Construction and Evaluation of Prognosis Prediction Model for Patients with Brain Contusion and Laceration Based on Machine Learning.

Objective: Finding valuable risk factors for the prognosis of brain contusion and laceration can help patients understand the condition and improve the prognosis. This study is aimed at analyzing the risk factors of poor prognosis in patients with brain contusion after the operation. Methods: A total of 136 patients with cerebral contusion and laceration combined with cerebral hernia treated by neurosurgical craniotomy in our hospital were retrospectively selected and divided into a training set (n = 95) and a test set (n = 41) by the 10-fold crossover method. Logistic regression and back-propagation neural network prediction models were established to predict poor prognosis factors. The receiver operating characteristic curve (ROC) and the calibration curve were used to verify the differentiation and consistency of the prediction model. Results: Based on logistic regression and back-propagation neural network prediction models, GCS score ≤ 8 on admission, blood loss ≥ 30 ml, mannitol ≥ 2 weeks, anticoagulants before admission, and surgical treatment are the risk factors that affect the poor prognosis of patients with a cerebral contusion after the operation. The area under the ROC was 0.816 (95% CI 0.705~0.926) and 0.819 (95% CI 0.708~0.931), respectively. Conclusion: The prediction model based on the risk factors that affect the poor prognosis of patients with brain contusion and laceration has good discrimination and accuracy.

Blood Pressure Model Based on Hybrid Feature Convolution Neural Network in Promoting Rehabilitation of Patients with Hypertensive Intracerebral Hemorrhage.

OBJECTIVE: Accurate prediction of the rise of blood pressure is essential for the hypertensive intracerebral hemorrhage. This study uses the hybrid feature convolution neural network to establish the blood pressure model instead of the traditional method of pulse waves. METHODS: The pulse waves of 100 patients were collected, and the pulse wave was decomposed into three bell wave compound forms to obtain the accurate pulse wave propagation time. Then, the mixed feature convolution neural network model ABP-net was proposed, which combined the pulse wave propagation time characteristics with the pulse wave waveform characteristics automatically extracted by one-dimensional convolution to predict the arterial blood pressure. Finally, according to the prediction results, 20 patients were treated before the high blood pressure appeared (model group), and another 20 patients with a daily fixed treatment scheme were selected as the control group. RESULTS: In 80 training sets, compared with linear regression and the random forest method, the hybrid feature convolution neural network has higher accuracy in predicting blood pressure. In 20 test sets, the blood pressure error was eliminated within 5 mmHg. The total effective rate in the model group and the control group was 95.0% and 85.0%, respectively (P = 0.035). After treatment, the scores of self-care ability of daily life and limb motor function in the model group were higher than those in the control group (P < 0.05). There were 8 cases (13.6%) in the model group and 17 cases (28.3%) in the control group due to the recurrence of cerebrovascular accident (P = 0.043). CONCLUSION: Drug treatment guided by a blood pressure model based on a hybrid feature convolution neural network for patients with hypertensive cerebral hemorrhage can significantly and smoothly reduce blood pressure, promote the health recovery, and reduce the occurrence of cerebrovascular accidents.

Femtosecond laser patterned superhydrophobic/hydrophobic SERS sensors for rapid positioning ultratrace detection.

Ultratrace molecular detections are vital for precancer diagnosis, forensic analysis, and food safety. Superhydrophobic (SH) surface-enhanced Raman scattering (SERS) sensors are regarded as an ideal approach to improve detection performance by concentrating analyte molecules within a small volume. However, due to the low adhesion of SH surfaces, the analyte droplet is prone to rolling, making it hard to deposit molecules on a predetermined position. Furthermore, the sediment with a very small area on the SH-SERS surface is difficult to be captured even with a Raman microscope. In this study, femtosecond laser fabricated hybrid SH/hydrophobic (SH/HB) surfaces are successfully applied to realize a rapid and highly sensitive SERS detection. By modulating dual surface structures and wetting behaviors, the analyte molecules can be enriched at the edge of HB pattern. This improves the convenience and speed of Raman test. On a hybrid SH/HB SERS substrate with a circular HB pattern at 300-µm-diameter, a femtomolar level (10-14 M) of rhodamine 6G can be detected by using analyte volumes of just 5 µL. The SERS enhancement factor can reach 5.7×108 and a good uniformity with a relative standard deviation of 6.98% is achieved. Our results indicate that the laser fabrication of hybrid SERS sensor offers an efficient and cost-effective approach for ultratrace molecular detection.

