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1.
Health Aff (Millwood) ; 43(10): 1410-1419, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39374462

RESUMEN

Little is known about how long it takes for new medicines to reach countries with different income levels. We analyzed data, sourced from IQVIA, on the timing of new drug launches in seventy-five low-, middle-, and high-income markets from 1982 to 2024. The sample captured the majority of essential medicines (as designated by the World Health Organization in the twenty-third Model List of Essential Medicines) that first came into medical use anywhere globally from 1982 onward. Kaplan-Meier estimates were used to quantify delays in launches across countries. Our analysis comprised 119 medicines with 6,871 observed launches. Nearly three-quarters (74 percent) of first launches occurred in just eight countries (in order of the most first launches, the US, the Netherlands, Sweden, Switzerland, the United Kingdom, France, Germany, and Japan). From the first launch globally, the median time to availability was 2.7 years for high-income countries, 4.5 years for upper-middle-income countries, 6.9 years for lower-middle-income countries, and 8.0 years for low-income countries. The gap between richer (high- and upper-middle-income) and poorer (lower-middle- and low-income) countries remained largely unchanged over time. Strategies to address the disparities highlighted by this analysis are urgently needed.


Asunto(s)
Países en Desarrollo , Medicamentos Esenciales , Accesibilidad a los Servicios de Salud , Medicamentos Esenciales/provisión & distribución , Medicamentos Esenciales/economía , Humanos , Factores de Tiempo , Renta , Organización Mundial de la Salud
2.
Int J Parasitol Parasites Wildl ; 25: 100976, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39351490

RESUMEN

The Brazilian porcupine (Coendou prehensilis, Rodentia, Erethizontidae) is an arboreal South American nocturnal rodent. Switzerland is home to one of the largest captive colonies in Europe. In June 2022, most of the animals in this colony showed severe diarrhoea, and Giardia sp. cysts were detected. All the animals were treated with metronidazole (75 mg/animal/day orally) for five days, repeating after two weeks. The diarrhoea continued, sometimes containing blood, and further analyses revealed Giardia sp. cysts and Trichuris sp. eggs with a particular undulating eggshell in pooled samples. The soil layer of some enclosures was removed to thoroughly clean and disinfect the underlying concrete floor. The animals were treated with fenbendazole (50 mg/kg/day orally) for 5 days repeating after three days. Giardia sp. cysts were not further detected. However, Trichuris sp. eggs were detected in branch bark samples and in six animals 2-3 months after treatment. The treatment with fenbendazole was repeated and no further Trichuris sp. eggs were detected. A 18S rRNA fragment consensus sequence showed 98.58% identity with Trichuris fossor. The Trichuris sp. in C. prehensilis may represent a new species, specific for arboreal porcupines. Demodex mites were observed in faecal flotations and thereafter in skin scrapings from five animals (four of them being family-related). A 16S consensus sequence showed 86.4% identity with other Demodex species. The animals were initially treated with moxidectin (0.4 and 0.8 mg/kg orally) and afterwards with sarolaner (10 mg/animal) but the treatments were not completely effective since in control scrapings, two animals evidenced few non-motile mites. An individual susceptibility and poor immunological control of the infection is suggested. Treatment with fenbendazole was effective against Giardia sp. and Trichuris sp. infections; however, reinfections may occur if the enclosures and tree branches are not deep cleaned and disinfected or replaced.

