Cognitive impairment in cerebral small vessel disease induced by hypertension

Hypertension is a primary risk factor for the progression of cognitive impairment caused by cerebral small vessel disease,the most common cerebrovascular disease.Howeve r,the causal relationship between hypertension and cerebral small vessel disease remains unclear.Hypertension has substantial negative impacts on brain health and is recognized as a risk factor for cerebrovascular disease.Chronic hypertension and lifestyle factors are associated with risks for stro ke and dementia,and cerebral small vessel disease can cause dementia and stroke.Hypertension is the main driver of cerebral small vessel disease,which changes the structure and function of cerebral vessels via various mechanisms and leads to lacunar infarction,leukoaraiosis,white matter lesions,and intracerebral hemorrhage,ultimately res ulting in cognitive decline and demonstrating that the brain is the to rget organ of hypertension.This review updates our understanding of the pathogenesis of hypertensioninduced cerebral small vessel disease and the res ulting changes in brain structure and function and declines in cognitive ability.We also discuss drugs to treat cerebral small vessel disease and cognitive impairment.

Identification of denatured and normal biological tissues based on compressed sensing and refined composite multi-scale fuzzy entropy during high intensity focused ultrasound treatment

In high intensity focused ultrasound(HIFU)treatment,it is crucial to accurately identify denatured and normal biological tissues.In this paper,a novel method based on compressed sensing(CS)and refined composite multi-scale fuzzy entropy(RCMFE)is proposed.First,CS is used to denoise the HIFU echo signals.Then the multi-scale fuzzy entropy(MFE)and RCMFE of the denoised HIFU echo signals are calculated.This study analyzed 90 cases of HIFU echo signals,including 45 cases in normal status and 45 cases in denatured status,and the results show that although both MFE and RCMFE can be used to identify denatured tissues,the intra-class distance of RCMFE on each scale factor is smaller than MFE,and the inter-class distance is larger than MFE.Compared with MFE,RCMFE can calculate the complexity of the signal more accurately and improve the stability,compactness,and separability.When RCMFE is selected as the characteristic parameter,the RCMFE difference between denatured and normal biological tissues is more evident than that of MFE,which helps doctors evaluate the treatment effect more accurately.When the scale factor is selected as 16,the best distinguishing effect can be obtained.

四极杆质谱仪中扫描速率对PFTBA信号强度和噪声的影响研究

Using quadrupole mass spectrometer,calibration gas PFTBA was turned on in constant flow to get the signal intensity,and off to get the noise value.Different scan time and dwell time was used separately for full scan mode and SIM to find out the effect of scan rate on signal intensity and noise.

Position of increased signal intensity in the spinal cord on MR images： does it predict the outcome of cervical spondylotic myelopathy？

Background Increased signal intensity （ISI） in the spinal cord on T2-weighted MR images has been reported in some previous researches, however no study focused on the position of the ISI in the spinal cord and its potential value. The aim of this study was to investigate the correlation between ISI position and the outcome of surgical treatment for cervical spondylotic myelopathy （CSM） patients. Methods A retrospective study was conducted. Pre- and post-operative clinical status was evaluated by modified Japanese Orthopaedic Association （JOA） score. ISI was evaluated according to the T2-weighted sequences. The JOA score and the recovery ratios among patients with ISI in gray matter （group A）, in both gray and white matter （group B）, and ISI-negative group were compared. Results Totally 64 patients were enrolled in this retrospective study. Preoperative JOA score of ISI positive and negative group had significant difference, but the recovery ratios had no significant difference （the recovery ratios of the two groups in week 1, week 26, and week 104 were （21.54±14.65）%, （50.56±14.76）%, （59.23±13.08）% and （20.25±14.32）%, （54.46±3.16）% and （61.26±29.4）%, respectively; P 〉0.05）. The recovery ratios of negative group and group A in week 104 were superior to group B （the recovery ratios of negative group, group A, and group B in week 104 were （61.26±29.49）%, （65.35±11.36）%, and （50.33±10.20）%, respectively; P 〈0.05）. Conclusions Patients with ISI in the gray matter alone on T2-weighted MR images did not have significantly different surgical outcomes compared with those without ISI. Patients with ISI in both gray and white matter had surgical outcomes that were worse than those without ISI.

Correlation between magnetic resonance T2 image signal intensity ratio and cell apoptosis in a rabbit spinal cord cervical myelopathy model

Background Cervical spondylotic myelopathy （CSM） is a common cause of disability in elderly patients.Previous studies have shown that spinal cord cell apoptosis due to spinal cord compression plays an important role in the pathology of myelopathy.Although changes in magnetic resonance imaging （MRI） T2 signal intensity ratio （SIR） are considered to be an indicator of CSM,little information is published supporting the correlation between changes in MRI signal and pathological changes.This study aims to testify the correlation between MRI T2 SIR changes and cell apoptosis using a CSM animal model.Methods Forty-eight rabbits were randomly assigned to four groups：one control group and three experimental chronic compression groups,with each group containing 12 animals.Chronic compression of the cervical spinal cord was implemented in the experimental groups by implanting a screw in the C3 vertebra.The control group underwent sham surgery.Experimental groups were observed for 3,6,or 9 months after surgery.MRI T2-weighted SIR Tarlov motor scores and cortical somatosensory-evoked potentials （CSEPs） were periodically monitored.At each time point,rabbits from one group were sacrificed to determine the level of apoptosis by histology （n=6） and Western blotting （n=6）.Results Tarlov motor scores in the compression groups were lower at all time points than the control group scores,with the lowest score at 9 months （P ＜0.001）.Electrophysiological testing showed a significantly prolonged latency in CSEP in the compression groups compared with the control group.All rabbits in the compression groups showed higher MRI T2 SIR in the injury epicenter compared with controls,and higher SIR was also found at 9 months compared with 3 or 6 months.Histological analysis showed significant apoptosis in the spinal cord tissue in the compression groups,but not in the control group.There were significant differences in apoptosis degree over time （P ＜0.001）,with the 9-month group displaying the most severe spinal cord apoptosis.Spearman＇s rank correlation test showed that there was close relation between MRI SIR and degree of caspase-3 expression in Western blotting （r=0.824.P ＜0.001）.Conclusions Clear apoptosis of spinal cord tissue was observed during chronic focal spinal compression.Changes in MRI T2 SIR mav be related to the severity of the apoptosis in cervical spinal cord.

