Mesenchymal stem cell-derived extracellular vesicles for treatment of bone loss within periodontitis in pre-clinical animal models: a meta-analysis.

BACKGROUND: Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) represent an effective and promising strategy for periodontitis, although studies remain pre-clinical. Herein, a meta-analysis was conducted to assess the efficacy of MSC-EVs in animal models of periodontitis. METHODS: The PubMed, Web of Science, and Embase electronic databases were searched up to Dec 2022 to retrieve preclinical studies examining the use of MSC-EVs for periodontitis treatment. Meta-analyses and sub-group analyses were performed to assess the effect of MSC-EVs on Bone Volume/Total Volume (BV/TV) or the distance between the cementoenamel junction and alveolar bone crest (CEJ-ABC) in pre-clinical animal models of periodontitis. RESULTS: 11 studies published from Mar 2019 to Oct 2022 met the inclusion criteria. Overall, MSC-EVs contributed to periodontal bone regeneration in the inflammatory bone loss area due to periodontitis, as represented by a weighted mean difference (WMD) of 14.07% (95% CI = 6.73, 21.41%, p < 0.001) for BV/TV and a WMD of -0.12 mm (95% CI= -0.14, -0.11 mm, p < 0.001) for CEJ-ABC. However, sub-analysis suggested that there was no significant difference in CEJ-ABC between studies with bioactive scaffolds and studies without bioactive scaffolds (p = 0.60). CONCLUSIONS: The present study suggests that MSC-EVs may represent an attractive therapy for the treatment of inflammatory bone loss within periodontitis.

Hydrated Hydroxide Complex Dominates the AIE Properties of Nonconjugated Polymeric Luminophores.

Nontraditional intrinsic luminescence (NTIL) which always accompanied with aggregation-induced emission (AIE) features has received considerable attention due to their importance in the understanding of basic luminescence principle and potential practical applications. However, the rational modulation of the NTIL of nonconventional luminophores remains difficult, on account of the limited understanding of emission mechanisms. Herein, the emission color of nonconjugated poly(methyl vinyl ether-alt-maleic anhydride) (PMVEMA) can be readily regulated from blue to red by controlling the alkalinity during the hydrolysis process. The nontraditional photoluminescence with AIE property is from the new formed p-band state, resulting from the strong overlapping of p orbitals of the clustered O atoms through space interactions. Hydrated hydroxide complexes embedded in the entangled polymer chain make big difference on the clustering of O atoms which dominates the AIE property of nonconjugated PMVEMA. These new insights into the photoluminescence mechanism of NTIL should stimulate additional experimental and theoretical studies and can benefit the molecular-level design of nontraditional chromophores for optoelectronics and other applications.

[Bioavailability in vivo and in vitro transepithelial transport across Caco-2 cell monolayer of pueraria flavonoids bio-adhesive and floating pellets].

To study the bioavailability of pueraria flavonoids bio-adhesive and floating pellets, the absorption of puerarin was studied using Caco-2 cell monolayer by liquid chromatography (HPLC) method, comparing the P(app) of pueraria flavonoids bio-adhesive and floating pellets with different bio-adhesive materials. Drugs were administered at a dose of 100 mg·kg(-1) via ig. The plasma concentration of puerarin was determined by HPLC, the pharmacokinetics were calculated with the WinNonlin 6.0 software. The results showed that the P(app) of bio-adhesive and floating pellets with hydroxypropyl methylcellulose (HPMC)-cabomer was largest, which had a significant difference (P < 0.05). The AUC(0-t) of pueraria flavonoids bio-adhesive and floating pellets was 1.79 times of pueraria flavonoids, the C(max) of pueraria flavonoids bio-adhesive and floating pellets and pueraria flavonoids had a significant difference (P < 0.05). What's more the MRT had prolonged. In conclusion, pueraria flavonoids bio-adhesive and floating pellets with HPMC-cabomer could significantly facilitate the transport of puerarin on Caco-2 cellular monolayers. The bioavailability of pueraria flavonoids bio-adhesive and floating pellets with HPMC-cabomer was increased more than pueraria flavonoids with a sustained release effect.

