Using machine learning to determine age over 16 based on development of third molar and periodontal ligament of second molar.

BACKGROUND: Having a reliable and feasible method to estimate whether an individual has reached 16 years of age would greatly benefit forensic analysis. The study of age using dental information has matured recently. In addition, machine learning (ML) is gradually being applied for dental age estimation. AIM: The purpose of this study was to evaluate the development of the third molar using the Demirjian method (Demirjian3M), measure the development index of the third molar (I3M) using the method by Cameriere, and assess the periodontal ligament development of the second molar (PL2M). This study aimed to predict whether Chinese adolescents have reached the age of criminal responsibility (16 years) by combining the above measurements with ML techniques. SUBJECTS & METHODS: A total of 665 Chinese adolescents aged between 12 and 20 years were recruited for this study. The development of the second and third molars was evaluated by taking orthopantomographs. ML algorithms, including random forests (RF), decision trees (DT), support vector machines (SVM), K-nearest neighbours (KNN), Bernoulli Naive Bayes (BNB), and logistic regression (LR), were used for training and testing to determine the dental age. This is the first study to combine ML with an evaluation of periodontal ligament and tooth development to predict whether individuals are over 16 years of age. RESULTS AND CONCLUSIONS: The study showed that SVM had the highest Bayesian posterior probability at 0.917 and a Youden index of 0.752. This finding provides an important reference for forensic identification, and the combination of traditional methods and ML is expected to improve the accuracy of age determination for this population, which is of substantial significance for criminal litigation.

RECQL1 plays an important role in the development of tongue squamous cell carcinoma.

BACKGROUND/AIMS: RECQL1, a member of the human RECQ helicase family, participates in DNA repair. Recent reports showed that RECQL1 silencing in cancer cells resulted in mitotic catastrophe, which prevented tumor growth in murine models. However, its therapeutic potential has never been examined in tongue squamous cell carcinoma (SCC). METHODS: To explore the role of RECQL1 in the development of tongue SCC, we used RNA interference technology to silence RECQL1 in SCC-9 and SCC-15 human tongue SCC cell lines, and to subsequently evaluate its effects both in vitro and in vivo. RESULTS: After RECQL1 was silenced in SCC cells by siRNA, we observed downregulation of RECQL1 mRNA and protein in cancer cells. RECQL1 is one of the predicted miR-203 targets, and we found that miR-203 downregulated the expression of RECQL1 at the post-transcriptional level. RECQL1-shRNA or miR-203 overexpression inhibited SCC-9 cell growth. In addition, there was accumulation of cells in the sub-G1 fraction and increased apoptosis 72 h post-transfection. In addition, knockdown of RECQL1 led to a strong anticancer effect, as the tumorigenicity of SCC-9 cells was inhibited in vivo. Moreover, we found that two immunosuppressive factors were also significantly downregulated upon RECQL1 knockdown or miR-203 overexpression in vitro. CONCLUSION: Collectively, these results indicate that RECQL1 plays an important regulatory role in cancer cell proliferation and tumor progression.

Trichome-specific expression of the amorpha-4,11-diene 12-hydroxylase (cyp71av1) gene, encoding a key enzyme of artemisinin biosynthesis in Artemisia annua, as reported by a promoter-GUS fusion.

Artemisinin derivatives are effective anti-malarial drugs. In order to design transgenic plants of Artemisia annua with enhanced biosynthesis of artemisinin, we are studying the promoters of genes encoding enzymes involved in artemisinin biosynthesis. A 1,151 bp promoter region of the cyp71av1 gene, encoding amorpha-4,11-diene 12-hydroxylase, was cloned. Alignment of the cloned promoter and other cyp71av1 promoter sequences indicated that the cyp71av1 promoter may be different in different A. annua varieties. Comparison to the promoter of amorpha-4,11-diene synthase gene showed a number of putative cis-acting regulatory elements in common, suggesting a co-regulation of the two genes. The cyp71av1 promoter sequence was fused to the ß-glucuronidase (GUS) reporter gene and two varieties of A. annua and Nicotiana tabacum were transformed. In A. annua, GUS expression was exclusively localized to glandular secretory trichomes (GSTs) of leaf primordia and top expanded leaves. In older leaves, there is a shift of expression to T-shaped trichomes (TSTs). Only TSTs showed GUS staining in lower leaves and there is no GUS staining in old leaves. GUS expression in flower buds was specifically localized to GSTs. The recombinant promoter carries the cis-acting regulatory elements required for GST-specific expression. The cyp71av1 promoter shows activity in young tissues. The recombinant promoter was up to 200 times more active than the wild type promoter. GUS expression in transgenic N. tabacum was localized to glandular heads. Transcript levels were up-regulated by MeJA. Wound responsiveness experiment showed that the cyp71av1 promoter does not appear to play any role in the response of A. annua to mechanical stress.

