RESUMO
Plasmonics enables the manipulation of light beyond the optical diffraction limit1-4 and may therefore confer advantages in applications such as photonic devices5-7, optical cloaking8,9, biochemical sensing10,11 and super-resolution imaging12,13. However, the essential field-confinement capability of plasmonic devices is always accompanied by a parasitic Ohmic loss, which severely reduces their performance. Therefore, plasmonic materials (those with collective oscillations of electrons) with a lower loss than noble metals have long been sought14-16. Here we present stable sodium-based plasmonic devices with state-of-the-art performance at near-infrared wavelengths. We fabricated high-quality sodium films with electron relaxation times as long as 0.42 picoseconds using a thermo-assisted spin-coating process. A direct-waveguide experiment shows that the propagation length of surface plasmon polaritons supported at the sodium-quartz interface can reach 200 micrometres at near-infrared wavelengths. We further demonstrate a room-temperature sodium-based plasmonic nanolaser with a lasing threshold of 140 kilowatts per square centimetre, lower than values previously reported for plasmonic nanolasers at near-infrared wavelengths. These sodium-based plasmonic devices show stable performance under ambient conditions over a period of several months after packaging with epoxy. These results indicate that the performance of plasmonic devices can be greatly improved beyond that of devices using noble metals, with implications for applications in plasmonics, nanophotonics and metamaterials.
RESUMO
Revealing the genetic basis for stress-resistant traits in extremophile plants will yield important information for crop improvement. Zygophyllum xanthoxylum, an extant species of the ancient Mediterranean, is a succulent xerophyte that can maintain a favorable water status under desert habitats; however, the genetic basis of this adaptive trait is poorly understood. Furthermore, the phylogenetic position of Zygophyllales, to which Z. xanthoxylum belongs, remains controversial. In this study, we sequenced and assembled the chromosome-level genome of Z. xanthoxylum. Phylogenetic analysis showed that Zygophyllales and Myrtales form a separated taxon as a sister to the clade comprising fabids and malvids, clarifying the phylogenetic position of Zygophyllales at whole-genome scale. Analysis of genomic and transcriptomic data revealed multiple critical mechanisms underlying the efficient osmotic adjustment using Na+ and K+ as "cheap" osmolytes that Z. xanthoxylum has evolved through the expansion and synchronized expression of genes encoding key transporters/channels and their regulators involved in Na+/K+ uptake, transport, and compartmentation. It is worth noting that ZxCNGC1;1 (cyclic nucleotide-gated channels) and ZxCNGC1;2 constituted a previously undiscovered energy-saving pathway for Na+ uptake. Meanwhile, the core genes involved in biosynthesis of cuticular wax also featured an expansion and upregulated expression, contributing to the water retention capacity of Z. xanthoxylum under desert environments. Overall, these findings boost the understanding of evolutionary relationships of eudicots, illustrate the unique water retention mechanism in the succulent xerophyte that is distinct from glycophyte, and thus provide valuable genetic resources for the improvement of stress tolerance in crops and insights into the remediation of sodic lands.
