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1.
Medicine (Baltimore) ; 98(39): e17357, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31574880

RESUMO

Preoperative autologous blood donation is a well-established procedure to reduce the need for allogeneic blood transfusion. We hypothesized that coagulation activity is maintained in cold-stored whole blood, because the fundamental polymerization properties of fibrin are preserved.Fifty adult patients who underwent elective cardiothoracic surgery were enrolled.Autologous whole blood collected 2 to 4 times at almost 1-week intervals before surgery was stored at approximately 4°C until reinfusion at the time of surgery. Blood samples were drawn just before reinfusion, and rotational thromboelastometry variables and fibrinogen levels were measured.A total of 158 samples were analyzed. The mean duration of cold storage was 16.7 ±â€Š7.4 days (range: 6-33 days). Platelet counts were very low due to collection through a leukoreduction filter. The mean fibrinogen level was 2.3 ±â€Š0.6 g/L. Amplitude at 10 minutes after CT (A10), amplitude at 20 minutes after CT (A20), and maximum clot firmness (MCF) values as determined by FIBTEM analysis were 10.8 ±â€Š3.8, 12.2 ±â€Š4.2, and 13.1 ±â€Š4.7 mm, respectively. Fibrinogen levels were strongly correlated with A10, A20, and FIBTEM-MCF values (ρ = 0.83, P < .0001, ρ = 0.84, P < .0001, ρ = 0.85, P < .0001, respectively). Fibrinogen levels were not correlated with the duration of cold storage (ρ = 0.06, P = .43).The results of the present study demonstrate that fibrin polymerization occurs in cold-stored autologous whole blood, and that such activity is strongly correlated with fibrinogen levels. Furthermore, our data suggest that cold-stored leukoreduced autologous whole blood retains fibrin polymerization properties throughout 33 days.


Assuntos
Coagulação Sanguínea , Transfusão de Sangue/métodos , Tromboelastografia/métodos , Tempo de Coagulação do Sangue Total , Idoso , Testes de Coagulação Sanguínea , Temperatura Baixa , Feminino , Fibrina/química , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Polimerização , Estudos Prospectivos
2.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(8): 960-964, 2019 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-31484261

RESUMO

Objective: To study the lag effect of temperature and the source of heterogeneity on other infectious diarrhea (OID) in Zhejiang province, so as to identify related vulnerable populations at risk. Methods: Data on OID and meteorology in Zhejiang province from 2014 to 2016 were collected. A two-stage model was conducted, including: 1) using the distributed lag non-linear model to estimate the city-specific lag effect of temperature on OID, 2) applying the multivariate Meta- analysis to pool the estimated city-specific effect, 3) using the multivariate Meta-regression to explore the sources of heterogeneity. Results: There were 301 593 cases of OID in Zhejiang province during the study period. At the provincial level, temperature that corresponding to the lowest risk of OID was 16.7 ℃, and the temperature corresponding to the highest risk was 6.2℃ (RR=2.298, 95%CI: 1.527- 3.459). 16.7 ℃ was recognized as the reference temperature. P(5) and P(95) of the average daily temperature represented low and high temperature respectively. When the temperature was cold, the risk was delayed by 2 days, with the highest risk found on the 5(th) day (RR=1.057, 95%CI: 1.030-1.084) before decreasing to the 23(rd) day. When the temperature got hot, the risk of OID occurred on the first day (RR=1.081, 95%CI: 1.045-1.118) and gradually decreasing to the 8(th) day. Differences on heterogeneous sources related to the risks of OID in different regions, presented on urban latitude and the rate of ageing in the population. Conclusions: Both high or low temperature could increase the risk of OID, with a lag effect noticed. Prevention program on OID should be focusing on populations living in the high latitude and the elderly population at the low temperature areas.


