AD Values Research Articles

Reduced White Matter Integrity in Patients With End-Stage and Non-end-Stage Chronic Kidney Disease: A Tract-Based Spatial Statistics Study.

Background and Purpose: Reduced white matter (WM) integrity has been implicated in chronic kidney disease (CKD), especially in end-stage renal disease (ESRD). However, whether the differences in WM abnormalities exist in ESRD and non-end-stage CKD (NES-CKD) remains unclear. Hence, this study aimed to investigate the WM microstructural changes between the two stages using diffusion tensor imaging (DTI) and explore the related influencing factors.Methods: Diffusion tensor imaging’ images were prospectively acquired from 18 patients with ESRD, 22 patients with NES-CKD, and 19 healthy controls (HCs). Tract-based spatial statistics (TBSS) was performed to assess the voxel-wise differences in WM abnormalities among the three groups. The relationships between DTI parameters and biochemical data were also analyzed.Results: Compared with NES-CKDs, FA value was significantly decreased, and AD value increased in ESRDs mainly in brain regions of bilateral anterior thalamic radiation (ATR), the genu and body of corpus callosum (CC), bilateral anterior corona radiata, superior corona radiata, and superior longitudinal fasciculus. Besides, extensive and symmetrical deep WM damages were observed in patients with ESRD, accompanied by increased MD and RD values. Multiple regression analysis revealed that uric acid and serum phosphorus level can be used as independent predictors of WM microstructural abnormalities in clusters with statistical differences in DTI parameters between ESRD and NES-CKD groups.Conclusion: In the progression of CKD, patients with ESRD have more severe WM microstructural abnormalities than NES-CKDs, and this progressive deterioration may be related to uric acid and phosphate levels.

Segmental Abnormalities of White Matter Microstructure in End-Stage Renal Disease Patients: An Automated Fiber Quantification Tractography Study.

Background and Purpose: End-stage renal disease (ESRD) results in extensive white matter abnormalities, but the specific damage segment cannot be identified. This study aimed to determine the segmental abnormalities of white matter microstructure in ESRD and its relationship with cognitive and renal function indicators.Methods: Eighteen ESRD patients and 19 healthy controls (HCs) were prospectively recruited. All participants underwent DTI and clinical assessments. Automatic fiber quantification (AFQ) was applied to generate bundle profiles along 16 main white matter tracts. We compared the DTI parameters between groups. Besides, we used partial correlation and multiple linear regression analyses to explore the associations between white matter integrity and cognitive performance as well as renal function indicators.Results: In the global tract level, compared to HCs, ESRD patients had greater MD, AD, and RD values and lower FA value in several fibers (P < 0.05, FDR correction). In the point-wise level, extensive damage existed in specific locations of different fiber tracts, particularly in the left hemisphere (P < 0.05, FDR correction). Among these tracts, the mean AD values of the left cingulum cingulate correlated negatively with MoCA score. Urea and UA level were independent predictors of the AD value of superior component of the left corticospinal. Besides, urea level was the independent predictors of mean MD value of left anterior thalamic radiation (ATR).Conclusion: White matter fiber tract damage in ESRD patients may be characterized by abnormalities in its specific location, especially in the left hemisphere. Aberrational specific located fibers were related to cognitive impairment and renal dysfunction.

Reliability of the freehand region-of-interest method in quantitative cerebral diffusion tensor imaging

BackgroundDiffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) technique used for evaluating changes in the white matter in brain parenchyma. The reliability of quantitative DTI analysis is influenced by several factors, such as the imaging protocol, pre-processing and post-processing methods, and selected diffusion parameters. The region-of-interest (ROI) method is most widely used of the post-processing methods because it is found in commercial software. The focus of our research was to study the reliability of the freehand ROI method using various intra- and inter-observer analyses.MethodsThis study included 40 neurologically healthy participants who underwent diffusion MRI of the brain with a 3 T scanner. The measurements were performed at nine different anatomical locations using a freehand ROI method. The data extracted from the ROIs included the regional mean values, intra- and inter-observer variability and reliability. The used DTI parameters were fractional anisotropy (FA), the apparent diffusion coefficient (ADC), and axial (AD) and radial (RD) diffusivity.ResultsThe average intra-class correlation coefficient (ICC) of the intra-observer was found to be 0.9 (excellent). The single ICC results were excellent (> 0.8) or adequate (> 0.69) in eight out of the nine regions in terms of FA and ADC. The most reliable results were found in the frontobasal regions. Significant differences between age groups were also found in the frontobasal regions. Specifically, the FA and AD values were significantly higher and the RD values lower in the youngest age group (18–30 years) compared to the other age groups.ConclusionsThe quantitative freehand ROI method can be considered highly reliable for the average ICC and mostly adequate for the single ICC. The freehand method is suitable for research work with a well-experienced observer. Measurements should be performed at least twice in the same region to ensure that the results are sufficiently reliable. In our study, reliability was slightly undermined by artifacts in some regions such as the cerebral peduncle and centrum semiovale. From a clinical point of view, the results are most reliable in adults under the age of 30, when age-related changes in brain white matter have not yet occurred.

Micro structural abnormalities of the Cingulum in children with focal epilepsy: DTI study

Abstract Aim of the work The aim of this study is to evaluate the microstructural alteration implicating the Cingulum (CG) as one of the major limbic system white matter fiber tracts; in children with focal epilepsy. Patients and methods Our study was carried out on twenty-one children with the clinical and EEG diagnosis of focal epilepsy and 22 control subjects who were age and sex matched to patient group in the study. All patients underwent an epilepsy specific MRI protocol. DTI and fiber tractography was performed to all subjects as well. Fractional anisotropy (FA), axial diffusivity, radial diffusivity (RD) and trace were calculated for CG. DTI metrics were compared between both hemispheres as well as between both groups patient group and control group. A p-value less than .05 was considered significant. Results Asymmetry in FA, RD, trace and AD values of the CG was demonstrated in patients with focal epilepsy between both hemispheres with significantly lower FA and higher diffusivity values reaching p &amp;lt; 0.001in CG in both hemispheres in patients with focal epilepsy when compared together regardless the seizure focus. Compared with controls, patients with left focal epilepsy demonstrated significant lower FA and higher diffusivity indices in both ipsilateral and contralateral fiber tracts as well p &amp;lt; 0.05. Patients with right focal epilepsy showed no significant asymmetry in different DTI metrics when compared to controls. Conclusion Reduction in FA values along with increased diffusivity measures in the CG reflects the microstructural changes taking place in children with focal epilepsy.

Hypothalamic structural integrity and temporal complexity of cortical information processing at rest in migraine without aura patients between attacks

The hypothalamus has been attributed an important role during the premonitory phase of a migraine attack. Less is known about the role played by the hypothalamus in the interictal period and its relationship with the putative neurocognitive networks previously identified in the pathophysiology of migraine. Our aim was to test whether the hypothalamic microstructure would be altered during the interictal period and whether this co-existed with aberrant connectivity at cortical level. We collected multimodal MRI data from 20 untreated patients with migraine without aura between attacks (MO) and 20 healthy controls (HC) and studied fractional anisotropy, mean (MD), radial (RD), and axial diffusivity of the hypothalamus ROI as a whole from diffusion tensor imaging (DTI). Moreover, we performed an exploratory analysis of the same DTI metrics separately for the anterior and posterior hypothalamic ROIs bilaterally. From resting-state functional MRI, we estimated the Higuchi’s fractal dimension (FD), an index of temporal complexity sensible to describe non-periodic patterns characterizing BOLD signature. Finally, we correlated neuroimaging findings with migraine clinical features. In comparison to HC, MO had significantly higher MD, AD, and RD values within the hypothalamus. These findings were confirmed also in the exploratory analysis on the sub-regions of the hypothalamus bilaterally, with the addition of lower FA values on the posterior ROIs. Patients showed higher FD values within the salience network (SN) and the cerebellum, and lower FD values within the primary visual (PV) network compared to HC. We found a positive correlation between cerebellar and SN FD values and severity of migraine. Our findings of hypothalamic abnormalities between migraine attacks may form part of the neuroanatomical substrate that predisposes the onset of the prodromal phase and, therefore, the initiation of an attack. The peculiar fractal dimensionality we found in PV, SN, and cerebellum may be interpreted as an expression of abnormal efficiency demand of brain networks devoted to the integration of sensory, emotional, and cognitive information related to the severity of migraine.