Assuntos
Filogenia , Água , Zygophyllum , Água/metabolismo , Zygophyllum/genética , Zygophyllum/metabolismo , Genoma de Planta , Regulação da Expressão Gênica de Plantas , Genômica/métodosRESUMO
OBJECTIVE: To investigate the impact of the combination of CICARE (C - Connect, I - Introduce, C - Communicate, A - Ask, R - Respond, E - Exit) communication model and traditional Chinese medicine (TCM) poultice on muscle strength and depression levels in patients. METHODS: Patients were divided into three groups: basic treatment group, basic treatment + TCM poultice group, and combined treatment group. Conventional rehabilitation therapy, TCM poultice external application, and the combination of both with the CICARE communication model were applied in the respective groups. Muscle strength (AMA muscle strength grading scale), self-care abilities (Barthel Index), depression symptoms (Hamilton Depression Rating Scale), neurological deficit status (NIHSS score) and serum inflammatory factor levels were assessed at admission, 3 weeks, and 8 weeks of treatment. RESULTS: After 3 and 8 weeks of treatment, the combined treatment group had higher AMA muscle strength scores and improved Barthel Index scores compared to other groups (p < 0.05). Depressive symptoms also improved significantly in the combined treatment group, with lower HDRS scores at 3 and 8 weeks (p < 0.05). After 8 weeks, IL-1, IL-6, and hs-CRP levels decreased in all groups, with the combined treatment group showing the lowest levels (p < 0.05). NIHSS scores decreased significantly in all groups post-intervention, with the combined treatment group showing the greatest improvement (p < 0.05). CONCLUSION: The integration of CICARE communication model with TCM poultice shows notable benefits in enhancing muscle strength, daily living self-care abilities, reducing depression, neurological impairment, and inflammatory factors in post-stroke hemiplegia patients.
RESUMO
Soil salinity is a significant threat to global agriculture. Understanding salt exclusion mechanisms in halophyte species may be instrumental in improving salt tolerance in crops. Puccinellia tenuiflora is a typical salt-excluding halophytic grass often found in potassium-deprived saline soils. Our previous work showed that P. tenuiflora possesses stronger selectivity for K+ than for Na+ ; however, the mechanistic basis of this phenomenon remained elusive. Here, P. tenuiflora PutHKT1;5 was cloned and the functions of PutHKT1;5 and PutSOS1 were characterized using heterologous expression systems. Yeast assays showed that PutHKT1;5 possessed Na+ transporting capacity and was highly selective for Na+ over K+ . PutSOS1 was located at the plasma membrane and operated as a Na+ /K+ exchanger, with much stronger Na+ extrusion capacity than its homolog from Arabidopsis. PutHKT2;1 mediated high-affinity K+ and Na+ uptake and its expression levels were upregulated by mild salinity and K+ deprivation. Salinity-induced changes of root PutHKT1;5 and PutHKT1;4 transcript levels matched the expression pattern of root PutSOS1, which was consistent with root Na+ efflux. The transcript levels of root PutHKT2;1 and PutAKT1 were downregulated by salinity. Taken together, these findings demonstrate that the functional activity of PutHKT1;5 and PutSOS1 in P. tenuiflora roots is fine-tuned under saline conditions as well as by operation of other ion transporters/channel (PutHKT1;4, PutHKT2;1, and PutAKT1). This leads to the coordination of radial Na+ and K+ transport processes, their loading to the xylem, or Na+ retrieval and extrusion under conditions of mild salinity and/or K+ deprivation.
Assuntos
Arabidopsis , Potássio , Potássio/metabolismo , Sódio/metabolismo , Salinidade , Poaceae/genética , Poaceae/metabolismo , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Solo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
Efficient transfer of charge carriers through a fast transport pathway is crucial to excellent photocatalytic reduction performance in solar-driven CO2 reduction, but it is still challenging to effectively modulate the electronic transport pathway between photoactive motifs by feasible chemical means. In this work, we propose a thermally induced strategy to precisely modulate the fast electron transport pathway formed between the photoactive motifs of a porphyrin metal-organic framework using thorium ion with large ionic radius and high coordination number as the coordination-labile metal node. As a result, the stacking pattern of porphyrin molecules in the framework before and after the crystal transformations has changed dramatically, which leads to significant differences in the separation efficiency of photogenerated carriers in MOFs. The rate of photocatalytic reduction of CO2 to CO by IHEP-22(Co) reaches 350.9 µmol·h-1·g-1, which is 3.60 times that of IHEP-21(Co) and 1.46 times that of IHEP-23(Co). Photoelectrochemical characterizations and theoretical calculations suggest that the electron transport channels formed between porphyrin molecules inhibit the recombination of photogenerated carriers, resulting in high performance for photocatalytic CO2 reduction. The interaction mechanism of CO2 with IHEP-22(Co) was clarified by using in-situ electron paramagnetic resonance, in-situ diffuse reflectance infrared Fourier transform spectroscopy, in-situ extended X-ray absorption fine structure spectroscopy, and theoretical calculations. These results provide a new method to regulate the efficient separation and migration of charge carriers in CO2 reduction photocatalysts and will be helpful to guide the design and synthesis of photocatalysts with superior performance for the production of solar fuels.
