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1.
bioRxiv ; 2024 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-39372748

RESUMO

Placozoa are millimeter-sized, flat, irregularly shaped ciliated animals that crawl on surfaces in warm oceans feeding on biofilms, which they digest externally. They stand out from other animals due to their simple body plans. They lack organs, body cavities, muscles and a nervous system and have only seven broadly defined morphological cell types, each with a unique distribution. Analyses of single cell transcriptomes of four species of placozoans revealed greater diversity of secretory cell types than evident from morphological studies, but the locations of many of these new cell types were unknown and it was unclear which morphological cell types they represent. Furthermore, there were contradictions between the conclusions of previous studies and the single cell RNAseq studies. To address these issues, we used mRNA probes for genes encoding secretory products expressed in different metacells in Trichoplax adhaerens to localize cells in whole mounts and in dissociated cell cultures, where their morphological features could be visualized and identified. The nature and functions of their secretory granules were further investigated with electron microscopic techniques and by imaging secretion in live animals during feeding episodes. We found that two cell types participate in disintegrating prey, one resembling a lytic cell type in mammals and another combining features of zymogen gland cells and enterocytes. We identified secretory epithelial cells expressing glycoproteins or short peptides implicated in defense. We located seven peptidergic cell types and two types of mucocytes. Our findings reveal mechanisms that placozoans use to feed and protect themselves from pathogens and clues about neuropeptidergic signaling. We compare placozoan secretory cell types with cell types in other animal phyla to gain insight about general evolutionary trends in cell type diversification, as well as pathways leading to the emergence of synapomorphies.

2.
Angew Chem Int Ed Engl ; : e202414938, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39255399

RESUMO

Polarity-reversal catalysts (PRCs) for hydrogen-atom transfer reactions have been known in radical chemistry for more than 60 years but are rarely described and utilized in the field of photopolymerization up to now. Herein, we present the use of thiols in a unique dual function as thiol-ene click reagents and as polarity-reversal catalyst (PRC) for the radical-mediated redox rearrangements of benzylidene acetals. During the rearrangement reaction, cyclic benzylidene acetals are transformed into benzoate esters leading to a significant volumetric expansion to reduce thermoset shrinkage. We were able to show that this expansion on a molecular level reduces shrinkage and polymerization stress but does not significantly affect the (thermo-)mechanical properties of the cross-linked networks. One of the key advantages of this process lies in its simplicity. No additives like sensitizers or combinations of different initiators (radical and cationic) are needed. Furthermore, the same light source can be used for both the polymerization reaction and expansion through rearrangement. Additionally, the applied photoinitiator enables spatial and temporal control of the polymerization; thus, the developed system can be an excellent platform for additive manufacturing processes.

3.
Sci Rep ; 14(1): 22244, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39333670

RESUMO

This paper analyzes effects of the mutual presentation of weak and strong arguments. Departing from the prevalent "the-more-the-better" heuristic, our research scrutinizes whether the inclusion of weak arguments enhances or diminishes the persuasive impact of strong arguments. Leveraging insights from judgment formation literature, we conducted four experimental studies on political and health-related topics to unravel whether the presenting weak arguments strengthens the persuasive effect of a strong argument (adding) or actually weakens this persuasive effect (averaging). The results show that providing supporting arguments of moderate strength along with a strong argument increases persuasion, representing an additive pattern. However, presenting weak supporting arguments along with a strong argument reduces the persuasive effect of the strong argument, representing an averaging pattern. Exposure to weak arguments diminishes the strength of strong ones, suggesting the omission of weak arguments. These findings underscore the vital role of strategically selecting arguments to optimize persuasion across disciplines.

