Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 257
Filtrar
1.
Adv Mater ; : e2008599, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33792090

RESUMO

The electronic metal-support interaction (EMSI) plays a crucial role in catalysis as it can induce electron transfer between metal and support, modulate the electronic state of the supported metal, and optimize the reduction of intermediate species. In this work, the tailoring of electronic structure of Pt single atoms supported on N-doped mesoporous hollow carbon spheres (Pt1 /NMHCS) via strong EMSI engineering is reported. The Pt1 /NMHCS composite is much more active and stable than the nanoparticle (PtNP ) counterpart and commercial 20 wt% Pt/C for catalyzing the electrocatalytic hydrogen evolution reaction (HER), exhibiting a low overpotential of 40 mV at a current density of 10 mA cm-2 , a high mass activity of 2.07 A mg-1 Pt at 50 mV overpotential, a large turnover frequency of 20.18 s-1 at 300 mV overpotential, and outstanding durability in acidic electrolyte. Detailed spectroscopic characterizations and theoretical simulations reveal that the strong EMSI effect in a unique N1 -Pt1 -C2 coordination structure significantly tailors the electronic structure of Pt 5d states, resulting in promoted reduction of adsorbed proton, facilitated H-H coupling, and thus Pt-like HER activity. This work provides a constructive route for precisely designing single-Pt-atom-based robust electrocatalysts with high HER activity and durability.

2.
Brain ; 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33792674

RESUMO

Direct electrical stimulation, the transient "lesional" method probing brain function, has been utilized in identifying the language cortex and preserving language function during epilepsy and neuro-oncological surgeries for about a century. However, comparison of functional maps of the language cortex across languages/continents based on cortical stimulation remains unclear. We conducted a retrospective multi-center study including four cohorts of direct electrical stimulation mapping from four centers across three continents, where three indigenous languages (English, French, and Mandarin) are spoken. All subjects performed the two most common language tasks: Number counting and picture naming during stimulation. All language sites were recorded and normalized to the same brain template. Next, Spearman's correlation analysis was performed to explore the consistency of the distributions of the language cortex across centers, a kernel density estimation to localize the peak coordinates, and a hierarchical cluster analysis was performed to detect the crucial epicenters. A total of 598 subjects with 917 speech arrest sites (complete interruption of ongoing counting) and 423 anomia sites (inability to name or misnaming) were included. Different centers presented highly consistent distribution patterns for speech arrest (Spearman's coefficient r ranged from 0.60-0.85, all pair-wise correlations p < 0.05), and similar patterns for anomia (Spearman's coefficient r ranged from 0.37-0.80). The combinational speech arrest map was divided into four clusters: Cluster 1 mainly located in ventral precentral gyrus and pars opercularis, which contained the peak of speech arrest in ventral precentral gyrus; cluster 2 in ventral and dorsal precentral gyrus; cluster 3 in supplementary motor area; cluster 4 in the posterior superior temporal gyrus and supramarginal gyrus. The anomia map revealed two clusters: One was in the posterior part of the superior and middle temporal gyri, which peaked at the posterior superior temporal gyrus; the other within the inferior frontal gyrus, peaked at the pars triangularis. This study constitutes the largest series to date of language maps generated from direct electrical stimulation mapping. The consistency of data provides evidence for common language networks across languages, in the context of both speech and naming circuit. Our results not only clinically offer an atlas for language mapping and protection, but also scientifically provide better insight into the functional organization of language networks.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33548926

RESUMO

BACKGROUND: To be efficient, intraoperative task-presentation systems must accurately present various language and cognitive tasks to patients undergoing awake surgery, and record behavioral data without compromising convenience of surgery. OBJECTIVE: To present an integrated brain mapping task-presentation system we developed and evaluate its effectiveness in intraoperative task presentation. METHODS: The Brain Mapping Interactive Stimulation System (Brain MISS) is a flexible task presentation system that adjusts for patient comfort, needs of the surgeon, and operating team, with multivideo recording for patients' behavior. A total of 48 patients from 3 centers underwent intraoperative language task test during awake brain surgery with the Brain MISS. Each patient was assigned 5 questions each on picture naming, reading, and listening comprehension before and during awake surgeries. The accuracy of intraoperative stimulus-response (without electrical stimulation) was recorded. The Brain MISS was to be considered effective, if the lower limit of 95% CI of patients' intraoperative response was ≥80% and also if the accuracy of intraoperative response of all patients was statistically higher than 80%. RESULTS: All patients successfully underwent intraoperative assessment with the Brain MISS. The overall accuracy of stimulus response was 95.8% (95% CI 90.18%-100.00%), with the lower limit being higher than 80% and the response accuracy also significantly being higher than 80% in all patients (P = .006). CONCLUSION: The Brain MISS is a portable and effective system for presenting and streamlining complicated language and cognitive tasks during awake surgery. It can also record standardized patient response data for neuroscientific research.

