Recombinant amelogenin peptide TRAP promoting remineralization of early enamel caries: An in vitro study

Objective: To explore the regulatory effect of recombinant amelogenin peptide TRAP on the remineralization of early enamel carious lesions.Methods: Forty-eight bovine enamel blocks that prepared initial lesions in vitro were split at random into four groups for immersion treatment for 12 days: 1) remineralizing medium; 2) studied peptide 1 (consisting of the N- and C-termini of porcine amelogenin) + remineralizing medium; 3) studied peptide 2 (TRAP) + remineralizing medium; 4) fluoride + remineralizing medium. After demineralization and remineralization immersion, each specimen’s mean mineral loss and lesion depth were measured using micro-computed tomography (micro-CT). The changes in lesion depth (∆LD) and mineral gain (∆Z) were computed following remineralization. The enamel samples were then cut into sections and examined with polarized light microscopy (PLM). The cross-section morphology was observed by scanning electron microscopy (SEM). The crystal phase was analyzed by an X-ray micro-diffractometer (XRD). The calcium-binding properties were determined using isothermal titration calorimetry (ITC).Results: Micro-CT analysis revealed a significant reduction in mineral loss in the four groups following the remineralization treatment (p < 0.05). The treatment with fluoride resulted in the greatest ∆Z and ∆LD, whereas the treatment with a remineralizing medium showed the least ∆Z and ∆LD among all groups. The ∆Z and ∆LD of the studied peptide 1 and studied peptide 2 groups were greater than those of the remineralizing medium group. However, there was no significant difference between the studied peptide 1 and studied peptide 2 groups (p > 0.05). All of the samples that the PLM analyzed had a thickening of the surface layer. A negative birefringent band changed in the lesion’s body. The SEM displayed that minerals were formed in all four groups of samples. The XRD results indicated that the products of remineralization of the studied peptide were hydroxyapatite crystals (HA). ITC showed that there were two binding modes between the calcium and peptide TRAP.Conclusion: This study confirmed the potential of the recombinant amelogenin peptide TRAP as a key functional motif of amelogenin protein for enamel remineralization and provided a promising biomaterial for remineralization in initial enamel carious lesion treatment

Patient-Specific Coronary Artery 3D Printing Based on Intravascular Optical Coherence Tomography and Coronary Angiography

Despite the new ideas were inspired in medical treatment by the rapid advancement of three-dimensional (3D) printing technology, there is still rare research work reported on 3D printing of coronary arteries being documented in the literature. In this work, the application value of 3D printing technology in the treatment of cardiovascular diseases has been explored via comparison study between the 3D printed vascular solid model and the computer aided design (CAD) model. In this paper, a new framework is proposed to achieve a 3D printing vascular model with high simulation. The patient-specific 3D reconstruction of the coronary arteries is performed by the detailed morphological information abstracted from the contour of the vessel lumen. In the process of reconstruction which has 5 steps, the morphological details of the contour view of the vessel lumen are merged along with the curvature and length information provided by the coronary angiography. After comparing with the diameter of the narrow section and the diameter of the normal section in CAD models and 3D printing model, it can be concluded that there is a high correlation between the diameter of vascular stenosis measured in 3D printing models and computer aided design models. The 3D printing model has high-modeling ability and high precision, which can represent the original coronary artery appearance accurately. It can be adapted for prevascularization planning to support doctors in determining the surgical procedures

YeastFab:the design and construction of standard biological parts for metabolic engineering in Saccharomyces cerevisiae

It is a routine task in metabolic engineering to introduce multicomponent pathways into a heterologous host for production of metabolites. However, this process sometimes may take weeks to months due to the lack of standardized genetic tools. Here, we present a method for the design and construction of biological parts based on the native genes and regulatory elements in Saccharomyces cerevisiae. We have developed highly efficient protocols (termed YeastFab Assembly) to synthesize these genetic elements as standardized biological parts, which can be used to assemble transcriptional units in a single-tube reaction. In addition, standardized characterization assays are developed using reporter constructs to calibrate the function of promoters. Furthermore, the assembled transcription units can be either assayed individually or applied to construct multi-gene metabolic pathways, which targets a genomic locus or a receiving plasmid effectively, through a simple in vitro reaction. Finally, using β-carotene biosynthesis pathway as an example, we demonstrate that our method allows us not only to construct and test a metabolic pathway in several days, but also to optimize the production through combinatorial assembly of a pathway using hundreds of regulatory biological parts

Medium and long-term wind energy forecasting method considering multi-scale periodic pattern

Medium and long-term weather sequence forecast becomes unreliable beyond two weeks since the weather is a chaotic system. Using values of same months for electricity prediction of wind power is the usual method. This approach defaults wind power output with annual cycle law. However, the periodic pattern can be very complicated in fact with multiple time scales. This paper proposes an approach with multi-scale periodic pattern considered. The application of parametric estimation on cumulative distribution function avoids the difficulty of predicting the power curve. Meteorological condition is considered to some extent via multi-scale periodic pattern explored basing on historical energy data. This work is an exploration for medium and long-term wind power forecasting that can well adapt to existing conditions. It has better prediction accuracy than the method without multi-scale periodicity considered

