NLISA versus enzyme-linked immunosorbent assay: Nanozyme-linked immunosorbent array based on platinum sub-nanocluster nanozyme for α-fetoprotein detection.

Rapid and accurate identification of tumor metabolic markers is important for early tumor diagnosis and individualized treatment. Here, a stable monodisperse sub-nanometer platinum (Pt) material was developed as a highly efficient nanozyme with a specific activity of peroxidase as high as 20.86 U mg-1 through the growth of in situ domain-limited Pt quantum dots via the polymer polyvinylpyrrolidone. Further, the synthesis of large quantities of Pt-loaded SiO2 (Pt-SiO2 ) was determined by silylation reaction and used for naked eye colorimetric testing of human alpha-fetoprotein (AFP). In particular, the immunization incubation process occurred in preprepared microplates. A nanozyme-based immunomodel was constructed in the presence of the target AFP, and a chromogenic reaction occurred with exogenous hydrogen peroxide and the chromogenic substrate tetramethylbenzidine. On optimization of experimental conditions, the dynamic working response range for AFP was found to be 0.05-20 ng mL-1 , with a limit of detection of 38.7 pg mL-1 . This work provides a new strategy to design efficient nanozyme-based enzyme-linked immunochromatographic platforms to meet the practical use of replacing natural enzymes.

Ion-selective electrode-based potentiometric immunoassays for the quantitative monitoring of alpha-fetoprotein by coupling rolling cycle amplification with silver nanoclusters.

Potentiometric immunoassays have been utilized for the quantitative detection of alpha-fetoprotein (AFP) in hepatocellular carcinoma, but most of them involve low sensitivity and enzyme labels, and thus are unfavorable for routine use. In this work, we report the proof-of-concept of a sensitive and powerful ion-selective potentiometric sensing method for AFP detection with an in situ amplified signal readout. This potentiometric immunoassay mainly contains a silver nanocluster-functionalized single-stranded DNA (AgNC-DNA), a short DNA primer and two antibodies. A sandwich-type immunoreaction is employed for AFP determination on an anti-AFP capture antibody-coated microplate using a biotinylated human AFP secondary antibody. Coupling with a typical biotin-avidin system, the biotinylated DNA initiator strands are conjugated on the microplate in the presence of AFP to induce the rolling cycle amplification (RCA) reaction, followed by AgNC-DNA hybridization. Upon addition of HNO3, the hybridized AgNCs are dissolved into numerous Ag(I) ions, which can be readily determined on a portable handheld silver-ion selective electrode (Ag-ISE). Under optimal conditions, the electrode potential increases with an increase in AFP concentration and exhibits a good linear range of 0.01-100 ng mL-1 at a detection limit of 7.9 pg mL-1. Moreover, the Ag-ISE-based potentiometric immune assay also shows good reproducibility, high specificity and long-term storage stability. Importantly, 18 human serum specimens containing the AFP analyte are screened using the potentiometric immunoassay, giving well-matched experimental results relative to the referenced enzyme-linked immunosorbent assay (ELISA) method.

DNA walker-amplified signal-on electrochemical aptasensors for prostate-specific antigen coupling with two hairpin DNA probe-based hybridization reaction.

Electrochemical aptasensing systems have been developed for screening low-abundance disease-related proteins, but most of them involve multiple washings and multi-step separation during measurements, and thus are disadvantageous for routine use. In this work, an innovative and simple electrochemical aptasensing platform was designed for the voltammetric detection of prostate-specific antigen (PSA) in biological fluids without any washing and separation steps. This system mainly included a PSA-specific aptamer, a DNA walker and two hairpin DNA probes (i.e., thiolated hairpin DNA1 and ferrocene-labeled hairpin DNA2). Introduction of target PSA caused the release of the DNA walker from a partially complementary aptamer/DNA walker hybridization strand. The dissociated DNA walker opened the immobilized hairpin DNA1 on the electrode, accompanying subsequent displacement reaction with hairpin DNA2, thus resulting in the DNA walker step-by-step reaction with numerous hairpin DNA1 probes on the sensing interface. In this case, numerous ferrocene molecules were close to the electrode to amplify the voltammetric signal within the applied potentials. All reactions and electrochemical measurements including the target/aptamer reaction and hybridization chain reaction were implemented in the same detection cell. Under optimal conditions, the fabricated electrochemical aptasensor gave good voltammetric responses relative to the PSA concentrations within the range of 0.001-10 ng mL-1 at an ultralow detection limit of 0.67 pg mL-1. A good reproducibility with batch-to-batch errors was acquired for target PSA down to 11.5%. Non-target analytes did not interfere with the voltammetric signals of the electrochemical aptasensors. Meanwhile, 15 human serum specimens were measured with electrochemical aptasensors, and displayed well-matched results in comparison with the referenced human PSA enzyme-linked immunosorbant assay (ELISA) method. Significantly, this method provides a new horizon for the quantitative monitoring of low-concentration biomarkers or nucleic acids.

Isolation and evaluation of strong endogenous promoters for the heterologous expression of proteins in Pichia pastoris.

BACKGROUND: The heterologous expression of biosynthetic pathway genes for pharmaceutical or fine chemical production usually requires to express more than one gene in the host cells. In eukaryotes, the pathway flux is typically balanced by controlling the transcript levels of the genes involved. It is difficult to balance the stoichiometric fine-tuning of the reaction steps of the pathway by acting on one or two promoters. Furthermore, the promoter used should not be identical to avoid loss of inserted genes by recombination or dilute its transcription factors. RESULTS: Based on RNA-seq data, 18 candidate genes with the highest transcription levels at three carbon sources (glucose, glycerol and methanol) were selected and their promoter regions were isolated from GS115 genome. The performance of these promoters on the level of protein production was evaluated using LacZ and EGFP genes as the reporters, respectively. These isolated promoters all exhibited activity to express LacZ gene. Using LacZ as a reporter, of the 18 promoter candidates, 9 promoters showed higher expression levels for the reporter compare to pGAP, a strong promoter widely used for constitutive expression of heterologous proteins in Pichia pastoris. These promoters with high expression levels were further employed to evaluate secreted expression using EGFP as a reporter. 6 promoters exhibited stronger protein expression compare to pGAP. Interestingly, the protein expression driven by pFDH1 was slightly higher than that of commonly used pAOX1 at methanol, and methanol-induced expression of pFDH1 was not repressed by glycerol. CONCLUSION: The various promoters identified in this study could be used for heterologous expression of biosynthetic pathway genes for pharmaceutical or fine chemical production. the methanol-induced pFDH1 that is not repressed by glycerol is an attractive alternative to pAOX1 and may provide a novel way to produce heterologous proteins in Pichia pastoris.

Codon pair optimization (CPO): a software tool for synthetic gene design based on codon pair bias to improve the expression of recombinant proteins in Pichia pastoris.

BACKGROUND: Codon optimization is a common method to improve protein expression levels in Pichia pastoris and the current strategy is to replace rare codons with preferred codons to match the codon usage bias. However, codon-pair contexts have a profound effect on translation efficiency by influencing both translational elongation rates and accuracy. Until now, it remains untested whether optimized genes based on codon pair bias results in higher protein expression levels compared to codon usage bias. RESULTS: In this study, an algorithm based on dynamic programming was introduced to develop codon pair optimization (CPO) which is a software tool to provide simple and efficient codon pair optimization for synthetic gene design in Pichia pastoris. Two reporters (MT1-MMP E2C6 and ADAM17 A9B8 scFvs) were employed to test the effects of codon pair bias and CPO optimization on their protein expression levels. Four variants of MT1-MMP E2C6 and ADAM17 A9B8 for each were generated, one variant with the best codon-pair context, one with the worst codon-pair context, one with unbiased codon-pair context, and another optimized based on codon usage. The expression levels of variants with the worst codon-pair context were almost undetectable by Western blot and the variants with the best codon-pair context were expressed well. The expression levels on MT1-MMP E2C6 and ADAM17 A9B8 were more than five times and seven times higher in the optimized sequences based on codon-pair context compared to that based on codon usage, respectively. The results indicated that the codon-pair context-based codon optimization is more effective in enhancing expression of protein in Pichia pastoris. CONCLUSIONS: Codon-pair context plays an important role on the protein expression in Pichia pastoris. The codon pair optimization (CPO) software developed in this study efficiently improved the protein expression levels of exogenous genes in Pichia pastoris, suggesting gene design based on codon pair bias is an alternative strategy for high expression of recombinant proteins in Pichia pastoris.

Biomimetic -mineralized multifunctional nanoflowers for anodic-stripping voltammetric immunoassay of rehabilitation-related proteins.

C-reactive proteins (CRPs; an acute-phase protein) in patients with initial acute cerebral infarction neurological rehabilitation prediction have a significant correlation. In this work, a simple and sensitive anodic-stripping voltammetric (ASV) immunosensing system was innovatively designed for the quantitative screening of target CRPs using biomimetic-mineralized bifunctional antibody-Cu3(PO4)2 nanoflowers as molecular tags. In this system, a monoclonal anti-CRP antibody-anchored microtiter plate was utilized to specifically capture target CRPs from the sample. For detection, a sandwiched immunoreaction mode was employed with the antibody-Cu3(PO4)2 nanoflowers in the presence of analytes. Subsequent ASV measurement of copper ions (Cu2+) released under acidic conditions from the bifunctional nanoflowers was conducted at an in situ prepared mercury film electrode. The introduction of hybrid nanoflowers greatly increased the loading amount of copper ions on the molecular tag, thereby amplifying the detectable signal of electrochemical immunoassay. Meanwhile, factors influencing the analytical properties of the electrochemical immunoassay were investigated in detail. By combining the high-efficiency nanohybrids with signal amplification, the dynamic concentration range of electrochemical immunoassay spanned from 0.01 ng mL-1 to 100 ng mL-1 toward the target CRP. The limit of detection was calculated to be 0.0079 ng mL-1 at 3Sblank criterion. Intra- and interassay imprecisions (relative standard deviations: RSDs) were less than or equal to 6.72%. Good anti-interference ability, long-term storage stability, and acceptable accuracy for the evaluation of human serum specimens were observed during a series of procedures to determine the target protein. In addition, the bifunctional nanoflower-based immunosensing system offers promise for the simple, cost-effective analysis of disease-related proteins.

Sensitive pH-responsive point-of-care electrochemical immunoassay for influenza A (H1N1) virus using glucose oxidase-functionalized Ti3C2-MXene nanosheets.

Influenza A (H1N1) virus is a serious health threat and potential leading cause of death around the world during the processes of immunity and inflammation. Herein a sensitive pH-responsive point-of-care (POC) electrochemical immunoassay was designed for the quantitative monitoring of H1N1 influenza virus using glucose oxidase (GOx) and secondary antibody-functionalized Ti3C2-MXene nanosheets. The assay was carried out on the basis of the sandwich-type immunoreaction in the capture antibody-coated microplate. Two-dimensional (2D) Ti3C2-MXene nanosheets with a large surface area could efficiently enhance the loading amount of GOx molecules, thereby resulting in the signal amplification. Accompanying the formed immunocomplexes, labeled GOx molecules catalyzed glucose into gluconic acid and hydrogen peroxide. The generated gluconic acid caused a pH change of the detection solution, which was quantitatively determined on a handheld pH meter. Two labeling strategies with and without Ti3C2-MXene nanosheets were investigated to determine the target H1N1 influenza virus, and improved properties were acquired with the Ti3C2-MXene-labeled system. Under optimum conditions, the Ti3C2-MXene-based immunoassay gave good dynamic responses toward the target H1N1 influenza virus from 0.01 µg mL-1 to 100 µg mL-1 with a detection limit of 1.3 ng mL-1. Good reproducibility, high specificity, and acceptable stability were also achieved in the analysis of the target H1N1 influenza virus. Significantly, measurements of the H1N1 influenza virus from clinical human samples were demonstrated to further confirm the method reliability and accuracy of the Ti3C2-MXene-based electrochemical immunoassay. Importantly, such a pH-meter-based immunoassay can be suitable for use in point-of-care applications and opens new opportunities for diagnostics.

Loss of miR-146b-3p Inhibits Perivascular Adipocyte Browning with Cold Exposure During Aging.

PURPOSE: Pathological changes of the perivascular adipose tissue (PVAT) are directly associated with increased risk of age-related vascular diseases. MicroRNAs regulate adipocyte biological functions including adipogenic differentiation and white adipocyte browning. The present study aims to determine whether miR-146b-3p is involved in the regulation of perivascular adipocyte browning during aging. METHODS: We utilized a cold-induced animal model to investigate the effect of aging on perivascular adipocyte browning. We also detected the miR-146b-3p expression in the PVAT of young or old mice after cold stimulus. We further investigated the role of miR-146b-3p in regulating perivascular adipocyte browning in vitro and in vivo via administrating miRNA mimics or inhibitors. RESULTS: Old mice showed decrease of perivascular adipocyte browning and downregulation of miR-146b-3p expression in the PVAT after cold stimulus. Oil red O staining and qPCR indicated that aging perturbed preadipocyte to brown adipocyte differentiation, and expression of miR-146b-3p gradually increased during differentiation. MiR-146b-3p inhibitors blocked brown adipocyte differentiation in young preadipocytes, whereas miR-146b-3p mimics rescued the differentiation of the old preadipocytes. Finally, miR-146b-3p knocks down inhibited perivascular adipocyte browning in young mice after cold stimulus. CONCLUSION: Aging inhibits perivascular adipocyte browning, and loss of miR-146b-3p is a potential regulator for this process.

Oxygen Vacancies in ZnO Nanosheets Enhance CO2 Electrochemical Reduction to CO.

As electron transfer to CO2 is generally considered to be the critical step during the activation of CO2 , it is important to develop approaches to engineer the electronic properties of catalysts to improve their performance in CO2 electrochemical reduction. Herein, we developed an efficient strategy to facilitate CO2 activation by introducing oxygen vacancies into electrocatalysts with electronic-rich surface. ZnO nanosheets rich in oxygen vacancies exhibited a current density of -16.1 mA cm-2 with a Faradaic efficiency of 83 % for CO production. Based on density functional theory (DFT) calculations, the introduction of oxygen vacancies increased the charge density of ZnO around the valence band maximum, resulting in the enhanced activation of CO2 . Mechanistic studies further revealed that the enhancement of CO production by introducing oxygen vacancies into ZnO nanosheets originated from the increased binding strength of CO2 and the eased CO2 activation.

Enhancing CO2 Electroreduction with the Metal-Oxide Interface.

The electrochemical CO2 reduction reaction (CO2RR) typically uses transition metals as the catalysts. To improve the efficiency, tremendous efforts have been dedicated to tuning the morphology, size, and structure of metal catalysts and employing electrolytes that enhance the adsorption of CO2. We report here a strategy to enhance CO2RR by constructing the metal-oxide interface. We demonstrate that Au-CeOx shows much higher activity and Faradaic efficiency than Au or CeOx alone for CO2RR. In situ scanning tunneling microscopy and synchrotron-radiation photoemission spectroscopy show that the Au-CeOx interface is dominant in enhancing CO2 adsorption and activation, which can be further promoted by the presence of hydroxyl groups. Density functional theory calculations indicate that the Au-CeOx interface is the active site for CO2 activation and the reduction to CO, where the synergy between Au and CeOx promotes the stability of key carboxyl intermediate (*COOH) and thus facilitates CO2RR. Similar interface-enhanced CO2RR is further observed on Ag-CeOx, demonstrating the generality of the strategy for enhancing CO2RR.

Digital multimeter-based portable photoelectrochemical immunoassay with enzyme-catalyzed precipitation for screening carbohydrate antigen 125.

The degree of the carbohydrate antigen 125 (CA-125) level in serum is positively correlated with the severity of ovarian cancer. In this study, a facile photoelectrochemical (PEC) immunoassay was devised for sensitive detection of CA-125 employing enzyme-catalyzed precipitation to weaken the photocurrent of hollow porous In2O3 nanotubes incorporating CdS nanoparticles. Upon the addition of the target analyte, horseradish peroxidase (HRP) enriches as a result of the formation of the sandwich immunocomplex, which can catalyze the conversion of 4-chloro1-naphthol (4-CN) to benzo-4-chlorohexadienone (4-CD) employing H2O2 as a cofactor. The as-produced insoluble precipitate acts as an obstacle to hinder the absorption of visible light by photoactive materials, thereby resulting in a decrease in photocurrent. Moreover, the weakened signal can be easily read out by a digital multimeter (DMM), advancing the convenience of the detection system. The preliminary analysis data indicate that the PEC immunoassay shows an efficient response to CA-125 levels ranging from 0.1 to 100 U mL-1 with a limit of detection (LOD) as low as 0.046 U mL-1 (S/N = 3). Most importantly, the proposed portable method has shown satisfactory performance in terms of selectivity, reproducibility, stability, and analysis in complex biological matrices.

Ultrasensitive fluorescence immunoassay of pepsinogen I based on enzyme-triggered decomposition of AuNCs/MnO2.

Gastric cancer is a prevalent malignant tumor of the gastrointestinal tract accompanied by a high mortality rate; therefore, early gastric cancer screening is critical for improving patient survival. In this study, we present a facile fluorescence immunoassay for highly sensitive screening of pepsinogen I (PG I) based on a one-pot biomimetic mineralization process for the synthesis of gold nanocluster-anchored manganese dioxide (AuNCs/MnO2) nanosheets. MnO2 first quenches the fluorescence of AuNCs through the Förster resonance energy transfer effect, whereas the introduction of ascorbic acid (AA) leads to the decomposition of MnO2 and rapidly recovers the fluorescence of AuNCs. Based on the above principles and phenomena, we developed a sensitive fluorescence immunoassay for the in situ generation of AA to detect PG I. Specifically, in the presence of PG I, the sandwich-type immunoreactivity-enriched alkaline phosphatase-labeled secondary antibody catalyzes the production of AA from the substrate, which enhances the fluorescence intensity. Under optimized conditions, the fluorescence intensity increased linearly with the concentration of PG I (0.05 to 200 ng mL-1) with a limit of detection (LOD) of 0.013 ng mL-1 (S/N = 3). The designed sensing platform has good stability (more than one year) and excellent anti-interference capability and demonstrates satisfactory accuracy for detection in real samples compared to commercial ELISA kits.

Rolling circle amplification (RCA) -based biosensor system for the fluorescent detection of miR-129-2-3p miRNA.

Herein, a versatile fluorescent bioanalysis platform for sensitive and specific screening of target miRNA (miR-129-2-3p) was innovatively designed by applying target-induced rolling circle amplification (RCA) for efficient signal amplification. Specifically, miR-129-2-3p was used as a ligation template to facilitate its ligation with padlock probes, followed by an RCA reaction in the presence of phi29 DNA polymerase. The dsDNA fragments and products were stained by SYBR Green I and then detected by fluorescence spectrophotometry. As a result, miR-129-2-3p concentrations as low as 50 nM could be detected. Furthermore, the expression of miR-129-2-3p in breast cancer patients was about twice that in healthy people. Therefore, the results indicated that the RCA-based biosensor system could be a valuable platform for miRNA detection in clinical diagnosis and biomedical study.

Investigation of Pesticide Residues in Fragaria and Myrica rubra Sold in Hangzhou.

ABSTRACT: This study investigated the concentration of the pesticide residues found in Fragaria and Myrica rubra sold in the city of Hangzhou, People's Republic of China. From an analysis of 151 (77 Fragaria and 74 M. rubra) samples using gas chromatography-tandem mass spectrometry (GC-MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), 41 pesticide residues were found to be present. Of the 41 residues, 14 were found using GC-MS/MS and 27 were found using LC-MS/MS. Of the 151 samples, 10 (13.0%) of the 77 Fragaria samples and 5 (6.8%) of the 74 M. rubra samples were found to contain a specific pesticide residue, and only 4 Fragaria samples and 2 M. rubra samples were found to be without pesticide residue. In addition, 18 of the 41 pesticides were not detected in either Fragaria or M. rubra samples. Of the 41 residues, 10 were detected in Fragaria samples and 20 were detected in M. rubra samples. In Fragaria, procymidone was the most commonly detected residue, with a detection rate of 88.3%, followed by prochloraz, with a detection rate of 53.2%. In M. rubra, prochloraz was the most commonly detected residue, with a detection rate of 71.6%, followed by carbendazim, with a detection rate of 68.9%. The pesticide residues in some samples exceeded the maximum residue limit set in China. The limit of dimethomorph was exceeded in three of the Fragaria samples, and that of dichlorvos was exceeded in two of the M. rubra samples.

In-vitro study of the effect of casein phosphopeptide amorphous calcium fluoride phosphate on iatrogenic damage to enamel during orthodontic adhesive removal.

