Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular ...carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells(HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.
Abstract
Background
The emergence of coronavirus disease 2019 (COVID-19) is a major healthcare threat. The current method of detection involves a quantitative polymerase chain reaction (qPCR)–based ...technique, which identifies the viral nucleic acids when present in sufficient quantity. False-negative results can be achieved and failure to quarantine the infected patient would be a major setback in containing the viral transmission. We aim to describe the time kinetics of various antibodies produced against the 2019 novel coronavirus (SARS-CoV-2) and evaluate the potential of antibody testing to diagnose COVID-19.
Methods
The host humoral response against SARS-CoV-2, including IgA, IgM, and IgG response, was examined by using an ELISA-based assay on the recombinant viral nucleocapsid protein. 208 plasma samples were collected from 82 confirmed and 58 probable cases (qPCR negative but with typical manifestation). The diagnostic value of IgM was evaluated in this cohort.
Results
The median duration of IgM and IgA antibody detection was 5 (IQR, 3–6) days, while IgG was detected 14 (IQR, 10–18) days after symptom onset, with a positive rate of 85.4%, 92.7%, and 77.9%, respectively. In confirmed and probable cases, the positive rates of IgM antibodies were 75.6% and 93.1%, respectively. The detection efficiency by IgM ELISA is higher than that of qPCR after 5.5 days of symptom onset. The positive detection rate is significantly increased (98.6%) when combining IgM ELISA assay with PCR for each patient compared with a single qPCR test (51.9%).
Conclusions
The humoral response to SARS-CoV-2 can aid in the diagnosis of COVID-19, including subclinical cases.
The time kinetics of humoral responses against the novel coronavirus (SARS-CoV-2) are characterized in patients with COVID-19 by nucleocapsid-based enzyme-linked immunosorbent assay. The antibody testing can aid in the diagnosis of COVID-19 when combined with quantitative polymerase chain reaction, including in subclinical cases.
In this paper, a novel dual-band dual-polarized array antenna with low frequency ratio and integrated filtering characteristics is proposed. By employing a dual-mode stub-loaded resonator (SLR) to ...feed and tune with two patches, the two feed networks for each polarization can be combined, resulting in the reduction of the feed networks and the input ports. In addition, owing to the native dual resonant features of the SLR, the proposed antenna exhibits second-order filtering characteristics with improved bandwidth and out-of-band rejections. The antenna is synthesized and the design methodology is explained. The coupling coefficients between the SLR and the patches are investigated. To verify the design concept, a C-/X-band element and a 2 \times 2 array are optimized and prototyped. Measured results agree well with the simulations, showing good performance in terms of bandwidth, filtering, harmonic suppression, and radiation at both bands. Such an integrated array design can be used to simplify the feed of a reflector antenna. To prove the concept, a paraboloid reflector fed by the proposed array is conceived and measured directivities of 24.6 dBi (24.7 dBi) and 28.6 dBi (29.2 dBi) for the X-polarization (Y-polarization) are obtained for the low- and high-band operations, respectively.
Structural instability and inferior storage property are bottlenecks of the Ni-rich cathodes. Herein, a coating and doping co-modified Ni-rich cathode, in which La and Al is homogeneously doped in ...the inner and an epitaxial layer is distributed in the outer surface region of secondary particle, is constructed. The outer surface layer tightly integrates a La2O3 coating layer, an epitaxial grown LaAl doped atomic structure and a Ni concentration gradient into the bulk phase. The La and Al act as a pillar ion enlarging c axis spacing and a positively charged center, enhancing Li+ transportation and suppressing the phase transition. The outer surface region with La-enriched layer and decreased Ni concentration suppresses the side reactions between organic electrolyte and oxidizing Ni4+ and improves the storage stability in air. During cycling, the modified material exhibits enhanced rate capability and cycling stability with capacity retention of 80.0% after 480 cycles at 10C in the cell potential range of 2.7–4.3 V.
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•Ni-rich cathode is modified with synergy of coating and doping by La and Al.•Lower lattice expansion and higher Li+ transportation due to La doping.•The coating layer suppresses erosion of electrolyte and improve storage stability.
A simple wet chemical process followed by high temperature calcination has been successfully used to coat Li-ion conductive Li4Ti5O12 on the surface of Ni-rich LiNi0.8Co0.1Mn0.1O2. Physicochemical ...characterization results indicate that a Li4Ti5O12 with a thickness of about 2–3 nm was uniformly distributed on the surface of microspheres, without inducing significant change of the structure and morphology. Electrochemical test results show that proper content of Li4Ti5O12 coating layer can greatly improve the cycling performance and rate capability of Ni-rich LiNi0.8Co0.1Mn0.1O2 for the improved Li+ ions diffusion rate and suppressed side reactions between electrode and electrolyte. Notably, the 1 wt% Li4Ti5O12 coated sample exhibits excellent cycling stability with the capacity retention of 75.86% at 1 C after 170 cycles when cycled between 2.7 and 4.3 V at 25 °C, while that is only 39.40% for bare LiNi0.8Co0.1Mn0.1O2.