Laser-Induced Wettability Gradient Surface of the Aluminum Matrix Used for Directional Transportation and Collection of Underwater Bubbles.

The control of underwater bubble behavior on a solid surface has great research significance. However, the control of the spontaneous directional transport and collection of numerous underwater bubbles remains a challenge. A new technique of a metal mesh with superhydrophobic/hydrophobic properties is demonstrated here, which creates a wettability gradient coupled with a microporous array by means of pulsed fiber laser ablation and chemical modification of the aluminum sheet. The resultant wettability surface effectively achieved the spontaneous movement of bubbles along the directional wettability gradient (superaerophobicity to aerophilicity) and through the metal mesh (aerophilicity to superaerophilicity) in the direction of decreasing free energy. Theoretical analysis accounted first for the spontaneous sliding of bubbles on the wettability gradient surface as a result of the action of an unbalanced surface tension force and second for the spontaneous transition of bubbles from the aerophilic to superaerophilic side as a result of the combined action of Laplace pressure and buoyancy. A device with the capability of directional transportation and collection of underwater bubbles was designed based on the samples with a wettability gradient and a superhydrophobic/hydrophobic microporous array as the core components. The potential application is laser ablation of wettability gradient surfaces and metal mesh with superhydrophobic/hydrophobic properties for directional transportation and collection of underwater bubbles.

Method of calculating the aberrations of soft X-ray and vacuum ultraviolet optical systems.

Based on the the third-order aberration theory of plane-symmetric optical systems, this paper studies the effect on aberrations of the second-order accuracy of aperture-ray coordinates and the extrinsic aberrations of this kind of optical system; their calculation expressions are derived. The resultant aberration expressions are then applied to calculate the aberrations of two design examples of soft X-ray and vacuum ultraviolet (XUV) optical systems; images are compared with ray-tracing results using SHADOW software to validate the aberration expressions. The study shows that the accuracy of the aberration expressions is satisfactory.

CdTe nanocrystals-enhanced chemiluminescence from peroxynitrous acid-carbonate and its application to the direct determination of nitrite.

It was found that CdTe semiconductor nanocrystals (NCs) can induce a great sensitized effect on chemiluminescence (CL) emission from peroxynitrous acid (ONOOH)-Na(2)CO(3) system. CL spectra, fluorescence (FL) spectra, and the quenching effect of reactive oxygen species were used to investigate the CL reaction mechanism. The CL intensity was proportional to the concentration of nitrite in the range from 0.05 to 50µM. The detection limit (S/N=3) was 0.024µM and the relative standard deviation (RSD) for five repeated measurements of 0.5µM nitrite was 4.2%. This method has been successfully applied to determine nitrite in well water samples with recoveries of 94.0-100.5%. This was the first work for direct (not inhibition effect) determination of analytes using semiconductor NCs-based CL sensor.

Fluorosurfactant-prepared triangular gold nanoparticles as postcolumn chemiluminescence reagents for high-performance liquid chromatography assay of low molecular weight aminothiols in biological fluids.