Histological evaluation of sex differentiation and early sex identification in hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages.

The histological process of gonadal differentiation, together with the endocrine changes of sex steroid hormones and some of their precursors, was studied in hatchery-produced greater amberjack Seriola dumerili from 101 until 408days post-hatching (dph), with samplings conducted every 50days. Histological processing showed that sex differentiation began at 101 dph with the formation of the ovarian cavity in females, while the presumptive males did not yet contain any germ cells in their gonad. At 150 dph, we observed the first germ cells in the developing testes. Sex differentiation in almost all sampled individuals was complete at 408 dph. No size dimorphism was observed between the sexes, and the sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) to examine their role in the sex differentiation process. From the seven hormones, the only one that exhibited differences between the sexes was 11-KT and the plasma 11-KT concentration was found to be a useful indication of greater amberjack sex. Variations were observed in the mean values of Ad, Δ4, 11-KT, T, P4 and 17,20βP over time in one or both sexes, indicating their involvement in the sex differentiation process.

Study of the Contact Thermal Compression Behavior of Copper using Scanning Contact Potentiometry Method and Finite Element Analysis

The issue of tracking residual stresses initiation in welding copper under various affected conditions is essential in increasing safety through improving the welding quality in particular, in the nuclear industry. This study investigated the behavior of welded copper numerically and experimentally under contact-heating compression test with constant clamping force. The scanning contact potentiometry (SCP) method was used to track the initiation and development of residual stresses within the weld zone. Furthermore, the finite element analysis (FEA) method was used to simulate and study the effect of thermal variations, with a constant compressive force, on mechanical factors that contribute to residual stresses formation within the weld zone. Additionally, scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to get further information about the topography and composition of the specimen's surface. SCP results show that residual stress initiated from within the volume after 200 °C, and with further oxidation, its formation began on the surface after 250 °C. Using the relationship between maximum values of linearized von Mises stresses and maximum values of ADS at high SLS = 4.523, it was found that residual stresses generation began after 150 °C within the weld zone, and thermal stresses linearly increase with temperature due to further thermal expansion, which is associated with variation in linearized von Mises stresses and ADS maximum values. Comparison between potentiograms after 300 °C and FEA results have shown that the distribution of von Mises stress, normal stress, and total deformation are matching those in the distribution of ADS and are localized within the weld zone.&#x0D; HIGHLIGHTS&#x0D; &#x0D; The behavior of welded copper under compression at medium-low temperature range&#x0D; Residual stresses detection at an early stage localized within weldment zone&#x0D; Residual stresses increase with increased oxidation at copper surface&#x0D; Matched the SCP Experimental and FEA simulation results&#x0D; &#x0D; GRAPHICAL ABSTRACT

Numerical study on the drag characteristics of rigid submerged vegetation patches

Aquatic plants play a crucial role in the hydrodynamic and material transport processes within the aquatic environments due to the additional flow resistance induced by vegetation stems. In this study, high-resolution numerical experiments were performed to investigate the drag characteristics of circular vegetation patches fully immersed in a turbulent open channel flow. The submerged vegetation patch was modeled as a rigid cylinder array with a diameter D composed of N cylinder elements with a diameter d. The effects of vegetation density Φ (0.023 ≤ Φ ≤ 1) and relative diameter d/D (d/D = 0.051 and 0.072) were tested. The simulation results show that Φ and d/D affect the flow resistance exerted by the vegetation patch by modifying the bleeding flow intensity. With the increase in Φ, the drag forces acting on the individual cylinder elements decrease, whereas the total drag forces of the patch increase. The oscillation strength of the drag force of individual cylinders depends on Φ and the fixed positions within the patch. The presence of the free end of submerged cylinder array leads to enhanced wake entrainment with the increase in Φ. The drag coefficient of the submerged patch is smaller than that of the emergent patch when the dimensionless frontal area aD &amp;gt; 3. However, the two patches exhibit comparable drag coefficients for smaller aD values.

