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Precipitation and wind, as the main external erosion forces in wind–water erosion crisscross regions, have profound impacts on water and soil loss. Meanwhile, with the intensification of climate change and human activities, the variation characteristics and risks caused by erosion forces need to be reassessed. In this study, we explored the time-varying characteristics, differences in action period and spatial distribution, and temporal evolution of risk for the compound events of two erosion forces, including precipitation and wind, in the Pisha sandstone area, one of the most seriously eroding and difficult-to-control areas in the Loess Plateau. The results indicated that: (1) the stationarity of regional precipitation was not destroyed, but the mean change existed in the five subseries divided by the detected change points in wind; (2) wind acted earlier than precipitation and increased from southeast to northwest, while precipitation did the opposite; and (3) precipitation-led erosion has become the main erosion type in this area. The above results reveal the evolution and dominant types of regional external erosion forces in a changing environment and thus have implications for regional erosion studies and policy adjustments.

This study explored the different influences of technical indicators on match results in different stages of football league play. Sample data from 2400 Chinese Super League matches during 2010–2019 were divided into three season stages according to round sequence: the early stage (1–10 rounds), the middle stage (11–20 rounds), and the late stage (21–30 rounds). A two-way, fixed-effect ordered logit model was then constructed and used, together with Fisher’s combination test, to compare regression results. The study results showed that: (1) when controlling for other variables, as the league progresses, an increase in goals will gradually increase the possibility of better match results, and this increase shows significant differences between the early and late stages ( p

In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with cast post and core with two kinds of surface treatment technology and acid etching preparation on the dentinal surface. Sixty-four recently extracted human single-rooted first premolars were endodontically treated and sectioned approximately 1.5 mm above the cementoenamel junction to remove the coronal portion. Each specimen received a cast post, core build-up and a metal alloy crown restoration. All teeth were randomly divided into the smooth surface post, core repair group, the sand blasting surface post, and core repair group, each group was divided into 10 s, 30 s, 60 s acid corrosion treatment group and control group. In acid test groups, an acid etching solution was applied for 10, 30 and 60 seconds, respectively, to the root canal wall surface. Each specimen was embedded in acrylic resin block and tested in an electronic universal testing machine. Fracture loads results showed that canal acid etching could increase teeth fracture resistance strength both in smooth groups and sandblasting group, and achieved the best effect when acid etching for 30 s. Sand spray treatment on the surface of the cast metal post can improve the flexural strength of the teeth after postcrown restoration. Acid etching on the root canal wall surfaces and sand spray treatment on the surface of the cast metal post can improve the flexural strength of the root after post-crown restoration. Therefore, these two methods could be used to strengthen the tooth fracture resistance, and maintain the long-term therapeutic effect of cast post and core restoration.

Constructing self-supported nanostructures on conductive substrates is an effective strategy to achieve non-enzymatic glucose sensors that possessing good reusability, reproducibility and stability. In the present study, vertical aligned CuO nanosheets on Cu foam are prepared with an in-situ electrochemical process including Cu-based metal-organic framework growing and subsequent electrochemical conversion. The scanning electron microscope results reveal that the totally electrochemical preparation guarantees the CuO nanosheets homogeneously free-standing on the Cu foam. The vertical aligned architecture endows the CuO/Cu electrodes good performances when using them as non-enzymatic glucose sensors, including a detection limit of 330 nM and a sensitivity of 33.95 mA cm−2 mM−1. We suggest that the facilitated ion transport in the vertical aligned architecture and the good conductivity originated from the totally electrochemical synthesis are responsible for the marked performances. More importantly, the good controllability of electrochemical preparation leads to remarkable reusability, reproducibility and stability of the electrodes, verified by multi-test of one electrode, consistency of multi-electrode and periodic test of one electrode in a long term. The practical detection of CuO/Cu electrodes on serum samples indicates the results are basically consistent with the clinical reports from hospital, further indicating their attractive potential in practical application.

