Addition of glyceryl monostearate affects the crystallization behavior and polymorphism of palm stearin.

Low crystallization-rate and formation of crystalline clusters makes palm stearin unpopular in fat-based products especially in their post-processing stage. Addition of emulsifiers is commonly used to overcome these drawbacks, since they are believed to induce or stabilize specific polymorphs of palm stearin. Glyceryl monostearate (GMS) was applied in palm stearin (1%, 2%, and 4% w/w) in this study, and the mechanisms on crystallization of palm stearin were investigated by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized light microscopic (PLM) method. Data showed that GMS prompted the isothermal crystallization (15-30 °C) in a dose-dependent manner. Crystallization turned to low super-cooling sporadic nucleation at 30 °C. Besides, GMS led to an earlier onset of crystallization during cooling. GMS-palm stearin blends crystallized to form α polymorphs at first and subsequently underwent polymorphic transition to become ß' polymorphs. Addition of 4% w/w GMS in palm stearin significantly decreased the size of crystals, which is helpful to reduce the grainy mouth feel of fat products in practice.

Flavanone-Based Fluorophores with Aggregation-Induced Emission Enhancement Characteristics for Mitochondria-Imaging and Zebrafish-Imaging.

Fluorophores with aggregation-induced emission enhancement (AIEE) characteristics applied in bioimaging have attracted more and more attention in recent years. In this work, a series of flavanone compounds with AIEE characteristics was developed and applied to fluorescence imaging of mitochondria and zebrafish. The compounds were readily prepared by the thermal dehydration of chalcone that was obtained by the reaction of o-hydroxyacetophenone and benzaldehyde. Two of these compounds showed significant AIEE characteristics by fluorescence performance experiments, including optical spectra, fluorescence spectra, fluorescence quantum yield (φF), fluorescence lifetime, and scanning electron microscopy (SEM). Compared with traditional organic fluorescent dyes, these compounds have high fluorescence emission and high fluorescence quantum yield in solid or aggregated state, which overcomes the shortcoming of aggregation-caused quenching (ACQ). More importantly, the two compounds exhibited low cytotoxicity and good cytocompatibility in A549 lung cells at the experimental concentration range and they specifically targeted mitochondria, which make it of great potential use in mitochondria labeling. In addition, they were embryonic membrane permeable and had different affinities for different tissues and organs of zebrafish, but mainly distributed in the digestive system, providing a basis for the application of such compounds in bioimaging. These AIEE compounds with superior properties could be of great potential use in mitochondria imaging and other in vivo studies.

A Dean-flow-coupled interfacial viscoelastic fluid for microparticle separation applied in a cell smear method.

We propose a novel microfluidic device for continuous, label-free and size-selective particle separation. The process consists of two stages: the particle separation based on the pre-focus of sheath flow and the size-selective interface between a Newtonian sample fluid and non-Newtonian poly(ethylene oxide) (PEO) solution (1st stage), and separation distance expansion due to the contraction-expansion structure (2nd stage). The force balance has been analyzed to explore the mechanism and the factors in the particle migration. In the 1st stage, the inertial lift force and the interfacial elastic lift force are a couple of counter forces which only allow the target particles to penetrate the interface. By controlling the flow rate ratio and the PEO concentration, all unwanted particles can be confined to the sample layer. In the 2nd stage, the elastic lift force is used to counteract the inertial lift force, which increases the predomination of the Dean drag force in the lateral migration of the target particles. We conclude that the separation distance is not monotonically increasing with the elastic lift force but peaks at 50-150 ppm. Thus, an optimal parameter for particle separation in our device is obtained. Compared to a similar method without the 2nd stage and the same device without the 1st stage, the distance between the target particles and the unwanted particles could increase by approximately 35.8% and 101.2%, respectively. Finally, a sensitive, time saving and no background-interfering cell smear method is approved to diagnose the malignant pleural effusion efficiently.

Preparation of phosphorus-doped chitosan derivative and its applications in polylactic acid: Crystallization, flame retardancy, anti-dripping and mechanical properties.

The topic of biobased flame-retardant PLA has always been of great interest. In our study, we successfully synthesized a phosphorus-containing chitosan derivative (PCS) and combined it with aluminum hypophosphate (AP) to create an effective flame-retardant PLA system. PCS acted as an enhancer, enhancing the thermal performance, crystallinity, and toughness of PLA/AP. Compared to PLA modified with 12 wt% AP achieving UL-94 V-2 level and 24.3 % of limited oxygen index, PLA containing 3 wt% PCS and 9 wt% AP achieved UL-94 V-0 level and limited oxygen index of 28 %. The system testing studies such as CCT, Raman, XPS, and TG-IR results indicated that PLA/AP/PCS exhibited a dual flame-retardant mechanism of condensed and gas phases.

Braided scaffolds with polypyrrole/polydopamine/hydroxyapatite coatings with electrical conductivity and osteogenic properties for bone tissue engineering.

When impaired bones are grafted with bone scaffolds, the behaviors of osteoblast are dependent on the implant materials and surface morphology. To this end, we modulated the surface morphology of scaffolds that promote cell growth. In this study, ice-template and spraying method methods are employed to coat different proportions of PDA and PPy over the PLA/PVA weaving scaffolds, after which HA is Coated over via the electrochemical deposition, forming weaving scaffolds with electrically conductive PDA/PPy/HA coating. The test results indicate that with a PPy/PDA concentration ratio is 30, the PPy particles are more uniformly distributed on the fiber surface. The scaffolds are wrapped in a HA coating layer with a high purity, and calcium and phosphorus elements are evenly dispersed with a Ca/P ratio being 1.69. Owing to the synergistic effect between PDA and PPy coating, the scaffolds demonstrate excellent electrochemical stability and electrochemical activity. The biological activity of the scaffold increased to 274.66% under electrical stimulation. The new thinking proposed by this study extends the worth of applying textile structure to the medical field, the application of which highly increases the prospect of bone tissue engineering.

A two-step strategy to deposit a hydroxyapatite coating on polydopamine-coated polymer fibers.

As the main inorganic component of human bones and teeth, hydroxyapatite (HA), with excellent bioactivity and biocompatibility, shows great potential in the bone tissue engineering field. Marine mussel-inspired polydopamine (PDA) possesses unique functional groups and thus can absorb the calcium ions from extracellular fluid, thereby triggering the precipitation of HA. This study is based on a two-step strategy. Using the chemical activity of PDA, polyvinyl alcohol/polylactic acid (PVA/PLA) braids were coated with a PDA layer that served as a template for the electrochemical deposition of a HA layer. The test results indicate that the resulting HA crystals were assembled on the polymer fibers in an urchin-like mannerwith a stratified structure. Subsequently, the HA/PDA-PVA/PLA braided bone scaffolds were immersed in simulated body fluid for ten days, after which the bone scaffolds were found to be completely coated with HA, indicating a good biomineralization capability. Cell activity of HA/PDA-PVA/PLA scaffolded by dopamine-assisted electrodeposition was 178.8% than that of PVA/PLA braids. This HA coating layer inspired by biochemical strategies may be useful in the field of bone tissue engineering.

Targeting delivery of synergistic dual drugs with elastic PEG-modified multi-functional nanoparticles for hepatocellular carcinoma therapy.

Integration of multiple advantages in one system has been leveraged to overcome multiple biological barriers in anti-tumor therapeutic strategies. In this study, multi-functional nanoparticles (MFNPs) are constructed by layer-by-layer method. MFNPs are modified with pH-responsive elastic PEG-GPC3MAb (glypican-3 monoclonal antibody), which draws back into PEG layer in blood and normal tissues; and stretches out of MFNPs surface in the acidic tumor microenvironment. It is proved that blank MFNPs have good biocompatibility by MTT and acute toxicity assays. Elastic PEG chains are able to respond sensitively in different pH environments (6.8 and 7.4), which is demonstrated by transmission electron microscope (TEM) and 1H nuclear magnetic resonance (1H NMR). In vitro experiments show that MFNPs have better specificity to Hepa 1-6 cells, can escape from lysosomes, and are able to increase the nuclear delivery of dual drugs for synergistic therapy, which are proved by flow cytometry, MTT, confocal laser scanning microscopy, and western blot studies. In vivo experiments indicate that MFNPs show extending circulation half-life in blood, promoting localization into tumor tissues, improving the therapeutic efficacy of BAL b/c nude mice with subcutaneous tumors. Overall, the results indicate that FMNPs are a potential candidate for hepatocellular carcinoma therapy.

Ultrasensitive and Simultaneous Detection of Two Specific SARS-CoV-2 Antigens in Human Specimens Using Direct/Enrichment Dual-Mode Fluorescence Lateral Flow Immunoassay.

Sensitive point-of-care methods for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in clinical specimens are urgently needed to achieve rapid screening of viral infection. We developed a magnetic quantum dot-based dual-mode lateral flow immunoassay (LFIA) biosensor for the high-sensitivity simultaneous detection of SARS-CoV-2 spike (S) and nucleocapsid protein (NP) antigens, which is beneficial for improving the detection accuracy and efficiency of SARS-CoV-2 infection in the point-of-care testing area. A high-performance magnetic quantum dot with a triple-QD shell (MagTQD) nanotag was first fabricated and integrated into the LFIA system to provide superior fluorescence signals, enrichment ability, and detectability for S/NP antigen testing. Two detection modes were provided by the proposed MagTQD-LFIA. The direct mode was used for rapid screening or urgent detection of suspected samples within 10 min, and the enrichment mode was used for the highly sensitive and quantitative analysis of SARS-CoV-2 antigens in biological samples without the interference of the "hook effect." The simultaneous detection of SARS-CoV-2 S/NP antigens was conducted in one LFIA strip, and the detection limits for two antigens under direct and enrichment modes were 1 and 0.5 pg/mL, respectively. The MagTQD-LFIA showed high accuracy, specificity, and stability in saliva and nasal swab samples and is an efficient tool with flexibility to meet the testing requirements for SARS-CoV-2 antigens in various situations.

EV71 vaccination impact on the incidence of encephalitis in patients with hand, foot and mouth disease.

In order to analyze the effect of EV71 vaccination on the incidence of encephalitis in patients with HFMD, 292 cases were vaccinated, and 2,486 cases were not vaccinated which were collected in 2018 and 2019. It shows that the incidence rate of encephalitis in vaccinated patients was significantly lower than that in non-vaccinated (P = .028), which suggests that EV71 vaccine has a protective effect on the occurrence of encephalitis. But some EV71 vaccinated patients still developed into encephalitis showed that they had not produced protection or protection was weak against EV71-related encephalitis; the reasons require further investigation.

A Simple and Efficient Method of Extracting DNA from Aged Bones and Teeth.

DNA is often difficult to extract from old bones and teeth due to low levels of DNA and high levels of degradation. This study established a simple yet efficient method for extracting DNA from 20 aged bones and teeth (approximately 60 years old). Based on the concentration and STR typing results, the new method of DNA extraction (OM) developed in this study was compared with the PrepFiler™ BTA Forensic DNA Extraction Kit (BM). The total amount of DNA extracted using the OM method was not significantly different from that extracted using the commercial kit (p > 0.05). However, the number of STR loci detected was significantly higher in the samples processed using the OM method than using the BM method (p < 0.05). This study aimed to establish a DNA extraction method for aged bones and teeth to improve the detection rate of STR typing and reduce costs compared to the BM technique.

The occurrence and fate of siloxanes in wastewater treatment plant in Harbin, China.

The occurrence and fate of four cyclic (D3 to D6) and 10 linear (L5 to L14) siloxanes were investigated in influent and effluent wastewater, sludge from a wastewater treatment plant (WWTP), and surrounding air and soil within the WWTP in Harbin, Northeast China. The mean concentrations of total siloxanes in influent and effluent were 4780 and 997 ng/L and in excess sludge and aerobic sludge were 25.1 and 32.3 µg/g dw, respectively. The concentrations in air and soil within the WWTP were 243 ng/m(3) and 4960 ng/g dw, respectively. A similar composition profile of siloxanes in influent and sludge suggests their same source. Seasonal variation with concentration was comprehensively studied. It was found that temperature and rainfall are the two important factors for the seasonal variation of siloxanes. Adsorption with sewage sludge was the major way for the removal of siloxanes during the municipal wastewater treatment process. Overall, on a daily basis, the mass loading of the Σsiloxanes into the WWTP, out of the WWTP with the effluent and sludge, were estimated to be 3.0, 0.6 and 1.3 kg, respectively. In general, 21 % of siloxanes were discharged into the receiving body (Songhua River), 43 % of siloxanes were absorbed on sludge, and 36 % of siloxanes were lost during the whole process of WWTP.

Association of Enterovirus 71 encephalitis with the interleukin-8 gene region in Chinese children.

The study was performed in 36 Chinese patients with Enterovirus 71 (EV71) encephalitis and 141 patients with EV71-related hand, foot and mouth disease (HFMD) without encephalitis. Genotyping was determined by polymerase chain reaction- restriction fragment length polymorphism. Patients with EV71 encephalitis had a significantly higher frequency of interleukin-8 (IL-8)-251TT genotype than patients with EV71-related HFMD without encephalitis (55.6% vs 31.2%, p = 0.023). The frequency of IL-8-251T alleles was significantly higher among patients with EV71 encephalitis than in patients with EV71-related HFMD without encephalitis (72.2% vs 58.9%, odds ratio 1.8, 95% confidence interval 1.0-3.2, p = 0.038). There were significant differences in gender, age, fever days, white blood cell count, C-reactive protein and blood glucose concentration and IL-8 levels among genotypes of IL-8-251A/T in EV71-infected patients, but no significant differences in alanine or aspartate aminotransferase, creatine kinase-myocardial isozyme and cerebrospinal fluid in patients with EV71 encephalitis. These findings suggest that the IL-8-251T allele is associated with susceptibility to EV71 encephalitis in Chinese patients.

Occurrence and profiles of phthalates in foodstuffs from China and their implications for human exposure.

Phthalate esters are used in a wide variety of consumer products, and human exposure to this class of compounds is widespread. Nevertheless, studies on dietary exposure of humans to phthalates are limited. In this study, nine phthalate esters were analyzed in eight categories of foodstuffs (n = 78) collected from Harbin and Shanghai, China, in 2011. Dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), benzyl butyl phthalate (BzBP), and diethylhexyl phthalate (DEHP) were frequently detected in food samples. DEHP was the major compound found in most of the food samples, with concentrations that ranged from below the limit of quantification (LOQ) to 762 ng/g wet weight (wt). The concentrations of phthalates in food samples from China were comparable to concentrations reported for several other countries, but the profiles were different; DMP was found more frequently in Chinese foods than in foods from other countries. The estimated daily dietary intake of phthalates (EDIdiet) was calculated based on the concentrations measured and the daily ingestion rates of food items. The EDIdiet values for DMP, DEP, DIBP, DBP, BzBP, and DEHP (based on mean concentrations) were 0.092, 0.051, 0.505, 0.703, 0.022, and 1.60 µg/kg-bw/d, respectively, for Chinese adults. The EDIdiet values calculated for phthalates were below the reference doses suggested by the United States Environmental Protection Agency (EPA). Comparison of total daily intakes, reported previously based on a biomonitoring study, with the current dietary intake estimates suggests that diet is the main source of DEHP exposure in China. Nevertheless, diet accounted for only <10% of the total exposure to DMP, DEP, DBP, and DIBP, which suggested the existence of other sources of exposure to these phthalates.