Background
Regeneration of lost periodontium is the ultimate goal of periodontal therapy. Advances in tissue engineering have demonstrated the multilineage potential and plasticity of adult stem ...cells located in periodontal apparatus. However, it remains unclear how epigenetic mechanisms controlling signals determine tissue specification and cell lineage decisions. To date, no data are available on micro‐RNA (miRNA) activity behind human‐derived dental stem cells (DSCs).
Material and Methods
In this study, we isolated periodontal ligament stem cells, dental pulp stem cells and gingival stem cells from extracted third molars; human bone marrow stem cells were used as a positive control. The expression of OCT4A and NANOG was confirmed in these undifferentiated cells. All cells were cultured under osteogenic inductive conditions and RUNX2 expression was analyzed as a marker of mineralized tissue differentiation. The miRNA expression profile was obtained at baseline and after osteogenic induction in all cell types.
Results
The expression of RUNX2 demonstrated successful osteogenic induction of all cell types, which was confirmed by alizarin red stain. The analysis of 765 miRNAs demonstrated a shift in miRNA expression that occurred in all four stem cell types, including a decrease in hsa‐mir‐218 across all differentiated cell populations. Hsa‐mir‐218 targets RUNX2 and decreases RUNX2 expression in undifferentiated human DSCs. DSC mineralized tissue type differentiation is associated with a decrease in hsa‐mir‐218 expression.
Conclusion
These data reveal a miRNA‐regulated pathway for the differentiation of human DSCs and a select network of human miRNAs that control DSC osteogenic differentiation.
Hosta or plantain lily (Hosta spp.) originates from northeast Asia and is cultivated worldwide. The Hosta'Undulata Erromena' is a common older variety, with large, glossy, dark green leaves. Necrotic ...spots (20.1 to 25.0 mm diameter) were observed on leaves of Hosta'Undulata Erromena' in mid-September 2015, in Guelph, Ontario, Canada (43.55degrees N, 80.25degrees W). Many plants throughout the city were affected, particularly the lower leaves. A total of 20 symptomatic leaves from five locations were collected, washed, and cut into small pieces (3 x 2 mm). The symptomatic tissue pieces were surface-sterilized in 70% ethanol for 45 s plus 1% sodium hypochlorite for 2 min, and then washed with sterilized water. Four morphological types of fungi were repeatedly isolated by single-spore methods from leaf sections placed on potato dextrose agar (PDA) and incubated at 25degreesC in the dark for 3 days. To validate Koch's postulates, 1-month-old 'Undulata Erromena' transplants with formed fully leaves were grown in plastic pots (20 cm diameter) with sandy soil. Isolates were grown on PDA for a week and the spores were harvested in sterile distilled water. Spores suspensions were adjusted to 1 x 10 super(7) spores/ml with sterilized water and injected into the middle of leaves using a syringe (0.1 ml per leaf and 10 leaves per isolate). Control plants were injected with sterilized water. Inoculated plants were placed in the greenhouse at 25degreesC (12/12 h light/dark with over 90% humidity). The experiment was repeated three times. Two weeks after inoculation, one isolate was found to induce symptoms similar to those observed in the field (the control and other isolate treatments remained symptomless). The spots began as small, round lesions, enlarged up to 2 to 3 cm in diameter, circular or irregular, and brown to dark brown. The pathogenic isolate was consistently reisolated from inoculated leaves but not from the control. The isolate formed dense, pale orange, aerial mycelium on Komada selective medium. Macroconidia were abundant, 17.1 to 43.9 x 2.4 to 2.9 mu m, relatively slender, curved to lunate, and three to five septate. Microconidia were abundant, oval or pyriform, and one to two septate. Chlamydospores were absent. The isolate was identified as Fusarium sp. according to morphology (Leslie and Summerell 2006). To confirm the morphological diagnosis, the internal transcribed spacer (ITS) region and a portion of the translation elongation factor 1-alpha (TEF-1 alpha ) regions were sequenced after PCR amplification using rDNA universal primers ITS1/ITS4 (White et al. 1990) and EF-728F/EF-986R (Carbone et al. 1999), respectively. ITS (KU170706) and TEF-1 alpha (KU170708) sequences showed 100 and 99% identity to Fusarium avenaceum(KF010838.1 KP964905.1), respectively. The pathogen was identified as F. avenaceum based on its morphological and molecular characteristics. F. avenaceum is reported as a pathogen of wheat in western Canada (Clear and Patrick 2000), but has not been reported on hosta. To the best of our knowledge, this is the first report of brown leaf spot caused by F. avenaceum on hosta in Canada and worldwide.