The objective of this finite element study was to investigate the effect of different framework designs, framework materials, and bone densities on the stress distribution of fixed implant-supported prostheses for edentulous mandibles.Under the condition of 2-mm cortical bone, 16 models were created in the edentulous mandible to simulate different framework designs (1-piece or 3-piece frameworks) with different framework material (pure titanium, zirconia, polyetheretherketone, or carbon fiber-reinforced polyetheretherketone) in-high or low-density trabecular bone. Then, vertical loading and oblique loading at 75° were applied to the anterior and posterior regions. The stress distribution and stress concentration region of implant and peri-implant bone with different combinations were compared by finite element analysis.The use of the 1-piece zirconia framework in high-density trabecular bone improved stress distribution on implants and peri-implant bone. The region of stress concentration is located in the buccal cervix of the distal implants and the distobuccal portion of the cortical bone in all models. To improve the stress distribution on fixed implant-supported dentures for edentulous mandibles, the 1-piece framework and zirconia represent the better combination.Under the condition of 2-mm cortical bone thickness, the full-arch zirconia framework had minimum von Mises stress on implants and peri-implant bone in all models, and high trabecular bone density greatly decreased the stress on cortical bone.

Gestational diabetes mellitus (GDM) is a serious life‑threatening disease that affects the mother and fetus. However, the pathogenesis of GDM is still unclear. microRNAs (miRs) play vital roles in the regulation of various cell functions. The present study aimed to investigate the effects of miR‑875‑5p and thioredoxin reductase 1 cytoplasmic (TXNRD1) in GDM rats and analyze the associated underlying mechanism. A GDM rat model was induced using an intraperitoneal injection of streptozotocin. miR‑875‑5p knockdown plasmids or TXNRD1 knockdown plasmids were injected into the rats via the caudal vein. miR‑875‑5p and TXNRD1 expression in the serum were detected using reverse transcription‑quantitative PCR (RT‑qPCR) or western blot (WB) analyses. The fasting blood‑glucose (FBG), fasting serum insulin, triglyceride and high density lipoprotein levels were detected by specific commercial kits. The inflammatory response and the induction of oxidative stress were analyzed by assessing the expression of associated markers via WB, RT‑qPCR or commercial kits. The pancreatic and placental injuries were detected by hematoxylin and eosin staining. The results indicated that miR‑875‑5p expression levels were downregulated, whereas TXNRD1 levels were upregulated in GDM rats compared with normal pregnancy rats. miR‑875‑5p significantly regulated TXNRD1 expression in GDM rats. miR‑875‑5p silencing notably reduced FBG and insulin resistance, which was accompanied by reduced expression levels of blood lipid and pro‑inflammatory markers as well as reduced oxidative stress. However, the effects of miR‑875‑5p could be reversed by TXNRD1 silencing. Therefore, the present study indicated that miR‑875‑5p regulated IR and inflammation by targeting TXNRD1 in GDM rats. miR‑875‑5p and TXNRD1 may be considered as potential targets for treating GDM.

Purpose This study aims to evaluate the clinical, occlusal and biomechanical performance of 1-piece and 3-piece designs for implant-supported fixed dentures in the edentulous mandible. Materials and methods A total of 65 patients with edentulous mandibles who underwent fixed implant-supported restorations were recruited and subsequently assigned to 1 of 2 groups based on the framework design (1-piece or 3-piece). The participants underwent clinical and occlusal examination using a periodontal probe, T-Scan III system, and electromyography 12 months after prosthesis delivery. Two mandibular finite element models were created to evaluate stress values and their distribution during function. Results Ninety-five point four percent (n = 62) of participants in the follow-up period underwent clinical and occlusal examination after prosthesis delivery. Clinical examination revealed a trend towards increased inflammation around the implants in the 1-piece prostheses. Occlusal parameters indicated that the 1-piece design was superior for the masticatory system than the 3-piece design. Biomechanical analysis revealed the highest stress values in the posterior region of the 3-piece design. Conclusions On the basis of ease of ensuring oral hygiene, when compared to the 3-piece design, the 1-piece framework design might be the superior therapy for restoring an edentulous mandible, based on occlusal and biomechanical outcomes.

