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1.
Gen Comp Endocrinol ; 355: 114545, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38701975

RESUMO

In birds, patterns of development of the adrenocortical response to stressors vary among individuals, types of stressors, and species. Since there are benefits and costs of exposure to elevated glucocorticoids, this variation is presumably a product of selection such that animals modulate glucocorticoid secretion in contexts where doing so increases their fitness. In this study, we evaluated hypothalamo-pituitary-adrenal (HPA) activity in first-hatched free-living seabird nestlings that engage in intense sibling competition and facultative siblicide (black-legged kittiwakes, Rissa tridactyla). We sampled 5 day old chicks (of the ∼45 day nestling period), a critical early age when food availability drives establishment of important parent-offspring and intra-brood dynamics. We experimentally supplemented parents with food ("supplemented") and measured chick baseline corticosterone secretion and capacity to rapidly increase corticosterone in response to an acute challenge (handling and 15 min of restraint in a bag). We also used topical administration of corticosterone to evaluate the ability of chicks to downregulate physiologically relevant corticosterone levels on a short time scale (minutes). We found that 5 day old chicks are not hypo-responsive but release corticosterone in proportion to the magnitude of the challenge, showing differences in baseline between parental feeding treatments (supplemented vs non-supplemented), moderate increases in response to handling, and a larger response to restraint (comparable to adults) that also differed between chicks from supplemented and control nests. Topical application of exogenous corticosterone increased circulating levels nearly to restraint-induced levels and induced downregulation of HPA responsiveness to the acute challenge of handling. Parental supplemental feeding did not affect absorbance/clearance or negative feedback. Thus, while endogenous secretion of corticosterone in young chicks is sensitive to environmental context, other aspects of the HPA function, such as rapid negative feedback and/or the ability to clear acute elevations in corticosterone, are not. We conclude that 5 day old kittiwake chicks are capable of robust adrenocortical responses to novel challenges, and are sensitive to parental food availability, which may be transduced behaviorally, nutritionally, or via maternal effects. Questions remain about the function of such rapid, large acute stress-induced increases in corticosterone in very young chicks.

2.
Microbiol Spectr ; : e0418023, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38666793

RESUMO

The high-consequence pathogen Bacillus anthracis causes human anthrax and often results in lethal infections without the rapid administration of effective antimicrobial treatment. Antimicrobial resistance profiling is therefore critical to inform post-exposure prophylaxis and treatment decisions, especially during emergencies such as outbreaks or where intentional release is suspected. Whole-genome sequencing using a rapid long-read sequencer can uncover antimicrobial resistance patterns if genetic markers of resistance are known. To identify genomic markers associated with antimicrobial resistance, we isolated B. anthracis derived from the avirulent Sterne strain with elevated minimal inhibitory concentrations to clarithromycin. Mutants were characterized both phenotypically through broth microdilution susceptibility testing and observations during culturing, as well as genotypically with whole-genome sequencing. We identified two different in-frame insertions in the L22 ribosomal protein-encoding gene rplV, which were subsequently confirmed to be involved in clarithromycin resistance through the reversion of the mutant gene to the parent (drug-susceptible) sequence. Detection of the rplV insertions was possible with rapid long-read sequencing, with a time-to-answer within 3 h. The mutations associated with clarithromycin resistance described here will be used in conjunction with known genetic markers of resistance for other antimicrobials to strengthen the prediction of antimicrobial resistance in B. anthracis.IMPORTANCEThe disease anthrax, caused by the pathogen Bacillus anthracis, is extremely deadly if not treated quickly and appropriately. Clarithromycin is an antibiotic recommended for the treatment and post-exposure prophylaxis of anthrax by the Centers for Disease Control and Prevention; however, little is known about the ability of B. anthracis to develop resistance to clarithromycin or the mechanism of that resistance. The characterization of clarithromycin-resistant isolates presented here provides valuable information for researchers and clinicians in the event of a release of the resistant strain. Additionally, knowledge of the genetic basis of resistance provides a foundation for susceptibility prediction through rapid genome sequencing to inform timely treatment decisions.

