RESUMO
The four carbon non-proteinogenic amino acid γ-aminobutyric acid (GABA) accumulates to high levels in plants in response to various abiotic and biotic stress stimuli, and plays a role in C:N balance, signaling and as a transport regulator. Expression in Xenopus oocytes and voltage-clamping allowed characterizing Arabidopsis GAT2 (At5g41800) as low affinity GABA transporter with a K0.5GABA~8 mM. L-alanine and butylamine represented additional substrates. GABA-induced currents were strongly dependent on the membrane potential, reaching highest affinity and highest transport rates at strongly negative membrane potentials. Mutation of Ser17, previously reported to be phosphorylated in planta, did not result in altered affinity. In short term stress experiment, AtGAT2 mRNA levels were upregulated at low water potential and under osmotic stress (polyethylene glycol, mannitol). Furthermore, AtGAT2 promoter activity was detected in vascular tissues, in maturating pollen, and the phloem unloading region of young seeds. Even though this suggested a role of AtGAT2 in long distance transport and loading of sink organs, under the conditions tested neither AtGAT2 overexpressing plants nor atgat2 or atgat1 T-DNA insertion lines, or atgat1 atgat2 double knockout mutants differed from wild type plants in growth on GABA, in amino acid levels or resistance to salt and osmotic stress.
RESUMO
PURPOSE: Triggers have been developed internationally to identify intensive care patients with palliative care needs. Due to their work, nurses are close to the patient and their perspective should therefore be included. In this study, potential triggers were first identified and then a questionnaire was developed to analyse their acceptance among German intensive care nurses. METHODS: For the qualitative part of this mixed methods study, focus groups were conducted with intensive care nurses from different disciplines (surgery, neurosurgery, internal medicine), which were selected by convenience. Data were analysed using the "content-structuring content analysis" according to Kuckartz. For the quantitative study part, the thus identified triggers formed the basis for questionnaire items. The questionnaire was tested for comprehensibility in cognitive pretests and for feasibility in a pilot survey. RESULTS: In the qualitative part six focus groups were conducted at four university hospitals. From the data four main categories (prognosis, interprofessional cooperation, relatives, patients) with three to 15 subcategories each could be identified. The nurses described situations requiring palliative care consults that related to the severity of the disease, the therapeutic course, communication within the team and between team and patient/relatives, and typical characteristics of patients and relatives. In addition, a professional conflict between nurses and physicians emerged. The questionnaire, which was developed after six cognitive interviews, consists of 32 items plus one open question. The pilot had a response rate of 76.7% (23/30), whereby 30 triggers were accepted with an agreement of ≥ 50%. CONCLUSION: Intensive care nurses see various triggers, with interprofessional collaboration and the patient's prognosis playing a major role. The questionnaire can be used for further surveys, e.g. interprofessional triggers could be developed.
Assuntos
Grupos Focais , Cuidados Paliativos , Humanos , Cuidados Paliativos/métodos , Cuidados Paliativos/psicologia , Grupos Focais/métodos , Inquéritos e Questionários , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Unidades de Terapia Intensiva/organização & administração , Unidades de Terapia Intensiva/estatística & dados numéricos , Atitude do Pessoal de Saúde , Pesquisa Qualitativa , Alemanha , Enfermeiras e Enfermeiros/psicologia , Enfermeiras e Enfermeiros/estatística & dados numéricos , Cuidados Críticos/métodos , Cuidados Críticos/psicologia , Enfermagem de Cuidados Críticos/métodos , Enfermagem de Cuidados Críticos/normas , Enfermagem de Cuidados Críticos/estatística & dados numéricosRESUMO
BACKGROUND: On 26 February 2020, the German Federal Constitutional Court revoked a law (§ 217 StGB) that had banned assisted suicide intended to be repeated on a regularly basis. Since then, a possible new legal regulation has been discussed. This study examined the knowledge, experiences, and attitudes of younger physicians towards physician-assisted suicide (PAS). METHODS: A quantitative survey of postgraduate courses in emergency medicine, critical care medicine, and hematology was conducted from November 2022 to March 2023. Possible factors influencing attitudes towards PAS were analyzed. RESULTS: A total of 1163 records (response rate 82.1%) were analyzed. Of the participants, 90.8% had experience with dying patients, 62.3% supported PAS only in palliative scenarios, 20.1% supported PAS regardless of the health status, 33.1% have been asked for PAS, and 3.3% had participated in PAS. In addition, 71.0% did not know the content of the Federal Constitutional Court's decision on § 217, 72.0% were not informed about the legislative proposals for the new regulation of PAS, and 66.4% saw doctors as the right person to decide whether a suicidal wish is permissible. CONCLUSION: Younger doctors differentiate in their attitude towards PAS between people without illnesses and those in palliative treatment situations. Further investigations into the causes of the frequent ignorance of the normative foundations are necessary. The results suggest that more educational work needs to be done about suicide alternatives and palliative care options.
