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1.
Nat Commun ; 11(1): 4945, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009378

RESUMO

Spring warming substantially advances leaf unfolding and flowering time for perennials. Winter warming, however, decreases chilling accumulation (CA), which increases the heat requirement (HR) and acts to delay spring phenology. Whether or not this negative CA-HR relationship is correctly interpreted in ecosystem models remains unknown. Using leaf unfolding and flowering data for 30 perennials in Europe, here we show that more than half (7 of 12) of current chilling models are invalid since they show a positive CA-HR relationship. The possible reason is that they overlook the effect of freezing temperature on dormancy release. Overestimation of the advance in spring phenology by the end of this century by these invalid chilling models could be as large as 7.6 and 20.0 days under RCPs 4.5 and 8.5, respectively. Our results highlight the need for a better representation of chilling for the correct understanding of spring phenological responses to future climate change.


Assuntos
Mudança Climática , Temperatura Baixa , Folhas de Planta/fisiologia , Estações do Ano , Betula/fisiologia , Temperatura Alta , Modelos Lineares , Modelos Biológicos
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1528-1531, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018282

RESUMO

Raynaud's phenomenon (RP) is a disease characterized by a transient ischemic process, in an exaggerated vascular response to cold or emotional stress. Thermography is a resource applied to support diagnosis of changes in the circulatory system. The aim of the study was to use the DistalDorsal Thermography Difference (DDD) in thermographic images to assess thermal behavior in individuals with secondary RP. The research was carried out in the period between 2018 and 2019. The sample means of the Distal-consisted of 44 individuals in a control group (Control) and 44 individuals in a pathological group (RP2). The participants, after acclimatization, were submitted to the cold stress protocol. The protocol consisted of immersing hands in a container of water at a temperature of 15°C for 60 seconds. The acquisition of thermographic images was performed at the pre-test moment and at the 1st, 3rd, 5th, 7th, 10th and 15th minute. At each time, the DDD values (of all fingers - minimum, maximum and sum) between the groups were analyzed. For statistical analysis, the independent t test and Cohen's d test were used. Regarding the results, there was a difference in relation to the rate of temperature recovery between the groups. The first group showed a rate of reheating just after the first minute subsequent to the cold stress test, while the RP2 group was unable to recover the temperature over 15 minutes. DDD, regardless of the selected criterion, proved to be a valid index for verifying the temperature gradient in the study with individuals identified with secondary RP.


Assuntos
Doença de Raynaud , Termografia , Temperatura Baixa , Dedos/irrigação sanguínea , Mãos , Humanos , Isquemia , Doença de Raynaud/diagnóstico
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2532-2535, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018522

RESUMO

Experiments with animal models of epilepsy have consistently shown that focal cooling of epilepsy-induced brain region reversibly suppresses or terminates epileptic discharge activity. Recently, we formulated a physiologically plausible temperature dependence in a neural mass model that can reproduce the effect of focal cooling on epileptic discharge activity. This can be used to implement a temperature control in an implantable cooling device for thermal neuromodulation of the epileptogenic zone in patients with partial epilepsy when seizure activity is detected. However, there have been no experiments that looked into the effect of focal cooling in animal models of epilepsy with secondary generalization in which the seizure activity spreads from the pathologic region to other regions of the brain. Using the temperature-dependent neural mass model and a physiological coupling model, we show that focal cooling stops the propagation of low-frequency discharge activity; on the other hand, it increases the amount of coupling required to propagate high-frequency discharge activity. Moreover, discharge activities that are propagated with cooling are lower in both magnitude and frequency compared to those propagated without cooling. These results suggest the feasibility of focal cooling as an effective alternative therapeutic treatment for medically intractable partial epilepsy even with secondary generalization.Clinical Relevance- The computational study establishes focal cooling of the brain region with partial epilepsy not only suppresses epileptic discharges but can also prevent its generalization to other brain regions.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Animais , Encéfalo , Temperatura Baixa , Epilepsias Parciais/terapia , Estudos de Viabilidade , Humanos
4.
Sci Total Environ ; 741: 140188, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32886981