Inclined distal implants with posterior framework cantilevers are an alternative to straight implants for the treatment of edentulous jaws, avoiding grafting procedures and utilizing pre-existing bone. However, little is known about the implant, framework, and peri-implant bone stresses exerted by this design.The purpose of this finite element analysis study was to assess the biomechanical properties of the inclined versus straight design, with different implant framework material to generate implant-supported complete-arch fixed mandibular prostheses.A finite element model of the edentulous mandible was generated by using 4 implants in 2 distinct configurations: the inclined design and the straight design. Different framework materials were tested: pure titanium, cobalt-chromium alloy, type IV gold alloy, zirconia, polyetheretherketone (PEEK), and carbon fiber-reinforced polyetheretherketone (CFR-PEEK). A 300-N load at a 75-degree angle was applied to the occlusal plane from the lingual side of the buccal cusps of the 2 premolars and the first molar teeth. Subsequently, stresses on the implant, surrounding bone, and framework were measured and analyzed quantitatively and qualitatively.In terms of implant configurations, the inclined design demonstrated less stress on the posterior cortical bone, implants, and framework than the straight design. Comparing the framework materials, zirconia and metal exhibited reduced cortical bone and implants stresses but elevated framework stress when compared with the polymeric frameworks.From a biomechanical viewpoint, in edentulous patients with excessive posterior alveolar bone resorption, the inclined design exhibited more favorable stress distribution around the posterior implants than the straight design. In implant-supported complete-arch fixed mandibular prostheses, zirconia and metal, particularly cobalt-chromium alloy, distributed the stresses more effectively to the implants and supporting bone than polymeric materials.

Non-enzymatic glucose sensors are attracting significant attention owing to their low cost, storage convenience and reusability; however, their poor anti-interference caused by their weak selectivity towards glucose limits their practicability. In the present study, a MIL-53(NiFe) metal-organic framework (MOF) was prepared on Ni foam to serve as a self-supported electrode for non-enzymatic glucose detection. Due to the abundant active sites in the MIL-53(NiFe) MOF and its good stability in an alkaline solution, the sensors exhibited a high sensitivity (41.95 mA mM-1 cm-2) and a low detection limit (0.67 μM). Moreover, the molecular sieve effect of the MIL-53(NiFe) MOF led to a remarkable anti-interference ability, even at the interference concentrations of up to 20% glucose, a higher value than that in human serum. In addition, a heat treatment was carried out to remove the residual terephthalic acid in the MOF tunnels, and this promoted the detection linear range to 2-1600 μM. The reusability, reproducibility and long-term stability of the sensors were also studied, and the results implied good practicability of the MIL-53(NiFe) MOF-based sensors. Furthermore, the good practicability of the sensors was verified by testing human serum samples. The results showed the relative standard deviation of 2.73% from the hospital results, and the standard recovery was nearly 100%.

Periodontal ligament stem cell (PDLSC)-based tissue engineering is an important method for regenerating lost bone in periodontitis. Maintaining or enhancing the osteogenic differentiation of PDLSCs, as well as enhancing the resistance of PDLSCs to oxidative stress, is necessary in this process. As a common hypoglycemic drug, metformin has been reported to have multiple effects on cell functions. This study found that low concentrations of metformin did not affect cell proliferation but did inhibit adipogenic differentiation and promote osteogenic differentiation of PDLSCs. This positive effect was associated with activation of Akt signaling by metformin. Moreover, applying metformin as either a pretreatment or co-treatment could reduce the amount of reactive oxygen species, enhance antioxidant capacity, and rescue the cell viability and osteogenic differentiation that were negatively affected by H2O2-induced oxidative stress in PDLSCs. In addition, metformin was found to activate the Nrf2 signaling pathway in PDLSCs, and knockdown of Nrf2 by siRNA impaired the protective effect of metformin. Taken together, these results indicate that metformin not only promotes osteogenic differentiation of PDLSCs, but also protects PDLSCs against oxidative stress-induced damage, suggesting that metformin could be potentially useful in promoting PDLSC-based bone regeneration in the treatment of periodontitis.

Wound healing after tooth extraction or dental implantation is an intricate process involving a series of biological events involving tissue repair and remodeling in response to injury. The healing process is greatly influenced by a variety of systemic and local factors. Wound failure remains a clinical problem that causes pain, dry socket, or other complications, and it can even affect dental implants and prosthodontic treatment. Numerous studies have demonstrated that stromal-cell-derived factor 1 (SDF-1) is an active chemokine for repair of injured blood vessels, and the SDF-1/CXCR4 signaling pathway might play an important role in repairing injured tissue by promoting host-cell recruitment and angiogenesis. In this article, the effectiveness of SDF-1 for enhancing wound healing is evaluated. It's hypothesized that increasing localized concentration of SDF-1 will contribute to the acceleration of wound healing after tooth extraction or dental implantation treatments, especially in diabetic and elderly patients.