Broccoli (Brassica oleracea L. var. italica) cultivars, Palam Samridhi and Palam Vichitra affect the growth of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)

Effect of the ethyl acetate seed extracts of two cultivars of broccoli, Brassica oleracea Italica, Palam Samridhi (PS) and Palam Vichitra (PV) on growth, development and nutritional physiology of an economically important insect pest, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) was evaluated by conducting bioassays and nutritional assays. The insect larvae were fed on diets amended with the seed extracts of two cultivars at different concentrations viz. 5, 25, 125, 625 and 3125 ppm and taking water as control. The response of the insect varied with plant varieties. The extracts disrupted the developmental cycle of the pest. Larval mortality and total adult emergence were negatively affected. Larval period and total development period were also negatively influenced. Nutritional indices of S. litura also showed considerable decrease in the RGR, RCR, ECI and ECD as compared to control. The AD values were also enhanced with both the cultivars. The findings of the study revealed a considerable anti-insect potential of the two extracts and needs to be further explored for identification and isolation of bioactive constituents from broccoli for efficient management of the pest population.

Selective Effects of Healthy Cognitive Aging and Catechol-O-Methyl Transferase Polymorphism on Limbic White Matter Tracts.

Introduction: The cingulum bundle and uncinate fasciculus are major limbic white matter tracts involved in emotion, memory, and cognition. The main goal of the present study was to investigate the relationship between age and structural properties of the uncinate fasciculus and the cingulum bundle using diffusion tensor imaging (DTI) tractography in a large cohort of healthy individuals. The second goal was to determine the effects of the catechol-O-methyl transferase (COMT) gene polymorphism on the DTI measurements of these white matter tracts. Methods: We recruited 140 healthy participants (18-85 years old). DTI data sets were acquired on a 1.5T magnetic resonance imaging system. The rostral, dorsal, and parahippocampal cingulum, as well as uncinate fasciculus, were delineated using deterministic tractography. Fractional anisotropy (FA), mean (MD), radial (RD), and axial (AD) diffusivities, tract volume, linear (Cl), planar (Cp), and spherical (Cs) tensor shapes were calculated. The COMT polymorphism (methionine homozygous vs. valine carriers) was determined using single nucleotide polymorphism. Results: We found that age was negatively associated with FA, but positively associated with MD and RD for the rostral cingulum, dorsal cingulum, and the uncinate fasciculus but not for the parahippocampal cingulum. Furthermore, individuals with the COMT methionine homozygous had higher FA and lower MD, RD, AD, and Cs values in the right rostral cingulum compared with the valine carriers across the entire adult life span. Discussion: This study indicates that limbic tracts might be nonuniformly affected by healthy aging, and the methionine homozygous genotype might be associated with micro/macro white matter properties of the right rostral cingulum.

The impact of advertising value of in-game pop-up ads in online gaming on gamers’ inspiration: An empirical investigation

In online gaming, pop-up ads are effective advertising strategies with a high conversion rate. Businesses are actively using pop-up ads in online games for advertising. However, research into the advertising value of pop-up ads and its effect on gamers’ inspiration states remains scarce. This study aims to deepen our understanding of the value of in-game pop-up ads by applying the Ducoffe advertising value model. Specifically, we investigated the factors that determine the advertising value of gamers’ inspired-by state and its resultant impact on the inspired-to state. Based on survey data of 321 online game players, the proposed conceptual model was tested using the Partial Least Squares (PLS) method. This study shows that incentives, entertainment, credibility, personalization, and irritation significantly impact the advertising value associated with online game pop-up ads. Additionally, this study empirically proves that the advertising value of in-game pop-up ads positively derives the inspired-by state, which in turn determines gamers’ inspired-to state. Beyond theoretical significance, this study offers several practical implications for advertising platforms and advertisers who want to attract gamers using pop-up ads.