5.
Biomolecules ; 11(2)2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33572741

RESUMO

Plants, due to their sessile nature, have an innate immune system that helps them to defend against different pathogen infections. The defense response of plants is composed of a highly regulated and complex molecular network, involving the extensive reprogramming of gene expression during the presence of pathogenic molecular signatures. Plants attain proper defense against pathogens through the transcriptional regulation of genes encoding defense regulatory proteins and hormone signaling pathways. Small RNAs are emerging as versatile regulators of plant development and act in different tiers of plant immunity, including pathogen-triggered immunity (PTI) and effector-triggered immunity (ETI). The versatile regulatory functions of small RNAs in plant growth and development and response to biotic and abiotic stresses have been widely studied in recent years. However, available information regarding the contribution of small RNAs in plant immunity against pathogens is more limited. This review article will focus on the role of small RNAs in innate immunity in plants.

6.
Nat Commun ; 12(1): 1161, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608548

RESUMO

Languages can use a common repertoire of vocal sounds to signify distinct meanings. In tonal languages, such as Mandarin Chinese, pitch contours of syllables distinguish one word from another, whereas in non-tonal languages, such as English, pitch is used to convey intonation. The neural computations underlying language specialization in speech perception are unknown. Here, we use a cross-linguistic approach to address this. Native Mandarin- and English- speaking participants each listened to both Mandarin and English speech, while neural activity was directly recorded from the non-primary auditory cortex. Both groups show language-general coding of speaker-invariant pitch at the single electrode level. At the electrode population level, we find language-specific distribution of cortical tuning parameters in Mandarin speakers only, with enhanced sensitivity to Mandarin tone categories. Our results show that speech perception relies upon a shared cortical auditory feature processing mechanism, which may be tuned to the statistics of a given language.


Assuntos
Idioma , Redes Neurais de Computação , Nível de Percepção Sonora , Percepção da Fala , Mapeamento Encefálico , Eletrodos , Feminino , Humanos , Linguística , Masculino , Fala
7.
Brain Imaging Behav ; 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33619646

RESUMO

Diffusive and progressive tumor infiltration within language-related areas of the brain induces functional reorganization. However, the macrostructural basis of subsequent language deficits is less clear. To address this issue, lesion topography data from 137 preoperative patients with left cerebral language-network gliomas (81 low-grade gliomas and 56 high-grade gliomas), were adopted for multivariate machine-learning-based lesion-language mapping analysis. We found that tumor location in the left posterior middle temporal gyrus-a bottleneck where both dorsal and ventral language pathways travel-predicted deficits of spontaneous speech (cluster size = 1356 mm3, false discovery rate corrected P < 0.05) and naming scores (cluster size = 1491 mm3, false discovery rate corrected P < 0.05) in the high-grade glioma group. In contrast, no significant lesion-language mapping results were observed in the low-grade glioma group, suggesting a large functional reorganization. These findings suggest that in patients with gliomas, the macrostructural plasticity mechanisms that modulate brain-behavior relationships depend on glioma grade.

8.
Artigo em Inglês | MEDLINE | ID: mdl-33634585

RESUMO

Theoretical calculations unveil the charge redistribution over abundant interfaces and the enhanced electronic states of Ru/RuS2 heterostructure. The resulting surface electron-deficient Ru sites display optimized adsorption behavior toward diverse reaction intermediates, thereby reducing the thermodynamic energy barriers. Experimentally, for the first time the laminar Ru/RuS2 heterostructure is rationally engineered by virtue of the synchronous reduction and sulfurization under eutectic salt system. Impressively, it exhibits extremely high catalytic activity for both OER (201 mV @ 10 mA cm-2 ) and HER (45 mV @ 10 mA cm-2 ) in acidic media due to favorable kinetics and excellent specific activity, consequently leading to a terrific performance in acidic overall water splitting devices (1.501 V @ 10 mA cm-2 ). The in-depth insight into the internal activity origin of interfacial effect could offer precise guidance for the rational establishment of hybrid interfaces.

