Protective Effect and Mechanism of Kuntai Capsule on Angiotensin II -Induced Hypertension in Ovariectomized Rats / 中国结合医学杂志

OBJECTIVE@#To explore the protective effect and mechanism of Kuntai (KT) Capsule on angiotensin II (Ang II)-induced hypertension in ovariectomized (OVX) rats.@*METHODS@#Fifty-four rats were randomly divided into 6 groups according to a random number table, 9 in each group: control, OVX sham+Ang II, OVX, OVX+Ang II, OVX+Ang II +E2, and OVX+Ang II +KT. OVX rats model was constructed by retroperitoneal bilateral ovariectomy. After 4 weeks of pretreatment with KT Capsule [0.8 g/(kg·d) and 17- β -estradiol (E2, 1.2 mg/(kg·d)] respectively, Ang II was injected into a micro-osmotic pump with a syringe to establish a hypertensive rat model. Blood pressure of rat tail artery was measured in a wake state of rats using a non-invasive sphygmomanometer. Blood pressure changes were compared between the intervention groups (OVX+Ang II +KT, OVX+Ang II +E2) and the negative control group (OVX+Ang II). Serum malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were detected respectively. The expressions of oxidative stress-related protein superoxide dismutase2 (SOD2) and anti-thioredoxin (TRX), autophagy marker protein [beclin1, light chain (LC) 3 II/I ratio and autophagy canonical pathway protein phosphatidylinositol 3-kinase (PI3K)/serine/threonine kinase (AKT)-mammalian target of rapamycin (mTOR)] were evaluated by Western blotting.@*RESULTS@#Compared with the OVX+Ang II group, the systolic blood pressure of OVX+Ang II +KT group was significantly lowered (P<0.05) but not the diastolic blood pressure. Besides, SOD2 and TRX protein levels in mycardial tissues were significantly reduced in the OVX+Ang II +KT group compared with the OVX+Ang II group (P<0.05). Oxidative stress serum markers MDA and SOD were down- and up-regulated in the OVX+Ang II +KT group, respectively (P<0.05). Compared with OVX+Ang II group, the levels of cardiac proteins beclin-1 and LC3II/LC3 I in OVX+Ang II +KT group were also up-regulated (P<0.05), and the expression levels of p-PI3K, p-AKT and mTOR protein were down-regulated (P<0.05).@*CONCLUSION@#KT could protect blood pressure of Ang II-induced OVX rats by inhibiting oxidative stress and up-regulating protective autophagy.

Analysis of management efficacy in patients with heavy menstrual bleeding associated with antithrombotic therapy / 中华妇产科杂志

