A Survey of PAPR Techniques Based on Machine Learning.

Orthogonal Frequency Division Multiplexing (OFDM) is the modulation technology used in Fourth Generation (4G) and Fifth Generation (5G) wireless communication systems, and it will likely be essential to Sixth Generation (6G) wireless communication systems. However, OFDM introduces a high Peak to Average Power Ratio (PAPR) in the time domain due to constructive interference among multiple subcarriers, increasing the complexity and cost of the amplifiers and, consequently, the cost and complexity of 6G networks. Therefore, the development of new solutions to reduce the PAPR in OFDM systems is crucial to 6G networks. The application of Machine Learning (ML) has emerged as a promising avenue for tackling PAPR issues. Along this line, this paper presents a comprehensive review of PAPR optimization techniques with a focus on ML approaches. From this survey, it becomes clear that ML solutions offer customized optimization, effective search space navigation, and real-time adaptability. In light of the demands of evolving 6G networks, integration of ML is a necessity to propel advancements and meet increasing prerequisites. This integration not only presents possibilities for PAPR reduction but also calls for continued exploration to harness its potential and ensure efficient and reliable communication within 6G networks.

Neoadjuvant Chemotherapy Versus Upfront Surgery for Resectable Pancreatic Adenocarcinoma: An Updated Nationwide Study.

OBJECTIVE: The objective of this study was to assess the association of survival with neoadjuvant chemotherapy (NAC) in resectable pancreatic adenocarcinoma (PDAC). BACKGROUND: The early control of potential micrometastases and patient selection using NAC has been advocated for patients with PDAC. However, the role of NAC for resectable PDAC remains unclear. METHODS: Patients with clinical T1 and T2 PDAC were identified in the National Cancer Database from 2010 to 2017. Kaplan-Meier estimates, and Cox regression models were used to compare survival. To address immortal time bias, landmark analysis was performed. Interactions between preoperative factors and NAC were investigated in subgroup analyses. A propensity score analysis was performed to compare survival between multiagent NAC and upfront surgery. RESULTS: In total, 4041 patients were treated with upfront surgery and 1,175 patients were treated with NAC (79.4% multiagent NAC, 20.6% single-agent NAC). Using a landmark time of 6 months after diagnosis, patients treated with multiagent NAC had longer median overall survival compared with upfront surgery and single-agent NAC. (35.8 vs 27.1 vs 27.4 mo). Multiagent NAC was associated with lower mortality rates compared with upfront surgery (adjusted hazard ratio, 0.77; 95% CI, 0.70-0.85), whereas single-agent NAC was not. The association of survival with multiagent NAC were consistent in analyses using the matched data sets. Interaction analysis revealed that the association between multiagent NAC and a lower mortality rate did not significantly differ across age, facility type, tumor location, CA 19-9 levels, and clinical T/N stages. CONCLUSIONS: The findings suggest that multiagent NAC followed by resection is associated with improved survival compared with upfront surgery.

Genomics of Plasmodium vivax in Colombia reveals evidence of local bottle-necking and inter-country connectivity in the Americas.

Colombia aims to eliminate malaria by 2030 but remains one of the highest burden countries in the Americas. Plasmodium vivax contributes half of all malaria cases, with its control challenged by relapsing parasitaemia, drug resistance and cross-border spread. Using 64 Colombian P. vivax genomes collected between 2013 and 2017, we explored diversity and selection in two major foci of transmission: Chocó and Córdoba. Open-access data from other countries were used for comparative assessment of drug resistance candidates and to assess cross-border spread. Across Colombia, polyclonal infections were infrequent (12%), and infection connectivity was relatively high (median IBD = 5%), consistent with low endemicity. Chocó exhibited a higher frequency of polyclonal infections (23%) than Córdoba (7%), although the difference was not significant (P = 0.300). Most Colombian infections carried double pvdhfr (95%) and single pvdhps (71%) mutants, but other drug resistance mutations were less prevalent (< 10%). There was no evidence of selection at the pvaat1 gene, whose P. falciparum orthologue has recently been implicated in chloroquine resistance. Global population comparisons identified other putative adaptations. Within the Americas, low-level connectivity was observed between Colombia and Peru, highlighting potential for cross-border spread. Our findings demonstrate the potential of molecular data to inform on infection spread and adaptation.