3.
Cell Metab ; 35(11): 1976-1995.e6, 2023 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-37939658

RESUMO

Low-protein diets promote health and longevity in diverse species. Restriction of the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine recapitulates many of these benefits in young C57BL/6J mice. Restriction of dietary isoleucine (IleR) is sufficient to promote metabolic health and is required for many benefits of a low-protein diet in C57BL/6J males. Here, we test the hypothesis that IleR will promote healthy aging in genetically heterogeneous adult UM-HET3 mice. We find that IleR improves metabolic health in young and old HET3 mice, promoting leanness and glycemic control in both sexes, and reprograms hepatic metabolism in a sex-specific manner. IleR reduces frailty and extends the lifespan of male and female mice, but to a greater degree in males. Our results demonstrate that IleR increases healthspan and longevity in genetically diverse mice and suggests that IleR, or pharmaceuticals that mimic this effect, may have potential as a geroprotective intervention.


Assuntos
Isoleucina , Longevidade , Masculino , Feminino , Animais , Camundongos , Isoleucina/farmacologia , Promoção da Saúde , Camundongos Endogâmicos C57BL , Aminoácidos de Cadeia Ramificada/metabolismo
4.
FEBS J ; 290(23): 5566-5580, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37634202

RESUMO

N-carbamoyl-ß-alanine amidohydrolase (CßAA) constitutes one of the most important groups of industrially relevant enzymes used in the production of optically pure amino acids and derivatives. In this study, a CßAA-encoding gene from Rhizobium radiobacter strain MDC 8606 was cloned and overexpressed in Escherichia coli. The purified recombinant enzyme (RrCßAA) showed a specific activity of 14 U·mg-1 using N-carbamoyl-ß-alanine as a substrate with an optimum activity at 55 °C and pH 8.0. In this work, we report also the first prokaryotic CßAA structure at a resolution of 2.0 Å. A discontinuous catalytic domain and a dimerisation domain attached through a flexible hinge region at the domain interface have been revealed. We identify key ligand binding residues, including a conserved glutamic acid (Glu131), histidine (H385) and arginine (Arg291). Our results allowed us to explain the preference of the enzyme for linear carbamoyl substrates, as large and branched carbamoyl substrates cannot fit in the active site of the enzyme. This work envisages the use of RrCßAA from R. radiobacter MDC 8606 for the industrial production of L-α-, L-ß- and L-γ-amino acids. The structural analysis provides new insights on enzyme-substrate interaction, which shed light on engineering of CßAAs for high catalytic activity and broad substrate specificity.


Assuntos
Agrobacterium tumefaciens , Aminoácidos , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/metabolismo , beta-Alanina , Amidoidrolases/genética , Amidoidrolases/metabolismo , Especificidade por Substrato
5.
ISME J ; 17(10): 1601-1611, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37422599

RESUMO

The ecophysiology of complete ammonia-oxidizing bacteria (CMX) of the genus Nitrospira and their widespread occurrence in groundwater suggests that CMX bacteria have a competitive advantage over ammonia-oxidizing bacteria (AOB) and archaea (AOA) in these environments. However, the specific contribution of their activity to nitrification processes has remained unclear. We aimed to disentangle the contribution of CMX, AOA and AOB to nitrification and to identify the environmental drivers of their niche differentiation at different levels of ammonium and oxygen in oligotrophic carbonate rock aquifers. CMX ammonia monooxygenase sub-unit A (amoA) genes accounted on average for 16 to 75% of the total groundwater amoA genes detected. Nitrification rates were positively correlated to CMX clade A associated phylotypes and AOB affiliated with Nitrosomonas ureae. Short-term incubations amended with the nitrification inhibitors allylthiourea and chlorate suggested that AOB contributed a large fraction to overall ammonia oxidation, while metaproteomics analysis confirmed an active role of CMX in both ammonia and nitrite oxidation. Ecophysiological niche differentiation of CMX clades A and B, AOB and AOA was linked to their requirements for ammonium, oxygen tolerance, and metabolic versatility. Our results demonstrate that despite numerical predominance of CMX, the first step of nitrification in oligotrophic groundwater appears to be primarily governed by AOB. Higher growth yields at lower ammonia turnover rates and energy derived from nitrite oxidation most likely enable CMX to maintain consistently high populations.


