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1.
J Chem Phys ; 160(16)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38661197

RESUMO

The focus of our study is an in-depth investigation of the quantum effects associated with the surface tension and other thermodynamic properties of nanoscopic liquid drops. The behavior of drops of quantum Lennard-Jones fluids is investigated with path-integral Monte Carlo simulations, and the test-area method is used to determine the surface tension of the spherical vapor-liquid interface. As the thermal de Broglie wavelength, λB, becomes more significant, the average density of the liquid drop decreases, with the drop becoming mechanically unstable at large wavelengths. As a consequence, the surface tension is found to decrease monotonically with λB, vanishing altogether for dominant quantum interactions. Quantum effects can be significant, leading to values that are notably lower than the classical thermodynamic limit, particularly for smaller drops. For planar interfaces (with infinite periodicity in the direction parallel to the interface), quantum effects are much less significant with the same values of λB but are, nevertheless, consequential for values representative of hydrogen or helium-4 at low temperatures corresponding to vapor-liquid coexistence. Large quantum effects are found for small drops of molecules with quantum interactions corresponding to water, ethane, methanol, and carbon dioxide, even at ambient conditions. The notable decrease in the density and tension has important consequences in reducing the Gibbs free-energy barrier of a nucleating cluster, enhancing the nucleation kinetics of liquid drops and of bubble formation. This implies that drops would form at a much greater rate than is predicted by classical nucleation theory.

2.
J Infect Dis ; 229(2): 403-412, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-37486790

RESUMO

BACKGROUND: Rhinovirus (RV) infections can progress from the upper (URT) to lower (LRT) respiratory tract in immunocompromised individuals, causing high rates of fatal pneumonia. Little is known about how RV evolves within hosts during infection. METHODS: We sequenced RV complete genomes from 12 hematopoietic cell transplant patients with infection for up to 190 days from both URT (nasal wash, NW) and LRT (bronchoalveolar lavage, BAL). Metagenomic and amplicon next-generation sequencing were used to track the emergence and evolution of intrahost single nucleotide variants (iSNVs). RESULTS: Identical RV intrahost populations in matched NW and BAL specimens indicated no genetic adaptation is required for RV to progress from URT to LRT. Coding iSNVs were 2.3-fold more prevalent in capsid over nonstructural genes. iSNVs modeled were significantly more likely to be found in capsid surface residues, but were not preferentially located in known RV-neutralizing antibody epitopes. Newly emergent, genotype-matched iSNV haplotypes from immunocompromised individuals in 2008-2010 could be detected in Seattle-area community RV sequences in 2020-2021. CONCLUSIONS: RV infections in immunocompromised hosts can progress from URT to LRT with no specific evolutionary requirement. Capsid proteins carry the highest variability and emergent mutations can be detected in other, including future, RV sequences.


Assuntos
Infecções por Enterovirus , Transplante de Células-Tronco Hematopoéticas , Humanos , Proteínas do Capsídeo/genética , Capsídeo , Rhinovirus/genética , Mutação
3.
J Chem Phys ; 159(19)2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37982487

RESUMO

There is an ever increasing use of local density dependent potentials in the mesoscale modeling of complex fluids. Questions remain, though, about the dependence of the thermodynamic and structural properties of such systems on the cutoff distance used to calculate these local densities. These questions are particularly acute when it comes to the stability and structure of the vapor/liquid interface. In this article, we consider local density dependent potentials derived from an underlying van der Waals equation of state. We use simulation and density functional theory to examine how the bulk thermodynamic and interfacial properties vary with the cutoff distance, rc, used to calculate the local densities. We show quantitatively how the simulation results for bulk thermodynamic properties and vapor-liquid equilibrium approach the van der Waals limit as rc increases and demonstrate a scaling law for the radial distribution function in the large rc limit. We show that the vapor-liquid interface is stable with a well-defined surface tension and that the interfacial density profile is oscillatory, except for temperatures close to critical. Finally, we show that in the large rc limit, the interfacial tension is proportional to rc and, therefore, unlike the bulk thermodynamic properties, does not approach a constant value as rc increases. We believe that these results give new insights into the properties of local density dependent potentials, in particular their unusual interfacial behavior, which is relevant for modeling complex fluids in soft matter.