Preparation and unique electrical behaviors of monodispersed hybrid nanorattles of metal nanocores with hairy electroactive polymer shells.

A versatile template-assisted strategy for the preparation of monodispersed rattle-type hybrid nanospheres, encapsulating a movable Au nanocore in the hollow cavity of a hairy electroactive polymer shell (Au@air@PTEMA-g-P3HT hybrid nanorattles; PTEMA: poly(2-(thiophen-3-yl)ethyl methacrylate; P3HT: poly(3-hexylthiophene), was reported. The Au@silica core-shell nanoparticles, prepared by the modified Stöber sol-gel process on Au nanoparticle seeds, were used as templates for the synthesis of Au@silica@PTEMA core-double shell nanospheres. Subsequent oxidative graft polymerization of 3-hexylthiophene from the exterior surface of the Au@silica@PTEMA core-double shell nanospheres allowed the tailoring of surface functionality with electroactive P3HT brushes (Au@silica@PTEMA-g-P3HT nanospheres). The Au@air@ PTEMA-g-P3HT hybrid nanorattles were obtained after etching of the silica interlayer by HF. The as-prepared nanorattles were dispersed into an electrically insulating polystyrene matrix and for the first time used to fabricate nonvolatile memory devices. As a result, unique electrical behaviors, including insulator behavior, write-once-read-many-times and rewritable memory effects, and conductor behavior as well, were observed in the Al/Au@air@PTEMA-g-P3HT+PS/ITO (ITO: indium-tin oxide) sandwich thin-film devices.

Three-dimensional nonlinear model of rock creep under freeze-thaw cycles.

In areas with large differences between day and night temperature, the freeze-thaw cycle and frost heaving force in rock mass generate cracks within the rock, which seriously threatens the stability and safety of geotechnical engineering structures and surrounding buildings. This problem can be solved by developing a reasonable model that accurately represents the rock creep behavior. In this study, we developed a nonlinear viscoelastic-plastic creep damage model by introducing material parameters and a damage factor while connecting an elastomer, a viscosity elastomer, a Kelvin element, and a viscoelastic-plastic element in series. One- and three-dimensional creep equations were derived, and triaxial creep data were used to determine the model parameters and to validate the model. The results showed that the nonlinear viscoelastic-plastic creep damage model can accurately describe rock deformation in three creep stages under freeze-thaw cycles. In addition, the model can describe the time-dependent strain in the third stage. Parameters G1, G2, and η20' decrease exponentially with the increase in the number of freeze-thaw cycles while parameter λ increases exponentially. These results provide a theoretical basis for studying the deformation behavior and long-term stability of geotechnical engineering structures in areas with large diurnal temperature differences.

In vitro and in vivo studies on a novel solid dispersion of repaglinide using polyvinylpyrrolidone as the carrier.

In order to improve the dissolution and absorption of the water insoluble drug repaglinide, a solid dispersion was developed by solvent method using polyvinylpyrrolidone K30 (PVP K30) as the hydrophilic carrier for the first time. Studies indicated that both solubility and the dissolution rate of repaglinide were significantly increased in the solid dispersion system compared with that of repaglinide raw material or physical mixtures. The repaglinide solid dispersions with PVP K30 solid state was characterized by polarizing microscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). DSC and XRD studies indicated that repaglinide existed in an amorphous form in the solid dispersion. FT-IR analysis demonstrated the presence of intermolecular hydrogen bonding between repaglinide and PVP K30 in the solid dispersion. In the in situ gastrointestinal perfusion experiment, solid dispersion was shown to remarkably enhance the absorption of repaglinide in stomach and all segments of intestine. In vivo pharmacokinetic study in rats showed that immediate and complete release of repaglinide from the solid dispersion resulted in rapid absorption that significantly increased the bioavailability and the maximum plasma concentration over repaglinide raw material. These results demonstrated PVP K30 was an appropriate carrier for solid dispersion of repaglinide, with increased dissolution and oral absorption.