3.
Parasit Vectors ; 17(1): 404, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39334428

RESUMEN

BACKGROUND: Leishmania infantum is endemic in Europe (and elsewhere) while L. donovani s.s., L. tropica and L. major are not but are present in neighboring countries in North Africa, the Middle East, (the Asian part of) Turkey and the Southern Caucasus. Lists of sand fly vector species in the scientific literature vary with the criteria for vector incrimination, and criteria vary because, for some, evidence is difficult to generate. With minimal criteria, about 20 sand fly species are proven or suspected vectors of L. infantum in Europe and neighboring countries, while for L. tropica and L. major, there are seven and four proven or suspected vector species, respectively, in this area. For L. donovani s.s., present in Cyprus, the Middle East and (the Asian part of) Turkey, no local vectors have been incriminated so far. The aim was to assess the degree of spatial agreement between Leishmania spp. and various vectors species and their relative contribution to the explained variation. METHODS: We used multivariate regression modeling to analyze the spatial relationship between autochthonous Leishmania spp. and clinical forms in humans and animals and 14 Phlebotomus spp. in Europe and neighboring countries. RESULTS: There was only fair agreement between parasite and vector distributions. The most parsimonious models describing the distribution of Leishmania spp. and clinical forms included three to six sand fly species and explained between 12% (L. infantum) and 37% (L. donovani) of the observed variation. Selected models included confirmed and suspected vector species as well as unexpected species. CONCLUSIONS: The relatively low agreement between Leishmania and vector distributions highlights the need to improve leishmaniasis reporting and vector surveillance in areas where no information is available, both for a better understanding of the epidemiology of infection in endemic areas and to monitor possible spread of infection into non-endemic areas. While some of the unexpected sand fly-Leishmania spp. statistical associations might be spurious, for others, the existence of sporadic or recent reports of infections warrants further vector competence studies that consider strain variation.


Asunto(s)
Insectos Vectores , Leishmania , Leishmaniasis , Animales , Europa (Continente)/epidemiología , Leishmaniasis/epidemiología , Leishmaniasis/transmisión , Insectos Vectores/parasitología , Insectos Vectores/clasificación , Leishmania/clasificación , Humanos , Psychodidae/parasitología , Psychodidae/clasificación , Medio Oriente/epidemiología , Phlebotomus/parasitología , Phlebotomus/clasificación , Turquía/epidemiología
4.
Heredity (Edinb) ; 133(4): 238-248, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39090317

RESUMEN

Selfing or mating between related individuals can lead to inbreeding depression (ID), which can influence the survival, growth and evolution of populations of tree species. As selective logging involves a decrease in the density of congeneric partners, it could lead to increasing biparental inbreeding or self-fertilization, exposing the population to higher ID. We assessed the influence of inbreeding on the growth of a commercial timber species, Pericopsis elata (Fabaceae), which produced about 54% of self-fertilized seedlings in a natural population of the Congo basin. We followed the survival and growth of 540 plants raised in a plantation along a gradient of plant density (0.07-15.9 plants per m2). Parentage analysis allowed us distinguishing selfed and outcrossed seedlings. The annual growth was higher for outcrossed than selfed plants, on average by 10.8% for diameter and 12.9% for height growth. Based on the difference in above ground biomass between selfed and outcrossed seedlings after 41 months, we estimated the level of ID at δ = 0.33, while a lifetime estimate of ID based on the proportions of selfed plants at seedling and adult stages led to δ = 0.7. The level of ID on growth rate did not change significantly with age but tended to vanish under high competition. Pericopsis elata is a particularly interesting model because inbreeding depression is partial, with about 26% of reproducing adults resulting from selfing, contrary to most tropical tree species where selfed individuals usually die before reaching adulthood. Hence, the risks of ID must be considered in the management and conservation of the species.


Asunto(s)
Depresión Endogámica , Plantones , Plantones/crecimiento & desarrollo , Plantones/genética , Fabaceae/genética , Fabaceae/crecimiento & desarrollo , Fabaceae/fisiología , Árboles/genética , Árboles/crecimiento & desarrollo , Reproducción/genética , Autofecundación , Congo , Endogamia
5.
Value Health ; 27(10): 1348-1357, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39154910

