bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Evaluation Method of Gas Entrainment on the Free Surface in the Reactor Vessel in Pool-Type Sodium-Cooled Fast Reactors -Gas Entrainment Judgment Based on Three-Dimensional Evaluation of Vortex Center Line and Distribution of Pressure Decrease
Authors: Matsushita Kentarou , Ezure Toshiki , Imai Yasutomo , Fujisaki Tatsuya , Tanaka Masaaki
Published: November 2022

In a sodium-cooled fast reactor (SFR), cover gas entrainment (GE) by vortices generated at the free surface in the upper plenum of the reactor vessel is one of the significant issues in the safety design and the development of an evaluation method for GE is required. A GE evaluation method using numerical results of three-dimensional computational fluid dynamics (CFD) analysis has been developed for loop-type SFRs in Japan Atomic Energy Agency, and an evaluation tool using this method, named StreamViewer, has been developed. However, the current evaluation model employed in the StreamViewer gives conservative results to keep safety margins in conventional design basis. In this study, the modification of the evaluation method of the StreamViewer to rationalize the conservativeness in the evaluation results was examined by identifying the vortex center lines and limiting the evaluation area to the vicinity of the suction port, and calculating the three-dimensional distribution of pressure decrease along the vortex center lines. The applicability of the modified method was checked using a water experimental result in a rectangular open channel in which unsteady vortices are generated. As the result, it was indicated that the evaluation results on gas core depth which were excessive in the current method were improved in the modified method, and it is confirmed that the modified method has a potential to discriminate the onset of GE with the appropriate criteria.
Measurement of Gas-Liquid Interfacial Area Concentration and Its Effect on Aerosol Behavior in Pool Scrubbing
Authors: Kadoma Sasuke , Fujiwara Kota , Yoshida Kohei , Kaneko Akiko
Published: November 2022

Pool scrubbing is one of the severe accidents (SA) countermeasures in nuclear power plants. In pool scrubbing, gas containing Fission Products (FPs) generated in the reactor during SA is passed through the pool water in the suppression chamber to move FPs into the pool water and prevent them from being released into the surrounding environment. Since FPs have a significant negative effect on the surrounding environment, it is important to predict and evaluate how much FPs will be removed by pool scrubbing.

Currently, SA analysis codes such as MELCOR are used to evaluate FPs removal in pool scrubbing. However, the removal mechanism is not fully understood because the phenomena occurring in pool scrubbing are very complicated. It has been shown that parameters such as pool water depth and FPs size affect FPs removal rate (DF: Decontamination Factor), but there have been few experimental evaluations of the interrelationship between two-phase flow behavior and FPs removal.

Therefore, we focus on the gas-liquid interfacial area, which is one of the most important parameters in FPs transport between gas and liquid and in two-phase flow behavior, and the aim of our study is development of gas-liquid interfacial area concentration using a Wire Mesh Sensor (WMS) and clarification of relationship with DF. First, the void fraction of two-phase flow was measured using WMS, and the bubble interfaces were reconstructed to estimate the interfacial area concentration. The interfacial area concentration diffused to the surrounding as the relative distance from the nozzle increased as well as the void fraction. The overall interfacial area concentration increased with increasing the flow rate and the relative distance from the nozzle. Moreover, the results of DF measurements were compared with those of flow parameters. It was found that there was an inverse trend between the two parameters, indicating that it is necessary to consider not only the above flow parameters but also FPs transport between gas and liquid and decontamination by unsteady behavior of bubbles such as bubble breakup.
Effect of Surface Treatment on the Corrosion Behavior of Stainless Steels in High-Temperature Supercritical Carbon Dioxide
Authors: Liu Zhu , Su Haozhan , Long Jiachen , Cong Shuo , Chen Kai , Guo Xianglong , Zhang Lefu
Published: November 2022

The corrosion behavior of two stainless steels (310S and alumina-formed 310S) treated by different surface treatment methods (polishing or grinding) has been investigated after exposed to high-temperature supercritical carbon dioxide (sCO2) at 650°C / 20 MPa. The microstructure and microchemistry of materials have been analyzed and compared before and after exposure. The results show that polishing deteriorates the corrosion resistance, while grinding enhances the anti-oxidation and anti-carburization capability of materials. Thick and unprotective Fe-rich oxides are formed on the polished 310S and alumina-formed 310S, which leads to the poor carburization resistance. Much thinner oxides and shallower carburization depths can be observed on the materials treated by grinding. Continuous Cr-rich oxide is formed on the grinded 310S, while outer Cr-rich and inner Al-rich oxides are formed on the grinded alumina-formed 310S. Grinding deforms the surface region of materials. An outer ultra-fine grain layer and an inner highly deformed grain layer are located at the surface, which own fast diffusion paths and enhance the element diffusion rates (especially Cr and Al). This leads to the transition from the formation of unprotective Fe-rich oxide layers to the protective Cr-rich or Al-rich oxide layers, which not only hinders further oxidation of the matrix, but also reduces the carbon permeation. Improved oxidation and carburization resistance therefore occurs on the materials treated by grinding after exposed to high temperature sCO2 environment.
Preliminary Research on Digital Twin of Main Thermodynamic Systems in Nuclear Power Plant for Thermal Performance Monitoring
Authors: Zhang Xun , Hou Jianfei , Zimmermann Heino , Xiang Zhaohui
Published: November 2022

