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Although the 9-minute mean withdrawal time (m-WT) is often reported to be associated with the optimal adenoma detection rate (ADR), no randomized trials of screening colonoscopy have confirmed the impact of a 9-minute m-WT on adenoma miss rate (AMR) and ADR.A multicenter tandem trial was conducted in 11 centers. Seven hundred thirty-three asymptomatic participants were randomized to receive segmental tandem screening colonoscopy with a 9-minute withdrawal, followed by a 6-minute withdrawal (9-minute-first group, 9MF, n = 366) or vice versa (6-minute-first group, 6MF, n = 367). The primary outcome was the lesion-level AMR.The intention-to-treat analysis revealed that 9MF significantly reduced the lesion-level (14.5% vs 36.6%, P0.001) and participant-level AMR (10.9% vs 25.9%, P0.001), advanced adenoma miss rate (AAMR, 5.3% vs 46.9%, P = 0.002), multiple adenomas miss rate (20.7% vs 56.5%, P = 0.01), and high-risk adenomas miss rate (14.6% vs 39.5%, P = 0.01) of 6MF without compromising detection efficiency ( P = 0.79). In addition, a lower false-negative rate for adenomas ( P = 0.002) and high-risk adenomas ( P0.05), and a lower rate of shortening surveillance schedule ( P0.001) were also found in 9MF, accompanying with an improved ADR in the 9-minute vs 6-minute m-WT (42.3% vs 33.5%, P = 0.02). The independent inverse association between m-WT and AMR remained significant even after adjusting ADR, and meanwhile, 9-minute m-WT was identified as an independent protector for AMR and AAMR.In addition to increasing ADR, 9-minute m-WT also significantly reduces the AMR and AAMR of screening colonoscopy without compromising detection efficiency.

Background and aimsCompared with self-prepared LRD, a prepackaged low-residue diet (LRD) can improve patient compliance, but whether it can further improve the quality of bowel preparation is uncertain. The study aimed to compare the application of the prepackaged formula LRD with self-prepared LRD in bowel preparation for colonoscopy.MethodsA multicenter randomized controlled trial was conducted in 15 centers. The eligible subjects were randomly assigned to one of two groups: the formula LRD group and the self-prepared LRD group. On the day before the colonoscopy, subjects in the self-prepared LRD group were instructed to consume a restricted LRD prepared by themselves, while subjects in the formula LRD group were given six bags of prepackaged formula LRD and instructed to consume them according to their individual need. The primary outcome was an adequate bowel preparation rate. Secondary outcomes mainly included Boston Bowel Preparation Scale (BBPS) scores, dietary restriction compliance rate, tolerance, satisfaction, adenoma detection rate (ADR), and adverse reactions. The trial was registered at ClinicalTrials.gov under the identifier NCT03943758.ResultsA total of 550 subjects were recruited. Compared with the self-prepared LRD group, the formula LRD group showed a higher adequate bowel preparation rate (94.5 vs. 80.4%; P < 0.01), BBPS scores (7.87 ± 1.13 vs. 6.75 ± 1.47; P < 0.01), dietary compliance rate (92.4 vs. 78.9%; P < 0.01), tolerance (P < 0.01 in degree of hunger, intensity of physical strength, and negative influence on daily activities), satisfaction (8.56 ± 1.61 vs. 7.20 ± 2.02; P < 0.01), and ADR (25.6 vs. 16.0%; P < 0.01). There was no significant difference in adverse reactions.ConclusionCompared with self-prepared LRD, the formula LRD showed similar safety and higher bowel preparation quality, compliance, and tolerance in bowel preparation. More formula LRDs could be designed according to different dietary habits and ethnic populations, and further researches are warranted to confirm their effect.Clinical trial registrationhttps://register.clinicaltrials.gov, identifier: NCT03943758.

Gastric variceal bleeding is often more serious and can be fatal. Currently, international consensus recommendations for the treatment of gastric variceal bleeding vary according to endoscopic classification. Few studies have investigated ligation versus gastric variceal obturation (GVO) for the treatment of gastric varices.The study included 79 patients with cirrhosis-induced bleeding from esophageal and fundal varices who were treated at the Second Hospital of Hebei Medical University between January 2016 and December 2020 and who met the inclusion criteria. Among them, 42 patients were included in the intensive gastric varices ligation (IGVL) group, and 37 were included in the GVO group. We conducted a retrospective cohort study to analyze the effectiveness and safety of these 2 treatments.The rebleeding rate after initial treatment was significantly lower in the IGVL group than in the GVO group (23.8% vs. 48.6%, P0.05). No significant between-group difference was observed in overall mortality (14.3% vs. 32.4%), 6-week mortality (0.0% vs. 2.7%), or 1-year mortality (11.9% vs. 13.5%, all P0.05). The1-year mortality and bleeding-related mortality rates were significantly higher in the GVO group than in the IGVL group (23.3% vs. 2.7%, P0.05; 27.0% vs. 9.5%, P0.05). The incidence of adverse events was 57.1% in the IGVL group and 48.6% in the GVO group, with no significant difference (P0.05). Independent predictors for rebleeding after initial treatment were the use of GVO as endoscopic treatment, total bilirubin17.1 µmol/L, liver cancer, and diabetes. For mortality, the independent predictors were male sex, liver cancer, ascites, and rebleeding after initial treatment.Rebleeding after initial treatment was lower after IGVL than GVO. Independent predictors for rebleeding after initial treatment were endoscopic treatment method, total bilirubin17.1 µmol/L, liver cancer, and diabetes. For mortality, the independent predictors were male sex, liver cancer, ascites, and rebleeding after initial treatment.

