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1.
bioRxiv ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38948736

RESUMO

Researchers choose different methods of making giant unilamellar vesicles in order to satisfy different constraints of their experimental designs. A challenge of using a variety of methods is that each may produce vesicles of different lipid compositions, even if all vesicles are made from a common stock mixture. Here, we use mass spectrometry to investigate ratios of lipids in vesicles made by five common methods: electroformation on indium tin oxide slides, electroformation on platinum wires, gentle hydration, emulsion transfer, and extrusion. We made vesicles from either 5-component or binary mixtures of lipids chosen to span a wide range of physical properties: di(18:1)PC, di(16:0)PC, di(18:1)PG, di(12:0)PE, and cholesterol. For a mixture of all five of these lipids, ITO electroformation, Pt electroformation, gentle hydration, and extrusion methods result in only minor shifts (≤ 5 mol%) in lipid ratios of vesicles relative to a common stock solution. In contrast, emulsion transfer results in ∼80% less cholesterol than expected from the stock solution, which is counterbalanced by a surprising overabundance of saturated PC-lipid relative to all other phospholipids. Experiments using binary mixtures of some of the lipids largely support results from the 5-component mixture. Exact values of lipid ratios variations likely depend on the details of each method, so a broader conclusion is that experiments that increment lipid ratios in small steps will be highly sensitive to the method of lipid formation and to sample-to-sample variations, which are low (roughly ±2 mol% in the 5-component mixture and either scale proportionally with increasing mole fraction or remain low). Experiments that increment lipid ratios in larger steps or that seek to explain general trends or new phenomena will be less sensitive to the method used. SIGNIFICANCE STATEMENT: Small changes to the amounts and types of lipids in membranes can drastically affect the membrane's behavior. Unfortunately, it is unknown whether (or to what extent) different methods of making vesicles alter the ratios of lipids in membranes, even when identical stock solutions are used. This presents challenges for researchers when comparing data with colleagues who use different methods. Here, we measure ratios of lipid types in vesicle membranes produced by five methods. We assess each method's reproducibility and compare resulting vesicle compositions across methods. In doing so, we provide a quantitative basis that the scientific community can use to estimate whether differences between their results can be simply attributed to differences between methods or to sample-to-sample variations.

2.
Chirurgie (Heidelb) ; 95(7): 539-545, 2024 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-38864879

RESUMO

BACKGROUND: Even now the further training in surgery faces considerable challenges. The planned hospital structural reform will result in new bureaucratic and organizational hurdles, which could lead to a considerable loss of quality in advanced surgical training across all disciplines. OBJECTIVE: The aim of this position paper is to describe the current and future challenges for advanced surgical training and to identify possible approaches and opportunities for the further development against the background of the planned hospital structural reform. MATERIAL AND METHODS: For the development of this position paper a committee of representatives of the Young Forums of the German surgical societies identified and critically discussed current problems and challenges of the present residency training system and formulated a list of demands for a sustainable residency training concept. RESULTS: The planned shift to outpatient treatment and centralization were identified as central challenges for surgical residency training. Surgical training must be considered consistently and from the outset in all political reform efforts. In addition to a transparent and cost-appropriate financing of residency training, we call for the involvement of all German surgical societies in the reform process. Furthermore, the social framework conditions for junior surgeons should be considered. CONCLUSION: The structural change in the hospital landscape in Germany, which is being forced by politicians, harbors the risk of a further loss of quality and experience in surgical treatment and training. At the same time, the planned hospital reform offers a unique opportunity to address existing problems and challenges in surgical training and to consider them as a starting point for structural changes which are fit for the future.


Assuntos
Reforma dos Serviços de Saúde , Internato e Residência , Alemanha , Humanos , Cirurgia Geral/educação , Educação de Pós-Graduação em Medicina , Previsões
3.
Microorganisms ; 12(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38792758

