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1.
Opt Express ; 32(8): 14490-14505, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38859392

RESUMO

This paper presents a theoretical and experimental characterization of an instability phenomenon observed in single-frequency fiber amplifiers when the frequency of the seed laser is modulated. The instability manifests itself as fluctuating elastic back-reflections that occur only when the frequency is decreasing with time. The theory is a generalization of a coupled-mode model developed for a single-frequency fiber amplifier back-seeded with a constant frequency shift relative to the main signal. It can explain most observed features of the experiments in a qualitative and semi-quantitative way. Open questions and directions for further developments are also discussed.

2.
Fluids Barriers CNS ; 21(1): 10, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273331

RESUMO

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a syndrome exhibiting elevated intracranial pressure (ICP), visual disturbances, and severe headache. IIH primarily affects young obese women, though it can occur in individuals of any age, BMI, and sex. IIH is characterized by systemic metabolic dysregulation with a profile of increased androgen hormones. However, the contribution of obesity/hormonal perturbations to cerebrospinal fluid (CSF) dynamics remains unresolved. METHODS: We employed obese female Zucker rats and adjuvant testosterone to reveal IIH causal drivers. ICP and CSF dynamics were determined with in vivo experimentation and magnetic resonance imaging, testosterone levels assessed with mass spectrometry, and choroid plexus function revealed with transcriptomics. RESULTS: Obese rats had undisturbed CSF testosterone levels and no changes in ICP or CSF dynamics. Adjuvant testosterone treatment of obese rats elevated the CSF secretion rate, although with no effect on the ICP, due to elevated CSF drainage capacity of these rats. CONCLUSIONS: Obesity in itself therefore does not suffice to recapitulate the IIH symptoms in rats, but modulation of CSF dynamics appears with adjuvant testosterone treatment, which mimics the androgen excess observed in female IIH patients. Obesity-induced androgen dysregulation may thus contribute to the disease mechanism of IIH and could potentially serve as a future therapeutic target.


Assuntos
Pseudotumor Cerebral , Humanos , Feminino , Ratos , Animais , Androgênios , Ratos Zucker , Obesidade , Testosterona
3.
Opt Express ; 31(21): 34325-34347, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37859192

RESUMO

It is widely acknowledged that the phase noise of an optical frequency comb primarily stems from the common mode (carrier-envelope) and the repetition rate phase noise. However, owing to technical noise sources or other intricate intra-cavity factors, residual phase noise components, distinct from the common mode and the repetition rate phase noise, may also exist. We introduce a measurement technique that combines subspace tracking and multi-heterodyne coherent detection for the separation of different phase noise sources. This method allows us to break down the overall phase noise sources associated with a specific comb-line into distinct phase noise components associated with the common mode, the repetition rate and the residual phase noise terms. The measurement method allow us, for the first time, to identify and measure residual phase noise sources of a frequency modulated mode-locked laser.

4.
Fluids Barriers CNS ; 20(1): 69, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37784168

RESUMO

BACKGROUND: Repetitive transient intracranial pressure waveform elevations up to 50 mmHg (ICP B-waves) are often used to define pathological conditions and determine indications for ICP-reducing treatment. We recently showed that nocturnal transient ICP elevations are present in patients without structural brain lesions or hydrocephalus in whom they are associated with sleep apnea. However, whether this signifies a general association between ICP macropatterns and sleep apnea remains unknown. METHODS: We included 34 patients with hydrocephalus, or idiopathic intracranial hypertension (IIH), who were referred to the Neurosurgical Department, Copenhagen, Denmark, from 2017 to 2021. Every patient underwent diagnostic overnight ICP monitoring for clinical indications, with simultaneous polysomnography (PSG) sleep studies. All transient ICP elevations were objectively quantified in all patients. Three patients were monitored with continuous positive airway pressure (CPAP) treatment for an additional night. RESULTS: All patients had transient ICP elevations associated with sleep apnea. The mean temporal delay from sleep apnea to transient ICP elevations for all patients was 3.6 s (SEM 0.2 s). Ramp-type transient ICP elevations with a large increase in ICP were associated with rapid eye movement (REM) sleep and sinusoidal-type elevations with non-REM (NREM) sleep. In three patients treated with CPAP, the treatment reduced the number of transient ICP elevations with a mean of 37%. CPAP treatment resulted in insignificant changes in the average ICP in two patients but elevated the average ICP during sleep in one patient by 5.6 mmHg. CONCLUSION: The findings suggest that sleep apnea causes a significant proportion of transient ICP elevations, such as B-waves, and sleep apnea should be considered in ICP evaluation. Treatment of sleep apnea with CPAP can reduce the occurrence of transient ICP elevations. More research is needed on the impact of slow oscillating mechanisms on transient ICP elevations during high ICP and REM sleep.