RESUMEN

OBJECTIVES: By September 2024, the Centers for Medicare and Medicaid Services (CMS) will publicly report the negotiated prices (Maximum Fair Prices) for the first 10 drugs selected for price negotiation. We estimate initial price offers based on net prices, statutorily defined ceilings, and comparative effectiveness data for the 10 drugs and their therapeutic alternatives. METHODS: We utilized net prices and other price benchmarks for the 10 drugs and their therapeutic alternatives. We searched for data on comparative clinical effectiveness for the primary indications. We outlined a range of plausible initial price offers based on CMS guidance and our interpretation of regulatory intent. RESULTS: For ibrutinib and ustekinumab, statutorily defined ceiling prices will likely determine the initial price offers. The integration of net pricing and clinical evidence from comparator branded products will inform the initial price offers for apixaban, empagliflozin, etanercept, and insulin aspart. Rivaroxaban and sacubitril/valsartan have therapeutic alternatives that are generics; therefore, CMS may apply a discount to current net prices. To achieve savings in the negotiation of dapagliflozin and sitagliptin, CMS will have to leverage additional negotiation factors because statutory defined ceilings and net prices of therapeutic alternatives are similar or higher. CONCLUSIONS: This analysis sheds light on important price benchmarks and clinical evidence factors for the determination of the initial price offers. Although we were not able to simulate the offer and counter-offer process, our findings provide a transparent and systematic way to produce initial offers that are consistent with CMS guidance.


Asunto(s)
Benchmarking , Costos de los Medicamentos , Estados Unidos , Humanos , Negociación , Centers for Medicare and Medicaid Services, U.S. , Medicare/economía , Investigación sobre la Eficacia Comparativa
6.
Biochem Pharmacol ; 229: 116464, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39111604

RESUMEN

CC chemokine receptor 2 and CCL2 are highly involved in cancer growth and metastasis, and immune escape. Raised sodium ion concentrations in solid tumours have also been correlated to metastasis and immune modulation. Sodium ions can modulate class A G protein-coupled receptors through the sodium ion binding site characterized by a highly conserved aspartic acid residue (D2.50), also present in CCR2. Hence, we further explored this binding site in CCR2 by radioligand binding studies and mutagenesis. Modulation of three distinctly binding radioligands by sodium ions and amiloride derivates was investigated. Sodium ions were observed to be relatively weak modulators of antagonist binding, but substantially increased 125I-CCL2 dissociation from CCR2. 6-Substituted Hexamethylene Amiloride (HMA) modulated all tested radioligands. Induced-fit docking of HMA in the presumed sodium ion binding site of CCR2 confirmed its binding site. Finally, investigation of (cancer-associated) mutations in the sodium ion binding site showed a markedly decreased expression compared to wild type. Only two mutants, G123A3.35 and G127K3.39, were able to be bound by [3H]INCB3344 and [3H]CCR2-RA-[R]. Thus, mutagenesis showed that the sodium ion binding site residues, which are distinct from other class A GPCRs and related to chemokine receptor evolution, are crucial for receptor integrity. Moreover, the tested mutations appeared to have no effect on modulation observed by HMA or a minor effect on sodium chloride modulation on the tested radioligands. All in all, these results invite further exploration of the CCR2 sodium ion binding site in (cancer) biology, and potentially as a third druggable binding site.

7.
Science ; 385(6709): 623-629, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39116218

RESUMEN

The upper mantle is critical for our understanding of terrestrial magmatism, crust formation, and element cycling between Earth's solid interior, hydrosphere, atmosphere, and biosphere. Mantle composition and evolution have been primarily inferred by surface sampling and indirect methods. We recovered a long (1268-meter) section of serpentinized abyssal mantle peridotite interleaved with thin gabbroic intrusions. We find depleted compositions with notable variations in mantle mineralogy controlled by melt flow. Dunite zones have predominantly intermediate dips, in contrast to the originally steep mantle fabrics, indicative of oblique melt transport. Extensive hydrothermal fluid-rock interaction is recorded across the full depth of the core and is overprinted by oxidation in the upper 200 meters. Alteration patterns are consistent with vent fluid composition in the nearby Lost City hydrothermal field.

