Fatty acids-modified liposomes for encapsulation of bioactive peptides: Fabrication, characterization, storage stability and in vitro release.

The fragile membranes of liposomes limit their application by the food industry. In this study, we hypothesized that interactions between fatty acids with different chain lengths and phospholipids might enhance liposome stability. Decanoic acid modified liposomes (Lipo-DA) and stearic acid modified liposomes (Lipo-SA) were fabricated for encapsulation of hydrophilic peptides. Fluorescence spectroscopy and FTIR analysis showed molecular interactions existed between alkyl chains and phospholipids, resulting in greater compactness and hydrophobicity of the membranes in Lipo-DA and Lipo-SA. This led to a reduction in melting point characterized by differential scanning calorimetry analysis. Lipo-DA and Lipo-SA could delay the release of hydrophilic peptides compared with unmodified liposomes in simulated digestion. Moreover, Lipo-DA showed better stability during storage, while Lipo-SA exhibited precipitation, resulting in the lowest peptide retention. Our study showed that decanoic acid is suitable to enhance the stability of liposomes, although this approach has yet to be tested in food products.

Analysis of Structural Parameters of Steel-NC-UHPC Composite Beams.

The cracking of the negative moment area of steel-normal concrete (NC) composite bridges is common owning to the low tensile strength of concrete. In order to solve the problem, Ultra High Performance Concrete (UHPC) is used to enhance the tensile performance of the negative moment area. This paper conducted interface experiments to study the bonding behaviour of the UHPC-NC interface. The design parametric analysis of steel-NC-UHPC composite bridges was carried out based on the interface experimental results. Firstly, slant shear tests and flexural shear tests were carried out to study the rationality of the interface handling methods. Then, the finite element model was used to analyze the state of every component in the composite beams based on experimental results, such as the stress of UHPC, concrete and steel plate. Finally, the calculation results of finite analysis were compared and summarized. It is concluded that (1) the chiseling interface can meet the utilization requirements of physical bridges. The average shear stress and flexural tensile strength of the chiseling interface are 10.29 MPa and 1.93 MPa, respectively. In the failure state, a slight interface damage occurs for specimens with a chiseling interface. (2) The influence on overall performance is different for changes in different design parameters. The thickness of concrete has a significant influence on the stress distribution of composite slabs. (3) Reliable interface simulation is conducted in the finite element models based on interface test results. The stress variation patterns are reflected in the change of design parameters.

Public health emergency response capacity in primary and secondary schools / 中国学校卫生

Objective@#To understand the public health emergency response capacity in primary and secondary schools, and to explore the problems and challenges in the prevention and control of public health emergency in primary and secondary schools for specific strategies.@*Methods@#By using the stratified group sampling method, a questionnaire survey on general situation, knowledge, attitude and training, as well as public health emergencies response capacity among 2 988 teachers or leaders responsible for school emergency response in primary and secondary schools from Beijing, Chongqing and Yunnan.@*Results@#Participants varied on their positions, titles, educational background and knowledge accuracy. Higher knowledge accuracy was associated with higher educational background ( χ 2=50.73-203.36, P < 0.05 ). The implementation of regular public health emergency related programs was poorly conducted in high schools (50.0%). Urban schools (42.0%) had higher proportion of qualified health care professionals than rural schools (18.2%), and private schools (48.5%) was higher than public schools (24.7%). The primary challenges included the shortage of guidance from professionals and the lack of related testing equipment (84.91%, 74.03%).@*Conclusion@#Although the ability of emergency handling of public health emergencies in schools in the three regions is advancing with the times, there are still many deficiencies, some omissions in the mastery of knowledge. It is suggested to inerease pre service and special training of school health work CDC should strengthen technical guidance and work supervision of infectious disease management in schools.

Long-term intermittent hypoxia induces anxiety-like behavior and affects expression of orexin and its receptors differently in the mouse brain.

