Changes and analysis of transvaginal forceps delivery rate in primary hospitals in the past 10 years

Objectives: This study analyzed the changes of vaginal forceps delivery rate in Jiading Maternal and Child Health Hospitalin the past 10 years in order to provide theoretical reference for reducing the rate of cesarean section and solving cephalicdystocia.Material and methods: The basic information, delivery means and vaginal forceps indication of 78,811 parturients whogave birth in our hospital between January 1, 2009 to December 31, 2018 were analyzed retrospectively, and statisticalanalysis was carried out by analysis of variance and Chi-square test.Results: In the past 10 years, there was a significant difference in the rate of vaginal forceps use among different years(p < 0. 05). With 2014 as the turning point, the rate of forceps use increased the fastest, from 0.7% in 2013 to 3.3% in2016. The main indications of forceps increased use in our hospital from high to low were fetal distress, abnormal occipitalposition, prolongation of the second stage of labor and shortening of the second stage of labor. And there was significantdifference among different years (p < 0.000). Although there was no significant difference among the years of labor forcepsuse in patients with prolonged second stage of labor and abnormal occipital position (p > 0.05), the proportion of forcepsdelivery in the second stage of labor was gradually decreased with 2014 as the dividing line. Although there was significantdifference among the patients who shortened the second stage of labor (X2 = 23,886, p < 0.01), it ranked fourth all the time.Conclusions: In the past 10 years, the rate of forceps use has been on the rise. With the implementation of the new stage oflabor and painless delivery in 2014, vaginal forceps have become the main means to solve the problem of cephalic dystocia

Experimental Study on the Flow Field, Force, and Moment Measurements of Submarines with Different Stern Control Surfaces

Flow field performance tests of submarine models with cross-rudder and X-rudder stern control surfaces were conducted to study X-rudders’ performance in non-uniform flow fields. The tests compared performance parameters such as resistance, lateral steering force, yaw moment, stern velocity field, and flow field inhomogeneity coefficient under low- and high-speed conditions. The test results show that, at low speed, the resistance of the X-rudder submarine is smaller than that of the cross-rudder one at the same rudder angle. In contrast, at high speed, the resistance of the cross-rudder submarine is smaller than that of the X-rudder submarine. Under low- and high-speed conditions, the X-rudder’s lateral steering force and yaw moment are larger than those of the cross rudder at the same rudder angle. The superiority of the maneuverability of the X-rudder becomes more apparent with increasing rudder angle. At a rudder angle of 10°, the X-rudder’s lateral steering force and yaw moment are about two times larger than the cross rudder’s. In the small-radius area of the propeller plane, the inhomogeneity coefficient of the X-rudder is generally smaller than that of the cross rudder. This is probably because the cross-rudder stern control surfaces have fixed stabilizers with flaps, and the X-rudder stern control surfaces are all-moving, with a small fixed part next to the submarine. This test provides a reference for designing the stern control surface of low-noise submarines

An optimized design of in-shoe heel lifts reduces plantar pressure of healthy males

Conventional heel lift with a flat surface increases the risk of foot problems related to higher plantar pressure and decreased stability. In this study, an optimized design of in-shoe heel lifts developed to maintain the midfoot function was tested to investigate if the plantar pressure distribution was improved. The design was based on three dimensional foot plantar contour which was captured by an Infoot 3D scanning system while the heel was elevated by a heel wedge. To facilitate midfoot function, an arch support was designed to support the lateral longitudinal arch, while allowing functional movement of the medial longitudinal arch. Twenty healthy male subjects were asked to walk along an 8m walkway while wearing high-cut footwear with and without the optimized heel lift. Peak pressure, contact area and force-time integral were measured using the Pedar insole system. Range and velocity of medial-lateral center of pressure during forefoot contact phase and foot flat phase were collected using a Footscan pressure plate. Compared to the shoe only condition, peak pressure under the rearfoot decreased with the optimized heel lift, while no increase of peak pressure was observed under the forefoot and midfoot regions, indicating improved plantar pressure distribution. The findings of this study suggest that this optimized heel lift has better biomechanical performance than a conventional flat heel lift. Results from this study may have implications for insole and shoe last design, especially for people who need additional heel height without sacrificing midfoot function.publisher: Elsevier articletitle: An optimized design of in-shoe heel lifts reduces plantar pressure of healthy males journaltitle: Gait & Posture articlelink: http://dx.doi.org/10.1016/j.gaitpost.2016.04.003 content_type: article copyright: © 2016 Elsevier B.V. All rights reserved.status: publishe

