Photocontrolled extraction of uric acid from biological samples based on photoresponsive surface molecularly imprinted polymer microspheres.

We aim to develop novel photoresponsive surface molecularly imprinted polymer (SIMP) microspheres, an SiO2 -SIMP, for the photocontrolled extraction of uric acid from biological samples. The SiO2 -SMIP was prepared on silica microspheres by surface polymerization and characterized by using scanning electron microscopy, transmission electron microscopy, FTIR spectroscopy, thermogravimetric analysis, nitrogen adsorption-desorption analysis, and UV-visible spectroscopy. The SiO2 -SMIP microspheres showed a photocontrolled uptake and release of uric acid in NaH2 PO4 buffer upon alternate irradiation at 365 and 440 nm. The SiO2 -SMIP microspheres were able to photocontrollably extract uric acid from complicated biological samples for concentration analysis with no significant interference encountered and it exhibited very good recognition ability and fast binding kinetics toward uric acid.

Photoresponsive molecularly imprinted hydrogel casting membrane for the determination of trace tetracycline in milk.

This study aimed to develop a photoresponsive molecularly imprinted hydrogel (MIH) casting membrane for the determination of trace tetracycline (TC) in milk. This MIH casting membrane combined the specificity of MIHs, the photoresponsive properties of azobenzene, and the portable properties of a membrane. Photoresponsive TC-imprinted MIHs were initially fabricated and then cast on sodium dodecyl sulfonate polyacrylamide gel. After TC removal, a photoresponsive MIH casting membrane was obtained. The photoresponsive properties of the MIH casting membrane were robust, and no obvious photodegradation was observed after 20 cycles. The MIH casting membrane displayed specific affinity to TC upon alternate irradiation at 365 and 440 nm; it could quantitatively uptake and release TC. The TC concentration (0.0-2.0 × 10(-4) mol l(-1)) in aqueous solution displayed a linear relationship with the photoisomerization rate constant of azobenzene within the MIH casting membrane. As such, a quick detection method for trace TC in aqueous foodstuff samples was established. The recovery of this method for TC in milk was investigated with a simple pretreatment of milk, and a high recovery of 100.54-106.35% was obtained. Therefore, the fabricated membrane can be used as a portable molecular sensor that can be easily recycled.

[Study on fatigue resistance of mechanical nickel-titanium files by phase-locked infrared flaw detection method].

PURPOSE: The movement trend of the posterior teeth and the distribution of the periodontal membrane stress were studied by using three-dimensional digital technology. METHODS: CBCT data of 88 patients admitted to our hospital from June 2017 to June 2022 were selected, and input into Mimics20.0 software for preliminary extraction of all parts and stored with STL files; then the data were repaired and optimized through Geomagic Studio 2014 software. With the help of normal phase extension, the invisible appliance and periodontal membrane were constructed. Finally, the six FEM models were simulated and observed by the current teeth in different groups. Statistical analysis was performed with SPSS 21.0 software package. RESULTS: The effect force of the largest periodontal membrane was distributed in the neck of the tooth, followed by the apical area, with the maximum effect force value in the NA group. In all accessory groups, the periodontal membrane maximum paradigm isoeffect force values of all patients in the accessory vertical rectangular group were significantly smaller than the values obtained in the horizontal rectangular group. CONCLUSIONS: The design of orthodontic tooth accessories has a strong inhibition effect on the position movement of anterior teeth during recovery, which improves the accuracy of tooth three-dimensional movement to a certain extent. Meanwhile, the normal equivalent stress of the periodontal membrane of patients in the initial application of the invisible appliance without brackets is large.

Predictive models for functional cure in patients with CHB receiving PEG-IFN therapy based on HBsAg quantification through meta-analysis.

