China experienced severe haze pollution in January 2013. Here we have a detailed characterization of the sources and evolution mechanisms of this haze pollution with a focus on four haze episodes ...that occurred during 10–14 January in Beijing. The main source of data analyzed is from submicron aerosol measurements by an Aerodyne Aerosol Chemical Speciation Monitor. The average PM1 mass concentration during the four haze episodes ranged from 144 to 300 µg m−3, which was more than 10 times higher than that observed during clean periods. All submicron aerosol species showed substantial increases during haze episodes with sulfate being the largest. Secondary inorganic species played enhanced roles in the haze formation as suggested by their elevated contributions during haze episodes. Positive matrix factorization analysis resolved six organic aerosol (OA) factors including three primary OA (POA) factors from traffic, cooking, and coal combustion emissions, respectively, and three secondary OA (SOA) factors. Overall, SOA contributed 41–59% of OA with the rest being POA. Coal combustion OA (CCOA) was the largest primary source, on average accounting for 20–32% of OA, and showed the most significant enhancement during haze episodes. A regional SOA (RSOA) was resolved for the first time which showed a pronounced peak only during the record‐breaking haze episode (Ep3) on 12–13 January. The regional contributions estimated based on the steep evolution of air pollutants were found to play dominant roles for the formation of Ep3, on average accounting for 66% of PM1 during the peak of Ep3 with sulfate, CCOA, and RSOA being the largest fractions (> ~ 75%). Our results suggest that stagnant meteorological conditions, coal combustion, secondary production, and regional transport are four main factors driving the formation and evolution of haze pollution in Beijing during wintertime.
Key Points
Sources and evolution processes of a record‐breaking haze episodeLarge increase of coal combustion organic aerosol during haze episodesEstimation of regional contributions from steep increases of aerosol species
Osteosarcoma (OSA) is the most common bone tumor in both humans and dogs and has a nearly ten-fold higher incidence in dogs than humans. Despite advances in the treatment of other cancers, the ...overall survival rates for OSA have stagnated for the past four decades. Therefore, there is a great need to identify novel and effective treatments. We screened a series of tyrosine kinase inhibitors and selected sorafenib, a multi-kinase inhibitor, for further evaluation alone and in combination with cisplatin, carboplatin, and doxorubicin on canine and human OSA cell lines. Our data point to synergistic effects when sorafenib is combined with doxorubicin, but not when combined with cisplatin or carboplatin, in both human and canine OSA. Based on current findings, clinical trials using a combination of doxorubicin and sorafenib in proof-of-concept studies in dogs are warranted. These studies can be carried out relatively quickly in dogs where case load is high and, in turn, provide useful data for the initiation of clinical trials in humans.
Background
To assess the association of cirrhosis and hepatocellular carcinoma (HCC) with the use of glucagon‐like peptide‐1 receptor agonists (GLP‐1RAs) versus long‐acting insulins (LAIs), which are ...the two commonly prescribed injectable glucose‐lowering agents (GLAs) for patients with type 2 diabetes (T2D) after the failure of multiple oral GLAs.
Methods
We emulated a target trial using the nationwide data of a Taiwanese cohort with T2D. Incident new users of GLP‐1RAs and LAIs during 2013–2018 were identified, and propensity score (PS) matching was applied to ensure between‐group comparability in baseline patient characteristics. The primary outcome was the composite liver disease including cirrhosis or HCC. Each patient was followed until the occurrence of a study outcome, death, or the end of 2019, whichever came first. Subdistribution hazard models were employed to assess the treatment‐outcome association. Sensitivity (e.g., stabilized inverse probability of treatment weighting analysis, time‐dependent analysis), E‐value, and negative control outcome analyses were performed to examine the robustness of study findings.
Results
We included 7171 PS‐matched pairs of GLP‐1RA and LAI users with no significant between‐group differences at baseline. Compared with LAIs, the use of GLP‐1RAs was associated with significantly reduced risks of composite liver disease (subdistribution hazard ratio 95% confidence interval: 0.56 0.42–0.76), cirrhosis (0.59 0.43–0.81), and HCC (0.47 0.24–0.93). Results were consistent across sensitivity analyses and among patients with different baseline characteristics.
Conclusion
Among T2D patients who require injectable GLAs, the use of GLP‐1RAs versus LAIs was associated with lower risks of cirrhosis and HCC.