The performance degradation and latent fault of equipment may cause unplanned outage or power reduction in nuclear power plant, as a result, the operation and maintenance costs increase. By developing a nuclear power plant digital twin, some potential abnormalities can be detected and predictive maintenance can be performed to avoid equipment failure. So, a digital twin for main thermodynamic systems in an operating nuclear power plant is built by using EPOS code to monitor its thermal performance. Firstly, a thermodynamic system simulation model containing primary loop, secondary loop and cooling system is developed according to design documents, and the design parameters under full load are used to calculate all the equipment’s nominal values. Then the thermal performance of specific equipment is identified under partial loads. Some fitting process are needed to find the correlations between different variables and the fitting curves will be embedded into the equipment model if necessary. Moreover, a data reconciliation technique is used to assimilate the system model depending on measurements of operating nuclear power plant and the digital twin is gained at last. The result shows that the digital twin can represent the thermal performance of real plant very well although a few of measure inconsistencies are detected during the data reconciliation process.
Research on Standardization System of Smart Site for Nuclear Power Plant Construction
Authors: Ren Changchun , Wu Gang
Published: November 2022

Beginning with the study of the engineering characteristics of nuclear power plant construction and the development situation of smart site of construction at home and abroad, this paper clearly puts forward the necessity and urgency of developing smart site standardization system in the field of nuclear power plant engineering. This paper researches the application scenarios of information technologies such as Internet of Things, 5G, Big Data and AI in the field of engineering construction, and systematically expounds the business architecture, functional architecture, technical architecture and data architecture of smart site of construction. By analyzing the specific requirements of each participant of the nuclear power plant construction on the vision, business objectives, functional requirements and information security constraints of the smart site, this paper researches and puts forward the standardized architecture of the smart site network infrastructure and information system consistent with the field of nuclear power plant construction, and focuses on the systematical framework and core contents of the General Technical Requirements, and the On-Site Implementation Guidelines, and the Construction & Operation Management Specifications, of the smart site information platform for nuclear power plant construction. The purpose of this paper is to provide a standardized system construction idea for all participants in the nuclear power plant construction to carry out digital transformation in the new round of nuclear power construction opportunity period.
Study of Effective Isolation Technology of Main Feedwater
Authors: Zhao Jiaming , Fang Liqiang , Ding Liang
Published: November 2022

This paper presents an effective isolation technology of main feed water including three sets of main feed water isolation devices for some nuclear power plant, and then model and calculate the whole feed water system using the commercial software “PIPENET”, including feed water hammer simulation, calculating the possible conditions of different isolation valves closing including one valve closing, two valves closing and three valves closing. Besides the special design for hydropneumatic type isolation valve having two sets of actuators is to ensure the availability of hydropneumatic type isolation valve during losing of power. However, the closing time of the valve is within a range, including the normal closing time and the unusual closing time during losing of power, which should be considered and designed by water hammer simulating and accident analysis. The final closing time of hydropneumatic type isolation valve is 6–12s. The effective isolation technology resolves the effective isolation of main feed water, reduces the risk of temperature and pressure exceeding of containment, ensures the tightness of containment, prevents the releasing of the radioactive substance during the occurring of main steam pipe break (MSLB) plus safety shutdown earthquake (SSE). Besides, when the steam generator rupture occurring, it can prevent the overflow of steam generator, the isolated accidental steam generator will not release a large amount of radioactive substance to environment. In addition, when the feed water rupture occurring, the accidental steam generator can be isolated; when there is accident in the feed water control, the relevant feed water can be isolated and the steam generator will not be overflowed. The effective isolation technology has great significance for reliability operation and safe operation of nuclear power plant.
Development and Application of a Real-Time Visualization and Simulation Platform Based on the Generic Platform Interface ICoCo and the Qt Framework
Authors: Shen Yanyi , Chen Hongli , Ding Tao , Liu Tianyi , Tang Junjie
Published: November 2022

It is of necessity and importance for the development of a real-time visualization and simulation platform for the lead-cooled fast reactor in order to provide a better learning and research platform for technicians. In this research, a visualization platform for the primary loop system of medium-sized modular lead-cooled fast reactor M2LFR-1000 has been developed based on Generic Platform Interface ICoCo and Qt framework, relying on the system code Relap5. The simulation code used in the visualization platform is first wrapped by the generic platform interface ICoCo (Interface for Code Coupling) and then compiled to a shared library. A multithreading C++ script is developed as the supervisor, which supervises the system code Relap5 and realizes the control of real-time simulation. The graphical man-machine interface of the platform is developed by a set of UI elements provided by Qt Widgets Module. The communication between simulation code and GUI is performed with the signals and slots mechanism, which requires a Qt’s C++ extension developed as the meta-object compiler (moc). Via the actual operation by the visualization and simulation platform, the results verify that the platform can realize the real-time simulation and control of the primary loop system of M2LFR-1000 and provide a practical means of real-time monitoring and regulation of reactor operations for technicians.
Preliminary Core Calculation on Reactivity Compensation for SiC Matrix Fuel Compact HTTR With Erbium Burnable Poison and Plutonium Fissile Material
Authors: Nishimura Yosuke , Allaf Mohammad Amer , Okita Shoichiro , Goto Minoru , Okamoto Koji
Published: November 2022

