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ABSTRACTBackground:Traditionally, hostile peripheral access patients undergo TAVR via alternative access. We describe the “transfemoral-first” (TF-1) approach in patients with hostile peripheral access.Methods:Clinical and procedural data were obtained for all TAVR cases performed from August 2016 to July 2017. Computed tomography was used to assess iliofemoral arteries. Patients were divided into three femoral access groups: routine, hostile, and prohibitive. We attempted TF access in all patients with routine and hostile access. Hostile access was defined as: (1) arterial segments with diameter <5.0 mm; or (2) <5.5 mm with severe calcification (270–360° arc of calcification) or severe tortuosity; or (3) severe tortuosity along with severe calcification. Outcomes of the hostile access group patients who underwent TF-1 are described. The primary endpoint was successful completion of the procedure without major complications by the intended route. The secondary endpoints were procedural complications as defined by the VARC-2 criteria.Results:Of 377 consecutive patients, 99.5% underwent TF-1 TAVR; two patients (0.4%) had prohibitive access. Twenty-eight (7.4%) patients had hostile access with access side mean minimal lumen diameter of 4.7 mm (range 3.8–5.4 mm). Twenty-six (92.8%) were successfully treated with TF-1 strategy. Twelve (42.8%) of the 26 patients underwent preparatory endovascular treatment prior to TAVR during the same operating room visit. There was 1 (3.5%) major or life-threatening bleeding complication and 2 (7.1%) major vascular complications. There were no deaths or strokes.Conclusion:Using the safe and effective endovascular approach, TF-1 TAVR is feasible for all-comers—including those with hostile access—with low complication rate. Larger studies are warranted to validate this approach.

Subclinical leaflet thrombosis has been increasingly recognized as a common imaging finding after surgical or transcatheter aortic valve replacement (TAVR) in recent studies. This finding has raised concerns over TAVR valve durability and debates on optimal postprocedural antithrombotic regime. Hypoattenuated leaflet thickening (HALT) and the associated reduced leaflet motion (RELM) were noted as computed tomography hallmarks of the phenomenon. The coexistence of HALT and significant RELM has been suggested as a threshold for reporting of subclinical leaflet thrombosis. This methodology may contribute to the standardization of reporting for research collaboration, hence the better understanding and management of this common yet largely unknown phenomenon.

Although inappropriate left ventricular mass has been associated with clustered cardiac geometric and functional abnormalities, its predictive value in patients with coronary artery disease is still unknown. This study examined the association of inappropriate left ventricular mass with clinical outcomes in patients with angina pectoris and normal ejection fraction.

Transcatheter aortic valve implantation (TAVI) is an established therapeutic option for high-risk patients with a tricuspid aortic valve, but patients with a bicuspid aortic valve (BAV) are contraindicated. In this Perspectives article, Zhao and colleagues summarize the available evidence for the use of TAVI in patients with a BAV and propose that this procedure might be appropriate in high-risk or inoperable individuals, but that more evidence is required before indications for TAVI can be extended to other patients with a BAV.

Small current grounding power system is widely used in overhead transmission line in medium voltage distribution network in China. Because of its long lines, branch, space truss structure is complex, low level of automation, It is easily influenced by outside force and the natural environment, and single-phase grounding failure rate is high. It is an important topic to quickly and accurately detect the location of the fault line, and improve the reliability of power supply and distribution system.This paper has carried on the induction and the comparison of various fault detection and location method of overhead transmission line which is currently used in single phase to ground, and analyzed their advantages and disadvantages,given the corresponding conclusions, provided the reference for finding out the reasonable single-phase earth fault location method or improvement.

Structure’s strain reflects the stability of the project, the excessive structural strain will destroy the stability of the structure. Fiber Bragg Grating has many features, such as, strong anti-interference ability, low optical loss, and it can be used for a long time in the project, etc. Base on the features, the Fiber Bragg Grating Strain Sensor can be used in slope and other projects for the long-term monitoring. In this paper, we develop a Fiber Bragg Grating Strain Sensor based on the spring-steel pipe, FBG be fixed to the inner of the steel pipe by epoxy glue, it is protected by a stainless steel pipe outside, the Flange be fixed to the both side of the spring-steel pipe. When the tension acting one the flanges, the spring-steel pipe occurs an axial strain, this axial strain makes the center wavelength of the Fiber Bragg Grating change, measuring the wavelength shift amount of the Fiber Bragg Grating can calculate the strain. The loading experiment indicates that the sensitivity of the Spring-steel pipe Fiber Bragg Grating Strain Sensor is 0.81pm/με, the linearity of the sensor is 2.1%FS, and the repeatability error of the sensor is 2.29%FS.