4.
ACS Appl Mater Interfaces ; 15(47): 55073-55081, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37967325

RESUMO

Self-healing materials inspire the next generation of multifunctional wearables and Internet of Things appliances. They expand the realm of thin film fabrication, enabling seamless conformational coverage irrespective of the shape complexity and surface geometry for electronic skins, smart textiles, soft robotics, and energy storage devices. Within this context, the layer-by-layer (LbL) technique is versatile for homogeneously dispersing materials onto various matrices. Moreover, it provides molecular level thickness control and coverage on practically any surface, with poly(ethylenimine) (PEI) and poly(acrylic acid) (PAA) being the most used materials primarily employed in self-healing LbL structures operating at room temperature. However, achieving thin film composites displaying controlled conductivity and healing ability is still challenging under ambient conditions. Here, PEI and PAA are mixed with conductive fillers (gold nanorods, poly(3,4-ethylene dioxythiophene): polystyrenesulfonate (PEDOT:PSS), reduced graphene oxides, and multiwalled carbon nanotubes) in distinct LbL film architectures. Electrical (AC and DC), optical (Raman spectroscopy), and mechanical (nanoindentation) measurements are used for characterizing composite structures and properties. A delicate balance among electrical, mechanical, and structural characteristics must be accomplished for a controlled design of conductive self-healing composites. As a proof-of-concept, four LbL composites were chosen as sensing units in the first reported self-healing e-tongue. The sensor can easily distinguish basic tastes at low molar concentrations and differentiate trace levels of glucose in artificial sweat. The formed nanostructures enable smart coverages that have unique features for solving current technological challenges.

5.
J Infect Dis ; 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37769216

RESUMO

BACKGROUND: The incidence of syphilis continues to increase in the United States, yet little is known about Treponema pallidum genomic epidemiology within American metropolitan areas. METHODS: We performed whole-genome sequencing and tprK deep sequencing of 28 T. pallidum-containing specimens, collected mostly from remnant Aptima swab specimens from 24 individuals from Seattle Sexual Health Clinic during 2021-2022. RESULTS: All 12 individuals infected with Nichols-lineage strains were men who have sex with men, while a specific SS14 cluster (mean, 0.33 single-nucleotide variant) included 1 man who has sex with women and 5 women. All T. pallidum strains sequenced were azithromycin resistant via 23S ribosomal RNA A2058G mutation. Identical T. pallidum genomic sequences were found in pharyngeal and rectal swab specimens taken concurrently from the same individuals. The tprK sequences were less variable between patient-matched specimens and between epidemiologically linked clusters. We detected a 528-base pair deletion in the tprK donor site locus, eliminating 9 donor sites, in T. pallidum genomes of 3 individuals with secondary syphilis, associated with diminution of TprK diversity. CONCLUSIONS: We developed an end-to-end workflow for public health genomic surveillance of T. pallidum from remnant Aptima swab specimens. tprK sequencing may assist in linking cases beyond routine T. pallidum genome sequencing. T. pallidum strains with deletions in tprK donor sites currently circulate and are associated with diminished TprK antigenic diversity.

6.
Sci Rep ; 13(1): 14828, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37684291

RESUMO

Rectal cancer is an increasing disease worldwide. The outcomes of its treatment are related to the preoperative characteristics of the patient. The objective of this study was to describe sociodemographic, clinical and surgical characteristics and outcomes of patients operated on for rectal cancer at Hospital Universitario Mayor Méderi (HUM) during the period within 2013-2017.A retrospective descriptive cohort-type study was carried out by consulting the clinical records of patients above the age of 18 years with a clinical/histopathological diagnosis of rectal cancer and an institutional follow-up in those who underwent surgery with laparoscopic anterior resection of the rectum carried out by the coloproctology service of the HUM between 2013 and 2017. For statistical analysis, the SPSS V22 program was used.Data from 133 patients were collected during the study period, most of them male, with more frequent involvement of the lower rectum. Complications occurred in 25% of the patients. Conversion rate to open surgery was 8.6%, in-hospital death was associated with cardiovascular comorbidity, corticosteroid uses and with the presence of complications. Sociodemographic characteristics of the patients were similar to the world population. The institution has a low prevalence of anastomotic dehiscence, global complications are comparable with international statistics.


