Cellular Immunity of SARS-CoV-2 in the Borriana COVID-19 Cohort: A Nested Case-Control Study.

Our goal was to determine the cellular immune response (CIR) in a sample of the Borriana COVID-19 cohort (Spain) to identify associated factors and their relationship with infection, reinfection and sequelae. We conducted a nested case-control study using a randomly selected sample of 225 individuals aged 18 and older, including 36 individuals naïve to the SARS-CoV-2 infection and 189 infected patients. We employed flow-cytometry-based immunoassays for intracellular cytokine staining, using Wuhan and BA.2 antigens, and chemiluminescence microparticle immunoassay to detect SARS-CoV-2 antibodies. Logistic regression models were applied. A total of 215 (95.6%) participants exhibited T-cell response (TCR) to at least one antigen. Positive responses of CD4+ and CD8+ T cells were 89.8% and 85.3%, respectively. No difference in CIR was found between naïve and infected patients. Patients who experienced sequelae exhibited a higher CIR than those without. A positive correlation was observed between TCR and anti-spike IgG levels. Factors positively associated with the TCR included blood group A, number of SARS-CoV-2 vaccine doses received, and anti-N IgM; factors inversely related were the time elapsed since the last vaccine dose or infection, and blood group B. These findings contribute valuable insights into the nuanced immune landscape shaped by SARS-CoV-2 infection and vaccination.

Thermal and Mechanical Properties of Reprocessed Polylactide/Titanium Dioxide Nanocomposites for Material Extrusion Additive Manufacturing.

Polylactic acid (PLA) is a biodegradable polymer that can replace petroleum-based polymers and is widely used in material extrusion additive manufacturing (AM). The reprocessing of PLA leads to a downcycling of its properties, so strategies are being sought to counteract this effect, such as blending with virgin material or creating nanocomposites. Thus, two sets of nanocomposites based respectively on virgin PLA and a blend of PLA and reprocessed PLA (rPLA) with the addition of 0, 3, and 7 wt% of titanium dioxide nanoparticles (TiO2) were created via a double screw extruder system. All blends were used for material extrusion for 3D printing directly from pellets without difficulty. Scanning electron micrographs of fractured samples' surfaces indicate that the nanoparticles gathered in agglomerations in some blends, which were well dispersed in the polymer matrix. The thermal stability and degree of crystallinity for every set of nanocomposites have a rising tendency with increasing nanoparticle concentration. The glass transition and melting temperatures of PLA/TiO2 and PLA/rPLA/TiO2 do not differ much. Tensile testing showed that although reprocessed material implies a detriment to the mechanical properties, in the specimens with 7% nano-TiO2, this effect is counteracted, reaching values like those of virgin PLA.

Manufacture and Characterization of Polylactic Acid Filaments Recycled from Real Waste for 3D Printing.

This paper studies the thermal, morphological, and mechanical properties of 3D-printed polylactic acid (PLA) blends of virgin and recycled material in the following proportions: 100/0, 25/75, 50/50, and 75/25, respectively. Real waste, used as recycled content, was shredded and sorted by size without a washing step. Regular dog-bone specimens were 3D printed from filaments, manufactured in a single screw extruder. Thermogravimetric analysis indicated that adding PLA debris to raw material did not significantly impact the thermal stability of the 3D-printed samples and showed that virgin and recycled PLA degraded at almost the same temperature. Differential scanning calorimetry revealed a significant reduction in crystallinity with increasing recycled content. Scanning electron microscopy showed a more homogenous structure for specimens from 100% pure PLA, as well as a more heterogeneous one for PLA blends. The tensile strength of the PLA blends increased by adding more recycled material, from 44.20 ± 2.18 MPa for primary PLA to 52.61 ± 2.28 MPa for the blend with the highest secondary PLA content. However, this study suggests that the mechanical properties of the reprocessed parts and their basic association are unique compared with those made up of virgin material.

ABO Blood Groups and Incidence of COVID-19 in the Mass Gathering Events in Borriana (Spain), March 2020: A Retrospective Cohort Study.