Lipid-polymer composite microspheres for colon-specific drug delivery prepared using an ultrasonic spray freeze-drying technique.

Lipid-polymer composite microspheres (LP-MS) for colon-specific drug delivery were prepared using an ultrasonic spray freeze-drying technique. These microspheres, which consist of the pH-sensitive polymer Eudragit S100 and the non-polar lipid Compritol 888 ATO, were characterized by morphological and physicochemical properties. It was found that the LP-MS have a spherical lipid porous matrix with a smooth pH-sensitive polymer film on both internal and external surfaces, and the insoluble drug 10-hydroxycamptothecin was dispersed in an amorphous state in the carrier. Morphological changes of microparticles under different pH conditions were observed by confocal laser scanning microscopy, which showed that the lipid matrix in LP-MS restricted the swelling property of the polymer at pH 6.8. In drug release studies, less than 15% of the drug was released below pH 6.8, whereas more than 30% was released with a sustained-release model at pH 7.4. The LP-MS could provide a promising vehicle for colon drug delivery.

Efficient bio-butanol production from lignocellulosic waste by elucidating the mechanisms of Clostridium acetobutylicum response to phenolic inhibitors.

Lignocellulosic biomass is considered abundant renewable feedstock to constitute a green and environmentally friendly approach for biofuels (bio-butanol) production as an effective substitute for fossil resources. However, a variety of fermentable inhibitors can be generated in hydrolysates during the biomass pretreatment process. Among them, phenolics including phenolic acids and phenolic aldehydes are the most toxic inhibitors to solventogenic clostridia for bio-butanol production. This study elucidates the physiological mechanism of Clostridium acetobutylicum ATCC 824 response to phenolic inhibitors by the integration of kinetics and transcriptional analysis. Butanol fermentations were stressed by 0.4 g/L phenolic acids or 0.4 g/L phenolic aldehydes at 12 h at the beginning of solventogenesis. With post-stress for 12 h, butanol titer was 7.01 g/L in fermentation with phenolic acid stress, while only 5.82 g/L butanol was produced in the case of phenolic aldehydes stress. Reductions in the two fermentations were 27.6% and 40.0% in comparison with the control (without stress), indicated that phenolic aldehydes had a stronger inhibitory effect on solvents synthesis in C. acetobutylicum than phenolic acids. Additionally, the transcriptional analysis revealed that phenolics altered the gene expression profiles related to membrane transporters such as ATP-binding cassette (ABC)-transporter and phosphotransferase system (PTS), glycolysis, and heat shock proteins. The lower expression levels of PTS-related genes might result in reduced glucose consumption and finally inhibited solvents synthesis under phenolic aldehydes stress. Some genes encoding histidine kinase (CA_C0323, CA_C0903, and CA_C3319) were also affected by phenolics, which might inhibit sporulation. In conclusion, our results provide valuable guidance for the construction of robust strain to efficiently produce bio-butanol from lignocellulosic biomass.

Small-sized copolymeric nanoparticles for tumor penetration and intracellular drug release.

Poor solid-tumor penetration of nanocarriers limits the drug efficacy. Herein, small-sized copolymeric nanoparticles are prepared for delivering the chemotherapeutic drug DOX into solid tumors deeply and releasing the drug effectively. These small-sized copolymeric nanoparticles represent substantial potential for clinical translation.

Gene Expression Profiling of Head and Neck Tumors Identifies FOXP1 and SOX10 Expression as Useful for Distinguishing Ameloblastoma From Basaloid Salivary Gland Tumors.

