Knockdown of OsNRT2.4 modulates root morphology and alters nitrogen metabolism in response to low nitrate availability in rice.

The expression patterns of the NRT2 genes have been well described; however, the role of OsNRT2.4 in root growth is not well known. In this study, we thus aimed at investigating the role of high-affinity NO3- transport OsNRT2.4 in root growth modulation. Through the amiRNA-mediated gene silencing technique, we successfully obtained osnrt2.4 knockdown lines to study the role of OsNRT2.4 on root growth under low nitrate conditions. We performed real-time PCR analysis to investigate the relative gene expression level in root and shoot, soluble metabolites, and measurement of root system. Knockdown of OsNRT2.4 decreased rice growth. The comparison with wild-type (WT) plants showed that (i) knockdown of OsNRT2.4 inhibited root formation under low NO3- supply; (ii) we demonstrated that the mutant lines had significantly increased NO3- uptake than WT plants when grown in different nitrate supplies; (iii) osnrt2.4 knockdown lines showed an alteration in nitrogen metabolism, and this affected the root growth; and (iv) the downregulation of OsNRT2.4 enhanced the expression of gene response of low external NO3- concentrations. Herein we provide new insights in OsNRT2.4 functions. Our data demonstrated that OsNRT2.4 plays a role in root growth, nitrogen metabolic pathway and probably have functions in nitrate transport from root to shoot under low nitrate availability in rice. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01273-6.

Sure, or unsure? Measuring students' confidence and the potential impact on patient safety in multiple-choice questions.

BACKGROUND: Multiple-choice questions (MCQs) provide useful information about correct and incorrect answers, but they do not offer information about students' confidence. METHODS: Ninety and another 81 medical students participated each in a curricular neurology multiple-choice exam and indicated their confidence for every single MCQ. Each MCQ had a defined level of potential clinical impact on patient safety (uncritical, risky, harmful). Our first objective was to detect informed (IF), guessed (GU), misinformed (MI), and uninformed (UI) answers. Further, we evaluated whether there were significant differences for confidence at correct and incorrect answers. Then, we explored if clinical impact had a significant influence on students' confidence. RESULTS: There were 1818 IF, 635 GU, 71 MI, and 176 UI answers in exam I and 1453 IF, 613 GU, 92 MI, and 191 UI answers in exam II. Students' confidence was significantly higher for correct than for incorrect answers at both exams (p < 0.001). For exam I, students' confidence was significantly higher for incorrect harmful than for incorrect risky classified MCQs (p = 0.01). At exam II, students' confidence was significantly higher for incorrect harmful than for incorrect benign (p < 0.01) and significantly higher for correct benign than for correct harmful categorized MCQs (p = 0.01). CONCLUSIONS: We were pleased to see that there were more informed than guessed, more uninformed than misinformed answers and higher students' confidence for correct than for incorrect answers. Our expectation that students state higher confidence in correct and harmful and lower confidence in incorrect and harmful MCQs could not be confirmed.

Single charge current in a normal mesoscopic region attached to superconductor leads via a coupled poisson nonequilibrium green function formalism.

We study the I-V characteristic of mesoscopic systems or quantum dot (QD) attached to a pair of superconducting leads. Interaction effects in the QD are considered through the charging energy of the QD; that is, the treatment of current transport under a voltage bias is performed within a coupled Poisson nonequilibrium Green function (PNEGF) formalism. We derive the expression for the current in full generality but consider only the regime where transport occurs only via a single particle current. We show for this case and for various charging energies values U 0 and associated capacitances of the QD the effect on the I-V characteristic. Also the influence of the coupling constants on the I-V characteristic is investigated. Our approach puts forward a novel interpretation of experiments in the strong Coulomb regime.

Transcatheter aortic valve replacement in patients with severe aortic valve stenosis and concomitant mitral valve regurgitation - 5 years follow-up.

