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Reservoir is easy to be polluted by nutrients and heavy metals in the surrounding soil. There is a close relationship between heavy metals and nutrients in soil. Nutrient salts will affect the activity of heavy metals, and heavy metal pollution will affect plant growth and nutrient salt absorption, thus affecting ecosystem health. This study was performed to evaluate nutrients (TN, TP) and heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in the upper watershed of Xiashan Reservoir by the enrichment factor, the geoaccumulation index, the enrichment factor and leaching experiments. The results showed that the average enrichment of TN and TP reached the level of moderate pollution. The nutrient enrichment of different sampling sites increased gradually from south to north, which may be affected by the topography of the study area. The comprehensive trophic level exceeds the criteria for a state of severe eutrophication of water bodies, which may lead to the enrichment of nitrogen and phosphorus in the water body through processes such as runoff. Evaluation of the geoaccumulation index and potential ecological risk index revealed that the soil was primarily contaminated by Cd and Hg, which are in the level of considerable potential ecological risk and high potential ecological risk. So most attention should be paid to Cd and Hg pollution. Pollution control of heavy metals in soil is a priority because they are more difficult to leach than nutrients. This study provided an insight into the nitrogen and phosphorus control and heavy metal pollution management in the upper watershed of Xiashan Reservoir. [ABSTRACT FROM AUTHOR]

Gas therapy (GT) combined with photodynamic therapy (PDT) is an effective strategy to compensate for the PDT limitation caused by the hypoxic tumor microenvironment, which can greatly improve PDT efficacy. The uncontrolled leakage of gas molecules during delivery seriously hinders its practical biological application. Herein, we report a multifunction nanomedicine that enables precise gas therapy (including carbon monoxide (CO) release and H2S depletion) using a multi-parameter-induced activation gas release strategy, enlarging the PDT efficacy. This nanomedicine uses a disulfide bond to covalently link a photosensitizer with the CO donor 3-hydroxyflavone (3-HF). The disulfide bond can be specifically consumed in H2S-rich tumor areas, releasing the CO donor (3-HF), and also depleting H2S. More importantly, the photo-controlled production of 1O2 can induce 3-HF precise release of CO in the tumor location. Such H2S, light, and 1O2 multi-parameter-induced activation of gas release strategy ensures the accuracy of GT to amplify PDT efficiency. As expected, in vitro and in vivo investigations show that GT makes up for the PDT limitation, exhibiting the highest tumor therapeutic effect. This multi-parameter-activated design strategy provides a new way to improve the precision and efficacy of multimodal synergistic therapy of tumorsy of tumors.. [ABSTRACT FROM AUTHOR]

Rammed earth ruins can be regarded as a special soil mass made by humans. Generally, the stability of rammed earth ruins is largely controlled by the morphological characteristics of rammed layer interfaces (RLIs), which have not been well studied yet. In this paper, the Yongchang Section of the Ming Great Wall, a representative of rammed earth ruins in northwestern China, was selected as the study area, and morphological data from three typical RLIs were collected uisng a handheld 3D scanner. For each typical RLI, within three concentric analysis domains with different sizes, the spatial characteristics of microslopes were explored by ArcGIS, and the 3D roughness values along eight analysis directions were calculated. Ultimately, this study indicates that the most notable characteristic of RLIs is the morphological regularity provided by the rammed pits. Thus, within the analysis domains employed here, the spatial characteristics of microslopes and 3D roughness values are size-independent overall. Moreover, the distributions of 3D roughness are basically more isotropic than anisotropic. Additionally, minor bumps on the RLIs were formed by construction, fracturing, and weathering, and they contribute to the limited heterogeneity of the RLI morphology. Thereinto, the weathering-induced can further be divided into minor bumps caused by wind erosion and rainfall erosion. On the whole, RLIs that have undergone wind erosion have significantly higher surface hardness values (60–90 HA) than rainfall-eroded RLIs (< 50 HA). [ABSTRACT FROM AUTHOR]

