Effects of Miscut on Step Instabilities in Homo-Epitaxially Grown GaN.

The rough morphology at the growth surface results in the non-uniform distribution of indium composition, intentionally or unintentionally doped impurity, and thus impacts the performance of GaN-based optoelectronic and vertical power electronic devices. We observed the morphologies of unintentionally doped GaN homo-epitaxially grown via MOCVD and identified the relations between rough surfaces and the miscut angle and direction of the substrate. The growth kinetics under the effect of the Ehrlich-Schwoebel barrier were studied, and it was found that asymmetric step motions in samples with a large miscut angle or those grown at high temperature were the causes of step-bunching. Meandering steps were believed to be caused by surface free energy minimization for steps with wide terraces or deviating from the [11¯00] m-direction.

Invasive mucinous adenocarcinoma of the lung with bronchorrhea - A marked reduction volume of sputum after SARS-CoV-2 infection.

Bronchorrhea is a watery sputum volume of at least 100 mL/day, which is commonly associated with lung malignancies. We report a 57-year-old woman was admitted to the hospital with a cough, profuse sputum. Chest CTs showed crazy paving pattern and lung nodules. Cell nests were visible on the Thinprep Cytologic Test. The case was considered an invasive mucinous adenocarcinoma of the lung combined with bronchorrhea. Significantly, the sputum volume declined rapidly and did not rise again when the patient was diagnosed with COVID-19 and treated with nirmatrelvir/ritonavir. This case is suggestive of studies related to regulatory mediators associated with bronchorrhea.

Comparison of traditional and novel tip-flexible suctioning ureteral access sheath combined with flexible ureteroscope to treat unilateral renal calculi.

OBJECTIVES: To compare the safety and efficacy of novel tip-flexible suctioning ureteral access sheath (NTFS-UAS) and traditional ureteral access sheath (T-UAS) combined with flexible ureteroscope for treating unilateral renal calculi. MATERIALS AND METHODS: The clinical data of 214 patients with unilateral renal calculi treated by NTFS-UAS (n = 102) and T-UAS (n = 112) combined with flexible ureteroscope from August 2021 to April 2022 were analyzed retrospectively. Demographic characteristics, stone-related parameters, operative time, stone-free rates (SFR), hospitalization time and complication rate (CR) were analyzed. RESULT: No significant difference was observed between the two groups in terms of demographic characteristics, stone-related parameters, intraoperative CR, and hospitalization time. The operative time of NTFS-UAS group was significantly shorter than T-UAS group (55.25 ± 11.42 min vs. 59.36 ± 15.59 min; P = 0.028). The NTFS-UAS group obtained significantly higher SFR on 1 day postoperatively (86.3% vs. 75.0%; P = 0.038), and higher SFR on 30 days postoperatively than T-UAS group (91.2% vs. 81.3%; P = 0.037). The hemoglobin loss of NTFS-UAS group (- 0.54 ± 0.69 g/dl) was significantly lower than T-UAS group (- 0.83 ± 0.66 g/dl; P = 0.002). There was a significantly lower incidence of overall CR (11.8% vs. 22.3%; P = 0.041), and infectious CR (8.8% vs. 18.8%; P = 0.037) in the NTFS-UAS group. CONCLUSION: Compared to T-UAS combined with flexible ureteroscope for treating unilateral renal calculi, NTFS-UAS had superiority in higher SFR on 1 day and 30 days postoperatively. Shorter operation time, lower hemoglobin loss, lower incidences of overall and infectious CR were observed in NTFS-UAS group. REGISTRATION NUMBER AND DATE: ChiCTR2300070210; April 5, 2023.

Structure-aware guided filtering for a ring artifact correction in synchrotron x-ray microtomography.

