An injectable active hydrogel based on BMSC-derived extracellular matrix for cartilage regeneration enhancement.

Articular cartilage injury impairs joint function and necessitates orthopedic intervention to restore the structure and function of the cartilage. Extracellular matrix (ECM) scaffolds derived from bone marrow mesenchymal stem cells (BMSCs) can effectively promote cell adhesion, proliferation, and chondrogenesis. However, pre-shaped ECM scaffolds have limited applicability due to their poor fit with the irregular surface of most articular cartilage defects. In this study, we fabricated an injectable active ECM hydrogel from autologous BMSCs-derived ECM by freeze-drying, liquid nitrogen milling, and enzymatic digestion. Moreover, our in vitro and in vivo results demonstrated that the prepared hydrogel enhanced chondrocyte adhesion and proliferation, chondrogenesis, cartilage regeneration, and integration with host tissue, respectively. These findings indicate that active ECM components can provide trophic support for cell proliferation and differentiation, restoring the structure and function of damaged cartilage.

Interpretation of the coupling mechanism of ecological security and urbanization based on a Computation-Verification-Coupling framework: Quantitative analysis of sustainable development.

In recent decades, China's rapid urbanization has produced numerous economic benefits while simultaneously creating substantial risks to ecological security. China's 14th Five-Year Plan and the United Nations Sustainable Development Goals (SDGs) have recently explicitly called for the coordinated development of ecological security and urbanization. Given this context, it is important to explore the mechanism by which ecological security and urbanization are coupled and coordinated to promote sustainable development. In this study, an index of the relationship between ecological security and urbanization was established via high-resolution data, and a "Computation-Verification-Coupling" (CVC) framework was constructed. The accuracy of the ecological security index was verified using a linear regression model, and the coordination level between ecological security and urbanization was analyzed via a coupled coordination model (CCM). The results revealed a steady increase in the ecological security index from 2010 to 2020; the proportion of the area above the medium level increased from 63.1 % to 74.1 %. The urbanization index in core counties exhibited rapid growth, with level V urbanized areas expanding from 5.5 % to 9.9 %. The ecological security verification model produced a coefficient of determination (R²) of 0.75685, indicating a satisfactory degree of predictive capability. From 2010-2020, the coupled coordination improved, with the high coordination area accounting for 48.8 % and the extreme discoordination area decreasing from 1.8 % to 1.0 %. Coordinated development exhibited a stable progression, characterized by a cyclical evolution from initial coupling to antagonistic coupling and finally to coordinated development. This framework can be used not only to investigate the relationship between ecological security and urbanization but also to provide a quantifiable measure of progress toward achieving the SDGs.

The evolution process of ecological vulnerability and its quantitative analysis of influencing factors: a case study of Longdong area.

Ecological vulnerability is the main index to evaluate areal environmental stability and monitor the development of ecological environment. Longdong area is a typical Loess Plateau area with complex terrain, serious soil erosion, mineral resource development, and other human activities leading to the ecological vulnerability evolution of the area, but the monitoring of its ecological status and the determination of its factors are still lacking. Based on the ecological characteristics of Longdong area, this study constructed an ecological vulnerability system including natural, social, and economic data and used the fuzzy analytic hierarchy process (FAHP) to study the temporal and spatial evolution of ecological vulnerability from 2006 to 2018. A model for quantitative analysis of the evolution of ecological vulnerability and correlation of influencing factors was ultimately developed. The results showed that (1) from 2006 to 2018, the ecological vulnerability index (EVI) had a minimum value of 0.232 and a maximum value of 0.695. EVI was high in the northeast and southwest of Longdong area and low in the central region. (2) At the same time, the areas of potential vulnerability and mild vulnerability increased, and the areas of slight vulnerability, moderate vulnerability, and severe vulnerability decreased. (3) The correlation coefficient between average annual temperature and EVI exceeded 0.5 in four years, and the correlation coefficient between population density and per capita arable land area and EVI exceeded 0.5 in two years showed significant correlation. The results reflect the spatial pattern and influencing factors of ecological vulnerability in typical arid areas of northern China. Additionally, it served as a resource for researching the interrelationships of the variables affecting ecological vulnerability.

