Optical and Acoustic Synergetic Sensing Platform Enabled by a Pyrene-Based Conjugated Polymer Self-Circulating Amplified System for Lung Cancer Detection.

A stable and reusable electrochemiluminescent (ECL) signal amplification strategy was proposed through a pyrene-based conjugated polymer (Py-CP) triggered self-circulating enhancement system. Specifically, the delocalized conjugated π-electrons of Py-CPs made it an excellent coreactant to arouse the initial ECL signal improvement of Ru(phen)32+, but the subsequent signal reduction was attributed to the consumption of Py-CPs, in which this stage was called the signal sensitization evoking phase (SSEP). Then, the maximum use of ECL luminescence of Ru(phen)32+ produced in the SSEP was made to irradiate the photosensitizer Py-CPs for in situ producing numerous ·OH, and a stronger and more stable ECL response stage defined as the signal sensitization stabilize phase was reached. Encouragingly, the incorporation of Nb2C MXene quantum dots with an exceptional physicochemical property not only foreshortens the SSEP for quickly acquiring a stable ECL signal but also introduces the photoacoustic (PA) transduce mechanism for achieving dual-signal outputting. Ultimately, the portable and miniaturized ECL-PA synergetic sensing platform based on the closed-bipolar electrode realized sensitive let-7a detection in a wide linear range from 10-9 to 10-2 nM with a low detection limit of 3.3 × 10-10 nM and also demonstrated good selectivity, excellent stability, and high reliability. The successful application of an innovative signal transduction mechanism and dexterous coupling modality will provide new insights for advancing the development of flexible analytical devices.

Design, Synthesis, and Biological Activities of Novel 2-Cyanoacrylate Compounds Containing Substituted Pyrazolyl or 1,2,3-Triazolyl Moiety.

To develop novel 2-cyanoacrylate derivatives with potential bioactivity, a number of 2-cyanoacrylate compounds, including substituted pyrazole or 1,2,3-triazole ring, were designed, prepared, and structurally detected by 1H NMR, 13C NMR, and elemental analysis. The biological assessment displayed that some designed compounds had significant herbicidal activities against Brassica juncea, Chenopodium serotinum, Rumex acetosa, Alopecurus aequalis, Polypogon fugax, and Poa annua at a dosage of 1500 g/ha. Furthermore, some derivatives still expressed satisfactory herbicidal activities against Brassica juncea, Chenopodium serotinum, and Rumex acetosa when the dosage was lowered to 150 g/ha, especially the inhibitory effects of compounds 9a, 9d, 9f, 9i, 10a, 10b, 10e, and 10n against Brassica juncea were all over 80%, compounds 9d, 9f, 9g, 9h, 9i, 10h, 10i, 10m, 10n, and 10o possessed more than 70% inhibition rates against Chenopodium serotinum, and compound 9d indicated 70% herbicidal activity against Rumex acetosa. These results provided an important basis for further design and discovery of biologically active 2-cyanoacrylate compounds.

Dual-readout immunosensor based on multifunctional MXene probe triggers the signal amplification for detection of autoimmune hepatitis marker.

A dual-readout immunosensor coupled with electrochemical impedance and temperature signal was successfully proposed to detect autoimmune hepatitis markers (ASGPR). Nb2C MXene with excellent conductivity, abundant surface functional groups, and extraordinary photothermal conversion efficiency, was designed to be a multifunctional biological probe, whose specific binding with antigen enhanced steric hindrance to generate electrochemical impedance signal, and at the same time, it had a strong optical response in the near-infrared band to achieve temperature output. In addition, poly(N-isopropyl acrylamide) (PNIPAM) was a temperature-sensitive polymer, which was adopted as the sensing matrix. When the multifunctional probe was specifically bound to the antigen, under 808-nm laser irradiation, the captured Nb2C MXene achieved photothermal conversion to increase the electrode surface temperature, and the conformation of PNIPAM changed from a free spiral to a spherical shape, further realizing double amplification of the EIS signal. Under the optimized experimental conditions, the impedance values and the temperature changes increased proportionally with the increase of the ASGPR concentration from 10-5 to 1 ng/mL, and the detection limit of the immunosensor was 3.3 × 10-6 ng/mL. The established dual-readout immunosensor exhibited good selectivity and acceptable stability and provided an effective detection method for autoimmune hepatitis marker detection.

