Differential diagnosis of different types of solid focal liver lesions using two-dimensional shear wave elastography

BACKGROUND The clinical management and prognosis differ between benign and malignant solid focal liver lesions(FLLs),as well as among different pathological types of malignant FLLs.Accurate diagnosis of the possible types of solid FLLs is important.Our previous study confirmed the value of shear wave elastography(SWE)using maximal elasticity(Emax)as the parameter in the differential diagnosis between benign and malignant FLLs.However,the value of SWE in the differential diagnosis among different pathological types of malignant FLLs has not been proved.AIM To explore the value of two-dimensional SWE(2D-SWE)using Emax in the differential diagnosis of FLLs,especially among different pathological types of malignant FLLs.METHODS All the patients enrolled in this study were diagnosed as benign,malignant or undetermined FLLs by conventional ultrasound.Emax of FLLs and the periphery of FLLs was measured using 2D-SWE and compared between benign and malignant FLLs or among different pathological types of malignant FLLs.RESULTS The study included 32 benign FLLs in 31 patients and 100 malignant FLLs in 96 patients,including 16 cholangiocellular carcinomas(CCCs),72 hepatocellular carcinomas(HCCs)and 12 liver metastases.Thirty-five FLLs were diagnosed as undetermined by conventional ultrasound.There were significant differences between Emax of malignant(2.21±0.57 m/s)and benign(1.59±0.37 m/s)FLLs(P=0.000),and between Emax of the periphery of malignant(1.52±0.39 m/s)and benign(1.36±0.44 m/s)FLLs(P=0.040).Emax of liver metastases(2.73±0.99 m/s)was significantly higher than that of CCCs(2.14±0.34 m/s)and HCCs(2.14±0.46 m/s)(P=0.002).The sensitivity,specificity and accuracy were 71.00%,84.38%and 74.24%respectively,using Emax>1.905 m/s(AUC 0.843)to diagnose as malignant and 23 of 35(65.74%)FLLs with undetermined diagnosis by conventional ultrasound were diagnosed correctly.CONCLUSION Malignant FLLs were stiffer than benign ones and liver metastases were stiffer than primary liver carcinomas.2D-SWE with Emax was a useful complement to conventional ultrasound for the differential diagnosis of FLLs.

New cooperative frequency domain differential modulation and demodulation

An innovative method of cooperative frequency domain differential modulation and demodulation is presented.This method applies the prior knowledge of channel propagation to selecting the variable differential length and carrying out frequency domain modulation.This strategy optimizes the design of system parameters to effectively improve the anti-interference ability of the differential system in time-varied multipath channel circumstance without making the execution more complicating.The simulations and comparisons demonstrate the proposed method is effective,and the results show that it is especially suitable for the fading channel with strong propagation and fast time-variation.

IDENTIFICATION OF DIFFERENTIAL PROTEINS IN UTERINE LEIOMYOMA BY TWO-DIMENSIONAL ELECTROPHORESIS

Objective： To establish and optimize the two-demensional electrophoresis maps of uterine leiomyoma and to study the difference of global protein patterns between uterine leiomyoma and normal myometrium. Methods： Using Two-dimensional electrophoresis followed by computer-assisted image analysis, the differential proteins between uterine leiomyoma and normal myometrium were compared. Results： The well-resolved and reproducible two-dimensional gel electrophoresis patterns of uterine leiomyoma and normal myometrium were established. Totally 1085±108 and 1103±151 protein spots were obtained by using the pH 4-7 IPG strips in uterine leiomyoma and normal myometrium map, respectively, of which 7 spots increased and 15 spots decreased in quantity in uterine leiomyoma compared with normal myometrium. Conclusion： The differentially expressed proteins are useful for studying the mechanism of the cause of uterine leiomyoma.

