Triheptanoin, an odd-medium-chain triglyceride, impacts brain cognitive function in young and aged mice.

ABSTRACTThe brain aging process triggers cognitive function impairment, such as memory loss and compromised quality of life. Cognitive impairment is based on bioenergetic status, with reduced glucose uptake and metabolism in aged brains. Anaplerotic substrates are reported to promote mitochondrial ATP generation, having been tested in clinical trials for the treatment of neurological disorders and metabolic diseases.Objectives and Methods: To assess whether the improvement in oxidative capacity ameliorates cognitive function in adults (12 weeks), and aged (22-month-old) C57/6BJ mice, they received (1) a ketogenic diet, (2) a ketogenic diet supplemented with the anaplerotic substance, triheptanoin, or (3) a control diet for 12 weeks. Spontaneous alternation and time spent in a previously closed arm in the Y-maze test and time interacting with an unknown object in the novel object recognition test (NORT) were used to evaluate working memory. Acetylcholinesterase (AChE) activity in the prefrontal lobe, brain left hemisphere, and cerebellum was also evaluated. Glucose transporter 3 (GLUT3) expression in the prefrontal lobe was analyzed by western blotting.Results: The ketogenic diet (KD) reduced spontaneous alternation in aged mice, leading to lower AChE activity in the aged prefrontal lobe and cerebellum, and in the parieto-temporal-occipital lobe of adult mice. Furthermore, KD decreased GLUT3 protein expression in the frontal lobe of the adults.Discussion: Supplementation of KD with triheptanoin prevented memory impairment and showed similar values of AChE activity and GLUT3 expression compared to the controls. Our data suggest that triheptanoin has a potential role in the bioenergetic capacity of the brain, improving cognitive function.

High frequency of non-susceptibility to ciprofloxacin in nontyphoid Salmonella recovered from Brazilian broiler chicken.

1. This study evaluated the minimal inhibitory concentration (MIC) of ciprofloxacin and the presence of plasmid-mediated quinolone resistance (PMQR) mechanisms in 97 nontyphoidal Salmonella spp. isolated from broilers and carcases from three different regions in Brazil. The presence of mutations in quinolone resistance determination regions (QRDRS) was investigated in the ciprofloxacin-resistant strain by DNA sequencing.2. Most of the Salmonella spp. (85.6%) had intermediate resistance to ciprofloxacin and only one isolate was resistant. MIC breakpoints ranged from ≤0.03 to 1 µg/ml and 67.0% of the strains had a MIC of 0.25 µg/ml (n=65). Thirteen strains (13.4%) were susceptible to ciprofloxacin with MIC ≤0.06 µg/ml. The qnrB gene was detected in eight isolates with intermediate resistance and in two susceptible strains. The other PMQR genes, qnrA, qnrC, qnrD, qnrS, qnrVC, aac(6')-Ib, qepA, oqxAB and mutations in QRDR were not detected in any strain.3. There was a high frequency of ciprofloxacin intermediate resistant Salmonella from broiler and broiler carcases from Brazil. The presence of these strains in poultry and derived products poses a risk to public health.

Peltate trichomes in the dormant shoot apex of Metrodorea nigra, a Rutaceae species with rhythmic growth.

In Metrodorea nigra, a Rutaceae species with rhythmic growth, the shoot apex in the dormant stage is enclosed by modified stipules. The young organs are fully covered with peltate secretory trichomes, and these structures remain immersed in a hyaline exudate within a hood-shaped structure. Our study focused on the morpho-functional characterization of the peltate trichomes and cytological events associated with secretion. Shoot apices were collected during both dormant and active stages and processed for anatomical, cytochemical and ultrastructural studies. Trichomes initiate secretion early on, remain active throughout leaf development, but collapse as the leaves expand; at which time secretory cavities start differentiation in the mesophyll and secretion increases as the leaf reaches full expansion. The subcellular apparatus of the trichome head cells is consistent with hydrophilic and lipophilic secretion. Secretion involves two vesicle types: the smaller vesicles are PATAg-positive (periodic acid/thiocarbohydrazide/silver proteinate) for carbohydrates and the larger ones are PATAg-negative. In the first phase of secretory activity, the vesicles containing polysaccharides discharge their contents through exocytosis with the secretion accumulating beneath the cuticle, which detaches from the cell wall. Later, a massive discharge of lipophilic substances (lipids and terpenes/phenols) results in their accumulation between the wall and cuticle. Release of the secretions occurs throughout the cuticular microchannels. Continued protection of the leaves throughout shoot development is ensured by replacement of the collapsed secretory trichomes by oil-secreting cavities. Our findings provide new perspectives for understanding secretion regulation in shoot apices of woody species with rhythmic growth.