Reinforced concrete piles are used when structures are constructed on soft ground, because it is necessary to transfer the loads into deeper strata with a sufficient bearing capacity. With the purpose of receiving more precise information about the pile features, four fiber Bragg grating strain sensors are embedded at different levels of the pile to measure the strain distribution during straining and pull-out tests. Test Pile vertical uplift static load test results show that, settlement of the test pile is steep variations, the steep rise starting point corresponding to the load of 3300 kN for the Uplift Ultimate Bearing capacity, the corresponding uplift amount is 12.45 mm; 4.4 m, 7.2 m, 11.0 m and 14.5 m sections axial strain were 115 με, 42 με, 6 με and-3 με. Maximum loading capacity is 3600 kN, the corresponding uplift amount is 30.13mm; 4.4 m, 7.2 m, 11.0 m and 14.5 m sections axial strain were 142 με, 61 με, 7 με and-1 με.

The air cooler reduce the working temperature of the transformer, high temperature will reduce the transformers life, and even make insulation overheating, aging, then the transformer will be damaged. The air cooler which is forced oil circulation in transformer outdoor in substation has been monitored. The real-time monitoring of 24-hours indicates that the temperature changes in the range of 3°C. The ambient temperature is lower than the temperature of fan about 1°C. At the long-term of 479 days, the average daily temperature range of fan is 35.32°C, the maximum temperature is 50.25°C on August 18,2011, and the maximum temperature is 14.93°C on January 17, 2011. The daily average of ambient temperature range is 37.59°C, the maximum temperature is 51.16°C on August 17, 2011,and the minimum temperature is 13.57°C on January 17, 2011. The maximum difference between the temperature of fan and the ambient temperature is 12.48°C on September 15, 2011. According to the relevant standards and monitoring results, the maximum threshold of fan temperature is defined to 80°C, and the threshold of temperature rise is 20°C.

During the period of tunnel excavation, shoring, forming and long-term operation, stress changes of tunnel surrounding rock are complex, the real-time monitoring of surrounding rock pressure is the key factor in ensuring long-term stability in tunnel. Fiber Bragg grating earth pressure sensors apply in surrounding rock pressure of tunnel which can change the pressure of the surrounding rock into fiber Bragg grating wavelength shift. According to the feature of pressure and temperature in Tian Xin Tunnel, 40 earth pressure sensors are embedded in 20 representative sections and one earth pressure sensor is embedded in each arch shoulder. In addition, one temperature compensation sensor is embedded in each arch crown. During the 235 monitoring days, the biggest daily change of surrounding rock pressure reaches 800 KPa. In 3 months of the sensor installation, the average monthly variation is within 50 KPa. The long-term measurement results indicate that the changes of surrounding rock pressure are different in different locations. When the surrounding rock is close to the excavated and blasted surface the surrounding rock pressure changes largely.

When porcelain insulator operates in a harsh environment for a long time, it will cause leakage current increase, and lead to heating phenomenon. As a result, the temperature of porcelain insulator can be changed, which probably due to crack, breakdown or other factors. In order to reflect the working state of the porcelain insulator, to monitor the temperature of porcelain insulator, optical fiber Bragg grating temperature sensors are installed respectively on the steel cap and the porcelain of porcelain insulator. In the interaction of industrial frequency voltage test of 15kV, thus the temperature of porcelain insulator can be distributed. The temperature of the porcelain insulator affects the center wavelength of optical fiber Bragg grating temperature sensors, which are installed on porcelain insulator. The tests show that in the pure condition, the temperature of porcelain insulator's steel cap and porcelain respectively rise 1.4°C and 1.5°C, in the polluted condition, the temperature of porcelain insulator's steel cap and porcelain respectively rise 5.8°C and 6.3°C, in the pollution level II condition, the temperature of Porcelain insulator's steel cap and porcelain respectively rise 6.8°C and 7.2°C. Therefore, by using optical fiber Bragg grating temperature sensors to monitor the change of porcelain insulator's temperature, combined with the researches of temperature characteristics, can directly reflect the porcelain insulator's working situation and real-time online monitoring.

MWNT –SiO2 composite film humidity sensors with different MWNTs proportions were fabricated and their performances under alternating current testing signals are investigated. Influence of MWNT content on humidity sensing characteristics of the sensors is explored and explained by vapor adsorption and capillary condensation effect. It is proved that 60% MWNT content sensors have humidity sensitivity of 1500% at 400 kHz testing frequency, much higher than those with other MWNT contents. In sensors’ sensitivity-frequency relation, maximum sensitivity comes from frequency section of 400kHz to 500kHz for sensors with higher MWNTs proportions.

