Effect of Glycolipids Application Combined with Nitrogen Fertilizer Reduction on Maize Nitrogen Use Efficiency and Yield.

Microbial-driven N turnover is important in regulating N fertilizer use efficiency through the secretion of metabolites like glycolipids. Currently, our understanding of the potential of glycolipids to partially reduce N fertilizer use and the effects of glycolipids on crop yield and N use efficiency is still limited. Here, a three-year in situ field experiment was conducted with seven treatments: no fertilization (CK); chemical N, phosphorus and potassium (NPK); NPK plus glycolipids (N+PKT); and PK plus glycolipids with 10% (0.9 N+PKT), 20% (0.8 N+PKT), 30% (0.7 N+PKT), and 100% (PKT) N reduction. Compared with NPK, glycolipids with 0-20% N reduction did not significantly reduce maize yields, and also increased N uptake by 6.26-11.07%, but no significant changes in grain or straw N uptake. The N resorption efficiency under 0.9 N+PKT was significantly greater than that under NPK, while the apparent utilization rates of N fertilizer and partial factor productivity of N under 0.9 N+PKT were significantly greater than those under NPK. Although 0.9 N+PKT led to additional labor and input costs, compared with NPK, it had a greater net economic benefit. Our study demonstrates the potential for using glycolipids in agroecosystem management and provides theoretical support for optimizing fertilization strategies.

Study of the radiofrequency-induced heating inside the human head with dental implants at 7 T.

Conductive dental implants are commonly used in restorative therapy to replace missing teeth in patients. Ensuring the radiofrequency (RF) safety of these patients is crucial when performing 7 T magnetic resonance scans of their heads. This study aimed to investigate RF-induced heating inside the human head with dental implants at 7 T. Dental implants and their attachments were fabricated and integrated into an anatomical head model, creating different measurement configurations (MCs). Numerical simulations were conducted using a 7 T transmit coil loaded with the anatomical head model, both with and without dental implants. The maximum temperatures inside the head for various MCs were computed using the maximum permissible input powers (MPIPs) obtained without dental implants and compared with published limits. Additionally, the MPIPs with dental implants were calculated for scenarios where the temperature limits were exceeded. The maximum temperatures observed inside the head ranged from 38.4°C to 39.6°C. The MPIPs in the presence of dental implants were 81.9%-97.3% of the MPIPs in the absence of dental implants for scenarios that exceeded the regulatory limit. RF-induced heating effect of the dental implants was not significant. The safe scanning condition in terms of RF exposure was achievable for patients with dental implants. For patients with conductive dental implants of unknown configuration, it is recommended to reduce the input power by 18.1% of MPIP without dental implants to ensure RF safety.

Low frequency pulsed electromagnetic fields exposure alleviate the abnormal subchondral bone remodeling at the early stage of temporomandibular joint osteoarthritis.

BACKGROUND: Temporomandibular joint osteoarthritis (TMJOA) is characterized by abnormal subchondral bone remodeling and cartilage degeneration. As a non-invasive biophysical technology, pulsed electromagnetic field (PEMF) treatment has been proven to be efficient in promoting osteogenesis. However, the potential bone protective effect and mechanism of PEMF on abnormal subchondral bone remodeling in TMJOA are unknown. METHODS: Unilateral anterior crossbite (UAC) was used to create TMJOA model in rats, and 17ß-estradiol (E2) were injected daily to mimic patients with high-physiological levels of estrogen. Mouse osteoblast-like MC3T3-E1 cells treated with recombinant murine IL-1ß was used to establish inflammatory environment in vitro. The treatment group were subjected to PEMF (2.0mT, 15 Hz, 2 h/d). Micro-CT scanning, histological staining, real-time PCR and western blotting assays were preformed to observe the changes in the subchondral bone. RESULTS: Abnormal resorption of subchondral bone induced by UAC, characterized by decreased bone mineral density, increased osteoclast activity and expression of osteoclast-related factors (RANKL) and down-regulated expression of osteogenesis-related factors (OPG, ALP, Runx2 and OCN) at the early stage, could be reversed by PEMF exposure, which was similar to the effect of estrogen. In addition, PEMF exposure and E2 supplement may have a synergistic effect to some extent. Moreover, PEMF exposure could promote the ALP activity and osteogenic mineralization ability of MC3T3-E1 cells. PEMF promoted the expression of factors related to Wnt/ß-Catenin signal pathway both in vivo and in vitro. CONCLUSIONS: Appropriate PEMF exposure have a protective effect on subchondral bone in TMJOA at early stage, in which canonical Wnt/ß-Catenin pathway may be involved. PEMF may be a promising biophysical approach for early intervention of TMJOA in clinic.