Proposed higher power density HTGR by removing the graphite sleeve and implementing the SiC matrix fuel compact has neutronics problem on criticality. Present study selected Er burnable poison and Pu fissile material as possible candidate to compensate the reactivity. To ensure core performance of HTTR modeled reactors, the various tests were carried out using Serpent 2 code, and nuclear characteristic data were obtained successfully. The obtained results verified the expected characteristics. It was demonstrated that both Er and Pu solved criticality issue. Furthermore, especially Pu-loaded core showed better burn-up performance compared to current HTGR. One possible option that proposed reactor can also burn Pu safely based on the concept of small-Clean Burn-HTGR was concluded.
Study on the Manufacturing Process of Large Super Alloy X-750 Forgings for Nuclear Equipment
Authors: Chen Mei-fang , Cao Sheng-qiang , Dong Kai
Published: November 2022

X-750 is a nickel-chromium based super alloy with high strength, high toughness, excellent creep resistance and good stress relaxation resistance at high temperature. It can be used in the manufacture of holddown springs for reactor vessel internals (RVI). Because of high content of alloying elements and the large size of ingot for the RVI holddown spring, observations by optical microscopy (OM) and scanning electron microscopy (SEM) showed that there was obvious dendrite segregation and serious carbonitride net in the as-cast electroslag remelting (ESR) ingot. Before forging, homogenization treatment was carried out for the ESR ingot to reduce element segregation, and promote the secondary carbonitrides dissolve into the alloy, which could significantly improve the malleability of the billet and reduce forging cracks. The homogenization process adopted in this study was annealing at 1220°C for 70 hours. In addition, the final forging temperature also played a key role in the control of formability of the billet and grain size of the forging. The carbonitrides or grain size of both the as-cast and forged samples annealed at 900°C∼1200°C for 10h were observed, and also charpy impact tests were carried out on the forged and annealed samples. The results showed that the final forging temperature for upsetting and drawing process should be no less than 1100°C, and the final forging temperature for forming process could be reduced to 1000°C. After solution and aging treatment, the comprehensive mechanical properties of the forging were excellent, with KV impact value at room temperature as high as 92J, yield strength of tensile test at 350°C up to 696MPa, and tensile strength up to 1019MPa.
Energy Analysis and Parametric Study of Hydrogen and Electricity Co-Production System Coupled With a Very-High-Temperature Gas-Cooled Reactor
Authors: Ni Hang , Qu Xinhe , Zhao Gang , Zhang Ping , Peng Wei
Published: November 2022

Hydrogen is an important clean alternative energy resource for the future, and nuclear hydrogen production can efficiently produce carbon-free hydrogen on a large scale. In this study, a hydrogen and electricity co-production system coupling iodine-sulfur cycle with a very-high-temperature gas-cooled reactor is proposed. The helium on the secondary side of the intermediate heat exchanger provides high-grade heat for the sulfuric acid decomposition reactor and hydroiodic acid decomposition reactor, and the steam extracted from the power generation circuit provides low-grade heat for other hydrogen production components. A supercritical steam generator is used and a reheating section is designed to improve power generation efficiency. The energy analysis reveals that as the hydrogen production rate increases, the power generation efficiency decreases, whereas the overall hydrogen and electricity efficiency increases. The power generation efficiency and overall hydrogen and electricity efficiency of the system are 38.2 % and 45.5 % at a hydrogen production rate of 161.73 mol/s. The parametric study shows that the power generation efficiency and overall hydrogen and electricity efficiency of the system increase with an increase in the main steam temperature or main steam pressure, and decrease with an increase in the reheated steam pressure. Among the three parameters, the main steam temperature markedly affects the performance of the system, followed by the reheated steam pressure and main steam pressure.
Analysis of Reliability and Life of Fission Ionization Chamber of Nuclear Instrumentation System (NIS)
Authors: Zhou Yulin , Qiu Shunli , Ge Mengtuan , Sun Guangzhi , Xiao Wei , Liu Haifeng
Published: November 2022

Fission ionization chamber of Nuclear Instrumentation System (NIS) is an essential equipment for the nuclear power plant. By measuring the neutron fluence rate in the immediate range (IR), the power level of the reactor can be determined. In order to ensure its performance to get accurate measurement results, the reliability and aging degree should be analyzed so that we can replace the fission ionization chamber before it expires. In this paper, the aging mechanism of NIS fission ionization chamber is analyzed and calculated from four aspects: moderator degradation, irradiation damage, sensitive uranium plating loss and detector working gas loss. The calculation model is the fission ionization chamber developed by our institute. As the results indicated, moderator degradation and irradiation damage of neutrons cause tiny effect of detector performance. The uranium plating loss caused by neutron reaction leads to 2% detector sensitivity decrease when irradiation time reaches 45.8 years. The working gas loss leads to less than 2% detector sensitivity decrease in 146.4 years if the gas leakage is highly controlled. Furthermore, the mean time between failure (MTBF) is analyzed and calculated. This research provides detailed analysis and methods to determine the reliability and life of NIS fission ionization chamber. And the results indicated that the detector developed by our institute has high reliability to apply in the cruel environment outside the reactor.
Anomalies Detection in Structures, System and Components for Supporting Nuclear Long Term Operation Program
Authors: Cancemi Salvatore Angelo , Lo Frano Rosa
Published: November 2022