INTRODUCTION: White-spot lesions (WSL) might be susceptible to mechanical damage during orthodontic bracket and adhesive removal. The aims of this in-vitro study were to investigate enamel loss on bracket and adhesive removal when the brackets were surrounded by WSL and to determine the effect of remineralizing these lesions with a 1% (w/v) casein phosphopeptide amorphous calcium fluoride phosphate (CPP-ACFP) solution before bracket and adhesive removal. METHODS: Precoated metal mandibular incisor brackets were centrally bonded onto polished third molars and WSL produced by exposure to a demineralization buffer for 4, 12, and 30 days (n = 20 per group). Half of the demineralized window was covered with acid-resistant nail varnish, and the specimens were then subjected to remineralization with 1% CPP-ACFP. Brackets and residual adhesive were removed, and enamel damage was assessed by digital photography, profilometry, and scanning electron microscopy. Lesion depth, mineral loss, and remineralization were measured by transverse microradiography. RESULTS: WSL enamel around the bracket was more susceptible to iatrogenic damage at adhesive removal compared with sound enamel. Remineralization of lesions with 1% CPP-ACFP before adhesive removal significantly (P <0.002) reduced the area and depth of damage. CONCLUSIONS: Remineralizing WSLs with CPP-ACFP before adhesive removal reduced iatrogenic enamel damage.

[Continuous PM2.5 Composition Measurements for Source Apportionment During Air Pollution Events].

To explore the application of high-temporal-resolution data in PM2.5 source apportionment during air pollution events, ambient air PM2.5 components were continuously monitored in urban Nanjing from January to December, 2017. Commercially available instruments for continuous measurements were deployed to obtain hourly concentrations of elements, water-soluble ions, and carbonaceous components of PM2.5. Data for 15 elements and 5 bulk components during three pollution events(firework combustion during the Spring Festival, a spring sandstorm, and a winter haze event) and across the whole year comprised four datasets for source apportionment using positive matrix factorization(PMF), and the distribution of factor/source contributions and estimations of average concentrations of characteristic components were compared based on different input datasets(PMFfirework-sand-haze and PMFfull-year). The results showed that the identified factors/sources, factor profiles, and contributions differed largely between PMFfirework-sand-haze and PMFfull-year solutions. For example, the relative average contribution of the firework combustion factor derived from the PMFfull-year solution(was 1.50%) was far less than that of the PMFfirework solution. The dust factor had an average contribution of 8.51% in the PMFsand solution, which was approximately double that of the PMFfull-year solution. This might be explained by the fact that PMF assumes unvaried source compositions during the measurement campaign, meaning that the source apportionment results based on long-term observations will include bias due to changes in emission sources. Furthermore, during the firework combustion event, the estimated average concentration of K from the PMFfirework solution[(1.32±1.17) µg·m-3, P=0.64]was closer to measured value[(1.36±1.19) µg·m-3]than that of the PMFfull-year solution[(1.16±1.19) µg·m-3, P=0.0090]. For the sand storm event, the concentrations of Fe, Si, and Ti were significantly underestimated by the PMFfull-year solution[(0.061±0.042)-(1.06±0.65) µg·m-3, P<0.05], while their peak concentrations agreed well between the PMFsand estimations and the observations. During the winter haze event, all PM2.5 bulk components were well estimated by both the PMFfull-year and PMFhaze solutions. Based on these results, PMF source apportionment results based on continuous measurement data during pollution events can reasonably reflect short-term variations in characteristic PM2.5 components and their sources, which can improve the timeliness of air pollution source apportionment.

Analysis of the expression, function, prognosis and co-expression genes of DDX20 in gastric cancer.

DDX20 (DEAD-box polypeptide 20) is implicated in many cellular processes involving alteration of RNA secondary structure. The role of DDX20 in gastric cancer is still unknown. In the research, the expression of DDX20 and the functional roles of DDX20 in gastric cancer were detected. The increased DDX20 expression in gastric cancer tissue compared with normal gastric tissue was observed. Functional experiments indicated that DDX20 promoted gastric cancer MGC-803 and AGS cells growth, migration, and invasion in vitro. Surprisingly, survival analysis showed that high expression of DDX20 is a favorable prognostic factor for patients with gastric cancer. In addition, enrichment analysis revealed that there is a positive correlation between DDX20 expression and T cell activation in gastric cancer. but not in normal gastric tissues. Furthermore, we found that DDX20 expression level has significant positive correlations with activated CD8 + T cells and activated CD4 + T cells in gastric cancer. Therefore, we hypothesize that the prognostic role of DDX20 in gastric cancer patients may be due to patients with high DDX20 expression contained better immune activation. Taken together, these findings suggest that DDX20 can promote the progression of gastric cancer in vitro and its prognostic value in gastric cancer may be related to many factors, including immune activation.

