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1.
Plant Mol Biol ; 114(3): 44, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630172

RESUMO

Albino tea cultivars have high economic value because their young leaves contain enhanced free amino acids that improve the quality and properties of tea. Zhonghuang 1 (ZH1) and Zhonghuang 2 (ZH2) are two such cultivars widely planted in China; however, the environmental factors and molecular mechanisms regulating their yellow-leaf phenotype remain unclear. In this study, we demonstrated that both ZH1 and ZH2 are light- and temperature-sensitive. Under natural sunlight and low-temperature conditions, their young shoots were yellow with decreased chlorophyll and an abnormal chloroplast ultrastructure. Conversely, young shoots were green with increased chlorophyll and a normal chloroplast ultrastructure under shading and high-temperature conditions. RNA-seq analysis was performed for high light and low light conditions, and pairwise comparisons identified genes exhibiting different light responses between albino and green-leaf cultivars, including transcription factors, cytochrome P450 genes, and heat shock proteins. Weighted gene coexpression network analyses of RNA-seq data identified the modules related to chlorophyll differences between cultivars. Genes involved in chloroplast biogenesis and development, light signaling, and JA biosynthesis and signaling were typically downregulated in albino cultivars, accompanied by a decrease in JA-ILE content in ZH2 during the albino period. Furthermore, we identified the hub genes that may regulate the yellow-leaf phenotype of ZH1 and ZH2, including CsGDC1, CsALB4, CsGUN4, and a TPR gene (TEA010575.1), which were related to chloroplast biogenesis. This study provides new insights into the molecular mechanisms underlying leaf color formation in albino tea cultivars.


Assuntos
Albinismo , Perfilação da Expressão Gênica , Temperatura , Temperatura Baixa , Clorofila
2.
Int J Mol Sci ; 25(7)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38612569

RESUMO

The treatment of the bulky Rind-based dibromosilanes, (Rind)2SiBr2 (2) [Rind = 1,1,7,7-tetra-R1-3,3,5,5-tetra-R2-s-hydrindacen-4-yl: EMind (a: R1 = Et, R2 = Me) and Eind (b: R1 = R2 = Et)], with two equivalents of tBuLi in Et2O at low temperatures resulted in the formation of blue solutions derived from the diarylsilylenes, (Rind)2Si: (3). Upon warming the solutions above -20 °C, the blue color gradually faded, accompanying the decomposition of 3 and yielding cyclic hydrosilanes (4) via intramolecular C-H bond insertion at the Si(II) center. The molecular structures of the bulky Eind-based 3b and 4b were confirmed by X-ray crystallography. Thus, at -20 °C, blue crystals were formed (Crystal-A), which were identified as mixed crystals of 3b and 4b. Additionally, colorless crystals of 4b as a singular component were isolated (Crystal-B), whose structure was also determined by an X-ray diffraction analysis. Although the isolation of 3 was difficult due to their thermally labile nature, their structural characteristics and electronic properties were discussed based on the experimental findings complemented by computational results. We also examined the hydrolysis of 3b to afford the silanol, (Eind)2SiH(OH) (5b).


Assuntos
Temperatura Baixa , Fibras na Dieta , Cristalografia por Raios X , Eletrônica , Hidrólise
3.
Int J Mol Sci ; 25(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38612659