Objectives: To investigate the change in severity of mitral regurgitation (MR) after transcatheter aortic valve replacement (TAVR) and its effect on 5-year mortality. Background: There is inconsistency in literature on pre-existing MR influencing long-term survival in patients who undergo TAVR. Methods: Patients who underwent TAVR at the University Hospital Schleswig-Holstein (USKH) Campus Kiel between March 2009 and February 2018 have been enrolled. Echocardiography determined the degree of MR before and within 7 days after TAVR. Patients were divided into two groups according to their MR at baseline: MR-grade ≤ 2 (non-relevant MR, nr-MR) and baseline MR-grade > 2 (relevant MR, r-MR). Primary endpoint was a composite of MR baseline influence on mortality and MR reduction and its' impact on mortality. Results: A total of 820 patients (642 nr-MR and 178 in r-MR) were included in this study. Of these, 167 patients showed an improvement in MR-grade. Thereof 106 (63.5 %) referred to r-MR with a significant decrease in mean MR-grade (p < 0.01). Systolic pulmonary artery pressure (sPAP) (p < 0.01) and NT-proBNP (p = 0.03) decreased in patients who had an improvement. There was no significant difference in 5-year mortality for MR at baseline (p = 0.35) or reduction in mortality for r-MR patients with an MR improvement compared to patients with worsening or equal MR status (p = 0.80). Conclusion: In patients undergoing TAVR, 63.5 % of patients with MR-grade ≥ 2 at baseline showed an improvement of grade of MR after TAVR with reduction of their sPAP and NT-proBNP values but there was no significant difference in mortality.

A contemporary training concept in critical care cardiology.

Critical care cardiology (CCC) in the modern era is shaped by a multitude of innovative treatment options and an increasingly complex, ageing patient population. Generating high-quality evidence for novel interventions and devices in an intensive care setting is exceptionally challenging. As a result, formulating the best possible therapeutic approach continues to rely predominantly on expert opinion and local standard operating procedures. Fostering the full potential of CCC and the maturation of the next generation of decision-makers in this field calls for an updated training concept, that encompasses the extensive knowledge and skills required to care for critically ill cardiac patients while remaining adaptable to the trainee's individual career planning and existing educational programs. In the present manuscript, we suggest a standardized training phase in preparation of the first ICU rotation, propose a modular CCC core curriculum, and outline how training components could be conceptualized within three sub-specialization tracks for aspiring cardiac intensivists.

Dataset of the temperature rise during granular flows in a rotating drum.

This paper provides experimental data on the temperature rise during granular flows in a small-scale rotating drum due to heat generation. All heat is believed to be generated by conversion of some mechanical energy, through mechanisms such as friction and collisions between particles and between particles and walls. Particles of different material types were used, while multiple rotation speeds were considered, and the drum was filled with different amounts of particles. The temperature of the granular materials inside the rotating drum was monitored using a thermal camera. The temperature increases at specific times of each experiment are presented in form of tables, along with the average and standard deviation of the repetitions of each setup configuration. The data can be used as a reference to set the operating conditions of rotating drums, in addition to calibrating numerical models and validating computer simulations.

Long-term outcome of endorectal advancement flap for complex anorectal fistulae.

The purpose of this study was to determine the long-term outcome of endorectal advancement flap (ERF) for complex anorectal fistulae. A total of 38 ERF were performed in 36 patients (2003-2007). Mean age was 45 years. The most common fistula type was transsphincteric. Eighty-one per cent of patients had prior surgical interventions. Primary closure rate was 83 per cent. Of the six initial failures, four were noted in patients operated for recurrent rectovaginal fistula. Postoperative complications occurred in seven patients (19%). During a mean follow-up of 27 months, recurrent disease was noted in five patients (14%). All recurrences were noted in patients with left sided fistulae. At last follow-up, all patients had healed their fistula except for two. We conclude that ERF closed most complex anorectal fistulae with an acceptable complication rate and low recurrence rate. Recurrent rectovaginal fistula was associated with a lower closure rate.

Pharmacological mechanisms involved in the antinociceptive effects of dexmedetomidine in mice.