RESUMO
BACKGROUND: Heat stress has adverse effects on the growth and reproduction of plants. Zygophyllum xanthoxylum, a typical xerophyte, is a dominant species in the desert where summer temperatures are around 40 °C. However, the mechanism underlying the thermotolerance of Z. xanthoxylum remained unclear. RESULTS: Here, we characterized the acclimation of Z. xanthoxylum to heat using a combination of physiological measurements and transcriptional profiles under treatments at 40 °C and 45 °C, respectively. Strikingly, moderate high temperature (40 °C) led to an increase in photosynthetic capacity and superior plant performance, whereas severe high temperature (45 °C) was accompanied by reduced photosynthetic capacity and inhibited growth. Transcriptome profiling indicated that the differentially expressed genes (DEGs) were related to transcription factor activity, protein folding and photosynthesis under heat conditions. Furthermore, numerous genes encoding heat transcription shock factors (HSFs) and heat shock proteins (HSPs) were significantly up-regulated under heat treatments, which were correlated with thermotolerance of Z. xanthoxylum. Interestingly, the up-regulation of PSI and PSII genes and the down-regulation of chlorophyll catabolism genes likely contribute to improving plant performance of Z. xanthoxylum under moderate high temperature. CONCLUSIONS: We identified key genes associated with of thermotolerance and growth in Z. xanthoxylum, which provide significant insights into the regulatory mechanisms of thermotolerance and growth regulation in Z. xanthoxylum under high temperature conditions.
Assuntos
Termotolerância , Zanthoxylum , Zygophyllum , Termotolerância/genética , Sódio/metabolismo , Zygophyllum/genética , Zygophyllum/metabolismo , Zanthoxylum/genética , Transcriptoma , Perfilação da Expressão Gênica , Resposta ao Choque Térmico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Temperatura Alta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
Replication factor C 5 (RFC5) is involved in a variety of biological functions of cancer. However, the expression pattern of RFC5 and the underlying mechanisms in colorectal cancer (CRC) remain elusive. Here, we show that RFC5 is significantly upregulated in CRC tissues and cells. Patients with CRC and increased RFC5 levels have an unfavorable prognosis. RFC5 can promote the proliferation, migration, and invasion of CRC cells and inhibit the apoptosis of CRC cells. Additionally, upstream of RFC5, we constructed the competing endogenous RNA network and confirmed that RFC5 in this network was inhibited by miR-3614-5p by directly targeting its 3'-untranslated regions. We verified that circ_0038985, which is positively correlated with RFC5, directly targeted miR-3614-5p. Overexpression of circ_0038985 promoted CRC cell migration and invasion, and these effects were partially reversed by the reintroduction of miR-3614-5p. Moreover, we found that RFC5 may promote the vascular endothelial growth factor A (VEGFa)/vascular endothelial growth factor receptor 2 (VEGFR2)/extracellular signal-regulated protein kinase (ERK) pathway. The knockdown of RFC5 reduced CRC tumorigenesis in vivo. Collectively, these data demonstrate that the circ_0038985/miR-3614-5p/RFC5 axis plays a critical role in the progression of CRC, and RFC5 may promote CRC progression by affecting the VEGFa/VEGFR2/ERK pathway.
