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The high concentration of fine particles and gaseous pollutants makes polluted areas, such as the urban setting of North China Plain (NCP) of China, a different environment for new particle formation (NPF) compared to many clean regions. Such conditions also hold for other polluted environments in this region (for instance, the rural area of NCP), yet the underlying mechanisms for NPF remain less understood, owing to the limited observations of particles in the sub−3 nm range. Comprehensive measurements, particularly covering the particle number size distribution down to 1.3 nm, were conducted at a rural background site of Gucheng (GC) in the North China Plain (NCP) from 12 November to 24 December 2018. In total, five NPF events during the 39 effective days of measurements for the campaign were identified, with the mean particle nucleation rate (J1.3) and growth rate (GR1.3–2.4) being 22.0 cm−3 s−1 and 3.9 nm h−1, respectively. During these 5 d, NPF concurrently occurred at an urban site in Beijing. Sharing similar sources and transport paths of air masses arriving at our site to that of urban Beijing, we hypothesize that NPF events during these days in this region might be a regional phenomenon. The simultaneous occurrence of NPF in both places implies that H2SO4-amine nucleation, concluded for urban Beijing there, could probably be the dominating mechanism for NPF at our rural site. The higher concentration of sulfuric acid during many non-event days compared to that of event days indicates that the content of sulfuric acid may not necessarily lead to NPF events under current atmosphere. Only when the condensation sink or coagulation sink was significantly lowered, atmospheric NPF occurred, implying that condensation sinks (CSs) and coagulation sinks (CoagSs) are the dominating factors controlling the occurrence of NPF for the present rural environment of the NCP, which is quite similar to the feature seen in urban Beijing.

Although massive data is quickly accumulating on protein sequence and structure, there is a small and limited number of protein architectural types (or structural folds). This study is addressing the following question: how well could one reveal underlying sequence-structure relationships and design protein sequences for an arbitrary, potentially novel, structural fold? In response to the question, we have developed novel deep generative models, namely, semisupervised gcWGAN (guided, conditional, Wasserstein Generative Adversarial Networks). To overcome training difficulties and improve design qualities, we build our models on conditional Wasserstein GAN (WGAN) that uses Wasserstein distance in the loss function. Our major contributions include (1) constructing a low-dimensional and generalizable representation of the fold space for the conditional input, (2) developing an ultrafast sequence-to-fold predictor (or oracle) and incorporating its feedback into WGAN as a loss to guide model training, and (3) exploiting sequence data with and without paired structures to enable a semisupervised training strategy. Assessed by the oracle over 100 novel folds not in the training set, gcWGAN generates more successful designs and covers 3.5 times more target folds compared to a competing data-driven method (cVAE). Assessed by sequence- and structure-based predictors, gcWGAN designs are physically and biologically sound. Assessed by a structure predictor over representative novel folds, including one not even part of basis folds, gcWGAN designs have comparable or better fold accuracy yet much more sequence diversity and novelty than cVAE. The ultrafast data-driven model is further shown to boost the success of a principle-driven de novo method (RosettaDesign), through generating design seeds and tailoring design space. In conclusion, gcWGAN explores uncharted sequence space to design proteins by learning generalizable principles from current sequence-structure data. Data, source codes, and trained models are available at https://github.com/Shen-Lab/gcWGAN.

Fe and Co doped Mn-Ce/TiO2 catalysts for low temperature NH3-SCR with SO2 resistance were investigated via in-situ DRIFTS, SO2-TPD and FTIR. The activity results indicated that Fe and Co co-doped catalyst with an Fe/Co molar ratio of 2:4 (2Fe4Co-MCT) showed excellent SO2 resistance (98% NO conversion) at 200 °C when compared to the Mn-Ce/TiO2 catalyst. In-situ DRIFTS and SO2-TPD results showed that SO2 reacted with NH3 to form (NH4)2SO4 or NH4HSO4 as reversible deactivation blocking the active sites. Moreover, SO2-TPD results further implied that irreversible deactivation of Mn-Ce/TiO2 occurred by SO2 due to the formation of thermal stable sulfated species (MnSO4, Ce(SO4)2 or Ce2(SO4)3) to reduce active substances. The adsorption characteristics by in-situ DRIFTS revealed that more absorbed SO3, surface sulfite/sulfate and bulk-like sulfate species were formed on Mn-Ce/TiO2 catalyst, while Fe and Co addition to Mn-Ce/TiO2 significantly decreased the sulfur adsorption. The uniform distribution of Fe and Co on the Mn-Ce/TiO2 surface stopped SO2 diffusing to the inner layer of catalyst. In-situ DRIFTS also illustrated that the SCR reaction over 2Fe4Co-MCT catalysts mainly followed by Eley–Rideal (E–R) mechanism in the presence of SO2, which the adsorbed NH3 and NH4+ species reacted with gaseous NO species to produce unstable NH4NO2 and then rapidly decomposed into N2 and H2O.