8.
Pest Manag Sci ; 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39162038

RESUMEN

BACKGROUND: Fertiliser applications are well-established tools in pasture-based agricultural landscapes. This study focuses on the impact of phosphorus (P) fertiliser on grass grub (Costelytra giveni), a major pasture pest. This research investigates the interplay between P, plant growth, and grass grub fitness in Epichloë endophyte-infected perennial ryegrass (Epichloë sp. LpTG-3 strain AR37) and meadow fescue infected with E. uncinata (strain MaxR; AR1017), alongside their endophyte-free counterparts. In a glasshouse trial, plants were grown in P-enriched soil with varying Olsen P levels (9, 18, 28 or 78 mg L-1), and grass grubs were introduced. Their survival and weight gain, and plant performance were measured. In a bioassay, grass grubs were placed in specimen vials with P-enriched soils (Olsen P levels 9, 18, 28 and 78 mg L-1) and provided with identical plant material to assess their diet consumption and weight gain. RESULTS: In the glasshouse trial, results highlighted a notable decrease in the survival of grass grub on plants infected with MaxR endophyte, but not with AR37, as well as increasing soil Olsen P levels in both plant species. While grass grub decreased plant performance at the low Olsen P level (9 mg L-1), this effect diminished with increasing P. Likewise, results from the bioassay showed a decrease in diet consumption with increasing soil Olsen P levels. In both trials increasing Olsen P levels correlated with diminished grass grub performance, revealing a nuanced relationship between soil fertility and pest dynamics. CONCLUSION: The study underscores the pivotal role of selected Epichloë endophyte-grass associations in mitigating grass grub damage across varying phosphorus levels. This study highlights the potential to integrate P applications for sustainable pest control against grass grub. Further field trials are required to validate these findings. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

9.
JAMA Netw Open ; 7(8): e2426641, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39141388

RESUMEN

IMPORTANCE: Long-term survival data from clinical trials show that survival curves of patients with advanced melanoma treated with immune checkpoint inhibitors (ICIs) gradually reach a plateau, suggesting that patients have a chance of achieving long-term survival. OBJECTIVE: To investigate long-term survival in patients with advanced melanoma treated with ICIs outside clinical trials. DESIGN, SETTING, AND PARTICIPANTS: Cohort study using prospectively collected data from the nationwide Dutch Melanoma Treatment Registry, including patients in the Netherlands with advanced melanoma treated with first-line ICIs from 2012 to 2019. Data were analyzed from January to September 2023. EXPOSURES: Patients were treated with first-line ipilimumab-nivolumab, antibodies that target programmed cell death (anti-PD-1), or ipilimumab. MAIN OUTCOMES AND MEASURES: Progression-free survival (PFS) and melanoma-specific survival were analyzed, and a Cox proportional hazards model was used to investigate factors associated with PFS after reaching partial response (PR) or complete response (CR). RESULTS: A total of 2490 patients treated with first-line ICIs were included (median [IQR] age, 65.0 [55.3-73.0] years; 1561 male patients [62.7%]). Most patients had an Eastern Cooperative Oncology Group Performance Status of 1 or lower (2202 patients [88.5%]) and normal lactate dehydrogenase levels (1715 patients [68.9%]). PFS for all patients was 23.4% (95% CI, 21.7%-25.2%) after 3 years and 19.7% (95% CI, 18.0%-21.4%) after 5 years. Overall survival for all patients was 44.0% (95% CI, 42.1%-46.1%) after 3 years and 35.9% (95% CI, 33.9%-38.0%) after 5 years. Patients with metastases in 3 or more organ sites had a significantly higher hazard of progression after reaching PR or CR (adjusted hazard ratio, 1.37; 95% CI, 1.11-1.69). CONCLUSIONS AND RELEVANCE: This cohort study of patients with advanced melanoma treated with ICIs in clinical practice showed that their survival reached a plateau, comparable with patients participating in clinical trials. These findings can be used in daily clinical practice to guide long-term surveillance strategies and inform both physicians and patients regarding long-term treatment outcomes.


