Orthodontic-surgical treatment for severe skeletal class Ⅱ malocclusion with vertical maxillary excess and four premolars extraction: A case report

BACKGROUND Patient satisfaction with facial appearance at the end of orthodontic camouflage treatment is very important, especially for skeletal malocclusion. This case report highlights the importance of the treatment plan for a patient initially treated with four-premolar-extraction camouflage, despite indications for orthognathic surgery.CASE SUMMARY A 23-year-old male sought treatment complaining about his unsatisfactory facial appearance. His maxillary first premolars and mandibular second premolars had been extracted, and a fixed appliance had been used to retract his anterior teeth for two years without improvement. He had a convex profile, a gummy smile, lip incompetence, inadequate maxillary incisor inclination, and almost a class I molar relationship. Cephalometric analysis showed severe skeletal class Ⅱ malocclusion(A point-nasion-B point = 11.5°) with a retrognathic mandible(sella-nasion-B point = 75.9°), a protruded maxilla(sella-nasion-A point = 87.4°), and vertical maxillary excess(upper incisor to palatal plane = 33.2 mm). The excessive lingual inclination of the maxillary incisors(upper incisor to nasion-A point line =-5.5°)was due to previous treatment attempts to compensate for the skeletal class Ⅱ malocclusion. The patient was successfully retreated with decompensating orthodontic treatment combined with orthognathic surgery. The maxillary incisors were repositioned and proclined in the alveolar bone, the overjet was increased, and a space was created for orthognathic surgery, including maxillary impaction, anterior maxillary back-setting, and bilateral sagittal split ramus osteotomy to correct his skeletal anteroposterior discrepancy. Gingival display was reduced, and lip competence was restored. In addition, the results remained stable after 2 years. The patient was satisfied with his new profile as well as with the functional malocclusion at the end of treatment.CONCLUSION This case report provides orthodontists a good example of how to treat an adult with severe skeletal class Ⅱ malocclusion with vertical maxillary excess after an unsatisfactory orthodontic camouflage treatment. Orthodontic and orthognathic treatment can significantly correct a patient’s facial appearance.

Veratrilla baillonii Franch alleviate the symptoms of diabetes in type 2 diabetic rats induced by high-fat diet and streptozotocin

Our previous research studies have shown that Veratrilla baillonii Franch,a food supplement used by ethnic minorities in Southwest China,has multiple pharmacological activities,such as detoxification,antiinflammatory,antioxidant,and anti-insulin resistance.However,the detailed signal pathways for its salutary effect on damages in multiple organs due to type 2 diabetes mellitus(T2DM)remains unclear.The current study is to evaluate the therapeutic effects of V.baillonii on T2DM rats and to explore the underlying mechanisms.The T2DM rat model was successfully established by a high-sugar and high-fat diet(HFD)combination with intraperitoneal injection of a small dose of streptozotocin(STZ,35 mg/kg).Biochemical analysis and histopatholgical examinations were conducted to evaluate the anti-diabetic potential of water extracts of V.baillonii(WVBF).The results showed that the WVBF treatment can improve hyperglycemia and insulin resistance,ameliorate the liver,kidney and pancreas injuries via decreasing inflammatory cytokines such as IL-6 and TNF-α,and oxidative damages.Further investigation suggested that WVBF modulates the signal transductions of the IRS1/PI3K/AKT/GLUT4 and AMPK pathways.These findings demonstrate potentials of WVBF in the treatment of T2DM and possible mechanisms for its hepatoprotective activities.