Two-dimensional Electrophoresis Analysis of Differential Protein Expression in Squamous Carcinoma of the Cervix

Objective： To establish and optimize the two-dimensional gel electrophoresis （2-DE） maps of squamous carcinoma of the cervix and to study the protein difference between squamous carcinoma of the cervix （SCC） and normal cervical tissue. Methods： Using Two-dimensional gel electrophoresis followed by computer-assisted image analysis, the differential proteins between squamous carcinoma of the cervical tissue and normal cervical tissue were compared. Then using matrix-assisted laser desorption/ionization-time of flight mass spectrometry, the differential proteins were identified. Results： The well-resolved and reproducible two-dimensional gel electrophoresis patterns of squamous carcinoma of the cervix tissue and normal cervical tissue were obtained. After silver staining, the average matching ratio of squamous carcinoma of the cervix was 86.1%. There was a good reproducibility of spot position in 2-DE map, with average deviation in IEF direction of 0.95±0.13 mm, while in SDS-PAGE direction it was 1.20±0.18 mm. Ten protein spots were identified by mass spectrometry, some of which were involved in cell proliferation, cell apoptosis, intracellular enzymes, structural proteins, cycle regulation, and tumor occurrence. Conclusion： The differentially expressed proteins provide a fundamental basis for further study of human squamous carcinoma of the cervix and screening of its specific markers.

BER Performance of Frequency Domain Differential Demodulation OFDM in Flat Fading Channel

A closed form expression for the bit error rate (BER) performance of frequency domaindifferential demodulation(FDDD) for orthogonal frequency division multiplexing system in flat fadingchannel is derived.The performance is evaluated by computer simulation and compared with the timedomain differential demodulation(TDDD).The results indicate that the performance of FDDD is betterthan that of TDDD,and the lower band of BER in the former is lower than that of the latter.

Differentiated self-assembly through orthogonal noncovalent interactions towards the synthesis of two-dimensional woven supramolecular polymers

Molecular weaving is a powerful approach to make molecularly woven materials that have showed unprecedented characteristics and properties intrinsically distinct to those of non-woven materials.We here report a facile and efficient approach for the synthesis of 2D woven supramolecular polymers by differentiated self-assembly through orthogonal noncovalent interactions.Importantly,the difference in binding strength of two orthogonal noncovalent interactions can be used to control the process of molecular weaving.Consequently,single-layered 2D woven supramolecular polymers were synthesized and fully characterized by various techniques.This study demonstrates a controllable method for molecular weaving,and will significantly hasten the development of molecularly woven materials.

Differential Gene and Protein Expression in Soybean at Early Stages of Incompatible Interaction with Phytophthora sojae

Soybean root and stem rot caused by Phytophthora sojae is a destructive disease worldwide. Using genetic resistance is an important and major component in the integrated pest management of this disease. To understand molecular mechanisms of root and stem rot resistance in soybeans, the gene and protein expression in hypocotyls and stems of variety Suinong 10 carrying resistance genes Rps1a and Rps2 was investigated by using mRNA differential display reverse transcription PCR and two-dimensional electrophoresis at 0, 0.5, 1, 2, and 4 h after inoculation with P. sojae race 1. The results of the comparison of gene and protein expression showed that at least eight differential fragments at the transcriptional level were related to metabolic pathway, phytoalexin, and signal transduction in defense responses. Sequence analyses indicated that these fragments represented cinnamic acid 4-hydroxylase gene, ATP b gene coding ATP synthase b subunit and ubiquitin-conjugating enzyme gene which upregulated at 0.5 h post inoculation, blue copper protein gene and UDP-N-acetyl-a-D-galactosamine gene which upregulated at 2 h post inoculation, TGA-type basic leucine zipper protein TGA1.1 gene, cyclophilin gene, and 14-3-3 protein gene which upregulated at 4 h post inoculation. Three resistance-related proteins, a-subunit and b-subunit of ATP synthase, and cytochrome P450-like protein, were upregulated at 2 h post inoculation. The results suggested that resistance-related multiple proteins and genes were expressed in the recognition between soybean and P. sojae during zoospore germination, penetration and mycelium growth of P. sojae in soybean.

Eigenfunction expansion method and its application to two-dimensional elasticity problems based on stress formulation

This paper proposes an eigenfunction expansion method to solve twodimensional （2D） elasticity problems based on stress formulation. By introducing appropriate state functions, the fundamental system of partial differential equations of the above 2D problems is rewritten as an upper triangular differential system. For the associated operator matrix, the existence and the completeness of two normed orthogonal eigenfunction systems in some space are obtained, which belong to the two block operators arising in the operator matrix. Moreover, the general solution to the above 2D problem is given by the eigenfunction expansion method.