Assuntos
Hospitais , Neoplasias Retais , Humanos , Masculino , Adolescente , Colômbia/epidemiologia , Estudos Retrospectivos , Mortalidade Hospitalar , Neoplasias Retais/cirurgia
7.
Rev. colomb. gastroenterol ; 38(3)sept. 2023.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1535926

RESUMO

Intestinal spirochaetosis refers to the colonization of the colorectal epithelium by anaerobic spirochetes of the genus Brachyspira. It is more frequently identified in developing countries or when sanitation conditions are suboptimal. It can affect anyone, although it is more common in gay men, particularly those infected with the human immunodeficiency virus (HIV). Its most common symptom is chronic watery diarrhea. A colonoscopy may be expected. We present the clinical case of a young male patient with chronic diarrhea of several years of evolution resolved by specific treatment. In addition, a review of the literature on this disease is provided.


La espiroquetosis intestinal se define como la colonización del epitelio colorrectal por espiroquetas anaerobias del género Brachyspira. Se identifica con mayor frecuencia en países en vías de desarrollo o cuando las condiciones de salubridad son subóptimas. Puede afectar a cualquier persona, aunque es más común en hombres homosexuales particularmente infectados por virus de la inmunodeficiencia humana (VIH). Su síntoma más frecuente es la diarrea crónica acuosa. La colonoscopia puede ser normal. Se presenta el caso clínico de un paciente masculino joven con diarrea crónica de varios años de evolución que se resuelve al brindar tratamiento específico. Además, se realiza, una revisión de la literatura sobre esta enfermedad.

8.
J Chem Phys ; 159(5)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37526165

RESUMO

For industrial applications of self-assembled wormlike micelles, measurement and characterization of a micellar material's microstructure and rheology are paramount for the development and deployment of new high-performing and cost-effective formulations. Within this workflow, there are significant bottlenecks associated with experimental delays and a lack of transferability of results from one chemistry to another. In this work, we outline a process to predict microscopic and thermodynamic characteristics of wormlike micelles directly from rheological data by combining a more robust and efficient fitting algorithm with a recently published constitutive model called the Toy Shuffling model [J. D. Peterson and M. E. Cates, J. Rheol. 64, 1465-1496 (2020) and J. D. Peterson and M. E. Cates, J. Rheol. 65, 633-662 (2021)]. To support this work, linear rheology measurements were taken for 143 samples comprising a common base formulation of commercial sodium lauryl ether sulfate, cocamidopropyl betaine, and salt (NaCl). The steady state zero shear viscosity evident in linear rheology was measured in duplicate via direct steady and oscillatory shear experiments. Fitting the collected data to the model, we found trends in the microstructural and thermodynamic characteristics that agree with molecular dynamics simulations. These trends validate our new perspective on the parameters that inform the study of the relationship between chemical formulation and rheology. This work, when implemented at scale, can potentially be used to inform and test strategies for predicting self-assembled micellar structures based on chemical formulation.

9.
J Chem Phys ; 159(2)2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37435943

RESUMO

The ability to predict transport properties of fluids, such as the self-diffusion coefficient and viscosity, has been an ongoing effort in the field of molecular modeling. While there are theoretical approaches to predict the transport properties of simple systems, they are typically applied in the dilute gas regime and are not directly applicable to more complex systems. Other attempts to predict transport properties are performed by fitting available experimental or molecular simulation data to empirical or semi-empirical correlations. Recently, there have been attempts to improve the accuracy of these fittings through the use of Machine-Learning (ML) methods. In this work, the application of ML algorithms to represent the transport properties of systems comprising spherical particles interacting via the Mie potential is investigated. To this end, the self-diffusion coefficient and shear viscosity of 54 potentials are obtained at different regions of the fluid-phase diagram. This data set is used together with three ML algorithms, namely, k-Nearest Neighbors (KNN), Artificial Neural Network (ANN), and Symbolic Regression (SR), to find correlations between the parameters of each potential and the transport properties at different densities and temperatures. It is shown that ANN and KNN perform to a similar extent, followed by SR, which exhibits larger deviations. Finally, the application of the three ML models to predict the self-diffusion coefficient of small molecular systems, such as krypton, methane, and carbon dioxide, is demonstrated using molecular parameters derived from the so-called SAFT-VR Mie equation of state [T. Lafitte et al. J. Chem. Phys. 139, 154504 (2013)] and available experimental vapor-liquid coexistence data.

