Magnetically Reusable and Well-dispersed Nanoparticles for Oxygen Detection in Water.

In this study, we aimed to synthesize magnetically well-dispersed nanosensors for detecting dissolved oxygen (DO) in water, and explore their biological applications. Firstly, we synthesized two kinds of magnetic nanoparticle with average sizes of approximately 82 nm by one-step emulsion polymerization: polystyrene magnetic nanoparticles (Fe3O4@Os1-PS) and polymethylmethacrylate magnetic nanoparticles (Fe3O4@Os1-PMMA). Both types of nanoparticle present good dispersibility and fluorescence stability. The nanoparticles could be used as oxygen sensors that exhibited a high DO-sensitivity response in the range 0-39.30 mg/L, with a strong linear relationship. The nanoparticles have good magnetic properties, and so they could be recycled by magnet for further use. Recovered Fe3O4@Os1-PS still presented high stability after continued use in oxygen sensing for one month. Furthermore, Fe3O4@Os1-PS was employed for detecting the bacterial oxygen consumption of Escherichia coli (E-coli) to monitor the metabolism of bacteria. The results show that Fe3O4@Os1-PS provide high biocompatibility and non-toxicity. Polystyrene magnetic nanoparticles therefore present significant potential for application in biological oxygen sensing.

Navigation in bone-impacted premaxillary supernumerary tooth removal: a preliminary clinical trial.

AIM: The present clinical trial aimed to preliminarily assess whether navigation could help to position impacted supernumerary teeth (STs) and reduce surgical trauma. MATERIALS AND METHODS: Subjects with an impacted supernumerary tooth (ST) in the premaxillary area were enrolled in the study and randomly distributed into a navigation group and a control group. In the navigation group, STs were positioned and extracted under real-time optic navigation. In the control group, STs were extracted depending on the surgeon's experience. Subjects were followed up for 12 to 24 weeks postsurgery. Operating time, futile bony trauma, and the positioning precision of the STs were the major outcomes assessed. Multivariate correlation analysis was performed. RESULTS: In 24 subjects, 32 STs were removed and no severe complications occurred in either group. The proportion of ST exposure at the planned access point was 100% in the navigation group and 68.75% in the control group (χ² = 5.926, P = 0.015). Futile length, futile width, and the distance between the point where the ST was initially exposed and the bony point planned for accessing it were related to both navigation/control grouping and bone thickness in the access side. For challenging STs with bone thickness of > 0.5 mm in the access side (N = 22), the futile length in the navigation group (0.0 [0.0, 4.0] mm) was significantly smaller than that in the control group (3.0 [0.0, 8.0] mm, P = 0.028). Similarly, the futile width in the navigation group (0.0 [0.0, 2.0] mm) was significantly smaller than that in the control group (2.0 [0.0, 4.0] mm, P = 0.018). CONCLUSIONS: Navigation helped to position impacted STs precisely and reduced surgical bony trauma to some extent, especially in challenging cases in which the bone in the access side was thicker than 0.5 mm.

Evaluation of controlled-release triamcinolone acetonide-loaded mPEG-PLGA nanoparticles in treating experimental autoimmune uveitis.

Uveitis is a recurrent, sight-threatening intraocular inflammatory disease and is treated with glucocorticoids in clinical practice. In the present study, methoxypoly(ethyleneglycol)-poly(dl-lactide-co-glycolic acid) (mPEG-PLGA) nanoparticles in combination with triamcinolone acetonide (TA) were fabricated using a modified double emulsification method. Further, we characterized the TA-loaded nanoparticles, and investigated the effects of TA-loaded nanoparticles on experimental autoimmune uveitis rats, including histopathological examination and the alterations in interleukin (IL)-17 and IL-10 at mRNA and protein levels in either aqueous humor or serum. As a result, the TA-loaded nanoparticles were a well-defined spherical shape with a mean particle size of 82 nm. The in vitro release profile showed that the TA-loaded nanoparticles could sustain for more than 45 days, and possessed higher anti-inflammatory effects compared to TA alone after pathological examination, resulting in decreased IL-17 and elevated IL-10 levels in both aqueous humor and serum. Based on these findings, it can be concluded that TA-loaded mPEG-PLGA nanoparticles can potentially provide a better anti-inflammatory effect in treating chronic and recurrent uveitis in clinical practice.

Efficacy and safety of using premedication with simethicone/Pronase during upper gastrointestinal endoscopy examination with sedation: A single center, prospective, single blinded, randomized controlled trial.

