Early left ventricular microvascular dysfunction in diabetic pigs: a longitudinal quantitative myocardial perfusion CMR study.

BACKGROUND: Microvascular pathology is one of the main characteristics of diabetic cardiomyopathy; however, the early longitudinal course of diabetic microvascular dysfunction remains uncertain. This study aimed to investigate the early dynamic changes in left ventricular (LV) microvascular function in diabetic pig model using the cardiac magnetic resonance (CMR)-derived quantitative perfusion technique. METHODS: Twelve pigs with streptozotocin-induced diabetes mellitus (DM) were included in this study, and longitudinal CMR scanning was performed before and 2, 6, 10, and 16 months after diabetic modeling. CMR-derived semiquantitative parameters (upslope, maximal signal intensity, perfusion index, and myocardial perfusion reserve index [MPRI]) and fully quantitative perfusion parameters (myocardial blood flow [MBF] and myocardial perfusion reserve [MPR]) were analyzed to evaluate longitudinal changes in LV myocardial microvascular function. Pearson correlation was used to analyze the relationship between LV structure and function and myocardial perfusion function. RESULTS: With the progression of DM duration, the upslope at rest showed a gradually increasing trend (P = 0.029); however, the upslope at stress and MBF did not change significantly (P > 0.05). Regarding perfusion reserve function, both MPRI and MPR showed a decreasing trend with the progression of disease duration (MPRI, P = 0.001; MPR, P = 0.042), with high consistency (r = 0.551, P < 0.001). Furthermore, LV MPR is moderately associated with LV longitudinal strain (r = - 0.353, P = 0.022), LV remodeling index (r = - 0.312, P = 0.033), fasting blood glucose (r = - 0.313, P = 0.043), and HbA1c (r = - 0.309, P = 0.046). Microscopically, pathological results showed that collagen volume fraction increased gradually, whereas no significant decrease in microvascular density was observed with the progression of DM duration. CONCLUSIONS: Myocardial microvascular reserve function decreased gradually in the early stage of DM, which is related to both structural (but not reduced microvascular density) and functional abnormalities of microvessels, and is associated with increased blood glucose, reduced LV deformation, and myocardial remodeling.

[Cardiac Structural and Functional Features in Patients With Type 2 Diabetes Mellitus and Heart Failure With Preserved Ejection Fraction:A Study Based on Propensity Score Matching].

Objective To investigate the cardiac structural and functional characteristics in the patients with heart failure with preserved ejection fraction (HFpEF) and type 2 diabetes mellitus (T2DM),and predict the factors influencing the characteristics. Methods A total of 783 HFpEF patients diagnosed in the Department of Geriatric Cardiology,the First Hospital of Lanzhou University from April 2009 to December 2020 were enrolled in this study.Echocardiography and tissue Doppler technique were employed to evaluate cardiac structure and function.According to the occurrence of T2DM,the patients were assigned into a HFpEF+T2DM group (n=332) and a HFpEF group (n=451).Propensity score matching (PSM)(in a 1∶1 ratio) was adopted to minimize confounding effect.According to urinary albumin excretion rate (UAER),the HFpEF+T2DM group was further divided into three subgroups with UAER<20 µg/min,of 20-200 µg/min,and>200 µg/min,respectively.The comorbidities,symptoms and signs,and cardiac structure and function were compared among the groups to clarify the features of diabetes related HFpEF.Multivariate linear regression was conducted to probe the relationship of systolic blood pressure,blood glucose,glycosylated hemoglobin,and UARE with cardiac structural and functional impairment. Results The HFpEF+T2DM group had higher prevalence of hypertension (P=0.001) and coronary heart disease (P=0.036),younger age (P=0.020),and larger body mass index (P=0.005) than the HFpEF group,with the median diabetic course of 10 (3,17) years.After PSM,the prevalence of hypertension and coronary heart disease,body mass index,and age had no significant differences between the two groups(all P>0.05).In addition,the HFpEF+T2DM group had higher interventricular septal thickness (P=0.015),left ventricular posterior wall thickness (P=0.040),and left ventricular mass (P=0.012) and lower early diastole velocity of mitral annular septum (P=0.030) and lateral wall (P=0.011) than the HFpEF group.Compared with the HFpEF group,the HFpEF+T2DM group showed increased ratio of early diastolic mitral filling velocity to early diastolic mitral annular velocity (E/e') (P=0.036).Glycosylated hemoglobin was correlated with left ventricular mass (P=0.011),and the natural logarithm of UAER with interventricular septal thickness (P=0.004),left ventricular posterior wall thickness (P=0.006),left ventricular mass (P<0.001),and E/e' ratio (P=0.049). Conclusion The patients with both T2DM and HFpEF have thicker left ventricular wall,larger left ventricular mass,more advanced left ventricular remodeling,severer impaired left ventricular diastolic function,and higher left ventricular filling pressure than the HFpEF patients without T2DM.Elevated blood glucose and diabetic microvascular diseases might play a role in the development of the detrimental structural and functional changes of the heart.

