Value of machine learning model based on MRI radiomics in predicting histological grade of cervical squamous cell carcinoma

Objective To explore the predictive value of different machine learning models based on MRI radiomics combined with clinical features for histological grade of cervical squamous cell carcinoma. Methods Clinical data of 150 patients with cervical squamous cell carcinoma confirmed by pathological biopsy were retrospectively analyzed. They were randomly divided into the training set and validation set at a ratio of 4∶1. Features were extracted from the regions of interest of T2WI fat suppression sequence （FS-T2WI） and enhanced T1WI （delayed phase）. After dimensionality reduction and feature selection， logistic regression （LR）， support vector machine （SVM）， naïve Bayes （NB）， random forest （RF）， Light Gradient Boosting Machine （LightGBM）， K-nearest neighbor （KNN） were used to construct a radiomics model for predicting the histological grade of cervical squamous cell carcinoma. The area under the receiver operating characteristic （ROC） curve （AUC） was used to evaluate the predictive performance of the six models. Univariate and multivariate logistic regression analyses were performed to predict the independent risk factors， and a combined model of clinical and radiomics was established. The differences of each model were compared by AUC， and the clinical value of the model was evaluated by decision curve （DCA）. Results In the radiomics model， the LightGBM model had the largest AUC （0.910 in the training set， and 0.839 in the validation set）. The AUC of clinical features combined with LightGBM model was the largest （0.935 in the training set， and 0.888 in the validation set）， which was higher than those of clinical model （0.762 in the training set， and 0.710 in the validation set） and LightGBM radiomics model. Conclusions The LightGBM model has a high predictive value in the radiomics model. The combined model has the optimal DCA effect and the highest clinical net benefit. The combined prediction model combining radiomics and clinical features has good predictive value for cervical squamous cell carcinoma with low differentiation， providing a non-invasive and efficient method for clinical decision-making

Design and Analysis of an Improved Tubular Permanent Magnet Linear Machine with a T-type Magnet Array

The surface-mounted tubular permanent magnet linear machine (SM-TPMLM) is widely used in many industrial applications. However, the PMs are fragile and easily fall off when linear machines are operated at reciprocating oscillation speed over long periods or encounter harsh environments, the exposed PMs are susceptible to corrosion, which reduces the service life of linear machines. To solve this problem, an improved tubular permanent magnet linear machine with a T-type magnet array (T-TPMLM) is proposed. The axial and radial magnets are combined in a magnetic pole array to increase the thrust force, power and protect the PMs. First, an equivalent analytical model of T-TPMLM is established to predict the magnetic field, the subdomain method with Schwarz-Christoffel mapping method is introduced to consider slotting effect and end effect. Then, to verify the merit of the proposed T-TPMLM, a quantitative electromagnetic performance comparison with two traditional SM-TPMLM including radial magnetization and Halbach magnetization is performed through the finite element analysis method (FEM). Besides, the mechanical strength of three linear machines is discussed briefly. Finally, a prototype of proposed T-TPMLM is manufactured and tested to validate the effectiveness of the analytical model and the FEA predicted results. The results show that the proposed machine offers high electromagnetic performance

Investigation of PVT-Aware STT-MRAM Sensing Circuits for Low-VDD Scenario

Spintronic based embedded magnetic random access memory (eMRAM) is becoming a foundry validated solution for the next-generation nonvolatile memory applications. The hybrid complementary metal-oxide-semiconductor (CMOS)/magnetic tunnel junction (MTJ) integration has been selected as a proper candidate for energy harvesting, area-constraint and energy-efficiency Internet of Things (IoT) systems-on-chips. Multi-VDD (low supply voltage) techniques were adopted to minimize energy dissipation in MRAM, at the cost of reduced writing/sensing speed and margin. Meanwhile, yield can be severely affected due to variations in process parameters. In this work, we conduct a thorough analysis of MRAM sensing margin and yield. We propose a current-mode sensing amplifier (CSA) named 1D high-sensing 1D margin, high 1D speed and 1D stability (HMSS-SA) with reconfigured reference path and pre-charge transistor. Process-voltage-temperature (PVT) aware analysis is performed based on an MTJ compact model and an industrial 28 nm CMOS technology, explicitly considering low-voltage (0.7 V), low tunneling magnetoresistance (TMR) (50%) and high temperature (85 °C) scenario as the worst sensing case. A case study takes a brief look at sensing circuits, which is applied to in-memory bit-wise computing. Simulation results indicate that the proposed high-sensing margin, high speed and stability sensing-sensing amplifier (HMSS-SA) achieves remarkable performance up to 2.5 GHz sensing frequency. At 0.65 V supply voltage, it can achieve 1 GHz operation frequency with only 0.3% failure rate

