Comparison of the Partition Efficiencies of Multiple Phenolic Compounds Contained in Propolis in Different Modes of Acetonitrile⁻Water-Based Homogenous Liquid⁻Liquid Extraction.

Homogeneous liquid⁻liquid extraction (HLLE) has attracted considerable interest in the sample preparation of multi-analyte analysis. In this study, HLLEs of multiple phenolic compounds in propolis, a polyphenol-enriched resinous substance collected by honeybees, were performed for improving the understanding of the differences in partition efficiencies in four acetonitrile⁻water-based HLLE methods, including salting-out assisted liquid⁻liquid extraction (SALLE), sugaring-out assisted liquid⁻liquid extraction (SULLE), hydrophobic-solvent assisted liquid⁻liquid extraction (HSLLE), and subzero-temperature assisted liquid⁻liquid extraction (STLLE). Phenolic compounds were separated in reversed-phase HPLC, and the partition efficiencies in different experimental conditions were evaluated. Results showed that less-polar phenolic compounds (kaempferol and caffeic acid phenethyl ester) were highly efficiently partitioned into the upper acetonitrile (ACN) phase in all four HLLE methods. For more-polar phenolic compounds (caffeic acid, p-coumaric acid, isoferulic acid, dimethoxycinnamic acid, and cinnamic acid), increasing the concentration of ACN in the ACN⁻H2O mixture could dramatically improve the partition efficiency. Moreover, results indicated that NaCl-based SALLE, HSLLE, and STLLE with ACN concentrations of 50:50 (ACN:H2O, v/v) could be used for the selective extraction of low-polarity phenolic compounds. MgSO4-based SALLE in the 50:50 ACN⁻H2O mixture (ACN:H2O, v/v) and the NaCl-based SALLE, SULLE, and STLLE with ACN concentrations of 70:30 (ACN:H2O, v/v) could be used as general extraction methods for multiple phenolic compounds.

Tracking the Turn Maneuvering Target Using the Multi-Target Bayes Filter with an Adaptive Estimation of Turn Rate.

Tracking the target that maneuvers at a variable turn rate is a challenging problem. The traditional solution for this problem is the use of the switching multiple models technique, which includes several dynamic models with different turn rates for matching the motion mode of the target at each point in time. However, the actual motion mode of a target at any time may be different from all of the dynamic models, because these models are usually limited. To address this problem, we establish a formula for estimating the turn rate of a maneuvering target. By applying the estimation method of the turn rate to the multi-target Bayes (MB) filter, we develop a MB filter with an adaptive estimation of the turn rate, in order to track multiple maneuvering targets. Simulation results indicate that the MB filter with an adaptive estimation of the turn rate, is better than the existing filter at tracking the target that maneuvers at a variable turn rate.

Creativity and Well-Being Among College Students: The Mediating Role of Meaning in Life.

The effects of creativity on well-being have been supported by many studies, but the mechanisms involved have not been fully studied. This study used the Creative Conceptual Behavioral Scale, the Well-Being Scale, and the Meaning of Life Questionnaire to survey 1124 college students, in order to explore the mechanism of creativity's influence on well-being from the perspective of meaning in life. The results showed that: (1) There was a bipartite positive correlation between creativity, well-being and meaning of life; and (2) meaning in life played a partial mediating role between creativity and well-being, that is to say, creativity not only directedly influenced well-being but also indirectedly influenced well-being through meaning in life. This study reveals the effect of creativity on well-being and its mechanism theoretically, which has certain practical reference value for the education of meaning in life for college students.

[Efficacy evaluation of percutaneous vertebroplasty via an extra-pedicular approach for osteoporotic compression fracture].

OBJECTIVE: To evaluate the effects of relieving pains and restoring vertebral heights of percutaneous balloon kyphoplasty by extra-pedicular approach as a minimally invasive treatment in patients with painful osteoporotic vertebral compressive fractures (OVCF). METHODS: A retrospective analysis was conducted for 96 consecutive patients. There were 64 females and 32 males with a mean age 67 years (range: 55 - 82). Symptomatic levels were identified by correlating their clinical presentations with the findings of magnetic resonance imaging (MRI). The interval between onset of symptoms and surgical intervention ranged from 2 days to 4 months. A total of 118 levels (56 thoracic, 62 lumbar) were treated in this cohort. Immediate and postoperative 3-month follow-up visits were conducted. Visual analog scale (VAS) pain scores, preoperative and postoperative anterior, midline vertebral heights for fractured vertebrae were measured on lateral radiographs to evaluate the procedural outcomes. RESULTS: There was swift pain relief associated with evident augmentation in weight-bearing resistance. Pain decreased from 8.1 to 2.1 points. Through kyphoplasty, the anterior, midline vertebral heights of 118 fractured vertebral bodies increased up to (75.83 ± 19.84)% and (71.23 ± 21.45)% respectively. None of them had worsening of fracture-induced narrowing of spinal canal. No device-related major complications occurred. CONCLUSION: Percutaneous kyphoplasty through an extra-pedicular approach results in immediate clinical improvement of mobility and pain relief. It safely increases vertebral body height and quickly returns geriatric patients to higher activity levels, increased independence and better quality-of-life. And its short-term outcomes are excellent.

