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Purpose: The purpose of this study was to examine characteristics of lamina cribrosa (LC) configuration in highly myopic (HM) eyes. Methods: Participants from the Beijing Eye Study 2011, free of optic nerve or retinal diseases, were randomly selected to examine LC depth (LCD) and LC tilt (LCT) using three-dimensional optical coherent tomography images of the optic nerve head (ONH). LCD and LCT were measured as the distance and angle between the LC plane with two reference planes, including the Bruch's membrane opening (BMO) plane and the peripapillary sclera (PPS) plane, respectively. Each parameter was measured in both horizontal and vertical B-scans. Results: The study included 685 individuals (685 eyes) aged 59.6 ± 7.7 years, including 72 HM eyes and 613 non-HM eyes. LCD measurements showed no significant differences between HM eyes and non-HM eyes in both horizontal (LCD-BMO = 421.83 ± 107.86 µm for HM eyes vs. 447.24 ± 104.94 µm for non-HM eyes, P = 0.18; and LCD-PPS = 406.39 ± 127.69 µm vs. 394.00 ± 101.64 µm, P = 1.00) and vertical directions (LCD-BMO = 435.78 ± 101.29 µm vs. 450.97 ± 106.54 µm, P = 0.70; and LCD-PPS = 401.62 ± 109.9 µm vs. 379.85 ± 110.35 µm, P = 0.35). However, the LCT was significantly more negative (tilted) in HM eyes than in non-HM eyes horizontally (LCT-BMO = -4.38 ± 5.94 degrees vs. -0.04 ± 5.86 degrees, P < 0.001; and LCT-PPS = -3.16 ± 5.23 degrees vs. -0.94 ± 4.71 degrees, P = 0.003), but not vertically (P = 1.00). Conclusions: Although LCD did not differ significantly between HM and non-HM eyes, LCT was more negative in HM eyes, suggesting that the temporal or inferior side of the LC was closer to the reference plane. These findings provide insights into morphological and structural changes in the LC and ONH between HM and non-HM eyes.
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Miopía Degenerativa , Disco Óptico , Tomografía de Coherencia Óptica , Humanos , Tomografía de Coherencia Óptica/métodos , Persona de Mediana Edad , Masculino , Femenino , Disco Óptico/patología , Disco Óptico/diagnóstico por imagen , Anciano , Miopía Degenerativa/diagnóstico , Imagenología Tridimensional , Beijing/epidemiología , Lámina Basal de la Coroides/patología , Lámina Basal de la Coroides/diagnóstico por imagen , Estudios Transversales , China/epidemiología , Miopía/fisiopatología , Esclerótica/patología , Esclerótica/diagnóstico por imagenRESUMEN
Epoxides are important bulk chemicals, playing irreplaceable role in the chemical industry, but facing serious pollution and low productivity in the production process. Therefore, the development of green and efficient epoxidation of olefins by stable catalysts with low prices is of great significance. In this study, a Mo-MATP catalyst was prepared by modifying Mo(CO)6 on attapulgite through Si-O bonding. Mo-MATP exhibits excellent performance (99% yield of cyclooctane oxide, CYCO) and stability (80% selectivity of CYCO after 17 cycles), highly tert-butyl hydroperoxide (TBHP) utilization, and extensive substrate scalability. Furthermore, the in-situ Fourier Transform Infrared Spectroscopy (FT-IR), Electron Spin-resonance Spectroscopy (ESR) and High Resolution Mass Spectrometry (HRMS) spectra suggest that TBHP would be activated by Mo-MATP to generate peroxyl radicals, which then oxidize alkenes to their corresponding epoxides. In this study, the stable loading of Mo would largely solve the problem of Mo loss during the catalytic process, thus providing a stable and dispersed Mo active center, enabling the catalyst to possess high catalytic performance and recycling stability.