Long Term Operation (LTO) of nuclear power plants (NPPs) will play a key role to reach net zero target. Monitoring and predictive approach detecting in advance faulty SCCs conditions may provide a further key tool in LTO framework. Detecting anomalies may allow the transition from time-based to condition-based predictive maintenance of the NNPs. Predictive algorithms could reduce the number of unplanned outages caused by reactor system failures (one-day outage of a 1000-MW NPPs causes losses of about 500 k$), improving the capacity factor, and keeping high safety margin level of NPPs. To this end, innovative approach by unsupervised machine learning technique (ML) is proposed to detect anomalies of SSCs. Based on principal component analysis and mahalanobis distance is possible to detect in advance the failure of the components. To the purpose a 2D digital twin of primary nuclear pipe under nominal conditions (inner temperature of 300° and an internal pressure of 15.5 MPa) is implemented in finite element code to provide a dataset for unsupervised ML code. The algorithm is then tested under anomaly pattern that deviate from nominal conditions. The results show good code prediction capabilities anticipating the pipe failure. Traditional monitoring combined with ML technique may support LTO program increasing the safety and competitiveness of NPPs.
Research on the Correlations of Fission Source Distribution in the Monte Carlo Algorithm Using Mathematical Tools
Authors: Shen Pengfei , Jiang Shihang , Hu Yingzhe , Wang Kan
Published: November 2022

In the Monte Carlo algorithm, the power iteration method is commonly used to obtain the Fission Neutron Bank of each cycle. This method uses the offspring produced by the neutrons of the previous cycle as the next cycle’s fission neutron bank. Thus, there is physical continuity between the adjacent cycle’s fission source distributions (FSD). This physical continuity of this process will lead to the mathematical correlation of fission source distributions. We extensively investigate the correlation of fission source distributions using mathematical approaches. We analyzed the correlations of the FSD with different geometric scales and the adjacent number of cycles. The results show that the correlations between two fission source distributions decline with the adjacent cycle number increases. The miniature models would take dozes of cycles for the correlations to decline to be negligible, while the standard reactor core model would use around 500 cycles to decline. These correlations should be carefully removed if a non-bias Monte Carlo calculation is carried out. In the BEAVRS core model, the correlations would result in around 80 percent underestimating the variance for the flux tally of assemblies. These methods can be easily implemented in the standard Monte Carlo codes.
Structural and biochemical characteristics of mRNA nanoparticles determine anti–SARS-CoV-2 humoral and cellular immune responses
Authors: Shi Yingying , Huang Jiaxin , Liu Yu , Liu Jing , Guo Xuemeng , Li Jianhua , Gong Liming , Zhou Xin , Cheng Guofeng , Qiu Yunqing , You Jian , Lou Yan
Published: November 2022

The coronavirus disease 2019 (COVID-19) pandemic underlines the urgent need for effective mRNA vaccines. However, current understanding of the immunological outcomes of mRNA vaccines formulated under different nanoplatforms is insufficient. Here, severe acute respiratory syndrome coronavirus 2 receptor binding domain mRNA delivered via lipid nanoparticle (LNP), cationic nanoemulsion (CNE), and cationic liposome (Lipo) was constructed. Results demonstrated that the structural and biochemical characteristics of nanoparticles shaped their tissue dissemination, cellular uptake, and intracellular trafficking, which eventually determined the activation of antiviral humoral and cellular immunity. Specifically, LNP was mainly internalized by myocyte and subsequently circumvented lysosome degradation, giving rise to humoral-biased immune responses. Meanwhile, CNE and Lipo induced cellular-preferred immunity, which was respectively attributed to the better lysosomal escape in dendritic cells and the superior biodistribution in secondary lymphoid organs. Overall, this study may guide the design and clinical use of mRNA vaccines against COVID-19.
An insecticide target in mechanoreceptor neurons
Authors: Qiao Xiaomu , Zhang Xiaoyu , Zhou Zhendong , Guo Lei , Wu Weiping , Ma Suhan , Zhang Xinzhong , Montell Craig , Huang Jia
Published: November 2022

Hundreds of neurotoxic insecticides are currently in use. However, only a few direct targets have been identified. Here, using
Drosophila
and the insecticide flonicamid, we identified nicotinamidase (Naam) as a previous unidentified molecular target for an insecticide. Naam is expressed in chordotonal stretch-receptor neurons, and inhibition of Naam by a metabolite of flonicamid, TFNA-AM (4-trifluoromethylnicotinamide), induces accumulation of substrate nicotinamide and greatly inhibits negative geotaxis. Engineered flies harboring a point mutation in the active site show insecticide resistance and defects in gravity sensing. Bees are resistant to flonicamid because of a gene duplication, resulting in the generation of a TFNA-AM–insensitive Naam. Our results, in combination with the absence of genes encoding Naam in vertebrate genomes, suggest that TFNA-AM and potential species-specific Naam inhibitors could be developed as novel insecticides, anthelmintics, and antimicrobials for agriculture and human health.
Intronic enhancers of the human
SNCA
gene predominantly regulate its expression in brain in vivo
Authors: Cheng Fubo , Zheng Wenxu , Liu Chang , Barbuti Peter Antony , Yu-Taeger Libo , Casadei Nicolas , Huebener-Schmid Jeannette , Admard Jakob , Boldt Karsten , Junger Katrin , Ueffing Marius , Houlden Henry , Sharma Manu , Kruger Rejko , Grundmann-Hauser Kathrin , Ott Thomas , Riess Olaf
Published: November 2022