Assuntos
Compostos de Amônio , Água Subterrânea , Nitrificação , Amônia/metabolismo , Oxirredução , Microbiologia do Solo , Bactérias , Archaea , Compostos de Amônio/metabolismo , Oxigênio/metabolismo , Filogenia
6.
J World Fed Orthod ; 12(4): 166-172, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37419789

RESUMO

The straight-wire appliance is an individualized, fully-programmed appliance system that has been in clinical use since the early 1970s. A study of tooth positions in individuals with naturally occurring harmonious occlusions led to the discovery of the Six Keys to Normal (Optimal) Occlusion which provided data for bracket features and prescription values incorporated into the straight-wire appliance. It was based on the notion that tooth anatomy, morphology, and optimal positions were alike enough among individuals, regardless of age, sex, or race to justify using prefabricated brackets with average prescription values. New technologies have led to advancements in appliance customization. Customized brackets can be made-to-order with one-of-a-kind prescription values and bracket base contours that fit precisely to the morphologic characteristics of the teeth. If costs and material qualities were comparable, would treatment efficiency or treatment outcomes be superior when using a customized appliance compared with a prefabricated straight-wire appliance? If not, why not?


Assuntos
Braquetes Ortodônticos , Fios Ortodônticos , Humanos , Oclusão Dentária , Resultado do Tratamento
7.
BMJ Open ; 13(3): e065769, 2023 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-36898757

RESUMO

INTRODUCTION: Sleep and epilepsy have an established bidirectional relationship yet only one randomised controlled clinical trial has assessed the effectiveness of behavioural sleep interventions for children with epilepsy. The intervention was successful, but was delivered via face-to-face educational sessions with parents, which are costly and non-scalable to population level. The Changing Agendas on Sleep, Treatment and Learning in Epilepsy (CASTLE) Sleep-E trial addresses this problem by comparing clinical and cost-effectiveness in children with Rolandic epilepsy between standard care (SC) and SC augmented with a novel, tailored parent-led CASTLE Online Sleep Intervention (COSI) that incorporates evidence-based behavioural components. METHODS AND ANALYSES: CASTLE Sleep-E is a UK-based, multicentre, open-label, active concurrent control, randomised, parallel-group, pragmatic superiority trial. A total of 110 children with Rolandic epilepsy will be recruited in outpatient clinics and allocated 1:1 to SC or SC augmented with COSI (SC+COSI). Primary clinical outcome is parent-reported sleep problem score (Children's Sleep Habits Questionnaire). Primary health economic outcome is the incremental cost-effectiveness ratio (National Health Service and Personal Social Services perspective, Child Health Utility 9D Instrument). Parents and children (≥7 years) can opt into qualitative interviews and activities to share their experiences and perceptions of trial participation and managing sleep with Rolandic epilepsy. ETHICS AND DISSEMINATION: The CASTLE Sleep-E protocol was approved by the Health Research Authority East Midlands (HRA)-Nottingham 1 Research Ethics Committee (reference: 21/EM/0205). Trial results will be disseminated to scientific audiences, families, professional groups, managers, commissioners and policymakers. Pseudo-anonymised individual patient data will be made available after dissemination on reasonable request. TRIAL REGISTRATION NUMBER: ISRCTN13202325.


Assuntos
Epilepsia Rolândica , Medicina Estatal , Humanos , Criança , Terapia Comportamental/métodos , Aprendizagem , Sono , Análise Custo-Benefício , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
8.
Cancer Med ; 12(6): 7029-7038, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36464833