Objective: To evaluate different methods' efficacy of controlling acute bleeding and managing long-term menstruation in patients with heavy menstrual bleeding (HMB) associated with antithrombotic therapy. Methods: The clinical data of 22 cases with HMB associated with antithrombotic therapy admitted to Peking University People's Hospital from January 2010 to August 2022 were analyzed, aged 39 years old (26-46 years). Changes in menstrual volume, hemoglobin (Hb), and quality of life were collected after control of acute bleeding and long-term menstrual management. Menstrual volume was assessed by pictorial blood assessment chart (PBAC), and quality of life was assessed by menorrhagia multi-attribute scale (MMAS). Results: (1) Treatment of acute bleeding: of the 22 cases with HMB associated with antithrombotic therapy, 16 cases were treated in our hospital and 6 in other hospital for emergency bleeding; of the 16 cases treated in our hospital, 3 underwent emergency intrauterine Foley catheter balloon compression due to severe bleeding (Hb decreased by 20 to 40 g/L within 12 hours). Of the 22 cases with antithrombotic therapy-related HMB, 15 (including 2 cases with severe bleeding) underwent emergency aspiration or endometrial resection, and intraoperative placement of levonorgestrel-releasing intrauterine system (LNG-IUS) followed by a significant reduction in bleeding volume; 3 cases had controlled acute bleeding after rivaroxaban dose reduction and continued observation; 2 cases were given gonadotropin-releasing hormone agonists to control acute bleeding in other hospital, of which 1 case was temporarily treated with periodic blood transfusion, and the other one patient underwent total hysterectomy; and 2 cases had temporary amenorrhea with oral mifepristone after intrauterine balloon compression or oral norethindrone. (2) Long-term menstrual management: of the 22 cases with antithrombotic therapy-related HMB, 15 had LNG-IUS placement and 12 had LNG-IUS placement for 6 months, and menstrual volume was significantly reduced [PBAC scores were 365.0 (272.5-460.0) vs 25.0 (12.5-37.5), respectively; Z=4.593, P<0.001], Hb was significantly increased [91.5 g/L (71.8-108.2 g/L) vs 128.5 g/L (121.2-142.5 g/L); Z=4.695, P<0.001], and quality of life was significantly improved [MMAS scores were 415.0 (327.5-472.5) vs 580.0 (570.0-580.0), respectively; Z=-3.062, P=0.002] before placement compared with 6 months after placement. Three rivaroxaban dose reduction patients' PBAC scores decreased by 20 to 35 but remained >100, and perceived quality of life did not change significantly. Two cases with temporary amenorrhea treated with oral mifepristone felt significantly improved quality of life, and the MMAS scores increased by 220 and 180, respectively. Conclusion: Intrauterine Foley catheter balloon compression, aspiration or endometrial ablation could be used to control acute bleeding in patients with antithrombotic therapy-related HMB, and LNG-IUS for long-term management could reduce menstrual volume, increase hemoglobin, and improve the quality of life of patients.

Seroprevalence of and Identification of Risk Factors in China / 生物医学与环境科学（英文）

Serum samples were tested for IgG antibodies using indirect immunofluorescence assays. We then analyzed associated risk factors. Serum samples were considered positive when reactive at a dilution of more than 1:320. Differences between groups and risk factors associated with exposure were statistically analyzed using Chi-square tests and the generalized linear model. 122 of 1,260 samples (9.68%) were positive for infection. The infection rate ranged from 0% to 30.43% and differed significantly among age groups ( < 0.01); infection rate in the 50-59 years group was significantly higher than that in other age groups. The seroprevalence of varied significantly among sites within the four provinces, and the infection rate of field workers was significantly higher than that of urban workers.

Comparison of the accuracy of intraoral scanner by three-dimensional analysis in single and 3-unit bridge abutment model: In vitro study / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the accuracy of three types of intraoral scanners and the accuracy of the single abutment and bridge abutment model. MATERIALS AND METHODS: In this study, a single abutment, and a bridge abutment with missing first molar was fabricated and set as the reference model. The reference model was scanned with an industrial three-dimensional scanner and set as reference scan data. The reference model was scanned five times using the three intraoral scanners (CS3600, CS3500, and EZIS PO). This was set as the evaluation scan data. In the three-dimensional analysis (Geomagic control X), the divided abutment region was selected and analyzed to verify the scan accuracy of the abutment. Statistical analysis was performed using SPSS software (α = .05). The accuracy of intraoral scanners was compared using the Kruskal-Wallis test and post-test was performed using the Pairwise test. The accuracy difference between the single abutment model and the bridge abutment model was analyzed by the Mann-Whitney U test. RESULTS: The accuracy according to the intraoral scanner was significantly different (P < .05). The trueness of the single abutment model and the bridge abutment model showed a statistically significant difference and showed better trueness in the single abutment (P < .05). There was no significant difference in the precision (P = .616). CONCLUSION: As a result of comparing the accuracy of single and bridge abutments, the error of abutment scan increased with increasing scan area, and the accuracy of bridge abutment model was clinically acceptable in three types of intraoral scanners.