10.
bioRxiv ; 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37214809

RESUMO

Background: Human rhinovirus (HRV) infections can progress from the upper (URT) to lower (LRT) respiratory tract in immunocompromised individuals, causing high rates of fatal pneumonia. Little is known about how HRV evolves within hosts during infection. Methods: We sequenced HRV complete genomes from 12 hematopoietic cell transplant patients with prolonged infection for up to 190 days from both URT (nasal wash, NW) and LRT (bronchoalveolar lavage, BAL) specimens. Metagenomic (mNGS) and amplicon-based NGS were used to study the emergence and evolution of intra-host single nucleotide variants (iSNVs). Results: Identical HRV intra-host populations in matched NW and BAL specimens indicated no genetic adaptation is required for HRV to progress from URT to LRT. Microbial composition between matched NW and BAL confirmed no cross-contamination during sampling procedure. Coding iSNVs were 2.3-fold more prevalent in capsid over non-structural genes, adjusted for length. iSNVs modeled onto HRV capsid structures were significantly more likely to be found in surface residues, but were not preferentially located in known HRV neutralizing antibody epitopes. Newly emergent, serotype-matched iSNV haplotypes from immunocompromised individuals from 2008-2010 could be detected in Seattle-area community HRV sequences from 2020-2021. Conclusion: HRV infections in immunocompromised hosts can progress from URT to LRT with no specific evolutionary requirement. Capsid proteins carry the highest variability and emergent mutations can be detected in other, including future, HRV sequences.

11.
Nanomaterials (Basel) ; 13(8)2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37110920

RESUMO

A numerical simulation is a valuable tool since it allows the optimization of both time and the cost of experimental processes for time optimization and the cost of experimental processes. In addition, it will enable the interpretation of developed measurements in complex structures, the design and optimization of solar cells, and the prediction of the optimal parameters that contribute to manufacturing a device with the best performance. In this sense, a detailed simulation study was carried out in this work by the Solar Cell Capacitance Simulator (SCAPS). In particular, we evaluate the influence of absorber and buffer thickness, absorber defect density, work function in back contact, Rs, Rsh, and carrier concentration on a CdTe/CdS cell to maximize its performance. Furthermore, the incorporation effect of ZnO:Al (TCO) and CuSCN (HTL) nanolayers was studied for the first time. As a result, the efficiency of the solar cell was maximized from 16.04% to 17.74% by increasing the Jsc and Voc. This work will play an essential role in enhancing the performance of CdTe-based devices with the best performance.

12.
PLoS Pathog ; 19(3): e1011259, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36940224

RESUMO

BACKGROUND: The TprK protein of the syphilis agent, Treponema pallidum subsp. pallidum (T. pallidum), undergoes antigenic variation in seven discrete variable (V) regions via non-reciprocal segmental gene conversion. These recombination events transfer information from a repertoire of 53 silent chromosomal donor cassettes (DCs) into the single tprK expression site to continually generate TprK variants. Several lines of research developed over the last two decades support the theory that this mechanism is central to T. pallidum's ability for immune avoidance and persistence in the host. Structural and modeling data, for example, identify TprK as an integral outer membrane porin with the V regions exposed on the pathogen's surface. Furthermore, infection-induced antibodies preferentially target the V regions rather than the predicted ß-barrel scaffolding, and sequence variation abrogates the binding of antibodies elicited by antigenically different V regions. Here, we engineered a T. pallidum strain to impair its ability to vary TprK and assessed its virulence in the rabbit model of syphilis. PRINCIPAL FINDINGS: A suicide vector was transformed into the wild-type (WT) SS14 T. pallidum isolate to eliminate 96% of its tprK DCs. The resulting SS14-DCKO strain exhibited an in vitro growth rate identical to the untransformed strain, supporting that the elimination of the DCs did not affect strain viability in absence of immune pressure. In rabbits injected intradermally with the SS14-DCKO strain, generation of new TprK sequences was impaired, and the animals developed attenuated lesions with a significantly reduced treponemal burden compared to control animals. During infection, clearance of V region variants originally in the inoculum mirrored the generation of antibodies to these variants, although no new variants were generated in the SS14-DCKO strain to overcome immune pressure. Naïve rabbits that received lymph node extracts from animals infected with the SS14-DCKO strain remained uninfected. CONCLUSION: These data further support the critical role of TprK in T. pallidum virulence and persistence during infection.


