To investigate the clinical and imaging characteristics of computed tomography (CT) in novel coronavirus pneumonia (NCP) caused by SARS-CoV-2.
A retrospective analysis was performed on the imaging ...findings of patients confirmed with COVID-19 pneumonia who had chest CT scanning and treatment after disease onset. The clinical and imaging data were analyzed.
Fifty patients were enrolled, including mild type in nine, common in 28, severe in 10 and critically severe in the rest three. Mild patients (29 years) were significantly (P<0.03) younger than either common (44.5 years) or severe (54.7) and critically severe (65.7 years) patients, and common patients were also significantly (P<0.03) younger than severe and critically severe patients. Mild patients had low to moderate fever (<39.1 °C), 49 (98%) patients had normal or slightly reduced leukocyte count, 14 (28%) had decreased counts of lymphocytes, and 26 (52%) patients had increased C-reactive protein. Nine mild patients were negative in CT imaging. For all the other types of NCP, the lesion was in the right upper lobe in 30 cases, right middle lobe in 22, right lower lobe in 39, left upper lobe in 33 and left lower lobe in 36. The lesion was primarily located in the peripheral area under the pleura with possible extension towards the pulmonary hilum. Symmetrical lesions were seen in 26 cases and asymmetrical in 15. The density of lesion was mostly uneven with ground glass opacity as the primary presentation accompanied by partial consolidation and fibrosis.
CT imaging presentations of NCP are mostly patchy ground glass opacities in the peripheral areas under the pleura with partial consolidation which will be absorbed with formation of fibrotic stripes if improved. CT scanning provides important bases for early diagnosis and treatment of NCP.
Memristors are emerging as a rising star of new computing and information storage techniques. However, the practical applications are severely challenged by their instability toward harsh conditions, ...including high moisture, high temperatures, fire, ionizing irradiation, and mechanical bending. In this work, for the first time, lead‐free double perovskite Cs2AgBiBr6 is utilized for environmentally robust memristors, enabling highly efficient information storage. The memory performance of the typical indium‐tin‐oxide/Cs2AgBiBr6/Au sandwich‐like memristors is retained after 1000 switching cycles, 105 s of reading, and 104 times of mechanical bending, comparable to other halide perovskite memristors. Most importantly, the memristive behavior remains robust in harsh environments, including humidity up to 80%, temperatures as high as 453 K, an alcohol burner flame for 10 s, and 60Co γ‐ray irradiation for a dosage of 5 × 105 rad (SI), which is not achieved by any other memristors and commercial flash memory techniques. The realization of an environmentally robust memristor from Cs2AgBiBr6 with a high memory performance will inspire further development of robust electronics using lead‐free double perovskites.
Double perovskite Cs2AgBiBr6 is fabricated into an indium tin oxide/Cs2AgBiBr6/Au device for the first time. Ultrastable memristive behavior is obtained owing to the tough crystallinity of Cs2AgBiBr6. Humidity‐, high temperature‐, fire‐, and radiation‐resistant properties of Cs2AgBiBr6‐based devices promote memristive devices to work in harsh environments, where most perovskite‐based devices may fail to work.
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•MF-templated rGO/GNP phase change materials containing paraffin wax were prepared.•The composite PCMs exhibited excellent comprehensive performances.•The composite PCM samples showed ...multiple energy conversion abilities.
Phase change materials (PCMs) have wide applications in many fields and they are thought to be one of the highest potential materials in the future. Developing advanced PCMs faces various problems, such as low thermal conductivity, poor shape stability and single energy conversion pattern, etc. In this work, novel composite PCMs were fabricated based on the commercial melamine foam (MF) incorporated by the graphene oxide (GO) and graphene nanoplatelets (GNPs). After hydrothermal reaction and carbonization, the composite aerogel still maintained the three-dimensional (3D) composite framework structure with reduced GO (rGO) and GNPs covering on the carbonized MF framework. The composite PCM samples exhibited high shape stability without leakage under the load of 265 times of its own mass at temperature much higher than the phase change temperature of paraffin wax (PW), high phase change enthalpy retention rate (nearly 100% of PW), high thermal conductivity (1.46 W/m·K) and electrical conductivity (2.787 S/cm) at a filler content of 4.89 wt%. Moreover, the composite PCM samples have excellent light-to-thermal and electric-to-thermal energy conversion abilities, which endow the composite PCMs with great potential in diverse applications, such as the energy saving and heat preservation of building and temperature protection of microelectronic devices, etc.
Considerable efforts have been devoted to achieving stable acene derivatives for electronic applications; however, the instability is still a major issue for such derivatives. To achieve higher ...stability with minimum structural change, CC units in the acenes were replaced with isoelectronic BN units to produce a novel BN‐embedded tetrabenzopentacene (BNTBP). BNTBP, with a planar structure, is highly stable to air, moisture, light, and heat. Compared with its carbon analogue tetrabenzopentacene (TBP), BN embedment lowered the highest occupied molecular orbital (HOMO) energy level of BNTBP, changed the orbital distribution, and decreased the HOMO orbital coefficients at the central carbon atoms, which stabilize BNTBP molecules upon exposure to oxygen and sunlight. The single‐crystal microribbons of BNTBP exhibited good performance in field‐effect transistors (FETs). The high stability and good mobility of BNTBP indicates that BN incorporation is an effective approach to afford stable large‐sized acenes with desired properties.
