Conclusions

A single peri-surgical product designed for the use with invasive surgery produced significant differences in ecchymosis, skin discoloration, edema, induration and ongoing resolution of fibrous banding over many weeks. This study validation provides an additional adjunct to surgical procedures.

Level of Evidence: 2
Microbial Cell-Free DNA Identifies the Causative Pathogen in Infective Endocarditis and Remains Detectable Longer Than Conventional Blood Culture in Patients with Prior Antibiotic Therapy
Authors: Eichenberger Emily M , Degner Nicholas , Scott Erick R , Ruffin Felicia , Franzone John , Sharma-Kuinkel Batu , Shah Pratik , Hong David , Dalai Sudeb C , Blair Lily , Hollemon Desiree , Chang Eliza , Ho Carine , Wanda Lisa , de Vries Christiaan R , Fowler Vance G , Ahmed Asim A
Published: June 2022

Background

The diagnosis of infective endocarditis (IE) can be difficult, particularly if blood cultures fail to yield a pathogen. This study evaluates the potential utility of microbial cell-free DNA (mcfDNA) as a tool to identify the microbial etiology of IE.

Methods

Blood samples from patients with suspected IE were serially collected. mcfDNA was extracted from plasma and underwent next-generation sequencing. Reads were aligned against a library containing DNA sequences belonging to >1400 different pathogens. mcfDNA from organisms present above a statistical threshold were reported and quantified in molecules per milliliter (MPM). Additional mcfDNA was collected on each subject every 2–3 days for a total of 7 collections or until discharge.

Results

Of 30 enrolled patients with suspected IE, 23 had definite IE, 2 had possible IE, and IE was rejected in 5 patients by modified Duke Criteria. Only the 23 patients with definite IE were included for analysis. Both mcfDNA and blood cultures achieved a sensitivity of 87%. The median duration of positivity from antibiotic treatment initiation was estimated to be approximately 38.1 days for mcfDNA versus 3.7 days for blood culture (proportional odds, 2.952; P = .02771), using a semiparametric survival analysis. mcfDNA (log10) levels significantly declined (−0.3 MPM log10 units, 95% credible interval −0.45 to −0.14) after surgical source control was performed (pre- vs postprocedure, posterior probability >0.99).

Conclusion

mcfDNA accurately identifies the microbial etiology of IE. Sequential mcfDNA levels may ultimately help to individualize therapy by estimating a patient’s burden of infection and response to treatment.
FAM19A4/miR124-2 Methylation Testing and Human Papillomavirus (HPV) 16/18 Genotyping in HPV-Positive Women Under the Age of 30 Years
Authors: Vink Frederique J , Meijer Chris J L M , Hesselink Albertus T , Floore Arno N , Lissenberg-Witte Birgit I , Bonde Jesper H , Pedersen Helle , Cuschieri Kate , Bhatia Ramya , Poljak Mario , Oštrbenk Valenčak Anja , Hillemanns Peter , Quint Wim G V , del Pino Marta , Kenter Gemma G , Steenbergen Renske D M , Heideman Daniëlle A M , Bleeker Maaike C G
Published: June 2022

Background

High-grade squamous intraepithelial lesions (HSIL) or cervical intraepithelial neoplasia (CIN) grade 2/3 lesions in human papillomavirus (HPV)–positive women <30 years of age have high spontaneous regression rates. To reduce overtreatment, biomarkers are needed to delineate advanced CIN lesions that require treatment. We analyzed the FAM19A4/miR124-2 methylation test and HPV16/18 genotyping in HPV-positive women aged <30 years, aiming to identify CIN2/3 lesions in need of treatment.

Methods

A European multicenter retrospective study was designed evaluating the FAM19A4/miR124-2 methylation test and HPV16/18 genotyping in cervical scrapes of 1061 HPV-positive women aged 15–29 years (690 ≤CIN1, 166 CIN2, and 205 CIN3+). A subset of 62 CIN2 and 103 CIN3 were immunohistochemically characterized by HPV E4 expression, a marker for a productive HPV infection, and p16ink4a and Ki-67, markers indicative for a transforming infection. CIN2/3 lesions with low HPV E4 expression and high p16ink4a/Ki-67 expression were considered as nonproductive, transforming CIN, compatible with advanced CIN2/3 lesions in need of treatment.