9.
Brain Res Bull ; 170: 174-186, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33600886

RESUMO

Chronic cerebral ischemia leads to vascular cognitive impairment (VCI) that exacerbates along with ischemia time and eventually develops into dementia. Recent advances in molecular neuroimaging contribute to understand its pathological characteristics. We previously traced the anisotropic diffusion of water molecules suggests that chronic cerebral ischemia leads to irreversible progressive damage to white matter integrity. However, the abnormalities of gray matter activity following chronic cerebral ischemia remains not entirely understood. In this study, in vivo hydrogen proton magnetic resonance spectroscopy (1H-MRS) was applied to longitudinally track the neurochemical metabolic disorder of gray matter associated with working memory, and optogenetics modulation of neurochemical metabolism was performed for targeted treatment of VCI. The results showed that the concentration of N-acetylaspartate (NAA) in the right hippocampus, left hippocampus, right medial prefrontal cortex (mPFC) and mediodorsal thalamus was decreased as early as 7 days after chronic cerebral ischemia, subsequently gamma-aminobutyric acid (GABA) declined whereas myo-inositol (mI) and glutamate (Glu) increased at 14 days, as well as choline (Cho) lost at 28 days, concurrently the change of Glu and GABA in the mPFC and hippocampus was ischemia time-dependent manner within 1 month. Behaviorally, working memory and object recognition memory were impaired at 14 days, 28 days that significantly correlated with neurochemical metabolic disorders. Interestingly, using optogenetics modulation of PV neurons in the mPFC, the metabolic abnormalities of NAA and GABA in working memory neural circuit could be repaired after chronic cerebral ischemia, together with behavior improvements. These findings suggested that as early as 1∼4 weeks after chronic cerebral ischemia, the metabolism of NAA, Glu, mI and Cho was synchronously impaired in neural circuit of hippocampus-mediodorsal thalamus-mPFC, and the loss of GABA delayed in the hippocampus, and optogenetics modulation of parvalbumin (PV) neurons in the mPFC can improve the neurochemical metabolism of working memory neural circuit and enhance working memory.

10.
Clin Neurol Neurosurg ; 203: 106562, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33631507

RESUMO

BACKGROUNDS: Optic radiation protection is crucial in the basal temporal approach to the mesial temporal lobe. Clear description of the optic radiation in the basal brain surface is lacking. Our aim is to describe the anatomy of optic radiation in the basal cerebral surface and define safety zone of basal temporal approach avoiding of optic radiation injury. METHODS: Five brain specimens (10 hemispheres) were dissected using Klingler method to observe the course of the optic radiation. Diffusion tensor imaging data of 25 volunteers were used to verify the fiber dissection results. The relationship of the optic radiation to nearby structures were illustrated and measured. RESULTS: The optic radiation bends from the lateral wall of the lateral ventricle to its bottom at a basal turning point of optic radiation (bTPOR). The bTPOR is at the plane crossing the center point of the splenium of corpus callosum. MRI measurements showed no significant difference in the distance from the center of the splenium of corpus callosum and the bTPOR to the occipital pole (59.46 ± 4.338 mm vs 59.54 ± 3.805 mm, p = 0.95). Anterior to bTPOR, no optic radiation fibers were found at the basal brain surface. CONCLUSIONS: The bTPOR was found as a landmark of the optic radiation in the cerebral basal surface. With neuronavigation, the splenium of corpus callosum can be a landmark of the bTPOR. By approaching mesial temporal lesions using the basal temporal approach anterior to bTPOR, optic radiation injury can be prevented.

11.
Artigo em Inglês | MEDLINE | ID: mdl-33499419

RESUMO

Aging is accompanied by changes in organ degeneration, and susceptibility to multiple diseases, leading to the frequent occurrence of adverse drug reactions resulting from polypharmacy (PP) and potentially inappropriate medications (PIM) in older patients. This study employs a retrospective cohort design and investigates the association of PP with PIM among older patients with high rates of medical utilization. Using records from a national pharmaceutical care database, an experimental group is formed from patients meeting these criteria, who are then offered home pharmaceutical care. Correspondingly, a control group is formed by identifying older patients with regular levels of use of medical services who had been dispensed medications at community pharmacies. Multivariate logistic regression is performed to assess the association between the rate of PIM and variables, including age, gender, and PP. The study finds that experimental PP participants had a higher rate of PIM prescription (odds ratio (OR) = 5.4) than non-PP control participants (all p < 0.001). In clinical practice, additional caution is required to avoid PIMs. Patients engaged in continuously using long-term medication should take precautions in daily life to alleviate related discomforts. Pharmacists should serve as a bridge between patients and physicians to enhance their health and improve their quality of life.