Evidence from patients with Parkinson’s disease (PD) and our previously reported α-synuclein (SNCA) transgenic rat model support the idea that increased SNCA protein is a substantial risk factor of PD pathogenesis. However, little is known about the transcription control of the human
SNCA
gene in the brain in vivo. Here, we identified that the
DYT6
gene product THAP1 (THAP domain-containing apoptosis-associated protein 1) and its interaction partner CTCF (CCCTC-binding factor) act as transcription regulators of
SNCA
. THAP1 controls
SNCA
intronic enhancers’ activities, while CTCF regulates its enhancer-promoter loop formation. The
SNCA
intronic enhancers present neurodevelopment-dependent activities and form enhancer clusters similar to “super-enhancers” in the brain, in which the PD-associated single-nucleotide polymorphisms are enriched. Deletion of the
SNCA
intronic enhancer clusters prevents the release of paused RNA polymerase II from its promoter and subsequently reduces its expression drastically in the brain, which may provide new therapeutic approaches to prevent its accumulation and thus related neurodegenerative diseases defined as synucleinopathies.
Application of combined CRISPR screening for genetic and chemical-genetic interaction profiling in
Mycobacterium tuberculosis
Authors: Yan Mei-Yi , Zheng Dandan , Li Si-Shang , Ding Xin-Yuan , Wang Chun-Liang , Guo Xiao-Peng , Zhan Lingjun , Jin Qi , Yang Jian , Sun Yi-Cheng
Published: November 2022

CRISPR screening, including CRISPR interference (CRISPRi) and CRISPR-knockout (CRISPR-KO) screening, has become a powerful technology in the genetic screening of eukaryotes. In contrast with eukaryotes, CRISPR-KO screening has not yet been applied to functional genomics studies in bacteria. Here, we constructed genome-scale CRISPR-KO and also CRISPRi libraries in
Mycobacterium tuberculosis
(Mtb). We first examined these libraries to identify genes essential for Mtb viability. Subsequent screening identified dozens of genes associated with resistance/susceptibility to the antitubercular drug bedaquiline (BDQ). Genetic and chemical validation of the screening results suggested that it provided a valuable resource to investigate mechanisms of action underlying the effects of BDQ and to identify chemical-genetic synergies that can be used to optimize tuberculosis therapy. In summary, our results demonstrate the potential for efficient genome-wide CRISPR-KO screening in bacteria and establish a combined CRISPR screening approach for high-throughput investigation of genetic and chemical-genetic interactions in Mtb.
Fully rubbery Schottky diode and integrated devices
Authors: Jang Seonmin , Shim Hyunseok , Yu Cunjiang
Published: November 2022

A fully rubbery stretchable diode, particularly entirely based on stretchy materials, is a crucial device for stretchable integrated electronics in a wide range of applications, ranging from energy to biomedical, to integrated circuits, and to robotics. However, its development has been very nascent. Here, we report a fully rubbery Schottky diode constructed all based on stretchable electronic materials, including a liquid metal cathode, a rubbery semiconductor, and a stretchable anode. The rubbery Schottky diode exhibited a forward current density of 6.99 × 10
−3
A/cm
2
at 5 V and a rectification ratio of 8.37 × 10
4
at ±5 V. Stretchy rectifiers and logic gates based on the rubbery Schottky diodes were developed and could retain their electrical performance even under 30% tensile stretching. With the rubbery diodes, fully rubbery integrated electronics, including an active matrix multiplexed tactile sensor and a triboelectric nanogenerator–based power management system, are further demonstrated.
A lightweight robotic leg prosthesis replicating the biomechanics of the knee, ankle, and toe joint
Authors: Tran Minh , Gabert Lukas , Hood Sarah , Lenzi Tommaso
Published: November 2022

Robotic leg prostheses promise to improve the mobility and quality of life of millions of individuals with lower-limb amputations by imitating the biomechanics of the missing biological leg. Unfortunately, existing powered prostheses are much heavier and bigger and have shorter battery life than conventional passive prostheses, severely limiting their clinical viability and utility in the daily life of amputees. Here, we present a robotic leg prosthesis that replicates the key biomechanical functions of the biological knee, ankle, and toe in the sagittal plane while matching the weight, size, and battery life of conventional microprocessor-controlled prostheses. The powered knee joint uses a unique torque-sensitive mechanism combining the benefits of elastic actuators with that of variable transmissions. A single actuator powers the ankle and toe joints through a compliant, underactuated mechanism. Because the biological toe dissipates energy while the biological ankle injects energy into the gait cycle, this underactuated system regenerates substantial mechanical energy and replicates the key biomechanical functions of the ankle/foot complex during walking. A compact prosthesis frame encloses all mechanical and electrical components for increased robustness and efficiency. Preclinical tests with three individuals with above-knee amputation show that the proposed robotic leg prosthesis allows for common ambulation activities with close to normative kinematics and kinetics. Using an optional passive mode, users can walk on level ground indefinitely without charging the battery, which has not been shown with any other powered or microprocessor-controlled prostheses. A prosthesis with these characteristics has the potential to improve real-world mobility in individuals with above-knee amputation.
Tumor-intrinsic NLRP3-HSP70-TLR4 axis drives premetastatic niche development and hyperprogression during anti–PD-1 immunotherapy
Authors: Theivanthiran Balamayooran , Yarla Nagendra , Haykal Tarek , Nguyen Y.-Van , Cao Linda , Ferreira Michelle , Holtzhausen Alisha , Al-Rohil Rami , Salama April K.S. , Beasley Georgia M. , Plebanek Michael P. , DeVito Nicholas C. , Hanks Brent A.
Published: November 2022

