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1.
Mol Ther Methods Clin Dev ; 32(1): 101191, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38352271

RESUMO

Despite the implementation of lifesaving newborn screening programs and a galactose-restricted diet, many patients with classic galactosemia develop long-term debilitating neurological deficits and primary ovarian insufficiency. Previously, we showed that the administration of human GALT mRNA predominantly expressed in the GalT gene-trapped mouse liver augmented the expression of hepatic GALT activity, which decreased not only galactose-1 phosphate (gal-1P) in the liver but also peripheral tissues. Since each peripheral tissue requires distinct methods to examine the biomarker and/or GALT effect, this highlights the necessity for alternative strategies to evaluate the overall impact of therapies. In this study, we established that whole-body galactose oxidation (WBGO) as a robust, noninvasive, and specific method to assess the in vivo pharmacokinetic and pharmacodynamic parameters of two experimental gene-based therapies that aimed to restore GALT activity in a mouse model of galactosemia. Although our results illustrated the long-lasting efficacy of AAVrh10-mediated GALT gene transfer, we found that GALT mRNA therapy that targets the liver predominantly is sufficient to sustain WBGO. The latter could have important implications in the design of novel targeted therapy to ensure optimal efficacy and safety.

2.
Rapid Commun Mass Spectrom ; 37(22): e9639, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37817343

RESUMO

13 C breath testing is increasingly used in physiology and ecology research because of what it reveals about the different fuels that animals oxidize to meet their energetic demands. Here I review the practice of 13 C breath testing in humans and other animals and describe the impact that contamination by ambient/background CO2 in the air can have on the accuracy of 13 C breath measurements. I briefly discuss physical methods to avoid sample contamination as well as the Keeling plot approach that researchers have been using for the past two decades to estimate δ13 C from breath samples mixed with ambient CO2 . Unfortunately, Keeling plots are not suited for 13 C breath testing in common situations where (1) a subject's VCO2 is dynamic, (2) ambient [CO2 ] may change, (3) a subject is sensitive to hypercapnia, or (4) in any flow-through indirect calorimetry system. As such, I present a mathematical solution that addresses these issues by using information about the instantaneous [CO2 ] and the δ13 CO2 of ambient air as well as the diluted breath sample to back-calculate the δ13 CO2 in the CO2 exhaled by the animal. I validate this approach by titrating a sample of 13 C-enriched gas into an air stream and demonstrate its ability to provide accurate values across a wide range of breath and air mixtures. This approach allows researchers to instantaneously calculate the δ13 C of exhaled gas of humans or other animals in real time without having to scrub ambient CO2 or rely on estimated values.


Assuntos
Dióxido de Carbono , Gases , Humanos , Animais , Expiração , Testes Respiratórios
4.
Musculoskeletal Care ; 21(4): 1248-1260, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37596866

RESUMO

INTRODUCTION: Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children and causes short- and long-term disability. Optimal management requires pharmacologic and non-pharmacologic interventions. Few studies have explored the youth and family experience of the management of JIA. This study's objective was to explore the management experience of youth with JIA and their parents. METHODS: This qualitative study used semi-structured interviews with youth 12-18 years of age with JIA receiving biological medication and parents of children with JIA on biological medication. Participants were recruited in clinics using convenience sampling. A thematic analysis approach was employed for data analysis. RESULTS: Nine youth and 14 parents participated. Four themes were identified that encompassed an overarching theme of participants managing JIA within the context of their life: aspects of life affected by JIA and its management, lived experience with JIA management, medication decision-making, and involvement in decision-making. Juvenile idiopathic arthritis management is situated within the context of their life but is normally (outside acute events) not central. CONCLUSION: Two dimensions were added to those in the literature: parents' overall approaches to health and the sense of urgency surrounding decision-making. Our findings reinforce the importance of person- and family-centred care in paediatric rheumatology. That is, identifying what matters most to youth and their parents given their current life circumstances to provide a foundation for discussions of how they want to manage their JIA.