[Efficacy of noninvasive high-frequency oscillatory ventilation versus nasal intermittent positive pressure ventilation as post-extubation respiratory support in preterm infants: a Meta analysis]. / æ— åˆ›é«˜é¢‘æŒ¯è¡é€šæ°”ä¸Žç»é¼»é—´æ­‡æ­£åŽ‹é€šæ°”ä½œä¸ºæ—©äº§å„¿æ‹”ç®¡åŽå‘¼å¸æ”¯æŒç–—æ•ˆæ¯”è¾ƒçš„Meta分析.

OBJECTIVES: To systematically evaluate the efficacy and safety of noninvasive high-frequency oscillatory ventilation (NHFOV) versus nasal intermittent positive pressure ventilation (NIPPV) as post-extubation respiratory support in preterm infants. METHODS: China National Knowledge Infrastructure, Wanfang Data, Chinese Journal Full-text Database, China Biology Medicine disc, PubMed, Web of Science, and the Cochrane Library were searched for articles on NHFOV and NIPPV as post-extubation respiratory support in preterm infants published up to August 31, 2022. RevMan 5.4 software and Stata 17.0 software were used for a Meta analysis to compare related indices between the NHFOV and NIPPV groups, including reintubation rate within 72 hours after extubation, partial pressure of carbon dioxide (PCO2) at 6-24 hours after switch to noninvasive assisted ventilation, and the incidence rates of bronchopulmonary dysplasia (BPD), air leak, nasal damage, periventricular leukomalacia (PVL), intraventricular hemorrhage (IVH), and retinopathy of prematurity (ROP). RESULTS: A total of 9 randomized controlled trials were included. The Meta analysis showed that compared with the NIPPV group, the NHFOV group had significantly lower reintubation rate within 72 hours after extubation (RR=0.67, 95%CI: 0.52-0.88, P=0.003) and PCO2 at 6-24 hours after switch to noninvasive assisted ventilation (MD=-4.12, 95%CI: -6.12 to -2.13, P<0.001). There was no significant difference between the two groups in the incidence rates of complications such as BPD, air leak, nasal damage, PVL, IVH, and ROP (P>0.05). CONCLUSIONS: Compared with NIPPV, NHFOV can effectively remove CO2 and reduce the risk of reintubation, without increasing the incidence of complications such as BPD, air leak, nasal damage, PVL, and IVH, and therefore, it can be used as a sequential respiratory support mode for preterm infants after extubation.

Niche overlap in rodents increases with competition but not ecological opportunity: A role of inter-individual difference.

Niche variation at population level mediates niche packing (i.e. patterns of species' spread within the niche space) and species coexistence at community level. Competition and ecological opportunity (resource diversity) are two of the main mechanisms underlying niche variation. Dense niche packing could occur through increased niche partitioning or increased niche overlap. In this study, we used stable carbon and nitrogen isotope data of 635 individual rodents from four species across nine sites in the montane region of a subtropical island to test the effects of competition and ecological opportunity on population isotope niche size, inter-individual niche difference within population and interspecific niche overlap within community. We used the Bayesian Standard Ellipse Area (SEAB, the ellipse area enclosed by carbon and nitrogen isotope values of organisms on a bi-plot) to estimate population niche size and interspecific niche overlap. Inter-individual niche difference within population was quantified as isotopic divergence and isotopic uniqueness. We used rodent abundance (the number of unique individuals captured) to measure competition and plant isotope niche size (plant SEAB) to measure ecological opportunity. The rodents experienced competition as evidenced by a negative relationship between population change rate and conspecific abundance. Rodent population niche size increased with ecological opportunity but not competition. The inter-individual niche difference (isotopic uniqueness) increased with competition (interspecific competition only) but not ecological opportunity. At community level, interspecific niche overlap (herbivore-omnivore pair only) increased with competition (the combined abundance of the pair) but not ecological opportunity. This study demonstrated that isotope niche variation of the rodents could be hierarchically influenced by ecological opportunity and competition, with the former setting the limit of population niche size across communities and the latter shaping inter-individual niche difference and interspecific niche overlap within communities. Under strong intraspecific competition and limited ecological opportunity for niche expansion, individuals may choose to increase their isotopic uniqueness from conspecifics at the cost of overlapping with heterospecifics of different trophic roles within the community niche space as overall competition increases. Denser niche packing of these rodent communities might be achieved through increased niche overlap.

