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PSTD (pseudospectral time domain) is recognized as one of the powerful models to accurately calculate the scattering properties of nonspherical particles. But it is only good at the computation in coarse spatial resolution, and large "staircase approximation error" will occur in the actual computation. To solve this problem, the variable dimension scheme is introduced to improve the PSTD computation, in which, the finer grid cells are set near the particle's surface. In order to ensure that the PSTD algorithm can be performed on non-uniform grids, we have improved the PSTD with the space mapping technique so that the FFT algorithm can be implemented. The performance of the improved PSTD (called "IPSTD" in this paper) is investigated from two aspects: for the calculation accuracy, the phase matrices calculated by IPSTD are compared with those well tested scattering models like Lorenz-Mie theory, T-matrix method and DDSCAT; for computational efficiency, the computational time of PSTD and IPSTD are compared for the spheres with different sizes. From the results, it can be found that, the IPSTD scheme can improve the simulation accuracy of phase matrix elements notably, especially in the large scattering angles; though the computational burden of IPSTD is larger than that of PSTD, its computational burden does not increase substantially.
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Objective:To evaluate the efficacy and safety of noninvasive high-frequency oscillatory ventilation (nHFOV) as the initial ventilation mode for respiratory distress syndrome (RDS) in premature infants.Methods:From the establishment of the databases [(PubMed, Embase, Cochrane Library, CNKI, Wanfang database, CQVIP and CBM (SinoMed)] to March 1, 2022, literature on randomized controlled trials (RCTs) using nHFOV and nasal continuous positive airway pressure(NCPAP) as the initial ventilation modes for RDS in premature infants were searched. The qualities of the included literature were evaluated according to Cochrane Evaluation Manual. RevMan 5.4 software was used for Meta-analysis.Results:Seven RCTs involving 786 children were included for the final Meta-analysis, with 395 cases in the nHFOV group and 391 cases in the NCPAP group. The results showed that the nHFOV group had lower intubation rates than the NCPAP group ( OR=0.34, 95% CI 0.22~0.51, P<0.001). No significant differences existed in mortality rates and complication rates between the two groups ( P>0.05). Conclusions:nHFOV as the initial treatment for RDS in premature infants may reduce the incidence of early treatment failure without increasing complications.
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AIM:To investigate the effects of Prunus cerasifera Ehrh.polyphenol extract(PCE)on glucose metabolism in insulin-resistant HepG2(IR-HepG2)cells.METHODS:An IR-HepG2 cells model was established using high sugar and high insulin induction;a control group,an insulin resistance(IR)model group,a PCE treatment group with different concentrations,and a metformin treatment group were set up.Cells were treated with 50,100,200,and 400 mg/L of polyphenol extract for 24 hours,respectively,to detect their effects on cellular glucose consumption.At the same time,use thiazole blue(MTT)colorimetry to evaluate cell viability.Real-time PCR and Western blot were used to detect expression of glucose metabolism-related mRNA and proteins.RESULTS:Prunus cerasifera Ehrh.polyphenol ex-tract can significantly increase glucose consumption in IR-HepG2 cells,and cell activity tends to increase and then decline as its concentration increases;At mRNA and protein levels,in addition to significantly increasing the expression of phos-phorylated adenosine monophosphate activated protein kinase(p-AMPK)protein in IR-HepG2 cells,it also decrease gly-cogen synthase kinase 3β(GSK3β)in glycogen synthesis and gluconeogenesis pathways,forked protein O1(FoxO1),peroxisome proliferator activates gamma co-receptor activation 1-alpha(PGC-1α),glucose-6-phosphatase(G6Pase)and phosphoenol pyruvate carboxykinase(PEPCK)expression.CONCLUSION:Prunus cerasifera Ehrh.polyphenol extract can activate the AMPK signaling pathway in IR-HepG2 cells,to further inhibit gluconeogenesis and glycogen synthesis pathways,thereby improving the insulin resistance state of HepG2 cells.