A Fluorescent Zn(II) Coordination Polymer: Sensitive Detection of Cr2O72- in Water and Prevention Activity On the Deep Vein Thrombosis in Orthopedic Nursing.

A novel coordination polymer (CP) based on Zn(II) of [Zn(tptc)0.5(bpy)(H2O)]n (1) was synthesized through utilizing the 2,2'-bipyridine (bpy) chelating N donors and p-terphenyl-2,2'',5'',5'''-tetracarboxylate acid (H4tptc) as the co-ligands. The measurements of the fluorescence were implemented for the complex 1 in solution and solid state, and the result reveals that 1 has a strong fluorescence and it is a sensory material with great development space to determine the trace Cr2O72- (with the detection limit of 36 ppb) in the water solutions via applying the fluorescence quenching effect. As the common disease in the orthopedic nursing, the deep vein thrombosis was the objective in this research. The weigh and length of the thrombus in the animals were measured and analyzed. In addition to this, the inflammatory response in the deep vein thrombosis animal was evaluated by RT-PCR. Molecular docking results indicate that only the carboxyl group could provide polar oxygen atoms for the formed hydrogen bonds to the protein.

[A multicenter, randomized, controlled, phase â ¢ clinical study of PEG-rhG-CSF for preventing chemotherapy-induced neutropenia in patients with breast cancer and non-small cell lung cancer].

OBJECTIVE: To explore the safety and efficacy of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in preventing chemotherapy-induced neutropenia in patients with breast cancer and non-small cell lung cancer (NSCLC), and to provide the basis for clinical application. METHODS: According to the principle of open-label, randomized, parallel-group controlled clinical trial, all patients were randomized by 1∶1∶1 into three groups to receive PEG-rhG-CSF 100 µg/kg, PEG-rhG-CSF 6 mg, or rhG-CSF 5 µg/kg, respectively. The patients with breast cancer received two chemotherapy cycles, and the NSCLC patients received 1-2 cycles of chemotherapy according to their condition. All patients were treated with the combination chemotherapy of TAC (docetaxel+ epirubicin+ cyclophosphamide) or TA (docetaxel+ epirubicin), or the chemotherapy of docetaxel combined with carboplatin, with a 21 day cycle. RESULTS: The duration of grade 3-4 neutropenia in the PEG-rhG-CSF 100 µg/kg and PEG-rhG-CSF 6 mg groups were similar with that in the rhG-CSF 5 µg/kg group (P>0.05 for all). The incidence rate of grade 3-4 neutropenia in the PEG-rhG-CSF 100 µg/kg group, PEG-rhG-CSF 6 mg group, and G-CSF 5 µg/kg group were 69.7%, 68.4%, and 69.5%, respectively, with a non-significant difference among the three groups (P=0.963). The incidence rate of febrile neutropenia in the PEG-rhG-CSF 100 µg/kg group, PEG-rhG-CSF 6 mg group and G-CSF 5 µg/kg group were 6.1%, 6.4%, and 5.5%, respectively, showing no significant difference among them (P=0.935). The incidence rate of adverse events in the PEG-rhG-CSF 100 µg/kg group, PEG-rhG-CSF 6 mg group and G-CSF 5 µg / kg group were 6.7%, 4.1%, and 5.5%, respectively, showing a non-significant difference among them (P=0.581). CONCLUSIONS: In patients with breast cancer and non-small cell lung cancer (NSCLC) undergoing TAC/TA chemotherapy, a single 100 µg/kg injection or a single fixed 6 mg dose of PEG-rhG-CSF at 48 hours after chemotherapy show definite therapeutic effect with a low incidence of adverse events and mild adverse reactions. Compared with the continuous daily injection of rhG-CSF 5 µg/kg/d, a single 100 µg/kg injection or a single fixed 6 mg dose of PEG-rhG-CSF has similar effect and is more advantageous in preventing chemotherapy-induced neutropenia.

Inhibition of pathogenic microbes in oral infectious diseases by natural products: Sources, mechanisms, and challenges.