The tumor-intrinsic NOD-, LRR- and pyrin domain-containing protein-3 (NLRP3) inflammasome–heat shock protein 70 (HSP70) signaling axis is triggered by CD8
+
T cell cytotoxicity and contributes to the development of adaptive resistance to anti–programmed cell death protein 1 (PD-1) immunotherapy by recruiting granulocytic polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) into the tumor microenvironment. Here, we demonstrate that the tumor NLRP3-HSP70 axis also drives the accumulation of PMN-MDSCs into distant lung tissues in a manner that depends on lung epithelial cell Toll-like receptor 4 (TLR4) signaling, establishing a premetastatic niche that supports disease hyperprogression in response to anti–PD-1 immunotherapy. Lung epithelial HSP70-TLR4 signaling induces the downstream Wnt5a-dependent release of granulocyte colony-stimulating factor (G-CSF) and C-X-C motif chemokine ligand 5 (CXCL5), thus promoting myeloid granulopoiesis and recruitment of PMN-MDSCs into pulmonary tissues. Treatment with anti–PD-1 immunotherapy enhanced the activation of this pathway through immunologic pressure and drove disease progression in the setting of
Nlrp3
amplification. Genetic and pharmacologic inhibition of NLRP3 and HSP70 blocked PMN-MDSC accumulation in the lung in response to anti–PD-1 therapy and suppressed metastatic progression in preclinical models of melanoma and breast cancer. Elevated baseline concentrations of plasma HSP70 and evidence of NLRP3 signaling activity in tumor tissue specimens correlated with the development of disease hyperprogression and inferior survival in patients with stage IV melanoma undergoing anti–PD-1 immunotherapy. Together, this work describes a pathogenic mechanism underlying the phenomenon of disease hyperprogression in melanoma and offers candidate targets and markers capable of improving the management of patients with melanoma.
The Multidrug Efflux Regulator AcrR of Escherichia coli Responds to Exogenous and Endogenous Ligands To Regulate Efflux and Detoxification
Authors: Harmon Dana E. , Ruiz Cristian
Published: November 2022

Multidrug efflux pumps can remove antibiotics and other toxic molecules from cells and are major contributors to antibiotic resistance and bacterial physiology. Therefore, it is essential to better understand their function and regulation.
Porcine Reproductive and Respiratory Syndrome Virus nsp1β Stabilizes HIF-1α to Enhance Viral Replication
Authors: Pang Yu , Zhou Yanrong , Wang Yuchen , Sun Zheng , Liu Jiao , Li Chenyu , Xiao Shaobo , Fang Liurong
Published: November 2022

Porcine reproductive and respiratory syndrome virus (PRRSV) has devastated the swine industry worldwide for over 30 years and shows no signs of slowing down. In this study, we found that PRRSV infection elevated hypoxia-inducible factor 1α (HIF-1α) expression.
Microbiota of the Rearing Water ofPenaeus stylirostrisLarvae Influenced by Lagoon Seawater and Specific Key Microbial Lineages of Larval Stage and Survival
Authors: Callac Nolwenn , Boulo Viviane , Giraud Carolane , Beauvais Maxime , Ansquer Dominique , Ballan Valentine , Maillez Jean-René , Wabete Nelly , Pham Dominique
Published: November 2022

In New Caledonia, rearing ofP. stylirostrisis one of the main economic activities; unfortunately, mass larval mortalities cause important production decreases, involving major economic losses for the farmers and the Territory. This phenomenon, which has occurred at any larval stage over the past decade, is poorly understood.
Early choroidal changes detected by swept-source OCT in type 2 diabetes and their association with diabetic kidney disease
Authors: Da Silva Monica Oliveira , Chaves Anne Elise Cruz do Carmo , Gobbato Glauber Correa , Lavinsky Fabio , Schaan Beatriz D'Agord , Lavinsky Daniel
Published: November 2022

Introduction

Microvascular changes in eye and kidney shares some common factors in diabetes mellitus (DM). The purpose was to evaluate choroidal thickness (CT) and choriocapillaris (CC) density in patients with type 2 diabetes (T2D) and their association with diabetic kidney disease (DKD) using swept-source optical coherence tomography (SS-OCT).

Research design and methods

A cross-sectional study was conducted with patients with T2D with mild or no diabetic retinopathy (DR) and non-diabetic controls. CT was measured with SS-OCT, and CC vascular density was measured with OCT angiography. These parameters were compared with inner retinal layers thickness in patients with and without DKD and non-diabetic controls.

Results

Ninety-three eyes from patients with T2D and 34 eyes from controls volunteers were included. Within the T2D group, 56 eyes with DKD and 37 eyes from patients with no diabetic kidney disease were examined. A statistically significant reduction of CT was observed in patients with DKD compared with controls, with no difference in CC density. There was an association between ganglion cell layer and central choroidal thickness reduction in the DKD group.