Odontogenic tumors show considerable morphologic heterogeneity and at times the diagnosis can be challenging. Ameloblastoma, the most common odontogenic tumor, can have morphologic similarity to some salivary gland tumors and therefore we sought to identify biomarkers that might aid in the diagnosis by performing transcriptome wide gene expression profiling of 80 odontogenic and salivary gland neoplasms. These data identified the FOXP1/SOX10 expression profile as characteristic of many odontogenic tumors including ameloblastoma but largely absent in salivary gland tumors. We then assessed 173 salivary gland tumors and 108 odontogenic tumors by immunohistochemistry for FOXP1 and SOX10 expression and found that 34/35 (97%) cases of ameloblastomas were diffusely positive for FOXP1 but completely negative for SOX10. None of the basaloid salivary neoplasms (basal cell adenoma, adenoid cystic carcinoma, polymorphous adenocarcinoma, and myoepitheloma) demonstrated FOXP1/SOX10 expression pattern. Taken together, the results of this study suggest that the FOXP1/SOX10 immunophenotype is common in odontogenic tumors including ameloblastoma and might be useful distinguishing these from similar appearing basaloid salivary gland tumors.

[Preparation and in vitro corneal retention behavior of novel cationic microemulsion/in situ gel system].

The aim was to prepare a novel ocular cationic microemulsion-in situ gel (CM-ISG) system with vitamin A palmitate (VAP) as model drug, and investigate the corneal retention behavior and corneal irritation of the system. VAP/CM was prepared by a process based on supply of energy, and the before-and-after gelation rheology of VAP/CM-ISG was investigated. In vitro VAP release and gel dissolution of both VAP/CM-ISG and Oculotect Gel was determined. And in vitro corneal retention behavior of both formulations was evaluated by captive bubble technique. Ocular irritation test was carried out based on the Draize method. Images of TEM showed that homogenous VAP/CM was made, and no significant differences of particle size were found between the VAP/CM and VAP/CM in Poloxamer 407 gel. Rheology study illustrated that VAP/CM reduced the phase transition temperature of Poloxamer 407 gel by 1.5 degrees C, and the elastic modulus increased about 15.7 times. The in vitro release and gel dissolution profile of both formulations exhibited the characteristics of zero order kinetics. Comparing with Oculotect Gel, desorption kinetics study of VAP/CM-ISG exhibited longer corneal retention time and smaller contact angle. Irritation test showed a good ocular compatibility of VAP/CM-ISG. Therefore, VAP/CM-ISG combined both advantages of the cationic microemulsion and in situ gel system, provided better wettability and longer ocular retention time. It might be a promising ocular drug delivery system.

[Preparation of PEG-modified nanostructured lipid carriers loaded with hydroxycamptothecin and tissue distribution in mice].

Hydroxycamptothecin (HCPT) loaded PEG modified nanostructured lipid carriers (HCPT-PEG-NLC) and nanostructured lipid carriers (HCPT-NLC) were prepared by melt emulsification and homogenization method. The morphology, particle size and encapsulation efficiency of them were investigated. HCPT concentrations in plasma, heart, liver, spleen, lung, kidney and ovary were determined after iv of HCPT injection, HCPT-PEG-NLC and HCPT-NLC in mice. The targeting indexes of HCPT-PEG-NLC and HCPT-NLC were calculated. The transmission electron microscope imaging showed that HCPT-PEG-NLC and HCPT-NLC exhibited a spherical shape. The particle sizes of them were (88.6 +/- 22.5) and (127.2 +/- 43.4) nm. The encapsulation efficiency were (90.51 +/- 3.29)% and (84.37 +/- 2.81)%, respectively. After iv injection into the tail vein of mice, HCPT plasma concentrations of HCPT-PEG-NLC and HCPT-NLC were higher than that of HCPT injection at each sampling time. They also showed longer elimination time in every tissue. HCPT-NLC accumulated in endothelial system (RES), Re and Ce of it in liver and spleen were significantly higher than HCPT-PEG-NLC. HPCT-PEG-NLC prolonged circulation time and increased bioavailability of HCPT. MRT and AUC0-24 h of it were 19.80 and 17.02 times higher than those of HCPT injection. It also significantly reduced phagocytosis of RES, and showed lung targeting effect (Re and Ce were 14.51 and 41.35). To summarize, HCPT-PEG-NLC could prolong the circulation time of HCPT in vivo, and had the lung targeting effect. It was a promising carrier to increase therapeutic effect of HCPT in treating lung cancer.

