Study on pulse current auxiliary heating process of submerged arc welding.

During the welding process, temperature filed distribution of weldment is one of the key factors which influence welding quality. In order to improve the mechanical properties of welding joint, a technology for heating process of weldment using auxiliary pulse current was proposed in this article. Firstly, through metallographic experiment, strength experiment and hardness experiment, it was proved that the auxiliary pulse current not only can refine grain size but also improves the mechanical property of the welding joint. Then the paper used ANSYS and its ANSYS Parametric Design Language parametric design language to simulate the welding process with assistant pulse current, and the temperature field, the pulse current density distribution and the time of effective pulse current in the welded joint were obtained. Quantitative analyses were undertaken on the influence laws of auxiliary pulse current parameters on weld temperature field, auxiliary pulse current density distribution and the time of effective pulse current. A new parameter was defined as time-current density (the time integral of current density) to demonstrate the change rule of auxiliary pulse current density distribution with time. Finally, analyzing the reasons for raising the welding quality. There were two reasons for such phenomenon: one was auxiliary pulse current change the state of heat distribution in the weld seam area, the other was that the impulse oscillation of the auxiliary pulse influences the nucleation process of melting region.

Impact of the Glycemic Level on the Salivary Proteome of Middle-Aged and Elderly People With Type 2 Diabetes Mellitus: An Observational Study.

Type 2 diabetes mellitus (T2DM) is an increasing global public health concern, but its impact on the salivary proteome is still unclear. To evaluate the effect of glycemic levels in middle-aged and elderly individuals with T2DM on salivary proteomics, we compared the differences by liquid chromatography tandem mass spectrometry (LC-MS/MS). Unstimulated whole saliva samples from 8 T2DM patients with good glycemic control (G group, HbA1c <6.5%) and 16 patients with poor control (P group, HbA1c ≥6.5%) were analyzed by LC-MS/MS in the data-independent acquisition mode (Clinical register number: ChiCTR1900023582.). After functional annotation, cluster analysis and receiver operating characteristic (ROC) curve analysis were carried out to screen and evaluate candidate proteins. A total of 5,721 proteins were quantified, while 40 proteins differed significantly. In the P group, proteins involved in oxidative stress-related processes were upregulated, whereas proteins related to salivary secretion were downregulated. The combination of thioredoxin domain-containing protein 17, zymogen granule protein 16B, and FAM3 metabolism regulating signaling molecule D yielded an area under the curve of 0.917 which showed a robust ability to distinguish the P and G groups. In conclusion, poorly controlled hyperglycemia may affect salivary proteins through various pathways, including oxidative stress and glandular secretion. Furthermore, the differentially expressed proteins, especially the three proteins with the best differentiation, might serve as an anchor point for the further study of hyperglycemia and oral diseases.

A protocol of systematic review and meta-analysis of narrow band imaging endoscopy in detection of early gastric cancer.

BACKGROUND: Early gastric cancer is the fifth common malignancy and the third leading cause of cancer death throughout the world. However, it is not clear how endoscopic screening for early gastric cancer affects incidence or mortality. We performed a systematic review and meta-analysis to evaluate the relationship between endoscopic screening for the mortality and incidence of early gastric cancer. MATERIALS AND METHODS: This protocol established in this study has been reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. Web of Science, PubMed, EMBASE, and the Cochrane Library were searched for cohort and case-control studies in cases without early gastric cancer until March 31, 2020. We will use a combination of Medical Subject Heading and free-text terms with various synonyms to search based on the Eligibility criteria. Two investigators independently reviewed the included studies and extracted relevant data. The relative risk and 95% confidence intervals were used as effect estimate. I-square test, substantial heterogeneity, sensitivity analysis, and publication bias assessment will be performed accordingly. Stata 15.0 and Review Manger 5.3 are used for meta-analysis and systematic review. RESULTS: The results will be published in a peer-reviewed journal. CONCLUSION: The results of this review will be widely disseminated through peer-reviewed publications and conference presentations. This evidence may also provide helpful evidence of whether endoscopic screening would reduce the mortality and incidence of early gastric cancer. PROSPERO REGISTRATION NUMBER: CRD42020171053.

Comparative evaluation of peptidome and microbiota in different types of saliva samples.