Endoscopic submucosal dissection (ESD) is now considered a standard treatment for selected patients with early gastric cancer. Compared with endoscopic mucosal resection (EMR), ESD provides a higher complete resection rate (R0), and therefore, a lower local recurrence rate. However, ESD is a more time-consuming procedure, creating a wider and deeper ulcer floor which may cause complications. Post-ESD bleeding is one of them. Although most post-ESD bleedings can be controlled by endoscopic hemostasis at the time of operation, some bleeding after ESD may result in serious conditions such as hemorrhagic shock. Even with preventive methods such as ulcer closure, the application of fibrin glue and polyglycolic acid shielding, acid secretion inhibitors and hemostasis on second-look endoscopy, our experiences told us that post-ESD bleeding cannot be entirely avoidable, especially for patients with big size ulcer bed, anticoagulants/antithrombosis and chronic kidney diseases. The present review first defined post-ESD bleeding, then the incidence, the risk factors, such as the location of operative lesion, the size and depth, chronic kidney diseases, the impacts of anticoagulant and antithrombotic agents. We finally reviewed the managements of post-ESD bleeding, including approaches of coagulating potential bleeding spots during the procedure, lesion closure, lesion shielding and the application of gastric acid secretion inhibitors.

Li- and Mn-rich cathodes (LMRs) with cationic and anionic redox reactions are considered as promising cathode materials for high-energy-density Li-ion batteries. However, the oxygen redox process leads to lattice oxygen loss and structure degradation, which would induce serious voltage fade and capacity loss and thus limit the practical application. High-valent and electrochemical inactive d

In this work, a non-binary low density parity check (LDPC) coded high dimensional multiple input multiple output (MIMO) scheme with partial mapping for high order modulation is proposed. For the proposed scheme, when $M$ -ary quadrature amplitude modulation (QAM) is employed, then non-binary LDPC code constructed over Galois field with order $\sqrt {M}$ is used for partial mapping, where $\sqrt {M}$ is an integer. At the receiver side, a real-valued expectation propagation (REP) based detection algorithm is used to couple with the non-binary decoder seamlessly. Meanwhile, the symbol-wise a-priori information returned by the non-binary decoder is used to aid the REP detection. Furthermore, a symbol-wise extrinsic information transfer (SEXIT) chart based iterative optimization algorithm is used to optimize the concatenated non-binary LDPC code. This work proposed to model the a-priori information of non-zero codes/symbols of detector/decoder as the output of a cyclic-symmetric additive white Gaussian noise (AWGN) channel and a simplified method based on interpolation is proposed to calculate the component-EXIT chart of the REP-detector for massive MIMO. The proposed method can facilitate the optimization and avoid a large amount of simulations. Both SEXIT chart based analysis and numerical simulation results demonstrate the validity of the above idea.

Surficial residual LiOH and/or Li2CO3 on Ni-rich cathodes arouse troubles for their practical applications, such as slurry gelling and durability degrading. To assure acceptable performance, the st...

Advances in wearable bioelectronics interfacing directly with skin offer important tools for non-invasive measurements of physiological parameters. However, wearable monitoring devices majorly conduct static sensing to avoid signal disturbance and unreliable contact with the skin. Dynamic multiparameter sensing is challenging even with the advanced flexible skin patches. This epidermal electronics system with self-adhesive conductive electrodes to supply stable skin contact and a unique synchronous correlation peak extraction (SCPE) algorithm to minimize motion artifacts in the photoplethysmogram (PPG) signals. The skin patch system can simultaneously and precisely monitor electrocardiogram (ECG), PPG, body temperature, and acceleration on chests under daily activities. The low latency between the ECG and the PPG signals enables the SCPE algorithm that leads to reduced errors in deduced heart rates and improved performance in oxygen level determination than conventional adaptive filtering and wavelet transformation approaches. Dynamic multiparameter recording over 24 hours by the system can reflect the circadian patterns of the wearers with low disturbance from motion artifacts. This demonstrated system may be applied for health monitoring in large populations to alleviate pressure on medical systems and assist management of public health crisis. This article is protected by copyright. All rights reserved.