BACKGROUND AND AIMS: The efficacy of achieving HBsAg clearance through pegylated interferon (PEG-IFNα) therapy in patients with chronic hepatitis B (CHB) remains uncertain, especially regarding the probability of achieving functional cure among patients with varying baseline HBsAg levels. We aimed to investigate the predictive value of HBsAg quantification for HBsAg seroclearance in CHB patients undergoing PEG-IFNα treatment. METHODS: A systematic search was conducted in PubMed, Embase, and the Cochrane Library up to January 11, 2022. Subgroup analyses were performed for HBeAg-positive and HBeAg-negative patients, PEG-IFNα monotherapy and PEG-IFNα combination therapy, treatment-naive and treatment-experienced patients, and patients with or without liver cirrhosis. RESULTS: This predictive model incorporated 102 studies. The overall HBsAg clearance rates at the end of treatment (EOT) and the end of follow-up (EOF) were 10.6% (95% CI 7.8-13.7%) and 11.1% (95% CI 8.4-14.1%), respectively. Baseline HBsAg quantification was the most significant factor. According to the model, it is projected that when baseline HBsAg levels are 100, 500, 1500, and 10,000 IU/ml, the HBsAg clearance rates at EOF could reach 53.9% (95% CI 40.4-66.8%), 32.1% (95% CI 24.8-38.7%), 14.2% (95% CI 9.8-18.8%), and 7.9% (95% CI 4.2-11.8%), respectively. Additionally, treatment-experienced patients with HBeAg-negative status, and without liver cirrhosis exhibited higher HBsAg clearance rates after PEG-IFNα treatment. CONCLUSION: A successful predictive model has been established to predict the achievement of functional cure in CHB patients receiving PEG-IFNα therapy.

UV-Triggered Hydrogel Coating of the Double Network Polyelectrolytes for Enhanced Endothelialization.

The left atrial appendage (LAA) occluder is an important medical device for closing the LAA and preventing stroke. The device-related thrombus (DRT) prevents the implantation of the occluder in exerting the desired therapeutic effect, which is primarily caused by the delayed endothelialization of the occluder. Functional coatings are an effective strategy for accelerating the endothelialization of occluders. However, the occluder surface area is particularly large and structurally complex, and the device is subjected to a large shear friction in the sheath during implantation, which poses a significant challenge to the coating. Herein, a hydrogel coating by the in situ UV-triggered polymerization of double-network polyelectrolytes is reported. The findings reveal that the double network and electrostatic interactions between the networks resulted in excellent mechanical properties of the hydrogel coating. The sulfonate and Arg-Gly-Asp (RGD) groups in the coating promoted hemocompatibility and endothelial growth of the occluder, respectively. The coating significantly accelerated the endothelialization of the LAA occluder in a canine model is further demonstrated. This study has potential clinical benefits in reducing both the incidence of DRT and the postoperative anticoagulant course for LAA closure.

A visible-light-responsive molecularly imprinted polyurethane for specific detection of dibenzothiophene in gasoline.

Dibenzothiophene and its derivatives in gasoline and diesel would release sulfur oxides during combustion, and this is harmful to human health and the environment. This paper reports a method based on a visible-light-responsive molecularly imprinted polyurethane (VMIPU) to monitor trace dibenzothiophene in gasoline. The VMIPU was prepared by a polyaddition reaction using N,N-bis-(2-hydroxyethyl)-4-phenylazoaniline as the functional monomer, dibenzothiophene as the template molecule, diphenylmethane diisocyanate as the crosslinker and castor oil as the chain extender. The VMIPU showed good visible-light-response and specific adsorption for dibenzothiophene. The trans → cis photoisomerization rate constant of azobenzene chromophores in the VMIPU shows a linear relationship with the dibenzothiophene concentration in the range of 0-20 µmol L-1. This was used to estimate trace dibenzothiophene in spiked gasoline with recoveries of 95.7-101.0% and relative standard deviations of 7.0-12.7%.

Association Between Chronic Periodontal Disease and Erectile Dysfunction: A Case-Control Study.