Effect of Different Repair and Reconstruction Methods Combined with Psychological Intervention on Quality of Life and Negative Emotion in Patients with Oral Cancer.

Objective: To explore the effects of different repair and reconstruction methods combined with psychological intervention on the quality of life and negative emotion of patients with oral cancer. Methods: 180 patients with oral cancer treated in our hospital from January 2018 to January 2020 were randomly divided into group A, group B, and group C, with 60 cases in each group. Group A and group B were repaired with submental island flap and free flap, respectively. Group C was divided into two groups, and group C was treated with routine nursing intervention. Group A and group B received psychological intervention. Clinical symptom scores, complication rate (CR), quality of life (according to the University of Washington quality of life questionnaire, UW-QOL), and negative emotion scores were compared. Results: After intervention, the clinical symptom scores and negative emotion scores of groups A and B were lower than those of group C (P < 0.001), as well as the CR (P < 0.05), and the UW-QOL scores of groups A and B were higher than those of group C (P < 0.05), but no significant differences in these aspects were presented between group A and group B (P > 0.05). The main factors affecting quality of life were swallowing/chewing, language, and saliva in group A; swallowing/chewing, language, and taste in group B; and appearance, swallowing/chewing, emotion, and language in group C. Conclusion: Psychological intervention can improve the mental state of patients with oral cancer after operation, optimize the effect of operation, and improve the quality of life. As the effect of psychological intervention on patients undergoing different repair and reconstruction methods is similar, it should be given according to patients' actual condition in the clinic.

Impacts of the COVID-19 epidemic on the department of stomatology in a tertiary hospital: A case study in the General Hospital of the Central Theater Command, Wuhan, China.

OBJECTIVE: The impact of the worldwide COVID-19 pandemic on the dental community is evident. Dental education programmes and academic activities have suffered from the ramifications of the pandemic. This study aimed to depict the impacts of the COVID-19 epidemic on the clinical services and academic activities in the department of stomatology of a tertiary hospital in Wuhan, China. METHODS: We obtained historical data of the Department of Stomatology from the Health Information System of the General Hospital of Central Theater Command, Wuhan, China between January 2018 and June 2020. Mean, standard deviation and median with interquartile range were used to summarize the variables. Line plots were used to illustrate the temporal trend. The Kruskal-Wallis equality-of-populations rank test was used to compare the difference between groups. RESULTS: A significant decrease was noted in the monthly average number of patients seeking outpatient services for the year 2020, which were decreased by two-thirds from 2018 to 2020. The number of emergency cases also decreased significantly by 57.6% in 2020. The monthly number of teaching hours decreased from 3.8 ± 1.5 in 2018 and 4.7 ± 1.4 in 2019 to 1.7 ± 1.9 in 2020. The number of interns also decreased by more than 77.0% in 2020. CONCLUSIONS: The impacts of COVID-19 in the stomatology clinic were significant with notable decreases in clinical services and education offered to the stomatology students. There is a need to find solutions to keep as many dental professionals as needed remaining on the frontline of oral health care.

Engineering of axially vascularized bone tissue using natural coral scaffold and osteogenic bone marrow mesenchymal stem cell sheets.

INTRODUCTION: Blood supply remains one of the obstacles to large bone tissue engineering. This study aimed to generate vascularized bone tissue by inducing axial vascularization into a construct combining natural coral scaffold and a bone marrow mesenchymal stem cells (BMSCs) sheet. MATERIAL AND METHODS: Isolated BMSCs were cultured to form an osteogenic cell sheet using a continuous culture method. Natural coral scaffolds were prepared into customized shape with a cylinder of 20 mm length, 8 mm in outer diameter and 5 mm in inner diameter. Then, the freed superficial inferior epigastric vessel of rabbits was first wrapped with a cell sheet, and then inserted into the central passage of the scaffold, after being wrapped with another cell sheet, the complexes were implanted subcutaneously into a rabbit groin area. In contrast, the sheet-scaffold construct that implanted into groin subcutaneous area of the other side of the same rabbit with the distal end of the blood vessel was ligated, which was considered as control. New bone and vascularization formation were evaluated at 12 weeks postoperatively. RESULTS: The volume of new bone formation and amount of capillary infiltration in the vascular circulation group were significantly greater than that in the vascular ligation group, which suggested that insertion of axial vessels could significantly promote angiogenesis and osteogenesis of the tissue-engineered bone. CONCLUSIONS: These findings indicate that inserting an arteriovenous bundle into the constructs of mesenchymal stem cell sheet and coral has great potential for clinical applications to repair large bone defects.