TVD-PB Logic Circuit Based on Camouflaging Circuit for IoT Security

Abstract Internet of Things (IoT) devices are vulnerable to many physical attacks, including reverse engineering and side‐channel analysis because the sensitive information of circuits may be leaked through the physical characteristics of the device. A logic camouflaging circuit is proposed that uses a balanced power consumption and threshold voltage‐defined technique to provide an antiphysical attack scheme to protect the hardware security for IoT devices. The proposed circuit uses a symmetric differential pull‐down network in implementing the different logic functions through the threshold voltage reconfiguration circuit. As a result, the power consumption of the circuit attains balance and stability between two different logical operations. The proposed threshold voltage‐defined power‐balance (TVD‐PB) design is fabricated using a 65‐nm CMOS technology, and the core area occupies approximately 0.0044 mm2, composed of NAND, NOR, XOR, and INV components and multiplier gates of the proposed TVD‐PB circuit. The entire chip passed the logic function tests. The measured results show that the average similarity of the TVD‐PB universal gate is 99.68%. In addition, the current margin is higher than 55 μA and power consumption of 0.455 mW during each clock cycle at 1.2 V derives 0.1072% of the normalized energy deviation and 0.0453% of the normalized standard deviation. Compared with other state‐of‐the‐art techniques, the power dependency against power attacks is improved effectively

Seasonal dynamics of water use efficiency of typical forest and grassland ecosystems in China

We selected four sites of ChinaFLUX representing four major ecosystem types in China-Changbaishan temperate broad-leaved Korean pine mixed forest (CBS), Dinghushan subtropical evergreen broadleaved forest (DHS), Inner Mongolia temperate steppe (NM), and Haibei alpine shrub-meadow (HBGC)-to study the seasonal dynamics of ecosystem water use efficiency (WUE = GPP/ET, where GPP is gross primary productivity and ET is evapotranspiration) and factors affecting it. Our seasonal dynamics results indicated single-peak variation of WUE in CBS, NM, and HBGC, which were affected by air temperature (Ta) and leaf area index (LAI), through their effects on the partitioning of evapotranspiration (ET) into transpiration (T) (i.e., T/ET). In DHS, WUE was higher at the beginning and the end of the year, and minimum in summer. Ta and soil water content affected the seasonal dynamics of WUE through their effects on GPP/T. Our results indicate that seasonal dynamics of WUE were different because factors affecting the seasonal dynamics and their mechanism were different among the key ecosystems

A MODIS-based Photosynthetic Capacity Model to estimate gross primary production in Northern China and the Tibetan Plateau

National Key Research and Development Program 2010CB833504；CAS Strategic Priority Research Program XDA05050600；National Natural Science Foundation of China 31290220Accurate quantification of the spatio-temporal variation of gross primary production (GPP) for terrestrial ecosystems is significant for ecosystem management and the study of the global carbon cycle. In this study, we propose a MODIS-based Photosynthetic Capacity Model (PCM) to estimate GPP in Northern China and the Tibetan Plateau. The PCM follows the logic of the light use efficiency model and is only driven by the Enhanced Vegetation Index (EVI) and the Land Surface Water Index (LSWI). Multi-year eddy CO2 flux data from five vegetation types in North China (temperate mixed forest, temperate steppe) and the Tibetan Plateau (alpine shrubland, alpine marsh and alpine meadow-steppe) were used for model parameterization and validation. In most cases, the seasonal and interannual variation in the simulated GPP agreed well with the observed GPP. Model comparisons showed that the predictive accuracy of the PCM was higher than that of the MODIS GPP products and was comparable with that of the Vegetation Photosynthesis Model (VPM) and the potential PAR-based GPP models. The model parameter (PCmax) of the PCM represents the maximum photosynthetic capacity, which showed a good linear relationship with the mean annual nighttime Land Surface Temperature (LSTan). With this linear function, the PCM-simulated GPP can explain approximately 93% of the variation in the flux-observed GPP across all five vegetation types. These analyses demonstrated the potential of the PCM as an alternative tool for regional GPP estimation

Spatial variation in annual actual evapotranspiration of terrestrial ecosystems in China: Results from eddy covariance measurements

Understanding the spatial variation in annual actual evapotranspiration (AET) and its influencing factors is crucial for a better understanding of hydrological processes and water resources management. By synthesizing ecosystem-level observations of eddy-covariance flux sites in China (a total of 61 sites), we constructed the most complete AET dataset in China up to now. Based on this dataset, we quantified the statistic characteristics of AET and water budgets (defined as the ratio of AET to annual mean precipitation (MAP), AET/MAP) of terrestrial ecosystems in China. Results showed that AET differed significantly among both different vegetation types and climate types in China, with overall mean AET of 534.7 +/- 232.8 mm yr(-1). AET/MAP also differed significantly among different climate types, but there were no distinct differences in AET/MAP values across vegetation types, with mean AET/MAP of 0.82 +/- 0.28 for non-irrigated ecosystems. We further investigated how the main climatic factors and vegetation attributes control the spatial variation in AET. Our findings revealed that the spatial variation of AET in China was closely correlated with the geographical patterns of climate and vegetation, in which the effects of total annual net radiation (R (n)), MAP and mean annual air temperature (MAT) were dominant. Thus, we proposed an empirical equation to describe the spatial patterns of AET in China, which could explain about 84% of the spatial variation in AET of terrestrial ecosystems in China. Based on the constructed dataset, we also evaluated the uncertainties of five published global evapotranspiration products in simulating site-specific AET in China. Results showed that large biases in site-specific AET values existed for all five global evapotranspiration products, which indicated that it is necessary to involve more observation data of China in their parameterization or validation, while our AET dataset would provide a data source for it