RESUMO

Photosystem I (PSI) is one of the two main pigment-protein complexes where the primary steps of oxygenic photosynthesis take place. This review describes low-temperature frequency-domain experiments (absorption, emission, circular dichroism, resonant and non-resonant hole-burned spectra) and modeling efforts reported for PSI in recent years. In particular, we focus on the spectral hole-burning studies, which are not as common in photosynthesis research as the time-domain spectroscopies. Experimental and modeling data obtained for trimeric cyanobacterial Photosystem I (PSI3), PSI3 mutants, and PSI3-IsiA18 supercomplexes are analyzed to provide a more comprehensive understanding of their excitonic structure and excitation energy transfer (EET) processes. Detailed information on the excitonic structure of photosynthetic complexes is essential to determine the structure-function relationship. We will focus on the so-called "red antenna states" of cyanobacterial PSI, as these states play an important role in photochemical processes and EET pathways. The high-resolution data and modeling studies presented here provide additional information on the energetics of the lowest energy states and their chlorophyll (Chl) compositions, as well as the EET pathways and how they are altered by mutations. We present evidence that the low-energy traps observed in PSI are excitonically coupled states with significant charge-transfer (CT) character. The analysis presented for various optical spectra of PSI3 and PSI3-IsiA18 supercomplexes allowed us to make inferences about EET from the IsiA18 ring to the PSI3 core and demonstrate that the number of entry points varies between sample preparations studied by different groups. In our most recent samples, there most likely are three entry points for EET from the IsiA18 ring per the PSI core monomer, with two of these entry points likely being located next to each other. Therefore, there are nine entry points from the IsiA18 ring to the PSI3 trimer. We anticipate that the data discussed below will stimulate further research in this area, providing even more insight into the structure-based models of these important cyanobacterial photosystems.


Assuntos
Clorofila , Complexo de Proteína do Fotossistema I , Complexo de Proteína do Fotossistema I/genética , Dicroísmo Circular , Transferência de Energia , Temperatura Baixa
4.
BMC Plant Biol ; 24(1): 274, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605295

RESUMO

Temperature is one of the important environmental factors affecting plant growth, yield and quality. Moreover, appropriately low temperature is also beneficial for tuber coloration. The red potato variety Jianchuanhong, whose tuber color is susceptible to temperature, and the purple potato variety Huaxinyangyu, whose tuber color is stable, were used as experimental materials and subjected to 20 °C (control check), 15 °C and 10 °C treatments during the whole growth period. The effects of temperature treatment on the phenotype, the expression levels of structural genes related to anthocyanins and the correlations of each indicator were analyzed. The results showed that treatment at 10 °C significantly inhibited the potato plant height, and the chlorophyll content and photosynthetic parameters in the leaves were reduced, and the enzyme activities of SOD and POD were significantly increased, all indicating that the leaves were damaged. Treatment at 10 °C also affected the tuberization of Huaxinyangyu and reduced the tuberization and coloring of Jianchuanhong, while treatment at 15 °C significantly increased the stem diameter, root-to-shoot ratio, yield and content of secondary metabolites, especially anthocyanins. Similarly, the expression of structural genes were enhanced in two pigmented potatoes under low-temperature treatment conditions. In short, proper low temperature can not only increase yield but also enhance secondary metabolites production. Previous studies have not focused on the effects of appropriate low-temperature treatment during the whole growth period of potato on the changes in metabolites during tuber growth and development, these results can provide a theoretical basis and technical guidance for the selection of pigmented potatoes with better nutritional quality planting environment and the formulation of cultivation measures.


Assuntos
Solanum tuberosum , Temperatura , Solanum tuberosum/metabolismo , Antocianinas/metabolismo , Temperatura Baixa , Fotossíntese , Tubérculos/genética
5.
Food Res Int ; 184: 114249, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38609227

RESUMO

Low temperature storage as an alternative to anti-sprouting chemicals in potato storage may induce reducing sugars (RS) accumulation (i.e. glucose and fructose) in potato tubers. This phenomenon is called "cold induced sweetening" (CIS) and occurs in certain varieties. CIS leads to a decrease in the organoleptic qualities and darkening of processed potato and the accumulation of toxic molecules such as acrylamide. To identify potato varieties suitable for storage at low temperatures, we screened six commercial processing varieties: Lady Claire (LC), Verdi, Kiebitz (KB), Pirol, Agria and Markies for their CIS characteristics and sprout-forming potential after storage at 4 °C and 8 °C. Our findings reveal that 4 °C storage allows for efficient sprout reduction in all six tested varieties for up to 4.5 months of storage. Three CIS-resistant varieties, namely Verdi, Lady Claire and Kiebitz, were identified as able to be stored for up to four months at 4 °C with limited increase in glucose content. Conversely, Pirol, Agria and Markies showed an increase in glucose content with a decrease in storage temperature and can be considered as CIS-susceptible varieties. After processing into crisps, the CIS-susceptible varieties displayed poor crisp color quality (brown to black color crisps) after storage for two months at 4 °C compared to the storage at 8 °C, whereas the CIS-resistant varieties had good crisp color quality (pale yellow color crisps) after storage at both 4 and 8 °C. Interestingly, the trends of total RS and/or glucose content in the CIS-resistant and in the CIS-susceptible varieties were correlated with the trends in Vacuolar Invertase (VInv) gene expression for most varieties, as well as with the trends in acrylamide content after processing. In addition, reconditioning of Markies variety after storage at 4 °C by gradually increasing the temperature to 15 °C resulted in a significant decrease of VInv transcript levels (reduction of 80 %), acrylamide content (reduction of 75 %) and glucose content when compared to a storage at 4 °C without reconditioning. Those results demonstrate that the reconditioning technique is a key factor for a sustainable potato storage and for improving the quality of processed potatoes.