Associations between Geriatric Nutrition Risk Index,bone mineral density and body composition in type 2 diabetes patients

BACKGROUND Type 2 diabetes mellitus(T2DM),a fast-growing issue in public health,is one of the most common chronic metabolic disorders in older individuals.Osteoporosis and sarcopenia are highly prevalent in T2DM patients and may result in fractures and disabilities.In people with T2DM,the association between nutrition,sarcopenia,and osteoporosis has rarely been explored.AIM To evaluate the connections among nutrition,bone mineral density(BMD)and body composition in patients with T2DM.METHODS We enrolled 689 patients with T2DM for this cross-sectional study.All patients underwent dual energy X-ray absorptiometry(DXA)examination and were categorized according to baseline Geriatric Nutritional Risk Index(GNRI)values calculated from serum albumin levels and body weight.The GNRI was used to evaluate nutritional status,and DXA was used to investigate BMD and body composition.Multivariate forward linear regression analysis was used to identify the factors associated with BMD and skeletal muscle mass index.RESULTS Of the total patients,394 were men and 295 were women.Compared with patients in tertile 1,those in tertile 3 who had a high GNRI tended to be younger and had lower HbA1c,higher BMD at all bone sites,and higher appendicular skeletal muscle index(ASMI).These important trends persisted even when the patients were divided into younger and older subgroups.The GNRI was positively related to ASMI(men:r=0.644,P<0.001;women:r=0.649,P<0.001),total body fat(men:r=0.453,P<0.001;women:r=0.557,P<0.001),BMD at all bone sites,lumbar spine(L1-L4)BMD(men:r=0.110,P=0.029;women:r=0.256,P<0.001),FN-BMD(men:r=0.293,P<0.001;women:r=0.273,P<0.001),and hip BMD(men:r=0.358,P<0.001;women:r=0.377,P<0.001).After adjustment for other clinical parameters,the GNRI was still significantly associated with BMD at the lumbar spine and femoral neck.Additionally,a low lean mass index and higherβ-collagen special sequence were associated with low BMD at all bone sites.Age was negatively correlated with ASMI,whereas weight was positively correlated with ASMI.CONCLUSION Poor nutrition,as indicated by a low GNRI,was associated with low levels of ASMI and BMD at all bone sites in T2DM patients.Using the GNRI to evaluate nutritional status and using DXA to investigate body composition in patients with T2DM is of value in assessing bone health and physical performance.

Thermal stability and mechanical properties of thick thermal barrier coatings with vertical type cracks

The thermal stability and failure mechanism of thick thermal barrier coatings(TBCs) with and without vertical type cracks were investigated through the cyclic thermal exposure and thermal-shock tests. The TBC systems with thickness of about 2000 μm in the top coat were prepared by an air plasma spray(APS) on the bond coat of about 150 μm in thickness prepared by APS. The adhesive strength values of the as-prepared TBCs with and without vertical type cracks were determined to be 24.7 and 11.0 MPa, respectively, indicating the better interface stability in the TBC with vertical type cracks. The TBC with vertical type cracks shows a better thermal durability than that without vertical type cracks in the thermal cyclic exposure and thermal-shock tests. The hardness values of the as-prepared TBCs with and without vertical type cracks were found to be 6.6 and 5.3 GPa, respectively, which were increased to 9.5 and 5.5 GPa, respectively, after the cyclic thermal exposure tests. These results indicate that the vertical type cracks developed in the top coat are important in improving the lifetime performance of thick TBC in high temperature environment.

Gene Expression Profile of Human Skeletal Muscle and Adipose Tissue of Chinese Han Patients with Type 2 Diabetes Mellitus

Objective To study the differential patterns of gene expression in skeletal muscle and adipose tissue between type 2 diabetes mellitus （T2DM） patients and healthy subjects using DNA microarray analysis, Methods T2DM patiens were divided into female group, young male group and old male group. DNA microarray analysis and quantitative real-time PCR were carried out to anaIyze the relation between gene expressions and T2DM. Results The mRNA expression of 298, 578, and 350 genes was changed in the skeletal muscle of diabetes mellitus patients compared with control subjects. The 1320, 1143, and 2847 genes were modified in adipose tissue of the three groups. Among the genes surveyed, the change of 25 and 39 gene transcripts in skeletal muscle and adipose tissue was ≥2 folds, These differentially expressed genes were classified into 15 categories according to their functions. Conclusion New genes are found and T2DM can be prevented or cured.

