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In order to explore the spatiotemporal variation characteristics and driving mechanism of water quality in the Xiangjiang River Basin, the data of 16 water quality parameters at 113 stations over 26 years from 1990 to 2016 in the Xiangjiang River Basin were collected for synthetically assessing the water quality and identifying its main pollutants through the water quality index and other methods. The causal mechanism of water quality, especially the driving effect of water level and land use pattern, was analyzed. The results showed that： ① The overall water quality grade of the Xiangjiang River Basin during the study period was "good." However, the water quality deteriorated first （from 1990 to 2003） and then improved （from 2004 to 2016）. The season variation in water quality was not obvious, but the water quality fluctuation of the wet season was larger. The water pollution load of the main stream decreased successively from the middle reaches, downstream reaches, and upstream reaches. The upstream tributaries had the best water quality, whereas areas with poor water quality were mainly distributed at the mouth of the middle and downstream tributaries, especially in areas where multiple tributaries converged. ② Toxic heavy metals had the characteristics of toxicity, persistence, and bioaccumulation. If they exceeded a certain concentration in water, they were difficult to purify, posing great harm to the natural environment and human health. The toxic metal index （CI1） was the leading factor affecting water quality, in which Hg and Cd were the main parameters affecting the overall water quality of the Xiangjiang River Basin. ③ The water level had a positive impact on the water quality of the Xiangjiang River by diluting environmental parameters. Land type had little effect on heavy metal concentration, whereas forest land could improve water quality. Grassland had a negative correlation with permanganate index over a large scale range （≥ 5 km）. The increase in water bodies, arable land, and impermeable surface areas within the watershed increased the probability of high fecal coliform concentration in the water body. ④ With the increase in buffer distance, the water quality explained by the land use pattern increased. On the scale of 10 km buffer zone in the riparian zone, the explanation degree by land use pattern on water quality was the highest, which was an effective scale for water quality control of the Xiangjiang River. This research showed that the driving factors of heavy metal pollution and other pollution were different, but their regional differences were all obvious in the Xiangjiang River Basin. Therefore, pollution control should be classified and taken according to local conditions.

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Trifluoromethyl cationic carbyne (CF3 C+ :) possessing dual carbene-carbocation behavior emulated as trifluoromethyl metal-carbynoid (CF3 C+ =M) has not been explored yet, and its reaction characteristics are unknown. Herein, a novel α-diazotrifluoroethyl sulfonium salt was prepared and used in Rh-catalyzed three-component [2+1+2] cycloadditions for the first time with commercially available N-fused heteroarenes and nitriles, yielding a series of imidazo[1,5-a] N-heterocycles that are of interest in medicinal chemistry, in which the insertion of trifluoromethyl Rh-carbynoid (CF3 C+ =Rh) into C=N bonds of N-fused heteroarenes was involved. This strategy demonstrates synthetic applications in late-stage modification of pharmaceuticals, construction of CD3 -containing N-heterocycles, gram-scale experiments, and synthesis of phosphodiesterase 10A inhibitor analog. These highly valuable and modifiable imidazo[1,5-a] N-heterocycles exhibit good antitumor activity in vitro, thus demonstrating their potential applications in medicinal chemistry.

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Animals exhibit a variety of strategies to avoid predation; spiders are no exception. We explored whether webbuilding spiders that differ in the architecture of their webs exhibit morphologies or behaviors suggestive of antipredator strategies that trade-off with the degree of protection offered by their webs. Spiders build webs of 3 types: the more protected tangles and sheet-and-tangles, which are three-dimensional (3D), and the more exposed orbs, which are two-dimensional (2D), both with or without a refuge. We hypothesize that spiders whose webs offer greater protection—a 3D architecture or a refuge—will be less likely to be armored or brightly colored when compared to spiders without these protections. We collected data on 446 spiders and their webs in 2 lowland tropical rainforest sites. We show that 2D web builders with no refuges tended to be brightly colored (background contrasting) and spiny (spiky), whereas those with refuges tended to blend against the background of their refuges. 3D web builders, on the other hand, were neither cryptic nor brightly colored nor armored but were more likely to drop out of the web upon simulated predator contact. These results support the hypothesis that web-building spiders tend to be protected either through the architecture of their webs or their morphology and behavior, suggesting a trade-off between different types of antipredator strategies.

