Efficient Self-Condensation of Cyclohexanone into Biojet Fuel Precursors over Sulfonic Acid-Modified Silicas: Insights on the Effect of Pore Size and Structure.

Mesoporous silica materials with different pore structures and sizes have been used for supporting aryl sulfonic acid catalytic sites via a postsynthetic grafting approach. The synthesized materials have been evaluated in the solventless acid-catalyzed self-condensation of cyclohexanone (CHO) to obtain the corresponding C12 adducts. These compounds display great potential as oxygenated fuel precursors as they can be transformed into jet fuel range alkanes in a subsequent hydrodeoxygenation process. In this work, the synthesized catalysts have displayed high selectivity values toward monocondensed compounds (>95%), thus limiting the formation of undesired heavier condensation products, together with CHO conversion values in the range 20-40% after 2 h of reaction at 100 °C. The structural and textural properties of the supports play an important role in the catalytic performance. Moreover, the activity per acid center is correlated with the textural properties of the supports, indicating that a lower surface density of the anchored aryl sulfonic groups affords an improvement in their specific activity. Finally, the benefit of using supports with large pore sizes and open structures, which limit the fouling of the catalysts by organic deposits, is demonstrated in a stability and reusability test.

Gold Nanoparticle-Decorated Catalytic Micromotor-Based Aptassay for Rapid Electrochemical Label-Free Amyloid-ß42 Oligomer Determination in Clinical Samples from Alzheimer's Patients.

Micromotor (MM) technology offers a valuable and smart on-the-move biosensing microscale approach in clinical settings where sample availability is scarce in the case of Alzheimer's disease (AD). Soluble amyloid-ß protein oligomers (AßO) (mainly AßO42) that circulate in biological fluids have been recognized as a molecular biomarker and therapeutic target of AD due to their high toxicity, and they are correlated much more strongly with AD compared to the insoluble Aß monomers. A graphene oxide (GO)-gold nanoparticles (AuNPs)/nickel (Ni)/platinum nanoparticles (PtNPs) micromotors (MMGO-AuNPs)-based electrochemical label-free aptassay is proposed for sensitive, accurate, and rapid determination of AßO42 in complex clinical samples such as brain tissue, cerebrospinal fluid (CSF), and plasma from AD patients. An approach that implies the in situ formation of AuNPs on the GO external layer of tubular MM in only one step during MM electrosynthesis was performed (MMGO-AuNPs). The AßO42 specific thiolated-aptamer (AptAßO42) was immobilized in the MMGO-AuNPs via Au-S interaction, allowing for the selective recognition of the AßO42 (MMGO-AuNPs-AptAßO42-AßO42). AuNPs were smartly used not only to covalently bind a specific thiolated-aptamer for the design of a label-free electrochemical aptassay but also to improve the final MM propulsion performance due to their catalytic activity (approximately 2.0× speed). This on-the-move bioplatform provided a fast (5 min), selective, precise (RSD < 8%), and accurate quantification of AßO42 (recoveries 94-102%) with excellent sensitivity (LOD = 0.10 pg mL-1) and wide linear range (0.5-500 pg mL-1) in ultralow volumes of the clinical sample of AD patients (5 µL), without any dilution. Remarkably, our MM-based bioplatform demonstrated the competitiveness for the determination of AßO42 in the target samples against the dot blot analysis, which requires more than 14 h to provide qualitative results only. It is also important to highlight its applicability to the potential analysis of liquid biopsies as plasma and CSF samples, improving the reliability of the diagnosis given the heterogeneity and temporal complexity of neurodegenerative diseases. The excellent results obtained demonstrate the analytical potency of our approach as a future tool for clinical/POCT (Point-of-care testing) routine scenarios.

Serum Autoantibody Biomarkers for Management of Rheumatoid Arthritis Disease.