The LiCoO2 cathode undergoes undesirable electrochemical performance when cycled with a high cut-off voltage (≥4.5 V versus Li/Li+). The unstable interface with poor kinetics is one of the main contributors to the performance failure. Hence, a hybrid Li-ion conductor (Li1.5Al0.5Ge1.5P3O12) and electron conductor (Al-doped ZnO) coating layer was built on the LiCoO2 surface. Characterization studies prove that a thick and conductive layer is homogeneously covered on LiCoO2 particles. The coating layer can not only enhance the interfacial ionic and electronic transport kinetics but also act as a protective layer to suppress the side reactions between the cathode and electrolyte. The modified LiCoO2 (HC-LCO) achieves an excellent cycling stability (77.1% capacity retention after 350 cycles at 1C) and rate capability (139.8 mAh g-1 at 10C) at 3.0-4.6 V. Investigations show that the protective layer can inhibit the particle cracks and Co dissolution and stabilize the cathode electrolyte interface (CEI). Furthermore, the irreversible phase transformation is still observed on the HC-LCO surface, indicating the phase transformation of the LiCoO2 surface may not be the main factor for fast performance failure. This work provides new insight of interfacial design for cathodes operating with a high cut-off voltage.

A gallium nitride (GaN) boundary conduction mode (BCM) dual-boost ac–dc converter for low-voltage electromagnetic energy harvesting (EH) is presented in this article. The μ W-to-mW EH system is very susceptible to any tiny losses from power converters, interconnections, and system parasitic. To have better utilizations of harvested energy, an output power enhanced power conversion design is proposed. First, impedance matching is satisfied between electromagnetic generator and ac–dc converter to achieve maximum delivered power. The ac–dc converter is designed under BCM for constant input impedance. EH's winding inductance is employed as the boost inductor in the ac–dc converter. A codesign principle for converter on -time with electromagnetic generator's winding characteristics is revealed. Second, power transistors in EH low-voltage conversion are optimized to realize high efficiency. Power transistors’ low-voltage switching characteristics are significantly different from high-voltage situation with no or little miller plateau region. Low-voltage power transistors are compared from both device characteristics and calculated power loss to provide device selection guidance. A GaN-based dual-boost ac–dc converter under BCM operation with constant on -time controller is designed in this article to provide 3.3 V output for a 500-Ω load resistor. It achieves peak efficiency of 82.4% for open-loop operation at 0.6 V/100 Hz input and peak efficiency of 72.3% for close-loop operation at 0.75 V/100 Hz.

The Capsule Endoscopy Group of the Chinese Society of Digestive Endoscopy has issued recommendations for capsule endoscopy (CE) practice during the COVID-19 pandemic to standardize workflow, preventive strategies, and management of a CE unit and in so doing, ensure the safety of both medical staff and patients.

Background and Aims. Computed tomography portal venography (CTPV) shows potential in detecting varices that need treatment and their drainage pathways. However, its agreement with endoscopy requires further study. We investigated the feasibility of CTPV as an alternative tool to endoscopy in screening gastroesophageal varices (GEVs) and developed a CTPV-based model to provide a less invasive assessment of endotherapy for cirrhotic patients with GEVs. Methods. The study included 33 cirrhotic patients with a recent history of variceal hemorrhage. The presence, grade, and classification of GEVs on endoscopy and CTPV were compared (kappa test). Twenty-four patients were treated endoscopically, including 12 for esophageal varices (EVs), 8 for gastric varices (GVs), and 4 for GEVs. Treatment efficacies were assessed with the newly developed CTPV-based method at 1 week and 1 month after treatment. Efficiency evaluated by CTPV and endoscopy was compared by Fisher’s exact test to determine whether CTPV is efficient in the assessment of endotherapy efficacy. Results. For the screening and grading/classification of EVs and GVs, substantial agreement (EV kappa: 0.63 and 0.68; GV kappa: 0.62 and 0.75, respectively) was noted between endoscopy and CTPV. The therapeutic efficacy of EVs was higher when assessed by CTPV than when evaluated by endoscopy (37.50% vs. 12.50% at 1 week postoperation, P=0.22; 62.50% vs. 25.00% at 1 month postoperation, P=0.07), but without statistical significance. The same trend was also found in the assessment of therapeutic efficacy for GVs (25.00% vs. 16.67% at 1 week postoperation, P=1; 58.33% vs. 41.67% at 1 month postoperation, P=0.68). Conclusion. CTPV is comparable to endoscopy in the detection of GEVs and in the evaluation of endotherapy efficacy, which suggests that it could be a less invasive alternative for endoscopy in cirrhotic patients with GEVs needing treatment.