RESUMO

To measure associations between gardening with different compost amendments and the human gut microbiota composition, gardeners (n = 25) were provided with one of three types of compost: chicken manure (CM), dairy manure and plant material (DMP), or plant-based (P). Stool samples were collected before gardening (T1), after compost amendment (T2), and at peak garden harvest (T3). Compost and soil samples were collected. DNA was extracted, 16S rRNA libraries were established, and libraries were sequenced by Illumina MiSeq. Sequences were processed using mothur, and data were analyzed in R software version 4.2.2. Fast expectation-maximization microbial source tracking analysis was used to determine stool bacteria sources. At T2/T3, the gut microbiotas of P participants had the lowest Shannon alpha diversity, which was also the trend at T1. In stool from T2, Ruminococcus 1 were less abundant in the microbiotas of those using P compost as compared to those using CM or DMP. At T2, Prevotella 9 had the highest abundance in the microbiotas of those using CM compost. In participants who used CM compost to amend their gardening plots, a larger proportion of the human stool bacteria were sourced from CM compared to soil. Soil exposure through gardening was associated with a small but detectable change in the gardeners' gut microbiota composition. These results suggest that human interactions with soil through gardening could potentially impact health through alterations to the gut microbiota.

4.
Sci Rep ; 14(1): 8741, 2024 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627583

RESUMO

Pulmonary embolism is a potentially fatal condition with increased mortality if anticoagulation is delayed. This study aimed to find influencing factors on the duration from requesting a computed tomography (CT) pulmonary angiography (CTPA) to performing a CTPA in suspected acute pulmonary embolism. In 1849 cases, automatically generated time data were extracted from the radiological information system. The impact of the distance to the scanner, case-related features (sector of patient care, triage), and workload (demand for CTs, performed CTs, available staff, hospital occupancy) were investigated retrospectively using multiple regression. The time to CTPA was shorter in cases from the emergency room (ER) than in inpatients and outpatients at distances below 160 m and 240 m, respectively. While requests from the ER were also performed faster than cases from regular wards (< 180 m), no difference was found between the ER and intensive care units. Compared to "not urgent" cases, the workflow was shorter in "urgent" (- 17%) and "life-threatening" (- 67%) situations. The process was prolonged with increasing demand (+ 5%/10 CTs). The presented analysis identified relevant in-hospital influences on the CTPA workflow, including the distance to the CT together with the sector of patient care, the case triage, and the demand for imaging.


Assuntos
Embolia Pulmonar , Tomografia Computadorizada por Raios X , Humanos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Embolia Pulmonar/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Angiografia/métodos
5.
bioRxiv ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38370758

RESUMO

Despite longstanding excitement and progress toward understanding liquid-liquid phase separation in natural and artificial membranes, fundamental questions have persisted about which molecules are required for this phenomenon. Except in extraordinary circumstances, the smallest number of components that has produced large-scale, liquid-liquid phase separation in bilayers has stubbornly remained at three: a sterol, a phospholipid with ordered chains, and a phospholipid with disordered chains. This requirement of three components is puzzling because only two components are required for liquid-liquid phase separation in lipid monolayers, which resemble half of a bilayer. Inspired by reports that sterols interact closely with lipids with ordered chains, we tested whether phase separation would occur in bilayers in which a sterol and lipid were replaced by a single, joined sterol-lipid. By evaluating a panel of sterol-lipids, some of which are found in bacteria, we discovered a minimal bilayer of only two components (PChemsPC and diPhyPC) that robustly demixes into micron-scale, liquid phases. It suggests a new role for sterol-lipids in nature, and it reveals a membrane in which tie-lines (and, therefore, the lipid composition of each phase) are straightforward to determine and will be consistent across multiple laboratories. Significance Statement: A wide diversity of bilayer membranes, from those with hundreds of lipids (e.g., vacuoles of living yeast cells) to those with very few (e.g., artificial vesicles) phase separate into micron-scale liquid domains. The number of components required for liquid-liquid phase separation has been perplexing: only two should be necessary, but more are required except in extraordinary circumstances. What minimal set of molecular characteristics leads to liquid-liquid phase separation in bilayer membranes? This question inspired us to search for single, joined "sterol-lipid" molecules to replace both a sterol and a phospholipid in membranes undergoing liquid-liquid phase separation. By producing phase-separating membranes with only two components, we mitigate experimental challenges in determining tie-lines and in maintaining constant chemical potentials of lipids.

