Tooth loss, denture use, and all-cause and cause-specific mortality in older adults: a community cohort study

ObjectivesThe available evidence on the connections between tooth loss, denture use, and mortality from all causes or specific causes among older adults is inconclusive. Therefore, we aimed to investigate the association between tooth loss, denture use, and all-cause and cause-specific mortality in older adults.MethodsA cohort of 5,403 participants aged 65 and older were recruited in the 2014 Chinese Longitudinal Healthy Longevity Survey wave and followed up in the 2018 wave. Cox proportional hazard models were used to examine the association between the number of natural teeth, denture use, and all-cause and cause-specific mortality.ResultsDuring a mean (SD) follow-up of 3.1  years (1.3), 2,126 deaths (39.3%) occurred. Individuals with 0 and 1–9 teeth had higher mortality due to all-cause, cardiovascular disease (CVD), cancer, and other causes (all p-trend <0.05) than those with 20+ teeth. At the same time, no association was found with respiratory disease mortality. Participants who used dentures had lower mortality due to all causes [hazard ratios (HR) 0.79, 95% confidence intervals (CI) 0.71–0.88], CVD (HR 0.80, 95% CI 0.64–1.00), respiratory disease (HR 0.66, 95% CI 0.48–0.92), and other causes (HR 0.77, 95% CI 0.68–0.88) than those without dentures. Joint analysis revealed that older adults with fewer natural teeth and no dentures had higher mortality. Additionally, interaction analyses showed that the effects of the number of natural teeth on all-cause mortality were more pronounced in older adults aged <80  years (p-value for interaction = 0.03).ConclusionHaving fewer natural teeth, particularly less than 10 teeth, is linked to an increased risk of mortality from all causes, including CVD, cancer, and other causes, but not respiratory disease. The use of dentures would mitigate the adverse impact of tooth loss on all-cause and some cause-specific mortality

Magnetic Photocatalyst BiVO4/Mn-Zn ferrite/Reduced Graphene Oxide: Synthesis Strategy and Its Highly Photocatalytic Activity

Magnetic photocatalyst BiVO4/Mn-Zn ferrite (Mn1−xZnxFe2O4)/reduced graphene oxide (RGO) was synthesized by a simple calcination and reduction method. The magnetic photocatalyst held high visible light-absorption ability with low band gap energy and wide absorption wavelength range. Electrochemical impedance spectroscopies illustrated good electrical conductivity which indicated low charge-transfer resistance due to incorporation of Mn1−xZnxFe2O4 and RGO. The test of photocatalytic activity showed that the degradation ratio of rhodamine B (RhB) reached 96.0% under visible light irradiation after only 1.5 h reaction. The photocatalytic mechanism for the prepared photocatalyst was explained in detail. Here, the incorporation of RGO enhanced the specific surface area compared with BiVO4/Mn1−xZnxFe2O4.The larger specific surface area provided more active surface sites, more free space to improve the mobility of photo-induced electrons, and further facilitated the effective migration of charge carriers, leading to the remarkable improvement of photocatalytic performance. Meanwhile, RGO was the effective acceptor as well as transporter of photo-generated electron hole pairs. •O2− was the most active species in the photocatalytic reaction. BiVO4/Mn1−xZnxFe2O4/RGO had quite a wide application in organic contaminants removal or environmental pollution control

Facile Synthesis of Magnetic Photocatalyst Ag/BiVO4/Mn1−xZnxFe2O4 and Its Highly Visible-Light-Driven Photocatalytic Activity

Ag/BiVO4/Mn1−xZnxFe2O4 was synthesized with a dip-calcination in situ synthesis method. This work was hoped to provide a simple method to synthesis three-phase composite. The phase structure, optical properties and magnetic feature were confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrometer (XPS), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectrophotometer (UV-vis DRS), and vibrating sample magnetometer (VSM). The photocatalytic activity was investigated by Rhodamine B (RhB) photo-degradation under visible light irradiation. The photo-degradation rate of RhB was 94.0~96.0% after only 60 min photocatalytic reaction under visible light irradiation, revealing that it had an excellent visible-light-induced photocatalytic activity. In the fifth recycle, the degradation rate of Ag/BiVO4/Mn1−xZnxFe2O4 still reached to 94.0%. Free radical tunnel experiments confirmed the dominant role of •O2− in the photocatalytic process for Ag/BiVO4/Mn1−xZnxFe2O4. Most importantly, the mechanism that multifunction Ag could enhance photocatalytic activity was explained in detail

Oxidation Behavior and Kinetics Parameters of a Lean Coal at Low Temperature Based on Different Oxygen Concentrations

The method of dividing the “three zones” of spontaneous combustion in goaf by oxygen volume fraction is the most widely used and effective method at present. However, the oxygen volume fraction method does not consider the influence of methane concentration in goaf, which is only applicable to low-gas goaf, not high-gassy goaf. In this work, the oxidation behavior and kinetics parameters of a lean coal at low temperatures under five different oxygen concentrations, including methane and its kinetics during low-temperature oxidation, were studied using temperature programming tests and thermogravimetric tests. The results showed that the decrease of oxygen content improves the adsorption capacity of coal to absorb different atmospheres at the initial stage. In the whole reaction process, there is a negative correlation between the strong-to-weak order of exothermicity and adsorption capacity, with a significant increase in apparent activation energy E. A marked hysteresis of the precipitation time of CO and CO2 and a decrease in their precipitation amount and a rise in the initial temperature for the generation of CO and CO2 were found