BACKGROUND: Clinical and research interest in salivary peptidome and microbiota is ever-growing owing to its great value for diagnosis, risk assessment and prediction of prognosis in oral and systemic diseases. Saliva can be stimulated for the purpose of rapid collection, but currently there are no studies systematically addressing the similarities and differences of salivary peptidome and microbiota in different types of samples. The purpose of this study was to investigate the variations of salivary peptidome and microbial profiles in response to different stimulating conditions. METHODS: Unstimulated saliva and three types of stimulated saliva samples (olfaction, gustation, and mastication stimulated saliva) were collected from 10 systematically and orally healthy donors. The peptidome profiles were detected by weak cation exchange magnetic beads and analyzed through matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF MS), while their microbial profiles were analyzed by 16S rDNA V3-V4 hypervariable region amplicon sequencing utilizing the Illumina MiSeq PE300 platform. The distance matrixes of salivary peptidome and microbial profiles were generated and the intra-individual distances were extracted, then the variations brought by different sampling conditions and repeated collections were compared. RESULTS: By comparisons of the overall salivary peptidome and microbial profiles, olfactory stimulation led to minimal variations comparing with that of unstimulated saliva, but appreciable variations were observed between saliva samples collected with gustatory/masticatory stimulation and unstimulated saliva. The three types of stimulated saliva exhibited significantly different peptidome and microbial profiles. CONCLUSIONS: Stimulated saliva collected in response to olfactory stimulation is an appropriate alternative to unstimulated saliva, whereas gustatory/masticatory stimulation introduced appreciable variations. It is suggested that only one type of stimulating method should be used throughout one peptidome/microbiome research, which provides comprehensive insight into the optimization of sampling methods for salivaomic studies in the future.

Prevalence of Caries in Mainland China: Evidence from 1980 to 2018: A Systematic Review and Meta-Analysis.

OBJECTIVE: To systematically review the prevalence of dental caries from 1980 to 2018 to provide evidence for caries prevention in mainland China. METHODS: Four databases were selected with online search tools to offer maximum coverage of the published literature on the provincial or national level of caries prevalence: Medline, EMBASE, China National Knowledge Infrastructure (CNKI, in Chinese) and Wanfang databases (in Chinese). We supplemented the results with relevant publications from the government health sectors, textbooks and web-based databases. Studies published between 1 January 1980 and 26 March 2018 were included. The quality of literature was assessed, and a meta-analysis was conducted using Stata12.0. RESULTS: A total of 82 studies were included in the final analysis. There were 1.49 million samples retrieved from 1980 to 2018, and the overall pooled prevalence of caries was 52.0% (95% CI: 49.4%-54.6%) in mainland China. The overall prevalence of caries increased from 36.4% (95% CI: 31.5%-41.5%) in the 1980s to 51.8% (95% CI: 34.9%-68.7%) in the 1990s, stabilised at 50.7% (95% CI: 43.8%-57.6%) in the 2000s and slightly increased to 53.1% (95% CI: 50.8%-55.5%) in the 2010s. The pooled caries prevalence was 64.8% (95% CI: 61.7%-67.8%), 47.3% (95% CI: 43.1%-51.5%), 42.4% (95% CI: 38.3%-46.5%), 66.7% (95% CI: 50.8%-82.6%) and 82.0% (95% CI: 72.5%-91.4%) for the ages/age groups 5, 12, 15, 35-44 and 65-74, respectively. The average dental caries pooled prevalence in urban areas was 51.4% (95% CI: 48.5%-54.2%), which was lower than 54.6% (95% CI: 47.9%-61.4%) in rural areas. CONCLUSION: The prevalence of dental caries in mainland China is generally high, and an increasing trend was observed over the past 38 years. The prevalence of dental caries in mainland China varied geographically, and its characteristics differed over time. Regional disparities between eastern/western China and rural/urban areas still exist. Comprehensive local prevalence data on caries are summarised here for the first time, which provide valuable evidence for the oral disease burden in China.

Effects of Premature Delivery and Birth Weight on Eruption Pattern of Primary Dentition among Beijing Children.

