Search

The production of hydrogen from water using ceramic semiconductors with photocatalytic properties has gained special relevance in the last years, due to their potential use for the generation of hydrogen in a direct and clean way. Doping with transition metals has demonstrated to be an effective method to obtain new active photocatalysts in the visible range of the solar spectrum by changing the band gap of the material. In this paper we study the effect of the addition of various dopants (Fe, Ni, Cr, Mn, Co, Cu) in the structure and band gap of Bi4Ti3O12, in order to improve its photocatalytic activity and make it visible light active. Accordingly, doped BIT based materials have been obtained by solid state processing and different amounts of an additional phase with sillenite structure, Bi12TiO20, have been detected. With the dopant a shift of the absorption spectra is produced towards higher wavelengths and consequently towards lower band gap values. The band gap values obtained for many of the prepared compositions are quite promising, promoting the study of their catalytic properties.La producción de hidrógeno a partir de agua mediante el empleo de semiconductores cerámicos con propiedades fotocatalíticas ha adquirido especial relevancia en los últimos años, debido a su potencial uso para la obtención de hidrógeno de un modo directo y limpio. En la búsqueda de nuevos materiales que presenten propiedades fotocatalíticas en la región visible del espectro solar, el dopado con metales de transición ha demostrado ser un método eficaz de adecuar los valores de band gap del semiconductor. En este trabajo se aborda el estudio del efecto de la adición de distintos dopantes (Fe, Ni, Cr, Mn, Co, Cu) sobre la estructura y valor de band gap del Bi4Ti3O12, con el objetivo de mejorar su actividad fotocatalítica y hacerlo activo en el visible. En este sentido se han preparado materiales dopados basados en BIT por procesamiento en estado sólido, obteniéndose distintas proporciones de una fase adicional con estructura tipo silenita, Bi12TiO20. Como consecuencia del dopado se produce un desplazamiento de los espectros de absorción a mayores longitudes de onda, y por tanto a menores valores del band gap. Los valores obtenidos de los band gaps son bastante prometedores para muchas de las composiciones, promoviendo el estudio de sus propiedades fotocatalíticas.

Titanium substitution can improve the multiferroic properties of bismuth ferrite materials, albeit the structural changes that this dopant produces in the perovskite structure of BiFeO3 are still not well understood. Due to its high sensitivity, Raman spectroscopy can be a useful tool for trailing the dopant incorporation. In this work, we study the Raman spectra of undoped and Ti4+-doped BiFeO3 ceramics that also contain small amounts of secondary phases - as it is usual for materials of this system. The micro-Raman study together with a rigorous derivative analysis of the experimental Raman spectra recorded at low temperature (73 K) enables, for the first time, the identification of the Raman bands associated with the BiFeO3 phase together with those belonging to the minor secondary phases. The comparison between the Raman spectra of the undoped and the Ti4+-doped materials indicates that some of the titanium added to the composition interacts with the secondary phases while only a partial amount of this dopant actually incorporates into the BiFeO3 phase. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The presented research used a driving simulator to study the effect of isolated vertical crest curves overlapped with horizontal curves on driver's perception and behavior. The curves were consistent with the existing design standards. The research was conducted in four phases: (1) Design a test road with road design software; (2) Convert the designed road to a scenario in the driving simulator; (3) Execute simulation experiments with 48 subjects; and (4) Analyze statistically the obtained simulation results. The participated in the experiments subjects were surveyed to assess their perception of the curve sharpness and the available sight distances. The survey results indicate that the driver's perception of curves depends on the algebraic difference of grades. On the other hand, the operating speeds on different curves were not statistically different from each other. In the matter of fact, the difference between the lowest and highest operating speeds on curves was only 10 km/h. Surprisingly, the operating speeds on a flat curve tended to be lower than on the curves superimposed on vertical crest curves. The likely causes of these results are discussed in the paper. [ABSTRACT FROM AUTHOR]

In the complex multicomponent formulation of standard commercial varistors used in high tension devices, those based in the ZnO-Bi2O3-Sb2O3 (ZBS) ternary system, the presence of iron is ordinarily prevented in any of its plausible sources: dopant, impurity and/or unwanted contamination. Otherwise the material undergoes a systematic degradation in its electrical performance which rapidly disallows it for practical uses. In order to understand the origin of such degradation phenomena, we have deliberately doped the ZBS varistor composition with different amounts of Fe2O3. The research here presented evidences that the prime reason for the varistor electrical ruination is the progressive incorporation of iron inside the spinel secondary grains, which eventually leads to the formation of a highly conductive skeleton of secondary phases with an unbearable level of leakage currents below the varistor breakdown voltage. [ABSTRACT FROM AUTHOR]