Periwinkle (Catharanthus roseus) is cultivated ornamentally and also as an herbal medicine in many parts of the world. Many vinca alkaloids were isolated from this plant and have been used against ...numerous human diseases (Noble 1990). Leaf and stem rot was observed on periwinkle in early September 2015 in Guelph, Ontario, Canada (43degrees11' N, 79degrees24' W). Approximately 20 to 80% of the plants (Pacifica Mix Xp) in five locations were infected. Occasionally, white mycelia and black sclerotia (3 to 5 mm long) were present on infected tissues. Several symptomatic leaves and stems were collected, washed in sterilized water, and cut into small pieces (3 x 2 mm). The tissue pieces were surface-sterilized in 70% ethanol for 50 s plus 1% sodium hypochlorite for 2 min, and then washed with sterilized water. Three types of fungi morphology were repeatedly isolated after surface-sterilized sections were placed on potato dextrose agar (PDA) plates and incubated at 25degreesC in dark for 2 days. To confirm Koch's postulates, 1-month-old periwinkle plants were grown in pots (20 cm diameter) containing sandy soil in greenhouse. Ten plants were used as controls. Leaves and stems were inoculated with a hyphal (5 mm diameter) plug separately for each isolate (10 plants per isolate). Control plants were inoculated with clean agar plugs. The inoculated plants were placed at 25degreesC (12/12 h light/dark with over 90% humidity). The experiment was repeated three times. After 2 days, only one of the isolates inoculated was found to induce disease similar to that observed in the field, showing water-soaked brown symptoms and after 5 days, leaf and stem necrosis, small, black, irregularly shaped sclerotia on the infected surface along with white mycelia were observed, while the control treatment remained symptomless. The fungus was consistently reisolated from inoculated plants but not from the control, and was culturally identical to the fungus originally observed on symptomatic plants. The internal transcribed spacer (ITS) region and a portion of the translation elongation factor 1-alpha (TEF-1 alpha ) regions were sequenced after PCR amplification using rDNA universal primers ITS1/ITS4 (White et al. 1990) and EF-728F/EF-986R (Carbone et al. 1999), respectively. ITS (KU170707) and TEF-1 alpha (KU170709) sequences both showed 100% identity to Sclerotinia sclerotiorum(KT935403.1 AF398888.1), respectively. S. sclerotiorum is virulent on a wide range of hosts, was reported on sunflower in Canada (Boland and Hall 1994; Huang 1977), but the best of our knowledge, this is the first report of leaf and stem rot caused by S. sclerotiorum on periwinkle in Canada. S. sclerotiorum is ubiquitous, and if more reports of this pathogen are found on periwinkle, then it may be necessary to develop effective management strategies for controlling this disease.
The Hi-C experiment can capture the genome-wide spatial proximities of the DNA, based on which it is possible to computationally reconstruct the three-dimensional (3D) structures of chromosomes. The ...transcripts of the long non-coding RNA (lncRNA) Xist spread throughout the entire X-chromosome and alter the 3D structure of the X-chromosome, which also inactivates one copy of the two X-chromosomes in a cell. The Hi-C experiments are expensive and time-consuming to conduct, but the Hi-C data of the active and inactive X-chromosomes are available. However, the Hi-C data of the X-chromosome during the process of X-chromosome inactivation (XCI) are not available. Therefore, the 3D structure of the X-chromosome during the process of X-chromosome inactivation (XCI) remains to be unknown. We have developed a new approach to reconstruct the 3D structure of the X-chromosome during XCI, in which the chain of DNA beads representing a chromosome is stored and simulated inside a 3D cubic lattice. A 2D Gaussian function is used to model the zero values in the 2D Hi-C contact matrices. By applying simulated annealing and Metropolis-Hastings simulations, we first generated the 3D structures of the X-chromosome before and after XCI. Then, we used Xist localization intensities on the X-chromosome (RAP data) to model the traveling speeds or acceleration between all bead pairs during the process of XCI. The 3D structures of the X-chromosome at 3 hours, 6 hours, and 24 hours after the start of the Xist expression, which initiates the XCI process, have been reconstructed. The source code and the reconstructed 3D structures of the X-chromosome can be downloaded from http://dna.cs.miami.edu/3D-XCI/.