Synchrotron-based x-ray microtomography (S-µCT) is a powerful non-invasive three-dimensional (3D) imaging technique used for visualizing the internal structure of objects with micron-scale spatial resolution. However, in practical applications, ring artifacts often occur in S-µCT, which significantly degrades image quality and hinders interpretation. In this study, we propose a ring artifact correction method based on guided image filtering (GIF). The method first extracts structural prior from the input S-µCT images and then uses it as the guidance image to correct the ring artifacts. Finally, GIF with a self-guidance image is employed to further enhance image quality. Extensive comparisons and analyses on simulations and real data experiments demonstrate that the proposed method is capable of effectively correcting ring artifacts, accompanied by low-dose noise suppression and sparse-view artifact reduction. These findings suggest that the proposed method has great potential to promote the wider applications of S-µCT in the future.

Chinese mini percutaneous nephrolithotomy for upper urinary calculi under local infiltration anesthesia.

Percutaneous nephrolithotomy is generally performed under general or regional anesthesia; however, it is rarely performed under local infiltration anesthesia (LIA). This study aimed to assess the safety and effectiveness of Chinese mini percutaneous nephrolithotomy (MPCNL) for upper urinary calculi under LIA. A retrospective analysis of 52 patients with upper urinary stones who underwent MPCNL under LIA from April 2019 to May 2022 was performed. Pethidine and Phenergan were intramuscularly injected 30 minutes preoperatively. Oxybuprocaine hydrochloride gel was applied to the urethra for lubricating and mucosal anesthesia. Ropivacaine hydrochloride and lidocaine were injected into the whole percutaneous channel for local anesthesia. An 8/9.8F ureteroscope and an 18F vacuum-assisted access sheath were applied in MPCNL. All 52 patients tolerated procedures and underwent operations successfully; none of them converted the anesthesia method or required additional analgesia. The mean visual analogue scale scores intraoperatively and at 6 hours, 24 hours, and 48 hours after surgery were 3.25 ± 0.52, 3.13 ± 0.69, 2.25 ± 0.56, and 1.58 ± 0.50, respectively. The stone free rate was 84.6%. Complications were seen in 6 (11.5%) patients, including fever in 2 patients (Clavien I), renal colic in 1 patient (Clavien I), clinically insignificant bleeding in 2 patients (Clavien I), and urinary tract infection in 1 patient (Clavien II). No severe complications were observed in any patients. Chinese MPCNL under LIA was a feasible option and achieved good outcomes in appropriately selected patients, and it may become the routine procedure for general patients.

Constructing origami power generator from one piece of electret thin film and application in AI-enabled transmission line vibration monitoring.

One of the crucial issues for applying electret/triboelectric power generators in the Internet of Things (IoT) is to take full advantage of specific high voltage signals and enable self-powered sensing. Therefore, inspired by Miura-origami, we present an innovative origami power generator (OPG) constructed from only one piece of electret thin film. The Miura-origami architecture realizes a generator with excellent deformability and stretchability and makes it unnecessary for any auxiliary support structure during the compress-release cycle. Various parameters of the generator are intensively investigated, including the excitation accelerations, excitation displacements, numbers of power generation units and deformation degree of the device. When stimulated with 5.0 g acceleration at 15 Hz frequency, the generator with 8 generation units can obtain an instantaneous peak-to-peak voltage and a remarkable optimum peak power of 328 V and 2152 µW at 50 MΩ, respectively. In addition, the regulable shape and multiple generation modes of the device greatly improve its applicability in various vibration energy collection requirements. Based on the above results, a hexagonal electret generator integrated with six-phase OPGs is developed as a "Buoy on Sky," after which the signal waveforms generated from internal power generators are recognized with 92% accuracy through a neural network algorithm that identifies the vibration conditions of transmission lines. This work demonstrates that a fusion of origami art and energy conversion techniques can achieve a multifunctional generator design satisfying the requirements for IoT applications.

Nitrogen vacancies in GaN templates and their critical role on the luminescence efficiency of blue quantum wells.