Skeletal muscle as a therapeutic target for delaying type 1 diabetic complications

Type 1 diabetes mellitus(T1DM) is a chronic autoimmune disease targeting the pancreatic beta-cells and rendering the person hypoinsulinemic and hyperglycemic. Despite exogenous insulin therapy, individuals with T1 DM will invariably develop long-term complications such as blindness, kidney failure and cardiovascular disease. Though often overlooked, skeletal muscle isalso adversely affected in T1 DM, with both physical and metabolic derangements reported. As the largest metabolic organ in the body, impairments to skeletal muscle health in T1 DM would impact insulin sensitivity, glucose/lipid disposal and basal metabolic rate and thus affect the ability of persons with T1 DM to manage their disease. In this review, we discuss the impact of T1 DM on skeletal muscle health with a particular focus on the proposed mechanisms involved. We then identify and discuss established and potential adjuvant therapies which, in association with insulin therapy, would improve the health of skeletal muscle in those with T1 DM and thereby improve disease managementultimately delaying the onset and severity of other longterm diabetic complications.

Ultrasonic beam focusing characteristics of shear-vertical waves for contact-type linear phased array in solid

We investigate the beam focusing technology of shear-vertical(SV) waves for a contact-type linear phased array to overcome the shortcomings of conventional wedge transducer arrays. The numerical simulation reveals the transient excitation and propagation characteristics of SV waves. It is found that the element size plays an important role in determining the transient radiation directivity of SV waves. The transient beam focusing characteristics of SV waves for various array parameters are deeply studied. It is particularly interesting to see that smaller element width will provide the focused beam of SV waves with higher quality, while larger element width may result in erratic fluctuation of focusing energy around the focal point. There exists a specific range of inter-element spacing for optimum focusing performance. Moreover, good beam focusing performance of SV waves can be achieved only at high steering angles.

Performance Improvement by Control of Wingtip Vortices for Vertical Axis Type Wind Turbine

The present paper describes control of wingtip vortices generated by vertical type wind turbine. The wind turbine consists of three circular cylinders. Each cylinder rotates on its own vertical axis and moves in orbit. It is known that wingtip vortices give rise to decrease of power generation performance as well as aerodynamic noise. Therefore, the goal of the study is to control wingtip vortices and to improve power generation performance. Numerical study was conducted for 14 models to find out control factors to suppress wingtip vortices. Numerical simulation visualized wingtips by streamlines as well as pressure distribution on the circular cylinder for evaluating Magnus effect. As a result, the following findings were obtained: 1) Installation of fully covered protection plates at both ends of the circular cylinder blades is greatly effective to suppress the wingtip vortices. 2) Curved wings attached to each cylinder are more effective to enhance power generation efficiency than flat ones, due to great increase in Magnus effect caused by large pressure difference on both sides of the curved wing. The power efficiency of the optimized model was improved up to 2.8%, which means 11 times that of the original model.

Skeletal muscle and whole body insulin resistance but not cardiac muscle insulin resistance could be improved by troglitazone therapy within 12 weeks in type-2 diabetes

Background: Existence of myocardial insulin resistance (IR) has been reported in type II diabetics (T2- DM) and coronary artery disease (CAD). Improvement in heart and skeletal muscle IR after thiazolidinedione’s therapy was reported in T2DM and CAD. However effects of troglitazone therapy (TRO) on myocardial IR remain uncertain. To clarify heart and skeletal muscle and whole body IR in T2DM without CAD by TRO to clarify whether TRO would provide different results. Methods: We analyzed data on 15 T2DM patients who underwent dynamic PET with 18F-FDG under insulin clamping before and during TRO (200 mg/day) and 17 controls. Results: Whole body glucose disposal rate (WBGR mg/min/kg) in T2DM before TRO (3.41 ± 1.72) was significantly lower than in controls (9.76 ± 2.97, p < 0.01) as was the skeletal muscle glucose utilization rate (SMGU mg/min/kg);T2DM (0.367 ± 0.217) vs. controls (1.34 ± 0.613, p < 0.01) and myocardial glucose utilization rate (MGU mg/min/kg;T2DM 5.86 ± 2.03 vs. controls 7.34 ± 1.80, p < 0.05). WBGR in T2DM during TRO (5.17 ± 2.75, p < 0.05) was significantly higher than that before TRO, as was the SMGU (0.782 ± 0.20, p < 0.05). The MGU in T2DM during TRO (6.59 ± 0.72) was comparable with that before TRO. Conclusion: Myocardial IR response to TRO differed from that in skeletal muscle and the whole body in T2DM without CAD.