Serotonin inhibits apoptosis of pulmonary artery smooth muscle cells through 5-HT2A receptors involved in the pulmonary artery remodeling of pulmonary artery hypertension.

Decreased pulmonary artery smooth muscle cell (PASMC) apoptosis play a key role in pulmonary artery remodeling during pulmonary artery hypertension (PAH), but the mechanisms involved are unclear. Serotonin (5-HT) inhibits apoptosis in many pathologic processes by activating the 5-HT2A receptor. Therefore, we hypothesized that 5-HT may be the promoter of decreased apoptosis in PAH through the 5-HT2A receptor. We found that inhibition of the 5-HT2A receptor prevented the increase in pulmonary artery pressure and pulmonary artery remodeling in rats stimulated by monocrotaline. This effect was accompanied by increased apoptosis in the pulmonary artery. Cultured PASMCs stimulated with 5-HT showed a decrease in apoptosis with increased phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2), pyruvate dehydrogenase kinase (PDK), and mitochondrial transmembrane potential. These effects were markedly prevented by a 5-HT2A receptor inhibitor, an ERK1/2 activation inhibitor peptide I, or a PDK inhibitor. In conclusion, 5-HT inhibited PASMC apoptosis by activating the 5-HT2A receptor through the pERK1/2 and PDK pathways.5-HT decreasing apoptosis through 5-HT2A receptor is involved, at least in part, in pulmonary artery remolding.

[Meta-analysis of the association between adiponectin gene +276g/T polymorphisms and coronary atherosclerotic heart disease].

OBJECTIVE: systemically evaluate the association between +276G/T single nucleotide polymorphisms of adiponectin gene and coronary atherosclerotic heart disease in Chinese population. METHODS: 8 case-control studies about +276G/T polymorphism that were based on our inclusion criterion and available in the literature were reviewed. Meta analysis was carried out by Review Manager 4.2 software. RESULTS: Results from Metaanalysis demonstrated no significant heterogeneity among the studies about +276G/T polymorphisms and showed significant association between the +276G/T polymorphism and coronary disease in the Chinese population, and the fixed effects OR of the allele +276G to susceptibility of the disease was (OR = 1.93, 95% CI 1.32-2.82, P = 0.0007). CONCLUSION: The current paper on Meta-analysis demonstrated a correlation between the +276G/T single nucleotide polymorphism and the cononary disease in Chinese population.

BAFF induces spleen CD4+ T cell proliferation by down-regulating phosphorylation of FOXO3A and activates cyclin D2 and D3 expression.

The TNF ligand family member "B cell-activating factor belonging to the TNF family" (BAFF, also called BLyS, TALL-1, zTNF-4, and THANK) is an important survival factor for B and T cells. In this study, we show that BAFF is able to induce CD4(+) spleen T cell proliferation when co-stimulated with anti-CD3. Expression of phosphorylated FOXO3A was notably down-regulated and cyclins D2 and D3 were up-regulated and higher in the CD4(+) T cells when treated with BAFF and anti-CD3, as assessed by Western blotting. Furthermore, after FOXO3A was knocked down, expression of cyclin D1 was unchanged, compared with control group levels, but the expression of cyclins D2 and D3 increased, compared with the control group. In conclusion, our results suggest that BAFF induced CD4(+) spleen T cell proliferation by down-regulating the phosphorylation of FOXO3A and then activating cyclin D2 and D3 expression, leading to CD4(+) T cell proliferation.

