Two new polyoxometalate (POM)‐based hybrid compounds modified by a Schiff base, Fe(DAPSC)(H2O)22HPMo2VMo10VIO40 ⋅ 5H2O (1) and Fe(DAPSC)(H2O)2HPV3IVMo4VMo7VIO42 ⋅ 6H2O (2), ...(DAPSC=2,6‐diacetylpyridine bis‐(semicarbazone)), have been successfully constructed from typical Keggin POMs, iron ions, and DAPSC ligands under hydrothermal condition. Structural analysis demonstrates that the Fe‐Schiff base ligand units are free from polyacid anions in compound 1. While in compound 2, the Fe‐Schiff base ligand units are bridged with polyacid anions via Fe−O bonds to emerge a stable double‐supported skeleton. Noticeably, owing to the introduction of vanadium in H5PMo10V2O40 ⋅ 32.5H2O, a divanadium‐capped configuration is shaped in compound 2. Besides, the third‐order nonlinear optical (NLO) properties of two compounds were explored. It should be noted that both compounds 1 and 2 have two‐photon absorption properties, which indicates that the two compounds are potential nonlinear optical materials.
Two POM‐based hybrid compounds Fe(DAPSC)(H2O)22HPMo2VMo10VIO40 ⋅ 5H2O (1) and Fe(DAPSC)(H2O)2HPV3IVMo4VMo7VIO42 ⋅ 6H2O (2) modified by iron and Schiff bases have been successfully prepared through adjusting POMs anions. Noticeably, owing to the introduction of vanadium in H5PMo10V2O40 ⋅ 32.5H2O, a divanadium‐capped configuration is formed in compound 2. In addition, the electrochemical activities and third‐order NLO properties of two compounds were explored. The σ value reached 1302 GM (1) and 2702 GM (2) respectively, which indicates that these two compounds are potential nonlinear optical materials.
Presently, China has the largest high-speed rail (HSR) system in the world. However, our understanding of the network structure of the world's largest HSR system remains largely incomplete due to the ...limited data available. In this study, a publicly available data source, namely, information from a ticketing website, was used to collect an exhaustive dataset on the stations and routes within the Chinese HSR system. The dataset included all 704 HSR stations that had been built as of June, 2016. A classical set of frequently used metrics based on complex network theory were analyzed, including degree centrality, betweenness centrality, and closeness centrality. The frequency distributions of all three metrics demonstrated highly consistent bimodal-like patterns, suggesting that the Chinese HSR network consists of two distinct regimes. The results indicate that the Chinese HSR system has a hierarchical structure, rather than a scale-free structure as has been commonly observed. To the best of our knowledge, such a network structure has not been found in other railway systems, or in transportation systems in general. Follow-up studies are needed to reveal the formation mechanisms of this hierarchical network structure.
•CitERF6 was identified as a novel positive regulator on chlorophyll degradation.•Auto- and mutual-regulation was found between CitERF6 and CitERF13.•Auto- and mutual-regulation facilitate the effect ...of ethylene, leading to fruit degreening.
Citrus fruit postharvest degreening is a critical stage in marketing, carried out by exposure to ethylene or ethephon. Genome-wide screening of the AP2/ERF superfamily indicated that a novel ERF-II (CitERF6) was shown to trans-activate the CitPPH promoter. Expression of CitERF6 is associated with both developmental and postharvest degreening in citrus fruit. Transient and stable over-expression of CitERF6 in Nicotiana tabacum leaves and ‘Ponkan’ fruit also results in rapid chlorophyll degradation. Auto- and mutual-regulation was also found between CitERF6 and the previously characterized CitERF13 using the dual-luciferase and yeast one-hybrid assays. Moreover, substitution of the 35S promoter for endogenous promoters showed that both pCitERF6::CitERF6 and pCitERF13::CitERF13 were effective in trans-activating their promoters or triggering chlorophyll degradation. It is proposed that ethylene is one of the triggers activating promoters of CitERF6 and CitERF13, and subsequent auto- and mutual-regulation between CitERF6 and CitERF13 might facilitate the effect of ethylene, leading to fruit degreening.
Lead halide perovskites are currently attracting a great deal of attentions due to their great promise as light absorbers in high‐efficiency hybrid organic–inorganic solid‐state solar cells. The ...reliable information about interface energetics of lead halide perovskite‐based interfaces is indispensable to unraveling the photon harvesting and charge separation process for this emerging photovoltaic technology. Here, we provide the direct evidence on energy level alignments at the hybrid interfaces between lead halide perovskite and organic hole‐transport materials (HTMs) using in situ ultraviolet and X‐ray photoemission techniques. The measured alignment schemes at perovskite/HTM hybrid interfaces reveal four entirely different energy level offsets with respect to the variation of HTMs, including spiro‐OMeTAD, NPB, F16CuPc, HATCN, and MoO3, and their impacts on charge separation are also elucidated. It is identified that the staggered‐gap heterojunction in contact with a HTM of higher‐lying occupied molecular orbital can facilitate the interfacial hole extraction. Our experimental findings provide the guideline of not only understanding the interfacial charge separation mechanisms but also optimizing the HTMs in perovskite‐based solar cells.
