An epigraphene platform for coherent 1D nanoelectronics

Exceptional edge state ballistic transport, first observed in graphene nanoribbons grown on the sidewalls of trenches etched in electronics grade silicon carbide even at room temperature, is shown here to manifest in micron scale epigraphene structures that are conventionally patterned on single crystal silicon carbide substrates. Electronic transport is dominated by a single electronic mode, in which electrons travel large distances without scattering, much like photons in an optical fiber. In addition, robust quantum coherence, non-local transport, and a ground state with half a conductance quantum are also observed. These properties are explained in terms of a ballistic edge state that is pinned at zero energy. The epigraphene platform allows interconnected nanostructures to be patterned, using standard microelectronics methods, to produce phase coherent 1D ballistic networks. This discovery is unique, providing the first feasible route to large scale quantum coherent graphene nanoelectronics, and a possible inroad towards quantum computing

Protected transport in the epigraphene edge state

The graphene edge state has long been predicted to be a zero energy, one-dimensional electronic waveguide mode that dominates transport in neutral graphene nanostructures, with potential application to graphene devices. However, its exceptional properties have been observed in only a few cases, each employing novel fabrication methods without a clear path to large-scale integration. We show here that interconnected edge-state networks can be produced using non-conventional facets of electronics grade silicon carbide wafers and scalable lithography, which cuts the epitaxial graphene and apparently fuses its edge atoms to the silicon carbide substrate. Measured epigraphene edge state (EGES) conduction is ballistic with mean free paths exceeding tens of microns, thousands of times greater than for the diffusive 2D bulk. It is essentially independent of temperature, decoupled from the bulk and substantially immune to disorder. Remarkably, EGES transport involves a non-degenerate conductance channel that is pinned at zero energy, yet it does not generate a Hall voltage, implying balanced electron and hole components. These properties, observed at all tested temperatures, magnetic fields, and charge densities, are not predicted by present theories, and point to a zero-energy spin one-half quasiparticle, composed of half an electron and a half a hole moving in opposite directions

Research on High Density Water-Based Drilling Fluid of Complete Tectonic for the Southern Edge of the Junggar Basin

The southern edge of the Junggar basin in China has great potential for oil and gas exploitation. However, during drilling in this area, many borehole problems occurred, which leads to low rate of penetration and long drilling cycle. The main reasons from the geological aspect was that this area was affected by tectonic process, which leaded to development of complete tectonic, formation nappe along fault, big dip angles and poor stability. The Formation E2-3a was dominated by mudstone which was sensitive to water and can easily cause shale hydration expansion and dispersal. The instability of the formation is one of the major causes of borehole collapse and tight hole shrinkage. In order to improve the drilling speed and accelerate the process of exploration of southern edge in Juggar basin, the drilling fluids used in this region are studied based on data of geology and drilling data in this paper, Based on the characteristics of the formation E2-3a, a new high density PRT-organic salt drilling fluid is selected by conducting a large number of laboratory tests. Test results of the inhibitory, sealing and stain resistance of this fluid indicates that it could satisfy the drilling requirement in southern edge of the Junggar basin. And field applications also turned out to be positive, the drilling speed was increased by 22% and drilling cycle was reduced by 4 days

In-Depth Study on the Effects of Impurity Ions in Saline Wastewater Electrolysis

Concentration followed by electrolysis is one of the most promising ways for saline wastewater treatment, since it could produce H2, Cl2, and an alkaline solution with deacidification potential. However, due to the diversity and difference of wastewater, knowledge on the suitable salt concentration for wastewater electrolysis and the effects of mixed ions are still lacking. In this work, electrolysis experiments of mixed saline water were conducted. The salt concentration for stable dechlorination was explored, with in-depth discussions on the effects of typical ions such as K+, Ca2+, Mg2+, and SO42−. Results showed that K+ had a positive effect on the H2/Cl2 production of saline wastewater through accelerating the mass transfer efficiency in the electrolyte. However, the existence of Ca2+ and Mg2+ had negative effects on the electrolysis performance by forming precipitates, which would adhere to the membrane, reduce the membrane permeability, occupy the active sites on the cathode surface, and also increase the transport resistance of the electrons in the electrolyte. Compared to Mg2+, the damaging effect of Ca2+ on the membrane was even worse. Additionally, the existence of SO42− reduced the current density of the salt solution by affecting the anodic reaction while having less of an effect on the membrane. Overall, Ca2+ ≤ 0.01 mol/L, Mg2+ ≤ 0.1 mol/L and SO42− ≤ 0.01 mol/L were allowable to ensure the continuous and stable dechlorination electrolysis of saline wastewater