Assuntos
Artrite Juvenil , Doenças Reumáticas , Criança , Humanos , Adolescente , Artrite Juvenil/terapia , Pesquisa Qualitativa , Projetos de Pesquisa , Pais , Qualidade de Vida
5.
Artigo em Inglês | MEDLINE | ID: mdl-37153691

RESUMO

Orthopaedic surgery is one of the most competitive and least diverse specialties in medicine. Affiliation of an orthopaedics with an allopathic medical school impacts research opportunities and early exposure to clinical orthopaedics. The purpose of this study is to examine the potential effect allopathic medical school affiliation has on orthopaedic surgery resident demographics and academic characteristics. Methods: All 202 Accreditation Council for Graduate Medical Education (ACGME)-accredited orthopaedics programs were divided into 2 groups: Group 1 consisted of residency programs without an affiliated allopathic medical school, and Group 2 consisted of programs with an affiliated allopathic medical school. Affiliations were determined by cross-referencing the ACGME residency program list with the medical school list published by Association of American Medical Colleges (AAMC). Program and resident characteristics were then compiled using AAMC's Residency Explorer including region, program setting, number of residents, and osteopathic recognition. Resident characteristics included race, gender, experiences (work, volunteer, and research), peer-reviewed publications, and US Medical Licensing Examination Step 1 scores. Results: Of the 202 ACGME-accredited orthopaedics residencies, Group 1 had 61 (30.2%) programs, and Group 2 had 141 (69.8%) programs. Group 2 had larger programs (4.9 vs. 3.2 resident positions/year; p < 0.001) and 1.7 times the number of residency applicants (655.8 vs. 385.5; p < 0.001). Most Group 2 residents were allopathic medical school graduates, 95.5%, compared with 41.6% in Group 1. Group 1 had 57.0% osteopathic medical school graduates, compared with 2.9% in Group 2. There were 6.1% more White residents in Group 1 residencies (p = 0.025), and Group 2 residencies consisted of 3.5% more Black residents in relation to Group 1 (p = 0.03). Academic performance metrics were comparable between the 2 groups (p > 0.05). Conclusion: This study demonstrated that candidates who successfully match into an orthopaedic surgery residency program achieve high academic performance, regardless of whether the program was affiliated with an allopathic medical school. Differences may be influenced by increased representation of minority faculty, greater demand for allopathic residents, or stronger emphasis on promotion of diversity in those residency programs. Availability of Data and Material: Available on reasonable request. Level of Evidence: Level III. See Instructions for Authors for a complete description of levels of evidence.

6.
Philos Trans A Math Phys Eng Sci ; 381(2249): 20220056, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37150205

RESUMO

The Southern Ocean greatly contributes to the regulation of the global climate by controlling important heat and carbon exchanges between the atmosphere and the ocean. Rates of climate change on decadal timescales are therefore impacted by oceanic processes taking place in the Southern Ocean, yet too little is known about these processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent processes at scales that are not well captured in current Earth system models. The Southern Ocean Carbon and Heat Impact on Climate programme was launched to address this knowledge gap, with the overall objective to understand and quantify variability of heat and carbon budgets in the Southern Ocean through an investigation of the key physical processes controlling exchanges between the atmosphere, ocean and sea ice using a combination of observational and modelling approaches. Here, we provide a brief overview of the programme, as well as a summary of some of the scientific progress achieved during its first half. Advances range from new evidence of the importance of specific processes in Southern Ocean ventilation rate (e.g. storm-induced turbulence, sea-ice meltwater fronts, wind-induced gyre circulation, dense shelf water formation and abyssal mixing) to refined descriptions of the physical changes currently ongoing in the Southern Ocean and of their link with global climate. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