Asunto(s)
Inhibidores de Puntos de Control Inmunológico , Melanoma , Humanos , Melanoma/tratamiento farmacológico , Melanoma/mortalidad , Masculino , Femenino , Persona de Mediana Edad , Anciano , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Países Bajos/epidemiología , Ipilimumab/uso terapéutico , Nivolumab/uso terapéutico , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/patología , Estudios de Cohortes , Sistema de Registros , Supervivencia sin Progresión , Estudios Prospectivos
10.
Nano Lett ; 24(33): 10305-10312, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39133749

RESUMEN

Nanoparticle manipulation requires careful analysis of the forces at play. Unfortunately, traditional force measurement techniques based on the particle velocity do not provide sufficient resolution, while balancing approaches involving counteracting forces are often cumbersome. Here, we demonstrate that a nanoparticle dielectrophoretic response can be quantitatively studied by a straightforward visual delineation of the dielectrophoretic trapping volume. We reveal this volume by detecting the width of the region depleted of gold nanoparticles by the dielectrophoretic force. Comparison of the measured widths for various nanoparticle sizes with numerical simulations obtained by solving the particle-conservation equation shows excellent agreement, thus providing access to the particle physical properties, such as polarizability and size. These findings can be further extended to investigate various types of nano-objects, including bio- and molecular aggregates, and offer a robust characterization tool that can enhance the control of matter at the nanoscale.

11.
Artículo en Inglés | MEDLINE | ID: mdl-39074527

RESUMEN

Fragile X Syndrome (FXS) stands out as a prominent cause of inherited intellectual disability and a prevalent disorder closely linked to autism. FXS is characterized by substantial alterations in social behavior, encompassing social withdrawal, avoidance of eye contact, heightened social anxiety, increased arousal levels, language deficits, and challenges in regulating emotions. Conventional behavioral assessments primarily focus on short-term interactions within controlled settings. In this study, we conducted a comprehensive examination of the adaptive group behavior of Fmr1 KO male mice over a three-day period, without introducing experimental interventions or task-based evaluations. The data unveiled intricate behavioral anomalies, with the most significant changes manifesting during the initial adaptation to unfamiliar environments. Notably, certain behaviors exhibited a gradual return to typical patterns over time. This dynamic Fmr1 KO phenotype exhibited heightened activity, featuring increased exploration, amplified social interest, and an unconventional approach to social interactions characterized by a higher frequency of shorter engagements. These findings contribute to the growing understanding of social behavior in individuals with FXS and underscore the significance of comprehending their adaptive responses in various environmental contexts.


Asunto(s)
Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil , Síndrome del Cromosoma X Frágil , Ratones Noqueados , Conducta Social , Animales , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Síndrome del Cromosoma X Frágil/psicología , Síndrome del Cromosoma X Frágil/genética , Masculino , Ratones , Ambiente , Adaptación Psicológica/fisiología , Modelos Animales de Enfermedad , Conducta Animal/fisiología , Ratones Endogámicos C57BL , Conducta Exploratoria/fisiología
12.
Value Health ; 27(10): 1373-1381, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38977188

RESUMEN

OBJECTIVES: This study aimed to analyze worldwide sales of new therapeutic agents and to estimate the time it takes for product sales to exceed industry-wide average drug development costs. METHODS: Data obtained from company reports were analyzed to track worldwide sales of new medicines approved by the US Food and Drug Administration from 1995 to 2014. All sales figures were reported in 2019 US dollars. Kaplan-Meier curves were used to evaluate the time it took for discounted product sales to exceed the average costs associated with developing 1 new drug (accounting for the costs of failed trials), using published estimates of these costs. RESULTS: Based on data for 361 of 558 new therapeutic agents approved over the study period (median follow-up 13.2 years), mean sales revenue per product was $15.2 billion through the end of 2019; the median was $6.7 billion. These products jointly generated global sales of $5.5 trillion since approval. Revenues were highly skewed, with the 25 best selling products (7%, 25 of 361) accounting for 38% of this amount ($2.1 trillion of $5.5 trillion). Approximately 47% of products had discounted sales that exceeded the estimated industry-wide average costs of development within 5 years of approval, and 75% within 10 years. After attributing potential production, marketing, and other costs, these numbers dropped to 21% of products within 5 years of approval, and 46% within 10 years. CONCLUSIONS: Sales of new medicines approved from 1995 to 2014 were highly skewed, but many products had net discounted sales that exceeded the industry-wide average costs of development within 10 years of approval. An understanding of how sales revenues accrue in the years after initial approval, alongside data on business costs, can inform discussions about how to incentivize private investment in innovation while ensuring affordable prices for patients and the healthcare system.