Results

FAM19A4/miR124-2 methylation positivity increased significantly with CIN grade and age groups (<25, 25–29, and ≥30 years), while HPV16/18 positivity was comparable across age groups. FAM19A4/miR124-2 methylation positivity was HPV type independent. Methylation-positive CIN2/3 lesions had higher p16ink4a/Ki-67-immunoscores (P = .003) and expressed less HPV E4 (P = .033) compared with methylation-negative CIN2/3 lesions. These differences in HPV E4 and p16ink4a/Ki-67 expression were not found between HPV16/18–positive and non-16/18 HPV–positive lesions.

Conclusions

Compared with HPV16/18 genotyping, the FAM19A4/miR124-2 methylation test detects nonproductive, transforming CIN2/3 lesions with high specificity in women aged <30 years, providing clinicians supportive information about the need for treatment of CIN2/3 in young HPV-positive women.
Incidence, Attributable Mortality, and Healthcare and Out-of-Pocket Costs of Clostridioides difficile Infection in US Medicare Advantage Enrollees
Authors: Yu Holly , Alfred Tamuno , Nguyen Jennifer L , Zhou Jingying , Olsen Margaret A
Published: June 2022

Background

US attributable Clostridioides difficile infection (CDI) mortality and cost data are primarily from Medicare fee-for-service populations, and little is known about Medicare Advantage Enrollees (MAEs). This study evaluated CDI incidence among MAEs from 2012 to 2019 and determined attributable mortality and costs by comparing MAEs with and without CDI occurring in 2018.

Methods

This retrospective cohort study assessed CDI incidence and associated mortality and costs for eligible MAEs ≥65 years of age using the de-identified Optum Clinformatics Data Mart database (Optum; Eden Prairie, Minnesota, USA). Outcomes included mortality, healthcare utilization, and costs, which were assessed via a propensity score–matched cohort using 2018 as the index year. Outcome analyses were stratified by infection acquisition and hospitalization status.

Results

From 2012 to 2019, overall annual CDI incidence declined from 609 to 442 per 100 000 person-years. Although the incidence of healthcare-associated CDI declined overall (2012, 53.2%; 2019, 47.2%), community-associated CDI increased (2012, 46.8%; 2019, 52.8%). The 1-year attributable mortality was 7.9% (CDI cases, 26.3%; non-CDI controls, 18.4%). At the 2-month follow-up, CDI-associated excess mean total healthcare and out-of-pocket costs were $13 476 and $396, respectively. Total excess mean healthcare costs were greater among hospitalized (healthcare-associated, $28 762; community-associated, $28 330) than nonhospitalized CDI patients ($5704 and $2320, respectively), whereas total excess mean out-of-pocket cost was highest among community-associated hospitalized CDI patients ($970).

Conclusions

CDI represents an important public health burden in the MAE population. Preventive strategies and treatments are needed to improve outcomes and reduce costs for healthcare systems and this growing population of older US adults.
Population-Weighted Seroprevalence From Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection, Vaccination, and Hybrid Immunity Among US Blood Donations From January to December 2021
Authors: Busch Michael P , Stramer Susan L , Stone Mars , Yu Elaine A , Grebe Eduard , Notari Edward , Saa Paula , Ferg Robyn , Manrique Irene Molina , Weil Natalia , Fink Rebecca V , Levy Matthew E , Green Valerie , Cyrus Sherri , Williamson Phillip C , Haynes James , Groves Jamel , Krysztof David , Custer Brian , Kleinman Steve , Biggerstaff Brad J , Opsomer Jean D , Jones Jefferson M
Published: June 2022

Background

Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) vaccination, independently and combined (“hybrid immunity”), result in partial protection from subsequent infection and strong protection from severe disease. Proportions of the US population who have been infected, vaccinated, or have hybrid immunity remain unclear, posing a challenge for assessing effective pandemic mitigation strategies.

Methods

In this serial cross-sectional study, nationwide blood donor specimens collected during January–December 2021 were tested for anti-spike and anti-nucleocapsid antibodies, and donor COVID-19 vaccination history of ≥1 dose was collected. Monthly seroprevalence induced from SARS-CoV-2 infection, COVID-19 vaccination, or both, were estimated. Estimates were weighted to account for demographic differences from the general population and were compared temporally and by demographic factors.

Results

Overall, 1 123 855 blood samples were assayed. From January to December 2021, the weighted percentage of donations with seropositivity changed as follows: seropositivity due to vaccination without previous infection, increase from 3.5% (95% confidence interval, 3.4%–3.7%) to 64.0%, (63.5%–64.5%); seropositivity due to previous infection without vaccination, decrease from 15.6% (15.2%–16.0%) to 11.7% (11.4%–12.0%); and seropositivity due to hybrid immunity, increase from 0.7% (0.6%–0.7%) to 18.9% (18.5%–19.3%). Combined seroprevalence from infection, vaccination, or both increased from 19.8% (19.3%–20.2%) to 94.5% (93.5%–94.0%). Infection- and vaccination-induced antibody responses varied significantly by age, race-ethnicity, and region, but not by sex.