In this study, the physical properties of refractory BC (rBC) including mass concentration, core size distribution and mixing state were in-situ characterized with a single particle soot photometer (SP2) at a polluted rural site in the North China Plain in November 2018. The average rBC mass concentration is 4.12 ± 2.47 μg m−3, accounting for 6.26% of PM1 mass. Its diurnal variation shows that the rBC concentration is affected by both the local residential activities and the evolution of planetary boundary layer (PBL). And a broader rBC core mass size distribution (CMSD) can be observed in the afternoon. The CMSD show a primary mode with peak diameter (Dm) of ~222 nm, and a small secondary mode with Dm of ~687 nm. The average absolute coating thickness (ACT) of rBC particles is 50 nm and the bulk relative coating thickness (BRCT) is about 1.7, indicating a relatively high aging level of rBC. The correlation analysis between SP2-separated rBC and PMF-separated OA factors indicate that rBC with different core size (Dc) and ACT may be originated from different sources. The rBC contributed by coal combustion is distributed throughout a large Dc range (~70–500 nm). The rBC particles emitted by traffic sources have small core sizes and thin coating thickness (Dc < 180 nm and ACT 250 nm). In addition, the secondary mode of rBC particles are likely to be originated from coal combustion.

Fe and Co co-doped Mn-Ce/TiO2 (MCT) catalysts were investigated for the simultaneous removal of nitric oxide (NO) and elemental mercury (Hg0) at reaction temperature lower than 200 °C. The catalysts were characterized by Brunauer–Emmett–Teller (BET), temperature program reduction (TPR), scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The experimental results showed that the co-doped 2Fe4Co-MCT catalyst exhibited better performance for the simultaneous removal of NO and Hg0 compared to Fe or Co doped catalysts. This could be due to higher BET surface area and better redox property of 2Fe4Co-MCT catalyst. In addition, we propose that chemisorbed O2 played a dominant role in selective catalytic reduction (SCR) of NO while lattice O2 played a key role in Hg0 oxidation. The results also indicate that the introduction of Fe species enhanced the activity of SCR, whereas the introduction of Co species enhanced the oxidation of Hg0. The synergistic effect of Fe and Co species in the 2Fe4Co-MCT catalyst are also suggested to be an important mechanism for simultaneously removing NO and Hg0.

Osteoclasts are responsible for bone resorption caused by bone microstructural damage and bone-related disorders. Evidence shows that tanshinone IIA (Tan‑IIA), a traditional Chinese medicine, is used clinically as a drug for the treatment of cardiovascular and cerebrovascular diseases. However, the efficacy and mechanism underlying the effect of Tan‑IIA on the viability of osteoclasts remain to be fully elucidated. The present study investigated the therapeutic effects of Tan‑IIA on osteoblast differentiation and oxidative stress in vitro and in vivo. Cell viability was analyzed and oxidative stress was examined in the osteoblasts. Wnt1sw/sw mice were used to investigate the therapeutic effects of Tan‑IIA on spontaneous tibia fractures and severe osteopenia. The bone strength, collagen and mineral were examined in the tibia. Osteoblast activity was also analyzed in the experimental mice. The Tan‑IIA‑induced differentiation of osteoclasts and the mechanism of action were investigated in osteocytes. The data showed that Tan‑IIA treatment improved cell viability. The data also demonstrated that Tan‑IIA decreased the levels of H2O2, accumulation of reactive oxygen species and apoptosis of osteoblasts. Tan‑IIA inhibited the deleterious outcomes triggered by oxidative stress. In addition, Tan‑IIA inhibited the activation of nuclear factor (NF)‑κB and its target genes, tumor necrosis factor (TNF)‑α, inducible nitric oxide synthase and cyclooxygenase 2, and increased the levels of TNF receptor‑associated factor 1 and inhibitor of apoptosis protein‑1/2 in the osteocytes. Furthermore, it was shown that Tan‑IIA reduced the propensity to fractures and severe osteopenia in mice with osteoporosis. Tan‑IIA also exhibited improved bone strength, mineral and collagen in the bone matrix of the experimental mice. It was found that the Tan‑IIA‑mediated benefits on osteoblast activity and function were through the NF‑κB signaling pathway. Taken together, the data obtained in the present study suggested that Tan‑IIA had protective effects against oxidative stress in osteoblastic differentiation in mice with osteoporosis by regulating the NF‑κB signaling pathway.