Assuntos
Sífilis , Animais , Coelhos , Treponema pallidum , Treponema , Variação Antigênica/genética , Anticorpos
13.
bioRxiv ; 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36711914

RESUMO

Background: The TprK protein of the syphilis agent, Treponema pallidum subsp. pallidum ( T. pallidum ), undergoes antigenic variation in seven discrete variable (V) regions via non-reciprocal segmental gene conversion. These recombination events transfer information from a repertoire of 53 silent chromosomal donor cassettes (DCs) into the single tprK expression site to continually generate TprK variants. Several lines of research developed over the last two decades support the theory that this mechanism is central to T. pallidum 's ability for immune avoidance and persistence in the host. Structural and modeling data, for example, identify TprK as an integral outer membrane porin with the V regions exposed on the pathogen's surface. Furthermore, infection-induced antibodies preferentially target the V regions rather than the predicted ß-barrel scaffolding, and sequence variation abrogates the binding of antibodies elicited by antigenically different V regions. Here, we engineered a T. pallidum strain to impair its ability to vary TprK and assessed its virulence in the rabbit model of syphilis. Principal findings: A suicide vector was transformed into the wild-type (WT) SS14 T. pallidum isolate to eliminate 96% of its tprK DCs. The resulting SS14-DC KO strain exhibited an in vitro growth rate identical to the untransformed strain, supporting that the elimination of the DCs did not affect strain viability in absence of immune pressure. In rabbits injected intradermally with the SS14-DC KO strain, generation of new TprK sequences was impaired, and the animals developed attenuated lesions with a significantly reduced treponemal burden compared to control animals. During infection, clearance of V region variants originally in the inoculum mirrored the generation of antibodies to these variants, although no new variants were generated in the SS14-DC KO strain to overcome immune pressure. Naïve rabbits that received lymph node extracts from animals infected with the SS14-DC KO strain remained uninfected. Conclusion: These data further support the critical role of TprK in T. pallidum virulence and persistence during infection. Author Summary: Syphilis is still endemic in low- and middle-income countries, and it has been resurgent in high-income nations, including the U.S., for years. In endemic areas, there is still significant morbidity and mortality associated with this disease, particularly when its causative agent, the spirochete Treponema pallidum subsp . pallidum ( T. pallidum ) infects the fetus during pregnancy. Improving our understanding of syphilis pathogenesis and T. pallidum biology could help investigators devise better control strategies for this serious infection. Now that tools to genetically manipulate this pathogen are available, we can engineer T. pallidum strains lacking specific genes or genomic regions known (or believed) to be associated with virulence. This approach can shed light on the role of the ablated genes or sequences in disease development using loss-of-function strains. Here, we derived a knockout (KO) T. pallidum mutant (SS14-DC KO ) impaired in its ability to undergo antigenic variation of TprK, a protein that has long been hypothesized to be central in evasion of the host immune response and pathogen persistence during infection. When compared to the WT isolate, which is still capable of antigenic variation, the SS14-DC KO strain is significantly attenuated in its ability to proliferate and to induce early disease manifestations in infected rabbits. Our results further support the importance of TprK antigenic variation in syphilis pathogenesis and pathogen persistence.