Evaluating usability of and satisfaction with two types of dental CAD software

PURPOSE: This study evaluated the usability of and satisfaction with two types of computer-aided design (CAD) software among users who had experience with dental implant CAD software and those who did not. MATERIALS AND METHODS: Dental technicians (n = 20) who had previous experience with dental implant CAD Software and students from the College of Dentistry (n = 12) who had never designed implant custom abutments were asked to evaluate two types of CAD Software, Exocad and Deltanine. In addition, the participants were asked to fill out a structured questionnaire (Section 1: Entering basic information and retrieving files; Section 2: Setting conditions before abutment design; Section 3: Setting abutment design; and Section 4: Overall satisfaction). For the statistical analysis of the collected data, Mann-Whitney U test was used (α = .05). RESULTS: The ease of design and satisfaction with the implant CAD Software, evaluated with respect to 21 statements divided into four Stages, were significantly higher for Exocad in both groups for Secion 1. For Sections 2 and 3, participants with experience evaluated Deltanine to be significantly better. For Section 4, both groups evaluated Exocad Software to be better. CONCLUSION: Overall, the Exocad Software was evaluated as having better usability and offering greater satisfaction. However, in terms of performance in the core of the design process, i.e. Sections 2 and 3, Deltanine was rated higher by the experienced users. Thus, if the user interface design parts are supplemented, Deltanine CAD Software could be put to a wider use in clinics.

Humerus Shaft Fractures Occurring in Fly Fishing Boat Riding: Injury Scene Analysis / 대한스포츠의학회지

PURPOSE: The aim of this study was to analyze an injury scene during fly fish boat riding (FBR).METHODS: We conducted survey on 12 patients who had humerus shaft fractures during FBR between 2011 and 2016 at three university-based emergency rooms. Individual information, injury mechanism, classification of humerus shaft fracture, and combined injury were recorded from medical document and telephone interview.RESULTS: The injury happened when the kite was turned over and fall into the water in 10 patients (82%); the kite was turned over in the air in one patient (9%), and a leash between kite and boat was broken in one patient (9%). All patients showed 12-B1 or 12-B3 type distal humerus shaft fracture. And there were combined contralateral distal humeral shaft fractures in two patients, vertebral compression fracture in one patient, and radial nerve injury in four patients.CONCLUSION: Riding position and injury mechanism such as turning over may affect distal humerus shaft fractures with butterfly fragment during FBR.

Accuracy evaluation of dental models manufactured by CAD/CAM milling method and 3D printing method

PURPOSE: To evaluate the accuracy of a model made using the computer-aided design/computer-aided manufacture (CAD/CAM) milling method and 3D printing method and to confirm its applicability as a work model for dental prosthesis production. MATERIALS AND METHODS: First, a natural tooth model (ANA-4, Frasaco, Germany) was scanned using an oral scanner. The obtained scan data were then used as a CAD reference model (CRM), to produce a total of 10 models each, either using the milling method or the 3D printing method. The 20 models were then scanned using a desktop scanner and the CAD test model was formed. The accuracy of the two groups was compared using dedicated software to calculate the root mean square (RMS) value after superimposing CRM and CAD test model (CTM). RESULTS: The RMS value (152±52 µm) of the model manufactured by the milling method was significantly higher than the RMS value (52±9 µm) of the model produced by the 3D printing method. CONCLUSION: The accuracy of the 3D printing method is superior to that of the milling method, but at present, both methods are limited in their application as a work model for prosthesis manufacture.

Incidence and Seasonal Variation of Distal Radius Fractures in Korea: a Population-based Study

BACKGROUND: The present study aimed to investigate the incidence and seasonal variation of distal radius fractures (DRFs) in Korea. METHODS: We analyzed a nationwide database acquired from the Korean Health Insurance Review and Assessment Service from 2011 to 2015. We used International Classification of Diseases, 10th revision codes and procedure codes to identify patients of all ages with newly diagnosed DRFs. RESULTS: An average of about 130,000 DRFs occurred annually in Korea. The incidence of DRF, by age group, was highest in the 10 to 14-year-old age group for males and the highest in the 70s age group for females, with a rapid increase of incidence after 50 years. The peak incidence of DRF occurred during winter; however, the incidence greatly varied annually when compared with that of other seasons. The incidence of DRFs during the winter season was correlated with the average temperature. CONCLUSION: The annual incidence of DRF was 130,000 in Korea. The incidence increased under an intense cold surge during winter. Active preventive measures are recommended especially in women exceeding 50 years considering the higher incidence in this age group.