The maintenance of oral health is of utmost importance for an individual's holistic well-being and standard of living. Within the oral cavity, symbiotic microorganisms actively safeguard themselves against potential foreign diseases by upholding a multifaceted equilibrium. Nevertheless, the occurrence of an imbalance can give rise to a range of oral infectious ailments, such as dental caries, periodontitis, and oral candidiasis. Presently, clinical interventions encompass the physical elimination of pathogens and the administration of antibiotics to regulate bacterial and fungal infections. Given the limitations of various antimicrobial drugs frequently employed in dental practice, the rising incidence of oral inflammation, and the escalating bacterial resistance to antibiotics, it is imperative to explore alternative remedies that are dependable, efficacious, and affordable for the prevention and management of oral infectious ailments. There is an increasing interest in the creation of novel antimicrobial agents derived from natural sources, which possess attributes such as safety, cost-effectiveness, and minimal adverse effects. This review provides a comprehensive overview of the impact of natural products on the development and progression of oral infectious diseases. Specifically, these products exert their influences by mitigating dental biofilm formation, impeding the proliferation of oral pathogens, and hindering bacterial adhesion to tooth surfaces. The review also encompasses an examination of the various classes of natural products, their antimicrobial mechanisms, and their potential therapeutic applications and limitations in the context of oral infections. The insights garnered from this review can support the promising application of natural products as viable therapeutic options for managing oral infectious diseases.

Electrochemiluminescence enhanced by molecular engineering linear π-conjugated polymer: An ingenious ECL emitter for the construction of exosome sensing platform.

Linear π-conjugated polymers (LCPs) with π-electron conjugation system have many remarkable optical characteristics such as fluorescence and electrochemiluminescence (ECL). However, the extremely strong interchain interaction and π-π stacking limit the luminescence efficiency. In this work, 1H-1,2,4-triazole-3,5-diamine was chosen as the polymer monomer and reacted with terephthalaldehyde via simple Schiff base condensation to synthesize LCPs. Subsequently, molecular engineering strategy was adopted to construct zirconium-based LCPs (MLCPs), which not only prevented π-π stacking but also ensured that extended π-coupling was maintained in the LCPs, thus effectively promoting charge transport and achieving strong luminescence. Second, the coreactant polyethyleneimine (PEI) was assembled onto the MLCPs (MLCPs@PEI) to further promote the emission of ECL. To further explore the potential of the obtained MLCPs@PEI as emerging ECL emitter, colorectal cancer exosome was chosen as model biomarker, and an innovative ECL ratiometric system based on MLCPs@PEI and luminol was designed to improve the validity and accuracy of the sensors. This research provides a fresh nanoplatform for exosome detection and broadens the application of LCPs in ECL immunoassay.

Zwitterion modified chitosan as a high-performance corrosion inhibitor for mild steel in hydrochloric acid solution.

Herein, a novel chitosan Schiff base (CS-FGA) as a sustainable corrosion inhibitor has been successfully synthesized via a simple amidation reaction by using an imidazolium zwitterion and chitosan (CS). The corrosion inhibition property of CS-FGA for mild steel (MS) in a 1.0 M HCl solution was studied by various electrochemical tests and physical characterization methods. The findings indicate that the maximum inhibition efficiency of CS-FGA as a mixed-type inhibitor for MS in 1.0 M HCl solution with 400 mg L-1 reaches 97.6 %, much much higher than the CS and the recently reported chitosan-based inhibitors. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and water contact angle (WCA) results reveal that the CS-FGA molecules firmly adsorb on the MS surface to form a protective layer. The adsorption of CS-FGA on the MS surface belongs to the Langmuir adsorption isotherm containing both the physisorption and chemisorption. According to the X-ray photoelectron spectroscopy (XPS) and UV-vis spectrum, FeN bonds presented on the MS surface further prove the chemisorption between CS-FGA and Fe to generate the stable protective layer. Additionally, theoretical calculations from quantum chemical calculation (DFT) and molecular simulations (MD) were performed to reveal the inhibition mechanism of CS-FGA.

MicroRNA-23b inhibits enterovirus 71 replication through downregulation of EV71 VPl protein.