Assuntos
Hidrocefalia , Hipertensão Intracraniana , Síndromes da Apneia do Sono , Humanos , Pressão Intracraniana , Síndromes da Apneia do Sono/complicações , Síndromes da Apneia do Sono/terapia , Sono REM , Pressão Positiva Contínua nas Vias Aéreas/métodos
6.
Front Psychol ; 14: 1193449, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37546468

RESUMO

Introduction: The purpose of this investigation was to examine the influence of supportive parent-adolescent relationships on adolescent adjustment (i.e., prosocial behavior, aggression, depressive symptoms) both directly and indirectly (via adolescent emotion regulation). Scholars have posited that adolescent emotion regulation (ER) may serve as an underlying mechanism in the link between parenting and adolescent adjustment. Supportive parent-adolescent relationships (i.e., openness, acceptance, emotional responsiveness) may be a key emotion socialization mechanism influencing adolescent ER. Methods: The sample included 206 adolescents (Age Range= 10-18years; 51% female; 70.4% ethnic minorities) and one primary caregiver (83.3% biological mothers, 38.7% single parents). Structural equation modeling (SEM) was implemented to investigate the direct and indirect (via adolescent ER) effects of supportive parent-adolescent relationships on adolescent adjustment. We also explored whether these indirect and direct effects varied by adolescent sex and age. Results: Results suggested direct and indirect (via adolescent ER) links between supportive parent-adolescent relationships and adolescent prosocial behavior, aggressive behavior, and depressive symptoms. Moreover, evidence indicated that many of these pathways were significant for boys but not girls. No evidence of youth age as a moderator was found. Discussion: These findings highlight the important role supportive parent-adolescent relationships play in adolescent emotional and behavioral adjustment. Parenting programs could focus on facilitating a mutually responsive parent-adolescent relationship with a specific focus on the dynamic nature of emotion socialization during adolescence.

7.
PLoS Pathog ; 19(6): e1011442, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37307293

RESUMO

A signature remains elusive of naturally-acquired immunity against Plasmodium falciparum. We identified P. falciparum in a 14-month cohort of 239 people in Kenya, genotyped at immunogenic parasite targets expressed in the pre-erythrocytic (circumsporozoite protein, CSP) and blood (apical membrane antigen 1, AMA-1) stages, and classified into epitope type based on variants in the DV10, Th2R, and Th3R epitopes in CSP and the c1L region of AMA-1. Compared to asymptomatic index infections, symptomatic malaria was associated with reduced reinfection by parasites bearing homologous CSP-Th2R (adjusted hazard ratio [aHR]:0.63; 95% CI:0.45-0.89; p = 0.008) CSP-Th3R (aHR:0.71; 95% CI:0.52-0.97; p = 0.033), and AMA-1 c1L (aHR:0.63; 95% CI:0.43-0.94; p = 0.022) epitope types. The association of symptomatic malaria with reduced hazard of homologous reinfection was strongest for rare epitope types. Symptomatic malaria provides more durable protection against reinfection with parasites bearing homologous epitope types. The phenotype represents a legible molecular epidemiologic signature of naturally-acquired immunity by which to identify new antigen targets.