BACKGROUND AND AIM: To investigate the efficacy and safety of premedication with simethicone/Pronase during esophagogastroduodenoscopy (EGD) with sedation. METHODS: Six hundred and ten patients were randomly allocated to two groups based on type of premedication given. Premedication used in the control group was 10 mL lidocaine hydrochloride mucilage (LHM, N = 314) and premedication used in the intervention group was 80 mL simethicone/Pronase solution plus 10 mL lidocaine hydrochloride mucilage (SP/LHM, N = 296). EGD was done under sedation. Visibility scores, number of mucosal areas that needed cleansing, water consumption for cleansing, time taken for examination, diminutive lesions, pathological diagnosis, patients' gag reflex and oxygenation (pulse oximetry) were recorded. RESULTS: SP/LHM has significantly lower total visibility score than LHM (7.978 ± 1.526 vs 6.348 ± 1.097, P < 0.01). During the procedure, number of intragastric areas that needed cleansing and amount of water consumed were significantly less in the SP/LHM than in the LHM group (P < 0.01). In SP/LHM (P = 0.01), endoscopy procedure duration was significantly longer. Although there was no significant difference in rate of detection of diminutive lesions between LHM and SP/LHM, the endoscopist carried out more biopsies in SP/LHM. This led to a higher rate of diagnosis of atrophic gastritis (P = 0.014) and intestinal metaplasia (P = 0.024). There was no significant difference in gag reflex (P = 0.604) and oxygenation during the endoscopy procedure for either group of patients. CONCLUSION: Routine use of premedication with simethicone/Pronase should be recommended during EGD with sedation.

Amphiphilic Fluorine-Containing Block Copolymers as Carriers for Hydrophobic PtTFPP for Dissolved Oxygen Sensing, Cell Respiration Monitoring and In Vivo Hypoxia Imaging with High Quantum Efficiency and Long Lifetime.

New amphiphilic star or multi-arm block copolymers with different structures were synthesized for enabling the use of hydrophobic oxygen probe of platinum (II)-tetrakis (pentafluorophenyl) porphyrin (PtTFPP) for bioanalysis. The amphiphilic star polymers were prepared through the Atom Transfer Radical Polymerization (ATRP) method by using hydrophilic 4-arm polyethylene glycol (4-arm-PEG) as an initiator. Among the five block copolymers, P1 series (P1a, P1b, and P1c) and P3 possess fluorine-containing moieties to improve the oxygen sensitivity with its excellent capacity to dissolve and carry oxygen. A polymer P2 without fluorine units was also synthesized for comparison. The structure-property relationship was investigated. Under nitrogen atmosphere, high quantum efficiency of PtTFPP in fluorine-containing micelles could reach to 22% and long lifetime could reach to 76 µs. One kind of representative PtTFPP-containing micelles was used to detect the respiration of Escherichia coli (E. coli) JM109 and macrophage cell J774A.1 by a high throughput plate reader. In vivo hypoxic imaging of tumor-bearing mice was also achieved successfully. This study demonstrated that using well-designed fluoropolymers to load PtTFPP could achieve high oxygen sensing properties, and long lifetime, showing the great capability for further in vivo sensing and imaging.

Hydrogel-Based Fluorescent Dual pH and Oxygen Sensors Loaded in 96-Well Plates for High-Throughput Cell Metabolism Studies.

In this study, we developed fluorescent dual pH and oxygen sensors loaded in multi-well plates for in-situ and high-throughput monitoring of oxygen respiration and extracellular acidification during microbial cell growth for understanding metabolism. Biocompatible PHEMA-co-PAM materials were used as the hydrogel matrix. A polymerizable oxygen probe (OS2) derived from PtTFPP and a polymerizable pH probe (S2) derived from fluorescein were chemically conjugated into the matrix to solve the problem of the probe leaching from the matrix. Gels were allowed to cure directly on the bottom of 96-well plates at room-temperature via redox polymerization. The influence of matrix's composition on the sensing behaviors was investigated to optimize hydrogels with enough robustness for repeatable use with good sensitivity. Responses of the dual sensing hydrogels to dissolved oxygen (DO) and pH were studied. These dual oxygen-pH sensing plates were successfully used for microbial cell-based screening assays, which are based on the measurement of fluorescence intensity changes induced by cellular oxygen consumption and pH changes during microbial growth. This method may provide a real-time monitoring of cellular respiration, acidification, and a rapid kinetic assessment of multiple samples for cell viability as well as high-throughput drug screening. All of these assays can be carried out by a conventional plate reader.

