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BACKGROUND Owing to their small particle size, good stability against photobleaching, high fluorescence stability, tunable fluorescence emission, easy surface functionalization, low toxicity and excellent biocompatibility, carbon dot (CD) has been widely applied in many fields including catalyst, cell imaging, drug delivery, fluorescence detection and photoelectronic devices. In recent years, synthetic methods for preparing high-performance fluorescent CD using different raw materials have attracted much attention. In addition, detection of trace metal ions by a fluorescent probe has been rapidly developed and widely used. The fluorescent probe can be constructed thus:the CD directly interact with the target analyte, the CD modified by the specific ligand interact with the target analyte, and the CD forming a complex with other substances interact with the target analyte. OBJECTIVES To provide references for researchers to synthesize CD and construct fluorescent probes based on CD for the determination of trace metal ions in complex samples. METHODS The optical properties and synthetic raw materials of CD were described. The process and characteristics of the commonly used top-down and bottom-up methods were summarized. The application progress of fluorescent probes constructed by the three interaction modes between CD and target analytes for the determination of biochemical reaction ions, Fe3+, Zn2+ and Cu2+, and other heavy metal ions such as Hg2+, As3+, Pb2+, Cr6+ and Cd2+ were reviewed. RESULTS Different raw materials had been utilized for synthesizing CD with different properties. The prepared CD were used to construct fluorescent probes for the determination of micro metal ions with high selectivity and sensitivity. CONCLUSIONS Further research on the determination mechanisms, development of new detection modes, construction of fluorescent probes for specific metal ions and sample components, and establishment of analytical methods, which can be applied to complex samples are the challenges and development orientation of the fluorescent probes based on CD.

Two types of soil covered by biological soil crusts (BSCs), i. e. moss and algae, and moving sand in the natural vegetation area at the southeast fringe of the Tengger Desert were collected intactly. They were incubated continuously for 20 days under two different temperatures (15°C and 25°C ) and moistures (10% and 25%) condition in the laboratory, and soil NO3-- contents were measured after 1, 2, 5, 8, 12, 20 days of incubation and net nitrification rate was evaluated during dehydration. The results showed that NO3-- content of the moss-covered soil ( 2. 29 mg.kg-1) was higher than that of the algae-covered soil ( 1.84 mg.kg-1 ) and sand ( 1.59 mg.kg-1). Net nitrification rate of the three soil types ranged from -3.47 to 2.97 mg.kg-1.d-1. For the moss-covered soil and algae-covered soil at 10% and 25% moisture levels, the net nitrification rates at 15°C75.1%, 0.7% and 99.1%, 21.3% higher than those at 25°C, respectively. Also, the net nitrification rates at 15°C and 10% moisture levels were 193.4% and 107.3% higher than those at 25°C and 25% moisture levels, respectively. The results suggested that regardless of soil moisture increasing or decreasing under the global warming senior, the net nitrification rate of BSCs-soil system in the desert would probably be limited to some extent during drought process. [ABSTRACT FROM AUTHOR]

Highlights: [•] Non-aqueous ASIL/sulfolane binary mixtures were designed for the absorption of SO2. [•] Detailed absorption performance of SO2 in the ASIL/sulfolane binary mixtures was investigated systematically. [•] A reaction equilibrium thermodynamic model (RETM) was derived to analyze the behaviour of SO2 absorption in the ASIL/sulfolane binary mixtures. [ABSTRACT FROM AUTHOR]

