RF characteristics of SU-8 and quartz particle composite dielectric for Terahertz applications

An SU-8 and quartz particle composite dielectric layer was fabricated and measured from 0.9 to 1.0 THz. It is well known that SU-8 attenuates the signal due to its inherent high loss if used as a dielectric [1,2]. In this paper we report the possibility of lowering the loss of plain SU-8 by adding quartz particles with a diameter of 1 μm for high packing density. The real permittivity of the fabricated dielectric layer increases and loss tangent decreases according to the increase of quartz particles mass fraction in the range from 0.9 to 1.0 THz. Higher quartz particle mass fraction has a great potential to lower the losses of plain SU-8 for Terahertz applications

Performance of organically grown tomato cultivars under greenhouse conditions

A agricultura orgânica no Brasil cresce a taxas superiores a 30% ao ano, devido principalmente à maior conscientização dos consumidores que buscam alimentos saudáveis, livres de resíduos químicos e biológicos. Dentre as hortaliças cultivadas em sistema orgânico, o tomate constitui grande desafio para os produtores devido à inexistência de recomendações de manejo cultural e de cultivares desenvolvidas específicas para esse sistema de cultivo. Diante disso, o presente trabalho teve como objetivo avaliar o desempenho de cultivares de tomate sob sistema orgânico, em ambiente protegido. O experimento foi conduzido de maio a outubro de 2004 em campo, no município de Araraquara-SP. O delineamento experimental adotado foi blocos ao acaso, com quatro repetições e oito tratamentos (cultivares Avalon, Colibri, HTX-5415, HTX-8027, Sahel, San Marzano, San Vito e Jane). As plantas foram conduzidas em fileiras duplas, com duas hastes por planta no espaçamento de 0,8 m entre linhas e 0,6 m entre plantas (cerca de 20.000 plantas ha-1), sem poda apical. O híbrido Sahel destacou-se com o melhor desempenho para rendimento comercial. A traça-do-tomateiro se revelou como fator limitante à produção de tomate em sistema orgânico, sendo responsável, em média, por 17% de danos nos frutos colhidos das oito cultivares que foram avaliadas.Organic agriculture in Brazil has been increasing about 30% per year over the last few years, since consumers are seeking for healthier foods, i.e. nutritious and free of pesticide residues. Among organically grown vegetable crops, tomato is an attractive economic opportunity for growers. However, the lack of information about management practices and adapted cultivars to organic production systems under protected cultivation are pointed out as important constraints that prevents this activity to expand. This work aimed at evaluating the performance of indeterminate tomato cultivars in organic management systems in unheated plastic greenhouse. In both experiments tomato plants were staked. Plant spacing was 1.5 m between rows and 0.35 m between plants. They were planted in double line and spaced 0.8 m between lines and 0.6 m between plants (about 20,000 plants ha-1). The experiment was set up in a randomized complete block design, with four replications and eight treatments (cultivars: Avalon, Colibri, HTX-5415, HTX-8027, Sahel, San Marzano, San Vito, and Jane). Sahel hybrid exhibited an outstanding performance for marketable yield under organic cultivation. Tomato pinworm (Tuta absoluta) was a serious limiting pest for organically grown tomatoes, responding for 17% of damage in the fruits harvested from the evaluated cultivars

Permittivity and loss characteristics of SU8-quartz composite photoresist at THz frequencies

An SU8-quartz composite photoresist has been fabricated and characterized from 1.2 to 1.4 THz; the material contains quartz particles from 0 to 50 wt%. The composite can reduce the inherent losses of SU8 photoresist at terahertz frequencies. Calculated and measured data is presented and compared with SU8 without quartz inclusions. The results show a reduction in losses and an increase in permittivity in the composite material as the density of quartz particles increases. This initial experiment proves the possibility of modifying the electrical parameters of SU8; increasing the quartz density of the composite will modify these parameters further at THz frequencies.Grant numbers : This work was supported by the Spanish Ministry of Economy and Competitiveness project AETHER (TEC2014-58341-C4-4-R. Part of this work has been supported by the Generalitat de Catalunya under grant 2014SGR 1551