Enterovirus 71 (EV71) is one of the causative pathogens of hand-foot-and-mouth disease and effective antiviral agents and vaccines against this virus have, to date, not been available. MicroRNAs (miRNAs) are a recently discovered class of RNAs with the function of post-transcriptional gene expression regulation. It has been demonstrated that miRNAs play important roles in the complicated interaction network between virus and host, while few studies have explored the role of miRNAs in EV71 infection. A recent study showed that hsa-miR-23b was downregulated significantly in cell-infected viruses. To address this issue, biological software miRanda was first used to predict possible target sites of miR-23b at EV71 gene sequence, then to confirm it by luciferase assay. miR-23b mimics were transfected to verify its effects on infection of EV71. These results suggest that miR-23b and upregulation of miR-23b inhibited the replication of EV71 by targeting at EV71 3'UTR conserved sequence. Taken together, miR-23b could inhibit EV71 replication through downregulation of EV71 VPl protein. These results may enhance our understanding on the prevention and treatment of hand-foot-and-mouth disease caused by EV71 infection.

[Prevalent characteristics in children with hand-foot-mouth disease in the Kunming area in 2010].

OBJECTIVE: To study the prevalent characteristics in children with hand-foot-mouth disease (HFMD) in the Kunming area in 2010. METHODS: The clinical data of 13286 outpatient and inpatient children with HFMD in Kunming Children's Hospital between January and December, 2010, including 8 death cases, 715 serious cases and 12563 non-serious cases, were retrospectively studied. RESULTS: Human enterovirus was detected in 8200 children (61.72%). Children infected with EV71 and CoxA16 accounted for 29.49% (2418/8200) and 53.21% (4363/8200), respectively. Seventy-five children (0.91%) were found to have a mixed infection of the two viruses. Other types of human enterovirus were detected in 1344 children (16.39%). There were significant differences in the total positive rate of human enterovirus in the four quarters of the year (P<0.01). The total positive rate in the second quarter represented the highest proportion (71.56%), and the number of patients was also highest, accounting for 52.94% of the total number of patients in the whole year. EV71 infection was common in the serious case group while CoxA16 was found to be the main pathogen in the non-serious case group. Serious cases were common in children under three years old. In the positive EV71 cases, the viral load of EV71 was not statistically different between the death cases, serious and non-serious cases. CONCLUSIONS: In 2010, children with HFMD in the Kunming area were mainly infected with CoxA16. Serious cases of HFMD were more common in those who were infected with EV71, and the majority of serious infections were suffered by children who were less than three years old. The viral load was not associated with disease severity. The highest morbidity rate was in the second quarter of the year.

Late hematoma, seroma, and galactocele in breasts injected with polyacrylamide gel.

Late hematoma or seroma and galactocele caused by augmentation mammaplasty have been reported in patients with silicon breast prostheses but are extremely rare in patients injected with polyacrylamide gel (PAAG). In a retrospective survey, the incidence, clinical manifestations, and management of late hematoma, seroma, and galactocele in 28 of 2,610 patients who underwent breast augmentation with PAAG injection were investigated, and 5 typical cases are presented. The diagnostic and managing methods for this complication have been assessed. The incidence of late hematoma or seroma was 0.65% and that of galactocele was 0.35% among patients with PAAG-injected breast augmentations. The clinical onsets of such late PAAG complications were of two types: rapid enlargement in 17 patients and progressive expansion in another 11 patients. Aspiration, ultrasound, and magnetic resonance imaging (MRI) are useful and sensitive tools for diagnosis. Foreign body reaction, PAAG-related tissue necrosis and fibrosis, and granuloma were shown, and the bacterial cultures in all 12 cases were negative. Needle aspiration with pressure dressing has been advocated as a reliable method for small diseases, and surgical exploration with irrigation-vacuum drainage and evacuation with capsulectomy have been considered more effective for recurrent, large, and long-term cases. In conclusion, these late complications rarely present after large-volume injections of PAAG for breast augmentation. The PAAG-related pathologic inflammatory tissue changes are suggested as the pathogenesis for the complication. Trauma and breastfeeding are considered to be stimulating factors.

Effect of different tooth preparation designs on the marginal and internal fit discrepancies of cobalt-chromium crowns produced by computer-aided designing and selective laser melting processes.