Assuntos
Neoplasias Colorretais , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteína de Replicação C/genética , Proteína de Replicação C/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , OncogenesRESUMO
Brassinosteroids (BRs) are an important group of plant steroid hormones that regulate growth and development. Several members of the SMALL AUXIN UP RNA (SAUR) family have roles in BR-regulated hypocotyl elongation and root growth. However, the mechanisms are unclear. Here, we show in Arabidopsis (Arabidopsis thaliana) that SAUR15 interacts with cell surface receptor-like kinase BRASSINOSTEROID-INSENSITIVE 1 (BRI1) in BR-treated plants, resulting in enhanced BRI1 phosphorylation status and recruitment of the co-receptor BRI1-ASSOCIATED RECEPTOR KINASE 1. Genetic and phenotypic assays indicated that the SAUR15 effect on BRI1 can be uncoupled from BRASSINOSTEROID INSENSITIVE 2 activity. Instead, we show that SAUR15 promotes BRI1 direct activation of plasma membrane H+-ATPase (PM H+-ATPase) via phosphorylation. Consequently, SAUR15-BRI1-PM H+-ATPase acts as a direct, PM-based mode of BR signaling that drives cell expansion to promote the growth and development of various organs. These data define an alternate mode of BR signaling in plants.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Brassinosteroides/farmacologia , Membrana Celular/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , ATPases Translocadoras de Prótons/genética , ATPases Translocadoras de Prótons/metabolismoRESUMO
BACKGROUND AND AIMS: Desert plants possess excellent water-conservation capacities to survive in extreme environments. Cuticular wax plays a pivotal role in reducing water loss through plant aerial surfaces. However, the role of cuticular wax in water retention by desert plants is poorly understood. METHODS: We investigated leaf epidermal morphology and wax composition of five desert shrubs from north-west China and characterized the wax morphology and composition for the typical xerophyte Zygophyllum xanthoxylum under salt, drought and heat treatments. Moreover, we examined leaf water loss and chlorophyll leaching of Z. xanthoxylum and analysed their relationships with wax composition under the above treatments. KEY RESULTS: The leaf epidermis of Z. xanthoxylum was densely covered by cuticular wax, whereas the other four desert shrubs had trichomes or cuticular folds in addition to cuticular wax. The total amount of cuticular wax on leaves of Z. xanthoxylum and Ammopiptanthus mongolicus was significantly higher than that of the other three shrubs. Strikingly, C31 alkane, the most abundant component, composed >71 % of total alkanes in Z. xanthoxylum, which was higher than for the other four shrubs studied here. Salt, drought and heat treatments resulted in significant increases in the amount of cuticular wax. Of these treatments, the combined drought plus 45 °C treatment led to the largest increase (107 %) in the total amount of cuticular wax, attributable primarily to an increase of 122 % in C31 alkane. Moreover, the proportion of C31 alkane within total alkanes remained >75 % in all the above treatments. Notably, the water loss and chlorophyll leaching were reduced, which was negatively correlated with C31 alkane content. CONCLUSION: Zygophyllum xanthoxylum could serve as a model desert plant for study of the function of cuticular wax in water retention because of its relatively uncomplicated leaf surface and because it accumulates C31 alkane massively to reduce cuticular permeability and resist abiotic stressors.