Controlling the spread of COVID-19 requires individuals to adopt preventive behaviours, but conspiracy beliefs about its origin are spreading. The aim of this paper is to better comprehend the strength of conspiracy beliefs versus objective COVID-19 information to predict people's adherence to protective behaviours (getting vaccinated, being tracked through APPs, and keeping social distance from infected people). Study 1 shows that COVID-19 implicit theories detected in the Pre-study were activated as independent factors that constitute people's interpretations of the virus origin. These beliefs were related to a lesser intention to engage in preventive behaviours and a higher level of mistrust in institutional information, although some beliefs generate positive expectations about COVID-19 consequences. In Study 2, conducted with a different sample, official COVID-19 information was included as an independent variable, but this new variable did not further explain results. Lastly, Study 3 consisting of both previous samples confirmed that conspiracy beliefs had a direct effect on a lesser willingness to engage in preventive actions, a higher mistrust, and positive expectations about COVID-19 consequences. We conclude that objective COVID-19 information did not buffer the effect of conspiracy beliefs; they interfere with actions to prevent it by taking institutions as scapegoats or complicit with secret powers., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Pinazo-Calatayud, Agut-Nieto, Arahuete, Peris, Barros and Vázquez-Rodríguez.)

Although calcineurin inhibitors are very effective as immunosuppressants in organ transplantation, complete graft acceptance remains as a challenge. Transfer of genes with immunosuppressant functions could contribute to improving the clinical evolution of transplantation. In this sense, hydrodynamic injection has proven very efficacious for liver gene transfer. In the present work, the hIL-10 gene was hydrofected 'ex vivo' to pig livers during the bench surgery stage, to circumvent the cardiovascular limitations of the procedure, in a model of porcine orthotopic transplantation with a 10-day follow-up. We used IL-10 because human and porcine proteins can be differentially quantified and for its immunomodulatory pleiotropic functions. Safety (biochemical parameters and histology), expression efficacy (RNA transcription and blood protein expression), and acute inflammatory response (cytokines panel) of the procedure were evaluated. The procedure proved safe as no change in biochemical parameters was observed in treated animals, and human IL-10 was efficaciously expressed, with stationary plasma protein levels over 20 pg/mL during the follow-up. Most studied cytokines showed increments (interferon-α, IFN-α; interleukin-1β, IL-1β; tumor necrosis factor α, TNFα; interleukin-6, IL-6; interleukin-8, IL-8; interleukin-4, IL-4; and transforming growth factor-β, TGF-β) in treated animals, without deleterious effects on tissue. Collectively, the results support the potential clinical interest in this gene therapy model that would require further longer-term dose-response studies to be confirmed.

Introduction: The multiparametric nature of recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) still leads to uncertainty with its practical management. This study aims to characterize the main posttransplant recurrence patterns of HCC and to explore the therapeutic modalities targeting recurrence., Methods: Consecutive patients who underwent LT for HCC at a single tertiary center were analyzed. The time from first recurrence to death was investigated for each site of presentation. The impact of each recurrence-targeted treatment on survival was studied., Results: Of 660 patients with HCC, any recurrence occurred in 96 (15.4%) patients with a median time to recurrence of 20.0 months (95% CI: 15.6-23.8). Patients recurred across different patters including solitary distant locations (30.8%, n = 28), liver only (24.2%, n = 22), lung (18.7%, n = 17), multi-organ disease (17.6%, n = 16), and bone (8.8%, n = 8). Multi-organ and bone recurrences had the poorest survival, while solitary distant lesions and pulmonary recurrences had the best outcomes. Each treatment modality carried a distinctive survival., Conclusions: Patients recurred across 3 patterns with different prognostic implications. The benefit of each treatment option on distinct recurrence patterns appears to be influenced by the biological behavior inherent in the recurrence pattern itself., (© 2024 S. Karger AG, Basel.)