Our recent study demonstrates the synthesized triangular gold nanoparticles (AuNPs) by trisodium citrate reduction of HAuCl(4) in the presence of nonionic fluorosurfactant (FSN) could display stronger catalytic activity towards luminol-chemiluminescence (CL) than spherical AuNPs. Ultratrace aminothiols may cause a great decrease in CL intensity of the triangular AuNPs-luminol CL system. In this article, we utilize the as-prepared triangular AuNPs as novel postcolumn CL reagents to explore a simple high-performance liquid chromatography (HPLC)-CL method for the determination of low molecular weight aminothiols (i.e., cysteine, homocysteine, glutathione, cysteinylglycine and glutamylcysteine). The as-prepared triangular AuNPs were easier to synthesize, stable at a wider pH range and high ionic strength, and highly selective and sensitive towards reduced aminothiols. The detection limits at a signal-to-noise ratio of 3 for cysteine, homocysteine, glutathione, cysteinylglycine and glutamylcysteine were 0.016, 0.08, 0.1, 0.04 and 0.1pmol, respectively. Recoveries from spiked urine and plasma samples were 95.7-104.3%. The applicability of the proposed method has been validated by determining these low molecular weight aminothiols in human urine and plasma samples with satisfactory results, and thus it will have great potential application in clinical diagnosis.

Gold nanorod-catalyzed luminol chemiluminescence and its selective determination of glutathione in the cell extracts of Saccharomyces cerevisiae.

In this study, gold nanorods were firstly found to exhibit a tremendously higher catalytic activity towards luminol chemiluminescence (CL) than spherical gold nanoparticles. More importantly, ultra-trace aminothiols can cause a great CL decrease in the gold nanorod-catalyzed luminol system by the formation of Au-S covalent bonds on the ends of gold nanorods. Aminothiols can occupy the active sites of gold nanorods, and further interrupt the generation of the active oxygen intermediates. Other biomolecules including 19 standard amino acids, alcohols, organic acids and saccharides have no effect on gold nanorod-catalyzed luminol CL signals. Moreover, in order to evaluate the applicability and reliability of the proposed method, it was applied to the determination of glutathione in the cell extracts of Saccharomyces cerevisiae. Good agreements were obtained for the determination of glutathione in the cell extracts of S. cerevisiae between the present approach and a standard Alloxan method. The recoveries of glutathione were found to fall in the range between 96 and 105%. The calibration curve for glutathione was found to be linear from 0.05 to 100 nM, and the detection limit (S/N=3) was 0.01 nM. The relative standard deviation (RSD) for five repeated measurements of 5.0 nM glutathione was 2.1%.

Life cycle assessment of a wastewater treatment plant focused on material and energy flows.

Life cycle assessment (LCA) was applied to analyze a food-processing wastewater treatment plant and investigate the economic and environmental effects of the plant. With the long-term operational data of this plant, an inventory of relative inputs, e.g., flow rate, chemical oxygen demand (COD), and suspended solids, etc., and outputs of the plant, e.g., effluent COD and suspended solids, methane production, etc., was compiled. The potential environmental effects associated with those inputs and outputs were evaluated, and the results of the inventory analysis and impact assessment phases of the plant were interpreted. One feature of this study was the assessment of the treatment plant based on both energy and material flows. Another feature was the establishment of an assessment model with an integration of plant operating parameters, system recognition and grey relation. The analytical results are helpful for the design and operation of wastewater treatment plants.

Cloud point extraction combined with high-performance liquid chromatography for speciation of chromium(III) and chromium(VI) in environmental sediment samples.

A sensitive and simple method for high-performance liquid chromatography (HPLC) determination of traces of chromium species in lake sediments after preconcentration by cloud point extraction (CPE) has been developed. Simultaneous preconcentration of Cr(III) and Cr(VI) in sediment samples was achieved by CPE with 1-(2-thiazolylazo)-2-naphthol (TAN) as the chelating agent and non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) as the extractant. Baseline separation of the TAN chelates of Cr(III) and Cr(VI) was realized on a RP-C(18) column by using a mixture of methanol-water (69:31, v/v) solution and 4.5 mmol L(-1) CTMAB buffered with 0.03 mol L(-1) NaAc-HAc solution (pH 5.5) as the mobile phase at a flow rate of 0.8 mL min(-1). The variables affecting the complexation and extraction steps were examined. The precision (R.S.D.) for seven replicate injections of a mixture of 100 microg L(-1) of Cr(III) and Cr(VI) was 1.2 and 0.9% for the retention time, 4.7 and 2.7% for the peak area, respectively. The concentration factor was 45 for Cr(III) and 40 for Cr(VI). The detection limit (LOD) of this method, calculated as three times the standard deviation of the blank signals was 7.5 microg L(-1) for Cr(III) and 3.5 microg L(-1) for Cr(VI), respectively. The proposed procedure was applied to the speciation of chromium in sediment samples with satisfactory results.