12.
Artigo em Inglês | MEDLINE | ID: mdl-33439618

RESUMO

Si is a well-known high-capacity lithium-ion battery anode material; however, it suffers from conductivity and volume expansion issues. Herein, we develop a "surface oxidation" strategy to introduce a SiOx layer on Si nanoparticles for subsequent carbon coating. It is found that the surface SiOx layer could facilitate the conformal resin coating process through strong interactions with phenolic resin, and well-defined core@double-shell-structured Si@SiOx@C can be obtained after further carbonization. Without the surface SiOx layer, only a negligible fraction of Si nanoparticles can be encapsulated into the carbon matrix. With enhanced conductivity and confined volume change, Si@SiOx@C demonstrates high reversible capacity as well as long-term durability.

13.
J Antibiot (Tokyo) ; 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33456052

RESUMO

The threat of antimicrobial resistance calls for more efforts in basic science, drug discovery, and clinical development, particularly gram-negative carbapenem-resistant pathogens. We sought to identify novel antibacterial agents against Acinetobacter baumannii ATCC19606 using whole cell-based screening. A small molecule named 6D1 with the chemical structure of 6-fluorobenzo[d]isothiazol-3(2H)-one was identified and exhibited activity against A. baumannii ATCC19606 strain (minimal inhibitory concentration, MIC = 1 mg l-1). The mutation in the plasmid-derived ohrB gene that encodes a peroxidase was identified in spontaneously resistant mutants. Treatment of the bacteria with 6D1 resulted in increased sensitivity to peroxide, such as tert-butyl hydroperoxide. The binding of 6D1 and OhrB was confirmed by surface plasmon resonance. Interestingly, the MIC of kanamycin and gentamicin against spontaneously resistant mutants decreased. Finally, we identified the effect of 6D1 on enhancing the antibacterial activity of kanamycin and gentamicin, including against New Delhi metallo-ß-lactamase (NDM-1)-producing carbapenem-resistant Klebsiella pneumoniae, but not in strains carrying aminoglycosides resistance genes. In this study, we identified a small molecule that suppresses the growth of A. baumannii, interacts with hydroperoxide reductase from A. baumannii ATCC19606 plasmid pMAC, and enhances the antibacterial activity of kanamycin and gentamicin. We propose that peroxidase may be potentially used as a target for aminoglycosides adjuvant development.

14.
BMC Surg ; 21(1): 40, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33461509

RESUMO

BACKGROUND: The Coronavirus disease 2019 (COVID-19) pandemic has extraordinarily impacted global healthcare. Neuro-oncological surgery units have peculiar features that make them highly relevant in the strategic reaction to the pandemic. In this Chinese Society of Neuro-Oncology (CSNO) initiated survey, we appraise the changes implemented in neuro-oncological surgery hospitals across different Asian countries and provide expert recommendations for responses at different stages of the pandemic. METHODS: We performed a 42-question survey of the early experience of neuro-oncological surgery practice in hospitals across different Asian countries on April 1, 2020, with responses closed on April 18, 2020. RESULTS: 144 hospitals completed the questionnaire. Most were in WHO post-peak phase of the pandemic and reported a median reduction in neuro-oncological surgery volume of 25-50%. Most (67.4%) resumed elective surgery in only COVID-19 negative patients;11.1% performed only emergency cases irrespective of COVID-19 status;2.1% suspended all surgical activity. Ninety-one (63.2%) relocated personnel from neurosurgery to other departments. Fifty-two (36.1%) hospitals suspended post-operative adjuvant therapy and 94 (65.2%) instituted different measures to administer post-operative adjuvant therapy. Majority (59.0%) of the hospitals suspended research activity. Most (70%) respondents anticipate that current neurosurgery restrictions will continue to remain for > 1 month. CONCLUSIONS: Majority of the respondents to our survey reported reduced neuro-oncological surgery activity, policy modification, personnel reallocation, and curtailment of educational/research activities in response to the COVID-19 pandemic. The persistent widespread interruption of surgical neuro-oncology in even post-peak phases of the pandemic raises serious concerns about the long-term impact of the pandemic on neuro-oncological patients and highlights the essence of timely measures for pandemic preparedness, patient triage, and workforce protection.