Both multiple-input multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM) are key technologies for the fifth-generation mobile communication systems. However, interference is one of the critical challenges in MIMO–OFDM systems that degrades the overall performance. In this study, a novel interference alignment (IA) design-based diagonal-block channel charter to mitigate the interference for MIMO–OFDM systems is proposed. The proposed IA scheme can be used in physical layer security, e.g. anti-location. Based on the diagonal-block charter of the channel matrix, the optimal degree of freedom, i.e. the maximum number of multiple data streams concurrently transmitted interference-free can be achieved by IA. Correspondingly, the authors present the closed-form IA design scheme for some special scenarios, and two iterative IA ones for general scenarios in detail. Furthermore, the performance analysis of IA systems with diagonal-block channel error is provided, where the imperfect channel state information case is considered. The simulation results show that the IA design based on the diagonal-block channel can improve the sum-rate performance effectively, by sufficiently exploiting the spatial and frequency resources.

A dual resonance vibration electromagnetic energy harvester (EMEH) is proposed in this paper to extend frequency range. Compared with the conventional dual resonance harvester, the proposed system realizes an enhanced “band-pass” harvesting characteristic by increasing the relative displacement between magnet and coil among two resonance frequencies with a significant improvement in the average harvested power. Furthermore, two resonant frequencies are decoupled in the proposed system, which leads to a more straightforward design. The proposed dual resonance EMEH is constructed with a tubular dual spring-mass structure. It is designed with a serpentine planar spring and the coil position is optimized for higher power density with an overall size of 53.9 cm3 for the dual resonance EMEH. It realizes an output power of 11 mW at the first resonant frequency of 58 Hz, 14.9 mW at the second resonant frequency of 74.5 Hz, and 0.52 mW at 65 Hz, which is in the middle of the two resonance frequencies. The frequency range of output power above 0.5 mW is from 55.8 Hz to 79.1 Hz. The maximum normalized power density (NPD) reaches up to 2.77 mW/(cm3·g2). Compared with a single resonance harvester design under the same topology and outer dimension at a resonant frequency of 74.5 Hz, the frequency range in the proposed EMEH achieves more than a 2× times extension. The proposed dual resonance EMEH also has more than 2 times wider frequency range than other state-of-art wideband EMEHs. Therefore, the proposed dual resonance EMEH is demonstrated in this paper for a high maximum NPD and higher NPD over a wide frequency range.

Pancreas divisum (PD) is a common pancreatic malformation caused by the failure of fusion between ventral and dorsal pancreatic ducts. There is a small branch of communication between the two systems in incomplete PD, and this variation has an incidence of 15%. A 43-year-old female patient presented to our department with recurrent abdominal pain. Magnetic resonance cholangiopancreatography (MRCP) showed that the ventral pancreatic duct was curved, with a local pouchlike dilatation. Endoscopic ultrasonography supported the diagnosis of incomplete PD and showed a thin branch of communication between ventral and dorsal pancreatic ducts. Endoscopic retrograde cholangiopancreatography (ERCP) and papillotomy of the minor papilla with double plastic stent implantation were performed. One pancreatic plastic stent was inserted across the minor and major papilla over the guide wire, creating a U-shape. The other wire-guided plastic stent was inserted through the minor papilla into the dorsal pancreatic duct. The pancreatic fluid drained smoothly after stent placement. During the 6-month follow-up, the patient remained well, without recurrence of pancreatitis.

A start-up system for AC-DC converter in low voltage electromagnetic energy harvesting (EMEH) is presented in this paper. Power conversion circuit is required in EMEH to regulator the low voltage AC to a stable DC output. Switchable AC-DC converter is efficient and well controllable, making it an optimal choice. However, the gate driver and control circuits in AC-DC converter needs to start up prior to main power stage. The output amplitude of EMEH is usually quite low to power these circuits directly through passive rectifier. Hence, a self-start-up circuit will be an optimal choice. Furthermore, in such a low power system, the power consumptions of low power control and logic circuits are comparable to actual output power. To have better utilizations of the harvested power, the power distributions of the whole power conversion is worth investigating. In this paper, an output regulated voltage multiplier based start-up circuit (SUC) is employed with comprehensive design considerations from output gain, charging time and efficiency. The AC-DC converter is firstly started through SUC. Once stable output is established, the output of AC-DC converter is employed to provide power to control circuits and the start-up circuit is cut off to reduce unnecessary energy consumption.