[Measuring and analyzing infrared spectrum of periodically polarized lithium niobate].

The present paper reports theoretical and experimental research on the tunable output characteristics of periodically polarized lithium niobate. We made six equal distance crystal grating sections, with each distance being 0.5 mm and the polarization period range of 29.0-31.5 mm. Especially, at room temperature, the signal-wavelength tunable output in the range of 1 449.7-1 665.0 nm and idle-wavelength tunable output in the range of 3 989.2-2 946.0 nm were achieved by LD end-pumped Nd : YVO4 laser with Q-switch in sound-wave. The lowest excitation threshold was 108.0 mW, while the highest excitation threshold was 149.2 mW. When the pump power was 649 mW, the highest gained signal-wave output was 118.5 mW and its conversion efficiency was 18.26%. Meanwhile, the idle-wave output was 46.6 mW and its conversion efficiency was 7.18%. These parameters approached the practicality level.

Remineralization of enamel subsurface lesions in situ by the use of three commercially available sugar-free gums.

BACKGROUND: Commercially available sugar-free chewing gums have been claimed to provide oral health benefits. AIM: The aim of this randomized, double-blind crossover in situ study was to compare the efficacy of three commercially available sugar-free chewing gums: Trident White, Orbit, and Orbit Professional, in remineralizing enamel subsurface lesions in situ. DESIGN: Specimens containing enamel subsurface lesions were sectioned into test and control half-slabs with the test half-slabs inserted into removable palatal appliances. For each test chewing period, subjects were randomly allocated one of three test gums. Subjects (n = 10) chewed the randomly allocated gum for a 20-min period four times per day for 14 days. Each subject chewed all three test gums, with a 7-day washout period between crossovers. After each 14-day cycle, test and control half-slabs were paired, embedded in resin, sectioned, and subjected to microradiography to determine remineralization. RESULTS: The gum TW produced significantly greater remineralization (18.4 +/- 0.9%) than Orbit (8.9 +/- 0.5%) and Orbit Professional (10.5 +/- 0.9%). CONCLUSION: The superior remineralization activity of the TW gum in situ was attributed to the presence of casein phosphopeptide-amorphous calcium phosphate nanocomplexes.

MicroRNA-146b-3p regulates the development and progression of cerebral infarction with diabetes through RAF1/P38MAPK/COX-2 signaling pathway.

Diabetes has been considered as an independent risk factor for cerebral infarction. However, the pathological mechanism of cerebral infarction with diabetes (DMCI) is still rarely known. In this study, we try to explore the relationship between microRNA-146b-3p (miR-146b-3p) and DMCI patients. The peripheral blood mononuclear cells were separated after the patients were selected from our hospital. Firstly, the content of IL-6 and COX-2 was detected by ELISA. Then, the total RNAs were extracted and analyzed by microRNA (miRNA) microarray. Moreover, the target genes of miR-146b-3p were predicted by online miRNA target prediction algorithms. Meanwhile, luciferase reporter system was used for assaying the target gene for miRNA-146b-3p. Simultaneously, RT-PCR assay was used for the miRNA expression detection. Furthermore, western blot was applied to determine the expression of the signal pathway involved proteins. Our results demonstrated that expression of IL-6 and COX-2 were remarkably up-regulated in peripheral blood of DMCI patients compared with that in normal control group. In addition, miRNA microarray data suggested that miR-146b-3p expression was significantly down-regulated in DMCI patients, with v-raf-1 expression negatively regulated. Moreover, miR-146b-3p regulated RAF1 expression was found to mediate P38MAPK signaling activation in thrombosis patients. The following research indicated that activation of RAF1 trough miR-146b-3p down-regulation contributed to activation of RAF/P38MAPK/COX-2 signaling pathway in vascular infarction. Our data have implied that altered expression of miR-146b-3p is closely related to the progression and development of DCMI mediating the RAF/P38MAPK/COX-2 signal transduction pathway.