Assuntos
Eutanásia , Médicos , Suicídio Assistido , Humanos , Atitude do Pessoal de Saúde , AlemanhaRESUMO
The process recommendations of the Ethics Section of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI) for ethically based decision-making in intensive care medicine are intended to create the framework for a structured procedure for seriously ill patients in intensive care. The processes require appropriate structures, e.g., for effective communication within the treatment team, with patients and relatives, legal representatives, as well as the availability of palliative medical expertise, ethical advisory committees and integrated psychosocial and spiritual care services. If the necessary competences and structures are not available in a facility, they can be consulted externally or by telemedicine if necessary. The present recommendations are based on an expert consensus and are not the result of a systematic review or a meta-analysis.
Assuntos
Cuidados Críticos , Tomada de Decisões , Medicina de Emergência , Humanos , Cuidados Críticos/normas , Medicina de Emergência/normas , Telemedicina , AlemanhaRESUMO
While protein aggregation is a hallmark of many neurodegenerative diseases, acquiring structural information on protein aggregates inside live cells remains challenging. Traditional microscopy does not provide structural information on protein systems. Routinely used fluorescent protein tags, such as Green Fluorescent Protein (GFP), might perturb native structures. Here, we report a counter-propagating mid-infrared photothermal imaging approach enabling mapping of secondary structure of protein aggregates in live cells modeling Huntington's disease. By comparing mid-infrared photothermal spectra of label-free and GFP-tagged huntingtin inclusions, we demonstrate that GFP fusions indeed perturb the secondary structure of aggregates. By implementing spectra with small spatial step for dissecting spectral features within sub-micrometer distances, we reveal that huntingtin inclusions partition into a ß-sheet-rich core and a É-helix-rich shell. We further demonstrate that this structural partition exists only in cells with the [RNQ+] prion state, while [rnq-] cells only carry smaller ß-rich non-toxic aggregates. Collectively, our methodology has the potential to unveil detailed structural information on protein assemblies in live cells, enabling high-throughput structural screenings of macromolecular assemblies.