In InGaN-based LEDs, an InGaN layer underlying active region has been widely used to improve the luminescence efficiency of the quantum wells (QWs). It has been reported recently that the role of InGaN underlayer (UL) is to block the diffusion of point defects or surface defects in n-GaN into QWs. The type and the source of the point defects need further investigations. In this paper, using temperature-dependent photoluminescence (PL) measurements, we observe emission peak related to nitrogen vacancies (VN) in n-GaN. In combination with secondary ion mass spectroscopy (SIMS) measurement and theoretical calculation, it is found that VN concentration in n-GaN is as high as about 3 × 1018 cm-3 in n-GaN grown with low growth V/III ratio and can be suppressed to about 1.5 × 1016 cm-3 by increasing growth V/III ratio. Luminescence efficiency of QWs grown on n-GaN under high V/III ratio is greatly improved. These results indicate high density of nitrogen vacancies are formed in n-GaN layer grown under low V/III ratio and diffuse into quantum wells during epitaxial growth and reduce the luminescence efficiency of the QWs.

Suppressing multi-material and streak artifacts with an accelerated 3D iterative image reconstruction algorithm for in-line X-ray phase-contrast computed tomography.

In-line X-ray phase-contrast computed tomography typically contains two independent procedures: phase retrieval and computed tomography reconstruction, in which multi-material and streak artifacts are two important problems. To address these problems simultaneously, an accelerated 3D iterative image reconstruction algorithm is proposed. It merges the above-mentioned two procedures into one step, and establishes the data fidelity term in raw projection domain while introducing 3D total variation regularization term in image domain. Specifically, a transport-of-intensity equation (TIE)-based phase retrieval method is updated alternately for different areas of the multi-material sample. Simulation and experimental results validate the effectiveness and efficiency of the proposed algorithm.

Synchrotron microtomography image restoration via regularization representation and deep CNN prior.

BACKGROUND AND OBJECTIVE: Synchrotron-based X-ray microtomography (S-µCT) is a promising imaging technique that plays an important role in modern medical science. S-µCT systems often cause various artifacts and noises in the reconstructed CT images, such as ring artifacts, quantum noise, and electronic noise. In most situations, such noise and artifacts occur simultaneously, which results in a deterioration in the image quality and affects subsequent research. Due to the complexity of the distribution of these mixed artifacts and noise, it is difficult to restore the corrupted images. To address this issue, we propose a novel algorithm to remove mixed artifacts and noise from S-µCT images simultaneously. METHODS: There are two important aspects of our method. Regarding ring artifacts, because of their specific structural characteristics, regularization-based methods are more suitable; thus, low-rank tensor decomposition and total variation are utilized to represent their directional and locally piecewise smoothness properties. Moreover, to determine the implicit prior of the random noise, a convolutional neural network (CNN) based method is used. The advantages of traditional regularization and the deep CNN are then combined and embedded in a plug-and-play framework. Hence, an efficient image restoration algorithm is proposed to address the problem of mixed artifacts and noise in S-µCT images. RESULTS: Our proposed method was assessed by utilizing simulations and real data experiments. The qualitative results showed that the proposed method could effectively remove ring artifacts as well as random noise. The quantitative results demonstrated that the proposed method achieved almost the best results in terms of PSNR, SSIM and MAE compared to other methods. CONCLUSIONS: The proposed method can serve as an effective tool for restoring corrupted S-µCT images, and it has the potential to promote the application of S-µCT.