7.
Ecol Evol ; 13(4): e9977, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37013101

RESUMO

Fire is a common disturbance in many biomes, with both beneficial and detrimental effects on soil biology, which largely depend on fire intensity. However, little is known about the impact of fire on soil nematode communities in terrestrial ecosystem. In the present study, we investigated the effects of short-term prescribed fire on soil nematode communities and soil properties in an old-field grassland in Northern China. The results showed that burning significantly increased soil nematode abundance by 77% and genus richness by 49% compared to the control. Burning also decreased taxon dominance by 45% (Simpson's D) and increased nematode diversity by 31% (Shannon-Weaver H'). However, burning increased plant parasites (particularly genera Cephalenchus and Pratylenchus) and shifted community to more bacterial-feeding genera (i.e., decreased Channel Index). Generally, burning increased soil bio-available nitrogen (NH4 +-N and NO3 --N) content, which would be the main drivers causing nematode community to flourish via a "bottom-up" effect. These results suggest that prescribed fire increases nematode diversity and alters community composition toward more plant parasites and bacterial feeders. Our findings highlight the importance of prescribed fire management in shaping short-term nematode community structure and function, but the long-term effects and impacts of these changes on soil nutrient and carbon cycling remain unknown.

8.
Ecol Appl ; 33(2): e2784, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36478617

RESUMO

Managing soils to retain new plant inputs is key to moving toward a sustainable and regenerative agriculture. Management practices, like diversifying and perennializing agroecosystems, may affect the decomposer organisms that regulate how new residue is converted to persistent soil organic matter. Here we tested whether 12 years of diversifying/perennializing plants in agroecosystems through extended rotations or grassland restoration would decrease losses of new plant residue inputs and, thus, increase retention of carbon (C) and nitrogen (N) in soil. We tracked dual-labeled (13 C and 15 N), isotopically enriched wheat (Triticum aestivum) residue in situ for 2 years as it decomposed in three agroecosystems: maize-soybean (CS) rotation, maize-soybean-wheat plus red clover and cereal rye cover crops (CSW2), and spring fallow management with regeneration of natural grassland species (seven to 10 species; SF). We measured losses of wheat residue (Cwheat and Nwheat ) in leached soil solution and greenhouse gas fluxes, as well as how much was recovered in microbial biomass and bulk soil at 5-cm increments down to 20 cm. CSW2 and SF both had unique, significant effects on residue decomposition and retention dynamics that were clear only when using nuanced metrics that able to tease apart subtle differences. For example, SF retained a greater portion of Cwheat in 0-5 cm surface soils (155%, p = 0.035) and narrowed the Cwheat to Nwheat ratio (p < 0.030) compared to CS. CSW2 increased an index of carbon-retention efficiency, Cwheat retained in the mesocosm divided by total measured, from 0.18 to 0.27 (49%, p = 0.001), compared to CS. Overall, we found that diversifying and extending the duration of living plants in agroecosystems can lead to greater retention of new residue inputs in subtle ways that require further investigation to fully understand.


Assuntos
Agricultura , Solo , Solo/química , Carbono , Produtos Agrícolas , Grão Comestível , Nitrogênio/análise , Triticum
9.
Osteoarthr Cartil Open ; 4(2): 100256, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36475282

RESUMO

Objective: Describe "usual care" patterns of education, exercise, weight management, pain medication and other nonsurgical treatments for knee osteoarthritis (OA) in people recommended for nonsurgical care by an orthopaedic surgeon. Methods: We used a telephone-administered questionnaire to capture treatments people with knee OA used over the three to six years after an orthopaedic surgeon recommended nonsurgical care. The primary outcome, guideline-consistent nonsurgical treatments, was an aggregate measure defined as using education, exercise, weight management, and at least one recommended medication. Secondary outcomes were first-line (education, exercise, and weight management) and guideline-inconsistent treatments (orthoses, opioids, hyaluronic acid, platelet rich plasma, and stem cell therapy). Multivariable robust Poisson regression assessed the association between participant characteristics and use of guideline-consistent, first-line and guideline-inconsistent treatments. Results: 479 people were invited and 250 participated (52%). Participants were 58% female with a mean age 66.2 years. Participants received education by a healthcare professional (64%), exercised regularly (74%), used weight management (38%), and used recommended pain medications (91%). All guideline-consistent nonsurgical treatments were used by 19% of participants, 19% of participants used first-line treatments, and 42% used guideline-inconsistent treatments. Over six years, 34% had another consult then underwent arthroplasty. Older participants were less likely to use any treatment. People without post-secondary education were less likely to use first-line treatments (RR 0.54, 95% CI: 0.30-0.96), and females were less likely to use guideline-inconsistent treatments (RR 0.62, 95% CI:0.47-0.81). Conclusions: Nonsurgical usual care for people with knee OA was not consistent with international clinical guidelines.

