A deep learning method for the automated assessment of paradoxical pulsation after myocardial infarction using multicenter cardiac MRI data.

OBJECTIVE: The current study aimed to explore a deep convolutional neural network (DCNN) model that integrates multidimensional CMR data to accurately identify LV paradoxical pulsation after reperfusion by primary percutaneous coronary intervention with isolated anterior infarction. METHODS: A total of 401 participants (311 patients and 90 age-matched volunteers) were recruited for this prospective study. The two-dimensional UNet segmentation model of the LV and classification model for identifying paradoxical pulsation were established using the DCNN model. Features of 2- and 3-chamber images were extracted with 2-dimensional (2D) and 3D ResNets with masks generated by a segmentation model. Next, the accuracy of the segmentation model was evaluated using the Dice score and classification model by receiver operating characteristic (ROC) curve and confusion matrix. The areas under the ROC curve (AUCs) of the physicians in training and DCNN models were compared using the DeLong method. RESULTS: The DCNN model showed that the AUCs for the detection of paradoxical pulsation were 0.97, 0.91, and 0.83 in the training, internal, and external testing cohorts, respectively (p < 0.001). The 2.5-dimensional model established using the end-systolic and end-diastolic images combined with 2-chamber and 3-chamber images was more efficient than the 3D model. The discrimination performance of the DCNN model was better than that of physicians in training (p < 0.05). CONCLUSIONS: Compared to the model trained by 2-chamber or 3-chamber images alone or 3D multiview, our 2.5D multiview model can combine the information of 2-chamber and 3-chamber more efficiently and obtain the highest diagnostic sensitivity. CLINICAL RELEVANCE STATEMENT: A deep convolutional neural network model that integrates 2-chamber and 3-chamber CMR images can identify LV paradoxical pulsation which correlates with LV thrombosis, heart failure, ventricular tachycardia after reperfusion by primary percutaneous coronary intervention with isolated anterior infarction. KEY POINTS: • The epicardial segmentation model was established using the 2D UNet based on end-diastole 2- and 3-chamber cine images. • The DCNN model proposed in this study had better performance for discriminating LV paradoxical pulsation accurately and objectively using CMR cine images after anterior AMI compared to the diagnosis of physicians in training. • The 2.5-dimensional multiview model combined the information of 2- and 3-chamber efficiently and obtained the highest diagnostic sensitivity.

Using pre-operative radiomics to predict microvascular invasion of hepatocellular carcinoma based on Gd-EOB-DTPA enhanced MRI.

OBJECTIVES: We aimed to investigate the value of performing gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced magnetic resonance imaging (MRI) radiomics for preoperative prediction of microvascular invasion (MVI) of hepatocellular carcinoma (HCC) based on multiple sequences. METHODS: We randomly allocated 165 patients with HCC who underwent partial hepatectomy to training and validation sets. Stepwise regression and the least absolute shrinkage and selection operator algorithm were used to select significant variables. A clinicoradiological model, radiomics model, and combined model were constructed using multivariate logistic regression. The performance of the models was evaluated, and a nomogram risk-prediction model was built based on the combined model. A concordance index and calibration curve were used to evaluate the discrimination and calibration of the nomogram model. RESULTS: The tumour margin, peritumoural hypointensity, and seven radiomics features were selected to build the combined model. The combined model outperformed the radiomics model and the clinicoradiological model and had the highest sensitivity (90.89%) in the validation set. The areas under the receiver operating characteristic curve were 0.826, 0.755, and 0.708 for the combined, radiomics, and clinicoradiological models, respectively. The nomogram model based on the combined model exhibited good discrimination (concordance index = 0.79) and calibration. CONCLUSIONS: The combined model based on radiomics features of Gd-EOB-DTPA enhanced MRI, tumour margin, and peritumoural hypointensity was valuable for predicting HCC microvascular invasion. The nomogram based on the combined model can intuitively show the probabilities of MVI.

LncRNA SNHG14 potentiates pancreatic cancer progression via modulation of annexin A2 expression by acting as a competing endogenous RNA for miR-613.