Three dual Lewis base functionalized ionic liquids (DLB-ILs) tethered with both carboxyl and tertiary amine groups on their anions were designed for highly efficient and selective absorption of H2S. It was found that the DLB-ILs could reversibly absorb 0.39-0.84 mol of H2S per mole of IL at 1 bar and 60 °C, which is significantly higher than that of other ILs. On the contrary, the CO2 absorption in this class of DLB-ILs was shown to be quite limited relative to H2S owing to the coupling effect of the two Lewis base groups. It is the dual Lewis base functionalization that enables the significantly high values calculated for the ideal absorption selectivity for H2S/CO2, that is, 13-26 at 1 bar and 29-70 at 0.1 bar (60 °C). The selectivity even goes up to >100 at low pressures and high temperatures. It was further illustrated from DFT calculations and spectroscopy studies that the cooperation interaction of carboxyl ⋅⋅⋅H2S ⋅⋅⋅amine and the reduced binding with CO2 were the major contributions to the high H2S absorption capacity and H2S/CO2 selectivity. [ABSTRACT FROM AUTHOR]

Solubilities of H2S in five 1-alkyl-3-methylimidazolium carboxylates ionic liquids (ILs) have been measured at temperatures from 293.15 to 333.15 K and pressures up to 350 kPa. It is shown that these ILs have significantly larger absorption capacities for H2S than those common ILs reported in the literature. The solubility is found to increase dramatically with the increasing alkalinity of the anions and slightly with the increasing length of the alkyl chains on the cations. It is further demonstrated that the absorption isotherms are typically nonideal. With the assumption of complex formation between H2S and ILs, a reaction equilibrium thermodynamic model is developed to correlate the experimental solubilities. The model favors a reaction mechanism of AB2 type that two IL molecules interact with one H2S molecule. Thermodynamic parameters such as Henry's law constants, reaction equilibrium constants, and heat of complex formation are also calculated to evaluate the absorption process of H2S in these ILs. © 2012 American Institute of Chemical Engineers AIChE J, 59: 2227-2235, 2013 [ABSTRACT FROM AUTHOR]

Yellow pond turtle (Mauremys mutica) eggs were incubated in vermiculite under nine combinations of temperature and humidity, i.e., 25 °C and -12 kPa, 29 °C and -12 kPa, 33 °C and -12 kPa, 25 °C and -150 kPa, 29 °C and -150 kPa, 33 °C and -150 kPa, 25 °C and -300 kPa, 29 °C and -300 kPa, and 33 °C and -300 kPa, aimed to study the effects of incubation temperature and its interaction with substrate humidity on the embryonic development of M. mutica. The initial egg mass, incubation temperature, substrate humidity, and the interaction of incubation temperature and substrate humidity had significant effects on the mass increment of egg in the course of hatching. At the same temperature, eggs incubated in wetter substrates (-12 kPa) gained more mass than those incubated in drier substrates (-150 kPa and -300 kPa). Incubation temperature affected hatching period significantly, while substrate humidity and its interaction with temperature did not. Both incubation temperature and substrate humidity affected hatching success and shell crack rate significantly. Abnormal hatchlings were found when incubated at 25 °C and 33 °C, but not at 29 °C. Incubation temperature had significant effects on the hatchling mass, carapace length and width, plastron length and width, body height, and tail length; while substrate humidity only affected hatchlings plastron length. The interaction of incubation temperature and substrate humidity did not affect the morphology of hatchlings [ABSTRACT FROM AUTHOR]

Purpose: To determine the effect of polysaccharides from Gleditsia on apoptosis of colorectal cancer cells, and the mechanism involved. Methods: Polysaccharides were extracted from Lycium barbarum, and their concentration was more than 85 %. Then, DLD-1 cells were cultured in medium with the polysaccharides at concentrations of 75 and 150 µg/mL. Cell proliferation was determined with MTT (3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide) assay and colony formation assay, while apoptosis was determined with flow cytometry. Changes in MMP were measured flow cytometrically. The protein levels of PARP, Bcl-2, Bax, and caspases 3 and 9 were determined with Western blot assay. Results: Cell viability decreased time-dependently. Compared with control without polysaccharide exposure, cell viability, colony forming cells, % apoptosis, red: green fluorescence ratio, and bcl-2 expression were significantly and concentration-dependently decreased, while the expression levels of PARP, Bax, caspase-3 and caspase-8 were significantly increased (p < 0.05). Conclusion: These results indicate that the polysaccharides suppressed apoptosis of colorectal cancer cells by inhibiting the mitochondrial and caspase-dependent apoptosis pathways. Gleditsia polysaccharide may be used as an adjuvant therapy for colorectal cancer. [ABSTRACT FROM AUTHOR]