Yiqi Yangyin and Huatan Quyu granule can improve skeletal muscle energy metabolism in a type 2 diabetic rat model by promoting the AMPK/SIRT/PGC-1α signalling pathway

Objective:To investigate how Yiqi Yangyin and Huatan Quyu granule (YYHO) improves skeletal muscle insulin resistance in a type 2 diabetic rat model and to discover whether the molecular mechanism is related to the promotion of the AMPK/SIRT/PGC-1α signalling pathway.Methods:Rats were randomly divided into 4 groups:the normal group,the model group,the YYHQ granule group,and the pioglitazone group.The type 2 diabetic rat model was established by feeding a high-fat diet for 5 weeks along with a single intraperitoneal injection of 30 mg/kg streptozotocin (STZ).After modelling successfully,the appropriate drug was intragastrically administered to diabetic rats for 2 weeks,once per day.The YYHQ granule group was given a dose of 4.8 g/kg body weight per day,the pioglitazone group was given a dose of 1.35 mg/kg body weight per day.The doses for both groups were equivalent to the clinical equivalent dose based on a previous study.Other groups were gavaged with the same amount of saline water.Body weight,food intake,water intake,urine volume and grip strength were recorded weekly.The fasting blood glucose(FBG) was determined weekly using blood glucose test strips.The related glucose and lipid metabolism indexes,e.g.,fasting insulin (Fins),glycated haemoglobin (GHb),HOMA-IR,ISI,triglycerides (TG),total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C) and free fatty acid (FFA),were determined using biochemical method.The mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK),peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α),carnitine palmitoyl transterase-1 (CPT-1),Sirtuin 1 (SIRT1),and Sirtuin 3 (SIRT3) were assessed using quantitative real-time PCR (qRT-PCR).The protein expression levels of creatine kinase (CK),Ca2+ ATPase,α-Actin,AMPK,PGC-1α and CPT-1 were determined using enzyme-linked immunosorbent assay method (ELISA).Results:Body weight decreased significantly (P <.01),food intake,water intake and urine volume increased significantly (P <.01),and grip strength decreased significantly (P <.01) in the model group compared with the normal group.The levels of FBG,Fins,GHb and HOMA-IR increased significantly (P <.01),and the ISI decreased significantly (P <.01) in the model group.The levels of TG,TC,LDL-C and FFA increased significantly (P <.05 or P <.01),and the level of HDL-C decreased significantly (P <.05) in the model group.These changes were reversed after treatment with YYHQ granule or pioglitazone.Compared with the model group,the YYHQ granule and pioglitazone groups significantly improve body weight,water intake and urine volume (P <.05 or P <.01),however,both treatments had no significant effect on food intake (P >.05).The levels of FBG,Fins,GHb,HOMA-IR and ISI were improved significantly (P <.01) and the levels of TG,TC and LDL-C were improved significantly (P <.05 or P <.01),however,both treatments had no significant effect on the levels of HDL-C and FFA (P >.05).Further results indicated that YYHQ granule significantly decreased the mRNA expression of AMPK,PGC-1α,CPT-1,SIRT1 and SIRT3 in skeletal muscle (P <.01) and the pioglitazone group showed similar effects;moreover,the protein expression levels of CK,Ca2+ATPase,α-Actin,AMPK,PGC-1α and CPT-1 in skeletal muscle significantly decreased (P <.01),however,pioglitazone had no significant effect on CK and α-Actin (P >.05).Conclusion:The possible molecular mechanism of YYHQ granule improving skeletal muscle insulin resistance in a type 2 diabetic rat model may be related to the stimulation of energy metabolism in skeletal muscle via the AMPK/SIRT/PGC-1α signalling pathway.