The present research examined the effectiveness of digital storytelling (DST) on foreign language learners' English speaking and creative thinking. In this study, DST was realized in the form of an ...interdisciplinary project integrated in a partnership between an English course and a computer course, with the class time of the former devoted to the content design and that of the latter to the multimedia design of learner-generated digital stories. The participants were required to work in small groups to create their digital stories in the target language, English, under an eight-week interdisciplinary curriculum. A two-group quasi-experiment with a pretest and posttest design was then conducted to compare the participants' learning outcomes. The findings reveal the authentic and meaningful learning opportunities that DST has to offer for effectively fostering the students' development of becoming proficient English speakers and creative thinkers. Future implementations on interdisciplinary DST projects are thus recommended for educators.
SUMMARY
Mantle convection induces dynamic topography, the lithosphere's surface deflections driven by the vertical stresses from sublithospheric mantle convection. Dynamic topography has important ...influences on a range of geophysical and geological observations. Here, we studied controls on the Earth's dynamic topography through 3-D spherical models of mantle convection, which use reconstructed past 410 Myr global plate motion history as time-dependent surface mechanical boundary condition. The numerical model assumes the extended-Boussinesq approximation and includes strongly depth- and temperature-dependent viscosity and phase changes in the mantle. Our results show that removing the chemical layer above the core–mantle boundary (CMB) and including depth-dependent thermal expansivity have both a limited influence on the predicted present-day dynamic topography. Considering phase transitions in our models increases the predicted amplitude of dynamic topography, which is mainly influenced by the 410 km exothermic phase transition. The predicted dynamic topography is very sensitive to shallow temperature-induced lateral viscosity variations (LVVs) and Rayleigh number. The preservation of LVVs significantly increases the negative dynamic topography at subduction zones. A decrease (or increase) of Rayleigh number increases (or decreases) the predicted present-day dynamic topography considerably. The dynamic topography predicted from the model considering LVVs and with a Rayleigh number of 6 × 108 is most compatible with residual topography models. This Rayleigh number is consistent with the convective vigor of the Earth as supported by generating more realistic lower mantle structure, slab sinking rate and surface and CMB heat fluxes. The evolution of the surface heat flux pattern is similar to the long-term eustatic sea level change. Before the formation of Pangea, large negative dynamic topography formed between the plate convergence region of Gondwana and Laurussia. The predicted dynamic topography similar to that of present-day has already emerged by about 262 Ma. Powers for degrees 1–3 dynamic topography at 337 and 104 Ma which correspond to times of higher plate velocities and higher surface heat fluxes are larger.
•Constructed wetland configuration, TN purification and mechanisms are discussed.•Biochemical process is the main pathway to remove TN in ammonia-dominant wastewater.•Nitrification-denitrification in ...CW needs large O2 and COD consumption in sequence.•Simultaneous nitrification-denitrification can use spatial heterogeneity of biofilm.•Anammox process can save the chemical cost but needs accurate condition control.
Constructed wetland (CW) for wastewater treatment has attracted increasing attention. In this review, the system configuration optimization, purification effect and general mechanisms of nitrogen removal in CW are systematically summarized and discussed. Ammonia oxidation is a crucial and primary process for total nitrogen (TN) removal in domestic or livestock wastewater treatment. Aeration, waterdrop influent and tidal operation are three main methods to strengthen the oxygen supplement and nitrification process in CW. Aeration significantly increases the ammonia removal rate (almost 100%), followed by the removal of chemical oxygen demand (COD) and TN. Solid carbon source, iron and anode material can be filled as electron donor for the denitrification process. The co-adjustment of oxygen and carbon/electron donor can form different conditions for different nitrogen removal pathways (e.g. the simultaneous nitrification-denitrification, the partial nitrification-denitrification and the anammox process), and achieve the optimal removal of nitrogen.