A dual-resonance vibration electromagnetic energy harvester is proposed in this paper to extend frequency range of available output voltage and power. A serpentine planar spring is employed and the coil position is optimized for higher normalized power density. Compared with single-resonance harvester and state-of-art, the proposed system has excellent performance when excitation frequency is between of two resonant frequencies. A $\Phi 31.2$ mm $\times 70.5$ mm dual-resonance EMEH is designed with output power reaching 11 mW at 58 Hz and 14.9 mW at 74.5 Hz. The max. normalized power density is 2.77 mW/(cm$^{3}\cdot \mathrm{g}^{2})$. The frequency range of output power above 0.5 mW is from 55.8 Hz to 79.1 Hz. Compared with single-resonance harvester with resonant frequency 74.5 Hz, the frequency range is from 70.1 Hz to 80.1 Hz. The frequency range in the dual-resonance harvester is more than twice of that in single-resonance harvester. At a load of $300 \Omega$, the frequency range of NPD above 0.8 mW/(cm$^{3}\cdot \mathrm{g}^{2})$ is from 55 Hz to 78 Hz, reaching frequency width of 23 Hz. This range is far beyond that in other literature. The proposed EMEH is verified with a very wide harvested frequency range and rather high max. NPD.

The Zhangbaoshan (ZBS) super-large Rubidium deposit, located in the Eastern Tianshan, is a typical granite-type Rb deposit. The ZBS deposit is mainly hosted in the highly evolved Baishitouquan (BST) pluton enriched in F and Rb, which exhibits five lithological zones from the bottom to the top: leucogranite (zone-a), amazonite-bearing granite (zone-b), amazonite granite (zone-c), topaz-bearing amazonite granite (zone-d) and topaz albite granite (zone-e), as well as minor small lodes of amazonite pegmatite. Two types of zircon were identified from the BST pluton. Type-I zircons mainly occur in the zone–a, are characterized by obvious oscillatory zoning, high Zr contents (47.4–67.3 wt% ZrO2) and Zr/Hf ratios (21.72–58.23), low trace element concentrations, and heavy rare earth elements (HREE)–enriched patterns with prominent positive Ce anomalies (Ce/Ce* = 1.21–385) and strong negative Eu anomalies (Eu/Eu* = 0.008–0.551), indicative of early magmatic zircon. Type–II zircons mainly occur in the upper zones (zone-c to zone-e), exhibit porous and dark Cathodoluminescence images, inhomogeneous internal structure, plenty of mineral inclusions, low Zr (38.7–51.0 wt% ZrO2) and Zr/Hf ratios (3.35–11.00), high Hf (34,094–85,754 ppm), Th (718–4,980 ppm), U (3,540–32,901 ppm), Ta (86.7–398 ppm), Y (1,630–28,890 ppm) and rare earth elements (REEs) (3,910–30,165 ppm), as well as slightly HREE–enriched patterns and significant M–type tetrad patterns with t3 values (quantification factor of tetrad effect) of 1.51–1.69. It is suggested that the type–II zircons are crystallized from a deuteric F–rich fluid coexisted with the highly evolved residual magma during the transition from the magmatic to the F–rich hydrothermal stage of the BST pluton. The F–rich fluid exsolution during the magmatic–hydrothermal transition is one of the most important factors controlling the modification of highly evolved granite and related Rb enrichment and mineralization. The type–I zircon samples from zone–a yield concordant ages of 250 ± 2.5 Ma and 250.5 ± 1.7 Ma, respectively, indicating that the BST pluton was emplaced in the Early Triassic. The type–II zircons from zone–c to zone–e yield lower intercept U–Pb ages between 238 and 257 Ma, which may represent the age of F–rich fluid–melt interaction during the transition from the magmatic to the hydrothermal stage. The mineralization of the ZBS super–large Rb deposit should have occurred shortly after emplacement of the BST pluton in the Early Triassic. Combined with available data, it is suggested that the Triassic is an important period for granitic magmatism and rare metal metallogeny in the Eastern Tianshan.

In this work, a non-binary low density parity check (LDPC) coded high dimensional multiple input multiple output (MIMO) scheme with partial mapping for high order modulation is proposed. For the proposed scheme, when $M$ -ary quadrature amplitude modulation (QAM) is employed, then non-binary LDPC code constructed over Galois field with order $\sqrt{M}$ is used for partial mapping, where $\sqrt{M}$ is an integer. At the receiver side, a real-valued expectation propagation (REP) based detection algorithm is used. Furthermore, symbol-wise extrinsic information transfer (SEXIT) chart based iterative optimization algorithm is used to optimize the concatenated non-binary LDPC code. A simplified method is proposed to calculate the component EXIT chart of the massive MIMO detector, which can avoid a large amount of simulations. Numerical simulation results demonstrate the validity of the above idea.