Circ_0072088 knockdown contributes to cisplatin sensitivity and inhibits tumor progression by miR-944/LASP1 axis in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is an aggressive tumor that accounts for a large proportion of cancer-related deaths. Cisplatin (CDDP) has been utilized to treat NSCLC. However, the efficacy of CDDP is usually restrained owing to the development of drug resistance. This study aims to reveal the molecular mechanism of the resistance of NSCLC cells to CDDP. METHODS: The expression levels of circRNA_0072088 (circ_0072088), microRNA-944 (miR-944), and LIM and SH3 protein 1 (LASP1) were measured by quantitative real-time PCR (qRT-PCR) in CDDP-resistant NSCLC tissues and cells. Protein expression was determined by Western blotting in CDDP-resistant NSCLC tissues and cells. The functional effects of circ_0072088, miR-944, and LASP1 on CDDP sensitivity and NSCLC progression were revealed by Cell Counting Kit-8 (CCK-8), flow cytometry, cell colony formation, wound healing, and transwell invasion assays. The binding relationship between miR-944 and circ_0072088 or LASP1 was identified by a dual-luciferase reporter and RNA immunoprecipitation assay. The effects of circ_0072088 knockdown on tumor growth in vivo were analyzed by an in vivo tumor formation assay. RESULTS: Circ_0072088 and LASP1 expression were significantly upregulated, while miR-944 expression was downregulated in CDDP-resistant NSCLC tissues and cells as compared with control groups. Circ_0072088 expression was significantly associated with tumor-node-metastasis stage and tumor size. Functionally, circ_0072088 knockdown improved CDDP sensitivity and repressed NSCLC cell malignancy, whereas miR-944 inhibitor hindered these effects. Mechanistically, circ_0072088 functioned as a sponge for miR-944 and miR-944 targeted LASP1. Circ_0072088 knockdown improved the sensitivity of tumor to CDDP in vivo. CONCLUSION: Circ_0072088 silencing improved CDDP sensitivity and inhibited NSCLC progression by downregulating LASP1 expression through sponging miR-944. These data provide novel insight into the resistance of NSCLC to CDDP.

3D ring artifacts removal algorithm combined low-rank tensor decomposition with spatial-sequential total variation regularization and its application in phase-contrast microtomography.

PURPOSE: High-resolution synchrotron radiation X-ray phase contrast microtomography (PC-µCT) images often suffer from severe ring artifacts, which are mainly caused by undesirable responses of detector elements. In the medical imaging field, the existence of ring artifacts can lead to degraded visual quality and can directly affect diagnosis accuracy. Thus, removing or at least effectively reducing ring artifacts is indispensable. METHOD: The existing ring artifacts removal algorithms mainly focus on two-dimensional (matrix-based) priors, and these algorithms fail to consider correlations hidden in sequential computed tomography (CT) images. This paper proposed a novel three-dimensional (tensor-based) ring artifacts removal algorithm for synchrotron radiation X-ray PC-µCT images. In the sinogram domain, ring artifacts manifest as vertical stripe artifacts. From an image decomposition perspective, a degraded sinogram can be decomposed into a stripe artifacts component and an underlying clean sinogram component. The proposed algorithm is designed to detect and remove stripe artifacts from a degraded sinogram by fully identifying the characteristics of the two components. Specifically, for the stripe artifacts component, tensor Tucker decomposition is used to describe its low-rank character. For the underlying clean sinogram component, spatial-sequential total variation regularization is adopted to enhance the piecewise smoothness. Moreover, the Frobenius norm term is further used to model Gaussian noise. An efficient augmented Lagrange multiplier method is designed to solve the proposed optimization model. RESULTS: The proposed method is evaluated utilizing both simulations and real data containing different ring artifacts patterns. In the simulations, the human chest CT images are used for evaluating the proposed method. We compare the peak signal-to-noise ratio (PSNR), structural similarity (SSIM), and mean absolute error (MAE) results of our algorithm with the Naghia's method, the RRRTV method, the wavelet-FFT method, and the SDRSD-GIF method. The proposed method was also evaluated on real data from rat liver samples and rat tooth samples. Our proposed method outperforms the competing methods in terms of both qualitative and quantitative evaluation results. Additionally, the 3D visualization results were presented to make the ring artifacts removal effect more intuitive. CONCLUSION: The experimental results on simulations and real data clearly demonstrated that the proposed algorithm can significantly improve the quality of PC-µCT images compared with the existing popular algorithms, and it has great potential to promote the application of high-resolution imaging for visualizing biological tissues.

All-in-One High-Power-Density Vibrational Energy Harvester with Impact-Induced Frequency Broadening Mechanisms.