2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素

目的观察2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素。方法前瞻性招募62例2型糖尿病患者(T2DM组)及60名健康成年人(HC组),以剪切波弹性成像(SWE)技术检测其放松及收缩状态下腹直肌和腓肠肌最大杨氏模量(E_(max)),比较组间2种状态下骨骼肌厚度及弹性模量,并采用多重线性回归分析影响腹直肌和腓肠肌弹性模量的因素。结果组间放松及收缩状态下腹直肌和腓肠肌厚度差异均无统计学意义(P均>0.05);T2DM组放松及收缩状态下腹直肌及腓肠肌Emax均低于HC组(P均<0.05)。多重线性回归分析显示,T2DM组放松及收缩状态下腹直肌及腓肠肌弹性模量均随病程、空腹血糖(FBG)及糖化血红蛋白(HbA1c)而呈线性降低(P均<0.05)。结论2型糖尿病患者骨骼肌弹性模量降低,且随病程、FBG及HbA1c而呈线性下降。

运动联合益生菌干预2型糖尿病大鼠糖脂代谢、氧化应激及骨骼肌卫星细胞成肌分化水平的变化

目的观察运动联合益生菌干预2型糖尿病大鼠糖脂代谢、氧化应激及骨骼肌卫星细胞表达的影响。方法8周龄SPF级SD雄性大鼠60只,随机选择10只大鼠为正常对照组(NC组),造模组大鼠腹腔注射链脲佐菌素,建立2型糖尿病大鼠模型,随机分为模型组(TN组)、运动+糖尿病组(YTN组)、益生菌+糖尿病组(GTN组)、运动+益生菌+糖尿病组(YGTN组),6周的递增负荷有氧跑台运动(第1周跑台速度为15 m/min,持续30 min;第2周跑台速度为15 m/min,持续60 min;第3~6周跑台速度为19.3 m/min,运动时间持续60 min,持续训练到第6周,每周5 d);GTN组和YGTN组在训练前1 h灌胃10.0 mL/(kg·d)的Lactibiane Iki益生菌溶液(浓度为10~7 CFU/mL)。最后,测定大鼠糖脂代谢指标、氧化应激指标及骨骼肌卫星细胞蛋白的表达。结果(1)TN组、YTN组、GTN组和YGTN组大鼠空腹血糖(fasting plasma glucose,FBG)、血清胰岛素(fasting serum insulin,FINS)、糖化血红蛋白(hemoglobin A1c,HBA1C)和胰岛素抵抗指数(homeostasis model assessment-insulin resistance index,HOMA-IR)水平均高于NC组(P<0.01),其中,YGTN组大鼠FBG水平均低于TN组、YTN组、GTN组(P<0.05);YTN组、GTN组和YGTN组大鼠血清FINS水平均与TN组比较均有所下降(P<0.01);YGTN组大鼠血清HBA1C水平均低于TN组、YTN组和GTN组水平(P<0.01);YGTN组大鼠HOMA-IR指数与TN组、YTN组和GTN组比较下降较显著(P<0.01)。结果表明有氧运动联合益生菌干预组大鼠FBG、FINS、HBA1C和HOMA-IR含量下降较明显。(2)TN组大鼠血清总胆固醇(total cholesterol,T-CHO)、甘油三酯(triglyceride,TG)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL)和游离脂肪酸(free fatty acid,FFA)水平均高于NC组(P<0.05),YGTN组大鼠血清T-CHO、TG、LDL和FFA水平均低于TN组(P<0.05),基本上恢复到NC组的水平。TN组大鼠血清高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL)水平低于NC组(P<0.05),YGTN组大鼠血清HDL水平高于TN组(P<0.05),基本上恢复到NC组水平。结果表明有氧运动联合益生菌干预糖尿病大鼠,可降低糖尿病大鼠血清T-CHO、TG、LDL、FFA含量,提高HDL水平较明显。(3)TN组大鼠血清丙二醛(malondialdehyde,MDA)和游离8-异前列腺素F2α(8-iso-prostaglandin F2α,8-isoPGF2α)水平均高于NC组(P<0.05或P<0.01),YGTN组大鼠血清MDA和8-isoPGF2α水平均低于TN组(P<0.05或P<0.01);TN组大鼠血清过氧化氢酶(catalase,CAT)、超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)和总抗氧化能力(total antioxidant capacity,T-AOC)水平均低于NC组(P<0.01),YGTN组大鼠血清CAT、SOD、GSH-Px和T-AOC水平均高于NC组(P<0.01),但基本上恢复到NC组的水平。(4)TN组大鼠骨骼肌卫星细胞配对盒基因7(paired box gene 7,Pax7)、成肌分化因子(myogenic determination gene,MyoD)、肌细胞生成素(myogenin,MyoG)和生肌因子5(myogenic factor 5,Myf5)蛋白表达均低于NC组(P<0.05或P<0.01),YGTN组大鼠骨骼肌Pax7、MyoD、MyoG和Myf5蛋白表达均高于TN组(P<0.05或P<0.01);基本上恢复到NC组水平。TN组大鼠骨骼肌生成抑制素(myostatin,MSTN)蛋白表达高于NC组(P<0.05),YGTN组大鼠骨骼肌MSTN蛋白表达低于TN组(P<0.05),基本上恢复到NC组水平。结论益生菌和有氧运动具有减轻胰岛素抵抗,改善血脂和氧化激的作用,在改善2型糖尿病大鼠血糖和胰岛素水平具有协同作用。此外,有氧运动联合益生菌干预促进了肌细胞的分化,可能对防止T2DM引起肌肉质量的流失和力量下降以及肌肉组织的并发症发挥一定的作用。