The Impact of China’s Grain for Green Program on Rural Economy and Precipitation: A Case Study of Yan River Basin in the Loess Plateau

Large-scale deforestation and abandoned planting will bring about the destruction of the ecological environment and the deterioration of the climate. In 1999, China initiated its “Grain for Green” Program (GGP) to improve the ecological environment, control soil erosion, and adjust the agricultural industrial structure to promote the sustainable development of the rural economy. In this paper, economic statistics, rainfall, and remote sensing data are used to analyze the impact of the GGP on agricultural and rural economic development and regional precipitation in the hilly and gully regions of the Loess Plateau. The results show that since the implementation of the program, the employment structure of the labor force has changed and the regional economic growth and farmers’ income have increased. From 2000 to 2016, the total gross domestic product (GDP) and per capita GDP of the Yan River Basin increased. The conversion of large-scale sloping farmland to forestry and grassland resulted in the decrease of farmland area and the increase of forestry area. The maximum, minimum, and mean value of vegetation coverage increased year by year. With the increase of vegetation coverage, the surface roughness, soil water content, and evapotranspiration improved and annual average precipitation grew significantly after the implementation of the program (2000 to 2018). From 1970 to the implementation of the project (1999), the annual average rainfall decreased at the trough from 1988 to 1999, and there was an overall upward trend from 1970 to 2018. The GGP has an important impact on the economy and people’s income in the Yan River Basin, and the vegetation change caused by the variation of land use types has a certain impact on regional rainfall. Under the background of global and regional climate change, it is of great significance to fully understand the impacts of vegetation conversion on climate and its mechanism for objective assessment of driving factors in regional and global climate, as well as for scientific planning of future land use

New Insights into Mn1−xZnxFe2O4 via Fabricating Magnetic Photocatalyst Material BiVO4/Mn1−xZnxFe2O4

BiVO4/Mn1−xZnxFe2O4 was prepared by the impregnation roasting method. XRD (X-ray Diffractometer) tests showed that the prepared BiVO4 is monoclinic crystal, and the introduction of Mn1−xZnxFe2O4 does not change the crystal structure of BiVO4. The introduction of a soft-magnetic material, Mn1−xZnxFe2O4, was beneficial to the composite photocatalyst’s separation from the liquid solution using an extra magnet after use. UV-vis spectra analysis indicated that Mn1−xZnxFe2O4 enhanced the absorption intensity of visible light for BiVO4. EIS (electrochemical impedance spectroscopy) investigation revealed that the introduction of Mn1−xZnxFe2O4 enhanced the conductivity of BiVO4, further decreasing its electron transfer impedance. The photocatalytic efficiency of BiVO4/Mn1−xZnxFe2O4 was higher than that of pure BiVO4. In other words, Mn1−xZnxFe2O4 could enhance the photocatalytic reaction rate

Dy(III) Doped BiOCl Powder with Superior Highly Visible-Light-Driven Photocatalytic Activity for Rhodamine B Photodegradation

Dy-doped BiOCl powder photocatalyst was synthesized A one–step coprecipitation method. The incorporation of Dy3+ replaced partial Bi3+ in BiOCl crystal lattice system. For Rhodamine B (RhB) under visible light irradiation, 2% Dy doped BiOCl possessed highly efficient photocatalytic activity and photodegradation efficiency. The photodegradation ratio of RhB could reach 97.3% after only 30 min of photocatalytic reaction; this was more than relative investigations have reported in the last two years. The main reason was that the 4f electron shell of Dy in the BiOCl crystal lattice system can generate a special electronic shell structure that facilitated the transfer of electron from valance band to conduction band and separation of the photoinduced charge carrier. Apart from material preparation, this research is expected to provide important references for RhB photodegradation in practical applications

Facile Synthesis of Magnetic Photocatalyst Ag/BiVO4/Mn1−xZnxFe2O4 and Its Highly Visible-Light-Driven Photocatalytic Activity

Ag/BiVO4/Mn1−xZnxFe2O4 was synthesized with a dip-calcination in situ synthesis method. This work was hoped to provide a simple method to synthesis three-phase composite. The phase structure, optical properties and magnetic feature were confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrometer (XPS), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectrophotometer (UV-vis DRS), and vibrating sample magnetometer (VSM). The photocatalytic activity was investigated by Rhodamine B (RhB) photo-degradation under visible light irradiation. The photo-degradation rate of RhB was 94.0~96.0% after only 60 min photocatalytic reaction under visible light irradiation, revealing that it had an excellent visible-light-induced photocatalytic activity. In the fifth recycle, the degradation rate of Ag/BiVO4/Mn1−xZnxFe2O4 still reached to 94.0%. Free radical tunnel experiments confirmed the dominant role of •O2− in the photocatalytic process for Ag/BiVO4/Mn1−xZnxFe2O4. Most importantly, the mechanism that multifunction Ag could enhance photocatalytic activity was explained in detail