Assuntos
Zanthoxylum , Zygophyllum , Zygophyllum/metabolismo , Zanthoxylum/metabolismo , Alcanos , Folhas de Planta/metabolismo , Cloreto de Sódio , Clorofila , Estresse Fisiológico , Água/metabolismo , Ceras , Regulação da Expressão Gênica de PlantasRESUMO
Separation of minor actinides from lanthanides is one of the biggest challenges in spent fuel reprocessing due to the similar physicochemical properties of trivalent lanthanides (Ln(III)) and actinides (An(III)). Therefore, developing ligands with excellent extraction and separation performance is essential at present. As an excellent pre-organization platform, calixarene has received more attention on Ln(III)/An(III) separation. In this work, we systematically explored the complexation behaviors of the diglycolamide (DGA)/dimethylacetamide (DMA)-functionalized calix[4]arene extractants for Eu(III) and Am(III) using relativistic density functional theory (DFT). These calix[4]arene-derived ligands were obtained by functionalization with two or four binding units at the narrow edge of the calix[4]arene platform. All bonding nature analyses suggested that the Eu-L complexes possess stronger interaction compared to Am-L analogues, resulting in the higher extraction capacity of the these calix[4]arene ligands toward Eu(III). Thermodynamic analysis demonstrates that these pre-organized ligands on the calix[4]arene platform with four binding units yield better extraction abilities than the single ligands. Although DMA-functionalized ligands show stronger complexation stability for metal ions, in acidic solutions, the calix[4]arene ligands with DGA binding units have better extraction performance for Eu(III) and Am(III) due to the basicity of the DMA ligand. This work enabled us to gain a deeper understanding of the bonding properties between supramolecular ligands and lanthanides/actinides and afford useful insights into designing efficient supramolecular ligands for separating Ln(III)/An(III).
RESUMO
BACKGROUND: Traditional open thyroidectomy is the surgical standard for thyroid cancer; however, it inevitably leaves a visible scar on the neck and affects the patient's quality of life. Therefore, to avoid making a neck incision, the transoral endoscopic thyroidectomy vestibular approach (TOETVA) and transoral robotic thyroidectomy (TORT) have been developed recently, and the surgical outcomes of these techniques are as favorable as open surgery for benign disease. Additionally, positive short-term surgical outcomes have also been achieved in a few patients with thyroid cancer. However, no data on the mid-to-long-term recurrence and survival rates of transoral thyroidectomy in thyroid cancer are available. Therefore, in this study, we analyzed the surgical outcomes and mid-term oncological results of the TOETVA and TORT in patients with thyroid cancer. METHODS: We reviewed patients who had received TOETVA or TORT between July 2017 and November 2021 and followed up on their oncological outcomes until December 2022. Perioperative surgical and mid-term oncological outcomes were analyzed. RESULTS: The 115 patients underwent 122 operations (57 TOETVAs and 65 TORTs), including seven complete thyroidectomies for differentiated thyroid cancer (DTC), Stage I-II, including T1-T3, N0-N1a, and initial low- to high-risk groups. There was no conversion from transoral to open surgery. TORT required a longer operating time (median [interquartile range]) than TOETVA (lobectomy: 279 [250, 318] vs. 196 [173, 253] min, p < 0.001; bilateral total thyroidectomy: 375 [309, 433] vs. 279 [238, 312] min, p < 0.001); however, no difference was found between the two groups regarding perioperative complications. Complete thyroidectomy with a second transoral approach was safe. TOETVA and TORT achieved favorable oncological outcomes with 100% survival and 98.2% acceptable response (excellent and indeterminate response) during a mean 37.88 ± 12.42 months mid-term follow-up. CONCLUSIONS: Transoral endoscopic and robotic thyroidectomy was safe and achieved favorable mid-term oncological outcomes in a selected cohort of patients with early-stage DTC.
Assuntos
Cirurgia Endoscópica por Orifício Natural , Procedimentos Cirúrgicos Robóticos , Neoplasias da Glândula Tireoide , Humanos , Cirurgia Endoscópica por Orifício Natural/métodos , Qualidade de Vida , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/métodosRESUMO
PURPOSE: The causes of acute stroke in patients with SLE are multifactorial. Antiphospholipid-associated hypercoagulability and inflammation-induced platelet activation are major causes of ischemic stroke in SLE patients. As such patients underwent intravenous thrombolysis and endovascular thrombectomy, they may have higher risk of complications and less favorable outcome. CASE REPORT: A 30-year-old woman with underline SLE and Takayasu arteritis who presented with right CCA and MCA occlusion status post rtPA and endovascular thrombectomy. Twelve hours after the procedure, head CT was ordered due to anisocoria with loss of pupillary light reflex. The head CT showed partial obliteration of suprasellar and quadrigeminal cistern due to extensive brain edema, leading to her decompressive craniectomy. Two days later, patient's both pupil became dilated with head CT showing occlusion of the left MCA. Her condition drastically went downhill when complications such as central DI and myocardial stunning occurred. CONCLUSION: Although autoimmune vasculitis is not listed as an absolute contraindication to endovascular thrombectomy, given the antecedent reports, it is prudent to disclose possible complications to both the patient and family while making the decision.