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INTRODUCTION: The aim of the study was to investigate associations between diabetic retinopathy (DR) and chronic kidney disease (CKD) in patients with type 2 diabetes (TD2). METHODS: The participants of the cross-sectional, community-based Tongren Health Care Study underwent a detailed medical and ophthalmological examination. We defined TD2 by a fasting plasma glucose concentration of ≥7.0 mmol/L or a medical history. CKD was classified as either reduced estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 mm2 or presence of albuminuria. DR was assessed using color fundus photographs. RESULTS: Out of 62,217 participants of the Tongren Health Care Study, 5,103 (8.2%) patients had TD2. The prevalence of DR was 12.8% (95% CI, 11.8%, 13.7%), CKD was 13.3% (95% CI, 12.4%, 14.3%), and the subtypes of CKD including reduced eGFR and albuminuria was 4.6% (95% CI, 4.2%, 5.1%) and 10.1% (95% CI, 9.3%, 10.9%), respectively. DR was detectable in 21.0% of the patients with CKD, while CKD was present in 20.9% of the DR patients. Higher DR prevalence was associated with higher prevalence of albuminuria and reduced eGFR (both p < 0.05). Factors independently associated with the presence of CKD instead of DR were older age (p < 0.001, OR = 1.05), a higher body mass index (p < 0.001, OR = 1.14), a higher serum concentration of triglycerides (p < 0.001, OR = 1.26), and a lower blood glucose (p < 0.001, OR = 0.93). Having hypertension was additionally associated with the presence of reduced eGFR as compared with DR (p = 0.005, OR = 4.47). CONCLUSIONS: TD2 patients of older age and with higher body mass index, hypertension, and dyslipidemia had a higher probability of being affected by CKD rather than DR, while those with a higher blood glucose level were more prone to DR than CKD.
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Diabetes Mellitus Tipo 2 , Nefropatías Diabéticas , Retinopatía Diabética , Hipertensión , Insuficiencia Renal Crónica , Humanos , Retinopatía Diabética/epidemiología , Retinopatía Diabética/diagnóstico , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Albuminuria/diagnóstico , Estudios Transversales , Glucemia , Nefropatías Diabéticas/diagnóstico , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/epidemiología , Hipertensión/complicaciones , Tasa de Filtración Glomerular , Prevalencia , Factores de RiesgoRESUMEN
PURPOSE: Chronic kidney disease (CKD) may elevate susceptibility to age-related macular degeneration (AMD) because of shared risk factors, pathogenic mechanisms, and genetic polymorphisms. Given the inconclusive findings in prior studies, we investigated this association using extensive datasets in the Asian Eye Epidemiology Consortium. DESIGN: Cross-sectional study. PARTICIPANTS: Fifty-one thousand two hundred fifty-three participants from 10 distinct population-based Asian studies. METHODS: Age-related macular degeneration was defined using the Wisconsin Age-Related Maculopathy Grading System, the International Age-Related Maculopathy Epidemiological Study Group Classification, or the Beckman Clinical Classification. Chronic kidney disease was defined as estimated glomerular filtration rate (eGFR) of less than 60 ml/min per 1.73 m2. A pooled analysis using individual-level participant data was performed to examine the associations between CKD and eGFR with AMD (early and late), adjusting for age, sex, hypertension, diabetes, body mass index, smoking status, total cholesterol, and study groups. MAIN OUTCOME MEASURES: Odds ratio (OR) of early and late AMD. RESULTS: Among 51 253 participants (mean age, 54.1 ± 14.5 years), 5079 had CKD (9.9%). The prevalence of early AMD was 9.0%, and that of late AMD was 0.71%. After adjusting for confounders, individuals with CKD were associated with higher odds of late AMD (OR, 1.46; 95% confidence interval [CI], 1.11-1.93; P = 0.008). Similarly, poorer kidney function (per 10-unit eGFR decrease) was associated with late AMD (OR, 1.12; 95% CI, 1.05-1.19; P = 0.001). Nevertheless, CKD and eGFR were not associated significantly with early AMD (all P ≥ 0.149). CONCLUSIONS: Pooled