Technological advancements have resulted in the implementation of technology in various fields. Technologies such as wireless network systems and artificial intelligence have opened new doors in ...education. The Chinese language reflects the rich tradition of the greatest civilization in the world. Therefore, the university courses in a language with excellent traditional and cultural values have to be updated concerning technological growth. This research article will study the construction of a Chinese university language learning mobile environment based on intelligent reinforcement learning technology in a wireless network environment. Reinforcement learning technology (RLT) is a machine learning training technique that provides rewards and penalties. It is a decision-making approach in which artificial intelligence will face a game-like situation. Artificial intelligence either get rewarded or penalized for its actions. This learning method will significantly increase the transmission level between the student and teacher communication. Still, identifying whether the children are attentive while listening to their online classes is one of the hardest things. Once the energy loss has been rectified, it is possible to improve the learning platform in all universities, colleges, and other educational platforms using cloud computing technologies. With the implementation of RLT, the students and the teachers will be rewarded when there is an increased performance for the Chinese learning system. The results have been recorded at a low packet rate with reduced wireless communication technology. When the learning mechanism is compared to the Q-learning (quality learning) mechanism, a 98.78% accuracy rate can be seen.
In this study, the practical accuracy (PA) of optical facial scanners for facial deformity patients in oral clinic was evaluated. Ten patients with a variety of facial deformities from oral clinical ...were included in the study. For each patient, a three-dimensional (3D) face model was acquired, via a high-accuracy industrial "line-laser" scanner (Faro), as the reference model and two test models were obtained, via a "stereophotography" (3dMD) and a "structured light" facial scanner (FaceScan) separately. Registration based on the iterative closest point (ICP) algorithm was executed to overlap the test models to reference models, and "3D error" as a new measurement indicator calculated by reverse engineering software (Geomagic Studio) was used to evaluate the 3D global and partial (upper, middle, and lower parts of face) PA of each facial scanner. The respective 3D accuracy of stereophotography and structured light facial scanners obtained for facial deformities was 0.58±0.11 mm and 0.57±0.07 mm. The 3D accuracy of different facial partitions was inconsistent; the middle face had the best performance. Although the PA of two facial scanners was lower than their nominal accuracy (NA), they all met the requirement for oral clinic use.
The genus Uncaria belongs to the family Rubiaceae, which mainly distributed in tropical regions, such as Southeast Asia, Africa and Southeast America. Their leaves and hooks have long been thought to ...have healing powers and are already being tested as a treatment for asthma, cancer, cirrhosis, diabetes, hypertension, stroke and rheumatism. The present review aims to provide systematically reorganized information on the ethnopharmacology, phytochemistry and pharmacology of the genus Uncaria to support for further therapeutic potential of this genus. To better understanding this genus, information on the stereo-chemistry and structure-activity relationships in indole alkaloids is also represented.
The literature study of this review is based on various databases search (SCIFinder, Science Direct, CNKI, Wiley online library, Spring Link, Web of Science, PubMed, Wanfang Data, Medalink, Google scholar, ACS, Tropicos, Council of Heads of Australasian Herbaria, The New York Botanical Garden, African Plants Database at Genera Botanical Garden, The Plant List and SEINet) and library search for Biological Abstract and some local books on ethnopharmacology.
19 species of the genus Uncaria are found to be important folk medicines in China, Malaysia, Phillippines, Africa and Southeast America, etc, and have been served for the treatment of asthma, rheumatism, hyperpyrexia, hypertension and headaches, etc. More than 200 compounds have been isolated from Uncaria, including indole alkaloids, triterpenes, flavonoids, phenols, phenylpropanoids, etc. As characteristic constituents, indole alkaloids have been considered as main efficacy component for hypertension, epilepsy, depressant, Parkinson’s disease and Alzheimer’s disease. In addition, pharmacokinetic and metabolism investigation reveal that the indole alkaloids are likely to be absorbed, metabolized and excreted at early time points. Moreover, the specific inhibition of CYP isozymes can regulate their hydroxylation metabolites at C-10 and C-11.
Preliminary investigations on pharmacological properties of the Uncaria species have enlightened their efficacious remedy for hypertension, asthma, cancer, diabetes, rheumatism and neurodegenerative diseases. To ensure the safety and effectiveness in clinical application, research on bioactive compounds, pharmacological mechanisms and toxicity of the genus Uncaria as well as the stereo-chemistry and structure-activity relationships of indole alkaloids seem very important.