Highly durable superhydrophobic surfaces based on a protective frame and crosslinked PDMS-candle soot coatings

Superhydrophobic surfaces can be applied to environmental, energy, and healthcare fields. However, the weak durability issue has significantly limited the practical industrial applications. To overcome the readily destroyed interfacial structures and chemical compositions, the superhydrophobic surfaces with high mechanical and chemical durability have been created on a stainless steel mesh (SSM) as a protective frame based on tightly crosslinked polydimethylsiloxane (PDMS)−candle soot (CS) composite coatings through simple mechanical transfer and candle burning processes, which abbreviated to SSM/PDMS−CS and showed a water contact angle (WCA) of 159.4° ± 1.6° and a sliding angle (SA) of 2.3° ± 0.5°. Harsh abrasion examinations based on sandpaper and fiber paper have been conducted by applying 100 g weight and 200 cm sliding distance. And the obtained WCAs and SAs were 155° ± 3.7°, 155.7° ± 2° and 3.7° ± 0.5°, 3.5° ± 0.3°. Scanning electron microscope showed scratches on the surface, but the superhydrophobic property has been well maintained. After 40 kHz ultrasonication treatment for 30 min, WCA and SA were 152° ± 0.9° and 4.1° ± 0.8°. Finally, SSM/PDMS−CS surfaces exhibit good chemical resistance to corrosive solutions even after pH 2, pH 10, 1 M NaCl, and toluene treatments for 15 days

The role of ZEB1 in regulating tight junctions in antrochoanal polyp

Background: Antrochoanal polyp (ACP) is a benign nasal mass of unknown etiology. Tight junctions (TJs) are essential to the epithelial barrier that protects the body from external damage. However, the phenotype of tight junction in ACP is currently unclear. Methods: The samples were collected from 20 controls, 37 patients with ACP and 45 patients with chronic rhinosinusitis with nasal polyp (CRSwNP). Quantitative Real-Time PCR (qRT-PCR) and immunofluorescence staining (IF) were performed to analyze the expressions of TJs markers (ZO-1, claudin-3 and occludin) and ZEB1. hNEpCs were transfected with ZEB1 small interfering RNA (si-ZEB1) or ZEB1 over-expression plasmid (OE-ZEB1). qRT-PCR and Western blotting were used to determine the levels of TJs-related markers. Primary human nasal epithelial cells (hNECs) were stimulated with IL-17A and si-ZEB1, and the expression of epithelial barrier markers were measured by qRT-PCR and Western blotting. Results: Compared to the control group, ACP group showed a significant downregulation in both mRNA and protein levels of ZO-1, occludin, and claudin-3. Furthermore, disease severity correlates positively with the degree of disruption of tight junctions. In addition, higher expression levels of ZEB1, IL-17A, and IFN-γ were observed in the ACP group compared to controls. Overexpression of ZEB1 in hNEpCs led to impairments in the levels of ZO-1, occludin, and claudin-3, while silencing of ZEB1 expression was found to enhance the barrier function of epithelial cells. Finally, IL-17 stimulation of hNECs impaired the expression of TJs-associated molecules (ZO-1, occludin, and claudin-3), which was effectively reversed by the IL-17A + si-ZEB1 group. Conclusions: The tight junctions in ACP were extremely damaged and were correlated with the severity of the disease. ZEB1 was involved in the pathogenesis of ACP mediated by IL-17A through regulating tight junctions

A comparative study of the influences of park physical factors on summer outdoor thermal environment, a pilot study of Mianyang, China

Along with global climate change and urbanisation, the thermal environment is increasingly worse in summer, especially (sub)tropical regions. In recent decades, approaches improving the thermal environment have been frequently investigated. Factors of urban design, planning, and landscaping have been found thermal relevant. These factors were indicated by sky view factor (SVF), vegetation cover, leaf area index (LAI) etc. However, most studies focused one single factor, thermal performance difference between various factors were rarely explored. This study compared park canopy closure (PCC) and LAI about their effects on park thermal comfort indicated by various indices (air temperature, Ta; mean radiant temperature, MRT; and physiological equivalent temperature, PET). The PCC was different from LAI by leaf layer quantity (overlapping). Through a field measurement conducting in 8 parks around Mianyang (a subtropical riverside city, China; summer of 2018). The results revealed, both PCC and LAI were significantly thermal effective, LAI showed less significant thermal effects than PCC in linear models. That is to say, leaf layers had little effect linearly. The effects of PCC on the various indices varied for daily periods, with a significant effect on MRT during the day, Ta in the evening, and PET throughout the day. Increasing PCC from 0 to 1 could reduce PET by 29.44 °C (afternoon, R2 = 0.4928). Findings of this study confirmed the different environmental factors’ impacts on microclimates and distinguished the characteristics of various thermal indices