14.
Health Sci Rep ; 5(5): e788, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36090626

RESUMO

Background: Hartmann's procedure (HP) is used in surgical emergencies such as colonic perforation and colonic obstruction. "Temporary" colostomy performed during HP is not always reversed in part due to potential morbidity and mortality associated with reversal. There are several contributing factors for patients requiring a permanent colostomy following HP. Therefore, there is still some discussion about which technique to use. The aim of this study was to evaluate perioperative variables of patients undergoing Hartmann's reversal using a laparoscopic and open approach. Methods: The multicenter retrospective cohort study was done between January 2009 and December 2019 at 14 institutions globally. Patients who underwent Hartmann's reversal laparoscopic (LS) and open (OS) approaches were evaluated and compared. Sociodemographic, preoperative, intraoperative variables, and surgical outcomes were analyzed. The main outcomes evaluated were 30-day mortality, length of stay, complications, and postoperative outcomes. Results: Five hundred and two patients (264 in the LS and 238 in the OS group) were included. The most prevalent sex was male in 53.7%, the most common indication was complicated diverticular disease in 69.9%, and 85% were American Society of Anesthesiologist (ASA) II-III. Intraoperative complications were noted in 5.3% and 3.4% in the LS and OS groups, respectively. Small bowel injuries were the most common intraoperative injury in 8.3%, with a higher incidence in the OS group compared with the LS group (12.2% vs. 4.9%, p < 0.5). Inadvertent injuries were more common in the small bowel (3%) in the LS group. A total of 17.2% in the OS versus 13.3% in the LS group required intensive care unit (ICU) admission (p = 0.2). The most frequent postoperative complication was ileus (12.6% in OS vs. 9.8% in LS group, p = 0.4)). Reintervention was required mainly in the OS group (15.5% vs. 5.3% in LS group, p < 0.5); mortality rate was 1%. Conclusions: Laparoscopic Hartmann's reversal is safe and feasible, associated with superior clinical outcomes compared with open surgery.

15.
Phys Rev E ; 106(1-1): 014604, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35974591

RESUMO

By Molecular Dynamics simulation, we investigate the dynamics of isotropic fluids of colloidal nanotrimers whose interactions are described by varying the strength of attractive and repulsive terms of the Mie potential. To provide a consistent comparison between the systems described by different force fields, we determine the phase diagram and critical points of each system, characterize the morphology of high-density liquid phases at the same reduced temperature and density, and finally investigate their long-time relaxation dynamics. In particular, we detect an especially complex dynamics that reveals the existence of slow and fast nanotrimers and the resulting occurrence of non-Gaussianity, which develops at intermediate timescales. Deviations from Gaussianity are temporary and vanish within the timescales of the system's density fluctuations decay, when a Fickian-like diffusion regime is eventually observed.

16.
Insects ; 13(3)2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35323519

RESUMO

In the absence of entomological information, tools for predicting Anopheles spp. presence can help evaluate the entomological risk of malaria transmission. Here, we illustrate how species distribution models (SDM) could quantify potential dominant vector species presence in malaria elimination settings. We fitted a 250 m resolution ensemble SDM for Anopheles albimanus Wiedemann. The ensemble SDM included predictions based on seven different algorithms, 110 occurrence records and 70 model projections. SDM covariates included nine environmental variables that were selected based on their importance from an original set of 28 layers that included remotely and spatially interpolated locally measured variables for the land surface of Costa Rica. Goodness of fit for the ensemble SDM was very high, with a minimum AUC of 0.79. We used the resulting ensemble SDM to evaluate differences in habitat suitability (HS) between commercial plantations and surrounding landscapes, finding a higher HS in pineapple and oil palm plantations, suggestive of An. albimanus presence, than in surrounding landscapes. The ensemble SDM suggested a low HS for An. albimanus at the presumed epicenter of malaria transmission during 2018-2019 in Costa Rica, yet this vector was likely present at the two main towns also affected by the epidemic. Our results illustrate how ensemble SDMs in malaria elimination settings can provide information that could help to improve vector surveillance and control.