6.
Muscle Nerve ; 69(3): 334-339, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38197490

RESUMO

INTRODUCTION/AIMS: The performance of magnetic resonance imaging (MRI) for diagnosing suspected idiopathic inflammatory myopathy (IIM) remains controversial. Furthermore, the role of contrast-enhanced magnetic resonance imaging (CE-MRI) sequences is unclear. The aim of this study was to evaluate the sensitivity and specificity of a non-enhanced magnetic resonance imaging (NE-MRI) protocol compared to a CE-MRI protocol in adult patients with confirmed IIM. METHODS: This study retrospectively enrolled patients with suspected IIM who underwent MRI of the upper thigh between 2008 and 2020. The protocol consisted of a T1-weighted (T1w) sequence, a turbo inversion recovery magnitude (TIRM) sequence and a contrast-enhanced T1-weighted sequence (CE-T1w). After randomly stratifying patients into a group with only the T1w and TIRM sequences available and another group with additional availability of CE-T1w, three blinded readers assessed the presence of IIM based on characteristic imaging features. Confirmation of the diagnosis was determined based on the 2017 ACR/EULAR criteria. RESULTS: Of the 80 patients (mean age 49.0 ± 21.1 years; 42 female, 38 male) included, 54 (67.5%) had a positive diagnosis of IIM. Cumulated sensitivity and specificity for MRI to detect IIM was 87.1% and 83.3% in the NE-MRI group versus 87.0% and 63.0% in the CE-MRI group. The group differences for sensitivity and specificity were non-significant for each of the three readers, respectively (p ≥ .081). DISCUSSION: NE-MRI detects suspected IIM with high diagnostic accuracy and performs equivalently to CE-MRI. Therefore, it may be appropriate to omit the use of contrast agents in MRI scans performed for suspected IIM.


Assuntos
Imageamento por Ressonância Magnética , Miosite , Humanos , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Miosite/diagnóstico por imagem , Sensibilidade e Especificidade , Coxa da Perna , Meios de Contraste
7.
Rofo ; 196(1): 15, 2024 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-38163429
8.
Biophys J ; 123(11): 1329-1341, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38160256

RESUMO

This review describes the major experimental challenges researchers meet when attempting to couple phase separation between membranes and condensates. Although it is well known that phase separation in a 2D membrane could affect molecules capable of forming a 3D condensate (and vice versa), few researchers have quantified the effects to date. The scarcity of these measurements is not due to a lack of intense interest or effort in the field. Rather, it reflects significant experimental challenges in manipulating coupled membranes and condensates to yield quantitative values. These challenges transcend many molecular details, which means they impact a wide range of systems. This review highlights recent exciting successes in the field, and it lays out a comprehensive list of tools that address potential pitfalls for researchers who are considering coupling membranes with condensates.


Assuntos
Membrana Celular , Membrana Celular/metabolismo , Membrana Celular/química
9.
JBJS Rev ; 11(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38100611

RESUMO

¼ Bone health optimization (BHO) has become an increasingly important consideration in orthopaedic surgery because deterioration of bone tissue and low bone density are associated with poor outcomes after orthopaedic surgeries.¼ Management of patients with compromised bone health requires numerous healthcare professionals including orthopaedic surgeons, primary care physicians, nutritionists, and metabolic bone specialists in endocrinology, rheumatology, or obstetrics and gynecology. Therefore, achieving optimal bone health before orthopaedic surgery necessitates a collaborative and synchronized effort among healthcare professionals.¼ Patients with poor bone health are often asymptomatic and may present to the orthopaedic surgeon for reasons other than poor bone health. Therefore, it is imperative to recognize risk factors such as old age, female sex, and low body mass index, which predispose to decreased bone density.¼ Workup of suspected poor bone health entails bone density evaluation. For patients without dual-energy x-ray absorptiometry (DXA) scan results within the past 2 years, perform DXA scan in all women aged 65 years and older, all men aged 70 years and older, and women younger than 65 years or men younger than 70 years with concurrent risk factors for poor bone health. All women and men presenting with a fracture secondary to low-energy trauma should receive DXA scan and bone health workup; for fractures secondary to high-energy trauma, perform DXA scan and further workup in women aged 65 years and older and men aged 70 years and older.¼ Failure to recognize and treat poor bone health can result in poor surgical outcomes including implant failure, periprosthetic infection, and nonunion after fracture fixation. However, collaborative healthcare teams can create personalized care plans involving nutritional supplements, antiresorptive or anabolic treatment, and weight-bearing exercise programs, resulting in BHO before surgery. Ultimately, this coordinated approach can enhance the success rate of surgical interventions, minimize complications, and improve patients' overall quality of life.