4.
Nat Commun ; 15(1): 6408, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39164229

RESUMO

Venomous animals have evolved diverse molecular mechanisms to incapacitate prey and defend against predators. Most venom components disrupt nervous, locomotor, and cardiovascular systems or cause tissue damage. The discovery that certain fish-hunting cone snails use weaponized insulins to induce hypoglycemic shock in prey highlights a unique example of toxins targeting glucose homeostasis. Here, we show that, in addition to insulins, the deadly fish hunter, Conus geographus, uses a selective somatostatin receptor 2 (SSTR2) agonist that blocks the release of the insulin-counteracting hormone glucagon, thereby exacerbating insulin-induced hypoglycemia in prey. The native toxin, Consomatin nG1, exists in several proteoforms with a minimized vertebrate somatostatin-like core motif connected to a heavily glycosylated N-terminal region. We demonstrate that the toxin's N-terminal tail closely mimics a glycosylated somatostatin from fish pancreas and is crucial for activating the fish SSTR2. Collectively, these findings provide a stunning example of chemical mimicry, highlight the combinatorial nature of venom components, and establish glucose homeostasis as an effective target for prey capture.


Assuntos
Caramujo Conus , Glucagon , Glucose , Homeostase , Insulina , Receptores de Somatostatina , Somatostatina , Animais , Somatostatina/metabolismo , Homeostase/efeitos dos fármacos , Insulina/metabolismo , Glucose/metabolismo , Receptores de Somatostatina/metabolismo , Glucagon/metabolismo , Peixes/metabolismo , Comportamento Predatório/efeitos dos fármacos , Hipoglicemia/metabolismo , Venenos de Moluscos/metabolismo , Humanos , Mimetismo Molecular
5.
Macromol Rapid Commun ; : e2400323, 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39207801

RESUMO

Vanillyl alcohol has emerged as a widely used building block for the development of biobased monomers. More specifically, the cationic (photo-)polymerization of the respective diglycidyl ether (DGEVA) is known to produce materials of outstanding thermomechanical performance. Generally, chain transfer agents (CTAs) are of interest in cationic resins not only because they lead to more homogeneous polymer networks but also because they strikingly improve the polymerization speed. Herein, the aim is to compare the cationic chain-growth photopolymerization with the thermally initiated anionic step-growth polymerization, with and without the addition of CTAs. Indeed, CTAs lead to faster polymerization reactions as well as the formation of more homogeneous networks, especially in the case of the thermal anionic step-growth polymerization. Resulting from curing above the TG of the respective anionic step-growth polymer, materials with outstanding tensile toughness (>5 MJ cm-3) are obtained that result in the manufacture of potential shape-memory polymers.

6.
Can J Vet Res ; 88(3): 87-93, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988333

RESUMO

There is a knowledge gap regarding the effect of extracorporeal shockwave treatment (ESWT) on the stress response and immunomodulatory and anti-inflammatory properties of equine umbilical cord blood mesenchymal stromal cells (CB-MSCs). The objective of this study was to investigate the presence of cellular oxidative stress, inflammatory response, and production of growth factors in CB-MSCs after treatment with ESWT. We hypothesized that CB-MSCs treated with ESWT will experience higher levels of cellular stress and increased production of anti-inflammatory cytokines and growth factors compared to untreated CB-MSCs.


Il existe un manque de connaissances concernant l'effet du traitement extracorporel par ondes de choc (ESWT) sur la réponse au stress et les propriétés immunomodulatrices et anti-inflammatoires des cellules stromales mésenchymateuses du sang de cordon ombilical équin (CB-MSCs). L'objectif de cette étude était d'étudier la présence de stress oxydatif cellulaire, de réponse inflammatoire et de production de facteurs de croissance dans les CB-MSCs après un traitement par ESWT. Nous avons émis l'hypothèse que les CB-MSCs traitées par ESWT connaîtront des niveaux plus élevés de stress cellulaire et une production accrue de cytokines anti-inflammatoires et de facteurs de croissance par rapport aux CB-MSCs non traitées.(Traduit par Docteur Serge Messier).