Laparoscopic hemihepatectomy (LHH) may offer advantages over open hemihepatectomy (OHH) in blood loss, recovery, and hospital stay. The aim of this study is to evaluate our recent experience performing hemihepatectomy and compare complications and costs up to 90 days following laparoscopic versus open procedures. Retrospective evaluation of patients undergoing hemihepatectomy at our center 01/2010-12/2018 was performed. Patient, tumor, and surgical characteristics; 90-day complications; and costs were analyzed. Inverse probability of treatment weighting (IPTW) was used to balance covariates. A total of 141 hemihepatectomies were included: 96 OHH and 45 LHH. While operative times were longer for LHH, blood loss and transfusions were less. At 90 days, there were similar rates of liver-specific and surgical complications but fewer medical complications following LHH. Medical complications that arose with greater frequency following OHH were primarily pulmonary complications and urinary and central venous catheter infections. Complications at 90 days were lower following LHH (Clavien-Dindo grade ≥ III OHH 23%, LHH 11%, p = 0.130; Comprehensive Complication Index OHH 20.0 ± 16.1, LHH 10.9 ± 14.2, p = 0.001). While operating costs were higher, costs for hospital stay and readmissions were lower with LHH. Patients undergoing LHH experience a significant reduction in postoperative medical complications and costs, resulting in 90-day cost equity compared with OHH.

Background: There is a lack of data on the use of direct-acting antivirals (DAA) on the risk of death and tumoral recurrence in patients with hepatitis C virus (HCV) and hepatocellular carcinoma (HCC) listed for liver transplantation (LT). We aimed to assess the impact of antiviral treatment on mortality and HCC recurrence patients with HCC-HCV., Methods: This was a retrospective multicenter study of patients with HCC-HCV listed for LT from 2005 to 2015. Patients were divided according to the antiviral treatment received after HCC diagnosis: DAA, interferon (IFN), or no antiviral. Intention-to-treat overall survival and HCC recurrence incidence were compared by the Kaplan-Meier method. Multivariable regression analysis was performed to identify risk factors for outcomes., Results: A total of 1012 HCV-HCC patients were listed for LT during the study period. The median follow-up was 4.0 (interquartile range = 2.3-6.7) years. Mortality was 5.6 (95% confidence interval [CI], 4.3-7.2), 13.1 (95% CI, 11.0-15.7), and 6.2 (95% CI, 5.4-7.2) deaths per 100 person-year among patients treated with DAA, IFN, and antiviral naïve, respectively (P < 0.001). Of the 875 HCV-HCC transplant recipients, the 5-year recurrence-free survival was 93.4%, 84.8%, 73.9% for the pre-LT DAA, pre-LT IFN, and antiviral naïve groups, respectively (P < 0.001). After multivariable regression, the use of pre-LT DAA was not associated to risk of recurrence (hazard ratio = 0.44 [95% CI, 0.19-1.00]). Post-LT DAA was not related to increased risk of recurrence (hazard ratio = 0.62 [95% CI, 0.33-1.16])., Conclusions: In this multicenter intent-to-treat study, DAA therapy was not found to be a risk factor for mortality or HCC recurrence after adjusting for potential confounders.

Objectives: The aim was to determine whether serum levels of carbohydrate antigen (CA) 19-9, interleukin 6 (IL-6), and YKL-40 could identify advanced disease and poor prognosis in pancreatic cancer (PC) patients intraoperatively diagnosed with locally advanced or metastatic disease., Methods: Two hundred ninety patients were included with preoperative blood samples. Plasma IL-6 and YKL-40 were determined by enzyme-linked immunosorbent assays., Results: Interleukin 6 was elevated in patients with unresectable PC compared with resectable PC (P = 0.03). Carbohydrate antigen 19-9 and YKL-40 were similar. Patients with resectable tumors and greater than median preoperative CA 19-9, IL-6, and YKL-40 had shorter overall survival than patients with low levels (CA 19-9: hazard ratio [HR], 1.79; 95% confidence interval [CI], 1.13-2.83; P = 0.01; IL-6: HR, 1.83; 95% CI, 1.20-2.78; P = 0.01; YKL-40: HR, 1.60; 95% CI, 1.02-2.49; P = 0.04). Patients with resectable tumors and 2 or 3 high biomarker levels had significantly reduced overall survival compared with patients with low levels (2 high: HR, 2.97; 95% CI, 1.44-6.10; P = 0.00; 3 high: HR, 3.10; 95% CI, 1.45-6.65; P = 0.00)., Conclusions: Preoperative levels of CA 19-9, IL-6, and YKL-40 may be useful to identify a subgroup of PC patients with poor prognosis.