Assuntos
Temperatura Baixa , Diarreia/epidemiologia , Disenteria/epidemiologia , Temperatura Alta , Idoso , China , Diarreia/diagnóstico , Disenteria/diagnóstico , Humanos , Temperatura Ambiente
3.
Bioresour Technol ; 291: 121844, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31400704

RESUMO

A low-temperature sodium hydroxide (NaOH) pretreatment for sugarcane bagasse (SCB) was obtained via the surface response design in this study. However, a large quantity of water consumption and wastewater generation which have been the common problems for alkaline pretreatment of lignocellulose still exists in this pretreatment. In order to reduce water consumption and wastewater generation, this study attempted to perform enzymatic hydrolysis and fermentation of NaOH-treated SCB without washing process. It showed that after pretreatment and solid-liquid separation, NaOH-treated SCB could be directly hydrolysed by cellulase via pH and solid-liquid adjustment without washing steps, and the maximum enzymatic hydrolysis efficiency could reach to 70.2%. A domesticated Saccharomyces cerevisiae Y2034 which can endure 6-times diluted BL was obtained, and realized 67.5% ethanol yield from the enzymatic hydrolysate of unwashed NaOH-treated SCB. It provided a clue for converting NaOH-treated lignocellulose to ethanol at low water consumption and wastewater generation.


Assuntos
Celulose/química , Etanol/química , Saccharum/química , Hidróxido de Sódio/química , Celulose/metabolismo , Temperatura Baixa , Etanol/metabolismo , Fermentação , Hidrólise , Lignina/química , Lignina/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharum/metabolismo , Águas Residuárias/química
4.
Oecologia ; 191(1): 205-215, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31420741

RESUMO

Avian responses to high environmental temperatures include retreating to cooler microsites and/or increasing rates of evaporative heat dissipation via panting, both of which may affect foraging success. We hypothesized that behavioural trade-offs constrain the maintenance of avian body condition in hot environments, and tested predictions arising from this hypothesis for male Southern Yellow-billed Hornbills (Tockus leucomelas) breeding in the Kalahari Desert. Operative temperatures experienced by the hornbills varied by up to 13 °C among four microsite categories used by foraging males. Lower prey capture rates while panting and reductions associated with the occupancy of off-ground microsites, resulted in sharp declines in foraging efficiency during hot weather. Consequently, male body mass (Mb) gain between sunrise and sunset decreased with increasing daily maximum air temperature (Tmax), from ~ 5% when Tmax < 25 °C to zero when Tmax = 38.4 °C. Overnight Mb loss averaged ~ 4.5% irrespective of Tmax, creating a situation where nett 24-h Mb loss approached 5% on extremely hot days. These findings support the notion that temperature is a major determinant of body condition for arid-zone birds. Moreover, the strong temperature dependence of foraging success and body condition among male hornbills provisioning nests raises the possibility that male behavioural trade-offs translate into equally strong effects of hot weather on female condition and nest success. Our results also reveal how rapid anthropogenic climate change is likely to substantially decrease the probability of arid-zone birds like hornbills being able to successfully provision nests while maintaining their own condition.


Assuntos
Aves , Regulação da Temperatura Corporal , Animais , Temperatura Baixa , Feminino , Temperatura Alta , Masculino , Temperatura Ambiente
5.
Phys Chem Chem Phys ; 21(35): 19298-19310, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31451813

RESUMO

The ice/water interface recognition mechanism of antifreeze proteins (AFPs) is highly contentious. Conventionally, protein adsorption on a solid surface is primarily driven by the polar interactions between the hydrophilic residues of the protein and interfacial water of the solid surface. Ice surface recognition by a type III AFP is surprising in this context where the ice binding surface (IBS) is hydrophobic. The present study provides molecular insight into the unusual interface recognition phenomenon of a type III AFP (QAE isoform) from Macrozoarces americanus. Potential of mean force calculations show that the type III AFP adsorbs on the ice surface mediated through a layer of ordered water. Molecular dynamics simulations at lower than ambient temperature reveal that the flat hydrophobic IBS induces ordering of water. The excellent geometrical synergy between the hydration water structure around the IBS and water arrangements on the pyramidal surface favours adsorption on the pyramidal plane. Mutations that interrupt the hydration shell water ordering essentially lead to less efficient adsorption, which greatly reduces the anti-freezing activity of the AFP. Binding free energy calculations of the wild-type and several mutant AFPs reveal that the binding affinity is linearly correlated with the experimentally observed thermal hysteresis activity. Therefore, binding to a specific ice plane with considerable affinity is the dictating factor of the anti-freeze activity for a type III AFP. Mechanistic insights into the ice binding process of the wild-type and different mutant AFPs obtained from this study pave the way for rational design of type III variants with much improved activity, which possesses ample industrial applicability, particularly in cryo-preservation.