PURPOSE: To evaluate the impact of five different tooth preparation designs on the marginal and internal fit discrepancies of cobalt-chromium (CoCr) crowns produced by computer-aided designing (CAD) and selective laser melting (SLM) processes. MATERIALS AND METHODS: Five preparation data were constructed, after which design crowns were obtained. Actual crowns were fabricated using an SLM process. After the data of actual crowns were obtained with structural light scanning, intaglio surfaces of the design crown and actual crown were virtually superimposed on the preparation. The fit-discrepancies were displayed with colors, while the root means square was calculated and analyzed with one-way analysis of variance (ANOVA), Tukey's test or Kruskal-Wallis test (α =.05). RESULTS: The marginal or internal color-coded images in the five design groups were not identical. The shoulder-lip and sharp line angle groups in the CAD or SLM process had larger marginal or internal fit discrepancies compared to other groups (P < .05). In the CAD process, the mean marginal and internal fit discrepancies were 10.0 to 24.2 µm and 29.6 to 31.4 µm, respectively. After the CAD and SLM processes, the mean marginal and internal fit discrepancies were 18.4 to 40.9 µm and 39.1 to 47.1 µm, respectively. The SLM process itself resulted in a positive increase of the marginal (6.0 - 16.7 µm) and internal (9.0 - 15.7 µm) fit discrepancies. CONCLUSION: The CAD and SLM processes affected the fit of CoCr crowns and varied based on the preparation designs. Typically, the shoulder-lip and sharp line angle designs had a more significant effect on crown fit. However, the differences between the design groups were relatively small, especially when compared to fit discrepancies observed clinically.

Mesoporous polydopamine-coated hydroxyapatite nano-composites for ROS-triggered nitric oxide-enhanced photothermal therapy of osteosarcoma.

In this paper, MPDA@hydroxyapatite nanocomposites (MPHA NCs) were prepared and applied to develop a novel reactive oxygen species (ROS)-triggered nitric oxide (NO)-enhanced photothermal therapy nanocomposite system composed of indocyanine green (ICG)/L-arginine-MPDA@HAp (AI-MPHA NCs) for displaying both NO gas therapy and photothermal osteosarcoma treatment. The nanosystem exhibited a mesoporous and core-shell structure and high ICG loading efficiency (about 90%). Under near infrared (NIR) irradiation, the AI-MPHA NCs could not only produce heat but also generate reactive oxygen species (ROS), inducing the catalysis of L-Arg to obtain NO. Under NIR irradiation, the AI-MPHA NCs achieved osteosarcoma ablation by a synergistic combination of photothermal therapy and NO-gas therapy. Additionally, the cell viability of MG-63 cells decreased to 23.6% (co-incubated with AI-MPHA NCs) under irradiation with a power density at 1.0 W cm-2 for 10 min. The study proposed a novel nano-platform for NO-enhanced photothermal therapy of osteosarcoma.

Direct electrochemistry of thermally denatured calf thymus DNA on a poly(methyl methacrylate)-graphite microcomposite electrode.

Remarkable direct electrochemical behaviors of thermally denatured calf thymus DNA (ssDNA) on the poly(methyl methacrylate)-graphite powder microcomposite electrode (PMMA/GME) were observed and investigated. The result indicated that the PMMA/GME showed great promotion of the electrochemical response towards the ssDNA oxidation due to the specific characteristics of the nanostructured interface on the resultant composite electrode. Two irreversible oxidation peaks at +1.04 and +0.76 V with obvious negative movement of oxidation potential and increase of the oxidation current (vs. Ag/AgCl) were observed on the PMMA/GME, which corresponded to the oxidation of adenine and guanine residues in the ssDNA molecules. Therefore, detection of ssDNA was then performed at the PMMA/GME. Under the optimal conditions, a good linear relationship was obtained between the oxidation peak currents of guanine or adenine residues and the ssDNA concentration in the range of 5.9 × 10(-3) to ca. 1.1 mg mL(-1) with a detection limit of 1.0 µg mL(-1). This PMMA/GME exhibits some outstanding advantages, such as ease of fabrication, high stability, renewable surface, excellent stability, mechanical rigidity and high electrochemical reactivity, which holds huge promise for further DNA biosensor design.

First-line therapy for chronic graft-versus-host disease that includes low-dose methotrexate is associated with a high response rate.