The direct experimental determination of interface energetics of lead halide perovskite‐based hybrid organic–inorganic interfaces is reported upon, which provides the guideline of not only understanding the interfacial charge separation mechanisms but also optimizing the hole‐transport materials (HTMs) in perovskite‐based solar cells.
A novel ultrasensitive electrochemiluminescence (ECL) biosensor was constructed using two-dimensional (2D) Co
O
nanosheets as a novel coreaction accelerator of the luminol/H
O
ECL system for the ...detection of microRNA-21 (miRNA-21). Impressively, coreaction accelerator 2D Co
O
nanosheets with effective mutual conversion of the Co
/Co
redox pair and abundant active sites could promote the decomposition of coreactant H
O
to generate more superoxide anion radicals (O
), which reacted with luminol for significantly enhancing ECL signals. Furthermore, the trace target miRNA-21 was transformed into a large number of G-wires through the strand displacement amplification (SDA) process to self-assemble the highly ordered rolling DNA nanomachine (HORDNM), which could tremendously improve the detection sensitivity of biosensors. Hence, on the basis of the novel luminol/H
O
/2D Co
O
nanosheet ternary ECL system, the biosensor implemented ultrasensitive detection of miRNA-21 with a detection limit as low as 4.1 aM, which provided a novel strategy to design an effective ECL emitter for ultrasensitive detection of biomarkers for early disease diagnosis.
The aim of the study was to determine the effect of tert-butylhydroquinone (tBHQ) supplementation on some biochemical parameters in pregnant diabetic rats and the foetus.
The global incidence of ...gestational diabetes mellitus (GDM) has been on the increase despite current interventional therapies, underscoring the need for alternative or complementary therapeutic approaches.
The objective is to determine the effect of tBHQ on blood glucose, insulin resistance, body weight, relative liver and kidney weights, serum lipid profile (total cholesterol, triacylglycerol, high-density lipoprotein cholesterol and very low-density lipoprotein cholesterol), liver function (albumin, aspartate and alanine amino transaminases) and kidney function markers (urea, creatinine and uric acid) in the sera, and study maternal and foetal renal levels of oxidative stress and inflammatory markers, foetal weights and histology of the kidney of streptozotocin (STZ)-induced GDM in rats.
Twenty female pregnant rats were used, and they were divided into four groups of control (normal pregnancy), disease (diabetic untreated), metformin (received 200 mg/kg metformin dissolved in distilled water) and tBHQ groups (received 25 mg/kg tBHQ in 1% corn oil), respectively, with five rats in each group. GDM was induced in the disease and treated groups by intraperitoneal injection of STZ (45 mg/kg in sodium citrate buffer, pH 4.5).
STZ induction in the disease group significantly increased their blood glucose levels (P<0.05), altered their body and foetal weights, relative liver and kidney weights, serum lipid profile, liver and kidney function markers in the sera (relative to the control), inducing oxidative stress and inflammation to the maternal and foetal kidneys and altering the maternal kidney histology, which was found to be improved following supplementation with tBHQ in a manner akin to or even better than metformin.
tBHQ was found beneficial in protecting the foetal kidneys against oxidative stress and the foetus against mortality arising from maternal hyperglycaemia. Finally, the study showed the potential of tBHQ in mitigating histological changes in the maternal kidney arising from STZinduced hyperglycemia in rats.