Assuntos
Proteínas Anticongelantes/química , Proteínas de Peixes/química , Gelo , Perciformes , Água/química , Animais , Proteínas Anticongelantes/genética , Temperatura Baixa , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Simulação de Dinâmica Molecular , Mutação , Ligação Proteica
6.
J Agric Food Chem ; 67(35): 9958-9966, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31419123

RESUMO

Chilling injury (CI) is a physiological disorder induced by cold, which heavily limit crop production and postharvest preservation worldwide. Methyl jasmonate (MeJA) can alleviate CI in various fruit species, including peach; however, the underlying molecular mechanism is poorly understood. Here, changes in contents of phenolics, lipids, and jasmonic acid (JA) and gene expressions are compared between MeJA and control fruit. Exogenous MeJA inhibited expressions of PpPAL1, PpPPO1, and PpPOD1/2 but did not affect the phenolic content. Furthermore, MeJA fruit showed lower relative electrolyte leakage, indicating less membrane damage. Meanwhile, the enrichment of linoleic acid in the potential lipid biomarkers, especially phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol, coincided with lower expressions of PpFAD8.1 but higher PpLOX3.1 and JA content. In the JA signaling pathway, MeJA significantly upregulated expressions of PpMYC2.2 and PpCBF3 but downregulated PpMYC2.1. In conclusion, adjustments of fatty acids in phospholipids contribute to MeJA-induced alleviation of CI in peach fruit via induction of the JA-mediated C-repeat-binding factor pathway.


Assuntos
Acetatos/farmacologia , Ciclopentanos/metabolismo , Ciclopentanos/farmacologia , Frutas/efeitos dos fármacos , Oxilipinas/metabolismo , Oxilipinas/farmacologia , Fosfolipídeos/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Prunus persica/metabolismo , Temperatura Baixa , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus persica/efeitos dos fármacos , Prunus persica/genética , Prunus persica/crescimento & desenvolvimento
7.
J Agric Food Chem ; 67(30): 8312-8318, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31287303

RESUMO

The role of inositol 1,4,5-trisphosphate (IP3) in nitric oxide (NO)-reduced chilling injury (CI) in peach fruit was investigated. The fruit were immersed in sodium nitroprusside (SNP) (NO donor) and neomycin (IP3 inhibitor). Results showed that chilling tolerance was enhanced upon exogenous SNP in postharvest peach fruit. Further, GABA accumulation was stimulated by SNP. The increase in protein expression and activity for enzymes in GABA biosynthesis, including glutamate decarboxylase (GAD), polyamine oxidase (PAO), and amino aldehyde dehydrogenase (AMADH), upon SNP treatment was also observed. Also, the up-regulation of Δ1-pyrroline-5-carboxylate synthetase (P5CS) and ornithine d-aminotransferase (OAT) and the down-regulation of proline dehydrogenase (PDH) were induced by SNP treatment, thereby accelating proline production. Additionally, SNP treatment elevated protein expression and activity of alternative oxidase (AOX). The above effects induced upon SNP were partly weakened by neomycin. Therefore, IP3 mediated NO-activated GABA and proline accumulation as well as AOX, thus inducing chilling tolerance in postharvest peach fruit.


Assuntos
Frutas/química , Inositol 1,4,5-Trifosfato/metabolismo , Óxido Nítrico/metabolismo , Prunus persica/metabolismo , Aldeído Desidrogenase/metabolismo , Temperatura Baixa , Armazenamento de Alimentos , Frutas/metabolismo , Glutamato Descarboxilase/metabolismo , Proteínas Mitocondriais/metabolismo , Oxirredutases/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Proteínas de Plantas/metabolismo , Prolina/metabolismo , Prunus persica/química , Prunus persica/enzimologia , Ácido gama-Aminobutírico/metabolismo
8.
Food Chem ; 298: 125083, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31261001

RESUMO

The effects of onion or caraway on changes in the content of biogenic amines were examined in sauerkraut during a fermentation process at 18 °C or 31 °C for 14 days and subsequent storage at 4 °C for 12 weeks. The amines were analysed by high-performance liquid chromatography with pre-column benzoylation. Total biogenic-amine concentration at the end of the fermentation was lower at 31 °C than at 18 °C. However, at this lower temperature, the presence of caraway or onion more significantly (than at 31 °C) reduced the total biogenic-amine content as compared to the control sample without an additive. After 12 weeks of refrigerated storage, concentrations of phenethylamine, tryptamine, and tyramine in the sauerkraut fermented with caraway (and concentrations of putrescine and tryptamine in the sauerkraut fermented with onion) at 31 °C increased as compared to the samples on the last day of fermentation, but did not pose a risk for consumer health.