We report the results of low-dose methotrexate (MTX) as first-line therapy mostly in combination with other immunosuppressive agents in patients with chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Between November 2001 and March 2008, 86 patients with cGVHD after allo-HSCT received low-dose MTX therapy until a complete or partial response (CR, PR) was achieved, or until treatment failure or intolerable side effects were found. The median time from HSCT to the start of MTX was 154 (range: 80-993) days. The median number of MTX administrations was 4 (range: 2-18). The overall response rate among all enrolled patients was 83% (71 of 86 patients). The response rate for GVHD involving various organs was 90% (45 of 50) in the skin, 75% (39 of 52) in the liver, 42% (5 of 12) in the mouth, 3 of 7 in the eye, and 2 of 2 in the gut. In addition, MTX treatment allowed for a significant reduction in the prednisone dosage (median 90%) from 20 (2.5-100) mg at the start of MTX administration to 5 (0-30) mg 1 month after MTX was last used. Multivariate analysis showed that the only significant factor related to higher CR rate was sole organ involvement (P = .007). Grade 3 toxicities occurred in only 3 patients presenting cytopenias or oral mucositis. From this analysis, MTX appears to be a well-tolerated, effective, and inexpensive agent when used as a first-line treatment in combination with other immunosuppressive agents for cGVHD, especially for skin or sole organ involvement without concomitant thrombocytopenia.

[Preparation and drug releasing property of curcumin nanoparticles].

OBJECTIVE: To prepare curcumin nanoparticles and evaluate the in vitro release of curcumin. METHODS: The chitosan-graft-vinyl acetate copolymers were synthesized by free radical polymerization. Curcumin nanoparticles were synthesized by ultrasonic irradiation. The encapsulation efficiency of the nanoparticles and the in vitro release of curcumin were studied. RESULTS: The nanoparticles were discrete and uniform spheres, covered with positive charges. The encapsulation efficiency of nanoparticles was up to 91.6%. The in vitro release profile showed the slower release rate of curcumin. CONCLUSION: The methods is simple. The nanoparticles possess good physical performance and sustained release character in vitro.

An ultrasensitive ratiometric electrochemiluminescence immunosensor combining photothermal amplification for ovarian cancer marker detection.

Signal amplification strategies play important functions in the development of highly sensitive electrochemiluminescence (ECL) immunosensing system. Herein, a photothermal enhanced ratiometric ECL immunosensor was proposed for the detection of human epididymis protein 4 (HE4), an ovarian cancer biomarker. Mesoporous SiO2 (ms-SiO2) and carbon nanohorns (CNHs) was served as carrier of ECL emitter carbon nitride nanosheet (g-C3N4) and anodic ECL emitter polymer dots (Pdots), respectively. The large specific area of ms-SiO2 and CNHs improved the loading capacity of g-C3N4 and Pdots, enhancing ECL signals. Furthermore, CNHs was innovatively utilized as thermal convert unit to increase the electrode surface temperature, which benefited from its extraordinary photothermal property at 808 nm that can convert laser energy into heat for elevating the temperature, further amplified ECL signal. The delicately designed ECL immunosensor exhibited excellent sensitivity to HE4 detection with wide linear range from 1.0 × 10-5 to 10 ng/mL and low detection limit of 3.3 × 10-6 ng/mL. This work not only provided an effective way to develop highly sensitive ECL immunosensor but could attract more attention on the application of photothermal material in the ECL field.

Titanium clasp fabricated by selective laser melting, CNC milling, and conventional casting: a comparative in vitro study.

PURPOSE: This study aimed to investigate the effects of selective laser melting (SLM), milling methods, and casting on the behavior of titanium clasp. METHODS: The clasp and its die simulating the molar were designed using 3D software. Clasp specimens were fabricated using SLM approaches (SLM Ti) and computerized numerical control (CNC) milling technology (Milling CPTi). Cast clasps of the same forms were also prepared as controls using titanium alloy powder (Cast Ti) and commercial pure titanium (Cast CPTi), following the conventional casting methods. The surface roughness and accuracy of clasps were analyzed. The changes in retentive force and permanent deformation were measured up to 10,000 insertion/removal cycles. One-way analysis of variance and Tukey's test or Kruskal-Wallis H test were performed for data analysis and comparisons. RESULTS: The Milling CPTi clasps had a smoother inner surface than the other groups (p<0.05). The accuracy of the inner surface showed no significant difference among the groups, whereas that of the outer surface showed significant differences (p<0.05). The SLM Ti clasp had significantly higher retentive forces than the other groups (p<0.05), but it rapidly reduced after 2000 insertion/removal cycles until the fracture of all specimens was at 4000 cycles. The Milling CPTi clasps had more permanent deformation, but the rate of reduction of retentive force was only 9.5% (at 10,000 cycles). CONCLUSIONS: Milling has the potential to replace casting for fabricating removable partial denture (RPD) titanium clasps. However, SLM should be further improved for fabricating RPD titanium clasps before clinical application.

