Metal oxide nanomaterials have been widely applied in the high-performance gas sensors. For metal oxide semiconductors, high surface-to-volume ratio and the exposed crystal facets are the two key ...factors for determining their gas sensing performances. In order to study the effect of surface structure on the gas sensing properties, in this work, two types of copper oxide (CuO) nanostructures, CuO nanotubes (CuO NTs) with exposed surface plane of (111) and CuO nanocubes (CuO NCs) with exposed surface plane of (110), were obtained from Cu nanowires (Cu NWs) and Cu2O nanocubes (Cu2O NCs), respectively. The morphologies, crystal and surface structures were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The gas-sensing performances of CuO NTs and CuO NCs for CO gas detection were then studied. The results demonstrated that compared to CuO NCs, the CuO NTs exhibited lower optimum working temperature and higher sensitivity for CO gas detection. At the operating temperature of 175 °C, the prepared CuO NTs exhibited high sensitivity, good selectivity, fast response and recovery times to CO gas. The present study indicates that for the same semiconductor sensing material, the surface crystal structure has significant influence on the sensing performance.
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•CuO nanotubes and nanocubes with exposed surface planes of (111) and (110), respectively, were synthesized.•CuO nanotubes exhibited higher sensing performance than CuO nanocubes for CO gas detection.•The CuO nanotubes show promising gas sensing applications.•Surface crystal structure of metal oxides has significant influence on their gas sensing properties.
A novel metal‐organic framework {Zn(XL)2(ClO4)2⋅6 H2O}n (XL=N,N′‐bicyclo2.2.2oct‐7‐ene‐2,3,5,6‐tetracarboxdiimide bi(1,2,4‐triazole)) was synthesized and structurally characterized, presenting the ...first example of six‐fold interpenetrating 3 D framework with the topology type of sqc6, which displays high thermostability and solvent stability. Additionally, the luminescence investigations reveal that this MOF can sensitively and selectively detect acetylacetone with a detection limit of 1.72 ppm. More importantly, it is rather rare for an MOF‐based luminescence probe to serve as a sensor to effectively detect acetylacetone.
Detecting acetylacetone: A novel metal–organic framework, {Zn(XL)2(ClO4)2⋅6 H2O}n, was synthesized and structurally characterized, presenting the first example of a six‐fold interpenetrating 3 D framework with the sqc6 topology and the first example of a transition‐metal MOF‐based luminescence sensor to effectively detect acetylacetone. The detection limit achieved was 1.72 ppm.
In this paper, the creep behavior of sandstone under the different confining pressures is investigated. The nuclear magnetic resonance (NMR) measurements are carried out to detect the micro-pore ...characteristics of sandstones before and after compression tests and creep tests. The variations of the parameters, including transverse relaxation time (T
2
) spectra distribution, percentage of the pore distribution and the changes of porosity are analyzed quantificationally. The experimental results show that creep behavior can be regarded as a process of gradual accumulation of damage to rocks. The confining pressure can limit the increase in porosity during the creep stage, and the effect of confining pressure on the incremental value of porosity is more obvious under high-stress conditions than under low-stress conditions. Moreover, the relationship between the creep stain and the incremental value of porosity is established to reveal the relationship between micro-crack expansion of rocks and macro-creep characteristics of sandstone. It is found that, as the loading ratio or confining pressure increases, the variation of the creep strain is similar to the variation of the incremental value of porosity. The larger the confining pressure, the smaller the effects of creep strain on the incremental value of porosity. However, the greater the loading ratio is, the faster the incremental value of porosity increases. The present study can provide a theoretical basis for the deep mining of mineral resources and the structural stability analysis of deep-buried underground engineering.
Percutaneous endoscopic lumbar discectomy (PELD) is a relatively safe and effective minimally invasive surgery in the treatment of calcified lumbar disc herniation (CLDH). However, studies on ...percutaneous endoscopic interlaminar discectomy (PEID) and percutaneous endoscopic transforaminal discectomy (PETD) for CLDH have rarely been reported. This research aimed to compare the clinical efficacy of PEID and PETD for L5-S1 CLDH.
We retrospectively analyzed 54 consecutive patients with L5-S1 CLDH treated with PELD at our institution from August 2016 to August 2020. Patients were divided into PEID group (n = 28) and PETD (n = 26) group according to the surgical methods. The demographic characteristics and surgical results of the two groups were compared. Clinical outcomes were estimated by the visual analog scale (VAS) for leg pain, Oswestry disability index (ODI) and modified MacNab criteria.