RESUMO

CONTEXT: A number of studies have shown that cold has an important impact on human health. However, almost no studies focused on cold warning systems to prevent those health effects. For Nordic regions, like the province of Quebec in Canada, winter is long and usually very cold with an observed increase in mortality and hospitalizations throughout the season. However, there is no existing system specifically designed to follow in real-time this mortality increase throughout the season and to alert public health authorities prior to cold waves. OBJECTIVE: The aim is to establish a watch and warning system specifically for health impacts of cold, applied to different climatic regions of the province of Quebec. METHODOLOGY: A methodology previously used to establish the health-heat warning system in Quebec is adapted to cold. The approach identifies cold weather indicators and establishes thresholds related to extreme over-mortality or over-hospitalization events in the province of Quebec, Canada. RESULTS AND CONCLUSION: The final health-related thresholds proposed are between (-15 °C, -23 °C) and (-20 °C, -29 °C) according to the climatic region for excesses of mortality, and between (-13 °C, -23 °C) and (-17 °C, -30 °C) for excesses of hospitalization. These results suggest that the system model has a high sensitivity and an acceptable number of false alarms. This could lead to the establishment of a cold-health watch and warning system with valid indicators and thresholds for each climatic region of Quebec. It can be seen as a complementary system to the existing one for heat warnings, in order to help the public health authorities to be well prepared during an extreme cold event.


Assuntos
Temperatura Baixa , Temperatura Alta , Canadá , Humanos , Quebeque , Estações do Ano
5.
Science ; 369(6509): 1304-1305, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32913090
6.
Oecologia ; 194(1-2): 41-50, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32960336

RESUMO

In temperate climates, as a consequence of warming winters, an increasing number of ectothermic species are remaining active throughout winter months instead of diapausing, rendering them increasingly vulnerable to unpredictable cold events. One species displaying a shift in overwintering strategy is the parasitoid wasp and biological control agent Aphidius avenae. The current study aimed to better understand the consequence of a changing overwintering strategy on the evolutionary potential of an insect population to adapt to the cold stress events, set to increase in frequency, even during milder winters. Using a parental half-sibling breeding design, narrow-sense heritability of the cold tolerance, morphology and longevity of A. avenae was estimated. The heritability of cold tolerance was estimated at 0.07 (CI95% = [0.00; 0.25]) for the Critical Thermal Minima (CTmin) and 0.11 (CI95% = [0.00; 0.34]) for chill coma temperature; estimates much lower than those obtained for morphological traits (tibia length 0.20 (CI95% = [0.03; 0.37]); head width 0.23 (CI95% = [0.09; 0.39]); wing surface area 0.28 (CI95% = [0.11; 0.47])), although comparable with the heritability estimate of 0.12 obtained for longevity (CI95% = [0.00; 0.25]). The heritability estimates obtained thus suggest that A. avenae possesses low adaptive potential against cold stress. If such estimates are indicative of the evolutionary potential of A. avenae cold tolerance, more emphasis may be placed on adaptive phenotypic plasticity at the individual level to persist in a changing climate, with potential implications for the biological control function they provide.


Assuntos
Afídeos , Vespas , Animais , Mudança Climática , Temperatura Baixa , Estações do Ano , Vespas/genética
7.
Anim Sci J ; 91(1): e13354, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32789990

RESUMO

The study was aimed to investigate the influence of animal age, post-slaughter chilling rate, and aging time on meat quality of M. longissimus dorsi (LD) of water buffalo (Bubalus bubalis) and humped cattle (Bos taurus indicus) bulls. After slaughtering, one side of carcasses was subjected to rapid chilling (RC) (0 ± 2°C) and other side was hanged in controlled room temperature (25 ± 2°C) for 3 hr, then allowed to the chiller (0 ± 2°C). The meat quality traits were analyzed at 1, 7, and 14 days of storage. It was noted that rapidly chilled carcasses from the younger animals of both species missed the ideal pH/temperature window, which affects the toughness of the meat. Buffalo meat presented higher shear force, color L* values, and lower b* value as compared to the cattle meat. Moreover, meat shear force values decreased while all color coordinates and cooking loss values increased with lengthening the storage time in both age groups of cattle and buffalo. In conclusion, the tenderness of cattle meat was superior to that of buffalo and RC adversely affect the shear force values of young cattle and both age groups of buffalo bulls.