Molecularly imprinted solid-phase extraction combined with high performance liquid chromatography for analysis of phenolic compounds from environmental water samples.

The molecularly imprinted bulk polymer with 2,4,6-trichlorophenol (2,4,6-TCP) as the template molecule and methylacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA) as functional monomer and the crosslinker, respectively, has been prepared and applied to the molecularly imprinted solid-phase extraction (MISPE) procedure for selective preconcentration of phenolic compounds from environmental water samples. Various parameters affecting the extraction efficiency of the polymer have been evaluated to optimize the selective preconcentration of the phenolic compounds from aqueous samples. The characteristics of the MISPE method were validated by HPLC. The recoveries ranged between 90% and 98% (RSD: 0.9-2.3%, n=3) for tap water, between 85% and 105% (RSD: 2.6-4.9%, n=3) for river water, between 78% and 98% (RSD: 2.6-5.4%, n=3) for sewage water fortified with 0.4 mg L(-1) of phenol, 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), pentachlorophenol (PCP). It was demonstrated that this MISPE-HPLC method could be applied to direct preconcentration and determination of phenolic compounds in environmental water samples.

Application of dimethyl-beta-cyclodextrin as a chiral selector in capillary electrophoresis for enantiomer separation of ephedrine and related compounds in some drugs.

Dimethyl-beta-cyclodextrin (DM-beta-CD) modified capillary electrophoresis has been developed for chiral separation of ephedrine and related compounds, such as (+/-)-norephedrine, (+/-)-N-methylephedrine, (+/-)-ephedrine and (+)-pseudoephedrine. The influence of some crucial parameters such as buffer concentration, pH value, DM-beta-CD concentration, applied voltage and separation temperature on the separation was investigated. Under the optimum conditions, i.e. 40 mM DM-beta-CD in 75 mM Tris (pH 2.5) as the running electrolyte, separation voltage +25 kV and temperature 25 degrees C, a satisfactory separation of the enantiomers was accomplished. The detection limits (S/N = 3) ranged from 65 to 161 ng/mL and the linear range was 0.15 to 101.0 microg/mL for pressure injection. The present method was successfully applied for the analysis of a series of drugs such as anti-tussive, the drug for rheum, the drug for rhinitis and a Chinese traditional herbal medicine, Ephedrae herba (Ma-Huang in Chinese). The recoveries of ephedrine and related compounds in real samples ranged from 97.6 to 103.5%. This method is useful in the simple and rapid analysis of ephedrine derivatives in marketed products.

Chiral separation based on ligand-exchange capillary electrophoresis using a copper(II)-L-ornithine ternary complex as selector.

A ligand-exchange capillary electrophoresis was explored, with L-ornithine as the ligand and copper(II) as the central ion. Its applicability was demonstrated with underivatized and dansyl amino acids, a dipeptide, and drugs with amino alcohol structure. The enantioselectivity was found to be strongly dependent on pH and copper(II)-L-Orn complex concentration. Due to the adsorption of the positively charged species onto the capillary inner walls, the chiral separation selectivity is very high while the efficiency is relatively low. Permanent 1,3-propanediamine-coated capillaries show an improved separation efficiency and theoretical plate numbers increasing from 10(4) to 10(5). Similar phenomena were observed when sodium dodecyl sulfate (SDS) micelles were added to the copper(II) complex solution. The poor separation efficiency of chiral compounds in uncoated capillaries may result from the low rate of the ligand-exchange reactions, and the high enantioselectivity may derive from the complexing process in the adsorbed phase.

