Ubiquitous Order-Disorder Transition in the Mn Antisite Sublattice of the (MnBi2Te4)(Bi2Te3)n Magnetic Topological Insulators.

Magnetic topological insulators (TIs) herald a wealth of applications in spin-based technologies, relying on the novel quantum phenomena provided by their topological properties. Particularly promising is the (MnBi2Te4)(Bi2Te3)n layered family of established intrinsic magnetic TIs that can flexibly realize various magnetic orders and topological states. High tunability of this material platform is enabled by manganese-pnictogen intermixing, whose amounts and distribution patterns are controlled by synthetic conditions. Here, nuclear magnetic resonance and muon spin spectroscopy, sensitive local probe techniques, are employed to scrutinize the impact of the intermixing on the magnetic properties of (MnBi2Te4)(Bi2Te3)n and MnSb2Te4. The measurements not only confirm the opposite alignment between the Mn magnetic moments on native sites and antisites in the ground state of MnSb2Te4, but for the first time directly show the same alignment in (MnBi2Te4)(Bi2Te3)n with n = 0, 1 and 2. Moreover, for all compounds, the static magnetic moment of the Mn antisite sublattice is found to disappear well below the intrinsic magnetic transition temperature, leaving a homogeneous magnetic structure undisturbed by the intermixing. The findings provide a microscopic understanding of the crucial role played by Mn-Bi intermixing in (MnBi2Te4)(Bi2Te3)n and offer pathways to optimizing the magnetic gap in its surface states.

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.

Characteristics of tracheostomized patients followed up by a Palliative Care and Complex Chronic Patient Service.

INTRODUCTION AND OBJECTIVES: In recent years, there has been an increase in the number of children with tracheostomies. The objective was to describe the characteristics of paediatric patients with a tracheostomy followed up by the Department of Palliative Care and Chronic Medically Complex Illness (DPCCMCI) of a tertiary care hospital. METHODS: Single-centre retrospective observational study in patients aged less than 18 years with a tracheostomy followed up by the PCCCPS of a tertiary care hospital (November 2020-June 2022). We analysed epidemiological, clinical, microbiological and social data by reviewing the health records. RESULTS: The sample included 44 tracheostomized patients. The most frequent underlying disease was acquired upper airway disease (20.5%). The most common indication for tracheostomy was upper airway obstruction (66%). Bacterial isolates were detected in 84% of the tracheal aspirates, among which P. aeruginosa was the most frequent (56.8%). The most frequently prescribed antibiotic was ciprofloxacin (84%). In addition, 18.1% of the patients received at least 1 course of intravenous antibiotherapy and 29.5% received more than 3 systemic antibiotic regimens in the past 20 months. Fifty-nine percent of the children were schooled: 38.6% attended a regular school, 15.9% a special needs school and 4.5% were home-schooled. We identified social difficulties in 53.7%. Also, 22.7% of the families received financial support to care for a child with severe illness. CONCLUSIONS: Because of the complexity of caring for tracheostomized children, integral and coordinated management is essential. Schooling is possible and safe if caregivers are trained.

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.

Simulation-based education in neurology: lessons from the COVID-19 pandemic.

OBJECTIVES: The COVID-19 pandemic has led to the disruption of all sectors of the economy including education. According to UNESCO over 1.37 million young people including medical students, were affected by the lockdowns in response to COVID-19 and the subsequent closure of the education system. The primary challenge for medical education was to provide clerkships in a biosafety environment. This study aimed to determine the impact of a simulated hospital in a neurology clerkship of 5-year medical students during the coronavirus pandemic and compare their results with a non-pandemic group in Bogotá, Colombia. RESULTS: The students in the pandemic group answered a Likert scale survey regarding their satisfaction with the simulated hospital. Both groups were required to perform an oral, mid-term and final examination. From the results, it is clear that students perceived that exposure to a simulated hospital facilitated their learning process (93.1%) and allowed greater interaction with the teacher compared to a face-to-face environment (77.3%). There were no clinically significant differences in test results. This experience indicates that a simulated hospital is a valuable method to acquire clinical skills in trainees, that could be integrated into the curricular milestones of medical education programs regardless of the pandemic.