analysis from 10 distinct Asian population-based studies revealed that CKD and compromised kidney function are associated significantly with late AMD. This finding further underscores the importance of ocular examinations in patients with CKD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Tasa de Filtración Glomerular , Degeneración Macular , Insuficiencia Renal Crónica , Humanos , Masculino , Estudios Transversales , Femenino , Persona de Mediana Edad , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/fisiopatología , Anciano , Degeneración Macular/fisiopatología , Degeneración Macular/epidemiología , Factores de Riesgo , Pueblo Asiatico/etnología , Adulto , Oportunidad Relativa , Prevalencia , Anciano de 80 o más AñosRESUMEN
The study aims to assess the thickness of the retinal outer nuclear layer (ONL), ellipsoid zone (EZ) and photoreceptor outer segment (POS) band in various macular regions and its associations with axial length and other parameters. Participants of the Beijing Eye Study 2011 underwent a series of examinations including spectral-domain optical coherence tomography of the macula. The current study included 2213 participants without retinal or optic nerve diseases (age: 61.7 ± 8.4 years; range 50-93 years); axial length: 23.15 ± 0.95 mm; range 18.96-29.15 mm). The ONL (fovea: 98.9 ± 8.8 µm), EZ (fovea: 24.1 ± 0.5 µm) and POS band (fovea: 24.3 ± 3.5 µm) were the thickest (P < 0.001) in the fovea (defined as the thinnest central point), followed by the temporal inner, nasal inner, inferior inner, superior inner, inferior outer, temporal outer, nasal outer, and superior outer region. In multivariable analysis, a thicker retinal ONL was associated (correlation coefficient r: 0.40) with shorter axial length (beta: - 0.14; P < 0.001) and shorter disc-fovea distance (beta: - 0.10; P = 0.001), after adjusting for younger age (beta: - 0.26; P < 0.001), male sex (beta: 0.24; P < 0.001), lower serum cholesterol concentration (beta: - 0.05; P = 0.04), and thicker subfoveal choroidal thickness (beta: 0.08; P < 0.001). The POS thickness increased with shorter axial length (beta: - 0.06; P < 0.001) and shorter optic disc-fovea distance (beta: - 0.05; P = 0.03), after adjusting for younger age (beta: - 0.34; P < 0.001), male sex (beta: 0.15; P < 0.001), and thicker subfoveal choroidal thickness (beta: 0.24; P < 0.001). As a conclusion, the photoreceptor ONL, EZ and POS band vary in thickness between different macular regions and differ in their correlations with axial length, disc-fovea distance, age, sex, and subfoveal choroidal thickness. The ONL thickness decrease with longer axial length and longer disc-fovea distance may point to an axial elongation-associated retinal stretching in the macula.
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Disco Óptico , Retina , Humanos , Masculino , Persona de Mediana Edad , Anciano , Coroides , Fóvea Central , Beijing , Tomografía de Coherencia Óptica/métodosRESUMEN
As the global consumption of plastics keeps increasing, the accumulated plastics in the natural environment have threatened the survival of human beings. Photoreforming, as a simple and low-energy way, could transform wasted plastic into fuel and small organic chemicals at ambient temperature. However, the previously reported photocatalysts have some drawbacks, such as low efficiency, containing precious or toxic metal. Herein, a noble-free, non-toxic, and easy prepared mesoporous ZnIn2S4 photocatalyst has been applied in photoreforming of polylactic acid (PLA), polyethylene terephthalate (PET) and polyurethane (PU), generating small organic chemicals and H2 fuel under simulated sunlight. Plastic was degraded into small organic molecules after the pretreatment, which futher acted as the substrate for photoreforming. Mesoporous ZnIn2S4 exhibits high H2 production efficiency, strong redox ability, and long-term photostability. Furthermore, mesoporous ZnIn2S4 could overcome the hindrances of dyes and additives of realistic wasted plastic bags and bottles with high decomposition efficiency, providing an efficient and sustainable strategy for the upcycling of wasted plastics.