夹带式散粮垂直提升实验测试平台设计

该文研发了一种用于测试夹带式散粮垂直提升机效率和性能的实验测试平台,平台包括喂料结构、夹带式垂直提升结构和调控结构等。该实验平台可根据不同物料种类调节喂料装置与垂直提升段的间距,并通过调节输入气流参数调整皮带对物料的夹持力,在水平运输段使用皮带秤实时监测物料量以计算垂直提升效率。此外,通过分析运输过程中不同输入条件下垂直提升段上特殊点的振动特性,可以探究夹持力与喂料工艺参数对运输质量的影响,帮助改进垂直提升装置的结构。该平台用振动信号的形式表达调节参数对输送质量的影响,可提高教学质量,为培养创新型人才提供支持。

超声造影在2型糖尿病患者骨骼肌微循环病变评估中的应用

目的通过超声造影(contrast-enhanced ultrasound,CEUS)评估小腿三头肌的微循环灌注情况,探讨CEUS在2型糖尿病(type 2 diabetes mellitus,T2DM)微血管病变评估中的应用价值。方法收集2020年8月至2023年1月在温州医科大学附属第二医院内分泌科住院治疗的T2DM患者51例,分为单纯T2DM组(n=15)、T2DM微循环病变组(n=36),记录每位患者的糖化血红蛋白(hemoglobin A1c,HbA1c)和胰岛素抵抗指数(homeostatic model assessment for insulin resistance,HOMA-IR)。CEUS观察小腿三头肌的造影情况,获取定量造影指标区域增强强度(enhanced intensity,PI-BI)和区域达峰时间(regional peak time,TTP-AT),并进行组间对比分析。结果T2DM微变组的HbA1c及HOMA-IR高于单纯T2DM组(P<0.05)。T2DM微变组腓肠肌内侧头(musculi gastrocnemii,MG)、腓肠肌外侧头(laterale musculi gastrocnemi,LG)、比目鱼肌(soleus,SOL)及交界区的TTP-AT均长于单纯T2DM组(P<0.05)。两组SOL的TTP-AT均为最长,LG次之,MG最短(P<0.05)。T2DM微变组MG的PI-BI高于SOL(P<0.05)。小腿三头肌交界区的TTP-AT与HbA1c、HOMA-IR之间均呈正相关(P<0.05)。结论CEUS小腿三头肌TTP-AT是评估T2DM患者微血管病变的新指标。

