Recent years, the emergence of hyper-scale data centers boosted the research field of integrated silicon photonics. One of the major challenges for compact photonic integrated circuits is silicon ...based lasers. In this paper, we demonstrate optically pumped InAs/GaAs quantum-dot micropillar laser on exact Si (001) by (111)-faceted-sawtooth Si hollow structure via IV/III-V hybrid epitaxy. The lasing threshold of InAs/GaAs quantum-dot micropillar is as low as 20 μW with the pillar diameter of 15 μm. Moreover, the micropillar laser is capable of operating at maximum temperature up to 100 °C.
•Photosensitive post-modification based on the super-stable UiO-67.•Greatly narrowed band gap and optimized band structure.•Significantly improved visible light utilization and optical-electronic ...properties.•Remarkably enhanced photocatalytic efficiencies and accelerated reaction kinetics.
As a new kind of organic-inorganic hybrid semiconductor materials, MOFs have come into focus as photocatalysts for decontamination of Cr(VI) oxates and reactive dyes from contaminated water. However, although most Zr-MOFs exhibit hydrolytic stability, they absorb almost only ultraviolet light. Assembly of MOFs with both hydrolytic stability and high visible light responsiveness thus has become a most feasible avenue recently. Here, composite of Ag@UiO-67 was intentionally designed by modifying the classical Zr-MOF of UiO-67 with highly photosensitive Ag+ ions. Results suggested that compared with pristine UiO-67, Ag@UiO-67 displays significantly narrowed band gap (Eg) value, sufficiently negative conduction band (CB) potential, suitable valence band (VB) potential and significantly improved charge transfer efficiency. Notably, the Eg value of 2.09 eV gives Ag@UiO-67 excellent ability of visible photocatalytic reduction of Cr(VI) and degradation of Reactive dark blue K-R (RB13), with reduction and degradation efficiencies of 91.37 % within 140 min (k = 0.024 min−1) and 92.63 % within 160 min (k = 0.016 min−1), respectively, which are 5.6 and 6.9 times of as synthesized UiO-67. Moreover, photocatalytic mechanism studies reveal that ·O2– plays key roles in bleaching RB13 and photogenerated species with sufficient negative potential can effectively reduce Cr(VI). And Ag@UiO-67 can utilize visible light more efficiently to accelerate the charge transfer rate. This work provides a feasible avenue to tailor the visible light sensitivity and band structure of classic Zr-MOFs, for eliminating inorganic and organic contaminants such as Cr(VI) ions and dye of RB13.
Visible photocatalytic reduction and degradation capacities towards Cr(VI) and reactive dye (RB13) have been successfully achieved, by firmly anchoring Ag+ ions in UiO-67. This study provides a feasible strategy to realize the low-energy light utilization and bifunctionality of robust Zr-MOFs platforms.
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Laser powder bed fusion (LPBF) technology realized the surgical personalized devices. However, LPBF-produced titanium alloys face several limitations, such as obvious metastable pits. This work ...presented a promising strategy to enhance the corrosion resistance of LPBF-produced Ti6Al4V alloy by the Cu alloying. Compared to the Ti6Al4V alloy, Ti6Al4V-Cu alloy possessed a more protective passive film with stable oxides due to its finer grains. Furthermore, Ti6Al4V-Cu alloy demonstrated superior metastable pitting corrosion resistance in a 3.5 wt% NaCl solution, because Cu substituents effectively consumed the cationic vacancies in the passive film, thus inhibited the nucleation of the metastable pits.
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•LPBF-produced Ti6Al4V-Cu alloy had finer grains to promote passive film formation.•Nucleation of metastable pits was inhibited in the passive film of Ti6Al4V-Cu alloy.•Cu addition enhanced metastable pitting corrosion resistance of LPBF-produced Ti6Al4V-Cu alloy.
The outbreak of COVID-19 has led to international concern. We aimed to establish an effective screening strategy in Shanghai, China, to aid early identification of patients with COVID-19.
We did a ...multicentre, observational cohort study in fever clinics of 25 hospitals in 16 districts of Shanghai. All patients visiting the clinics within the study period were included. A strategy for COVID-19 screening was presented and then suspected cases were monitored and analysed until they were confirmed as cases or excluded. Logistic regression was used to determine the risk factors of COVID-19.
We enrolled patients visiting fever clinics from Jan 17 to Feb 16, 2020. Among 53 617 patients visiting fever clinics, 1004 (1·9%) were considered as suspected cases, with 188 (0·4% of all patients, 18·7% of suspected cases) eventually diagnosed as confirmed cases. 154 patients with missing data were excluded from the analysis. Exposure history (odds ratio OR 4·16, 95% CI 2·74–6·33; p<0·0001), fatigue (OR 1·56, 1·01–2·41; p=0·043), white blood cell count less than 4 × 109 per L (OR 2·44, 1·28–4·64; p=0·0066), lymphocyte count less than 0·8 × 109 per L (OR 1·82, 1·00–3·31; p=0·049), ground glass opacity (OR 1·95, 1·32–2·89; p=0·0009), and having both lungs affected (OR 1·54, 1·04–2·28; p=0·032) were independent risk factors for confirmed COVID-19.
The screening strategy was effective for confirming or excluding COVID-19 during the spread of this contagious disease. Relevant independent risk factors identified in this study might be helpful for early recognition of the disease.