[Expression and Role of PD-L1 in a Mouse Model of Necrotizing Enterocolitis].

Objective: To investigate the expression and role of programmed death ligand-1 (PD-L1) in a mouse model of necrotizing enterocolitis (NEC). Methods: A total of 20 wild-type C57 BL/6 J mice were randomly assigned to the control and the model groups. Mice in the control group were breastfed, while mice in the model group were given lipopolysaccharide, formula feeding, hypoxia, and cold stimulation for NEC induction. Then, the intestines of the mice were collected in order to assess the pathological changes through HE staining, to examine PD-L1 expression and localization with immunofluorescence co-localization, and to evaluate intestinal PD-L1 expression with Western blot. Peripheral blood was collected for flow cytometry to examine leukocyte subpopulations and their PD-L1 expression. On the other hand, 14 PD-L1 (+/+) mice and 14 PD-L1 (-/-) mice were randomly divided into their respective genotype control groups and model groups. The same induction method as was already mentioned was adopted for the model groups. The intestines of the mice were collected for HE staining to evaluate the pathological change and peripheral blood was collected to examine the expression of inflammatory factors. Results: The NEC mouse model was successfully constructed. PD-L1 was widely expressed in enterocytes and inflammatory cells in the mouse intestines and in T cells, monocytes, and neutrophils in peripheral blood. The expression of PD-L1 in NEC mouse intestines increased in comparison with that of the control group. In the peripheral blood of NEC mice, the proportion of T cells and monocytes and their PD-L1 expression showed no significant changes compared with those of the control group, while the proportion of neutrophils and their PD-L1 expression increased by about 140% and 150%, respectively, in comparison with those of the control group ( P<0.05). According to the results of the PD-L1 gene mouse experiment, the control groups of PD-L1 (+/+) mice and PD-L1 (-/-) mice showed no significant difference in their intestinal conditions and serum inflammatory factor levels, while the PD-L1 (-/-) NEC mouse had worse intestinal pathological changes and increased mean pathological scores compared with those of PD-L1 (+/+) NEC mouse ( P<0.05). In addition, serum interleukin (IL)-10 in PD-L1 (-/-) NEC mouse decreased by about 44% compared with that of PD-L1 (+/+) NEC mice, and chemokine (C-X-C motif) ligand 1/IL-6/IL-1ß all increased by more than 25% (all P<0.05). Conclusion: PD-L1 is widely expressed in inflammatory cells and enterocytes in mice. Knocking out PD-L1 aggravates the degree of NEC inflammation and intestinal pathological changes. PD-L1 plays a protective role by reducing inflammation in the pathogenesis of NEC, the mechanism of which may be related to the regulation of neutrophils/enterocytes.

Hepatitis E virus prevalence among blood donors in Dali, China.

BACKGROUND: Hepatitis E virus (HEV) is a nonenveloped RNA virus causing hepatitis E worldwide. The increase in transfusion-transmitted cases of HEV infections from asymptomatic blood donors causing serious illnesses among immunosuppressed recipients has been reported in the past few years. China is one of the most prevalent regions of HEV; as a result, it is important to evaluate the risk of transfusion-transmitted HEV. METHODS: A total of 1864 serum samples (including demographic characteristics) from blood donors were randomly collected from February to March 2018 in Dali city. Anti-HEV IgG, IgM and IgA antibodies and HEV antigen were examined by enzyme-linked immunosorbent assay (ELISA). HEV RNA was detected by real-time PCR. Multivariable logistic regression modelling was used to examine the risk factors associated with HEV prevalence. RESULTS: Overall, the positive rates of anti-HEV IgG, IgM, and IgA antibodies were 13.36% (249/1864), 1.13% (21/1864), and 1.82% (34/1864), respectively. However, none of the 1864 serum samples were HEV antigen positive or HEV RNA positive. Females (16.69%) had a significantly higher HEV seroprevalence than males (13.04%) (odds ratio [OR] 1.34 [95% CI, 1.02-1.75]). Bai (18.85%) donors had a significantly higher HEV seroprevalence than Han (12.21%) blood donors (odds ratio [OR], 1.65 [95% CI, 1.24-2.19] for Bai). CONCLUSIONS: HEV showed a seroprevalence among blood donors in Yunnan Province, some of which were even recent infections, indicating a threat to the safety of blood transfusions. Whether to formulate a strategy for HEV screening in blood centres needs further research.

Myocardial perfusion assessment in the infarct core and penumbra zones in an in-vivo porcine model of the acute, sub-acute, and chronic infarction.

