Prediction model of land surface settlement deformation based on improved LSTM method: CEEMDAN-ICA-AM-LSTM (CIAL) prediction model.

The uneven settlement of the surrounding ground surface caused by subway construction is not only complicated but also liable to cause casualties and property damage, so a timely understanding of the ground settlement deformation in the subway excavation and its prediction in real time is of practical significance. Due to the complex nonlinear relationship between subway settlement deformation and numerous influencing factors, as well as the existence of a time lag effect and the influence of various factors in the process, the prediction performance and accuracy of traditional prediction methods can no longer meet industry demands. Therefore, this paper proposes a surface settlement deformation prediction model by combining noise reduction and attention mechanism (AM) with the long short-term memory (LSTM). The complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and independent component analysis (ICA) methods are used to denoise the input original data and then combined with AM and LSTM for prediction to obtain the CEEMDAN-ICA-AM-LSTM (CIAL) prediction model. Taking the settlement monitoring data of the construction site of Urumqi Rail Transit Line 1 as an example for analysis reveals that the model in this paper has better effectiveness and applicability in the prediction of surface settlement deformation than multiple prediction models. The RMSE, MAE, and MAPE values of the CIAL model are 0.041, 0.033 and 0.384%; R2 is the largest; the prediction effect is the best; the prediction accuracy is the highest; and its reliability is good. The new method is effective for monitoring the safety of surface settlement deformation.

A rapid method for the assessment of the surface group density of carboxylic acid-functionalized polystyrene microparticles.

Particle-based assays are becoming versatile analytical tools due to their cost-effectiveness, speed, straightforward and diverse functionalization chemistries, especially when polystyrene particles are used. The introduction of functional groups (-COOH, -NH2, etc.) to the surface of such polystyrene particles promotes their application in bioanalytics. However, the traditional method to determine the amount of surface carboxylate groups is conductivity titration, which is usually time- and resources-consuming and discontinuous. Here, we synthesized polystyrene microparticles with different contents of carboxylate groups, and then investigated a simpler and potentially continuous approach to determine the amount of surface carboxylate groups by Zeta potential measurements. The results were compared to the traditional titration method and to actual coupling efficiencies of the functionalized particles with a model oligonucleotide probe as determined by flow cytometry. All quantification methods revealed good agreement.

Dye/DNA conjugates as multiple labels for antibodies in sensitive fluorescence immunoassays.

Fluorescence immunoassays are widely used in life science research, medical diagnostics, and environmental monitoring due to the intrinsically high specificity, simplicity, and versatility of immunoassays as well as the availability of a large variety of fluorescent labeling molecules. However, the sensitivity of immunoassays needs to be improved further to meet the ever-increasing demands of the new proteomics era. We have developed a novel and simple method to increase immunoassay sensitivity by attaching multiple fluorescent labels on an antibody with a dye/DNA conjugate. Our strategy is to use a DNA fragment as a molecular carrier to attach multiple fluorescent dyes to an antibody at a single site. The dye/DNA conjugate is not presynthesized, but rather formed in situ as part of the immunoassay. Our results demonstrate that by using a 219-bp DNA fragment in conjunction with SYBR Green I fluorescent DNA-binder, the sensitivity of both direct and competitive fluorescence immunoassays is improved by orders of magnitude, reaching a lower detection limit of 1.9 pg/mL for 17ß-estradiol.

Luminescence amplification strategies integrated with microparticle and nanoparticle platforms.

The amplification of luminescence signals is often the key to sensitive and powerful detection protocols. Besides optimized fluorescent probes and labels, functionalized nano- and microparticles have received strongly increasing attention in this context during the past decade. This contribution introduces the main signalling concepts for particle-based amplification strategies and stresses, especially the important role that metal and semiconductor nanoparticles play in this field. Besides resonance energy transfer, metal-enhanced emission and the catalytic generation of luminescence, the impact of multi-chromophoric objects such as dye nanocrystals, dendrimers, conjugated polymers or mesoporous hybrid materials is assessed. The representative examples discussed cover a broad range of analytes from metal ions and small organic molecules to oligonucleotides and enzyme activity.

Part-per-trillion level detection of estradiol by competitive fluorescence immunoassay using DNA/dye conjugate as antibody multiple labels.

Fluorescent organic dyes are currently the standard signal-generating labels used in microarray quantification. However, new labeling strategies are needed to meet the demand for high sensitivity in the detection of low-abundance proteins and small molecules. In this report, a long-chain DNA/dye conjugate was used to attach multiple fluorescence labels on antibodies to improve signal intensity and immunoassay sensitivity. Compared with the 30 base-pair (bp) oligonucleotide used in our previous work [Q. Zhang, L.-H. Guo, Bioconjugate Chem. 18 (2007) 1668-1672], conjugation of a 219 bp DNA in solution with a fluorescent DNA binder SYBR Green I resulted in more than sixfold increase in signal intensity, consistent with the increase in bp number. In a direct immunoassay for the detection of goat anti-mouse IgG in a mouse IgG-coated 96-well plate, the long DNA conjugate label also produced higher fluorescence than the short one, accompanied by about 15-fold improvement in the detection limit. To demonstrate its advantage in real applications, the DNA/dye conjugate was employed in the competitive immunoassay of 17beta-estradiol, a clinically and environmentally important analyte. The biotin-terminated DNA was attached to biotinylated anti-estradiol antibody through the biotin/streptavidin/biotin bridge after the immuno-reaction was completed, followed by conjugation with SYBR Green I. The limit of detection for 17beta-estradiol is 1.9 pg mL(-1), which is 200-fold lower than the assay using fluorescein-labeled antibodies. The new multiple labeling strategy uses readily available reagents, and is also compatible with current biochip platform. It has great potential in the sensitive detection of protein and antibody microarrays.