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PURPOSE: With arterial hypertension as a global risk factor for cerebrovascular and cardiovascular diseases, we examined whether retinal blood vessel caliber and tortuosity assessed by a vessel-constraint network model can predict the incidence of hypertension. METHODS: The community-based prospective study included 9230 individuals who were followed for 5 years. Ocular fundus photographs taken at baseline were analyzed by a vessel-constraint network model. RESULTS: Within the 5-year follow-up, 1279 (18.8%) and 474 (7.0%) participants out of 6813 individuals free of hypertension at baseline developed hypertension and severe hypertension, respectively. In multivariable analysis, a higher incidence of hypertension was related to a narrower retinal arteriolar diameter ( P â<â0.001), wider venular diameter ( P â=â0.005), and a smaller arteriole-to-venule diameter ratio ( P â<â0.001) at baseline. Individuals with the 5% narrowest arteriole or the 5% widest venule diameter had a 17.1-fold [95% confidence interval (CI):7.9, 37.2] or 2.3-fold (95% CI: 1.4, 3.7) increased risk for developing hypertension, as compared with those with the 5% widest arteriole or the 5% narrowest venule. The area under the receiver operator characteristic curve for predicting the 5-year incidence of hypertension and severe hypertension was 0.791 (95% CI: 0.778, 0.804) and 0.839 (95% CI: 0.821, 0.856), respectively. Although the venular tortuosity was positively associated with the presence of hypertension at baseline ( P â=â0.01), neither arteriolar tortuosity nor venular tortuosity was associated with incident hypertension (both P â≥â0.10). CONCLUSION AND RELEVANCE: Narrower retinal arterioles and wider venules indicate an increased risk for incident hypertension within 5 years, while tortuous retinal venules are associated with the presence rather than the incidence of hypertension. The automatic assessment of retinal vessel features performed well in identifying individuals at risk of developing hypertension.
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Enfermedades Cardiovasculares , Hipertensión , Humanos , Estudios Prospectivos , Incidencia , Vasos Retinianos/diagnóstico por imagen , Hipertensión/epidemiología , Factores de Riesgo , Arteriolas , VénulasRESUMEN
Attempts to develop photocatalysts for hydrogen production from water usually result in low efficiency. Here we report the finding of photocatalysts by integrated interfacial design of stable covalent organic frameworks. We predesigned and constructed different molecular interfaces by fabricating ordered or amorphous π skeletons, installing ligating or non-ligating walls and engineering hydrophobic or hydrophilic pores. This systematic interfacial control over electron transfer, active site immobilisation and water transport enables to identify their distinct roles in the photocatalytic process. The frameworks, combined ordered π skeletons, ligating walls and hydrophilic channels, work under 300-1000 nm with non-noble metal co-catalyst and achieve a hydrogen evolution rate over 11 mmol g-1 h-1, a quantum yield of 3.6% at 600 nm and a three-order-of-magnitude-increased turnover frequency of 18.8 h-1 compared to those obtained with hydrophobic networks. This integrated interfacial design approach is a step towards designing solar-to-chemical energy conversion systems.
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We report the controllable synthesis of AuNi core-shell (c-AuNi) and Janus (j-AuNi) nanocrystals (NCs) with uniform shape, tunable size and compositions in the presence of trioctylphosphine (TOP) or triphenylphosphine (TPP). The morphology of the AuNi bimetallic NCs could be regulated by varying the structure and concentration of phosphine ligands. The ligand-directed structural evolution mechanism of AuNi bimetallic NCs was investigated and discussed in detail. When loaded on graphitic carbon nitride (GCN) for photocatalytic hydrogen generation, the obtained j-AuNi NCs showed much higher activity for hydrogen evolution than the monometallic (Au and Ni) counterparts, owing to the synergistic effect of plasmon enhanced light absorption from the Au portion and additional electron sink effect from the Ni portion. This work provides a promising route for preparing low-cost Au-based bimetallic catalysts with controllable morphologies and high activities for hydrogen production.
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Under the background of carbon dioxide emission reduction, how to realize the treatment and the high value-added conversion of typical olefin volatile organic compounds (olefin-VOCs), such as styrene, is a big challenge. In this contribution, the ceria-supported coinage metal catalysts (M/CeO2, M = Au, Ag, and Cu) are successfully synthesized by a dry mechanochemical method, and their catalytic performance for styrene-VOC epoxidation with tert-butyl hydrogen peroxide (TBHP) as an oxidant to prepare high-value styrene oxide (SO) is investigated. The oxygen vacancies of ceria play a key role in the anchoring of metal nanoparticles. After ball milling, Au(III) is partially reduced and coexists on ceria in two valence states (Au3+ and Au0), and the reactive oxygen species of the as-prepared catalyst are enhanced. The catalytic behaviors, including solvents effect, substrate concentration, oxidant ratio, catalyst dosage, reaction time, and temperature, are systematically investigated. Au/CeO2 exhibits good styrene epoxidation performance with a total styrene conversion of 94% and a SO yield of 63%, along with good reusability and substrate scalability. Thermodynamics and kinetics show that Au/CeO2 was more favorable for styrene epoxidation and this reaction is dominated by the rate of intrinsic chemical reactions on the surface of the catalyst. Based on experimental discussions and a set of characterizations (XPS, XRD, in-situ FT-IR, ESR, ESI-HSMS, etc.), the mechanism is revealed as the synergistic catalysis between the reactive oxygen species of Au/CeO2 and the peroxide radicals generated by the homolysis of TBHP.
