Apoptotic vesicles are required to repair DNA damage and suppress premature cellular senescence.

It is well known that DNA damage can cause apoptosis. However, whether apoptosis and its metabolites contribute to DNA repair is largely unknown. In this study, we found that apoptosis-deficient Fasmut and Bim- /- mice show significantly elevated DNA damage and premature cellular senescence, along with a significantly reduced number of 16,000 g apoptotic vesicles (apoVs). Intravenous infusion of mesenchymal stromal cell (MSC)-derived 16,000 g apoVs rescued the DNA damage and premature senescence in Fasmut and Bim-/- mice. Moreover, a sublethal dose of radiation exposure caused more severe DNA damage, reduced survival rate, and loss of body weight in Fasmut mice than in wild-type mice, which can be recovered by the infusion of MSC-apoVs. Mechanistically, we showed that apoptosis can assemble multiple nuclear DNA repair enzymes, such as the full-length PARP1, into 16,000 g apoVs. These DNA repair components are directly transferred by 16,000 g apoVs to recipient cells, leading to the rescue of DNA damage and elimination of senescent cells. Finally, we showed that embryonic stem cell-derived 16,000 g apoVs have superior DNA repair capacity due to containing a high level of nuclear DNA repair enzymes to rescue lethal dose-irradiated mice. This study uncovers a previously unknown role of 16,000 g apoVs in safeguarding tissues from DNA damage and demonstrates a strategy for using stem cell-derived apoVs to ameliorate irradiation-induced DNA damage.

Striking impacts of biomass burning on PM2.5 concentrations in Northeast China through the emission inventory improvement.

Biomass burning exerts substantial influences on air quality and climate, which in turn to further aggravate air quality. The biomass burning emissions in particular of the agricultural burning may suffer large uncertainties which limits the understanding of their impact on air quality. Based on an improved emission inventory of the Visible Infrared Imaging Radiometer Suite (VIIRS) relative to commonly used Global Fire Emissions Database (GFED), we thoroughly evaluate the impact of biomass burning on air quality and climate during the episodes of November 2017 in Northeast China which is rich in agriculture burning. The results first indicate substantial underestimates in simulated PM2.5 concentrations without the inclusion of biomass burning emission inventory, based on a regional air quality model Weather Research and Forecasting model and Community Multiscale Air Quality model (WRF-CMAQ). The addition of biomass burning emissions from GFED then reduces the bias to a certain extent, which is further reduced by replacing the agricultural fires data in GFED with VIIRS. Numerical sensitivity experiments show that based on the improved emission inventory, the contribution of biomass burning emissions to PM2.5 concentrations in Northeast China reaches 32%, contrasting to 15% based on GFED, during the episode from November 1 to 7, 2017. Aerosol direct radiative effects from biomass burning are finally elucidated, which not only reduce downward surface shortwave radiation and planetary boundary layer height, but also affect the vertical distribution of air temperature, wind speed and relative humidity, favorable to the accumulation of PM2.5. During November 1-7, 2017, the mean daily PM2.5 enhancement due to aerosol radiative effects from VIIRS_G is 16 µg m-3, a few times higher than that of 2.8 µg m-3 from GFED. The study stresses the critical role of biomass burning, particularly of small fires easily missed in the traditional low-resolution satellite products, on air quality.

Advances in the superhydrophilicity-modified titanium surfaces with antibacterial and pro-osteogenesis properties: A review.