Dexmedetomidine (DEX) is a α2 -adrenoceptor (α2 -AR) agonist used as an anesthetic adjuvant and as sedative in critical care settings. Typically, α2 -AR agonists release nitric oxide (NO) and subsequently activate NO-GMPc pathway and have been implicated with antinociception. In this study, we investigate the pharmacological mechanisms involved in the antinociceptive effects of DEX, using an acetic acid-induced writhing assay in mice. Saline or DEX (1, 2, 5, or 10 µg/kg) was intravenously injected 5 min before ip administration of acetic acid and the resulting abdominal constrictions were then counted for 10 min. To investigate the possible mechanisms related to antinociceptive effect of DEX (10 µg/kg), the animals were also pretreated with one of the following drugs: 7-nitroindazole (7-NI; 30 mg/kg ip); 1H-[1,2,4] oxadiazole [4,3-a] quinoxaline-1-one (ODQ; 2.5 mg/kg, ip); yohimbine (YOH; 1 mg/kg, ip); atropine (ATRO; 2 mg/kg, ip); glibenclamide (GLIB; 1 mg/kg, i.p.) and naloxone (NAL; 0.2 mg/kg, ip). A rotarod and open-field performance test were performed with DEX at 10 µg/kg dose. DEX demonstrated its potent antinociceptive effect in a dose-dependent manner. The pretreatment with 7-NI, ODQ, GLIB, ATRO, and YOH significantly reduced the antinociceptive affects of DEX. However, NAL showed no effecting DEX-induced antinociception. The rotarod and open-field tests confirmed there is no detectable sedation or even significant motor impairment with DEX at 10 µg/kg dose. Our results suggest that the α2 -AR and NO-GMPc pathways play important roles in the systemic antinociceptive effect of DEX in a murine model of inflammatory pain. Furthermore, the antinociceptive effect exerted by DEX appears to be dependent on KATP channels, independent of opioid receptor activity.

Geração de renda no assentamento agroecológico Jacy Rocha com venda direta: construção de alternativas sustentáveis

A segurança alimentar e a comercialização dos excedentes, produzidos pelos agricultores familiares, são pilares para consolidação dos mesmos no campo. A partir da promoção do desenvolvimento sustentável de assentamentos de reforma agrária na região do Extremo Sul da Bahia, o modelo de comércio justo e solidário dialoga diretamente com a demanda mundial por alimentos saudáveis de procedência confiável. O objetivo deste trabalho foi descrever o acesso ao Programa Nacional de Alimentação Escolar (PNAE) do Assentamento Agroecológico Jacy Rocha no ano de 2018, construído coletivamente com o Projeto de Assentamentos Agroecológicos, Brigada Olga Benário e a Frente de Comercialização da região. Para tanto, foi realizado o acompanhamento do Projeto Assentamentos Agroecológicos (PAA), na área do Jacy Rocha, na qual já se verificou resultados significativos para as famílias, influenciando positivamente na organicidade e no empoderamento das famílias do Jacy Rocha sobre a produção, acesso e fornecimento de alimentos ao PNAE. Contudo, torna-se necessário o aperfeiçoamento da interlocução e planejamento das famílias com o PNAE e o aumento da oferta de outros canais de comercialização para inclusão de todas as famílias do assentamento.

Quebrando paradigmas: intercâmbio com agricultura sintrópica, Jaguaquara/BA.

O presente artigo tem como objetivo apresentar a experiência de agricultores assentados da reforma agrária num intercâmbio com agricultura sintrópica, com vivência realizada na fazenda Ouro Fino. Essa fazenda está localizada no distrito de Itiúba município de Jaguaquara/BA, o intercâmbio teve como proposta vivenciar práticas de manejos da Agricultura Sintrópica. Assim, quebrando paradigmas em relação à capacidade de resiliência de agroecossistemas complexos, a produção de alimentos saudáveis e uso de árvores nos sistemas produtivos. A partir dessa experiência foi possível desmistificar a visão que os agricultores tinham que as árvores nos sistemas agrícolas não "cumprem função nenhuma e só ocupavam espaço que poderia ser cultivado", compreendendo de fato os preceitos do redesenho e complexidade biológica proposta pela Agroecologia. Com base na experiência vivida pelos participantes, bem como nos relatos coletados e replicação dos arranjos e práticas já iniciadas em seus respectivos lotes da reforma agrária, nos assentamentos agroecológicos, verificou-se que o intercâmbio na fazenda de agricultura sintrópica serviu como ferramenta de construção, sensibilização e impulsionamento das práticas agroecológicas sintrópicas, transformando os agricultores e técnicos em novos agentes multiplicadores deste conhecimento.