RESUMO
Cardiac electrophysiology is regulated by continuous trafficking and internalization of ion channels occurring over minutes to hours. Kv 11.1 (also known as hERG) underlies the rapidly activating delayed-rectifier K+ current (IKr ), which plays a major role in cardiac ventricular repolarization. Experimental characterization of the distinct temporal effects of genetic and acquired modulators on channel trafficking and gating is challenging. Computer models are instrumental in elucidating these effects, but no currently available model incorporates ion-channel trafficking. Here, we present a novel computational model that reproduces the experimentally observed production, forward trafficking, internalization, recycling and degradation of Kv 11.1 channels, as well as their modulation by temperature, pentamidine, dofetilide and extracellular K+ . The acute effects of these modulators on channel gating were also incorporated and integrated with the trafficking model in the O'Hara-Rudy human ventricular cardiomyocyte model. Supraphysiological dofetilide concentrations substantially increased Kv 11.1 membrane levels while also producing a significant channel block. However, clinically relevant concentrations did not affect trafficking. Similarly, severe hypokalaemia reduced Kv 11.1 membrane levels based on long-term culture data, but had limited effect based on short-term data. By contrast, clinically relevant elevations in temperature acutely increased IKr due to faster kinetics, while after 24 h, IKr was decreased due to reduced Kv 11.1 membrane levels. The opposite was true for lower temperatures. Taken together, our model reveals a complex temporal regulation of cardiac electrophysiology by temperature, hypokalaemia, and dofetilide through competing effects on channel gating and trafficking, and provides a framework for future studies assessing the role of impaired trafficking in cardiac arrhythmias. KEY POINTS: Kv 11.1 channels underlying the rapidly activating delayed-rectifier K+ current are important for ventricular repolarization and are continuously shuttled from the cytoplasm to the plasma membrane and back over minutes to hours. Kv 11.1 gating and trafficking are modulated by temperature, drugs and extracellular K+ concentration but experimental characterization of their combined effects is challenging. Computer models may facilitate these analyses, but no currently available model incorporates ion-channel trafficking. We introduce a new two-state ion-channel trafficking model able to reproduce a wide range of experimental data, along with the effects of modulators of Kv 11.1 channel functioning and trafficking. The model reveals complex dynamic regulation of ventricular repolarization by temperature, extracellular K+ concentration and dofetilide through opposing acute (millisecond) effects on Kv 11.1 gating and long-term (hours) modulation of Kv 11.1 trafficking. This in silico trafficking framework provides a tool to investigate the roles of acute and long-term processes on arrhythmia promotion and maintenance.
Assuntos
Antiarrítmicos , Hipopotassemia , Humanos , Antiarrítmicos/farmacologia , Hipopotassemia/metabolismo , Técnicas Eletrofisiológicas Cardíacas , Canais Iônicos/metabolismo , Arritmias Cardíacas/metabolismo , Miócitos Cardíacos/metabolismo , Canais de Potássio Éter-A-Go-Go/metabolismoRESUMO
IR spectroscopic studies of the gaseous metal carbonyl cations [Co(CO)5 ]+ â mCO (m=1-4) indicated that the weakly bound CO molecules in a second coordination sphere perturb the structure of [Co(CO)5 ]+ causing the CO stretching frequencies ν(CO) to become noticeably redshifted. In this work, we aimed to establish the relationship between such gas phase IR spectra and those recorded in condensed phases, either as a solid salt or as a solution in the weakly basic solvent o-difluorobenzene. For this purpose, a series of [Co(CO)5 ]+ [WCA]- salts (WCA=weakly coordinating anion), with the counterions varying between more coordinating (WCA=F-Al(ORF )3 , (RF O)3 Al-F-Al(F)(ORF )2 ; RF =C(CF3 )3 ) and almost non-coordinating (WCA=Al(ORF )4 , F{Al(ORF )3 }2 ), were synthesized and characterized by vibrational spectroscopy as well as X-ray structure analysis. The experimental spectra differ considerably from that of the undisturbed gaseous [Co(CO)5 ]+ ion, as the structural deformation of [Co(CO)5 ]+ requires very little energy. Together with previously reported data, the perturbed condensed phase [Co(CO)5 ]+ ions were analyzed and compared with the gaseous [Co(CO)5 ]+ â mCO ions. DFT calculations were performed on simply adapted [Co(CO)5 ]+ structures to allow the assignment of all the ν(CO) modes and a qualitative interpretation of structural deformations by external influences as a function of the environment (ligands, solvation, crystal packing). The analysis showed that especially the degenerate E' mode νe and the averaged asymmetric equatorial CO stretch ν â¾ e , which originates from a split of the E' mode, are a function of the interaction with the environment. Whereas for the more coordinating counterions ν â¾ e values of 2112-2120â cm-1 were obtained, for the less coordinating counterions ν â¾ e values of up to 2133â cm-1 were found, which is very close to that of gaseous [Co(CO)5 ]+ â 4CO, with a ν â¾ e value of 2135â cm-1 . This indicates the possibility of approximating the gas phase conditions in the condensed phases with the [Co(CO)5 ]+ ion probably being the prototypical probe molecule for investigating the strengths of interactions in different environments.