OBJECTIVES: To assess the longitudinal changes of microvascular function in different myocardial regions after myocardial infarction (MI) using myocardial blood flow derived by dynamic CT perfusion (CTP-MBF), and compare CTP-MBF with the results of cardiac magnetic resonance (CMR) and histopathology. METHODS: The CTP scanning was performed in a MI porcine model 1 day (n = 15), 7 days (n = 10), and 3 months (n = 5) following induction surgery. CTP-MBF was measured in the infarcted myocardium, penumbra, and remote myocardium, respectively. CMR perfusion and histopathology were performed for validation. RESULTS: From baseline to follow-up scans, CTP-MBF presented a stepwise increase in the infarcted myocardium (68.51 ± 11.04 vs. 86.73 ± 13.32 vs. 109.53 ± 26.64 ml/100 ml/min, p = 0.001) and the penumbra (104.92 ± 29.29 vs. 120.32 ± 24.74 vs. 183.01 ± 57.98 ml/100 ml/min, p = 0.008), but not in the remote myocardium (150.05 ± 35.70 vs. 166.66 ± 38.17 vs. 195.36 ± 49.64 ml/100 ml/min, p = 0.120). The CTP-MBF correlated with max slope (r = 0.584, p < 0.001), max signal intensity (r = 0.357, p < 0.001), and time to max (r = - 0.378, p < 0.001) by CMR perfusion. Moreover, CTP-MBF defined the infarcted myocardium on triphenyl tetrazolium chloride staining (AUC: 0.810, p < 0.001) and correlated with microvascular density on CD31 staining (r = 0.561, p = 0.002). CONCLUSION: CTP-MBF could quantify the longitudinal changes of microvascular function in different regions of the post-MI myocardium, which demonstrates good agreement with contemporary CMR and histopathological findings. KEY POINTS: • The CT perfusion-based myocardial blood flow (CTP-MBF) could quantify the microvascular impairment in different myocardial regions after myocardial infarction (MI) and track its recovery over time. • The assessment of CTP-MBF is in good agreement with contemporary cardiac MRI and histopathological findings, which potentially facilitates a rapid approach for pathophysiological insights following MI.

[Application of 3.0T Time-of-flight Magnetic Resonance Angiography with Sparse Undersampling and Iterative Reconstruction in the Diagnosis of Unruptured Intracranial Aneurysms].

OBJECTIVE: To evaluate the diagnostic value of 3.0T time-of-flight MR angiography with sparse undersampling and iterative reconstruction (TOFu-MRA) for unruptured intracranial aneurysms (UIAs) on the basis of using digital subtraction angiography (DSA) as the reference standard. METHODS: A total of 65 patients with suspected UIAs were prospectively enrolled and all patients underwent TOFu-MRA and DSA. Relying on DSA as the reference standard, the sensitivity (SEN), specificity (SPE), positive predictive value (PPV) and negative predictive value (NPV) of using TOFu-MRA in UIA diagnosis were calculated, and the inter-observer agreement between two doctors was determined. Comparison of maximum intensity projection (MIP) and volume rendering (VR) image datasets was made to evaluate the agreement between DSA results and TOFu-MRA in the measurement of UIA morphological parameters, including the neck width (D neck), height (H) , and width (D width) of UIAs. RESULTS: The study covered 55 UIAs from 46 patients. The SEN, SPE, PPV and NPV of the two doctors using TOFu-MRA in UIA diagnosis were as follows: (95.7%, 95.7%), (94.7%, 94.7%), (97.8%, 97.8%) and (90.0%, 90.0%), respectively for patient-based assessment; (96.4%, 94.5%), (94.7%, 94.7%), (98.1%, 98.1%) and (90.0%, 85.7%), respectively, for aneurysm-based assessment. There is a strong inter-observer agreement (Kappa=0.93 for patient-based assessment and 0.96 for aneurysm-based assessment) between the two doctors. Moreover, Bland-Altman analysis showed that more than 95% points fell within the limits of agreement (LoA), suggesting strong agreement between the two examination methods for the measurement of UIAs morphological parameters. CONCLUSION: TOFu-MRA showed good diagnostic efficacy for UIAs and the results were in good agreement with those of DSA, the reference standard, for assessing UIA morphological parameter. TOFu-MRA can be used as a first choice for noninvasive diagnostic evaluation of UIAs.

[Noise Reduction Effect of Deep-learning-based Image Reconstruction Algorithms in Thin-section Chest CT].