Phosphorus uptake kinetics and nitrogen fractions in maize grown in nutrient solutions / Cinética de absorção de fósforo e frações nitrogenadas em milho cultivado em solução nutritiva

The analysis of ion uptake kinetics is the key experimental procedure for determining the uptake efficiency of different species and varieties. The principal goal of this study was to evaluate phosphorus (P) uptake and its effect on nitrogen (N) metabolism in two maize varieties (Sol da Manhã and Eldorado) and one improved maize cultivar (AG 122®) exposed to a resupply of 10 or 100 μM of P following a period of P deprivation. The experiment was based on a completely randomized design with four replicates, with treatments arranged in a 3x2 factorial scheme consisting of three genotypes and two P doses. The treatments were applied at 16 days after germination (DAG), and samples of nutrient solution were collected over time to estimate the kinetics of P uptake (Vmax, KM and Cmin). At the end of the experiment, a portion of the total fresh weight was stored to determine N fractions and soluble sugars. Under the experimental conditions, the AG 122® cultivar showed the lowest KM and Cmin values for both P doses, indicating a higher uptake efficiency for these plants. In contrast, the Eldorado and Sol da Manhã varieties showed the highest Vmax values. An absence of P from the nutrient solution for one day, followed by the addition of 10 μM of P for the same period, did not result in alterations in N metabolism in any of the genotypes. However, it was observed that the Sol da Manhã and Eldorado varieties concentrated their NO3--N metabolism in their roots, whereas the AG 122® cultivar concentrated its NO3--N metabolism in its shoots.(AU)

A análise das variáveis cinéticas de absorção de íons é o principal procedimento experimental para a diferenciação da eficiência de absorção entre espécies e variedades. Baseado nisso, o objetivo desse trabalho foi avaliar a absorção de fósforo (P) e o seu efeito no metabolismo de nitrogênio (N) em variedades (Sol da Manhã e Eldorado) e cultivar (AG 122®) de milho (Zea mays L.) submetidos ao ressuprimento com 10 e 100 μM de P. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições. Os tratamentos foram dispostos em esquema fatorial 3x2, sendo três genótipos e dois níveis de P. Aos 16 dias após a germinação (DAG) foram aplicados os tratamentos e procedeu-se a coleta da solução nutritiva ao longo do tempo para estimar as variáveis cinéticas de absorção de P (Vmáx, KM e Cmín) e na coleta final parte da massa fresca total foi armazenada para determinação das frações nitrogenadas e açúcares solúveis. Nas condições do experimento, a cultivar AG 122® apresentou o menor valor de KM e Cmín nas duas doses de P, o que indica uma maior eficiência de absorção por essas plantas, enquanto as variedades Eldorado e Sol da Manhã apresentaram os maiores valores de Vmáx. A omissão de P da solução nutritiva por um dia, seguido da adição de uma dose de 10 μM desse nutriente por igual período não provocou alterações no metabolismo de N entre os genótipos estudados, no entanto, foi observado que as variedades Sol da manhã e Eldorado têm preferência para o metabolismo de N-NO3- na raiz quando comparadas a cultivar AG 122® que o faz preferencialmente na parte aérea.(AU)

El financiamiento de la investigación científica en las universidades de las ciencias médicas de Cuba: realidades, retos y aspectos legales / Scientific research financing at cuban medical sciences universities: realities, challenges and legal a spects

El financiamiento de la actividad científica es muy importante para su buen desarrollo y para que a su vez ésta contribuya al desarrollo del país. En las Universidades de las Ciencias Médicas de Cuba existen muchos problemas tanto para planificar ese presupuesto como para ejecutarlo, situación que se extiende al resto de los centros del Sistema Nacional de Salud. Este trabajo además de llamar la atención sobre esa situación presenta un resumen de las leyes y resoluciones existente en el país que permiten realizar una correcta planificación y ejecución del presupuesto en función del desarrollo de la ciencia. Temas legales que deben tener en cuenta de manera responsable tanto los investigadores como las personas con poder de decisión del sistema(AU)

The financing of scientific activity is very important for the proper development and in turn it will contribute to national development. In the Universities of Medical Sciences in Cuba there are many problems for both planning to execute this budget, a situation that extends to the rest of the centers of the National Health System. This work also draw attention to this situation presents a summary of the laws and resolutions in the country to allow proper planning and implementation of the budget according to the development of science. Legal issues to be taken into account in a responsible manner both researchers and people with decision-making system(AU)