Conclusions

Our results indicate substantial increases in population humoral immunity from SARS-CoV-2 infection, COVID-19 vaccination, and hybrid immunity during 2021. These findings are important to consider in future COVID-19 studies and long-term pandemic mitigation efforts.
In vivo and in vitro cartilage differentiation from embryonic epicardial progenitor cells
Authors: Marin Sedeno E , Palmquist-Gomes P , Rico-Llanos GA , Ruiz-Villalba A , Perez-Pomares JM , Guadix JA
Published: June 2022

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Spanish Ministry of Science and Universities and Consejería de Salud y Familias, Junta de Andalucía.

The presence of cartilage tissue in embryonic and adult hearts of various vertebrate species is a well-recorded fact. However, while the embryonic neural crest has been historically considered as the main source of cardiac cartilage, recently reported results on the wide connective potential of epicardial lineage cells suggest they could also differentiate into chondrocytes. During heart embryogenesis, the epicardial epithelium forms over the originally bare myocardial surface from epicardial progenitor (proepicardial) cells to then give rise to a large population of mesenchymal Epicardial-Derived Cells (EPDCs) that will crucially contribute to the building, growth and maturation of the ventricle and atrioventricular cardiac structures. In this work, we describe the formation of cardiac cartilage clusters from proepicardial cells, both in vivo and in vitro. Our findings report, for the first time, cartilage formation from epicardial progenitor cells in the embryonic heart, and strongly support the concept of proepicardial cells as multipotent connective progenitors. These results are relevant to our understanding of cardiac cell complexity and responses to pathologic stimuli.
Inhibition of RhoA and Cdc42 by miR-133a modulates retinoic acid signaling during early development of the posterior cardiac tube segment
Authors: Lopez-Sanchez C , Garcia-Padilla C , Garcia-Lopez V , Aranega A , Franco D , Garcia-Martinez V
Published: June 2022

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Junta de Extremadura with FEDER co-financing.

Introduction

It has been demonstrated that multiple microRNAs play crucial roles in diverse biological processes, including cardiovascular development. In particular, we have previously observed miR-133a expressing at different stages of the primitive streak precardiac cells until the formation of the cardiac tube. MiR-133a role has also been reported as a modulator of proliferation and differentiation during heart development, involving many target genes and signaling pathways. Furthermore, we have shown in previous studies that retinoic acid plays a crucial role in cardiac development, modulating the expression of atrial markers.

Purpose

The aim of this work is to analyze the miR-133a modulation role on the retinoic acid signaling pathway in the posterior segment of the heart tube during cardiac looping formation.

Methods

By means of microinjections in both primitive endocardial tubes of chick embryo culture, gain- and loss-of-function experiments were performed with premiR-133a and anti-miR-133a, respectively. Subsequently, embryos were subjected to whole mount in situ hybridization with Tbx5 and AMHC1 probes, and qPCR. After TargetScan analysis and luciferase assays, immunohistochemistry was carried out by using anti-RhoA, -Cdc42 and -Raldh2/ALDH1A2 antibodies.

Results

Luciferase assays show that miR-133a is capable to recognize and bind to RhoA and Cdc42 3´UTR, thus triggering their mRNA degradation. Our results reveal that miR-133a gain-of-function experiments repress the expression of atrial markers Tbx5 and AMHC1, as well as RhoA, Cdc42 and -Raldh2/ALDH1A2 signals. Supporting these data, miR-133a loss-of-function experiments show the opposite effect: they increase the expression of Tbx5 and AMHC1, as well as RhoA, Cdc42 and Raldh2/ALDH1A2 signals.

Conclusion

Our results suggest that miR-133a could modulate negatively retinoic acid signaling by triggering degradation of pivotal genes RhoA and Cdc42, both required for Raldh2/ALDH1A2 expression, crucial to the synthesis of retinoic acid.
The euchromatic histone-lysine N-methyltransferases EHMT1/2 suppress post-natal cardiomyocyte proliferation via histone 3 lysine 9 (H3K9) dimethylation
Authors: Chatzieleftheriadis K , Sadredini MS , Donate Puertas RDP , Sjaastad IS , Roderick LR
Published: June 2022

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): KULeuven C14/17/088

Flemish Research Foundation (FWO) G0C6419N

Cardiomyocytes proliferate rapidly during developmental growth in utero, but this proliferative capacity dramatically declines postnatally, rendering the heart unable to repair itself subsequent to injury or during ageing. The mechanisms governing this postnatal loss of cell cycle activity are not fully understood. During maturation, epigenomic remodelling drives wholesale changes in the cardiomyocyte transcriptome from the neonatal to the adult state. This is associated with silencing of foetally-expressed genes and activation of expression of genes required for adulthood. Here, we tested the hypothesis that epigenomic remodelling silences cell cycle-associated genes and hence cell cycle activity postnatally. In this regard, we focused on the role of the repressive H3K9me2 mark.