Assuntos
Vacinas Antimaláricas , Malária Falciparum , Malária , Parasitos , Animais , Plasmodium falciparum/metabolismo , Reinfecção , Proteínas de Protozoários/metabolismo , Malária/parasitologia , Malária Falciparum/parasitologia , Antígenos de Protozoários , Epitopos/genética , Anticorpos Antiprotozoários/metabolismo
8.
Fluids Barriers CNS ; 20(1): 44, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328884

RESUMO

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a condition characterized by increased intracranial pressure (ICP), impaired vision, and headache. Most cases of IIH occur in obese women of childbearing age, though age, BMI, and female sex do not encompass all aspects of IIH pathophysiology. Systemic metabolic dysregulation has been identified in IIH with a profile of androgen excess. However, the mechanistic coupling between obesity/hormonal perturbations and cerebrospinal fluid dynamics remains unresolved. METHODS: Female Wistar rats were either fed a high fat diet (HFD) for 21 weeks or exposed to adjuvant testosterone treatment for 28 days to recapitulate IIH causal drivers. Cerebrospinal fluid (CSF) and blood testosterone levels were determined with mass spectrometry, ICP and CSF dynamics with in vivo experimentation, and the choroid plexus function revealed with transcriptomics and ex vivo isotope-based flux assays. RESULTS: HFD-fed rats presented with increased ICP (65%), which was accompanied by increased CSF outflow resistance (50%) without altered CSF secretion rate or choroid plexus gene expression. Chronic adjuvant testosterone treatment of lean rats caused elevated ICP (55%) and CSF secretion rate (85%), in association with increased activity of the choroid plexus Na+,K+,2Cl- cotransporter, NKCC1. CONCLUSIONS: HFD-induced ICP elevation in experimental rats occurred with decreased CSF drainage capacity. Adjuvant testosterone, mimicking the androgen excess observed in female IIH patients, elevated the CSF secretion rate and thus ICP. Obesity-induced androgen dysregulation may thus contribute to the disease mechanism of IIH.


Assuntos
Hipertensão Intracraniana , Pseudotumor Cerebral , Feminino , Ratos , Animais , Pressão Intracraniana/fisiologia , Testosterona , Androgênios , Dieta Hiperlipídica/efeitos adversos , Ratos Wistar , Obesidade/complicações
9.
Am J Cardiol ; 199: 92-99, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37202325

RESUMO

Pulmonary embolism is a risk factor for chronic thromboembolic pulmonary hypertension (CTEPH), but the prognostic impact of CTEPH on venous thromboembolism (VTE) mortality remains unclear. We examined the impact of CTEPH and other pulmonary hypertension (PH) subtypes on long-term mortality after VTE. We conducted a nationwide, population-based cohort study of all adult Danish patients alive 2 years after incident VTE without previous PH from 1995 to 2020 (n = 129,040). We used inverse probability of treatment weights in a Cox model to calculate standardized mortality rate ratios (SMRs) of the association between receiving a first-time PH diagnosis ≤2 years after incident VTE and mortality (all-cause, cardiovascular, and cancer). We grouped PH as PH associated with left-sided cardiac disease (group II), PH associated with lung diseases and/or hypoxia (group III), CTEPH (group IV), and unclassified (remaining patients). Total follow-up was 858,954 years. The SMR associated with PH overall was 1.99 (95% confidence interval 1.75 to 2.27) for all-cause, 2.48 (1.90 to 3.23) for cardiovascular, and 0.84 (0.60 to 1.17) for cancer mortality. The SMR for all-cause mortality was 2.62 (1.77 to 3.88) for group II, 3.98 (2.85 to 5.56) for group III, 1.88 (1.11 to 3.20) for group IV, and 1.73 (1.47 to 2.04) for unclassified PH. The cardiovascular mortality rate was increased approximately threefold for groups II and III but was not increased for group IV. Only group III was associated with increased cancer mortality. In conclusion, PH diagnosed ≤2 years after incident VTE was associated with an overall twofold increased long-term mortality driven by cardiovascular causes.