Two compact coradiator multiple-input-multiple-out (MIMO) antennas operating in the UWB frequency band with dual polarization are proposed. Different from traditional MIMO antennas, the radiator is ...shared by two antenna elements, which greatly reduce the overall size of the MIMO system. High isolation between the two antenna elements is achieved by etching a T-shaped slot in the radiator and extending a stub on the ground. Dual polarization can be realized by exciting the pentagonal radiator with perpendicular feeding structure. The simulated results of current and electric-field distribution show the dual-polarization characteristics of the diversity system. Besides, a four units UWB MIMO antenna is also proposed. Furthermore, the diversity characteristics of mean effective gains (MEGs) and diversity gain (DG) are also studied. The simulated and measured results demonstrate that the UWB-MIMO antenna has good impedance matching, isolation and dual polarization characteristics.
This paper presents a novel tri-band (X/Ku/Ka-band) planar antenna array with dual polarizations and shared aperture. Compared with traditional dual-polarized arrays, the proposed array has ...advantages of low cost, low profile, and high integration. Three types of antennas resonating at different frequencies, including the perforated patch, stacked patch, and slim crosspatch, are innovatively interleaved in the same aperture. The crosspatch fed by proximity coupling is presented as Ku-band element for its advantages of compact size, high isolation, and pure polarization. The techniques such as series feed and reverse feed are utilized to implement the six feed networks in a compact size with reduced cross polarizations. Measured results agree well with the simulations, showing three operation bands at X-, Ku-, and Ka-bands with the bandwidths of 3.6%, 6.7%, and 5.3%, respectively. The antenna also exhibits excellent radiation performance with the cross-polarization discrimination over 25 dB at the three bands. To the best of the author's knowledge, this is the first shared-aperture X/Ku/Ka-band dual-polarized antenna array reported, which is useful for potential synthetic aperture radar applications.
This paper proposes a novel dual-band full-duplex antenna/array for intelligent transport systems applications. Different from traditional single-port single-band antennas, the two ports of the ...antenna are highly isolated and designed to operate at different frequency bands simultaneously. Such a property could support the full-duplex operation-mode, which significantly simplifies the complexity of the RF frontend subsystem. The other contribution of this work is that multiple functions such as filtering, duplexing, and radiation are combined into one single device, resulting in a simplified RF frontend. This co-design multifunctional device could also remove the separate filters, duplexers, and interfaces between them, resulting in the reduction of the size, weight, and cost. In addition, cross-coupling is investigated and employed to generate additional transmission zeros so as to improve the channel isolation and out-of-band interference. To verify the concept, an antenna element and two 2 × 2 arrays at C-band are designed, prototyped, and tested. All the measurements agree well with the simulations, showing two full-duplex channels of 4.58-4.83 GHz and 5.86-6.2 GHz for transmitting and receiving, respectively. The proposed antennas also exhibit excellent performance in terms of channel isolations, frequency selectivity, out-of-band rejections, and gains.
In this paper, a compact, broadband, planar array antenna with omnidirectional radiation in horizontal plane is proposed for the 26 GHz fifth-generation (5G) broadcast applications. The antenna ...element is composed of two dipoles and a substrate integrated cavity (SIC) as the power splitter. The two dipoles are placed side-by-side at both sides of the SIC, and they are compensated with each other to form an omnidirectional pattern in horizontal plane. By properly combing the resonant frequencies of the dipoles and the SIC, a wide impedance bandwidth from 24 to 29.5 GHz is achieved. To realize a large array while reducing the complexity, loss, and size of the feeding network, a novel dual-port structure combined with radiation and power splitting functions is proposed for the first time. The amplitude and phase on each element of the array can be tuned, and therefore, the grating lobes level can be significantly reduced. Based on the dual-port structure, an eight-element array with an enhanced gain of over 12 dBi is designed and prototyped. The proposed antenna also features low profile, low weight, and low cost, which is desirable for 5G commercial applications. Measured results agree well with the simulations, showing that the proposed high-gain array antenna has a broad bandwidth, omnidirectional pattern in horizontal plane, and low side-lobes.
Demands for large‐scale energy storage systems have driven the development of layered transition‐metal oxide cathodes for room‐temperature rechargeable sodium ion batteries (SIBs). Now, an abnormal ...layered‐tunnel heterostructure Na0.44Co0.1Mn0.9O2 cathode material induced by chemical element substitution is reported. By virtue of beneficial synergistic effects, this layered‐tunnel electrode shows outstanding electrochemical performance in sodium half‐cell system and excellent compatibility with hard carbon anode in sodium full‐cell system. The underlying formation process, charge compensation mechanism, phase transition, and sodium‐ion storage electrochemistry are clearly articulated and confirmed through combined analyses of in situ high‐energy X‐ray diffraction and ex situ X‐ray absorption spectroscopy as well as operando X‐ray diffraction. This crystal structure engineering regulation strategy offers a future outlook into advanced cathode materials for SIBs.
An abnormal layered‐tunnel heterostructure Na0.44Co0.1Mn0.9O2 cathode material induced by chemical element substitution is described. The crystal‐structure engineering strategy that was used gives an outlook into high‐performance sodium ion batteries.
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