scholarly journals Crystalline and Electrical Property Improvement of Filtrated, Exfoliated Graphite Sheets by an In-Plane Current and Heating Treatment

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Naoyuki Matsumoto ◽  
Azusa Oshima ◽  
Motoo Yumura ◽  
Kenji Hata ◽  
Don N. Futaba
Keyword(s):  
Electrical Conductivity ◽  
Large Scale ◽  
Treatment Time ◽  
Fold Increase ◽  
Electrical Current ◽  
Current Treatment ◽  
Exfoliated Graphite ◽  
Heating Treatment ◽  
Electrical Current Flow ◽  
Graphite Sheets

Abstract We report an approach to fabricate high conductivity graphite sheets based on a heat-and-current treatment of filtrated, exfoliated graphite flakes. This treatment combines heating (~ 900 °C) and in-plane electrical current flow (550 A·cm−2) to improve electrical conductivity through the reduction of crystalline defects. This process was shown to require only a 1-min treatment time, which resulted in a 2.1-fold increase in electrical conductivity (from 1088 ± 72 to 2275 ± 50 S·cm−1). Structural characterization by Raman spectroscopy and X-ray diffraction indicated that the improvement electrical conductivity originated from a 30-fold improvement in the crystallinity (Raman G/D ratio increase from 2.8 to 85.3) with no other observable structural transformations. Significantly, this treatment was found to act uniformly across a macroscopic (10 mm) sheet surface indicating it is on the development of applications, such as electrodes for energy generation and storage and electromagnetic shielding, as well as on the potential for the development of large-scale treatment technologies.

The emerging roles of extracellular vesicles in ovarian cancer

2020 ◽  
Vol 21 ◽  
Author(s):  
Yin-xue Wang ◽  
Yi-xiang Wang ◽  
Yi-ke Li ◽  
Shi-yan Tu ◽  
Yi-qing Wang
Keyword(s):  
Ovarian Cancer ◽  
Extracellular Vesicles ◽  
Large Scale ◽  
Current Treatment ◽  
Detection Methods ◽  
Drug Resistant ◽  
Apoptotic Bodies ◽  
Biological Mechanisms ◽  
Gynecological Malignancy ◽  
Resistance To Chemotherapy

: Ovarian cancer (OC) is one of the deadliest gynecological malignancy. Epithelial ovarian cancer (EOC) is its most common form. OC has both a poor prognosis and a high mortality rate due to the difficulties of early diagnosis, the limitation of current treatment and resistance to chemotherapy. Extracellular vesicles is a heterogeneous group of cellderived submicron vesicles which can be detected in body fluids, and it can be classified into three main types including exosomes, micro-vesicles, and apoptotic bodies. Cancer cells can produce more EVs than healthy cells. Moreover, the contents of these EVs have been found distinct from each other. It has been considered that EVs shedding from tumor cells may be implicated in clinical applications. Such as a tool for tumor diagnosis, prognosis and potential treatment of certain cancers. In this review, we provide a brief description of EVs in diagnosis, prognosis, treatment, drug-resistant of OC. Cancer-related EVs show powerful influences on tumors by various biological mechanisms. However, the contents mentioned above remain in the laboratory stage and there is a lack of large-scale clinical trials, and the maturity of the purification and detection methods is a constraint. In addition, amplification of oncogenes on ecDNA is remarkably prevalent in cancer, it may be possible that ecDNA can be encapsulated in EVs and thus detected by us. In summary, much more research on EVs needs to be perform to reveal breakthroughs in OC and to accelerate the process of its application on clinic.

scholarly journals Challenges and opportunities for ovarian cancer management in the epidemic of Covid-19: lessons learned from Wuhan, China

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Zhilan Chen ◽  
Chun Zhang ◽  
Jiu Yin ◽  
Xin Xin ◽  
Hemei Li ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Large Scale ◽  
Treatment Plan ◽  
Clinical Care ◽  
Gynecologic Cancer ◽  
Treatment Phase ◽  
Tumor Stage ◽  
Current Treatment ◽  
Lessons Learned ◽  
Cancer Management