OBJECTIVE: To evaluate the effect of premature delivery and birth weight (BW) on primary tooth eruption. METHODS: A total of 2,230 children aged 3 to 36 months from urban and rural areas in Beijing, China, were classified for analysis by gestational age at delivery (89 preterm and 2,141 full term) and BW (low, normal and high). The tooth eruption status of these children was examined and recorded every 3 months. RESULTS: The timing of first primary tooth eruption was significantly delayed in preterm infants (8.4 months versus 7.3 months for full term; P < 0.05). Furthermore, the number of teeth was significantly less for the preterm and low-BW groups at 12 to 18 and 24 to 30 months, but the number of teeth caught up with normal-BW children by 30 to 36 months. In contrast, the time of first tooth eruption of high-BW children was earlier, while the erupted teeth at each month range was more than the normal-BW group. This research also demonstrated a negative correlation (r = -0.202; P = 0.009) between the time of first primary tooth eruption and BW as well as a positive correlation between the number of erupted teeth and BW. CONCLUSION: Premature delivery and BW were the influencing factors for the timing of primary tooth eruption in children from Beijing, China. Recommendations for feeding habits and oral healthcare implementation may vary according to different primary tooth eruption status among individuals.

The Bio-Safety Concerns of Three Domestic Temporary Hair Dye Molecules: Fuchsin Basic, Victoria Blue B and Basic Red 2.

Hair-coloring products include permanent, semi-permanent and temporary dyes that vary by chemical formulation and are distinguished mainly by how long they last. Domestic temporary hair dyes, such as fuchsin basic, basic red 2 and Victoria blue B, are especially popular because of their cheapness and facile applications. Despite numerous studies on the relationship between permanent hair dyes and disease, there are few studies addressing whether these domestic temporary hair dyes are associated with an increased cancer risk. Herein, to ascertain the bio-safety of these temporary hair dyes, we comparatively studied their percutaneous absorption, hemolytic effect and cytotoxic effects in this paper. Furthermore, to better understand the risk of these dyes after penetrating the skin, experimental and theoretical studies were carried out examining the interactions between the dyes and serum albumins as well as calf thymus (CT)-DNA. The results showed that these domestic temporary hair dyes are cytotoxic with regard to human red blood cells and NIH/3T3 cell lines, due to intense interactions with bovine serum albumin (BSA)/DNA. We conclude that the temporary hair dyes may have risk to human health, and those who use them should be aware of their potential toxic effects.

Anthocyanin accumulation and biosynthesis are modulated by regulated deficit irrigation in Cabernet Sauvignon (Vitis Vinifera L.) grapes and wines.

Anthocyanins contents and compositions play an important role in grape berries and wines. Grapevines are widely cultivated in arid and semi-arid areas, and water shortage restricts the development of wine industry. The aim of this work was to gain insight on the effect of regulated deficit irrigation (RDI) on the accumulation and biosynthesis of anthocyanins in Cabernet Sauvignon (Vitis Vinifera L.) grapes and wines. High-performance liquid chromatography (HPLC) was used for anthocyanins profiles analyses and real-time quantitative PCR (qRT-PCR) was used for the genes expressions measurement. The grapevines were treated with 60% (RDI-1), 70% (RDI-2), 80% (RDI-3), 100% (CK, traditional drip irrigation) of their estimated evapotranspiration (ETc) respectively. RDI treatments significantly reduced titration acid and increased pH with higher total soluble solids. RDI-1 treatment increased total anthocyanins contents in berries and wines in both two vintages. RDI-1 and RDI-2 treatments significantly increased the contents of acylated anthocyanins in berries and wines, especially Malvidin-3-acetly-glucoside. RDI treatments significantly increased non-acylated anthocyanins contents in wines, such as Delphinidin-3-gliucoside and Malvidin-3-glucoside. RDI treatments upregulated the expressions of VvPAL, VvC4H, VvCHS, VvF3'H, VvF3'5'H, VvLDOX, and VvOMT in both two vintages. Correlation analysis showed the accumulation of anthocyanins was closely related to the key genes expressions, including VvPAL, VvF3'H, VvF3'5'H etc. The present results provided direct evidence and detailed data to explain that RDI treatments regulated the accumulation of anthocyanins by regulating genes expressions in the anthocyanin synthesis pathway.

Report of the National Investigation of Resources for Oral Health in China.

