Occlusal-maxillo-facial structural change of crossbite malocclusion after orthodontic therapy by modified ACTIVATOR appliance was investigated. Eighty crossbite cases of deciduous dentition and mixed dentition were treated by modified ACTIVATOR. Through pre- and post-treatment analysis of stone model, Schuller's position X-ray and craniofaciometrics, the change in craniofacial length, width and height in early-phase crossbite malocclusion was studied. The results showed that there was no significant change in the width of maxillary and mandibular dental arch. Maxillary length and protrusion was increased significantly, upper incisors slopped labially. The lower incisors slopped lingually, mental angle decreased more severely. The lower and posterior facial height was increased to normal level.
Cephalometry ; Dental Arch/anatomy & histology ; Dental Stress Analysis ; Dentition, Mixed ; Malocclusion/*therapy ; Maxilla/*anatomy & histology ; Maxilla/growth & development ; *Orthodontic Appliances, Removable ; Orthodontics, Corrective/*instrumentation ; Orthodontics, Interceptive/instrumentation ; Tooth, Deciduous

Objective:To investigate medical students' views on College English curriculum system, teaching methods and their needs for follow-up English courses, so as to provide reference for setting College English curriculum system.Methods:In January 2018, 2 000 non-English major undergraduates from Batch 2013-2017 in Xi'an Medical University were surveyed by the questionnaire of College English Curriculum System of Xi'an Medical College released on the website of WJX.com, and the questionnaire data were statistically analyzed in real time.Results:A total of 1 815 questionnaires were collected and the valid rate was 90.75%. It was shown that three top-listed reasons for English learning were "to pass CET-4/6 or other English examinations and obtain corresponding certificates (1 366, 75.26%)", "to prepare for future career (1 093, 60.22%)", and "to prepare for postgraduate entrance examination (1 060, 58.4%)". A large proportion of the students expected "reading, writing, translation and other skills training" and "oral practice and cross-cultural knowledge learning", accounting for 78.51% (1 425) and 65.84% (1 195) respectively. 68.76% of the students (1 248) endorsed the necessity of "courses on humanistic English or EGAP (English for general academic purposes) in medicine".Conclusion:The current single college English curriculum system and teaching methods can not meet the learning needs of medical students. It is necessary to explore the construction of a multi-level College English curriculum system that highlights the characteristics of medical colleges and meets the needs of different majors under the guidance of College English Teaching Guide.

The effect of saliva contamination on the shear bond strength of orthodontic brackets, at various stages of the bonding procedure using a new self-etch primer was studied. The samples were divided into 4 groups according to 4 different enamel surface conditions: Group A: dry; Group B: saliva contamination before priming; Group C: saliva contamination after priming, and Group D: saliva contamination before and after priming. Stainless steel brackets were bonded in each test group with a light-cured composite resin (TransbondXT 3M). The shear bond strength was determined in the first 30 min after bonding. The analysis of variance indicated that the shear bond strengths of the 4 groups were significantly different (F = 11.89, P < 0.05). Tukey HSD tests indicated that contamination both before and after the application of the acid-etch primer resulted in a significantly lower (=4.6 +/- 1.7 MPa) shear bond strength than either the control group (=8. 8 +/- 1.9 MPa) or the groups where contamination occurred either before ( = 7.9 +/- 2.0 MPa) or after (= 6. 9 +/- 1.5 MPa) the application of the primer. It was concluded that the new acid-etch primer could maintain adequate shear bond strength if contamination occurred either before or after the application of the primer. On the other hand, contamination both before and after the application of the primer could significantly reduce the shear bond strength of orthodontic brackets.
Acid Etching, Dental ; Orthodontic Brackets ; Saliva ; Shear Strength

Objective To study the clinic effect and safety of inhaled nitric oxide for the neonates with hypoxic respiratory failure. Methods A total of 21 neonates with hypoxic respiratory failure were trea-ted with nitric oxide inhalation after ineffective treatment of conventional mechanical ventilation. The values of mean airway pressure( MAP) ,oxygenation index( OI) ,mean blood pressure and saturation of blood oxy-gen percutem( TcSaO2 ) were detected before and after nitric oxide inhalation. Meanwhile,the values of coag-ulation function,nitrogen dioxide concentration and methaemoglobin were monitored. Results The lung oxy-genation of 21 cases were significantly improved in 48 hours after nitric oxide inhalation,OI declined from 26. 600 ±4. 169 to 7. 500 ±1. 716,MAP decreased from(15. 100 ±2. 132)cmH2O(1 cmH2O=0. 098 kPa) to (8. 000 ± 0. 816) cmH2O,which all had statistical differences(P <0. 01). The monitoring of coagulation function was in the normal range. The levels of methaemoglobin were less than 3% and nitrogen dioxide less than 1 × 10 -6 . In this study,18 neonates survived,2 neonates died and 1 neonate gave up treatment. Conclu-sion Inhaled nitric oxide early can improve oxygenation effectively for neonates with hypoxic respiratory failure without obvious side-effect. However,it is not yet clear for its long-term prognosis and whether there is influence development of the nervous system.