Assuntos
Solanum tuberosum , Humanos , Criopreservação , Temperatura Baixa , Acrilamida , Glucose , beta-Frutofuranosidase
6.
Food Res Int ; 184: 114267, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38609244

RESUMO

Hot extrusion is utilized for starch modification due to its high mechanical input and product output. Amylose recrystallization commences and primarily depends on intermolecular interactions after conventional extrusion. Hence, the design of a new component based on the existed extrusion system was aimed at facilitating molecular aggregation, potentially accelerating starch recrystallization. In this study, a nozzle sheet comprising 89 holes was integrated into the cooling die. The impact of the multihole nozzle on the structure and in vitro digestibility of extruded maize starches after retrogradation was examined at varying cooling die temperatures. The results showed that the nozzle-assembled extrusion system operated effectively without additional mechanical or yield losses. At 50 °C, the crystallinity of nozzle-produced starch was approximately 70 % higher than that of conventionally extruded starch, predominantly owing to the B-type allomorph of the amylose double helix. Recrystallized amylopectin was also found in these nozzle-produced starches, indicating that multihole nozzle-induced uniaxial elongational flow resulted in the rapid starch crystallization. The increased formation of recrystallized amylose led to improved molecular order in starch structures while reducing their digestibility. These findings revealed a new approach to improve starch crystallinity by incorporating a nozzle sheet in the extrusion process.


Assuntos
Amilose , Zea mays , Temperatura , Temperatura Baixa , Amido
7.
Food Res Int ; 184: 114265, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38609243

RESUMO

Radio frequency explosion puffing (RFEP) is a novel oil-free puffing technique used to produce crispy textured and nutritious puffed snacks. This study aimed to investigate the effects of freezing at different temperatures (-20 °C, -40 °C, -80 °C) for14 h and freezing times (1 and 2 times) on the cellular structure of purple sweet potato and the quality of RFEP chips. The analysis of cell microstructure, conductivity, and rheology revealed that higher freezing temperatures and more freezing times resulted in increased damage to the cellular structure, leading to greater cell membrane permeability and decreased cell wall stiffness. However, excessive damage to cellular structure caused tissue structure to collapse. Compared with the control group (4 °C), the RFEP sample pre-frozen once at -40 °C had a 47.13 % increase in puffing ratio and a 61.93 % increase in crispness, while hardness decreased by 23.44 % (p < 0.05). There was no significant change in anthocyanin retention or color difference. X-ray microtomography demonstrated that the RFEP sample pre-frozen once at -40 °C exhibited a more homogeneous morphology and uniform pore distribution, resulting in the highest overall acceptability. In conclusion, freezing pre-treatment before RFEP can significantly enhance the puffing quality, making this an effective method for preparing oil-free puffing products for fruits and vegetables.