This study aimed to determine long non-coding RNA (lncRNA) small nucleolar RNA host gene 14 (SNHG14) expression in pancreatic cancer and to explore the potential molecular actions of SNHG14 in mediating pancreatic cancer progression. Gene expression was detected by quantitative real-time PCR. Cell proliferation, growth and invasion were detected by respective CCK-8, colony formation, and transwell invasion assays. Protein levels were measured by Western blotting. Cell apoptosis and caspase-3 activity were detected by flow cytometry and caspase-3 activity assay. The link between miR-613 and its targets was evaluated by luciferase reporter assay. In vivo tumour growth was evaluated using a xenograft model of nude mice. SNHG14 expression was up-regulated in cancerous tissues from pancreatic cancer patients. High expression of SNHG14 was associated with poor tumour differentiation, advanced TNM stage and nodal metastasis. SNHG14 overexpression enhanced cell proliferative, growth and invasive abilities, and suppressed apoptotic rates and caspase-3 activity in pancreatic cancer cells, while SNHG14 knockdown exerted opposite effects. Mechanistic studies revealed that miR-613 was targeted by SNHG14, and Annexin A2 (ANXA2) was targeted and inversely regulated by miR-613 in pancreatic cancer cells. In vivo studies showed that SNHG14 knockdown attenuated tumour growth. MiR-613 was down-regulated and ANXA2 was up-regulated in the pancreatic cancer tissues, and SNHG14 expression levels were inversely correlated with miR-613 expression levels and positively correlated with the ANXA2 mRNA expression levels. Collectively, our results suggest that SNHG14 potentiates pancreatic cancer progression through modulation of annexin A2 expression via acting as a competing endogenous RNA for miR-613.

Investigation of diffusion kurtosis imaging for discriminating tumors from inflammatory lesions after treatment for bladder cancer.

BACKGROUND: The bladder wall may thicken resulting from chronic inflammation after initial treatment (transurethral resection [TUR] or neoadjuvant chemotherapy), which may mimic the feature of recurrent or residual bladder tumors (RBT). Therefore, it is critical to discriminate RBT from benign lesions after initial treatment. PURPOSE: To investigate whether diffusion kurtosis imaging (DKI) could discriminate RBT from post-therapy bladder inflammatory lesions. STUDY TYPE: Retrospective. SUBJECTS: Fifty patients diagnosed with bladder cancer underwent TUR or received neoadjuvant chemotherapy. FIELD STRENGTH/SEQUENCE: 3.0T MRI/conventional T1 -weighted imaging (T1 WI), T2 WI, and diffusion-weighted imaging (DWI) with nine b-values ranging from 0-2000 s/mm2 . ASSESSMENT: Mean diffusion coefficients (MDa , MDb , and MDc ) and mean kurtosis values (MKa , MKb , and MKc ) were obtained from three different measurement methods. The region of interest (ROI) was placed 1) to encompass the entire portion of the thickening bladder wall or to portions that were the most restricted, with a b-value of 2) 2000 s/mm2 or 3) 1000 s/mm2 . STATISTICAL TESTS: The independent-samples t-test was used to compare the differences between RBT and the inflammatory group. Differences in DKI parameters were analyzed by comparing the areas under the receiver-operator characteristic curves (AUCs). RESULTS: In patients with RBT, the MD (MDa , MDb , MDc ) values were significantly lower and the MK (MKa , MKb , MKc ) values were significantly higher than those in patients in the inflammatory lesions group (all P < 0.01). The AUC of MKb (0.934) was significantly larger than those of MDb , MKa , and MKc (0.793, P < 0.05; 0.694, P < 0.01; 0.719, P < 0.01, respectively). DATA CONCLUSION: MK obtained from DKI provided better performance than conventional DWI in distinguishing RBT from inflammatory lesions after bladder cancer treatment. MK calculated with high b-values setting provided better performance in differentiation. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage 3 J. Magn. Reson. Imaging 2017.

PP2Acα positively regulates the termination of liver regeneration in mice through the AKT/GSK3ß/Cyclin D1 pathway.