Assuntos
Aminas Biogênicas/metabolismo , Carum , Alimentos Fermentados , Armazenamento de Alimentos/métodos , Cebolas , Aminas Biogênicas/análise , Brassica , Cromatografia Líquida de Alta Pressão , Temperatura Baixa , Fermentação , Alimentos Fermentados/análise , Humanos , Concentração de Íons de Hidrogênio , Putrescina/análise , Putrescina/metabolismo , Paladar , Tiramina/análise , Tiramina/metabolismo
9.
Nature ; 571(7766): 550-554, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31341300

RESUMO

Earth's climate history is often understood by breaking it down into constituent climatic epochs1. Over the Common Era (the past 2,000 years) these epochs, such as the Little Ice Age2-4, have been characterized as having occurred at the same time across extensive spatial scales5. Although the rapid global warming seen in observations over the past 150 years does show nearly global coherence6, the spatiotemporal coherence of climate epochs earlier in the Common Era has yet to be robustly tested. Here we use global palaeoclimate reconstructions for the past 2,000 years, and find no evidence for preindustrial globally coherent cold and warm epochs. In particular, we find that the coldest epoch of the last millennium-the putative Little Ice Age-is most likely to have experienced the coldest temperatures during the fifteenth century in the central and eastern Pacific Ocean, during the seventeenth century in northwestern Europe and southeastern North America, and during the mid-nineteenth century over most of the remaining regions. Furthermore, the spatial coherence that does exist over the preindustrial Common Era is consistent with the spatial coherence of stochastic climatic variability. This lack of spatiotemporal coherence indicates that preindustrial forcing was not sufficient to produce globally synchronous extreme temperatures at multidecadal and centennial timescales. By contrast, we find that the warmest period of the past two millennia occurred during the twentieth century for more than 98 per cent of the globe. This provides strong evidence that anthropogenic global warming is not only unparalleled in terms of absolute temperatures5, but also unprecedented in spatial consistency within the context of the past 2,000 years.


Assuntos
Temperatura Baixa , Terra (Planeta) , Aquecimento Global/história , Aquecimento Global/estatística & dados numéricos , Temperatura Alta , Indústrias/história , Indústrias/estatística & dados numéricos , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , História Antiga , História Medieval , Atividades Humanas , Camada de Gelo , Análise Espaço-Temporal
10.
Zhongguo Zhong Yao Za Zhi ; 44(10): 2084-2089, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355565

RESUMO

To reveal the transformation and attribution of drug properties in Galla Chinesis fermented Baiyaojian by studying the effect of Galla Chinesis and Baiyaojian on cold and heat syndrome rats. Euthyrox was used to induce the hyperthyrosis model,ice water stimulation was used to induce the cold syndrome model,and different concentrations of Galla Chinesis and Baiyaojian water decoction were administrated by gavage for 15 d continuously. Symptom indexes were evaluated,content of pyruvic acid( PA),ATPase activity in liver and contents of DA,T4,cAMP,5-HT,NE,17-OHCS,TRH and TSH in serum were assayed by enzyme linked immunosorbent assay and spectrophotometry. The rectal temperature,water consumption and body weight of heat syndrome rats in model group were increased,cAMP,NE,17-OHCS,TRH and PA were increased,TSH,Na-K ATPase and Ca-Mg ATPase were increased significantly( P<0. 01),while 5-HT was decreased,compared with those of the blank group( P< 0. 05),the contents of T4,DA,NE,TSH,TRH,cAMP and 17-OHCS were decreased significantly( P<0. 01),PA and Ca-Mg ATPase in WG and BG groups were decreased compared with those of the model group( P<0. 05),and the Galla Chinesis content of WG group was lower than that of BG group,while the contents of 5-HT in WG and BG groups were increased,and the Galla Chinesis content of WG group was higher than that of BG group,with no significant difference of viscera index between heat syndrome rats in blank group,model group and drug groups. The rectal temperature,water consumption and body weight of cold syndrome rats in model group were decreased,DA,T4,cAMP,NE,17-OHCS,TRH,TSH,PA,Na-K ATPase and Ca-Mg ATPase of rats in model group were decreased,whereas 5-HT was increased compared with those of the blank group( P<0. 05),the indexes of heart,lung and kidney were significantly higher than those in the blank group( P<0. 05). Both Galla Chinesis and Baiyaojian can significantly alleviate the symptoms of heat syndrome rats caused by levothyroxine sodium. Galla Chinesis has a better effect than Baiyaojian,but cannot alleviate the symptoms of cold syndrome caused by ice water stimulation,suggestting that the decoction of Galla Chinesis and Baiyaojian are both cold,but Galla Chinesis is colder than Baiyaojian. Cold property in Galla Chinesis fermented Baiyaojian can be relieved. In clinical application,the property of " slight cold" is more accurate than " neutral property" for Baiyaojian.