Industrial security issues have always been an important and urgent issue globally.Industrial control protocols are widely used in the communication between industrial control system(ICS) components.Their security is related to the safe and stable operation of the entire system,and there is an urgent need to ensure the security of all industrial control protocols.The network protocol fuzzing plays an important role in ensuring the security and reliability of ICS.Traditional fuzzing methods can improve the security testing of industrial control protocols,and many of which have practical applications.However,most traditional fuzzing methods rely heavily on specifications of industrial control protocols,making the test process costly,time-consuming,cumbersome and boring.If the norm does not exist,the task is difficult to carry out.This paper proposes an intelligent and automatic protocol fuzzing method based on pointer-generation networks(PGN),and gives a series of performance indicators.On the basis of this method,an intelligent and automatic fuzzing framework based on PGNFuzz for application is designed,which can be used for various industrial control protocols.Several typical industrial control protocols such as Modbus and EtherCAT are used to test the validity and efficiency of our framework.Experiment results show that our method is superior to other general purpose fuzzers(GPF) and other deep learning based fuzzing methods in terms of convenience,effectiveness and efficiency.

Background: Complications of Crohn's disease such as intestinal obstruction, fistula or perforation often need surgical treatment. Nearly 70%-80% patients with Crohn's disease would receive surgical treatment during the lifetime. However, surgical treatment is incurable for Crohn's disease. The challenge of recurrence postoperatively troubles both doctors and patients. Over 50% patients would suffer recurrence postoperatively. Some certain risk factors are associated with recurrence of Crohn's disease., Aim: To evaluate the risk factors for endoscopic recurrence and clinical recurrence after bowel resection in Crohn's disease., Methods: Patients diagnosed Crohn's disease and received intestinal resection between April 2007 and December 2013 were included in this study. Data on the general demographic information, preoperative clinical characteristics, surgical information, postoperative clinical characteristics were collected. Continuous data are expressed as median (inter quartile range), and categorical data as frequencies and percentages. Kaplan-Meier method was applied to estimate the impact of the clinical variables above on the cumulative rate of postoperative endoscopic recurrence and clinical recurrence, then log-rank test was applied to test the homogeneity of those clinical variables. Multivariate Cox proportional hazard regression analysis was performed to identify the risk factors of postoperative endoscopic recurrence and clinical recurrence., Results: A total of 64 patients were included in this study. The median follow-up time for the patients was 17 (9.25-25.75) mo. In this period, 41 patients (64.1%) had endoscopic recurrence or clinical recurrence. Endoscopic recurrence occurred in 34 (59.6%) patients while clinical recurrence occurred in 28 (43.8%) patients, with the interval between the operation and recurrence of 13.0 (8.0-24.5) months and 17.0 (8.0-27.8) mo, respectively. In univariate analysis, diagnosis at younger age ( P < 0.001), disease behavior of penetrating ( P = 0.044) and preoperative use of anti-tumor necrosis factor (TNF) ( P = 0.020) were significantly correlated with endoscopic recurrence, while complication with perianal lesions ( P = 0.032) and preoperative use of immunomodulatory ( P = 0.031) were significantly correlated with clinical recurrence. As to multivariate analysis, diagnostic age ( P = 0.004), disease behavior ( P = 0.041) and preoperative use of anti-TNF ( P = 0.010) were independent prognostic factors for endoscopic recurrence, while complication with perianal lesions ( P = 0.023) was an independent prognostic factor for clinical recurrence., Conclusion: Diagnostic age, disease behavior, preoperative use of anti-TNF and complication with perianal lesions were independent risk factors for postoperative recurrence in Crohn's disease., Competing Interests: Conflict-of-interest statement: All the Authors have no conflict of interest related to the manuscript., (©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.)