A spatial distribution - Principal component analysis (SD-PCA) model to assess pollution of heavy metals in soil.

With the rapid development of urbanization, heavy metal pollution of soil has received great attention. Over-enrichment of heavy metals in soil may endanger human health. Assessing soil pollution and identifying potential sources of heavy metals are crucial for prevention and control of soil heavy metal pollution. This study introduced a spatial distribution - principal component analysis (SD-PCA) model that couples the spatial attributes of soil pollution with linear data transformation by the eigenvector-based principal component analysis. By evaluating soil pollution in the spatial dimension it identifies the potential sources of heavy metals more easily. In this study, soil contamination by eight heavy metals was investigated in the Lintong District, a typical multi-source urban area in Northwest China. In general, the soils in the study area were lightly contaminated by Cr and Pb. Pearson correlation analysis showed that Cr was negatively correlated with other heavy metals, whereas the spatial autocorrelation analysis revealed that there was strong association in the spatial distribution of eight heavy metals. The aggregation forms were more varied and the correlation between Cr contamination and other heavy metals was lower. The aggregation forms of Mn and Cu, Zn and Pb, on the other hand, were remarkably comparable. Agriculture was the largest pollution source, contributing 65.5 % to soil pollution, which was caused by the superposition of multiple heavy metals. Additionally, traffic and natural pollution sources contributed 17.9 % and 11.1 %, respectively. The ability of this model to track pollution of heavy metals has important practical significance for the assessment and control of multi-source soil pollution.

Combining GOES-R and ECOSTRESS land surface temperature data to investigate diurnal variations of surface urban heat island.

The surface urban heat island (SUHI) phenomenon is characterized by both high spatial and temporal variability, while its diurnal (i.e., diel) variations have rarely been investigated because traditional satellites and sensors flying on polar orbits (e.g., Landsat, MODIS) have no diurnal sampling capability. Here we combined land surface temperature (LST) data from the Geostationary Operational Environmental Satellites (GOES-R) and the Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) to explore the diurnal variations of SUHI and thermal differentiation among various land covers over the Boston Metropolitan Area. With the combined use of the LST data from GOES-R and ECOSTRESS, we took advantage of the strengths of both GOES-R (i.e., high frequency in each day and night) and ECOSTRESS (i.e., much finer spatial resolution). The SUHI intensity of the urban-core and suburban areas both exhibited clear diurnal patterns for different seasons: a continuous increase in the SUHI intensity from sunrise to noon and a decrease thereafter to sunset, followed by a relatively low and constant intensity during nighttime. The LST contrasts among different land cover types were clearly larger in the daytime than at nighttime and peaked around midday. At noon in summer, the LST of 'Developed, High Intensity' was 2.6 °C higher than that of 'Developed, Medium Intensity', and about 4.6 °C higher than that of "Developed, Open Space" and "Developed, Low Intensity". Controlling the percent impervious surface in construction land at a relatively low level (e.g., below ~49%) could effectively alleviate the impacts of SUHI. Compared with GOES-R data, ECOSTRESS LST is suitable for monitoring the diurnal variations of intracity thermal environment at the subdistrict (or neighborhood) scale. Our study highlights the value of the combined use of geostationary satellite and ECOSTRESS LST in exploring the diurnal cycling of the SUHI, and can help inform urban planning and land-based climate mitigation policies in the context of climate change.