Background: The advantages of laparoscopy over open liver resection in patients with cirrhosis have been widely demonstrated. On the other hand, information on the role of minimally invasive liver surgery in the presence of clinically significant portal hypertension (CSPH) is scarce. The aim of this study was to evaluate the role of laparoscopic liver resection in selected cirrhotic patients with CSPH., Methods: A retrospective case-control study of cirrhotic patients with hepatocellular carcinoma who were treated with laparoscopic liver resection was conducted from December 2005 to April 2016. A total of 45 patients were included. Patients were divided into two groups according to the presence or absence of clinically significant portal hypertension. Fifteen cirrhotic patients with CSPH were matched with 30 patients without CSPH., Results: Overall, there were no differences in intraoperative results. No conversion to open surgery occurred in the CSPH group, and 3 patients were converted in the Non-CSPH group (0 vs. 10% p = 0.57). Only 2 (7%) patients in the Non-CSPH group and 1 (7%) in the CSPH group had relevant complications (modified Clavien-Dindo classification III). Two patients in the Non-CSPH group and one in the CSPH group developed transient ascites (7 vs. 7%). Postoperative hospital stay was similar in both groups, with a median of 4 days in the CSPH group and 3 days in the Non-CSPH group (p = 0.37). The median follow-up of the entire cohort was 38 months (range 7-100). Overall survival rates at 1 and 3 years were 100 and 87%, respectively. There was no significant difference between the groups in terms of survival (p = 0.8)., Conclusion: This initial study showed that laparoscopic resection in patients with CSPH can be performed safely in well-selected patients and expand the current surgical indications in patients with CSPH. Prospective trials with a larger sample size are necessary to confirm these results.

Introduction: We analyze major liver resections performed in 10 years, with the objective of evaluating perioperative results. As secondary objectives, factors related to major complications and comparative analyses of 25-year periods are evaluated., Methods: Retrospective analysis of patients undergoing major hepatic resection (3 or more segments) from January 2005 to December 2014, from pre, intra and postoperative data. The Clavien classification is used for postoperative morbidity., Results: A total of 416 major hepatectomies were performed. Transfusions were performed in 38 patients (9.1%). A Pringle maneuver was used in 47.7% of the cases. Half of the patients had no complications, and only 96 patients (23%) had a major complication. Bile leakage was the most frequent complication (n=72, 17.3% of patients), especially due to malignant disease and biliary reconstruction, high risk ASA (III-IV) and prolonged surgical time. Thirteen patients met criteria for liver failure, of which 7died (5 associated a bacterial infection). The mean hospital stay was 12.5 days, with an 11,8% readmission rate. When comparing 25-year periods, at present more complex patients are operated on, with a lower incidence of transfusions and complications (ns)., Conclusions: Liver surgery has increased significantly in recent years. Surgical management of the liver now allows safe and effective surgery, with a very low complication rate. The limit of resectability depends on the residual hepatic volume., (Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.)

Background: The HMGA2 protein has experimentally been linked to EMT and cancer stemness. Recent studies imply that tumour-stroma interactions regulate these features and thereby contribute to tumour aggressiveness., Methods: We analysed 253 cases of pancreatic ductal adenocarcinoma (PDAC) and 155 cases of ampullary adenocarcinoma (AAC) for HMGA2 expression by IHC. The data were correlated with stroma abundance and supplemented by experimental studies., Results: HMGA2 acts as an independent prognostic marker associated with a significantly shorter overall survival in both tumour types. Overall, HMGA2-positivity was more frequent in patients with PDAC than with AAC. The HMGA2 status in tumour cells significantly correlated with the abundance of PDGFRβ-defined stroma cells. In vivo co-injection of Panc-1 cancer cells with pancreatic stellate cells increased tumour growth in a manner associated with increased HMGA2 expression. Furthermore, in vitro treatment of Panc-1 with conditioned media from PDGF-BB-activated stellate cells increased their ability to form tumour spheroids., Conclusions: This study identifies HMGA2 expression in tumour cells as an independent prognostic marker in PDAC and AAC. Correlative data analysis gives novel tissue-based evidence for a heterotypic cross-talk with stroma cells as a possible mechanism for HMGA2 induction, which is further supported by experimental models.