RESUMO

PURPOSE: Patients with unresectable dedifferentiated liposarcoma (DDLPS) have poor overall outcomes. Few genomic alterations have been identified with limited therapeutic options. EXPERIMENTAL DESIGN: Patients treated at Levine Cancer Institute with DDLPS were identified. Next generation sequencing (NGS), immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) testing were performed on tumor tissue collected at diagnosis or recurrence/progression. Confirmation of genomic alterations was performed by orthologous methods and correlated with clinical outcomes. Univariate Cox regression was used to identify genomic alterations associated with clinical outcomes. RESULTS: Thirty-eight DDLPS patients with adequate tissue for genomic profiling and clinical data were identified. Patient characteristics included: median age at diagnosis (66 years), race (84.2% Caucasian), and median follow-up time for the entire cohort was 12.1 years with a range from approximately 3.5 months to 14.1 years. Genes involved in cell cycle regulation, including MDM2 (74%) CDK4 (65%), and CDKN2A (23%), were amplified along with WNT/Notch pathway markers: HMGA2, LGR5, MCL1, and CALR (19%-29%). While common gene mutations were identified, PDE4DIP and FOXO3 were also mutated in 47% and 34% of patients, respectively, neither of which have been previously reported. FOXO3 was associated with improved overall survival (OS) (HR 0.37; p = 0.043) along with MAML2 (HR 0.30; p = 0.040). Mutations that portended worse prognosis included RECQL4 (disease-specific survival HR 4.67; p = 0.007), MN1 (OS HR = 3.38; p = 0.013), NOTCH1 (OS HR 2.28, p = 0.086), and CNTRL (OS HR 2.42; p = 0.090). CONCLUSIONS: This is one of the largest retrospective reports analyzing genomic aberrations in relation to clinical outcomes for patients with DDLPS. Our results suggest therapies targeting abnormalities should be explored and confirmation of prognostic markers is needed. Dedifferentiated liposarcoma is one of the most common subtypes of soft tissue sarcoma yet little is known of its molecular aberrations and possible impact on outcomes. The work presented here is an evaluation of genetic abnormalities among a population of patients with dedifferentiated liposarcoma and how they corresponded with survival and risk of metastases. There were notable gene mutations and amplifications commonly found, some of which had interesting prognostic implications.


Assuntos
Lipossarcoma , Humanos , Hibridização in Situ Fluorescente , Estudos Retrospectivos , Prognóstico , Lipossarcoma/genética , Lipossarcoma/diagnóstico , Lipossarcoma/patologia , Genômica , Proteínas Proto-Oncogênicas c-mdm2/genética
9.
Teach Learn Med ; : 1-15, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36426664

RESUMO

Problem: One in four American adults have a disability, which makes people with disabilities the largest minority group in the United States (U.S.). Chronic diseases are prevalent within this population, which faces myriad barriers that limit access to healthcare and create significant health care disparities. Yet, disability awareness programs are limited in U.S. medical schools and graduates report a sense of unpreparedness to care for this population. Intervention: Come Roll with Me (CRWM) was implemented as an interprofessional, preclinical experience to provide medical and Doctor of Physical Therapy (DPT) students an opportunity to engage with wheelchair users and one another. Students rotated through four stations with a licensed physical therapist and wheelchair user facilitator. Stations included (1) manual wheelchair self-propulsion, (2) accessible parking, (3) transfers, and (4) open dialog on barriers to healthcare led by the wheelchair user. Context: This study sought to assess the impact of CRWM on students' understanding of the barriers and health disparities faced by individuals with disabilities. Assessment was conducted using course evaluations, thematic analysis of student reflection essays and a focus group with the wheelchair user facilitators to determine if CRWM met pre-implementation program goals and objectives, including the Interprofessional Educational Collaborative (IPEC) core competencies. Impact: Student reflections from both disciplines indicated that learners were able to identify a variety of barriers faced by people with disabilities and prioritize methods to mitigate these factors. Approximately 91% of medical students agreed or strongly agreed that CRWM was effective in their learning on course evaluations. Wheelchair user facilitators noted three important outcomes of CRWM: educating, teaming, and impact on students. Lesson Learned: Come Roll with Me is a robust educational activity, as evidenced by the program meeting all goals and objectives as well as (IPEC) core competencies. It provides students a unique opportunity to learn about disability from another profession and wheelchair users. People with disabilities and DPT students are a unique and underutilized pool of educators in undergraduate medical education.