AbstractChina and the rest of the world are experiencing an outbreak of the 2019 novel coronavirus disease (COVID-19). Patients with cancer are more susceptible to viral infection and are more likely to develop severe complications, as compared to healthy individuals. The growing spread of COVID-19 presents challenges for the clinical care of patients with gynecological malignancies. Ovarian debulking surgery combined with the frequent need for chemotherapy is most likely why ovarian cancer was rated as the gynecologic cancer most affected by COVID-19. Therefore, ovarian cancer presents a particular challenging task. Concerning the ovarian cancer studies with confirmed COVID-19 reported from large-scale general hospitals in Wuhan, we hold that the treatment plan was adjusted appropriately and an individualized remedy was implemented. The recommendations discussed here were developed mainly based on the experience from Wuhan. We advise that the management strategy for ovarian cancer patients should be adjusted in the light of the local epidemic situation and formulated according to the pathological type, tumor stage and the current treatment phase. Online medical service is an effective and convenient communication platform during the pandemic.

Surveillance Models of Large-Scale ESP With High Viscosity Fluids and Gas

2012 ◽  
Author(s):  
Lissett Barrios ◽  
Stuart Scott ◽  
Charles Deuel
Keyword(s):  
Large Scale ◽  
Two Phase Flow ◽  
Electrical Current ◽  
High Viscosity ◽  
Viscous Fluids ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Operational Parameters ◽  
Two Phase ◽  
Operational Conditions

The paper reports on developmental research on the effects of viscosity and two phases, liquid–gas fluids on ESPs which are multi stage centrifugal pumps for deep bore holes. Multiphase viscous performance in a full-scale Electrical Submersible Pump (ESP) system at Shell’s Gasmer facility has been studied experimentally and theoretically. The main objectives is to predict the operational conditions that cause degradations for high viscosity fluids when operating in high Gas Liquid Radio (GLR) wells to support operation in Shell major Projects. The system studied was a 1025 series tandem WJE 1000. The test was performed using this configuration with ten or more pump stages moving fluids with viscosity from 2 to 200 cP at various speed, intake pressure and Gas Void Fractions (GVF). For safety considerations the injected gas was restricted to nitrogen or air. The ESP system is a central artificial lift method commonly used for medium to high flow rate wells. Multiphase flow and viscous fluids causes problems in pump applications. Viscous fluids and free gas inside an ESP can cause head degradation and gas locking. Substantial attempts have been made to model centrifugal pump performance under gas-liquid viscous applications, however due to the complexity this is still a uncertain problem. The determination of the two-phase flow performance in these harmful conditions in the ESP is fundamental aspects in the surveillance operation. The testing at Shell’s Gasmer facility revealed that the ESP system performed as theoretical over the range of single flowrates and light viscosity oils up to Gas Volume Fractions (GVF) around 25%. The developed correlations predict GVF at the pump intake based on the operational parameters. ESP performance degrades at viscosity higher than 100cp as compared to light oil applications, gas lock condition is observed at gas fraction higher than 45%. Pump flowrate can be obtained from electrical current and boost for all range of GVF and speed. The main technical contributions are the analysis of pump head degradation under two important variables, high viscosity and two-phase flow inside the ESP.

Intercomponent Momentum Transport and Electrical Conductivity of Collisionless Plasma

1973 ◽  
Vol 51 (24) ◽  
pp. 2604-2611 ◽  
Author(s):  
H. E. Wilhelm
Keyword(s):  
Electrical Conductivity ◽  
Electric Field ◽  
Collisionless Plasma ◽  
Electrical Current ◽  
Distribution Functions ◽  
Momentum Transport ◽  
Ion Drift ◽  
Moment Approximation ◽  
Electrons And Ions ◽  
Two Component

Based on the Lenard–Balescu equation, the interaction integral for the intercomponent momentum transfer in a two-component, collisionless plasma is evaluated in closed form. The distribution functions of the electrons and ions are represented in the form of nonisothermal, displaced Max wellians corresponding to the 5-moment approximation. As an application, the transport of electrical current in an electric field is discussed for infrasonic up to sonic electron–ion drift velocities.