BACKGROUND & AIMS: Liver injury triggers a highly organized and ordered liver regeneration (LR) process. Once regeneration is complete, a stop signal ensures that the regenerated liver is an appropriate functional size. The inhibitors and stop signals that regulate LR are unknown, and only limited information is available about these mechanisms. METHODS: A 70% partial hepatectomy (PH) was performed in hepatocyte-specific PP2Acα-deleted (PP2Acα(-/-)) and control (PP2Acα(+/+)) mice. LR was estimated by liver weight, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and cell proliferation, and the related cellular signals were analyzed. RESULTS: We found that the catalytic subunit of PP2A was markedly upregulated during the late stage of LR. PP2Acα(-/-) mice showed prolonged LR termination, an increased liver size compared to the original mass and lower levels of serum ALT and AST compared with control mice. In these mice, cyclin D1 protein levels, but not mRNA levels, were increased. Mechanistically, AKT activated by the loss of PP2Acα inhibited glycogen synthase kinase 3ß (GSK3ß) activity, which led to the accumulation of cyclin D1 protein and accelerated hepatocyte proliferation at the termination stage. Treatment with the PI3K inhibitor wortmannin at the termination stage was sufficient to inhibit cyclin D1 accumulation and hepatocyte proliferation. CONCLUSIONS: PP2Acα plays an essential role in the proper termination of LR via the AKT/GSK3ß/Cyclin D1 pathway. Our findings enrich the understanding of the molecular mechanism that controls the termination of LR and provides a potential therapeutic target for treating liver injury.

Feasibility of three-dimensional ultrashort echo time magnetic resonance imaging at 1.5 T for the diagnosis of skull fractures.

OBJECTIVES: To investigate the feasibility of ultrashort echo time (UTE) magnetic resonance imaging (MRI) for the diagnosis of skull fractures. METHODS: The skull fracture models of ten Bama pigs and 364 patients with craniocerebral trauma were subjected to computed tomography (CT), UTE and conventional MRI sequences. The accuracy of UTE imaging in skull fracture diagnosis was analysed using receiver operating characteristic (ROC) curve analysis, McNemar's test and Kappa values. Differences among CT, UTE imaging and anatomical measurement (AM) values for linear fractures (LFs) and depressed fractures (DFs) were compared using one-way ANOVA and a paired-samples t-test. RESULTS: UTE imaging clearly demonstrated skull structures and fractures. The accuracy, validity and reliability of UTE MRI were excellent, with no significant differences between expert readings (P > 0.05; Kappa, 0.899). The values obtained for 42 LFs and 13 DFs in the ten specimens were not significantly different among CT, UTE MRI and AMs, while those obtained for 55 LFs and ten DFs in 44 patients were not significantly different between CT and UTE MRI (P > 0.05). CONCLUSIONS: UTE MRI sequences are feasible for the evaluation of skull structures and fractures, with no radiation exposure, particularly for paediatric and pregnant patients. KEY POINTS: Despite ionising radiation, CT is standard for skull fracture assessment. Conventional MRI cannot depict skull structures. 3D-UTE sequences clearly demonstrate skull structures and fractures. UTE plus conventional MRI are superior to CT in craniocerebral trauma assessment. Paediatric and pregnant patients will benefit from this imaging modality.

Preoperative inflammation-based markers predict early and late recurrence of hepatocellular carcinoma after curative hepatectomy.

BACKGROUND: Recurrence of hepatocellular carcinoma (HCC) after curative resection remains a major cause of treatment failure and tumor-related death. Patterns of HCC recurrence can be categorized into early recurrence and late recurrence which have different underlying mechanisms. In this study, we investigated if simple inflammation-based clinical markers can distinguish patterns of recurrence after curative resection of HCC. METHODS: A retrospective analysis of 223 patients who underwent curative hepatectomy for HCC was performed. Preoperative inflammation-based factors including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio, gamma-glutamyl transferase/alanine aminotransferase ratio, aspartate aminotransferase/platelet ratio index (APRI) and prognostic nutritional index together with other clinicopathologic parameters were evaluated by univariate analysis and multivariate analysis to identify independent prognostic factors. By combining risk factors, predictive models were established to distinguish populations at high risk of early or late recurrence. RESULTS: Age ≤50 years, resection margin ≤1 cm, TNM stage III-IV, NLR>2.75, APRI>0.23 and positive alpha-fetoprotein were independent adverse prognostic factors for early recurrence. Patients with three or more risk factors were at significant higher risk of early recurrence. APRI>0.23 and positive hepatitis B e antigen (HBeAg) were independent risk factors of late recurrence, the coexistence of high APRI and positive HBeAg increased the risk of late recurrence. CONCLUSIONS: Preoperative inflammation-based prognostic factors predict early and late recurrence of HCC after curative resection. Different prognostic factor combinations distinguish high-risk populations of early or late HCC recurrence.