Erectile dysfunction (ED) and chronic periodontal disease (CPD) share mutual risk factors, and the incidence of ED is increasing among young adults. The relation of CPD and ED remains obscure due to inconsistent clinical evidence. This study aimed to further assess the relationship between CPD and ED using the Community Periodontal Index of Treatment Need (CPITN) and the International Index of Erectile Function (IIEF). Totally, 202 adult men were included, with 100 subjects with ED in the case group and 102 subjects without ED undergoing routine dental examinations in the control group. The IIEF questionnaire was used to assess the severity of ED, and CPD was assessed through the Community Periodontal Index (CPI) score. Periodontal assessments were performed by one single calibrated examiner. Logistic regression analysis was performed for the association between CPD and ED. After adjustment for age, smoking status, tooth brushing time, education level, monthly income, tooth brushing frequency, and gum bleeding, higher CPI score was identified to be associated with a greater risk of ED (odds ratio [OR] = 2.755, 95% confidence interval [CI] = [1.400, 5.423], p = .003), suggesting that CPD was positively associated with the odds of ED. CPD was getting more severe with the progress of ED (p < .05). Men with ED could be encouraged to receive routine dental examinations and appropriate preventive dental measures to maintain oral and periodontal health.

Well-dispersed platelet lysate entrapped nanoparticles incorporate with injectable PDLLA-PEG-PDLLA triblock for preferable cartilage engineering application.

Platelet lysate (PL) as a cost-effective cocktail of growth factors is an emerging ingredient in regenerative medicine, especially in cartilage tissue engineering. However, most studies fail to pay attention to PL's intrinsic characteristics and incorporate it directly with scaffolds or hydrogels by simple mixture. Currently, the particle size distribution of PL was determined to be scattered. Directly introducing PL into a thermosensitive poly(d,l-lactide)-poly(ethylene glycol)-poly(d,l-lactide) (PLEL) hydrogel disturbed its sol-gel transition. Electrostatic self-assembly heparin (Hep) and ε-poly-l-lysine (EPL) nanoparticles (NPs) were fabricated to improve the dispersity of PL. Such PL-NPs-incorporated PLEL gels retained the initial gelling capacity and showed a long-term PL-releasing ability. Moreover, the PL-loaded composite hydrogels inhibited the inflammatory response and dedifferentiation of IL-1ß-induced chondrocytes. For in vivo applications, the PLEL@PL-NPs system ameliorated the early cartilage degeneration and promoted cartilage repair in the late stage of osteoarthritis. RNA sequencing analysis indicated that PL's protective effects might be associated with modulating hyaluronan synthase 1 (HAS-1) expression. Taken together, these results suggest that well-dispersed PL by Hep/EPL NPs is a preferable approach for its incorporation into hydrogels and the constructed PLEL@PL-NPs system is a promising cell-free and stepwise treatment option for cartilage tissue engineering.

A hollow visible-light-responsive surface molecularly imprinted polymer for the detection of chlorpyrifos in vegetables and fruits.

A visible-light-responsive azobenzene derivative, 3,5-dichloro-4-((2,6-dichloro-4-(methacryloyloxy)phenyl)diazenyl)benzoic acid, was synthesized and used as the functional monomer to fabricate a visible-light-responsive core-shell structured surface molecularly imprinted polymer (PS-co-PMAA@VSMIP). After removal of the sacrificial PS-co-PMAA core, a hollow structured surface molecularly imprinted polymer (HVSMIP) was obtained. Both the PS-co-PMAA@VSMIP and HVSMIP were used for the detection of chlorpyrifos, a moderately toxic organophosphate pesticide. They exhibited good visible-light-responsive properties (550 nm for trans→cis and 440 nm for cis→trans isomerization for an azobenzene chromophore) in ethanol/water (9:1, v/v). Compared with the PS-co-PMAA@VSMIP, the HVSMIP had a larger surface area, pore volume, binding capacity, imprinting effect, maximum chemical binding capacity, dissociation constant, and photo-isomerization rate. The HVSMIP was applied to detect trace chlorpyrifos in fruit and vegetable samples. This was achieved by measuring the trans→cis rate constant of the HVSMIP in the sample solution, with good recoveries, low relative standard deviations, and a low detection limit.

Production and characterization of HA and SiHA coatings.