Photoelectrochemical sensor for the rapid detection of in situ DNA damage induced by enzyme-catalyzed fenton reaction.

Photoelectrochemical sensors were developed for the rapid detection of oxidative DNA damage induced by Fe2+ and H2O2 generated in situ by the enzyme glucose oxidase. The sensor is a multilayer film prepared on a tin oxide nanoparticle electrode by layer-by-layer self-assembly and is composed of separate layers of a photoelectrochemical indicator, DNA, and glucose oxidase. The enzyme catalyzes the formation of H2O2 in the presence of glucose, which then reacts with Fe2+ and generates hydroxyl radicals by the Fenton reaction. The radicals attack DNA in the sensor film, mimicking metal toxicity pathways in vivo. The DNA damage is detected by monitoring the change of photocurrent of the indicator. In one sensor configuration, a DNA intercalator, Ru(bpy)2(dppz)2+ (bpy = 2,2'-bipyridine, dppz = dipyrido[3,2-a:2',3'-c]phenazine), was employed as the photoelectrochemical indicator. The damaged DNA on the sensor bound less Ru(bpy)2(dppz)2+ than the intact DNA, resulting in a drop in photocurrent. In another configuration, ruthenium tris(bipyridine) was used as the indicator and was immobilized on the electrode underneath the DNA layer. After oxidative damage, the DNA bases became more accessible to photoelectrochemical oxidation than the intact DNA, producing a rise in photocurrent. Both sensors displayed substantial photocurrent change after incubation in Fe2+/glucose in a time-dependent manner. And the detection limit of the first sensor was less than 50 microM. The results were verified independently by fluorescence and gel electrophoresis experiments. When fully integrated with cell-mimicking components, the photoelectrochemical DNA sensor has the potential to become a rapid, high-throughput, and inexpensive screening tool for chemical genotoxicity.

[Regulation effects of arbuscular mycorrhizal fungi on the interactions between barnyard grass and upland rice under enhanced nitrogen supply].

A pot experiment was conducted to study the regulation effects of arbuscular mycorrhizal fungi (AMF) on the interactions between Echinochloa crus-galli var. mitis L. and Oryza sativa L. under enhanced N supply (4.0 g N x m(-2) x a(-1)). The results showed that under monoculture condition, the AMF colonization on E. crus-galli increased but that on O. sativa decreased. In the treatments with and without AMF inoculation, upland rice biomass and its P and N uptake increased by 42.35% and 13.48%, 4.07% and 2.55%, and 30.35% and 62.09%, respectively, and barnyard grass biomass and its P and N uptake increased by 20.24% and 15.65%, 3.88% and 4.06%, and 15.10% and 30.35%, respectively. Under mixed cropping, the AMF colonization on E. crus-galli increased but that on O. sativa had little change. In the treatments with and without AMF inoculation, the biomass ratio of O. sativa to E. crus-galli decreased, but N uptake ratio changed a little. The P uptake ratio of O. sativa to E. crus-galli increased in treatment without AMF inoculation but decreased in treatment with AMF inoculation. It was suggested that AMF tended to enhance the competition of E. crus-galli to O. sativa under enhanced N supply.

[Effect of Eu3+ molar ratio on the spectra of Y2O2:Eu3+, Mg2+ and Ti4+ red phosphor].

Synthesis of Y2O2S:Eu3+, Mg2+ and Ti4+ red phosphor by flux fusion method was presented. The decay curve of Y2O2S:Eu3+, Mg2+ and Ti4+ red phosphor was measured and the afterglow time was over one hour. The emission spectra and excitation spectra were measured, and the effect of Eu3+ molar ratio on the emission spectra and excitation spectra were also discussed. The emission spectra showed that Y2O2S:Eu3+, Mg2+ and Ti4+ had narrow emission peaks. The emission peaks ascribed to Eu3+ ions transition from 5D(J) (J = 0, 1, 2, 3,) to 7F(J) (J = 0, 1, 2, 3, 4, 5) were found. With the increase of Eu3+ molar ratio, the emission peaks 513.6, 540.1, 556.4, 587.3 and 589.3 nm ascribed to the energy transition 5D2, 5D1 to 7F(J) (J = 0, 1, 2, 3, 4) deteriorated gradually relative to the main emission peak at 627.0 nm. The emission peaks ascribed to energy transition 5D0 to 7F(J) (J = 0, 1, 2, 3, 4) didn't weaken relative to the main emission peak. It was probably due to the so-called true activator saturation effect. This function on the higher activated states 5D2 and 5D1 was more distinct. The excitation spectra of Y2O2S:Eu3+, Mg2+ and Ti4+ showed that it had excitation peaks at 350 nm nearby, which was ascribed to the absorption of charge transfer (Eu3+-O2-, Eu3+-S2-). The excitation peaks at 468, 520 and 540 nm were ascribed to the representative energy transition 4f-4f of Eu3+ ions. With the increase of Eu3+ molar ratio, the excitation peaks 468, 520 and 540 nm strengthened relative to the main absorption peak at 350 nm nearby.

[Resources of medicinal pteridophyta in Fengyang Mountain and Baishanzu Nature Reservation].

Natural environment of Fengyang Mountain and Baishanzu Nature Reservation is superiority. The vegetation is preserved well and the plant resources is rich. There are 79 species medicinal pteridophyta in this area. According to potency, it can be divided into 16 types, such as medicines for relieving exterior syndrome, medicines for clearing away heat, antirheumatic, medicines for inducing diuresis, medicines for expelling the parasites, hemostasis medicines, medicines for activating blood circulation to remove blood stasis, medicines for restoring vital energy, medicines for calming the liver to stop the wind, etc.