10.
Mol Ther Oncolytics ; 27: 239-255, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36458203

RESUMO

Historically, the clinical utility of oncolytic virotherapy as a treatment for a wide range of cancer types was first demonstrated by three pilot human clinical trials conducted in Japan in the 1970s and 1980s using a wild-type Urabe mumps virus (MuV) clinical isolate. Using a sample of the actual original oncolytic Urabe MuV clinical trial virus stock (MuV-U-Japan) used in these Japanese clinical trials, we found that MuV-U-Japan consisted of a wide variety of very closely related Urabe MuVs that differed by an average of only three amino acids. Two MuV-U-Japan isolates, MuV-UA and MuV-UC, potently killed a panel of established human breast cancer cell lines in vitro, significantly extended survival of nude mice with human triple-negative breast cancer (TNBC) MDA-MB-231 tumor xenografts in vivo, and demonstrated significant killing activity against breast cancer patient-derived xenograft (PDX) cell lines grown as 3D organoids, including PDXs from patients resistant to anthracycline- and taxane-based chemotherapy. We also report success in developing a large-scale MuV-U production and purification process suitable for supporting Investigational New Drug applications for clinical trials. This study demonstrates the suitability of the MuV-UC virus for translation to modern clinical trials for treating patients with TNBC.

11.
BMC Rheumatol ; 6(1): 85, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376987

RESUMO

BACKGROUND: Juvenile idiopathic arthritis (JIA) is a childhood autoimmune disease that causes swelling and pain in at least one joint. Young people with JIA experience symptoms that persist into adulthood, and thus will undergo a transition including the o transfer of care from a pediatric rheumatologist an adult rheumatologist. Missing from the literature is research that centres the transition experience of young people with JIA in Canada. This goal of this patient-led research was to explore the experience young people with JIA through the process of transition. METHODS: Qualitative study using the Patient and Community Engaged Research (PaCER) approach. Trained patient-researchers conducted three focus groups using the Set, Collect and Reflect PaCER process. Participants, recruited via purposive and snowball sampling using research/personal networks and social media, were young people with JIA in Canada between 18 and 28 years who had experienced with the process of transition to adult care. Recordings were transcribed verbatim. Patient researchers individually coded overlapping sections of the data, and thematic analysis was conducted. RESULTS: In total, nine individuals participated in one or more focus groups. Three themes were identified, with sub-themes: preparedness for transition (readiness for the transfer of care, developing self-advocacy skills), continuity and breadth of care (changing relationships, culture shock, new responsibilities), need for support (social support, mental health support, and ongoing support needs - beyond the transfer of care. Peer support was a connecting concept in the support sub-themes. Transition was more than a change in primary physician but also a change in the care model and breadth of care provided, which was challenging for young people especially if they had insufficient information. CONCLUSIONS: Transition from pediatric to adult care in rheumatology is a significant period for young people living with JIA, and this patient-led study provided insight into the experience from the perspective of young people with JIA which is critical to informing the development of supports for patients through the process. Patients, caregivers, pediatric and adult rheumatologists and members of the multi-disciplinary care team need to collaborate in terms of resources preparing for transfer, and support throughout the transition process to ensure a successful transition process.