Using immunostaining of Ki-67 and Aurora Kinase B as well as analysis of EdU incorporation to identify cell cycle activity in primary cardiomyocytes culture and in cryosections from rat hearts spanning from embryonic day 18 to adulthood, the abundance of H3K9me2 was found to be inversely correlated with cell proliferation. In line with these data, the expression of a gene panel associated with cell cycle activity decreased postnatally and was inversely related with H3K9me2 abundance in cardiomyocyte nuclei, purified by flow cytometry based on H3K9me2 abundance. Inhibition of the euchromatic histone lysine methyltransferases (Ehmt1/2 aka GLP/G9a), with the highly selective inhibitor A-366, enhanced proliferation of neonatal rat cardiomyocytes in vitro, as well as in vivo, in neonatal mice, via concomitant reduction of the repressive histone mark, H3K9me2. Similar effects were observed in vitro by overexpression of the histone di/tri-methyl demethylase KDM4B. Notably, forced induction of cell cycle activity by overexpression of cyclin/cyclin-dependent kinase significantly reduced H3K9me2 levels, in vitro. Together, these data point to a key role of H3K9me2 and its deposition by Ehmts in post-natal suppression of proliferation. Targeting this repressive mark could provide a strategy to enhance cardiac repair for therapeutic benefit.
Assessment of proarrhythmogenic risk for cannabidiol using dog and rabbit cardiac preparations: the electrophysiological effects on action potential and transmembrane potassium currents
Authors: Naveed M , Topal L , Prorok J , Paszti B , Csupor D , Baczko I , Virag L , Jost N , Varro A
Published: June 2022

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Economic Development and Innovation Operative Programme GINOP-2.3.2-15-2016-00012, the National Research Development and Innovation Office (NKFIH K 135464 and NKFIH K 128851), the Ministry of Human Capacities Hungary (20391-3/2018/FEKUSTRAT and EFOP-3.6.2-16-2017-00006), and from the Eötvös Loránd Research Network

Background

Cannabidiol (CBD), a major active phytogenic cannabinoid, is one of the main constituents of cannabis. Cannabis has been widely used as recreational drug over the decades and its use is constantly increasing as hallucinogenic and/or medicinal agent. However, significant cardiovascular side effects can accompany its use ranging from arrhythmia to sudden cardiac death.

Purpose

The aim of the present work was to investigate the possible cardiac adverse electrophysiological effects of cannabidiol (CBD) on action potentials and various transmembrane potassium currents, such as the rapid (IKr) and slow (IKs) delayed rectifier, the transient outward (Ito) and inward rectifier (IK1) potassium currents in rabbit and dog cardiac preparations to assess the cardiac safety profile and proarrhythmic risk.

Methods

In the current study, conventional microelectrode and voltage clamp techniques were used to record the action potential and transmembrane ionic currents in dog and rabbit ventricular tissue preparations and enzymatically isolated myocytes, respectively.

Results

The results show that CBD lengthens APD90 significantly at the concentration of 5 µM both in dog and rabbit ventricular tissues without changing other action potential parameters significantly. To further investigate the APD90 lengthening effect of CBD, transmembrane potassium currents (IKr, IKs, Ito and IK1) were investigated in dog and/or rabbit ventricular myocytes using voltage clamp technique. CBD significantly inhibited IKr and IKs currents in rabbit ventricular myocytes with an estimated EC50 values of 4.9 and 3.1 µM, respectively. The effect of CBD on rabbit’s Ito current was not significant while it was significant on dog’s Ito current with an estimated EC50 value of 5 µM. IK1 was not responsive to CBD even at high concentration.

Conclusion

In conclusion, looking at the inhibitory effects of CBD on repolarizing potassium currents, despite of the fact that these calculated EC50 values are higher than pharmacokinetics based Cmax values of CBD recorded after smoking and oral intake, it can be speculated that in the presence of certain cardio active drugs or co-morbidity where CBD metabolism or cardiac repolarization reserve is impaired CBD can have an additive and proarrhythmic effect.