Our objective was to estimate the incidence of COVID-19 and the ABO blood Groups in the mass-gathering events (MGEs) during the Falles Festival in Borriana (Spain) from 6-10 March 2020. We conducted a population-based retrospective cohort study and measured anti-SARS-CoV-2 antibodies and the ABO of participants. We performed laboratory COVID-19 tests and obtained the ABO in 775 subjects (72.8% of the original exposed cohort): O-group (45.2%), A-group (43.1%), B-group (8.5%) and AB-group (3.4%). Adjusted for confounding factors, including COVID-19 exposure during the MGEs, attack rates of COVID-19 for each ABO group were 55.4%, 59.6%, 60.2%, and 63.7%. The adjusted relative risks were for O-group 0.93 (95% Confidence Interval [CI] 0.83-1.04), for A-group 1.06 (95% CI 0.94-1.18), for B-group 1.04 (95%CI 0.88-1.24), and for AB-group 1.11 (95% CI 0.81-1.51) with no significant differences. Conclusions: Our results suggest no effect of ABO on COVID-19 incidence. We observed weak but not significant protection of the O-group and not a significantly greater infection risk for the remaining groups compared with the O-group. More studies are needed to resolve the controversies regarding the association between ABO and COVID-19.

A Machine Learning Approach for Modelling Cold-Rolling Curves for Various Stainless Steels.

Stainless steel is a cold-work-hardened material. The degree and mechanism of hardening depend on the grade and family of the steel. This characteristic has a direct effect on the mechanical behaviour of stainless steel when it is cold-formed. Since cold rolling is one of the most widespread processes for manufacturing flat stainless steel products, the prediction of their strain-hardening mechanical properties is of great importance to materials engineering. This work uses artificial neural networks (ANNs) to forecast the mechanical properties of the stainless steel as a function of the chemical composition and the applied cold thickness reduction. Multiple linear regression (MLR) is also used as a benchmark model. To achieve this, both traditional and new-generation austenitic, ferritic, and duplex stainless steel sheets are cold-rolled at a laboratory scale with different thickness reductions after the industrial intermediate annealing stage. Subsequently, the mechanical properties of the cold-rolled sheets are determined by tensile tests, and the experimental cold-rolling curves are drawn based on those results. A database is created from these curves to generate a model applying machine learning techniques to predict the values of the tensile strength (Rm), yield strength (Rp), hardness (H), and elongation (A) based on the chemical composition and the applied cold thickness reduction. These models can be used as supporting tools for designing and developing new stainless steel grades and/or adjusting cold-forming processes.

Effect of Thermal and Hydrothermal Accelerated Aging on 3D Printed Polylactic Acid.

In the new transformation of 'Industry 4.0', additive manufacturing technologies have become one of the fastest developed industries, with polylactic acid (PLA) playing a significant role. However, there is an increasing amount of garbage generated during the printing process and after prototypes or end-of-life parts. Re-3D printing is one way to recycle PLA waste from fused filament fabrication. To do this process successfully, the properties of the waste mixture should be known. Previous studies have found that PLA degrades hydrolytically, but the time at which this process occurs for 3D printed products is not specified. This work aims to establish the baseline of the degradation kinetics of 3D printed PLA products to predict the service time until which these properties are retained. To achieve this, 3D printed specimens were thermally and hydrothermally aged during several time intervals. Thermal and mechanical properties were also determined. This study reveals that tensile strength decreases after 1344 h of hydrothermal ageing, simulating 1.5-2.5 years of real service time. PLA therefore has the same thermo-mechanical properties before reaching 1.5-years of age, so it could be recycled.

Complications Post-COVID-19 and Risk Factors among Patients after Six Months of a SARS-CoV-2 Infection: A Population-Based Prospective Cohort Study.

