Evaluation of the Thermal, Chemical, Mechanical, and Microbial Stability of New Nanohybrids Based on Carboxymethyl-Scleroglucan and Silica Nanoparticles for EOR Applications.

Scleroglucan (SG) is resistant to harsh reservoir conditions such as high temperature, high shear stresses, and the presence of chemical substances. However, it is susceptible to biological degradation because bacteria use SG as a source of energy and carbon. All degradation effects lead to viscosity loss of the SG solutions, affecting their performance as an enhanced oil recovery (EOR) polymer. Recent studies have shown that nanoparticles (NPs) can mitigate these degradative effects. For this reason, the EOR performance of two new nanohybrids (NH-A and NH-B) based on carboxymethyl-scleroglucan and amino-functionalized silica nanoparticles was studied. The susceptibility of these products to chemical, mechanical, and thermal degradation was evaluated following standard procedures (API RP 63), and the microbial degradation was assessed under reservoir-relevant conditions (1311 ppm and 100 °C) using a bottle test system. The results showed that the chemical reactions for the nanohybrids obtained modified the SG triple helix configuration, impacting its viscosifying power. However, the nanohybrid solutions retained their viscosity during thermal, mechanical, and chemical degradation experiments due to the formation of a tridimensional network between the nanoparticles (NPs) and the SG. Also, NH-A and NH-B solutions exhibited bacterial control because of steric hindrances caused by nanoparticle modifications to SG. This prevents extracellular glucanases from recognizing the site of catalysis, limiting free glucose availability and generating cell death due to substrate depletion. This study provides insights into the performance of these nanohybrids and promotes their application in reservoirs with harsh conditions.

Synthesis and Characterization of New Nanohybrids Based on Carboxymethyl Scleroglucan and Silica Nanoparticles.

In this study, two new nanohybrids (NH-A and NH-B) were synthesized through carbodiimide-assisted coupling. The reaction was performed between carboxymethyl-scleroglucans (CMS-A and CMS-B) with different degrees of substitution and commercial amino-functionalized silica nanoparticles using 4-(dimethylamino)-pyridine (DMAP) and N,N'-dicyclohexylcarbodiimide (DCC) as catalysts. The morphology and properties of the nanohybrids were investigated by using transmission (TEM) and scanning electron microscopy (SEM), electron-dispersive scanning (EDS), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FT-IR), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-OES), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic light scattering (DLS). The nanohybrids exhibited differences in structure due to the incorporation of polyhedral oligomeric silsesquioxane (POSS) materials. The results reveal that hybrid nanomaterials exhibit similar thermal properties but differ in morphology, chemical structure, and crystallinity properties. Finally, a viscosity study was performed on the newly obtained nanohybrid materials; viscosities of nanohybrids increased significantly in comparison to the carboxymethyl-scleroglucans, with a viscosity difference of 7.2% for NH-A and up to 32.6% for NH-B.

Flow Behavior through Porous Media and Displacement Performance of a SILICA/PAM Nanohybrid: Experimental and Numerical Simulation Study.

Nanoparticles (NPs) have been proposed as additives to improve the rheological properties of polymer solutions and reduce mechanical degradation. This study presents the results of the retention experiment and the numerical simulation of the displacement efficiency of a SiO2/hydrolyzed polyacrylamide (HPAM) nanohybrid (CSNH-AC). The CSNH-AC was obtained from SiO2 NPs (synthesized by the Stöber method) chemically modified with HPAM chains. Attenuated total reflection-Fourier transform infrared spectroscopy, field emission gun-scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis were used to characterize the nanohybrid. The injectivity and dynamic retention tests were performed at 56 °C in a sandstone core with a porosity of ∼26% and a permeability of 117 and 287 mD. A history matching of the dynamic retention test was performed to determine the maximum and residual adsorption, IPV, and residual resistance factor (RRF). A laboratory-scale model was used to evaluate the displacement efficiency of CSNH-AC and HPAM through numerical simulation. According to the results, the nanohybrid exhibits better rheological behavior than the HPAM solution at a lower concentration. The nanopolymer sol adsorption and IPV (29,7 µg/grock, 14,5) are greater than those of the HPAM solution (9,2 µg/grock, 10), which was attributed to the difference between the rock permeabilities used in the laboratory tests (HPAM: 287 mD and CSNH-AC: 117 mD). The RF of both samples gradually increases with the increase in shear rate, while the RRF slightly decreases and tends to balance. However, the nanopolymer sol exhibits greater RF and RRF values than that of the polymer solution due to the strong flow resistance of the nanohybrid (higher retention in the porous media). According to the field-scale simulation, the incremental oil production could be 295,505 and 174,465 barrels for the nanopolymer sol and the HPAM solution, respectively (compared to waterflooding). This will represent an incremental recovery factor of 11.3% for the nanopolymer sol and 6.7% for the HPAM solution.