Assuntos
Neurocirurgia , Procedimentos Neurocirúrgicos , Pandemias , Procedimentos Cirúrgicos Eletivos , Humanos
15.
Adv Mater ; 33(11): e2004711, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33511690

RESUMO

To achieve high ionic conductivity for solid electrolyte, an artificial Li-rich interface layer of about 60 nm thick has been constructed in polymer-based poly(ethylene oxide)-lithium bis(trifluoromethanesulfonyl)imide composite solid electrolyte (briefly noted as PEOm ) by adding Li-based alloys. As revealed by high-resolution transmission electron microscopy and electron energy loss spectroscopy, an artificial interface layer of amorphous feature is created around the Li-based alloy particles with the gradient distribution of Li across it. Electrochemical analysis and theoretical modeling demonstrate that the interface layer provides fast ion transport path and plays a key role in achieving high and stable ionic conductivity for PEOm -Li21 Si5 composite solid electrolyte. The PEOm -5%Li21 Si5 composite electrolyte exhibits an ionic conductivity of 3.9 × 10-5  S cm-1 at 30 °C and 5.6 × 10-4  S cm-1 at 45 °C. The LiFePO4 | PEOm -5%Li21 Si5 | Li all-solid-state batteries could maintain a stable capacity of 129.2 mA h g-1 at 0.2 C and 30 °C after 100 cycles, and 111.3 mA h g-1 after 200 cycles at 0.5 C and 45 °C, demonstrating excellent cycling stability and high-rate capability.

16.
World Neurosurg ; 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33242666

RESUMO

Classically mesiotemporal lesions are approached from the lateral temporal approach, which frequently injures the visual and language tracts. We present the posterior approach through which the language tracts and visual tracts at the roof and lateral wall of the temporal horn (Meyer's Loop), can be avoided minimizing the risk of neurologic injury. The patient, a 32-year-old male, presented with the chief complaint of experiencing seizures for six years with rare generalized tonic clonic seizures. Physical examination showed no neurological deficits and past-medical history was not remarkable. Magnetic resonance imaging (MRI) revealed a left mesiotemporal lesion which showed no contrast enhancement and infiltrated the atrium. For surgery, the patient was laid in prone position and a tailored bone flap was lifted. Next the occipital lobe was retracted gently to expose the lesion. Penfield dissectors were used to gradually resect the lesion. The roof and inner wall of the atrium were exposed during resection. These structures were protected. Residues of the lesion and its capsule were seen attached to the lateral ventricle and were carefully coagulated and removed. The hippocampus was also exposed and a small segment resected. Exposure of the roof and inner wall of the atrium confirmed that the entire lesion has been resected. Intra-operative MRI evaluation confirmed a total resection of the lesion. Pathological analysis confirmed the diagnosis of epidermoid cyst. Cognitive evaluation results showed no post-op deficiencies and his visual field was also not affected by the surgery. Informed patient content was obtained.

17.
Infect Drug Resist ; 13: 4125-4132, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33209042

RESUMO

Objective: We aimed to establish a tool for rapid identification of KL49 Acinetobacter baumannii. Methods: Based on the capsular polysaccharide (CPS) synthesis genes database, we investigated the distribution of K locus type 49 (KL49) genes in other KL types and established a rapid identification method for KL49. We collected 61 clinical carbapenem-resistant A. baumannii (CRAB) strains, identified KL49 by gtr100 detection, and used whole genome sequencing (WGS) for verification. A mouse pneumonia model was used to confirm the hypervirulence phenotype. We tested the presence of gtr100 gene in 165 CRAB strains from three provinces in China and evaluated the correlation of gtr100 carrying CRAB infection with mortality. Results: The gtr100 gene is the CPS synthesis gene found only in KL49. We screened out nine WGS-validated KL49 strains from 61 CRAB clinical strains using polymerase chain reaction (PCR) to detect the gtr100 gene. The survival rates of KL49 strains were significantly lower than nonKL49 strains in a mouse pneumonia model. The survival rates of LAC-4 gtr100 knockout strain decreased significantly. Analysis of phylogenetics showed the worldwide spread of KL49 A. baumannii. Infection of gtr100 carrying CRAB is an independent risk for mortality (OR, 10.76; 95%CI: 3.08-37.55; p<0.001). Conclusion: The hypervirulence phenotype of KL49 CRAB and the association with mortality highlight the urgent need for implementing control measures. The rapid identification assay has the potential to facilitate early medical intervention and worldwide surveillance.