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Quantum key distribution (QKD) uses individual light quanta in quantum superposition states to guarantee unconditional communication security between distant parties. However, the distance over which QKD is achievable has been limited to a few hundred kilometres, owing to the channel loss that occurs when using optical fibres or terrestrial free space that exponentially reduces the photon transmission rate. Satellite-based QKD has the potential to help to establish a global-scale quantum network, owing to the negligible photon loss and decoherence experienced in empty space. Here we report the development and launch of a low-Earth-orbit satellite for implementing decoy-state QKD-a form of QKD that uses weak coherent pulses at high channel loss and is secure because photon-number-splitting eavesdropping can be detected. We achieve a kilohertz key rate from the satellite to the ground over a distance of up to 1,200 kilometres. This key rate is around 20 orders of magnitudes greater than that expected using an optical fibre of the same length. The establishment of a reliable and efficient space-to-ground link for quantum-state transmission paves the way to global-scale quantum networks.

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Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers.

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TNF-α, one of the most potent pro-inflammatory cytokines, plays a critical role in inhibition of osteoblast differentiation and bone regeneration in persistent inflammatory microenvironment. To explore the mechanism, quantitative proteomics based on iTRAQ and MRM was employed. The results showed 6 proteins involved in BMP-2 induced osteoblast differentiation inhibition by TNF-α: Periostin, Protein S100-A4, ATPase inhibitor, Cytochrome b5, SERCA3, and ELP2. The altered proteins were involved in molecular transport, tissue development, energy metabolism, and inflammation. One specific protein, ELP2 (STAT3-interacting protein 1, StIP1) up-regulated in the inhibition of osteoblast differentiation by TNF-α was verified to play a critical role in STAT3 pathway. Overexpression or knockdown of ELP2 in C2C12 and MC3T3-E1 cells affected osteoblast differentiation inhibition induced by TNF-α. These results highlight the function of ELP2 in inflammatory microenvironment, ELP2 up-regulation and STAT3 pathway activation may down-regulate BMPR2, then BMP-2 was blocked and osteoblast differentiation inhibited. The protein-expression profile revealed here should offer at least partly new clues to understand the mechanism of osteoblast differentiation inhibition by inflammation. BIOLOGICAL SIGNIFICANCE: Persistent inflammation is always associated with osteogenesis and affects this balance to reduce bone mass including traumatic open bone fracture, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), but the cellular mechanisms are not fully elucidated. Tumor necrosis factor-α (TNF-α) is one of the most potent pro-inflammatory cytokines and is known to be a catabolic factor in these inflammatory reaction of diseases. We show for the first time using proteomics methods that in inflammatory microenvironment, osteoblast differentiation will be inhibited by TNF-α induced ELP2 up-regulation and STAT3 pathway activation. Our results are significant since they point to targeting ELP2 activity as a novel therapeutic option to limit the inhibition of osteoblast differentiation by inflammatory microenvironment.

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Anurans often have species-specific vocalizations. To quantify and compare the characteristics of anuran calls in Gutianshan National Nature Reserve, Zhejiang Province, we recorded the advertisement calls of eight species belonging to four families (Ranidae, Microhylidae, Megophryidae and Bufonidae) from June to September 2012 using Sony ICD-FX8 IC recorders. All recordings were analyzed using the "Praat" software. Five acoustics parameters were measured, including temporal traits (call duration, number of notes or pulse number/call) and spectral traits (fundamental frequency, the first three formants and dominant frequency). The characteristic parameters of Microhyla ornate and Fejervarya limnocharis calls were different as were the calls of some populations of the same species recorded in different regions. The advertisement calls of the eight species were specific. Our study has provided a useful reference for identifying the calls of some common Chinese anurans.

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BACKGROUND: The aim of this study was to determine the effectiveness and short-term outcomes of endovenous laser therapy (EVLT) combined with pinhole high ligation (PHL) in the treatment of great saphenous varicose veins. METHODS: From February 2011 to May 2012, 200 patients with great saphenous varicose veins were treated using combined EVLT and PHL. Sixty-eight of them had concurrent TriVex suction. There were 118 men and 82 women with a median age of 61 (range 28-82) years. All patients had more than one of the following presentations, including lower extremity heaviness, pain, edema, varicose vein, skin changes, or ulceration. Based on the CEAP clinical classification, 20 patients had C2, 85 had C3, 48 had C4, 23 had C5, and 24 had C6 chronic venous disease. Ninety patients had VV involving the left lower extremity, 56 involving the right lower extremity, and 54 involving the bilateral lower extremities. Duplex ultrasound (US) was performed for all the 200 patients, and showed great saphenous valve dysfunction and reflux in 148 patients. Fifty-two of the 200 patients had concurrent mild femoral vein reflux. Deep venous thrombosis (DVT) was ruled out in all the patients. RESULTS: Technical success rate of PHL and laser ablation was 100%. Median follow-up was 9 months, ranging from 3 to 20 months. Symptoms were resolved or significantly improved in all patients after surgery. The ulcers healed in 23 of the 24 patients (96%) within 3 months. Ten patients developed subcutaneous hematoma, and 8 had slightly worsening edema. Ten patients with complications of numbness due to saphenous nerve burning injury were treated with mecobalamin, and the numbness sensation improved within 1 month and disappeared within 3 months. Nine patients sustained saphenous vein thrombophlebitis postoperatively and were treated with ibuprofen and a heating pad. There was no recanalization of the great saphenous vein, deep venous thrombosis (DVT), or deaths in this group of patients. CONCLUSIONS: Combined EVLT and PHL are less invasive and are effective in the treatment of symptomatic great saphenous varicose veins. PHL prevents DVT, and significantly decreases recanalization of the great saphenous vein after endovenous laser ablation. Short-term outcomes have been satisfactory, but long-term follow-up is needed.