不同垂直骨面型下颌第一磨牙横向位置差异的CBCT研究

目的:使用锥形束CT(cone beam CT,CBCT)测量不同垂直骨面型下颌第一磨牙生理牙槽骨厚度,评估横向磨牙位置。方法:选取2023年1~10月在合肥市口腔医院正畸二科就诊患者50例,分为高角组、均角组及低角组,术前拍摄CBCT,数据导入配套三维软件进行4个部位不同深度牙槽骨厚度的测量分析。结果:高角患者下颌第一磨牙的骨厚度最小。下颌第一磨牙舌侧骨厚度高于颊侧。下颌第一磨牙釉牙骨质界根方4 mm处近中舌侧牙槽骨厚度高于远中舌侧,近中颊侧牙槽骨厚度与远中颊侧比较差异无统计学意义。下颌第一磨牙釉牙骨质界根方8 mm处远中颊侧牙槽骨厚度高于近中颊侧,近中舌侧的牙槽骨厚度与远中舌侧比较差异无统计学意义。下颌第一磨牙同一测量位点釉牙骨质界根方8 mm的牙槽骨厚度高于根方4 mm的牙槽骨厚度。结论:不同的垂直骨面型、测量部位、测量深度、牙齿解剖形态都会反映出下颌第一磨牙在牙槽骨中横向位置的差异。

垂直循环类机械式停车设备速度偏差超标原因分析

机械式停车设备的运行速度是设计过程中需要保证的主要参数之一,也是型式试验过程中的一个主要测试项目。针对一台垂直循环类机械式停车设备型式试验样机在型式试验中发现的额定速度偏差超标问题,对传动系统和设计计算中可能会影响运行速度的因素进行了深入的分析和讨论,确定了速度偏差超标的主要原因。文中的分析方法和结论为垂直循环类机械式停车设备的设计、制造、安装、修理、检验检测和故障分析提供参考。

静力性训练改善2型糖尿病骨骼肌胰岛素抵抗的机制

背景:骨骼肌胰岛素抵抗是2型糖尿病的关键病理环节,静力性训练可以有效改善骨骼肌胰岛素抵抗,但其机制尚未明确。目的:基于PI3K/AKT/GLUT4信号通路,探讨静力性训练对2型糖尿病小鼠骨骼肌胰岛素抵抗的作用机制。方法:将40只C57BL/6小鼠适应性喂养1周后,随机选取7只作为空白组,普通饲料喂养;其余小鼠通过高脂饲料联合小剂量链脲佐菌素腹腔注射建立2型糖尿病模型。将24只造模成功的小鼠随机分为模型组(n=8)、二甲双胍组(n=8)及静力性训练组(n=8),继续以高脂饲料喂养。二甲双胍组以二甲双胍200 mg/kg的剂量溶于生理盐水(2 mL/kg)灌胃,1次/d;静力性训练组每日以生理盐水灌胃后予静力性训练,每日30 min,每周运动6 d;模型组每日予同等剂量生理盐水灌胃,无运动干预。干预6周结束后检测各组小鼠空腹血糖,行腹腔葡萄糖耐量测试并计算血糖曲线下面积;ELISA检测糖化血红蛋白、血清胰岛素、胰岛素抵抗指数;生化法检测总胆固醇、三酰甘油、高密度脂蛋白、低密度脂蛋白;RT-qPCR法检测小鼠腓肠肌PI3K、AKT和GLUT4的mRNA表达量;苏木精-伊红染色观察腓肠肌形态学变化,并计算肌纤维横截面积。结果与结论:①与空白组相比,模型组小鼠的空腹血糖、糖化血红蛋白、血糖曲线下面积、胰岛素抵抗指数、总胆固醇、三酰甘油、低密度脂蛋白显著升高(P<0.01,P<0.05);静力性训练组和二甲双胍组小鼠上述指标显著低于模型组(P<0.01,P<0.05);②与空白组相比,模型组小鼠血清胰岛素和高密度脂蛋白显著下降(P<0.01),腓肠肌组织中PI3K、AKT和GLUT4 mRNA表达量显著下降(P<0.01);静力性训练组和二甲双胍组小鼠上述指标显著升高(P<0.01);③与空白组相比,模型组小鼠肌纤维排列紊乱,肌细胞萎缩,肌纤维间隙变大,肌纤维横截面积显著减少(P<0.01);与模型组相比,静力性训练组和二甲双胍组小鼠的腓肠肌纤维萎缩和肌纤维间隙情况有一定程度的改善,肌纤维横截面积均显著增加(P<0.01);④结果提示,静力性训练可能通过上调骨骼肌组织中PI3K、AKT和GLUT4 mRNA表达,促进葡萄糖的摄取和利用,从而改善骨骼肌组织的形态与功能,减轻胰岛素抵抗,调节机体的葡萄糖稳态。

