基于CAXA制造工程师的健腹轮内壳动内模的数控加工

为提高数控铣削效率,针对健腹轮内壳动内模及CAXA制造工程师的特点,采用一种高效的加工策略,将Pro/E中已生成的实体模型转换成IGES文件,导入到CAXA后生成刀具轨迹,仿真加工后进行后置处理,将生成的G代码传到数控铣床,实际加工结果符合要求,验证了该加工方法正确,编程效率提高。

普罗布考联合瑞舒伐他汀治疗对脑梗死伴颈动脉斑块患者颈动脑内膜中层厚度及血清hs-CRP、脂蛋白水平的影响

目的观察普罗布考联合瑞舒伐他汀治疗脑梗死伴颈动脉斑块的临床效果。方法收集2013年7月-2015年6月医院收治的脑梗死伴颈动脉斑块患者113例,根据随机、单盲、平行对照设计原则分为对照组55例和观察组58例,对照组给予普罗布考治疗,观察组在此基础上联合使用瑞舒伐他汀治疗,将2组患者治疗后的颈动脉内膜中层厚度、血清超敏C反应蛋白(hs-CRP)以及脂蛋白水平进行观察和对比。结果观察组治疗后的颈动脉内膜中层厚度为(1.0±0.1)mm明显低于对照组的(1.2±0.3)mm,观察组血清hs-CRP水平为(2.8±0.6)mg/L显著低于对照组的(6.3±1.2)mg/L,观察组脂蛋白水平为(15.4±3.2)U/m L显著低于对照组的(25.9±6.3)U/m L,差异均有统计学意义(P<0.05)。结论在脑梗死伴颈动脉斑块患者的治疗过程中,普罗布考联合瑞舒伐他汀能够使颈动脉粥样硬化斑块得到稳定,优化炎症因子,降低血脂水平,患者预后良好,值得推广应用。

Effect of early nutrition on intestine development of intrauterine growth retardation in rats and its correlation to leptin

AIM：To investigate the intestine and body development of intrauterine growth retardation（IUGR）rats under early different protein diet and to analyze the correlation between leptin and intestine and body development．METHODS：An IUGR rat model was established by food restriction of pregnant female rats．Fifty-six neonatal IUGR rats and 24 neonatal normal rats were randomly divided into normal control group（Cgroup），IUGR model group （scgroup），low protein diet IUGR group（SL group），and high protein diet IUGR group（SH group）．Eight rats were killed per group at wk 0，4，and 12．Serum leptin，body weight（BW），body length（BL），intestinal weight（IW），intestinal length（IL），andintestinal disaccharidase（including lactase，maltase，and saccharase） were detected．RESULTS：BW（4．50±0．41g），BL（5．96±0．40cm），IW（0．05±0．01g），and IL（15.9±2．8cm）in neonatal IUGR rats were much lower than those in Cgroup（6．01±0．55g，6．26±0．44cm，0．10±0．02g，21.8±2．7cm，P〈0．05），while intestinal lactase and maltase activities were higher than those in Cgroup．SH group showed the fastest catch up growth and their BW，BL，IW，and IL reached the Cgroup level at wk 4．SC group showed relatively slower catch up growth than SH group，and their BW，BL，IW did not reach the Cgroup level at wk 4．SL group did not show intestine and body catch up growth．Intestinal maltase [344±33μmol／（min·q）]and saccharase activities[138±32μmol／（min·g）]in SL group were both markedly lower than nose in C group [751±102，258±271μmol／（min·g），P〈0．05]．There were no significant difierences in lactase activities at wk 4 and disaccharidase activities at wk 12 among all groups（P〈0．05）．The leptin level in SL group（0．58±0．12ng／mL） was the highest in all groups，and much lower in SH group（0．21±0．03ng／mL） than that in any other IUGR groups at wk 4（P〈0．05）．Leptin was negatively related to BW （r=-0．556，P=0．001），IW（r=-0．692，P=0．001） and IL（r=-0．738，P=0．000）at wk 4，while no correlation was found at wk 12．CONCLUSION：High protein diet is a reasonable early nutritional mode to IUGR rats in promoting intestine and body catch up growth．

BTEB2 antisense RNA inhibits intimal hyperplasia in a rat carotid balloon injury model