Assuntos
Acidente Vascular Cerebral , Humanos , Adulto , Acidente Vascular Cerebral/complicaçõesRESUMO
Solar-initiated CO2 reduction is significant for green energy development. Herein, we have prepared a new mesoporous/microporous porphyrin metal-organic framework (MOF), IHEP-20, loaded with polymetallic oxygen clusters (POMs) to form a composite material POMs@IHEP-20 for visible-light-driven photocatalytic CO2 reduction. The as-made composite material exhibits good stability in water from pH 0 to 11. After POMs were introduced to IHEP-20, they showed superior activity toward photocatalytic CO2 reduction with a CO production rate of 970 µmol·g-1·h-1, which is 3.27 times higher than that of pristine IHEP-20. This study opens a new door for the design and synthesis of high-performance catalysts for the photocatalytic reduction of CO2.
RESUMO
Effective separation and recovery of chemically similar transplutonium elements from adjacent actinides is extremely challenging in spent fuel reprocessing. Deep comprehension of the complexation of transplutonium elements and ligands is significant for the design and development of ligands for the in-group separation of transplutonium elements. Because of experimental difficulties of transplutonium elements, theoretical calculation has become an effective means of exploring transplutonium complexes. In this work, we systematically investigated the coordination mechanism between transplutonium elements (An = Am, Cm, Bk, Cf) and two crown ether macrocyclic ligands [N,N'- bis[(6-carboxy-2-pyridyl)methyl]-1,10-diaza-18-crown-6 (H2bp18c6) and N,N'-bis[(6-methylphosphinic-2-pyridyl)methyl]-1,10-diaza-18-crown-6 (H2bpp18c6)] through quasi-relativistic density functional theory. The extraction complexes of [Anbp18c6]+ and [Anbpp18c6]+ possess similar geometrical structures with actinide atoms located in the cavity of the ligands. Bonding nature analysis indicates that the coordination ability of the coordinating atoms in pendent arms is stronger than that in the crown ether macrocycle because of the limitation of the macrocycle. Most of the coordination atoms of the H2bp18c6 ligand have a stronger ability to coordinate with metal ions than those of the H2bpp18c6 ligand. In addition, the bonding strength between the metal ions and ligands gradually weakens from Am to Cf, which is mainly attributed to the size selectivity of the ligands. Thermodynamic analysis shows that the H2bp18c6 ligand has a stronger extraction capacity than the H2bpp18c6 ligand, while the H2bpp18c6 ligand is superior in terms of the in-group separation ability. The extraction capacity of the two ligands for metal ions gradually decreases across the actinide series, indicating that these crown ether macrocycle ligands have size selectivity for these actinide cations as a result of steric constraint of the crown ether ring. We hope that these results offer theoretical clues for the development of macrocycle ligands for in-group transplutonium separation.