In October 2020, we conducted a population-based prospective cohort study to determine post-COVID-19 complications, recovery, return to usual health, and associated risk factors in 536 cases of COVID-19 outbreak in Borriana (Spain) by administering an epidemiological questionnaire via phone interviews. A total of 484 patients participated (90.3%), age mean 37.2 ± 17.1 years, and 301 females (62.2%). Mild illness was the most common COVID-19 manifestation. After six months, 160 patients (33.1%) suffered at least one complication post-COVID-19, and 47 (29.4%) of them sought medical assistance. The most frequent persistent symptoms were hair loss, fatigue, loss of smell or taste, and headache. Risk factors associated with a complication were female sex (adjusted relative risk, [aRR] = 1.93 95% confidence interval [CI] 1.41-2.65), age 35 years and above (aRR = 1.50 95% CI 1.14-1.99), B blood group (aRR = 1.51 95% CI 1.04-2.16), current smoker (RR = 1.61 95% CI 1.02-2.54), and at least a COVID-19 exposure (aRR = 2.13 95% CI 1.11-4.09). Male sex, age younger than 35 years, and low COVID-19 exposures were associated with better recovery and return to usual health. A third of patients presented persistent symptoms compatible with the long-COVID-19 syndrome. In conclusion, an active medical follow-up of post-COVID-19 patients must be implemented.

ABO Blood Groups and the Incidence of Complications in COVID-19 Patients: A Population-Based Prospective Cohort Study.

After a COVID-19 outbreak in the Falles festival of Borriana (Spain) during March 2020, a cohort of patients were followed until October 2020 to estimate complications post-COVID-19, considering ABO blood groups (ABO). From 536 laboratory-confirmed cases, 483 completed the study (90.1%) carried by the Public Health Center of Castelló and the Emergency and Microbiology and Clinical Analysis of Hospital de la Plana Vila-real. The study included ABO determination and telephone interviews of patients. The participants had a mean age of 37.2 ± 17.1 years, 300 females (62.1%). ABO were O (41.4%), A (45.5%), B (9.1%), and AB (3.9%). We found no difference in the incidence of COVID-19 infections. A total of 159 (32.9%) patients reported one or more post-COVID-19 complications with divergent incidences after adjustment: O (32.3%), A (32.6%), B (54.1%), and AB (27.6%); B groups had more complications post-COVID-19 when compared with O group (adjusted relative risk [aRR] 95% confidence interval [CI] 1.68, 95% CI 1.24-2.27), and symptoms of fatigue (1.79, 95% CI 1.08-2.95), myalgia (2.06, 95% CI 1.10-3.84), headache (2.61, 95% CI 1.58-4.31), and disorder of vision (4.26 95% CI 1.33-13.60). In conclusion, we observed significant differences in post-COVID-19 complications by ABO, with a higher incidence in B group. Additional research is justified to confirm our results.

"Mass gathering events and COVID-19 transmission in Borriana (Spain): A retrospective cohort study".

OBJECTIVE: Mass gathering events (MGEs) are associated with the transmission of COVID-19. Between 6 and 10 March 2020, several MGEs related to the Falles festival took place in Borriana, a municipality in the province of Castellon (Spain). The aim of this study was to estimate the incidence of COVID-19 and its association with these MGEs, and to quantify the potential risk factors of its occurrence. METHODS: During May and June 2020, a population-based retrospective cohort study was carried out by the Public Health Center of Castelló and the Hospital de la Plana in Vila-real. Participants were obtained from a representative sample of 1663 people with potential exposure at six MGEs. A questionnaire survey was carried out to obtain information about attendance at MGEs and COVID-19 disease. In addition, a serologic survey of antibodies against SARS-Cov-2 was implemented. Inverse probability weighted regression was used in the statistical analysis. RESULTS: A total of 1338 subjects participated in the questionnaire survey (80.5%), 997 of whom undertook the serologic survey. Five hundred and seventy cases were observed with an attack rate (AR) of 42.6%; average age was 36 years, 62.3% were female, 536 cases were confirmed by laboratory tests, and 514 cases were found with SARS-CoV-2 total antibodies. Considering MGE exposure, AR was 39.2% (496/1264). A dose-response relationship was found between MGE attendance and the disease, (adjusted relative risk [aRR] = 4.11 95% confidence interval [CI]3.25-5.19). Two MGEs with a dinner and dance in the same building had higher risks. Associated risk factors with the incidence were older age, obesity, and upper and middle class versus lower class; current smoking was protective. CONCLUSIONS: The study suggests the significance of MGEs in the COVID-19 transmission that could explain the subsequent outbreak in Borriana.

Bismuth incorporation and the role of ordering in GaAsBi/GaAs structures.