This article endeavors to discuss the adaptive fuzzy funnel consensus tracking issue for uncertain nonlinear multi-agent systems (MASs) with unknown dynamics, non-affine nonlinear faults (NANFs), ...high powers (possibly different), performance constraints and fixed-time convergence. The performance constraints include pre-specified transient and steady-state tracking error behaviors. Firstly, to overcome the "explosion of complexity" issue, an enhanced nonlinear filter with adaptive parameter estimator and cubic function is constructed, which can ensure that the boundary layer errors fixed-time convergence and fully compensate their effects. Then, under the backstepping and separation function framework, a distributed algorithm is presented via Butterworth low-pass filter (BLPF) technique, funnel method and dynamic surface control (DSC) technique. The results confirm that the proposed algorithm can not only guarantee the considered MASs is practical fixed-time stability (PFTS), but also ensure the asymptotic convergence of the consensus errors and meet the constraints imposed by the funnel. Moreover, compared to the barrier Lyapunov function (BLF) technique for MASs, the considered system is more versatile, and the complex control algorithm can be avoided. Finally, simulation results are performed to verify the effectiveness of the developed theoretical findings. Note to Practitioners -It is well known that some underactuated and weakly coupled mechanical systems cannot be accurately represented by traditional low-power models. Therefore, it is of great practical significance to study high-power systems to better understand and control this kind of complex systems. Besides, in actual complex systems, actuator failures are inevitable, for example, in the process of signal processing, image processing, communication and wireless transmission, etc., may suffer from non-affine faults. Furthermore, to optimize system performance, some engineering applications often require to constraint the convergence time, the maximum error overshoot and the minimum steady-state error. Thus, the distributed fixed-time funnel performance constraint control is studied for MASs with NANFs.
Here we report a study of the 204 P450 genes in the whole genome sequence of larvae and adult Culex quinquefasciatus mosquitoes. The expression profiles of the P450 genes were compared for ...susceptible (S-Lab) and resistant mosquito populations, two different field populations of mosquitoes (HAmCq and MAmCq), and field parental mosquitoes (HAmCq(G0) and MAmCq(G0)) and their permethrin selected offspring (HAmCq(G8) and MAmCq(G6)). While the majority of the P450 genes were expressed at a similar level between the field parental strains and their permethrin selected offspring, an up- or down-regulation feature in the P450 gene expression was observed following permethrin selection. Compared to their parental strains and the susceptible S-Lab strain, HAmCq(G8) and MAmCq(G6) were found to up-regulate 11 and 6% of total P450 genes in larvae and 7 and 4% in adults, respectively, while 5 and 11% were down-regulated in larvae and 4 and 2% in adults. Although the majority of these up- and down-regulated P450 genes appeared to be developmentally controlled, a few were either up- or down-regulated in both the larvae and adult stages. Interestingly, a different gene set was found to be up- or down-regulated in the HAmCq(G8) and MAmCq(G6) mosquito populations in response to insecticide selection. Several genes were identified as being up- or down-regulated in either the larvae or adults for both HAmCq(G8) and MAmCq(G6); of these, CYP6AA7 and CYP4C52v1 were up-regulated and CYP6BY3 was down-regulated across the life stages and populations of mosquitoes, suggesting a link with the permethrin selection in these mosquitoes. Taken together, the findings from this study indicate that not only are multiple P450 genes involved in insecticide resistance but up- or down-regulation of P450 genes may also be co-responsible for detoxification of insecticides, insecticide selection, and the homeostatic response of mosquitoes to changes in cellular environment.
This study aimed to evaluate the effects of the stromal vascular fraction (SVF) and adipose-derived stem cells (ADSCs) on cartilage injury in an osteoarthritis (OA) rat model. Sodium iodoacetate ...(3 mg/50 μL) was used to induce OA in the left knee joint of rats. On day 14 after OA induction, 50 μL of SVF (5 × 10
cells), ADSCs (1 × 10
cells), or 0.9% normal saline (NS) was injected into the left knee-joint cavity of each group. The macroscopic view and histological sections revealed that the articular cartilage in the NS group was damaged, inflamed, uneven and thin, and had hyperchromatic cell infiltration. Notably, the cartilage surface had recovered to nearly normal and appeared smooth and bright on day 14 in the SVF and ADSC groups. Additionally, the white blood cell counts in the SVF and ADSC groups were higher than those in the NS group on day 14. Plasma IL-1β levels on days 7 and 14 were reduced in the SVF and ADSC groups. These results indicated that both SVF and ADSC treatments may assist in articular cartilage regeneration after cartilage injury. Cell therapy may benefit patients with OA. However, clinical trials with humans are required before the application of SVF and ADSC treatments in patients with OA.
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