Modified keystone flap used to repair nose defect after Mohs micrographic surgery.

Mohs micrographic surgery (MMS) is a surgical technique used to remove skin tumors with a complete evaluation of the margins. The keystone flap technique is generally used to repair large surgical defects on limbs. We present a case where a modified keystone flap technique was used to close a large defect after Mohs micrographic surgery in a patient with a basal cell carcinoma on the nose. An excellent functional and aesthetic result was obtained with no complications during or after the procedure. We offer a novel indication for this technique for surgical defects in this area.

Ischemic stroke on hormonal contraceptives: Characteristics, mechanisms and outcome.

INTRODUCTION: Systemic contraceptives increase the risk of ischemic stroke but little is known about the characteristics, mechanisms and long-term outcome post stroke of patients on hormonal contraception. We sought to To assess characteristics and outcome of acute ischemic stroke (AIS) in young women using systemic hormonal contraceptives (SHC) and compare them to strokes in non-contraceptive users. PATIENTS AND METHODS: Using the Acute STroke Registry and Analysis of Lausanne (ASTRAL), we analyzed demographics, risk factors, clinical, radiological and treatment data of consecutive female patients of <50 years between 2003 to 2015. We compared groups with and without SHC in a logistic regression analysis. RESULTS: Of the 179 female patients of <50 years during the observation period, 57 (39.6%) used SHC, 71.9% of whom, a combined oral contraceptive pill. On logistic regression contraceptive users were significantly younger but had comparable stroke severity. They had less migraine with aura and tobacco use, and more hyperlipidaemia. Also, contraceptive users had significantly less intra and extracranial stenosis and occlusion on arterial imaging, but more focal hypoperfusion on CT-perfusion. Undetermined mechanism of stroke was more frequent with SHC users, whereas rare mechanisms were more frequent in non-users. The contraceptive user group had a more favourable adjusted 12-month outcome with significantly fewer ischemic recurrences after stopping systemic contraception in all. CONCLUSION: Contraceptive users with ischemic strokes are younger and have lesser tobacco use and migraine with aura and more hyperlipidemia. Their stroke mechanism is more often undetermined using a standardised work-up, and their adjusted long-term outcome is more favourable with less stroke recurrence.

A molecular survey reveals high occurrence of co-infections in intensive pork production farms with increased rates of mummified swine fetuses in Southern Brazil / [Pesquisa molecular revela alta ocorrência de coinfecções em granjas de produção intensiva de suínos com altas taxas de mumificação fetal no sul do Brasil]

Neste estudo, 308 amostras de fetos mumificados foram testadas para parvovírus suíno (PPV), circovírus suíno tipos 2 e 3 (PCV2 e PCV3) e leptospiras patogênicas. A idade gestacional no momento da perda gestacional e a frequência da mumificação fetal de acordo com a ordem de parto também foram investigadas. As amostras foram coletadas em granjas comerciais de criação de suínos da região sul do Brasil que apresentassem taxas de mumificação fetal igual ou maiores a 2,5%. Fragmentos de pulmão, rim, fígado e coração de fetos suínos mumificados foram coletados para análise molecular. Resultados da PCR foram classificados de acordo com a região de origem das amostras, tendo Santa Catarina, Paraná e Rio Grande do Sul contabilizado 87 (28,25%), 89 (28,90%) e 132 (42,86%) do total de amostras de fetos suínos mumificados, respectivamente. Coinfecções foram observadas na maioria dos casos e PCV3 foi o agente mais prevalente detectado, encontrado em 298 amostras (96,75%). A maioria das perdas gestacionais foi observada entre 50 e 70 dias de gestação (168; 54,5%) e a mumificação fetal não foi associada à ordem de parto das matrizes. Os achados sugerem que as altas taxas de fetos suínos mumificados na região Sul do Brasil podem ser explicadas pela infecção com esses agentes virais.(AU)

Toxicity of silver nanoparticles on different tissues in adult Danio rerio.