Asunto(s)
Comercio , Aprobación de Drogas , United States Food and Drug Administration , Estados Unidos , Humanos , Comercio/economía , Comercio/tendencias , Costos de los Medicamentos/tendencias , Industria Farmacéutica/economía
13.
bioRxiv ; 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38979171

RESUMEN

Many expectant mothers use CBD to alleviate symptoms like nausea, insomnia, anxiety, and pain, despite limited research on its long-term effects. However, CBD passes through the placenta, affecting fetal development and impacting offspring behavior. We investigated how prenatal CBD exposure affects the insular cortex (IC), a brain region involved in emotional processing and linked to psychiatric disorders. The IC is divided into two territories: the anterior IC (aIC), processing socioemotional signals, and the posterior IC (pIC), specializing in interoception and pain perception. Pyramidal neurons in the aIC and pIC exhibit sex-specific electrophysiological properties, including variations in excitability and the excitatory/inhibitory balance. We investigated IC's cellular properties and synaptic strength in the offspring of both sexes from mice exposed to low-dose CBD during gestation (E5-E18; 3mg/kg, s.c.). Prenatal CBD exposure induced sex-specific and territory-specific changes in the active and passive membrane properties, as well as intrinsic excitability and the excitatory/inhibitory balance, in the IC of adult offspring. The data indicate that in-utero CBD exposure disrupts IC neuronal development, leading to a loss of functional distinction between IC territories. These findings may have significant implications for understanding the effects of CBD on emotional behaviors in offspring.

14.
ACS Appl Mater Interfaces ; 16(31): 40326-40355, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39042830

RESUMEN

Microencapsulation is an advanced methodology for the protection, preservation, and/or delivery of active materials in a wide range of industrial sectors, such as pharmaceuticals, cosmetics, fragrances, paints, coatings, detergents, food products, and agrochemicals. Polymeric materials have been extensively used as microcapsule shells to provide appropriate barrier properties to achieve controlled release of the encapsulated active ingredient. However, significant limitations are associated with such capsules, including undesired leaching and the nonbiodegradable nature of the typically used polymers. In addition, the energy cost of manufacturing microcapsules is an important factor to be considered when designing microcapsule systems and the corresponding production processes. Recent factors linked to UN sustainability goals are modifying how such microencapsulation systems should be designed in pursuit of "ideal" microcapsules that are efficient, safe, cost-effective and environmentally friendly. This review provides an overview of advances in microencapsulation, with emphasis on sustainable microcapsule designs. The key evaluation techniques to assess the biodegradability of microcapsules, in compliance with recently evolving European Union requirements, are also described. Moreover, the most common methodologies for the fabrication of microcapsules are presented within the framework of their energy demand. Recent promising microcapsule designs are also highlighted for their suitability toward meeting current design requirements and stringent regulations, tackling the ongoing challenges, limitations, and opportunities.


Asunto(s)
Cápsulas , Composición de Medicamentos , Cápsulas/química , Composición de Medicamentos/métodos , Polímeros/química
15.
ACS Omega ; 9(26): 28385-28396, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38973847