Objective： To investigate the effects of basic transcriptional element binding protein-2 （BTEB2） antisense RNA on vascular smooth muscle cells （VSMCs） proliferation and the neointimal formation after carotid balloon injury in rats. Methods： The cultured VSMCs were transfected with an adenoviral vector containing BTEB2 antisense gene, Ad ASBTEB2. Effects of BTEB2 antisense RNA on the expression of BTEB2 were investigated by Western blot analysis. The cell cycle was analyzed using flow cytometry. Ad ASBTEB2, control adenoviral vector Ad. LacZ or PBS was transduced into the rat carotid artery after balloon injury. The expression of BTEB2 at 7, 14, and 21 d after gene transfer was detected by immunohistochemistry and neointima-to-media （I/M） area ratio at these time points was calculated. Resuits： The cell cycle was arrested in G0/G1 phase and the expression of BETB2 was downregulated after transfection with Ad ASBTEB2. Ad ASBTEB2 treatment reduced I/M area ratios on day 7, 14, and 21 after injury by 45%, 50% and 53% respectively, whereas the Ad LacZ treatment did not significantly alter these ratios compared with control group. Conclusion： BTEB2 antisense RNA mediated by adenoviral vector inhibits proliferation of VSMCs and significantly reduces neointimal hyperplasia in the rat carotid balloon injury model. BTEB2 antisense RNA is a potential therapeutic approach to preventing neointimal formation after balloon injury.

COVID-19 Resulting in Potential Hearing Damage of Rodents

Objectives To find out the association between the sensorineural hearing loss and coronavirus disease 2019(COVID-19),the expression of ACE2 and TMPRSS2 in hamsters and mice was detected.Design Using the public data from the National Center for Biotechnology Information and the Global Initiative on Sharing All Influenza Data,the expression of ACE2 and TMPRSS2 at the transcriptomic,DNA,and protein levels of ACE2 in the brain,inner ear,and muscle from the golden Syrian hamsters(Mesocricetus auratus)and mice(Mus musculus)was assessed.Results We identified ACE2 and TMPRSS2 expressed at different levels in the inner ear and brain at DNA and transcriptomic levels of both mice and hamsters.The protein expression from the brain and inner ear showed a similar pattern,while the expression of ACE2 from the inner ear was relatively higher than that from the muscle.Conclusion Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)shows genetic potential to infect the hearing system of rodents and lead to sudden sensorineural hearing loss that can be used as a characteristic to detect asymptomatic patients of COVID-19.

Trial of a novel endoscopic tattooing biopsy forceps on animal model

AIM: To tattoo gastric mucosa with a novel medical device which could be used to monitor and follow-up gastric mucosal lesions.METHODS: Combining endoscopic biopsy with sclerotherapy injection, we designed a new device that could perform biopsy and injection simultaneously. We performed endoscopies on a pig by using a novel endoscope tattoo biopsy forceps for 15 mo. At the same time, we used two-step method combining sclerotherapy injection needle with endoscopic biopsy. The acuity, inflammation and duration of endoscopy were compared between two methods.RESULTS:Compared with the old two-step method,although the inflammation induced by our new device was similar, the duration of procedure was markedly decreased and the acuity of tattooing was better than the old two-step method. All characteristics of the novel device complied with national safety guidelines. Follow-up gastroscopy after 15 mo showed the stained site with injection of 1:100 0.5 mL of India ink was still markedly visible with little inflammatory reaction.CONCLUSION: Endoscopic tattooing biopsy forceps can be widely used in monitoring precancerous lesions.Its safety and effectiveness has been established in animals.