The Epidemiology of Dupuytren's Disease in Korea: a Nationwide Population-based Study

BACKGROUND: To date, there have been few reports on the nationwide population-based epidemiology of Dupuytren's disease (DD). We investigated the prevalence and incidence of DD in Korea using the large dataset provided by the Korean Health Insurance Review and Assessment Service. This study is the second nationwide epidemiological study of DD after the study in Taiwan. METHODS: Records of patients diagnosed with DD between 2007 and 2014 were extracted from the large dataset by diagnostic code searching (International Classification of Disease 10th revision code M72.0) and were included in the study. We calculated the prevalence and incidence of DD based on the total population of Korea provided by the Korean Statistical Information Service. Diseases associated with DD and the trends in surgery for DD were also analyzed. RESULTS: A total 16,630 patients were diagnosed with DD during the study period. The mean annual prevalence was 32.2 per 100,000 population (41.8 per 100,000 for men; 22.5 per 100,000 for women). The mean annual incidence was 1.09 per 100,000 population (1.80 per 100,000 for men; 0.38 per 100,000 for women). The common diseases associated with DD were hypertension (30.5%), diabetes mellitus (26.7%), hyperlipidemia (20.4%), ischemic heart disease (7.9%), and cerebrovascular disease (4.6%). The mean annual proportion of the patients who had surgery for DD was 5.24% of all DD patients. CONCLUSION: The prevalence and incidence of DD in Korea were 100–1,000 times lower than those in western countries; however, it was slightly larger than that in Taiwan.

A comparative study on the user satisfaction between two different piezoelectric engines

PURPOSE: The aim of this study is to compare the performance of two piezoelectric engine systems by surveying satisfaction from dental clinicians. MATERIALS AND METHODS: Two piezoelectric systems were evaluated: TRAUS XUS10 (Saeshin), PIEZOSURGERY touch (Mectron). For this study, 20 dentists responded to the 11 questionnaires in which 5 point Likert-type scale was used. The two devices were operated for 10 seconds and measured 5 times to compare the maximum noise values. In heat emission test, the handpiece was operated for 3 minutes and heat was measured at three positions each. RESULTS: TRAUS XUS10 had higher satisfaction level on motor noise (P < 0.05). About function key and handpiece heat generation, PIEZOSURGERY touch showed higher satisfaction (P < 0.05) than TRAUS XUS10. The maximum noise level for each of the devices was confirmed to be 56.6 dB for the TRAUS XUS10 and 56.0 dB for PIEZOSURGERY touch. The two piezoelectric engines satisfied the safety standards with an operation temperature below 41℃ after having been operated for 3 minutes. CONCLUSION: Except for the function key and handpiece heat emission, TRAUS XUS10 has comparable performance with PIEZOSURGERY touch.

National Surgical Trends for Distal Radius Fractures in Korea

The objective of this study was to investigate national surgical trends for distal radius fractures (DRFs) in Korea and analyze healthcare institution type-specific surgical trends. We analyzed a nationwide database acquired from the Korean Health Insurance Review and Assessment Service (HIRA) from 2011 to 2015. International Classification of Diseases, 10th revision (ICD-10) codes and procedure codes were used to identify patients aged ≥ 20 years with newly diagnosed DRFs. A total of 459,388 DRFs occurred from 2011 to 2015. The proportion of DRF cases treated by surgery tended to increase over time, from 32.6% in 2011 to 38.3% in 2015 (P < 0.001). Open reduction with internal fixation (ORIF) using a plate steadily gained in popularity each year, increasing from 39.2% of overall surgeries in 2011 to 60.9% in 2015. The type of surgery for DRFs differed depending on the type of healthcare institution. ORIF (91%) was the most popular procedure in tertiary hospitals, whereas percutaneous pinning (58%) was most popular in clinics. In addition, general hospitals and hospitals with 30–100 beds used external fixation more frequently than tertiary hospitals and clinics did. Overall, our findings indicate that surgical treatment of DRF, particularly ORIF, continues to increase, and that the component ratio of operation codes differed according to the healthcare institution type.