Burden of respiratory failure in pediatric patients: Analysis of a prospective multicenter cohort in Bogotá, Colombia.

Background and Aims: The approach to the burden of disease is a demographic, economic, and a health problem, which requires the design and application of specific measures of cost of the disease, such as disability-adjusted life years (DALYs), to establish better public health policies in the pediatric population. The aim of this study is to approach the burden of disease in children with acute respiratory failure (ARF) through the calculation of DALYs. Methods: This study was conducted in the framework of a prospective, multicenter cohort in Bogotá, Colombia. Inclusion criteria were all pediatric patients admitted to the emergency department, hospitalization, and intensive care unit with respiratory distress; eligible patients were all those who developed ARF between April 2020 and December 2021. They were followed-up during hospitalization, at 30 and 60 days after admission. The Infant/Toddler Quality of Life Questionnaire and KIDSCREEN quality of life scales were applied for follow-up according to the age group. The results were used to calculate DALYs. Results: Six hundred and eighty-five eligible patients, 296 (43.08%) developed ARF, of these 22 (6.08%) patients died (mortality rate = 7.43%). The total DALYs was 277.164 years. For younger than 9 years, the DALYs were 302.64 years, while for older than 10 years were 40.49 years. Conclusion: ARF is one of the main causes of preventable mortality in pediatrics, its progression to respiratory failure is a highly prevalent condition in pediatric age, a condition that has a great impact on mortality, morbidity, and disability in our patients.

An immunostimulatory glycolipid that blocks SARS-CoV-2, RSV, and influenza infections in vivo.

Prophylactic vaccines for SARS-CoV-2 have lowered the incidence of severe COVID-19, but emergence of viral variants that are antigenically distinct from the vaccine strains are of concern and additional, broadly acting preventive approaches are desirable. Here, we report on a glycolipid termed 7DW8-5 that exploits the host innate immune system to enable rapid control of viral infections in vivo. This glycolipid binds to CD1d on antigen-presenting cells and thereby stimulates NKT cells to release a cascade of cytokines and chemokines. The intranasal administration of 7DW8-5 prior to virus exposure significantly blocked infection by three different authentic variants of SARS-CoV-2, as well as by respiratory syncytial virus and influenza virus, in mice or hamsters. We also found that this protective antiviral effect is both host-directed and mechanism-specific, requiring both the CD1d molecule and interferon-[Formula: see text]. A chemical compound like 7DW8-5 that is easy to administer and cheap to manufacture may be useful not only in slowing the spread of COVID-19 but also in responding to future pandemics long before vaccines or drugs are developed.

Synthesis and Characterization of Oxide Chloride Sr2VO3Cl, a Layered S = 1 Compound.

The mixed-anion compound with composition Sr2VO3Cl has been synthesized for the first time, using the conventional high-temperature solid-state synthesis technique in a closed silica ampule under inert conditions. This compound belongs to the known Sr2 TmO3Cl (Tm = Sc, Mn, Fe, Co, Ni) family, but with Tm = V. All homologues within this family can be described with the tetragonal space group P4/nmm (No. 129); from a Rietveld refinement of powder X-ray diffraction data on the Tm = V homologue, the unit cell parameters were determined to a = 3.95974(8) and c = 14.0660(4) Å, and the atomic parameters in the crystal structure could be estimated. The synthesized powder is black, implying that the compound is a semiconductor. The magnetic investigations suggest that Sr2VO3Cl is a paramagnet at high temperatures, exhibiting a µeff = 2.0 µB V-1 and antiferromagnetic (AFM) interactions between the magnetic vanadium spins (θCW = -50 K), in line with the V-O-V advantageous super-exchange paths in the V-O layers. Specific heat capacity studies indicate two small anomalies around 5 and 35 K, which however are not associated with long-range magnetic ordering. 35Cl ss-NMR investigations suggest a slow spin freezing below 4.2 K resulting in a glassy-like spin ground state.