In recent years, the rate of implant failure has been increasing. Microbial infection was the primary cause, and the main stages included bacterial adhesion, biofilm formation, and severe inhibition of implant osseointegration. Various biomaterials and their preparation methods have emerged to produce specific implants with antimicrobial or bactericidal properties to reduce implant infection caused by bacterial adhesion and effectively promote bone and implant integration. In this study, we reviewed the research progress of bone integration promotion and antibacterial action of superhydrophilic surfaces based on titanium alloys. First, the adverse reactions caused by bacterial adhesion to the implant surface, including infection and bone integration deficiency, are briefly introduced. Several commonly used antibacterial methods of titanium alloys are introduced. Secondly, we discuss the antibacterial properties of superhydrophilic surfaces based on ultraviolet photo-functionalization and plasma treatment, in contrast to the antibacterial principle of superhydrophobic surface morphology. Thirdly, the osteogenic effects of superhydrophilic surfaces are described, according to the processes of osseointegration: osteogenic immunity, angiogenesis, and osteogenic related cells. Finally, we discuss the challenges and prospects for the development of this superhydrophilic surface in clinical applications, as well as the prominent strategies and directions for future research.

Mechanical properties and marginal fit of prefabricated versus customized dental implant abutments: A comparative study.

INTRODUCTION: Dental implant abutments play an important role in the health and aesthetics of soft and hard tissues around implants. PURPOSE: To compare mechanical properties and marginal fit of prefabricated and customized dental implant abutments and provide references to evaluate the relationship between abutment choice and clinical indications. METHODS: Titanium abutments were randomly divided into prefabricated and customized abutments. Static and dynamic loads were applied according to ISO14801:2016. Mechanical properties, including fracture strength, fatigue strength, rotational torque value, and torque loss rate, were measured. The biological properties of the implant abutments were assessed using an internal marginal fit. The samples were sliced, and the internal marginal fit was examined using a scanning electron microscope before and after cyclic loading. The length of the tight contact was calculated at the level of the conical connection, lower internal connection, and screw threads. Microleakage was evaluated by immersing the samples in 1% methylene blue and measuring the absorbance. RESULTS: The fracture strengths of the prefabricated abutments were greater than those of the customized abutments before and after cyclic loading. The average fatigue strengths of the prefabricated and customized abutments were 350 and 300 N, respectively. The removal torque loss of the customized abutments was significantly greater than that of the prefabricated abutments. Significant differences were found in conical connection before loading, while the screw threads showed substantial differences between the two groups after loading. Microleakage in the customized abutments was significantly higher than that in the prefabricated abutments before and after loading. CONCLUSIONS: Prefabricated abutments showed superior mechanical and biological properties compared with customized abutments in vitro, suggesting a greater risk of mechanical and biological complications occurring with the use of customized abutments. This study provides a reference for the clinical selection of implant abutments.

The Impact of Meteorology and Emissions on Surface Ozone in Shandong Province, China, during 2014-2019.

China has been experiencing severe ozone pollution problems in recent years. While a number of studies have focused on the ozone-pollution-prone regions such as the North China Plain, Yangtze River Delta, and Pearl River Delta regions, few studies have investigated the mechanisms modulating the interannual variability of ozone concentrations in Shandong Province, where a large population is located and is often subject to ozone pollution. By utilizing both the reanalysis dataset and regional numerical model (WRF-CMAQ), we delve into the potential governing mechanisms of ozone pollution in Shandong Province-especially over the major port city of Qingdao-during summer 2014-2019. During this period, ozone pollution in Qingdao exceeded the tier II standard of the Chinese National Ambient Air Quality (GB 3095-2012) for 75 days. From the perspective of meteorology, the high-pressure ridge over Baikal Lake and to its northeast, which leads to a relatively low humidity and sufficient sunlight, is the most critical weather system inducing high-ozone events in Qingdao. In terms of emissions, biogenic emissions contribute to ozone enhancement close to 10 ppb in the west and north of Shandong Province. Numerical experiments show that the local impact of biogenic emissions on ozone production in Shandong Province is relatively small, whereas biogenic emissions on the southern flank of Shandong Province enhance ozone production and further transport northeastward, resulting in an increase in ozone concentrations over Shandong Province. For the port city of Qingdao, ship emissions increase ozone concentrations when sea breezes (easterlies) prevail over Qingdao, with the 95th percentile reaching 8.7 ppb. The findings in this study have important implications for future ozone pollution in Shandong Province, as well as the northern and coastal areas in China.

The enhanced role of atmospheric reduced nitrogen deposition in future over East Asia-Northwest Pacific.