A novel animal model for in vivo study of liver cancer metastasis

AIM:To establish an animal model with human hepatocyte-repopulated liver for the study of liver cancer metastasis.METHODS:Cell transplantation into mouse livers was conducted using alpha-fetoprotein(AFP)-producing hu-man gastric cancer cells(h-GCCs) and h-hepatocytes as donor cells in a transgenic mouse line expressing urokinase-type plasminogen activator(uPA) driven by the albumin enhancer/promoter crossed with a severe combined immunodeficient(SCID) mouse line(uPA/SCID mice).Host mice were divided into two groups(A and B).Group A mice were transplanted with h-GCCs alone,and group B mice were transplanted with h-GCCs and h-hepatocytes together.The replacement index(RI),which is the ratio of transplanted h-GCCs and h-hepatocytes that occupy the examined area of a histological section,was estimated by measuring h-AFP and h-albumin concentrations in sera,respectively,as well as by immunohistochemical analyses of h-AFP and human cytokeratin 18 in histological sections.RESULTS:The h-GCCs successfully engrafted,repopulated,and colonized the livers of mice in group A(RI = 22.0% ± 2.6%).These mice had moderately differentiated adenocarcinomatous lesions with disrupted glandular structures,which is a characteristics feature of gastric cancers.The serum h-AFP level reached 211.0 ± 142.2 g/mL(range,7.1-324.2 g/mL).In group B mice,the h-GCCs and h-hepatocytes independently engrafted,repopulated the host liver,and developed colonies(RI = 12.0% ± 6.8% and 66.0% ± 12.3%,respectively).h-GCC colonies also showed typical adenocarcinomatous glandular structures around the h-hepatocyte-colonies.These mice survived for the full 56 day-study and did not exhibit any metastasis of h-GCCs in the extrahepatic regions during the observational period.The mice with an h-hepatocyte-repopulated liver possessed metastasized h-GCCs and therefore could be a useful humanized liver animal model for studying liver cancer metastasis in vivo.CONCLUSION:A novel animal model of human liver cancer metastasis was established using the uPA/SCID mouse line.This model could be useful for in vivo testing of anti-cancer drugs and for studying the mechanisms of human liver cancer metastasis.

Study on fuzzy control of dynamic equalization based on state prediction

A new method of using dynamic equalization technology to realize the maximum energy storage utilization was presented to overcome the influence of the disaccord among units of series super capacitor （SC） bank and ensure that the units could work safely. By considering in combination with the high specific power, low working voltage, wide voltage working range and noulinear external characteristics, we present constant duty ratio pulse frequency modulation mode and fuzzy control method based on state prediction in the active equalization circuit and accomplish the software and hardware design for the equalization system. The simulation analysis and experiment results of constant current muhi-cycle and variable current multi-cycle charge-discharge process verify the validity of the design.

DYNAMIC CHANGES OF SERUM VASCULAR ENDOTHELIAL GROWTH FACTOR LEVELS IN A RAT MYOCARDIAL INFARCTION MODEL

To investigate the dynamic changes of serum vascular endothelial growth factor(VEGF) levels in a rat model of acute myocardial infarction. Materials and methods.Eighty eight adult male Sprague Dawley rats weighing approximately 270 g were used in this study. Eighty rats were subjected to left coronary artery ligation, with 8 rats for each different duration of infarct. Eight sham operated animals in which the left coronary artery was surgically exposed without ligation were used as controls. Blood samples were drawn from the right atrium before (sham animals) and 1,3,6,12,24 h and 2,3,5,7,14 d after myocardial infarction. The concentrations of serum VEGF were measured by a sensitive enzyme linked immunosorbent assay with a rabbit polyclonal antibody specific for VEGF. Results. In the 8 control animals, the mean concentration of serum VEGF was 66.99±17.83 pg/ml. Six hours after myocardial infarction, the level of serum VEGF significantly increased to 125.68±28.07 pg/ml (P<0.01 vs. sham controls), and reached a peak (240.61±70.63 pg/ml. P<0.01 vs. sham animals) at 24 h after ligation and then decreased gradually over the remaining 2 weeks. However, the level remained significantly elevated for 14 d (107.64±30.13pg/ml, P<0.01 vs. sham controls). Conclusion. The present study shows that the levels of serum VEGF are markedly increased until 14 d in the rat model of acute myocardial infarction. The increased serum VEGF level may play an important role in the angiogenesis associated with myocardial infarction.

COMPARISON OF CELLULOSE ACETATE POLYMER AND ELECTROLYTIC DETACHABLE COILS FOR TREATMENT OF CANINE ANEURYSMAL MODELS

Electrolytic detachable coils (EDC) have been the main embolic materi als for intracranial aneurysms. Liquid aneurysmal embolic materials represented by cellulose acetate polymer (CAP) are still in controversy. In this research, t he embolization results and pathological reactions after embolization of canine aneurysmal models with EDC or CAP were observed and compared. Methods. The canine aneurysmal models constructed by anastomosis of venous pouch es were randomly grouped. The aneurysms were respectively occluded with CAP and electrolytic detachable coils that was named by Wu electrolytic detachable coil (WEDC) and made by us. Angiogram follow ups were performed at 24 hour, 2 week , and 2 month after embolization. The occluded aneurysms were dissected in each stage for light microscopic, electron microscopic, and histochemical research. Results. The effect of embolization was significantly better with WEDC than that with CAP . Post embolized complications such as aneurysm rupture and stenosis of parent arteries could only be found in CAP group. Pathol ogical research showed that CAP mass could packed the aneurysms more densely tha n coils. Acute chemical damage of aneurysmal wall and inflammatory cell infiltra tion was prominently found in early stage after CAP embolization. Organization of thrombus inside aneurysms and formation of endothelial tissue over the orific es of aneurysmal necks could be found in both groups 2 months after embolization . But parts of coils might be exposed outside endothelial layer. Conclusions. EDC are still the most safe, efficient, and reliable instruments to embolize aneurysm. CAP should be improved further to solve the problem of stron g chemical corrosion and difficulty in control before it is widely used.