Exercise-Induced Muscle Damage after a High-Intensity Interval Exercise Session: Systematic Review.

High-intensity interval training (HIIT) is considered an effective method to improve fitness and health indicators, but its high-intensity exercises and the mechanical and metabolic stress generated during the session can lead to the occurrence of exercise-induced muscle damage. Therefore, this study aimed to describe, by means of a systematic review, the effects of a single HIIT session on exercise-induced muscle damage. A total of 43 studies were found in the Medline/PubMed Science Direct/Embase/Scielo/CINAHL/LILACS databases; however, after applying the exclusion criteria, only 15 articles were considered eligible for this review. The total sample was 315 participants. Among them, 77.2% were men, 13.3% were women and 9.5 uninformed. Their age ranged from 20.1 ± 2 to 47.8 ± 7.5 years. HIIT protocols included running with ergometers (n = 6), CrossFit-specific exercises (n = 2), running without ergometers (n = 3), swimming (n = 1), the Wingate test on stationary bicycles (n = 2), and cycling (n = 1). The most applied intensity controls were %vVO2max, "all out", MV, MAV, Vmax, and HRreserve%. The most used markers to evaluate muscle damage were creatine kinase, myoglobin, and lactate dehydrogenase. The time for muscle damage assessment ranged from immediately post exercise to seven days. HIIT protocols were able to promote changes in markers of exercise-induced muscle damage, evidenced by increases in CK, Mb, LDH, AST, ALT, pain, and muscle circumference observed mainly immediately and 24 h after the HIIT session.

SiO2-Based Nanofluids for the Inhibition of Wax Precipitation in Production Pipelines.

Wax deposition in high-wax (waxy) crude oil has been an important challenge in the oil and gas industry due to the repercussions in flow assurance during oil extraction and transportation. However, the nanotechnology has emerged as a potential solution for the optimization of conventional wax removal and/or inhibition processes due to its exceptional performance in the alteration of wax morphology and co-crystallization behavior. In this sense, this study aims to study the performance of two commercial wax inhibitor treatments (WT1 and WT2) on the wax formation and crystallization due to the addition of SiO2 nanoparticles. Differential scanning calorimetry experiments and cold finger tests were carried out to study the effect of the WT on wax appearance temperature (WAT) and the wax inhibition efficiency (WIE) in a scenario with an initial temperature difference. In the first stage, the behavior of both WT in the inhibition of wax deposition was achieved, ranging in the concentration of the WT in the waxy crude (WC) oil from 5000 to 50,000 mg·L-1. Then, NanoWT was prepared by the addition of SiO2 nanoparticles on WT1 and WT2 for concentrations between 1000 and 500 mg·L-1, and the performance of the prepared NanoWT was studied at the best concentration of WIT in the absence of nanoparticles. Finally, the role of the nanofluid concentration in wax inhibition was accomplished for the best NanoWT. Selected NanoWT with nanoparticle dosage of 100 mg·L-1 added to WC oil at 5000 mg·L-1 displays reductions in WAT and WIE of 15.3 and 71.6 for NanoWT1 and -2.2 and 42.5% for NanoWT2. In flow loop experiments for the crude oil at temperatures above (30 °C) and below (16 °C), the WAT value indicates an increase of 8.3 times the pressure drops when the crude oil is flowing at a temperature below the WAT value. Therefore, when NanoWT1 is added to the crude oil, a reduction of 31.8% was found in the pressure drop in comparison with the scenario below the WAT value, ensuring the flow assurance in the pipeline in an unfavorable environment. Based on the pressure-drop method, a reduction greater than 5% in the wax deposit thickness confirms the wax deposition inhibitory character of the designed NanoWT.