Phosphorus uptake kinetics and nitrogen fractions in maize grown in nutrient solutions / Cinética de absorção de fósforo e frações nitrogenadas em milho cultivado em solução nutritiva

The analysis of ion uptake kinetics is the key experimental procedure for determining the uptake efficiency of different species and varieties. The principal goal of this study was to evaluate phosphorus (P) uptake and its effect on nitrogen (N) metabolism in two maize varieties (Sol da Manhã and Eldorado) and one improved maize cultivar (AG 122®) exposed to a resupply of 10 or 100 μM of P following a period of P deprivation. The experiment was based on a completely randomized design with four replicates, with treatments arranged in a 3x2 factorial scheme consisting of three genotypes and two P doses. The treatments were applied at 16 days after germination (DAG), and samples of nutrient solution were collected over time to estimate the kinetics of P uptake (Vmax, KM and Cmin). At the end of the experiment, a portion of the total fresh weight was stored to determine N fractions and soluble sugars. Under the experimental conditions, the AG 122® cultivar showed the lowest KM and Cmin values for both P doses, indicating a higher uptake efficiency for these plants. In contrast, the Eldorado and Sol da Manhã varieties showed the highest Vmax values. An absence of P from the nutrient solution for one day, followed by the addition of 10 μM of P for the same period, did not result in alterations in N metabolism in any of the genotypes. However, it was observed that the Sol da Manhã and Eldorado varieties concentrated their NO3--N metabolism in their roots, whereas the AG 122® cultivar concentrated its NO3--N metabolism in its shoots.

A análise das variáveis cinéticas de absorção de íons é o principal procedimento experimental para a diferenciação da eficiência de absorção entre espécies e variedades. Baseado nisso, o objetivo desse trabalho foi avaliar a absorção de fósforo (P) e o seu efeito no metabolismo de nitrogênio (N) em variedades (Sol da Manhã e Eldorado) e cultivar (AG 122®) de milho (Zea mays L.) submetidos ao ressuprimento com 10 e 100 μM de P. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições. Os tratamentos foram dispostos em esquema fatorial 3x2, sendo três genótipos e dois níveis de P. Aos 16 dias após a germinação (DAG) foram aplicados os tratamentos e procedeu-se a coleta da solução nutritiva ao longo do tempo para estimar as variáveis cinéticas de absorção de P (Vmáx, KM e Cmín) e na coleta final parte da massa fresca total foi armazenada para determinação das frações nitrogenadas e açúcares solúveis. Nas condições do experimento, a cultivar AG 122® apresentou o menor valor de KM e Cmín nas duas doses de P, o que indica uma maior eficiência de absorção por essas plantas, enquanto as variedades Eldorado e Sol da Manhã apresentaram os maiores valores de Vmáx. A omissão de P da solução nutritiva por um dia, seguido da adição de uma dose de 10 μM desse nutriente por igual período não provocou alterações no metabolismo de N entre os genótipos estudados, no entanto, foi observado que as variedades Sol da manhã e Eldorado têm preferência para o metabolismo de N-NO3- na raiz quando comparadas a cultivar AG 122® que o faz preferencialmente na parte aérea.

Teorías del sistema nervioso / Theories of the nervous system

En el presente trabajo se exponen sucintamente, varias de las teorías sobre el Sistema nervioso, descubrimientos, trabajos y el movimiento científico relacionado con este sistema, propuestos por numerosos investigadores de finales del siglo XIX; que intentan explicar la morfología y funcionamineto del sistema nervioso, sobre todo aquellos que han causado una verdadera revolución en ese ramo de las ciencias universales, como la Teoría de las neuronas

Etiología de ciertas anemias graves de Venezuela: comunicación al Colegio de Médicos de Venezuela, sobre el descubrimiento del Ankilostoma o Uncinaria duiodenalis, como causa específica de las anemias graves de Petare, Guarenas, Guatire, Santa Lucia y sus alrededores / Etiology of certain graves' anemias in Venezuela: communication the Venezuela Medical Shcool, on the discovery the Ancylostoma or Uncinaria duodenalis, as cause it specifies of the grave anemia of Petare, Guarenas, Santa Lucia and surroundings