Experimental Investigation of the Viscosity and Stability of Scleroglucan-Based Nanofluids for Enhanced Oil Recovery.

Biopolymers emerge as promising candidates for enhanced oil recovery (EOR) applications due to their molecular structures, which exhibit better stability than polyacrylamides under harsh conditions. Nonetheless, biopolymers are susceptible to oxidation and biological degradation. Biopolymers reinforced with nanoparticles could be a potential solution to the issue. The nanofluids' stability and performance depend on the nanoparticles' properties and the preparation method. The primary objective of this study was to evaluate the effect of the preparation method and the nanoparticle type (SiO2, Al2O3, and TiO2) on the viscosity and stability of the scleroglucan (SG). The thickening effect of the SG solution was improved by adding all NPs due to the formation of three-dimensional structures between the NPs and the SG chains. The stability test showed that the SG + Al2O3 and SG + TiO2 nanofluids are highly unstable, but the SG + SiO2 nanofluids are highly stable (regardless of the preparation method). According to the ANOVA results, the preparation method and standing time influence the nanofluid viscosity with a statistical significance of 95%. On the contrary, the heating temperature and NP type are insignificant. Finally, the nanofluid with the best performance was 1000 ppm of SG + 100 ppm of SiO2_120 NPs prepared by method II.

Carboxymethyl Scleroglucan Synthesized via O-Alkylation Reaction with Different Degrees of Substitution: Rheology and Thermal Stability.

This paper presents the methodology for synthesizing and characterizing two carboxymethyl EOR-grade Scleroglucans (CMS-A and CMS-B). An O-Alkylation reaction was used to insert a hydrophilic group (monochloroacetic acid-MCAA) into the biopolymer's anhydroglucose subunits (AGUs). The effect of the degree of the carboxymethyl substitution on the rheology and thermal stability of the Scleroglucan (SG) was also evaluated. Simultaneous thermal analysis (STA/TGA-DSC), differential scanning calorimetry (DSC), X-ray Diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscopy, and Energy Dispersive Spectroscopy (SEM/EDS) were employed to characterize both CMS products. FTIR analysis revealed characteristic peaks corresponding to the carboxymethyl functional groups, confirming the modification. Also, SEM analysis provided insights into the structural changes in the polysaccharide after the O-Alkylation reaction. TGA results showed that the carboxymethylation of SG lowered its dehydroxylation temperature but increased its thermal stability above 300 °C. The CMS products and SG exhibited a pseudoplastic behavior; however, lower shear viscosities and relaxation times were observed for the CMS products due to the breakage of the SG triple helix for the chemical modification. Despite the viscosity results, the modified Scleroglucans are promising candidates for developing new engineering materials for EOR processes.

Automatic Urticaria Activity Score: Deep Learning-Based Automatic Hive Counting for Urticaria Severity Assessment.