Assuntos
Hipertensão Pulmonar , Neoplasias , Embolia Pulmonar , Tromboembolia Venosa , Adulto , Humanos , Tromboembolia Venosa/epidemiologia , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/complicações , Estudos de Coortes , Prognóstico , Embolia Pulmonar/complicações , Embolia Pulmonar/epidemiologia , Embolia Pulmonar/diagnóstico , Fatores de Risco , Neoplasias/complicações , Neoplasias/epidemiologia
10.
J Reprod Infant Psychol ; : 1-11, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36912502

RESUMO

INTRODUCTION: Prior research has identified associations between pregnancy intendedness and maternal-foetal bonding, but no studies have examined the potential mediation of pregnancy happiness on the development of the maternal-infant relationship. METHODS: In 2017-2018, a clinic-based pregnancy cohort of 177 low-income and racially diverse women in a South-Central U.S. state participated in a study examining their pregnancy intentions, attitudes and behaviours. Pregnancy intentions and happiness and demographic characteristics were measured during the first trimester assessment, and maternal-foetal bonding was measured with the Prenatal Attachment Inventory (PAI) during the second trimester. Structural equation modelling was used to examine the associations between intendedness, happiness and bonding. RESULTS: Findings indicate positive associations between intended pregnancies and pregnancy happiness and pregnancy happiness to bonding. The direct effect from intended pregnancy to maternal-foetal bonding was not significant, providing evidence for full mediation. We did not find any associations between pregnancies that were unintended or ambivalent with pregnancy happiness or maternal-foetal bonding. CONCLUSIONS: Pregnancy happiness provides one potential explanation for the association between intended pregnancies and maternal-foetal bonding. These findings have implications for research and practice, as inquiring about mothers' pregnancy attitudes (e.g. how happy they are about their pregnancy) may be more important for maternal psychological health outcomes, such as the maternal-child relationship, than whether or not their pregnancies were intended.

11.
Heliyon ; 9(2): e13562, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36846684

RESUMO

Methods for determination of elements in various types of samples are generally considered to be very precise and highly accurate. For reliable analysis of elements Na, Mg and Ni in food samples is it worthwhile to perform an extensive method validation of high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) according to the principle of pooled calibrations (PoPC). Under routine laboratory conditions of analysis, elevated levels of relative uncertainty of measurement reaching values of more than 50% were detected, which jeopardized the validity of results, even when the measurements in the present study were performed with samples of tap water and borehole water. Comparison of relative uncertainties with corresponding literature results indicates that sample-signal differences may be due to detector noise rather than specimen variations.

12.
J Exerc Sci Fit ; 21(1): 165-176, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36688001

RESUMO

Background/objective: The holistic concept of physical literacy (PL) embraces different person-centered qualities (physical, cognitive, affective/psychological) necessary to lead physically active lifestyles. PL has recently gained increasing attention globally and Europe is no exception. However, scientific endeavors summarizing the current state of PL in Europe are lacking. Therefore, the goal of this study was to comprehensively assess and compare the implementation of PL in research, policy, and practice across the continent. Methods: We assembled a panel of experts representing 25 European countries. Employing a complementary mixed-methods design, the experts first prepared reviews about the current state of PL in their countries (categories: research, practice/policy). The reviews underwent comparative document analysis, ensuring a transnational four-eyes principle. For re-validation purposes, the representatives completed a quantitative survey with questions reflecting the inductive themes from the document analysis. Results: The document analysis resulted in ten disjunct themes (related to "concept", "research", "practice/policy", "future/prospect") and yielded a heterogenous PL situation in Europe. The implementation state was strongly linked to conceptual discussions (e.g., existence of competing approaches), linguistic issues (e.g., translations), and country-specific traditions. Despite growing scholarly attention, PL hesitantly permeates practice and policy in most countries. Nevertheless, the experts largely anticipate increasing popularity of PL for the future. Conclusion: Despite the heterogeneous situation across Europe, the analysis has uncovered similarities among the countries, such as the presence of established yet not identical concepts. Research should intensify academic activities (conceptual-linguistic elaborations, empirical work) before PL may gain further access into practical and political spheres in the long term.