Pharmacokinetics and correlation between in vitro release and in vivo absorption of bio-adhesive pellets of panax notoginseng saponins.

The present study was designed to prepare and compare bio-adhesive pellets of panax notoginseng saponins (PNS) with hydroxy propyl methyl cellulose (HPMC), chitosan, and chitosan : carbomer, explore the influence of different bio-adhesive materials on pharmacokinetics behaviors of PNSbio-adhesive pellets, and evaluate the correlation between in vivo absorption and in vitro release (IVIVC). In order to predict the in vivo concentration-time profile by the in vitro release data of bio-adhesive pellets, the release experiment was performed using the rotating basket method in pH 6.8 phosphate buffer. The PNS concentrations in rat plasma were analyzed by HPLC-MS-MS method and the relative bioavailability and other pharmacokinetic parameters were estimated using Kinetica4.4 pharmacokinetic software. Numerical deconvolution method was used to evaluate IVIVC. Our results indicated that, compared with ordinary pellets, PNS bio-adhesive pellets showed increased oral bioavailability by 1.45 to 3.20 times, increased Cmax, and extended MRT. What's more, the release behavior of drug in HPMC pellets was shown to follow a Fickian diffusion mechanism, a synergetic function of diffusion and skeleton corrosion. The in vitro release and the in vivo biological activity had a good correlation, demonstrating that the PNS bio-adhesive pellets had a better sustained release. Numerical deconvolution technique showed the advantage in evaluation of IVIVC for self-designed bio-adhesive pellets with HPMC. In conclusion, the in vitro release data of bio-adhesive pellets with HPMC can predict its concentration-time profile in vivo.

Comparison of efficacy and safety of hyoscine butylbromide versus anisodamine for acute gastric or intestinal spasm-like pain: A randomized, double-blinded, multicenter Phase III trial.

OBJECTIVE: Acute gastric or intestinal spasm-like pain is common in clinical setting. Hyoscine butylbromide (HBB), an anti-cholinergic agent, relieves pain in stomach and bowel cramps by inhibiting smooth muscle contractility. In this study, we aimed to compare the efficacy and safety of parenteral HBB and anisodamine for treating acute gastric or intestinal pain. METHODS: In this randomized, controlled, double-blind, parallel-group, multicenter non-inferiority trial, 299 Chinese patients were randomly assigned to HBB or anisodamine in a ratio of 1:1. They were administrated a single dose of either HBB 20 mg or anisodamine 10 mg, and a second dose was given when needed. The primary end-point was the difference in pain intensity (PID) from the pre-dose baseline at 20 min after the first injection. RESULTS: Altogether 295 patients completed the protocol (153 in the HBB and 142 in the anisodamine group). For the primary end-point, the PID was -4.09 (95% confidence interval [CI]: -4.41, -3.76) for the HBB group and -3.66 (95% CI: -4.02, -3.31) for the anisodamine group (P < 0.0001 for non-inferiority). The percentage of patients with at least one adverse event was lower in the HBB group than in the anisodamine group (13.1% vs 17.6%), but there was no statistical significance (P = 0.279). The most frequent adverse events were thirst (7.8%) and dry mouth (2.6%) in the HBB group, and thirst (7.0%), dry mouth (3.5%) and nodal arrhythmia (2.1%) in the anisodamine group. CONCLUSIONS: HBB 20 mg was not inferior to anisodamine 10 mg in pain relief of patients with acute gastric or intestinal spasm-like pain. Both drugs were safe and well tolerated.

A solid-phase microextraction coating of sol-gel-derived perhydroxy cucurbit[6]uril and its application on to the determination of polycyclic aromatic hydrocarbon.