Estudo da formação de aderências e da cicatrização de anastomoses colônicas em ratos com sepse peritoneal induzida

OBJETIVO: Avaliar os efeitos da sepse abdominal sobre a formação de aderências e a cicatrização de anastomoses colônicas em ratos. MÉTODOS: 40 ratos distribuídos em dois grupos contendo 20 animais, para anastomose do cólon esquerdo na presença (grupo S) ou ausência (grupo N) de indução de sepse por ligadura e punção do ceco (CLP). Cada grupo foi dividido em subgrupos para eutanásia no terceiro (N3 e S3) ou sétimo (N7 e S7) dia de pós-operatório (DPO). Foi avaliada a quantidade de aderências e removido um segmento colônico contendo a anastomose para análise histopatológica, força de ruptura, hidroxiprolina e conteúdo de colágeno tecidual. RESULTADOS: Os animais submetidos à CLP apresentaram maior quantidade de aderências intra-abdominais tanto no 3° DPO (p=0,00) quanto no 7° DPO (p=0,00). Tiveram menores valores de força de ruptura no 3° DPO (p=0,00), porém maiores valores no 7° DPO (p=0,00). Não houve diferença na variação da concentração de hidroxiprolina, conteúdo de colágeno e histopatologia. CONCLUSÕES: A infecção peritoneal desencadeada por CLP aumentou a quantidade de aderências intra-cavitárias. Houve diminuição da resistência de anastomoses cólicas no 3° DPO, com posterior aumento no 7° DPO, sem efeito sobre os outros parâmetros da cicatrização. ________________________________________________________________________________ ABSTRACTPURPOSE: To evaluate the effects of abdominal sepsis on adhesion formation and colon anastomosis healing in rats. METHODS: Forty rats were distributed in two groups containing 20 rats each for left colon anastomosis in the presence (Group S) or absence (Group N) of induced sepsis by cecal ligation and puncture. Each group was divided into subgroups for euthanasia on the third (N3 and S3) or seventh (N7 or S7) post-operative day. The amount of adhesions was evaluated and a segment of the colon was removed for histopathologic analysis, bursting strength assessment, hydroxyproline and the determination of tissue collagen. RESULTS: The subjects which underwent cecal ligation and puncture presented a higher amount of intra-abdominal adherences in both third (p=0,00) and seventh (p=0,00) post-operatory days. Smaller bursting strengths were found in the S3 subgroup, and greater bursting strengths were found in the S7 subgroup. There was no difference in the variations on the concentrations of hydroxyproline, tissue collagen and histopathology. CONCLUSIONS: The peritoneal infection which was developed by cecal ligation and puncture raised the amount of intra-cavitary adhesions. There was a decrease in the amount of colonic anastomosis on the third post-operatory day with a following raise on the seventh without any effects on other healing parameters

Evaluation of potential of gamma radiation as a conservation treatment for blackberry fruits

BACKGROUND: Blackberries consumption has been associated with health benefits. However, these fruits present a short shelf-life. Thus, food irradiation is a potential alternative technology for conservation of these fruits without use of chemicals. OBJECTIVE: Analyse the potentiality of gamma radiation as a decontamination method for blackberry fruits. METHODS: Fresh packed blackberries were irradiated in a Co-60 source at two doses (1.0 and 1.5 kGy). Bioburden, physical and rheological, sensorial and total soluble content parameters were assessed before irradiation, immediately after and at two days storage time at 4°C. RESULTS: The characterization of blackberries microbiota point out to an average bioburden value of 104 CFU/g and to a microbial population predominantly composed by filamentous fungi. The inactivation studies on the blackberries mesophilic population indicated a limited microbial inactivation (<1 log decimal reduction) for the applied radiation doses, being the surviving population mainly constituted by filamentous fungi and yeast. No effect of irradiation on colour of blackberries was observed. Concerning texture parameters, no significant differences were observed in both fracturability and firmness between non-irradiated and irradiated blackberries immediately after irradiation. In blackberries stored for two days, both parameters were slightly lower in irradiated blackberries, compared to non-irradiated blackberries. The performed sensorial analysis indicated a similar acceptability among irradiated and non-irradiated fruits. CONCLUSION: This work reveals gamma irradiation treatment potential since no major impact was detected on blackberries physical, rheological and sensory attributes. Further studies with longer periods of storage are needed to elucidate the advantages of irradiation as a conservation treatment.© 2013 - IOS Press and the authors. All rights reserved