Assuntos
Sangue Fetal , Células-Tronco Mesenquimais , Animais , Cavalos , Sangue Fetal/citologia , Tratamento por Ondas de Choque Extracorpóreas/métodos , Citocinas/metabolismo , Células Cultivadas
7.
J Exp Orthop ; 11(3): e12110, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39055394

RESUMO

Purpose: The purpose of this study was to compare the biomechanical properties of a latest generation all-suture anchor repair device (ASARD) for meniscal repair with that of a latest generation PEEK-cage anchor repair device (PCARD) in an experimental setting using cadaveric menisci. Methods: Twenty-six menisci were obtained from the knees of fresh body donors. Artificially created meniscal lesions were treated randomly, using a single stitch with either an ASARD or a PCARD. Cyclic biomechanical testing, utilising a universal material testing machine and following an established protocol, was carried out and load-to-failure (LTF), displacement, stiffness, and mode-of-failure (MOF) reported. Results: Mean LTF was found to be 61% higher in the ASARD group at 107.10 N (standard deviation [SD], 42.34), compared to 65.86 N (SD, 27.42) in the PCARD group with statistical significance (p = 0.022). The ASARD exhibited a trend towards higher stiffness (10.35 N; SD, 3.92 versus 7.78 N; SD; 3.59) and higher displacement at cycles one, 100, and 499 (1.64, 3.27, and 4.17 mm versus 0.93, 2.19, and 2.83 mm) compared to the PCARD. Cheese wiring was the most common mode-of-failure in both groups (76.9%). Conclusions: This study demonstrates that an ASARD shows a higher mean LTF than a PCARD when compared in an experimental biomechanical setting. Level of evidence: Level III.

8.
Mol Biol Evol ; 41(8)2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-38935574

RESUMO

Venom systems are complex traits that have independently emerged multiple times in diverse plant and animal phyla. Within each venomous lineage there typically exists interspecific variation in venom composition where several factors have been proposed as drivers of variation, including phylogeny and diet. Understanding these factors is of broad biological interest and has implications for the development of antivenom therapies and venom-based drug discovery. Because of their high species richness and the presence of several major evolutionary prey shifts, venomous marine cone snails (genus Conus) provide an ideal system to investigate drivers of interspecific venom variation. Here, by analyzing the venom gland expression profiles of ∼3,000 toxin genes from 42 species of cone snail, we elucidate the role of prey-specific selection pressures in shaping venom variation. By analyzing overall venom composition and individual toxin structures, we demonstrate that the shifts from vermivory to piscivory in Conus are complemented by distinct changes in venom composition independent of phylogeny. In vivo injections of venom from piscivorous cone snails in fish further showed a higher potency compared with venom of nonpiscivores demonstrating a selective advantage. Together, our findings provide compelling evidence for the role of prey shifts in directing the venom composition of cone snails and expand our understanding of the mechanisms of venom variation and diversification.


Assuntos
Caramujo Conus , Venenos de Moluscos , Animais , Caramujo Conus/genética , Venenos de Moluscos/genética , Comportamento Predatório , Evolução Biológica , Filogenia , Evolução Molecular
9.
bioRxiv ; 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38746149

RESUMO

Persistent pain affects one in five people worldwide, often with severely debilitating consequences. Current treatment options, which can be effective for mild or acute pain, are ill-suited for moderate-to-severe persistent pain, resulting in an urgent need for new therapeutics. In recent years, the somatostatin receptor 4 (SSTR 4 ), which is expressed in sensory neurons of the peripheral nervous system, has emerged as a promising target for pain relief. However, the presence of several closely related receptors with similar ligand-binding surfaces complicates the design of receptor-specific agonists. In this study, we report the discovery of a potent and selective SSTR 4 peptide, consomatin Fj1, derived from extensive venom gene datasets from marine cone snails. Consomatin Fj1 is a mimetic of the endogenous hormone somatostatin and contains a minimized binding motif that provides stability and drives peptide selectivity. Peripheral administration of synthetic consomatin Fj1 provided analgesia in mouse models of postoperative and neuropathic pain. Using structure-activity studies, we designed and functionally evaluated several Fj1 analogs, resulting in compounds with improved potency and selectivity. Our findings present a novel avenue for addressing persistent pain through the design of venom-inspired SSTR 4 -selective pain therapeutics. One Sentence Summary: Venom peptides from predatory marine mollusks provide new leads for treating peripheral pain conditions through a non-opioid target.

