710 research outputs found
Métodos de remoção da mucilagem e qualidade fisiológica de sementes de tomate (Lycopersicon esculentum, Mill.)
Different methods of mucilage remotion and quality of tomato (Lycopersicon esculentum Mill.) seeds were studied, in a complete randomized design experiment with four replications. After manual extraction, seeds and slimes were submitted to the following remotion treatments: immediate washing, three-day fermentation, hydrochloric acid at 2,5% (25 mg/kg for 2 hrs.), acetic acid at 10% (25 ml/kg of material), and ammonia hydroxide at 2,5% (25 ml/kg, for 2 hrs.). A physiological quality evaluation of seeds was carried out through the percentage of germination and vigor, percentage of in-sand emergence, electrical conductivity, and weight of fresh and dry matters of seedlings. The results showed that the methods of immediate washing, fermentation, commercial hydrochloric and acetic acids do not affect the physiological quality of tomato seeds; the germination percentage was not affected by the different remotion methods, and the ammonia hydroxide method affects seed vigor.Objetivando estudar diferentes mĂ©todos de remoção da mucilagem e a qualidade de sementes de tomate (Lycopersicon esculentum Mill.), conduziu-se um experimento, em delineamento inteiramente casualizado com quatro repetiçÔes. ApĂłs extração manual, sementes e mucilagens foram submetidas aos seguintes tratamentos de remoção: lavagem imediata, fermentação por trĂȘs dias, ĂĄcido clorĂdrico a 2,5% (25 ml/kg, durante 2 horas), ĂĄcido acĂ©tico a 10% (25 ml/kg de material) e hidrĂłxido de amĂŽnia a 2,5% (25 ml/kg, durante 2 horas). Seguiu-se a avaliação da qualidade fisiolĂłgica das sementes atravĂ©s das determinaçÔes de porcentagem de germinação e vigor, pela porcentagem de emergĂȘncia em areia, condutividade elĂ©trica e pesos das matĂ©rias verde e seca de plĂąntulas. Os resultados permitiram concluir que os mĂ©todos de remoção por lavagem imediata, fermentação, ĂĄcido clorĂdrico e ĂĄcido acĂ©tico comercial nĂŁo afetaram a qualidade fisiolĂłgica de sementes de tomate; a porcentagem de germinação nĂŁo foi afetada pelos diferentes mĂ©todos de remoção e o mĂ©todo hidrĂłxido de amĂŽnia prejudica o vigor das sementes
Efeito da profundidade de semeadura na emergĂȘncia de plĂąntulas de tomate (Lycopersicon esculentum Mill.)
The effect of seeding depth on the emergence of tomato (Lycopersicon esculentum Mill.) seedlings variety Tropic was tested for 0.5; 1.5; 2.5; 3.5; 4.5, and 5.5 cm depth of seeding in soil and sand medium, at a 3:1 ratio with a constant water content around 70% of field capacity. The experimental design was totally randomized with four replications of 50 seeds per treatment, quantifying the depth effects by determining the emergence time and percentage of the final stand. The results showed that the 1.5 cm seeding depth provided an emergence time and a final stand significantly higher than the others, thus being considered as ideal for tomato seeding.Com o objetivo de avaliar o efeito da profundidade de semeadura na emergĂȘncia de plĂąntulas de tomate (Lycopersicon esculentum Mill.), utilizou-se sementes da cultivar Tropic Ă profundidade de 0,5; 1,5; 2,5; 3,5; 4.5 e 5,5 cm em substrato solo e areia na proporção de 3:1, mantendo-se constante o teor de ĂĄgua do mesmo em 70% da capacidade de campo. O delineamento experimental empregado foi inteiramente casualizado com quatro repetiçÔes de 50 sementes por tratamento, quantificando-se os efeitos das profundidades atravĂ©s das determinaçÔes de Ăndice e velocidade de emergĂȘncia e estande final em porcentagem. Os resultados revelaram que a profundidade de semeadura de 1,5 cm proporcionou Ăndice de velocidade de emergĂȘncia e estande final, significativamente superiores Ă s demais, razĂŁo por que pode ser considerada como a mais indicada Ă semeadura de tomate
Water availability and germination of onion seeds (Allium cepa L.)