We report a single-center experience in treating 18 consecutive patients with severe aplastic anemia (SAA) who received unrelated cord blood transplantation (CBT). The median age was 17 years (range ...5-61 years). Sixteen cases received a reduced-intensity regimen composed of CY (total dose 1200 mg/m(2)), rabbit antithymocyte globulin (ATG, total dose 30 mg/kg) and fludarabine (FLU, total dose 120 mg/m(2)). CYA and mycophenolate mofetil were used as GVHD prophylaxis. Two patients were not evaluable for engraftment because of early death on day +21 and +22. Only one of the sixteen cases achieved engraftment, but experienced secondary graft failure 3 months post transplantation. Fifteen patients experienced primary graft rejection, but all of them acquired autologous recovery. The 3-month and 6-month cumulative incidence of response was 56% and 81%, respectively. So far, 16 patients have survived for 330-1913 days (median, 750 days) after transplantation. The probability of OS at 2 years was 88.9%. Our data indicate that CBT for newly diagnosed SAA using no irradiation but FLU and ATG-based conditioning still seems to inevitably lead to the high risk of rejection, but may facilitate autologous recovery and improve survival with low risk of transplant-related mortality.
A facile method has been developed to prepare a freestanding binder-free nitrogen-doped delaminated-Ti3C2/reduced graphene oxide hybrid films for high-performance supercapacitor electrodes. This film ...exhibits a high specific capacitance of 247 F g−1 (∼445.2 F cm−3) at 1 A g−1 in 6 M KOH, which is still well maintained after 10000 cycles at 10 A g−1, demonstrating excellent long-term electrochemical stability. In addition, a flexible symmetric supercapacitor has been assembled with such films that delivers a maximum energy density of 15.7 W h kg−1 (at 309.3 W kg−1) and a power density of 3738.7 W kg−1 (at 11.1 W h kg−1) in PVA/H2SO4 gel. This impressive electrochemical performance can be attributed to the enhanced conductivity and high pseudocapacitance offered by the heteroatoms of nitrogen and the alleviated self-restacking of MXene layers by the introduction of reduced graphene oxide nanosheets.
Femtosecond laser filament could produce THz wave in forward direction. In our experiment, THz pulse emitted from a femtosecond laser filament has been investigated. It was found that the ...polarization of the studied THz pulse mainly appears as elliptical. This observation supplements the previous conclusion obtained by C. D'Amico et al. that THz wave emitted by a filament is radially polarized. The mechanism of generating elliptically polarized THz wave has been interpreted by either four-wave optical rectification or second order optical rectification inside the filament zone where centro-symmetry of the air is broken by the femtosecond laser pulse.
The SiO2f/SiO2 composite and the Invar alloy were brazed at 860°C from 5min to 25min using an AgCuTi alloy. Scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) ...was employed to examine the elemental distribution in the joint. X-ray diffraction (XRD) and transmission electron microscopy (TEM) was selected to accurately identify the species, morphologies and crystal structures of the reaction products. The effect of the holding time on the interfacial microstructure evolution of the joint was studied in detail. The shear strength of the joints and the fracture morphologies were closely related to the thickness of the whole reaction layer, as well as the thickness ratio of the Ti5Si3+TiO2 layer to the CuxTi6-xO layer. The maximum shear strength was 26MPa obtained at 860°C for 10min. Finally, the formation of the reaction products in the joint was analyzed by thermodynamic calculations. A brazing mechanism was proposed based on the experimental results.
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•A double layer of columnar monoclinic TiO2, hexagonal Ti5Si3 phases and equiaxed cubic CuxTi6-xO formed on the SiO2f/SiO2 composite side.•A formation mechanism of the Invar/AgCuTi/SiO2f-SiO2 brazed joint was proposed.•Effect of brazing duration on microstructure evolution and mechanical response of the brazed joint was investigated.•Fracture morphologies with different holding times were discussed and the optimal brazing duration was 10min at 860°C.
Jilin Oilfield in the Songliao Basin has gone through three stages of increase, stabilization, and decrease in crude oil production during the development process. In this paper, the water flooding ...experiment was carried out by means of rock core in series combination, to analyze and study the water flooding characteristic curve and the recovery ratio curve of the core in Jilin Oilfield. According to the experimental analysis, when the PV number changed slightly (usually 0~1), the pressure at the monitoring point and the instantaneous liquid volume increased, and the water flood front, the oil displacement efficiency, and the water cut increased significantly. When the injected PV number continued to increase (PV number>1), the pressure at the monitoring point changed slowly, the water flood front, the oil output, and the water cut increased slightly, and the oil displacement efficiency was low. According to the experimental results, we explored the characteristics of water flooding by means of rock core in series combination to improve the recovery ratio of the oilfield.
Long-term alcohol stimulation may inhibit the expression of silent information regulator 1 in hepatocytes, which increases the acetylation level of forkhead box transcription factor O1, reduces ...nuclear localization, and reduces the binding capacity of DNA sequence. This further downregulates the expression of downstream adiponectin receptor 2 and microsomal triglyceride transfer protein, causes lipid metabolism disorders and triglyceride deposition in hepatocytes by affecting adiponectin signal transduction and synthesis of very-low-density lipoprotein, and finally promotes the development of alcoholic fatty liver disease.
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