Assuntos
Fraturas Ósseas , Procedimentos Ortopédicos , Masculino , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Qualidade de Vida , Osso e Ossos
10.
Artigo em Inglês | MEDLINE | ID: mdl-37947540

RESUMO

Area-based social disadvantage, which measures the income, employment, and housing quality in one's community, can impact an individual's health above person-level factors. A life course approach examines how exposure to disadvantage can affect health in later life. This systematic review aimed to summarize the approaches used to assess exposure to area-based disadvantage over a life course, specifically those that define the length and timing of exposure. We reviewed the abstracts of 831 articles based on the following criteria: (1) whether the abstract described original research; (2) whether the study was longitudinal; (3) whether area-based social disadvantage was an exposure variable; (4) whether area-based social disadvantage was assessed at multiple points; and (5) whether exposure was assessed from childhood to older adulthood. Zero articles met all the above criteria, so we relaxed the fifth criterion in a secondary review. Six studies met our secondary criteria and were eligible for data extraction. The included studies followed subjects from childhood into adulthood, but none assessed disadvantages in late life. The approaches used to assess exposure included creating a cumulative disadvantage score, conducting a comparison between life course periods, and modeling the trajectory of disadvantage over time. Additional research was needed to validate the methodologies described here, specifically in terms of measuring the impact of area-based social disadvantage on health.


Assuntos
Renda , Acontecimentos que Mudam a Vida , Humanos , Idoso , Criança , Emprego
11.
PLoS One ; 18(11): e0294693, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38019893

RESUMO

PURPOSE: Muscular overuse injuries are a common health issue in elite athletes. Changes in the muscular microenvironment can be depicted by Diffusion Tensor Imaging (DTI). We hypothesize that the biomechanics of different stroke typologies plays a role in muscle injury and tested our hypothesis by magnetic resonance imaging (MRI) examination of the lumbar spine muscles of adolescent rowers utilizing DTI. METHODS AND MATERIALS: Twenty-two male elite rowers (12 sweep, 10 scull rowers) with a mean age of 15.8 ± 1.2 years underwent 3-Tesla MRI of the lumbar spine 6 hours after cessation of training. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated for the erector spinae and multifidus muscle. Student's t-test was used to test differences of DTI parameters between sweep and scull rowers and a Pearson correlation was utilized to correlate the parameters to training volume. RESULTS: ADC values in the erector spinae and multifidus muscle were significantly higher (p = 0.039) and FA values significantly lower (p < 0.001) in sweep rowers compared to scull rowers. There was no significant association between DTI parameters and training volume (r ≤ -0.459, p ≥ 0.074). CONCLUSIONS: Our DTI results show that lumbar spine muscle diffusivity is higher in sweep rowers than in scull rowers. Altered muscle diffusivity is suggestive of microscopic tissue disruption and might be attributable to biomechanical differences between stroke typologies.


Assuntos
Imagem de Tensor de Difusão , Imageamento por Ressonância Magnética , Humanos , Masculino , Adolescente , Imagem de Tensor de Difusão/métodos , Imagem de Difusão por Ressonância Magnética , Vértebras Lombares , Músculos , Anisotropia
12.
Acta Radiol Open ; 12(10): 20584601231213740, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38034076

RESUMO

Background: The growing role of artificial intelligence (AI) in healthcare, particularly radiology, requires its unbiased and fair development and implementation, starting with the constitution of the scientific community. Purpose: To examine the gender and country distribution among academic editors in leading computer science and AI journals. Material and Methods: This cross-sectional study analyzed the gender and country distribution among editors-in-chief, senior, and associate editors in all 75 Q1 computer science and AI journals in the Clarivate Journal Citations Report and SCImago Journal Ranking 2022. Gender was determined using an open-source algorithm (Gender Guesser™), selecting the gender with the highest calibrated probability. Result: Among 4,948 editorial board members, women were underrepresented in all positions (editors-in-chief/senior editors/associate editors: 14%/18%/17%). The proportion of women correlated positively with the SCImago Journal Rank indicator (ρ = 0.329; p = .004). The U.S., the U.K., and China comprised 50% of editors, while Australia, Finland, Estonia, Denmark, the Netherlands, the U.K., Switzerland, and Slovenia had the highest women editor representation per million women population. Conclusion: Our results highlight gender and geographic disparities on leading computer science and AI journal editorial boards, with women being underrepresented in all positions and a disproportional relationship between the Global North and South.