Assuntos
Ipomoea batatas , Congelamento , Explosões , Parede Celular , Temperatura Baixa
8.
BMC Plant Biol ; 24(1): 279, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38609850

RESUMO

BACKGROUND: Climate change is expected to alter the factors that drive changes in adaptive variation. This is especially true for species with long life spans and limited dispersal capabilities. Rapid climate changes may disrupt the migration of beneficial genetic variations, making it challenging for them to keep up with changing environments. Understanding adaptive genetic variations in tree species is crucial for conservation and effective forest management. Our study used landscape genomic analyses and phenotypic traits from a thorough sampling across the entire range of Quercus longinux, an oak species native to Taiwan, to investigate the signals of adaptation within this species. RESULTS: Using ecological data, phenotypic traits, and 1,933 single-nucleotide polymorphisms (SNPs) from 205 individuals, we classified three genetic groups, which were also phenotypically and ecologically divergent. Thirty-five genes related to drought and freeze resistance displayed signatures of natural selection. The adaptive variation was driven by diverse environmental pressures such as low spring precipitation, low annual temperature, and soil grid sizes. Using linear-regression-based methods, we identified isolation by environment (IBE) as the optimal model for adaptive SNPs. Redundancy analysis (RDA) further revealed a substantial joint influence of demography, geology, and environments, suggesting a covariation between environmental gradients and colonization history. Lastly, we utilized adaptive signals to estimate the genetic offset for each individual under diverse climate change scenarios. The required genetic changes and migration distance are larger in severe climates. Our prediction also reveals potential threats to edge populations in northern and southeastern Taiwan due to escalating temperatures and precipitation reallocation. CONCLUSIONS: We demonstrate the intricate influence of ecological heterogeneity on genetic and phenotypic adaptation of an oak species. The adaptation is also driven by some rarely studied environmental factors, including wind speed and soil features. Furthermore, the genetic offset analysis predicted that the edge populations of Q. longinux in lower elevations might face higher risks of local extinctions under climate change.


Assuntos
Quercus , Humanos , Quercus/genética , Mudança Climática , Genômica , Temperatura Baixa , Solo
9.
Sensors (Basel) ; 24(7)2024 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-38610278

RESUMO

Transient terahertz time-domain spectroscopy (THz-TDS) imaging has emerged as a novel non-ionizing and noninvasive biomedical imaging modality, designed for the detection and characterization of a variety of tissue malignancies due to their high signal-to-noise ratio and submillimeter resolution. We report our design of a pair of aspheric focusing lenses using a commercially available lens-design software that resulted in about 200 × 200-µm2 focal spot size corresponding to the 1-THz frequency. The lenses are made of high-density polyethylene (HDPE) obtained using a lathe fabrication and are integrated into a THz-TDS system that includes low-temperature GaAs photoconductive antennae as both a THz emitter and detector. The system is used to generate high-resolution, two-dimensional (2D) images of formalin-fixed, paraffin-embedded murine pancreas tissue blocks. The performance of these focusing lenses is compared to the older system based on a pair of short-focal-length, hemispherical polytetrafluoroethylene (TeflonTM) lenses and is characterized using THz-domain measurements, resulting in 2D maps of the tissue refractive index and absorption coefficient as imaging markers. For a quantitative evaluation of the lens effect on the image resolution, we formulated a lateral resolution parameter, R2080, defined as the distance required for a 20-80% transition of the imaging marker from the bare paraffin region to the tissue region in the same image frame. The R2080 parameter clearly demonstrates the advantage of the HDPE lenses over TeflonTM lenses. The lens-design approach presented here can be successfully implemented in other THz-TDS setups with known THz emitter and detector specifications.


Assuntos
Lentes , Imagem Terahertz , Animais , Camundongos , Polietileno , Politetrafluoretileno , Temperatura Baixa
10.
Sensors (Basel) ; 24(7)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38610298

RESUMO

Radial pulse diagnosis is the most common method to examine the human health state in Traditional East Asian Medicine (TEAM). A cold stress-related suboptimal health state (subhealth) is often undetectable during routine medical examinations, however, it can be detected through the palpation of specific pulse waves, particularly a 'tight pulse', in TEAM. Therefore, this study examined a correlation between 'tight pulse' and vascular changes in the radial artery (RA) induced by a cold pressor trial (CPT). Twenty healthy subjects underwent sequentially control trial and CPT with room-temperature and ice-cold water, respectively, on the right forearm. The radial pulse and vascular changes were then examined on the left arm. The radial pulse scores for frequencies of 'tight pulse' with strong arterial tension increased after the CPT compared with the control trial. The pulse scores were reversely correlated with the RA thickness and volumes in ultrasonography, but not with changes in the systolic/diastolic blood pressure. The RA thickness-based vascular surface and three-dimensional images visualized a 'tight pulse' showing the vasoconstriction and bumpy-/rope-shaped vascular changes in the radial pulse diagnostic region after the CPT. These findings provide valuable insights into the potential integration of clinical radial pulse diagnosis with ultrasonography for cold-related subhealth.