Assuntos
Temperatura Baixa , Conservação de Alimentos/métodos , Qualidade dos Alimentos , Carne Vermelha , Envelhecimento , Animais , Búfalos , Bovinos , Temperatura Baixa/efeitos adversos , Masculino , Fatores de Tempo
8.
Epidemiol Psychiatr Sci ; 29: e163, 2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32829741

RESUMO

AIMS: We aimed to investigate the heterogeneity of seasonal suicide patterns among multiple geographically, demographically and socioeconomically diverse populations. METHODS: Weekly time-series data of suicide counts for 354 communities in 12 countries during 1986-2016 were analysed. Two-stage analysis was performed. In the first stage, a generalised linear model, including cyclic splines, was used to estimate seasonal patterns of suicide for each community. In the second stage, the community-specific seasonal patterns were combined for each country using meta-regression. In addition, the community-specific seasonal patterns were regressed onto community-level socioeconomic, demographic and environmental indicators using meta-regression. RESULTS: We observed seasonal patterns in suicide, with the counts peaking in spring and declining to a trough in winter in most of the countries. However, the shape of seasonal patterns varied among countries from bimodal to unimodal seasonality. The amplitude of seasonal patterns (i.e. the peak/trough relative risk) also varied from 1.47 (95% confidence interval [CI]: 1.33-1.62) to 1.05 (95% CI: 1.01-1.1) among 12 countries. The subgroup difference in the seasonal pattern also varied over countries. In some countries, larger amplitude was shown for females and for the elderly population (≥65 years of age) than for males and for younger people, respectively. The subperiod difference also varied; some countries showed increasing seasonality while others showed a decrease or little change. Finally, the amplitude was larger for communities with colder climates, higher proportions of elderly people and lower unemployment rates (p-values < 0.05). CONCLUSIONS: Despite the common features of a spring peak and a winter trough, seasonal suicide patterns were largely heterogeneous in shape, amplitude, subgroup differences and temporal changes among different populations, as influenced by climate, demographic and socioeconomic conditions. Our findings may help elucidate the underlying mechanisms of seasonal suicide patterns and aid in improving the design of population-specific suicide prevention programmes based on these patterns.


Assuntos
Estações do Ano , Suicídio/estatística & dados numéricos , Temperatura Baixa , Feminino , Temperatura Alta , Humanos , Masculino , Periodicidade , Distribuição por Sexo , Fatores Socioeconômicos , Suicídio/psicologia
9.
Sci Total Environ ; 739: 140028, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758947

RESUMO

Many studies have reported effects of global climate change on wildlife, including changes in species distributions and population sizes but perspectives on interactions between the biosphere and the anthroposphere are limited. Bears have a worldwide range and often come into conflict with humans. We assessed the effects of weather variables including temperature, precipitation, and sunshine on human-bear conflicts. Given that the relationship between climate and bear physiology is poorly understood, we first conducted an exploratory analysis using regression techniques. We then built a final predictive model using generalized linear mixed modelling and Akaike's Information Criterion (AIC)-based model selection. Our model highlighted the influence of cold temperatures during denning on the frequency of human-bear conflicts. Cold temperatures during denning are related to increased energy requirements for thermoregulation. It is likely that the resulting increase in demand for food following denning leads to an increase in human-bear conflicts. Our results also indicate that cool springs, lingering winter snowpacks, and hot summers may increase human-bear conflicts due to associated reductions in key food sources.