Enhanced recovery after surgery protocols in total knee arthroplasty via midvastus approach: a randomized controlled trial.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocols were rapidly adopted in many surgeries such as fast-track arthroplasty. The study aimed to investigate the impact of ERAS protocols on the clinical effect of total knee arthroplasty (TKA) via the midvastus approach. METHODS: A total of 69 patients who underwent primary unilateral TKA via the midvastus approach from October 2018 to June 2019 were enrolled and randomly divided into two groups: ERAS group and Control group. The ERAS protocols were adopted for the ERAS group and consisted of pure juice drinking 2 h before the surgery, optimization of the preoperative anesthesia plan, phased use of tourniquets, and the use of tranexamic acid as well as a drug cocktail. The operative time, first postoperative walking time, first straight leg elevation time, postoperative hospitalization time, visual analogue scale score (VAS score), Hospital for Special Surgery score (HSS score), conventional Knee Society score (KSS), and knee range of motion (ROM) were used to assess the clinical effects in the two groups. All the included patients were followed up for 12 months. RESULTS: There were no significant differences in the basic demographic information and operation time between the ERAS and Control groups (P > 0.05). The first postoperative walking time (2.11 ± 0.11 h) and first postoperative straight leg elevation time (6.14 ± 1.73 h) in the ERAS group were significantly earlier than those in the Control group (P < 0.001) and the postoperative hospitalization time was significantly shorter (3.11 ± 0.32 days). The postoperative mean VAS scores in both groups were significantly reduced compared with those before surgery (P < 0.001). The VAS scores for the ERAS group were significantly lower than those for the Control group at 1, 2, and 7 days after surgery (P < 0.001). The mean HSS scores, KSS, and knee ROM were significantly increased in both the ERAS and Control groups at 1, 3, 6, and 12 months after surgery (P < 0.001). In addition, the HSS scores, KSS, and knee ROM in the ERAS group were significantly higher than those in the Control group at 1 month after surgery (P < 0.001). CONCLUSIONS: ERAS protocols improved the clinical effects of TKA via the midvastus approach, facilitating early out-of-bed activity and comfortable postoperative rehabilitation exercise, and further increasing patient satisfaction. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04873544 .

Difference Analysis of Ecological Vulnerability and Zoning Changes of National Energy and Chemical Bases Using FAHP Method.

Ecological vulnerability zoning research is an important basis for taking targeted regional ecological environment restoration and governance measures. This study analyzes the ecological vulnerability pattern and trend in the National Energy and Chemical Base (NECB) in the typical region of the Loess Plateau using GIS (Geographic Information System) data and the fuzzy analytic hierarchy process (FAHP) approach. Based on the human activity-natural environment factor index system, 13 factors representing human activities, socioeconomics, meteorology, soil and topography are selected to build an ecological vulnerability index (EVI) system in the NECB region, which aims at identifying the regional features of eco-environment and major environmental problems in the Loess Plateau. By calculating ecological vulnerability zoning, a model of ecological vulnerability trend change is constructed to quantitatively study the overall temporal and spatial variation of ecological vulnerability. The results indicate that the medium and heavy levels of ecological vulnerability index were mostly distributed in the areas with developed energy and chemical industries, and the slight and light levels were distributed in the southern area and developed agricultural regions. A comprehensive ecological vulnerability index had a score of 2.3207 in 2015 and 2.441 in 2000, indicating that the ecological security gradually improved. Nevertheless, highly intense human activities accelerated the degradation of regional eco-environment in recent years.

Unravelling the mechanism of amitriptyline removal from water by natural montmorillonite through batch adsorption, molecular simulation and adsorbent characterization studies.

Amitriptyline (AMI) is one of the most common tricyclic antidepressant personal care medications. Due to its environmental persistence and bioaccumulation, release of AMI into the environment via wastewater streams in elevated levels could lead to significant ecological and human health impacts. In this study, the adsorption of AMI by montmorillonite (SWy-2), a naturally abundant smectite clay with sodium ions as the main interlayer cations, was investigated. Maximum AMI adsorption (276 mg/g) occurred at pH 7-8. After adsorption, examination of the adsorbent's X-ray diffraction pattern indicated that interlayer expansion had occurred, where chemical stoichiometry confirmed cation exchange as the principal adsorption mechanism. AMI adsorption reached equilibrium within 4 h, with kinetic data best fitting the pseudo-second order kinetic model (R2 = 0.98). AMI adsorption was unaffected by solution pH in the range 2-11, where adsorption was endothermic, and molecular simulations substantiated by Fourier transform infrared spectroscopy and thermogravimetric investigations indicated that the orientation of AMI molecules in the interlayer was via an amine group and a benzene ring. Overall this research shows that SWy-2 has significant potential as a low cost, effective, and geologically derived natural material for AMI removal in wastewater systems.

Exploring diurnal cycles of surface urban heat island intensity in Boston with land surface temperature data derived from GOES-R geostationary satellites.