Assuntos
Resposta ao Choque Frio , Medicamentos de Ervas Chinesas/farmacologia , Resposta ao Choque Térmico , Animais , Temperatura Baixa , Coração , Temperatura Alta , Rim , Fígado , Pulmão , Medicina Tradicional Chinesa , Ratos
11.
Rev Bras Enferm ; 72(3): 818-824, 2019 Jun 07.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31269151

RESUMO

OBJECTIVE: To identify, in the scientific literature, real and illusory perceptions of adult patients in induced coma. METHODS: This is an integrative review of 15 primary studies from the Medline, Web of Science, LILACS, CINAHL and SCOPUS databases. RESULTS: The main memories reported after induced coma were thirst, cold, and pain. In some studies, patients reported they were unable to tell whether they were awake or dreaming, whether it was real or unreal. Satisfactory memories were reported by patients related to the care received and the use of bedside journals. CONCLUSION: Evidence showed a number of studies aiming to identify delirium, but without a focus on analyzing real or illusory perceptions of patients after induced coma. Thus, this integrative review identified scientific evidence of memories related to perceptions of sedated patients in the intensive care unit.


Assuntos
Coma/complicações , Memória , Pacientes/psicologia , Percepção , Temperatura Baixa , Coma/psicologia , Coma/terapia , Humanos , Dor/etiologia , Dor/psicologia , Sede
12.
Zhongguo Zhong Yao Za Zhi ; 44(11): 2213-2218, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359644

RESUMO

The aim of the study is to explore exogenous S3307 on alleviating low-temperature stress of coix seedlings. The coix cultivar, "No 5 Yiliao", was selected as the plant material, through nutrient solution cultivating in greenhouse, the effect of different S3307 concentrations(1, 3, 5, 7, 9 mg·L~(-1)) on coix seedlings traits and physiological indicators were explored under low-temperature stress. The results showed, under low-temperature 5 mg·L~(-1) S3307 could significantly increase coix seedlings stem diameter and biomass, which stem diameter and above-ground biomass, low-ground biomass separately were enhanced 11.90%, 13.59%, 10.99%. Leaf width and lateral root number separately were enhanced 7.63%, 37.52%. Meanwhile, addition of 5 mg·L~(-1) S3307 could significantly reduce relative conductivity and MDA, separately being reduced 23.33%, 17.42% compared to CKL. S3307 could also significantly increase soluble sugar and proline content, which leaf soluble sugar and proline content separately were enhanced 17.16%, 11.87%, which root soluble sugar and proline content separately were enhanced 20.00%, 33.42%. Additionally, S3307 could alleviate the cells destroy in ultra-structure level by improving cell membrane structure and chloroplast capsule layer structure. 5 mg·L~(-1) S3307 could enhance the low temperature tolerance of coix seedlings by regulating the growth and physiological indexes, and thus alleviate the damage caused by low-temperature to the coix seedlings.