Dong Yang Tunnel is located in the low mountains and hilly areas with tectonic denudation, where the tunnel of K147+535~K147+575 passes mainly through the maroon and purple red completely weathered mudstone. A differential fiber Bragg grating strain sensor is developed for monitoring the surface strain of tunnel lining. By converting the strain of gauge rod into the strain of beam, two fiber Bragg gratings are separately mounted on the top and bottom surfaces of beam, and as a result shifts its Bragg wavelength. The difference of relative Bragg wavelength shifts of the sensing gratings is 1.05×10-6 /. Grating sensors are installed on the tunnel lining of K147+540~K147+610. Especially, the second lining of K147+592~K147+598 is enhanced by the steel plate. The strains of >100 occur on the lining of K147+560 and K147+590 in the reinforcing period of 20 days. Following a 160 days operation period, the measurement results indicate that the tunnel structures are gradually tending towards stability.

The cracks have emerged on the second lining of right tunnel for three months after tunneling in the Xin Chang Tunnel. The maximum crack depth is 264.0 mm which is explored by a RS-ST01C type ultrasonic tester. A fiber Bragg grating strain sensor is developed for measuring the surface strain of second lining. By converting the deflection of structure into the strain of displacement telescopic gauge, a fiber Bragg grating is mounted on two ends of gauge where suffers the strain, and as a result its Bragg wavelength will be shifted. The strain sensitivity and temperature sensitivity of the grating sensor are separately 0.677×10-6/ and 0.968×10-5 /°C. Grating sensors are installed on the corresponding linings according to the crack distribution. In an observation period of 51 days, the measurement results indicate that the lining cracks are derived from the tilted pressure of surrounding rock. After a backfill period of 29 days, the tunnel structures are gradually tending to be stability in the following operation period of 429 days.

Power transmission tower is an important part of power transmission equipment. The tower foundation is suffered by landslides, debris flows, erections of foundation settlement and so on. The power transmission tower near Yanjin transformer substation is selected to be measured. By using fiber Bragg grating (FBG) earth pressure sensor, the earth pressure of tower foundation is measured. The long-term monitoring data indicate that the #1 sensor daily variations amplitude of earth pressure is 7.22KPa, and the #2 sensor daily variations amplitude of earth pressure is 4.69KPa. In the 479 days, the rangeability of average data is 61.55KPa in sensor #1 and 64.05KPa in sensor #2. Compared with the local precipitation, the earth pressure of tower foundation is seasonal change. According to the history data, the warning threshold value is set as 280KPa.

Under the influence of ice coating and other natural factors, Power tower cross arm will deform, damage and even fracture with the increasing stress. On the power tower of Yanjin converting station, four fiber Bragg grating strain sensors were installed. By changing the internal force that main material of the cross arm suffered, deflection change of each main material occurred, resulting in fiber Bragg grating wavelength of the fiber Bragg grating strain sensors which on the surface of the cross arm shifting. During the 479 days monitoring, the # 2 sensor daily mean strain range is the largest with the value of 1700.98, while the 3 # sensors have the smallest value of 1122.91. On the July 20th 2011, daily mean strain of the 2# strain sensor located in the insulation cross arm reached the maximum value 382.01, while on the February 19th 2011, that of the 4# sensor achieved the minimum value -1477.75.On the February 19th 2011, both local wind direction and speed had the biggest changes through the testing process, which indicates that the cable sweeping wind is the mainly reason to cause the power tower cross arm deformation.

The influences of jet flow rate and temperature on cathodic polarization of nickel deposits have been studied in this paper. The results indicate that increasing jet flow rate and temperature of the electrolyte make the equilibrium electrode potential decrease. When jet flow rate increases from 1.0 L/min to 6.0 L/min, the grain size of nickel deposits decreases from 22.6 nm to 18.9 nm. X-ray diffraction patterns show that increasing jet flow rate results in (111) preferred growth orientation for nickel deposits.

This paper researches on the temperature effects of a fully-symmetrical micromachined gyroscope. The Young’s modulus and thermal expansion coefficient of silicon vary with the environment temperature, which affects the modes’ resonant frequencies of micromachined gyroscopes. The effects of temperature fluctuation on the modes’ resonant frequencies is simulated by the FEM software ANSYS. The simulation results show that the fully-symmetrical gyroscope’s resonance frequencies decrease with the increase of temperature and the decrease degree nearly 0.256Hz/°C, but the two modes’ resonance frequencies matches well. The micromachined gyroscope’s dynamic characteristics are tested. The resonant frequencies and the quality factor are reduced with the increase of temperature and the decrease degree of the fit linear about the resonant frequencies is 0.276 Hz/°C. The test results are in good accordance with the simulation results.

The resonance phenomenon is suppressed by adjusting the damping of the comb accelerometer structure to widen the frequency bandwidth of the capacitive accelerometer. The capacitive accelerometer with asymmetrical combs, fabricated with DRIE and anodic bonding, is presented. The damping category of the accelerometer is introduced, in which the squeeze-film damping coefficient and the damping ratio factor are detailed. The damping ratio factor of the accelerometer, measured by a vibration method, is 0.17. The damping ratio factor of the optimized structure is calculated of 0.15 to 0.18 with the change of experiential modulus C from 25 to 30, theoretically.