OBJECTIVE: To evaluate the noise reduction effect of deep learning-based reconstruction algorithms in thin-section chest CT images by analyzing images reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), and deep learning image reconstruction (DLIR) algorithms. METHODS: The chest CT scan raw data of 47 patients were included in this study. Images of 0.625 mm were reconstructed using six reconstruction methods, including FBP, ASIR hybrid reconstruction (ASIR50%, ASIR70%), and deep learning low, medium and high modes (DL-L, DL-M, and DL-H). After the regions of interest were outlined in the aorta, skeletal muscle and lung tissue of each group of images, the CT values, SD values and signal-to-noise ratio (SNR) of the regions of interest were measured, and two radiologists evaluated the image quality. RESULTS: CT values, SD values and SNR of the images obtained by the six reconstruction methods showed statistically significant difference ( P<0.001). There were statistically significant differences in the image quality scores of the six reconstruction methods ( P<0.001). Images reconstruced with DL-H have the lowest noise and the highest overall quality score. CONCLUSION: The model based on deep learning can effectively reduce the noise of thin-section chest CT images and improve the image quality. Among the three deep-learning models, DL-H showed the best noise reduction effect.

[The Application Value of Artificial Intelligence-based Filtering and Interpolated Image Reconstruction Algorithm in Abdominal Magnetic Resonance Image Denoising].

OBJECTIVE: To compare the noise reduction performance of conventional filtering and artificial intelligence-based filtering and interpolation (AIFI) and to explore for optimal parameters of applying AIFI in the noise reduction of abdominal magnetic resonance imaging (MRI). METHODS: Sixty patients who underwent upper abdominal MRI examination in our hospital were retrospectively included. The raw data of T1-weighted image (T1WI), T2-weighted image (T2WI), and dualecho sequences were reconstructed with two image denoising techniques, conventional filtering and AIFI of different levels of intensity. The difference in objective image quality indicators, peak signal-to-noise ratio (pSNR) and image sharpness, of the different denoising techniques was compared. Two radiologists evaluated the image noise, contrast, sharpness, and overall image quality. Their scores were compared and the interobserver agreement was calculated. RESULTS: Compared with the original images, improvement of varying degrees were shown in the pSNR and the sharpness of the images of the three sequences, T1W1, T2W2, and dual echo sequence, after denoising filtering and AIFI were used (all P<0.05). In addition, compared with conventional filtering, the objective quality scores of the reconstructed images were improved when conventional filtering was combined with AIFI reconstruction methods in T1WI sequence, AIFI level≥3 was used in T2WI and echo1 sequence, and AIFI level≥4 was used in echo2 sequence (all P<0.05). The subjective scores given by the two radiologists for the image noise, contrast, sharpness, and overall image quality in each sequence of conventional filtering reconstruction, AIFI reconstruction (except for AIFI level=1), and two-method combination reconstruction were higher than those of the original images (all P<0.05). However, the image contrast scores were reduced for AIFI level=5. There was good interobserver agreement between the two radiologists (all r>0.75, P<0.05). After multidimensional comparison, the optimal parameters of using AIFI technique for noise reduction in abdominal MRI were conventional filtering+AIFI level=3 in the T1WI sequence and AIFI level=4 in the T2WI and dualecho sequences. CONCLUSION: AIFI is superior to filtering in imaging denoising at medium and high levels. It is a promising noise reduction technique. The optimal parameters of using AIFI for abdominal MRI are Filtering+AIFI level=3 in the T1WI sequence and AIFI level=4 in T2WI and dualecho sequences.

[Application of Deep Learning Reconstruction Algorithm in Low-Dose Thin-Slice Liver CT of Healthy Volunteers].

OBJECTIVE: To explore the clinical feasibility of applying deep learning (DL) reconstruction algorithm in low-dose thin-slice liver CT examination of healthy volunteers by comparing the reconstruction algorithm based on DL, filtered back projection (FBP) reconstruction algorithm and iterative reconstruction (IR) algorithm. METHODS: A standard water phantom with a diameter of 180 mm was scanned, using the 160 slice multi-detector CT scanning of United Imaging Healthcare, to compare the noise power spectrums of DL, FBP and IR algorithms. 100 healthy volunteers were prospectively enrolled, with 50 assigned to the normal dose group (ND) and 50 to the low dose group (LD). IR algorithm was used in the ND group to reconstruct images, while DL, FBP and IR algorithms were used in the LD group to reconstruct images. One-way analysis of variance was used to compare the liver CT values, the liver noise, liver signal-to-noise ratio (SNR), contrast noise ratio (CNR) and figure of merit (FOM) of the images of ND-IR, LD-FBP, LD-IR and LD-DL. The Kruskal-Wallis test was used to analyse subjective scores of anatomical structures. RESULTS: The DL algorithm had the lowest average peak value of noise power spectrum, and its shape was similar to that of medium-level IR algorithm. Liver CT values of ND-IR, LD-FBP, LD-IR and LD-DL did not show statistically significant difference. The noise of LD-DL was lower than that of LD-FBP, LD-IR and ND-IR ( P<0.05), and the SNR, CNR and FOM of LD-DL were higher than those of LD-FBP, LD-IR and ND-IR ( P<0.05). The subjective scores of anatomical structures of LD-DL did not show significant difference compared to those of ND-IR ( P >0.05), and were higher than those of LD-FBP and LD-IR. The radiation dose of the LD group was reduced by about 50.2% compared with that of the ND group. CONCLUSION: The DL algorithm with noise shape similar to the medium iterative grade IR commonly used in clinical practice showed higher noise reduction ability than IR did. Compared with FBP, the DL algorithm had smoother noise shape, but much better noise reduction ability. The application of DL algorithm in low-dose thin-slice liver CT of healthy volunteers can help achieve the standard image quality of liver CT.