10.
J Pediatr Neurosci ; 17(Suppl 1): S21-S28, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36388007

RESUMO

Three-dimensional (3D) photography is becoming more common in craniosynostosis practice and may be used for research, archiving, and as a planning tool. In this article, an overview of the uses of 3D photography will be given, including systems available and illustrations of how they can be used. Important innovations in 3D computer vision will also be discussed, including the potential role of statistical shape modeling and analysis as an outcomes tool with presentation of some results and a review of the literature on the topic. Potential future applications in diagnostics using machine learning will also be presented.

11.
Sci Rep ; 12(1): 17286, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36241663

RESUMO

Cellular biology occurs through myriad interactions between diverse molecular components, many of which assemble in to specific complexes. Various techniques can provide a qualitative survey of which components are found in a given complex. However, quantitative analysis of the absolute number of molecules within a complex (known as stoichiometry) remains challenging. Here we provide a novel method that combines fluorescence microscopy and statistical modelling to derive accurate molecular counts. We have devised a system in which batches of a given biomolecule are differentially labelled with spectrally distinct fluorescent dyes (label A or B), and mixed such that B-labelled molecules are vastly outnumbered by those with label A. Complexes, containing this component, are then simply scored as either being positive or negative for label B. The frequency of positive complexes is directly related to the stoichiometry of interaction and molecular counts can be inferred by statistical modelling. We demonstrate this method using complexes of Adenovirus particles and monoclonal antibodies, achieving counts that are in excellent agreement with previous estimates. Beyond virology, this approach is readily transferable to other experimental systems and, therefore, provides a powerful tool for quantitative molecular biology.


Assuntos
Corantes Fluorescentes , Modelos Estatísticos , Anticorpos Monoclonais , Microscopia de Fluorescência
12.
Environ Microbiol ; 24(11): 5437-5449, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36123312

RESUMO

The candidate phylum Omnitrophica-recently termed Omnitrophota, and originally known as OP3-is an understudied bacterial clade that has primarily been found in aquatic ecosystems. To characterize the diversity and ecology of this phylum, we reconstructed 55 Omnitrophota metagenome-assembled genomes (MAGs) from a well-characterized groundwater system within central Germany and placed them within the context of publicly available genomes. Seven clades were identified, four of which contained novel genomes obtained from our groundwater system. All clades exhibited the capacity for type IV pili, type II secretion systems, glycogen storage, and carbohydrate degradation. Only the characterized Cand. Omnitrophus magneticus genome exhibited functions associated with magnetosome construction. Clades were characterized by sets of traits rather than unique pathways, which were then used to infer ecological strategies. These lifestyles consisted of mixotrophs, obligate fermenters, and versatile respiratory heterotrophs. Patterns in 16S rRNA gene amplicons from a 6 years, monthly sampled groundwater time-series dataset reflected the persistent and widespread occurrence of Clade 7 Wood-Ljungdahl utilizing mixotrophs and highlight this group as a core member of the groundwater community. Overall, this study uncovered, characterized, and contextualized the metabolic and phylogenetic diversity within phylum Omnitrophota, and predicts that environmental populations may mediate both nitrogen and sulfur cycling, along with organic matter production and degradation within aquatic ecosystems.


Assuntos
Ecossistema , Metagenoma , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Filogenia , Bactérias
13.
Proc Biol Sci ; 289(1978): 20220139, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35858061

RESUMO

Determinants of individual variation in reallocation of limited resources towards self-maintenance versus reproduction are not well known. We tested the hypothesis that individual heterogeneity in long-term 'somatic state' (i) explains variation in endocrine and behavioural responses to environmental challenges, and (ii) is associated with variation in strategies for allocating to self-maintenance versus reproduction. We used relative telomere length as an indicator of somatic state and experimentally generated an abrupt short-term reduction of food availability (withdrawal of food supplementation) for free-living seabirds (black-legged kittiwakes, Rissa tridactyla). Incubating male kittiwakes responded to withdrawal by increasing circulating corticosterone and losing more weight compared to continuously supplemented controls. Males with longer telomeres increased time in directed travel regardless of treatment, while experiencing smaller increases in corticosterone. Males with longer telomeres fledged more chicks in the control group and tended to be more likely to return regardless of treatment. This study supports the hypothesis that somatic state can explain variation in short-term physiological and behavioural responses to challenges, and longer-term consequences for fitness. Male kittiwakes with longer telomeres appear to have prioritized investment in self over investment in offspring under challenging conditions.