Se describen los métodos utilizados para examinar la sangre de 25 casos de anemia con un cortejo sintomático. Los análisis de sangre y de la médula ósea después de la autopsia, no nos han revelado luz alguna sobre la etiología de la anemia; ni parásitos animales, ni bacterias, ni hongos de origen vegetal. Se propone la idea de si la anemia mencionada no sería la producida por Ankylostoma duodenalis, Himenolspis murina, Botriocéfalus latus, Lamblia intestinales, amibas, etc., de origen intestinal; y nos propusimos examinar las heces en los casos que se nos fueran presentando; el primer ensayo confirmó nuestras sospechas. Se describe el curso de la enfermedad hasta la muerte de un individuo y la autopsia en detalle. se encontraron seis lombrices repartidas en todo el tubo intestinal y una multitud de gusanos de 3 a 15 mm de largo identificados como Ankilostoma o Uncinaria duodenales. Se hacen deducciones racionales de las observaciones realizadas, como la leucocitosis; el papel de los mononucleares; la ausencia de mal olor en las Heces, el infarto de los ganglios mesentéricos y el aumento de volumen de folículos linfáticos de la mucosa intestinal

La ankilostomiasis en Venezuela / The ankilostomiasis in Venezuela

La Ankilostomiasis en Venezuela abunda más de lo que creímos al principio; vienen enfermos de distintos lugares del centro del país. Suponemos que la anemia del Centro de la República no es otra cosa que Uncinariasis; además de la helmintiasis por áscaris, oxiuros y solitaria; y hay coincidencias con el tun tun, malcoeur de los franceses y el Erdessen (geofagia) de los alemanes. Se alude al estado de chimbombera de los caquécticos andantes; y se relacionan como víctimas del Strongilus duodenalis.Nos llegó un joven de 25 años, a quien habíamos estado tratando con hierro y arsénico, quien había mejorado mucho; pero sufría de varios síntomas; nosotros analizamos las heces y encontramos los huevos de Ankilostoma duodenal. Le impusimos tratamiento, dieta láctea y pedacitos de hielo, aplicamos un purgante y el resultado fue 1.035 parásitos que se aislaron de las heces líquidas. Se continuó con otro tratamiento, baños fríos y ejercicios moderados; han desaparecido las cefalalgias y la constipación y el enfermo se encuentra muy bien.

Estudios sobre el anquilostomo duodenal: (con 17 figuras en una plancha) / Studies of the duodenal ancylostoma: (with 17 figures in an iron)

El anquilostomo duodenal es uno de los parásitos intestinales que más daño causa a la humanidad; el cual encontramos en la autopsia de un anémico y lo participamos al "colegio de Médicos", el 18 de septiembre último; así como demostramos que él es responsable de las anemias tan comunes en todo el país. Anchylostomum duodenalis, Dubini, 1838, habita el duodeno, el yeyuno, y rara vez, el íleon del hombre y de los animales superiores. En el presente trabajo citamos: Sinonimias del parásito, Nombres que se le da en distintos países a la enfermedad producida por el mismo; Descubrimiento, origen y distribución geográfica; Clasificación zoológica, forma, dirección y dimensiones; anatomía; Diferentes especies de Uncinarias y la común en Venezuela; Reproducción y modo de infección; Diagnóstico diferencial; Profilaxis y al final se incorpora una plancha con las figuras citadas en el trabajo, con surespectiva descripción

La uncinaria americana-stile / The uncinaria american-stile

En nuestros estudios previos expusimos nuestras dudas y vacilaciones en la clasificación de ese verme intestinal Uncinaria Americana-Stiles. Hicimos la enumeración de las demás especies conocidas como anemiantes o patógenas de los mamíferos: U. trigonocéfala, U. stenocéfala, U. ceinua, etc; y dedujimos la semejanza que existía entre nuestra especia y la U. estenocéfala. Posteriormente identificamos el anquilostomo nuestro con el de Stiles, y en este trabajo resumimos sus caracteres específicos y hábitat, comparados con los del U. duodenalis, Dubini, con sus respectivas láminas. Puede decirse que la U. americana es la que por si sola causa las anemias de Venezuela. En la colección del Hospital Vargas se encuentra cerca de cincuenta mil parásitos expulsados por los enfermos y mezclados a ellos se ha encontrado 32 ejemplares de la U. duodenal