Visible light positioning (VLP) system using low-cost organic photovoltaic cell (OPVC) for low illumination environments.

We propose and demonstrate a received-signal-strength (RSS) based visible light positioning (VLP) system using a low-cost organic photovoltaic cell (OPVC) receiver (Rx). The OPVC is a passive device without the need of external power supply. It could detect VLC signal and harvest energy. Our developed OPVC has a high power conversion efficiency (PCE) of 9.8%. The VLP system can be operated at a low illumination of 130 lux. The regression machine learning (ML) algorithm is used to enhance the positioning accuracy.

Rolling-shutter-effect camera-based visible light communication using RGB channel separation and an artificial neural network.

We propose and demonstrate a light-panel and rolling-shutter-effect (RSE) camera-based visible light communication (VLC) system using Z-score normalization, red/green/blue (RGB) color channel separation, and 1-D artificial neural network (ANN). The proposed scheme can mitigate the high inter-symbol interference (ISI) generated by the RSE pattern due to the low pixel-per-bit and high noise-ratio (NR) of the display contents.

CMOS camera based visible light communication (VLC) using grayscale value distribution and machine learning algorithm.

We demonstrate a visible light communication (VLC) system using light emitting diode (LED) backlight display panel and mobile-phone complementary-metal-oxide-semiconductor (CMOS) camera. The panel is primarily used for displaying advertisements. By modulating its backlight, dynamic contents (i.e. secondary information) can be transmitted wirelessly to users based on rolling shutter effect (RSE) of the CMOS camera. As different display content will be displayed on the panel, the VLC performance is significantly limited if the noise-ratio (NR) is too high. Here, we propose and demonstrate a CMOS RSE pattern demodulation scheme using grayscale value distribution (GVD) and machine learning algorithm (MLA) to significantly enhance the demodulation.

Evaluate performance of the Abbott chemiluminescent microparticle immunoassay assay for detection of syphilis infection in Chinese blood donors.

BACKGROUND AND OBJECTIVES: To prevent Treponema Pallidum (TP) transmission from blood transfusion, enzyme-linked immunosorbent assay (EIA) for anti-TP has been widely used in routine blood donation screening in China for many years. The aim of this study was to evaluate the performance of the Abbott CMIA assay for detection of anti-TP in Chinese blood donors. MATERIALS AND METHODS: A total of 2420 plasma samples, already routinely screened for anti-TP by two different EIAs, from four blood Centers were tested for anti-TP by Abbott CMIA. Subsequently, all samples with positive results by one or both EIAs and/or by Abbott CMIA were subjected to confirmatory testing (CT) using recombinant immunoblot assay (RIBA) or Treponema Pallidum particle agglutination assay (TPPA). TP infection was defined by a RIBA or TPPA positive. RESULTS: Compared with two EIAs strategy, Abbott CMIA showed a relatively best sensitivity as 98.80% (95% CI: 97.44%-100.16%) and a relatively best specificity as 99.58% (95% CI: 99.30%-99.85%), yielding the best consistency (99.49%) between anti-TP CT results with the highest κ value of .98. CONCLUSION: This is the first study to evaluate the performance of the Abbott CMIA assays for detection of syphilis in Chinese blood donors. Our results suggested that CMIA performed better than both EIAs, and implementation of CMIA replacing two different EIA reagents might help to further reduce the risk of transfusion-transmitted TP infection, decrease unnecessary blood waste and loss of blood donors.

Estimation of hepatitis B-positive rates in Chinese blood donors by combining predonation and postdonation screening results.

