Three-dimensional flow visualization system by holographic interferometry

A holographic system has been developed to visualize a three-dimensional fluid flow. The system consists principally of a thermoplastic film, a monochrome video camera, a microcomputer with image-processing capability and a printer. The system makes it possible to measure a slow flow. Two examples of such, the bimodal mixed-mode convection flows within a Bénard cell, are presented

Gastrectomia parcial e vagotomia troncular anterior: alterações no metabolismo de cálcio. Estudo experimental em ratos

BACKGROUND: The calcium is not absorbed in the lack of hydrochloric acid and the osteomalacia and osteoporosis may occurs; it is well recognized in patients that had gastric resection. AIM: To evaluate the effects of the partial gastrectomy associated to anterior truncal vagotomy in the absorption and metabolism of calcium. METHODS: Eighteen adults male Wistar rats were submitted to partial gastrectomy associated to anterior truncal vagotomy (GXT, eight animals) and the sham operation (10 animals, control group). The diet consumption and the weight gains of the animals were measured three times during the week. The animals received formulated experimental diet orally (AIN-93M) by eight weeks. The serum calcium, urinary and fecal calcium, apparent absorption of the calcium, activity of the enzyme alkaline fosfatase and calcium in the bone were measured after 60 days. RESULTS: The sham operated animals showed higher diet consumption, weight gains, serum and urinary calcium, excretion of calcium in feces, apparent absorption of calcium and activity of the enzyme alkaline fosfatase (P<0,05) as compared to the animals of the gastrectomized group. However, the concentration of the bone calcium was increased in the animals of the gastrectomized group. CONCLUSION: Partial gastrectomy associated to anterior truncal vagotomy showed to be a good experimental model the study calcium metabolism, decreasing the calcium absorption, serum and urinary calcium and activity of the enzyme alkaline fosfatase. However, for alterations at bone level in rats suggests an experimental study in larger period.RACIONAL: O cálcio não é absorvido na ausência de ácido clorídrico e a osteomalácia e osteoporose podem ocorrer; este fato é bem reconhecido em pacientes que se submeteram à gastrectomias. OBJETIVO: Avaliar os efeitos da gastrectomia parcial associada à vagotomia troncular anterior na absorção e metabolismo de cálcio. MÉTODOS: Dezoito ratos Wistar machos e adultos foram submetidos à gastrectomia parcial e vagotomia troncular anterior (oito animais) e à laparotomia simples como grupo controle (10 animais). O consumo de dieta e o peso dos animais foram monitorados três vezes por semana. Os animais receberam dieta oral formulada experimentalmente (AIN-93M), durante 8 semanas. O cálcio sérico, cálcio urinário e fecal, absorção aparente de cálcio, atividade da enzima fosfatase alcalina e cálcio ósseo foram mensurados após 60 dias de observação. RESULTADOS: Os animais controle apresentaram médias estatísticas maiores (P<0.05) para o consumo de dieta, ganho de peso, cálcio sérico, cálcio urinário, excreção de cálcio nas fezes, absorção aparente de cálcio e atividade da enzima fosfatase alcalina comparados aos animais do grupo gastrectomizado. Entretanto, a concentração de cálcio ósseo foi superior no grupo de animais gastrectomizados (P<0,05) quando comparado com o grupo controle. CONCLUSÃO: A gastrectomia parcial associada à vagotomia troncular anterior mostrou ser um bom modelo experimental para estudo com o metabolismo de cálcio, ocasionando diminuição da absorção de cálcio, cálcio sérico, cálcio urinário e fosfatase alcalina. No entanto, para alterações a nível ósseo em ratos, sugere-se um estudo experimental em período maior.105109Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Doubly linked chiral phenanthrene oligomers for homogeneously π-extended helicenes with large effective conjugation length

Helically twisted conductive nanocarbon materials are applicable to optoelectronic and electromagnetic molecular devices working on the nanometer scale. Herein, we report the synthesis of per-peri-perbenzo[5]- and [9]helicenes in addition to previously reported π-extended [7]helicene. The homogeneously π-extended helicenes can be regarded as helically fused oligo-phenanthrenes. The HOMO−LUMO gap decreased significantly from 2.14 to 1.15 eV with increasing helical length, suggesting the large effective conjugation length (ECL) of the π-extended helical framework. The large ECL of π-extended helicenes is attributed to the large orbital interactions between the phenanthrene subunits at the 9- and 10-positions, which form a polyene-like electronic structure. Based on the experimental results and DFT calculations, the ultrafast decay dynamics on the sub-picosecond timescale were attributed to the low-lying conical intersection

Laser-driven phase transitions in aqueous colloidal gold nanoparticles under high pressure : picosecond pump–probe study

Pump-probe transient extinction spectroscopy was applied to analyze 355-nm picosecond laser heating-induced phenomena of 60-nm-diameter aqueous gold nanoparticles (AuNPs) under a high pressure of 60 MPa. Kinetic spectroscopy revealed that a supercritical layer surrounding the AuNP nucleated with a lifetime of approximately 1 ns in its dynamic expansion and decay behavior for a fluence of 19.6 mJ cm−2. Moreover, we observed in the post-mortem transmission electron micrographs a number of fragments, a small percentage of size-reduced cores, and erupted particles, among the intact particles after 60 shots, suggesting that evaporation occurs under laser illumination. The particle temperature calculation indicated that evaporation begins with a liquid droplet AuNP surrounded by a supercritical layer at temperatures below the boiling point of gold. By applying high pressure, we are able to obtain a clear picture of the evaporation event, which was not possible at ambient pressure because the forming bubble caused particle temperatures to rise uncontrollably. In this study, we shed light on the critical role of the supercritical layer formed around the AuNP under high pressure during laser-induced evaporation.Pulsed-laser illumination of aqueous gold colloids under high pressure enables the evaporation from liquid droplets surrounded by supercritical water layer

Ingestion Of Polydextrose Increase The Iron Absorption In Rats Submitted To Partial Gastrectomy.