Rheumatoid arthritis (RA) is a systemic chronic autoimmune inflammatory disease that is characterized by the destruction of bone and production of autoantibodies such as rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPAs). The high prevalence of this disease and the need of affordable tools for its early detection led us to prepare the first electrochemical immunoplatform for the simultaneous determination of four RA biomarkers, the autoantibodies: RF, anti-peptidyl-arginine deiminase enzyme (anti-PAD4), anti-cyclic citrullinated peptide (anti-CCP), and anti-citrullinated vimentin (anti-MCV). Functionalized magnetic beads (MBs) were used to immobilize the specific antigens, and sandwich-type immunoassays were implemented for the amperometric detection of the four autoantibodies, using the horseradish peroxidase (HRP)/H2O2/hydroquinone (HQ) system. The immunoplatform was applied to the determination of the biomarkers in human serum of twenty-two patients diagnosed with RA and four healthy individuals, and the results were validated against ELISA tests and the certified values.

Has the COVID-19 pandemic changed the clinical picture and tumour stage at the time of presentation of patients with colorectal cancer? A retrospective cohort study.

INTRODUCTION: Treatment of patients with Coronavirus Disease 2019 (COVID-19) has affected the management of patients with colorectal cancer (CRC). The aim of this study was to compare the diagnosis delay, symptoms, and stage of patients with CRC during the pandemic with a control cohort. MATERIAL AND METHODS: Patients referred to the CRC multidisciplinary team between September 2019 and January 2020 (cohort 1, control group) were compared with those who presented between September 2020 and March 2021 (cohort 2, pandemic group). RESULTS: 389 patients were included, 169 in cohort 1 and 220 in cohort 2. No differences were observed in the main characteristics of the patients. CRC screening and anaemia were the most common causes leading to the diagnosis of the tumour in cohort 1 and 2, respectively (p<0.001). Diagnostic and therapeutic delay was longer in cohort 2 [6.4 (95% CI 5.8-6.9) vs. 4.8 (95% CI 4.3-5.3) months, p<0.001]. More patients required non-elective treatment in the pandemic cohort (15.5% vs. 9.5%, p=0.080). The tumour stage was more advanced in patients in cohort 2 [positive nodes in 52.3% vs. 36.7% (p=0.002), and metastatic disease in 23.6% vs. 16.6% (p=0.087)]. CONCLUSION: CRC patients in the pandemic cohort had a longer diagnostic and therapeutic delay and less patients were diagnosed because of CRC screening. In addition, patients with CRC during the pandemic needed non-elective treatment more frequently than patients in the control cohort, and their tumour stage tended to be more advanced.

Has the COVID-19 pandemic changed the clinical picture and tumour stage at the time of presentation of patients with colorectal cancer? A retrospective cohort study / ¿Ha cambiado la pandemia de COVID-19 la presentación clínica y el estadio tumoral en el momento del diagnóstico en los pacientes con cáncer colorrectal? Estudio retrospectivo de cohortes

Introduction: Treatment of patients with Coronavirus Disease 2019 (COVID-19) has affected the management of patients with colorectal cancer (CRC). The aim of this study was to compare the diagnosis delay, symptoms, and stage of patients with CRC during the pandemic with a control cohort.Material and methods: Patients referred to the CRC multidisciplinary team between September 2019 and January 2020 (cohort 1, control group) were compared with those who presented between September 2020 and March 2021 (cohort 2, pandemic group).Results: 389 patients were included, 169 in cohort 1 and 220 in cohort 2. No differences were observed in the main characteristics of the patients. CRC screening and anaemia were the most common causes leading to the diagnosis of the tumour in cohort 1 and 2, respectively (p<0.001). Diagnostic and therapeutic delay was longer in cohort 2 [6.4 (95% CI 5.8–6.9) vs. 4.8 (95% CI 4.3–5.3) months, p<0.001]. More patients required non-elective treatment in the pandemic cohort (15.5% vs. 9.5%, p=0.080). The tumour stage was more advanced in patients in cohort 2 [positive nodes in 52.3% vs. 36.7% (p=0.002), and metastatic disease in 23.6% vs. 16.6% (p=0.087)].Conclusion: CRC patients in the pandemic cohort had a longer diagnostic and therapeutic delay and less patients were diagnosed because of CRC screening. In addition, patients with CRC during the pandemic needed non-elective treatment more frequently than patients in the control cohort, and their tumour stage tended to be more advanced. (AU)