Conclusions

Patients with T2D with DKD showed a decrease in CT with no difference in CC density compared with non-diabetic controls. This thinning might be related to vascular changes of choroidal layers such as Haller’s and Sattler’s with preservation of CC density, which is crucial for outer retina and retinal pigment epithelium health. Longitudinal studies are warranted to determine the association of choroidal changes with the pathogenesis of diabetes, and its association with early DKD and progression to more severe DR.
Investigating transmission of SARS-CoV-2 using novel face mask sampling: a protocol for an observational prospective study of index cases and their contacts in a congregate setting
Authors: Jaenisch Thomas , Lamb Molly M , Gallichotte Emily N , Adams Brian , Henry Charles , Riess Jeannine , van Sickle Joni Triantis , Hawkins Kellie L , Montague Brian T , Coburn Cody , Conners Bauer Leisha , Kovarik Jennifer , Hernandez Mark T , Bronson Amy , Graham Lucy , James Stephanie , Hanenberg Stephanie , Kovacs James , Spencer John S , Zabel Mark , Fox Philip D , Pluss Olivia , Windsor William , Winstanley Geoffrey , Olson Daniel , Barer Michael , Berman Stephen , Ebel Gregory , Chu May
Published: November 2022

Introduction

This study aims to measure how transmission of SARS-CoV-2 occurs in communities and to identify conditions that lend to increased transmission focusing on congregate situations. We will measure SARS-CoV-2 in exhaled breath of asymptomatic and symptomatic persons using face mask sampling—a non-invasive method for SARS-CoV-2 detection in exhaled air. We aim to detect transmission clusters and identify risk factors for SARS-CoV-2 transmission in presymptomatic, asymptomatic and symptomatic individuals.

Methods and analysis

In this observational prospective study with daily follow-up, index cases and their respective contacts are identified at each participating institution. Contact definitions are based on Centers for Disease Control and Prevention and local health department guidelines. Participants will wear masks with polyvinyl alcohol test strips adhered to the inside for 2 hours daily. The strips are applied to all masks used over at least 7 days. In addition, self-administered nasal swabs and (optional) finger prick blood samples are performed by participants. Samples are tested by standard PCR protocols and by novel antigen tests.

Ethics and dissemination

This study was approved by the Colorado Multiple Institutional Review Board and the WHO Ethics Review Committee. From the data generated, we will analyse transmission clusters and risk factors for transmission of SARS-CoV-2 in congregate settings. The kinetics of asymptomatic transmission and the evaluation of non-invasive tools for detection of transmissibility are of crucial importance for the development of more targeted control interventions—and ultimately to assist with keeping congregate settings open that are essential for our social fabric.

Trial registration number

ClinicalTrials.gov (#NCT05145803).
Exploratory qualitative study examining acceptability of strategies to improve access to substance use treatment and HIV prevention services for young adults on probation in Ukraine
Authors: Dauria Emily , Skipalska Halyna , Gopalakrishnan Lakshmi , Savenko Oksana , Sabadash Liudmyla , Tolou-Shams Marina , Flanigan Timothy , Navario Peter , Castillo Theresa P
Published: November 2022

Objective

Adults <30 years’ of age experience elevated HIV-rates in Ukraine. Young adults (YA) involved in the criminal justice system (CJS) are at an increased HIV-risk given elevated rates of substance use, engagement in high-risk sexual behaviour and insufficient healthcare access. The objective of this exploratory study was to investigate the acceptability of strategies to refer and link CJS-involved YA to HIV-prevention and substance use treatment services from CJS settings.

Design

We conducted qualitative individual interviews with CJS-involved YA (18–24 years), and CJS stakeholders. Interviews were guided by the Social Ecological Model. Interviews with YA explored substance use and sexual behaviour, and acceptability of strategies to link YA to HIV-prevention and substance use treatment services from CJS. Stakeholder interviews explored system practices addressing HIV-prevention and substance use and addiction. Data were analysed using Inductive Thematic Analysis.

Setting

Data were collected in three locales, prior to the 2022 Russian–Ukrainian conflict.

Participants

Thirty YA and 20 stakeholders.

Results

Most YA were men, reported recent injection drug use and wereMage=23 years. YA were receptive to linkage to HIV-prevention services from CJS; this was shaped by self-perceived HIV-risk and lack of access to HIV-prevention services. YA were less receptive to being referred to substance use treatment services, citing a lack of self-perceived need and mistrust in treatment efficacy. Stakeholders identified multilevel contextual factors shaping acceptability of HIV-prevention and substance use treatment from CJS (eg, stigma).

Conclusions

Findings should be reviewed as a historical record of the pre-conflict context. In that context, we identified strategies that may have been used to help curtail the transmission of HIV in a population most-at-risk, including CJS-involved YA. This study demonstrates that improving access to substance use treatment and HIV-prevention services via CJS linkage were acceptable if provided in the right conditions (eg, low or no-cost, confidential).
Can anthropometric indices predict the chance of hypertension? A multicentre cross-sectional study in Iran
Authors: Akbari-khezrabadi Ali , Zibaeenezhad Mohammad Javad , Shojaeefard Ehsan , Naseri Arzhang , Mousavi Shahrokh , Sarejloo Shirin , Karimi Mohammadreza , Hosseinpour Morteza , Salimi Maryam , Bazrafshan Mehdi , Salimi Amirhossein , Parsa Nader , Sayadi Mehrab , Razeghian-Jahromi Iman , Zibaeenejad Fatemeh , Mohammadi Seyyed Saeed , Bazrafshan Drissi Hamed
Published: November 2022

Objectives

This study aims to assess the prevalence of hypertension (HTN), and determine the relationship between HTN and anthropometric indices including fat distribution, body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) in Shiraz Heart Study.

Setting

In this cross-sectional study, subjects were enrolled in 25 clinics in Shiraz. I.R. Iran between 2019 and 2021.