The structure and composition of single GaAsBi/GaAs epilayers grown by molecular beam epitaxy were investigated by optical and transmission electron microscopy techniques. Firstly, the GaAsBi layers exhibit two distinct regions and a varying Bi composition profile in the growth direction. In the lower (25 nm) region, the Bi content decays exponentially from an initial maximum value, while the upper region comprises an almost constant Bi content until the end of the layer. Secondly, despite the relatively low Bi content, CuPtB-type ordering was observed both in electron diffraction patterns and in fast Fourier transform reconstructions from high-resolution transmission electron microscopy images. The estimation of the long-range ordering parameter and the development of ordering maps by using geometrical phase algorithms indicate a direct connection between the solubility of Bi and the amount of ordering. The occurrence of both phase separation and atomic ordering has a significant effect on the optical properties of these layers. PACS: 78.55.Cr III-V semiconductors; 68.55.Nq composition and phase identification; 68.55.Ln defects and impurities: doping, implantation, distribution, concentration, etc; 64.75.St phase separation and segregation in.

Impact of N on the atomic-scale Sb distribution in quaternary GaAsSbN-capped InAs quantum dots.

The use of GaAsSbN capping layers on InAs/GaAs quantum dots (QDs) has recently been proposed for micro- and optoelectronic applications for their ability to independently tailor electron and hole confinement potentials. However, there is a lack of knowledge about the structural and compositional changes associated with the process of simultaneous Sb and N incorporation. In the present work, we have characterized using transmission electron microscopy techniques the effects of adding N in the GaAsSb/InAs/GaAs QD system. Firstly, strain maps of the regions away from the InAs QDs had revealed a huge reduction of the strain fields with the N incorporation but a higher inhomogeneity, which points to a composition modulation enhancement with the presence of Sb-rich and Sb-poor regions in the range of a few nanometers. On the other hand, the average strain in the QDs and surroundings is also similar in both cases. It could be explained by the accumulation of Sb above the QDs, compensating the tensile strain induced by the N incorporation together with an In-Ga intermixing inhibition. Indeed, compositional maps of column resolution from aberration-corrected Z-contrast images confirmed that the addition of N enhances the preferential deposition of Sb above the InAs QD, giving rise to an undulation of the growth front. As an outcome, the strong redshift in the photoluminescence spectrum of the GaAsSbN sample cannot be attributed only to the N-related reduction of the conduction band offset but also to an enhancement of the effect of Sb on the QD band structure.

Calculation of integrated intensities in aberration-corrected Z-contrast images.

Inclusion of spatial incoherence has been shown to give quantitative agreement between non-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images and theoretical simulations. Here we show that, using the same approach, a significant improvement in the correlation between calculated and experimental normalized integrated intensities is obtained in the InAsP ternary semiconductor alloy, but residual discrepancies remain. We have demonstrated, in good agreement with experimental intensities obtained in calibrated samples, that normalized integrated intensities show a low dependence on the sample thickness over a wide range of thickness values. This behaviour does not occur in conventional (non-aberration-corrected) images and constitutes a powerful tool for straightforward interpretation of high-resolution images in terms of atomic column-resolved compositional maps.

Blueprinting for clinical performance deficiencies--lessons and principles from the General Medical Council's fitness to practise procedures.

BACKGROUND: The UK General Medical Council (GMC) in its regulatory capacity conducts formal tests of competence (TOCs) on doctors whose performance is of concern. TOCs are individually tailored to each doctor's specialty and grade. AIMS: To describe the development and implementation of an electronic blueprinting system that supports the delivery of TOCs. METHOD: A case study that describes the evolution of the GMC electronic blueprint including the derivation of its content and its functionality. RESULTS: A question bank has been created with all items classified according to the competencies defined by Good Medical Practice. This database aids test assembly and ensures that each assessment maps across the breadth of the blueprint. CONCLUSIONS: The blueprint described was easy to construct and is easy to use. It reflects the knowledge, skills and behaviours (learning outcomes) to be assessed. It guides commissioning of test material and enables the systematic and faithful sampling of common and important problems. The principles described have potential for wider application to blueprinting in undergraduate or clinical training programmes. Such a blueprint can provide the essential link between a curriculum and its assessment system and ensure that assessment content is stable over time.