Chemometrics-based Discrimination of Virgin and Recycled Acrylonitrile-Butadiene-Styrene Plastics Toys via Non-targeted Screening of Volatile Substances.

Owing to the growing emphasis on child safety, it is greatly urgent to identify and assess the unknown compounds and discriminate the recycled materials for plastic toys. In this study, gas chromatography mass spectrometry coupled with static headspace has been optimized by response surface methodology for non-targeted screening of unknown volatiles in acrylonitrile-butadiene-styrene (ABS) plastic toys. Optimum conditions for static headspace were 120 °C for extraction temperature and 48 min for extraction time. A total of 83 volatiles in 11 categories were qualitatively identified by matching the NIST database library, retention index and standard materials. Considering high positive rate and potential toxicity, high-risk volatiles in ABS plastic toys were listed and traced for safety pre-warning. Moreover, the differential volatiles between virgin and recycled ABS plastics were screened out by orthogonal partial least-squares discrimination analysis. Principal component analysis, hierarchical cluster analysis and linear discrimination analysis were employed to successfully discriminate recycled ABS plastic toys based on the differential volatiles. The proposed strategy represents an effective and promising analytical method for non-targeted screening and risk assessment of unknown volatiles and discrimination of recycled materials combining with various chemometric techniques for children's plastic products to safeguard children's health.

Learning curve for flexible bronchoscope-guided orotracheal intubation for anesthesiology residents: A cumulative sum analysis.

BACKGROUND: Endotracheal intubation with a flexible bronchoscope is a well-recognized airway management technique that anesthesiologists must master. Skill acquisition and knowledge must reach an appropriate level before trainees perform independent practice on patients. There are a paucity of evidence-based outcome measures of trainee competence in performing flexible bronchoscopy. The objectives of this study were to 1) construct a learning curve for flexible bronchoscope-guided orotracheal intubation for anesthesiology residents using the CUSUM method and 2) determine the number of procedures required to achieve proficiency. METHODS: This study included 12 first-year anesthesiology residents with no previous experience with flexible bronchoscopic intubation. Trainees attended theoretical and simulation training and performed flexible bronchoscope-guided orotracheal intubation in adult patients with normal airways under general anesthesia. Number of intubation attempts, intubation success rate, time to intubation, and incidence of dental and mucosal injuries were recorded. The cumulative sum (CUSUM) method was used to evaluate the learning curve of flexible bronchoscope-guided orotracheal intubation. RESULTS: Trainees performed flexible bronchoscope-guided orotracheal intubation on 364 patients. First-attempt intubation success occurred in 317 (87.1%) patients. Second-attempt intubation success occurred in 23 (6.3%) patients. Overall, the flexible bronchoscope-guided orotracheal intubation success rate was 93.4% (range, 85.3% to 100%). The mean number of orotracheal intubation procedures per trainee was 31 ± 5 (range, 23 to 40). All trainees crossed the lower decision boundary (H0) after 15.1 ± 5.6 procedures (range, 8 to 25 procedures). There was a significant decrease in median intubation time [39s (IQR: 30, 50) vs. 76s (IQR: 54, 119)] (P < 0.001) after crossing the lower decision boundary (H0) compared to before. There were no dental, mucosa, arytenoid or vocal cord trauma events associated with intubation. CONCLUSIONS: Learning curves constructed with CUSUM analysis showed that all trainees (anesthesiologist residents) included in this study achieved competence (intubation success rates ≥ 80%) in flexible bronchoscope-guided orotracheal intubation. Trainees needed to perform 15 (range, 8 to 25) procedures to achieve proficiency. There was wide variability between trainees. TRIAL REGISTRATION: Trial registration: Chinese Clinical Trial Register, ChiCTR 2000032166.

Efficacy of Arthroscopic Discopexy on Condylar Growth in Temporomandibular Joint Anterior Disc Displacement: A Randomized Clinical Trial.