Although silver nanoparticles (AgNP) are among the most studied nanomaterials by virtue of their broad application in many areas, little is known about their overall toxicity to aquatic organisms after their contamination of the water environment. This study aimed to analyze the effect of the exposure (96 h) to different AgNP concentrations on Danio rerio (zebrafish) tissues. AgNP were synthesized and characterized by transmission electron microscopy (TEM), showing spherical AgNP of 30.00 ± 16.80 nm size. The effects of different AgNP concentrations (1, 3, and 5 µg L-1) on brain, muscle, gill, and liver tissues of zebrafish were investigated. The results show a significant decrease in brain and muscle acetylcholinesterase (AChE) activity. Liver and gill catalase (CAT) activity also decreased significantly. At the highest exposure concentration, muscle AChE was more inhibited (37.3%) than brain AChE (26.4%) and gill CAT was more inhibited (67.4%) than liver CAT (51.2%). D. rerio also showed gill morphological changes such as fusion of secondary lamellae, curvature, dilated marginal channel, and epithelial lifting. This study indicates that gill CAT together with morphological studies are potential biomarkers for AgNP.

Screening and optimizing fermentation production of l-asparaginase by Aspergillus terreus strain S-18 isolated from the Brazilian Caatinga Biome.

AIMS: The aim of this study was to find new eukaryotic sources of the l-asparaginase (l-ASNase), since the prokaryotic sources of the enzyme are well-reported as causing allergic hypersensitivity reactions in a significant number of patients. This report describes screening for l-ASNase production by filamentous fungi isolated from the Brazilian Caatinga, and the optimization of fermentation parameters to increase fungal growth and improve yield in the production of l-ASNase. METHODS AND RESULTS: Thirty-two filamentous fungi were investigated in this study. When Aspergillus terreus strain S-18 was cultured in a proline-enriched medium, intracellular l-ASNase was expressed in concurrence with reduced l-glutaminase (l-GLUase) and protease activities. Fermentation conditions were then optimized in a 5-l bioreactor system to produce a maximum volumetric yield of 108 U total of l-ASNase activity. CONCLUSIONS: The work reported here represents the first attempt to produce l-ASNase by filamentous fungi isolated from Brazil and offers a promising alternative eukaryotic source for l-ASNase production. SIGNIFICANCE AND IMPACT OF THE STUDY: In order to minimize the side effects caused by bacterial l-ASNase, the search of eukaryotic micro-organism for l-ASNase was carried out in fungi. This study demonstrates the diversity of filamentous fungi isolated from the Brazilian Caatinga Biome and the importance of knowledge of the microbial metabolism to obtain high concentrations of biotechnological products.

Growing without a mother results in poorer sexual behaviour in adult rams.

The aim of this study was to determine if the absence of the mother during rearing has long-term effects on sexual behaviour and physiological reproductive parameters of adult rams. Two groups of rams were: (1) artificially reared, separated from their dams 24 to 36 h after birth (Week 0) and fed using sheep milk until 10 weeks of age (group AR, n=14); and (2) reared by their dams until 10 weeks of age (group DR, n=13). Sexual behaviour (tests of 20 min) and physiological reproductive parameters were analysed separately for the non-breeding (Weeks 42 to 64) and the breeding (Weeks 66 to 90) seasons. Body weight, scrotal circumference, gonado-somatic index, testosterone concentrations or sperm parameters were similar in both rearing conditions (AR v. DR) in both seasons. During the non-breeding season AR rams displayed fewer ano-genital sniffings (AR: 4.2±0.4 v. DR: 5.3±0.4, P=0.04) and matings (AR: 1.2±0.2 v. DR: 1.8±0.2, P=0.002) than DR rams. During the breeding season AR rams displayed fewer ano-genital sniffings (AR: 4.3±0.5 v. DR: 5.7±0.5, P=0.005), flehmen (AR: 0.7±0.2 v. DR: 1.1±0.2, P=0.03), mount attempts (AR: 1.4±0.2 v. DR: 2.1±0.2, P=0.04), and tended to mount less frequently (AR: 6.6±0.9 v. DR: 8.8±0.9, P=0.08) than DR rams. In conclusion, the absence of the mother during the rearing period negatively affected display of sexual behaviour towards oestrous ewes during a rams adult life in both breeding and non-breeding seasons. However, it did not affect testis size, testosterone secretion or sperm variables.