The development of a new method of knowledge assessment: tailoring a test to a doctor's area of practice.

The practice of clinical medicine is becoming increasingly specialized, and this change has increased the challenge of developing fair, valid, and reliable tests of knowledge, particularly for single candidates or small groups of candidates. The problem is particularly relevant to the UK's General Medical Council's Fitness to Practice procedures, which investigate individual doctors. In such cases, there is a need for an alternative to the conventional approach to reliability estimation that will still allow the delivery of reproducible and standardized tests. This report describes the three-year process (starting in 2005) of developing a knowledge test that can be tailored for individual doctors practicing in narrowly specialized fields or at various stages in their training. The process of test development for this study consisted of five stages: item writing, to create individual questions; blueprinting, to establish the content and context that each item might test; standard setting, to calculate for each question a theoretical probability that a doctor of just-adequate capability would answer the question correctly; reference data collection, to determine for each item the distribution of scores to be expected from a large population of doctors in good standing; and test assembly, to select sets of questions that together formed complete and balanced tests. Tailored testing is a valid, feasible, and reproducible method of assessing the knowledge of one doctor or small groups of doctors who are practicing in narrow or subspecialty areas.

A method to determine the strain and nucleation sites of stacked nano-objects.

We determine the compositional distribution with atomic column resolution in a horizontal nanowire from the analysis of aberration-corrected high resolution Z-contrast images. The strain field in a layer capping the analysed nanowire is determined by anisotropic elastic theory from the resulting compositional map. The reported method allows preferential nucleation sites for epitaxial nanowires to be predicted with high spatial resolution, as required for accurate tuning of desired optical properties. The application of this method has been exemplified in this work for stacked InAs(P) horizontal nanowires grown on InP separated by 3 nm thick InP layers, but we propose it as a general method to be applied to other stacked nano-objects.

A randomized, double blind, dose-response comparison of balsalazide (6.75 g), balsalazide (2.25 g), and mesalamine (2.4 g) in the treatment of active, mild-to-moderate ulcerative colitis.

OBJECTIVE: Balsalazide is a new innovative, mesalamine-containing prodrug that is activated by bacteria in the colon. Balsalazide has been shown previously to be well tolerated and effective in the treatment of acute ulcerative colitis. The aim of this study was to determine the dose-response of balsalazide for efficacy and safety in active, mild-to-moderate ulcerative colitis and to compare this profile with that of mesalamine, pH-dependent, delayed-release tablets. METHODS: A multicenter, randomized, active control, double-blind, double-dummy, dose-response, parallel-group study was performed comparing balsalazide (6.75 g daily), balsalazide (2.25 g daily), and mesalamine (2.4 g daily), administered for 8 wk to 154 patients with active, mild-to-moderate ulcerative colitis as verified by sigmoidoscopy. RESULTS: Eight weeks of treatment with 6.75 g of balsalazide daily provided significantly greater improvement than did balsalazide (2.25 g daily) in rectal bleeding (64.7% [6.75-g balsalazide] vs 32.4% [2.25-g balsalazide], p < 0.006), stool frequency (58.8% vs 29.4%, p < 0.006), sigmoidoscopic score (78.9% vs 52.5%, p < 0.015), and Physician's Global Assessment (73.7% vs 51.3%, p < 0.03). The efficacy of balsalazide showed a significantly more rapid onset of action than that of mesalamine (2.4 g daily) (2-wk sigmoidocopic score improvement, 54.7% [6.75-g balsalazide] vs 29.4% [2.4-g mesalamine], p = 0.006) with numerically greater improvement at 8 wk in five of seven measured signs and symptoms. Balsalazide (6.75 g daily) was well tolerated, and the safety profile did not differ significantly from that of balsalazide (2.25 g daily) or mesalamine. CONCLUSIONS: Eight weeks of treatment with balsalazide (6.75 g daily) is significantly more effective than balsalazide (2.25 g daily) and more rapid in onset than mesalamine (2.4 g daily) in improving signs and symptoms of acute ulcerative colitis. Balsalazide (6.75 g daily) is well tolerated, and the safety profile does not differ from that of balsalazide (2.25 g daily) and mesalamine (2.4 g daily).