Cultivated Land Monitoring System Based on Dynamic Wake-Up UAV and Wireless of Distributed Storage

The drawbacks of the traditional multi-hop structure of wireless sensor networks(WSNS)are susceptible to reflection,scattering and diffraction,serious attenuation of signal intensity and phase deviation due to various obstacles in cultivated land environment and mountains.In this paper,the wireless signal intensity is measured and curve fitting is done respectively in both open environment and obstacle-environment with both sending and receiving height of 0 m,1 m,and 2 m.It is found out that packet loss probability is too high when an obstacle exists.In such a case,unmanned aerial vehicle(UAV)is introduced to activate terrestrial nodes and operation mechanism of distributed storage.Experimental results show that both ground-to-air barrier-free communication and communication with obstacles can greatly reduce the energy consumption of each node and packet loss probability,thus greatly improving the reliability of UAV-WSN system.

Magnetic resonance imaging features of intrahepatic extramedullary hematopoiesis: Three case reports

BACKGROUND Extramedullary hematopoiesis rarely occurs within the liver alone,and is easily misdiagnosed.The radiological literature on this disease is exclusively case reports.There is a paucity of literature on the role of magnetic resonance imaging(MRI).The most common imaging modalities used are computed tomography and ultrasound.This report aims to provide more data on the appearance of extramedullary hematopoiesis using MRI to help radiologists establish the diagnosis.CASE SUMMARY Three patients(one male and two females)were incidentally found to have a hepatic mass or nodule,without hepatomegaly or splenomegaly.Laboratory tests including liver function,serum hepatic tumor markers,and hepatitis serologic markers were normal.On MRI scans,all lesions showed lower signal intensity on in-phase images than on out-phase images.One case showed changes in signal intensity on T2 weighted images(WI)and diffusion WI,which shifted from hyperintensity to hypointensity with size enlargement between two rounds of imaging examination.These lesions exhibited different enhancement patterns on dynamic contrast enhancement series.CONCLUSION The MRI signal change and in-/out-phase image might provide useful information and help radiologists establish the diagnosis of intrahepatic extramedullary hematopoiesis.

Assessment the Optimal Effect of Time of Repetition: Extrinsic Pulse Parameter on Gd-DTPA Enhanced, Spin-Echo T1-Weighted MR Images under Low Magnetic Field Strength

The contrast agent concentration, the time of repetition (TR) and magnetic field strength are significant parameters that influence for the accurate signal intensity (SI) in quantitative Magnetic Resonance Imaging (MRI). Therefore, this study was conducted to investigate and refine the dependence and the optimal effect of Time of Repetition (TR) on the relationship between signal intensity and Gd-DTPA (Gadolinium-diethylene-triaminepenta-acetic acid) concentration, after applying two-dimensional (2D) Spin Echo (SE) pulse sequence under low-field MRI. In addition to that, the optimal concentration of Gd-DTPA at given sequence parameters at low-field MRI was also evaluated. A water-filled phantom was constructed for a range of Gd-DTPA concentrations (0 - 6 mmol/L) and the mean signal intensities (SIs) were assessed in the defined region of interest on T1-weighted images with different TR values (40 - 2000 ms). The generated signal-concentration curves for Gd-DTPA revealed that increasing TR was associated with the increase of the overall SIs and the maximum relationship between SI to concentration. Moreover, the required Gd-DTPA concentration to produce the maximum SI was associated to decrease with the increase of TR. In addition to this, the application of beyond 100 ms TR values in this study with relatively higher concentrations (beyond 1 - 2 mmol/L) has resulted predominantly non-linear patterns in the signal-concentration curves and it appears the saturation or decay of the SIs due to T2 effect. From these results, it can be suggested that the selection of relatively lower Gd-DTPA concentration ( mmol/L) with less than 800 ms (<800 ms) TR values can produce a better linear relationship between the concertation and SIs in T1-weighted SE low field contrast-enhanced MRI. Furthermore, this study also outlined the significance and necessity of the optimization of TR in SE sequence in low field MRI prior to a particular examination.

New proposal of modulation of amplitude-squeezed state of light by intensity variation of a low-frequency coherent message signal

Squeezed state of light explores a new era in noiseless communication and data processing recently breaking the quantum limit of noise. We propose a new mechanism of modulating an amplitude-squeezed signal with the instantaneous intensity variation of a coherent signal. The modulating signal is a coherent light where the amplitude-squeezed light takes the role of a carrier signal.