10.
Glob Chall ; 8(4): 2300315, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38617029

RESUMO

Carbons form critical components in biogas purification and energy storage systems and are used to modify polymer matrices. The environmental impact of producing carbons has driven research interest in biomass-derived carbons, although these have yield, processing, and resource competition limitations. Naturally formed fungal filaments are investigated, which are abundantly available as food- and biotechnology-industry by-products and wastes as cost-effective and sustainable templates for carbon networks. Pyrolyzed Agaricus bisporus and Pleurotus eryngii filament networks are mesoporous and microscale with a size regime close to carbon fibers. Their BET surface areas of ≈282 m2 g-1 and ≈60 m2 g-1, respectively, greatly exceed values associated with carbon fibers and non-activated pyrolyzed bacterial cellulose and approximately on par with values for carbon black and CNTs in addition to pyrolyzed pinewood, rice husk, corn stover or olive mill waste. They also exhibit greater specific capacitance than both non-activated and activated pyrolyzed bacterial cellulose in addition to YP-50F (coconut shell based) commercial carbons. The high surface area and specific capacitance of fungal carbon coupled with the potential to tune these properties through species- and growth-environment-associated differences in network and filament morphology and inclusion of inorganic material through biomineralization makes them potentially useful in creating supercapacitors.

11.
Beilstein J Nanotechnol ; 15: 317-332, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38590429

RESUMO

Titanium dioxide (TiO2) pigment is a non-toxic, particulate material in widespread use and found in everyone's daily life. The particle size of the anatase or rutile crystals are optimised to produce a pigment that provides the best possible whiteness and opacity. The average particle size is intentionally much larger than the 100 nm boundary of the EU nanomaterial definition, but the TiO2 pigment manufacturing processes results in a finite nanoscale content fraction. This optically inefficient nanoscale fraction needs to be quantified in line with EU regulations. In this paper, we describe the measurement procedures used for product quality assurance by three TiO2 manufacturing companies and present number-based primary particle size distributions (PSDs) obtained in a round-robin study performed on five anatase pigments fabricated by means of sulfate processes in different plants and commonly used worldwide in food, feed, pharmaceutical and cosmetic applications. The PSDs measured by the three titanium dioxide manufacturers based on electron micrographs are in excellent agreement with one another but differ significantly from those published elsewhere. Importantly, in some cases, the PSDs result in a different regulatory classification for some of the samples tested. The electron microscopy results published here are supported by results from other complementary methods including surface area measurements. It is the intention of this publication to contribute to an ongoing discussion on size measurements of TiO2 pigments and other particulate materials and advance the development of widely acceptable, precise, and reproducible measurement protocols for measuring the number-based PSDs of particulate products in the size range of TiO2 pigments.

12.
Chem Rev ; 124(7): 3978-4020, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38546847

RESUMO

Photopolymers have been optimized as protective and decorative coating materials for decades. However, with the rise of additive manufacturing technologies, vat photopolymerization has unlocked the use of photopolymers for three-dimensional objects with new material requirements. Thus, the originally highly cross-linked, amorphous architecture of photopolymers cannot match the expectations for modern materials anymore, revealing the largely unanswered question of how diverse properties can be achieved in photopolymers. Herein, we review how microstructural features in soft matter materials should be designed and implemented to obtain high performance materials. We then translate these findings into chemical design suggestions for enhanced printable photopolymers. Based on this analysis, we have found microstructural heterogenization to be the most powerful tool to tune photopolymer performance. By combining the chemical toolbox for photopolymerization and the analytical toolbox for microstructural characterization, we examine current strategies for physical heterogenization (fillers, inkjet printing) and chemical heterogenization (semicrystalline polymers, block copolymers, interpenetrating networks, photopolymerization induced phase separation) of photopolymers and put them into a material scientific context to develop a roadmap for improving and diversifying photopolymers' performance.