Assuntos
Artéria Radial , Diagnóstico Tradicional pelo Pulso , Humanos , Resposta ao Choque Frio , Frequência Cardíaca , Temperatura Baixa
11.
Cryo Letters ; 45(2): 88-99, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38557987

RESUMO

BACKGROUND: 'Dingjiaba' is an important Prunus persica cultivar (cv) mainly grown in the Hexi corridor in northwest China, which has an inherited strong cold tolerance. OBJECTIVE: To compare the transcriptome and physiology data of leaves of cvs 'Dingjiaba' (D) and 'Kanoiwa' (K) following cold treatment at different time periods, in order to gain new insights into the mechanisms of cold adaptation in 'Dingjiaba'. MATERIALS AND METHODS: We analyzed the transcriptomic and physiological data of leaves of D and K cvs exposed to 0 h (D0/K0), 2 h (D2/K2), 6 h (D6/K6) and 12 h (D12/K12) cold stress. RESULTS: Low temperature stress caused membrane damage and led to increased rate of electrolyte leakage and increased MDA content. Cold stress induced the accumulation of soluble sugars, soluble proteins and proline in leaves of both cvs, with a lower increase in K compared to D. Transcriptome analysis identified 4,631, 5,069, 5,662 and 3,886 differentially expressed genes (DEGs) between D0 and K0, D2 and K2, D6 and K6 and D12 and K12, respectively. The differentially expressed genes significantly enriched in metabolic pathways and biosynthesis of secondary metabolites. We further validated the reliability of sequencing data of the RNA-Seq with Real-Time Quantitative PCR, which suggested that the expression trend of the RNA-Seq were same as RT-PCR. CONCLUSIONS: These results provide novel insights into a series of molecular mechanisms underlying physiological metabolism and defense. https://doi.org/10.54680/fr24210110312.


Assuntos
Resposta ao Choque Frio , Prunus persica , Resposta ao Choque Frio/genética , RNA-Seq , Prunus persica/genética , Reprodutibilidade dos Testes , Criopreservação , Temperatura Baixa , Regulação da Expressão Gênica de Plantas
12.
Arch Microbiol ; 206(5): 224, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38642319

RESUMO

BACKGROUND: Vibrio cholerae can endure harsh environmental conditions by transitioning into viable but non-culturable (VBNC) form and resuscitate upon return of appropriate conditions. METHOD: In this study, we assessed the impact of physicochemical and microbiological factors, on the development of low temperature-induced VBNC state and subsequent recovery by temperature upshift. RESULTS: In estuarine water, Vibrio cholerae exhibits a slower decline in culturability over a period of 77 days as compared to 10 days in fresh water. When variable cell numbers from different growth phases were used for VBNC induction, it was observed that the higher inoculum size (106-107 cfu ml-1) from the late log phase culture appears to be crucial for entering the VBNC state. Conversely, starved cells could enter the VBNC state with an initial inoculum of 104-105 cfu ml-1, followed by resuscitation as well. The addition of glucose, GlcNAc and mannitol differentially affects progression into VBNC, while the addition of tryptone, yeast extract and casamino acid facilitated early entry into the VBNC state and shortened the length of the recovery period. CONCLUSION: Altogether these findings demonstrated that the ionic strength of water, inoculum size and the availability of nutrients played distinct roles during VBNC induction and resuscitation.