Phosphorus removal from municipal wastewater through a novel Trichosporon asahii BZ: Performance and mechanism.

A yeast BZ was screened from a laboratory-scale anaerobic/aerobic reactor and designated as Trichosporon asahii through 26S rDNA gene sequence analysis. The screened BZ abated over 70% of phosphorus in municipal sewage with 2-10 mg/L phosphorus in the appropriate conditions. The yeast BZ had strong adaptability to pH and the dissolved oxygen, but the cultivation temperature, carbon source, the ratio of C/P and the ratio of N/P had a critical influence on the phosphorus abatement performance of yeast BZ. The analysis of phosphorus concentration in the wastewater, cells, and extracellular polymeric substances (EPS) suggested that about 55%-66% of the removed phosphorus was in the yeast cells and 34%-45% in the EPS. The proposed probable metabolic mechanism of phosphorus in yeast BZ showed that EPS acted as a dynamic phosphorous transfer station, and most of phosphorus was transferred into yeast cells through EPS transfer station. These findings have crucial implications for the development of a promising stable and easy-operation biological phosphorus abatement process for municipal wastewater treatment.

Rheological Properties of Organic Kerosene Gel Fuel.

Gel fuel potentially combines the advantages of solid fuel and liquid fuel due to its special rheological properties, which have essential impacts on the application of gel fuel in propulsion systems. In this paper, we study the rheological property of organic kerosene gel through a series of measurements on its viscosity as a function of the shear rate, temperature, and shear history. The measured datasets are then fitted with constitutive relationships between the viscosity and shear rate at three different levels: the power law shear-thinning model, the power law dependency on both the temperature and shear rate, and the thixotropic property. It is found that intense pre-shear could exhaust thixotropy and reduce viscosity of the kerosene gel. For the power law shear-thinning model, the consistency index increases with the gellant mass fraction, whereas the power law exponent remains constant. The dependence of viscosity on temperature could be well approximated by an empirical power law relationship. As for the thixotropic property of the kerosene gel, the fitted second-order kinetic model corresponds accurately to the viscosity at different shear rates and shear times. The constitutive models fitted in this work at different levels are consistent with each other and provide useful tools for further applications of organic kerosene gel fuel.

Effect of Microstructure on Micro-Mechanical Properties of Composite Solid Propellant.

This study was aimed at determining the effect of microstructure on the macro-mechanical behavior of a composite solid propellant. The microstructure model of a composite solid propellant was generated using molecular dynamics algorithm. The correlation of how microstructural mechanical properties and the effect of initial interface defects in propellant act on the macro-mechanics were studied. Results of this study showed that the mechanical properties of propellant rely heavily on its mesoscopic structure. The grain filling volume fraction mainly influences the propellant initial modulus, the higher the volume fraction, the higher initial modulus. Additionally, it was found that the ratio of particles influences the tensile strength and breaking elongation rate of the propellant. The big particles could also improve the initial modulus of a propellant, but decrease its tensile strength and breaking elongation rate. Furthermore, the initial defects lowered the uniaxial tensile modulus, tensile strength, and the relaxation modulus of propellant, but did not affect the relaxation behavior of the propellant.

Phosphate removal via biological process coupling with hydroxyapatite crystallization in alternating anaerobic/aerobic biofilter reactor.

In this work, a laboratory-scale alternating anaerobic/aerobic biofilter (A/O BF) filled with self-made steel slag media was constructed, where the integrated biological and crystalline phosphorus removal process was realized to remove phosphorus and achieve phosphorus recovery from wastewater. Phosphorus accumulating organisms (PAOs) were successfully enriched within 30 days operation, the maximum phosphate removal efficiency was close to 80% under the optimal conditions with the anaerobic time of 34 h, HRT of 4 h and influent COD of 300 mg/L. The analysis of SEM-EDS and XRD indicated that hydroxyapatite (HAP) crystals were formed inside biofilms without addition of chemical reagents. The high phosphate environment created by PAOs and the release of Ca2+ from the steel slag media might be responsible for the generation of HAP. These findings have crucial implications for the application BF technology to remove and recover phosphorus from wastewater.

Removal of phosphorus from wastewater by Diutina rugosa BL3: Efficiency and pathway.