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AIMS: To investigate the association between the backward configuration of the peripapillary sclera (PPS), measured as PPS angle (PPSA), and presence and extent of parapapillary gamma zone. METHODS: Out of the population-based Beijing Eye Study 2011, we randomly selected individuals free of optic nerve and retinal diseases. With Spectralis optical coherence tomography, we measured gamma zone (zone free of Bruch's membrane (BM)) and determined the PPSA, defined as the angle between the anterior scleral surface lines from both sides of the optic nerve head (ONH). RESULTS: The study included 678 individuals with age of 59.5±7.6 years (range: 50-90) and axial length of 23.5±1.3 mm (20.9-29.2). Gamma zone was more prevalent in eyes with larger PPSA (p=0.006) after adjustment for axial length (p<0.001) and BM opening area (p<0.001). Gamma zone width was positively associated with PPSA, axial length and BM opening area (all p<0.001) in multivariable analysis. Circular gamma zone was accompanied with larger PPSA as compared with focal gamma zone (19.9°±7.2° vs 6.3°±5.3°, p<0.001). Focal temporal gamma and focal inferior gamma had similar mean PPSA (p=0.69). However, the horizontal PPSA was significantly larger than the vertical PPSA in inferior gamma (6.9°±6.3° vs 4.7°±6.6°; p=0.005), while they were comparable in temporal gamma (6.1°±5.8° vs 6.3°±6.4°; p=0.073). CONCLUSIONS: A more backward bowing of the PPS was linearly and spatially associated with the presence, size and extent of gamma zone. It suggested that the BM and the sclera were closely related in participating the biomechanical behaviour of the ONH.
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Disco Óptico , Esclerótica , Humanos , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Beijing/epidemiología , Longitud Axial del Ojo , Lámina Basal de la Coroides , Tomografía de Coherencia Óptica/métodosRESUMEN
Metal-free 2D phosphorus-based materials are emerging catalysts for ammonia (NH3 ) production through a sustainable electrochemical nitrogen reduction reaction route under ambient conditions. However, their efficiency and stability remain challenging due to the surface oxidization. Herein, a stable phosphorus-based electrocatalyst, silicon phosphide (SiP), is explored. Density functional theory calculations certify that the N2 activation can be realized on the zigzag Si sites with a dimeric end-on coordinated mode. Such sites also allow the subsequent protonation process via the alternating associative mechanism. As the proof-of-concept demonstration, both the crystalline and amorphous SiP nanosheets (denoted as C-SiP NSs and A-SiP NSs, respectively) are obtained through ultrasonic exfoliation processes, but only the crystalline one enables effective and stable electrocatalytic nitrogen reduction reaction, in terms of an NH3 yield rate of 16.12 µg h-1 mgcat. -1 and a Faradaic efficiency of 22.48% at -0.3 V versus reversible hydrogen electrode. The resistance to oxidization plays the decisive role in guaranteeing the NH3 electrosynthesis activity for C-SiP NSs. This surface stability endows C-SiP NSs with the capability to serve as appealing electrocatalysts for nitrogen reduction reactions and other promising applications.
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The time-resolved electron paramagnetic resonance (EPR) technique under operando photochemical conditions as an efficient strategy to investigate the fast formation of abundant long-lived PINO radicals (t1/2 = 204 s) and their activation of the C(sp3)-H process has been researched. This developed method offers a pathway for investigating the properties and tracking the transformations of radical species in the photoredox reaction process.