Blood Flow Restriction Attenuates Muscle Damage in Resistance Exercise Performed Until Concentric Muscle Failure.

The present study aimed to evaluate whether blood flow restriction (BFR) can prevent exercise-induced muscle damage in resistance exercise (RE) performed until concentric muscle failure (CMF). Twenty healthy volunteers (25 ± 4 years, 80.4 ± 11.8 kg, 175 ± 8 cm) performed three sets of unilateral biceps curl exercise (40% of 1RM) with (RE + BFR) and without (RE) BFR until CMF. A third condition was to perform the same number of repetitions as RE + BFR without using BFR (matched). Performing fewer repetitions, RE + BFR caused muscle fatigue post-exercise as high as that caused by RE. In addition, the range of motion, upper arm circumference, pressure pain threshold, and maximal voluntary contraction were immediately affected by our exercise protocol with BFR, returning rapidly to basal values within 24 h, while in RE, muscle damage markers remained elevated until 48 h post-exercise. The same results were observed concerning serum creatine kinase and lactate dehydrogenase activity. Thus, BFR + RE performed until CMF attenuated muscle damage following similar metabolic stress to RE alone performed until CMF, with less work volume.

T-cell activation, senescence, and exhaustion in asymptomatic HIV/Leishmania infantum co-infection.

Background: Leishmania infantum is an opportunistic parasitic infection. An immunocompromised state increases the risk of converting asymptomatic infection to symptomatic visceral leishmaniasis (VL), which has a ~5% fatality rate even with treatment. HIV coinfection increases the risk of death from VL. Methods: A cross-sectional study was performed between 2014 and 2016 to determine the prevalence of L. infantum infection in HIV positive subjects residing in the state of Rio Grande do Norte, Brazil (n=1,372) and of these a subgroup of subjects were followed longitudinally. Subsequent incident cases of VL were ascertained from a public health database through 2018. A subgroup (n=69) of the cross-sectional study subjects was chosen to assess immune status (T cell activation, senescence, exhaustion) and outcome. The data were compared between asymptomatic HIV+/L. infantum+ (HIV/Leish), symptomatic visceral leishmaniasis (VL), recovered VL, DTH+ (Delayed-Type Hypersensitivity response - Leishmanin skin test), AIDS/VL, HIV+ only (HIV+), and Non-HIV/Non L. infantum infection (control subjects). Results: The cross-sectional study showed 24.2% of HIV+ subjects had positive anti-IgG Leishmania antibodies. After 3 years, 2.4% (8 of 333) of these HIV/Leish coinfected subjects developed AIDS/VL, whereas 1.05% (11 of 1,039) of HIV subjects with negative leishmania serology developed AIDS/VL. Poor adherence to antiretroviral therapy (p=0.0008) or prior opportunistic infections (p=0.0007) was associated with development of AIDS/VL. CD4+ (p=0.29) and CD8+ (p=0.38) T cells counts or viral load (p=0.34) were similar between asymptomatic HIV/Leish and HIV subjects. However, activated CD8+CD38+HLA-DR+ T cells were higher in asymptomatic HIV/Leish than HIV group. Likewise, senescent (CD57+) or exhausted (PD1+) CD8+ T cells were higher in asymptomatic HIV/Leish than in AIDS/VL or HIV groups. Conclusion: Although asymptomatic HIV/Leish subjects had normal and similar CD4+ and CD8+ T cells counts, their CD8+T cells had increased activation, senescence, and exhaustion, which could contribute to risk of developing VL.

Development of a Halochromic, Antimicrobial, and Antioxidant Starch-Based Film Containing Phenolic Extract from Jaboticaba Peel.