13.
J Sports Sci ; 41(16): 1558-1563, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37979193

RESUMO

Adult elite rowers are at risk of developing low back pain (LBP). However, LBP data on adolescent elite rowers is currently insufficient. Therefore, the aim of this study was to assess LBP prevalence, LBP intensity and training characteristics in male adolescent elite rowers and a healthy control group. Twenty rowers (mean age 15.8 ± 1.2 years) and a non-athletic control group matched by age and gender (n = 13) were prospectively enrolled and underwent LBP assessment with a validated questionnaire and magnetic resonance imaging (MRI) of the lumbar spine muscles, which included a T2-mapping sequence. From the quantitative image data, T2 relaxation times were calculated. The prevalence of LBP in the last 24 hours and 3 months in the rowing group was 55.0% and 85.0%, respectively, compared to 23.1% and 30.8% in the control group (p < 0.001). Rowers had significantly longer T2 relaxation times of the paraspinal muscles compared to controls (p ≤ 0.041). LBP intensity was associated with longer T2 relaxation times (p < 0.001). Adolescent rowers had a higher prevalence of LBP compared to an age-matched control group. The observed increase in T2 relaxation might be explained by muscle soreness due to strenuous exercise, which is correlated with short-term pain intensity.


Assuntos
Dor Lombar , Esportes Aquáticos , Adulto , Humanos , Masculino , Adolescente , Dor Lombar/epidemiologia , Região Lombossacral , Músculos , Imageamento por Ressonância Magnética
14.
Eur Radiol ; 33(8): 5664-5674, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36897346

RESUMO

OBJECTIVES: To evaluate work expectations of radiologists at different career levels, their fulfillment, prevalence of exhaustion, and exhaustion-associated factors. METHODS: A standardized digital questionnaire was distributed internationally to radiologists of all career levels in the hospital and in ambulatory care via radiological societies and sent manually to 4500 radiologists of the largest German hospitals between December 2020 and April 2021. Statistics were based on age- and gender-adjusted regression analyses of respondents working in Germany (510 out of 594 total respondents). RESULTS: The most frequent expectations were "joy at work" (97%) and a "good working atmosphere" (97%), which were considered fulfilled by at least 78%. The expectation of a "structured residency within the regular time interval" (79%) was more frequently judged fulfilled by senior physicians (83%, odds ratio (OR) 4.31 [95% confidence interval (95% CI) 1.95-9.52]), chief physicians (85%, 6.81 [95% CI 1.91-24.29]), and radiologists outside the hospital (88%, 7.59 [95% CI 2.40-24.03]) than by residents (68%). Exhaustion was most common among residents (physical exhaustion: 38%; emotional exhaustion: 36%), in-hospital specialists (29%; 38%), and senior physicians (30%; 29%). In contrast to paid extra hours, unpaid extra hours were associated with physical exhaustion (5-10 extra hours: OR 2.54 [95% CI 1.54-4.19]). Fewer opportunities to shape the work environment were related to a higher probability of physical (2.03 [95% CI 1.32-3.13]) and emotional (2.15 [95% CI 1.39-3.33]) exhaustion. CONCLUSIONS: While most radiologists enjoy their work, residents wish for more training structure. Ensuring payment of extra hours and employee empowerment may help preventing burnout in high-risk groups. KEY POINTS: • Most important work expectations of radiologists who work in Germany are "joy at work," a "good working atmosphere," "support for further qualification," and a "structured residency within the regular time interval," with the latter containing potential for improvement according to residents. • Physical and emotional exhaustion are common at all career levels except for chief physicians and for radiologists who work outside the hospital in ambulatory care. • Exhaustion as a major burnout criterion is associated with unpaid extra hours and reduced opportunities to shape the work environment.