Human adenoid cystic carcinoma (ACC) is characterized by diffused invasion of the tumor into adjacent organs and early distant metastasis. Anoikis resistance and epithelial mesenchymal transition ...(EMT) are considered prerequisites for cancer cells to metastasize. Exploring the relationship between these processes and their underlying mechanism of action is a promising way to better understand ACC tumors. We initially established anoikis-resistant sublines of ACC cells; the variant cells revealed a mesenchymal phenotype through Slug-mediated EMT-like transformation and displayed enhanced metastatic potential both in vitro and in vivo. Suppression of EMT by knockdown of Slug significantly impaired anoikis resistance, migration, and invasion of the variant cells. With overexpression of Slug and Twist, we determined that induction of EMT in normal ACC cells could prevent anoikis, albeit partially. These findings strongly suggest that EMT is indispensable in anoikis resistance, at least in ACC cells. Furthermore, we found that the EGFR/PI3K/Akt pathway acts as the common regulator for EMT-like transformation and anoikis resistance, as confirmed by their specific inhibitors. Gefitinib and LY294003 restored the sensibilities of anoikis-resistant cells to anoikis and simultaneously impaired their metastatic potential. In addition, the results from our in vivo model of metastasis suggest that pretreatment with gefitinib promotes mouse survival by alleviating pulmonary metastasis. Most importantly, immunohistochemistry of human ACC specimens showed a correlation between the overexpression of Slug and EGFR staining. This study has demonstrated that Slug-mediated EMT-like transformation is required by human ACC cells to achieve anoikis resistance and their metastatic potential. Targeting the EGFR/PI3K/Akt pathway holds potential as a preventive strategy against distant metastasis of ACC.
•An anti-lodging machine, comprising an anti-lodging device and an AGV (Automated Guided Vehicle) was designed to replace manual methods.•A machine vision system was developed to aim the anti-lodging ...device at the crown buds.•The YOLOv5s algorithm is enhanced for detecting immature pineapple crown buds.•The mAP_0.5 of the improved YOLOv5s algorithm is 3.71 %, 1.69 %, and 1.19 % higher than the original YOLOv5s, SSD, and Faster R-CNN, respectively.•The operating speed of this intelligent anti-lodging method is 2.7 times faster than manual binding.
Sunscorch, a common disease in pineapple cultivation, is caused by direct sunlight on the surface of lodging pineapple fruits. To mitigate this issue, pineapple fruits are often bagged or supported with fixing rods. This paper presents the design of an anti-lodging machine, comprising an anti-lodging device and an AGV (Automated Guided Vehicle), and develops a machine vision system to precisely aim the anti-lodging device at the crown buds. The YOLOv5s algorithm is enhanced for detecting crown buds. The improvement of the YOLOv5s algorithm includes the introduction of the attention mechanism CBAM to enhance feature extraction, the addition of BiFPN and GhostNet to strengthen feature fusion and to reduce detection time and computational cost. By transforming pixel coordinates, the relative coordinates between the crown bud and the device are calculated to achieve accurate targeting. The experiments demonstrate that the precision, recall, and map_0.5 of the improved YOLOv5s algorithm are 91.89 %, 92.25 %, 94.01 %, and the detection speed is 15.71 ms/image. The average detection speed is 1.14 ms/image and 9.45 ms/image faster than that of SSD and Faster R-CNN, benefiting from a parameter number only 3/4 and 3/7 of SSD and Faster R-CNN, respectively. The results of contrast experiments indicate that, although the lodging prevention rate of this intelligent anti-lodging method is 4 % lower than the manual binding, its operating speed is 2.7 times faster.
Dose-response meta-analysis (DRMA) is a useful tool to investigate potential dose-response relationship between certain exposure or intervention and the outcome of interest. A large number of DRMAs ...have been published in the past several years. However, the standard of reporting for such studies is not known.
Medline, Embase, and Wiley Library were searched for systematic reviews with DRMAs (SR-DRMAs) published from January 2011 to July 2017. We used the combination of PRISMA and MOOSE statements, containing 33 items, to assess the reporting of included SR-DRMAs. The adherence of reporting was defined as the proportion of SR-DRMAs meeting the reporting requirement of an item. We explored the association between five pre-specified variables with the total score of reporting on both fully as well as each domain of the checklist.
In total, 529 SR-DRMAs were eligible. Ten out of 33 items were under reported, and this mainly refers to the methods domain: only a small proportion of SR-DRMAs stated whether a review protocol existed (45, 8.5%); clarified the qualifications of searchers (1.7%); presented full electronic search strategy (25.9%); described any effort to include all available studies (22.9%), described methods for languages other than English (27.4%), and stated the process for selecting studies (20.2%). Multiple regression analysis suggested that studies with more authors (regression coefficient = 0.78; 95% CI: 0.35, 1.20; P < 0.001), published more recently (regression coefficient = 0.38; 95% CI: 0.28 to 0.47; trend P < 0.001), used reporting guideline (regression coefficient = 0.98; 95% CI: 0.68 to 1.32; P < 0.001), and involvement of methodologist (regression coefficient = 0.86; 95% CI: 0.42 to 1.32; P < 0.001) were associated with higher score of reporting. Further regression suggested that the improvement on the quality mainly concentrated on the methods and results domains.
The reporting of SR-DRMAs needs to be further improved, particularly in the issues refer to the methods. The quality of reporting may improve when involving more authors and methodologists and employing any reporting guidelines.
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