Intermixing-Driven Surface and Bulk Ferromagnetism in the Quantum Anomalous Hall Candidate MnBi6 Te10.

The recent realizations of the quantum anomalous Hall effect (QAHE) in MnBi2 Te4 and MnBi4 Te7 benchmark the (MnBi2 Te4 )(Bi2 Te3 )n family as a promising hotbed for further QAHE improvements. The family owes its potential to its ferromagnetically (FM) ordered MnBi2 Te4 septuple layers (SLs). However, the QAHE realization is complicated in MnBi2 Te4 and MnBi4 Te7 due to the substantial antiferromagnetic (AFM) coupling between the SLs. An FM state, advantageous for the QAHE, can be stabilized by interlacing the SLs with an increasing number n of Bi2 Te3 quintuple layers (QLs). However, the mechanisms driving the FM state and the number of necessary QLs are not understood, and the surface magnetism remains obscure. Here, robust FM properties in MnBi6 Te10 (n = 2) with Tc ≈ 12 K are demonstrated and their origin is established in the Mn/Bi intermixing phenomenon by a combined experimental and theoretical study. The measurements reveal a magnetically intact surface with a large magnetic moment, and with FM properties similar to the bulk. This investigation thus consolidates the MnBi6 Te10 system as perspective for the QAHE at elevated temperatures.

Embarazo postmanga gástrica en pacientes con irregularidades menstruales / Pregnancy after gastric sleeve in patients with menstrual irregularities

Resumen OBJETIVO: Estimar la cantidad de pacientes con irregularidades menstruales que se embarazaron luego de una cirugía bariátrica (manga gástrica) y describir los desenlaces de los embarazos. MATERIALES Y MÉTODOS: Estudio retrospectivo de serie de casos de pacientes obesas y con irregularidades menstruales intervenidas mediante cirugía bariátrica (manga gástrica). Se operaron entre el 1 de junio de 2014 y el 31 de diciembre de 2019 en el Centro Médico Imbanaco Cali, Colombia. RESULTADOS: De 1418 cirugías bariátricas, tipo manga gástrica, 117 pacientes cumplieron con los criterios de inclusión, 80 de ellas se localizaron telefónicamente y aceptaron incluirse al estudio. Luego de la manga gástrica, el 86.25% (n = 69) de las pacientes logró la regularización de sus ciclos menstruales. Además, el 31% (n = 25) consiguió el embarazo, 80% (n = 20) de ellas tenían la intención de buscar el embarazo. Los desenlaces de esos embarazos fueron favorables, con partos a término, con adecuado peso y talla al nacer. CONCLUSIONES: Después de la cirugía bariátrica, tipo manga gástrica, en mujeres con irregularidades menstruales, 25 de las 80 pacientes se embarazaron y los desenlaces obstétricos fueron satisfactorios. Sin duda, hacen falta más estudios prospectivos para poder afirmar, con una mejor representación estadística, las repercusiones de la disminución del peso corporal en la tasa de fertilidad.

Abstract OBJECTIVE: To estimate the number of patients with menstrual irregularities who became pregnant after bariatric surgery (gastric sleeve) and to describe the pregnancy outcomes. MATERIALS AND METHODS: Retrospective study of a series of cases of obese patients with menstrual irregularities who underwent bariatric surgery (gastric sleeve). They were operated between June 1, 2014 and December 31, 2019 at the Imbanaco Cali Medical Center, Colombia. RESULTS: Of 1418 bariatric surgeries, gastric sleeve type, 117 patients met the inclusion criteria, 80 of them were located by telephone and agreed to be included in the study. After gastric sleeve, 86.25% (n = 69) of the patients achieved regularization of their menstrual cycles. In addition, 31% (n = 25) achieved pregnancy, 80% (n = 20) of them intended to seek pregnancy. The outcomes of these pregnancies were favorable, with full-term deliveries, with adequate weight and height at birth. CONCLUSIONS: After bariatric surgery, gastric sleeve type, in women with menstrual irregularities, 25 of the 80 patients became pregnant and the obstetric outcomes were satisfactory. Undoubtedly, more prospective studies are needed to be able to affirm, with a better statistical representation, the repercussions of the decrease in body weight on the fertility rate.