Preoperative serum liver enzyme markers for predicting early recurrence after curative resection of hepatocellular carcinoma.

BACKGROUND: Early recurrence of hepatocellular carcinoma (HCC) is associated with worse prognosis after liver resection. This study aimed to investigate the prognostic value of common liver enzyme markers in HCC early recurrence after curative hepatectomy and to establish a simple predictive model for HCC early recurrence. METHODS: A total of 200 patients who had undergone curative resection for HCC were retrospectively analyzed. The patients were divided into early recurrence (within 2 years) and non-early recurrence groups. Demographical characteristics, preoperative liver function parameters, surgical factors and tumor related factors of the patients were assessed by univariate analysis to identify potential significant predictors for early recurrence after resection of HCC. Parameters with statistical significance were entered into a Cox proportional hazard model to find independent risk factors. Receiver operating characteristic analysis was done to determine optimal cut-off values and the number of combined factors in multi-factor predictive model. RESULTS: Of 13 potential risk factors for early recurrence identified by univariate analysis, high lactate dehydrogenase (LDH>206 U/L, HR=1.711, P=0.006), high aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio (AST/ALT>0.96, HR=1.769, P=0.006), elevated alpha-fetoprotein (AFP<8.6 ng/mL, HR=2.079, P=0.007), small resection margin (≤1 cm, HR=2.354, P<0.001) and advanced TNM stage (TNM III-IV, HR=2.164, P<0.001) were independent risk factors for early recurrence of HCC shown by multivariate analysis. Patients with three or more concurrent independent risk factors had significantly higher risk for early recurrence than those with low risk factors. The sensitivity and specificity of this predictive model are 53.6% and 80.7%, respectively (area under curve=0.741, 95% CI 0.674-0.800, P<0.0001). CONCLUSIONS: Preoperative common liver enzyme markers, LDH and AST/ALT ratio, were independently associated with early recurrence of HCC. The combination of serum liver enzyme markers with AFP, resection margin and TNM stage better predicted early recurrence of HCC after curative resection in a simple multi-factor model.

Artificial neural network modeling of dissolved oxygen in reservoir.

The water quality of reservoirs is one of the key factors in the operation and water quality management of reservoirs. Dissolved oxygen (DO) in water column is essential for microorganisms and a significant indicator of the state of aquatic ecosystems. In this study, two artificial neural network (ANN) models including back propagation neural network (BPNN) and adaptive neural-based fuzzy inference system (ANFIS) approaches and multilinear regression (MLR) model were developed to estimate the DO concentration in the Feitsui Reservoir of northern Taiwan. The input variables of the neural network are determined as water temperature, pH, conductivity, turbidity, suspended solids, total hardness, total alkalinity, and ammonium nitrogen. The performance of the ANN models and MLR model was assessed through the mean absolute error, root mean square error, and correlation coefficient computed from the measured and model-simulated DO values. The results reveal that ANN estimation performances were superior to those of MLR. Comparing to the BPNN and ANFIS models through the performance criteria, the ANFIS model is better than the BPNN model for predicting the DO values. Study results show that the neural network particularly using ANFIS model is able to predict the DO concentrations with reasonable accuracy, suggesting that the neural network is a valuable tool for reservoir management in Taiwan.

Fractal analysis of left ventricular trabeculae in heart failure with preserved ejection fraction patients with multivessel coronary artery disease.