RESUMO
SMALL AUXIN-UP RNAs (SAURs) comprise the largest family of early auxin response genes. Some SAURs have been reported to play important roles in plant growth and development, but their functional relationships with auxin signaling remain unestablished. Here, we report Arabidopsis (Arabidopsis thaliana) SAUR15 acts downstream of the auxin response factors ARF6,8 and ARF7,19 to regulate auxin signaling-mediated lateral root (LR) and adventitious root (AR) formation. The loss-of-function mutant saur15-1 exhibits fewer LRs and ARs. By contrast, plants overexpressing SAUR15 exhibit more LRs and ARs. We find that the SAUR15 promoter contains four tandem auxin-responsive elements, which are directly bound by ARF6 and ARF7 and are essential for SAUR15 expression. LR and AR impairment in arf6 and arf7 mutants is partially reduced by ectopic expression of SAUR15 Additionally, we demonstrate that the ARF6,7-upregulated SAUR15 promotes LR and AR development using two mechanisms. On the one hand, SAUR15 interacts with PP2C-D subfamily type 2C protein phosphatases to inhibit their activities, thereby stimulating plasma membrane H+-ATPases, which drives cell expansion and facilitates LR and AR formation. On the other hand, SAUR15 promotes auxin accumulation, potentially by inducing the expression of auxin biosynthesis genes. A resulting increase in free auxin concentration likely triggers LR and AR formation, forming a feedback loop. Our study provides insights and a better understanding of how SAURs function at the molecular level in regulating auxin-mediated LR and AR development.
Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Ácidos Indolacéticos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Organogênese Vegetal/genética , Organogênese Vegetal/fisiologiaRESUMO
The stability of many MOFs is not satisfactory, which severely limits the exploration of their potential applications. Given this, we have proposed a strategy to improve the stability of MOFs by introducing alkali metal K+ capable of coordinating with metal nodes, which finally induces the interpenetrating uranyl-porphyrin framework to connect as a whole (IHEP-9). The stability experiments reveal that the IHEP-9 has good thermal stability up to 400 °C and can maintain its crystalline state in the aqueous solution with pH ranging from 2 to 11. The catalytic activity of IHEP-9 as a heterogeneous photocatalyst for CO2 cycloaddition under the driving of visible light at room temperature is also demonstrated. This induced interpenetration and fixation method may be promising for the fabrication of more functional MOFs with improved structural stability.
RESUMO
Drought and salinity can result in cell dehydration and water unbalance in plants, which seriously diminish plant growth and development. Cellular water homeostasis maintained by aquaporin is one of the important strategies for plants to cope with these two stresses. In this study, a stress-induced aquaporin, ZxPIP1;3, belonging to the PIP1 subgroup, was identified from the succulent xerophyte Zygophyllum xanthoxylum. The subcellular localization showed that ZxPIP1;3-GFP was located in the plasma membrane. The overexpression of ZxPIP1;3 in Arabidopsis prompted plant growth under favorable condition. In addition, it also conferred salt and drought tolerance with better water status as well as less ion toxicity and membrane injury, which led to more efficient photosynthesis and improved growth vigor via inducing stress-related responsive genes. This study reveals the molecular mechanisms of xerophytes' stress tolerance and provides a valuable candidate that could be used in genetic engineering to improve crop growth and stress tolerance.
Assuntos
Adaptação Fisiológica , Aquaporinas/genética , Regulação da Expressão Gênica de Plantas , Desenvolvimento Vegetal , Proteínas de Plantas/genética , Estresse Fisiológico , Zygophyllum/crescimento & desenvolvimento , Zygophyllum/genética , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Sequência de Aminoácidos , Aquaporinas/metabolismo , Arabidopsis/genética , Secas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Pressão Osmótica , Desenvolvimento Vegetal/efeitos dos fármacos , Desenvolvimento Vegetal/genética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Zygophyllum/efeitos dos fármacosRESUMO
Chloride (Cl-) is pervasive in saline soils, and research on its influence on plants has mainly focused on its role as an essential nutrient and its toxicity when excessive accumulation occurs. However, the possible functions of Cl- in plants adapting to abiotic stresses have not been well documented. Previous studies have shown that the salt tolerance of the xerophytic species Pugionium cornutum might be related to high Cl- accumulation. In this study, we investigated the Cl--tolerant characteristics and possible physiological functions of Cl- in the salt tolerance and drought resistance of P. cornutum. We found that P. cornutum can accumulate a large amount of Cl- in its shoots, facilitating osmotic adjustment and turgor generation under saline conditions. Application of DIDS (4,4´-diisothiocyanostilbene-2,2´-disulfonic acid), a blocker of anion channels, significantly inhibited Cl- uptake, and decreased both the Cl- content and its contribution to leaf osmotic adjustment, resulting in the exacerbation of growth inhibition in response to NaCl. Unlike glycophytes, P. cornutum was able to maintain NO3- homeostasis in its shoots when large amounts of Cl- were absorbed and accumulated. The addition of NaCl mitigated the deleterious effects of osmotic stress on P. cornutum because Cl- accumulation elicited a strong osmotic adjustment capacity. These findings suggest that P. cornutum is a Cl--tolerant species that can absorb and accumulate Cl- to improve growth under salt and drought stresses.