Exigência de proteína bruta para juvenis de curimatã-pacu / Crude protein requeriment to curimatã-pacu juveniles

O objetivo deste estudo foi determinar a exigência de proteína bruta (PB) de juvenis de curimatã-pacu (Prochilodus argenteus). O experimento foi conduzido por um período de 60 dias, utilizando um delineamento inteiramente ao acaso, com quatro tratamentos (dieta contendo 24,0; 28,0; 32,0 e 36,0% de PB) e cinco repetições cada, em que 100 juvenis (peso inicial de 0,33 ± 0,01g) foram distribuídos em 20 aquários experimentais com volume de 130L, sendo considerada como unidade experimental uma caixa com cinco peixes, sob recirculação de água. Avaliaram-se o desempenho produtivo, o crescimento heterogêneo, os parâmetros morfométricos, fisiológicos e a viabilidade econômica das rações em função do nível de PB. Pela análise de regressão, foi verificado um aumento linear nos parâmetros de desempenho, morfométricos e fisiológicos, com o aumento do nível proteico nas rações. Quando comparados pelo teste de Tukey, o melhor resultado (P>0,05) foi obtido com 36% de PB. Verificou-se menor heterogeneidade de crescimento dos peixes à medida que se aumentavam os níveis de PB na ração. Assim, considerando também a viabilidade econômica, recomenda-se a utilização de rações com 36% de proteína bruta para juvenis de curimatã-pacu.(AU)

The aim of this study was to determinate crude protein (CP) requirement to curimatã-pacu juveniles (Prochilodus argenteus). The experiment was conducted during 60 days in a completely randomized design, with four treatments (24.0, 28.0, 32.0 and 36.0% CP of diet) and five replications, where a hundred juvenile fishes (initial weight de 0.33 ± 0.01g), were distributed in twenty tanks (130L each). Each tank with five juveniles was considered an experimental unit, with water recirculation. Performance, heterogeneous growth, morphometric and physiological parameters, and economic viability of the rations according to the CP levels were evaluated. For the regression analysis, a linear increase in performance, heterogeneous growth and morphometric and physiological parameters with increased of the protein in rations were observed. When compared by the Tukey test (P>0.05), the best results were obtained with 36% CP. There was lower fish growth heterogeneity as the levels of CP in the diet increased. Thus, taking into consideration the economic viability it is recommended to use feed containing 36% of crude protein to curimatã-pacu juveniles.(AU)

Wii-based exercise program to improve physical fitness, motor proficiency and functional mobility in adults with Down syndrome.

BACKGROUND: People with Down syndrome (DS) usually display reduced physical fitness (aerobic capacity, muscle strength and abnormal body composition), motor proficiency impairments (balance and postural control) and physical functional limitations. Exergames can be an appealing alternative to enhance exercise engagement and compliance, whilst improving physical fitness and motor function. This study aims to analyse the effects of a Wii-based exercise program on physical fitness, functional mobility and motor proficiency of adults with DS. METHODS: Twenty-seven adults with DS were randomly allocated to an experimental group (Wii; n = 14) or control group (n = 13). Participants in the experimental group completed a 2-month Wii-based exercise program, with three 1-h sessions per week that included training games for aerobic endurance, balance and isometric strength. Participants completed assessments regarding anthropometric measures, physical fitness, functional mobility and motor proficiency. RESULTS: Mixed ANOVA analysis showed a significant group by time interaction for aerobic endurance, explosive leg power and flexibility. Independent samples t-test for change scores indicated significant between-group differences favouring the experimental group regarding speed of limb movement, trunk strength and functional mobility, as well as a trend towards significance on body weight. Mann-Whitney's U test for change scores demonstrated between-group differences favouring the experimental group for visceral fat as well as running speed and agility. Large within-group effect sizes were observed for explosive leg power (d = 1.691), body weight (d = 1.281), functional mobility (d = 1.218), aerobic endurance (d = 1.020), speed of limb movement (d = 0.867) and flexibility (d = 0.818) in the experimental group. CONCLUSIONS: Our findings suggest that Wii-based exercise can be an effective tool to improve physical fitness, functional mobility and motor proficiency of adults with DS, including crucial measures such as aerobic capacity and lower limb strength. Exergames using Wii Fit or other equipment can be appealing alternatives for adults with DS to engage in regular physical activity, preventing sedentary behaviour and decreasing the risk to develop cardiovascular diseases.