OBJECTIVES: Endocardial trabeculae undergo varicose changes and hyperplasia in response to hemodynamic influences and are a variable phenotype reflecting changes in disease. Fractal analysis has been used to analyze the complexity of endocardial trabeculae in a variety of cardiomyopathies. The aim of this paper was to quantify the myocardial trabecular complexity through fractal analysis and to investigate its predictive value for the diagnosis of heart failure with preserved ejection fraction (HFpEF) in patients with multivessel coronary artery disease (CAD). METHODS: The retrospective study population consisted of 97 patients with multivessel CAD, 39 of them were diagnosed with HFpEF, while 46 healthy volunteers were recruited as controls. Fractal dimension (FD) was obtained through fractal analysis of endocardial trabeculae on LV short-axis cine images. Logistic regression analyses were used to confirm the predictors and compare different prediction models. RESULTS: Mean basal FD was significantly higher in patients with HFpEF than in patients without HFpEF or in the healthy group (median: 1.289; IQR: 0.078; p < 0.05). Mean basal FD was also a significant independent predictor in univariate and multivariate logistic regression (OR: 1.107 and 1.043, p < 0.05). Furthermore, adding FD to the prediction model improved the calibration and accuracy of the model (c-index: 0.806). CONCLUSION: The left ventricular FD obtained with fractal analysis can reflect the complexity of myocardial trabeculae and has an independent predictive value for the diagnosis of HFpEF in patients with multivessel CAD. Including FD into the diagnostic model can help improve the diagnosis. CRITICAL RELEVANCE STATEMENT: Differences show in the complexity of endocardial trabeculae in multivessel coronary artery disease patients, and obtaining fractal dimensions (FD) by fractal analysis can help identify heart failure with preserved ejection fraction (HFpEF) patients. KEY POINTS: The complexity of myocardial trabeculae differs among patients with multivessel coronary artery disease. Left ventricular fractal dimensions can reflect the complexity of the myocardial trabecular. Fractal dimensions have predictive value for the diagnosis of heart failure with preserved ejection fraction.

Risk assessment in patients undergoing liver resection.

BACKGROUND: Liver resection is still a risky procedure with high morbidity and mortality. It is significant to predict the morbidity and mortality with some models after liver resection. DATA SOURCES: The MEDLINE/PubMed, Web of Science, Google Scholar, and Cochrane Library databases were searched using the terms "hepatectomy" and "risk assessment" for relevant studies before August 2012. Papers published in English were included. RESULTS: Thirty-four original papers were included finally. Some models, such as MELD, APACHE II, E-PASS, or POSSUM, widely used in other populations, are useful to predict the morbidity and mortality after liver resection. Some special models for liver resection are used to predict outcomes after liver resection, such as mortality, liver dysfunction, transfusion, or acute renal failure. However, there is no good scoring system to predict or classify surgical complications because of shortage of internal or external validation. CONCLUSION: It is important to validate the models for the major complications after liver resection with further internal or external databases.

The influences of weir construction on salt water intrusion and water quality in a tidal estuary--assessment with modeling study.

A three-dimensional hydrodynamic and water quality model was developed and applied to predict the changes in physical and biochemical processes that would result from the proposed Dadu Weir construction in the Wu River estuary, located in central Taiwan. A high-resolution unstructured grid was constructed to represent the narrow channels in the tidal estuary. The model was calibrated and verified with available hydrographic and water quality data measured in 2011. The overall performance of the model is in reasonable agreement with the measured water level, salinity, and water quality state variables. The model was then used to investigate the changes in salt water intrusion and water quality as a result of weir construction under low-flow conditions. The model simulations indicate that more tidal energy will propagate into the estuary after weir construction because of decreased freshwater discharges. The limits of salt water intrusion before and after weir construction coincide at a distance of 11.6 km from the mouth of the Wu River. This salt water intrusion limit is the reason that the Dadu Weir will be constructed at a distance of 12 km from the mouth of the Wu River. The weir will become a barrier to salt water intrusion. The simulation results indicate that the concentrations of dissolved oxygen and nutrients will decrease slightly after weir construction, while the chlorophyll a concentration in the middle reach will increase after weir construction. However, construction of the weir is predicted to have little influence on water quality conditions downstream of the Wu River estuary. The results of this case study provide quantitative estimates of the physical and biochemical changes expected to occur in this nature system due to human action.