A novel solid-phase microextraction coating that contains perhydroxy cucurbit[6]uril((OH)12Q[6]) was prepared by a sol-gel method. (OH)12Q[6] was used as a starting coating material with hydroxy-terminated poly(dimethylsiloxane) (OH-PDMS) to bond chemically to a fused-silica substrate using 3-(2-cyclooxypropoxyl)propyltrimethoxysilane as cross-linking agent; hydrolysis and polycondensation reactions then led to the formation of a (OH)12Q[6]/PDMS-coating. The coating has a high thermal stability (360°C), long lifetime and can withstand organic and inorganic solvent rinsing because of the chemical binding between the coating and silica substrate. Its performance was tested by headspace (HS) solid-phase microextraction fiber coupled with gas chromatography to determine polycyclic aromatic hydrocarbon (PAHs) compounds in water samples. The (OH)12Q[6]/PDMS-coated fiber exhibited higher enrichment factors from fourfold for naphthalene to tenfold for pyrene compared with commercial PDMS fiber, and the enrichment factors increased with the number of condensed PAH rings. The strong adsorption affinity is believed to be attributed to hydrogen bonding and CH⋯π interactions between PAHs and (OH)12Q[6], according to the results of quantum chemical calculations. In the PAH analysis, the (OH)12Q[6]-coated fiber showed a good repeatability (<4.7%) and reproducibility between fibers (<9.4%), low detection limits (0.03-0.15µgL-1), and a wide linearity (0.1-1000µgL-1) under optimized conditions. This method was used for the simultaneous determination of seven PAHs with satisfactory recoveries of 90.56%-107.4% for Huaxi river water samples and 90.23%-109.5% for local wastewater samples, respectively.

Fabrication of Thickness-Controllable Micropatterned Polyelectrolyte-Film/Nanoparticle Surfaces by Using the Plasma Oxidation Method.

We have demonstrated a novel way to form thickness-controllable polyelectrolyte-film/nanoparticle patterns by using a plasma etching technique to form, first, a patterned self-assembled monolayer surface, followed by layer-by-layer assembly of polyelectrolyte-films/nanoparticles. Octadecyltrimethoxysilane (ODS) and (3-aminopropyl)triethoxysilane (APTES) self-assembled monolayers (SAMs) were used for polyelectrolyte-film and nanoparticle patterning, respectively. The resolution of the proposed patterning method can easily reach approximately 2.5 µm. The height of the groove structure was tunable from approximately 2.5 to 150 nm. The suspended lipid membrane across the grooves was fabricated by incubating the patterned polyelectrolyte groove arrays in solutions of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) giant unilamellar vesicles (GUVs). The method demonstrated here reveals a new path to create patterned 2D or 3D structures.

Baicalin inhibits toll-like receptor 2/4 expression and downstream signaling in rat experimental periodontitis.

Periodontitis is a severe inflammatory response, leading to characteristic periodontal soft tissue destruction and alveolar bone resorption. Baicalin possesses potent anti-inflammatory activity; however, it is still unclear whether baicalin regulates toll-like receptor (TLR) 2/4 expression and downstream signaling during the process of periodontitis. In this study, the cervical area of the maxillary second molars of rats was ligated and inoculated with Porphyromonas gingivalis (P. gingivalis) for 4weeks to induce periodontitis. Some rats with periodontitis were treated intragastrically with baicalin (50, 100 or 200mg/kg/day) or vehicle for 4weeks. Compared with the sham group, the levels of TLR2, TLR4 and MyD88 expression and the p38 MAPK and NF-κB activation were up-regulated in the experimental periodontitis group (EPG), accompanied by marked alveolar bone loss and severe inflammation. Treatment with 100 or 200mg/kg/day baicalin dramatically reduced the alveolar bone loss, the levels of HMGB1, TNF-α, IL-1ß, and MPO expression, and the numbers of inflammatory infiltrates in the gingival tissues. Importantly, treatment with 100 or 200mg/kg/day baicalin mitigated the periodontitis-up-regulated TLR2, TLR4 and MyD88 expression, and the p38 MAPK and NF-κB activation. Hence, the blockage of the TLR2 and TLR4/MyD88/p38 MAPK/NF-κB signaling by baicalin may contribute to its anti-inflammatory effects in rat model of periodontitis. In conclusion, these novel findings indicate that baicalin inhibits the TLR2 and TLR4 expression and the downstream signaling and mitigates inflammatory responses and the alveolar bone loss in rat experimental periodontitis. Therefore, baicalin may be a potential therapeutic agent for treatment of periodontitis.