The surface urban heat island (SUHI) is one of the most significant human-induced alterations to the Earth's surface climate and can aggravate health risks for city dwellers during heat waves. Although the SUHI effect has received growing attention, its diurnal cycles (i.e., the variations over the full 24 h within the diel cycle) are poorly understood because polar-orbiting satellites (e.g., Landsat Series, Sentinel, Terra, Aqua) only provide one or two observations over each repeat cycle (e.g., 16 days) with constant overpass time for the same area. Geostationary satellites provide high-frequency land surface temperature (LST) observations throughout the day and the night, and thereby offer unprecedented opportunities for exploring the diurnal cycles of SUHI. Here we examined how the SUHI intensity varied over the course of the diurnal cycle in the Boston Metropolitan Area using LST observations from the NOAA's latest generation of Geostationary Operational Environmental Satellites (GOES-R). GOES-R LST was strongly correlated with MODIS LST (R2 = 0.98, p < 0.0001) across urban core, suburban, and rural areas. We calculated the SUHI intensity at an hourly time step for both the urban core and suburban areas using GOES-R LST data. The maximum SUHI intensity for the urban core occurred near noon, and was +3.0 °C (12:00), +5.4 °C (12:00), +4.9 °C (11:00), and +3.7 °C (12:00) in winter, spring, summer, and autumn, respectively. The maximum intensity for the suburban area was about 3.0 °C lower in spring and summer and 2.0 °C lower in autumn and winter than that of the urban-core area. The minimum SUHI intensity occurred at nighttime, and ranged from -1.0 °C to +1.0 °C. The difference in the nighttime SUHI intensity between urban core and suburban area was insignificant for all seasons except the summer. The SUHI intensity showed similar diurnal variations across the seasons. Throughout the year, the maximum SUHI intensity (+2.7-+5.8 °C) at the urban core occurred at 11:00-14:00 (local time), while the minimum SUHI intensity (-0.6-+0.9 °C) was commonly observed at 00:00-07:00 and 17:00-23:00. We also found different relationships between SUHI intensity and potential drivers within a diurnal cycle, characterized by the strongest correlation with impervious surface area and population size during the middle of the day, and with tree canopy cover at night. Our research highlights the great potential of the new-generation geostationary satellites in revealing the detailed diurnal variations of SUHI. Our findings have implications for informing urban planning and public health risk management.

Three-Dimensional-Printed Guiding Template for Unicompartmental Knee Arthroplasty.

BACKGROUND: For unicompartmental knee arthroplasty (UKA), accurate alignment of the limb is crucial. This study is aimed at investigating the efficacy and safety of a three-dimensional printed patient-customized guiding template (3DGT) for UKA. METHODS: A total of 22 patients receiving UKA were randomly divided into the 3DGT-UKA group (n = 11) and traditional UKA group (T-UKA group; n = 11). In the 3DGT-UKA group, the line and angle of osteotomy were decided on a 3D image of the limb reconstructed from imaging data; a guiding template was then designed and printed out. The patients in the T-UKA group underwent conventional UKA. Prosthesis size, operation time, postoperative drainage, hip-knee angle (HKA), pain, and Hospital for Special Surgery (HSS) scores were recorded at day 1, week 1, month 1, and month 3 after surgery. RESULTS: There was no significant difference in the size of prostheses between the preoperatively designed and actually used in the 3DGT-UKA group (p > 0.05). HKA was comparable in 3DGT-UKA and T-UKA patients. Operation time was shorter (53.6 ± 6.4 minutes vs. 75.8 ± 7.1 minutes) and wound drainage was less (93.2 ± 3.9 mL vs. 85.2 ± 3.0 mL) in 3DGT-UKA than in T-UKA (p < 0.05). Hospital stay was shorter in the 3DGT-UKA group. The 3DGT-UKA group had a lower VAS score on day 1, week 1, and month 1 and a higher HSS score on week 1 and month 1 after surgery. No varus/valgus deformity or prosthesis loosening was observed in either group at the final follow-up. CONCLUSION: The 3D-printed patient-customized guiding template may help decrease operation time, decrease blood loss, and improve short-term clinical outcomes in patients undergoing UKA surgery.