BACKGROUND: Chinese blood centers use Hepatitis B surface antigen (HBsAg) rapid test (RT) in pre-donation and two rounds of screening with different enzyme-linked immunosorbent assays in post-donation. Nucleic acid testing (NAT) on screening non-reactive (SC-) donations has been gradually implemented since 2010. Yet RT+ and SC-/NAT+ donors are seldom included in hepatitis B virus (HBV) positive rate estimates in Chinese blood donors. METHODS: We performed HBsAg neutralization test (NT) on whole blood (WB) with pre-donation RT+ results and post-donation screening reactive (SC+) samples from Mianyang and Chongqing in 2015. The annual totals of pre- and post-donation NT+ donors were combined with the annual totals of SC-/NAT+ donors to derive the estimated HBV positive rates. RESULT: In Mianyang and Chongqing, 59.4% and 68.2% of RT+ donors in Jan-Aug 2015 contributed for NT, 95.5% and 97.2% of which were NT+ respectively. In 2015, 422 and 667 donors from Mianyang and Chongqing respectively were HBsAg RT+, yielding estimated 403 and 648 pre-donation RT+/NT+ deferrals. 411 and 668 post-donation SC+ samples were NT tested from Mianyang and Chongqing, of which 249 and 323 were NT+ respectively. An estimated 63 donors in Mianyang and 88 donors in Chongqing were SC-/NAT+. The estimated HBV confirmed positive rate in blood donors are 1.59% in Mianyang and 1.01% in Chongqing. CONCLUSION: Pre-donation HBsAg RT effectively intercepts donations from HBV infected donors. Using NT confirmatory results from RT+, SC+ and SC-/NAT+ donors, this study provides a model for more accurate estimation for HBV positive rates in China.

Hepatitis C virus prevalence and incidence estimates among Chinese blood donors.

BACKGROUND: Hepatitis C virus (HCV) is an important transfusion-transmitted virus with global significance. The objective of this study was to evaluate the HCV prevalence and incidence among Chinese blood donors from 2013 to 2016. STUDY DESIGN AND METHODS: Whole blood and apheresis platelet donations collected from five Chinese blood centers from June 1, 2013, to December 31, 2016, were screened in parallel by two different enzyme-linked immunosorbent assays for anti-HIV 1/2, hepatitis B surface antigen, anti-HCV, and syphilis. Screening-reactive samples were further confirmed by western blot. Confirmatory positive rates among first-time and repeat donors were used to estimate the prevalence and incidence rates. Multivariable logistic regression modeling was used to examine factors associated with HCV infection. RESULTS: A total of 1,276,544 donations were collected from five Chinese blood centers, of which an estimated 1203 were confirmed HCV positive. The overall HCV prevalence among first-time donors was 166.56 per 100,000 donors (95% confidence interval, 156.04-177.08). The HCV incidence rate was estimated to be 15.21 (95% confidence interval, 11.83-19.56) per 100,000 person-years among repeat donors. Multivariable logistic regression results showed that increased age, lower educational levels, ethnicity, and occupation were all important factors associated with HCV confirmatory status among first-time donors (p < 0.01). CONCLUSIONS: HCV infection is still an important concern for transfusion safety in China. Our findings indicate that continued strong efforts are needed to monitor and control the risk of transfusion-transmitted HCV infection in China. Moreover, to reduce unnecessary donor loss, HCV donor screening procedures should be improved by incorporating confirmatory testing into routine blood center operations.

[Automated Estimation of Stenosis Severity in Coronary Computed Tomography Angiography].

OBJECTIVE: To determine the value of automated detection in computed tomography angiography (CTA) for cases with greater than 70% coronary stenosis. METHODS: Fifty-seven patients who had both coronary CTA and digital subtraction angiography (DSA) were retrospectively recruited in this study. The patients were categorized into two groups using a cutoff value of 70% stenosis in DSA. The AW4.6 software was used to estimate the diameter and square values from the data obtained from CTA. The sensitivity (SE), specificity (SPE), positive predictive value (PPV) and negative predictive value (NPV) of the automated CTA estimations were calculated. RESULTS: A total of 178 vessels from the 57 patients were analyzed. The automated CTA estimations had moderate to high levels of agreements (Kappa value: 0.716-0.804, P < 0.001) with the DSA diagnoses, compared with low to moderate levels of agreements (Kappa value: 0.385-0.533, P < 0.001) in manual interpretations. The square estimations generated high SE (100%) and NPV (100%) for patient diagnoses (P < 0.016 7 vs. manual interpretations). The diameter estimations generated high SPE (90.48%) and PPV (94.12%) for patient diagnoses (P < 0.016 7, vs. manual interpretations). Similarly, high SE (96.92%) and NPV (97.89%) were found for square estimations in vessel diagnoses, while high SPE (94.69%) and PPV (90.16%) were found for diameter estimations in vessel diagnoses. CONCLUSIONS: Both automated diameter and square algorithms have high accuracy for diagnosing patients with greater than 70% coronary artery stenosis. The AW4.6 can improve the detection of severe stenosis that needs stent interventions.