Plasma sprayed hydroxyapatite (HA) coatings on metallic prostheses have been used clinically in dentistry and orthopedics since the mid 1980s. The coating properties are dependent on the spraying parameters. Since silicon-substituted hydroxyapatite (SiHA) has been shown to offer improved bioactivity over phase pure HA, SiHA coatings have the potential for enhanced performance in clinical application. In this study, phase pure HA and 0.8 wt% SiHA powders were synthesized with similar particle size distribution and morphology. The powders were plasma sprayed onto Ti-6Al-4V substrates at 37 kW and 40 kW plasma gun input power respectively. Four kinds of samples were prepared, HAC 37, HAC 40, SiHAC 37 and SiHAC 40. Materials characterization showed that the coatings were of relatively high phase purity. In vitro cell culture demonstrated that human osteoblast cells grew well on all samples, with the highest cell growth observed on SiHA coatings produced under the lower plasma gun input power.

An NIR-light-responsive surface molecularly imprinted polymer for photoregulated drug release in aqueous solution through porcine tissue.

The application of photoresponsive surface molecularly imprinted polymers based on azobenzene is limited by the UV light source required and their poor water solubility. Reducing the phototoxicity and solvent toxicity of the polymers therefore presents a challenge. In this work, an NIR-light-responsive surface molecularly imprinted polymer was fabricated by atom transfer radical polymerization using up-conversion nanoparticles as the core, a hydrophilic green-light-responsive azobenzene derivative as the functional monomer, and a drug as the template. The up-conversion nanoparticles core emitted green fluorescence in the range of 520-550 nm upon NIR irradiation (980 nm, 5 W cm-2), which was absorbed by the azobenzene containing molecularly imprinted polymers layer on the up-conversion nanoparticles surface. This caused the azobenzene chromophores to undergo trans→cis isomerization in phosphate buffered solution (pH = 7.4), thus resulting in NIR-light-induced drug release. The up-conversion fluorescence spectra were used to study the interaction mechanism between the azobenzene monomer and NIR light. Compared with structural analogues of the template (antifebrin and phenacetin), the NIR-light-responsive surface molecularly imprinted polymer showed excellent specificity of recognition for the template drug (paracetamol). The maximum adsorption capacity of the NIR-light-responsive surface molecularly imprinted polymer for loading of paracetamol was 16.80 µmol g-1. The NIR-light-responsive surface molecularly imprinted polymer was applied for NIR-light-induced paracetamol release in phosphate buffered solution (pH = 7.4) through porcine tissue. This work demonstrates the potential of drug delivery systems based on molecularly imprinted polymers for application in deep tissue delivery.

A photoresponsive surface molecularly imprinted polymer shell for determination of trace griseofulvin in milk.

A new photoresponsive surface molecularly imprinted polymer shell (PMIPS) was developed for determination of trace griseofulvin from milk. The PMIPS was prepared by surface imprinting technique using poly(styrene-co-methacrylic acid) (PS-co-PMMA) microspheres as the sacrificial substrate, griseofulvin as the template, a photoresponsive azobenzene derivative 4-((4-(methacryloyloxy)phenyl)diazenyl)-3,5-dimethyl benzenesulfonic acid as the functional monomer, and triethanolamine trimethacrylate as the cross-linker. The PMIPS was obtained after the removal of the sacrificial PS-co-PMMA core from the surface imprinted core-shell microspheres, PS-co-PMAA@PMIP. Compared with PS-co-PMAA@PMIP, PMIPS displayed better properties such as higher surface area and pore volume, rapid photo-isomerization rate, and higher adsorption capacities, specific binding constant and binding density. The PMIPS could efficiently detect griseofulvin in complex samples such as milk.

Photoresponsive hollow molecularly imprinted polymer for trace triamterene in biological samples.