12.
J Chem Phys ; 157(2): 020401, 2022 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-35840385
13.
Int J Cardiol ; 360: 83-90, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35609714

RESUMO

BACKGROUND: We assessed trends in aortic dissection (AD) death rates in 23 countries from 2000 to 2017. METHODS: We extracted AD mortality data for countries with high usability data from the World Health Organization (WHO) Mortality Database and from the Center for Disease Control (CDC) WONDER Database for the United States of America (USA). Age Standardized Death Rates (ASDRs) per 100,000 population were computed. Trends were assessed by locally weighted scatter plot smoother (LOWESS) regression. RESULTS: Between 2000 and 2017, ASDRs from AD decreased in Australia, Belgium, Croatia, Denmark, France, Italy, New Zealand, Norway, Sweden, the United Kingdom, and the USA for both sexes. Increasing AD mortality was observed in Austria, Czech Republic, Germany, Hungary, Israel, and Japan for both sexes. The largest absolute increases in ASDR were in Japan for men (+1.59) and women (+1.11). The largest percentage decreases were in Norway for men (-0.91) and in New Zealand (-0.6) for women. In 2017, the highest mortality rates were in Japan for both sexes (3.22 and 2.09, respectively). The lowest ASDR was in Kyrgyzstan for both sexes (0.16 and 0.10, respectively). ASDRs for AD in 2017 were higher for men than women in all countries included. Spain had the greatest difference between the gender's mortality rates with a 2.71-fold higher mortality average rate in men. CONCLUSION: We identified an overall decrease in AD mortality in most included countries, while an increase was noted in other countries including Israel and Japan.


Assuntos
Dissecção Aórtica , Dissecção Aórtica/diagnóstico , República Tcheca , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Mortalidade , Noruega , Reino Unido/epidemiologia , Estados Unidos , Organização Mundial da Saúde
14.
J Phys Chem Lett ; 13(14): 3297-3303, 2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35389644

RESUMO

Bandshape analysis of charge-transfer optical bands in room-temperature ionic liquids (ILs) was performed to extract the reorganization energy of electron transfer. Remarkably, the reorganization energies in ILs are close to those in cyclohexane. This result runs against common wisdom in the field since conducting ILs, which are characterized by an infinite static dielectric constant, and nonpolar cyclohexane fall to the opposite ends of the polarity scale based on their dielectric constants. Theoretical calculations employing structure factors of ILs from molecular dynamics simulations support the low values of the reorganization energy. Standard dielectric arguments do not apply to solvation in ILs, and nonergodic reorganization energies are required for a quantitative analysis.


Assuntos
Líquidos Iônicos , Transporte de Elétrons , Elétrons , Líquidos Iônicos/química , Simulação de Dinâmica Molecular
15.
Artigo em Inglês | MEDLINE | ID: mdl-35290257

RESUMO

INTRODUCTION: In the past decade, online physician review websites have become an important source of information for patients, with the largest and most popular being Healthgrades.com. Our study aims to investigate demographic and volume-based trends for online reviews of every Healthgrades-listed orthopaedic surgeon through a nationwide, retrospective analysis. METHODS: All available demographic and rating information for orthopaedic surgeons (n = 28,713; Healthgrades.com) was analyzed using one-way Analysis of Variance, Tukey Studentized Range (Honestly Significant Difference), linear regression, and Pearson correlation coefficient. RESULTS: The mean rating for all surgeons was 3.99 (SD 0.92), and the mean number of ratings was 13.43 (SD 20.4). Men had a greater mean rating at 4.02 compared with women at 3.91 (P < 0.0001), and DO surgeons had greater mean rating at 4.11 compared with MD surgeons at 3.90 (P < 0.0001). The correlation between rating and age had a significant negative correlation (P < 0.0001). The correlation between average online rating and number of reviews had a significant positive correlation (P < 0.0001). DISCUSSION: Our analysis suggests that greater online ratings are associated with the male sex and DO degrees. In addition, our study discovered that the number of ratings was positively correlated with greater mean online ratings, whereas older age was negatively correlated with greater mean online ratings.