13.
medRxiv ; 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36711685

RESUMO

A signature remains elusive of naturally-acquired immunity against Plasmodium falciparum . We identified P. falciparum in a 14-month cohort of 239 people in Kenya, genotyped at immunogenic parasite targets expressed in the pre-erythrocytic (circumsporozoite protein, CSP) and blood (apical membrane antigen 1, AMA-1) stages, and classified into epitope type based on variants in the DV10, Th2R, and Th3R epitopes in CSP and the c1L region of AMA-1. Compared to asymptomatic index infections, symptomatic malaria was associated with a reduced reinfection by parasites bearing homologous CSP-Th2R (adjusted hazard ratio [aHR]:0.63; 95% CI:0.45-0.89; p=0.008) CSP-Th3R (aHR:0.71; 95% CI:0.52-0.97; p=0.033), and AMA-1 c1L (aHR:0.63; 95% CI:0.43-0.94; p=0.022) epitope types. The association of symptomatic malaria with reduced risk of homologous reinfection was strongest for rare epitope types. Symptomatic malaria more effectively promotes functional immune responses. The phenotype represents a legible molecular epidemiologic signature of naturally-acquired immunity by which to identify new antigen targets.

14.
Catheter Cardiovasc Interv ; 99(7): 2071-2079, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35582829

RESUMO

BACKGROUND: The natural history of peridevice leak (PDL) following left atrial appendage occlusion (LAAO) is unknown. This study sought to investigate changes of PDL from 2 until 12 months after LAAO, using cardiac computed tomography (CT), and to assess the potential association between persistent PDL and clinical outcomes METHODS: Single-center observational study of Amplatzer LAAO implants between 2010 and 2017 (n = 206). Patients with 2 and 12 months cardiac CT were included in the study (n = 153). Images were blindly analyzed. PDL was characterized by frequency and size at the device disc, lobe, and left atrial appendage contrast patency. Patients were followed for the composite outcome of ischemic stroke, transient ischemic attack, systemic embolism, or all-cause death. Median follow up from LAAO was 3.1 (2.3-4.3) years. RESULTS: Contrast patency was present in 101 (66%) and 72 (47%) (p < 0.001) at 2 and 12 months, respectively. PDL was identified at the disc in 103 (67%) patients at 2 months versus 93 (61%) at 12 months (p = 0.08), and at the lobe in 29 (19%) at both time points. PDL area at the disc did not change significantly over time, ∆$\unicode{x02206}$ area: -8.95 mm (95% confidence interval [CI]: -18.9; 1.01) p = 0.08. Permanent atrial fibrillation was independently associated with persistent PDL. Persistent versus no PDL was associated with a 62% worse clinical outcome, however not statistically significant, hazard ratio (HR): 1.62 (95% CI: 0.9-2.93), p = 0.11. CONCLUSION: Persistent PDL was frequently observed following LAAO with Amplatzer devices. The PDL frequency and size appeared unchanged between 2 and 12 months. Persistent PDL was not significantly associated with worse clinical outcomes, yet this needs further delineation in future studies.


Assuntos
Apêndice Atrial , Fibrilação Atrial , Dispositivo para Oclusão Septal , Acidente Vascular Cerebral , Apêndice Atrial/diagnóstico por imagem , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/terapia , Cateterismo Cardíaco , Ecocardiografia Transesofagiana , Humanos , Dispositivo para Oclusão Septal/efeitos adversos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Tomografia , Resultado do Tratamento
15.
Genes (Basel) ; 13(3)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35328005

RESUMO

Fragile X-associated primary ovarian insufficiency (FXPOI) is characterized by oligo/amenorrhea and hypergonadotropic hypogonadism and is caused by the expansion of the CGG repeat in the 5'UTR of Fragile X Mental Retardation 1 (FMR1). Approximately 20% of women carrying an FMR1 premutation (PM) allele (55-200 CGG repeat) develop FXPOI. Repeat Associated Non-AUG (RAN)-translation dependent on the variable CGG-repeat length is thought to cause FXPOI, due to the production of a polyglycine-containing FMR1 protein, FMRpolyG. Peripheral blood monocyte cells (PBMCs) and granulosa cells (GCs) were collected to detect FMRpolyG and its cell type-specific expression in FMR1 PM carriers by immunofluorescence staining (IF), Western blotting (WB), and flow cytometric analysis (FACS). For the first time, FMRpolyG aggregates were detected as ubiquitin-positive inclusions in PBMCs from PM carriers, whereas only a weak signal without inclusions was detected in the controls. The expression pattern of FMRpolyG in GCs was comparable to that in the lymphocytes. We detected FMRpolyG as a 15- to 25-kDa protein in the PBMCs from two FMR1 PM carriers, with 124 and 81 CGG repeats. Flow cytometric analysis revealed that FMRpolyG was significantly higher in the T cells from PM carriers than in those from non-PM carriers. The detection of FMRpolyG aggregates in the peripheral blood and granulosa cells of PM carriers suggests that it may have a toxic potential and an immunological role in ovarian damage in the development of FXPOI.