RESUMEN

Commercial perfume microcapsules are becoming popular across the globe to fulfill consumers' demands. However, most of microcapsules rely on synthetic polymers and/or animal-sourced ingredients to form the shells. Therefore, replacement of the shell materials is imperative to minimize environmental microplastic pollution, as well as to meeting peoples' needs, religious beliefs, and lifestyles. Herein, we report a methodology to fabricate environmentally benign dual-shell (fungal chitosan-SiO2) microcapsules laden with fragrance oil (hexyl salicylate). Anionically stabilized oil droplets were coated with fungal chitosan via interfacial electrostatic interactions at pH 2, which were then covered by an inorganic coating of SiO2 produced via external alkaline mineralization of sodium silicate. Core-shell microcapsules with a spherical morphology were achieved. Under compression, dual-shell chitosan-SiO2 microcapsules yielded a mean nominal rupture stress of 3.0 ± 0.2 MPa, which was significantly higher than that of single-shell microcapsules (1.7 ± 0.2 MPa). After 20 days in neutral pH water, only ∼2.5% of the oil was released from dual-shell microcapsules, while single-shell microcapsules cumulatively released more than 10%. These findings showed that the additional SiO2 coating significantly enhanced both mechanical and barrier properties of microcapsules, which may be appealing for multiple commercial applications, including cosmetics and detergents.

16.
ArXiv ; 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39070038

RESUMEN

Human ability to recognize complex visual patterns arises through transformations performed by successive areas in the ventral visual cortex. Deep neural networks trained end-to-end for object recognition approach human capabilities, and offer the best descriptions to date of neural responses in the late stages of the hierarchy. But these networks provide a poor account of the early stages, compared to traditional hand-engineered models, or models optimized for coding efficiency or prediction. Moreover, the gradient backpropagation used in end-to-end learning is generally considered to be biologically implausible. Here, we overcome both of these limitations by developing a bottom-up self-supervised training methodology that operates independently on successive layers. Specifically, we maximize feature similarity between pairs of locally-deformed natural image patches, while decorrelating features across patches sampled from other images. Crucially, the deformation amplitudes are adjusted proportionally to receptive field sizes in each layer, thus matching the task complexity to the capacity at each stage of processing. In comparison with architecture-matched versions of previous models, we demonstrate that our layerwise complexity-matched learning (LCL) formulation produces a two-stage model (LCL-V2) that is better aligned with selectivity properties and neural activity in primate area V2. We demonstrate that the complexity-matched learning paradigm is responsible for much of the emergence of the improved biological alignment. Finally, when the two-stage model is used as a fixed front-end for a deep network trained to perform object recognition, the resultant model (LCL-V2Net) is significantly better than standard end-to-end self-supervised, supervised, and adversarially-trained models in terms of generalization to out-of-distribution tasks and alignment with human behavior. Our code and pre-trained checkpoints are available at https://github.com/nikparth/LCL-V2.git.

17.
J Neurosci ; 44(30)2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38830765

RESUMEN

Fragile X syndrome (FXS) is a genetic cause of intellectual disability and autism spectrum disorder. The mesocorticolimbic system, which includes the prefrontal cortex (PFC), basolateral amygdala (BLA), and nucleus accumbens core (NAcC), is essential for regulating socioemotional behaviors. We employed optogenetics to compare the functional properties of the BLA→NAcC, PFC→NAcC, and reciprocal PFC↔BLA pathways in Fmr1-/y::Drd1a-tdTomato male mice. In FXS mice, the PFC↔BLA reciprocal pathway was unaffected, while significant synaptic modifications occurred in the BLA/PFC→NAcC pathways. We observed distinct changes in D1 striatal projection neurons (SPNs) and separate modifications in D2 SPNs. In FXS mice, the BLA/PFC→NAcC-D2 SPN pathways demonstrated heightened synaptic strength. Focusing on the BLA→NAcC pathway, linked to autistic symptoms, we found increased AMPAR and NMDAR currents and elevated spine density in D2 SPNs. Conversely, the amplified firing probability of BLA→NAcC-D1 SPNs was not accompanied by increased synaptic strength, AMPAR and NMDAR currents, or spine density. These pathway-specific alterations resulted in an overall enhancement of excitatory-to-spike coupling, a physiologically relevant index of how efficiently excitatory inputs drive neuronal firing, in both BLA→NAcC-D1 and BLA→NAcC-D2 pathways. Finally, the absence of fragile X messenger ribonucleoprotein 1 (FMRP) led to impaired long-term depression specifically in BLA→D1 SPNs. These distinct alterations in synaptic transmission and plasticity within circuits targeting the NAcC highlight the potential role of postsynaptic mechanisms in selected SPNs in the observed circuit-level changes. This research underscores the heightened vulnerability of the NAcC in the context of FMRP deficiency, emphasizing its pivotal role in the pathophysiology of FXS.