Constipation, fiber intake and non-compliance contribute to inadequate colonoscopy bowel preparation: a prospective cohort study.

OBJECTIVE: Adequate bowel preparation is important for colonoscopy. Currently available evidence on the determinants of poor bowel preparation is largely derived from studies in Western countries. We aimed to identify the risk factors for inadequate bowel preparation for colonoscopy in the Chinese population. METHODS: In this single-center study, patients admitted to the Outpatient Department between March 2013 and December 2015 and had indications for colonoscopy were prospectively enrolled. Questionnaires were administered to the patients. Their characteristics and procedure-related parameters such as procedure time were recorded. Bowel preparation was assessed using Boston bowel preparation scale score. RESULTS: A total of 409 patients with a mean age of 48.8 ± 12.9 years were enrolled in the study, 60.9% of whom were men. On univariate analysis, poor educational level (P = 0.020), chronic constipation (P = 0.001), taking no physical exercise after medication (P < 0.001), a high-fiber diet during the 24-h period immediately preceding the colonoscopy (P < 0.001), incomplete intake of medication (P < 0.001), the passage of yellow or dark stools before colonoscopy (P < 0.001), waiting time (P = 0.001) and stool frequency after medication (P = 0.048) were significantly associated with inadequate bowel preparation. On multivariate analysis, chronic constipation [odds ratio (OR) 2.05, 95% confidence interval (CI) 1.31-3.23, P = 0.002], incomplete intake of the medication (OR 2.77, 95% CI 1.47-5.21, P = 0.002) and a high-fiber diet within 24 h before colonoscopy (OR 2.15, 95% CI 1.40-3.28, P < 0.001) were independent risk factors for inadequate bowel preparation. CONCLUSIONS: Chronic constipation, poor compliance with treatment and high-fiber diet were predictors of poor bowel preparation. Patients with these risk factors require more effective strategies for bowel preparation.

Charge dynamic characteristics in corona-charged polytetrafluoroethylene film electrets.

In this work, the charge dynamics characteristics of injection, transport and decay in porous and non-porous polytetrafluoroethylene (PTFE) film electrets were investigated by means of corona charging, isothermal and thermal stimulating surface-potential decay measurements. The results showed that the initial surface potential, whether positively or negatively charging, is much higher in non-porous PTFE than in porous PTFE. For porous film the value of initial surface potentials increases with increase of film thickness. Higher charging temperature can remarkably improve charge stability. The charge dynamics are correlated to materials microstructure according to their scanning electron micrographs. For non-porous PTFE films, polarizability change of C-F bonds is the main origin of electret charges; but for porous PTFE film a large number of bulk and interface type traps are expected because of the greater area of interface and higher crystallinity.

[Evaluation and selection of VOCs treatment technologies in packaging and printing industry].

Volatile organic compounds (VOCs) play an important role in urban air pollution. Activities of industries including the packaging and printing industries are regarded as the major sources. How to select the suitable treating techniques is the major problem for emission control. In this article, based on the VOCs emission characteristics of the packaging and printing industry and the existing treatment technologies, using the analytic hierarchy process (AHP) model, an evaluation system for VOCs selection was established and all the technologies used for treatment were assessed. It showed that the priority selection was in the following order: Carbon Fiber Adsorption-Desorption > Granular Carbon Adsorption-Desorption > Thermal Combustion > Regenerative Combustion > Catalytic combustion > Rotary adsorption-concentration and combustion > Granular Carbon adsorption-concentration and combustion. Carbon Fiber Adsorption-Desorption was selected as the best available technology due to its highest weight among those technologies.