Generation of Superpositions of Two-Mode Coherent States for the Motion of Two Trapped Ions

We propose a method for the generation of superpositions of two-mode coherent states for the center-of-mass and relative vibrational modes of two trapped ions. In the scheme the ions are driven by a single travelling-wave laser field tuned to the carrier. Then a measurement of the internal states collapses the vibrational modes to the entangled coherent state.

Real-Time Arm Animation with Natural Collision Avoidance

A novel approach to realistic collision-free animation of the upper limb was proposed.According to the obstacle-avoidance strategy of human hand,the movement trajectory was computed by manipulability model and minimum-jerk based interpolation.In each key frame,an improved in～verse kinematics method was adopted to obtain a believable posture of the upper limb.By comparing with the real movement data obtained from the motion capture device,the resultant animation was testified to be natural.This method can be performed in interactive time,and therefore is applicable in animation edit and control of virtual humans.

DNS analysis of incipient drop impact dynamics using an accurate level set method

A series of 2D direct numerical simulations were performed with an accurate level set method for single drop impacts.The adopted ACLS method was validated to be efficient with perfect mass conservation in both normal and oblique impacts.A square-root correction for neck bases was modified in accuracy as well as scope of applications.In addition,process of jet formation and evolution was studied to reveal internal dynamics in drop impacts.It's found that pressure gradient and vortex are coexisting and completive reasons for jet topology while the inclined angle has a significant effect on them.Mechanisms of jet formation and evolution are different in the front and back necks.With the help of PDF distribution and correction calculation,a compromise in the competition is observed.This work lays a solid foundation for further studies of dynamics in gas-liquid flows.

Three-dimensional transient numerical simulation for intake process in the engine intake port-valve-cylinder system

This paper presents a KIVA-3 code based numerical model for three-dimensional transient intake flow in the intake port-valve-cylinder system of internal combustion engine using body-fitted technique, which can be used in numerical study on internal combustion engine with vertical and inclined valves, and has higher calculation precision. A numerical simulation (on the intake process of a two-valve engine with a semi-sphere combustion chamber and a radial intake port) is provided for analysis of the velocity field and pressure field of different plane at different crank angles. The results revealed the formation of the tumble motion, the evolution of flow field parameters and the variation of tumble ratios as important information for the design of engine in-take system.

In-Pipe Mobile Minimachine and Its Control

This paper deals with utilization possibility of a kinematical couple of screw-matrix in minimachine mechatronic concept which is assigned to move within the pipes having less than 25 mm of the inner diameter. The principle of the movement for a straightforward motion consists in transformation of the actuator rotary movement through a screw and a nut to the linear motion. It causes a change of distance between the front and rear parts of the minimachine modules. Due to minimization of the dimensions, the electrical control and power supply components are placed outside of the minimachine operating area. The control module is based on a programmable integrated circuit （PIC）.

Numerical investigation of wake-collapse internal waves generated by a submerged moving body

The state-of-the-art OpenFOAM technology is used to develop a numerical model that can be devoted to numerically investigating wake-collapse internal waves generated by a submerged moving body.The model incorporates body geometry,propeller forcing,and stratification magnitude of seawater.The generation mechanism and wave properties are discussed based on model results.It was found that the generation of the wave and its properties depend greatly on the body speed.Only when that speed exceeds some critical value,between 1.5 and 4.5 m/s,can the moving body generate wake-collapse internal waves,and with increases of this speed,the time of generation advances and wave amplitude increases.The generated wake-collapse internal waves are confirmed to have characteristics of the second baroclinic mode.As the body speed increases,wave amplitude and length increase and its waveform tends to take on a regular sinusoidal shape.For three linearly temperature-stratified profiles examined,the weaker the stratification,the stronger the wake-collapse internal wave.