BACKGROUND: Adolescents with temporomandibular joint (TMJ) anterior disc displacement (ADD) frequently develop dentofacial deformities. It is unknown if adjunctive arthroscopic discopexy compared to orthodontic treatment alone increases condylar growth and then improves dentofacial deformity. This study aimed to determine whether arthroscopic discopexy before functional appliance (joint-occlusal treatment) or single functional appliance (occlusal treatment) increases condylar growth and improves dentofacial deformity among adolescents with TMJ ADD. METHODS: A multicenter, randomized, parallel controlled trial was conducted in three centers in China. Adolescents diagnosed with TMJ ADD and dentofacial deformity were enrolled. Eligible participants were randomly assigned to a joint-occlusal group or occlusal group at a ratio of 2:1. MRI, cephalometric radiographs were evaluated at baseline, 8 months and 14 months. The primary outcome was changes in condylar height from 14 months to baseline. Secondary outcomes were changes in skeletal position. RESULTS: A total of 240 patients (14.65±1.88 years of age) were randomized (joint-occlusal group: 160; occlusal group: 80). The overall difference in condylar height between groups was 3.65 mm (95% CI, 3.10 to 4.19; p < 0.001). The between-group differences in condylar height on the left and right sides were 3.60 mm (95% CI, 2.92 to 4.28; p < 0.001) and 3.69 mm (95% CI, 3.06 to 4.32; p < 0.001), respectively. Significant between-group differences were noted in skeletal position (all p < 0.001). CONCLUSIONS: Joint-occlusal treatment can promote condylar growth and improve dentofacial deformity in adolescents after 14 months when compared with single occlusal treatment.

Genomic analysis of Thalassospira sp. SW-3-3 reveals its genetic potential for phthalate pollution remediation.

Thalassospira sp. SW-3-3 is a bacterial strain isolated from deep seawater of the Pacific Ocean at a water depth of 3112 m. It is a Gram-negative, aerobic, and curved rod-shaped bacterium belonging to the family Thalassospiraceae. In this study, we report the complete genome sequence of strain SW-3-3. It has a circular chromosome with a size of 4,764,478 bp and a G + C content of 54.7%. The genome contains 4296 protein-coding genes, 63 tRNA genes, and 12 rRNA genes. Genomic analysis shows that strain SW-3-3 contains genes and catalytic pathways relevant to phthalate metabolism. Phthalates are well-known emerging contaminants that are harmful to environments and human health. They are chemically stable compounds that are widely used in plastic products and are pervasive in our life. With the discharge of plastic pollutants, a huge number of phthalate compounds enter the ocean. The genetic information of strain SW-3-3 suggests that it has the potential to metabolize phthalates. There are 9 key enzymes in the metabolization pathway, and phthalates are finally catalyzed to produce succinyl-CoA which is further degraded through the tricarboxylic acid (TCA) cycle pathway. This genomic analysis will be helpful for further understanding of the applications of strain SW-3-3 in the remediation of phthalate pollution.

Characterization of potential cellulose fiber from cattail fiber: A study on micro/nano structure and other properties.

Exploration of the application prospects of cattail fibers (CFs) in natural composites, and other fields is important for the sustainable development of new, green, light-weight, functional biomass materials. In this study, the physical and chemical properties, micro/nano structure, and mechanical characteristics of CFs were investigated. The CFs have a low density (618.0 kg m-3). The results of transmission electron microscopy and tensile testing data indicated that the cattail trunk fiber (CTF) bundle is composed of parenchyma cells and solid stone cells, demonstrating high specific modulus (10.1 MPa∙m3·kg-1) and high elongation at break (3.9%). In turn, the cattail branch fiber (CBF) bundle is composed of parenchyma cells with specific "half-honeycomb" shape. The inner diaphragms divide these cells into the open cavities. This structural feature endows the CTF bundles with stable structure, good oil absorption and storage capacities. The chemical component and the Fourier transform infrared spectroscopy analyses show that the CFs have higher lignin content (20.6%) and wax content (11.5%), which are conducive to the improvement of corrosion resistance, thermal stability and lipophilic-hydrophobic property of CF. Finally, the thermogravimetric analysis indicates that its final degradation temperature is 404.5 °C, which is beneficial to the increase in processability of CFs-reinforced composites.

Comparison of fibrosis regression of entecavir alone or combined with pegylated interferon alpha2a in patients with chronic hepatitis B.