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PURPOSE: To investigate relationships between blood pressure and the thickness of single retinal layers in the macula. METHODS: Participants of the population-based Beijing Eye Study, free of retinal or optic nerve disease, underwent medical and ophthalmological examinations including optical coherence tomographic examination of the macula. Applying a multiple-surface segmentation solution, we automatically segmented the retina into its various layers. RESULTS: The study included 2237 participants (mean age 61.8±8.4 years, range 50-93 years). Mean thicknesses of the retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer, inner nuclear layer (INL), outer plexiform layer, outer nuclear layer/external limiting membrane, ellipsoid zone, photoreceptor outer segments (POS) and retinal pigment epithelium-Bruch membrane were 31.1±2.3 µm, 39.7±3.5 µm, 38.4±3.3 µm, 34.8±2.0 µm, 28.1±3.0 µm, 79.2±7.3 µm, 22.9±0.6 µm, 19.2±3.3 µm and 20.7±1.4 µm, respectively. In multivariable analysis, higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) were associated with thinner GCL and thicker INL, after adjusting for age, sex and axial length (all p<0.0056). Higher SBP was additionally associated with thinner POS and higher DBP with thinner RNFL. For an elevation of SBP/DBP by 10 mm Hg, the RNFL, GCL, INL and POS changed by 2.0, 3.0, 1.5 and 2.0 µm, respectively. CONCLUSIONS: Thickness of RNFL, GCL and POS was inversely and INL thickness was positively associated with higher blood pressure, while the thickness of the other retinal layers was not significantly correlated with blood pressure. The findings may be helpful for refinement of the morphometric detection of retinal diseases.
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With the emergence of COVID-19, social distancing detection is a crucial technique for epidemic prevention and control. However, the current mainstream detection technology cannot obtain accurate social distance in real-time. To address this problem, this paper presents a first study on smartphone-based social distance detection technology based on near-ultrasonic signals. Firstly, according to auditory characteristics of the human ear and smartphone frequency response characteristics, a group of 18 kHz-23 kHz inaudible Chirp signals accompanied with single frequency signals are designed to complete ranging and ID identification in a short time. Secondly, an improved mutual ranging algorithm is proposed by combining the cubic spline interpolation and a two-stage search to obtain robust mutual ranging performance against multipath and NLoS affect. Thirdly, a hybrid channel access protocol is proposed consisting of Chirp BOK, FDMA, and CSMA/CA to increase the number of concurrencies and reduce the probability of collision. The results show that in our ranging algorithm, 95% of the mutual ranging error within 5 m is less than 10 cm and gets the best performance compared to the other traditional methods in both LoS and NLoS. The protocol can efficiently utilize the limited near-ultrasonic channel resources and achieve a high refresh rate ranging under the premise of reducing the collision probability. Our study can realize high-precision, high-refresh-rate social distance detection on smartphones and has significant application value during an epidemic.
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COVID-19 , Teléfono Inteligente , Humanos , Distanciamiento Físico , Tecnología , UltrasonidoRESUMEN
Artificial nitrogen conversion reactions, such as the production of ammonia via dinitrogen or nitrate reduction and the synthesis of organonitrogen compounds via C-N coupling, play a pivotal role in the modern life. As alternatives to the traditional industrial processes that are energy- and carbon-emission-intensive, electrocatalytic nitrogen conversion reactions under mild conditions have attracted significant research interests. However, the electrosynthesis process still suffers from low product yield and Faradaic efficiency, which highlight the importance of developing efficient catalysts. In contrast to the transition-metal-based catalysts that have been widely studied, the p-block-element-based catalysts have recently shown promising performance because of their intriguing physiochemical properties and intrinsically poor hydrogen adsorption ability. In this Perspective, we summarize the latest breakthroughs in the development of p-block-element-based electrocatalysts toward nitrogen conversion applications, including ammonia electrosynthesis from N2 reduction and nitrate reduction and urea electrosynthesis using nitrogen-containing feedstocks and carbon dioxide. The catalyst design strategies and the underlying reaction mechanisms are discussed. Finally, major challenges and opportunities in future research directions are also proposed.
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Developing highly efficient catalytic protocols for C-sp(3)-H bond aerobic oxidation under mild conditions is a long-desired goal of chemists. Inspired by nature, a biomimetic approach for the aerobic oxidation of C-sp(3)-H by galactose oxidase model compound CuIIL and NHPI (N-hydroxyphthalimide) was developed. The CuIIL-NHPI system exhibited excellent performance in the oxidation of C-sp(3)-H bonds to ketones, especially for light alkanes. The biomimetic catalytic protocol had a broad substrate scope. Mechanistic studies revealed that the CuI-radical intermediate species generated from the intramolecular redox process of CuIILH2 was critical for O2 activation. Kinetic experiments showed that the activation of NHPI was the rate-determining step. Furthermore, activation of NHPI in the CuIIL-NHPI system was demonstrated by time-resolved EPR results. The persistent PINO (phthalimide-N-oxyl) radical mechanism for the aerobic oxidation of C-sp(3)-H bond was demonstrated.