The atmospheric nitrogen deposition plays a crucial role in natural ecosystem, and the changes in emissions substantially affect the amount of nitrogen deposition. Along with the decrease in NOx emissions and increase in NH3 emissions, the reduced nitrogen deposition may play a more important role in future. However, to what extent these changes may modify the reduced nitrogen deposition across East Asia, which is fulfilled with a large amount of nitrogen deposition, to the northwestern Pacific has not yet to be clear. Based on the results of multi-model ensemble of Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), the future changes of reduced nitrogen (NHx) deposition is firstly examined. Here we show the changes of NHx deposition flux is substantially modulated by both climate change and emissions, exhibiting an increasing trend over East Asia-Northwest Pacific in future under representative concentration pathways (RCP) 8.5 scenario, largely controlled by increase of NH3 emissions, contrasting to the oxidized nitrogen deposition which is projected to decrease. Specifically, the ratio of NHx to total nitrogen deposition in eastern China increases from 38% at present to 56% by the end of the century under RCP 8.5, indicative of a transition in the form of dominant nitrogen deposition from oxidized to reduced one. The increase is clearly discernable over the marginal seas and northwestern Pacific. Moreover, we identify a meridional shift of high wet NHx deposition from northern China in summer to southern China in the other seasons. Based on simulations from regional models Weather Research and Forecasting (WRF) and Community Multi-scale Air Quality (CMAQ), we find that the synergistically nonlinear modulation of NHx concentration and precipitation triggers the north-south shift of wet NHx deposition. The findings in this study indicate a potentially more important role of reduced nitrogen deposition on the natural ecosystem in future.

Impacts of biogenic emissions from urban landscapes on summer ozone and secondary organic aerosol formation in megacities.

The impact of biogenic emissions on ozone and secondary organic aerosol (SOA) has been widely acknowledged; nevertheless, biogenic emissions emitted from urban landscapes have been largely ignored. We find that including urban isoprene in megacities like Beijing improves not only the modeled isoprene concentrations but also its diurnal cycle. Specifically, the mean bias of the simulated isoprene concentrations is reduced from 87% to 39% by adding urban isoprene emissions while keeping the diurnal cycle the same as that in non-urban or rural areas. Further adjusting the diurnal cycle of isoprene emissions to the urban profile steers the original early morning peak of the isoprene concentration to a double quasi-peak, i.e., bell shape, consistent with observations. The efficiency of ozone generation caused by isoprene emissions in urban Beijing is found to be twice as large as those in rural areas, indicative of vital roles of urban BVOC emissions in modulating the ozone formation. Our study also shows that in the future along with NOx emission reduction, isoprene emissions from urban landscapes will become more important for the formation of ozone in urban area, and their contributions may exceed that of isoprene caused by transport from rural areas. Finally, the impact of biogenic emissions on SOA is examined, revealing that biogenic induced SOA accounts for 16% of the total SOA in urban Beijing. The effect of isoprene on SOA (iSOA) is modulated through two pathways associated with the abundance of NOx emissions, and the effect can be amplified in future when NOx emissions are reduced. The findings of our study are not limited to Beijing but also apply to other megacities or densely populated regions, suggesting an urgent need to construct an accurate emission inventory for urban landscapes and evaluate their impact on ozone and SOA in air quality planning and management.

Characterizing the distinct modulation of future emissions on summer ozone concentrations between urban and rural areas over China.