이미지 기반 검색광고의 기대가치가 광고효과에 미치는 영향 : 기술적, 인지적 기대가치와 효율성 인식을 중심으로

이미지 기반 검색광고의 기대가치가 광고효과에 미치는 영향 : 기술적, 인지적 기대가치와 효율성 인식을 중심으로

Study on varietal preference and nutritional indices of tea looper Hyposidra talaca (Lepidoptera: Geometridae) on ten selected tea varieties

To find out the varietal preference of H. talaca larvae, leaves of ten selected tea cultivars were provided separately to II, III, IV, and V instars. The food consumption by different larval instars was the maximum on TV20 followed by TV1 > K1/1 > TV22 > TV26 > TV16 > SNT8 > TS520 > HP12 > B157. The nutritional indices showed the highest ECD and ECI values on TV20 followed by other cultivars. However, AD values were inversely proportional to the ECI and ECD. Biochemical analysis of the host leaves indicated higher carbohydrate and lipid concentrations in TV20 which was positively correlated (r = 0.6351) with the mean food consumption, whereas, the lowest carbohydrate and lipid concentration was observed in TS520. The levels of secondary metabolites such as alkaloids (r = -0.6137) and flavonoids (r = -0.7403) showed a negative correlation with larval food consumption. Results of HPLC analysis showed the presence of different types of catechins like, EGC, Catechin, EC, EGCG, ECG, and caffeine in variable quantity in all cultivars that were positively correlated with larval feeding except the Gallic acid which showed a negative correlation (r = -0.5610). Based on the larval food consumption, the susceptible index of cultivars were categorized as ‘highly susceptible’ (TV20, TV1, K1/1, TV22, TV26, TV16, and SNT8), ‘susceptible’ (TS520 and HP12), and ‘moderately susceptible’ (B157). Based on cluster analysis A1 grouped (TS520 and HP12), A2 indicated B157 whereas sub-branches B1 grouped (TV22, TV16, TV26, and SNT8) and B2 grouped (TV1, TV20, and K1/1).

UNDERSTANDING IMPACT OF MEDIA ENGAGEMENT ON ADVERTISING ACCEPTANCE AND VALUE WITHIN MOBILE SOCIAL NETWORK IN INDIAN MILLENNIALS

Social Networking sites have changed the face of advertising and media consumption massively. Even within them, Mobile Social Network or MSN’s are the latest mode of Social Media consumption that is taking over the social media sites. This study takes a conceptual model developed earlier by Linwan Wu, 2016 and applies it to the millennial populace of India. The target group was selected because they are among the highest users of MSNs in the world. The model aims to check the antecedents of MSN engagement and test the relationship between MSN engagement and advertising effectiveness. The relevant data was collected using an online survey and the results showed a significant difference from the prior study. Though Utilitarian motivation still shows a significant effect on Media Engagement, the other antecedents seemed to have stopped having an effect altogether. Additionaly, the study also shows that in the target group, the engagement with media has no effect in advertising acceptance nor on the value gained from advertising. However, perceived value of advertisement and its acceptance still hold a close relation which presents an opportunity for future researches into the reason, ie, what other factors affect engagement, acceptance and ultimately, the perceived value of ads on mobile social networks.

Physicochemical Properties of Peking Duck Skin Gelatin Extracted Using Acid Pretreatment (ADS) or Mixed Alkaline-Acid Pretreatment (ALDS)

Duck skin is the by-product of duck meat production, and it is a readily available source of gelatin that may serve as an alternative to gelatin made from pigs and cows. In this study, the physicochemical properties of Peking duck skin gelatin were assessed. Duck skin gelatin was extracted using acid pretreatment (ADS) or mixed alkaline-acid pretreatment (ALDS). The extraction yield of ALDS (1.95%) was significantly higher than that of ADS (1.33%), and the recovery of protein of ALDS was 46.47% compared to 43.77% for ADS. The bloom value of ADS (364.10 g) was significantly higher than that of ALDS (205.13 g) and commercial type B bovine gelatin (BG, 224.20 g). The high bloom value of ADS and medium bloom value of ALDS mean that they can be used in many food applications. The hydroxyproline content of ADS (13.84 g/100 g) also was significantly higher than that of ALDS (10.25 g/100 g) and BG (12.87 g/100 g). The pH of ADS and BG (5.31 and 4.90, respectively) did not differ significantly, whereas the pH of ALDS was 8.34. Viscosity values of ADS and ADLS were 13.51 and 12.35 mPas, respectively, which were significantly higher than that of BG (3.62 mPas). Overall, these results show that duck skin is a potential raw material for gelatin production, as it has a high bloom value and is readily available in Malaysia.