Cytotoxicity and Potential Pathway to Vascular Smooth Muscle Cells Induced by PM2.5 Emitted from Raw Coal Chunks and Clean Coal Combustion.

Coal combustion emits a large amount of PM2.5 (particulate matters with aerodynamic diameters less than 2.5 µm) and causes adverse damages to the cardiovascular system. In this study, emissions from anthracite and bitumite were examined. Red mud (RM) acts as an additive and is mixed in coal briquettes with a content of 0-10% as a single variable to demonstrate the reduction in the PM2.5 emissions. Burnt in a regulated combustion chamber, the 10% RM-containing bitumite and anthracite briquettes showed 52.3 and 18.6% reduction in PM2.5, respectively, compared with their chunk coals. Lower cytotoxicity (in terms of oxidative stresses and inflammation factors) was observed for PM2.5 emitted from the RM-containing briquettes than those from non-RM briquettes, especially for the bitumite groups. Besides, the results of western blotting illustrated that the inhibition of NF-κB and MAPK was the potential pathway for the reduction of cytokine levels by the RM addition. The regression analyses further demonstrated that the reduction was attributed to the lower emissions of transition metals (i.e., Mn) and PAHs (i.e., acenaphthene). This pilot study provides solid evidence for the cytotoxicity to vascular smooth muscle cells induced by PM2.5 from coal combustion and potential solutions for reducing the emission of toxic pollutants from human health perspectives.

Recent anthropogenic curtailing of Yellow River runoff and sediment load is unprecedented over the past 500 y.

The Yellow River (YR) is the fifth-longest and the most sediment-laden river in the world. Frequent historical YR flooding events, however, have resulted in tremendous loss of life and property, whereas in recent decades YR runoff and sediment load have fallen sharply. To put these recent changes in a longer-term context, we reconstructed natural runoff for the middle reach of the YR back to 1492 CE using a network of 31 moisture-sensitive tree-ring width chronologies. Prior to anthropogenic interference that started in the 1960s, the lowest natural runoff over the past 500 y occurred during 1926 to 1932 CE, a drought period that can serve as a benchmark for future planning of YR water allocation. Since the late 1980s, the low observed YR runoff has exceeded the natural range of runoff variability, a consequence of the combination of decreasing precipitation and increasing water consumption by direct and indirect human activities, particularly agricultural irrigation. This reduced runoff has resulted in an estimated 58% reduction of the sediment load in the upper reach of the YR and 29% reduction in the middle reach.

Source apportionment of and potential health risks posed by trace elements in agricultural soils: A case study of the Guanzhong Plain, northwest China.

A comprehensive study aimed at improving the understanding of trace elements (TEs) pollution of agricultural soils on Guanzhong Plain, northwest China, was performed. We apportioned the sources of TEs using various methods, and assessed the health risks for inhabitants by exposure to TEs. The results showed that the mean concentration of 9 TE A, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn of 227 topsoil samples exceeded the background contents for the Guanzhong Plain but were lower than the relevant national soil quality standards. The total non-cancer risk values for adults and children were 4.3 and 9.5, respectively, and the total carcinogenic risks were 2.1 × 10-3 and 4.7 × 10-3, respectively. All these values were cause of the high health risk, and the results indicated that children were more susceptible than adults to environmental pollutants. Furthermore, Cr was the primary hazardous metal element to human health in agricultural soil, followed by Cu and As. Natural materials are the dominant sources of TEs to agricultural soil on the Guanzhong Plain, contributing 48% by mass of the total TE burden. Agricultural activities and traffic emissions contributed 29.4% and 22.6%, respectively, of the total TE burden. Even though natural source contributed most to the TE contents, anthropogenic sources contributed far more to the potential health risks posed to inhabitants of the study area. Our results show that health risk assessment in combination with TE source apportionment can serve as highly effective method in identification of primary harmfulness pollution source in the future.

A new inverse distance model to calculate the percentage contribution of various Pb sources.