Protein expression of sensory and motor nerves Two-dimensional gel electrophoresis and mass spectrometry

The present study utilized samples from bilateral motor branches of the femoral nerve, as well as saphenous nerves, ventral roots, and dorsal roots of the spinal cord, to detect differential protein expression using two-dimensional gel electrophoresis and nano ultra-high performance liquid chromatography electrospray ionization mass spectrometry tandem mass spectrometry techniques. A mass spectrum was identified using the Mascot search. Results revealed differential expression of 11 proteins, including transgelin, Ig kappa chain precursor, plasma glutathione peroxidase precursor, an unnamed protein product （gil55628）, gfyceraldehyde-3-phosphate dehydrogenase-like protein, lactoylgfutathione lyase, adenyfate kinase isozyme 1, two unnamed proteins products （gil55628 and gi11334163）, and poly（rC）-binding protein 1 in motor and sensory nerves. Results suggested that these proteins played roles in specific nerve regeneration following peripheral nerve injury and served as specific markers for motor and sensory nerves.

Performance Comparison of Three Algorithms Applied to UM2000 Signal Demodulation

UM2000 signal is a type of multi-audio frequency-modulated signal which is widely used for railway blocking. Principles of three typical demodulating algorithms are presented in details in this paper. Bit error rates of the three methods at different SNRs are achieved by Monte Carlo simulation experiments. Among the three algorithms, the quadrature demodulation has the best performance at the real working environment. However, the three methods have the same problem of phase hopping when noise is too strong.

Static response of functionally graded multilayered two-dimensional quasicrystal plates with mixed boundary conditions

The unusual properties of quasicrystals(QCs)have attracted tremendous attention from researchers.In this paper,a semi-analytical solution is presented for the static response of a functionally graded(FG)multilayered two-dimensional(2 D)decagonal QC rectangular plate with mixed boundary conditions.Based on the elastic theory of FG 2 D QCs,the state-space method is used to derive the state equations composed of partial differential along the thickness direction.Besides,the Fourier series expansion and the differential quadrature technique are utilized to simulate the simply supported boundary conditions and the mixed boundary conditions,respectively.Then,the propagator matrix which connects the field variables at the upper interface to those at the lower interface of any homogeneous layer can be derived based on the state equations.Combined with the interface continuity condition,the static response can be obtained by imposing the sinusoidal load on the top surfaces of laminates.Finally,the numerical examples are presented to verify the effectiveness of this method,and the results are very useful for the design and understanding of the characterization of FG QC materials in their applications to multilayered systems.

On Negative Differential Mobility in Nanophotonic Device Functionality

A negative differential mobility (NDM) of the two-dimensional carrier-gas against some proper external regulator allowing for gradual controlled modification of the nanointerfacial environment tends to occur as interwoven with nanophotonic device functionality. In this work, several instances, in our two-decade principal research, of both experimental observation and conceptual prediction concerning nanophotonics NDM are reconsidered towards outlining a global potential for the appearance of the effect.

一种支持向量机的相干解调系统误码率模拟预测算法

针对信道中高斯加性噪声引起接收端相干解调系统的误码问题,提出了一种支持向量机的相干解调系统误码率模拟预测算法,为提高通信系统的抗噪特性提供研究基础。文中采用差分进化算法与支持向量机SVM算法相结合的方法,通过差分进化算法优化SVM算法中的惩罚因子与高斯径向基的核函数参数,并对模拟环境下相干解调系统受高斯加性噪声影响所产生的误码数据进行了预测。实验结果表明,基于差分进化的SVM算法预测模型相比经典遗传算法预测精度提高了3.7%,预测精度基本满足误码率数据的预测要求,并具有较强的泛化能力。

双模三维索引调制差分混沌移位键控系统的设计及性能分析

针对传统差分混沌移位键控系统速率低、误码性能差的问题,提出了一种双模三维索引调制差分混沌移位键控系统。该系统利用时隙、正交码和顺序索引,在选中与未选中的时隙上均传输信息比特。在接收端,通过采用降噪技术,减小了噪声的方差,提升了系统误码性能。推导了在加性白高斯噪声信道和多径瑞利衰落信道下的比特差错率公式。仿真结果显示,与相似的混沌键控系统相比,所提系统具备更高的数据速率和更为优越的误码性能。