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OBJECTIVE: To evaluate three alternative methods for LD50 test-Fixed Dose Procedure (FDP), the Acute Toxic Class Method (ATC) and Up and Down Procedure (UDP). METHODS: Female SD rats (8-12 weeks of age, 160-200 g) were used. Three alternative methods from OECD were applied to assess 22 chemicals (10 cosmetic raw materials and 12 raw materials of personal and home care products). The toxicity ranking for tested chemicals was established according to Globally Harmonized System (GSH). The results LD50 test were compared for the consistency and correlation between alternative methods and traditional test. RESULTS: For cosmetic raw materials, the concordance rate of the three alternative methods was 80% (8/10); for raw material of personal and home care products, the concordance rates of FDP, ATC and UDP was 91.7% (11/12), 75.0% (9/12) and 83.0% (10/12), respectively. The number of animals required in three alternative methods was significantly lower than that in traditional test (P < 0.05), but the time required in three alternative methods was significantly higher than that in traditional test (P < 0.05). CONCLUSIONS: High consistency and correlation were found between each alternative method and LD50 test. FDP may be more potential when applied to assess acute oral toxicity of cosmetic raw materials.

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OBJECTIVE: To study the effects of combination of angiopoietin-1 (ANG-1) and vascular endothelial growth factor165 (VEGF165) gene transfer mediated by recombinant adeno-associated viral vector on the neovascularization in chronic ischemic porcine myocardium. METHODS: An ameroid constrictor was implanted around the left circumflex coronary artery (LCX) via endoscopy. Six weeks later, coronary angiography revealed that the myocardial ischemia was established by gradual occlusion of the left circumflex coronary artery (LCX). Sixteen swine with the total occlusion or partial stenosis (> 85 %) of the LCX were divided into 4 groups (4 in each group): group I, group II and group IV (control) received direct myocardium injection of rAAV2 VEGF165, rAAV2 ANG-1 or PBS alone, respectively; group III received rAAV2 VEGF165 and rAAV2 ANG-1. Selective coronary angiography and ultrasonography were performed perioperatively to evaluate the cardiac function and the formation of collateral circulation. The expression of VEGF165 and ANG-1 proteins were assessed using ELISA or Western blot. The degree of angiogenesis was assessed by use of immunohistochemical analysis. RESULT: Angiography showed that the occlusion of all LCX was completed or exceeded 95% 6 weeks after ameroid constrictor implantation, indicating the successful establishment of animal model. The expression levels of VEGF165 in group I and III and ANG-1 in groups II and III began to increase at d7 after transfection and reached the peak at d14; then decreased gradually to the normal level after 3 months. The expression levels of VEGF165 in group II and group IV or that of ANG-1 protein in group I and group IV had no markedly changes at different time after transfection. There were significant increase in capillary density and arteriole density and more side branch vessels formed in group III compared with other groups. Echocardiographic measurements showed that the left ventricular systolic function of animals in groups I, II and III increased significantly after gene transfection, especially in group III; but there was no changes in group IV. CONCLUSION: Myocardial perfusion and the left ventricular systolic function are improved after rAAV2 VEGF165 or rAAV2 ANG-1 transfection, which is associated with the angiogenesis in porcine model of chronic myocardial ischemia.

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Studies on the peroxidation of polyunsaturated fatty acid from yolk lipoprotein induced by iron was curried out. A comparison of the experimental conditions for the model system of peroxidation was made. The system was successfully applied to determine the activity of the anti-oxidative activity of some effective ingredients of Chinese traditional medicine.