Tooth eruption is a series of complicated physiological processes occurring once the crown is formed completely, as well as when the tooth moves toward the occasion plane. As such, the tooth moves through the alveolar bone and the oral mucosa until it finally reaches its functional position. Most studies indicate that the process of tooth eruption involves the alveolar bone, dental follicles, osteoclasts, osteoblasts, and multiple cytokines. Dental follicles regulate both resorption and formation of the alveolar bone, which is required for tooth eruption. Furthermore, root formation with periodontal ligament facilitates continuous tooth eruption. However, the exact mechanism underlying tooth eruption remains unclear. Hence, this review describes the recent research progress on the cellular and molecular mechanisms of tooth eruption.
Dental Sac ; Humans ; Osteoblasts ; Osteoclasts ; Periodontal Ligament ; Tooth ; Tooth Eruption ; physiology ; Tooth Root

Objective To investigate the chemical constituents of red algae Hypnea charoides. MethodsThe constituents were isolated by column chromatography and their structures were elucidated by chemical properties and spectroscopic analyses. Results Three compounds were isolated and their structures were identified as 3, 6-dimethyl-8-(4-methyleneheptan-3-yloxy) octane-1-amine (Ⅰ), palmitate-K (Ⅱ), and (2R, 1′S, 2′S, 3′R)-N-(1′-hydroxymethyl-2′, 3′-dihydroxy-heptadecenyl)-2-hydroxy-12, 13-methylene-tetracosanamide (Ⅲ). Conclusion Compounds Ⅰ and Ⅲ are new compounds named as charoidesine and charoidesamide.

Agitator is one of the essential factors to realize high efficient fermentation for high aerobic and viscous microorganisms, and the influence of different impeller combination on the fermentation process is very important. Welan gum is a microbial exopolysaccharide produced by Alcaligenes sp. under high aerobic and high viscos conditions. Computational fluid dynamics (CFD) numerical simulation was used for analyzing the distribution of velocity, shear rate and gas holdup in the welan fermentation reactor under six different impeller combinations. The best three combinations of impellers were applied to the fermentation of welan. By analyzing the fermentation performance, the MB-4-6 combination had better effect on dissolved oxygen and velocity. The content of welan was increased by 13%. Furthermore, the viscosity of production were also increased.
Alcaligenes ; metabolism ; Fermentation ; Hydrodynamics ; Industrial Microbiology ; methods ; Oxygen ; Polysaccharides, Bacterial ; biosynthesis ; Viscosity

Objective:To investigate the risk factors of deep venous thrombosis in patients before hip arthroplasty, and to explore the possible causes of postoperative thrombosis.Methods:The clinical data of 361 patients with hip arthroplasty treated in the Department of Orthopaedic Trauma of Xi′an Honghui Hospital from September 2015 to December 2019 were studied retrospectively, including 102 males and 259 females, aged 65 to 94 years, and the average age was 72.25 years old. All fracture patients were given subcutaneous injection of low molecular weight heparin calcium to prevent lower extremity thrombosis. The deep veins of both lower extremities were examined before and after operation. The general data of the two groups of patients were collected and recorded, including age, sex, whether complicated with medical diseases (essential hypertension, type 2 diabetes, coronary heart disease), serological indexes, time from injury to admission, and time from admission to operation. The software of SPSS 19.0 was used for statistical analysis.Results:The incidence of lower limb DVT, before operation was 29.92%, including 26 males (24.07%) and 82 females (75.93%). The results of multivariate logistic regression analysis showed that diabetes mellitus ( OR=2.127, 95% CI: 1.134-3.989, P=0.019), coronary heart disease ( OR=1.692, 95% CI: 1.056-2.713, P=0.029) and the time from injury to admission ( OR=1.677, 95% CI: 1.037-2.712, P=0.035) were independent risk factors for DVT in elderly patients undergoing hip arthroplasty. The incidence of lower limb DVT, after operation was 46.54%. After operation, proximal thrombus were occurred in 2 cases (1.19%), distal thrombus in 143 cases (85.12%), and mixed thrombus in 23 cases (13.69%). Postoperative thrombus was ipsilateral to the fracture limb in 84 cases (50.00%), thrombus was located in the healthy side of the fracture in 19 cases (11.31%), and DVT occurred in 65 cases (38.69%) in both lower limbs. Conclusions:Delayed admission longed than 48 hours, coronary heart disease and diabetes mellitus are the risk factors for the formation of DVT. The thrombus that existed before operation and did not disappear after operation accounted for 48.81% of the total incidence of postoperative thrombosis, and the new thrombus accounted for 51.19% of the total incidence of postoperative thrombosis. For the elderly patients with femoral neck fracture undergoing hip arthroplasty, ultrasonic examination of both lower limbs should be performed before and after operation to find the changes of thrombus in time and do a good job of prevention and treatment.