[Posterior interbody fusion versus improved transforaminal lumbar interbody fusion in segmental spinal fixation for aged spondylolisthesis with lumbar spinal canal stenosis].

OBJECTIVE: To assess the clinical and radiographic outcomes of posterior lumbar fixation and posterior interbody fusion or improved transforaminal lumbar interbody fusion for Meyerding grade II/III spondylolisthesis so as to address the suitability of a dynamic stabilization. METHODS: A total of 28 consecutive patients underwent posterior lumbar fixation and posterior interbody fusion or improved transforaminal lumbar interbody fusion for Meyerding grade II/III spondylolisthesis. Among them, 13 patients underwent posterior interface fusion (PLIF) and pedicle screw fixation. And improved transforaminal lumbar interbody fusion (ITLIF) and placement of the same system were performed in 15 patients. Their clinical, economic, functional, and radiographic data were recorded both pre- and postoperatively. RESULTS: The average changes of economic and functional scores on the Prolo scale were 1.36 and 1.48 respectively. In patients with posterior interbody fusion; the average preoperative vertebral slippage was 46.9% (range: 25 - 75%) versus 14.6% (range: 15 - 25%) postoperatively. In patients with ITLIF, the average changes in economic and functional scores were 1.75 and 1.63 respectively. And the average preoperative vertebral slippage was 45.2% (range: 28 - 78%) compared with 26.3% (range: 14 - 28%) postoperatively. When two fusion techniques were compared, an overall superior reliability and resistance of systems was associated with the ITLIF procedure. But their clinical outcomes did not differ greatly (P > 0.05). CONCLUSIONS: The application of a segmental pedicle screw fixation is both feasible and efficacious.

[Treatment of upper cervical spine instability with posterior fusion plus atlantoaxial pedicle screw].

OBJECTIVE: To evaluate the clinical efficacies, indications and application values of posterior fusion plus pedicle screw fixation in the treatment of upper cervical spine instability. METHODS: From May 2006 to December 2010, a total of 24 patients with atlantoaxial instability were treated with C1-2 pedicle screws and rod fixation under general anesthesia. There were 18 males and 6 females with a mean age of 49.8 years old (range: 17 - 69). RESULTS: The postoperative radiographs verified a good position of all screws with satisfactory atlantoaxial reduction. A mean follow-up period of 23 months (range: 3 - 45) showed no injury of spinal cord and vertebral artery or inter fixation failure. Atlantoaxial alignment and stability were restored without instrumentation-related complications. CONCLUSION: Posterior atlantoaxial pedicle screw and rod fixation provide immediate three-dimensional rigid fixation of atlantoaxial joint. It is a more effective technique than with previously reported techniques.

Insight into the role of pre-assembly and desolvation in crystal nucleation: a case of p-nitrobenzoic acid.

As one of the most important phenomena in crystallization, the crystal nucleation process has always been the focus of research. In this work, influences of pre-assembly species and the desolvation process on the crystal nucleation process were studied. p-Nitrobenzoic acid (PNBA) was taken as a model compound to investigate the relationship between solution chemistry and nucleation kinetics in seven different solvents. One unsolvated form and four solvates of PNBA were obtained and one of the solvates was newly discovered. The nucleation behaviours and nucleation kinetics of PNBA in the seven solvents were studied and analyzed. Density functional theory (DFT) and solvation energy calculation were adopted to evaluate the strength of solute-solvent interactions. Vibrational spectroscopy combined with molecular simulation was applied to reveal the pre-assembly species in the solution. Based on these results, a comprehensive understanding of the relationship between molecular structure, crystal structure, solution chemistry and nucleation dynamics was proposed and discussed. It was found that the structural similarity between solution chemistry and crystal structure, the interaction between specific sites and the overall strength of solvation will jointly affect the nucleation process.

[Online soft sensing method for freezing point of diesel fuel based on NIR spectrometry].

To solve the problems of real-time online measurement for the freezing point of diesel fuel products, a soft sensing method by near-infrared (NIR) spectrometry was proposed. Firstly, the information of diesel fuel samples in the spectral region of 750-1 550 nm was extracted by spectrum analyzer, and the polynomial convolution algorithm was also applied in spectrogram smoothness, baseline correction and standardization. Principal component analysis (PCA) was then used to extract the features of NIR spectrum data sets, which not only reduced the number of input dimension, but increased their sensitivity to output. Finally the soft sensing model for freezing point was built using SVR algorithm. One hundred fifty diesel fuel samples were used as experimental materials, 100 of which were used as training (calibrating) samples and the others as testing samples. Four hundred and one dimensional original NIR absorption spectrum data sets, through PCA, were reduced to 6 dimensions. To investigate the measuring effect, the freezing points of the testing samples were estimated by four different soft sensing models, BP, SVR, PCA-BP and PCA+SVR. Experimental results show that (1) the soft sensing models using PCA to extract features are generally better than those used directly in spectrum wavelength domain; (2) SVR based model outperforms its main competitors-BP model in the limited training data, the error of which is only half of the latter; (3) The MSE between the estimated values by the presented method and the standard chemical values of freezing point by condensing method are less than 4.2. The research suggests that the proposed method can be used in fast measurement of the freezing point of diesel fuel products by NIRS.