Assuntos
Ursidae , Animais , Mudança Climática , Temperatura Baixa , Humanos , Japão , Estações do Ano
10.
Nat Commun ; 11(1): 4313, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855402

RESUMO

It has been suggested that beige fat thermogenesis is tightly controlled by epigenetic regulators that sense environmental cues such as temperature. Here, we report that subcutaneous adipose expression of the DNA demethylase TET1 is suppressed by cold and other stimulators of beige adipocyte thermogenesis. TET1 acts as an autonomous repressor of key thermogenic genes, including Ucp1 and Ppargc1a, in beige adipocytes. Adipose-selective Tet1 knockout mice generated by using Fabp4-Cre improves cold tolerance and increases energy expenditure and protects against diet-induced obesity and insulin resistance. Moreover, the suppressive role of TET1 in the thermogenic gene regulation of beige adipocytes is largely DNA demethylase-independent. Rather, TET1 coordinates with HDAC1 to mediate the epigenetic changes to suppress thermogenic gene transcription. Taken together, TET1 is a potent beige-selective epigenetic breaker of the thermogenic gene program. Our findings may lead to a therapeutic strategy to increase energy expenditure in obesity and related metabolic disorders.


Assuntos
Adipócitos Bege/metabolismo , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Obesidade/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Termogênese/genética , Animais , Calorimetria Indireta , Linhagem Celular , Temperatura Baixa/efeitos adversos , Proteínas de Ligação a DNA/genética , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Metabolismo Energético/genética , Regulação da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Resistência à Insulina/genética , Masculino , Camundongos , Camundongos Knockout , Obesidade/etiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteínas Proto-Oncogênicas/genética , RNA-Seq , Gordura Subcutânea/citologia , Gordura Subcutânea/metabolismo , Proteína Desacopladora 1/metabolismo
11.
Artigo em Chinês | MEDLINE | ID: mdl-32842196

RESUMO

Objective:This study aimed to compare the nasal response of cold dry air(CDA) provocation in patients with idiopathic rhinitis(IR) and healthy individuals, and further assess its ability in diagnosing IR. Method:CDA provocation was performed among 15 healthy volunteers and 17 IR patients from Beijing Tongren Hospital Outpatient Department. Nasal symptom scores, total nasal volume(TNV), total nasal resistance(TNR) and minimal cross-sectional area(MCA) were checked before and after the provocation. Logistic regression analysis and Receiver Operating Characteristic(ROC) curves were used in data evaluation. Result:Subjects in the IR group showed significantly larger changes after CDA provocation in total nasal symptom score(TNSS), total nasal resistance(TNR), minimal cross-sectional area(MCA) and total nasal volume(TNV), compared with healthy volunteers. We built a predictive model for IR, Y=0.394×ΔTNSS-0.061 ×ΔTNV(%)+0.014×ΔTNV(%) -2.318, whose area under curve was 0.919 based on multi-factor logistic regression and ROC curve. According to the Youden index, the cut-off criteria was set to be Y >0.49, when its sensitivity and specificity were 82.4% and 84.6%, respectively. Conclusion:Aggravated nasal symptoms and decreased nasal ventilation could be seen after CDA provocation in the IR population. The CDA provocation provides a possible method for assisting the diagnosis of IR, and we'll expand the sample size in future research to verify its clinical application value.


Assuntos
Rinite , Temperatura Baixa , Humanos , Testes de Provocação Nasal , Nariz , Sensibilidade e Especificidade
12.
PLoS One ; 15(8): e0237343, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764811

RESUMO

The aim of the Mont Blanc Study was to investigate the relationship between intraocular pressure (IOP), central corneal thickness (CCT), and altitude in healthy subjects. Thirty-three eyes of 33 healthy volunteers (mean age: 24.8 years, 17 females) had their IOP measured with Perkins and I-Care tonometers and their CCT using ultrasound pachymetry at three locations in Italy with different altitudes: Pavia, (PV), 77 meters above sea level (a.s.l); Courmayeur (CM), 1300 meters a.s.l; Pointe Helbronner (PH), 3466 meters a.s.l.). The measurements were performed at 9 am, 11 am, 1 pm and 3 pm (±30') in indoor settings (mean temperature of 19°C) in PV and PH. At 9 am, CCT and IOP were measured outdoor (mean temperature of -1.4°C) at PH. The mean values of the IOP curve decreased from PV to PH with the Perkins (p = 0.02) and I-Care tonometers (p = 0.001). Instead, CCT increased upon ascension from PV to PH (p = 0.01), and from CM to PH (p = 0.002). When exposed to sub-zero temperature, the IOP increased (p<0.001), while the CCT did not change (p = 0.30). The results suggest that IOP significantly decreased and CCT significantly increased upon ascension from the sea level to higher altitudes.