Accurate wave prediction can help avoid disasters. In this study, the significant wave height (SWH) prediction performances of the recurrent neural network (RNN), long short-term memory network (LSTM), and gated recurrent unit network (GRU) were compared. The 10 m u-component of wind (U10), 10 m v-component of wind (V10), and SWH of the previous 24 h were used as input parameters to predict the SWHs of the future 1, 3, 6, 12, and 24 h. The SWH prediction model was established at three different sites located in the Bohai Sea, the East China Sea, and the South China Sea, separately. The experimental results show that the performance of LSTM and GRU networks based on the gating mechanism was better than that of traditional RNNs, and the performances of the LSTM and GRU networks were comparable. The EMD method was found to be useful in the improvement of the LSTM network to forecast the significant wave heights of 12 and 24 h.

Extracellular vesicles (EVs), mainly exosomes and microvesicles, are bilayer lipids containing biologically active information, including nucleic acids and proteins. They are involved in cell communication and signalling, mediating many biological functions including cell growth, migration and proliferation. Recently, EVs have received great attention in the field of tissue engineering and regenerative medicine. Many in vivo and in vitro studies have attempted to evaluate the chondrogenesis potential of these microstructures and their roles in cartilage regeneration. EVs derived from mesenchymal stem cells (MSCs) or chondrocytes have been found to induce chondrocyte proliferation and chondrogenic differentiation of stem cells in vitro. Preclinical studies have shown that exosomes derived from MSCs have promising results in cartilage repair and in cell‐free therapy of osteoarthritis. This review will focus on the in vitro and in vivo chondrogenesis and cartilage regeneration of EVs as well as their potential in the treatment of osteoarthritis.

Although Ni-rich cathode materials have made a great success in the field of electric vehicles due to their high capacity and low cost, many efforts are still focused on further increasing their capacity through increasing the Ni content. However, the increased Ni content usually leads to a more serious surface structure reconstruction and hence higher resistance during electrochemical cycling, which has become a major issue for Ni-rich cathodes. In order to explore a balance between surface structure stability and high energy density, a model Ni-rich material with transition metal ion gradient is prepared using a mechanical fusion and co-lithiation method, which is easy for large-scale fabrication. The gradient structure sample contains an inter bulk of LiNi0.90Co0.05Mn0.05O2 and a thin gradient outer layer with lower nickel content. The gradient sample shows a superior cycling property, rate retention, and improved safety performance. Systematic study suggests that the possible reasons for the improved electrochemical and mechanical performance of the gradient nickel-rich materials are the high stability of lower-Ni surface and the decreased surface tensile stress. This work provides an easy up-scaled method to build a gradient structure and a further in-depth understanding on its structure stabilization mechanisms, which are essential for developing high energy-density lithium-ion batteries.

A new planar energy harvester based powering supply unit is proposed in this paper with copper plate planar spring, PCB integrated coils and voltage multiplier. The flat architecture has the advantages of low profile and high power density. It is also flexible to adapt to different shapes of the vibration sources and can be applied to the surface to vibration source to capture as much energy as possible. PCB substrate is also more cost-effective than semi-conductor or micro electromechanical substrate. Vibration frequency for copper plate spring is well investigated. It shows a positively linear relationship with spring thickness and reverse proportional to spring length. The magnetic field and flux distribution are deeply explored. The physical size of the coil and magnets are carefully designed to maximize the harvested voltage. The optimal vertical location between magnets and coil is also revealed. A 3.5mm×3.5mm planar energy harvester is designed in this paper. The peak output amplitude is 178.3mV at 150Hz vibration frequency. It achieves twice higher output levels than prior-arts.

A compact and efficient self-powered micro-power system, composing of energy harvesting unit and electric power conversion unit is the most promising candidate to support widely distributed information equipment to overcome the constraints of wired and portable power supply. However, current works fail to provide an integrated and optimized system, which suffer from large attenuation loss. Thus, the output power is too micro for board applications with unsatisfied efficiency. To overcome those problems, this paper proposes a novel PCB integrated self-powered micro-electric generator for vehicle engine vibration harvesting. The generator windings and power conversion unit are implemented on same PCB substrate. The micro-generator has the output of ± 2341.85mV AC at 52.3Hz. An all GaN high frequency dual-boost AC-DC converter with boundary conduction mode is employed with impedance matching for maximum power transferring. It also utilizes the output inductance of micro-generator as boost inductor and sensing inductor. The peak output efficiency of the converter reaches to 83% at 3.3V/21.35mW output, which is much higher than state-of-art.