All patients were successfully operated on by PEID or PETD. No significant differences in the demographic characteristics, intraoperative blood loss, postoperative hospital stay and complication rate were noted between the PEID and PETD groups. The excellent and good rates in the PEID group were similar to those in the PETD group (89.29% vs 88.46%, P = 1.000), whereas the PEID group exhibited superior results for operative time (min) (64.61 ± 5.60 vs 85.58 ± 8.52, P < 0.001) and fluoroscopy times (n) (2.93 ± 0.90 vs 13.35 ± 2.30, P < 0.001) compared with the PETD group.
PEID has achieved good clinical efficacy as PETD for L5-S1 CLDH. Compared with PETD, PEID has the advantages of shorter operative time and a reduced number of fluoroscopy times in the treatment of CLDH.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Stable metal clusters that can resist both highly concentrated acid and alkali are unknown. Herein, we present a discrete neutral cluster, Hf13(μ4‐O)8(OCH3)36 (1), which features extraordinary ...chemical stability by preserving its crystalline state in concentrated aqueous solutions of both acid (10 m HNO3) and alkali (20 m boiling NaOH). Importantly, 1 can serve as a luminescent probe for detecting both concentrated alkali (20 m NaOH) and strong acid (1 m HNO3) with high selectivity and repeatability. DFT studies of the electronic structure and bonding revealed that 1 has an extremely large HOMO–LUMO gap due to strong d π–p π bonding that accounts for the ultrahigh stability.
Tough beyond belief: An ultrastable Hf13(μ4‐O)8(OCH3)36 nanocluster (see picture; Hf green, O red, C gray) preserved its crystalline state in concentrated alkali (20 m boiling NaOH) and concentrated acid (10 m HNO3). The cluster acted as a luminescent sensor for the detection of both strong acid and concentrated alkali with high selectivity and repeatability.
Thoracic spinal stenosis (TSS), a common vertebral degenerative disease, is generally treated via surgical decompression. Percutaneous endoscopic thoracic decompression (PETD) under local anesthesia ...is considered a relatively safe, minimally invasive procedure. Few reports detail the success of endoscopic decompression for treatment of TSS caused by ossification of ligamentum flavum, the most common cause of TSS. This study investigated application of PETD for treatment of TSS caused by ossification of ligamentum flavum, ossification of posterior longitudinal ligament, or thoracic disc herniation.
From January 2017 to January 2019, 12 consecutive patients (6 men and 6 women) underwent PETD. TSS was caused by ossification of ligamentum flavum in 5 patients, thoracic disc herniation in 5 patients, and ossification of posterior longitudinal ligament in 2 patients. All cases were followed up for 1 year postoperatively. Preoperative and postoperative neurologic status was evaluated using the modified Japanese Orthopaedic Association score, and complications were documented.
Average modified Japanese Orthopaedic Association score improved significantly from 6.25 ± 1.60 preoperatively to 9.75 ± 1.21 at final follow-up. Dural tear was observed in 1 case during the intervention, and 1 case had transient worsening of preoperative paralysis. Recovery at final follow-up was classified as excellent in 5 cases, good in 6 cases, and poor in 1 case.
This retrospective analysis showed that PETD under local anesthesia may be a feasible alternative to treat TSS in elderly patients with other underlying complications for whom general anesthesia or major surgical trauma would be harmful.
Cancer has been the most deadly disease, and 13 million cancer casualties are estimated to occur each year by 2030. Gold nanoparticles (AuNPs)‐based photothermal therapy (PTT) has attracted great ...interest due to its high spatiotemporal controllability and noninvasiveness. Due to the trade‐off between particle size and photothermal efficiency of AuNPs, rational design is needed to realize aggregation of AuNPs into larger particles with desirable NIR adsorption in tumor site. Exploiting the bioorthogonal “Click and Release” (BCR) reaction between iminosydnone and cycloalkyne, aggregation of AuNPs can be achieved and attractively accompanied by the release of chemotherapeutic drug purposed to photothermal synergizing. We synthesize iminosydnone‐lonidamine (ImLND) as a prodrug and choose dibenzocyclooctyne (DBCO) as the trigger of BCR reaction. A PEGylated AuNPs‐based two‐component nanoplatform consisting of prodrug‐loaded AuNPs‐ImLND and tumor‐targeting peptide RGD‐conjugated AuNPs‐DBCO‐RGD is designed. In the therapeutic regimen, AuNPs‐DBCO‐RGD are intravenously injected first for tumor‐specific enrichment and retention. Once the arrival of AuNPs‐ImLND injected later at tumor site, highly photothermally active nanoaggregates of AuNPs are formed via the BCR reaction between ImLND and DBCO. The simultaneous release of lonidamine further enhanced the therapeutic performance by sensitizing cancer cells to PTT.
We reported the application of bioorthogonal “Click and Release” (BCR) reaction between prodrug iminosydnone‐lonidamine (ImLND) and dibenzocyclooctyne (DBCO) to form highly photothermal‐active nanoaggregates with synergistic drug release. The reactants of BCR reaction were grafted on surface of gold nanoparticles (AuNPs) and was proven both in vitro and in vivo to robustly enhance the therapeutic outcome of photothermal therapy.