Six-fold increase in historical Northern Hemisphere concurrent large heatwaves driven by warming and changing atmospheric circulations

2021 ◽  
pp. 1-39
Author(s):  
Cassandra D.W. Rogers ◽  
Kai Kornhuber ◽  
Sarah E. Perkins-Kirkpatrick ◽  
Paul C. Loikith ◽  
Deepti Singh
Keyword(s):  
Northern Hemisphere ◽  
Large Scale ◽  
Warm Season ◽  
Fold Increase ◽  
Circulation Pattern ◽  
Positive Influence ◽  
Climate Risks ◽  
Circulation Patterns ◽  
Multiple Regions ◽  
Barents And Kara Seas

AbstractSimultaneous heatwaves affecting multiple regions (referred to as concurrent heatwaves), pose compounding threats to various natural and societal systems, including global food chains, emergency response systems, and reinsurance industries. While anthropogenic climate change is increasing heatwave risks across most regions, the interactions between warming and circulation changes that yield concurrent heatwaves remain understudied. Here, we quantify historical (1979-2019) trends in concurrent heatwaves during the warm-season (May-September, MJJAS) across the Northern Hemisphere mid- to high-latitudes. We find a significant increase of ~46% in the mean spatial extent of concurrent heatwaves, ~17% increase in their maximum intensity, and ~6-fold increase in their frequency. Using Self-Organising Maps, we identify large-scale circulation patterns (300 hPa) associated with specific concurrent heatwave configurations across Northern Hemisphere regions. We show that observed changes in the frequency of specific circulation patterns preferentially increase the risk of concurrent heatwaves across particular regions. Patterns linking concurrent heatwaves across eastern North America, eastern and northern Europe, parts of Asia, and the Barents and Kara Seas, show the largest increases in frequency (~5.9 additional days per decade). We also quantify the relative contributions of circulation pattern changes and warming to overall observed concurrent heatwave day frequency trends. While warming has a predominant and positive influence on increasing concurrent heatwaves, circulation pattern changes have a varying influence and account for up to 0.8 additional concurrent heatwave days per decade. Identifying regions with an elevated risk of concurrent heatwaves and understanding their drivers is indispensable for evaluating projected climate risks on interconnected societal systems and fostering regional preparedness in a changing climate.

scholarly journals The Arteriovenous Loop: Engineering of Axially Vascularized Tissue

2018 ◽  
Vol 59 (3-4) ◽  
pp. 286-299 ◽  
Author(s):  
Annika Weigand ◽  
Raymund E. Horch ◽  
Anja M. Boos ◽  
Justus P. Beier ◽  
Andreas Arkudas
Keyword(s):  
Tissue Engineering ◽  
Large Scale ◽  
Treatment Options ◽  
Current Treatment ◽  
Loop Model ◽  
Engineering Approach ◽  
In Vivo Tissue Engineering ◽  
Tissue Engineering Approach ◽  
Tissue Defects

Background: Most of the current treatment options for large-scale tissue defects represent a serious burden for the patients, are often not satisfying, and can be associated with significant side effects. Although major achievements have already been made in the field of tissue engineering, the clinical translation in case of extensive tissue defects is only in its early stages. The main challenge and reason for the failure of most tissue engineering approaches is the missing vascularization within large-scale transplants. Summary: The arteriovenous (AV) loop model is an in vivo tissue engineering strategy for generating axially vascularized tissues using the own body as a bioreactor. A superficial artery and vein are anastomosed to create an AV loop. This AV loop is placed into an implantation chamber for prevascularization of the chamber inside, e.g., a scaffold, cells, and growth factors. Subsequently, the generated tissue can be transplanted with its vascular axis into the defect site and anastomosed to the local vasculature. Since the blood supply of the growing tissue is based on the AV loop, it will be immediately perfused with blood in the recipient site leading to optimal healing conditions even in the case of poorly vascularized defects. Using this tissue engineering approach, a multitude of different axially vascularized tissues could be generated, such as bone, skeletal or heart muscle, or lymphatic tissues. Upscaling from the small animal AV loop model into a preclinical large animal model could pave the way for the first successful attempt in clinical application. Key Messages: The AV loop model is a powerful tool for the generation of different axially vascularized replacement tissues. Due to minimal donor site morbidity and the possibility to generate patient-specific tissues variable in type and size, this in vivo tissue engineering approach can be considered as a promising alternative therapy to current treatment options of large-scale defects.