Protection of the Liuzheng Water Source: A Karst Water System in Dawu, Zibo, China

The Dawu water source is a rare, large-scale groundwater source located in northern China. The water supply function from this water source has, however, been lost due to anthropogenic pollution. In order to fully utilize valuable groundwater resources, a new water source of urban domestic water in Liu Zheng is planned. In this study, a tracer test and a numerical simulation method are used to examine the hydraulic connection between the Liuzheng water source and the Wangzhai industrial park; to optimize the exploitation layout of the Liuzheng water source and Dawu water source; and to propose the extent of the Liuzheng water source protection area. Results indicate that: (1) Karst development in the study area is uneven, and the Wangzhai area is a recharge area of the Liuzheng water source; (2) it is predicted that the groundwater flow field will not be significantly changed when a groundwater volume of 150,000 m3/day is exploited from the Liuzheng water source; (3) it is predicted that the proposed chemical park in Wangzhai will gradually pollute to the groundwater in the northern area of Liuzheng; and (4) results using the empirical formula method and the numerical simulation method indicate that the area of the primary protection area of the Liuzheng water source is about 0.59 km2, and the area of the secondary protection area is about 14.98 km2. Results from this study provide a certain technical basis for the exploitation and protection of groundwater in the Liuzheng water source

Conical intersection–regulated intermediates in bimolecular reactions: Insights from C( 1 D) + HD dynamics

International audienc

Dynamical importance of van der Waals saddle and excited potential surface in C(D-1) + D-2 complex-forming reaction

Encouraged by recent advances in revealing significant effects of van der Waals wells on reaction dynamics, many people assume that van der Waals wells are inevitable in chemical reactions. Here we find that the weak long-range forces cause van der Waals saddles in the prototypical C(D-1) + D-2 complex-forming reaction that have very different dynamical effects from van der Waals wells at low collision energies. Accurate quantum dynamics calculations on our highly accurate ab initio potential energy surfaces with van der Waals saddles yield cross-sections in close agreement with crossed-beam experiments, whereas the same calculations on an earlier surface with van der Waals wells produce much smaller cross-sections at low energies. Further trajectory calculations reveal that the van der Waals saddle leads to a torsion then sideways insertion reaction mechanism, whereas the well suppresses reactivity. Quantum diffraction oscillations and sharp resonances are also predicted based on our ground- and excited-state potential energy surfaces

Influence of NaCl on lipid oxidation and endogenous pro-oxidants/antioxidants in chicken meat

The aim of this study was to investigate the effect of different content of sodium chloride (NaCl) on lipid oxidation of chicken breast meat and the endogenous pro-oxidants/antioxidants contributing to lipid oxidation. The results demonstrated that NaCl could promote lipid oxidation in chicken meat until NaCl content reached up to 4.5%. Generation of reactive oxygen species and H2O2 initiated by NaCl might be responsible for the increased lipid oxidation, and lipoxygenase activity was highly correlated with oxidative stability of meat. However, oxidation of lipid was not negatively correlated with superoxide dismutase, glutathione peroxidase and catalase activity. The sensory evaluation by electronic nose showed an increase in saltiness, richness and umami taste and a decrease in bitterness with increasing NaCl content, but there was no significant change in these sensory ratings when the NaCl content exceeded 3.0%. The volatile compounds obtained by gas chromatography-mass spectrometry (GC-MS) showed that NaCl increased the formation of most flavor components in chicken meat. This study could provide a reference for the control of lipid oxidation in meat and development of low salt meat products

Mechanism of Filling and Feeding of Thin-Walled Structures during Gravity Casting

The filling and feeding of thin-walled structures in metal castings pose significant difficulties in manufacturing aerospace structural materials. Samples containing 2 mm and 5 mm thin-walled structures were designed to study the kinetics of filling. The microstructural evolution of the solidification of thin-walled structures was studied with synchrotron X-radiation imaging. The formation of dendritic networks and the isotherm profiles of samples of different thickness were examined. The experimental results showed solidification microstructures of 2 mm and 5 mm thin-walled parts containing elongated equiaxed grains and normal equiaxed grains, respectively. The filling and feeding abilities of thin-walled parts were found to depend more on the wall thickness than on the pouring temperature