Assuntos
Coix/efeitos dos fármacos , Temperatura Baixa , Plântula/efeitos dos fármacos , Estresse Fisiológico , Triazóis/farmacologia
13.
BMC Evol Biol ; 19(1): 148, 2019 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-31331267

RESUMO

BACKGROUND: In the wake of climate change many environments will be exposed to increased and more variable temperatures. Knowledge about how species and populations respond to altered temperature regimes is therefore important to improve projections of how ecosystems will be affected by global warming, and to aid management. We conducted a common garden, split-brood temperature gradient (4.5 °C, 9.7 °C and 12.3 °C) experiment to study the effects of temperature in two populations (10 families from each population) of anadromous pike (Esox lucius) that normally experience different temperatures during spawning. Four offspring performance measures (hatching success, day degrees until hatching, fry survival, and fry body length) were compared between populations and among families. RESULTS: Temperature affected all performance measures in a population-specific manner. Low temperature had a positive effect on the Harfjärden population and a negative effect on the Lervik population. Further, the effects of temperature differed among families within populations. CONCLUSIONS: The population-specific responses to temperature indicate genetic differentiation in developmental plasticity between populations, and may reflect an adaptation to low temperature during early fry development in Harfjärden, where the stream leading up to the wetland dries out relatively early in the spring, forcing individuals to spawn early. The family-specific responses to temperature treatment indicate presence of genetic variation for developmental plasticity (G x E) within both populations. Protecting between- and within-population genetic variation for developmental plasticity and high temperature-related adaptive potential of early life history traits will be key to long-term viability and persistence in the face of continued climate change.


Assuntos
Adaptação Fisiológica , Esocidae/fisiologia , Temperatura Ambiente , Animais , Temperatura Baixa , Esocidae/anatomia & histologia , Feminino , Geografia , Masculino , Reprodução , Suécia , Água
14.
Nature ; 571(7763): 99-102, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31270485

RESUMO

The long-term cooling, decline in the partial pressure of carbon dioxide, and the establishment of permanent polar ice sheets during the Neogene period1,2 have frequently been attributed to increased uplift and erosion of mountains and consequent increases in silicate weathering, which removes atmospheric carbon dioxide3,4. However, geological records of erosion rates are potentially subject to averaging biases5,6, and the magnitude of the increase in weathering fluxes-and even its existence-remain debated7-9. Moreover, an increase in weathering scaled to the proposed erosional increase would have removed nearly all carbon from the atmosphere10, which has led to suggestions of compensatory carbon fluxes11-13 in order to preserve mass balance in the carbon cycle. Alternatively, an increase in land surface reactivity-resulting from greater fresh-mineral surface area or an increase in the supply of reactive minerals-rather than an increase in the weathering flux, has been proposed to reconcile these disparate views8,9. Here we use a parsimonious carbon cycle model that tracks two weathering-sensitive isotopic tracers (stable 7Li/6Li and cosmogenic 10Be/9Be) to show that an increase in land surface reactivity is necessary to simultaneously decrease atmospheric carbon dioxide, increase seawater 7Li/6Li and retain constant seawater 10Be/9Be over the past 16 million years. We find that the global silicate weathering flux remained constant, even as the global silicate weathering intensity-the fraction of the total denudation flux that is derived from silicate weathering-decreased, sustained by an increase in erosion. Long-term cooling during the Neogene thus reflects a change in the partitioning of denudation into weathering and erosion. Variable partitioning of denudation and consequent changes in silicate weathering intensity reconcile marine isotope and erosion records with the need to maintain mass balance in the carbon cycle and without requiring increases in the silicate weathering flux.


Assuntos
Atmosfera/química , Ciclo do Carbono , Dióxido de Carbono/análise , Dióxido de Carbono/história , Temperatura Baixa , Sedimentos Geológicos/química , Geologia/história , Retroalimentação , Sedimentos Geológicos/análise , História Antiga , Camada de Gelo/química , Modelos Teóricos , Rios/química , Água do Mar/química , Silicatos/análise
15.
Food Chem ; 300: 125194, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31325749

RESUMO

The effects of near freezing temperature (NFT) storage at -1.9 °C on cell wall degradation of 'Shushanggan' apricot was studied comparing to 0 °C and 5 °C storage. Our results indicated that NFT storage strongly inhibited the solubilization of Na2CO3-soluble pectin and cellulose, by the suppression of cell wall modifying enzymes (polygalacturonase, ß-Galactosidase, pectin methyl esterase and cellulase) and related genes expressions. The loss of side chains was the main modification in CDTA (Cyclohexane-diamine-tetraacetic Acid)-soluble pectin during storage and made the main contribution to the softening of apricot, while the loss of side chain was suppressed by NFT storage. Microscopic observation showed that NFT storage delayed the degradation of pectin fraction and protected cell wall structure from loosing. This study proves that NFT storage is an effective technology to suppress the cell wall polysaccharides degradation and ultrastructure modification of apricot.