In this study, the antioxidant, antimicrobial, mechanical, optical, and barrier attributes of Solanum lycocarpum starch bio-based edible films incorporated with a phenolic extract from jaboticaba peel were investigated. Aiming to determine the effect of the polymers and the phenolic extract on the properties of the films, a three-factor simplex-lattice design was employed, and the formulation optimization was based on the produced films' antioxidant potential. The optimized formulation of the starch-PEJP film showed a reddish-pink color with no cracks or bubbles and 91% antioxidant activity against DPPH radical. The optimized starch-PEJP film showed good transparency properties and a potent UV-blocking action, presenting color variation as a function of the pH values. The optimized film was also considerably resistant and highly flexible, showing a water vapor permeability of 3.28 × 10-6 g m-1 h-1 Pa-1. The microbial permeation test and antimicrobial evaluation demonstrated that the optimized starch-PEJP film avoided microbial contamination and was potent in reducing the growth of Escherichia coli, Staphylococcus aureus, and Salmonella spp. In summary, the active starch-PEJP film showed great potential as an environmentally friendly and halochromic material, presenting antioxidant and antimicrobial properties and high UV-protecting activity.

Real-World Evidence of Neutralizing Monoclonal Antibodies for Preventing Hospitalization and Mortality in COVID-19 Outpatients.

BACKGROUND: Neutralizing monoclonal antibodies (mAbs) were authorized for the treatment of COVID-19 outpatients based on clinical trials completed early in the pandemic, which were underpowered for mortality and subgroup analyses. Real-world data studies are promising for further assessing rapidly deployed therapeutics. RESEARCH QUESTION: Did mAb treatment prevent progression to severe disease and death across pandemic phases and based on risk factors, including prior vaccination status? STUDY DESIGN AND METHODS: This observational cohort study included nonhospitalized adult patients with SARS-CoV-2 infection from November 2020 to October 2021 using electronic health records from a statewide health system plus state-level vaccine and mortality data. Using propensity matching, we selected approximately 2.5 patients not receiving mAbs for each patient who received mAb treatment under emergency use authorization. The primary outcome was 28-day hospitalization; secondary outcomes included mortality and hospitalization severity. RESULTS: Of 36,077 patients with SARS-CoV-2 infection, 2,675 receiving mAbs were matched to 6,677 patients not receiving mAbs. Compared with mAb-untreated patients, mAb-treated patients had lower all-cause hospitalization (4.0% vs 7.7%; adjusted OR, 0.48; 95% CI, 0.38-0.60) and all-cause mortality (0.1% vs 0.9%; adjusted OR, 0.11; 95% CI, 0.03-0.29) to day 28; differences persisted to day 90. Among hospitalized patients, mAb-treated patients had shorter hospital length of stay (5.8 vs 8.5 days) and lower risk of mechanical ventilation (4.6% vs 16.6%). Results were similar for preventing hospitalizations during the Delta variant phase (adjusted OR, 0.35; 95% CI, 0.25-0.50) and across subgroups. Number-needed-to-treat (NNT) to prevent hospitalization was lower for subgroups with higher baseline risk of hospitalization; for example, multiple comorbidities (NNT = 17) and not fully vaccinated (NNT = 24) vs no comorbidities (NNT = 88) and fully vaccinated (NNT = 81). INTERPRETATION: Real-world data revealed a strong association between receipt of mAbs and reduced hospitalization and deaths among COVID-19 outpatients across pandemic phases. Real-world data studies should be used to guide practice and policy decisions, including allocation of scarce resources.

Anatomic nomenclature and 3-dimensional regional model of the human ovary: call for a new paradigm.