Assuntos
Charadriiformes , Corticosterona , Animais , Charadriiformes/fisiologia , Alimentos , Masculino , Reprodução/fisiologia , Telômero
14.
Am J Sports Med ; 50(9): 2381-2389, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35833923

RESUMO

BACKGROUND: Lateral meniscal oblique radial tears (LMORTs) affect joint and meniscal stability in anterior cruciate ligament (ACL)-deficient knees. PURPOSE: To determine the clinically relevant kinematics associated with the most common posterior horn LMORT lesion types, types 3 (LMORT3) and 4 (LMORT4), untreated versus arthroscopic repair versus partial meniscectomy in combination with ACL reconstruction (ACLR). STUDY: Controlled laboratory study. METHODS: Sixteen cadaveric knees underwent robotic testing for anterior drawer and pivot-shift simulations at multiple knee flexion angles in ACL-intact and ACL-deficient states, followed by sequential testing of arthroscopic ACLR, LMORT3 lesion, LMORT3 repair, and partial meniscectomy (n = 8). The same testing sequence was performed for LMORT4 lesions (n = 8). RESULTS: ACLR restored kinematics in ACL-deficient knees to intact levels for all metrics tested. For anterior drawer, ACLR + LMORT3 tear and partial meniscectomy resulted in significantly greater anterior translation compared with ACL-intact at all angles (P < .05) and compared with ACLR at 60° and 90° (P < .014). For pivot shift, compared with ACL-intact knees, ACLR + LMORT3 tear resulted in significantly more anterior translation at 15° (P = .041); and for ACLR + partial meniscectomy, at both 0° and 15° (P < .03). ACLR + LMORT4 tear and partial meniscectomy resulted in significantly greater anterior translation for anterior drawer (P < .04) and pivot-shift testing (P < .05) compared with intact and ACLR knees at all angles tested. ACLR + LMORT3 repair and ACLR + LMORT4 repair restored kinematics to ACLR and intact levels at all angles tested. ACLR + LMORT3 tear (P < .008) and both LMORT4 tear and partial meniscectomy (P < .05) resulted in increased meniscal extrusion compared with intact and ACLR statuses at all tested angles for anterior drawer and pivot shift, while repairs restored meniscal stability to ACLR and intact levels. CONCLUSION: Untreated LMORT tears increased anterior translation, pivot shift, and meniscal extrusion after ACLR, while partial meniscectomy further exacerbated these detrimental effects in this cadaveric model. In contrast, arthroscopic side-to-side repair of LMORT lesions effectively restored measured knee kinematics. CLINICAL RELEVANCE: LMORT lesions are common with ACL tears and adversely affect joint stability and meniscal extrusion. This study highlights the importance of repair of LMORT 3 and 4 lesions at the time of ACLR.


Assuntos
Lesões do Ligamento Cruzado Anterior , Instabilidade Articular , Lacerações , Ligamento Cruzado Anterior/cirurgia , Lesões do Ligamento Cruzado Anterior/cirurgia , Fenômenos Biomecânicos , Cadáver , Humanos , Instabilidade Articular/cirurgia , Articulação do Joelho/cirurgia , Meniscectomia , Meniscos Tibiais/cirurgia , Ruptura
15.
Rev Sci Instrum ; 93(6): 065102, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35778016

RESUMO

A dual-axis torsional thrust stand was successfully demonstrated at the Air Force Research Laboratory, enabling direct simultaneous thrust and mass loss measurement for the Air Force Electrospray Thruster Series 2 passively fed electrospray thruster. The dual-axis system is effectively two nulled torsional thrust stands sharing a single dual-axis gimbal with a thrust and mass resolution of ±0.2 µN and ±0.04 mg, respectively. The development of this system was inspired by a need for direct efficiency characterization of electrosprays via in situ mass measurements, and performance was compared to thruster masses measured pre- and post-testing using an analytical balance. Mass consumption data captured via the dual-axis stand, which is calibrated to a traceable uncertainty of 1.6%, varied between -5% and 18% as compared to analytical balance measurements throughout a multi-month testing effort highlighting the limitations in pre/post-weighing as a method for capturing propellant consumption due to absorption of atmospheric moisture when thrusters are removed from vacuum. Thrust stand tests were limited to short term operation with a daily available testing window of ∼5 h due to thrust stand drift following the 24 h cyclic temperature variations of the testing facility. A thorough investigation into the root cause of ambient thermal drift suggests that the thermal response of commercial flex-pivot bearings is directly producing spurious torques on the order of 10 µN m/°C. Additionally, unresolved charging effects on thrust stand hardware currently limit thrust stand operation to tests operating with a positive thruster polarity. Further development and long duration test stability require both a targeted investigation into flex-pivot thermal response and minimization of facility effects.