A novel phosphorus removal yeast BL3 was isolated from an alternating anaerobic/aerobic biofilter and identified as Diutina rugosa by 26S rDNA gene sequence analysis. Yeast BL3 could effectively remove phosphorus from synthetic wastewater containing 2-20 mg/L phosphorus under optimal environmental conditions. The highest phosphorus removal efficiency was above 70% under the conditions of DO 6.86 mg/L, C/P ratios of 60, N/P ratios of 3.3, pH 6.0-9.0, and at 25.0-35.0 °C. The phosphorus distribution in the aqueous solution and different components of yeast BL3 analysis indicated that around 55%-70% and 20%-40% of removed phosphorus were transferred into extracellular polymeric substances (EPS) and yeast cells, respectively. The plausible phosphorus transfer pathway was proposed based on the phosphorus distribution and species analysis, suggesting the important role of EPS as a phosphorus reservoir. These results indicate that yeast BL3 can efficiently remove phosphorus under aerobic conditions without alternating anaerobic/aerobic cycling, and thus has significant potential for practical application in wastewater phosphorus removal.

Association of bone mineral density with nine urinary personal care and consumer product chemicals and metabolites: A national-representative, population-based study.

Personal care and consumer products are extensively used and contain various chemicals that are recognized as endocrine disrupting chemicals. Few epidemiological studies measured the associations of these chemicals and metabolites, especially phenols, with bone health. We measured the associations between nine urinary phenol biomarkers and BMD and the subsequent prevalence of osteopenia/osteoporosis. National representative data from US adults aged over 20 years who participated in the National Health and Nutrition Examination Survey from 2005 to 2010 were used. 2,267 men, 1,145 premenopausal women and 1,033 postmenopausal women were included in the final analyses. Bisphenol A, benzophenone-3, triclosan, butylparaben, ethylparaben, methylparaben, propylparaben, 2,5-dichlorophenol and 2,4-dichlorophenol were measured by high-performance liquid chromatography-isotope dilution tandem mass spectrometry. Paraben concentrations, especially ethyl-, methyl- and propylparabens, were related to greater BMD in the femoral neck and intertrochanter and lumbar spine in men and premenopausal women. 2,4-dichlorophenol concentrations was associated with lower BMD and a higher prevalence of osteopenia + osteoporosis in men. Bisphenol A was associated with a higher prevalence of osteopenia + osteoporosis in the lumbar spine in postmenopausal women. Benzophenone-3 tended to be associated with a higher BMD of femur in men and premenopausal women. In conclusion, certain urinary personal care and consumer product chemicals and metabolites were significantly associated with BMD or osteopenia + osteoporosis. These results further indicate that, in future research, determination of the causal relationships and detection of undelying mechanism could be next important directions.

Psychological effects of project-based learning in participants receiving clinical oncology teaching: A protocol of systematic review of randomized controlled trials.

BACKGROUND: This study will assess the effects of the project-based learning (PBL) for participants undergoing clinical oncology teaching (COT). METHODS: A systematic and comprehensive literature records will be identified from the electronic databases of PUBMED, EMBASE, Cochrane Library, Web of Science, Springer, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. All electronic databases will be searched from their inceptions up to the present. Any relevant randomized controlled trials on the effects of PBL in participants receiving COT will be considered for inclusion. Study quality will be assessed using the Cochrane risk of bias tool. RevMan 5.3 software will be utilized for statistical analysis. RESULTS: This study will assess the effects of PBL in participants receiving COT through assessing the primary outcomes of psychological disorders, student satisfaction, and student feedback, and secondary outcomes of examination scores, excellence rates, course examination pass rates, and clinical knowledge or skills. CONCLUSION: The findings of this study will summarize the latest evidence on the effects of PBL in participants receiving in COT. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019150433.

Sarpogrelate attenuates pulmonary arterial hypertension via calcium/calcineurin axis.

