28 research outputs found
3-DimethylÂamino-1-(4-methylÂphenÂyl)prop-2-en-1-one
In the title compound, C12H15NO, the C=C and C=O functional groups and the benzene ring are involved in an extended conjugated system. The molÂecules are essentially planar with a maximal deviation from planarity for the non-H atoms of 0.062â
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SingleâMolecule Study of DNAzyme Reveals Its Intrinsic Conformational Dynamics
DNAzyme is a class of DNA molecules that can perform catalytic functions with high selectivity towards specific metal ions. Due to its potential applications for biosensors and medical therapeutics, DNAzyme has been extensively studied to characterize the relationships between its biochemical properties and functions. Similar to protein enzymes and ribozymes, DNAzymes have been found to undergo conformational changes in a metalâionâdependent manner for catalysis. Despite the important role the conformation plays in the catalysis process, such structural and dynamic information might not be revealed by conventional approaches. Here, by using the singleâmolecule fluorescence resonance energy transfer (smFRET) technique, we were able to investigate the detailed conformational dynamics of a uranylâspecific DNAzyme 39E. We observed conformation switches of 39E to a folded state with the addition of Mg2+ and to an extended state with the addition of UO22+. Furthermore, 39E can switch to a more compact configuration with or without divalent metal ions. Our findings reveal that 39E can undergo conformational changes spontaneously between different configurations
Impact of Morphological Characteristics of Green Roofs on Pedestrian Cooling in Subtropical Climates
Growing and densifying cities set a challenge for preserving and enhancing green spaces to cool urban spaces. Green roofs, involving the planting of vegetation on rooftops, are regarded as an alternative approach to enhancing urban greenery and urban cooling. For better cooling performances, it is essential to reasonably configure green roofs, especially in real and complex neighborhoods. Therefore, the aim of this paper is to investigate the impact of morphological characteristics of green roofs on pedestrian cooling in real and complex neighborhoods. In specific, based on an ENVI-met model, we studied the effect of greening layout, coverage ratio, vegetation height, and building height on pedestrian air temperature reduction in the tropical city of Hangzhou, China. Results indicate green roofs could generate moderate effects on pedestrian air temperature reduction (around 0.10â0.30 °C), while achieving a cooling performance of 0.82 °C. Green roofs in upwind zones were able to generate the most favorable cooling performance, while green roofs in downwind zones made slight differences to pedestrian thermal environments. Green roofs with a low coverage ratio were not useful for lowering pedestrian temperature, and a greening coverage ratio of 25â75% in upwind zones was cost-effective in real neighborhoods. Locations that were horizontally close to green roofs enjoyed better cooling performances. Increasing vegetation height could strengthen cooling effects of green roofs, while an increase in building height weakened the cooling performance. Nevertheless, higher building height could enhance pedestrian cooling performances because of building shading effects. In addition, because of wind effects and building shading, building height limits for the cooling performance of green roofs could be higher than 60 m
New real-time endoscopy image processing technology of hemoglobin color enhancement
Video endoscopes play an important role in clinic practice for gastrointestine and bronchial tracts. Using these video endoscopes, a depressing type of early cancer which has recently been focused on can be identified with change in color tone such as reddening or discoloration. Some hemoglobin color enhancement processing algorithms have been developed to make this slight color tone change clear in real-time. In this paper, we will introduce a new algorithm which has been partially incorporated into a commercial endoscope system AQ-100. The basic principle of the algorithm is to adjust the RGB components based on the IHb value. Through Matlab simulation result and application feedback in clinic practice, this partially incorporated algorithm is confirmed effective in both simulation and clinic practice. Though the complete algorithm has a better effect in simulation, it still has some problems to be resolved before it can be applied into clinic practice.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000295055800186&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701OpticsPhysics, AppliedRadiology, Nuclear Medicine & Medical ImagingEICPCI-S(ISTP)
Adsorption Behavior and Mechanism for the Uptake of Fluoride Ions by Reed Residues
The adsorption behavior and mechanism for the uptake of fluoride ions by untreated and desugared reed residues (roots, stems and leaves) were studied through adsorption experiments, elemental analysis, infrared spectroscopy and surface area analysis. The results showed that the adsorption capacity of untreated and desugared reeds followed the order: desugared roots 2136 mg/kg > desugared leaves 1825 mg/kg > desugared stems 1551 mg/kg > untreated roots 191 mg/kg > untreated stems 175 mg/kg > untreated leaves 150 mg/kg, so adsorption capacity of desugared reeds was larger than that of the untreated reeds. The adsorption kinetic of fluoride ions followed a pseudo-first-order model. A Langmuir model could be used to fit the isothermal adsorption process which was a spontaneous endothermic reaction involving mainly physical adsorption. The ÎG for the uptake of fluoride by the desugared reeds was more negative, so the degree of spontaneity was higher than for the use of the untreated reeds. After samples were desugared, the specific surface area and aromaticity of the reed increased, while the polarity and hydrophilicity decreased, which explained the adsorption amount of desugared reed was higher than that of the untreated. This study enriches techniques and methods of removing fluoride ions from water
Effects of Dissolved Organic Matter on Sorption of Oxytetracycline to Sediments
The effects of two representative dissolved organic matters (DOMs) (derived from corrupt plants (PDOM) and chicken manure (MDOM)) on sorption characteristic of oxytetracycline to three typical sediments (first terrace (FT), river floodplain (RF), and riverbed (RB) sediments collected from the Weihe River) were investigated. Results showed that both DOMs can make the adsorption equilibrium time advance about 6 hours. The presence of DOMs changed the sorption kinetics model and the spontaneous degree of the reaction but did not change the sorption isotherm models. The adsorption of oxytetracycline (OTC) could be promoted by adding PDOM, and its maximum adsorption amount increased by 23.8% for FT, 38.0% for RB, and 28.3% for RF, respectively, whereas MDOM could inhibit the adsorption and maximum adsorption amount decreased by 23.3% for FT, 11.6% for RB, and 16.1% for RF, respectively. In addition, the DOM concentration also affected the adsorption. Overall, this study suggests that the humus-like DOM can promote the adsorption of OTC while the protein-like DOM can inhibit the adsorption of OTC to sediments, which is determined by the aromaticity, hydrophilicity, and polarity of the DOMs
Janus kinase inhibitors in atopic dermatitis: an umbrella review of meta-analyses
BackgroundClinicians and healthcare policymakers have been drenched with a deluge of overlapping meta-analyses (MAs), and the necessity for comprehensive and clearly defined evidence of Janus kinase inhibitors (JKIs) in atopic dermatitis (AD) is urgent.MethodsSix databases were searched for MAs published until October 2023. Qualitative description of MAs was mainly used, and Investigator's Global Assessment response (IGA response), the 75% improvement in Eczema Area and Severity Index (the EASI75), peak pruritus Numerical rating score (PP-NRS), and adverse effects were cited to describe the efficacy and safety of JKIs. The methodological quality of the included MAs was assessed by A Measurement Tool to Assess Systematic Reviews II (AMSTAR II), and the quality of evidence was evaluated by the grading of recommendations, assessment, development, and evaluation (GRADE).ResultsSixteen MAs were pooled in this review, of which five studies appraised JKIs, five appraised systemic JKIs, five papers assessed abrocitinib only, and one assessed baricitinib. Two studies were of âhighâ methodological quality and 14 MAs were of âmoderateâ quality. Eleven MAs integrated the results of JKIs and reported that JKIs provide faster onset of IGA response (RR=2.83, 95% CI [2.25, 3.56], high-quality evidence). Similarly, 10 MAs showed that JAK inhibitors were more effective in improving the EASI75 (RR=2.84, 95% CI [2.2, 3.67], high-quality evidence). Results from 12 MAs showed JKIs were active in reducing the PP-NRS (SMD=-0.49, 95% CI [-0.67, -0.32]). All MAs affirmed JKIs added no adverse effects leading to discontinuation and serious adverse events (P<0.05). However, 200mg of abrocitinib had a higher risk of acne (RR=4.34, 95% CI [1.61, 11.71), herpes zoster (RR=1.64, 95% CI [0.42, 6.39]), headache (RR=1.76, 95% CI [1.03, 3]), and nausea (RR=7.81, 95% CI [3.84, 15.87]). Upadacitinib was known to increase acne (RR=6.23, 95% CI [4.08, 9.49]), nasopharyngitis (RR=1.36, 95% CI [1.03, 1.8]) and blood creatine phosphokinase (blood CPK) (RR=2.41, 95% CI [1.47, 3.95]). Baricitinib at 2mg was associated with increased blood CPK (RR=2.25, 95% CI [1.1, 2.97]).ConclusionCompared to placebo or dupilumab, the administration of JKIs can ameliorate IGA response more effectively, improve the EASI75, and relieve pruritus without severe adverse effect, while accompanied by more acne, nasopharyngitis, headache, and digestive disturbances. The curative effect of 200 mg of abrocitinib is significant and more caution should be given in patients with gastrointestinal dysfunction, herpes zoster, and those who are acne-prone. Baricitinib and upadacitinib should be avoided in populations at high risk for cardiovascular events.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=369369, PROSPERO (CRD42022369369)
Characterizing the Interaction between Antibiotics and Humic Acid by Fluorescence Quenching Method
The method of Three-Dimensional Excitation Emission Matrix Fluorescence Spectrophotometer was used to identify the interaction mechanism between humic acid (HA) and antibiotics. The effects of antibiotic concentration, temperature, and pH on the bonding strength between HA and antibiotics were investigated. The results showed that with the increase of antibiotics concentration, the quenching effect on HA was enhanced. The quenching of HA by both oxytetracycline (OTC) and sulfadiazine (SD) is a single static quenching of the complexes, and the interaction forces are mainly a hydrogen bond and the van der Waals force. The quenching constant KsvOTC > KsvSD and the binding constant KbOTC > KbSD, indicates that HA has a more obvious quenching effect on OTC. The Kb of HA by OTC ranged from 3.223 × 103 to 12.784 × 103 L·mol−1 in the range of 298 K to 313 K, while the Kb of HA by SD ranged from 2.051 × 103 to 5.533 × 103 L·mol−1. With the increase of temperature, the quenching constant Ksv and binding constant Kb of both OTC and SD by HA gradually decrease, and the low temperature is beneficial to the interaction. The composite of OTC and HA is more stable than SD. Under neutral alkaline conditions, both OTC and SD had the strongest quenching effect on HA, and the resulting complex was the most stable. However, the Ksv and Kb of HA by OTC were greater than SD in the pH range of the experiment and the pH effect on quenching of HA by OTC (Ksv) was greater than that of SD