17.
Brain Struct Funct ; 227(3): 865-879, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34807302

RESUMO

Nervous systems respond with structural changes to environmental changes even in adulthood. In recent years, experience-dependent structural plasticity was shown not to be restricted to the cerebral cortex, as it also occurs at subcortical and even peripheral levels. We have previously shown that two populations of trigeminal nuclei neurons, trigeminothalamic barrelette neurons of the principal nucleus (Pr5), and intersubnuclear neurons in the caudal division of the spinal trigeminal nucleus (Sp5C) that project to Pr5 underwent morphometric and topological changes in their dendritic trees after a prolonged total or partial loss of afferent input from the vibrissae. Here we examined whether and what structural alterations could be elicited in the dendritic trees of the same cell populations in young adult rats after being exposed for 2 months to an enriched environment (EE), and how these changes evolved when animals were returned to standard housing for an additional 2 months. Neurons were retrogradely labeled with BDA delivered to, respectively, the ventral posteromedial thalamic nucleus or Pr5. Fully labeled cells were digitally reconstructed with Neurolucida and analyzed with NeuroExplorer. EE gave rise to increases in dendritic length, number of trees and branching nodes, spatial expansion of the trees, and dendritic spines, which were less pronounced in Sp5C than in Pr5 and differed between sides. In Pr5, these parameters returned, but only partially, to control values after EE withdrawal. These results underscore a ubiquity of experience-dependent changes that should not be overlooked when interpreting neuroplasticity and developing plasticity-based therapeutic strategies.


Assuntos
Núcleos do Trigêmeo , Vibrissas , Animais , Dendritos/fisiologia , Percepção , Ratos , Ratos Sprague-Dawley , Núcleos do Trigêmeo/fisiologia , Vibrissas/fisiologia
18.
Cienc. tecnol. salud ; 9(1): 19-40, 2022. il^c27
Artigo em Inglês | LILACS, DIGIUSAC, LIGCSA | ID: biblio-1390597

RESUMO

The hydrological network in the Lachuá Ecoregion (EL), Alta Verapaz, Guatemala, hosts high levels of biodiversity and supplies water to 44 Mayan communities. Despite this critical fact, this network has been threatened by scarcely monitored industrial activities including the rapidly expanding oil palm monoculture (Elaeis guineensisJacq). Regardless of Lachua's freshwaters importance, there is little information on how this monoculture impacts them. We compared water-quality properties from streams in oil palm plantations (P), paddock and milpa systems (M), and primary forests (F) in the EL. During 2015-2016, 13 rivers were sampled (5 times) for water temperature, pH, dissolved oxygen (DO), conductivity, hardness, chemical and biochemical oxygen demand (COD and BOD), and concentration of silica, nitrates, phosphates, and ammonia. Several parameters showed significant differences. P were 2.7 ºC and 1.8 ºC warmer than M and F and carried 1.4 mg/L more nitrates than F. F carried 10.8 mg/L and 11.8 mg/L more silica than M and P. M showed intermediate temperatures and silica concentrations, as well as 14.8 µS/cm and 8.9 µS/cm lower conductivities than P and F, respectively. Additionally, COD in M was 9.9 mg/L and 4.6 mg/L lower than P and F, respectively. We believe higher temperatures and lower silica in P are due to the loss of riparian forest and their role in buffering temperatures and recycling silicon. In addition, the existence of secondary forest (guamil) in M might explain the intermediate temperatures and silica concentrations. Our results highlight the contributions of forests to waterways and suggest potential water-quality depletion from the oil palm expansion in the EL.


La red hídrica en la Ecorregión Lachuá (EL), Alta Verapaz, Guatemala, alberga una alta biodiversidad y abastece de agua a 44 comunidades mayas. Sin embargo, recientemente se ha visto amenazada por actividades industriales escasamente monitoreadas, incluido el creciente monocultivo de palma africana (Elaeis guineensis Jacq) del cual se desconocen sus impactos en la EL. Este estudio explora la calidad del agua de arroyos en plantaciones de palma africana (P), bosques primarios (B), y sistemas de potrero y milpa (M) en Lachuá. Durante 2015-2016, se tomaron muestras de 13 ríos (5 veces) para medir la temperatura del agua, pH, oxígeno disuelto (OD), conductividad, dureza, demanda química y bioquímica de oxígeno (DQO y DBO) y la concentración de sílice, nitratos, fosfatos, y amoníaco. Varios parámetros mostraron diferencias significativas. P fue 2.7 ºC y 1.8 ºC más calientes que M y F y portó 1.4 mg/L más nitrato que F. F portó 10.8 mg/L y 11.8 mg/L más sílice que M y P. M mostró temperaturas y concentraciones de sílice intermedias y conductividades 14.8 µS/cm y 8.9 µS/cm menores que P y F. La DQO en M fue 9.9 mg/L y 4.6 mg/L menor que P y F. El aumento de temperatura y la disminución de sílice en P podría deberse a la pérdida de bosques ribereños los cuales amortiguan la tempe-ratura y reciclan el silicio. La presencia de bosque secundarios (guamil) en M podría explicar las temperaturas y las concentraciones de sílice intermedias resaltando la importancia de los bosques en la red hídrica. Se predice un posible deterioro en el agua resultado de la expansión de palma africana en la EL.