Nitro-oleic acid ameliorates erectile dysfunction in a streptozotocin-induced rat model of diabetes by inhibiting oxidative stress and apoptosis and activating the NO/cGMP pathway.

The major vascular complications associated with diabetes make the management of diabetic mellitus erectile dysfunction (DMED) a challenging endeavor. Notable factors contributing to DMED include oxidative stress, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway activation, and apoptosis, while nitro-oleic acid (NO2-OA) has been shown to be beneficial in treating these aspects of this condition. We, herein, investigated the effects and possible mechanisms of NO2-OA on erectile function as assessed in a streptozotocin-induced rat model of diabetes. Our results revealed that the erectile function of DMED rats was significantly impaired compared with that of the control group. However, in response to 4 weeks of NO2-OA treatment, there was an improvement in erectile function. The expression of oxidative stress-related indicators was significantly increased and the NO/cGMP pathway was impaired in the DMED group. The expression of proapoptotic factors was increased, while that of antiapoptotic factors was decreased in the DMED group. Moreover, the cell morphology in the cavernous tissue of the DMED group also changed adversely. NO2-OA treatment significantly reversed all these changes observed in the DMED group. In conclusion, NO2-OA treatment partially improved erectile function in DMED rats through mechanisms that included inhibition of oxidative stress, activation of the NO/cGMP pathway, and a reduction in apoptosis.

Mid-term outcomes of microfragmented adipose tissue plus arthroscopic surgery for knee osteoarthritis: A randomized, active-control, multicenter clinical trial.

BACKGROUND: Osteoarthritis (OA) is the most prevalent form of degenerative whole-joint disease. Before the final option of knee replacement, arthroscopic surgery was the most widely used joint-preserving surgical treatment. Emerging regenerative therapies, such as those involving platelet-rich plasma, mesenchymal stem cells, and microfragmented adipose tissue (MFAT), have been pushed to the forefront of treatment to prevent the progression of OA. Currently, MFAT has been successfully applied to treat different types of orthopedic diseases. AIM: To assess the efficacy and safety of MFAT with arthroscopic surgery in patients with knee OA (KOA). METHODS: A randomized, multicenter study was conducted between June 2017 and November 2022 in 10 hospitals in Zhejiang, China. Overall, 302 patients diagnosed with KOA (Kellgren-Lawrence grades 2-3) were randomized to the MFAT group (n = 151, were administered MFAT following arthroscopic surgery), or the control group (n = 151, were administered hyaluronic acid following arthroscopic surgery). The study outcomes were changes in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the visual analog scale (VAS) score, the Lequesne index score, the Whole-Organ Magnetic Resonance Imaging Score (WORMS), and safety over a 24-mo period from baseline. RESULTS: The changes in the WOMAC score (including the three subscale scores), VAS pain score, and Lequesne index score at the 24-mo mark were significantly different in the MFAT and control groups, as well as when comparing values at the posttreatment visit and those at baseline (P < 0.001). The MFAT group consistently demonstrated significant decreases in the WOMAC pain scores and VAS scores at all follow-ups compared to the control group (P < 0.05). Furthermore, the WOMAC stiffness score, WOMAC function score, and Lequesne index score differed significantly between the groups at 12 and 24 mo (P < 0.05). However, no significant between-group differences were observed in the WORMS at 24 mo (P = 0.367). No serious adverse events occurred in both groups. CONCLUSION: The MFAT injection combined with arthroscopic surgery treatment group showed better mid-term clinical outcomes compared to the control group, suggesting its efficacy as a therapeutic approach for patients with KOA.

Monitoring sediment oxygen demand for assessment of dissolved oxygen distribution in river.