Previous studies on ozone pollution primarily focus on the characterization of ozone on a large regional scale, yet much less attention has been paid towards the contrast between urban and surrounding suburban-rural areas. As anthropogenic emissions are projected to decrease in the coming decades, the evolutions of ozone concentrations over urban and suburban-rural areas are compared using the Community Multiscale Air Quality (CMAQ) model coupled with the Weather Research and Forecasting (WRF). The top 25 city clusters are firstly identified across China based on the amount of NOx emissions and population size. At present, the averages of maximum daily 8-h (MDA8) ozone concentrations over the suburban-rural areas (65.74 ppbv) among these city clusters are higher than the corresponding urban areas (62.00 ppbv). The projections in 2050s depend on the scenarios. Under the Shared Socioeconomic Pathways (SSPs) scenarios such as SSP1-2.6, SSP2-4.5 and SSP5-8.5 indicative of primary decreases in anthropogenic emissions, the mean MDA8 ozone concentrations in suburban-rural areas decrease more than urban areas. In contrast, the gap of higher MDA8 ozone concentrations in suburban-rural than urban areas increases under SSP3-7.0 concomitant with increase in anthropogenic emissions. The strongest response to emission changes is found in SSP1-2.6, in which anthropogenic emission reduction leads to lower MDA8 ozone concentrations in the suburban-rural than urban areas, reversing the present state of higher ozone concentrations in the suburban-rural areas. The feature abovementioned regarding changes of mean MDA8 ozone concentrations is largely reproduced in the response of ozone exceedance. The finding highlights different efficacies of anthropogenic emissions in urban from suburban-rural areas. In a region like China where the population density is much higher in urban than suburban-rural regions, the benefit of ozone reduction due to large emission reductions (e.g., SSP1-2.6) is diminished to some extent because the effect is larger in suburban-rural areas.

Development and Assessment of a High-Resolution Biogenic Emission Inventory from Urban Green Spaces in China.

Biogenic volatile organic compound (BVOC) emissions have long been known to play vital roles in modulating the formation of ozone and secondary organic aerosols (SOAs). While early studies have evaluated their impact globally or regionally, the BVOC emissions emitted from urban green spaces (denoted as U-BVOC emissions) have been largely ignored primarily due to the failure of low-resolution land cover in resolving such processes, but also because their important contribution to urban BVOCs was previously unrecognized. In this study, by utilizing a recently released high-resolution land cover dataset, we develop the first set of emission inventories of U-BVOCs in China at spatial resolutions as high as 1 km. This new dataset resolved densely distributed U-BVOCs in urban core areas. The U-BVOC emissions in megacities could account for a large fraction of total BVOC emissions, and the good agreement of the interannual variations between the U-BVOC emissions and ozone concentrations over certain regions stresses their potentially crucial role in influencing ozone variations. The newly constructed U-BVOC emission inventory is expected to provide an improved dataset to enable the research community to re-examine the modulation of BVOCs on the formation of ozone, SOA, and atmospheric chemistry in urban environments.

Unveiling the dipole synergic effect of biogenic and anthropogenic emissions on ozone concentrations.

Biogenic emissions are widely known as important precursors of ozone, yet there is potentially a strong interaction and synergy between biogenic and anthropogenic emissions, including volatile organic compounds (VOCs) and nitrogen oxides (NOx), in modulating ozone formation. To a large extent, the synergy affects the effectiveness of anthropogenic emission control, thereby reshaping the O3-NOx-VOC empirical kinetic modeling approach (EKMA) diagram. Focusing on the ozone pollution period of June 2017 in the North China Plain, we design almost 500 numerical experiments using regional air quality model Community Multiscale Air Quality (CMAQ) that revealed an interesting synergic effect, defined as the contribution of biogenic emissions to ozone concentrations concomitant with a reduction in anthropogenic emissions. A quasi-EKMA diagram is constructed to delineate the contribution of biogenic emissions to ozone concentrations, indicative of a linearly amplified or nonlinearly weakened result associated with reductions in anthropogenic VOCs or NOx emissions, respectively, illustrating the dipole characteristics of the synergic effect. The reduced ozone contribution from biogenic emissions along with NOx emission reduction can be used to represent controllable biogenically induced ozone (BIO). Both the amplified and controllable BIO are tightly linked to both local emissions and regional transport, implicative of an essential role in joint regional emission control. In regard to ozone exceedance, the role of biogenic emissions may be even more important, in that its contribution is comparable to or even larger than that of anthropogenic emissions when associated with a reduction in anthropogenic emissions, which is clearly demonstrated based on the near carbon neutrality scenario shared socioeconomic pathway (SSP) 126. Meanwhile, the biogenic emissions may steer the modulation of anthropogenic emissions in the change rate of MDA8 ozone concentration. Therefore, the synergic effect of biogenic and anthropogenic emissions elucidated in this study should be carefully considered in future ozone pollution control.