Objetivando verificar a influĂȘncia do teor de ĂĄgua do substrato na germinação de sementes de cebola (Allium cepa L.), conduziu-se um ensaio sob condiçÔes de ambiente de laboratĂłrio. Os efeitos de cinco nĂveis de ĂĄgua no substrato solo x areia (3:1), 20, 40, 60, 80 e 100% da capacidade de retenção foram avaliados atravĂ©s da porcentagem de emergĂȘncia no 14° dia da semeadura e pesos da matĂ©ria verde e seca das plĂąntulas normais. Para tanto, 200 sementes do cultivar Pira Ouro por tratamento, em quatro repetiçÔes de 50, foram semeadas a 1,5 cm de profundidade, mantendo-se constantes os nĂveis de ĂĄgua no substrato. Os resultados possibilitaram concluir que os nĂveis de umidade do solo indicados para germinação de sementes de cebola sĂŁo de 40% e 60% da capacidade de retenção do substrato, por possibilitarem uma melhor emergĂȘncia, peso da matĂ©ria verde e seca das plĂąntulas.One essay was conducted under laboratory conditions, in order to verify the influence of substrate water content on the germination of onion (Allium cepa L.) seeds. The effect of five water levels in the medium soil x sand (3:1) - 20, 40, 60, 80 and 100% retention capacity-were evaluated through the emergence percentage 14 days after seedling and the weight of fresh and dry matters of normal seedlings. For that purpose, 200 treated seeds of Pira Ouro cultivar were sown 1.5 cm deep in four replicĂĄtions of 50, with a constant water content in the medium. The best results showed that the soil moisture levels suggested for the germination of onion seeds were 40% to 60% of the substrate retention capacity, once they provide better emergence, weight of the fresh and dry matters of seedlings
Comparison among several media for the rooting of croton (Codiaeum variegatum L.) cuttings
To determine the best medium for rooting of crotĂłn (Codiaeum variegatum L.) cuttings, the media: sand, medium grade vermiculite, sand x vermiculite (75% x 25%); (50% x 50%); (25% x 75%), phenolic foam and soil were used. The experiment was conducted in a mist chamber in a randomized block design with four replicĂĄtions of twenty cuttings each. The physical properties of the media were determined and the following evaluations made: rooted cutting percentage, shooted cutting percentage, number of roots per cutting, lenght of the longest root, and weight of root dry matter. The results show that the medium grade vermiculite medium is the most suitable for the rooting of crotĂłn cuttings although the others may also be used, except soil and sand which presented the poorest performances.Com o objetivo de determinar o melhor substrato para o enraizamento de estacas de crotĂłn (Codiaeum variegatum L.), utilizou-se areia, vermiculita mĂ©dia, areia x vermiculita (75% x 25%); (50% x 50%); (25% x 75%), esponja fenĂłlica e solo. O experimento foi conduzido em cĂąmara de nebulização com delineamento em blocos casualizados com quatro repetiçÔes de vinte estacas cada. Determinaram-se as propriedades fĂsicas dos substratos e foram efetuadas as seguintes avaliaçÔes: porcentagem de estacas enraizadas, porcentagem de estacas brotadas, nĂșmero de raĂzes por estaca, comprimento da maior raiz e peso da matĂ©ria seca das raĂzes. Os resultados permitem concluir que o substrato vermiculita mĂ©dia Ă© o mais indicado para o enraizamento de estacas de crotĂłn, embora os demais, exceto o solo e areia que apresentaram os piores desempenhos, tambĂ©m possam ser utilizados
Correction: Substituent interference on supramolecular assembly in urea gelators: synthesis, structure prediction and NMR
Correction for âSubstituent interference on supramolecular assembly in urea gelators: synthesis, structure prediction and NMRâ by Francesca Piana et al., Soft Matter, 2016, 12, 4034â4043
Substituent interference on supramolecular assembly in urea gelators: synthesis, structure prediction and NMR