An antibody class with a common CDRH3 motif broadly neutralizes sarbecoviruses.

The devastation caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made clear the importance of pandemic preparedness. To address future zoonotic outbreaks due to related viruses in the sarbecovirus subgenus, we identified a human monoclonal antibody, 10-40, that neutralized or bound all sarbecoviruses tested in vitro and protected against SARS-CoV-2 and SARS-CoV in vivo. Comparative studies with other receptor-binding domain (RBD)-directed antibodies showed 10-40 to have the greatest breadth against sarbecoviruses, suggesting that 10-40 is a promising agent for pandemic preparedness. Moreover, structural analyses on 10-40 and similar antibodies not only defined an epitope cluster in the inner face of the RBD that is well conserved among sarbecoviruses but also uncovered a distinct antibody class with a common CDRH3 motif. Our analyses also suggested that elicitation of this class of antibodies may not be overly difficult, an observation that bodes well for the development of a pan-sarbecovirus vaccine.

An approach to the integration of beach litter data from official monitoring programmes and citizen science.

Marine litter on Spanish beaches is assessed through two monitoring programmes: the Official Monitoring Programme of Marine Litter on Beaches (BM-1) developed by the Spanish Ministry for the Ecological Transition and the Demographic Challenge and the Citizen Science Monitoring Programme (BM-7) that provides beach litter data from voluntary clean-up initiatives. So far, the data provided by both programmes have been analysed separately although their integration could improve the assessment of the situation of Spanish beaches regarding marine litter. To this end, this paper studies the possible integration of both datasets through the calculation of a baseline value for marine litter on Spanish beaches. Statistical analysis of data shows that both datasets produce similar values and also integrate in a consistent way to achieve a value of 128 items/100 m as a baseline value for beach litter in Spain.

Morphological and Structural Properties of Amino-Functionalized Fumed Nanosilica and Its Comparison with Nanoparticles Obtained by Modified Stöber Method.

In industry, silica nanoparticles (NPs) are obtained by the fuming and the precipitation method. Fumed silica NPs are commonly used in the preparation of nanocomposites because they have an extremely low bulk density (160-190 kg/m3), large surface area (50-600 m2/g), and nonporous surface, which promotes strong physical contact between the NPs and the organic phase. Fumed silica has fewer silanol groups (Si-OH) on its surface than the silica prepared by the Stöber method. However, the number of -OH groups on the fumed silica surface can be increased by pretreating them with sodium hydroxide (NaOH) before further surface modification. In this study, the effectiveness of the NaOH pretreatment was evaluated on commercial fumed silica NPs with a surface area of 200 m2/g. The number of surface -OH groups was estimated by potentiometric titration. The pretreated fumed NPs, and the precipitated NPs (prepared by the Stöber method) were modified with 3-aminopropyltriethoxysilane (APTES) to obtain A200S and nSiO2-APTES, respectively. The NPs were characterized using electron dispersive scanning (EDS), scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), BET (Brunauer-Emmett-Teller) analysis, and ζ-potential. XRD confirmed the presence of the organo-functional group on the surface of both NPs. After the amino-functionalization, the ζ-potential values of the nSiO2 and A200 changed from -35.5 mV and -14.4 mV to +26.2 mV and +11.76 mV, respectively. Consequently, we have successfully synthesized functionalized NPs with interesting, specific surface area and porosity (pore volume and size), which can be attractive materials for chemical and energy industries.