Intraoperative ventilator settings and their association with postoperative pulmonary complications in neurosurgical patients : post-hoc analysis of LAS VEGAS study

Background Limited information is available regarding intraoperative ventilator settings and the incidence of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgical procedures. The aim of this post-hoc analysis of the 'Multicentre Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS) study was to examine the ventilator settings of patients undergoing neurosurgical procedures, and to explore the association between perioperative variables and the development of PPCs in neurosurgical patients. Methods Post-hoc analysis of LAS VEGAS study, restricted to patients undergoing neurosurgery. Patients were stratified into groups based on the type of surgery (brain and spine), the occurrence of PPCs and the assess respiratory risk in surgical patients in Catalonia (ARISCAT) score risk for PPCs. Results Seven hundred eighty-four patients were included in the analysis; 408 patients (52%) underwent spine surgery and 376 patients (48%) brain surgery. Median tidal volume (V-T) was 8 ml [Interquartile Range, IQR = 7.3-9] per predicted body weight; median positive end-expiratory pressure (PEEP) was 5 [3 to 5] cmH(2)0. Planned recruitment manoeuvres were used in the 6.9% of patients. No differences in ventilator settings were found among the sub-groups. PPCs occurred in 81 patients (10.3%). Duration of anaesthesia (odds ratio, 1.295 [95% confidence interval 1.067 to 1.572]; p = 0.009) and higher age for the brain group (odds ratio, 0.000 [0.000 to 0.189]; p = 0.031), but not intraoperative ventilator settings were independently associated with development of PPCs. Conclusions Neurosurgical patients are ventilated with low V-T and low PEEP, while recruitment manoeuvres are seldom applied. Intraoperative ventilator settings are not associated with PPCs

A comparative analysis reveals weak relationships between ecological factors and beta diversity of stream insect metacommunities at two spatial levels.

The hypotheses that beta diversity should increase with decreasing latitude and increase with spatial extent of a region have rarely been tested based on a comparative analysis of multiple datasets, and no such study has focused on stream insects. We first assessed how well variability in beta diversity of stream insect metacommunities is predicted by insect group, latitude, spatial extent, altitudinal range, and dataset properties across multiple drainage basins throughout the world. Second, we assessed the relative roles of environmental and spatial factors in driving variation in assemblage composition within each drainage basin. Our analyses were based on a dataset of 95 stream insect metacommunities from 31 drainage basins distributed around the world. We used dissimilarity-based indices to quantify beta diversity for each metacommunity and, subsequently, regressed beta diversity on insect group, latitude, spatial extent, altitudinal range, and dataset properties (e.g., number of sites and percentage of presences). Within each metacommunity, we used a combination of spatial eigenfunction analyses and partial redundancy analysis to partition variation in assemblage structure into environmental, shared, spatial, and unexplained fractions. We found that dataset properties were more important predictors of beta diversity than ecological and geographical factors across multiple drainage basins. In the within-basin analyses, environmental and spatial variables were generally poor predictors of variation in assemblage composition. Our results revealed deviation from general biodiversity patterns because beta diversity did not show the expected decreasing trend with latitude. Our results also call for reconsideration of just how predictable stream assemblages are along ecological gradients, with implications for environmental assessment and conservation decisions. Our findings may also be applicable to other dynamic systems where predictability is low