With the consumption of energy, blackouts, and a series of social development problems, the discussion of energy security has become the focus of international attention. This paper aims to construct a universal multidimensional index system from four dimensions, and compare the energy security systems of different countries by measuring the Energy Security Index (ESI) of 19 countries of G20 and analyzing their evolution characteristics. The results of this paper show that the ESI of the G20 countries is increasing, the number of dangerous countries is decreasing, mainly concentrated in the Asian and African regions, and environmental sustainability and safety use are the main factors affecting their energy security. The security countries are mainly concentrated in the developed countries of the Americas and Europe. Since 1995, the ESI of China has continued to rise and now China is a generally safe country, which reflects China&rsquo, s continuous optimization of energy structure and continuous improvement of the relationship of energy systems and economic, population, and environmental systems.

Platelet glycoprotein Ib (GPIb) is a primary adhesion receptor and involved in platelet-related disorders. However, it is difficult to study GPIb-specific platelet stimulation using physiological ligands in vivo. GPIb-binding snake C-type lectins (snaclecs) are useful tools for exploring GPIb in vitro because they act on platelets differently. In the present study, a novel GPIb-binding snaclec, named jerdonibitin, was purified, molecular cloned and characterized from Trimeresurus jerdonii venom. On SDS-polyacrylamide gel electrophoresis, it showed a single band with an apparent molecular weight of 25 kDa under non-reducing conditions and two distinct bands with apparent molecular weights of 15 kDa (α-subunit) and 13 kDa (β-subunit) under reducing conditions. The cDNA sequences of each subunit of jerdonibitin were identified and both deduced amino acid sequences were confirmed by N-terminal protein sequencing and trypsin-digested peptide mass fingerprinting of MALDI-TOF. Sequence alignment showed that jerdonibitin is a snaclec and has sequence similarity with TSV-GPIb-BP (a GPIb-inhibitory snaclec). Jerdonibitin dose-dependently inhibited platelet aggregation induced by ristocetin or low-dose thrombin, but not by high-dose thrombin. The GPIbα was detected by affinity chromatography on jerdonibitin. In vivo, jerdonibitin also dose-dependently induced thrombocytopenia of mice and platelet counts remained at very low level after 18 h intravenous injection. In summary, a novel GPIb-inhibitory snaclec was molecular cloned and characterized, which might provide insights into investigation of how GPIb-inhibitory snaclecs work and development of new antiplatelet agents.

To compare the biomechanical characteristics of the less invasive stabilization system (LISS) and the dynamic condylar screw (DCS) in the fixation of subtrochanteric fractures of the femur so as to provide theoretical basis for choosing internal fixator in clinical application.Twelve cadaveric human femurs (35-50 years old) were selected with similar proximal femur, excluding deformities, fractures, and other lesions. The twelve femur specimens were randomly divided into 2 groups, 6 specimens per group. An 1 cm gap of osteotomy model was made in the proximal femur up to 1 cm below the lesser trochanter to simulate a comminuted subtrochanteric fracture of femur, and the distal end was embedded with denture acrylic and liquid for denture acrylic. Fracture was fixed by LISS in group A, and was fixed by DCS in group B. The specimens were fixed on Instron-8874 servo-hydraulic mechanical testing machine in a single-leg standing position, and the axial compression test and dynamic fatigue test were carried out to compare the compressive strength and the strain distribution at both sides of the fracture line.Axial compression test: the strain values of the 2 strain gauges in group A were significantly smaller than those in group B (P0.01); the vertical down displacement of the femoral head in group A was significantly smaller than that in group B (P0.01) under the same load; when the load was 600 N, the axial rigidity of group A was (209.06 +/- 18.63) N/mm, which was significantly higher than that of group B [(65.79 +/- 7.26) N/mm] (t = 3.787, P = 0.004). Dynamic fatigue test: the vertical down displacement of the femoral head in group A was significantly smaller than that in group B in the same cyclic loading cycle (P0.01); when the vertical down displacement of the femoral head was 0.5 mm, the force and the cyclic loading cycles in group A were significantly larger than those in group B (P0.01).LISS, which has good mechanical stability, can meet the requirements for subtrochanteric fracture of femur fixation in biomechanics and anatomical structures. It can be proven that the LISS internal fixator is firmer than the DCS internal fixator by biomechanical comparison.