A standardization model based on image recognition for performance evaluation of an oral scanner

PURPOSE: Accurate information is essential in dentistry. The image information of missing teeth is used in optically based medical equipment in prosthodontic treatment. To evaluate oral scanners, the standardized model was examined from cases of image recognition errors of linear discriminant analysis (LDA), and a model that combines the variables with reference to ISO 12836:2015 was designed. MATERIALS AND METHODS: The basic model was fabricated by applying 4 factors to the tooth profile (chamfer, groove, curve, and square) and the bottom surface. Photo-type and video-type scanners were used to analyze 3D images after image capture. The scans were performed several times according to the prescribed sequence to distinguish the model from the one that did not form, and the results confirmed it to be the best. RESULTS: In the case of the initial basic model, a 3D shape could not be obtained by scanning even if several shots were taken. Subsequently, the recognition rate of the image was improved with every variable factor, and the difference depends on the tooth profile and the pattern of the floor surface. CONCLUSION: Based on the recognition error of the LDA, the recognition rate decreases when the model has a similar pattern. Therefore, to obtain the accurate 3D data, the difference of each class needs to be provided when developing a standardized model.

Effect of repeated learning for two dental CAD software programs

PURPOSE: The purpose of this study is to assess the relationship between the time spent designing custom abutments and repeated learning using dental implant computer aided design (CAD) software. MATERIALS AND METHODS: The design of customized abutments was performed four stages using the 3DS CAD software and the EXO CAD software, and measured repeatedly three times by each stage. Learning effect by repetition was presented with the learning curve, and the significance of the reduction in the total time and the time at each stage spent on designing was evaluated using the Friedman test and the Wilcoxon signed rank test. The difference in the design time between groups was analyzed using the repeated measure two-way ANOVA. Statistical analysis was performed using the SPSS statistics software (P < 0.05). RESULTS: Repeated learning of the customized abutment design displayed a significant difference according to the number of repetition and the stage (P < 0.001). The difference in the time spent designing was found to be significant (P < 0.001), and that between the CAD software programs was also significant (P = 0.006). CONCLUSION: Repeated learning of CAD software shortened the time spent designing. While less design time on average was spent with the 3DS CAD than with the EXO CAD, the EXO CAD showed better results in terms of learning rate according to learning effect.

Evaluation of internal fit of interim crown fabricated with CAD/CAM milling and 3D printing system

PURPOSE: This study is to evaluate the internal fit of the crown manufactured by CAD/CAM milling method and 3D printing method. MATERIALS AND METHODS: The master model was fabricated with stainless steel by using CNC machine and the work model was created from the vinyl-polysiloxane impression. After scanning the working model, the design software is used to design the crown. The saved STL file is used on the CAD/CAM milling method and two types of 3D printing method to produce 10 interim crowns per group. Internal discrepancy measurement uses the silicon replica method and the measured data are analyzed with One-way ANOVA to verify the statistic significance. RESULTS: The discrepancy means (standard deviation) of the 3 groups are 171.6 (97.4) µm for the crown manufactured by the milling system and 149.1 (65.9) and 91.1 (36.4) µm, respectively, for the crowns manufactured with the two types of 3D printing system. There was a statistically significant difference and the 3D printing system group showed more outstanding value than the milling system group. CONCLUSION: The marginal and internal fit of the interim restoration has more outstanding 3D printing method than the CAD/CAM milling method. Therefore, the 3D printing method is considered as applicable for not only the interim restoration production, but also in the dental prosthesis production with a higher level of completion.