Assuntos
Cirurgiões Ortopédicos , Ortopedia , Cirurgiões , Feminino , Humanos , Masculino , Satisfação do Paciente , Estudos Retrospectivos
16.
Am J Obstet Gynecol ; 226(2S): S819-S834, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32882208

RESUMO

Qualitative and quantitative measurement of urine protein excretion is one of the most common tests performed during pregnancy. For more than 100 years, proteinuria was necessary for the diagnosis of preeclampsia, but recent guidelines recommend that proteinuria is sufficient but not necessary for the diagnosis. Still, in clinical practice, most patients with gestational hypertension will be diagnosed as having preeclampsia based on the presence of proteinuria. Although the reference standard for measuring urinary protein excretion is a 24-hour urine collection, spot urine protein-to-creatinine ratio is a reasonable "rule-out" test for proteinuria. Urine dipstick screening for proteinuria does not provide any clinical benefit and should not be used to diagnose proteinuria. The classic cutoff cited to define proteinuria during pregnancy is a value of >300 mg/24 hours or a urine protein-to-creatinine ratio of at least 0.3. Using this cutoff, the rate of isolated proteinuria in pregnancy may reach 8%, whereas preeclampsia occurs among 3% to 8% of pregnancies. Although this threshold is widely accepted, its origin is not based on evidence on adverse pregnancy outcomes but rather on expert opinion and results of small studies. After reviewing the available data, the most important factor that influences maternal and neonatal outcome is the severity of blood pressures and presence of end organ damage, rather than the excess protein excretion. Because the management of gestational hypertension and preeclampsia without severe features is almost identical in frequency of surveillance and timing of delivery, the separation into 2 disorders is unnecessary. If the management of women with gestational hypertension with a positive assessment of proteinuria will not change, we believe that urine assessment for proteinuria is unnecessary in women who develop new-onset blood pressure at or after 20 weeks' gestation. Furthermore, we do not recommend repeated measurement of proteinuria for women with preeclampsia, the amount of proteinuria does not seem to be related to poor maternal and neonatal outcomes, and monitoring proteinuria may lead to unindicated preterm deliveries and related neonatal complications. Our current diagnosis of preeclampsia in women with chronic kidney disease may be based on a change in protein excretion, a baseline protein excretion evaluation is critical in certain conditions such as chronic hypertension, diabetes, and autoimmune or other renal disorders. The current definition of superimposed preeclampsia possesses a diagnostic dilemma, and it is unclear whether a change in the baseline proteinuria reflects another systemic disease such as preeclampsia or whether women with chronic disease such as chronic hypertension or diabetes will experience a different "normal" pattern of protein excretion during pregnancy. Finally, limited data are available regarding angiogenic and other biomarkers in women with chronic kidney disease as a potential aid in distinguishing the worsening of baseline chronic kidney disease and chronic hypertension from superimposed preeclampsia.


Assuntos
Hipertensão/fisiopatologia , Pré-Eclâmpsia/fisiopatologia , Proteinúria/fisiopatologia , Feminino , Taxa de Filtração Glomerular , Humanos , Hipertensão Induzida pela Gravidez/diagnóstico , Pré-Eclâmpsia/diagnóstico , Gravidez , Proteinúria/diagnóstico , Insuficiência Renal Crônica/fisiopatologia , Urinálise/métodos
17.
J Card Fail ; 28(3): 415-421, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34670174

RESUMO

Adults with congenital heart diseases may not be candidates for conventional therapies to control ventricular systolic dysfunction, including mechanical circulatory support, which moves potential heart-transplantation recipients to a listing status of higher priority. This results in longer waitlist times and greater mortality rates. Exception-status listing allows a pathway for this complex and anatomically heterogenous group of patients to be listed for heart transplantation at appropriately high listing status. Our study queried the United Network for Organ Sharing registry to evaluate trends in the use of exception-status listing among adults with congenital heart diseases awaiting heart transplantation. Uptrend in the use of exception-status listing precedes the new allocation system, but it has been greatest since changes were made in the allocation system. It continues to remain a vital pathway for adults with congenital heart disease (whose waitlist mortality rates are often not characterized adequately by using the waitlist-status criteria) timely access to heart transplantation.