Separation of enantiomers in microemulsion electrokinetic chromatography using chiral alcohols as cosurfactants.

A novel chiral microemulsion, which involved the use of chiral alcohols as cosurfactants, was demonstrated for the enantiomeric separation of a number of pharmaceutical drugs in microemulsion electrokinetic chromatography (MEEKC). The chiral alcohols investigated were optically active 2-alkanols, with the alkyl chain length having carbon number ranging from 4 to 7. The data indicated that, except for R-(-)-2-butanol, the use of R-(-)-2-pentanol, R-(-)-2-hexanol or R-(-)-2-heptanol as the chiral cosurfactant resulted in the baseline or partial resolution of most of the test solutes, i.e., (+/-)-norephedrine, (+/-)-ephedrine, DL-nadolol, and DL-propranolol. In addition to the chain length of the chiral 2-alkanols, the effects of other experimental conditions, such as the concentration and chirality of the 2-alkanols, as well as the pH of the run buffer and the oil phase of the microemulsion, on the enantiomeric separation of the test solutes were also investigated. An interesting finding was that the water-immiscible organic solvent (oil core) within the microemulsion droplets appeared to play an important role in the chiral separation mechanism. Also, the importance of hydrogen bonding between the test solutes ((+/-)-ephedrine and related compounds) and the chiral microemulsion was demonstrated, as it was not possible to resolve a pair of enantiomers which lacked a beta-amino proton (i.e., (+/-)-N-methyl ephedrine) under optimized run buffer conditions (e.g., 5.0% R-(-)-2-hexanol, 0.8% n-octane, and 3.5% SDS in 90.7% borate buffer at pH 9.2).

Chiral separation with ligand-exchange micellar electrokinetic chromatography using a D-penicillamine-copper(II) ternary complex as chiral selector.

D-Penicillamine is demonstrated for the first time as a chiral ligand for the enantioseparation of dansyl amino acids based on ligand-exchange micellar electrokinetic chromatography (LE-MEKC). Copper(II) was used as the central ion in the ternary complex. The effect of surfactant on the resolution was significant. A concentration of 20 mM sodium dodecyl sulfate (SDS) was shown to be necessary for the separation. Other important parameters, such as the concentration ratio of D-penicillamine (D-PEN) to Cu2+, the kind of metal central ion, the type and pH value of buffer, were also investigated. N-Acetyl-D-penicillamine and L-valine (Val), with similar structure to D-penicillamine, were applied as their copper(II) complexes as chiral selector and the chiral recognition mechanism is briefly discussed. Under optimum experimental conditions, i.e., 20 mM NH4OAc, pH 6.5, a 2:1 concentration ratio of D-penicillamine to Cu(II), 4 mM CuSO4 and 8 mM D-penicillamine, the chiral separation of eight pairs of different dansyl amino acid enantiomers was accomplished with resolution ranging from 1.1 to 5.9. When L-PEN was used instead of D-PEN, reversal of the migration order was observed.

Chiral separation of underivatized and dansyl amino acids by ligand-exchange micellar electrokinetic capillary chromatography using a copper(II)-L-valine complex as selector.

Ligand-exchange micellar electrokinetic capillary chromatography was used for the chiral resolution of underivatized and dansyl amino acid enantiomers simultaneously. The separation was achieved by chiral copper(II)-L-valine complexes incorporated in micelles of sodium dodecyl sulfate (SDS). The enantioresolution was strongly affected by SDS and a concentration of 20 mM SDS was shown to be necessary for the separation. Other impacting factors were investigated including pH, the molar ratio of copper(II) to L-valine and the total concentration of complex. Using the proposed method, 11 different dansyl amino acids and two underivatized amino acids were separated successfully with a running electrolyte of 20 mM NH4OAc, 4 mM CuSO4, 8 mM L-valine and 20 mM SDS at pH 9.0 in less than 25 min. Experiments were also performed with other amino acid ligands in order to vary the stability and the sterical arrangement of the copper(II) complexes and the possible chiral recognition mechanism was also discussed briefly.