The ability of Distichlis spicata to grow sustainably within a saline discharge zone while improving the soil chemical and physical properties

Soil Research ◽  
2008 ◽  
Vol 46 (1) ◽  
pp. 37 ◽  
Author(s):  
M. R. Sargeant ◽  
C. Tang ◽  
P. W. G. Sale
Keyword(s):  
Electrical Conductivity ◽  
Hydraulic Conductivity ◽  
Physical Properties ◽  
Soil Nitrogen ◽  
Fold Increase ◽  
Dry Weight ◽  
Saturated Hydraulic Conductivity ◽  
Distichlis Spicata ◽  
Discharge Zone ◽  
Spatial And Temporal Variation

Landholder observations indicate that the growth of Distichlis spicata in saline discharge sites improves the soil condition. An extensive soil sampling survey was conducted at the Wickepin field site in Western Australia, where D. spicata had been growing for 8 years, to test the hypothesis that this halophytic grass will make improvements in chemical and physical properties of the soil. Soil measurements included saturated hydraulic conductivity, water-stable aggregates, root length and dry weight, electrical conductivity, pH, and soil nitrogen and carbon. Results confirm that marked differences in soil properties occurred under D. spicata. For example, a 12-fold increase in saturated hydraulic conductivity occurred where D. spicata had been growing for 8 years, compared to adjacent control soil where no grass had been growing. There were also improvements in aggregate stability, with the most notable improvements in the top 0.10 m of soil, again with the greatest improvements occurring where 8 years of growth had occurred. Soil nitrogen and carbon increased under the sward, with the biggest increases occurring in the top 0.10 m of soil. Electrical conductivity measurements were more variable, mostly due to the large spatial and temporal variation encountered. However, the findings generally support the proposition that the growth of D. spicata does not lead to an accumulation of salt within the rooting zone.

Improvement of the electrical conductivity of carbon fiber reinforced polymer by incorporation of nanofillers and the resulting thermal and mechanical behavior

2017 ◽  
Vol 52 (11) ◽  
pp. 1495-1503 ◽  
Author(s):  
K Hamdi ◽  
Z Aboura ◽  
W Harizi ◽  
K Khellil
Keyword(s):  
Electrical Conductivity ◽  
Carbon Fiber ◽  
Carbon Black ◽  
Electrical Current ◽  
Polyamide 6 ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

This work tends to characterize the effect of carbon black nanofillers on the properties of the woven carbon fiber reinforced thermoplastic polymers. First of all, composites from nanofilled Polyamide 6 resin reinforced by carbon fibers were fabricated. Scanning electron microscopy observations were performed to localize the nanoparticles and showed that particles penetrated the fiber zone. In fact, by reaching this zone, the carbon black nanofillers create a connectivity's network between fibers, which produces an easy pathway for the electrical current. It explains the noticed improvement of the electrical conductivity of the carbon black nanofilled composites. Electrical conductivity of neat matrix composite passed from 20 to 80 S/cm by adding 8 wt% of carbon black and to 140 S/cm by adding 16 wt% of the same nanofiller. The addition of nanofillers modifies the heating and cooling laws of carbon fiber reinforced polymer: the nanofilled carbon fiber reinforced polymer with 16 wt% is the most conductive so it heats less. Based on these results, the use of the composite itself as an indicator of this mechanical state might be possible. In fact, the study of the influence of a mechanical loading on the electrical properties of the composite by recording the variance of an electrical set is possible.

Plasma Surface Modification of Silica and its Application in Epoxy Molding Compounds for Large-Scale Integrated Circuits Packaging

2010 ◽  
Vol 158 ◽  
pp. 184-188 ◽  
Author(s):  
Ming Shan Yang ◽  
Lin Kai Li ◽  
Jian Guo Zhang
Keyword(s):  
Surface Modification ◽  
Acrylic Acid ◽  
Integrated Circuits ◽  
Plasma Polymerization ◽  
High Speed ◽  
Large Scale ◽  
Treatment Time ◽  
Rf Plasma ◽  
Formaldehyde Resin ◽  
Molding Compounds

The surface modification of silica for epoxy molding compounds (EMC) was conducted by plasma polymerization using RF plasma (13.56MPa), and the modification factors such as plasma power, gas pressure and treatment time were investigated systematically in this paper. The monomers utilized for the plasma polymer coatings were pyrrole, 1,3-diaminopropane, acrylic acid and urea. The plasma polymerization coating of silica was characterized by FTIR, contact angle. Using the silica treated by plasma as filler, ortho-cresol novolac epoxy as main resin, novolac phenolic-formaldehyde resin as cross-linking agent and 2-methylmizole as curing accelerating agent, the EMCs used for the packaging of large-scale integrated circuits were prepared by high-speed pre-mixture and twin roller mixing technology. The results have shown that the surface of silica can be coated by plasma polymerization of pyrrole, 1,3-diaminopropane, acrylic acid and urea, and the comprehensive properties of EMC were improved.

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