A series of pneumonia cases caused by 2019 novel coronavirus (2019-nCoV, also named COVID-19) are being reported globally. Based on recent publications,1–3 the most common symptoms in patients infected by 2019-nCoV were fever and cough. However, the incidence of other clinical features differs in different reports. To address this issue, we collected the data from three reports1–3 and compared the incidence accordingly. We found that the incidence of leucopenia, fever and diarrhoea in the three studies showed a statistically significant difference (table 1). Among these symptoms, diarrhoea displayed the smallest p-value (p=0.016), suggesting that the criteria for diagnosing diarrhoea may differ in different hospitals. Due to the different criteria, clinicians may underestimate the value of this symptom in clinical practice, and it may affect the preliminary diagnostic accuracy. View this table: Table 1 Intergroup comparison between three recent publications Recent studies showed that the spike protein of 2019-nCoV shared the same cell entry receptor ACE2 as SARS-CoV.4 5 In terms of the pathological importance of ACE2 in modulating intestinal inflammation and diarrhoea,6 we examined the expression profiles of ACE2 in various human tissues and found that ACE2 was highly expressed in the human small intestine (online supplementary file 1). Intriguingly, the RNA level of ACE2 was quite low in lung tissues from healthy donors.### Supplementary data [gutjnl-2020-320832supp001.pdf] Given that the distribution of ACE2 may determine the route of 2019-nCoV infection, we next evaluated the expression of ACE2 in different cell …

SummaryThe outbreak of pneumonia caused by the 2019 Novel Coronavirus (2019-nCoV) was reported in Wuhan City, China. However, the clinical symptoms varied in different reports. Based on results of inter-group difference test, we found that the incidence of diarrhea differed in three recent reports. As 2019-nCoV utilizes the same cell entry receptor ACE2 as severe acute respiratory syndrome coronavirus (SARS-CoV) and ACE2 tightly controls intestinal inflammation, to trace the route of infection mediated by 2019-nCoV, we used the single-cell RNA sequencing data for analysis. We found that the ACE2 mRNA was highly expressed in the healthy human small intestine rather than the lung. Besides, single-cell RNA sequencing data showed that ACE2 was significantly elevated in the proximal and distal enterocytes, where the small intestinal epithelium is exposed to the foreign pathogen. Thus, we suspect that ACE2-expressing small intestinal epithelium cells might be vulnerable to 2019-nCoV infection when people eat infected wild animals and diarrhea may serve as an indicator for infection, suggesting that clinicians should pay more attention to patients with diarrhea during the outbreak of pneumonia.

Lithium-excess cation disordered rock-salt materials have received much attention because of their high-capacity as a candidate for cathodes for lithium-ion batteries. The ultra-high specific capacity comes from the coordinated charge compensation of both transition metal and lattice oxygen. However, the oxygen redox at high voltage usually leads to irreversible oxygen release, thereby degrading the structure stability and electrochemical performance. Lithium-excess Li1.14Ni0.57+0.5 x Ti0.19 – 0.5 x Mo0.10O2 – x F x (x = 0, 0.05, 0.10, 0.15, and 0.20) with different amounts of fluorine substitution were synthesized. Among them, Li1.14Ni0.620Ti0.140Mo0.10O1.85F0.15 exhibits a lower capacity decline, better rate performance, and lower structure damage. The effects of fluorine substitution on the electrochemical property and structural stability were systematic studied by x-ray photoelectron spectroscopy and in situ XRD etc. Results show that fluorine substitution reduces the average valence of the anion, allowing a larger proportion of low-valent redox active transition metals, increasing the transition metal redox capacity, inhibiting irreversible oxygen release and side reaction. Fluorine substitution further improves the structural stability and suppresses lattice deformation of the material.

Search and data retrieval services have attracted significant attention in blockchain networks, especially for rare resources. Therefore, our paper proposes a novel Gossip-based appropriate degree search strategy (GADSS) for rare resources. This strategy employs a periodical probing mechanism (PPM) to judge whether these resources are rare resources. Once the resource types are determined, searching probability for rare ones is increased by two-hop index replication with resource weight (TIR-RW). In addition, we also provide a Gossip-based appropriate degree search algorithm (GADSA), which utilizes the appropriate degree property as heuristic information to guide the search in dynamic environment. As compared to the conventional blockchain resource search algorithms, GADSA has the ability to reduce the message quantity substantially. The simulation results show that GADSS has the better search performance for rare resources, and maintains the lower network overhead.

We present and analyze a minimalist model for the vertical transport of people in a tall building by elevators. We focus on start-of-day operation in which people arrive at the ground floor of the building at a fixed rate. When an elevator arrives on the ground floor, passengers enter until the elevator capacity is reached, and then they are transported to their destination floors. We determine the distribution of times that each person waits until an elevator arrives, the number of people waiting for elevators, and transition to synchrony for multiple elevators when the arrival rate of people is sufficiently large. We validate many of our predictions by event-driven simulations., Comment: 19 pages in IOP format, 11 figures. Version 2 is slightly expanded and contains some additional results and a new figure

In the present paper, the topological design problem of lightweight stiffening structures are studied. Multiple design criteria like static compliance, dynamic compliance, eigenfrequency/eigenfrequency gaps and weight are considered simultaneously as sub-objectives in the optimization model. A bound formulation is developed and implemented to deal with the problem concerned, by which the difficulties of non-continuity of the multiple objective functions can be got over. Comparing with the empirical adjustment design or more elaborated parametric design, the topological design may introduce more degrees of design freedom, and thus is possible to produce more innovative conceptual design. The method of sequential convex programming is employed to find the solution of the optimization problem. Numerical examples show that, using the presented approach, the optimized layout of the stiffening structures with enhanced static and dynamic mechanical properties can be obtained.