OBJECTIVE: To investigate the current status and distribution of resources for oral health in China, by means of analysing national data from the National Investigation of Resources for Oral Health. METHODS: The National Investigation of Resources for Oral Health in China was performed in 2015, in parallel with the 4th National Oral Health Survey of China (2015 to 2016). A structured questionnaire on resources for oral health was used to collect the data of professional institutions and stomatological/dental workforce in each province. For each province, the local Investigation Group was responsible to summarise the status and distribution of institutions with stomatological/dental departments and stomatological/dental workforce. Descriptive analysis of resources for oral health was performed to learn about the number and percentage of each category both for each province and nationally. The ratio of number of stomatological/dental workforce to population was also calculated and compared with the criteria of the World Health Organisation (WHO). RESULTS: There were totally 75,399 stomatological/dental departments nationally in all professional institutions in the mainland of China, most of which were set in institutions of primary health care services. Institutions of private sectors accounted for a higher proportion (69.8%) which was over two-fold compared to that of public ones (30.2%). General hospitals were the major part of hospitals with stomatological/dental departments compared with stomatological/dental specialised hospitals. Stomatological/dental clinics were the majority of institutions of primary health care services, compared to community health care service centres/stations and township health care services. Amongst all professional institutions of public health with stomatological/dental departments, 35.0% were maternal and child health care services and 11.2% were institutions for prevention and control of oral diseases. The total number of stomatological/dental workforce in the country was 314,347, among whom 171,587 (54.6%) were stomatologists/dentists. The ratio of number of stomatologists/dentists to population was 1:7,768 nationally, which was lower than the WHO standard of 1:5,000. CONCLUSION: The National Investigation of Resources for Oral Health in China exhibited the current status and distribution of resources for oral health over the country, whereas insufficiencies of stomatological/dental workforce and institutions and inequalities of their distribution were found nationally. This could provide some policy suggestions for the health authorities in China to promote oral health in the Chinese population in the future.

Oral Health Status of 12-year-olds from Regions with and without Coverage of the National Oral Health Comprehensive Intervention Program for Children in China.

OBJECTIVE: To investigate the oral health status and related factors of 12-year-olds from regions with and without coverage of the National Oral Health Comprehensive Intervention Program in China by means of analysing national data from the 4th National Oral Health Survey. METHODS: Data of 12-year-olds participating in the 4th National Oral Health Survey of China were used for statistical analysis. Children who were recruited in the survey completed a dental examination and filled in a questionnaire. Oral health status, pit-and-fissure sealant history, oral hygiene behaviours, sugar consumption habits, status of dental service utilisation, and oral health knowledge were compared between children from regions with and without coverage of the national programme. For the number of decayed, missing and filled permanent teeth (DMFT) and its components, as well as the number of teeth with pit-and-fissure sealants, mean values were statistically tested to see if significance existed between regions covered by the national programme and uncovered regions, whereas caries prevalence and percentage of pit-and-fissure sealants presented were also compared. RESULTS: Data from 27,821 12-year-old children were analysed, among whom 7,726 were from regions covered by the national programme and 20,095 were from uncovered regions. Statistical significance was found in caries experience and activity, pit-and-fissure sealant history, sugar consumption habits, utilisation of dental services and oral health knowledge when compared between the covered and uncovered regions. Prevalence of dental caries and indices for caries experience and activity was lower in regions covered by the national programme than those not covered, while the percentage of pit-and-fissure sealants presented and the number of teeth with pit-and-fissure sealants exhibited higher in the covered regions. This remained the same even if we focused only on the first molars instead of the full dentition. CONCLUSION: The National Oral Health Comprehensive Intervention Program for Children in China potentially contributed to better oral health status, behaviour and knowledge in 12-year-old children. The expansion and extension of coverage of the national programme was expected to be beneficial for improving oral health status in children, as well as constructing teams of oral and dental workforce and working mechanisms in some underdeveloped regions.