Uniting dual-modality of fluorescence and photoacoustic (PA) imaging into theranostic nanoprobes is imperative for spatio-temporally tracking of drug delivery, distribution, and release. Herein, we present a rational design strategy of molecularly precise amphiphilic prodrugs BPn-Cy-S-CPT (n=0, 5, and 20, refers to the degree of polyethylene glycol (PEG) polymerization; CPT=camptothecin) to tune their self-assembly behaviour, innovatively integrating dual-modal PA and near-infrared (NIR) fluorescence imaging in a single-molecular framework. Among these elaborately designed prodrugs, it is found that only BP20-Cy-S-CPT could form uniform and highly stable self-assemblies, especially in showing synergistically enhanced PA and dual-channel NIR signals. In detail, PA signal is employed to trace the in vivo delivery with high spatial resolution, meanwhile the glutathione (GSH)-triggered dual-channel fluorescence response could real-timely monitor drug distribution and release without "blind spot". The results of in vivo dual-modal PA/NIR imaging have verified that BP20-Cy-S-CPT displayed synergistic targeting (including passive, active, and activatable targeting) for tumor-specific delivery, and thereby executed CPT release in the tumor site. Consequently, our molecularly precise BP20-Cy-S-CPT self-assemblies could make a breakthrough to spatio-temporally track the in vivo drug release profile, expanding the intelligent theranostic toolbox for precise cancer treatment. [ABSTRACT FROM AUTHOR]

Intramolecular charge transfer (ICT) is a fundamental mechanism that enables the development of numerous fluorophores and probes for bioimaging and sensing. However, the electron-withdrawing targets (EWTs)-induced fluorescence quenching is a long-standing and unsolved issue in ICT fluorophores, and significantly limits the widespread applicability. Here we report a simple and generalizable structural-modification for completely overturning the intramolecular rotation driving energy, and thus fully reversing the ICT fluorophores' quenching mode into light-up mode. Specifically, the insertion of an indazole unit into ICT scaffold can fully amplify the intramolecular rotation in donor-indazole-π-acceptor fluorophores (fluorescence OFF), whereas efficiently suppressing the rotation in their EWT-substituted system (fluorescence ON). This molecular strategy is generalizable, yielding a palette of chromophores with fluorescence umpolung that spans visible and near-infrared range. This strategy expands the bio-analytical toolboxes and allows exploiting ICT fluorophores for light-up sensing of EWTs including N-acetyltransferases and nerve agents. The electron-withdrawing target (EWT)-induced fluorescence quenching is an unsolved issue in intramolecular charge transfer (ICT) fluorophores that limits their applicability. Here, the authors report a simple and generalizable strategy to reverse the EWT-induced quenching mode into light-up mode, by introducing an indazole building block between the π-bridge and the donor in the ICT scaffold. [ABSTRACT FROM AUTHOR]

The Ming Great Wall distributed in Qinghai Province is a significant part of the Great Wall, which is the most world-renowned heritage site in China. However, compared to the Great Wall sections in other provinces, this section has not been systematically researched due to the later complete investigation and not enough attention paid from the public. It is of importance to study the Ming Great Wall Military Defense System (M-GWMDS), as it is the premise and foundation for further systematic researches about the Ming Great Wall. To supplement and improve the whole M-GWMDS in China, the authors researched the M-GWMDS in Qinghai Province from a new perspective, namely the castle-based military settlement. By consulting and summarizing related literature, the architectural features and military functions of castles have been clarified. After that, the castle-based military settlement in Qinghai Province was further analyzed, including its spatial distribution, troops deployment, three defense districts, and the reachable domain of troops. Finally, the authors explored to comprehensively research the military defense system, which contains four elements, i.e., the Great Wall mainline, military settlements, beacon tower system, and the relay system. Such components have made up a close network to defense, attack, and transfer vital information/staff with practical cooperation, which revealed the scientificity and practicability of Chinese ancient military thoughts. This study is helpful to enrich the systematic research on the Ming Great Wall and meaningful to expand the analysis of local history and ethnology of Qinghai Province. [ABSTRACT FROM AUTHOR]