Intravascular ultrasound-based analysis of factors affecting minimum lumen area in coronary artery intermediate lesions

Objective To identify clinical characteristics associated with the minimum lumen area （MLA） of proximal or middle intermediate lesions in the left anterior descending （LAD） artery, and to develop a model to predict MLA. Methods We retrospectively analyzed demographic data, medical history, and intravascular ultrasound findings for 90 patients with intermediate lesions in the LAD artery. Linear regression was used to identify factors affecting MLA, and multiple regression was used to develop a model for predicting MLA. Results Age, number of lesions, and diabetes mellitus correlated significantly with MLA of proximal or middle intermediate lesions. A regression model for predicting MLA （mm2） was derived from the data： 7.00 - 0.05 × （age） - 0.50 × （number of lesions）. A cut-off value of 3.1 mm2 was proposed for deciding when to perform percutaneous coronary intervention. Conclusion This model for predicting MLA of proximal or middle intermediate lesions in the LAD artery showed high accuracy, sensitivity, and specificity, indicating good diagnostic potential.

Labour Productivity and the Chaotic Economic Growth Model： G7

Chaos theory is used to prove that erratic and chaotic fluctuations can indeed arise in completely deterministic models. Chaos theory reveals structure in aperiodic, dynamic systems. The number of nonlinear business cycle models use chaos theory to explain complex motion of the economy. Almost three years after the crisis, the G7 countries continue to be challenged with economic volatility. The global economy has slowed. Growth in the United States has weakened. In Europe, economic instability is generated by the financial and economic imbalances. Europe is gripped with financial strains from the sovereign debt crisis in the euro area periphery. How these G7 economies confront their fiscal challenges will profoundly affect their economic stability. The basic aim of this paper is to provide a relatively simple chaotic economic growth model that is capable of generating stable equilibria, cycles, or chaos. This paper looks in more detail at the GDP growth stability issues in each of the G7 countries in the period 1990-2012 （Retrieved from http：//www, imf.org）. A key hypothesis of this work is based on the idea that the coefficient π =[p（s_p-i-n/pb-p_mb_m）] plays a crucial role in explaining local stability of the gross domestic product growth, where, p---the coefficient of labour productivity; p.,--the coefficient of the marginal labour productivity, sp-private saving rate;i--investment rate; b-percent of the gross domestic product which belongs to budget deficit; bm-marginal budget deficit coefficient; n-net capital outflow rate.

Adenovirus-mediated gene transfer of TIMP-4 reduces neointimal hyperplasia in balloon-injured rat carotid artery

Objective:To determine the effects of a recombinant replication-deficient adenovirus encoding human tissue inhibitor of metalloproteinase-4(Ad.TIMP-4) on vascular smooth muscle cell(VSMC) function in vitro and neointimal development in the injured rat carotid artery.Methods:Western blotting,gelatin zymography and reverse zymography were used to characterize the expression and functional activity of the TIMP-4 secreted by Ad.TIMP-4-infected VSMCs.The migration and proliferation of VSMCs in vitro were separately detected by using Millicell-PCF invasion chambers and [3H]-thymidine incorporation assay.Immunohistochemistry and morphometric analysis were used to determine the local expression of TIMP-4 and its effect on neointima development in a rat carotid artery balloon injury model.Results:VSMCs infected with Ad.TIMP-4 expressed functionally active human TIMP-4 which increased with the duration of infection.TIMP-4 expression inhibited VSMC migration,but not significantly affect VSMC proliferation.In a balloon-injured rat carotid artery model,a significant 62% reduction in neointimal area was found in Ad.TIMP-4-infected vessels at 14 days after injury.Ad.TIMP-4 infection had no effect on medial area.Conclusion:Our results indicated TIMP-4 over expression can significantly inhibit the migration of cultured VSMCs and prevent neointimal formation after vascular injury.Our findings provide additional evidence that TIMP-4 could play an important role in vascular pathophysiology,and may be an important therapeutic target for future drug development.

Coupled analysis of engine noise and interior noise of an automobile

The coupled model of a four-cylinder internal combustion engine and a dash panel was constructed to analyze the relationship between the engine noise and interior noise of an automobile. Finite element analysis, flexible multi-body dynamics, and boundary element analysis were integrated to obtain the tetrahedron-element models, structural vibration response, and radiated noise,respectively. The accuracy of the finite-element model of the engine was validated by modal analysis via single-input multi-output technology, while the dash panel was validated by sound transmission loss experiment. The block was optimized to reduce the radiated acoustic power from the engine surface. The acoustic transfer path between the engine cabin and passenger compartment was then established. The coupled analysis results reveal that the interior noise is optimized due to the engine noise reduction.