This paper proposes an electrostatic-piezoelectric-electromagnetic hybrid vibrational power generator with different frequency broadening schemes. Both the nonlinear frequency broadening mechanisms and the synergized effect of the electrostatic-piezoelectric-electromagnetic hybrid structures are investigated. The structure and performance of the composite generator are optimized to improve the response bandwidth and performance. We propose that the electrostatic power generation module and the electromagnetic power generation module be introduced into the cantilever beam to make the multifunctional cantilever beam, realizing small integrated output loss, high output voltage, and high current characteristics. When the external load of the electrostatic power generation module is 10 kΩ, its peak power can reach 3.6 mW; when the external load of the piezoelectric power generation module is 2 kΩ, its peak power is 2.2 mW; and when the external load of the electromagnetic power generation module is 170 Ω, its peak power is 0.735 mW. This means that under the same space utilization, the performance is improved by 90%. Moreover, an energy management circuit (ECM) at the rear end of the device is added, through the energy conditioning circuit, the device can directly export a 3.3 V DC voltage to supply power to most of the sensing equipment. In this paper, the hybrid generator's structure and performance are optimized, and the response bandwidth and performance are improved. In general, the primary advantages of the device in this paper are its larger bandwidth and enhanced performance.

Dual-path deep learning reconstruction framework for propagation-based X-ray phase-contrast computed tomography with sparse-view projections.

Propagation-based X-ray phase-contrast computed tomography (PB-PCCT) can serve as an effective tool for studying organ function and pathologies. However, it usually suffers from a high radiation dose due to the long scan time. To alleviate this problem, we propose a deep learning reconstruction framework for PB-PCCT with sparse-view projections. The framework consists of dual-path deep neural networks, where the edge detection, edge guidance, and artifact removal models are incorporated into two subnetworks. It is worth noting that the framework has the ability to achieve excellent performance by exploiting the data-based knowledge of the sample material characteristics and the model-based knowledge of PB-PCCT. To evaluate the effectiveness and capability of the proposed framework, simulations and real experiments were performed. The results demonstrated that the proposed framework could significantly suppress streaking artifacts and produce high-contrast and high-resolution computed tomography images.

The energy absorption and bearing capacity of light-weight bio-inspired structures produced by selective laser melting.

Sandwich structures are widely used in aviation and aerospace fields because they can absorb vast energy due to their excellent continuous compression behaviors. And in this work, the light-weight bio-inspired sandwich structure of titanium alloy was designed based on cybister elytra and produced by selective laser melting (SLM). The results show that bio-inspired structures can realize the light-weight effectively by increasing the core height. The specific and ultimate flatwise compressive strengths first increase and then decrease when core height increases. The load-displacement curves of bio-inspired structures during flatwise compression consists of elastic deformation, buffer and compaction zone. Comparatively, the edgewise compression lacks buffer zone. And the bio-inspired structure has an excellent flatwise comprehensive performance when its core height is 6 mm, whose peak flatwise compressive strength and specific volume energy absorption are 84.30 MPa, 101.30 MJ/m3, respectively. The specific ultimate strength of bio-inspired structures is optimized at the core height of 4 mm on the edgewise compression tests. And the fracture of the side arc damaged area shows an obviously ductile fracture and the panel and core of the middle area are brittle fracture in the flatwise compressive tests. Finally, The ANSYS simulation results are consistent with experimental results during the whole compressions, which will provide an accurate guidance in next researches.

Risk factors of community-associated infections in Chinese patients with diabetes: A meta-analysis.

OBJECTIVE: To identify the common sites and risk factors of community-associated infections in Chinese patients with diabetes. MATERIALS AND METHODS: The Wanfang, CNKI, PUBMED and VIP databases restricting to Chinese patients with diabetes were queried without restriction to time period. Randomized controlled trials (RCTs) on the risk factors of community-associated infections in Chinese patients with diabetes were considered. Polled odd ratios (OR) and 95% confidence intervals (95% CI) were used for each factor in fixed or random-effect meta-analyses. RESULTS: Twelve studies were identified that investigated seven risk factors of community-associated infections in Chinese patients with diabetes. The average infection incidence was 39.55%. The respiratory tract and urology tract were the predilection sites. Meta-analysis results are as follows: Diabetic patients with chronic complications (OR: 1.63; 95% CI 1.45-1.82), advanced age (OR: 1.30; 95% CI 1.19-1.42), longer duration (OR: 1.47; 95% CI 1.35-1.61) or ketoacidosis (OR: 1.37; 95% CI 1.13-1.66) were more prone to suffer from infections. Those with better glycemic control (OR: 0.68; 95% CI 0.61-0.76) or males (OR: 0.69; 95% CI 0.64-0.75) were less prone to suffer from infections. CONCLUSION: Chinese patients with diabetes had a high incidence of community-associated infections. We should highlight the risk factors that might provide a reference for the same.