Assuntos
Vibrio cholerae , Temperatura , Temperatura Baixa , Aminoácidos , Água , Viabilidade Microbiana
13.
BMC Microbiol ; 24(1): 131, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38643098

RESUMO

BACKGROUND: Exposure to extreme cold or heat temperature is one leading cause of weather-associated mortality and morbidity in animals. Emerging studies demonstrate that the microbiota residing in guts act as an integral factor required to modulate host tolerance to cold or heat exposure, but common and unique patterns of animal-temperature associations between cold and heat have not been simultaneously examined. Therefore, we attempted to investigate the roles of gut microbiota in modulating tolerance to cold or heat exposure in mice. RESULTS: The results showed that both cold and heat acutely change the body temperature of mice, but mice efficiently maintain their body temperature at conditions of chronic extreme temperatures. Mice adapt to extreme temperatures by adjusting body weight gain, food intake and energy harvest. Fascinatingly, 16 S rRNA sequencing shows that extreme temperatures result in a differential shift in the gut microbiota. Moreover, transplantation of the extreme-temperature microbiota is sufficient to enhance host tolerance to cold and heat, respectively. Metagenomic sequencing shows that the microbiota assists their hosts in resisting extreme temperatures through regulating the host insulin pathway. CONCLUSIONS: Our findings highlight that the microbiota is a key factor orchestrating the overall energy homeostasis under extreme temperatures, providing an insight into the interaction and coevolution of hosts and gut microbiota.


Assuntos
Microbioma Gastrointestinal , Temperatura Alta , Animais , Camundongos , Temperatura , Microbioma Gastrointestinal/fisiologia , Temperatura Baixa , Adaptação Fisiológica/fisiologia
14.
Neurosci Lett ; 828: 137763, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38574849

RESUMO

The role of the hypothalamic cold-sensitive ion channels - transient receptor potential melastatin 8 (TRPM8) and transient receptor potential ankyrin 1 (TRPA1) in homeostatic systems of thermoregulation and water-salt balance - is not clear. The interaction of homeostatic systems of thermoregulation and water-salt balance without additional temperature load did not receive due attention, too. On the models of water-balance disturbance, we tried to elucidate some aspect of these problems. Body temperature (Tbody), O2 consumption, CO2 excretion, electrical muscle activity (EMA), temperature of tail skin (Ttail), plasma osmolality, as well as gene expression of hypothalamic TRPM8 and TRPA1 have been registered in rats of 3 groups: control; water-deprived (3 days under dry-eating); and hyperhydrated (6 days without dry food, drinking liquid 4 % sucrose). No relationship was observed between plasma osmolality and gene expression of Trpm8 and Trpa1. In water-deprived rats, the constriction of skin vessels, increased fat metabolism by 10 % and increased EMA by 48 % allowed the animals to maintain Tbody unchanged. The hyperhydrated rats did not develop sufficient mechanisms, and their Tbody decreased by 0.8 °C. The development of reactions was correlated with the expression of genes of thermosensitive ion channels in the anterior hypothalamus. Ttail had a direct correlation with the expression of the Trpm8 gene, whereas EMA directly correlated with the expression of the Trpa1 gene in water-deprived group. The obtained data attract attention from the point of view of management and correction of physiological functions by modulating the ion channel gene expression.


Assuntos
Canais de Cátion TRPM , Canais de Potencial de Receptor Transitório , Ratos , Animais , Canais de Potencial de Receptor Transitório/metabolismo , Temperatura , Canais de Cátion TRPM/metabolismo , Canal de Cátion TRPA1/metabolismo , Temperatura Baixa , Regulação da Temperatura Corporal , Proteínas do Citoesqueleto/metabolismo
15.
PLoS One ; 19(4): e0299940, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38620031