RESUMO
The synthesis and structural characterization of the hitherto unknown parent Co(bz)2+ (bz=benzene) complex and several of its derivatives are described. Their synthesis starts either from a CoCO5+ salt, or directly from Co2 (CO)8 and a Ag+ salt. Stability and solubility of these complexes was achieved by using the weakly coordinating anions (WCAs) [Al(ORF )4 ]- and [F{Al(ORF )3 }2 ]- {RF =C(CF3 )3 } and the solvent ortho-difluorobenzene (o-DFB). The magnetic properties of Co(bz)2+ were measured and compared in the condensed and gas phases. The weakly bound Co(o-dfb)2+ salts are of particular interest for the preparation of further CoI salts, for example, the structurally characterized low-coordinate 12 valence electron Co(Pt Bu3 )2+ and Co(NHC)2+ salts.
RESUMO
The facile synthesis of a pentacarbonyl cobalt(I) salt without the need for a superacid as solvent is presented. This salt, [Co(CO)5 ]+ [Al(ORF )4 ]- {RF =C(CF3 )3 }, readily accessible on a multigram scale, undergoes substitution reactions with arenes yielding the hitherto unknown class of two-legged cobalt piano-stool complexes [(arene)Co(CO)2 ]+ with four different arene ligands. Such a substitution chemistry would have been impossible in superacid solution, as the arenes used would have been oxidized and/or protonated. Thus, the general approach described herein may have a wide synthetic use. Additionally, the thermochemistry of the piano-stool complexes is shown to be not easy to describe computationally and most of the established DFT methods overestimate the reaction energies. Only CCSD(T) calculations close to the basis set limit gave energies fully agreeing with the experiment.
RESUMO
Amino acid transporters are crucial for parasite survival since the cellular metabolism of parasitic protozoa depends on the up-take of exogenous amino acids. Amino acid transporters are also of high pharmacological relevance because they may mediate uptake of toxic amino acid analogues. In the present study we show that the eflornithine transporter AAT6 from Trypanosoma brucei (TbAAT6) mediates growth on neutral amino acids when expressed in Saccharomyces cerevisiae mutants. The transport was electrogenic and further analysed in Xenopus laevis oocytes. Neutral amino acids, proline analogues, eflornithine and acivicin induced inward currents. For proline, glycine and tryptophan the apparent affinities and maximal transport rates increased with more negative membrane potentials. Proline-induced currents were dependent on pH, but not on sodium. Although proline represents the primary energy source of T. brucei in the tsetse fly, down-regulation of TbAAT6-expression by RNAi showed that in culture TbAAT6 is not essential for growth of procyclic form trypanosomes in the presence of glucose or proline as energy source. TbAAT6-RNAi lines of both bloodstream and procyclic form trypanosomes showed reduced susceptibility to eflornithine, whereas the sensitivity to acivicin remained unchanged, indicating that acivicin enters the cell by more than one transporter.
Assuntos
Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Eflornitina/farmacocinética , Proteínas de Protozoários/metabolismo , Tripanossomicidas/farmacocinética , Trypanosoma brucei brucei/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/genética , Aminoácidos/genética , Aminoácidos/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/genética , Eflornitina/farmacologia , Inibidores Enzimáticos/farmacologia , Concentração de Íons de Hidrogênio , Isoxazóis/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Proteínas de Protozoários/genética , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/genética , XenopusRESUMO
Di- and tripeptide transporters of the PTR/NRT1 (peptide transporter/nitrate transporter1)-family are localized either at the tonoplast (TP) or plasma membrane (PM). As limited information is available on structural determinants required for targeting of plant membrane proteins, we performed gene shuffling and domain swapping experiments of Arabidopsis PTRs. A 7 amino acid fragment of the hydrophilic N-terminal region of PTR2, PTR4 and PTR6 was required for TP localization and sufficient to redirect not only PM-localized PTR1 or PTR5, but also sucrose transporter SUC2 to the TP. Alanine scanning mutagenesis identified L(11) and I(12) of PTR2 to be essential for TP targeting, while only one acidic amino acid at position 5, 6 or 7 was required, revealing a dileucine (LL or LI) motif with at least one upstream acidic residue. Similar dileucine motifs could be identified in other plant TP transporters, indicating a broader role of this targeting motif in plants. Targeting to the PM required the loop between transmembrane domain 6 and 7 of PTR1 or PTR5. Deletion of either PM or TP targeting signals resulted in retention in internal membranes, indicating that PTR trafficking to these destination membranes requires distinct signals and is in both cases not by default.
Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Membrana Celular/metabolismo , Proteínas de Membrana Transportadoras/química , Proteínas de Membrana Transportadoras/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Membrana Transportadoras/genética , Microscopia de Fluorescência , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Sinais Direcionadores de Proteínas , Transporte Proteico/genética , Protoplastos/citologia , Protoplastos/metabolismo , Proteínas Recombinantes de Fusão , Saccharomyces cerevisiae/genética , Nicotiana/metabolismo , Vacúolos/metabolismoRESUMO
BACKGROUND: Despite its extensive use as a nitrogen fertilizer, the role of urea as a directly accessible nitrogen source for crop plants is still poorly understood. So far, the physiological and molecular aspects of urea acquisition have been investigated only in few plant species highlighting the importance of a high-affinity transport system. With respect to maize, a worldwide-cultivated crop requiring high amounts of nitrogen fertilizer, the mechanisms involved in the transport of urea have not yet been identified. The aim of the present work was to characterize the high-affinity urea transport system in maize roots and to identify the high affinity urea transporter. RESULTS: Kinetic characterization of urea uptake (<300 µM) demonstrated the presence in maize roots of a high-affinity and saturable transport system; this system is inducible by urea itself showing higher Vmax and Km upon induction. At molecular level, the ORF sequence coding for the urea transporter, ZmDUR3, was isolated and functionally characterized using different heterologous systems: a dur3 yeast mutant strain, tobacco protoplasts and a dur3 Arabidopsis mutant. The expression of the isolated sequence, ZmDUR3-ORF, in dur3 yeast mutant demonstrated the ability of the encoded protein to mediate urea uptake into cells. The subcellular targeting of DUR3/GFP fusion proteins in tobacco protoplasts gave results comparable to the localization of the orthologous transporters of Arabidopsis and rice, suggesting a partial localization at the plasma membrane. Moreover, the overexpression of ZmDUR3 in the atdur3-3 Arabidopsis mutant showed to complement the phenotype, since different ZmDUR3-overexpressing lines showed either comparable or enhanced 15[N]-urea influx than wild-type plants. These data provide a clear evidence in planta for a role of ZmDUR3 in urea acquisition from an extra-radical solution. CONCLUSIONS: This work highlights the capability of maize plants to take up urea via an inducible and high-affinity transport system. ZmDUR3 is a high-affinity urea transporter mediating the uptake of this molecule into roots. Data may provide a key to better understand the mechanisms involved in urea acquisition and contribute to deepen the knowledge on the overall nitrogen-use efficiency in crop plants.
Assuntos
Proteínas de Membrana Transportadoras/metabolismo , Raízes de Plantas/metabolismo , Zea mays/metabolismo , Arabidopsis , Proteínas de Fluorescência Verde , Proteínas de Membrana Transportadoras/isolamento & purificação , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Protoplastos , Análise de Sequência de RNA , Nicotiana , Transportadores de UreiaRESUMO
IMPORTANCE: Cardiopulmonary resuscitation (CPR) is an exceptional physical situation and may lead to significant psychological, spiritual, and social distress in patients and their next of kin. Furthermore, clinicians might experience distress related to a CPR event. Specialist palliative care (sPC) integration could address these aspects but is not part of routine care. OBJECTIVES: This study aimed to explore perspectives on sPC integration during and after CPR. A needs assessment for sPC, possible triggers indicating need, and implementation strategies were addressed. DESIGN SETTING AND PARTICIPANTS: A multiprofessional qualitative semistructured focus group study was conducted in a German urban academic teaching hospital. Participants were clinicians (nursing staff, residents, and consultants) working in the emergency department and ICUs (internal medicine and surgical). ANALYSIS: The focus groups were recorded and subsequently transcribed. Data material was analyzed using the content-structuring content analysis according to Kuckartz. RESULTS: Seven focus groups with 18 participants in total were conducted online from July to November 2022. Six main categories (two to five subcategories) were identified: understanding (of palliative care and death), general CPR conditions (e.g., team, debriefing, and strains), prognosis (e.g., preexisting situation, use of extracorporeal support), next of kin (e.g., communication, presence during CPR), treatment plan (patient will and decision-making), and implementation of sPC (e.g., timing, trigger factors). CONCLUSIONS: Perceptions about the need for sPC to support during and after CPR depend on roles, areas of practice, and individual understanding of sPC. Although some participants perceive CPR itself as a trigger for sPC, others define, for example, pre-CPR-existing multimorbidity or complex family dynamics as possible triggers. Suggestions for implementation are multifaceted, especially communication by sPC is emphasized. Specific challenges of extracorporeal CPR need to be explored further. Overall, the focus groups show that the topic is considered relevant, and studies on outcomes are warranted.