Diffuse Tract Damage Correlates With Global Cognitive Impairment in Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy: A Tract-Based Spatial Statistics Study.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common familial arteriopathy characterized by recurrent lacunar stroke, migraine, and depression. The mechanism of cognitive dysfunction in CADASIL is still uncertain. The aim of this study was to use tract-based spatial statistics (TBSS) to map voxelwise the spatial distribution of brain microstructural change revealed by DTI-derived indices in patients with CADASIL to further study the underlying neuropsychopathological mechanism of CADASIL. Twelve patients with CADASIL and 11 age-, sex-matched healthy controls underwent magnetic resonance imaging at 3 T. Then we evaluated DTI-derived indices (fractional anisotropy [FA], mode of anisotropy [MO], mean diffusivity [MD], axial diffusivity [AD] and radial diffusivity [RD]) of brain white matter (WM) between CADASIL patients and healthy subjects through TBSS. Compared with healthy controls, patients with CADASIL showed extensive decreased FA, MO and increased RD, AD, and MD throughout the entire brain (mainly the WM of the temporal poles, inferior and superior longitudinal fasciculus, inferior fronto-occipital fasciculus, corpus callosum, uncinate fasciculus, internal capsule, external capsule, corona radiata, thalamic radiation, and cingulum). Furthermore, these WM microstructural alterations were significantly correlated with cognitive scores and Scheltens scores. Decreased FA values and MO values were positively correlated with Montreal Cognitive Assessment scores in CADASIL patients. Increased AD, RD, and MD values were significantly negatively correlated with Montreal Cognitive Assessment scores. Widespread WM abnormalities were clearly shown in CADASIL by using TBSS. Severity of microstructural changes correlates significantly with extension of T2 hyperintensity. Moreover, WM microstructural damage and cognitive impairment were significantly correlated. This study indicated that WM tract damage plays an important role in cognitive impairment in CADASIL.

Combing multiple site-directed mutagenesis of penicillin G acylase from Achromobacter xylosoxidans PX02 with improved catalytic properties for cefamandole synthesis

Penicillin G acylase (PGA) was an important biocatalyst for enzymatic production of second-generation cephalosporin. PGA from Achromobacter xylosoxidans PX02 (AxPGA) showed relatively lower identity to EcPGA (54.9% in α subunit and 51.7% in β subunit), which could synthesize cefamandole in the kinetically controlled N-acylation (kcNa). Semi-rational design of AxPGA and “small and smart” mutant libraries were developed with minimal screening to improve cefamandole production. A triple mutant αR141A/αF142I/βF24G by combining the mutational sites (βF24, αR141, and αF142) from different subunits of AxPGA showed better performance in cefamandole production, with 4.2-fold of improvement in the (kcat/Km)AD value for activated acyl donor (R)-Methyl mandelate. Meanwhile, the (kcat/Km)Ps value for cefamandole by mutant αR141A/αF142I/βF24G was sharply dropped by 25.5 times, indicating its highly synthetic activity and extremely low hydrolysis of cefamandole. Strikingly, the triple mutant αR141A/αF142I/βF24G could form cefamandole with a yield of 85% at an economical substrate ratio (acyl donor/nucleophile) of 1.3:1 (82% at 1.1:1), which advanced the greener and more sustainable process of cefamandole production than the wild type. Furtherly, the improved synthetic ability and lower hydrolysis of cefamandole by mutant were rationalized using molecular docking.

Risk Stratification Based on Chronic Liver Failure Consortium Acute Decompensation Score in Patients With Child-Pugh B Cirrhosis and Acute Variceal Bleeding.