Assuntos
Esgotamento Profissional , Internato e Residência , Médicos , Humanos , Motivação , Radiologistas/psicologia , Médicos/psicologia , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/psicologia , Inquéritos e Questionários
15.
Biophys J ; 122(6): 1043-1057, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36635960

RESUMO

Upon nutrient limitation, budding yeast of Saccharomyces cerevisiae shift from fast growth (the log stage) to quiescence (the stationary stage). This shift is accompanied by liquid-liquid phase separation in the membrane of the vacuole, an endosomal organelle. Recent work indicates that the resulting micrometer-scale domains in vacuole membranes enable yeast to survive periods of stress. An outstanding question is which molecular changes might cause this membrane phase separation. Here, we conduct lipidomics of vacuole membranes in both the log and stationary stages. Isolation of pure vacuole membranes is challenging in the stationary stage, when lipid droplets are in close contact with vacuoles. Immuno-isolation has previously been shown to successfully purify log-stage vacuole membranes with high organelle specificity, but it was not previously possible to immuno-isolate stationary-stage vacuole membranes. Here, we develop Mam3 as a bait protein for vacuole immuno-isolation, and demonstrate low contamination by non-vacuolar membranes. We find that stationary-stage vacuole membranes contain surprisingly high fractions of phosphatidylcholine lipids (∼40%), roughly twice as much as log-stage membranes. Moreover, in the stationary stage, these lipids have higher melting temperatures, due to longer and more saturated acyl chains. Another surprise is that no significant change in sterol content is observed. These lipidomic changes, which are largely reflected on the whole-cell level, fit within the predominant view that phase separation in membranes requires at least three types of molecules to be present: lipids with high melting temperatures, lipids with low melting temperatures, and sterols.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Lipidômica , Vacúolos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Lipídeos
17.
ACS Earth Space Chem ; 7(1): 11-27, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36704178

RESUMO

The first cells were plausibly bounded by membranes assembled from fatty acids with at least 8 carbons. Although the presence of fatty acids on the early Earth is widely assumed within the astrobiology community, there is no consensus regarding their origin and abundance. In this Review, we highlight three possible sources of fatty acids: (1) delivery by carbonaceous meteorites, (2) synthesis on metals delivered by impactors, and (3) electrochemical synthesis by spark discharges. We also discuss fatty acid synthesis by UV or particle irradiation, gas-phase ion-molecule reactions, and aqueous redox reactions. We compare estimates for the total mass of fatty acids supplied to Earth by each source during the Hadean eon after an extremely massive asteroid impact that would have reset Earth's fatty acid inventory. We find that synthesis on iron-rich surfaces derived from the massive impactor in contact with an impact-generated reducing atmosphere could have contributed ∼102 times more total mass of fatty acids than subsequent delivery by either carbonaceous meteorites or electrochemical synthesis. Additionally, we estimate that a single carbonaceous meteorite would not deliver a high enough concentration of fatty acids (∼15 mM for decanoic acid) into an existing body of water on the Earth's surface to spontaneously form membranes unless the fatty acids were further concentrated by another mechanism, such as subsequent evaporation of the water. Our estimates rely heavily on various assumptions, leading to significant uncertainties; nevertheless, these estimates provide rough order-of-magnitude comparisons of various sources of fatty acids on the early Earth. We also suggest specific experiments to improve future estimates. Our calculations support the view that fatty acids would have been available on the early Earth. Further investigation is needed to assess the mechanisms by which fatty acids could have been concentrated sufficiently to assemble into membranes during the origin of life.