Assuntos
Altitude , Córnea/anatomia & histologia , Pressão Intraocular , Adulto , Temperatura Baixa , Paquimetria Corneana , Feminino , Voluntários Saudáveis , Humanos , Masculino , Estudos Prospectivos , Adulto Jovem
13.
Sci Total Environ ; 746: 141261, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32745866

RESUMO

Although injury is a leading cause of death worldwide, the association between ambient temperature and injury has received little research attention compared to the association of temperature with mortality and morbidity from non-external causes. With current climate change and increases in weather extremes, assessing the association between temperature and injury is important for determining public health priorities. Therefore, the present study examined the association between ambient temperature and injury risk with a focus on the intentions and mechanisms of injury. Using the national emergency database, we identified a total of 703,503 injured patients who had visited emergency departments in Seoul, South Korea from 2008 to 2016. We conducted a time-stratified case-crossover study using a conditional Poisson regression model, and applied a distributed lag nonlinear model to explore possible nonlinear and delayed effects of daily mean temperature on injury risk. Injury risk was significantly associated with ambient temperature, and temperature-injury association curves markedly differed with respect to intentions and mechanisms of injury. Although unintentional injuries increased significantly at both high and low temperatures, intentional injuries - including self-harm and assault - significantly increased only at high temperatures. The mechanism-specific analyses showed that injuries caused by traffic accidents and burns significantly increased at both high and low temperatures. However, injuries caused by all other mechanisms (i.e., fall, blunt object, machinery, penetration, and poisoning) significantly increased only at high temperatures, while injury due to slipping increased at low temperatures. Our study provides evidence that ambient temperature is associated with risk of injury, and this association differs depending on the intentions and mechanisms of injury. Overall, our findings help foster a more comprehensive understanding of the association between temperature and injury that can be used to establish appropriate public health policies and targeted interventions.


Assuntos
Intenção , Dinâmica não Linear , Temperatura Baixa , Estudos Cross-Over , Temperatura Alta , Humanos , República da Coreia/epidemiologia , Seul , Temperatura
14.
Sci Total Environ ; 746: 141033, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32750577

RESUMO

Although impacts of extremely cold temperatures on human health have been widely studied, adverse effects of other extreme weather phenomena have so far received much less attention. We employed a high-quality long-term mortality time series (1982-2017) to evaluate impacts of extreme winter weather in the Czech Republic. We aimed to clarify whether compound events of extreme weather cause larger impacts on mortality than do each type of extreme if evaluated individually. Using daily data from the E-OBS and ERA5 datasets, we analyzed 9 types of extreme events: extreme wind gust, precipitation, snowfall, and sudden temperature and pressure changes. Relative mortality deviations from the adjusted baseline were used to estimate the immediate effect of the selected extreme events on excess mortality. The impact was adjusted for the effect of extreme cold. Extreme events associated with sudden rise of minimum temperature and pressure drops had generally significant impact on excess mortality (3.7% and 1.4% increase). The impacts were even more pronounced if these events occurred simultaneously or were compounded with other types of extremes, such as heavy precipitation, snowfall, maximum temperature rise, and their combinations (increase as great as 14.4%). Effects of some compound events were significant even for combinations of extremes having no significant impact on mortality when evaluated separately. On the other hand, a "protective" effect of pressure increases reduced the risk for its compound events. Meteorological patterns during extreme events linked to excess mortality indicate passage of a low-pressure system northerly from the study domain. We identified extreme winter weather events other than cold temperatures with significant impact on excess mortality. Our results suggest that occurrence of compound extreme events strengthen the impacts on mortality and therefore analysis of multiple meteorological parameters is a useful approach in defining adverse weather conditions.