Assuntos
Parede Celular/ultraestrutura , Armazenamento de Alimentos/métodos , Polissacarídeos/química , Prunus armeniaca/química , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/metabolismo , Parede Celular/química , Parede Celular/metabolismo , Celulose/química , Temperatura Baixa , Congelamento , Frutas/química , Frutas/citologia , Frutas/ultraestrutura , Pectinas/química , Células Vegetais/química , Células Vegetais/ultraestrutura , Poligalacturonase/química , Poligalacturonase/metabolismo , Polissacarídeos/metabolismo , Prunus armeniaca/citologia , Solubilidade , beta-Galactosidase/química , beta-Galactosidase/metabolismo
16.
Environ Sci Process Impacts ; 21(7): 1076-1084, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31241094

RESUMO

Dissolved organic matter (DOM) is a common solute in snow and ice at Earth's surface. Its effects on reaction kinetics in ice and at air-ice interfaces can be large, but are currently difficult to quantify. We used Raman microscopy to characterize the surface and bulk of frozen aqueous solutions containing humic acid, sodium dodecyl sulfate (SDS), and citric acid at a range of concentrations and temperatures. The surface-active species (humic acid and SDS) were distributed differently than citric acid. Humic acid and SDS are almost completely excluded to the air-ice interface during freezing, where they form a film that coats the surface nearly completely. A liquid layer that coats the majority of the surface was observed at all humic acid and SDS concentrations. Citric acid, which is smaller and less surface active, is excluded to liquid channels at the air-ice interface and within the ice bulk, as has previously been reported for ionic solutes such as sodium chloride. Incomplete surface wetting was observed at all citric acid concentrations and at all temperatures (up to -5 °C). Citric acid appears to be solvated in frozen samples, but SDS and humic acid do not. These results will improve our understanding of the effects of organic solutes on environmental and atmospheric chemistry within ice and at air-ice interfaces.


Assuntos
Ar/análise , Substâncias Húmicas/análise , Camada de Gelo/química , Ácido Cítrico/análise , Temperatura Baixa , Congelamento , Cinética , Modelos Teóricos , Dodecilsulfato de Sódio/análise , Solubilidade , Soluções , Análise Espectral Raman , Tensoativos/análise
17.
Environ Sci Pollut Res Int ; 26(23): 23603-23614, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203548

RESUMO

The associations between exposure to short-term ambient air pollution and daily atherosclerotic heart disease (ASHD) mortality in cool climate have not been established. We performed a time-series analysis in Shenyang, the largest city of Northeastern China. We identified 7659 ASHD deaths and obtained deaths, ambient air pollution levels, and meteorological data for Shenyang during 2014-2017. The impact of ambient air pollution on daily ASHD deaths was analyzed using generalized additive models (GAMs). Cumulative lag effects were investigated using distributed lag non-linear models (DLNM). We found ASHD deaths significantly increased during days with higher air pollution. Particulate matter with diameter < 2.5 µm (PM2.5), PM10, and sulfur dioxide (SO2) were positively associated with ASHD deaths among the total population. Both single- and multi-pollutants models indicated that PM2.5, PM10, and sulfur dioxide (SO2) were positively associated with the deaths of women with AHSD, whereas only SO2 was significant in men. This suggests significant gender-based differences in the fatal effects of ambient air pollution. Up to 28 days of single-day lag effects were observed for PM2.5 and PM10 in women. The cumulative lag effects of PM2.5 and PM10 showed increasing trends in both men and women; however, exposure to higher pollutant concentrations did not necessarily translate to greater risks. The ERRs differences between women and men were larger in cold days than in hot days, suggesting that lower temperature may exacerbate the adverse effects of air pollution on vulnerable women.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Doenças Cardiovasculares/mortalidade , Exposição Ambiental/estatística & dados numéricos , Poluição do Ar/análise , China/epidemiologia , Clima , Temperatura Baixa , Feminino , Cardiopatias , Humanos , Masculino , Material Particulado/análise , Transição de Fase , Fatores Sexuais , Dióxido de Enxofre/análise
18.
J Chem Phys ; 150(23): 234904, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31228891