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Objective:To create radiomics models based on abbreviated multimodal magnetic resonance imaging (MRI) for the diagnosis of breast cancer.Methods:All breast MR imaging data between Jun 2014 and Mar 2019 were retrospectively collected. Patients with pathological results of puncture or surgical resection were involved in this study. One thousand three hundred and six patients (416 benign and 890 breast cancer) were divided into training cohort ( n=702), internal validation cohort ( n=302), and external validation cohort ( n=302). All images were reduced to: the joint model group [including T2 weighted imaging (T2WI), DWI (diffusion-weighted imaging) and first contrast-enhanced sequences], non-enhanced group (T2WI and DWI) and single-phase enhanced group (first contrast-enhanced sequences). Analysis of variance (ANOVA) and least absolute shrinkage and selection operator (LASSO) were used to reduce the dimension of texture features. Three supervised machine learning algorithms (Bagging decision tree, Gaussian process, support vector machine) were used to predict benign and malignant breast lesions, and the best classifier was selected to construct breast cancer diagnosis model. Models were validated by internal and external validation cohorts. Results:The Gaussian process algorithm was chosen. The area under the curve (AUC) of the joint model and the non-enhanced model for predicting breast cancer were 0.903 and 0.893 for the training cohort, 0.893 and 0.863 for the internal validation cohort, and 0.878 and 0.864 for the external validation cohort.Conclusions:The radiomics model based on abbreviated multimodal MRI can accurately diagnose breast cancer. And the non-enhanced model can accurately diagnose breast cancer without contrast enhancement, which provides feasibility for simplifying the diagnosis process.
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Bronchopulmonary dysplasia(BPD)is a common chronic lung disease during the newborn period.It not only affects the quality of life of the children, but causes complications that have a certain impact on the future growth and development of them.Currently, there is still a lack of specific prevention and treatment measures.MicroRNAs(miRNAs)are a class of endogenous small molecule non-coding RNAs.In recent years, some abnormally-expressed miRNAs have been found to be involved in the pathogenesis of BPD through regulating apoptosis pathway, but the specific pathogenic link and mechanisms are still not clear enough.In this article, the molecular mechanisms of miRNAs involved in apoptosis in the pathogenesis of BPD were reviewed to provide a theoretical basis for exploring new diagnosis and treatment methods for BPD.
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BACKGROUND: As a debilitating neurodegenerative disease, neovascular age-related macular degeneration (nAMD) accounts for more than 90% of severe visual loss or legal blindness among AMD patients. Anti-vascular endothelial growth factor (VEGF) had been applied widely in nAMD treatment. To date, debate regarding efficacy and safety still exists among different anti-VEGF regimens as management of nAMD. To provide substantial evidence for clinical nAMD treatment, this study ranks the priority of anti-VEGF regimens via Bayesian network meta-analysis (NMA), comparing data collected from randomized controlled trials (RCTs). METHODS: We searched PubMed Central, MEDLINE Ovid, Embase Ovid, ISRCTN, ICTRP and ClinicalTrials. gov from a database established until 1 April 2019 systematically for anti-VEGF regimens. Bayesian NMA with random-effect was conducted to compare efficacy and safety and rank priority of anti-VEGF regimens. The primary efficacy and safety outcomes were the proportion of patients gaining 15 or more letters, and the incidence of arterial thromboembolic (ATC) events. The effect measure is the standard mean difference (SMD), or the odds ratio (OR) with their 95% confidence interval (CI). The study protocol is registered with PROSPERO, number CRD42019132243. RESULTS: We obtained 6467 citations and identified 29 RCTs including 13,596 participants; 86% of these trials were low risk or of uncertain risk bias. In NMA, ORs compared with sham injection for the proportion of patients gaining 15 or more letters (12,699 participants from 23 trials) ranged from 4.05 [95% Bayesian credible interval (CrI) 1.62-10.11] for ranibizumab quarterly regimen to 8.57 (95% CrI 4.66-15.73) for a ranibizumab treat-and-extend regimen. No difference was found between sham injection and anti-VEGF regimens for ATC events (11,500 participants from 18 trials). Results for the primary outcome did not substantially change in sensitivity analyses after removing studies at high risk of bias and small sample size (n < 100), respectively. CONCLUSION: The treat-and-extend regimen of ranibizumab and aflibercept are the preferred anti-VEGF regimens for nAMD. Bevacizumab treat-and-extend regimens need more head-to-head comparisons with other regimens or sham injection for advanced application. The treat-and-extend regimen proved to be the most effective regimen for each anti-VEGF drug in the NMA. Pegaptanib every 6 weeks and Conbercept quarterly are unable to satisfy the best corrected visual acuity (BCVA) improvement requirement of nAMD patients.