Optimal candidates for early transjugular intrahepatic portosystemic shunt (TIPS) in patients with Child-Pugh B cirrhosis and acute variceal bleeding (AVB) remain unclear. This study aimed to test the hypothesis that risk stratification using the Chronic Liver Failure Consortium Acute Decompensation score (CLIF-C ADs) may be useful to identify a subgroup at high risk of mortality or further bleeding that may benefit from early TIPS in patients with Child-Pugh B cirrhosis and AVB. We analyzed the pooled individual data from two previous studies of 608 patients with Child-Pugh B cirrhosis and AVB who received standard treatment between 2010 and 2017 in China. The concordance index values of CLIF-C ADs for 6-week and 1-year mortality (0.715 and 0.708) were significantly better than those of active bleeding at endoscopy (0.633 [P<0.001] and 0.556 [P<0.001]) and other prognostic models. With X-tile software identifying an optimal cutoff value, patients were categorized as low risk (CLIF-C ADs <48), intermediate risk (CLIF-C ADs 48-56), and high risk (CLIF-C ADs >56), with a 5.6%, 16.8%, and 25.4% risk of 6-week death, respectively. Nevertheless, the performance of CLIF-C ADs for predicting a composite endpoint of 6-week death or further bleeding was not satisfactory (area under the receiver operating characteristics curve [AUC], 0.588). A nomogram incorporating components of CLIF-C ADs and albumin, platelet, active bleeding, and ascites significantly improved the prediction accuracy (AUC, 0.725). In patients with Child-Pugh B cirrhosis and AVB, risk stratification using CLIF-C ADs identifies a subgroup with high risk of death that may derive survival benefit from early TIPS. With improved prediction accuracy for 6-week death or further bleeding, the data-driven nomogram may help to stratify patients in randomized trials. Future external validation of these findings in patients with different etiologies is required.

The use of 4-methylbenzenesulfonate ionic liquid derivatives as environmentally friendly corrosion inhibitors for mild steel in hydrochloric acid

The effectiveness of two synthesized ionic liquids, 1-(benzyloxy)-1-oxopropan-2-aminium 4-methylbenzenesulfonate (1-BOPAMS) and 4-(benzyloxy)-4-oxobutan-1-aminium 4-methylbenzenesulfonate (4-BOBAMS), were evaluated for mild steel corrosion inhibition in 1.0 M hydro-chloric acid solution, using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and gravimetric techniques. Organic moieties responsible for the adsorption process on mild steel surface were investigated using Fourier transform infrared spectroscopy (FTIR). Gravimetric analysis revealed that the inhibition efficiency of 1-BOPAMS and 4-BOBAMS increased with concentration, with maximum inhibition values of 90.32% and 97.91%, respectively, at the highest concentration of the inhibitors. Gibbs free energy (nG°ads) values indicated a strong interaction between the mild steel surface and the molecules of the ionic liquids, and that the adsorption process was spontaneous. These values also show that the inhibitive nature of ionic liquids against mild steel corrosion is caused by a mixedtype of adsorption film formed on the steel surface. The Langmuir adsorption isotherm was used to describe the adsorption of ionic liquid molecules onto the mild steel surface. Polarization curves showed that 1-BOPAMS and 4-BOBAMS have a similar effect on both the anodic and cathodic half-reactions, indicating that they prevent the dissolution of mild steel through both physical and chemical process. Nyquist plots were defined by incomplete semicircle capacitive loops, showing that the charge transfer mechanism controls the corrosion of mild steel in acidic solution.

Optimal Design of “Free” Content Provision for Online Platforms: Impacts of Advertising and Network Effects

The strategy of hybrid free trial has been adopted by online content platforms. This paper uses an analytical model to address a monopolistic platform’s optimal design of “free” content provision. We find that, given a fixed trial period, when the network effects are weak, offering an ad-sponsored free service is not typically optimal if the advertising rate is small; otherwise, the platform has incentives to provide free service without ads. Counterintuitively, a larger advertising rate does not always mean more ads should be offered when network effects are weak. When ads’ number is fixed, a trial period is desired if both the network effect strength and advertising rate are small. We also identify the threshold value of ads’ number, under which offering a trial period can be optimal even under relatively strong network effects if the advertising rate is moderate. The study advances our understanding of content provision strategy for platforms.