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Polyethylene (PE) has been considered nonbiodegradable for decades. Although the biodegradation of PE by bacterial cultures has been occasionally described, valid evidence of PE biodegradation has ...remained limited in the literature. We found that waxworms, or Indian mealmoths (the larvae of Plodia interpunctella), were capable of chewing and eating PE films. Two bacterial strains capable of degrading PE were isolated from this worm’s gut, Enterobacter asburiae YT1 and Bacillus sp. YP1. Over a 28-day incubation period of the two strains on PE films, viable biofilms formed, and the PE films’ hydrophobicity decreased. Obvious damage, including pits and cavities (0.3–0.4 μm in depth), was observed on the surfaces of the PE films using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The formation of carbonyl groups was verified using X-ray photoelectron spectroscopy (XPS) and microattenuated total reflectance/Fourier transform infrared (micro-ATR/FTIR) imaging microscope. Suspension cultures of YT1 and YP1 (108 cells/mL) were able to degrade approximately 6.1 ± 0.3% and 10.7 ± 0.2% of the PE films (100 mg), respectively, over a 60-day incubation period. The molecular weights of the residual PE films were lower, and the release of 12 water-soluble daughter products was also detected. The results demonstrated the presence of PE-degrading bacteria in the guts of waxworms and provided promising evidence for the biodegradation of PE in the environment.
BackgroundTo evaluate the changes in corneal endothelium cell density (ECD) and the correlated factors after Implantable Collamer Lens (ICL) V4c implantation.MethodsIn this retrospective, consecutive ...study, 48 eyes of 25 patients with myopia who underwent ICL V4c implantation were enrolled. Patients were followed up for at least 4 years, during which manifest refraction, uncorrected distance visual acuity, corrected distance visual acuity (CDVA), intraocular pressure, ECD, anterior chamber depth, anterior chamber volume (ACV), anterior chamber angle (ACA), vault and distance from the corneal endothelium to the central ICL (C-ICL) were measured. Spearman’s correlation analysis was used to identify variables correlated with changes in ECD, and generalised estimating equation model adjusting within-patient intereye correlations was used to predict changes in ECD.ResultsAll surgeries were performed safely with no complications during follow-up (average 52±2.9 months). Safety and efficacy indices were 1.23±0.22 and 1.04±0.16, respectively. No eyes had decreased CDVA, and 67% gained one or more lines. Further, 79% were within ±0.50 D, and 100% were within ±1.0 D of the attempted refraction. Additionally, a 4.03%±2.2% reduction in ECD compared with the preoperative value was observed at the last follow-up visit. Changes in ECD were significantly correlated with vault, C-ICL, change in ACA and change in ACV. Vault was the most significant factor for changes in ECD.ConclusionsICL V4c implantation is safe and effective for myopia correction. Anterior segment biometric parameters including the vault, ACA and C-ICL may influence changes in ECD; specifically, the vault plays a major role.
The contents of lead, cadmium, chromium, copper, and nickel were determined in 25 tea samples from China, including green, yellow, white, oolong, black, Pu'er, and jasmine tea products, using ...high-resolution continuum source graphite furnace atomic absorption spectrometry. The methods used for sample preparation, digestion, and quantificational analysis were established, generating satisfactory analytical precisions (represented by relative standard deviations ranging from 0.6% to 2.5%) and recoveries (98.91–101.32%). The lead contents in tea leaves were 0.48–10.57 mg/kg, and 80% of these values were below the maximum values stated by the guidelines in China. The contents of cadmium and chromium ranged from 0.01 mg/kg to 0.39 mg/kg and from 0.27 mg/kg to 2.45 mg/kg, respectively, remaining in compliance with the limits stipulated by China's Ministry of Agriculture. The copper contents were 7.73–63.71 mg/kg; only 64% of these values complied with the standards stipulated by the Ministry of Agriculture. The nickel contents ranged from 2.70 mg/kg to 13.41 mg/kg. Consequently, more attention must be paid to the risks of heavy metal contamination in tea. The quantitative method established in this work lays a foundation for preventing heavy metal toxicity in human from drinking tea and will help establish regulations to control the contents of heavy metals in tea.