Introducción: La pandemia de la enfermedad por coronavirus 2019 ha afectado al manejo de los pacientes con cáncer colorrectal (CCR). El objetivo de este estudio fue comparar el retraso diagnóstico, la sintomatología y el estadio de los pacientes con CCR durante la pandemia con una cohorte histórica. Material y métodos: Los pacientes valorados en el comité multidisciplinar de CCR entre septiembre de 2019 y enero de 2020 (cohorte 1) se compararon con los presentados entre septiembre de 2020 y marzo de 2021 (cohorte 2). Resultados: Trescientos ochenta y nueve pacientes fueron incluidos, 169 en la cohorte 1 y 220 en la cohorte 2. El cribado del CCR y la anemia fueron las causas que llevaron al diagnóstico en más pacientes en la cohorte 1 y 2, respectivamente (p<0,001). El retraso diagnóstico y terapéutico fue mayor en la cohorte 2 (6,4 [IC 95%: 5,8-6,9] vs. 4,8 [IC 95%: 4,3-5,3] meses, p<0,001). En la cohorte pandémica hubo más pacientes que requirieron tratamiento urgente (15,5% vs. 9,5%, p=0,080). El estadio tumoral fue más avanzado en la cohorte 2 (ganglios positivos en el 52,3% vs. 36,7% [p=0,002] y enfermedad metastásica en el 23,6% vs. 16,6% [p=0,087]). Conclusión: Los pacientes con CCR en la cohorte pandémica tenían un retraso diagnóstico y terapéutico más largo, y menos pacientes fueron diagnosticados en el cribado de CCR. Además, los pacientes con CCR durante la pandemia necesitaron tratamiento urgente con más frecuencia y su estadio tumoral fue más avanzado. (AU)

Has the COVID-19 pandemic changed the clinical picture and tumour stage at the time of presentation of patients with colorectal cancer? A retrospective cohort study.

Introduction: Treatment of patients with Coronavirus Disease 2019 (COVID-19) has affected the management of patients with colorectal cancer (CRC). The aim of this study was to compare the diagnosis delay, symptoms, and stage of patients with CRC during the pandemic with a control cohort. Material and methods: Patients referred to the CRC multidisciplinary team between September 2019 and January 2020 (cohort 1, control group) were compared with those who presented between September 2020 and March 2021 (cohort 2, pandemic group). Results: 389 patients were included, 169 in cohort 1 and 220 in cohort 2. No differences were observed in the main characteristics of the patients. CRC screening and anaemia were the most common causes leading to the diagnosis of the tumour in cohort 1 and 2, respectively (p < 0.001). Diagnostic and therapeutic delay was longer in cohort 2 [6.4 (95% CI 5.8-6.9) vs. 4.8 (95% CI 4.3-5.3) months, p < 0.001]. More patients required non-elective treatment in the pandemic cohort (15.5% vs. 9.5%, p = 0.080). The tumour stage was more advanced in patients in cohort 2 [positive nodes in 52.3% vs. 36.7% (p = 0.002), and metastatic disease in 23.6% vs. 16.6% (p = 0.087)]. Conclusion: CRC patients in the pandemic cohort had a longer diagnostic and therapeutic delay and less patients were diagnosed because of CRC screening. In addition, patients with CRC during the pandemic needed non-elective treatment more frequently than patients in the control cohort, and their tumour stage tended to be more advanced.

Introducción: La pandemia de la enfermedad por coronavirus 2019 ha afectado al manejo de los pacientes con cáncer colorrectal (CCR). El objetivo de este estudio fue comparar el retraso diagnóstico, la sintomatología y el estadio de los pacientes con CCR durante la pandemia con una cohorte histórica. Material y métodos: Los pacientes valorados en el comité multidisciplinar de CCR entre septiembre de 2019 y enero de 2020 (cohorte 1) se compararon con los presentados entre septiembre de 2020 y marzo de 2021 (cohorte 2). Resultados: Trescientos ochenta y nueve pacientes fueron incluidos, 169 en la cohorte 1 y 220 en la cohorte 2. El cribado del CCR y la anemia fueron las causas que llevaron al diagnóstico en más pacientes en la cohorte 1 y 2, respectivamente (p < 0,001). El retraso diagnóstico y terapéutico fue mayor en la cohorte 2 (6,4 [IC 95%: 5,8-6,9] vs. 4,8 [IC 95%: 4,3-5,3] meses, p < 0,001). En la cohorte pandémica hubo más pacientes que requirieron tratamiento urgente (15,5% vs. 9,5%, p = 0,080). El estadio tumoral fue más avanzado en la cohorte 2 (ganglios positivos en el 52,3% vs. 36,7% [p = 0,002] y enfermedad metastásica en el 23,6% vs. 16,6% [p = 0,087]). Conclusión: Los pacientes con CCR en la cohorte pandémica tenían un retraso diagnóstico y terapéutico más largo, y menos pacientes fueron diagnosticados en el cribado de CCR. Además, los pacientes con CCR durante la pandemia necesitaron tratamiento urgente con más frecuencia y su estadio tumoral fue más avanzado.