Eighteen N-aryl-N?-alkyl urea gelators were synthesised in order to understand the effect of head substituents on gelation performance. Minimum gelation concentration values obtained from gel formation studies were used to rank the compounds and revealed the remarkable performance of 4-methoxyphenyl urea gelator 15 in comparison to 4-nitrophenyl analogue 14, which could not be simply ascribed to substituent effects on the hydrogen bonding capabilities of the urea protons. Crystal structure prediction calculations indicated alternative low energy hydrogen bonding arrangements between the nitro group and urea protons in gelator 14, which were supported experimentally by NMR spectroscopy. As a consequence, it was possible to relate the observed differences to interference of the head substituents with the urea tape motif, disrupting the order of supramolecular packing. The combination of unbiased structure prediction calculations with NMR is proposed as a powerful approach to investigate the supramolecular arrangement in gel fibres and help understand the relationships between molecular structure and gel formation
Malignancy risk analysis in patients with inadequate fine needle aspiration cytology (FNAC) of the thyroid
Background
Thyroid fine needle aspiration cytology (FNAC) is the standard diagnostic modality for thyroid nodules. However, it has limitations among which is the incidence of non-diagnostic results (Thy1). Management of cases with repeatedly non-diagnostic FNAC ranges from simple observation to surgical intervention. We aim to evaluate the incidence of malignancy in non-diagnostic FNAC, and the success rate of repeated FNAC. We also aim to evaluate risk factors for malignancy in patients with non-diagnostic FNAC.
Materials and Methods
Retrospective analyses of consecutive cases with thyroid non diagnostic FNAC results were included.
Results
Out of total 1657 thyroid FNAC done during the study period, there were 264 (15.9%) non-diagnostic FNAC on the first attempt. On repeating those, the rate of a non-diagnostic result on second FNAC was 61.8% and on third FNAC was 47.2%. The overall malignancy rate in Thy1 FNAC was 4.5% (42% papillary, 42% follicular and 8% anaplastic), and the yield of malignancy decreased considerably with successive non-diagnostic FNAC. Ultrasound guidance by an experienced head neck radiologist produced the lowest non-diagnostic rate (38%) on repetition compared to US guidance by a generalist radiologist (65%) and by non US guidance (90%).
Conclusions
There is a low risk of malignancy in patients with a non-diagnostic FNAC result, commensurate to the risk of any nodule. The yield of malignancy decreased considerably with successive non-diagnostic FNAC
The Influence of Molecular Adsorption on Elongating Gold Nanowires
Using molecular dynamics simulations, we study the impact of physisorbing
adsorbates on the structural and mechanical evolution of gold nanowires (AuNWs)
undergoing elongation. We used various adsorbate models in our simulations,
with each model giving rise to a different surface coverage and mobility of the
adsorbed phase. We find that the local structure and mobility of the adsorbed
phase remains relatively uniform across all segments of an elongating AuNW,
except for the thinning region of the wire where the high mobility of Au atoms
disrupts the monolayer structure, giving rise to higher solvent mobility. We
analyzed the AuNW trajectories by measuring the ductile elongation of the wires
and detecting the presence of characteristic structural motifs that appeared
during elongation. Our findings indicate that adsorbates facilitate the
formation of high-energy structural motifs and lead to significantly higher
ductile elongations. In particular, our simulations result in a large number of
monatomic chains and helical structures possessing mechanical stability in
excess of what we observe in vacuum. Conversely, we find that a molecular
species that interacts weakly (i.e., does not adsorb) with AuNWs worsens the
mechanical stability of monatomic chains.Comment: To appear in Journal of Physical Chemistry
Substituent interference on supramolecular assembly in urea gelators: synthesis, structure prediction and NMR