18.
Plant Sci ; 300: 110627, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33180707

RESUMO

The trade-off between plant growth and resistance to herbivory is thought to be at least partly mediated by the interactions between jasmonates and gibberellins (GAs). Insect herbivory activates jasmonate biosynthesis and signaling, and plant growth is concomitantly inhibited. Whether or not the herbivory-induced jasmonates suppress the accumulation of GAs and thus reduce plant growth, and which jasmonates are functional in this process, remain unclear. In this study, we show that herbivory-induced stunted growth of Nicotiana attenuata was completely dependent on allene oxide cyclase (AOC) and coronatine insensitive1 (COI1), which encode a JA biosynthetic enzyme and the receptor, respectively, but only partially dependent on jasmonic acid-isoleucine conjugate (JA-Ile), the bioactive jasmonate. Quantification of GAs and exogenous treatments indicated that herbivory-induced growth inhibition was caused by GA4 deficiency, and that the reduction in GA4 accumulation was strongly associated with both decreased concentrations of GA biosynthetic gene transcripts and transcriptional activation of GA catabolic genes. We further show that JA-Ile only positively regulated the levels of GA catabolic genes, while the accumulation of GA biosynthetic gene transcripts was controlled by certain AOC-derived jasmonate(s) rather than by JA-Ile. This work sheds light on the mechanisms by which plants adapt to herbivory by using intricate phytohormone signaling and transcriptional regulatory networks.

19.
Front Hum Neurosci ; 14: 569463, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33132884

RESUMO

Background: FMRI signal amplitude can change during stimulus presentation due to underlying neural function and hemodynamic responses limiting the accuracy of fMRI in pre-surgical planning. To account for these changes in fMRI activation signal, we used breath-hold tasks to mimic hemodynamic changes in brain tumor subjects and scaled the activation response. Methods: Motor and/or language fMRI was performed in 21 subjects with brain tumor. A breath-hold task was also performed in these subjects to obtain the hemodynamic response changes independent of neural changes. The task activation signals were calibrated on a voxel wise basis for all the subjects. Direct cortical stimulation was used to verify the scaled results of task-based fMRI. Results: After scaling for the hemodynamic response function (HRF) on a voxel wise basis, the spatial extent of the scaled activation was more clustered together and appeared to minimize false positives. Similarly, accounting for the underlying canonical HRF, the percentage increase of active voxels after scaling had lower standard non-deviation suggesting that the activation response across voxels were more similar. Conclusion: Although preliminary in nature, this study suggests that the variation in hemodynamic changes can be calibrated using breath-hold in brain tumor subjects and can also be used for other clinical cases where the underlying HRF has been altered.

20.
Plant Cell Rep ; 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33048182

RESUMO

KEY MESSAGE: Here, we reported that a pathogen- and herbivore-induced Kunitz trypsin inhibitor gene, NaKTI2, is required for herbivore resistance, and transcriptionally regulated mainly by NaWRKY3 and NaWRKY6 but not Jasmonate signaling. Plant protease inhibitor (PI) occurs widely in plant species, and is considered as an important part of plant defense arsenal against herbivores. Transcriptome analysis of Nicotiana attenuata leaves revealed that a Kunitz trypsin inhibitor gene, NaKTI2, was highly elicited after inoculation of Alternaria alternata (tobacco pathotype). However, the roles of NaKTI2 in pathogen- and herbivore resistance and its regulation were unclear. NaKTI2 had typical domains of Kunitz trypsin inhibitors and exhibited a high level of trypsin protease inhibitor activities when transiently over-expressed. The transcripts of NaKTI2 could be induced by A. alternata and Spodoptera litura oral secretions (OS). Silencing NaKTI2 via virus-induced gene silencing technique has no influence on lesion diameters developed on N. attenuata leaves after A. alternata inoculation, but S. litura larvae gained more mass and had higher survivorship on NaKTI2-silenced plants. Meanwhile, the expression of NaPI, a PI gene essential for herbivore resistance previously identified in N. attenuata, was not affected in NaKTI2-silenced plants. Unlike NaPI, which was predominantly regulated by jasmonate (JA) signaling, OS-elicited NaKTI2 transcripts were only slightly reduced in JA-deficient plants, but were dramatically decreased in NaWRKY3- and NaWRKY6- silenced plants, respectively. Further electromobility shift assays indicated that NaWRKY3 and NaWRKY6 could directly bind to the promoter regions of NaKTI2 in vitro. Taken together, our results demonstrate that in addition to NaPI, NaKTI2, a pathogen- and herbivore-induced Kunitz trypsin inhibitor gene, is also required for herbivore resistance, and mainly regulated by NaWRKY3 and NaWRKY6.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...