Lead (Pb) isotopic composition analysis is a useful tool to accurately identify the origin of Pb in environmental media. The existing calculation method of the contribution of Pb sources from Pb isotope ratios greatly restricted the development of Pb contamination source apportionment. In the present study, a new distance model for calculating the mass proportion of Pb sources, which is based on the distance between the samples and the possible Pb sources in the Pb isotope ratios plot, was presented. The inverse distance model was applied to calculate the contribution proportion of two Pb sources in three previous studies. The average absolute differences between the proportions calculated by the conventional binary mixing equation and the inverse distance model were 0.21%, 1% and 1.9%, respectively, indicating that the new model agreeably calculated the contribution of two Pb sources. The anthropogenic sources proportion (52%) calculated by the inverse distance model of three Pb sources to park soil Pb in Shanghai was comparable to the result that was calculated by the conventional ternary mixing equation (53%), which showed the validity of the new model in calculating the contribution proportion of three Pb sources. Rational results were obtained by the inverse distance model in calculating the contribution of four Pb sources, illustrating that the new model has potential use in calculating the apportionment of four or more Pb sources. These results suggest that the inverse distance model is a simple and efficient approach for calculating the contribution proportion of various Pb contamination sources, and provides a prospective in the study of this field.

Associations between geographical environment and systolic pulmonary arterial pressure of Chinese adults: impact analysis and predictive modeling.

Since systolic pulmonary arterial pressure (SPAP) is an important diagnostic indicator for various cardiovascular diseases, it is of great significance to determine scientific SPAP reference value in clinical application. However, the SPAP reference values currently have not been applied under a unified standard, and its formulation does not consider the impacts from geographical environment which has proved to be closely associated with SPAP. This study aims to quantify the impacts of geographical factors on SPAP and formulate scientific SPAP reference values, thereby providing support for more accurate diagnosis. Measured SPAP values of 4550 healthy adults were collected from 88 cities across China, and 11 geographical factors were selected. Four geographical factors with significant impacts on SPAP were determined via correlation analysis, including two positive factors (altitude, soil organic matter) and two negative ones (longitude, annual average temperature). Then partial least-squares regression analysis (PLSR) and trend surface analysis were applied to establish predictive models. Through model test using both collected and simulated SPAP data of control points, the PLSR model was determined to have better prediction accuracy and was selected as optimal model to calculate the SPAP reference values of 2322 cities in China. The predictive results ranged from 22.09 to 31.77 mmHg. Finally, hotspot analysis and kriging interpolation method were applied to explore the spatial distribution of SPAP reference values. The result of spatial analysis shows that SPAP reference values of Chinese adults decreased gradually from the West to East in China. This study indicated the significant impacts of geographical environment on SPAP and established predictive model for determining SPAP reference values, which is expected to help enhance clinical diagnostic accuracy.

Source profiles of PM2.5 emitted from four typical open burning sources and its cytotoxicity to vascular smooth muscle cells.

This study investigated the chemical profiles of PM2.5 from open burning of electronic waste (E-waste), household garbage, wheat residue, and outdoor barbeque in a combustion chamber. Carbonaceous fractions, including polycyclic aromatic hydrocarbons (PAHs), and water-soluble ions and elements in PM2.5 were quantified. A PM2.5 exposure study was performed to detect PM2.5-induced bioreactivities in vascular smooth muscle cells (VSMCs). Among all fractions, organic carbon (OC) exhibited the highest mass contribution to PM2.5-ranging from 39.9% ±â€¯0.82% to 53.1% ±â€¯8.76%. Proportions of total water-soluble ions and total elements both followed the sequence E-waste > wheat straw > outdoor barbeque > household garbage. Because of the high burning temperature, outdoor barbeque PM2.5 exhibited the highest total quantified PAHs (29.7‰). E-waste PM2.5 exhibited the highest heavy metal contents, derived mainly from the materials in printed circuit boards. The coefficients of divergence among the four source profiles ranged from 0.47 to 0.75, indicating that the collinear problems could be avoided in source apportionment in receptor models. The induced production of reactive oxygen species exhibited a significant dose-dependent increase and followed the sequence E-waste > household garbage > outdoor barbeque > wheat residue. Similar patterns and sequence among the four sources were observed in monocyte chemoattractant protein 1 (MCP-1) and interleukin 1ß (IL-1ß) production. The data indicated that PM2.5 emitted from E-waste has the highest cytotoxicity and special protections should be aimed at mitigating it. The Pearson correlation coefficient demonstrated that elemental carbon, heavy metals, and nitrated PAHs were strongly correlated with VSMC bioreactivity. Light elements exhibited moderate negative correlations with bioreactivities, implying that light elements (e.g., Ca) could mitigate heavy metal-induced cytotoxicity. This study summarized the chemical profiles of PM2.5 from four typical open burning sources and demonstrated their high cytotoxicity to the cardiovascular system.