DNA analysis of cattle parasitic protozoan Tritrichomonas foetus after photodynamic therapy.

Photodynamic therapy (PDT) is a modality of therapy that involves the activation of photosensitive substances and the generation of cytotoxic oxygen species and free radicals to promote the selective destruction of target tissues. This study analyzed the application of PDT to Tritrichomonas foetus, a scourged and etiological agent of bovine trichomoniasis, a sexually transmitted infectious disease. As it is an amitochondrial and aerotolerant protozoan, it produces energy under low O2 tension via hydrogenosome. T. foetus from an axenic culture was incubated with photosensitizer tetrasulfonated aluminium phthalocyanine and then irradiated with a laser source (InGaAIP) at a density of 4.5Jcm-2. The DNA integrity of the control and treated group parasites was analyzed by conventional gel electrophoresis and comet assay techniques. In previous results, morphological changes characterized by apoptotic cell death were observed after T. foetus was submitted to PDT treatment. In the treated groups, T. foetus DNA showed a higher concentration of small fragments, about 200pb, in gel electrophoresis after PDT. In the comet assay, the DNA tail percentage was significantly higher in the treated groups. These results demonstrate that PDT leads to DNA fragmentation with changes in nuclear morphology and apoptotic features.

Molecular characterization of the species Salvinia (Salviniaceae) from the upper Paraná River floodplain.

The pteridophytes Salvinia minima, S. herzogii, and S. auriculata are among the most abundant aquatic macrophytes in the upper Paraná River floodplain. Since some species have highly similar morphological features, it is very difficult to identify members of this genus to the species level. An indication of this difficulty is a set of poorly differentiated taxa comprising S. auriculata and S. herzogii known as the 'S. auriculata complex', which is found in the Paraná River together with other Salvinia species such as S. biloba and S. molesta. Some authors have reported the existence of inter-species hybrids. Despite the complex Salvinia taxonomy, few genetic studies have been performed on purported species within the genus to resolve this complexity. The present study was conducted to determine useful molecular sequences for the discrimination of Salvinia species of the upper Paraná River floodplain. Molecular data were compared with data of other species of the genus to clarify phylogenetic relationships, employing the nucleotide sequence trnL-trnF from the chloroplast DNA. The results revealed that Salvinia populations in the upper Paraná River floodplain belong to different species and indicated that species of the S. auriculata complex may be distinguished from one another after the division of the S. minima group, corroborating results by other researchers. Although the taxonomic position of S. oblongifolia was clarified, as high closeness between S. oblongifolia and the S. auriculata complex was reported, Salvinia kinship is still not thoroughly established and further investigations in morphology and molecular diversity are required.

The effect of white light on normal and malignant murine melanocytes: A link between opsins, clock genes, and melanogenesis.

The skin possesses a photosensitive system comprised of opsins whose function is not fully understood, and clock genes which exert an important regulatory role in skin biology. Here, we evaluated the presence of opsins in normal (Melan-a cells) and malignant (B16-F10 cells) murine melanocytes. Both cell lines express Opn2, Opn4--for the first time reported in these cell types--as well as S-opsin. OPN4 protein was found in a small area capping the cell nuclei of B16-F10 cells kept in constant dark (DD); twenty-four hours after the white light pulse (WLP), OPN4 was found in the cell membrane. Despite the fact that B16-F10 cells expressed less Opn2 and Opn4 than Melan-a cells, our data indicate that the malignant melanocytes exhibited increased photoresponsiveness. The clock gene machinery is also severely downregulated in B16-F10 cells as compared to Melan-a cells. Per1, Per2, and Bmal1 expression increased in B16-F10 cells in response to WLP. Although no response in clock gene expression to WLP was observed in Melan-a cells, gene correlational data suggest a minor effect of WLP. In contrast to opsins and clock genes, melanogenesis is significantly upregulated in malignant melanocytes in comparison to Melan-a cells. Tyrosinase expression increased after WLP only in B16-F10 cells; however no increase in melanin content after WLP was seen in either cell line. Our findings may prove useful in the treatment and the development of new pharmacological approaches of depigmentation diseases and skin cancer.