This paper reports a photoresponsive hollow molecularly imprinted polymer for the determination of trace triamterene in biological sample. The photoresponsive hollow molecularly imprinted polymer was prepared on sacrificial silica microspheres via surface imprinting technique through atom transfer radical polymerization using a novel water-soluble azobenzene derivative, 4-[(4-methacryloyloxy)phenylazo]-3,5-dimethyl benzenesulfonic acid, as the functional monomer, and the sacrificial silica core was subsequently removed using HF etching method with 1.25vol.% HF ethanolic solution. The morphologies and properties of the photoresponsive hollow molecularly imprinted polymer were further characterized and compared systematically with the corresponding photoresponsive surface molecularly imprinted polymer. Compared with surface imprinted polymer, the hollow material displayed higher binding capacity, better recognition ability, faster mass-transfer rate, and larger isomerization rate constants toward triamterene. The static binding properties of the imprinted materials were investigated under three irradiation conditions. The photoresponsive hollow molecularly imprinted polymer showed better specificity toward triamterene than its structural analogues (folic acid and caffeine) as examined by UV-vis and HPLC. The photoresponsive hollow molecularly imprinted polymer was utilized for the determination of trace triamterene in biological samples (human urine and serum) with advantages of simple sample pre-treatment, good recovery and good sensitivity.

[Simultaneous occlusal orthodontics during mandibular distraction osteogenesis].

OBJECTIVE: To study the significance and principle of simultaneous orthodontics during mandibular distraction osteogenesis. METHODS: Totally 11 patients simultaneously underwent occlusal orthodontic treatment for 3-4 months during mandibular distraction osteogenesis. Square-wire and elastic loops were adapted to perform the orthodontics by ways of more frequent adjustment of orthodontic device than routine method. RESULTS: All 11 patients with mandibular micronathia obtained the improved occlusion with their mandibular expected elongation, for instance, their open-bite and teeth displacement were partially corrected. CONCLUSION: Simultanous orthodontics with mandibular distraction osteogenesis may improve the malocclusion, decrease the orthodontic time, and lead the mandibular distraction direction.

Photoresponsive surface molecularly imprinted polymer on ZnO nanorods for uric acid detection in physiological fluids.

A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22×10(-5)M in aqueous NaH2PO4 buffer at pH=7.0 and a maximal adsorption capacity of 1.45µmolg(-1). Upon alternate irradiation at 365 and 440nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid.

[A study of dental caries and risk factors in children of Guangxi area].

PURPOSE: To observe the trends of dental caries and identify risk factors which may be associated with caries among children in Guangxi province between 2011 and 2013. METHODS: Three age groups of children (3-year-old, 6-year-old, 12-year-old) were selected from 3 urban and rural areas in Guilin, Baise and Beihai of Guangxi province and examined annually from 2011 to 2013.The caries prevalence, mean DMFT/dmft, caries incidence rate and filling rate were recorded. The data was analyzed with SPSS19.0 software package. RESULTS: The caries prevalence, mean DMFT/dmft and caries incidence rate in the 3 groups were increased year by year. The caries prevalence of deciduous teeth in 3-year-old group was 53.2%, 68.7% and 79.1% respectively, and the growth rate was 48.6%; The mean dmft was 2.34, 4.06 and 5.68, and the caries incidence rate increased from 55.9% to 61.2%. In the 6-year-old group, the caries prevalence of permanent teeth was 8.6%, 21.6% and 48.0% respectively, and the growth rate was 458.1%; The mean DMFT was 0.13, 0.34 and 0.99, and the caries incidence rate increased from 15.6% to 36.6%. The caries prevalence of permanent teeth in 12-year-old group was 52.8%, 60.2% and 71.3%, and the growth rate was 35.0%; The mean DMFT was 1.49, 1.92 and 2.96, and the caries incidence rate increased from 26.1% to 46.9%. The frequency of drinking soft drink or sweet, taking sweets at bedtime or after brushing teeth, brushing teeth with help, frequency of brushing, fluoride toothpaste may be the risk factors related to dental caries among children in this study. CONCLUSIONS: Dental caries increase fast among children in Guangxi area. It is necessary to take appropriate measures to improve children's oral health.

Review of the recent progress in photoresponsive molecularly imprinted polymers containing azobenzene chromophores.