Assuntos
Síndrome do Cromossomo X Frágil , Deficiência Intelectual , Ataxia/genética , Ataxia/metabolismo , Estudos de Casos e Controles , Feminino , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Humanos , Deficiência Intelectual/genética , Leucócitos Mononucleares/metabolismo , Tremor/genética , Tremor/metabolismo
16.
Fluids Barriers CNS ; 19(1): 12, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123535

RESUMO

BACKGROUND: Intracranial pressure (ICP) monitoring is a core component of neurosurgical diagnostics. With the introduction of telemetric monitoring devices in the last years, ICP monitoring has become feasible in a broader clinical setting including monitoring during full mobilization and at home, where a greater diversity of ICP waveforms are present. The need for identification of these variations, the so-called macro-patterns lasting seconds to minutes-emerges as a potential tool for better understanding the physiological underpinnings of patient symptoms. METHODS: We introduce a new methodology that serves as a foundation for future automatic macro-pattern identification in the ICP signal to comprehensively understand the appearance and distribution of these macro-patterns in the ICP signal and their clinical significance. Specifically, we describe an algorithm based on k-Shape clustering to build a standard library of such macro-patterns. RESULTS: In total, seven macro-patterns were extracted from the ICP signals. This macro-pattern library may be used as a basis for the classification of new ICP variation distributions based on clinical disease entities. CONCLUSIONS: We provide the starting point for future researchers to use a computational approach to characterize ICP recordings from a wide cohort of disorders.


Assuntos
Pressão Intracraniana/fisiologia , Monitorização Neurofisiológica , Processamento de Sinais Assistido por Computador , Adulto , Idoso , Análise por Conglomerados , Feminino , Humanos , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Monitorização Neurofisiológica/métodos , Adulto Jovem
17.
Opt Lett ; 47(21): 5497-5500, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37219253

RESUMO

We report on the observation of unstable two-wave mixing in a Yb-doped optical fiber amplifier induced by frequency modulation of a single-frequency laser. What is believed to be a reflection of the main signal experiences a gain much higher than that provided by the optical pumping and potentially limits power scaling under frequency modulation. We propose an explanation for the effect based on the dynamic population and refractive index gratings formed by the interference between the main signal and its slightly frequency-detuned reflection.

18.
J Ultrasound Med ; 41(2): 311-325, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33870532

RESUMO

Optimal visualization of needles in clinical ultrasound imaging is important and challenging, especially at steep angles. Improvement of visualization has been attempted with various techniques, for example, coatings and dimples. This systematic review summarizes enhancement techniques and identifies superior echogenic surface enhancements. Twenty-four papers were identified providing visibility measures for 33 different echogenic needles. These were grouped according to surface characteristics and ranked. Echogenic needles ranked higher than standard needles especially at steeper angles. Among the echogenic needles, coated needles were seemingly better visualized "in vivo" than noncoated needles, despite heterogeneity in study conditions. No unambiguous comparison revealed which needle was best visualized.