New Nanohybrid Based on Hydrolyzed Polyacrylamide and Silica Nanoparticles: Morphological, Structural and Thermal Properties.

In this study, a set of advanced characterization techniques were used to evaluate the morphological, structural, and thermal properties of a novel molecular hybrid based on silica nanoparticles/hydrolyzed polyacrylamide (CSNH-PC1), which was efficiently obtained using a two-step synthetic pathway. The morphology of the nanohybrid CSNH-PC1 was determined using scanning electron microscopy (SEM), dynamic light scattering (DLS), and nanotracking analysis (NTA) techniques. The presence of C, N, O, and Si atoms in the nanohybrid structure was verified using electron dispersive scanning (EDS). Moreover, the corresponding structural analysis was complemented using powder X-ray diffraction (XRD) and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FT-IR). The covalent bond between APTES-functionalized SiO2 nanoparticles (nSiO2-APTES), and the hydrolyzed polyacrylamide (HPAM) chain (MW ≈ 20.106 Da) was confirmed with high-resolution X-ray spectroscopy (XPS). Finally, the thermal properties of the nanohybrid were evaluated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results showed that the CSNH-PC1 has a spherical morphology, with sizes between 420-480 nm and higher thermal resistance compared to HPAM polymers without modification, with a glass transition temperature of 360 °C. The integration of these advanced characterization techniques implemented here shows promising results for the study and evaluation of new nanomaterials with multiple applications.

Peritoneal histoplasmosis. case report

ABSTRACT Introduction: Histoplasmosis is an opportunistic granulomatous fungal infection. Peritoneal histoplasmosis (PH) is a rare form of disseminated histoplasmosis (DH). Case description: A 44-year-old male patient with history of HIV infection, systemic lupus erythematosus with lupus nephritis, and chronic kidney disease on peritoneal dialysis, presented with recurrent ascites without clear etiology in the serial study of ascitic fluid. Contrast computed tomography of the abdomen showed a nonspecific peritoneal nodule, for which laparoscopy and biopsy were performed, identifying Histoplasma capsulatum infection. The subject received 15 days of in-hospital treatment with amphotericin B deoxycholate with good evolution, no recurrence of ascites, and indefinite outpatient management with itraconazole. Discussion: The first case of PH was described in 1970 but this is the first case reported in Colombia. Most cases of PH have been associated with peritoneal dialysis. Its diagnosis is based on the study of ascitic fluid and its treatment follows the guidelines of other forms DH. Conclusions: PH is a rare entity that requires high clinical suspicion, especially in immunocompromised patients.

RESUMEN Introducción. La histoplasmosis es una infección micótica oportunista granulomatosa. La histoplasmosis peritoneal (HP) es una forma rara de histoplasmosis diseminada (HD). Presentación del caso. Paciente masculino de 44 años con antecedentes de infección por VIH, lupus eritematoso sistémico con nefropatia lúpica y enfermedad renal crónica en diálisis peritoneal, quien presenta ascitis recurrente sin etiología en estudio seriado de líquido ascítico. Se realiza tomografía de abdomen contrastada que evidencia lesión peritoneal inespecífica, luego estudiada con laparoscopia y biopsia, documentándose infección por Histoplasma capsulatum. El sujeto recibe 15 días de tratamiento intrahospitalario con anfotericina B deoxicolato con buena evolución, sin recurrencia de ascitis, y continúa con manejo ambulatorio indefinido con itraconazol. Discusión. El primer caso de HP se describe en 1970 y el primero en Colombia es el que aquí se presenta. La mayoría de los casos de este tipo de infección se han asociado a diálisis peritoneal, su diagnóstico se basa en el estudio de líquido ascítico y su tratamiento depende de los lineamientos de otras formas de HD. Conclusiones. La HP es una entidad rara que requiere alta sospecha clínica, principalmente en pacientes con inmunocompromiso.