Synthesis, characterization and use of enzyme cashew gum nanoparticles for biosensing applications.

This research reports, for the first time, the immobilization of an enzyme - Rhus vernificera laccase - on cashew gum (CG) nanoparticles (NPs) and its application as a biological layer in the design and development of an electrochemical biosensor. Laccase-CG nanoparticles (LacCG-NPs) were prepared by the nanoprecipitation method and characterized by UV-Vis spectrophotometry, atomic force microscopy, scanning electron microscopy, attenuated total reflectance-Fourier-transform infrared spectroscopy, circular dichroism, cyclic voltammetry, and electrochemical impedance spectroscopy. The average size and stability of the NPs were predicted by DLS and zeta potential. The ATR-FTIR results clearly demonstrated an interaction between -NH and -OH groups to form LacCG-NPs. The average size found for LacCG-NPs was 280 ± 53 nm and a polydispersity index of 0.309 ± 0.08 indicated a good particle size distribution. The zeta potential shows a good colloidal stability. The use of a natural product to prepare the enzymatic nanoparticles, its easy synthesis and the immobilization efficiency should be highlighted. LacCG-NPs were successfully applied as a biolayer in the development of an amperometric biosensor for catechol detection. The resulting device showed a low response time (6 s), good sensitivity (7.86 µA µM-1 cm-2), wide linear range of 2.5 × 10-7-2.0 × 10-4 M, and low detection limit (50 nM).

Microwave ablation of colorectal liver metastases: Impact of a 10-mm safety margin on local recurrence in a tertiary care hospital.

Microwave ablation (MWA) for colorectal liver metastasis (CLM) has been traditionally considered inferior to surgery due to the higher rate of local recurrence. The study investigated whether a safety margin of 10 mm can improve local control in patients undergoing surgical MWA. Surgical MWA was used to treat 53 lesions in 22 patients with CLM at our Institution from June 2012 to June 2017. The patients' mean age was 64.5 years, and the median size of the lesion was 16.5 mm (9-34 mm). MWA was associated with liver resection in 16 patients (72.7%). The median follow-up was 32.4 months. Univariate and multivariate analyses were performed to identify factors associated with tumor recurrence. Median ablation area was 36.6 mm2 (30-50 mm2). The complication rate was 22.7%. No local recurrence was observed during follow-up. Disease-free survival was 20 months (4.8-55.2 months). Univariate analysis revealed that the number of liver metastases and node-positive primary tumors were associated with tumor recurrence. Multivariate analysis revealed that node-positive primary tumor was the only factor significantly associated with tumor recurrence (p = 0.049; odds ratio, 12; 95% confidence interval, 1-143). When performed with a 10-mm safety margin, surgical MWA can lead to acceptable oncological outcomes with low morbidity. Therefore, it represents a good option in selected patients with CLM.

Fast and sensitive diagnosis of autoimmune disorders through amperometric biosensing of serum anti-dsDNA autoantibodies.