AIM: To explore the anatomical changes of the optic nerve head in cats after radial optic neurotomy (RON).METHODS: The normal anatomic data were obtained from 12 healthy cats. A total of 18 healthy cats were used in the experiment, which were divided into four groups: each operative group was executed at the :Lst, 15th, 30th, 90th day after undergoing RON unilaterally.(six in 1st group). The enucleated eyes of each operative group were cut section routinely and embedded in paraffin, the cross sections were stained by special staining.RESULTS: At the 1st day after operation, the incision came into being and connected with cerebral subarachnoid space of orbital optic nerve. At 15th day, incision was fusiform and hyperplastic neuroglial cells and fibroblasts aggregated at the incision. At 30th day, there was obvious proliferation of type fibril at the neurotomy. The aligned texture of collagen fibril of the lamina cribrosa near the incision was moved close to each other. At the 90th day, a discrete scar was noted at the site which reached the cribriform and sclera.CONCLUSION: RON can cut scleral ring and piamater of optic nerve sharply. The incision of RON connects with subarachnoid space of orbital optic nerve and becomes broaden gradually at the site of scleral ring. The potential role of incision of RON is relevant to the subject.

Objective By studying the expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in rats′ cardiac muscle after acute myocardial infarction, we try to find out the relation between the expression of these two factors and the formation of new blood vessels under ischemia. Methods Wistar rats were divided into control group and infarction group (3, 7, 14, 28, 42, 56 d). The expression of VEGF and bFGF in cardiac muscle and endothelial cells is detected by means of immunohisto-chemial staining while the density of newly formed ressels is detected by marking the endothelial cells with antigens associated with factor Ⅷ. Results After ligating the left anterior descending coronary artery of the rats, the expression of VEGF and bFGF increased along with the prolongation of myocardial ischemia and reached the peak on the 7th day. The expression of the 2 factors began to decrease on the 28th day and the most significant decrease happened on the 42th and 56th day. The density of the newly formed capillaries is directly propontimal to the levels of the 2 factors. Less expression of VEGF and bFGF was observed in the control group. Conclusion The up-regulation of VEGF and bFGF expression might play important roles in neovascularization. Dicrectly intramyocardial injection of bFGF and VEGF gene at the time when the expression of bFGF and VEGF began to decrease maybe optimal.

In order to study mechanical stress on root from orthodontic tooth movement by sliding mechanics, a 3-dimensional finite element model incorporating all layers of a human mandibular dental arch with orthodontic appliance has been developed to simulate mechanical stress on root from the orthodontic tooth movement. Simulated orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis was applied to the crown of the teeth. The finite element analysis showed when orthodontic forces were applied to the tooth, the stress was mainly concentrated at the neck of the tooth decreasing uniformly to the apex and crown. The highest stress on the root was 0.621 N/mm(2) for cervical margin of the canine, and 0.114 N/mm(2) for apical region of the canine. The top of canine crown showed the largest amount of displacement (2.417 microm), while the lowest amount of displacement was located at the apical region of canine (0.043 microm). In conclusion, this model might enable one to simulate orthodontic tooth movements clinically. Sliding force at 2 N is ideal to ensure the bodily orthodontic tooth movement. The highest stress concentration in the roots was always localized at the cervical margin when orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis, so there may be the same risk of root resorption when orthodontic force of 2 N at 0, 30 and 45 degree was used in clinic cases.
Computer Simulation ; Dental Arch/*physiology ; Finite Element Analysis ; Orthodontic Anchorage Procedures ; Orthodontic Appliances ; Stress, Mechanical ; Tooth Movement ; Tooth Root/*physiology

Diagnosis, Differential ; Heart Failure ; diagnosis ; therapy ; Humans ; Medicine, Chinese Traditional

The expressions of transforming growth factor β1 (TGF-β1), fibronectin (FN), and collagen Ⅳ in human mesangial cells were augmented with increased concentrations of glucose.Pigment epithelium-derived factor (PEDF) at concentrations of 40-160 nmol/L significantly inhibited TGF-β1 expression in a dose-dependent manner(P＜0.01).PEDF at concentrations of 5-40 nmol/L significantly decreased FN and collagen Ⅳ expressions in a dose-dependent manner(P＜0.01) ,suggesting that PEDF may play a salutary role in diabetic nephropathy by its antifibrogenic activity.

Drug Interactions ; Humans ; Proton Pump Inhibitors ; pharmacology ; Ticlopidine ; analogs & derivatives ; pharmacology