Eighteen N-aryl-N'-alkyl urea gelators were synthesised in order to understand the effect of head substituents on gelation performance. Minimum gelation concentration values obtained from gel formation studies were used to rank the compounds and revealed the remarkable performance of 4-methoxyphenyl urea gelator 15 in comparison to 4-nitrophenyl analogue 14, which could not be simply ascribed to substituent effects on the hydrogen bonding capabilities of the urea protons. Crystal structure prediction calculations indicated alternative low energy hydrogen bonding arrangements between the nitro group and urea protons in gelator 14, which were supported experimentally by NMR spectroscopy. As a consequence, it was possible to relate the observed differences to interference of the head substituents with the urea tape motif, disrupting the order of supramolecular packing. The combination of unbiased structure prediction calculations with NMR is proposed as a powerful approach to investigate the supramolecular arrangement in gel fibres and help understand the relationships between molecular structure and gel formation
New Ultra-minimally Invasive Surgical Treatment for Benign Prostatic Hyperplasia: A Systematic Review and Analysis of Comparative Outcomes
Context: Benign prostatic hyperplasia (BPH) associated with lower urinary tract symptoms (LUTS) is diagnosed in up to 80% of men during their lifetime. Several novel ultra-minimally invasive surgical treatments (uMISTs) for BPH/benign prostatic obstruction (BPO) have become available over the past 5 yr. Objective: To evaluate the perioperative and functional outcomes of recently introduced uMISTs for BPH/BPO, including Urolift, RezĆ«m, temporary implantable nitinol device, prostatic artery embolization (PAE), and intraprostatic injection. Evidence acquisition: A systematic literature search was conducted in December 2020 using Medline (via PubMed), Embase (via Ovid), Scopus, and Web of Science (registered on PROSPERO as CRD42021225014). The search strategy used PICO criteria and article selection was conducted in accordance with the PRISMA guidelines. The risk of bias and the quality of the articles included were assessed. A dedicated data extraction form was used to collect the data of interest. Pooled and cumulative analyses were performed to compare perioperative and functional outcomes between study groups. A random-effects model using the DerSimonian and Laird method was used to evaluate heterogeneity. Stata version 15.0 software was used for all statistical analyses. Evidence synthesis: The initial electronic search identified 3978 papers, of which 48 ultimately met the inclusion criteria and were included in the analysis. Pooled analysis revealed a uMIST benefit in terms of International Prostate Symptom Score (IPSS; â9.81 points, 95% confidence interval [CI] â11.37 to â8.25 at 1 mo; â13.13 points, 95% CI â14.98 to â11.64 at 12 mo), maximum flow rate (from +3.66 ml/s, 95% CI 2.8â4.5 to +4.14 ml/s, 95% CI 0.72â7.56 at 12 mo), and postvoid residual volume (â10.10 ml, 95% CI â27.90 to 7.71 at 12 mo). No negative impact was observed on scores for the International Index of Erectile Function-5, Male Sexual Health Questionnaire-Ejaculatory Dysfunction bother and function scales (overall postintervention change in pooled median score of 1.88, 95% CI 1.34â2.42 at the start of follow-up; and 1.04, 95% CI 0.28â1.8 after 1 yr), or the IPSS-Quality of Life questionnaire. Conclusions: Novel uMISTs can yield fast and effective relief of LUTS without affecting patient quality of life. Only RezĆ«m, UroLift, and PAE had a minimal impact on patientsâ sexual function with respect to baseline, especially regarding preservation of ejaculation. Patient summary: We reviewed outcomes for recently introduced ultra-minimally invasive surgical treatments for patients with lower urinary tract symptoms caused by benign prostate enlargement or obstruction. The evidence suggests that these novel techniques are beneficial in terms of controlling symptoms while preserving sexual function. Take Home Message: Novel ultra-minimally invasive treatments can yield fast and effective relief of lower urinary tract symptoms without affecting a patient's quality of life
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