Introduction: Living donor liver transplantation (LDLT) is an alternative to conventional transplantation given its excellent results. The aim of this study is to evaluate long-term outcomes in LDLT recipients., Methods: 100 consecutive THDV recipients from the Hospital Clínic of Barcelona from March 2000 to October 2015 were included. The main indication for transplantation was end-stage liver disease (58%) followed by hepatocellular carcinoma (41%). 95% of grafts consisted of the right liver of the donor and the 5% of the left liver., Results: After a median follow-up of 65.5 months, patient and graft survival at 1, 3, and 5 years was 93%, 80% and 74% and 90%, 76%, and 71%, respectively. The overall re-transplant rate was 9%. The most common long-term complication was biliary stenosis (40%) with an average time of onset of 13.5±12 months, with repeated admissions and an average of 1.9±2 endoscopic procedures and 3.5±3 Radiological procedures per patient. The definitive treatment was radiological dilation in 40% of cases, surgical intervention in 22.5% and re-transplantation in 7.5%., Conclusions: Given the long-term results, LDLT is confirmed as an alternative to conventional transplantation. However, the high rate of late biliary complications involves repeated admissions and invasive treatments that, while not compromising survival, can affect the patient's quality of life., (Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.)

Background: The aim of this study was to validate previously described diagnostic and prognostic microRNA expression profiles in tissue samples from patients with pancreatic cancer and other periampullary cancers., Methods: Expression of 46 selected microRNAs was studied in formalin-fixed paraffin-embedded tissue from patients with resected pancreatic ductal adenocarcinoma ( n  = 165), ampullary cancer ( n =59), duodenal cancer ( n  = 6), distal common bile duct cancer ( n  = 21), and gastric cancer ( n  = 20); chronic pancreatitis ( n  = 39); and normal pancreas ( n  = 35). The microRNAs were analyzed by PCR using the Fluidigm platform., Results: Twenty-two microRNAs were significantly differently expressed in patients with pancreatic cancer when compared to healthy controls and chronic pancreatitis patients; 17 miRNAs were upregulated (miR-21-5p, -23a-3p, -31-5p, -34c-5p, -93-3p, -135b-3p, -155-5p, -186-5p, -196b-5p, -203, -205-5p, -210, -222-3p, -451, -492, -614, and miR-622) and 5 were downregulated (miR-122-5p, -130b-3p, -216b, -217, and miR-375). MicroRNAs were grouped into diagnostic indices of varying complexity. Ten microRNAs associated with prognosis were identified (let-7 g, miR-29a-5p, -34a-5p, -125a-3p, -146a-5p, -187, -205-5p, -212-3p, -222-5p, and miR-450b-5p). Prognostic indices based on differences in expression of 2 different microRNAs were constructed for pancreatic and ampullary cancer combined and separately (30, 5, and 21 indices)., Conclusion: The study confirms that pancreatic cancer tissue has a microRNA expression profile that is different from that of other periampullary cancers, chronic pancreatitis, and normal pancreas. We identified prognostic microRNAs and microRNA indices that were associated with shorter overall survival in patients with radically resected pancreatic cancer.

Biomarkers for early diagnosis of patients with pancreatic cancer (PC) are needed. Our aim was to identify panels of miRNAs in serum in combination with CA 19-9 for use in the diagnosis of PC. Four hundred seventeen patients with PC were included prospectively from Denmark (n = 306) and Germany (n = 111). Controls included 59 patients with chronic pancreatitis (CP) and 248 healthy subjects (HS). MiRNAs were analyzed in pretreatment serum samples from 3 cohorts: discovery cohort (754 human miRNAs, TaqMan(®) Human MicroRNA assay, Applied Biosystem; PC n = 133, controls n = 72); training cohort (34 miRNAs, real-time qPCR using the Fluidigm BioMark™ System; PC n = 198, controls n = 184); validation cohort (13 miRNAs, real-time qPCR using the Fluidigm BioMark™ System; PC n = 86, controls n = 51). We found that 34 miRNAs in serum from PC patients in the discovery cohort were expressed differently than in controls. These miRNAs were tested in the training cohort, and four diagnostic panels were constructed that included 5 or 12 miRNAs (miR-16, -18a, -20a, -24, -25, -27a, -29c, -30a.5p, -191, -323.3p, -345 and -483.5p). Diagnostic accuracy of detecting PC in the training cohort was AUC (Index I 0.85; II 0.87; III 0.85; IV 0.95; CA 19-9 0.93); specificity (I 0.71; II 0.76; III 0.66; IV 0.90 (fixed sensitivity at 0.85); CA 19-9 0.93). Combining serum CA 19-9 and Index II best discriminated Stages I and II PC from HS [AUC 0.93 (0.90-0.96), sensitivity 0.77 (0.69-0.84), specificity 0.94 (0.90-0.96) and accuracy 0.88 (0.84-0.91)]. In conclusion, we identified four diagnostic panels based on 5 or 12 miRNAs in serum that could distinguish patients with PC from HS and CP., (© 2016 UICC.)