Representing a new type of biodegradable cationic block copolymer, well-defined poly(ethylene glycol)-block-cationic polylactides (PEG-b-CPLAs) with tertiary amine-based cationic groups were synthesized by thiol-ene functionalization of an allyl-functionalized diblock precursor. Subsequently the application of PEG-b-CPLAs as biodegradable vectors for the delivery of plasmid DNAs (pDNAs) was investigated. Via the formation of PEG-b-CPLA:pDNA nanocomplexes by spontaneous electrostatic interaction, pDNAs encoding luciferase or enhanced green fluorescent protein were successfully delivered to four physiologically distinct cell lines (including macrophage, fibroblast, epithelial, and stem cell). Formulated nanocomplexes demonstrated high levels of transfection with low levels of cytotoxicity and hemolysis when compared to a positive control. Biophysical characterization of charge densities of nanocomplexes at various polymer:pDNA weight ratios revealed a positive correlation between surface charge and gene delivery. Nanocomplexes with high surface charge densities were utilized in an in vitro serum gene delivery inhibition assay, and effective gene delivery was observed despite high levels of serum. Overall, these results help to elucidate the influence of charge, size, and PEGylation of nanocomplexes upon the delivery of nucleic acids in physiologically relevant conditions.

This study evaluated the efficacy of implant supported dental restorations in patients with chronic periodontal diseases at various stages within 2 years of completing treatment. 30 patients with periodontal diseases and 30 patients without periodontal diseases were studied. Total counts of 276 implant bodies were divided into group A (patients with periodontal diseases; a total of 149 implants) and group B (patients with healthy periodontium; a total of 127 implants). In group A subjects, periodontitis was treated prior to implant placement. The study focused on patients' modified sulcus bleeding index, modified plaque index, implant mobility index, periodontal probing depth and implant success rate 12 and 24 months after the completion of the treatment. The result show: there were no significant differences in implant success rate between groups A and B; modified sulcus bleeding index scores showed differences between the groups 24 months after treatment; there were no significant differences in other clinical indexes during the study between the groups; there were no significant differences in periodontal probing depth between the groups; modified plaque index and modified sulcus bleeding index were positively correlated in implant supported dental restoration patients with chronic periodontal diseases.

Studying effects of 50 Hz sinusoidal electromagnetic fields (SEMFs) with different intensities on peak bone mass (PBM) of rats may provide a theoretical basis for application of electromagnetic clinical field. 30 female SD rats, 6 weeks of age, were randomly divided into three groups: the control group, 0.1 mT electromagnetic field group (EMFs) and 0.6 mT EMFs. The EMFs groups were treated for 3 h/day. After 8 weeks, we examined their bone mineral densities (BMD) , measured their bone biomechanical properties, and made serum levels of osteocalcin (OC), tartrate-resistant acid phosphatase 5b (TRACP 5b), and histomorphometry. It was found that the BMD (P0.01), maximum mechanical load (P0.01) in the 0.1 mT group were significantly higher than those in the control group, and Yield strength (P0.05), the analyses of serum bone turnover markers and histomorphometric parameters were better than those in the control group (P0.05). However, the 0.6 mT group did not have significantly difference comparing with that in the control group. This study proved that 50 Hz 0.1 mT SEMFs can increased BMD, bone strength, and bone tissue microstructure. Therefore, 50 Hz 0.1 mT SEMFs can improve peak bone mass of rats.

In this paper, through a simple and fast electroless metal deposition route, gold dendritic nanostructures are synthesized in aqueous conditions. The gold dendrites with a threefold symmetric characteristic were built up of numerous nanoparticles roughly 5–10 nm in size. The aggregated nanoparticles spontaneously experience a self-assembly process along crystallographic orientations and finally form a monocrystalline dendrite. An oriented attachment mechanism can be used to explain the nanoparticle-aggregated self-assembly process.