RESUMO

Injecting carbon dioxide is the most effective means of preventing and extinguishing fires in sealing hazardous areas, but the traditional method slowly and remotely injects carbon dioxide gas into the well after gasification on the ground, which is dependent on the complete mine pipe network without cooling effect. To inject liquid directly from the tank with vacuum interlayer and heat insulating powder for rapid inerting and cooling, a new approach using track mobile platform to go deep into the underground mine disaster area is proposed, so the liquid can be delivered to the nozzle at the end of DN40 large diameter pipe, and the continuous gasification jet can be realized. The experimental results show that: (1) The liquid volume in a tank of vacuum degree within 2.0 Pa and 200 mm interlayer reduced no more than 15.5% after 48 days; (2) Taking the pressure in the tank as the power source, because of environmental differences inside and outside the pipe after 100 m pressure holding delivery, the physical form of liquid and gas could be converted instantly; (3) The continuous discharge time without ice blocking for a tank full of 2 m3 liquid was about 10.5 min under 25 L dual mode nitrogen pressurization, which is 1/12 of injection time after ground gasification; (4) Based on the temperature decrease trend measured at different positions, the cooling characteristics on liquid gasification jet path are quantified, and the calculation formula of temperature changing with time on the center line of liquid gasification jet is obtained. Through this new approach, the integration of vacuum insulated storage, safe mobile transportation, and continuous and rapid release with large flow can be achieved for the liquid carbon dioxide.


Assuntos
Dióxido de Carbono , Incêndios , Incêndios/prevenção & controle , Nitrogênio , Temperatura Alta , Temperatura Baixa
16.
Glob Chang Biol ; 30(4): e17260, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38563236

RESUMO

The impact of anthropogenic global warming has induced significant upward dispersal of trees to higher elevations at alpine treelines. Assessing vertical deviation from current uppermost tree distributions to potential treeline positions is crucial for understanding ecosystem responses to evolving global climate. However, due to data resolution constraints and research scale limitation, comprehending the global pattern of alpine treeline elevations and driving factors remains challenging. This study constructed a comprehensive quasi-observational dataset of uppermost tree distribution across global mountains using Google Earth imagery. Validating the isotherm of mean growing-season air temperature at 6.6 ± 0.3°C as the global indicator of thermal treeline, we found that around two-thirds of uppermost tree distribution records significantly deviated from it. Drought conditions constitute the primary driver in 51% of cases, followed by mountain elevation effect which indicates surface heat (27%). Our analyses underscore the multifaceted determinants of global patterns of alpine treeline, explaining divergent treeline responses to climate warming. Moisture, along with temperature and disturbance, plays the most fundamental roles in understanding global variation of alpine treeline elevation and forecasting alpine treeline response to ongoing global warming.


Assuntos
Ecossistema , Árvores , Árvores/fisiologia , Temperatura , Temperatura Baixa , Clima , Altitude
17.
Environ Sci Technol ; 58(14): 6226-6235, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38557021

RESUMO

The updated climate models provide projections at a fine scale, allowing us to estimate health risks due to future warming after accounting for spatial heterogeneity. Here, we utilized an ensemble of high-resolution (25 km) climate simulations and nationwide mortality data from 306 Chinese cities to estimate death anomalies attributable to future warming. Historical estimation (1986-2014) reveals that about 15.5% [95% empirical confidence interval (eCI):13.1%, 17.6%] of deaths are attributable to nonoptimal temperature, of which heat and cold corresponded to attributable fractions of 4.1% (eCI:2.4%, 5.5%) and 11.4% (eCI:10.7%, 12.1%), respectively. Under three climate scenarios (SSP126, SSP245, and SSP585), the national average temperature was projected to increase by 1.45, 2.57, and 4.98 °C by the 2090s, respectively. The corresponding mortality fractions attributable to heat would be 6.5% (eCI:5.2%, 7.7%), 7.9% (eCI:6.3%, 9.4%), and 11.4% (eCI:9.2%, 13.3%). More than half of the attributable deaths due to future warming would occur in north China and cardiovascular mortality would increase more drastically than respiratory mortality. Our study shows that the increased heat-attributable mortality burden would outweigh the decreased cold-attributable burden even under a moderate climate change scenario across China. The results are helpful for national or local policymakers to better address the challenges of future warming.