Studies have revealed a possible connection between orexin, narcolepsy, and obstructive sleep apnea (OSA). Orexin has an important role in the maintenance of arousal and wakefulness/sleeping states. To better understand the pathophysiological mechanism of OSA, we used a chronic intermittent hypoxia (CIH) model in mice to mimic OSA. In this way, we explored the effect of CIH on the locomotor activity and orexin system in the hypothalamus, cerebral cortex, and brainstem of mice. Male C57BL/6 J mice (8 weeks) in the CIH group were exposed in a hypoxia chamber for 8 h/day for 28 weeks. The re-oxygenation groups comprised the W2 group and W4 group, which were exposed to 28 weeks of CIH followed by 2 weeks and 4 weeks of re-oxygenation, respectively. The open field test was undertaken to observe locomotor activity. mRNA expression of orexin, orexin receptor type 1 (OX1R), and OX2R mRNA was evaluated by real-time reverse transcription-quantitative polymerase chain reaction. Mice subjected to long-term CIH exhibited significant anxiety-like behavior during the light period, and this behavior lasted until 4 weeks of re-oxygenation. mRNA expression of orexin was upregulated in the hypothalamus. mRNA expression of OX1R mRNA in the cerebral cortex and brainstem was downregulated by CIH. Two weeks and 4 weeks of re-oxygenation could not reverse these alternations. Long-term CIH may induce anxiety-like behavior and re-oxygenation cannot reverse these behavior. Moreover, OX1R has a significant role in the anxiety-related symptoms observed in long-term CIH.

Singlet Oxygen Generation from a Water-Soluble Hypervalent Iodine(V) Reagent AIBX and H2O2: An Access to Artemisinin.

Herein, we report an efficient method for the chemical generation of 1O2 by treatment of H2O2 with AIBX, a highly water-soluble, bench-stable, recyclable hypervalent iodine(V) reagent developed by our group. The generation of 1O2 was confirmed by the following results: (1) capture of 1O2 with the sodium salt of anthracene-9,10-bis(ethanesulfonate) produced the corresponding endoperoxide and (2) TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) produced by the oxidation of 2,2,6,6-tetramethylpiperidine with 1O2 generated using the AIBX/H2O2 system was detected by electron spin resonance spectroscopy. To illustrate the potential utility of this method for organic synthesis, we used the AIBX/H2O2 system to perform typical reactions of 1O2: [2 + 2]/[4 + 2] cycloadditions, Schenck ene reactions, and heteroatom oxidation reactions, which afforded the corresponding products in high yields. Moreover, we used the method to synthesize the antimalarial drug artemisinin. Finally, we demonstrated that AIBX could be regenerated after the reaction by means of a workup involving extraction and removal of water to obtain a precursor of AIBX, which could then be re-oxidized.

Redetermination of the Structure of a Water-Soluble Hypervalent Iodine(V) Reagent AIBX and Its Synthetic Utility in the Oxidation of Alcohols and Synthesis of Isoxazoline N-Oxides.

The structure of a water-soluble hypervalent iodine(V) reagent AIBX is re-examined through its single-crystal X-ray analysis and theoretical calculations including Mayer bond order and localized orbital locator (LOL) and AIBX is believed to be a pseudocyclic iodylarene because of the strong electron-withdrawing nature of the trimethylammonium cation on its phenyl ring, which would decrease the electron density of carboxylic anion and make the ortho-carboxyl oxygen anion incapable to form hypervalent bond with iodine atom. However, the cyclic benziodoxole structure of AIBX could be obtained by adding a Brønsted acid, which was supported by the calculation result including the increase of Mayer bond order and the shortening of the I-O bond length. Moreover, the fact that the system of AIBX and TFA could oxidize various alcohols to their corresponding carbonyl compounds would indicate that AIBX constitutes a cyclic benziodoxole structure under acidic conditions. In addition, an efficient method has been developed for the synthesis of isoxazoline N-oxides via AIBX-induced dehydrogenative cyclization using ß-keto esters as substrates and methyl nitroacetate as a nucleophile.

Microwave treatment regulates the free volume of rice starch.

The aim of this work was to investigate the role of microwave parameters and moisture content on the free volume (FV) changes of rice starch by positron annihilation lifetime spectroscopy analysis (PALS) and to explore the potential relationship between the changes of FV and physicochemical properties of rice starch. Microwave heating and water molecules lead to the increasing of FV of starch. However, this result is largely influenced by the plasticization of water molecule. The anti-plasticization caused by water evaporation resulting in a decrease in the size and concentration of FV during microwave heating. Significant decrease (p < 0.05) in the thickness of amorphous region of microwave-heated rice starch was found by small angle X-ray scattering (SAXS), and the glass transition temperature (Tg) and gelatinization temperature significantly increase (p < 0.05) after microwave heating. According to correlation analysis, the power intensity and heating time were correlated negatively with the lifetime of o-Ps. In addition, the changes of amorphous region and Tg of rice starch were strongly related to FV changes. These results provided a theoretical basis for further research on the directional regulation of FV and improvement the quality of starch-based food by using microwave treatment.

Effect of low-level laser therapy on tooth-related pain and somatosensory function evoked by orthodontic treatment.