In the field of structural topology optimization, an important but often neglected problem in previous studies is how to translate the optimal conceptual design obtained by topology optimization to engineering CAD model which can meet requirements of reliability and manufacturability efficiently. This paper carried out exploratory research on full stage design of typical aircraft components. A set of integrated schemes are proposed as a complete design flow from the conceptual design to engineering geometry scheme, including multi-objective dynamic topology optimization, transformation from the optimal topological conceptual design to engineering geometry model, CAE analysis and manufacturing by 3D printing. The method above has strong portability and broad application prospects, which can provide references and technical routes.

(Ba, Sr)TiO 3 –Mg 2 TiO 4 composite ceramics were fabricated via solid-state reaction method. X-ray diffraction, scanning electron microscopy and Raman spectroscopy were used to characterize the phase compositions and microstructures. The dielectric characteristics and tunability of composite ceramics were investigated. Depending on the tunability, the composition of (Ba, Sr)TiO 3 –Mg 2 TiO 4 can be divided into three regions: initial decreasing region, unusual increasing region and final decreasing region. This unusual increased tunability is due to electric field redistribution caused by composite effect, that is proved by the simulation result. Moreover, the change of Curie temperature also has a great impact on the tunability in this region.

Bi1−x La x FeO3 (x = 0.05, 0.1, 0.15 and 0.2) powders and ceramics were prepared by a polyvinyl alcohol (PVA) sol–gel route. Differential scanning calorimetry and thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy and environmental scanning electron microscope were used to characterize the precursors, the derived oxide powders and sintered ceramics. Single-phase Bi1−x La x FeO3 powders were obtained at a temperature as low as 500 °C for 2 h, without the formation of any intermediate phase. All samples were found to be rhombohedrally distorted perovskite structure with a space group of R3c. The effect of La substitution on the dielectric properties of Bi1−x La x FeO3 ceramics was studied over the frequency range of 10 kHz–1 MHz. The real part of permittivity of Bi1−x La x FeO3 samples decreased with the increase of La content. The remnant magnetization M r and coercive field H c increase with La doping content. A H c of as high as 2 × 106 A/m was obtained for Bi0.8La0.2FeO3.

As the intelligent mobile phone stores more and more users’ privacy information, the privacy information security in mobile terminal has become more and more important to mobile users. So how to protect the sensitive information of mobile phone users has become the focus of research in recent years. This paper analyzed the security mechanism of iOS platform and security status and development of iOS Apps, and then proposed a scheme–iOS software sensitive information analysis and security assessment system, for detection of iOS analysis software of leaking sensitive information. The system is used to detect whether APPs in iOS platform is revealing user privacy data, and make evaluation of safety grade according to the severity of privacy disclosure of APPs. We give an evaluation algorithm about security level for evaluating the severity of APPs. This system is the overall solution of the iOS application software acquisition, privacy leak detection and security assessment.

To investigate the effects of ET-1 on isolated perfused rat liver and vascular rings at early and late stages of cirrhosis.Liver cirrhosis was induced by an intraperitoneal injection of 50% CCl(4) (0.3 ml/100 g, twice a week). In the 9th and 14th weekend after injecting CCl(4), the isolated perfused liver and vascular rings were performed to evaluate effects of four concentrations of ET-1 on early and late stages of cirrhosis.The Ppv of L-HC group at baseline was higher than that of E-HC group, both were higher than that of the controls. However, there showed no differences on Phv in these groups. With the concentration of ET-1 increasing, PVP was elevated accordingly in E-HC and L-HC group. L-HC group showed higher PVP compared with E-HC group, both were higher than the controls. While in isolated vascular rings, with the deteriorating of cirrhosis, the cumulative response curves showed right-shift. 0.1 nmol/L ET-1 showed mild relaxation on vascular rings in L-HC group.ET-1 can increase the PVP, especially with the deterioration of cirrhosis, there showed higher reaction compared with normal controls. The vascular rings showed low response on the contrary. So ET-1 plays an important role in the pathogenesis of portal hypertension. In view of its different roles on liver and vascular rings at early and late stages, administration of different selective antagonist of ET receptor at different stages of cirrhosis should be well considered.