Effect of Shear Strain Rate on Microstructure and Properties of Austenitic Steel Processed by Cyclic Forward/Reverse Torsion.

In this work, commercial AISI 304 stainless steel rods were subjected to cyclic forward/reverse torsion (CFRT) treatments at low-speed and high-speed torsion at room temperature. Microstructures in the core and surface layers of the CFRT-treated samples were systematically characterized. Results show that the CFRT treatment can introduce martensite phase on the surface of the rods via strain-induced martensitic transformation. High-speed twisting is more effective in inducing martensite in the surface layer compared to low-speed twisting. During the stretching process, the overall strain-hardening behavior of the gradient material is related to the content of its gradient defects. Higher gradient martensite content results in a higher surface hardness of the material, but less overall tensile properties. The effect of twisting speed on torsion behavior and the strain-hardening mechanisms in tensile of the gradient structured steels was also addressed.

miR-26b is downregulated in human tongue squamous cell carcinoma and regulates cell proliferation and metastasis through a COX-2-dependent mechanism.

MicroRNAs (miRNAs) are important gene regulators that play a profound role in tumorigenesis. Previous studies have revealed that miR-26b is downregulated in a wide range of malignant tumors and plays an important role in the regulation of carcinogenesis and tumor progression. In the present study, we revealed that miR-26b expression was decreased in human tongue squamous cell carcinoma and was associated with clinical stage, lymph node metastasis and survival prognosis. Ectopic expression of miR-26b suppressed the proliferation and metastasis of human tongue squamous cell carcinoma cells. Using a luciferase reporter assay, combined with western blot analysis results, we identified PTGS2 (prostaglandin-endoperoxide synthase-2, encoding COX-2) as the functional target of miR-26b. Specific inhibition of COX-2 activity by nimesulide further confirmed that miR-26b was able to regulate the cell proliferation and metastasis of the human tongue squamous cell carcinoma cells through a COX-2-dependent mechanism. Taken together, these results suggest that miR-26b serves as a tumor suppressor by targeting COX-2 and calls for the use of miR-26b as a potential therapeutic tool for human tongue squamous cell carcinoma, where COX-2 is often hyperactivated.

Intraoral approach for surgical removal of a nail in penetrating maxillofacial injury.

An unusual case of penetrating maxillofacial injury caused by a nail gun is presented. In this case, the foreign body was shot into the left infratemporal fossa and maxillary sinus through the left cheek. We used an intraoral approach that allowed precise localization of the point of the infratemporal surface of the maxilla through which the nail penetrated the maxillary sinus. The nail was successfully removed and the patient was discharged with complete recovery. The details of the surgical approach as well as localization techniques are described. Different approaches to remove the nail as well as the advantages and disadvantages of each approach are discussed.

Gorham-Stout syndrome affecting the left mandible: A case report.

Gorham-Stout syndrome is an extremely rare condition in which spontaneous, progressive resorption of bone occurs. Owing to its low incidence and variable clinical presentation, the diagnosis is often missed or delayed, and at present, there are no specific guidelines for its treatment. We present the case of a 20-year-old male diagnosed with Gorham-Stout syndrome with involvement of the left mandible, and discuss its diagnostic and therapeutic features.

[Application of cone-beam computed tomography in the diagnosis and treatment of external root resorption of adjacent teeth caused by impacted teeth].