Electrochemical immunosensor for ethinylestradiol using diazonium salt grafting onto silver nanoparticles-silica-graphene oxide hybrids.

This work describes the preparation of an electrochemical immunosensor for ethinylestradiol (EE2) based on grafting of diazonium salt of 4-aminobenzoic acid onto a glassy carbon electrode modified with silver nanoparticles/SiO2/graphene oxide hybrid followed by covalent binding of anti-ethinylestradiol (anti-EE2) to activated carboxyl groups. A competitive immunoassay was developed for the determination of the hormone using peroxidase-labeled ethinylestradiol (HRP-EE2) and measurement of the amperometric response at -200mV in the presence of hydroquinone (HQ) as redox mediator. The calibration curve for EE2 exhibited a linear range between 0.1 and 50ng/mL (r(2)=0.996), with a detection limit of 65pg/mL. Interference studies with other hormones related with EE2 revealed the practical specificity of the developed method for the analyte. A good reproducibility, with RSD=4.5% (n=10) was also observed. The operating stability of a single bioelectrode modified with anti-EE2 was maintained at least for 15 days when it was stored at 4°C under humid conditions between measurements. The developed immunosensor was applied to the analysis of spiked urine with good results.

Prediction of anastomotic leak in colorectal cancer surgery based on a new prognostic index PROCOLE (prognostic colorectal leakage) developed from the meta-analysis of observational studies of risk factors.

PURPOSE: To obtain a prognostic index, which has been named PROCOLE (prognostic colorectal leakage), it can predict the risk that a certain individual may suffer anastomotic leakage. METHODS: The methodology consists of a systematic review to identify potential risk factors for anastomotic leakage and a meta-analysis of studies of each of these factors. In the meta-analysis, the prognostic index integrates factors that are statistically significant, which are weighted according to the estimated value of the effect size. The prognostic index was validated using retrospectively collected data from patients who underwent colorectal cancer surgery anastomosis at our institution. RESULTS: The mean and standard deviation of the PROCOLE prognostic index in patients with anastomotic leakage is 1.9 ± 6.13, whereas in controls, it is 3.63 ± 2.1. The predictive ability of the PROCOLE, assessed by calculating the area under the curve (AUC) of the receiver operating characteristic (ROC), results in an AUC of 0.82 with a 95% confidence interval (CI) (0.75, 0.89) of the AUC, and it can be considered a good prognostic indicator. CONCLUSIONS: The PROCOLE prognostic index predicts the risk of a certain individual developing anastomotic leakage after colorectal cancer surgery. Specifically, the PROCOLE prognostic index establishes a discrimination value threshold of 4.83 for recommending the implementation of a protective stoma. We have developed free software with a simple interface that only requires the selection of risk factors to obtain the PROCOLE value.

A reappraisal of ICU and long-term outcome of allogeneic hematopoietic stem cell transplantation patients and reassessment of prognosis factors: results of a 5-year cohort study (2009-2013).

Epidemiology and prognosis of complications related to allogeneic hematopoietic stem cell transplant (HSCT) recipients requiring admission to intensive care unit (ICU) have not been reassessed precisely in the past few years. We performed a retrospective single-center study on 318 consecutive HSCT patients (2009-2013), analyzing outcome and factors prognostic of ICU admission. Among these patients, 73 were admitted to the ICU. In all, 32 patients (40.3%) died in ICU, 46 at hospital discharge (63%) and 61 (83.6%) 1 year later. Survivors had a significantly lower sequential organ failure assessment (SOFA) score, serum lactate and bilirubin upon ICU admission. Catecholamine support, mechanical ventilation (MV) and/or renal replacement therapy during ICU stay, a delayed organ support and an active graft versus host disease (GvHD) significantly worsen the outcome. By multivariate analysis, the worsening of SOFA score from days 1 to 3, the need for MV and the occurrence of an active GvHD were predictive of mortality. In conclusion, the incidence of HSCT-related complications requiring an admission to an ICU was at 22%, with an ICU mortality rate of 44%, and 84% 1 year later. A degradation of SOFA score at day 3 of ICU, need of MV and occurrence of an active GvHD are main predictive factors of mortality.