Assuntos
Cardiopatias Congênitas , Insuficiência Cardíaca , Transplante de Coração , Adulto , Procedimentos Clínicos , Cardiopatias Congênitas/cirurgia , Insuficiência Cardíaca/terapia , Humanos , Estudos Retrospectivos , Listas de Espera
18.
J Phys Chem B ; 125(44): 12264-12273, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34714656

RESUMO

The pathway of activationless proton transfer induced by an electron-transfer reaction is studied theoretically. Long-range electron transfer produces highly nonequilibrium medium polarization that can drive proton transfer through an activationless transition during the process of thermalization, dynamically altering the screening of the electron-proton Coulomb interaction by the medium. The cross electron-proton reorganization energy is the main energy parameter of the theory, which exceeds in magnitude the proton-transfer reorganization energy roughly by the ratio of the electron-transfer to proton-transfer distance. This parameter, which can be either positive or negative, is related to the difference in pKa values in two electron-transfer states. The relaxation time of the medium is on the (sub)picosecond time scale, which establishes the characteristic time for activationless proton transfer. Microscopic calculations predict substantial retardation of the collective relaxation dynamics compared to the continuum estimates due to the phenomenology analogous to de Gennes narrowing. Nonequilibrium medium configuration promoting proton transfer can be induced by either thermal or photoinduced charge transfer.


Assuntos
Elétrons , Prótons , Transporte de Elétrons
19.
mSystems ; 6(5): e0020121, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34546069

RESUMO

Genes belonging to the same functional group may include numerous and variable gene sequences, making characterizing and quantifying difficult. Therefore, high-throughput design tools are needed to simultaneously create primers for improved quantification of target genes. We developed MetaFunPrimer, a bioinformatic pipeline, to design primers for numerous genes of interest. This tool also enables gene target prioritization based on ranking the presence of genes in user-defined references, such as environment-specific metagenomes. Given inputs of protein and nucleotide sequences for gene targets of interest and an accompanying set of reference metagenomes or genomes, MetaFunPrimer generates primers for ranked genes of interest. To demonstrate the usage and benefits of MetaFunPrimer, a total of 78 primer pairs were designed to target observed ammonia monooxygenase subunit A (amoA) genes of ammonia-oxidizing bacteria (AOB) in 1,550 publicly available soil metagenomes. We demonstrate computationally that these amoA-AOB primers can cover 94% of the amoA-AOB genes observed in the 1,550 soil metagenomes compared with a 49% estimated coverage by previously published primers. Finally, we verified the utility of these primer sets in incubation experiments that used long-term nitrogen fertilized or unfertilized soils. High-throughput quantitative PCR (qPCR) results and statistical analyses showed significant differences in relative quantification patterns between the two soils, and subsequent absolute quantifications also confirmed that target genes enumerated by six selected primer pairs were significantly more abundant in the nitrogen-fertilized soils. This new tool gives microbial ecologists a new approach to assess functional gene abundance and related microbial community dynamics quickly and affordably. IMPORTANCE Amplification-based gene characterization allows for sensitive and specific quantification of functional genes. There is often a large diversity of genes represented for functional gene groups, and multiple primers may be necessary to target associated genes. Current primer design tools are limited to designing primers for only a few genes of interest. MetaFunPrimer allows for high-throughput primer design for various genes of interest and also allows for ranking gene targets by their presence and abundance in environmental data sets. Primers designed by this tool improve the characterization and quantification of functional genes in broad gene amplification platforms and can be powerful with high-throughput qPCR approaches.

20.
J Phys Chem A ; 125(19): 4037-4038, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33891390
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