Volatile organic compounds emissions from traditional and clean domestic heating appliances in Guanzhong Plain, China: Emission factors, source profiles, and effects on regional air quality.

Solid (biomass and coal) fuels burned for residential heating are major sources of atmospheric volatile organic compounds (VOCs). In this study, VOC samples were collected in-situ from chimneys in 10 typical heating scenarios in rural areas of the Guanzhong Plain. A modified SUMA canister approach was then employed, followed by gas chromatography/mass spectrometry analysis. Emission factors (EFs) (as received basis) of targeted non-methane VOCs (NMVOCs) varied from 90.3 ±â€¯29.3 to 12300 ±â€¯1510 mg kg-1 in descending order of fuel wood > maize straw > bitumite ≫ anthracite (p < 0.05). Both clean stove and coal briquetting technologies effectively reduced VOC EFs compared with traditional heating methods. The EFs of methane (CH4) had similar characteristics to those of NMVOCs. However, they yielded different correlations with CO because of their differing mechanisms of formation. Coefficient of divergence (CD) values showed that a semi-gasifier has a limited effect on changing VOC profiles compared with a traditional stove using the same fuels. However, different types of fuel produce CD values over 0.50, which should therefore be classified as different sub-categories in source apportionment models. Correlation analysis showed that volatile matter content (V%) and modified combustion efficiency (MCE) were the two primary factors influencing NMVOC and CH4 emissions. A stepwise linear regression analysis showed that V%, MCE, and element nitrogen content (N%) can be used to predict total VOC (TVOCs, including CH4 and NMVOCs) emissions with regression coefficients of 0.23, -72.8 and -6.53, respectively (R2 = 0.92, p < 0.001). Ozone formation potential (OFP) EFs from burning solid fuel ranged from 72 to 18680 mg kg-1, with an approximate 50% contribution from alkenes. VOCs from burning solid fuel were equivalent to 62 to 22200 mg kg-1 secondary organic aerosol formation potential (SOAP), most of which (>95%) were contributed by aromatics. A semi-gasifier and coal briquettes were effective in reducing TVOC emissions, even when used in conjunction with a traditional stove and fuels. It is estimated that over 15,000 ton year-1 emissions can be reduced in Guanzhong Plain by adopting a semi-gasifier and coal briquettes, resulting in a 57,000 and 65,000 ton year-1 reduction of OFP and SOAP emissions, respectively. These results demonstrate that the use of clean heating technologies in Guanzhong Plain has considerable potential in relation to emissions reduction and thus provides a feasible solution to mitigate VOCs and related secondary pollutants emitted by residential solid fuel burning.

Copper-incorporated bioactive glass-ceramics inducing anti-inflammatory phenotype and regeneration of cartilage/bone interface.

Osteoarthritis not only results in cartilage lesion, but also is accompanied with subchondral bone damage caused by the inflammatory response. It is of great significance to treat osteoarthritis by regulating the immune response. As copper (Cu) plays an essential role in immune response and anti-arthritis, a copper-incorporated bioactive glass-ceramics (Cu-BGC) may achieve the aim of healing cartilage lesion and reducing inflammatory response caused by osteoarthritis. We hypothesized that the Cu2+ released from Cu-BGC scaffolds may satisfy the requirements of cartilage regeneration and anti-arthritis. Methods: 3D-printing method was employed to prepare Cu-BGC scaffolds. The stimulating effect on the chondrocytes and macrophages cultured with Cu-BGC extracts was investigated. Furthermore, the in vivo regenerative effect of Cu-BGC scaffolds on osteochondral defects was studied. Results: The incorporation of Cu2+ into BGC considerably promoted the proliferation and maturation of chondrocytes, and induced macrophages shifting to anti-inflammatory phenotype. Histological analysis demonstrated that the Cu-BGC scaffolds meaningfully improved the regeneration of cartilage and elevated the recovery of the osteochondral interface as compared with the CTR and BGC groups. The potential mechanism is related to Cu2+ ions triggering the immune response of cartilage via activating HIF signaling pathway and inhibiting the inflammatory response in osteochondral tissue. Conclusion: These results demonstrated that Cu-BGC scaffolds significantly facilitated the regeneration of cartilage and osteochondral interface, as well as inhibited inflammatory response, which may prevent the development of osteoarthritis associated with osteochondral defects.