Assuntos
Temperatura Baixa , Tempo (Meteorologia) , República Tcheca/epidemiologia , Humanos , Mortalidade , Estações do Ano , Temperatura
15.
PLoS One ; 15(8): e0237347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785272

RESUMO

Here we examine a class of neurons that have been recently explored, the somatosensory neuronal subclass of cold thermosensors. We create a mathematical model of a cold sensing neuron that has been formulated to understand the variety of ionic channels involved. In particular this model showcases the role of TRPM8 and voltage gated potassium channels in setting the temperature dependent activation and inactivation threshold level. Bifurcation analysis of the model demonstrates that a Hodgkin-Huxley type model with additional TRPM8 channels is sufficient to replicate observable experimental features of when different threshold level cold thermosensors turn on. Additionally, our analysis gives insight into what is happening at the temperature levels at which these neurons shut off and the role sodium and leak currents may have in this. This type of model construction and analysis provides a framework moving forward that will help tackle less well understood neuronal classes and their important ionic channels.


Assuntos
Temperatura Baixa , Modelos Neurológicos , Canais de Cátion TRPM/metabolismo , Termorreceptores/fisiologia , Sensação Térmica/fisiologia , Animais , Potenciais da Membrana/fisiologia , Potássio/metabolismo , Sódio/metabolismo
16.
Proc Natl Acad Sci U S A ; 117(33): 20298-20304, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32747539

RESUMO

In mammals, temperature-sensitive TRP channels make membrane conductance of cells extremely temperature dependent, allowing the detection of temperature ranging from noxious cold to noxious heat. We progressively deleted the distal carboxyl terminus domain (CTD) of the cold-activated melastatin receptor channel, TRPM8. We found that the enthalpy change associated with channel gating is proportional to the length of the CTD. Deletion of the last 36 amino acids of the CTD transforms TRPM8 into a reduced temperature-sensitivity channel (Q10 ∼4). Exposing the intracellular domain to a denaturing agent increases the energy required to open the channel indicating that cold drives channel gating by stabilizing the folded state of the CTD. Experiments in the presence of an osmoticant agent suggest that channel gating involves a change in solute-inaccessible volume in the CTD of ∼1,900 Å3 This volume matches the void space inside the coiled coil according to the cryogenic electron microscopy structure of TRPM8. The results indicate that a folding-unfolding reaction of a specialized temperature-sensitive structure is coupled to TRPM8 gating.


Assuntos
Domínios Proteicos , Dobramento de Proteína , Canais de Cátion TRPM/química , Animais , Temperatura Baixa , Microscopia Crioeletrônica , Humanos , Ativação do Canal Iônico , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mutação , Oócitos , Conformação Proteica , Canais de Cátion TRPM/metabolismo , Termodinâmica , Xenopus laevis
17.
Transplantation ; 104(9): 1929-1942, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32769628

RESUMO

BACKGROUND: Liver graft viability assessment has long been considered a limit of hypothermic oxygenated machine perfusion (HOPE). Aim of this study was assessing correlations of easily available perfusate parameters (PP) (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, glucose, lactate, and pH) with graft features and outcome. METHODS: In the period October 2018-February 2020, perfusate samples were obtained every 30 minutes during 50 dual-HOPE (D-HOPE) procedures. Correlations of PP with graft factors, 90-day graft loss, early allograft dysfunction (EAD), L-GrAFT score, acute kidney injury, and comprehensive complication index were analyzed using Pearson coefficient, receiver-operating characteristics analysis and by univariable and multivariable regression. RESULTS: Median D-HOPE time was 122 minutes. All parameters were normalized to liver weight. Only macrovesicular steatosis (MaS) significantly impacted PP levels and slope. Grafts with ≥30% MaS exhibited significantly different PP values and slope. Graft loss and EAD rate were 2% (n = 1) and 26% (n = 13). All PP except lactate correlated with EAD, 90-minute alanine aminotransferase showing the highest area under the receiver-operating characteristics curve (0.84). However, at multivariable analysis, the only factor independently associated with EAD was MaS (odds ratio, 5.44; confidence interval, 1.05-28.21; P = 0.04). Ninety minutes lactate dehydrogenase had the strongest correlation with L-GrAFT (R = 0.70; P < 0.001). PP correlated poorly with comprehensive complication index and grades 2-3 acute kidney injury rate. CONCLUSIONS: PP were predictive of graft function after transplant, but their association with graft survival and clinical outcomes requires further evaluation. MaS influenced levels of PP and was the only independent predictor of EAD.