错[牙合]畸形患者髁突位置及正畸治疗前后髁突位置变化的CBCT评估

口颌系统的功能健康、稳定是口腔正畸治疗的基本目标之一。健康人群的下颌处于牙尖交错位(in-tercuspal position,ICP)时髁突位置基本位于关节窝的中央,颞下颌关节功能稳定。错[牙合]畸形患者由于正畸牙齿移动及咬合改变,可能发生颞下颌关节的相关改建,特别是髁突位置的改变。传统的髁突位置的评估方法是通过架来转移下颌位置,然后在髁突位置测量仪上进行测量,但此方法得到的髁突位置变化缺乏一致性。近年来,锥形束CT(cone beam computed tomography,CBCT)成为正畸治疗检查的首选,CBCT可精准地测量关节间隙,确定髁突位置的改变。本文对髁突位置的CBCT评估及正畸治疗前后的错[牙合]畸形髁突位置变化的研究进行综述。文献复习结果表明,不同错[牙合]畸形患者的髁突位置存在差异,正畸治疗前后髁突位置也可能发生变化,使用CBCT可以较低的辐射剂量和更高的精确度评价错[牙合]畸形的髁突位置,有助于进一步研究错畸[牙合]形患者髁突位置变化的机制,并为患者治疗提供更准确、个性化的指导。

高质量碲镉汞双层异质结材料制备

本文重点介绍了富汞垂直液相外延技术,在对该技术进行研究时,提出了一种温场优化方法和一种生长方法来提升材料质量和工艺稳定性。最后介绍基于双层异质结材料采用台面结器件加工等碲镉汞探测器组件制备方法,制备中波、长波和甚长波碲镉汞探测器组件的进展情况。

干红花收获机立式辊刷采摘装置设计与试验

针对旱地干红花人工采收时不易捏取导致采摘效率低、掉落率高等问题,该研究结合红花的物理特性和种植模式,设计了立式辊刷干红花收获机采摘装置。根据机具结构对刷丝排布方案进行理论分析,确定刷丝排布方案为螺旋式,螺旋升角为30°,旋向为右旋。对辊刷采摘干红花进行力学分析,得出使花丝脱离果球的关键作用力为法向力FN。采用Hertz弹性接触理论对FN进行分析,并建立刷丝-果球接触力学模型,揭示干红花的采摘原理,明确影响采摘质量的主要因素为刷丝材质、丝径、长度和辊刷转速,进一步对立式辊刷结构与运动参数进行分析,得出采摘装置优化参数组合为:辊刷长度300 mm,辊刷直径100 mm,辊刷转速360 r/min,刷丝材质为聚酰胺610(PA-610),刷丝长度30 mm,刷丝丝径0.3 mm。通过植株通过率试验确定立式辊刷与栅条架的间隙为12 mm。田间采摘试验表明,该装置的红花采摘率和伤果率分别为87.04%和4.19%,机具采摘效率为人工采摘效率的7.71~10.92倍。研究结果可为辊刷式干红花收获机的设计与优化提供参考。