Rapid and sensitive determination of doxorubicin in human whole blood by vertically-ordered mesoporous silica film modified electrochemically pretreated glassy carbon electrodes.

Direct and accurate detection of doxorubicin (DOX) in unprocessed human whole blood is of vital importance in medical diagnosis and monitoring. In this work, we demonstrate the utilization of electrochemically pretreated glassy carbon electrodes (p-GCE) modified with vertically-ordered mesoporous silica films (VMSF) for rapid and sensitive electrochemical detection of DOX. The electrochemically pretreated process is a simple, cost-effective and environmentally friendly approach for improving interface catalytic properties and introducing oxygen-containing groups into the GCE surface, which could be suitable for stably growing VMSF without any adhesive layer simultaneously retaining the underlying electrode activity. Benefiting from the highly sensitive electrode substrate of p-GCE and electrostatic preconcentration effect of VMSF, the present VMSF/p-GCE sensor was able to determine DOX with an ultrahigh sensitivity (23.94 µA µM-1) and a relatively low limit of detection (0.2 nM) and a rather wide linear range (0.5 nM to 23 µM). Furthermore, direct and reliable electrochemical detection of DOX in human whole blood without complicated sample pretreatments was achieved owing to the excellent anti-fouling and anti-interference ability of VMSF.

Revealing the modulation of boundary conditions and governing processes on ozone formation over northern China in June 2017.

In this study, ozonesonde data were used to evaluate the impact of different boundary conditions on the vertical distribution of ozone over urban Beijing. The comparison shows that the clean and static boundary conditions, referred to as PROFILE, apparently underestimate the ozone concentration over the upper troposphere and stratosphere, whereas the global chemical transport model (CTM) provides much more reasonable performance. Further investigation reveals that the boundary conditions exert larger impacts over areas with high altitudes and close distances to boundaries, such as the Tibetan Plateau, while they yield weak impacts on regions relatively far from the boundary, such as the North China Plain (NCP). Process analysis was conducted to investigate the modulation of physical and chemical processes on ozone formation in June 2017, illustrating that during the daytime of the high-O3 period, the photochemical reactions within the planetary boundary layer (PBL) almost become the only source favorable to ozone accumulation. Motivated by this phenomenon, we constructed a linear regression and found that the maximum daily 8-hr ozone (MDA8) ozone concentration was highly correlated with the surface ozone change rate and chemical reactions in the PBL during the pollution period, with MDA8 ozone exceeding 70 ppbv over NCP. Based on this relationship as well as the design of numerical experiments, we propose a strategy of dynamic emission control. Firstly, the emission reduction during the peak ozone formation period may weaken the fast chemical reactions in the PBL and subsequent surface ozone concentration. Secondly, emission reduction one or two days prior to an episode might achieve larger ozone reduction through the accumulation effect. Lastly, emission control outside of the NCP may surpass the local impact under favorable meteorological conditions. Therefore, the efficacy of dynamic emission control was striking when both the accumulation and transport effect were taken into consideration.

Effect of Massage on the TLR4 Signalling Pathway in Rats with Neuropathic Pain.