Objective:To investigate the differences in incidence of deep vein thrombosis (DVT) after closed fracture of lower extremity between patients with different blood types ABO.Methods:A retrospective study was conducted in the 1, 951 patients who had been admitted to Department of Orthopaedics Trauma, Honghui Hospital Affiliated to Xi'an Jiaotong University for lower extremity fractures from August 2014 to June 2018. They were 924 males and 1,027 females with a mean age of 63 (46, 78) years (range, from 16 to 102 years). Of them, 572 were type O, 564 type A, 609 type B and 206 type AB. Venous ultrasonography was performed on both lower extremities within 12 hours after admission. The incidences of DVT after fracture were compared between different blood types in all the patients, patients with proximal fracture of the knee, peri-knee fracture and distal fracture of the knee, and patients<60 years old and ≥60 years old.Results:The incidences of DVT were, respectively, 26.75% (153/572), 28.72% (162/564), 34.32% (209/609) and 29.61% (61/206) for patients with blood type O, type A, type B and type AB. The DVT incidence for type B was significantly higher than that for type O ( P< 0.008). The incidences of DVT were, respectively, 28.74% (98/341), 28.99% (100/345), 39.45% (144/365) and 30.97% (35/113) for blood type O, type A, type B and type AB in the patients with proximal fracture of the knee. The DVT incidence for blood type B was significantly higher than those for blood type O and blood type A ( P< 0.008). There were no significant differences in the DVT incidence between different blood types ABO in the patients with peri-knee fracture, distal fracture of the knee,<60 years old or ≥60 years old( P>0.05). The incidences of DVT were, respectively, 30.99% (97/313), 33.33% (108/324), 45.22% (156/345), 34.74% (33/95) for blood type O, type A, type B and type AB in the patients ≥60 years old. The DVT incidence for blood type B was significantly higher than those for blood type O and blood type A ( P< 0.008). Conclusions:The incidence of DVT varied with different blood types ABO after lower extremity fracture. The highest DVT incidence was found in patients with blood type B. The impact of blood type on the DVT incidence after lower extremity fracture was mainly observed in the patients with proximal fracture of the knee or an age of ≥ 60 years old.

OBJECTIVETo investigate the outcome of skeletal Class Ⅲ patients treated with Fränkel function regulator type Ⅲ (FR Ⅲ)in the early mixed and late mixed dentition.

METHODSThe samples consisted of 45 mild and moderate skeletal Class Ⅲ patients(26 males, 19 females; meanage, [7.9±1.3] years) treated with FR Ⅲ. According to Hellman's dental developmental stages, these samples were divided into early-treated group(n=24) and late-treated group(n=21). Lateral cephalograms were taken at the beginning and the end of treatment. Twenty-one measurements on hard and soft tissue were included.

RESULTSAfter treatment, SNA, ANB, NA-Apo, Wits, U1-SN, U1-NA, Overjet, UL-EP were significantly increased (1.0±1.9)°, (1.2±1.6)°, (2.6±4.2)°, (1.8±2.7) mm, (4.2±7.6)°, (2.6±7.5)°, (3.6±2.3) mm and (0.8±2.2) mm(P<0.05). OP-SN and IMPA were significantly decreased (1.5±3.7)°and (1.4±4.2)°(P<0.05). There were significant differences in SNA, ANB, UL-EP, IMPA, L1-NB between early-treated group and late-treated group(P<0.05).

CONCLUSIONSFR Ⅲ was suitable for the treatment of mild and moderate skeletal Class Ⅲ patients. The result was better in the early-treated patients than in late-treated ones.

Cephalometry ; Child ; Dentition, Mixed ; Female ; Humans ; Male ; Malocclusion, Angle Class III ; therapy ; Orthodontic Appliances, Functional ; Overbite ; etiology ; Time-to-Treatment ; Treatment Outcome