Development of A Multiplex PCR Method for Detecting Six Types of Viruses Causing Encephalitis / 现代检验医学杂志

Objective To develop a new mPCR method for rapid diagnosis of six types of encephalitis causing viruses of HS-VI,HSVII,VZV,EBV,EV71 and CMV.Methods Six pairs of specific primers for CMV,EV71,HSV I,VZV,EBV and HSV II were designed.The mPCR detection method was established and the sensitivity was detected.In order to verify the clinical application value of their multiplex PCR system,fifteen cerebrospinal fluid specimens of clinically suspected VE from the First Affiliated Hospital of Soochow University from 2014 to 2015 were examined by the mPCR method.Results The 6 pairs of primers did not interfere with each other,and the sensitivity of the mPCR system was over 103copies/μl.Among 15 cerebrospinal fluid specimens from patients with suspected viral encephalitis,six specimens(6/15,40%)were tested positive by the mPCR.Among them,HSV I was 5 and CMV was 1.Conclusion The mPCR method for detecting six types of en-cephalitis-associated virus at same time was established with high specificity,sensitivity and stability.

The effect of powder A2/powder A3 mixing ratio on color and translucency parameters of dental porcelain

PURPOSE: The purpose of this study is to mix dental ceramic powder in varying ratios and evaluate the effect of the mixing ratio on color and translucency. MATERIALS AND METHODS: The ceramic powder of shade A3 of the same product was mixed with the shade A2 of three products: IPS e.max Ceram (Ivoclar Vivadent, Schaan, Liechtenstein), Vintage Halo (SHOFU Inc., Kyoto, Japan), and Ceramco 3 (Ceramco-Dentsply, Burlington, NJ, USA) in the following fixed ratios (0 wt%, 25 wt%, 50 wt%, 75 wt%, and 100 wt%) and then fired. A total of 150 specimen of ceramic fired were manufactured in a regular size (W: 8.5 mm, L: 10.5 mm, and H: 1.5 mm). For color and translucency, L*, a*, and b* were measured and Two-way analysis of variance (ANOVA) and One-way analysis of variance (ANOVA) were used for data analysis (alpha=0.05). RESULTS: The higher the mixing ratio was, L*, a*, and b* of IPS e.max Ceram were all increased, and L* of Vintage Halo was reduced and a* and b* were increased. L* and a* of Ceramco3 were reduced and b* of Ceramco3 was increased. Color difference (DeltaE*ab) was increased in all three products as the mixing ratio got higher. Increased mixing ratios resulted in decreased translucency parameter (TP) values for IPS e.max Ceram but increased TP values for Vintage Halo and Ceramco3. CONCLUSION: In this limited study, CIE L*, a*, and b* were influenced by the mixing ratio of the A3 powders and porcelain powder mixtures represented a various color and translucency.

Accuracy evaluation of metal copings fabricated by computer-aided milling and direct metal laser sintering systems

PURPOSE: To assess the marginal and internal gaps of the copings fabricated by computer-aided milling and direct metal laser sintering (DMLS) systems in comparison to casting method. MATERIALS AND METHODS: Ten metal copings were fabricated by casting, computer-aided milling, and DMLS. Seven mesiodistal and labiolingual positions were then measured, and each of these were divided into the categories; marginal gap (MG), cervical gap (CG), axial wall at internal gap (AG), and incisal edge at internal gap (IG). Evaluation was performed by a silicone replica technique. A digital microscope was used for measurement of silicone layer. Statistical analyses included one-way and repeated measure ANOVA to test the difference between the fabrication methods and categories of measured points (alpha=.05), respectively. RESULTS: The mean gap differed significantly with fabrication methods (P<.001). Casting produced the narrowest gap in each of the four measured positions, whereas CG, AG, and IG proved narrower in computer-aided milling than in DMLS. Thus, with the exception of MG, all positions exhibited a significant difference between computer-aided milling and DMLS (P<.05). CONCLUSION: Although the gap was found to vary with fabrication methods, the marginal and internal gaps of the copings fabricated by computer-aided milling and DMLS fell within the range of clinical acceptance (<120 microm). However, the statistically significant difference to conventional casting indicates that the gaps in computer-aided milling and DMLS fabricated restorations still need to be further reduced.