Low-level laser therapy (LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals (12-33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group (LG) or a placebo group (PG) (1:1). The LG received LLLT (810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm-2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale (NRS) of pain, pressure pain thresholds (PPTs), cold detection thresholds (CDTs), warmth detection thresholds (WDTs), cold pain thresholds (CPTs), and heat pain thresholds (HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance (ANOVA). The NRS pain scores were significantly lower in the LG group (P = 0.01). The CDTs, CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG (P < 0.033). The parameters tested also showed significantly less sensitivity on the non-treatment side of the LG compared to that of the PG (P < 0.043). There were no differences between the groups for any quantitative sensory testing (QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment. Further clinical applications are suggested.

Transient Pain Following Orthodontic Fixed Appliances Induces Sensitization of Gingival and Periodontal Tissues.

AIMS: To evaluate the transient effects of orthodontic treatment on the mechanical detection threshold (MDT) and mechanical pain threshold (MPT) of the buccal attached gingiva and the pressure pain threshold (PPT) of the buccal attached gingiva and of the teeth in two directions (perpendicular and parallel). METHODS: A total of 20 patients (15 females and 5 males) aged 18 to 30 years participated in the study. Perceived pain on a 0- to 10-cm visual analog scale (VAS) and MDT, MPT, and PPT scores were evaluated at two time points at the masseter muscle, gingiva, teeth, and hand (control) prior to orthodontic treatment (T0) and 24 hours after the first archwire placement (T1). Mean values and SEMs were calculated for all continuous variables. The differences between T0 and T1 of MDT, MPT, and PPT were analyzed by means of a paired Student t test. RESULTS: The pain intensity as assessed on the VAS was 4.2 ± 1.8 cm. No significant changes in MDT or MPT were found at the hand and buccal attached gingiva (P > .06). The PPTs at the buccal attached gingiva of teeth 21, 23, 24, and 34, at teeth 21, 23, 24, and 34 (perpendicular) and at teeth 21 and 23 (parallel) were lower (ie, more sensitive) at T1 compared with T0 (P < .04). CONCLUSION: This study indicates for the first time that pain following insertion of an archwire causes sensitization to blunt-pressure stimuli both in the attached gingiva and in the periodontal ligament. Quantitative assessment of mechanical sensitivity may provide more insights into procedural pain and allow for better monitoring and evaluation of the effects of orthodontic treatment in the future.

Fixed orthodontic appliances cause pain and disturbance in somatosensory function.

This study aimed to assess the short-term effects of orthodontic pain on quantitative sensory testing (QST) in subjects receiving fixed orthodontic treatment. Twenty patients and 12 healthy volunteers (as controls) participated. All 20 patients had bonded AO self-ligating brackets, with a 0.014 super elastic nickel-titanium arch wire placed in the brackets. Pain [self-reported on a visual analog scale (VAS)], and thermal and mechanical thresholds, were tested at six time points--before (baseline), and 2 h, 24 h, 7 d, 14 d, and 30 d after, force application--in the treatment group. The attached gingiva adjacent to the left upper central incisor (21 gingiva) was hypersensitive to cold stimuli (i.e. increased cold detection thresholds were detected) in the treatment group. The pressure pain thresholds of the left upper central incisor (21) and 21 gingiva were significantly reduced. Our results suggest clear signs of sensitization of the trigeminal nociceptive system up to 1 month after force application and orthodontic pain. Quantitative assessment of somatosensory function may help to provide a better understanding and profiling of the underlying neurobiological mechanisms related to orthodontic pain.

Organic/inorganic hybrid mesoporous silica membrane rapidly synthesized by a microwave-assisted method and its application in enzyme adsorption and electrocatalysis.

An organic/inorganic hybrid mesoporous silica membrane (HMSM) composed of mesoporous silica rods in the channels of a polycarbonate (PC) membrane was rapidly synthesized by employing the microwave-assisted method combined with solvent extraction. As-synthesized HMSMs were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), N2 adsorption-desorption, X-ray diffraction (XRD) and thermogravimetry (TG). The results indicated that silica rods with 200 nm diameter and 9 µm length grew in the confined spaces of the PC membrane. The average diameter of mesopores with partially ordered hexagonal mesostructure was about 6.0 nm. In addition, it was found that an enzyme with suitable size, such as horseradish peroxidase (HRP), could be immobilized inside the mesopores of HMSM through physical adsorption. Moreover, an electrode modified by HMSM with adsorbed HRP exhibits excellent direct electrochemical behavior of HRP and electrocatalytic effect toward H2O2, and can be further potentially applied in biosensors.