RESUMO
AIMS: Short-QT-syndrome type 1 (SQT1) is a genetic channelopathy caused by gain-of-function variants in HERG underlying the rapid delayed-rectifier K+ current (IKr), leading to QT-shortening, ventricular arrhythmias, and sudden cardiac death. Data on efficient pharmaco-therapy for SQT1 are scarce. In patients with primary carnitine-deficiency, acquired-SQTS has been observed and rescued by carnitine-supplementation. Here, we assessed whether carnitine exerts direct beneficial (prolonging) effects on cardiac repolarization in genetic SQTS. METHODS AND RESULTS: Adult wild-type (WT) and transgenic SQT1 rabbits (HERG-N588K, gain of IKr) were used. In vivo ECGs, ex vivo monophasic action potentials (APs) in Langendorff-perfused hearts, and cellular ventricular APs and ion currents were assessed at baseline and during L-Carnitine/C16-Carnitine-perfusion. 2D computer simulations were performed to assess reentry-based VT-inducibility.L-Carnitine/C16-Carnitine prolonged QT intervals in WT and SQT1, leading to QT-normalization in SQT1. Similarly, monophasic and cellular AP duration (APD) was prolonged by L-Carnitine/C16-Carnitine in WT and SQT1. As underlying mechanisms, we identified acute effects on the main repolarizing ion currents: IKr-steady, which is pathologically increased in SQT1, was reduced by L-Carnitine/C16-Carnitine and deactivation kinetics were accelerated. Moreover, L-Carnitine/C16-Carnitine decreased IKs-steady and IK1. In silico modelling identified IKr-changes as main factor for L-Carnitine/C16-Carnitine-induced APD-prolongation. 2D-simulations revealed increased sustained reentry-based arrhythmia formation in SQT1 compared to WT, which was decreased to the WT-level when adding carnitine-induced ion current changes. CONCLUSION: L-Carnitine/C16-Carnitine prolong/normalize QT and whole heart/cellular APD in SQT1 rabbits. These beneficial effects are mediated by acute effects on IKr. L-Carnitine may serve as potential future QT-normalizing, anti-arrhythmic therapy in SQT1.
RESUMO
The rise in intensive care treatment procedures is accompanied by an increase in the complexity of decisions regarding the selection, administration and duration of treatment measures. Whether a treatment goal is desirable in an individual case and the treatment plan required to achieve it is acceptable for the patient depends on the patient's preferences, values and life plans. There is often uncertainty as to whether a patient-centered treatment goal can be achieved. The use of a time-limited treatment trial (TLT) as a binding agreement between the intensive care unit (ICU) team and the patient or their legal representative on a treatment concept over a defined period of time in the ICU can be helpful to reduce uncertainties and to ensure the continuation of intensive care measures in the patients' best interest.