The ovaries are the female gonads that are crucial for reproduction, steroid production, and overall health. Historically, the ovary was broadly divided into regions defined as the cortex, medulla, and hilum. This current nomenclature lacks specificity and fails to consider the significant anatomic variations in the ovary. Recent technological advances in imaging modalities and high-resolution omic analyses have brought about the need for revision of the existing definitions, which will facilitate the integration of generated data and enable the characterization of organ subanatomy and function at the cellular level. The creation of these high-resolution multimodal maps of the ovary will enhance collaboration and communication among disciplines and between clinicians and researchers. Beginning in March 2021, the Pediatric and Adolescent Gynecology Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development invited subject-matter experts to participate in a series of workshops and meetings to standardize ovarian nomenclature and define the organ's features. The goal was to develop a spatially defined and semantically consistent terminology of the ovary to support collaborative, team science-based endeavors aimed at generating reference atlases of the human ovary. The group recommended a standardized, 3-dimensional description of the ovary and an ontological approach to the subanatomy of the ovary and definition of follicles. This new greater precision in nomenclature and mapping will better reflect the ovary's heterogeneous composition and function, support the standardization of tissue collection, facilitate functional analyses, and enable clinical and research collaborations. The conceptualization process and outcomes of the effort, which spanned the better part of 2021 and early 2022, are introduced in this article. The institute and the workshop participants encourage researchers and clinicians to adopt the new systems in their everyday work to advance the overarching goal of improving human reproductive health.

Cost standard set program: moving forward to standardization of cost assessment based on clinical condition.

This communication piece is reporting the launching of the International Cost Standard set program, aiming to introduce standardized frameworks to measure costs for specific clinical conditions worldwide. A scientific committee including 16 international healthcare cost assessment experts from several countries, and International Consortium for Health Outcomes Measurement was formed to introduce the program. The committee got together in Lisbon for a first scientific meeting, followed by an international conference where time-driven activity-based costing applied studies were shared with the community. The cost standard set program start to offer instruments for people to measure with real-world data, the financial impact of having access to health technologies, improving the ability to evaluate inequity. Those advances might represent a paradigm shift in our ability to generate cost information on an individual level.

Extracts from Argentinian native plants reverse fluconazole resistance in Candida species by inhibiting the efflux transporters Mdr1 and Cdr1.

BACKGROUND: The development of multidrug resistance (MDR) associated with the overexpression of the efflux transporters Mdr1 and Cdr1 in Candida species impedes antifungal therapies. The urgent need for novel agents able to inhibit the function of both pumps, led us to evaluate this property in 137 extracts obtained from Argentinian plants. METHODS: The ability of the extracts to reverse efflux pump-mediated MDR was determined with an agar chemosensitization assay using fluconazole (FCZ) resistant Mdr1- and Cdr1-overexpressing clinical isolates of Candida albicans and Candida glabrata as well as Saccharomyces cerevisiae strains selectively expressing Mdr1 (AD/CaMDR1) or Cdr1 (AD/CaCDR1). The resistance-reversing activity of the most potent extracts was further confirmed using a Nile Red accumulation assay. RESULTS: Fifteen plant extracts overcame the FCZ resistance of Candida albicans 1114, which overexpresses CaMdr1 and CaCdr1, and AD/CaMDR1, with those from Acalypha communis and Solanum atriplicifolium being the most effective showing 4- to 16-fold reversal of resistance at concentrations ≥ 25 µg/mL. Both extracts, and to a lesser extent that from Pterocaulon alopecuroides, also restored FCZ sensitivity in CgCdr1-overexpressing C. glabrata 109 and in AD/CaCDR1 with fold reversal values ranging from 4 to 32 and therefore demonstrating a dual effect against Mdr1 and Cdr1. Both, A. communis and S. atriplicifolium extracts at concentrations ≥ 12.5 and ≥ 25 µg/mL, respectively, increased the intracellular Nile Red accumulation in all yeast strains overexpressing efflux pumps. CONCLUSIONS: The non-toxic and highly active extracts from A. communis and S. atripicifolium, provide promising sources of compounds for potentiating the antifungal effect of FCZ by blocking the efflux function of Mdr1 and Cdr1 transporters.

Neuroprotective Effect of Exogenous Galectin-1 in Status Epilepticus.