Sediment oxygen demand (SOD) has become an integral part of modeling dissolved oxygen (DO) within surface water bodies. Because very few data on SOD are available, it is common for modeler to take SOD values from literature for use within DO models. SOD is such an important parameter in modeling DO that this approach may lead to erroneous results. This paper reported on developing an approach for monitoring sediment oxygen demand conducted with undisturbed sediment core samples, where the measured results were incorporated into a water quality model for simulating and assessing dissolved oxygen distribution in the Xindian River of northern Taiwan. The measured results indicate that a higher freshwater discharge results in a lower SOD. Throughout a 1-year observation in 2004, the measured SOD ranged from 0.367 to 1.246 g/m(2)/day at the temperature of 20°C. The mean values of the measured SOD at each station were adopted in a vertical two-dimensional water quality model to simulate the DO distribution along the Xindian River. The simulating results accurately depict the field-measured DO distribution during the low and high flow conditions. Model sensitivity analyses were also conducted with increasing and decreasing SOD values for the low and high flow conditions and revealed that SOD had a significant impact on the DO distribution along the Xindian River. The present work combined with field measurements and numerical simulation should assist in river water quality management.

Flood risk influenced by the compound effect of storm surge and rainfall under climate change for low-lying coastal areas.

Under climate change, compound flooding has resulted in severe disasters in coastal areas around the world. In this study, an integrated framework is proposed to determine the range of compound flood risk without the requirement of joint probability analysis between storm surge and rainfall. In the framework, the flood risks are analyzed under four extreme scenarios with/without the compound effect of storm surge and rainfall in the past and the future. From the end of the 20th century to the middle of the 21st century, the worst scenario shows that the flood area significantly increases by 92% for the low-lying coastal areas in southwest Taiwan under the compound effect of storm surge and rainfall if they are fully correlated. In the most optimistic scenario, the flood area slightly increases by 15% without compound effect (only storm surge is considered). To coastal flooding, the synchronization of storm surge and rainfall contributes much more than the climate-induced amplification of individual factors. When storm surge and rainfall happen at the same time, the extent and duration of flooding increase simultaneously under the influence of pluvial and surge-induced flooding. Risk analysis shows an obvious increase of risk level for villages originally at low risks, which require integrated countermeasures against the consequence brought by compound flooding in the future. The framework can be applied in other low-lying coastal areas to quantify the potential impacts on human and environment caused by compound flooding under climate change.

Quantitative assessment of liver function with hepatocyte fraction: Comparison with T1 relaxation-based indices.

PURPOSE: This study aimed to assess the use of hepatocyte fraction in gadoxetic acid-enhanced magnetic resonance imaging (MRI) for quantitatively evaluating the liver function in comparison with T1 relaxation-based indices. METHODS: This retrospective study included 79 patients with chronic liver disease, who were divided into 2 groups based on the results of the indocyanine green retention test (ICG). All patients underwent a gadoxetic acid-enhanced MRI of the liver. Pre- and post-contrast Look-Locker sequences were used 20 min after gadoxetic acid administration to acquire T1 mapping. Two readers independently identified and measured the MRI parameters [five T1 relaxation-based indices (T1pre, T1post, rrT1, R1post/R1pre and ΔR1) and two hepatocyte fraction indices (HeF and KHep)]. An Independent-samples t test was used to compare each parameter for the two groups. Pearson correlation analysis was used to analyze the correction in each parameter and 15-minute ICG retention rate (ICG-R15). Receiver operating characteristic analyses were performed to differentiate the diagnostic performance of each parameter in ICG-R15 ≤ 20 % and ICG-R15 > 20 % groups. RESULTS: T1pre and T1post were significantly lower in the ICG-R15 ≤ 20 % group than in the ICG-R15 > 20 % group (P < 0.05). rrT1, R1post/R1pre, ΔR1, HeF, and KHep were significantly higher in the ICG-R15 ≤ 20 % group than in the ICG-R15 > 20 % group (P < 0.05). The correction coefficients between T1pre, T1post, rrT1, R1post/R1pre, ΔR1, HeF, KHep, and ICG-R15 were 0.343, 0.783, -0.833, -0.781, -0.803, -0.819, and -0.832, respectively. The area under the curves (AUCs) of T1pre, T1post, rrT1, R1post/R1pre, ΔR1, HeF, and KHep in assessing the ICG-R15＞20 % groups were 0.761, 0.945, 0.912, 0.912, 0.948, 0.945, and 0.950, respectively. KHep had the highest AUC, sensitivity, and specificity. CONCLUSION: Hepatocyte fraction based on gadoxetic acid-enhanced T1-mapping MRI is an efficient diagnostic tool for the quantitative evaluation of liver function.