National Natural Science Foundation of China.
MYCN amplification plays a critical role in defining high-risk subgroup of patients with neuroblastoma. We aimed to develop and validate the CT-based machine learning models for predicting MYCN ...amplification in pediatric abdominal neuroblastoma.
A total of 172 patients with MYCN amplified (n = 47) and non-amplified (n = 125) were enrolled. The cohort was randomly stratified sampling into training and testing groups. Clinicopathological parameters and radiographic features were selected to construct the clinical predictive model. The regions of interest (ROIs) were segmented on three-phrase CT images to extract first-, second- and higher-order radiomics features. The ICCs, mRMR and LASSO methods were used for dimensionality reduction. The selected features from the training group were used to establish radiomics models using Logistic regression, Support Vector Machine (SVM), Bayes and Random Forest methods. The performance of four different radiomics models was evaluated according to the area under the receiver operator characteristic (ROC) curve (AUC), and then compared by Delong test. The nomogram incorporated of clinicopathological parameters, radiographic features and radiomics signature was developed through multivariate logistic regression. Finally, the predictive performance of the clinical model, radiomics models, and nomogram was evaluated in both training and testing groups.
In total, 1,218 radiomics features were extracted from the ROIs on three-phrase CT images, and then 14 optimal features, including one original first-order feature and eight wavelet-transformed features and five LoG-transformed features, were identified and selected to construct the radiomics models. In the training group, the AUC of the Logistic, SVM, Bayes and Random Forest model was 0.940, 0.940, 0.780 and 0.927, respectively, and the corresponding AUC in the testing group was 0.909, 0.909, 0.729, 0.851, respectively. There was no significant difference among the Logistic, SVM and Random Forest model, but all better than the Bayes model (p <0.005). The predictive performance of the Logistic radiomics model based on three-phrase is similar to nomogram, but both better than the clinical model and radiomics model based on single venous phase.
The CT-based radiomics signature is able to predict MYCN amplification of pediatric abdominal NB with high accuracy based on SVM, Logistic and Random Forest classifiers, while Bayes classifier yields lower predictive performance. When combined with clinical and radiographic qualitative features, the clinics-radiomics nomogram can improve the performance of predicting MYCN amplification.
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•The might risks of indoor VOCs and Rn are present.•The MOFs adsorption researches under practical conditions are summarized.•The use of appropriate evaluation metrics is critical for ...adsorption researches.•The sensing of indoor VOCs based on MOFs as preconcentration materials are discussed.•Current challenges and potentials of MOFs-based absorbents are discussed.
Volatile organic chemicals (VOCs) and radon (Rn) gas are well-known indoor air pollutants that cause indoor air problems and pose health risks. Thus, it is extremely important to adsorb and sense them under practical conditions. Metal-organic frameworks (MOFs) are ideal choice for adsorption and sensing due to their extensive tunability and complexation with gas, which endow them with sufficient adsorption capacity and specific affinity for overcoming the limitations of applications. This review summarizes the recent advances in the adsorption of indoor VOCs and Rn gas under practical conditions based on the use of suitable evaluation metrics and discussed the sensing of indoor VOCs based on the superior adsorption performance of MOFs (preconcentration materials). Finally, based on the excellent adsorption properties of MOFs, we present new insights into possible future developments and challenges in the atmosphere to further advance the research in this field.
This study aimed to investigate the research hotspots and global trends of acupuncture in the treatment of headaches from 1974 to 2022. The Web of Science core collection database and literature ...related to acupuncture for headache treatment were retrieved. The CiteSpace (version 5.1.R8) and VOSviewer (version 1.6.19) software perform collaborative network analysis on the information of countries, academic institutions, authors, and co-occurrence network analysis on keywords, co-cited journals, and references. A total of 841 studies were included. Overall, the number of publications has increased over the past 5 decades. We identified and analyzed the countries, institutions, authors, and journals that were most active in the domain of acupuncture treatment for headaches. The most productive countries were the United States and China. Chengdu University of Traditional Chinese Medicine was the most productive institution and Linde Klaus was the most productive author. Cephalalgia was the most productive and co-cited journal, whereas Lancet had the highest impact factor. The research hotspots mainly focus on headache, migraine, tension headache, electroacupuncture, and acupuncture. Research trends have mainly focused on acupuncture therapy and its curative effects, migraine without aura, paroxysmal migraine, and the mechanism of acupuncture treatment. The main research hotspots and frontier trends were the therapeutic effect and mechanism of acupuncture for headaches. The mechanism of acupuncture in the treatment of headache mainly focused on the neural mechanism by multimodal MRI.
Transient flow caused by air expulsion is investigated. Earlier experimental studies involved the horizontal or horizontal-vertical pipe cases, or the vertical pipe case with relatively less test ...range. This paper focuses on the vertical pipe case with much broader ranges of orifice size and air length to more completely characterize the transient response. Observations show air release undergoes two distinct stages: stage 1 with pressurization, expansion and release of air pocket; stage 2 with an impacting water hammer pressure when water reaches the pipe end. Two types of pressure oscillation patterns are found, depending on orifice size. When orifice sizes are small, air cushioning effect prevents high water hammer pressures from being generated. As orifice size increases, the water hammer pressure is dominant. As initial air length increases, the maximum pressure firstly increases and then decreases. An elastic-water model could well reproduce the measured air pressure oscillations and impact pressure.
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