A Global Proteomic Change in Petroleum Hydrocarbon-Degrading Pseudomonas aeruginosa in Response to High and Low Concentrations of Petroleum Hydrocarbons.

In this study, iTRAQ analysis and bioinformatics analysis were used to reveal the changes in key proteins induced by different concentrations of petroleum hydrocarbons during the biodegradation of petroleum hydrocarbons in Pseudomonas aeruginosa P6. Sixty-three proteins were identified as differentially expressed proteins, and all of them were strongly associated with the cellular processes related to the biodegradation of petroleum hydrocarbons. The results further showed that among the differentially expressed proteins, 3 chemotaxis-related proteins, 10 terminal oxidation of short-chain alkane-related proteins, and 13 transmembrane transport-related proteins were down regulated, while 1 uptake of petroleum hydrocarbon-related protein, 3 terminal oxidation of long-chain alkane-related proteins, 4 dehydrogenation-related proteins, 12 ß-oxidation-related proteins, and 2 metabolisms of acyl-CoA-related proteins were up regulated. These results indicated that during the biodegradation of petroleum hydrocarbons in P. aeruginosa P6, the activity of chemotaxis, the terminal oxidation of short-chain alkanes, and transmembrane transport decreased, while the activity of the uptake of petroleum hydrocarbons, the terminal oxidation of long-chain alkanes, dehydrogenation, ß-oxidation, and the metabolism of acyl-CoA increased under the 20,000 mg/L petroleum hydrocarbon condition compared with the 500 mg/L petroleum hydrocarbon condition. The findings revealed changes in the key proteins and the corresponding cellular process of the biodegradation of petroleum hydrocarbons in P. aeruginosa P6 under high and low concentrations of petroleum hydrocarbons and provided references for future studies.

Urban VOC profiles, possible sources, and its role in ozone formation for a summer campaign over Xi'an, China.

To insight the urban volatile organic compound (VOC) profiles and its contribution to ozone, four-time per day (8:00-9:00, 15:00-16:00, 19:00-20:00, and 23:00-24:00) off-line VOC samples were collected from 16th July to 28th July 2018 for a summer investigation campaign over Xi'an, China. The diurnal variation was significant that the lowest TVOC concentrations were observed in the midnight period (28.4 ± 25.6 ppbv) while the highest was shown in the morning (49.6 ± 40.1 ppbv). The differences of total non-methane VOCs (TVOCs) between weekdays and weekend were also significant that the weekend showed significantly high VOC levels than weekdays (p < 0.05) but did not lead to significant ambient O3 increase (p > 0.05). Isopentane, a general marker for vehicle exhaust, showed descending concentrations from morning to midnight and good correlation with vehicle numbers on road, indicating a potential source to the VOCs at this site. The results from PMF proved that vehicular exhaust was the largest source to the VOCs in this study (64.4%). VOC categories showed a reverse sequence in abundance of concentrations and OFP contributions that alkenes showed the highest OFPs although with the lowest abundance in TOVCs due to their high reactivity in photochemical reactions. High OFPs from ethylene and isopentane indicated that vehicular emissions could be the largest potential OFP source in this site. OFPs from isoprene (from 1.85 to 13.4 ppbv) indicated that biogenic VOCs should not be negligible in urban Xi'an city when controlling O3 pollutants. Comparison of two OFP methods was conducted and MIR method was proved to be more reasonable and scientific in summer Xi'an. Therefore, vehicular emission, the largest contributor to ambient VOCs and also OFPs, as well as biological source should be priority controlled in guiding VOC emissions and reducing O3 control policies.