Floral nectar production and nectary structure of a bee-pollinated shrub from Neotropical savanna.

Biotic pollination is critical for tropical ecosystem functioning, and nectar plays an essential role as it represents the main trophic resource for pollinators. Nevertheless, little is known about the mechanisms that underlie its production, which is essential for understanding the basis of nectar-mediated interactions in ecological and evolutionary approaches. Therefore, this study explores the relationship between the nectar secretion pattern and nectary functional changes in Anemopaegma album, a bee-pollinated species. We analysed the pattern of nectar production under field conditions and investigated floral nectary structural changes in two different developmental stages using light, transmission and scanning electron microscopy. We measured 30.95 ± 23.02 µl (mean ± SD, n = 30) of nectar accumulated inside the nectar chamber (29.26 ± 3.48% sucrose equivalents) at the moment of flower opening. Nectar removal did not influence the pattern of floral nectar production in terms of volume or total sugar but reduced the concentration of the nectar produced during the first 24 h of anthesis. The nectary consisted of an epidermis, a nectary parenchyma and a subnectary parenchyma supplied only by phloem. Starch grains decreased in size and abundance from the subnectary parenchyma toward the epidermis. We observed the degradation of starch grains and incorporation of amyloplasts into vacuoles at the pre-anthesis stage as well as the transformation of amyloplasts into elaioplasts during anthesis. Nectar secretion was continuous during the A. album flower life span, which was related to the functional features of its floral nectary, especially the presence of starch stored in the parenchyma.

Vagus nerve stimulation in treating depression: A tale of two stories.

Vagus nerve stimulation (VNS) has been widely used to treat different neurological disorders, especially epilepsy. Accumulating evidence also suggests its potential application in antidepressive therapy, given that VNS has been confirmed by several clinical trials to exert long-term effects on mitigating depression and reducing the risk of relapse in depressed patients. Likewise, VNS has also proven to ameliorate the behavioral deficits in a rat model of depression. While the influences of VNS on monoamine metabolism and mood improvement are well-recognized, the underlying mechanisms mediating its antidepressive action remain poorly understood. Recent findings suggest that VNS-enhanced proliferation of hippocampal neural progenitor cells (NPCs) and synaptic transmission might serve as a monoamine-independent pathway contributive to the beneficial effects of VNS on depression. Here we briefly reviewed the recent progress in this field, based on which we propose that there might be, at least, two little-overlapped, and yet interactive pathways mediating the antidepressive action of VNS.

Characterization of green zero-valent iron nanoparticles produced with tree leaf extracts.

In the last decades nanotechnology has become increasingly important because it offers indisputable advantages to almost every area of expertise, including environmental remediation. In this area the synthesis of highly reactive nanomaterials (e.g. zero-valent iron nanoparticles, nZVI) is gaining the attention of the scientific community, service providers and other stakeholders. The synthesis of nZVI by the recently developed green bottom-up method is extremely promising. However, the lack of information about the characteristics of the synthetized particles hinders a wider and more extensive application. This work aims to evaluate the characteristics of nZVI synthesized through the green method using leaves from different trees. Considering the requirements of a product for environmental remediation the following characteristics were studied: size, shape, reactivity and agglomeration tendency. The mulberry and pomegranate leaf extracts produced the smallest nZVIs (5-10 nm), the peach, pear and vine leaf extracts produced the most reactive nZVIs while the ones produced with passion fruit, medlar and cherry extracts did not settle at high nZVI concentrations (931 and 266 ppm). Considering all tests, the nZVIs obtained from medlar and vine leaf extracts are the ones that could present better performances in the environmental remediation. The information gathered in this paper will be useful to choose the most appropriate leaf extracts and operational conditions for the application of the green nZVIs in environmental remediation.