To study the effects of low temperature and simulated warming on respiration of biocrust-soil systems, intact soil columns covered by two dominant types of biocrusts (moss and algae-lichen crusts), were collected in a natural vegetation area in the southeast fringe of the Tengger Desert. Automated soil respiration system (Li-8150) was used to measure respiration rates in biocrust-soil systems under warming (by placing them in an open top chamber) and non-warming treatments in winter (from November 2015 to January 2016). During the whole observation period, soil respiration rates covered by moss crusts were significantly higher than those covered by algae-lichen crusts, which were -0.052 to 0.418 and -0.032 to 0.493 μmol·m -2 ·s -1 , respectively. The respiration rates of the two types of biocrust-soil systems showed significant positive linear correlations with soil temperature and volumetric soil water content at 5 cm depth. Through speeding-up the evaporation rates of soil moisture, imitated warming in winter impeded respiration rates of the two biocrust-soil systems. During the whole observation period, the cumulative carbon (C) release by moss crust-soil system (9.90 g C·m -2 ) was dramatically higher than that of algae-lichen crust-soil system (7.00 g C·m -2 ). The cumulative C release by the biocrust-soil systems in this region in winter was 7.40 g C·m -2 , thus comprising an important part of annual C budget in the desert ecosystems.

Two types of soil covered by biological soil crusts (BSCs) , i.e. moss and algae, and moving sand in the natural vegetation area at the southeast fringe of the Tengger Desert were collected intactly. They were incubated continuously for 20 days under two different temperatures (15 degrees C and 25 degrees C) and moistures (10% and 25%) condition in the laboratory, and soil NO3(-)-N contents were measured after 1, 2, 5, 8, 12, 20 days of incubation and net nitrification rate was evaluated during dehydration. The results showed that NO3(-)-N content of the moss-covered soil (2.29 mg x kg(-1)) was higher than that of the algae-covered soil (1.84 mg x kg(-1)) and sand (1.59 mg x kg(-1)). Net nitrification rate of the three soil types ranged from -3.47 to 2.97 mg x kg(-1) x d(-1). For the moss-covered soil and algae-covered soil at 10% and 25% moisture levels, the net nitrification rates at 15 degrees C were 75.1%, 0.7% and 99.1%, 21.3% higher than those at 25 degrees C, respectively. Also, the net nitrification rates at 15 degrees C and 10% moisture levels were 193.4% and 107.3% higher than those at 25 degrees C and 25% moisture levels, respectively. The results suggested that regardless of soil moisture increasing or decreasing under the global warming senior, the net nitrification rate of BSCs-soil system in the desert would probably be limited to some extent during drought process.

Three dual Lewis base functionalized ionic liquids (DLB-ILs) tethered with both carboxyl and tertiary amine groups on their anions were designed for highly efficient and selective absorption of H 2 S. It was found that the DLB-ILs could reversibly absorb 0.39-0.84 mol of H 2 S per mole of IL at 1 bar and 60 °C, which is significantly higher than that of other ILs. On the contrary, the CO 2 absorption in this class of DLB-ILs was shown to be quite limited relative to H 2 S owing to the coupling effect of the two Lewis base groups. It is the dual Lewis base functionalization that enables the significantly high values calculated for the ideal absorption selectivity for H 2 S/CO 2 , that is, 13-26 at 1 bar and 29-70 at 0.1 bar (60 °C). The selectivity even goes up to >100 at low pressures and high temperatures. It was further illustrated from DFT calculations and spectroscopy studies that the cooperation interaction of carboxyl⋅⋅⋅H 2 S⋅⋅⋅amine and the reduced binding with CO 2 were the major contributions to the high H 2 S absorption capacity and H 2 S/CO 2 selectivity., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)