Make stable: BN‐embedment is demonstrated to play an important role in stabilizing a pentacene derivative by tuning the orbital distribution and lowering the HOMO energy level. This study provides an effective strategy to attain stable acenes without changing the molecular configuration or intermolecular packing structure, and thus improves the potential application of large acenes in electronic devices.
Conjugated coordination polymers have become an emerging category of redox‐active materials. Although recent studies heavily focus on the tailoring of metal centers in the complexes to achieve stable ...electrochemical performance, the effect on different substitutions of the bridging bonds has rarely been studied. An innovative tailoring strategy is presented toward the enhancement of the capacity storage and the stability of metal–organic conjugated coordination polymers. Two nanostructured d‐π conjugated compounds, NiC6H2(NH)4n (Ni‐NH) and NiC6H2(NH)2S2n (Ni‐S), are evaluated and demonstrated to exhibit hybrid electrochemical processes. In particular, Ni‐S delivers a high reversible capacity of 1164 mAh g−1, an ultralong stability up to 1500 cycles, and a fully recharge ability in 67 s. This tailoring strategy provides a guideline to design future effective conjugated coordination‐polymer‐based electrodes.
An innovative tailoring strategy toward the enhancement of the capacity storage and stability of d‐π metal‐organic conjugated coordination polymers is proposed. The tailored compound Ni‐S shows a high reversible capacity of 1164 mAh g−1, an ultralong stability up to 1500 cycles, and a fully recharge ability of only 67 s.
The modification of the terminal electron‐donating groups induces a critical change in molecular aggregation and the intermolecular charge‐transfer effect of the symmetric D–A1–A2–A1–D molecules that ...correlate with an addressable variation of memory performance from binary to ternary.
•A new model for automobile exhaust thermoelectric generator system is proposed.•Based on the system reliability, the counter flow cooling pattern is recommended.•There exists an optimal ...thermoelectric unit number to maximize system output power.•Better performance is predicted with less thermoelectric materials consumption.
This work develops a multiphysics thermoelectric generator model for automobile exhaust waste heat recovery, in which the exhaust heat source and water-cooling heat sink are actually modeled. Special emphasis is put on the non-uniformity of temperature difference across thermoelectric units along the streamwise direction, which may affect the performance of exhaust thermoelectric generator systems significantly. The main findings are: (1) The counter flow cooling pattern is recommended, although it cannot elevate the overall output power as compared with the parallel flow counterpart, it reduces the temperature non-uniformity effectively, and hence ensures the system reliability. (2) The temperature non-uniformity strikingly deteriorates the output power of thermoelectric unit along the streamwise direction; meanwhile, an additional lateral heat conduction effect exists within the exhaust channel wall, the both mechanisms leads to that the maximum output power of the system is not enhanced but is actually reduced when too many thermoelectric units are adopted. (3) When the exhaust channel length is fixed, the maximum output power of the system can be elevated by increasing the thermoelectric unit number but keeping thermoelectric unit spacing unchanged. This means that the system performance can be improved under the condition of less thermoelectric materials consumption.
A practical, Pd(0)/Pd(II)-catalyzed reaction was developed for phenol-directed C–H activation/C–O cyclization using air as an oxidant. The turnover-limiting step of the process was found to be C–O ...reductive elimination instead of C–H activation. This reaction can tolerate a variety of functional groups and is complementary to the previous methods for the synthesis of substituted dibenzofurans.
The incorporation of carbon nanotubes (CNTs) into binary immiscible polymer blends is attracting considerable attention both from fundamental and application point of view. This paper provides a ...comprehensive overview about the notable recent progress in the field of polymer blend/CNT composites. Following a brief introduction of the polymer blend/CNT composites, progress in the selective localization of CNTs in immiscible blends (thermodynamic and kinetic effects), the morphology changes induced by CNTs (compatibilization, phase separation, blend morphology transition), the rheological and crystallization behaviors, and functional properties (mechanical, electrical, shape memory, dielectric, electromagnetic interference shielding, sensor properties, etc.) are reviewed. Finally, the current challenges and opportunities of utilizing CNTs for immiscible blends are proposed.
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The implementation of memristors that are wearable and transparent has attracted significant attention. However, the development of high‐performance memristors that simultaneously possess high ...flexibility and environmental stability has remained a tremendous challenge suffering from limited choice of materials with both good ion‐electron mobility and structural flexibility. Inspired by the unique poly‐ionic nature of ammonium polyphosphate (APP), a novel Au/APP/ITO memristor with favorable flexibility and stability is prepared. Synaptic behaviors can be stimulated by voltage pulses that are 20 ns in width, 0.1 V in amplitude, and repeatable under 104 pulse cycles, thereby outperforming several other benchmark memristors. Further, the device, prepared on conductive silicone, can sustain its synaptic performance even under 360° bending. Furthermore, the device can sustain its synaptic behaviors even after exposure to fire for 60 s and 5.6 kGy of ionic irradiation. Additionally, APP is determined to be nontoxic, biodegradable, and transparent when compared with all the organics and inorganics used in previous memristors. The results of this study will inspire the development of more inorganic polymers for their utilization in future environmentally stable and flexible electronics.
Ammonium polyphosphate (APP) can be spin‐coated on various substrates including ITO, conductive silicone, cellulose tape, leaves, and carbon cloth to develop a memristor with a Au/APP/base. In addition, after exposure to fire for 60 s or irradiation of 5.6 kGy, this memristor can sustain its memristive properties. These measurements exhibit biocompatible, wearable, degradable and stable memristive performance.
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