13.
Adv Mater ; 36(34): e2308497, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38303404

RESUMO

Two-photon polymerization (2PP) is becoming increasingly established as additive manufacturing technology for microfabrication due to its high-resolution and the feasibility of generating complex parts. Until now, the high resolution of 2PP is also its bottleneck, as it limited throughput and therefore restricted the application to the production of microparts. Thus, mechanical properties of 2PP materials can only be characterized using nonstandardized specialized microtesting methods. Due to recent advances in 2PP technology, it is now possible to produce parts in the size of several millimeters to even centimeters, finally permitting the fabrication of macrosized testing specimens. Besides suitable hardware systems, 2PP materials exhibiting favorable mechanical properties that allow printing of up-scaled parts are strongly demanded. In this work, the up-scalability of three different photopolymers is investigated using a high-throughput 2PP system and low numerical aperture optics. Testing specimens in the cm-range are produced and tested with common or even standardized material testing methods available in conventionally equipped polymer testing labs. Examples of the characterization of mechanical, thermo-mechanical, and fracture properties of 2PP processed materials are shown. Additionally, aspects such as postprocessing and aging are investigated. This lays a foundation for future expansion of the 2PP technology to broader industrial application.

14.
J Biol Rhythms ; 39(3): 237-269, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38379166

RESUMO

Circadian biology's impact on human physical health and its role in disease development and progression is widely recognized. The forefront of circadian rhythm research now focuses on translational applications to clinical medicine, aiming to enhance disease diagnosis, prognosis, and treatment responses. However, the field of circadian medicine has predominantly concentrated on human healthcare, neglecting its potential for transformative applications in veterinary medicine, thereby overlooking opportunities to improve non-human animal health and welfare. This review consists of three main sections. The first section focuses on the translational potential of circadian medicine into current industry practices of agricultural animals, with a particular emphasis on horses, broiler chickens, and laying hens. The second section delves into the potential applications of circadian medicine in small animal veterinary care, primarily focusing on our companion animals, namely dogs and cats. The final section explores emerging frontiers in circadian medicine, encompassing aquaculture, veterinary hospital care, and non-human animal welfare and concludes with the integration of One Health principles. In summary, circadian medicine represents a highly promising field of medicine that holds the potential to significantly enhance the clinical care and overall health of all animals, extending its impact beyond human healthcare.


Assuntos
Ritmo Circadiano , Saúde Única , Animais , Humanos , Bem-Estar do Animal , Cães , Galinhas , Gatos , Cavalos , Medicina Veterinária
15.
PLoS One ; 19(2): e0297303, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38394252

RESUMO

Osteoarthritis (OA) is a leading cause of lameness in horses with no effective disease-modifying treatment and challenging early diagnosis. OA is considered a disease of the joint involving the articular cartilage, subchondral bone, synovial membrane, and ligaments. Osteochondritis dissecans (OCD) is a joint disease consisting of focal defects in the osteochondral unit which may progress to OA later in life. MicroRNAs (miRNAs) have been recognized as small non-coding RNAs that regulate a variety of biological processes and have been detected in biological fluids. MiRNAs are currently investigated for their utility as biomarkers and druggable targets for a variety of diseases. The current study hypothesizes that miRNA profiles can be used to actively monitor joint health and differences in miRNA profiles will be found in healthy vs diseased joints and that differences will be detectable in blood plasma of tested horses. Five horses with OA, OCD, and 4 controls (C) had blood plasma and synovial fluid collected. Total RNA, including miRNA was isolated before generating miRNA libraries from the plasma of the horses. Libraries were sequenced at the Schroeder Arthritis Institute (Toronto). Differential expression analysis was done using DESeq2 and validated using ddPCR. KEGG pathway analysis was done using mirPath v.3 (Diana Tools). 57 differentially expressed miRNAs were identified in OA vs C plasma, 45 differentially expressed miRNAs in OC vs C plasma, and 21 differentially expressed miRNAs in OA vs OCD plasma. Notably, miR-140-5p expression was observed to be elevated in OA synovial fluid suggesting that miR-140-5p may serve as a protective marker early on to attenuate OA progression. KEGG pathway analysis of differentially expressed plasma miRNAs showed relationships with glycan degradation, glycosaminoglycan degradation, and hippo signaling pathway. Interestingly, ddPCR was unable to validate the NGS data suggesting that isomiRs may play an integral role in miRNA expression when assessed using NGS technologies.