Intrahippocampal pilocarpine microinjection (H-PILO) induces status epilepticus (SE) that can lead to spontaneous recurrent seizures (SRS) and neurodegeneration in rodents. Studies using animal models have indicated that lectins mediate a variety of biological activities with neuronal benefits, especially galectin-1 (GAL-1), which has been identified as an effective neuroprotective compound. GAL-1 is associated with the regulation of cell adhesion, proliferation, programmed cell death, and immune responses, as well as attenuating neuroinflammation. Here, we administrated GAL-1 to Wistar rats and evaluated the severity of the SE, neurodegenerative and inflammatory patterns in the hippocampal formation. Administration of GAL-1 caused a reduction in the number of class 2 and 4 seizures, indicating a decrease in seizure severity. Furthermore, we observed a reduction in inflammation and neurodegeneration 24 h and 15 days after SE. Overall, these results suggest that GAL-1 has a neuroprotective effect in the early stage of epileptogenesis and provides new insights into the roles of exogenous lectins in temporal lobe epilepsy (TLE).

Cardiopulmonary Exercise Testing with Elastic Resistance: A New Reproducible Proposal for Determination of Ventilatory Thresholds and Maximum Oxygen Consumption.

To propose a new Cardiopulmonary Exercise Test with Elastic Resistance (CPxEL) and compare the physiological responses to conventional cardiopulmonary exercise test (CPx) performed on a treadmill. In addition, we tested the reproducibility of the CPxEL. Twenty-four physically active participants completed the CPx (first session) and CPxEL twice (second and third sessions) interspersed by seven days. A treadmill protocol with increments of 1km·h-1 every minute until exhaustion was used in CPx. The CPxEL consisted of performing alternating steps back-and-forth against an elastic resistance attached to a belt and an incremental protocol with 1 stage (S) per minute following a cadence of 200 bpm controlled by a metronome in an 8-stage rubber mat. First analysis: first ventilatory threshold (VT1) occurred at 69.7% and 75.3% of maximal heart rate (HRmax) and 53.5% and 65.7% of maximal oxygen consumption (V̇O2max). Second VT (VT2) occurred at 93.3% and 96.8% of the HRmax and 87.0% and 96.9% of V̇O2max for CPx and CPxEL, respectively. At exhaustion, V̇O2max, perceived exertion (BORG-CR10 and OMNI-RES EB), and test duration presented lower values for CPxEL (P < 0.05). Second analysis: VT1 occurred at warm-up (S0) (P = 0.731), VT2 occurred at S5 (P = 0.912), and the exhaustion occurred at S6 and S7 (P = 0.271) for CPxEL and retest, respectively. The intraclass correlation coefficient (ICC) for V̇O2max was 0.921 and for HRmax was 0.930. The CPxEL has good test-retest reproducibility and represents a possible and interesting add-on to determine maximal oxygen consumption, maximal heart rate, and second ventilatory threshold without using traditional ergometers.

Soft-Tissue, Rare Earth Element, and Molecular Analyses of Dreadnoughtus schrani, an Exceptionally Complete Titanosaur from Argentina.

Evidence that organic material preserves in deep time (>1 Ma) has been reported using a wide variety of analytical techniques. However, the comprehensive geochemical data that could aid in building robust hypotheses for how soft-tissues persist over millions of years are lacking from most paleomolecular reports. Here, we analyze the molecular preservation and taphonomic history of the Dreadnougtus schrani holotype (MPM-PV 1156) at both macroscopic and microscopic levels. We review the stratigraphy, depositional setting, and physical taphonomy of the D. schrani skeletal assemblage, and extensively characterize the preservation and taphonomic history of the humerus at a micro-scale via: (1) histological analysis (structural integrity) and X-ray diffraction (exogenous mineral content); (2) laser ablation-inductively coupled plasma mass spectrometry (analyses of rare earth element content throughout cortex); (3) demineralization and optical microscopy (soft-tissue microstructures); (4) in situ and in-solution immunological assays (presence of endogenous protein). Our data show the D. schrani holotype preserves soft-tissue microstructures and remnants of endogenous bone protein. Further, it was exposed to LREE-enriched groundwaters and weakly-oxidizing conditions after burial, but experienced negligible further chemical alteration after early-diagenetic fossilization. These findings support previous hypotheses that fossils that display low trace element uptake are favorable targets for paleomolecular analyses.