Pulmonary arterial hypertension (PAH) is a syndrome caused by restricted blood flow in the pulmonary circulation, which results in a poor patient prognosis. The serotonin (5-HT), TRPC1 (Transient receptor potencial channel 1), TRPC6 (Transient receptor potencial channel 6), calcineurin A, and NFATc3 (an isoform of nuclear factor of activated T-cells family) are involved in cell proliferation and hypertrophy and the crosstalk between these molecules may play an essential role in the pathogenesis of pulmonary arterial hypertension. We hypothesized that 5-HT promotes PAH by affecting TRPC channels. We investigated the effects of sarpogrelate, a 5-HT2A receptor antagonist, on pulmonary arterial pressure, cardiac remodeling, pulmonary artery remodeling, and TRPC1, TRPC6, calcineurin A, and NFATc3 expression in pulmonary arteries from rats with PAH. The results showed that sarpogrelate reduced pulmonary arterial pressure, cardiac remodeling, pulmonary artery remodeling, and expression of TRPC1, TRPC6, calcineurin A, and NFATc3 in pulmonary arteries. In conclusion, Sarpogrelate reduced the severity of PAH in rat model and decreased the expression of TRPC1, TRPC6, calcineurin A, and NFATc3 in pulmonary arteries.

[Effect of serum starvation and culture to confluence on cell cycle synchronization and mineralization of human dental pulp cells].

PURPOSE: To compare the effect of serum starvation and culture to confluence on cell cycle synchronization and mineralization of human dental pulp cells (hDPCs). METHODS: HDPCs were cultured to 80% and 100% confluence respectively, and then cultured for 24, 48 and 72 hours by culture medium containing 0.5% fetal bovine serum(FBS). Cell cycle of hDPCs were identified by flow cytometry. Then hDPCs cultured by serum starvation for 48h after culturing to 100% confluence were used as the experimental group, and hDPCs cultured to 80% confluence were used as the control group. The expression of alkaline phosphatase(ALP), collagen type Ⅰ(COL-Ⅰ) and osteocalcin(OCN) was detected at gene level; activity of ALPase was detected at protein level. SPSS 13.0 software was used for statistical analysis. RESULTS: When hDPCs were cultured by serum starvation for 48h after culturing to 100% confluence, cells at G0/G1 stage were more than culture to 100% confluence and serum starvation group (P＜0.05). At the genetic level, the expression of COL-Ⅰand OC in the experimental group was not statistically different from that of the control group, but can promote the expression of ALP(P＜0.05), and stimulate the secretion of hDPCs at protein level at the same time (P＜0.05). CONCLUSIONS: Culture to confluence combined serum starvation can synchronize more hDPCs at G0/G1 stage and promote mineralization of hDPCs.

[Evaluation of the efficacy of two kinds of NiTi retreatment instruments for removing filling material during root canal retreatment].

PURPOSE: To compare the efficacy of Mtwo R and Reciproc with that of hand files in removing filling material during root canal retreatment. METHODS: The root canals of forty-five human extracted mandibular central incisors were cleaned and shaped to a size 40 and filled with gutta-percha and sealer using a lateral compaction technique. The teeth were divided into 3 groups. The filling material was removed with hand files, Mtwo R and Reciproc, respectively. The debris extruded out of the apical foramen was collected and weighted. The working time was recorded. Then the teeth were split longitudinally, observed under microscope, and evaluated. The data were statistically analyzed with SPSS 13.0 software package. RESULTS: There was no significant difference among 3 groups for debris extrusion (P>0.05). Removal of filling material with Mtwo R and Reciproc consumed less time (P<0.05). CONCLUTIONS: NiTi retreatment instruments can not remove all filling material during root canal retreatment, but can reduce working time.

[Clinical management of calcified root canal with Mtwo NiTi files].

PURPOSE: To evaluate the effect of Mtwo NiTi files in the management of calcified root canals. METHODS: Thirty-five calcified root canals from 21 cases unsuccessfully prepared with C-Pilot files and EDTA were treated with Mtwo NiTi files and EDTA. The data was analyzed with SAS 9.4 software package. RESULTS: Twenty-three calcified root canals were successfully prepared. The success rate was 65.71%. Instrument separation occurred in 4 root canals, and ledge occurred in 3 root canals. Categorized by calcified position, the success rate of three groups had no significant differences (P>0.05). CONCLUSION: Mtwo NiTi files can effectively process calcified root canals.

Dental age assessment in a northern Chinese population.