Chronic urticaria is a chronic skin disease that affects up to 1% of the general population worldwide, with chronic spontaneous urticaria accounting for more than two-thirds of all chronic urticaria cases. The Urticaria Activity Score (UAS) is a dynamic severity assessment tool that can be incorporated into daily clinical practice, as well as clinical trials for treatments. The UAS helps in measuring disease severity and guiding the therapeutic strategy. However, UAS assessment is a time-consuming and manual process, with high interobserver variability and high dependence on the observer. To tackle this issue, we introduce Automatic UAS, an automatic equivalent of UAS that deploys a deep learning, lesion-detecting model called Legit.Health-UAS-HiveNet. Our results show that our model assesses the severity of chronic urticaria cases with a performance comparable to that of expert physicians. Furthermore, the model can be implemented into CADx systems to support doctors in their clinical practice and act as a new end point in clinical trials. This proves the usefulness of artificial intelligence in the practice of evidence-based medicine; models trained on the consensus of large clinical boards have the potential of empowering clinicians in their daily practice and replacing current standard clinical end points in clinical trials.

Automatic International Hidradenitis Suppurativa Severity Score System (AIHS4): A novel tool to assess the severity of hidradenitis suppurativa using artificial intelligence.

BACKGROUND: Hidradenitis suppurativa (HS) is a painful chronic inflammatory skin disease that affects up to 4% of the European adult population. International Hidradenitis Suppurativa Severity Score System (IHS4) is a dynamic scoring tool that was developed to be incorporated into the doctor's daily clinical practice and clinical studies. This helps measure disease severity and guides the therapeutic strategy. However, IHS4 assessment is a time-consuming and manual process, with high inter-observer variability and high dependence on the observer's expertise. MATERIALS AND METHODS: We introduce the Automatic International Hidradenitis Suppurativa Severity Score System (AIHS4), an automatic equivalent of IHS4 that deploys a deep learning model for lesion detection, called Legit.Health-IHS4net, based on the YOLOv5 architecture. AIHS4 was trained on Legit.Health-HS-IHS4, a collection of HS images manually annotated by six specialists and processed by a novel knowledge unification algorithm. RESULTS: Our results show that, with the current dataset size, our tool assesses the severity of HS cases with a performance comparable to that of the most expert physician. Furthermore, the model can be implemented into CADx systems to support doctors in their clinical practice and act as a new endpoint in clinical trials. CONCLUSION: Our work proves the potential usefulness of artificial intelligence in the practice of evidence-based dermatology: models trained on the consensus of large clinical boards have the potential to empower dermatologists in their daily practice and replace current standard clinical endpoints.

Bilateral vocal fold paralysis after COVID-19 infection. Another neuro-invasive manifestation? Case series / Parálisis bilateral de cuerdas vocales tras infección por COVID-19. ¿Una manifestación neuroinvasiva? Serie de casos

Abstract The agent that causes the coronavirus disease (COVID-19), associated with the severe acute respiratory syndrome (SARS-CoV-2), produces a spectrum of symptoms that mainly affect the respiratory system, the central nervous system (CNS), the regulation of hemostasis and the immune system. Bilateral vocal fold paralysis (BVFP) is a condition of unknown incidence among infected patients, either because it is short-lived or because of the difficulty in establishing a direct cause to the virus. Viral infection has been described in the literature as a cause of BVFP and there is the suspicion that a proportion of the idiopathic cases are due to undiagnosed viral infections. Although the neurotropic mechanisms for SARS-CoV-2 remain unclear, there is strong evidence to ensure its neuroinvasive potential. The most frequent etiologies of BVFP are trauma, neoplasm, and neurological, but a viral origin should not be ruled out. Causality between COVID-19 and BVFP is plausible and will require further study in the short and long term. We present a case series that support and discuss the hypothesis under consideration.