BACKGROUND AND AIMS: Antiviral treatment with necleos(t)ide analogues contributes to histological improvement and virologic response in chronic hepatitis B (CHB) patients. However, whether adding pegylated interferon alpha2a (Peg-IFN-α-2a) can help additional clinical benefit, particularly on fibrosis regression was still unknown. METHODS: Chronic hepatitis B patients with pre-treatment biopsy-proven Ishak fibrosis score 2, 3 or 4 were randomly assigned to entecavir (ETV) alone or ETV plus Peg-IFN-α-2a (Peg-IFN-α-2a add-on) group (1:2 ratio). Post-treatment liver biopsy was performed at week 78. Fibrosis regression was defined as decrease in Ishak fibrosis score by ≥ 1 stage or predominantly regressive categorized by P-I-R score. Serum HBV DNA levels were assessed at baseline and every 26 weeks, while HBsAg and HBeAg were evaluated at baseline and every 52 weeks. RESULTS: A total of 218 treatment-naive CHB patients were randomly assigned to ETV alone or Peg-IFN-α-2a add-on group. Totals of 155 patients (ETV alone: Peg-IFN-α-2a add-on, 47:108) were included in statistical analysis. Fibrosis regression rates were 68% (32/47) in the ETV alone and 56% (60/108) in Peg-IFN-α-2a add-on group (p = 0.144). Both groups showed a similar trend of virological suppression during the process of 104-week antiviral therapy (p = 0.132). HBeAg or HBsAg loss or seroconversion rates in the ETV alone group were lower than Peg-IFN-α-2a add-on group though without statistical significance. CONCLUSIONS: Peg-IFN-α-2a add-on therapy did not yield additional fibrosis regression and virologic response than ETV alone therapy.

Processivity and the Mechanisms of Processive Endoglucanases.

Cellulases, as environmentally appropriate catalysts specifically acting on cellulosic substrates, are important for the industrial conversion of lignocellulose and modification of cellulose products. After decades of research, a fundamental understanding of cellulase-mediated hydrolysis of cellulose is that its ability to processively act as a key for the complete enzymatic hydrolysis of natural crystalline cellulose. Two types of processive cellulases are known: exoglucanases and processive endoglucanases. Exoglucanases are typical processive enzymes, and they have been studied in detail so that their modes of action and mechanisms are reasonably well characterized. Conversely, endoglucanases are less well characterized because of the non-universality and structural diversity. However, processive endoglucanases have certain characteristics that exoglucanases lack such as hydrolysis product diversity and independent hydrolyze natural crystalline cellulose. Therefore, besides the conversion of cellulose to monosaccharide, they might be useful for modification of fibrous substrates and preparation of cellulose oligosaccharides. Herein, we review in detail the sources, hydrolysis products, application, and possible hydrolysis mechanisms of processive endoglucanases.

Effectiveness of fluoride varnish on caries in the first molars of primary schoolchildren: a 3-year longitudinal study in Guangxi Province, China.

AIMS: To evaluate the effectiveness of 5% sodium fluoride varnish on caries in first permanent molars and to assess the suitability of using this method to control caries among children in rural areas of Guangxi province, China. METHODS: A total of nine schools with 32 classes were selected by simple random sampling. There were 999 students in the experimental group and 1,004 in the control group. The experimental group received oral health education and topical application of 5% sodium fluoride varnish, while the control group received oral health education only. Dental examinations were performed in November 2014 and November 2017, and the modified International Caries Detection and Assessment System (ICDAS-II) was used to record the caries status of the first permanent molars. The data were entered into SPSS 22 for statistical analysis. RESULTS: A total of 1,748 students (853 in the experimental group and 895 in the control group) completed the study. After 3 years of intervention, the experimental group had a lower prevalence of caries, a lower caries increment, a lower decayed, missing and filled teeth (DMFT) index and a lower decayed, missing and filled surfaces (DMFS) index compared with the control group (respectively: 58.9% vs 65.5%, 34.8% vs 42.1%, 1.38 vs 1.59 and 2.06 vs 2.38). All the differences were statistically significant (P < 0.05). CONCLUSION: In this study population, twice-yearly application of 5% sodium fluoride varnish and oral health education were more effective for preventing caries in first permanent molars than oral health education alone. The implementation of fluoride varnish application as a public health measure in schools in rural areas is recommended.

Lithography-free formation of nanopores in plastic membranes using laser heating.

Synthetic nanopores are a new class of single-molecule sensors capable of electronically detecting, counting, and characterizing biomolecules. There have been studies of nanopore formation in solid-state materials. This paper reports a novel lithography-free method of nanopore formation in plastic membranes fluidized using laser heating. It was found that the pore shrinking dynamics follows a universal behavior with the diameter of a pore decreasing linearly with time similar to that found in fluidized SiO(2). A theoretical model based on a surface-tension-driven mass flow mechanism is proposed to successfully explain the observed universality in the pore shrinking dynamics. We demonstrate the potential of this lithography-free nanofabrication technique in biomolecular sensing with a lambda-DNA detection experiment.