Assuntos
Brassicaceae , Secas , Cloretos , Osmose , Pressão Osmótica , Tolerância ao Sal , Estresse FisiológicoRESUMO
BACKGROUND/PURPOSE: This study investigates the safety and feasibility to perform laparoscopic nephroureterectomy (LNU) for upper tract urothelial carcinoma (UTUC) without routine nasogastric tube (NGT) decompression. METHODS: The hospital-based samples comprised of 100 consecutive UTUC patients receiving elective LNU performed by two experienced surgeons. The nationwide data was based on LHID2005 composed of one million beneficiaries randomly selected from the Taiwan National Health Insurance Research Database to identify patients with the diagnoses of UTUCs receiving LNUs. We then compared baseline characteristics, peri-operative data, convalescence parameters and complications between two groups stratified by use of NGT tube. RESULTS: The hospital-based samples composed of 50 subjects with NGT and 50 without. There were no significant differences in baseline characteristics between two groups. Peri-operative and convalescence parameters were similar when comparing no NGT versus NGT: blood loss of 206 vs. 165 mL; operative time of 180.5 vs.181.1 min; days to intake was 2.1 vs.1.7 days; and hospital stay of 7.8 vs. 7.5 days (all p > 0.05). The nationwide study samples comprised 140 subjects, of which 72 were with NGT and 68 were with no NGT. The baseline data, complications and length of hospital stay were similar between two groups. CONCLUSION: Surgery-naïve patients with localized UTUC received LNU without peri-operative NGT is safe and feasible.
Assuntos
Carcinoma de Células de Transição , Descompressão , Intubação Gastrointestinal , Laparoscopia , Nefroureterectomia , Carcinoma de Células de Transição/cirurgia , Humanos , Taiwan/epidemiologia , Resultado do TratamentoRESUMO
AtNPF7.3/AtNRT1.5, which is a nitrate transporter that drives root-to-shoot transport of NO3-, is also involved in modulating the response to K+ deprivation in Arabidopsis by affecting root development and K+ transport. However, whether NPF7.3/NRT1.5 functions in regulating plant responses to deficiencies of other nutrients remains unknown. In this study, we found that the expression of AtNPF7.3/AtNRT1.5 was predominant in the roots and was substantially induced by phosphate (Pi) starvation. The atnrt1.5 mutants displayed conspicuously longer primary roots along with a significantly reduced lateral root density under Pi-deficient conditions than did the wild-type plants, and these morphological differences in the roots were eliminated to a certain extent by the ethylene synthesis antagonist Co2+. Further analyses revealed that the expression of important Pi starvation-induced genes, which are directly involved in Pi transport, mobilization and distribution, were significantly higher in the atnrt1.5 mutants than that in the wild-type plants under Pi-starvation conditions; therefore, the atnrt1.5 mutants retained higher tissue Pi concentrations. Taken together, our results suggest that NPF7.3/NRT1.5 is an important component in the regulation of phosphate deficiency responses in Arabidopsis.