Treatment of upper cervical spine instability with posterior fusion plus atlantoaxial pedicle screw.

Clinical results of posterior fusion plus pedicle screw fixation in the treatment of upper cervical spine instability were taken under consideration. 24 patients with atlantoaxial instability were treated with C1-2 pedicle screws and rods fixation under general anesthesia. There were 18 males and 6 females with mean age of 49.8 years (age range 17-69 years). The postoperative radiographs verified good position of all screws, with satisfactory atlantoaxial reduction. Follow-up for 3-45 months (average 23 months) showed no spinal cord and vertebral artery injury or interfixation failure. Atlantoaxial alignment and stability were restored without complication due to instrumentation. In conclusion, posterior atlantoaxial pedicle screw and rod fixation provide immediate three-dimensional rigid fixation of atlantoaxial joint and are more effective techniques compared with previously reported techniques.

[Surgical treatment of postoperative deep wound infection after posterior lumbar interlumbar fusion of the lumbar stenosis].

OBJECTIVE: To study surgical treatment for the deep wound infections after the operation of posterior lumbar interlumbar fusion (PLIF) in lumbar spinal stenosis. METHODS: From December 2005 to December 2010,10 patients with the deep wound infection of the PLIF were analyzed retrospectively, including 4 males and 6 females, with a mean age of 52.8 years (ranged from 34 to 70 years). All the patients were treated with debridement and the drainage. The sensitive antibiotics were used. The VAS score, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and JOA lumbar score were used to compare the clinical results pre-and post-operation. RESULTS: All the patients were followed up, and the mean duration was 24 months (ranged from 19 to 28 months). One patient developed to an intervertebral space infection and the cage was removed. One patient suffered a radical central nerve system infection and died after the debridement. Other 8 patients got a good clinical result. The VAS score decreased from preoperative 8.0 +/- 0.4 to postoperative 2.8 +/- 0.3; JOA score improved from preoperative 10.30 +/- 3.02 to postoperative 24.10 +/- 2.85; ESR decreased from preoperative (85.0 +/- 17.0) mm/h to postoperative (14.0 +/- 6.0) mm/h; both CRP and WBC decreased from preoperative (73.5 +/- 14.3) mg/L, (11.1 +/- 1.8) x 10(9)/L to postoperative (5.1 +/- 1.1) mg/L, (7.4 +/- 0.5) x 10(9)/L respectively. CONCLUSION: Treatment of patients with deep wound infections after PLIF with debridement, drainage, and sensitive antibiotics could get a good long-term clinical result, which is important to treat the patients with high-risk factors. Early diagnosis and operation is the key to deal with the patients with deep wound infections after PLIF.

[Comparison between bipedicular approach and uni-extrapedicular approach in application of vertebroplasty].

OBJECTIVE: To analyze the advantages and disadvantages of bipedicular approach and uni-extrapedicular approach of vertebroplasty in treating osteoporotic vertebral compression fractures (OVCFs). METHODS: From January 2008 to December 2010,53 patients with OVCFs were retrospectively analyzed. There were 24 males, 30 females with an average age of 66.9 years (ranged,59 to 88 years). Among them, 26 cases were treated with bipedicular approach, 28 cases were treated with uni-extrapedicular approach. The data of bone cement injection, radiology exposure times, operation time, bone cement leakage and vessels nerve complications were observed. Cobb angle, vertebral compression ration were observed by imaging data, and evaluate recovery of deformity. RESULTS: The data of bone cement injection, radiology exposure times, operation time, VAS score were (6.6 +/- 0.8) ml and (6.8 +/- 1.5) ml, (21.7 +/- 4.0) times and (17.9 +/- 3.6) times, (40.5 +/- 5.5) min and (31.6 +/- 9.1) min, (2.8 +/- 0.6) scores and (3.1 +/- 0.5) scores respectively. Cobb angle,vertebral compression ration were (7.6 +/- 2.0) degrees and (6.9 +/- 2.6) degrees, (18.1 +/- 5.8)% and (16.5 +/- 6.1)%. There were no vascular nerve complications occurred. For bone cement leakage, 3 cases (11%) in bipedicular approach and 3 cases (11%)in uni-extrapedicular approach. There was no significant differences between two groups in VAS score, recovery of vetebral body, Cobb angle, bone cement injection and bone cement leakage, but had significant differences in radiology exposure times and operation time (P<0.05). CONCLUSION: Both of two approaches can treat OVCFs well, especially extropedicle approach which could reduce operation time and radiation shoot frequency.