Assuntos
Agulhas , Ultrassonografia de Intervenção , Humanos , Ultrassonografia
19.
Health Promot Int ; 37(2)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-34339493

RESUMO

For public health promotion to succeed, popular support is necessary and the chosen policies and measures have to be perceived as legitimate by the public. In other words, health authorities need to build on and sustain established trust when they recommend a certain policy. When the policy is criticized, this trust is challenged, and the authorities enter into a negotiation of credibility (ethos). In this article, we research a particular instance of such negotiation, drawing lessons for health promotion and for COVID-19 communication. We study a Norwegian television debate in which an MD presented harsh criticism of the health authorities' chosen crisis response in the early phase of the pandemic. Unpacking the rhetorical constitution of the expert ethos of the MD and of the health authorities, respectively, we find that representatives of the authorities are more open to participation and better at connecting to everyday experiences than the MD, who primarily builds her expert ethos on mastery of scientific language and methods, combined with alarmist rhetoric. Further, we identify main tenets of the public's reception of the debate through an analysis of 1961 tweets that commented on the program. The analysis indicates that public health authorities might maintain high levels of trust by rhetorically cultivating their positions within institutional and (social) media networks of expertise.


Assuntos
COVID-19 , Mídias Sociais , Humanos , Negociação , Pandemias , SARS-CoV-2
20.
mSphere ; 6(5): e0075521, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34668757

RESUMO

Sickle-trait hemoglobin (HbAS) confers nearly complete protection from severe, life-threatening falciparum malaria in African children. Despite this clear protection, the molecular mechanisms by which HbAS confers these protective phenotypes remain incompletely understood. As a forward genetic screen for aberrant parasite transcriptional responses associated with parasite neutralization in HbAS red blood cells (RBCs), we performed comparative transcriptomic analyses of Plasmodium falciparum in normal (HbAA) and HbAS erythrocytes during both in vitro cultivation of reference parasite strains and naturally occurring P. falciparum infections in Malian children with HbAA or HbAS. During in vitro cultivation, parasites matured normally in HbAS RBCs, and the temporal expression was largely unperturbed of the highly ordered transcriptional program that underlies the parasite's maturation throughout the intraerythrocytic development cycle (IDC). However, differential expression analysis identified hundreds of transcripts aberrantly expressed in HbAS, largely occurring late in the IDC. Surprisingly, transcripts encoding members of the Maurer's clefts were overexpressed in HbAS despite impaired parasite protein export in these RBCs, while parasites in HbAS RBCs underexpressed transcripts associated with the endoplasmic reticulum and those encoding serine repeat antigen proteases that promote parasite egress. Analyses of P. falciparum transcriptomes from 32 children with uncomplicated malaria identified stage-specific differential expression: among infections composed of ring-stage parasites, only cyclophilin 19B was underexpressed in children with HbAS, while trophozoite-stage infections identified a range of differentially expressed transcripts, including downregulation in HbAS of several transcripts associated with severe malaria in collateral studies. Collectively, our comparative transcriptomic screen in vitro and in vivo indicates that P. falciparum adapts to HbAS by altering its protein chaperone and folding machinery, oxidative stress response, and protein export machinery. Because HbAS consistently protects from severe P. falciparum, modulation of these responses may offer avenues by which to neutralize P. falciparum parasites. IMPORTANCE Sickle-trait hemoglobin (HbAS) confers nearly complete protection from severe, life-threatening malaria, yet the molecular mechanisms that underlie HbAS protection from severe malaria remain incompletely understood. Here, we used transcriptome sequencing (RNA-seq) to measure the impact of HbAS on the blood-stage transcriptome of Plasmodium falciparum in in vitro time series experiments and in vivo samples from natural infections. Our in vitro time series data reveal that, during its blood stage, P. falciparum's gene expression in HbAS is impacted primarily through alterations in the abundance of gene products as opposed to variations in the timing of gene expression. Collectively, our in vitro and in vivo data indicate that P. falciparum adapts to HbAS by altering its protein chaperone and folding machinery, oxidative stress response, and protein export machinery. Due to the persistent association of HbAS and protection from severe disease, these processes that are modified in HbAS may offer strategies to neutralize P. falciparum.


Assuntos
Hemoglobina A/genética , Hemoglobina Falciforme/genética , Malária Falciparum/genética , Traço Falciforme/genética , Adolescente , Criança , Pré-Escolar , Feminino , Hemoglobinas/metabolismo , Humanos , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Masculino , Plasmodium falciparum/fisiologia , Traço Falciforme/sangue , Traço Falciforme/parasitologia , Ativação Transcricional
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