Short text sentiment analysis is challenging because short texts are limited in length and lack context. Short texts are usually rather ambiguous because of polysemy and the typos these texts ...contain. Polysemy is the coexistence of multiple word meanings and commonly appears in every language. Various uses of a word may assign the word both positive and negative meanings. In previous studies, the variability of words is often ignored, which may cause analysis errors. In this study, to resolve this problem, we proposed a novel text representation model named Word2PLTS for short text sentiment analysis by introducing probabilistic linguistic terms sets (PLTSs) and the relevant theory. In this model, every word is represented as a PLTS that fully describes the possibilities for the sentiment polarity of the word. Then, by using support vector machines (SVM), a novel sentiment analysis and polarity classification framework named SACPC is obtained. This framework is a technique that combines supervised learning and unsupervised learning. We compare SAPCP to lexicon-based approaches and machine learning approaches on three benchmark datasets. A noticeable improvement in performance is achieved. To further verify the superiority of SAPCP, state of the art performance comparisons are conducted, and the results are impressive.
Coronavirus disease 2019 (COVID-19) is an emerging infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Up to 20%–30% of patients hospitalized with COVID-19 have ...evidence of cardiac dysfunction. Xuebijing injection is a compound injection containing five traditional Chinese medicine ingredients, which can protect cells from SARS-CoV-2-induced cell death and improve cardiac function. However, the specific protective mechanism of Xuebijing injection on COVID-19-induced cardiac dysfunction remains unclear.
The therapeutic effect of Xuebijing injection on COVID-19 was validated by the TCM Anti COVID-19 (TCMATCOV) platform. RNA-sequencing (RNA-seq) data from GSE150392 was used to find differentially expressed genes (DEGs) from human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) infected with SARS-CoV-2. Data from GSE151879 was used to verify the expression of Angiotensin I Converting Enzyme 2 (ACE2) and central hub genes in both human embryonic-stem-cell-derived cardiomyocytes (hESC-CMs) and adult human CMs with SARS-CoV-2 infection.
A total of 97 proteins were identified as the therapeutic targets of Xuebijing injection for COVID-19. There were 22 DEGs in SARS-CoV-2 infected hiPSC-CMs overlapped with the 97 therapeutic targets, which might be the therapeutic targets of Xuebijing injection on COVID-19-induced cardiac dysfunction. Based on the bioinformatics analysis, 7 genes (CCL2, CXCL8, FOS, IFNB1, IL-1A, IL-1B, SERPINE1) were identified as central hub genes and enriched in pathways including cytokines, inflammation, cell senescence and oxidative stress. ACE2, the receptor of SARS-CoV-2, and the 7 central hub genes were differentially expressed in at least two kinds of SARS-CoV-2 infected CMs. Besides, FOS and quercetin exhibited the tightest binding by molecular docking analysis.
Our study indicated the underlying protective effect of Xuebijing injection on COVID-19, especially on COVID19-induced cardiac dysfunction, which provided the theoretical basis for exploring the potential protective mechanism of Xuebijing injection on COVID19-induced cardiac dysfunction.
•The hub genes of Xuebijing injection on heart in COVID-19 patients were identified.•The expression levels of ACE2 and 7 hub genes were verified in three kinds of CMs.•The analysis results of GSE150392 and GSE151879 corroborated each other.
Percutaneous transforaminal endoscopic decompression (PTED) is an ultra-minimally invasive surgical option for patients that does not involve the same amount of destabilizing facet joint removal as a ...traditional laminectomy. The objective of this study was to describe the procedure of PTED under local anesthesia for geriatric patients with central spinal stenosis and degenerative lumbar spondylolisthesis (CSS-DLS).
From January 2016 to December 2018, 30 consecutive geriatric patients who underwent surgery for single-level CSS-DLS were retrospectively reviewed. All patients were followed for at least 12 months (12-24 months). The visual analog scale (VAS) scores, Oswestry disability index (ODI) scores and modified MacNab criteria were used to evaluate the clinical results.
The mean age was 73.1±6.0 years. Follow-up ranged from 12 to 36 months. The mean±SD values of the preoperative VAS for leg pain and ODI were 7.4±1.0 and 67.2±8.4, respectively. The values improved to 2.2±1.1 and 19.9±8.1 at 12 months postoperatively. The outcomes of the modified MacNab criteria showed that 93.3% of patients obtained a good-to-excellent rate. The percent slippage of spondylolisthesis before surgery (13.8±2.5%) and at the end of follow-up (14.0±2.5%) was not significantly different.
PTED under local anesthesia could be a useful supplement to traditional decompression in geriatric patients with CSS-DLS.
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