Assuntos
Humanos , Qualidade da Água , Produção Agrícola , Florestas , Elaeis guineensis , Rios , Silício/análise , Oxigênio Dissolvido , Dióxido de Silício , Biodiversidade , Análise da Demanda Biológica de Oxigênio , Nitratos/análise
19.
Cells ; 10(7)2021 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-34359856

RESUMO

Insulin-like growth factor 1 (IGF-1) deficiency is an ultrarare syndromic human sensorineural deafness. Accordingly, IGF-1 is essential for the postnatal maturation of the cochlea and the correct wiring of hearing in mice. Less severe decreases in human IGF-1 levels have been associated with other hearing loss rare genetic syndromes, as well as with age-related hearing loss (ARHL). However, the underlying mechanisms linking IGF-1 haploinsufficiency with auditory pathology and ARHL have not been studied. Igf1-heterozygous mice express less Igf1 transcription and have 40% lower IGF-1 serum levels than wild-type mice. Along with ageing, IGF-1 levels decreased concomitantly with the increased expression of inflammatory cytokines, Tgfb1 and Il1b, but there was no associated hearing loss. However, noise exposure of these mice caused increased injury to sensory hair cells and irreversible hearing loss. Concomitantly, there was a significant alteration in the expression ratio of pro- and anti-inflammatory cytokines in Igf1+/- mice. Unbalanced inflammation led to the activation of the stress kinase JNK and the failure to activate AKT. Our data show that IGF-1 haploinsufficiency causes a chronic subclinical proinflammatory age-associated state and, consequently, greater susceptibility to stressors. This work provides the molecular bases to further understand hearing disorders linked to IGF-1 deficiency.


Assuntos
Envelhecimento/patologia , Cóclea/patologia , Haploinsuficiência/genética , Perda Auditiva Provocada por Ruído/patologia , Inflamação/patologia , Fator de Crescimento Insulin-Like I/metabolismo , Animais , Limiar Auditivo , Biomarcadores/metabolismo , Morte Celular/genética , Cóclea/fisiopatologia , Citocinas/genética , Citocinas/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Perda Auditiva Provocada por Ruído/sangue , Perda Auditiva Provocada por Ruído/genética , Perda Auditiva Provocada por Ruído/fisiopatologia , Heterozigoto , Inflamação/sangue , Inflamação/genética , Inflamação/fisiopatologia , Fator de Crescimento Insulin-Like I/genética , Camundongos , Ruído , Estresse Oxidativo/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sinapses/metabolismo
20.
BMJ Case Rep ; 14(7)2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215633

RESUMO

We report a fifth case of a transverse colon primary synovial sarcoma. A 31-year-old man with history of grade I obesity presented to an outpatient clinic reporting 6 months of intermittent colicky abdominal pain associated with haematochezia and rectal bleeding. Colonoscopy reported a partially obstructive intraluminal tumour lesion located in the transverse colon. There was no evidence of metastatic disease in the extension studies, so the patient was admitted to the hospital for a laparoscopic subtotal colectomy. Histopathology demonstrated intermediate-grade synovial sarcoma. At the third year of follow-up, the patient presented metastases on the chest wall, which required extensive resection and complementary oncological management.


Assuntos
Colo Transverso , Sarcoma Sinovial , Parede Torácica , Adulto , Colectomia , Seguimentos , Humanos , Masculino , Sarcoma Sinovial/cirurgia
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