16.
Elife ; 112022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35522041

RESUMO

Internephron interaction is fundamental for kidney function. Earlier studies have shown that nephrons signal to each other, synchronize over short distances, and potentially form large synchronized clusters. Such clusters would play an important role in renal autoregulation, but due to the technological limitations, their presence is yet to be confirmed. In the present study, we introduce an approach for high-resolution laser speckle imaging of renal blood flow and apply it to estimate the frequency and phase differences in rat kidney microcirculation under different conditions. The analysis unveiled the spatial and temporal evolution of synchronized blood flow clusters of various sizes, including the formation of large (>90 vessels) and long-lived clusters (>10 periods) locked at the frequency of the tubular glomerular feedback mechanism. Administration of vasoactive agents caused significant changes in the synchronization patterns and, thus, in nephrons' co-operative dynamics. Specifically, infusion of vasoconstrictor angiotensin II promoted stronger synchronization, while acetylcholine caused complete desynchronization. The results confirm the presence of the local synchronization in the renal microcirculatory blood flow and that it changes depending on the condition of the vascular network and the blood pressure, which will have further implications for the role of such synchronization in pathologies development.


Assuntos
Rim , Circulação Renal , Animais , Glomérulos Renais/irrigação sanguínea , Glomérulos Renais/fisiologia , Microcirculação , Néfrons/fisiologia , Ratos , Circulação Renal/fisiologia
17.
Hum Gene Ther ; 33(17-18): 845-856, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35435758

RESUMO

There are two significant challenges for analysts conducting economic evaluations of advanced therapy medicinal products (ATMPs): (1) estimating long-term treatment effects in the absence of mature clinical data and (2) capturing potentially complex hazard functions. This review identifies and critiques a variety of methods that can be used to overcome these challenges. The narrative review is informed by a rapid literature review of methods used for the extrapolation of survival analyses in the economic evaluation of ATMPs. There are several methods that are more suitable than traditional parametric survival modeling approaches for capturing complex hazard functions, including, cure-mixture models and restricted cubic spline models. In the absence of mature clinical data, analysts may augment clinical trial data with data from other sources to aid extrapolation, however, the relative merits of applying methods for including data from different sources is not well understood. Given the high and potentially irrecoverable costs of making incorrect decisions concerning the reimbursement or commissioning of ATMPs, it is important that economic evaluations are correctly specified, and that both parameter and structural uncertainty associated with survival extrapolations are considered. Value of information analyses allow for this uncertainty to be expressed explicitly, and in monetary terms.


Assuntos
Análise Custo-Benefício , Análise de Sobrevida
18.
Annu Rev Chem Biomol Eng ; 13: 255-278, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35320695

RESUMO

The emergence of human pluripotent stem cell (hPSC) technology over the past two decades has provided a source of normal and diseased human cells for a wide variety of in vitro and in vivo applications. Notably, hPSC-derived cardiomyocytes (hPSC-CMs) are widely used to model human heart development and disease and are in clinical trials for treating heart disease. The success of hPSC-CMs in these applications requires robust, scalable approaches to manufacture large numbers of safe and potent cells. Although significant advances have been made over the past decade in improving the purity and yield of hPSC-CMs and scaling the differentiation process from 2D to 3D, efforts to induce maturation phenotypes during manufacturing have been slow. Process monitoring and closed-loop manufacturing strategies are just being developed. We discuss recent advances in hPSC-CM manufacturing, including differentiation process development and scaling and downstream processes as well as separation and stabilization.