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Objective To explore the feasibility of quantitative evaluation in fibrosis by geometrical characteristics of hepatic capsule based on computer technology . Methods Fifty-nine rabbits models of fibrosis were established and then were divided into four groups according to the results of pathologic examination:S0-S1 ,S2 ,S3 and S4 groups . Two-dimensional high-frequency ultrasound images of hepatic capsule of the rabbits were collected at 6th week ,12th week and 18th week . All the images were collected to obtain the contour line of the capsule and its shape control points by combining manual monitoring and gradient optimization methods . Subsequently ,the mean value and variance of angles between adjacent seed points and the number of continuous segments of the contour line ,were extracted to evaluate the smoothness and continuity of the contour line of the hepatic capsule . Results With aggravating fibrosis ,the mean value and variance of the angles were gradually increased ,and the differences between S0-S1 and other 3 groups were all statistically significant( P <0 .05) . Similarly ,the number of segments required to make the sum of lengths of continuous segments reach up to 80% of the total width of the imaging section was gradually increased . The differences between S0-S1 and S4 group( P =0 .025) ,S2 and S4 group( P =0 .004) were also statistically significant . Conclusions Analysis of geometrical characteristics of the hepatic capsule partially indicates the presence of early-stage fibrosis ,and is expected to provide a quantitative method for non-invasive assessment of fibrosis .
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Objective To summarize the multimodal ultrasonographic characteristics primary thyroid lymphoma (PTLs), and to discuss the diagnosis and differential diagnosis of PTLs. Methods Multimodal ultrasonographic charactericsits of six cases of PTLs were analyzed retrospectively. All of the patients were examined by the conventional two-dimensional ultrasound (2DUS), color Doppler flow imaging (CDFI), contrast-enhanced ultrasound (CEUS), three-dimensional ultrasound (3DUS) reconstruction and elastography imaging (EI) from October 2011 to February 2016 in Changzheng Hospital, affiliated to Secondary Military Medical University. All diagnoses were confirmed by ultrasound-guided percutaneous biopsy.Results (1) 2DUS: six cases of PTLs without capsule were observed as diffusely enlargement type (two cases), unilateral nodular type (one case, on left lobe),and bilateral multiple nodular type (the other three cases). The margin of the multiple nodules were not clear, and some nodules were fused with each other.There were four cases of heterogeneous (extremely) hypoechogenicity and two cases of mixed echogenicity, All of the lesions were characterized by various striped and reticular hyperechogenicity interiorly on ultrasonograms, and only one case showed slightly posterior enhancement. Except one case, multiple cervical lymphnodes hyperplasia were identified on neck regionⅡ-Ⅴin five cases. (2) CDFI and CEUS:CDFI showed abundant blood flow signals in the PTLs nodules peripherally and internally. The striped blood flow was observed in the lesions, and spectrum showed as artery and veins. The plentiful vascular tree was also found in the enlarged lymphnodes. By using high frequency CEUS, six cases of the PTLs demonstrated diffuse and heterogeneous enhancement significantly, including little necrosis area without prominent contrast agent filling in two cases. (3) 3DUS reconstruction: Various striped and reticular hyperechoic features were found on the surface of six cases of PTL nodules. (4) EI: All lesions were soft in six cases. The ratio of elastic strain rate was 1.28-1.96, average (1.82±0.29).Conclusion The ultrasonographic features of PTLs are of certain characteristics, and multiple modes of ultrasound examination can help to grasp the comprehensive imaging informations of PTLs, which should be encouraged positively to facilitate the early detection, early diagnosis and early treatment for PTLs.