Assuntos
Artropatias , MicroRNAs , Osteoartrite , Osteocondrite Dissecante , Animais , Cavalos/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Osteocondrite Dissecante/genética , Osteocondrite Dissecante/veterinária , Osteoartrite/genética , Osteoartrite/veterinária , Osteoartrite/diagnóstico , Membrana Sinovial/metabolismo
16.
Polymers (Basel) ; 16(3)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38337301

RESUMO

The widespread adoption of renewable energy hinges on the efficient transportation of hydrogen. Reciprocating piston compressor technology in non-lubricated operation will play a key role, ensuring high flow rates and compression ratios. These systems rely on advanced high-strength sealing solutions for piston and rod packing rings utilizing advanced fiber-reinforced polymers. Polyphenylene sulfide (PPS) polymer matrix composites have seen use in tribological applications and promise high mechanical strength and wear resistance. The presented work describes carbon and glass fiber-reinforced PPS matrix polymers in comparison, which are characterized by complementary methods to investigate their properties and potential for application in reciprocating compressor under non-lubricated operation. Thermo-mechanical and tribological testing was supported by microstructure analysis utilizing advanced X-ray and electron imaging techniques. New insights in micromechanical deformation behavior in regard to fiber materials, interface strength and orientation in fiber-reinforced polymers are given. Conclusions on the suitability of different PPS matrix composites for high-pressure hydrogen compression applications were obtained.

17.
Biotechnol Bioeng ; 121(1): 192-205, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37772415

RESUMO

Equine mesenchymal stromal cells (MSCs) have been found to be beneficial for the treatment of many ailments, including orthopedic injuries, due to their superior differentiation potential and immunomodulating properties. Cell therapies require large cell numbers, which are not efficiently generated using conventional static expansion methods. Expansion of equine cord blood-derived MSCs (eCB-MSCs) in bioreactors, using microcarriers as an attachment surface, has the potential to generate large numbers of cells with increased reproducibility and homogeneity compared with static T-flask expansion. This study investigated the development of an expansion process using Vertical-Wheel (VW) bioreactors, a single-use bioreactor technology that incorporates a wheel instead of an impeller. Initially, microcarriers were screened at small scale to assess eCB-MSC attachment and growth and then in bioreactors to assess cell expansion and harvesting. The effect of different donors, serial passaging, and batch versus fed batch were all examined in 0.1 L VW bioreactors. The use of VW bioreactors with an appropriate microcarrier was shown to be able to produce cell densities of up to 1E6 cells/mL, while maintaining cell phenotype and functionality, thus demonstrating great potential for the use of these bioreactors to produce large cell numbers for cell therapies.


Assuntos
Técnicas de Cultura de Células , Células-Tronco Mesenquimais , Animais , Cavalos , Técnicas de Cultura de Células/métodos , Sangue Fetal , Reprodutibilidade dos Testes , Reatores Biológicos , Diferenciação Celular , Proliferação de Células
18.
Health Serv Res ; 59(2): e14228, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37751289

RESUMO

OBJECTIVE: The aim was to quantify changes in the market structure of primary care physicians and examine its relationship with access to care. DATA SOURCES AND STUDY SETTING: We created measures of market structure from a 5% sample of Medicare fee-for-service claims and examined access to care using nationally representative data from the Medical Expenditure Panel Survey (MEPS). Our study spanned from 2008 to 2019. STUDY DESIGN: We used a linear probability model to estimate the relationship between access to care and two measures of market structure: concentration, measured by the Herfindahl-Hirschman Index (HHI), and vertical integration, measured by the market share of multispecialty firms. Our model controlled for year and ZIP code fixed effects, respondents' demographics and health status, and other measures of market structure. DATA COLLECTION/EXTRACTION METHODS: All adult respondents in the MEPS were included. PRINCIPAL FINDINGS: The percentage of people living in concentrated ZIP codes (HHI above 1500) increased from 37% in 2008 to 53% in 2019. During the same period, the median market share of multispecialty firms rose from 30% to 48%. Respondents in highly concentrated ZIP codes (HHI over 2500) were 5.9 percentage points (95% CI: -1.4 to -10.4) less likely to report having access to immediate care than respondents in unconcentrated ZIP codes. The association was largest among Medicaid beneficiaries, a 17.3 percentage point reduction (95% CI: -5.1 to -29.4). When we applied a model that was robust to biases from treatments with staggered timing, the estimated association remained negative but was not statistically significant. We found no association between HHI and indicators for having a usual source of care and annual checkups. The multispecialty market share was negatively associated with checkups, but not other measures of access. CONCLUSIONS: Increases in concentration may reduce some types of access to healthcare. These effects appear most pronounced among Medicaid beneficiaries.