INTRODUCTION: Age estimation is imperative in the fields of paediatric dentistry, orthodontics and forensic science. Studies have shown that dental age estimation by the radiological method is reliable and non-destructive. Although Demirjian's method was the most widely used estimation method, in recent studies, the Willems' method has been found to be more accurate. The aim of this study was to compare the accuracy of dental age estimation methods and to modify the Demirjian method to make it more applicable for a northern Chinese population. MATERIALS AND METHODS: An assessment was made of 1004 digital orthopantomographs of a northern Chinese population (392 boys and 612 girls) ranging in age from 11 to 18 years old. Dental ages were calculated using both the Demirjian method and the Willems method. Discrepancies between chronological ages and dental ages were statistically analysed by the paired t-test and the Wilcoxon signed rank test. A nonlinear fitting method was applied to construct a mathematical model to modify the Demirjian method. RESULTS: The Demirjian method underestimated age by 0.47 y in boys and 0.63 y in girls, while the Willems method underestimated age by 0.54 y and 1.01 y in boys and girls, respectively. The mean absolute error was 1.08 y for the Demirjian method and 1.22 y for the Willems method. CONCLUSION: The Demirjian method was more accurate for estimating dental age compared with the Willems method. However, the Demirjian method may not be suitable for the northern Chinese population; therefore, it should be modified so that it can be used for this population.

Circadian Rhythm Regulates Development of Enamel in Mouse Mandibular First Molar.

Rhythmic incremental growth lines and the presence of melatonin receptors were discovered in tooth enamel, suggesting possible role of circadian rhythm. We therefore hypothesized that circadian rhythm may regulate enamel formation through melatonin receptors. To test this hypothesis, we examined expression of melatonin receptors (MTs) and amelogenin (AMELX), a maker of enamel formation, during tooth germ development in mouse. Using qRT-PCR and immunocytochemistry, we found that mRNA and protein levels of both MTs and AMELX in normal mandibular first molar tooth germs increased gradually after birth, peaked at 3 or 4 day postnatal, and then decreased. Expression of MTs and AMELX by immunocytochemistry was significantly delayed in neonatal mice raised in all-dark or all-light environment as well as the enamel development. Furthermore, development of tooth enamel was also delayed showing significant immature histology in those animals, especially for newborn mice raised in all daylight condition. Interestingly, disruption in circadian rhythm in pregnant mice also resulted in delayed enamel development in their babies. Treatment with melatonin receptor antagonist 4P-PDOT in pregnant mice caused underexpression of MTs and AMELX associated with long-lasting deficiency in baby enamel tissue. Electromicroscopic evidence demonstrated increased necrosis and poor enamel mineralization in ameloblasts. The above results suggest that circadian rhythm is important for normal enamel development at both pre- and postnatal stages. Melatonin receptors were partly responsible for the regulation.

[Impact of visit-to-visit blood pressure variability on vascular function in elderly hypertensive patients].

OBJECTIVE: To assess the relationship between visit-to-visit blood pressure (BP) variability (BPV) and vascular endothelial function in a cohort of elderly hypertensive patients. METHODS: A total of 174 elderly patients with essential hypertension were included in the study. The participants had their office BP measured during the 12-month follow-up. Right brachial artery diameter was assessed at rest, during reactive hyperemia (flow-mediated dilation, FMD), and after nitroglycerin administration (nitroglycerin-mediated dilation, NMD). The participants were divided into two groups according to FMD% or FMD/NMD ratio. The correlations between BPV and endothelial function were analyzed by univariate analysis and multiple linear regression analysis. RESULTS: The participants classified as having a decreased endothelial function according to FMD/NMD ratio had significantly lower FMD% and higher BPV and NMD% (P<0.05). The percentage of CCBs use in normal endothelial function group was significantly higher than that in decreased endothelial function group (79.55% vs 63.95%, P<0.05). Multiple linear regression analysis revealed a significant negative association between FMD/NMD ratio and BPV, and this association remained significant after adjustment for age, body mass index, and mean BP levels. CONCLUSIONS: FMD/NMD ratio is a better marker of endothelial function than FMD, and an increased visit-to-visit variability of BP is associated with a decreased endothelial function.