Permanent Teeth Caries Status of 12- to 15-year-olds in China: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To investigate the dental caries status of teenagers in China by means of analysing national data from the 4th National Oral Health Survey of China. METHODS: Data for 12- to 15-year-olds participated in the 4th National Oral Health Survey of China were used for statistical analysis. Children who were recruited in the survey completed a dental examination and filled in a questionnaire. Social demographic factors, oral hygiene behaviours, sugar consumption habits, status of dental service utilisation, and pit-and-fissure sealant history were compared between adolescents with caries experiences and those without. For decayed, missing and filled permanent teeth (DMFT) and each of its components, mean values were statistically tested to see if significance existed between or among different categories of all involved variables. RESULTS: In total, data from 27,821, 30,961, 30,691 and 29,128 Chinese 12-, 13-, 14-, and 15-year-olds respectively, were analysed. Social demographic factors, sugar consumption and dental service utilisation showed statistical significance when compared between those with and without dental caries experience in the 12- and 15-year-old groups. Certain categories of these factors above also had important influence on the mean value of the number of decayed teeth (DT), filled teeth (FT) and DMFT, and they might be potential determinants of dental caries experience of permanent teeth for teenagers. CONCLUSION: Dental caries in 12- and 15-year-old Chinese adolescents was impacted by certain social demographic and dental behavioural factors, which could provide some implications for policy makers and dental public health professionals when attempting to enhance oral health status for those teenagers in the early stages of permanent dentition.

High Dynamic Micro Vibrator with Integrated Optical Displacement Detector for In-Situ Self-Calibration of MEMS Inertial Sensors.

The scale factor drifts and other long-term instability drifts of Micro-Electro-Mechanical System (MEMS) inertial sensors are the main contributors of the position and orientation errors in high dynamic environments. In this paper, a novel high dynamic micro vibrator, which could provide high acceleration and high angular rate rotation with integrated optical displacement detector, is proposed. Commercial MEMS inertial sensors, including 3-axis accelerometer and 6-axis inertial measurement unit which is about 3 mm * 3 mm * 1 mm with 19 mg, could be bonded on the vibration platform of the micro vibrator to perform in-situ during the self-calibration procedure. The high dynamic micro vibrator is fabricated by a fully-integrated MEMS process, including lead zirconate titanate (PZT) film deposition, PZT and electrodes patterning, and structural ion etching. The optical displacement detector, using vertical-cavity surface-emitting laser (VCSEL) and photoelectric diodes (PD), is integrated on the top of the package to measure the 6-DOF vibrating displacement with the detecting resolution of 150 nm in the range of 500 μm. The maximum out-of-plane acceleration of the z-axis vibrating platform loaded with commercial 3-axis accelerometer (H3LIS331DL) achieves above 16 g and the maximum angular velocity achieves above 720°/s when the driving voltage is ±6 V.

Peroxiredoxin 1 promoted tumor metastasis and angiogenesis in colorectal cancer.

Peroxiredoxin1 (Prdx1) is a member of the PrdxS family, and it regulates cellular signaling and differentiation. The role of Prdx1in colorectal cancer (CRC) remains unclear. In this study, we investigated the relevance of Prdx1 in the metastasis and angiogenesis of CRC. The expression of Prdx1 in 60 cases human CRC tissues was detected through immunohistochemistry. The tumors that highly expressed Prdx1 (42/60) exhibited higher tumor grade and lymph node metastasis than those with low expression of Prdx1 (18/60) (p < 0.05). Kaplan-Meier survival analysis showed that the survival time of thePrdx1-positive group was shorter than that of thePrdx1-negative group (p = 0.046).Moreover, a statistically significant correlation was observed between the Prdx1 expression and microvessel density (p = 0.004). Transwell migration assay revealed that Prdx1 was down-regulated in the CRC cell line HCT116, thereby suppressing the invasion and migration capacities of tumor cells, whereas Prdx1was up-regulated in HT29 cells, thereby increasing the invasion and migration capacities of tumor cells. The tube formation capacity of human umbilical vein endothelial cells cultured in 3D medium was increased after conditioned medium from overexpressed Prdx1cancer cells was added relative to that when down-regulated Prdx1 cell medium was added (p < 0.05). In addition, up-regulated Prdx1 increased the protein expression of MMP2, MMP9, and VEGFA. These data suggested that Prdx1 expression predicted poor prognosis by regulating the tumor metastasis and angiogenesis of CRC. Therefore, Prdx1 may serve as a potential therapeutic target.

Core/Shell Structured Fe3O4@TiO2-DNM Nanospheres as Multifunctional Anticancer Platform: Chemotherapy and Photodynamic Therapy Research.