Spontaneous vulvar hematoma as a rare manifestation of congenital hypofibrinogenemia. case report

ABSTRACT Introduction: Congenital fibrinogen disorders are rare conditions in which there are quantitative and qualitative alterations of factor I; the vast majority of patients are asymptomatic. Case presentation: A 19-year-old female patient with a history of congenital hypofibrinogenemia presented with spontaneous vulvar hematoma along with hypotension, tachycardia, stupor and hematoma of 20cm in the right labium majus. On admission, the young woman had hemoglobin 6.6 g/dL, fibrinogen 74 mg/dL and prolonged clotting times. She received red blood cells transfusion and cryoprecipitates, followed by surgical drainage and intravenous fibrinogen replacement, adjusting the dose according to fibrinogen levels in plasma. The patient presented progressive improvement without hemorrhagic recurrence and fibrinogen levels within the target values until hospital discharge. Discussion: Afibrinogenemia and hypofibrinogenemia are part of the quantitative factor I disorders; in the first case, there is total absence of circulating fibrinogen, and in the second case the levels are below 150 mg/dL. Spontaneous vulvar hematoma as a severe hemorrhagic manifestation is not frequent in symptomatic patients; its treatment is based on fibrinogen replacement in an individualized manner and surgical management when required. Conclusion: Hypofibrinogenemia is a rare disease, and fibrinogen replacement is one of the mainstays of treatment.

RESUMEN Introducción. Los trastornos congénitos del fibrinógeno son una rara condición donde se presentan alteraciones cuantitativas y cualitativas del factor I, siendo asintomáticos la gran mayoría de pacientes. Presentación del caso. Paciente femenino de 19 años con antecedente de hipofibrinogenemia congénita, quien cursa con hematoma espontáneo en vulva y presenta hipotensión, taquicardia, estupor y hematoma de 20cm en labio mayor derecho. Al ingreso, la joven registra hemoglobina 6.6 g/dL, fibrinógeno 74 mg/dL y prolongación de tiempos de coagulación. Se transfunden glóbulos rojos y crioprecipitados; luego se hace drenaje quirúrgico y reposición de fibrinógeno ajustando dosis acorde a fibrinógeno plasmático. La paciente presenta mejoría progresiva sin recurrencia hemorrágica y niveles de fibrinógeno en metas hasta egreso hospitalario. Discusión. La afibrinogenemia y la hipofibrinogenemia hacen parte de los trastornos cuantitativos del factor I, con ausencia total para la primera y niveles <150 mg/dL para la segunda. El hematoma espontáneo de vulva como manifestación hemorrágica severa no es una presentación habitual en pacientes sintomáticos; su tratamiento se basa en la reposición de fibrinógeno de forma individualizada y manejo quirúrgico cuando sea requerido. Conclusión. La hipofibrinogenemia es una enfermedad rara, donde el reemplazo de fibrinógeno es uno de los pilares de tratamiento.

A review of polymer nanohybrids for oil recovery.

As oil fields go into their final stage of production, new technologies are necessary to sustain production and increase the recovery of the hydrocarbon. Chemical injection is an enhanced recovery technique, which focuses on increasing the effectiveness of waterfloods. However, the use of chemical flooding has been hampered by its relatively high cost and the adsorption of the injected chemicals onto the reservoir rocks. In recent years, nanofluids have been launched as an overall less expensive and more efficient alternative to other chemical agents. Nanoparticle inclusion is also proposed to mitigate polymer flooding performance limitations under harsh reservoir conditions. This review presents a comprehensive discussion of the most recent developments of polymer nanohybrids for oil recovery. First, the preparation methods of polymer nanohybrids are summarized and explained. Then, an explanation of the different mechanisms leading to improved oil recovery are highlighted. Finally, the current challenges and opportunities for future development and application of polymer nanohybrids for chemical flooding are identified.