MG-Pe: A Novel Galectin-3 Ligand with Antimelanoma Properties and Adjuvant Effects to Dacarbazine.

Melanoma is a highly metastatic and rapidly progressing cancer, a leading cause of mortality among skin cancers. The melanoma microenvironment, formed from the activity of malignant cells on the extracellular matrix and the recruitment of immune cells, plays an active role in the development of drug resistance and tumor recurrence, which are clinical challenges in cancer treatment. These tumoral metabolic processes are affected by proteins, including Galectin-3 (Gal-3), which is extensively involved in cancer development. Previously, we characterized a partially methylated mannogalactan (MG-Pe) with antimelanoma activities. In vivo models of melanoma were used to observe MG-Pe effects in survival, spontaneous, and experimental metastases and in tissue oxidative stress. Analytical assays for the molecular interaction of MG-Pe and Gal-3 were performed using a quartz crystal microbalance, atomic force microscopy, and contact angle tensiometer. MG-Pe exhibits an additive effect when administered together with the chemotherapeutic agent dacarbazine, leading to increased survival of treated mice, metastases reduction, and the modulation of oxidative stress. MG-Pe binds to galectin-3. Furthermore, MG-Pe antitumor effects were substantially reduced in Gal-3/KO mice. Our results showed that the novel Gal-3 ligand, MG-Pe, has both antitumor and antimetastatic effects, alone or in combination with chemotherapy.

Development and Evaluation from Laboratory to Field Trial of a Dual-Purpose Fracturing Nanofluid: Inhibition of Associated Formation Damage and Increasing Heavy Crude Oil Mobility.

This study aims to develop and evaluate fracturing nanofluids from the laboratory to the field trial with the dual purpose of increasing heavy crude oil mobility and reducing formation damage caused by the remaining fracturing fluid (FF). Two fumed silica nanoparticles of different sizes, and alumina nanoparticles were modified on the surface through basic and acidic treatments. The nanoparticles were characterized by transmission electron microscopy, dynamic light scattering, zeta potential and total acidity. The rheological behavior of the linear gel and the heavy crude oil after adding different chemical nature nanoparticles were measured at two concentrations of 100 and 1000 mg/L. Also, the contact angle assessed the alteration of the rock wettability. The nanoparticle with better performance was the raw fumed silica of 7 nm at 1000 mg/L. These were employed to prepare a fracturing nanofluid from a commercial FF. Both fluids were evaluated through their rheological behavior as a function of time at high pressure following the API RP39 test, and spontaneous imbibition tests were carried out to assess the FF's capacity to modify the wettability of the porous media. It was possible to conclude that the inclusion of 7 nm commercial silica nanoparticles allowed obtaining a reduction of 10 and 20% in the two breakers used in the commercial fracture fluid formulation without altering the rheological properties of the system. Displacement tests were also performed on proppant and rock samples at reservoir conditions of overburden and pore pressures of 3200 and 1200 psi, respectively, while the temperature was set at 77 °C and the flow rate at 0.3 cm3/min. According to the effective oil permeability, a decrease of 31% in the damage was obtained. Based on these results, the fracturing nanofluid was selected and used in the first worldwide field application in a Colombian oil field with a basic sediment and water (BSW%) of 100 and without oil production. After two weeks of the hydraulic fracture operation, crude oil was produced. Finally, one year after this work, crude oil viscosity and BSW% kept showing reductions near 75% and 33%, respectively; and having passed two years, the cumulative incremental oil production is around 120,000 barrels.

Weight gain post-ART in HIV+ Latinos/as differs in the USA, Haiti, and Latin America.