Photoresponsive molecularly imprinted polymers (PMIPs) containing azobenzene have received wide research attention in recent years and made notable achievements. This article reviews the recent developments on PMIPs containing azobenzene. Topics include the following: (i) brief introduction of azobenzene, molecularly imprinted polymers, and PMIPs containing azobenzene; (ii) progress in functional monomers, cross-linkers, and polymerization conditions; (iii) preparation methods, properties, applications, as well as advantages and disadvantages of conventional PMIPs; (iv) substrate, preparation method, and applications of photoresponsive surface molecularly imprinted polymers; and (v) some perspectives for further development of PMIPs containing azobenzene.

Photocontrolled solid-phase extraction of guanine from complex samples using a novel photoresponsive molecularly imprinted polymer.

A novel photoresponsive molecularly imprinted polymer (MIP) was developed for the selective extraction of guanine from complex samples. The photoresponsive MIP was fabricated using guanine as the template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as the functional monomer, and water-soluble triethanolamine trimethacrylate as the cross-linker. The MIP displayed good selectivity toward guanine with a dissociation constant of (2.70 ± 0.16) × 10(-5) mol L(-1) in aqueous media. The density of the guanine-specific receptor sites in the MIP material was (4.49 ± 0.22)µmol g(-1). Quantitatively release and uptake of guanine by the MIP occurred with irradiation at 365 and 440 nm, respectively. The MIP could efficiently extract guanine from beer and then release it into aqueous media under photocontrol. This method could be used for selective separation and subsequent determination of a specific analytes from complex samples.

Efficacy and side-effects of a semi-individualized Chinese herb mixture "Tiáo Geng Tang" for menopausal syndrome in China.

BACKGROUND: Chinese herbal medicine is an alternative therapy for menopausal problems and is widely practiced in China and many other Asian countries. However, efficacies and side-effects are rarely assessed according to the standards of evidence-based medicine. PATIENTS AND METHODS: This is a prospective observatory study following efficacy and side-effects of a semi-individualized Chinese herbal mixture "Tiáo Geng Tang (TGT)" in 30 patients for 3 months. Another group of 30 patients receiving hormone therapy with tibolone was included as a positive comparison. Common questionnaire-based measuring instruments were: modified Kupperman index, menopause rating scale, life quality and Chinese medical symptom scale (CMSS). Follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) were determined before and three months after the treatments. RESULTS: Significant improvement was seen in overall scores of all the four measurements in both groups. For some symptoms, including dry mouth, tinnitus, poor appetite and constipation, TGT was more effective than tibolone. For psychosocial and sexual sub-scales of life quality, tibolone has a slightly higher remedy rate than TGT. TGT lowered FSH and LH significantly, as tibolone did, but elevated E2 significantly less than tibolone. Various adverse events, including body weight increase, abdomen discomfort, nausea/vomiting, emotional instability, pressure in breasts and dizziness, were reported by patients treated with tibolone, whereas only diarrhea was observed in two patients treated with TGT. CONCLUSION: TGT alleviates menopausal symptoms with similar efficacy as tibolone but has fewer side effects.

[Clinical evaluation of masticatory function of implant supported dentures in partially edentulous patients].

OBJECTIVE: To evaluate the masticatory efficiency of implant supported dentures in partially edentulous patients and the patients' satisfaction on masticatory function. METHODS: The masticatory efficiency of implant supported dentures of 22 patients were tested. The questionnaire of the patients' satisfaction about masticatory function had also been collected. The correlativity of the masticatory efficiency of implant supported dentures and the scores evaluated by patients on masticatory function were analyzed. RESULTS: There were no differences in masticatory efficiency between implant supported denture and non-implant supported denture (natural teeth and porcelain-fused-to-metal fixed bridges). The patients gave high scores to the satisfaction about masticatory function in the questionnaire. But the test results of masticatory efficiency were not related with the scores evaluated by patients. CONCLUSION: The implant supported denture could meet the requirement of normal masticatory function. The patients were satisfactory with the masticatory function of implant supported dentures, but the patients' subjective evaluation about masticatory function was probably influenced by varied factors.