Hydrothermally synthesized LiFePO4 crystals with enhanced electrochemical properties: simultaneous suppression of crystal growth along [010] and antisite defect formation.

Improving electrochemical properties of hydrothermally synthesized LiFePO(4) powders is of immense technological significance and has been a subject of much scientific inquiry for many years. As reported previously, reversing the feeding sequence of starting materials and/or introducing ethylene glycol (EG) could significantly improve the electrochemical performance of hydrothermally synthesized LiFePO(4). However, the mechanism remains unclear. Here, we report a systematic study to understand the mechanism from viewpoints of crystal growth and defect concentration control. Combining the results of experimental and theoretical investigations, the improvement in electrochemical performance is attributed to simultaneous suppression of crystal growth along the [010] direction and reduced defect concentration of the antisite. The reduction in antisite defects is readily monitored by significant red shift of the infrared (IR) absorption band around 1000 cm(-1) which is assigned to the symmetric stretching P-O vibration of the PO(4) tetrahedron, as indicated by theoretical calculation. With this knowledge in mind, an output as high as 450 g L(-1) (autoclave volume), and an enhanced specific discharge capacity of 165 A h kg(-1) (close to the theoretical unity of 170 A h kg(-1)) at 0.1 C are achieved.

Regioselective grafting of poly(ethylene glycol) onto chitosan and the properties of the resulting copolymers.

PEG was grafted onto chitosan regioselectively at the hydroxyl groups with phthaloylchitosan as an intermediate. After the graft reaction, the phthaloyl groups were deprotected to give chitosan-g-PEG copolymers with free amino groups. The chemical structure of the graft copolymers was confirmed by FT-IR, (1)H and (13)C NMR spectroscopy. The resulting graft copolymers showed improved thermal stability compared to the original chitosan, and showed a lower thermal transition temperature at around 185 degrees C. Chitosan-g-PEG exhibited a high affinity not only for aqueous acid but also for some organic solvents because of the presence of abundant free amino groups and PEG branches, and it exhibited higher hygroscopicity and moisture retention ability than chitosan. [structure: see text]

[A retrospective study of one case of X-linked agammaglobulinemia].

OBJECTIVE: To investigate the clinical manifestations, diagnostic methods and treatment of X-linked agammaglobulinemia (XLA). METHODS: Flow cytometric analysis of the peripheral monocytes using the anti-BTK antibody was used to characterize the expression of BTK in a 21 year old male patient and his mother. The patient suffered from frequent pneumonia, and was found to be complicated with lymphocytopenia in the B cell populations, hypogammaglobulinemia (IgG 1.38 g/L, IgA 0.25 g/L, IgM 0.17 g/L) and angiotelectasis (which had not been reported in XLA patients). Sequencing of the BTK cDNA obtained from the peripheral monocytes of the patient and his mother was performed to confirm the genetic defect. RESULTS: The BTK expressions in peripheral monocytes of the patient and his mother were 96.9% and 97.8% respectively. Sequencing of the BTK gene revealed a missense mutation of R525Q in exon 16, and his mother was confirmed to be an XLA carrier. The patient was treated with immunoglobulin replacement therapy (2 g/kg). One month later, the serum IgG level of the patient was elevated to 5.79 g/L, and the clinical symptoms (included angiotelectasis), lung function and the CT scan results significantly improved. CONCLUSION: Genetic diagnosis was made for one Chinese XLA adult patient complicated with angiotelectasis. This case suggests that some XLA cases may present angiotelectasis. High dose intravenous immunoglobulin given at 2 g/kg may be of efficacy in severe XLA cases. More attention should be paid to the disease in China.