一种基于差分极性判别的AIS船载信号解码技术

基于船舶自动识别系统(Automatic Identification System,AIS)信号格式与频谱特征,给出了一种能够对AIS船载信号进行正确解调并获取AIS报文内容的方法。利用脉冲检测获取AIS信号,通过相位差分以及频率极性判别,能够准确对AIS进行解调。进一步依据信号结构,通过寻找开始和结束标记,匹配消息ID,成功获取AIS报文数据。通过仿真分析和搭建平台实测,对采用的算法和设计方案进行了验证,表明该方法能够准确对AIS船载信号进行解码。

OSCILLATION THEOREMS FOR A CLASS OF TWO-DIMENSIONAL DELAY DIFFERENTIAL SYSTEMS

By Riccati transformation, we establish some oscillation theorems for a class of two-dimensional nonlinear delay differential systems. The results obtained generalize some relatively known results.

Negative differential friction coefficients of two-dimensional commensurate contacts dominated by electronic phase transition

Friction force(f)usually increases with the normal load(N)macroscopically,according to the classic law of Da Vinci–Amontons(f=μN),with a positive and finite friction coefficient(μ).Herein near-zero and negative differential friction(ZNDF)coefficients are discovered in two-dimensional(2D)van der Waals(vdW)magnetic CrI_(3)commensurate contacts.It is identified that the ferromagnetic–antiferromagnetic phase transition of the interlayer couplings of the bilayer CrI_(3)can significantly reduce the interfacial sliding energy barriers and thus contribute to ZNDF.Moreover,phase transition between the in-plane(p_(x)and p_(y))and out-of-plane(p_(z))wave-functions dominates the sliding barrier evolutions,which is attributed to the delicate interplays among the interlayer vdW,electrostatic interactions,and the intralayer deformation of the CrI_(3)layers under external load.The present findings may motivate a new concept of slide-spintronics and are expected to play an instrumental role in design of novel magnetic solid lubricants applied in various spintronic nano-devices.

一种高动态弱GNSS信号跟踪解调算法研究与实现

在某些高动态弱信号场景中,载波相位难以锁定。为实现对高动态弱全球导航卫星系统(GNSS)信号的跟踪,考虑锁频环较锁相环更为鲁棒,提出了一种基于锁频环(FLL)+差分解调的算法,实现对GNSS信号的跟踪和解调。该算法采用二阶FLL实现对卫星信号的频率进行跟踪,差分解调算法实现对比特数据的解调。工程应用上,算法采用现场可编程门阵列和数字信号处理器(FPGA+DSP)的架构实现,在FPGA中实现信号的跟踪信号的前处理,在DSP中实现跟踪环路算法、位同步和差分解调。本文在Matlab平台中实现算法的仿真,通过模拟器平台和对天接收真实的GNSS信号对算法进行验证。仿真结果与实验结果表明,该算法在高动态弱信号条件下能实现对卫星信号的稳定跟踪和数据的解调,克服了锁相环难以锁定导致数据无法解调的难题,最终实现GNSS信号在该条件下的位置、速度和时间(PVT)解算。

2DPSK调制与解调系统的仿真设计与分析

二进制差分相移键控(2DPSK)法能够避免2PSK信号传输中相位不确定和倒“π”缺陷,误码率极低,实际应用较广。为了更好地理解2DPSK调制和解调的原理,借助于MATLAB/Simulink仿真技术实现了2DPSK调制和解调系统的建模和分析。仿真实验表明,仿真结果和理论分析内容一致,验证了仿真模型的正确性。

GMSK多通道接收机的非相干解调算法及FPGA实现

针对硬件资源受限的高斯最小频移键控(Gaussian Filtered Minimum Shift Keying,GMSK)信号多通道接收机,设计了一种硬件资源占用极少、译码性能良好的解调算法。对通用数字环路硬件资源进行优化,提出了一种改进算法,将环路捕获速度提升了5倍,引入一种位同步算法,该算法同步精度高、占用硬件资源少、采样率低、易于工程实现。并对2-bit差分解调算法进行改进,完成差分解调模块设计。测试结果表明,改进后的差分解调算法比改进前译码性能提升了约2 dB。该解调算法与理论值相比仅有0.6 dB的解调损耗,具有良好的解调性能,满足工程实际应用需求。