Resumen El agente causal de la enfermedad por coronavirus (COVID-19), asociado a síndrome respiratorio agudo grave (SARS-CoV-2), genera un espectro de síntomas que afectan fundamentalmente el sistema respiratorio, el sistema nervioso central (SNC), la regulación hemostásica y el sistema inmune. La parálisis bilateral de cuerdas vocales (PBCV) es una entidad cuya incidencia en infectados se desconoce, bien porque no se presentan durante el tiempo suficiente o por la dificultad de establecer una causalidad directa con el virus. La infección vírica, como causa de PBCV, está descrita en la literatura y se sospecha que una parte de los casos idiopáticos corresponden a infecciones víricas no diagnosticadas. Aunque los mecanismos neurotrópicos no están completamente aclarados para el SARS-CoV-2, existen indicios sólidos para asegurar su potencial neuroinvasivo. Las causas traumáticas, neoplásicas y neurológicas son las etiologías más comunes de PBCV, sin que se pueda descartar el origen vírico. Es plausible una causalidad entre el COVID-19 y la PBCV, que requerirá mayores estudios a corto y largo plazo. Presentamos una serie de casos que sostienen y discuten la hipótesis en consideración.

Plastic Surgery and Music: Examining Plastic Surgery References in Hit Songs.

The purpose of this study was to assess the frequency by which plastic surgery-related terms have been included in the lyrics of Western music hits from the 1970s to the present day as a proxy for estimating the cultural impact of plastic surgery. A list of the Billboard Year-End Hot 100 songs from 1968 to 2019 and the Billboard Year-End Hot R&B/Hip-Hop songs from 1970 to 2019 was obtained for a combined total of 8550 songs. Lyrics for each song were extracted via a web-scraping system, and a database of plastic surgery-related terms was developed by our team. Each term was then queried amongst the compiled lyrics data sets, and the total frequency of plastic surgery-related terms per year and per decade was determined. Each term was also examined in its context of usage to validate its relevance to plastic surgery and determine its connotation through sentiment analysis. The frequency of plastic surgery-related terms referenced in the Billboard Year-End Hot 100 and Billboard Year-End Hot R&B/Hip-Hop charts has increased 15-fold from the 1970s (n = 1 song) to 2010s (n = 15 songs). The terms most often mentioned included "doctor," "silicone," "plastic," "surgery," "nip-tuck," and "lipo." Artists who most frequently used plastic surgery-related terms were Kanye West, 2 Chainz, and Nicki Minaj. The current study is the first to evaluate trends in plastic surgery references in music formally. In turn, this study helps further our understanding of the interplay between plastic surgery and popular culture.

Adding a Social Risk Adjustment Into the Estimation of Efficiency: The Case of Chilean Hospitals.

BACKGROUND AND OBJECTIVES: There is much interest in adding social variables to hospital performance assessments. Many of the existing analyses, however, already include patients' diagnosis data, and it is not clear that adding a social adjustment variable would improve the quality of the results: the growing literature on this issue provides mixed results. The purpose in this study was to add evidence from a developing country into this discussion. METHODS: We estimate the efficiency of hospitals controlling for casemix, with and without adjusting the hospital's casemix for the patients' sociodemographic variables. The magnitude of the adjustment is based on the observed impact of age, sex, and income on length of stay, conditional on the diagnosis related group (DRG). We use a data envelopment analysis (DEA) to assess the efficiency of 50 Chilean hospitals' discharges, including 780 DRGs and covering about 60% of total discharges in Chile from 2013 to 2015. RESULTS: We found that the sociodemographic adjustment introduces very small changes in the DEA estimation of efficiency. The underlying reason is the relatively low influence of sociodemographics on hospital costs, conditional on DRG, and the changing pattern of sociodemographics across DRGs for any given hospital. CONCLUSION: We conclude that the casemix-adjusted estimation of hospital efficiency is robust to the heterogeneity of patients' sociodemographic heterogeneity across hospitals. These results confirm, in a developing country, what has been observed in developed countries. For management purposes, then, the processing costs of adding social variables into hospitals' performance assessments might not be justified.

Cost-effectiveness of Erenumab Versus Surgical Trigger Site Deactivation for the Treatment of Migraine Headaches: A Systematic Review.