OBJECTIVE: This study aims to investigate the diagnosis and treatment of external root resorption of adjacent teeth caused by impacted teeth via cone-beam computed tomography (CBCT). METHODS: A total of 19 teeth from 15 patients with uncertain external root resorption caused by an adjacent impacted tooth were examined from January 2011 to December 2011. All teeth with uncertain external root resorption were scanned by CBCT. Three dimensions reconstruction were the conducted to determine the location and extent of resorption. RESULTS: In all cases, CBCT identified the accurate location and extent of external root resorption caused by adjacent impacted teeth. Furthermore, the technique provided impacted teeth location in three dimensions, including the relation between the impacted teeth and surrounding vital structures. CONCLUSION: CBCT can provide direct and accurate images of the location and extent of external root resorption, as well as the location of the adjacent impacted teeth in three dimensions. Therefore, the proposed technique provides reliable information for clinical diagnosis and treatment.

Prefabrication of axial vascularized tissue engineering coral bone by an arteriovenous loop: a better model.

The most important problem for the survival of thick 3-dimensional tissues is the lack of vascularization in the context of bone tissue engineering. In this study, a modified arteriovenous loop (AVL) was developed to prefabricate an axial vascularized tissue engineering coral bone in rabbit, with comparison of the arteriovenous bundle (AVB) model. An arteriovenous fistula between rabbit femoral artery and vein was anastomosed to form an AVL. It was placed in a circular side groove of the coral block. The complex was wrapped with an expanded-polytetrafluoroethylene membrane and implanted beneath inguinal skin. After 2, 4, 6 and 8 weeks, the degree of vascularization was evaluated by India ink perfusion, histological examination, vascular casts, and scanning electron microscopy images of vascular endangium. Newly formed fibrous tissues and vasculature extended over the surfaces and invaded the interspaces of entire coral block. The new blood vessels robustly sprouted from the AVL. Those invaginated cavities in the vascular endangium from scanning electron microscopy indicated vessel's sprouted pores. Above indexes in AVL model are all superior to that in AVB model, indicating that the modified AVL model could more effectively develop vascularization in larger tissue engineering bone.

Modified approach to construct a vascularized coral bone in rabbit using an arteriovenous loop.

The most important factor for the survival of thick three-dimensional tissues is the degree of vascularization. In this study, a modified arteriovenous loop (AVL) model was developed to prefabricate an axial vascularized tissue-engineered coral bone. In group A (n = 28), an arteriovenous fistula between rabbit femoral artery and vein was anastomosed to form an AVL. The AVL was placed in a coral block (6 x 8 x 10 mm (3)) as a vascular carrier. The complex was wrapped with polytetrafluoroethylene membrane and implanted subcutaneously. In group B (n = 20), there was no vascular carrier, and the same dimensional coral was directly implanted beneath inguinal skin. After 2, 4, 6, and 8 weeks, the rabbits were perfused with heparinized saline (for scanning electron microscopy), India ink (for histological examination), and ethylene perchloride (for vascular casts) via the abdominal aorta. In group A, histology showed that newly formed vasculature extended over the surfaces and invaded the entire coral blocks. The vascular density was significantly superior to that in group B. Vascular casts showed that new blood vessels robustly sprouted from the AVL. Scanning electron microscopy demonstrated that there were minute sprouting cavities in the vascular endangium. In this model, an axial vascularized coral bone could be effectively constructed.

Dental implants with the periodontium: a new approach for the restoration of missing teeth.

Tooth loss is a common occurrence in mankind and damages human health. Osseointegrated dental implants have been successfully used as a popular prosthetic restoration for the missing teeth for many years. However, osseointegration, representing a direct connection between the implant and bone tissue without the periodontium, causes some inevitable problems, such as masticatory force concentration and immobility of the dental implant. Thus, an ideal dental implant should have its own peri-implant periodontium, as do the natural teeth. A number of attempts have been made to reconstruct the periodontium around the implants. Unfortunately, it has been established that a predictable periodontal reconstruction, especially the acellular cementum reconstruction on the surface of the implant, is a very difficult task. In this paper, we propose the hypothesis that the cementum may be a special phenotype of the bone tissue, on the basis of its strong similarity in development, structure, and function. In a certain condition, the bone tissue may change to cementum for special functional needs. In accordance with this hypothesis, we consider a novel approach to reconstruct the peri-implant tissues. Unlike previous studies, this approach imitates the tooth re-plantation process. The key point is to convert the implant-surrounding bone tissues to cementum as a result of adaptive changes to the implant-support demands. This hypothesis, if proven to be valid, will not only represent a breakthrough in cementum research, but also will open a new door to the restoration of missing teeth.