Asunto(s)
Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil , Síndrome del Cromosoma X Frágil , Núcleo Accumbens , Animales , Síndrome del Cromosoma X Frágil/fisiopatología , Síndrome del Cromosoma X Frágil/metabolismo , Síndrome del Cromosoma X Frágil/genética , Ratones , Masculino , Núcleo Accumbens/metabolismo , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/metabolismo , Vías Nerviosas/fisiopatología , Optogenética , Corteza Prefrontal/metabolismo , Corteza Prefrontal/fisiopatología , Ratones Endogámicos C57BL , Complejo Nuclear Basolateral/metabolismo , Complejo Nuclear Basolateral/fisiopatología , Ratones Noqueados , Neuronas/metabolismo , Neuronas/fisiología , Plasticidad Neuronal/fisiología
19.
Am J Bot ; 111(6): e16352, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38853465

RESUMEN

PREMISE: Phylogenetic approaches can provide valuable insights on how and when a biome emerged and developed using its structuring species. In this context, Brachystegia Benth, a dominant genus of trees in miombo woodlands, appears as a key witness of the history of the largest woodland and savanna biome of Africa. METHODS: We reconstructed the evolutionary history of the genus using targeted-enrichment sequencing on 60 Brachystegia specimens for a nearly complete species sampling. Phylogenomic inferences used supermatrix (RAxML-NG) and summary-method (ASTRAL-III) approaches. Conflicts between species and gene trees were assessed, and the phylogeny was time-calibrated in BEAST. Introgression between species was explored using Phylonet. RESULTS: The phylogenies were globally congruent regardless of the method used. Most of the species were recovered as monophyletic, unlike previous plastid phylogenetic reconstructions where lineages were shared among geographically close individuals independently of species identity. Still, most of the individual gene trees had low levels of phylogenetic information and, when informative, were mostly in conflict with the reconstructed species trees. These results suggest incomplete lineage sorting and/or reticulate evolution, which was supported by network analyses. The BEAST analysis supported a Pliocene origin for current Brachystegia lineages, with most of the diversification events dated to the Pliocene-Pleistocene. CONCLUSIONS: These results suggest a recent origin of species of the miombo, congruently with their spatial expansion documented from plastid data. Brachystegia species appear to behave potentially as a syngameon, a group of interfertile but still relatively well-delineated species, an aspect that deserves further investigations.


Asunto(s)
Filogenia , Bosques , Evolución Biológica
20.
J Vis ; 24(6): 12, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38884544

RESUMEN

Neural population activity in sensory cortex informs our perceptual interpretation of the environment. Oftentimes, this population activity will support multiple alternative interpretations. The larger the spread of probability over different alternatives, the more uncertain the selected perceptual interpretation. We test the hypothesis that the reliability of perceptual interpretations can be revealed through simple transformations of sensory population activity. We recorded V1 population activity in fixating macaques while presenting oriented stimuli under different levels of nuisance variability and signal strength. We developed a decoding procedure to infer from V1 activity the most likely stimulus orientation as well as the certainty of this estimate. Our analysis shows that response magnitude, response dispersion, and variability in response gain all offer useful proxies for orientation certainty. Of these three metrics, the last one has the strongest association with the decoder's uncertainty estimates. These results clarify that the nature of neural population activity in sensory cortex provides downstream circuits with multiple options to assess the reliability of perceptual interpretations.


Asunto(s)
Macaca mulatta , Estimulación Luminosa , Corteza Visual , Animales , Corteza Visual/fisiología , Estimulación Luminosa/métodos , Percepción Visual/fisiología , Masculino , Orientación/fisiología , Neuronas/fisiología
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