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Objective To construct the DNA vaccine pIRES2-MLAA34-HSP70,and to detect its immune effect.Methods The acute monocytic leukemia associated antigen gene MLAA-34 and heat-shock protein (HSP)70 gene were extracted by using RT-PCR.The specific overlapping primer was designed,and the fusion gene MLAA34-HSP70 was amplified by using SOE-PCR technique.Then the DNA vaccine pIRES2-MLAA34-HSP70 was constructed,and BALB/c mice were immunized with this DNA vaccine.The splenic lymphocyte killing activity was detected by using MTT,levels of IL-2,IL-4 and IFN-γ were also detected by using ELISA.Results The MLAA34-HSP70 gene (2 956 bp) and the DNA vaccine pIRES2-MLAA34-HSP70 was amplified and constructed successfully.The killing efficiency of DNA vaccine pIRES2-MLAA34-HSP70 in U937 cells was significantly higher than that in other experimental groups and control group (P<0.01),and levels of IL-4,IL-2 and IFN-γin DNA vaccine pIRES2-MLAA34-HSP70 group were significantly higher than those in the other experimental groups and control group (P<0.01).Conclnsion The DNA vaccine pIRES2-MLAA34-HSP70 is constructed successfully.It is shown that the DNA vaccine induces strong humoral immunity,which could enhance immune responses to tumor cells and specificlly kill MLAA34 positive cells.
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Objective: To observe the impact of high thoracic epidural blockade (HTEB) on atrial autonomic nerve remodeling in dogs with atrial ifbrillation (AF) induced by long-term rapid right atrial appendage pacing and to explore the effect of nerve growth factor (NGF) on atrial autonomic nerve remodeling. Methods: AF model was established by consistent rapid atrial pacing for 6 weeks. 18 experimental dogs were randomly divided into 3 groups: Sham group, the dogs had no pacing while received normal saline injection; Control group, the dogs had pacing and normal saline injection; HTEB group, the dogs had pacing and 0.5% lidocaine injection for HTEB.n=6 in each group. Atrial myocardium collagen volume fraction (CVF) was examined by Masson staining; sprouting of NGF related protein 43 (GAP43) and tyrosine hydroxylase (TH) were assessed by immunohistochemistry; protein expressions of NGF, GAP43 and TH were measured by Western blot analysis. Results: Compared with Sham group, HTEB group showed decreased CVF and sprouting of GAP43, TH,P Conclusion: Long-term rapid atrial pacing induced AF dog had inhomogeneous sprouting of atrial myocardial nerve which may cause autonomic nerve remodeling; NGF played the important role in such process. HTEB could effectively inhibit NGF up-regulation and suppress the autonomic nerve remodeling in experimental dogs.
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Objective To investigate the ultrasonic and pathological features of porcine striped muscle injury from thermal and chemical factors respectively, and to analyze the limitation of ultrasound diagnosis given by doctors with different skill levels. Methods An experimental study using fresh porcine striped muscle in vitro was designed, where the injury were caused by microwave ablation (2 450 MHz) and Anhydrous acetic acid (99.8%) injection separately. Blind to pathologic results, the two-dimensiona sonograms taken from each model were analyzed by sonographers with different skill levels independently. Finally, the diagnoses were evaluated and compared among them. Results Two-dimensional sonograms showed distinct changes of the textures in both injury models, which was characterized as the disappearance of regular tissue structure. However, the corresponding histopathology revealed obvious differences between the two interventions on ultrasonograms. There was no statistical difference between chief physician and attending doctor (both of them had over 5-year experiences on skeletal muscle ultrasound ) in identifying the ultrasonic features of boundary, shape and muscle texture (Kappa=0.933, 0.845, 0.789;Kappa=0.790, 0.935, 0.865, all P<0.05). Compared with residents′diagnosis, there were signiifcant differences in identifying the ultrasonic features of echo level and muscle texture in both injury models:Echo level in thermal injury group:chief physician vs residents, Kappa=0.323;attending doctor vs residents, Kappa=0.297. Texture feature in thermal injury group:chief physician vs residents, Kappa=0.259;attending doctor vs residents, Kappa=0.112. Texture feature in chemical injury group:chief physician vsresidents, Kappa=0.253;attending doctor vs residents, Kappa=0.070. Conclusions Microwave ablation and Anhydrous acetic acid can cause different histopathologic changes in correspondence with various features on two-dimensional sonograms. But ultrasonographers with different skill levels leads to signiifcant variations in identiifcation and qualitative diagnosis, which is impossible to be quantitatively analyzed. Chief physician and attending doctor can draw a consistent conclusion and demonstrate the ultrasounic characteristics in porcine striped muscle injury model from thermal or chemical factors.