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Sulfonamides exhibit the advantages of wide prevalence, excellent prefunctionalization capability, and broad functional group compatibility. We report here utilizing sulfonyl imines as sulfonyl radical precursors for hydrosulfonylation of activated alkenes via visible-light irradiation. By preinstallation of functional groups into the sulfonamides and subsequent hydrosulfonylation, a variety of complex sulfones were synthesized with good efficiency under Ir/Cu dual photoredox catalysis. Additionally, this protocol expands the research in late-stage N-S bond modification in sulfonamides.
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Alquenos , Iminas , Alquenos/química , Catálisis , Iminas/química , Sulfonamidas/química , Sulfonas/químicaRESUMEN
PURPOSE: To investigate the prevalence of Gunn's dots (GDs) and associated systemic factors in adult Chinese. METHODS: A cross-sectional study enrolling participants older than 45 years from a community-based study. Gunn's dots were evaluated using fundus photography, and associated systemic factors were analyzed. Patients with any retinal or optic neuropathy were excluded. RESULTS: The study included 4,118 participants (mean age: 58.3 ± 9.9 years; male: 1,699/41.3%). Gunn's dots were found in 931 participants, with a prevalence of 22.6 ± 0.8% (95% confidence interval [CI]: 21.3-23.9). Systemic factors associated with a higher GD prevalence were younger age (odds ratio [OR]: 0.92; 95% CI: 0.91-0.93; P < 0.001), higher estimated glomerular filtration rate (eGFR) (OR: 1.01; 95% CI: 1.001-1.02; P = 0.022), and higher serum concentration of triglycerides (OR: 1.08; 95% CI: 1.004-1.16; P = 0.040). The GD prevalence was 3.5 (OR = 3.46; 95% CI: 1.06-11.35) and 4.4 (OR = 4.37; 95% CI: 1.27-15.09) times greater for participants with an eGFR of ≥90 mL/minute/1.73 m2 and an eGFR of ≥100 mL/minute/1.73 m2, respectively, as compared with participants with an eGFR of <60 mL/minute/1.73 m2. CONCLUSION: The GD prevalence (mean: 22.6%) was associated with younger age, higher eGFR, and higher serum triglyceride concentrations. The presence of GDs may serve as indicators of healthy renal function.
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Riñón , Retina , Adulto , Anciano , Estudios Transversales , Atención a la Salud , Tasa de Filtración Glomerular , Humanos , Riñón/fisiología , Masculino , Persona de Mediana EdadRESUMEN
Activation of inert propylene to produce propylene oxide (PO) is critical, but still faces some challenges in realizing higher PO selectivity and productivity. Herein, a temperature-controlled phase transfer catalyst (MoOO·DMF) is prepared for the liquid-phase epoxidation of propylene with tert-butyl hydroperoxide (TBHP) as oxidant, which exhibit the selectivity of 90.6% and the productivity of 1286.42·h-1 for PO (catalyst/propylene = 0.77 mol). Some experimental factors (solvent types, reaction temperature, contact time, the dosage of catalyst, TBHP and substrate) were investigated, and the reaction kinetics and thermodynamics are discussed. MoOO·DMF has the characteristic of both homogeneous and heterogeneous catalysts, which can be dissolved in the solvent at higher temperatures and separated from the solvent after reaction by lowering the temperature. Importantly, MoOO·DMF has a wonderful epoxidation performance for many olefins (e.g., light olefins, linear α-olefins, cyclic olefins and others). The mechanisms are proved by in-situ FT-IR, ESR and HRMS spectrum to be the selective oxygen transfer from tert-butyl peroxide radical and the MoOO bridge in MoOO·DMF to propylene. Density functional theory (DFT) calculations show that the MoOO bridge in catalyst is the key role for the activation of both the OH bond in TBHP and the CC bond in propylene, thus enhanced the epoxidation of propylene.