This work reports the first amperometric biosensor involving the use of neutravidin-functionalized magnetic microbeads (NA-MBs) modified with a biotinylated-anti-dsDNA (b-dsDNA) as efficient magnetic microcarriers to selectively capture anti-dsDNA autoantibodies (IgG, IgA and IgM AAbs) present in the sera of patients with rheumatoid arthritis (RA). Subsequently, the attached anti-dsDNA AAbs are detected with a mixture of conventional HRP-labeled secondary antibodies (HRP-anti-human IgG/IgM/IgA mixture). The biorecognition event is monitored by amperometric transduction using the hydroquinone (HQ)/H2O2 system upon capturing the modified MBs on the surface of screen-printed carbon electrodes (SPCEs). The developed bioplatform exhibits a linear calibration plot ranging from 1 to 200 IU mL-1 with a LOD of 0.3 IU mL-1 for anti-dsDNA AAbs standards. In addition, the biosensor allows performing the determination of the anti-dsDNA AAbs levels directly in 100-times diluted serum samples from patients diagnosed with RA and in just 75 min. The obtained results are in agreement with those provided by an ELISA kit and allow discrimination between positive and negative samples.

Xylose isomerization with zeolites in a two-step alcohol-water process.

Isomerization of xylose to xylulose was efficiently catalyzed by large-pore zeolites in a two-step methanol-water process that enhanced the product yield significantly. The reaction pathway involves xylose isomerization to xylulose, which, in part, subsequently reacts with methanol to form methyl xyluloside (step 1) followed by hydrolysis after water addition to form additional xylulose (step 2). NMR spectroscopy studies performed with (13) C-labeled xylose confirmed the proposed reaction pathway. The most active catalyst examined was zeolite Y, which proved more active than zeolite beta, ZSM-5, and mordenite. The yield of xylulose obtained over H-USY (Si/Al=6) after 1 h of reaction at 100 °C was 39%. After water hydrolysis in the second reaction step, the yield increased to 47%. Results obtained from pyridine adsorption studies confirm that H-USY (6) is a catalyst that combines Brønsted and Lewis acid sites, and isomerizes xylose in alcohol media to form xylulose at low temperature. The applied zeolites are commercially available; do not contain any auxiliary tetravalent metals, for example, tin, titanium, or zirconium; isomerize xylose efficiently; are easy to regenerate; and are prone to recycling.

Conformal sulfated zirconia monolayer catalysts for the one-pot synthesis of ethyl levulinate from glucose.

Here we describe a simple route to creating conformal sulphated zirconia monolayers throughout an SBA-15 architecture that confers efficient acid-catalysed one-pot conversion of glucose to ethyl levulinate.

Efficient isomerization of glucose to fructose over zeolites in consecutive reactions in alcohol and aqueous media.

Isomerization reactions of glucose were catalyzed by different types of commercial zeolites in methanol and water in two reaction steps. The most active catalyst was zeolite Y, which was found to be more active than the zeolites beta, ZSM-5, and mordenite. The novel reaction pathway involves glucose isomerization to fructose and subsequent reaction with methanol to form methyl fructoside (step 1), followed by hydrolysis to re-form fructose after water addition (step 2). NMR analysis with (13)C-labeled sugars confirmed this reaction pathway. Conversion of glucose for 1 h at 120 °C with H-USY (Si/Al = 6) gave a remarkable 55% yield of fructose after the second reaction step. A main advantage of applying alcohol media and a catalyst that combines Brønsted and Lewis acid sites is that glucose is isomerized to fructose at low temperatures, while direct conversion to industrially important chemicals like alkyl levulinates is viable at higher temperatures.

Etherification of biodiesel-derived glycerol with ethanol for fuel formulation over sulfonic modified catalysts.

The present study is focused on the etherification of biodiesel-derived glycerol with anhydrous ethanol over arenesulfonic acid-functionalized mesostructured silicas to produce ethyl ethers of glycerol that can be used as gasoline or diesel fuel biocomponents. Within the studied range, the best conditions to maximize glycerol conversion and yield towards ethyl-glycerols are: T=200 °C, ethanol/glycerol molar ratio=15/1, and catalyst loading=19 wt%. Under these reaction conditions, 74% glycerol conversion and 42% yield to ethyl ethers have been achieved after 4 h of reaction but with a significant presence of glycerol by-products. In contrast, lower reaction temperatures (T=160 °C) and moderate catalyst loading (14 wt%) in presence of a high ethanol concentration (ethanol/glycerol molar ratio=15/1) are necessary to avoid the formation of glycerol by-products and maximize ethyl-glycerols selectivity. Interestingly, a close catalytic performance to that achieved using high purity glycerol has been obtained with low-grade water-containing glycerol.