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Objective To detect fat emboli in cardiac chamber of the patients undergoing total knee arthroplasty(TKA) by transesophageal echocardiography(TEE), and to discuss the relevant clinical value.Methods Eleven female patients with 12 osteoarthritis(OA) knees were underwent TKA. According to whether using tourniquet or not,12 knees were divided into 2 groups at random:tourniquet-related group (6 knees) and control group(6 knees). Echo intensity and ultrasonic characteristics of fat emboli in cardiac chamber were studied dynamically by multiplane TEE in various periods of the whole operation. Results All of the patients were implanted knee prostheses successfully. In different periods of TKA, fat emboli appeared as isoechoic or hyperechoic particles, which were found in right atrium, but nothing could be found in left heart. The imaging of the particles was flowing with duration time of 10~600s, like dots, lines, "moving star" or "shower". While femur expanding(0~3mins),the particles in right atrium and ventricle became more and more, and the echo intensity became significantly higher than those in other periods. After releasing tourniquet(0~5mins),most particles with highest echo intensity were observed in right heart,showing like "snowstorm" in tourniquet-related group, and more emboli were still detected at the end of monitoring (10 min after releasing tourniquet) by TEE,compared to the control group. No patient suffered from fat embolism syndrome(FES) with clinical manifestation. Conclusions Fat emboli in cardiac chamber can be observed sensitively by real-time TEE dynamically during TKA. It should be encouraged and promoted to analyze ultrasonic characteristics to facilitate the early detection, early diagnosis and early clinical intervention for the subclinical type of FES.
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Objective To investigate the technical feasibility and clinical significance of non-vascular contrast-enhanced ultrasound(NVCEUS) in screening pyelogenie cyst out of simple renal cysts so as to avoid damage to the urinary tract from absolute ethanol while undergoing percutaneous aspiration and ethanol sclerotherapy(PAEST). Methods Following an inclusion criteria 23 patients with renal cysts were selected to receive NVCEUS scanning by means of administrating SonoVue contrast agents through puncture needle into their renal cyst lumen prior to the injection of absolute ethanol for sclerosing treatment. By the demonstration of hyperechoic contrast agents leaving from intra cyst into renal collecting system,a pyelogenic cyst was defined. The patients with this kind of cyst was not allowed for further ethanol sclerotherapy. Results NVCEUS made 3 patients with pyelogenic cyst resembling simple ones free from ethanol selerotherapy,and 4 patients suspicious of pyelogenic cyst due to weird cyst configuration remain in the list of simple cyst for further selerotherapy. Conclusions NVCEUS of renal cyst is highly capable of differentiating pyelogenie cyst from simple cyst and highly valuable in increasing the safety for the procedure of PAEST.
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During the past few years, it was found that hemophiliacs suffered from AIDS increasingly from year to year. The first case of hemophilia with AIDS was found in the fourth quater of 1981. Eight cases of hemophilia occurred in 1982, and 12 cases of AIDS were found in the hemophiliacs in 1983. The goal of this paper was to test the titer of CMV, EBV, HTLV and EA in the blood stream of hemophiliacs. Hemophiliacs had much higher sensitivity to CMV and EBV than the healthy control. There was a significant difference between these hemophiliacs without any symptoms of AIDS and healthy man. The relationship between hemophilia and AIDS and the cause that the hemophiliac suffers from AIDS are discussed.