This study set out to investigate the effect of massage on the Toll-like receptor 4 (TLR4) signalling pathway in the dorsal root ganglia of rats that had undergone spinal nerve ligation (SNL), with the hypothesis that massage could be used as an analgesic. Forty female SD rats were randomly divided into 5 groups: the control group, sham-operated group, model group, sham massage group, and massage group. There were 8 rats in each group. SNL rat models were established in the model group, sham massage group, and massage group. Rats in the sham-operated group underwent surgery to expose the vertebral nerves, but no further procedures were performed. The control group consisted of intact animals. The rats in the massage group underwent massage using a massage simulation machine once a day for 14 d in succession; the hind limbs of the rats in the sham massage group were gently touched with a cloth bag once a day for 14 continuous days. The rats in the control group, the sham-operated group, and the model group did not receive any intervention and were observed for 14 d. Paw withdrawal thermal latency (PWTL) and paw withdrawal mechanical threshold (PWMT) of rats in each group were detected 1 d before modelling and at 1, 3, 7, and 14 d after modelling. Fourteen days after modelling, the expression levels of TLR4, IRAK1, TRAF6, TNF-α, and IL-6 were detected in all rats. The PWTL and PWMT of SNL rats were decreased, while these parameters were elevated after massage. SNL rats showed higher levels of TLR4, IRAK1, TRAF6, IL-6, and TNF-α, and massage effectively lowered the expression levels of these molecules. Inhibiting activation of the TLR4 signalling pathway, which can reduce the release of inflammatory factors, may be one mechanism by which massage treats neuropathic pain.

A systematic review of the efficacy comparison of acupuncture and traditional Chinese medicine in the treatment of primary dysmenorrhea.

BACKGROUND: Dysmenorrhea is one of the most common symptoms in gynecology. It refers to people who experience lower abdominal pain, swelling, backache, or another discomfort before and after menstruation or during menstruation, which seriously affects the quality of life and work. Clinically, there are many methods to treat primary dysmenorrhea, among which acupuncture and traditional Chinese medicine (TCM) are beneficial. This work aimed to test the efficacy of acupuncture and TCM in the treatment of primary dysmenorrhea and hope to supply more reliable evidence for clinical treatment. METHODS: We searched articles from the Wanfang database and China National Knowledge Infrastructure and collected the clinical, randomized, or quasi-randomized controlled trials of acupuncture compared with TCM for primary dysmenorrhea. We tested the quality and data of the included studies according to the Cochrane criteria and compiled detailed systematic reviews and meta-analysis. RESULTS: Seven articles (including 492 patients) on acupuncture and TCM for primary dysmenorrhea were included in the systematic review. Seven studies were included in the final analysis, and there was no heterogeneity among the studies (P=0.98, I2=0%). The results showed that the clinical effectiveness of acupuncture was better than TCM (OR: 4.86, 95% CI: 2.84-8.33, Z =5.75, P<0.00001). CONCLUSIONS: The efficacy of acupuncture is superior to TCM in the treatment of primary dysmenorrhea.

Characteristics and sources of PM2.5 with focus on two severe pollution events in a coastal city of Qingdao, China.

In this study, the seasonal mean PM2.5 concentration in Qingdao, a coastal city, during 2014-2018 was first analyzed and the winter, in particular of 2015, showed the highest concentration. To elucidate the sources and control factors of PM2.5, three dimensional model Weather Research and Forecasting (WRF), Community Multiscale Air Quality model (CMAQ), as well as Flexible Particle model (FLEXPART), were used. During December 2015 and January 2016, modeling results showed that the mean contribution to PM2.5 mass concentrations from local emissions in Qingdao was 25%, and the transport from north and west accounted for almost half. Over the two episodically polluted periods (29-31 December 2015; 15-17 January 2016), the local emissions in Qingdao surprisingly contributed to only 18% and 24% to PM2.5 mass concentrations, respectively, indicating the dominant contributions from other regions, such as areas outside Qingdao in Shandong and Beijing-Tianjin-Hebei (BTH). The results show the sources region and contribution may vary remarkably along with the change in the pathways of the air parcel, inferred by the FLEXPART, while the near-surface PM2.5 enhancement is largely caused by downward vertical advection and enhanced aerosol chemistry reactions, accompanied by simultaneous drop in the boundary layer height. This study also reveals that the transport contribution is sensitive to the air parcel trajectories. We, therefore, recommend the efficient emission control based on transport trajectories in short-term air quality improvement in Qingdao.