Assuntos
Transplante de Fígado/métodos , Preservação de Órgãos/métodos , Perfusão/métodos , Doadores de Tecidos , Alanina Transaminase/análise , Aspartato Aminotransferases/análise , Temperatura Baixa , Feminino , Sobrevivência de Enxerto , Humanos , Concentração de Íons de Hidrogênio , L-Lactato Desidrogenase/análise , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
18.
Proc Biol Sci ; 287(1931): 20201134, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32693727

RESUMO

Antarctica is estimated to contain as much as a quarter of earth's marine methane, however we have not discovered an active Antarctic methane seep limiting our understanding of the methane cycle. In 2011, an expansive (70 m × 1 m) microbial mat formed at 10 m water depth in the Ross Sea, Antarctica which we identify here to be a high latitude hydrogen sulfide and methane seep. Through 16S rRNA gene analysis on samples collected 1 year and 5 years after the methane seep formed, we identify the taxa involved in the Antarctic methane cycle and quantify the response rate of the microbial community to a novel input of methane. One year after the seep formed, ANaerobic MEthane oxidizing archaea (ANME), the dominant sink of methane globally, were absent. Five years later, ANME were found to make up to 4% of the microbial community, however the dominant member of this group observed (ANME-1) were unexpected considering the cold temperature (-1.8°C) and high sulfate concentrations (greater than 24 mM) present at this site. Additionally, the microbial community had not yet formed a sufficient filter to mitigate the release of methane from the sediment; methane flux from the sediment was still significant at 3.1 mmol CH4 m-2 d-1. We hypothesize that this 5 year time point represents an early successional stage of the microbiota in response to methane input. This study provides the first report of the evolution of a seep system from a non-seep environment, and reveals that the rate of microbial succession may have an unrealized impact on greenhouse gas emission from marine methane reservoirs.


Assuntos
Metano , Regiões Antárticas , Archaea/fisiologia , Temperatura Baixa , Fenômenos Ecológicos e Ambientais , Sedimentos Geológicos , Microbiota , Filogenia , Água do Mar , Análise de Sequência de DNA , Sulfatos
19.
PLoS Genet ; 16(7): e1008882, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32673315

RESUMO

Expansion of the maize growing area was central for food security in temperate regions. In addition to the suppression of the short-day requirement for floral induction, it required breeding for a large range of flowering time that compensates the effect of South-North gradients of temperatures. Here we show the role of a novel florigen gene, ZCN12, in the latter adaptation in cooperation with ZCN8. Strong eQTLs of ZCN8 and ZCN12, measured in 327 maize lines, accounted for most of the genetic variance of flowering time in platform and field experiments. ZCN12 had a strong effect on flowering time of transgenic Arabidopsis thaliana plants; a path analysis showed that it directly affected maize flowering time together with ZCN8. The allelic composition at ZCN QTLs showed clear signs of selection by breeders. This suggests that florigens played a central role in ensuring a large range of flowering time, necessary for adaptation to temperate areas.


Assuntos
Adaptação Fisiológica/genética , Florígeno/metabolismo , Proteínas de Plantas/genética , Zea mays/genética , Aclimatação/genética , Temperatura Baixa , Flores/genética , Flores/crescimento & desenvolvimento , Humanos , Fotoperíodo , Proteínas de Plantas/metabolismo , Locos de Características Quantitativas/genética , Zea mays/crescimento & desenvolvimento
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