Particle release transport in Danshuei River estuarine system and adjacent coastal ocean: a modeling assessment.

A three-dimensional hydrodynamic model was created to study the Danshuei River estuarine system and adjacent coastal ocean in Taiwan. The model was verified using measurements of the time-series water surface elevation, tidal current, and salinity from 1999. We conclude that our model is consistent with these observations. Our particle-tracking model was also used to explore the transport of particles released from the Hsin-Hai Bridge, an area that is heavily polluted. The results suggest that it takes a much longer time for the estuary to be flushed out under low freshwater discharge conditions than with high freshwater discharge. We conclude that the northeast and southwest winds minimally impact particle dispersion in the estuary. The particles fail to settle to the bottom in the absence of density-induced circulation. Our model was also used to simulate the ocean outfall at the Bali. Our experimental results suggest that the tidal current dominates the particle trajectories and influences the transport properties in the absence of a wind stress condition. The particles tend to move northeast or southwest along the coast when northeast or southwest winds prevail. Our data suggest that wind-driven currents and tidal currents play important roles in water movement as linked with ocean outfall in the context of the Danshuei River.

Evaluation of liver function using the hepatocyte enhancement fraction based on gadoxetic acid-enhanced MRI in patients with chronic hepatitis B.

OBJECTIVES: This study aimed to evaluate the feasibility of using the hepatocyte enhancement fraction (HEF) based on gadoxetic acid-enhanced magnetic resonance imaging (MRI) for assessing the liver function in patients with chronic hepatitis B. METHODS: Sixty patients with Child-Pugh grade A (CP-A), 18 with Child-Pugh grade B (CP-B), 2 with Child-Pugh grade C (CP-C), and 20 with normal liver function (NLF) were enrolled. Gadolinium ethoxybenzyldiethy-lenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MRI was conducted. T1 mapping imaging was performed before and 20 min after Gd-EOB-DTPA administration. The pre- and post-contrast T1 values of the liver (T1pre and T1post), increase in the T1 relaxation rate (ΔR1), rate of decrease in the T1 relaxation time (ΔT1), HEF, and uptake coefficient (K) parameters in the NLF, CP-A, and CP-B + CP-C groups were compared using one-way analysis of variance. The effectiveness of each parameter in differentiating the NLF + CP-A group from the CP-B + CP-C group was evaluated using the receiver operating characteristic (ROC) curve. RESULTS: The HEF, K, ΔT1, and ΔR1 values decreased, while the T1post and T1pre values increased, with the increase in liver function damage. Significant differences in T1post, ΔT1, ΔR1, and HEF were found between different groups, except for the CP-A and NLF groups. However, no significant difference was observed in the T1pre among the three groups. HEF exhibited the largest area under the ROC curve. CONCLUSION: The HEF is an effective method for evaluating liver function in patients with hepatitis B.

Impact of phosphorus load reduction on water quality in a stratified reservoir-eutrophication modeling study.

Monitoring data collected from the Mingder Reservoir in Taiwan indicate that the water quality is between mesotrophic and eutrophic. Chlorophyll a concentration is higher in the summer and anoxic conditions occur in the bottom. The data also reveal that a pronounced vertical thermal gradient in summer and vertical mixing the end of fall. A vertical two-dimensional, laterally averaged hydrodynamic and water quality model (CE-QUAL-W2) was adopted to simulate the water surface elevation, water temperature, and water quality conditions in the water column. The modeling effort was supported with monitoring data collected in the field for a 2-year period in the reservoir. The hydrodynamic model reproduced the time series water surface elevation. Spatial and temporal distributions of temperature in the water column of the reservoir were also well reproduced by the hydrodynamic model. Model-calculated concentrations of key water quality constituents such as nutrients, dissolved oxygen, and algal biomass matched the measured values closely in the reservoir. The calibrated model was then applied to simulate water quality response to various nutrient reduction scenarios. Results of the model scenario runs reveal that a 20% and 80% reduction of the phosphorus loads will improve the water quality from eutrophic to mesotrophic and oligotrophic conditions, respectively. The modeling effort has yielded valuable information that can be used by decision makers for the evaluation of different management strategies of reducing watershed nutrient loads.