Three novel Cd(
ii
)/Zn(
ii
) coordination polymers (CPs), namely Cd(L)(BPDC)
0.5
H
2
O·0.5H
2
O (
1
), Zn
2
(L)
2
(BPDC)·2H
2
O (
2
) and Cd
2
(L)(BTC)H
2
O·3H
2
O (
3
) (L = ...4-(tetrazol-5-yl)phenyl-4,2′:6′,4′′-terpyridine, H
2
BPDC = 4,4′-biphenyldicarboxylic acid, and H
3
BTC = 1,3,5-benzenetricarboxylic acid), have been successfully synthesized and characterized. CP
1
and CP
2
display new two-dimensional double-layered honeycomb frameworks containing uncoordinated nitrogen atoms from pyridine and tetrazole rings, which can easily form hydrogen bonds with various analytes. CP
3
exhibits a 3D framework also with uncoordinated nitrogen atoms from pyridine and tetrazole rings. The fluorescence explorations indicate that CPs
1-3
exhibit strong blue luminescence and excellent chemical stability under a relatively wide range of pH conditions. It is worth noting that CPs
1-3
can quantitatively detect hippuric acid (HA), which is a metabolite of toluene in human urine, with high selectivity, sensitivity, fast response and relatively low detection limits. Moreover, the sensing mechanism of CPs
1-3
for HA can mainly be ascribed to fluorescence resonance energy transfer (FRET). CPs
1-3
could be ideal candidates as HA sensors in human urine samples for practical applications. Notably, to the best of our knowledge, we report for the first time Cd(
ii
)/Zn(
ii
)-based luminescent sensors for detecting HA in simulated urine.
Water stable Cd(
ii
)/Zn(
ii
) coordination polymers exhibit rapid, sensitive, selective and recyclable detection towards hippuric acid in simulated urine for indexing toluene exposure.
Tuning the surface strain of heterogeneous catalysts is recognized as a powerful strategy for tailoring their catalytic activity. However, a clear understanding of the strain effect in ...electrocatalysis at single‐particle resolution is still lacking. Here, we explore the electrochemical hydrogen evolution reaction (HER) of single Pd octahedra and icosahedra with the same surface bounded {111} crystal facet and similar sizes using scanning electrochemical cell microscopy (SECCM). It is revealed that tensilely strained Pd icosahedra display significantly superior HER electrocatalytic activity. The estimated turnover frequency at −0.87 V vs RHE on Pd icosahedra is about two times higher than that on Pd octahedra. Our single‐particle electrochemistry study using SECCM at Pd nanocrystals unambiguously highlights the importance of tensile strain on electrocatalytic activity and may offer new strategy for understanding the fundamental relationship between surface strain and reactivity.
Scanning electrochemical cell microscopy enables the high throughput analysis of individual well‐shaped Pd nanocrystals to estimate the intrinsic hydrogen evolution reaction catalytic activity and reveal the structural origin of surface strain for the superior activity.
Abstract
To explore any relationship between the ABO blood group and the coronavirus disease 2019 (COVID-19) susceptibility, we compared ABO blood group distributions in 2173 COVID-19 patients with ...local control populations, and found that blood group A was associated with an increased risk of infection, whereas group O was associated with a decreased risk.
The electrochemical properties of V2C and V2CT2 (T = O, S) MXenes with and without vacancy as anode materials for Na-ion and Li-ion batteries, have been studied using first-principles calculation. ...The present results indicate that the adsorption strength of Li-ion and Na-ion on V2CS2 are less than that of O-functionalized, together with a lower diffusion barrier. Simultaneously, V2CS2 monolayer exhibits lower open-circuit voltage (OCV) values of 0.72 and 0.49 V for Li- and Na-ion, respectively. Interestingly, the presence of atomic vanadium vacancy on V2CS2 monolayer exerts more prominent effects on enhancing adsorption strength than that of carbon vacancy for Li-ion and Na-ion, but with an exception for the diffusion of Li-ion and Na-ion on V2CS2 monolayer. The finding suggests that the V2CS2 monolayer is expected to be a potential candidate as anode material for Li-ion and Na-ion battery due to its lower open-circuit voltages and diffusion barriers.
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•The S-group decreased the adsorption ability of Li- and Na-ion on V2C than O-group.•The vacancy has no effects to Li- and Na-ion diffusion property on V2CS2 monolayer.•The S-group significantly reduces the high diffusion barrier of Na-ion.•The storage capacity of Li- and Na-ion reaches to 301.12 mAh/g for V2CS2 monolayer.
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