18.
BMC Med Educ ; 23(1): 68, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707803

RESUMO

BACKGROUND: Career prospects in academic medicine are strongly linked to scientific authorship and this marker has been widely used as an indicator of gender equity in academia. However, direct comparisons of medical disciplines regarding their proportion of female physicians (FP) in different countries are missing. This study examines the gender parity and gender cooperation using first authorships (FA) and senior authorships (SA) of scientific publications in five medical disciplines and six different OECD countries over a 10-year time-trend. METHODS: Articles from three high-impact journals in each of the medical discipline radiology, urology, surgery, gynecology, and pediatrics from the years 2007/8 and 2017/18 were retrospectively reviewed. The gender and affiliation location of the FA and SA of original research articles and reviews were assigned and compared with the proportion of in each discipline for the United States of America, Canada, United Kingdom, France, Germany, and Japan. Mantel-Haenszel test and multinomial logistic regression models were used to calculate differences in proportions of women authors and FP and to assess trends and proportions of FA and SA. RESULTS: 30,803 articles were evaluated. Equally, with rising proportions of FP in all disciplines, the number of women authors increased across years. The shares of women FAs were either significantly higher (urology/surgery/gynecology) or balanced (pediatrics/radiology) compared to the proportion of FP. In contrast, the shares of women SA were balanced only in disciplines with a low proportion of FP (urology and surgery) and otherwise reduced. Women same-gender cooperation was as common as men same-gender cooperation and preferred over a women-led mixed gender cooperation in disciplines where this seemed to be practicable due to the high proportions of FP. CONCLUSION: In contrast to FA, a significant disparity persists in SA, particularly in disciplines with a high proportion of FP. The discrepancy between FA and SA may reflect, among others, dropout from an academic career in early or mid-academic levels, for example, due to structural inequality; together with the findings on gender preference in authorship collaborations, this may inform future strategies for promoting equal career advancement for women physicians.


Assuntos
Autoria , Bibliometria , Masculino , Humanos , Feminino , Estados Unidos , Criança , Fatores Sexuais , Estudos Retrospectivos , Publicações
19.
Healthcare (Basel) ; 10(12)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36553863

RESUMO

OBJECTIVE: To identify facilitators and barriers and derive concrete measures towards better workplace integration of migrants working in the German healthcare sector. DESIGN: Two-centre cross-sectional quantitative online survey of experiences of discrimination among healthcare professionals with a migration history in two large German university hospitals. PARTICIPANTS: 251 participants fully completed the questionnaires. MAIN OUTCOME MEASURES: Experiences of discrimination and perception of inequality. RESULTS: Fifty-five percent of migrant health workers had had at least some command of German before arriving in Germany. Members of all professional groups surveyed expressed experiences of discrimination related to language, nationality, race/ethnicity, and sex/gender. The proportions of staff with experiences of discrimination by peers differed significantly among occupational roles, with nurses and technologists having the most experiences of discrimination. The perception of inequality was reported more frequently than experiences of discrimination and had a negative impact on workplace satisfaction. Specifically, the compulsion to compete was a frequent feeling stated by participants. CONCLUSION: The mechanisms of discrimination and structural inequality revealed by our survey could inform specific measures, for example at the management level, to increase workplace satisfaction and attract migrant health workers in the long term.

20.
Langmuir ; 38(49): 15106-15112, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36445982

RESUMO

Fatty acid vesicles may have played a role in the origin of life as a major structural component of protocells, with the potential for encapsulation of genetic materials. Vesicles that grew and divided more rapidly than other vesicles could have had a selective advantage. Fatty acid vesicles grow by incorporating additional fatty acids from micelles, and certain prebiotic molecules (e.g., sugars, nucleobases, and amino acids) can bind to fatty acid vesicles and stabilize them. Here, we investigated whether the presence of a variety of biomolecules affects the overall growth of vesicles composed of decanoic acid, a prebiotically plausible fatty acid, upon micelle addition. We tested 31 molecules, including 15 dipeptides, 7 amino acids, 6 nucleobases or nucleosides, and 3 sugars. We find that the initial radius and final radius of vesicles are largely unaffected by the presence of the additional compounds. However, three dipeptides enhanced the initial rates of growth compared to control vesicles with no small molecules added; another three dipeptides decreased the initial rates of growth. We conclude that vesicles can indeed grow in the presence of a wide range of molecules likely to have been involved in the origin of life. These results imply that vesicles would have been able to grow in complex and heterogeneous chemical environments. We find that the molecules that enhance the initial growth rate tend to have hydrophobic groups (e.g., leucine), which may interact with the lipid membrane to affect growth rate; furthermore, the molecules that cause the largest decrease in initial growth rate are dipeptides containing a serine residue, which contains a hydroxyl group that could potentially hydrogen-bond with the fatty acid carboxylate groups.


Assuntos
Ácidos Graxos , Ácidos Nucleicos , Ácidos Graxos/química , Aminoácidos/química , Açúcares , Dipeptídeos , Micelas
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