BACKGROUND: Migraine headache is a common, debilitating condition responsible for astronomical societal burden. The chronicity of migraine headaches necessitates the use of many healthcare services. Preventative treatment remains the desirable option for this patient population. Pharmacologic advances have led to the development of erenumab, a monoclonal antibody calcitonin gene-related peptide receptor antagonist that directly interferes with the known biochemical pathway of migraine initiation. Alternatively, surgical decompression of migraine trigger sites is a historically effective preventative option for certain patients experiencing migraine headaches. As new treatments emerge, the large economic burden of migraine headaches requires cost evaluation against already available preventative modalities. METHODS: Studies evaluating the cost-effectiveness of both erenumab and surgical trigger site deactivation were found using EMBASE and MedLine. Relevant economic data was extracted from this literature and the cost of treatment with erenumab was compared with surgical decompression. RESULTS: The market price of erenumab is $6900/yr. Speculative models predicted a direct annual healthcare cost ranging from $11,404 to $12,988 for patients experiencing episodic migraine. For chronic migraine patients, this range extended to $25,604. Annual indirect costs ranged from $7601 to $19,377. Prospective and model-based studies evaluating surgical trigger site deactivation reported an average 1 time surgical cost between $6956 and $10,303. In episodic migraine, subsequent annual healthcare costs were $900. CONCLUSIONS: Erenumab has potential to be a revolutionary noninvasive preventative treatment for migraine headache. With that said, the cost-conscious option for patients receiving more than 1 year of treatment remains surgical trigger site deactivation.

Painless, inexpensive and non-permanent tattoo sticker for the eyebrow alopecia in children.

Children who suffer from scarring alopecia, especially in areas such as the eyebrows which are an important part in facial mimicry, are at risk of social stigmatization. Inexpensive, painless and non-permanent options are available for online purchase, which can be useful in such infants and children. Dermatologists should be aware of the availability of these product and could offer advice in this regard.

Standard photopatch test battery? Proposal based on current epidemiology and experience in our Skin Allergy Unit.

BACKGROUND: The diagnosis of photoallergic contact dermatitis (PACD) is confirmed by photopatch testing (PPT). In Spain, the latest recommendation on which allergens to test in PPT dates from 1995. METHODS: In the last 4 years, we studied 455 patients with epicutaneous tests and performed PPT on 33 of those patients (7.3%). RESULTS: The most prevalent allergens in PPT were as follows: non-steroidal anti-inflammatory drugs (NSAIDs) (46%), fragrances (21%), and solar filters (18%). DISCUSSION: In our country, the most common photoallergens continue to be NSAIDs (ketoprofen). The increasingly common use of sunscreens has led to a growing involvement of solar filters in PACD, which can be also contained in other cosmetics. In our experience, PACD due to fragrances is nonetheless at least similar in frequency. CONCLUSIONS: The PPT battery must adapt to the prescription, use, and exposure habits of each country. We propose a diagnostic model to guide which allergens to test in PPT, which in our experience should also include fragrances.

Health, childlessness and poverty in Latin American countries.

Recent literature proposes that poverty could lead women to remain childless, thus attenuating or reverting higher fertility typically observed among women of lower schooling level. We explore the role of health in this approach: does health have a distinctive detrimental effect on fertility among women of lower schooling levels? To that end, we compute the gap in the definite childlessness rate by self-reported disability status across schooling levels. Due to the scarcity of survey data from definite childless women, in addition to the small sample sizes, we use census samples. Focusing on women between 40-50 years old and using 23 census samples from Latin America countries (2000-2011), we found that only in the group with lower schooling level there is a clear gap in the definite childlessness rate by self-reported disability status. From our descriptive analysis we conclude that health could indeed play an influential role in the childless by poverty approach.