Assuntos
Temperatura Baixa , Temperatura Alta , Temperatura , Cidades , China/epidemiologia , Mudança Climática , Mortalidade
18.
PLoS One ; 19(4): e0301528, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635694

RESUMO

An inexpensive and high-performing solid Coumarone resin was added to Styrene-butadiene-styrene (SBS) copolymer-modified asphalt to enhance its storage stability and road performance. To assess the effect of Coumarone resin dosage on the SBS-modified asphalt, a series of laboratory tests were conducted. The composite modified asphalt's segregation test was used to evaluate its storage stability, Dynamic Shear Rheometer (DSR) and Multiple Stress Creep Recovery (MSCR) tests were employed to investigate its high-temperature performance and permanent deformation resistance, and the Bending Beam Rheology (BBR) test was utilized to measure its low-temperature performance. Fluorescence microscopy was used to observe the composite modified asphalt's microstructure, and Fourier Transform Infrared Spectroscopy (FTIR) was conducted to study the changes in chemical structure during the modification process. The results showed that Coumarone resin can improve the compatibility of SBS and asphalt, improve the high-temperature performance and deformation resistance of SBS-modified asphalt, and adding an appropriate amount of Coumarone resin can help enhance the low-temperature cracking resistance of modified asphalt. The optimal dosage of Coumarone resin recommended for SBS-modified asphalt performance enhancement is 2% under the test conditions, as determined by comparing the test results of samples with various dosages.


Assuntos
Benzofuranos , Hidrocarbonetos , Estireno , Temperatura Baixa , Resinas Vegetais
19.
Physiol Plant ; 176(2): e14272, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38566275

RESUMO

The Dehydration-Responsive Element Binding (DREB) subfamily of transcription factors plays crucial roles in plant abiotic stress response. Ammopiptanthus nanus (A. nanus) is an eremophyte exhibiting remarkable tolerance to environmental stress and DREB proteins may contribute to its tolerance to water deficit and low-temperature stress. In the present study, an A. nanus DREB A5 group transcription factor gene, AnDREB5.1, was isolated and characterized in terms of structure and function in abiotic stress tolerance. AnDREB5.1 protein is distributed in the nucleus, possesses transactivation capacity, and is capable of binding to DRE core cis-acting element. The transcription of AnDREB5.1 was induced under osmotic and cold stress. Tobacco seedlings overexpressing AnDREB5.1 displayed higher tolerance to cold stress, osmotic stress, and oxidative stress compared to wild-type tobacco (WT). Under osmotic and cold stress, overexpression of AnDREB5.1 increased antioxidant enzyme activity in tobacco leaves, inhibiting excessive elevation of ROS levels. Transcriptome sequencing analysis showed that overexpression of AnDREB5.1 raised the tolerance of transgenic tobacco seedlings to abiotic stress by regulating multiple genes, including antioxidant enzymes, transcription factors, and stress-tolerant related functional genes like NtCOR413 and NtLEA14. This study provides new evidence for understanding the potential roles of the DREB A5 subgroup members in plants.


Assuntos
Resposta ao Choque Frio , Fabaceae , Resposta ao Choque Frio/genética , Antioxidantes , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Fabaceae/genética , Estresse Fisiológico/genética , Plântula/genética , Plântula/metabolismo , Tabaco/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Temperatura Baixa
20.
PLoS One ; 19(4): e0300138, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38573935

RESUMO

Using the climate model CLIMBER-X, we present an efficient method for assimilating the temporal evolution of surface temperatures for the last deglaciation covering the period 22000 to 6500 years before the present. The data assimilation methodology combines the data and the underlying dynamical principles governing the climate system to provide a state estimate of the system, which is better than that which could be obtained using just the data or the model alone. In applying an ensemble Kalman filter approach, we make use of the advances in the parallel data assimilation framework (PDAF), which provides parallel data assimilation functionality with a relatively small increase in computation time. We find that the data assimilation solution depends strongly on the background evolution of the decaying ice sheets rather than the assimilated temperatures. Two different ice sheet reconstructions result in a different deglacial meltwater history, affecting the large-scale ocean circulation and, consequently, the surface temperature. We find that the influence of data assimilation is more pronounced on regional scales than on the global mean. In particular, data assimilation has a stronger effect during millennial warming and cooling phases, such as the Bølling-Allerød and Younger Dryas, especially at high latitudes with heterogeneous temperature patterns. Our approach is a step toward a comprehensive paleo-reanalysis on multi-millennial time scales, including incorporating available paleoclimate data and accounting for their uncertainties in representing regional climates.


Assuntos
Clima , Temperatura Baixa , Temperatura
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