The dose-dependent toxicity and low specificity against cancerous cells have restricted the clinical use of daunomycin (DNM). Titanium dioxide (TiO2) has been wildly used as an inorganic photodynamic therapy (PDT) agent and drug carrier. To facilitate the targeted drug delivery and combined therapy, in the present study, TiO2-coated Fe3O4 nanoparticles (Fe3O4@TiO2 NPs) were employed to load DNM and the drug-loaded Fe3O4@TiO2-DNM Nps exhibited smart pH-controlled releasing and satisfactory cytotoxicity as well as photocytotocity. The combination of prussian blue staining and fluorescence methods evidenced the effortless cell internalization of the fabricated Fe3O4@TiO2-DNM Nps for the cancer cells. The cell cycle status experiments indicated that the as-prepared nanospheres arrested the S and G2/M periods of the cancer cell proliferation in the dark, and further induced the apoptosis under the irradiation of ultraviolet light. The cell apoptotic results revealed that the apoptosis induced by the Fe3O4@TiO2-DNM Nps was in the early stage. The constructed Fe3O4@TiO2-DNM NPs have been endowed with multifunctions that allow them to selectively deliver combinatorial therapeutic payload and exhibit integrated therapeutic effectiveness to tumors.

Calcium carbonate end-capped, folate-mediated Fe3O4@mSiO2 core-shell nanocarriers as targeted controlled-release drug delivery system.

Magnetic mesoporous silica nanospheres (MMSN) were prepared and the surface was modified with cancer cell-specific ligand folic acid. Calcium carbonate was then employed as acid-activated gatekeepers to cap the mesopores of the MMSN, namely, MMSN-FA-CaCO3. The formation of the MMSN-FA-CaCO3 was proved by several characterization techniques, viz. transmission electron microscopy, zeta potential measurement, Fourier transform infrared spectroscopy, BET surface area measurement, and UV-Vis spectroscopy. Daunomycin was successfully loaded in the MMSN-FA-CaCO3 and the system exhibited sensitive pH stimuli-responsive release characteristics under blood or tumor microenvironment. Cellular uptake by folate receptor (FR)-overexpressing HeLa cells of the MMSN-FA-CaCO3 was higher than that by non-folated-conjugated ones. Intracellular-uptake studies revealed preferential uptake of these nanoparticles into FR-positive [FR(+)] HeLa than FR-negative [FR(-)]A549 cell lines. DAPI stain experiment showed high apoptotic rate of MMSN-FA-DNM-CaCO3 to HeLa cells. The present data suggest that the CaCO3 coating and folic acid modification of MMSN are able to create a targeted, pH-sensitive template for drug delivery system with application in cancer therapy.

Effect of TET1 regulating MGMT on chemotherapy resistance of oral squamous cell carcinoma stem cells.

The study was to evaluate the effect of ten-eleven translocation 1 (TET1) regulating o6-methylguanine-DNA methyltransferase (MGMT) in chemotherapy resistance of oral squamous cell carcinoma (OSCC) stem cells. OSCC stem cells were divided into the blank, negative control (NC), TET1-siRNA, TET1-siRNA + MGMT-OE, and MGMT-OE groups. Methylation-specific polymerase chain reaction (MSP), qRT-PCR and Western blotting were conducted to detect the methylation status of MGMT, expressions of TET1, MGMT, ABCG2, and Oct-4. Cell proliferation, cisplatin chemosensitivity, and cell cycle and apoptosis, were detected using CCK8 and flow cytometry. A chromatin immunoprecipitation (ChIP) assay was employed for detecting the link between TET1 and MGMT gene promoters. In comparison to the NC group, the TET1-siRNA group exhibited increased levels of MGMT methylation, the number of apoptotic cells and cisplatin chemosensitivity consisting of varying concentrations, however, decreased levels of mRNA and protein expressions of TET1 as well as MGMT, cell viability, the number of cells in the S phase, and protein expressions of ABCG2 and Oct-4 were all have diminished amounts. The TET1-siRNA + MGMT-OE and MGMT-OE groups had higher MGMT mRNA and protein expression, as well as increased protein expressions of ABCG2 and Oct-4, greater cell activity, higher number of cells in the S phase, decreased apoptotic rates in cells and decreased cisplatin chemosensitivity with different concentrations. Our study provided evidence that low-expression of TET1 in OSCC stem cells may stimulate MGMT promoter methylation, while inhibiting MGMT mRNA expression, this ultimately strengthens the sensitivity of OSCC stem cells in regards to chemotherapeutics.

Shedding lights on the flexible-armed porphyrins: Human telomeric G4 DNA interaction and cell photocytotoxicity research.