OBJECTIVE: To observe the short-term clinical effectiveness of bone ring graft technique and to summarize the key points of related surgical operation to provide comprehensive clinical guidelines. METHODS: Fifteen patients with severe alveolar bone absorption were selected to receive bone ring grafting and immediate dental implant. Final fixed prostheses were cemented five months after initial implantation. Cone beam CT scans were conducted on all subjects before the procedure, as well as four months post-operation to evaluate alveolar bone height and level of bone height and absorption around the implants. Four to six months after prosthesis installation, each implant's Jemt classification, gingiva attachment, and probing depth (PD) were analyzed. The difference of PD between implants and adjacent teeth, as well as the difference of the bone absorption between labial and lingual sides, was compared. The survival rate of the bone ring and the retention rate of implants were calculated. Complications and patient satisfaction were also investigated. RESULTS: Bone graft survival rate was 94.4% and dental implantation retention rate was 100% four months post-operation. Average bone level increase was (6.06±1.06) mm, average bone absorption was (1.33±0.84) mm, and average bone thickness at the neck of the dental implant body was (6.94±0.73) mm. Approximately 4 to 6 months after crown restoration, average bone level increase was (5.62±1.03) mm, average bone absorption was (1.51±1.02) mm, and average bone thickness at the neck of the dental implant body was (6.77±0.72) mm. The PD around the implant body and the adjacent teeth was statistically insignificant. No major post-operative complication was observed, restorations were successful, and patient satisfaction level was high. CONCLUSION: Bone ring graft technique and immediate dental implantation are relatively simple to perform, and these techniques facilitate reduction in required treatment time. Short-term effect is reliable and satisfactory, whereas long-term outcomes require further follow up and study.

The present research was aimed to investigate the effect of 50Hz, 1. 8mT of sinusoidal electromagnetic fields(SEMFs)on femur tissue cultivation in vitro. The rat femur tissue was isolated from SD rats by method of enzyme digestion, and randomly divided into two groups: SEMFs group and control. The femur tissue of SEMFs groups were exposured under 50Hz 1. 8mT of SEMFs for 1. 5h/time/d, but those in the control groups were without SEMFs treatment. The correlative gene was detected by the Real-time RT-PCR that after SEMFs treatment for 0 (first times treatments is 0 days), 1, 2, 3, 4 and 5d. The alkaline phosphatase (ALP) activity was measured after SEMFs treatment for 3, 6, 9 and 12d respectively. The calcium content was detected after SEMFs treatment for 3, 6, 9 and 12d. The results showed that the OPG and Collagen-1 mRNA expression level was kept at a relatively stable level by SEMFs in the SEMFs group significantly. The Runx-2 mRNA expression level was significantly increased after the SEMFs treatment for 1d and 5d. The ALP activity of femur tissue was significantly increased alter SEMFs treatment for 3d and 9d. The calcium content was higher than untreated groups after SEMFs treatment for 6, 9 and 12d. The SEMFs promoted OPG, Collagen-1, Runx-2 mRNA expression level, ALP activity and calcium content. The result indicated that SEMFs increased the metabolism activity of femur tissues.

The aim of this study is to optimize conditions for labeling human periodontal ligament stem cells (PDLSCs) using enhanced green fluorescent protein (eGFP) infected by lentivirus vector and to obtain PDLSCs with high stable expressed eGFP.PDLSCs were transfected with eGFP by lentivirus vector for 48 h via different multiplicity of infection (MOI) (25, 50, 100, 200 and 400) and the infection efficiency were analyzed by both fluorescent microscope and flow cytometry. The proliferation rate of infected PDLSCs was evaluated by MTT. The infected PDLSCs were further for detection of pluripotent, differentiation ability and alkaline phosphatase (ALP) expression ability.The infection efficiency for each group were 44.7%, 60.9%, 71.7%, 85.8% and 86.9% respectively. Proliferation of PDLSCs was not affected when MOI was below 200; however, at MOI 400, the proliferation ability was affected compared with control group. The pluripotent and ALP abilities of PDLSCs were not changed by the infection.Infection for 48 h at MOI 200 is optimal for labeling PDLSCs with eGFP using lentivirus vector, and the proliferation and differentiation abilities of PDLSCs are not affected obviously.

To establish three-dimension finite element model of mandible with two kinds of Replace implant, and to study stress of implant and abutment.The data of components of the dental implant was measured, cross section of the mandible was scanned by spiral CT and image reconstruction technique was conducted. Three-dimension finite element analysis software UG and MSC. Marc/Mentat were used to built the conjunction model and bone model of two implant systems. Axial loading (200N) and 30 degrees oblique loading (100N) were applied on the models respectively, the stress distribution patterns of the implant and abutment of two implant systems were analyzed.The peak stress district was concentrated on the structure of the implant cervix, which was more obviously displayed on the Replace Select implant. The peak stress of oblique loading was higher than that of axial loading. The peak stress on the implant cervix of Replace Select implant was higher than that of Replace External Hex implant in all loadings.To Replace Select especially, oblique force should be avoided on clinical practice in case of the implant fracture.