Participants

A total number of 7225 individuals were selected, aged between 40 and 70 years of whom 52.3% were female. Among the people living in Shiraz, individuals living far from clinics, cases of mental or physical disabilitiy and documented cardiovascular diseases were excluded.

Primary and secondary outcome measures

Primary outcome: The association of body composition, WHR, WHtR and BMI with HTN.

Secondary outcome: The sensitivity and specificity of the WHtR for the prediction of HTN.

Results

HTN prevalence was 19.3%. Obesity prevalence was estimated to be 28.5%. WHR and lean body mass showed a significant association with HTN (p<0.05). Receiver operating characteristic for WHtR yielded an area under the curve of 0.62 (95% CI 0.61 to 0.64) and 0.63 (95% CI 0.62 to 0.65) for males and females, respectively. The optimal threshold value yielded 0.54 in men and 0.61 in women. The sensitivity was 72.3% and 73.9% in women and men, with specificity of 48.4% and 44.3%, respectively.

Conclusion

HTN had a meaningful association with all the noted anthropometric indices. WHtR performed well as a predictor of HTN.
Midodrine therapy for vasopressor dependent shock in the intensive care unit: a protocol for a systematic review and meta-analysis
Authors: Kamaleldin Mostafa , Kilcommons Sebastian , Opgenorth Dawn , Fiest Kirsten , Karvellas Constantine Jason , Kutsogiannis Jim , Lau Vincent , MacIntyre Erika , Rochwerg Bram , Senaratne Janek , Slemko Jocelyn , Sligl Wendy , Wang Xiaoming , Bagshaw Sean M , Rewa Oleksa G
Published: November 2022

Introduction

Intensive care unit (ICU) lengths of stay are modified by ongoing need for haemodynamic support in critically ill patients. This is most commonly provided by intravenous vasopressor therapy. Midodrine has been used as an oral agent for haemodynamic support in patients with orthostatic hypotension or cirrhosis. However, its efficacy in treating shock in the ICU, particularly for patients weaning from intravenous vasopressors, remains uncertain. The objective of this systematic review is to determine the efficacy of midodrine in vasopressor dependent shock.

Methods and analysis

We will search Ovid MEDLINE, Ovid Embase, CINAHL and Cochrane Library for observational trials and randomised controlled trials evaluating midodrine in critically ill patients from inception to 21 April 2022. We will also review unpublished data and relevant conference abstracts. Outcomes will include ICU length of stay, duration of intravenous vasopressor support, ICU mortality, hospital mortality, hospital length of stay and rates of ICU readmission. Data will be analysed in aggregate, where appropriate. We will evaluate risk of bias using the modified Cochrane tool and certainty of evidence using Grading of Recommendations, Assessment, Development and Evaluations methodology. We will perform trial sequential analysis for the outcome of ICU length of stay.

Ethics and dissemination

Ethics approval is not required as primary data will not be collected. Findings of this review will be disseminated through peer-related publication and will inform future clinical trials.

PROSPERO registration number

CRD42021260375.
Prevalence and factors associated with undiagnosed type 2 diabetes among adults in Iraq: analysis of cross-sectional data from the 2015 STEPS survey
Authors: Pengpid Supa , Peltzer Karl
Published: November 2022

Objective

The purpose of the study was to assess the prevalence and correlates of undiagnosed type 2 diabetes (UT2D) among adults (aged 18 years and older) in Iraq.

Design

Cross-sectional, population-based study.

Setting

Nationally representative sample of general community-dwelling adult population in Iraq from the 2015 Iraq STEPS survey.

Participants

The sample included 3853 adults (mean age 41.8 years, SD=15.8), with complete fasting blood glucose values, from the 2015 Iraq STEPS survey.

Outcome measures

Data collection included: (1) social and behavioural information, (2) physical parameters and blood pressure measurements and (3) biochemical measurements. UT2D was classified as not being diagnosed with T2D and fasting plasma glucose level ≥126 mg/dL. Multivariable multinomial and logistic regression was used to identify factors associated with UT2D.

Results

The prevalence of UT2D was 8.1% and the prevalence of diagnosed T2D (DT2D) was 8.9%. Participants aged 50 years and older (adjusted relative risk ratio (ARRR): 2.11, 95% CI 1.30 to 3.43) and those with high cholesterol (ARRR: 1.54, 95% CI 1.05 to 2.24) had a higher risk of UT2D. Older age (≥50 years) (ARRR: 17.90, 95% CI 8.42 to 38.06), receipt of healthcare advice (ARRR: 2.15, 95% CI 1.56 to 2.96), history of cholesterol testing (ARRR: 2.17, 95% CI 1.58 to 2.99), stroke or heart attack (ARRR: 1.81, 95% CI 1.13 to 2.92), and high cholesterol (ARRR: 1.55, 95% CI 1.17 to 2.06) were positively associated with DT2D, and high physical activity (ARRR: 0.57, 95% CI 0.38 to 0.84) was negatively associated with DT2D. Higher than primary education (adjusted OR (AOR): 2.02, 95% CI 1.21 to 3.37) was positively associated with UT2D versus DT2D, while older age (≥50 years) (AOR: 0.12, 95% CI 0.06 to 0.25), healthcare advice (AOR: 0.45, 95% CI 0.29 to 0.70), and history of cholesterol screening (AOR: 0.37, 95% CI 0.24 to 0.58) were inversely associated with UT2D versus DT2D.

Conclusion

Almost one in ten adults in Iraq had UT2D, and various associated factors were identified that could be useful in planning interventions.