Health, childlessness and poverty in Latin American countries / Salud, no tener hijos y pobreza en países latino americanos / Saúde, mulheres sem filhos e pobreza em países da América Latina

Abstract: Recent literature proposes that poverty could lead women to remain childless, thus attenuating or reverting higher fertility typically observed among women of lower schooling level. We explore the role of health in this approach: does health have a distinctive detrimental effect on fertility among women of lower schooling levels? To that end, we compute the gap in the definite childlessness rate by self-reported disability status across schooling levels. Due to the scarcity of survey data from definite childless women, in addition to the small sample sizes, we use census samples. Focusing on women between 40-50 years old and using 23 census samples from Latin America countries (2000-2011), we found that only in the group with lower schooling level there is a clear gap in the definite childlessness rate by self-reported disability status. From our descriptive analysis we conclude that health could indeed play an influential role in the childless by poverty approach.

Resumen: La literatura reciente propone que la pobreza puede llevar a las mujeres a decidir no tener hijos, por lo que se atenúa o revierte la fertilidad, típicamente más alta, observada entre mujeres con formación educativa baja. Investigamos el papel de la salud en este planteamiento: ¿Tiene la salud un efecto distinto en la fertilidad entre mujeres con baja educación? Para tal fin, calculamos la brecha en la tasa de mujeres sin hijos según el estado de discapacidad autoinformado y nivel de educación. Debido a la escasez de datos sobre mujeres sin hijos en las encuestas, además del tamaño pequeño de las muestras, usamos muestras del censo. Centrándonos en mujeres con un intervalo de edad entre 40 y 50 años, y usando 23 muestras de censos de países latinoamericanos (2000-2011), hallamos que solo en el grupo con baja educación hay una clara brecha en la tasa de mujeres sin hijos según estado de discapacidad autoinformado. Desde nuestro análisis descriptivo concluimos que la salud puede jugar de hecho un papel influyente en la ausencia de hijos por el enfoque de pobreza.

Resumo: A literatura recente sugere que a pobreza pode fazer com que as mulheres permaneçam sem filhos, assim atenuando ou revertendo as taxas de fertilidade mais elevadas observadas tipicamente em mulheres com baixa escolaridade. O estudo investiga o papel da saúde nessa abordagem: A saúde tem efeito negativo discernível na fertilidade de mulheres com baixa escolaridade? Para responder a essa pergunta, calculamos a diferença na taxa de ausência definitiva de filhos de acordo com a infertilidade autorrelatada, entre diferentes níveis de escolaridade. Devido à escassez de dados sobre mulheres definitivamente sem filhos, além das amostras pequenas, utilizamos amostras censitárias. Com foco nas mulheres na faixa etária entre 40 e 50 anos, e utilizando 23 amostras censitárias de países latino-americanos (2000-2011), detectamos que apenas no grupo de baixa escolaridade, há uma defasagem clara na taxa de ausência definitiva de filhos de acordo com a infertilidade autorrelatada. Com base em nossa análise descritiva, concluímos que a saúde pode desempenhar um papel importante na análise da ausência de filhos em mulheres pobres.

Pseudolymphomatous Atypical Fibroxanthoma.

Atypical fibroxanthoma is a rare mesenchymal skin tumor of intermediate malignancy that typically occurs on sun-damaged skin of elderly patients. Histologically, it is composed of pleomorphic cells with hyperchromatic nuclei and abundant cytoplasm, commonly arranged in a spindle cell pattern. Different histologic variants have been described during the past years. We present a case of atypical fibroxanthoma containing a dense inflammatory infiltrate, which in conjunction with the existence of immunoblast-like and Reed-Sternberg-like neoplastic cells could be misinterpreted as a lymphoid neoplasm. Immunohistochemical studies revealed strong positivity of tumor cells for CD10 and negativity for cytokeratins, p63, p40, S100, SOX10, ERG, actin, desmin, B and T-cell markers, BCL6, CD15, and CD30. The inflammatory infiltrate contained a mixed reactive T- and B-cell population with negative T-cell receptor and immunoglobulin heavy rearrangements. We discuss the differential diagnosis of this entity in which clinical, immunohistochemical, and molecular features are essential to avoid the diagnosis of a lymphoproliferative disease.