RESUMO

The dynamics of water at supercooled temperatures in aqueous solutions of different types of solutes has been deeply analyzed in the literature. In these previous works and in most of the cases, a single relaxation of water molecules is observed. In this work, we analyze the dynamics of water in solutions for which a dual relaxation of water molecules is experimentally measured. We discuss the criteria for observing these two water relaxations in these specific solutions and their most likely origins. We also discuss how these two water relaxations relate to the relaxation behavior of bulk water and how the slower one is coupled to the solute dynamics and is essential for the dynamics and functional properties of proteins.


Assuntos
Biopolímeros/química , Polímeros/química , Água/química , Varredura Diferencial de Calorimetria , Temperatura Baixa , Concentração de Íons de Hidrogênio , Soluções/química , Espectroscopia de Infravermelho com Transformada de Fourier
19.
J Chem Phys ; 150(23): 235101, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31228916

RESUMO

We investigate by molecular dynamics simulations the mobility of the water located at the DNA minor and major grooves. We employ the TIP3P water model, and our system is analyzed for a range of temperatures 190-300 K. For high temperatures, the water at the grooves shows an Arrhenius behavior similar to that observed in the bulk water. At lower temperatures, a departure from the bulk behavior is observed. This slowing down in the dynamics is compared with the dynamics of the hydrogen of the DNA at the grooves and with the autocorrelation functions of the water hydrogen bonds. Our results indicate that the hydrogen bonds of the water at the minor grooves are highly correlated, which suggests that this is the mechanism for the slow dynamics at this high confinement.


Assuntos
Temperatura Baixa , DNA/química , Modelos Moleculares , Água/química , Difusão , Ligações de Hidrogênio , Simulação de Dinâmica Molecular
20.
Yakugaku Zasshi ; 139(6): 861-866, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31155526

RESUMO

Brown adipose tissue is a critical regulator of metabolic health, and contributes to thermogenesis by uncoupling oxidative phosphorylation through the action of mitochondrial uncoupling protein 1 (Ucp1). Recent studies have shown that cold exposure and the stimulation of ß3-adrenergic receptors induce the development of brown cell-like "beige" adipocytes in white adipose tissue. Brown and/or beige adipocyte-mediated thermogenesis suppresses high-fat diet-associated obesity. Therefore, the development of brown/beige adipocytes may prevent obesity and metabolic diseases. In the present study, we elucidated whether naturally occurring compounds contribute to regulating the cellular differentiation of brown/beige adipocytes. We screened for the up-regulated expression of Ucp1 during beige adipogenesis using extracts of crude herbal drugs frequently used in Kampo prescriptions (therapeutic drugs in Japanese traditional medicine). This screening revealed that the extract prepared from Citri Unshiu Pericarpium [the peel of Citrus unshiu (Swingle) Marcov.] increased the expression of Ucp1 in beige adipocytes. We also focused on the function of clock genes in regulating brown/beige adipogenesis. Therefore, another aim of the present study was to evaluate naturally occurring compounds that regulate brain and muscle Arnt-like 1 (Bmal1) gene expression. In this review, we focus on naturally occurring compounds that affect regulatory processes in brown/beige adipogenesis, and discuss better preventive strategies for the management of obesity and other metabolic disorders.


Assuntos
Fatores de Transcrição ARNTL , Adipócitos Bege/fisiologia , Adipócitos Marrons/fisiologia , Adipogenia/efeitos dos fármacos , Adipogenia/genética , Diferenciação Celular , Medicamentos de Ervas Chinesas/farmacologia , Proteína Desacopladora 1 , Fatores de Transcrição ARNTL/metabolismo , Fatores de Transcrição ARNTL/fisiologia , Animais , Relógios Biológicos/genética , Temperatura Baixa , Dieta Hiperlipídica/efeitos adversos , Expressão Gênica , Humanos , Medicina Kampo , Doenças Metabólicas/prevenção & controle , Obesidade/etiologia , Obesidade/prevenção & controle , Fosforilação Oxidativa , Receptores Adrenérgicos beta 3/metabolismo , Termogênese , Proteína Desacopladora 1/metabolismo
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