Assuntos
Unidades de Terapia Intensiva , Humanos , Alemanha , Unidades de Terapia Intensiva/ética , Cuidados Críticos/ética , Comunicação Interdisciplinar , Preferência do Paciente , Futilidade Médica/ética , Futilidade Médica/legislação & jurisprudência , Colaboração IntersetorialRESUMO
The plant PTR/NRT1 (peptide transporter/nitrate transporter 1) gene family comprises di/tripeptide and low-affinity nitrate transporters; some members also recognize other substrates such as carboxylates, phytohormones (auxin and abscisic acid), or defence compounds (glucosinolates). Little is known about the members of this gene family in rice (Oryza sativa L.). Here, we report the influence of altered OsPTR9 expression on nitrogen utilization efficiency, growth, and grain yield. OsPTR9 expression is regulated by exogenous nitrogen and by the day-night cycle. Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake, promotion of lateral root formation and increased grain yield. On the other hand, down-regulation of OsPTR9 in a T-DNA insertion line (osptr9) and in OsPTR9-RNAi rice plants had the opposite effect. These results suggest that OsPTR9 might hold potential for improving nitrogen utilization efficiency and grain yield in rice breeding.
Assuntos
Nitrogênio/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Oryza/genética , Proteínas de Plantas/genéticaRESUMO
Current publications on the topic of communication in intensive care units (ITS) are shaped by the experiences of the COVID19 pandemic and the restrictions on personal contact and communication experienced during this time. Virtual, computer-based and telemedical concepts have grown out of this situation with limited contact and communication possibilities with patients and their relatives, but also between the individual service providers in the health system. It can also be assumed that artificial intelligence will increasingly be an issue in communication in intensive care units in the coming years. However, the significance, consequences and risks of the use of these new possibilities remain to be seen.
Assuntos
Família , Telemedicina , Humanos , Inteligência Artificial , Unidades de Terapia Intensiva , ComunicaçãoRESUMO
Purpose: For children with blindness and visual impairment (BVI) of all ages, disability sport and/or regular Physical Activity (PA) are deemed beneficial, promoting physical and mental health as well as increasing wellbeing and life satisfaction. In this regard, Physical Education (PE) serves as a foundation to regular and lifelong participation in PA, mainstream and/or disability sport. Research points towards manifold participation barriers for children with BVI in PE, which so far have mainly been investigated in inclusive settings and from the perspectives of sighted parents, teachers and peers. Consequently, people with BVI frequently consider PE a missed opportunity for lifelong PA. As transitioning from general to special schooling deems the only alternative to continue their education, questions arise in how far and in which ways specialized schools manage to accommodate their needs in PE. To address these gaps in literature, we investigated BVI students' perceived opportunities and barriers to participation in PE within a specialized school setting and their imaginations for possible (digital) improvements and solutions. Materials and methods: Within the framework of Inclusive and Youth Participatory Action Research, we adopted the Mosaic Approach to investigate a sample of 19 students aged 14-20 at lower and upper secondary level in a specialized school in Austria. Data material included audio-recordings of interviews, student-guided school tours, photographs of significant places and objects and field protocols. The analysis was conducted with Interpretative Phenomenological Analysis. Results and conclusion: Through the analysis, we identified three themes. The data material firstly revealed the complex intricacies of how PE teachers can act as facilitators and gatekeepers to autonomous PA. Secondly, material norms function not only as barriers to participation even in a specialized school setting, but also constitute the basis for social hierarchies between students with various degrees of visual impairment. Thirdly, students imagined manifold digital solutions to enhance participation derived from their perceived barriers. The findings contribute to amplifying BVI individuals' voices and provide revealing insights in how participation in PA is enabled and prohibited for students with BVI which can not only help to improve specialized but also inclusive settings.
RESUMO
Quintessential parameters for needle tip-based electron sources are the work function, the tip apex radius, and the field reduction factor. They determine the static emission properties and strongly influence laser-triggered photoemission experiments at these needle tips. We present a simple method based on photoemission with two different commonly available continuous-wave laser diodes to determine both parameters in situ. We demonstrate our technique at tungsten needle tips. In a first application, use the method to in situ monitor changes of the emitter caused by illumination with strong femtosecond laser pulses. After illumination, we observe an increase in the work function caused by laser-induced changes to the apex of the tip. These changes are reversible upon field evaporation and are accompanied by a change in the spatial electron emission distribution. We believe that this simple in situ work function determination technique is applicable to any metal and in many experimental settings.