Some of the largest and best-preserved Buddhist art treasure houses in the world, namely the Mogao Grottoes, are located at the northwest edge of the region of the Qinghai-Tibet plateau and are adjacent to the Altun and Qilian mountains, where the geotectonic activity is intense and large earthquakes have occurred. Future earthquakes are one of the major threats to the caves of the Mogao Grottoes; therefore, it is important that their dynamic performance is studied when an earthquake occurs. To understand the dynamic performance of the densely distributed caves under the effect of earthquakes, as well as the long-term stability of the Mogao Grottoes, the stress distribution, deformation characteristics, and peak-acceleration amplification factor were analysed under rare-earthquake conditions using a finite-difference element. The numerical study revealed that the most dangerous state of the caves is the initial time when an earthquake occurs. The obvious tensile stress concentration appeared at the top and the bottom of the caves of the middle floor; the main damage was caused by the shear failure towards the direction of the free face and not by the tensile failure. A large permanent horizontal displacement of the caves occurred after an earthquake, mostly at the densely distributed caves of the middle floor. The acceleration amplification effect of the middle-floor caves was significant; the Fourier amplitudes of the acceleration (which were monitored in all caves) were significantly magnified at the frequencies of 3 ~ 4 Hz and 7 ~ 9 Hz, whereas the Fourier amplitudes of the acceleration which were monitored in the middle-floor caves were almost amplified within the entire frequency range. Although the maximum stress was within the allowed limit and no tensile failure occurred, great permanent inhomogeneous horizontal displacements and large accelerations could have a negative effect on the stability of caves and the preservation of wall paintings. Moreover, it was assumed that the calculation results could serve as a type of guidance and as advice on the preventive protection of the Mogao Grottoes. [ABSTRACT FROM AUTHOR]

The overall nutritional properties of tubers from 67 potato cultivars were systematically evaluated in this study by adopting the Nutrient-Rich Foods (NRF11.3) Index Model. The macronutrients including dry matter, crude protein, total dietary fiber, and starch contents were found to be in the range of 14.8-30.5 g/100 g fresh weight, 5.71-12.0, 1.99-3.39, and 56.0-75.5 g/100 g dry weight, respectively. Additionally, the amounts of vitamin C, K and Fe were 22.6-86.6, 1457-3111, and 1.40-5.06 mg/100 g dry weight, respectively. The NRF11.3 index model has a score of 66.4-102 per 100 kcal for male and 70.8-107 per 100 kcal for female over 18 years old. This model was utilized to determine the macrocomponents and micronutrients of diverse potato cultivars and aid in comprehensive nutritional study on potato as a desirable raw material for staple food processing to human nutrition and daily intake. [ABSTRACT FROM AUTHOR]

Fluorescence-based technologies have revolutionized in vivo monitoring of biomolecules. However, significant technical hurdles in both probe chemistry and complex cellular environments have limited the accuracy of quantifying these biomolecules. Herein, we report a generalizable engineering strategy for dual-emission anti-Kasha-active fluorophores, which combine an integrated fluorescein with chromene (IFC) building block with donor-π-acceptor structural modification. These fluorophores exhibit an invariant near-infrared Kasha emission from the S1 state, while their anti-Kasha emission from the S2 state at around 520 nm can be finely regulated via a spirolactone open/closed switch. We introduce bio-recognition moieties to IFC structures, and demonstrate ratiometric quantification of cysteine and glutathione in living cells and animals, using the ratio (S2/S1) with the S1 emission as a reliable internal reference signal. This de novo strategy of tuning anti-Kasha-active properties expands the in vivo ratiometric quantification toolbox for highly accurate analysis in both basic life science research and clinical applications. Fluorescent probes are used in a number of fields but suffer from a lack of quantifiable results due to environmental effects. Here, the authors report on a dual-emission probe which can be used to detect the amount of probe present and the emission from detection applications to allow for quantification. [ABSTRACT FROM AUTHOR]

Light-triggered drug delivery system is an effective strategy for precise diagnosis and therapy in cancer treatment. However, it suffers from difficultly balancing the dosimetry of drug with light dose and a lack of in vivo models for validating their clinical benefits. Here we report an unprecedented near-infrared (NIR) light photocaged cyanine-based prodrug Cy-CPT-Biotin with dual-channel fluorescence mode, enabling NIR light to precisely regulate where, when and how the intact and active prodrugs are delivered. The synergy of photochemical reaction and modulation in π-conjugated polyene backbone of cyanine can fully perform distinct dual-channel fluorescence changes in a NIR light-mediated manner. The prodrug has striking characteristics of excellent tumor-targeting ability, real-time monitoring of the in vivo behaviors by dual-channel mode and NIR-light triggering, especially for achieving fine regulation and on-demand drug release in the precise dosimetry of drug with light dose in living animals. This optical orthogonality strategy that conjuncts with NIR light-triggered and dual-channel fluorescence in vivo imaging provides a powerful tool for in vivo real-time tracking and finely tuning the prodrug release for precise drug delivery. [ABSTRACT FROM AUTHOR]

The Mogao Grottoes are among the most famous sites on the World Heritage list. Several large-scale preservation projects were implemented in 1962, 1982, and 2008, respectively, to improve their preservation conditions. According to field investigation and assessment in recent years, the cliff is stable on the whole because of the reinforcement projects. Among them, there are still 42 potentially dangerous bodies, which may not be stable in some conditions. For the purpose of building the monitoring and early warning system and the long-term preventive preservation of the Mogao Grottoes, an innovative analytical method based on the Analytic Hierarchy Process (AHP) and Fuzzy-AHP was applied to assess the hazard of potentially dangerous bodies within the cliff. Firstly, the hazard was classified into six groups: very high, high, moderate, low, very low, and no hazard, in this study. Secondly, the AHP method was applied to calculate the impact index of each causative factor, and then the hazard assessment of dangerous bodies was made based on statistical analysis. Finally, the Fuzzy-AHP method was applied to calculate the correlation of each factor and determine the comprehensive hazard class. The results indicate that Fuzzy-AHP seems to be more accurate than AHP in hazard assessment. Meanwhile, there is a very high risk body that can threaten 10 caves, three high risk bodies that can threaten 13 caves, and 15 moderate risk bodies can threaten 69 caves in total, while the remaining bodies are defined as low or very low grades. Overall, the results of this study provide much data and a theoretical model in the construction of a monitoring and early warning system currently. Furthermore, the new numerical simulation method also holds the potential application to assess the hazards of other types of heritage sites. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) plays a critical role in maintaining oxidation-reduction homeostasis in biological systems. Considering the detection of GSH by fluorescence sensors is limited by either the short wavelength emission or the poor photostability, a highly stable colorimetric and ratiometric NIR fluorescent sensor (DCM-S) for GSH detection has been constructed on the basis of dicyanomethylene-4 H-pyran (DCM) chromophore. The specific disulfide bond is incorporated via a carbamate linker as the GSH responsive group, which simultaneously blue-shifts and quenches the fluorescence. Upon addition of GSH, DCM-S exhibits outstanding colorimetric (from yellow to red) and ratiometric fluorescent response with the 6-fold enhancement of NIR fluorescence at 665 nm in quantum yield. More importantly, the GSH-treated DCM-S (DCM-NH actually) possesses 20-fold longer fluorescence half-life period as well as much better photostability than the FDA-approved ICG. Finally, the ratiometric detection of GSH is also successfully operated in the living cell imaging, exhibiting NIR fluorescence and large Stokes shift (215 nm) with nearly no background fluorescence interference. As a consequence, DCM-S can be utilized as colorimetric and ratiometric NIR fluorescent sensor for GSH, with a great potential in the development of GSH-induced drug delivery system. [ABSTRACT FROM AUTHOR]

A novel hydrophilic copolymer P(NI-HEMA) containing the pendant group of naphthalimide moiety has been prepared. In the aqueous buffer solution, its film on the glass substrate shows an obvious fluorescence change and excellent linear relevance in the pH range of 5.8–8.0. Specifically, using the isobestic point at 406 nm as excitation wavelength can avoid the UV irradiation and the tedious calibration process. The film stability and hydrophilicity of copolymer P(NI-HEMA) were studied. Because of the easy synthesis, low price and high linear relevance to pH, the hydrophilic chemosensor film of P(NI-HEMA) could be potentially applied as a low-cost pH indicator for high-throughput bioprocessing in microreactors. [ABSTRACT FROM AUTHOR]