Assuntos
Miócitos Cardíacos , Células-Tronco Pluripotentes , Diferenciação Celular , Humanos
19.
J Knee Surg ; 35(4): 456-465, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32942333

RESUMO

Multiligament knee injury (MLKI) typically requires surgical reconstruction to achieve the optimal outcomes for patients. Revision and failure rates after surgical reconstruction for MLKI can be as high as 40%, suggesting the need for improvements in graft constructs and implantation techniques. This study assessed novel graft constructs and surgical implantation and fixation techniques for anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), posterior medial corner (PMC), and posterior lateral corner (PLC) reconstruction. Study objectives were (1) to describe each construct and technique in detail, and (2) to optimize MLKI reconstruction surgical techniques using these constructs so as to consistently implant grafts in correct anatomical locations while preserving bone stock and minimizing overlap. Cadaveric knees (n = 3) were instrumented to perform arthroscopic-assisted and open surgical creation of sockets and tunnels for all components of MLKI reconstruction using our novel techniques. Sockets and tunnels with potential for overlap were identified and assessed to measure the minimum distances between them using gross, computed tomographic, and finite element analysis-based measurements. Percentage of bone volume spared for each knee was also calculated. Femoral PLC-lateral collateral ligament and femoral PMC sockets, as well as tibial PCL and tibial PMC posterior oblique ligament sockets, were at high risk for overlap. Femoral ACL and femoral PLC lateral collateral ligament sockets and tibial popliteal tendon and tibial posterior oblique ligament sockets were at moderate risk for overlap. However, with careful planning based on awareness of at-risk MLKI graft combinations in conjunction with protection of the socket/tunnel and trajectory adjustment using fluoroscopic guidance, the novel constructs and techniques allow for consistent surgical reconstruction of all major ligaments in MLKIs such that socket and tunnel overlap can be consistently avoided. As such, the potential advantages of the constructs, including improved graft-to-bone integration, capabilities for sequential tensioning of the graft, and bone sparing effects, can be implemented.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Traumatismos do Joelho , Ligamento Cruzado Posterior , Ligamento Cruzado Anterior/cirurgia , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Humanos , Traumatismos do Joelho/cirurgia , Articulação do Joelho/cirurgia , Ligamento Cruzado Posterior/cirurgia
20.
Angle Orthod ; 92(1): 3-10, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34383019

RESUMO

OBJECTIVES: To evaluate incisor position and its relationship to alveolar bone in untreated optimal occlusions and in untreated Class II malocclusions. MATERIALS AND METHODS: Fifty-seven lateral cephalograms of individuals with naturally occurring optimal occlusions (mean age = 23 years) were used to assess positions of central incisors and their relationships to alveolar bone. Data were compared to a sample of 57 individuals with untreated Class II malocclusions with concurrent anterior-posterior (AP) skeletal discrepancies (mean age = 16.9 years). RESULTS: Significant intergroup differences were found for AP jaw relationship, maxillary alveolar bone thickness, mandibular incisor inclination, maxillary incisor root distance to labial surface of alveolar bone, and mandibular incisor root apex distance to labial surface of alveolar bone. Small differences between females and males existed for several variables. In both samples, maxillary incisor roots were located closer to the labial surface of alveolar process than to the palatal surface by roughly a 2:1 ratio. Mandibular incisor root apices were generally equidistant from the labial and lingual surfaces of the alveolus in the optimal sample but closer to the lingual surface in the Class II sample. CONCLUSIONS: Maxillary incisors tend to occupy the anterior one-third of the alveolus in untreated individuals, regardless of AP interarch dental relationships or AP jaw relationships. Mandibular incisor root apices tend to be centered within the alveolus in untreated optimal occlusions but are more positively inclined, and their root apices are more posterior in untreated Class II malocclusions.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Incisivo , Adolescente , Adulto , Processo Alveolar/diagnóstico por imagem , Feminino , Humanos , Incisivo/diagnóstico por imagem , Masculino , Mandíbula/diagnóstico por imagem , Maxila/diagnóstico por imagem , Adulto Jovem
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