Background: An obesity epidemic has been documented among adult Latinos/as in Latin America and the United States (US); however, little is known about obesity among Latinos/as with HIV (PWH). Moreover, Latinos/as PWH in the US may have different weight trajectories than those in Latin America due to the cultural and environmental contexts. We assessed weight and body mass index (BMI) trajectories among PWH initiating antiretroviral therapy (ART) across 5 countries in Latin America and the Caribbean and the US. Methods: ART-naÿve PWH ≥18 years old, enrolled in Brazil, Honduras, Mexico, Peru, and Haiti (sites within CCA-SAnet) and the US (NA-ACCORD) starting ART between 2000 and 2017, with at least one weight measured after ART initiation were included. Participants were classified according to site/ethnicity as: Latinos/as in US, non-Latinos/as in US, Haitians, and Latinos/as in Latin America. Generalized least squares models were used to assess trends in weight and BMI. Models estimating probabilities of becoming overweight/obese (BMI ≥25 kg/m2) and of becoming obese (BMI ≥30 kg/m2) post ART initiation for males and females were fit using generalized estimating equations with a logit link and an independence working correlation structure. Findings: Among 59,207 PWH, 9% were Latinos/as from Latin America, 9% Latinos/as from the US, 68% non-Latinos/as from the US and 14% were Haitian. At ART initiation, 29% were overweight and 14% were obese. Post-ART weight and BMI increases were steeper for Latinos/as in Latin America compared with other sites/ethnicities; however, BMI at 3-years post ART remained lower compared to Latinos/as and non-Latinos/as in the US. Among females, at 3-years post ART initiation the greatest adjusted probability of obesity was found among non-Latinas in the US (15·2%) and lowest among Latinas in Latin America (8.6%). Among males, while starting with a lower BMI, Latinos in Latin America had the greatest adjusted probability of becoming overweight or obese 3-years post-ART initiation. Interpretation: In the Americas, PWH gain substantial weight after ART initiation. Despite environmental and cultural differences, PWH in Latin America, Haiti and Latinos and non-Latinos in the US share similar BMI trajectories on ART and high probabilities of becoming overweight and obese over time. Multicohort studies are needed to better understand the burden of other metabolic syndrome components in PWH across different countries.

Parasite communities and their ecological implications: comparative approach on three sympatric clupeiform fish populations (Actinopterygii: Clupeiformes), off Rio de Janeiro, Brazil.

Fish parasite communities can be directly influenced by characteristics of host species. However, little is known about the host-parasite relationships in commercially important fish of the southeastern Atlantic. To address this knowledge gap, a comparative analysis of the parasite communities of three sympatric Clupeiformes was conducted. Cetengraulis edentulus (Engraulidae), Opisthonema oglinum (Clupeidae) and Sardinella brasiliensis (Clupeidae) were collected from an estuarine lagoon near Rio de Janeiro, Brazil. Prevalence, abundance and aggregation were estimated for infrapopulations; richness, diversity, evenness and dominance for infracommunities. The three component communities were compared using both quantitative and qualitative components. Canonical discriminant analysis was used to determine if a host population could be characterised by the component community of its parasites. Multivariate models revealed that host species, a proxy for diet and phylogenetic relationships, was the main factor influencing the composition of parasite infracommunities. Diet was found to be the main factor shaping the communities of endoparasites, in which digeneans were dominant and best indicator of host population. Ectoparasites (copepods, isopods and monogeneans) displayed strong host-specificity with some species restricted to a single host population. The similarity of the component communities of the two clupeid populations demonstrated the influence of host phylogeny. Parasite infracommunities exhibited low diversity and high dominance, with many taxa restricted to a single host species (specialists) and few occurring in more than one (generalists). Host phylogeny and by extension, diet, morphology and coevolution with parasites appear to be important factors in determining the host-parasite relationships of clupeiform fish in the southeastern Atlantic.