Accuracy evaluation of metal copings fabricated by computer-aided milling and direct metal laser sintering systems

PURPOSE: To assess the marginal and internal gaps of the copings fabricated by computer-aided milling and direct metal laser sintering (DMLS) systems in comparison to casting method. MATERIALS AND METHODS: Ten metal copings were fabricated by casting, computer-aided milling, and DMLS. Seven mesiodistal and labiolingual positions were then measured, and each of these were divided into the categories; marginal gap (MG), cervical gap (CG), axial wall at internal gap (AG), and incisal edge at internal gap (IG). Evaluation was performed by a silicone replica technique. A digital microscope was used for measurement of silicone layer. Statistical analyses included one-way and repeated measure ANOVA to test the difference between the fabrication methods and categories of measured points (alpha=.05), respectively. RESULTS: The mean gap differed significantly with fabrication methods (P<.001). Casting produced the narrowest gap in each of the four measured positions, whereas CG, AG, and IG proved narrower in computer-aided milling than in DMLS. Thus, with the exception of MG, all positions exhibited a significant difference between computer-aided milling and DMLS (P<.05). CONCLUSION: Although the gap was found to vary with fabrication methods, the marginal and internal gaps of the copings fabricated by computer-aided milling and DMLS fell within the range of clinical acceptance (<120 microm). However, the statistically significant difference to conventional casting indicates that the gaps in computer-aided milling and DMLS fabricated restorations still need to be further reduced.

Evaluation of different approaches for using a laser scanner in digitization of dental impressions

PURPOSE: This study aimed to investigate the potential clinical application of digitized silicone rubber impressions by comparing the accuracy of zirconia 3-unit fixed partial dentures (FPDs) fabricated from 2 types of data (working model and impression) obtained from a laser scanner. MATERIALS AND METHODS: Ten working models and impressions were prepared with epoxy resin and vinyl polysiloxane, respectively. Based on the data obtained from the laser scanner (D-700; 3Shape A/S, Copenhagen, Denmark), a total of 20 zirconia frameworks were prepared using a dental CAD/CAM system (DentalDesigner; 3shape A/S, Copenhagen, Denmark / Ener-mill, Dentaim, Seoul, Korea). The silicone replicas were sectioned into four pieces to evaluate the framework fit. The replicas were imaged using a digital microscope, and the fit of the reference points (P1, P2, P3, P4, P5, P6, and P7) were measured using the program in the device. Measured discrepancies were divided into 5 categories of gaps (MG, CG, AWG, AOTG, OG). Data were analyzed with Student's t-test (alpha=0.05), repeated measures ANOVA and two-way ANOVA (alpha=0.05). RESULTS: The mean gap of the zirconia framework prepared from the working models presented a narrower discrepancy than the frameworks fabricated from the impression bodies. The mean of the total gap in premolars (P=.003) and molars (P=.002) exhibited a statistical difference between two groups. CONCLUSION: The mean gap dimensions of each category showed statistically significant difference. Nonetheless, the digitized impression bodies obtained with a laser scanner were applicable to clinical settings, considering the clinically acceptable marginal fit (120 microm).

Pretreatment of ramie and kenaf stalk for bioethanol production / 生物工程学报

Ramie and kenaf were traditional fiber crops in China, but their stalk after decorticating has not been used effectively. The stalk contains a lot of cellulose, and can therefore be used for the production of bioethanol. We studied the effects of different chemical pretreatment on enzymatic digestibility of ramie stalk and kenaf stalk. Ramie and kenaf stalks pretreated with alkali were chosen to produce ethanol using quasi-simultaneous saccharification and fermentation (Q-SSF) process. The results show that for the stalks pretreated with 4% NaOH and 0.02% anthraquinone-2-sulfonic acid sodium salt (AQSS) as catalyzer at 170 degrees C for 1 h, the ethanol concentration could reach 51 g/L after fermentation for 168 h at 18% of solid substrate concentration. By fed-batch to 20% of solid substrate concentration, the ethanol concentration could reach 63 g/L, 77% and 79% of the cellulose conversion could get for ramie stalk and kenaf stalk, respectively. For kenaf stalk pretreated with 5.2% NaHSO3 and 0.2% H2SO4 at 170 degrees C for 1 h, the ethanol concentration and cellulose conversion could reach to 65 g/L and 72%, respectively.