Assuntos
Atenção à Saúde , Medicare , Idoso , Adulto , Humanos , Estados Unidos , Planos de Pagamento por Serviço Prestado , Medicaid
19.
Br J Ophthalmol ; 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37844999

RESUMO

BACKGROUND/AIMS: We sought to evaluate widefield swept-source optical coherence tomography angiography (WF SS-OCTA) among eyes with concomitant age-related macular degeneration (AMD) and diabetes mellitus or diabetic retinopathy (DM/DR). METHODS: This cross-sectional, comparative study consisted of three study groups: eyes with (1) AMD and DM/DR, (2) AMD alone and (3) DM/DR alone. WF SS-OCTA (3×3, 6×6 and 12×12 mm) images were captured. Vascular metrics included foveal avascular zone (FAZ), vessel density (VD) and vessel skeletonised density (VSD). Mixed-effects multivariable regression models adjusted for age were performed by cohort and subgroup based on AMD and DR stages. RESULTS: Our cohort included 287 eyes from 186 patients with an average age of 64±14.0 years old. Results revealed significantly reduced vascular metrics in concomitant AMD and DM/DR eyes (N=68) compared with AMD-only eyes (N=71) on all angiograms but not compared with DM/DR-only eyes (N=148). For example, when compared with AMD-only eyes, AMD and DM/DR eyes had significantly reduced VD (ß=-0.03, p=0.016) and VSD (ß=-1.09, p=0.022) on 12×12 mm angiograms, increased FAZ perimeter (ß=0.51, p=0.025) and FAZ area (ß=0.11, p=0.015) on 6×6 mm angiogram, and reductions in all VD and VSD metrics on 3×3 and 6×6 mm angiograms. However, only 3×3 mm angiogram FAZ metrics were significantly different when comparing DM/DR eyes with concomitant AMD and DM/DR eyes. CONCLUSION: WF SS-OCTA revealed significant reductions in retinal microvasculature metrics in AMD and DM/DR eyes compared with AMD-only eyes but not compared with DM/DR-only eyes.

20.
Br J Ophthalmol ; 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37857454

RESUMO

AIM: To investigate if active learning of contrast sensitivity (CS) in bilateral age-related macular degeneration (AMD) correlates better than visual acuity (VA) with vision-related quality of life (VRQoL) using factor analysis-calibrated National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). METHODS: Prospective cross-sectional observational study in 93 patients (186 eyes) with bilateral AMD. CS was measured in one eye at a time with the quantitative CS function (qCSF) method (Adaptive Sensory Technology). Same-day VRQoL was assessed with factor analysis-calibrated NEI VFQ-25 visual function and socioemotional scales. Mixed-effects multiple linear regression analyses evaluated the associations of the qCSF outcomes and VA with the NEI VFQ-25 scales. A subgroup analysis on patients with AMD with VA more than 20/25 in both eyes was performed. RESULTS: Compared with VA, CS outcomes were associated with larger effect on both visual function scale (standardised beta coefficients (ß*) for area under the logarithm of CSF (AULCSF) curve and CS thresholds at 1.5, 3 and 6 cycles per degree (cpd): ß*=0.50, 0.48, 0.52, 0.46, all p<0.001, respectively, vs ß*=-0.45 for VA, all p<0.001) and socioemotional scale (ß* for AULCSF and CS threshold at 6 cpd: ß*=0.44, 0.44 vs ß*=-0.42 for VA, all p<0.001). In patients with AMD with VA more than 20/25 in both eyes (N=20), both VFQ-25 scales and all CS outcomes were significantly reduced. CONCLUSIONS: qCSF-measured CS strongly correlates with patient-reported VRQoL in bilateral AMD, even stronger than VA does. This study further validates qCSF-measured CS as a promising functional endpoint for future clinical trials in AMD.

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