To investigate whether polydextrose stimulates iron absorption in rats submitted to partial gastrectomy and sham operated. The rats were submitted to partial gastrectomy (Billroth II) or laparotomy (sham-operated control), in groups of 20 and 20 each respectively. The animals were fed with a control diet (AIN-93M) without polydextrose or a diet containing polydextrose (50g/Kg of diet) for eight weeks. They were divided into four subgroups: sham-operated and Billroth II gastrectomy and with or without polydextrose. Two animals died during the experiment. All rats submitted to gastrectomy received B-12 vitamin (intramuscular) each two weeks. The hematocrit and hemoglobin concentration were measured at the start and on day 30 and 56 after the beginning of the experimental period. At the end of the study, the blood was collected for determination of serum iron concentration. The diet with polydextrose reduced the excretion of iron. Apparent iron absorption was higher in the polydextrose fed groups than in the control group. The haematocrit and haemoglobin concentration were lower after Billroth II gastrectomy rats fed the control diet as compared to the polydextrose diet groups. Polydextrose increase iron absorption and prevents postgastrectomy anemia.25518-2

Fuzzy Rolling Control of High-speed Catamaran

The high-speed catamaran boat used by this study has attached trim tabs to the stern both sides as the antirolling device for reducing the rolling. A PD control was initially employed in the system, and the observed data from the instrument showed the anti-rolling effect. However no significant improvement was observed for passengers although instrumental data showed good results. Therefore, it is not evaluated highly as the anti-rolling device. In this paper, fuzzy control system is applied to the anti-rolling device of a high-speed catamaran boat in order to improve the passenger comfort. Measurements of rolling data using the real ship were carried out. From the analysis results of the frequency analysis, the presented fuzzy control system suppressed the rolling of ship about 60% in maximum peak than the PD control. Also, crews have felt the anti-rolling effect of the fuzzy control, and it showed that this system provided good comfort ride.本研究で扱う高速双胴船には,横揺れの低減のためのアンチ・ローリング装置として,両側の船尾にト リムタブが取り付けられている.この装置の制御にはPD制御が用いられており,計測器から得られるデー タより,減揺効果がある程度認められている.しかし,実際の乗客の体感としては,さほど効果が得られ ておらず,減揺装置としては高い評価が得られていない.そこで本論文では,乗客の乗り心地を改善する ために,高速双胴船のアンチ・ローリング装置の制御にファジィ制御を用いる.実船における実験より, ローリングデータを計測し,周波数分析を行った.分析結果より,最大ピーク時でファジィ制御の方がPD 制御より約60%揺動が抑制されていた.また,ファジィ制御の揺動抑制効果は乗組員によっても体感する ことができ,スムーズな制御を感じることができた

Efeitos da ovariectomia experimental no metabolismo ósseo de ratas wistar adultas: um modelo para estudo da osteoporose

The ovarian hormone privation causes functional and hormonal disorders, as sexual dysfunction, loss of libido, increase of osteoporosis risk and heart disease, lioprotein levels change and ponderal gain. Osteoporosis is a systemic skeletal disease characterized by an disorder between resorption and bone formation with a consequent increase in bone fragility. The objective of the present investigation was to describe the experimental ovariectomy (OVT) effects on the bone metabolism and on the ponderal gain of the adults wistar rats. Adult rats were under the OVT procedure or sham operated. After 30 days, blood was collectded for the quantitative serum estrogen and after 60 days the animals were sacrified for the serum and bone analysis. The dietary consumption and the weight increase were evaluated twice and once a week respectively. The OVT rats had statistically higher averages (p > 0,05) for the dietary consumption, weight gain and alkaline phosphatase activity in the serum and lower (p < 0,05) for the serum estrogen concentration, calcium content, radiodensity and bone proportional limit comparing to the sham-operated rats. Besides the quantitative analysis, the OVT rats had femurs with theirs surface containing deep resorption gaps, confirming that the ovariectomy rats are a great osteoporosis study model on post menopause women.A privação dos hormônios ovarianos acarreta distúrbios endócrinos e funcionais, tais como disfunção sexual, perda da libido, maior risco de osteoporose e de doenças cardíacas, níveis alterados de lipoproteínas, ganho ponderal, entre outros. A osteoporose é uma patologia óssea sistêmica caracterizada por um desequilíbrio entre reabsorção e formação óssea, resultando em um aumento da fragilidade óssea. O objetivo do nosso estudo foi descrever os efeitos da ovariectomia (OVT) experimental no metabolismo ósseo e no ganho ponderal de ratas wistar adultas. Ratas adultas foram submetidas ao procedimento de OVT (G1) bilateralmente ou uma falsa castração (G2). Após 30 dias, foi coletado sangue para dosagem de estrogênio sérico e após 60 dias os animais foram sacrificados para a realização das análises séricas e ósseas. O consumo de ração e o ganho de peso foram monitorados duas e uma vez por semana, respectivamente. As ratas OVT apresentaram médias estatisticamente maiores (p < 0,05) para o consumo de dieta, ganho de peso e atividade sérica da fosfatase alcalina e, menores (p < 0,05) para concentração de estrogênio sérico, conteúdo de cálcio, radiodensidade e limite proporcional ósseo quando comparadas às ratas sham-operadas. Além das análises quantitativas, as ratas OVT apresentaram fêmures com superfície com fossas de reabsorção visivelmente profundas, confirmando que ratas ovariectomizadas são um bom modelo de estudo de osteoporose em mulheres na pós-menopausa