DNA polymorphism exerts a fascination on a large scientific community. Without crystallographic structural data, clarification of the binding modes between G-quadruplex (G4) and ligand (complex) is a challenging job. In the present work, three porphyrin compounds with different flexible carbon chains (arms) were designed, synthesized and characterized. Their binding, folding and stabilizing abilities to human telomeric G4 DNA structures were comparatively researched. Positive charges at the end of the flexible carbon chains seem to be favorable for the DNA-porphyrin interactions, which were evidenced by the spectral results and further confirmed by the molecular docking calculations. Biological function analysis demonstrated that these porphyrins show no substantial inhibition to Hela, A549 and BEL 7402 cancer cell lines under dark while exhibit broad inhibition under visible light. This significantly enhanced photocytotoxicity relative to the dark control is an essential property of photochemotherapeutic agents. The feature of the flexible arms emerges as critical influencing factors in the cell photocytotoxicity. Moreover, an ROS-mediated mitochondrial dysfunction pathway was suggested for the cell apoptosis induced by these flexible-armed porphyrins. It is found that the porphyrins with positive charges located at the end of the flexible arms represent an exciting opportunity for photochemotherapeutic anti-cancer drug design.

MTR, MTRR, and MTHFR Gene Polymorphisms and Susceptibility to Nonsyndromic Cleft Lip With or Without Cleft Palate.

OBJECTIVE: To examine the associations of methionine synthase (MTR), methionine synthase reductase (MTRR), and methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms with the susceptibility to nonsyndromic cleft lip with or without cleft palate (NSCL/P). METHODS: Between May 2012 and August 2014, 147 NSCL/P patients (case group) and 129 healthy volunteers (control group) were recruited for the study. The MTR A2756G, MTRR A66G, MTHFR C677T and MTHFR A1298C polymorphisms were assessed by polymerase chain reaction-restriction fragment length polymorphism. Haplotype analyses were performed with SHEsis software. Logistic regression analysis was used to evaluate the possible risk factors for NSCL/P. Generalized multifactor dimensionality reduction (GMDR) was applied to detect gene-gene interactions. RESULTS: MTR A2756G, MTRR A66G, and MTHFR C677T gene polymorphisms were associated with the risk of NSCL/P (all p < 0.05). Logistic regression analysis revealed that MTR A2756G, MTR RA66G, and MTHFR C667T might increase the risk of NSCL/P (odds ratio [OR] = 0.270, 95% confidence interval [95% CI] = 0.106-0.689; OR = 0.159, 95% CI = 0.069-0.368; OR = 0.343, 95% CI = 0.139-0.844). The CA haplotype in the MTHFR gene may serve as a protective factor for NSCL/P (OR = 0.658, 95% CI = 0.470-0.923), and the TA haplotype might be a risk factor (OR = 2.001, 95% CI = 1.301-3.077). GMDR revealed that the optimal models were two- and four-dimensional models with prediction accuracies of 75.73% (p = 0.001) and 77.21% (p = 0.001) and the best cross-validation consistencies of 10/10 and 10/10, respectively. CONCLUSION: MTR A2756G, MTRR A66G, and MTHFR C677T polymorphisms may be related to NSCL/P, and interactions were detected between the MTR A2756G, MTRR A66G, and MTHFR C677T and A1298C polymorphisms.

Evaluation of the Effect of the Closed-eruption Technique on Impacted Immature Maxillary Incisors.

OBJECTIVE: To investigate the effects of the closed-eruption technique on impacted immature maxillary incisors. METHODS: The contour and position of the gingival margin, root development, and pulp status were evaluated in 50 impacted immature maxillary incisors immediately after treatment and 2 years later. RESULTS: Chronic periapical periodontitis and trauma of the primary teeth were the main causes of impacted immature maxillary incisors. The average treatment time was 11 months. After treatment, the contour of the impacted incisor gingival margin, which had already erupted, conformed with the contralateral incisors; the gingival margin positions of 34 (68%) impacted incisors were the same as those of the contralateral incisors but the other 16 (32%) were more apical. All roots developed normally; pulp vitality was normal and conformed with the contralateral incisor change into a period. Three (6%) impacted incisors were slightly labially inclined because the dilacerated part of their roots was too long. CONCLUSION: The closed-eruption technique is an effective method of treating impacted immature maxillary incisors.

Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation.

At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China's stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress.