The effective detection of organic amines is particularly important for environmental protection and human health. Herein, according to hard and soft acid base theory, a novel three-dimensional (3D) ...butterfly shaped Eu4(OH)2 cluster-based metal–organic framework with Lewis basic triazole sites, {Eu4(taip)4(ox)(OH)2(H2O)4·3H2O}n (1) (H2taip = 5-(1,2,4-triazol-1-yl) isophthalic acid, H2ox = oxalic acid), was successfully synthesized under solvothermal conditions, and was characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, infrared spectroscopy and thermogravimetric analysis. Structural analysis reveals that compound 1 is a 3D net constructed from butterfly shaped Eu4(OH)2 clusters and contains isosceles triangular channels with dimensions of 8.84 × 8.84 × 8.63 Å3, which shows an unprecedented 8-connected topology with a Schläfli symbol {36·418·53·6}. Fluorescence experiments of compound 1 show sensitive luminescence quenching responses to organic amines such as diethylamine (DEA), trimethylamine (TMA), triethylamine (TEA), ethylenediamine (EDA) and aniline, and the quenching constants (KSV) decrease in the following order: EDA > DEA > TMA > TEA > aniline. The fluorescence quenching responses may be attributed to the energy gap between the LUMO energy values of H2taip and organic amines, which hinders the transfer of excited state energy to the emission state of Eu3+ and results in luminescence quenching. The fluorescence lifetimes of compound 1 in ethanol and organic anilines indicate that the fluorescence recognition process of organic amines was static.
Xishan mining area in Taiyuan is a typical coal industry cluster with a variety of coal-related industrial sites such as coal mines, power plants and coking plants, which seriously pollute the native ...ecological environment. Study of the hydrochemical characteristics and pollution sources of groundwater in the area can contribute to the ecological protection and remediation of regional groundwater resources. In this study, we collected surface water and groundwater samples from the Xishan mining area and measured and analyzed hydrochemical and sulfur–oxygen isotopes. Results showed that 64.7% of groundwater in the study area exceeded the sulfate standard due to the influence of the coal industry, with some karst groundwater up to 2000 mg/L. In the runoff and discharge area of karst groundwater, the proportion of anthropogenic input of SO42− increased, which led to the hydrochemical type of karst groundwater gradually changing from HCO3-Ca·Mg (recharge area) to SO4-Ca·Mg (discharge area). Results of sulfur–oxygen isotope tests indicated that the δ34SSO4 and δ18OSO4 values of samples were −10.01~24.42‰ and −4.90~12.40‰, respectively, and the sulfur–oxygen isotope values of some karst groundwater were close to the dissolved end of sulfide minerals, indicating their sulfate mainly came from the oxidation of pyrite. Sulfate sources in groundwater water were parsed using IsoSource model. Calculated results revealed that sulfate in pore groundwater mostly originated from pyrite oxidation, and karst groundwater in the recharge area was mainly influenced by atmosphere precipitation, while groundwater in the runoff and discharge areas were significantly affected by pyrite oxidation, accounting for up to 90% in some karst groundwater. Comparing the sulfur–oxygen isotope values of karst groundwater in 1989, 2016 and 2022, we found that the δ34SSO4 values in 2022 decreased significantly, which indicated the expansion of karst groundwater pollution in the Xishan mining area. This study highlights the pollution of regional groundwater by coal-related industrial agglomerations, and the groundwater pollution in the Xishan mining area requires urgent remediation and restoration.
Guidance commands of flight vehicles can be regarded as a series of data sets having fixed time intervals, thus guidance design constitutes a typical sequential decision problem and satisfies the ...basic conditions for using the deep reinforcement learning (DRL) technique. In this paper, we consider the scenario where the escape flight vehicle (EFV) generates guidance commands based on the DRL technique and the pursuit flight vehicle (PFV) generates guidance commands based on the proportional navigation method. Evasion distance is described as the minimum distance between the EFV and the PFV during the escape-and-pursuit process. For the EFV, the objective of the guidance design entails progressively maximizing the residual velocity, which is described as the EFV's velocity when the evasion distance occurs, subject to the constraint imposed by the given evasion distance. Thus an irregular dynamic max-min problem of extremely large-scale is formulated. In this problem, the time instant when the optimal solution (i.e., the maximum residual velocity satisfying the evasion distance constraint) can be attained is uncertain and the optimum solution is dependent on all the intermediate guidance commands generated before. For solving this challenging problem, a two-step strategy is conceived. In the first step, we use the proximal policy optimization (PPO) algorithm to generate the guidance commands of the EFV. The results obtained by PPO in the global search space are coarse, despite the fact that the reward function, the neural network parameters and the learning rate are designed elaborately. Therefore, in the second step, we propose to invoke the evolution strategy (ES) based algorithm, which uses the result of PPO as the initial value, to further improve the quality of the solution by searching in the local space. Extensive simulation results demonstrate that the proposed guidance design method based on the PPO algorithm is capable of achieving a residual velocity of 67.24 m/s, higher than the residual velocities achieved by the benchmark soft actor-critic and deep deterministic policy gradient algorithms. Furthermore, the proposed ES-enhanced PPO algorithm outperforms the PPO algorithm by 2.7%, achieving a residual velocity of 69.04 m/s.
OBJECTIVE:To determine the effect of remote ischemic post-conditioning (RIPC) on acute ischemic stroke (AIS) patients undergoing intravenous thrombolysis (IVT).
METHODS:A single-center, randomized ...controlled trial was performed with AIS patients receiving IVT. Patients in the RIPC group were administered RIPC treatment (after IVT) during hospitalization. The primary endpoint was a score of 0 or 1 on the modified Rankin scale (mRS) at day 90. The safety, tolerability and neuroprotection biomarkers associated with RIPC were also examined.
RESULTS:We collected data from both RIPC (n=34) and controls (n=34). The average duration of hospitalization was 11.2 days. There was no significant difference between the two groups at admission for the NIHSS score (p=0.364) or occur to treatment time (p=0.889). An excellent recovery (mRS 0–1) at 3 months was obtained in 71.9% of the patients in the RIPC group vs 50.0% in the control group (adjusted risk ratio, 9.85; 95% CI, 1.54 to 63.16; P = 0.016). We further found significantly lower plasma S100 β (p=0.007) and higher vascular endothelial growth factor (p = 0.003) levels in the RIPC group than in controls.
CONCLUSIONS:Repeated RIPC combined with IVT can significantly facilitate recovery of nerve function and improve clinical prognosis of patients with AIS.
CLINICALTRIAL.GOV IDENTIFIER:NCT03218293
CLASSIFICATION OF EVIDENCE:This study provides Class IV evidence that RIPC following tPA treatment of AIS significantly increases the proportion of patients with MRS 0 or 1 at 90 days.
The lack of suitable lightweight current collectors is one of the primary obstacles preventing the energy density of aqueous lithium-ion batteries (ALIBs) from becoming competitive. Using silver ...nanowire (AgNW) films as current collectors and a molecular crowding electrolyte, we herein report the fabrication of ALIBs with relatively good energy densities. In the 2 m LiTFSI-94% PEG-6% H
O solution, the AgNW films with a sheet resistance of less than 1.0 ohm/square exhibited an electrochemical stability window as broad as 3.8 V. The LiMn
O
//Li
Ti
O
ALIBs using AgNW films as the current collectors demonstrated an initial energy density of 70 Wh/kg weighed by the total mass of the cathode and anode, which retained 89.1% after 50 cycles.
The multi-slit charge developed from the traditional double-slit charge has more and more engineering applications in roadway blasting and excavation. In this paper, numerical simulation and model ...experiments are used to compare the dynamic behaviors of double-slit/three-slit charge blasting in crack propagation, stress evolution and blasting vibration. The research results show that the directional fracture effect at the borehole middle and borehole bottom in the slit charge blasting is the best, followed by the directional fracture effect at the borehole orifice, and the length of the directional crack formed along the slit direction at the borehole middle is the largest. Compared with the double-slit charge blasting, the dynamic stress intensity factor of the directional crack at initiation stage and early propagation stage in the three-slit charge blasting is smaller, and the directional cracks formed are shorter. In addition, the effective stress evolution and blasting vibration attenuation of the gauging points along the slit direction are affected by slit number and cross-section position. The effective stress and blasting vibration of gauging points at the borehole bottom in the slit charge blasting are significantly larger than those of gauging points at the borehole orifice. For the three-slit charge blasting, the model experiment finds that the directional crack deflected to the side of protected rock mass during the propagation process. The occurrence of such deflection phenomenon is likely to cause overbreak of rock mass, which is not conducive to the formation of a straight profile surface in the rock roadway excavation.
•Numerical simulation and model experiments are used to compare the dynamic behaviors of double-slit/three-slit charge blasting in crack propagation, stress evolution and blasting vibration.•Compared with the double-slit charge blasting, the dynamic stress intensity factor of the directional crack at initiation stage and early propagation stage in the three-slit charge blasting is smaller, and the directional cracks formed are shorter.•For the three-slit charge blasting, the model experiment finds that the directional crack deflected to the side of protected rock mass during the propagation process.
Short-term air pollution exposure and intracerebral hemorrhage (ICH) risk are related. However, the impact of the pollutant levels decline on this relationship, which attributes to clean air policy ...implementation and the COVID-19 pandemic lockdown, is unclear. In the present research, we explored the influence of different pollutant levels on ICH risk during eight years in a southwestern China megacity.
Our research used a time-stratified case-crossover design. We retrospectively analyzed ICH patients in a teaching hospital from January 1, 2014, to December 31, 2021, and divided 1571 eligible cases into two groups (1st group: 2014-2017; 2nd group: 2018-2021). We observed the trend of every pollutant in the entire study period and compared the pollution levels in each group, using air pollutants data (PM
, PM
, SO
, NO
, CO, and O
) documented by the local government. We further established a single pollutant model via conditional logistic regression to analyze the association between short-term air pollutants exposure and ICH risk. We also discussed the association of pollution levels and ICH risk in subpopulations according to individual factors and monthly mean temperature.
We found that five air pollutants (PM
, PM
, SO
, NO
, CO) exhibited a continuous downward trend for the whole duration, and the daily concentration of all six pollutants decreased significantly in 2018-2021 compared with 2014-2017. Overall, the elevation of daily PM
, SO
, and CO was associated with increased ICH risk in the first group and was not positively associated with risk escalation in the second group. For patients in subgroups, the changes in the influence of lower pollutant levels on ICH risk were diverse. In the second group, for instance, PM
and PM
were associated with lower ICH risk in non-hypertension, smoking, and alcohol-drinking participants; however, SO
had associations with increased ICH risk for smokers, and O
had associations with raised risk in men, non-drinking, warm month population.
Our study suggests that decreased pollution levels diminish the adverse effects of short-term air pollutants exposure and ICH risk in general. Nevertheless, the influence of lower air pollutants on ICH risk in subgroups is heterogeneous, indicating unequal benefits among subpopulations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Interlaid rock is an important component in the construction of neighborhood tunnels that supports and reinforces the area between two tunnels. However, the blasting load during excavation can ...sometimes damage the interlaid rock and threaten the stability of a tunnel’s structure. This paper presents a case study of the small clearance section of the Liantang highway tunnel project in Shenzhen, China, where the minimum distance between the two tunnels involved is only 0.5 m. To reduce the damage to the interlaid rock caused by blasting loads, we proposed a four-part excavation method with a vibration-cushioning rock layer in the following tunnel of neighborhood tunnels. Numerical simulation was used to model the damage prevention mechanism of the vibration-cushioning rock layer and to better understand the propagation of cracks in the interlaid rock. Furthermore, based on the simulation results, combined microseismic controlled-blasting technology was implemented, using innovative blasting patterns combined with different charge structures and blasting equipment designed according to the varying thickness of the interlaid rock. Finally, this implementation succeeded in protecting interlaid rock during blasting operations.
The genus Zingiber of the Zingiberaceae is distributed in tropical, subtropical, and in Far East Asia. This genus contains about 100-150 species, with many species valued as important agricultural, ...medicinal and horticultural resources. However, genomic resources and suitable molecular markers for species identification are currently sparse.
We conducted comparative genomics and phylogenetic analyses on Zingiber species. The Zingiber chloroplast genome (size range 162,507-163,711 bp) possess typical quadripartite structures that consist of a large single copy (LSC, 86,986-88,200 bp), a small single copy (SSC, 15,498-15,891 bp) and a pair of inverted repeats (IRs, 29,765-29,934 bp). The genomes contain 113 unique genes, including 79 protein coding genes, 30 tRNA and 4 rRNA genes. The genome structures, gene contents, amino acid frequencies, codon usage patterns, RNA editing sites, simple sequence repeats and long repeats are conservative in the genomes of Zingiber. The analysis of sequence divergence indicates that the following genes undergo positive selection (ccsA, ndhA, ndhB, petD, psbA, psbB, psbC, rbcL, rpl12, rpl20, rpl23, rpl33, rpoC2, rps7, rps12 and ycf3). Eight highly variable regions are identified including seven intergenic regions (petA-pabJ, rbcL-accD, rpl32-trnL-UAG, rps16-trnQ-UUG, trnC-GCA-psbM, psbC-trnS-UGA and ndhF-rpl32) and one genic regions (ycf1). The phylogenetic analysis revealed that the sect. Zingiber was sister to sect. Cryptanthium rather than sect. Pleuranthesis.
This study reports 14 complete chloroplast genomes of Zingiber species. Overall, this study provided a solid backbone phylogeny of Zingiber. The polymorphisms we have uncovered in the sequencing of the genome offer a rare possibility (for Zingiber) of the generation of DNA markers. These results provide a foundation for future studies that seek to understand the molecular evolutionary dynamics or individual population variation in the genus Zingiber.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