“Low-age, low-frequency” lung cancer screening strategies maybe adaptable to the situation in China

Abstract Background The object was to compare changes in patients undergoing lung surgery before and after COVID-19 outbreak, and to explore the impact of COVID-19 on lung surgery and its coping strategies. Method A retrospective review of patients undergoing thoracic surgery at a single institution was conducted. Group A included patients treated between January 23, 2019, and January 23, 2020, while Group B included patients treated between June 1, 2020, and June 1, 2021, at our center. We compared the reasons of seeking medical treatment, the general characteristics of patients, imaging features, pathological features, surgical methods and postoperative recovery. Result Compared to Group A, the number of patients with pulmonary nodules screened by routine check-up increased in Group B (57.6% vs 46.9%, p < 0.05). Female patient increased (55.2%vs 44.7%). Patient without smoking history or with family history of lung cancer increased (70.7% vs 60.7%) (10.1%vs 7.8%). Early stage lung cancer increased. Lobectomy decreased (53.4% vs 64.1%). Segmental resection increased (33.3% vs 12.7%). Patients without postoperative comorbidities increased (96.1%vs 85.7%). In the case of patients with Ground Glass Opacity(GGO), their age was comparatively lower (52 ± 9.9 vs. 55 ± 10.7), the female patients increased, patient without smoking history, tumor history, family history of tumor increased, small GGO increased. Lobectomy decreased (35.2% vs 49.7%). Segmental resection increased (49.6% vs 21.2%). Patients without postoperative comorbidities increased (96.5% vs 87.4%). Conclusion Since COVID-19 outbreak, more young, non-smoking, female lung cancers, more Ground Glass Opacity, none high risk patients have been detected through screening, suggesting that our current screening criteria for lung cancer may need to be revised. Higher requirements, including the selection of the timing of nodular surgery, surgical methods were put forward for thoracic surgeons’ skills

Bioenergetic dysfunction in the pathogenesis of intervertebral disc degeneration

Intervertebral disc (IVD) degeneration is a frequent cause of low back pain and is the most common cause of disability. Treatments for symptomatic IVD degeneration, including conservative treatments such as analgesics, physical therapy, anti-inflammatories and surgeries, are aimed at alleviating neurological symptoms. However, there are no effective treatments to prevent or delay IVD degeneration. Previous studies have identified risk factors for IVD degeneration such as aging, inflammation, genetic factors, mechanical overload, nutrient deprivation and smoking, but metabolic dysfunction has not been highlighted. IVDs are the largest avascular structures in the human body and determine the hypoxic and glycolytic features of nucleus pulposus (NP) cells. Accumulating evidence has demonstrated that intracellular metabolic dysfunction is associated with IVD degeneration, but a comprehensive review is lacking. Here, by reviewing the physiological features of IVDs, pathological processes and metabolic changes associated with IVD degeneration and the functions of metabolic genes in IVDs, we highlight that glycolytic pathway and intact mitochondrial function are essential for IVD homeostasis. In degenerated NPs, glycolysis and mitochondrial function are downregulated. Boosting glycolysis such as HIF1α overexpression protects against IVD degeneration. Moreover, the correlations between metabolic diseases such as diabetes, obesity and IVD degeneration and their underlying molecular mechanisms are discussed. Hyperglycemia in diabetic diseases leads to cell senescence, the senescence-associated phenotype (SASP), apoptosis and catabolism of extracellualr matrix in IVDs. Correcting the global metabolic disorders such as insulin or GLP-1 receptor agonist administration is beneficial for diabetes associated IVD degeneration. Overall, we summarized the recent progress of investigations on metabolic contributions to IVD degeneration and provide a new perspective that correcting metabolic dysfunction may be beneficial for treating IVD degeneration

Minimally Invasive Detection Technologies for the Defects in Ancient Timber Structural Building

How to examine and describe the defects in timber is vital for assessing the performance of an ancient timber structural building. This paper mainly elaborates the methodology of detecting the defects in ancient timber structures. The detection method includes preliminary condition survey, stress-wave tomography test, and correction with resistographic drilling. By means of above detection, the defects inside a timber structural building could be described more accurately