[The Application Value of One-stop CT Myocardial Perfusion Imaging in the Evaluation of Patients with Severe Coronary Artery Stenosis].

ObstractPurpose "One-stop" CT myocardial perfusion imaging (CT-MPI) was compared with cardiac magnetic resonance(CMR) to investigate its application value in evaluating patients with severe coronary artery stenosis.MethodsFifty patients with coronary artery stenosis≥90% of at least one major coronary arteries comfirmed by coronary angiography (CAG) in the department of cardiology in our hospital, who referred for coronary artery stent implantation were prospectively enrolled. All the patients underwent "One-stop" CT-MPI within a week before surgery, among which 22 patients underwent CMR examination simultaneously. The postprocessing software Ziostation2 was used to obatin and compare the perfusion parameters of patients with normal and perfusion defect myocardium, including blood flow (BF), blood volume (BV), peak time (TTP), and mean transit time (MTT). Pearson correlation analysis was used to compare the correlation of relative perfusion parameters (defect/normal myocardium) between CT and CMR. Bland-Altman analysis was used to analyze the consistency between CT and CMR in left ventricular (LV) function parameters measurements.ResultsCompared with normal myocardium, BV and BF of perfusion defect myocardium were significantly decreased, while MTT and TTP were significantly prolonged (all P < 0.05). The rBV, rBF, rMTT and rTTP were medium to high positive correlated between CT and CMR (r=0.685, 0.641, 0.871, 0.733, respectively, all P < 0.05). Bland-Altman analysis showed that 95% (21/22) points were within the 95% limits of agreement (LoA), suggesting the LV function parameters measurements between two methods were highly consistent.Conclusion"One-stop" CT-MPI can simultaneously obtain the information about coronary anatomy, myocardial perfusion and LV function. It is of great value in the evaluation of patients with severe coronary artery stenosis, with shorter scan time and less contraindications compared with CMR.

[An Improved Acute Pancreatitis Apoptosis/Necrosis In vitro Model of Acinar Cells].

OBJECTIVE: To improve the apoptosis/necrosis In vitromodel of ascites-induced acute pancreatitic (AP) acinar cells by using the co-culture system and mixed ascites technology for the first time. Furthermore, we compared this improved model with cerulein and cerulein+LPS models, and observed the effects of three models on acinar apoptotic/necrotic-related indicators. METHODS: The In vitrocultured rat acinar cells AR42J were divided in four groups: control group (medium+PBS), cerulein group (medium+10 nmol/L cerulein), cerulein+LPS group (medium+10 nmol/L cerulein+10 mg/L LPS) and improved ascites group. In the improved ascites group, the ascites of sodium taurocholate-induced rat model was mixed and added into the co-culture system to stimulated In vitrocultured homogenous acinar cells. The co-culture system was set as follows: the chambers with the pore size of 1 µm were placed in the cultue plate, and the culture medium and mixed ascites were respectively added to the culture plate and the chamber at a ratio of 1:1. The acinar cells in each group were collected after 24 h stimulation. The apoptotic/necrotic rates, the expressions of apoptosis/necrosis related proteins [B-cell lymphoma protein 2 (Bcl-2), Bcl-2-associated X protein (Bax) and receptor interacting protein 1 (RIP1)], and the ultra-structure of acinar cells were detected by flow cytometry, Western blot and transmission electron microscopy (TEM). RESULTS: The acinar cells in the improved ascites model were mainly characterized by necrosis; compared with the other 3 groups, the apoptosis rate and necrosis rate were both up-regulated, RIP1 and BAX protein expression levels were up-regulated, and Bcl-2 protein was down-regulated. TEM results showed the organelle structure of acinar cells was destroyed, and the cell membrane was degraded in the improved ascites model. Compared with the control group, apoptosis rate of acinar cells in the cerulein and cerulein+LPS models were increased and necrosis rate were not changed. The expression of pro-apoptotic protein Bax was increased, while the expression level of RIP1 was not significantly increased. TEM results showed that in cerulein group and cerulein+LPS group, the chromatin of the cells was condensed into a mass, the cytoplasm was degraded and the cell membrane was intact, showing typical apoptosis characteristics. CONCLUSION: Compared with cerulein and cerulein +LPS models, which mainly focus on apoptosis of acinar cells and applied to mild acute pancreatitis study, the improved ascites model mainly focuses on the necrosis of acinar cells and is a good model for studying acinar cell necrosis and severe acute pancreatitis.