[Effect of different root control attachments on the mesially movement of upper molar with plastic aligner].

PURPOSE: Three-dimensional (3D) finite element analysis (FEA) was used to explore the mechanical effect of the upper molar with different root control attachment in plastic aligner-based orthodontic technology. METHODS: A three-dimensional(3D) finite element model was derived from a cone-beam CT(CBCT) scan data and then built in the software of Mimics, Geomagic, Solidworks and Ansys. A model with an upper left first molar and its periodontal apparatus, different types of light-cured composite attachments and thermoformed plastic aligners were constructed. Four models were constructed: model A without composite attachments, model B with vertical rectangular attachment, model C with one optimized semiterete attachment, model D with two optimized semiterete attachments. Four FE models were used to analyze the effects of initial force system and displacement pattern of the molar in plastic aligner-mediated simulating mesial movement with different attachments. The initial tooth displacement, tension-compression pattern at the PDL and Von Mises stress in mesial alveolar fossa of different FE models were compared. RESULTS: In model D with two optmisied semiterete attachments, the compression stress of mesial periodontal ligament and the stress of mesial alveolar fossa were most widely distributed. The rotation axis was closest to the apical foramen, the root control effect of the molar was the best. In model B with buccal vertical rectangular, the compression stress of mesial periodontal ligament closer to buccal side was obviously wider than that of the palate. The rotation center of the buccal side was obviously near the apical foramen than the palatal side. The effect of buccal root control was better than that of palatal side. In model C with one semiterete optimized attachment, the stress pattern of the periodontal ligament in the mesial surface and the displacement patterns were not significantly different from those of model A with no attachments, but the maximum displacement of model C was greater than that of model A. CONCLUSIONS: The addition of attachments increased the molar's movement efficiency. Two semiterete optimized attachments on the buccal side had the best root control effect during mesial movement of the molar, but all attachments achieved tipping movement of the molar.

[Expression of Forkhead boxO1 and Runt-related transcription factor 2 in periodontal tissue during orthodontic movement of teeth in rats].

PURPOSE: To investigate the expression of FoxO1 and Runx2 in periodontal tissue and their effect during orthodontic teeth movement(OTM) in rats. METHODS: Forty 8-week old male Sprague-Dawley (SD) rats were used to establish animal models of orthodontic teeth movement and divided into 5 groups randomly. The right side of jaws of each rat was set as experimental side, and the left side as control side. At 1, 3, 5, 7, 14 d after orthodontic treatment, the rats were sacrificed and the maxillary bone containing the first molar was dissected. H-E staining and immunohistochemical staining were used to detect the morphological changes, the expression of FoxO1 and Runx2 of the periodontal tissue at different points. Computer image analysis was used to evaluate the expression of FoxO1 and Runx2 in the periodontal tissues of the rats. The differences were analyzed by using SPSS19.0 software package. RESULTS: The expression of FoxO1 in periodontal ligament was mainly in osteoblasts and cementoblasts; and the expression of Runx2 was mainly in osteoblasts, fibroblasts and cementoblasts. In the experimental group,the expressions of FoxO1 and Runx2 in the periodontal tissues of rats increased significantly, reached the peak within 3-5 days, then decreased. There was no significant difference between the experimental group and the control group at 14th day (P>0.05), but significant difference was found between other group and control group (P<0.05). CONCLUSIONS: FoxO1 and Runx2 play a role in the reconstruction of periodontal tissue during orthodontic movement of teeth, and they are mainly involved in the process of osteoblast formation and bone formation.