Submicrosecond Spectroscopy of Lightning-Like Discharges: Exploring New Time Regimes.

Submicrosecond (0.476 µs per frame with an exposure time of 160 ns) high-resolution (0.38 nm) time-resolved spectra of laboratory-produced lightning-like electrical discharges have been recorded for the first time within the visible spectral range (645-665 nm). The spectra were recorded with the GrAnada LIghtning Ultrafast Spectrograph (GALIUS), a high-speed imaging spectrograph recently developed for lightning research in the IAA-CSIC. Unprecedented spectral time dynamics are explored for meter long laboratory electrical discharges produced with a 2.0 MV Marx generator. The maximum electron density and gas temperature measured in a timescale of ≤0.50 µs (160 ns) were, respectively, ≃1018 cm-3 and ≃32,000 K. Overpressure in the lightning-like plasma channel, black-body dynamics, and self-absorption in spectral lines were investigated.

Computer-based quantification of an atraumatic sinus augmentation technique using CBCT.

Our group recently developed an innovative maxillary sinus augmentation technique without the need of sinus membrane elevation, termed as "IPG" DET protocol. This technique utilizes autologous platelet concentrates (including platelet rich plasma (PRP), platelet rich fibrin (PRF), growth factors (GFs) and CD34+ stem cells), together with bone grafting materials positioned through intentionally perforated Schneider's membrane for flapless implant placement. This study aimed at evaluating the performance of "IPG" DET protocol in terms of new bone formation and implant stability at 8 months post-op. This prospective study consisted of forty-eight patients with a mean age of 52.8 years. A total of eighty-five implants were placed with "IPG" DET protocol in combination with autologous platelet concentrates. CBCT (cone beam computed tomography) was performed at two different time points: pre-operatively and at 8 months post-op. CBCT images were then compared by an intensity-based image algorithm to assess the newly formed bone in terms of gray scale values. Additionally, implant stability quotient (ISQ) was used to estimate implant osseointegration and success rate. The average new bone formation was 5.9 ± 0.9 mm2 per implant. All implants successfully osseointegrated, and ISQ ranged 62.3-71.7. According to the results of this study, "IPG" DET protocol in combination with autologous platelet concentrates is a successful technique for implant-supported rehabilitation of the edentulous posterior maxilla without the need of sinus floor elevation.

Phototactic behavior of Daphnia and the continuous monitoring of water quality: interference of fish kairomones and food quality.

We carried out a laboratory study to evaluate the sensitivity of phototactic behavior of Daphnia magna to sublethal concentrations of pentachlorophenol (PCP) and copper. More specifically, we determined whether the sensitivity of a D. magna clone to those pollutants is influenced by food quality and the presence of fish kairomones. Test animals were fed either unicellular green algae (Scenedesmus acutus) or fresh baker's yeast (Saccharomyces cerevisiae) and were cultured in the presence or absence of fish kairomones. Four concentrations of PCP (0.4, 0.8, 1.2, and 1.6 mg/L PCP) and one concentration of copper (0.02 mg/L Cu2+) in International Standards Organisation (ISO, Geneva, Switzerland) standard medium were applied in the experiments. Animals were exposed for 3 h to the pollutants prior to the experiments. In the absence of fish kairomones, a strong negative relationship between the phototactic index and nominal sublethal concentrations of PCP was found in animals fed either algae or yeast. The sensitivity of the Daphnia clone to sublethal concentrations of PCP was, however, less clear cut in animals fed yeast than in animals fed algae. The detection limit was 0.4 mg/L PCP with algae as food but was as high as 1.2 mg/L PCP when yeast was used as food. The ability to detect sublethal concentrations of copper and PCP using phototactic behavior was lost when the clones were cultured in the presence of fish kairomones. At a concentration of 0.02 mg/L Cu2+ and in the absence of fish kairomones, the D. magna clone tested became significantly less positively phototactic than in the control treatment regardless of the quality of the food used to culture the test animals. These results suggest that assays using the phototactic behavior of Daphnia to monitor water quality should use genetically stable (clonal) material, positively phototactic, and insensitive to the presence of fish kairomones.

Genistein inhibits growth of estrogen-independent human breast cancer cells in culture but not in athymic mice.

The studies presented were conducted to assess the effect of the soy isoflavone genistein on proliferation of estrogen-independent human breast cancer cells (MDA-MB-231) in vitro and in vivo. Genistein (20 mcmol/L) inhibited cell proliferation in vitro by approximately 50%. Cell cycle progression was blocked in G(2)/M with 40 and 80 mcmol/L genistein. To evaluate the effect of dietary genistein on tumor growth in vivo, genistein was fed to female athymic mice inoculated with MDA-MB-231 cells. After solid tumor masses had formed, mice were fed genistein at a dose (750 mcg/g AIN-93G diet), shown to produce a total plasma genistein concentration of approximately 1 mcmol/L. This dose of genistein did not significantly (P > 0.05) alter tumor growth. Studies were then conducted to assess the effect of dietary genistein on initial tumor development and growth. Genistein (750 mcg/g AIN-93G diet), fed 3 d before cells were inoculated into mice, did not significantly (P > 0.05) inhibit tumor formation or growth. The plasma concentration of genistein in mice fed this dose of dietary genistein (750 mcg/g AIN-93G diet) does not appear sufficient to inhibit tumor formation or growth. Dietary genistein at 750 mcg/g AIN-93G diet does not inhibit tumor formation or growth. Additional studies were conducted to determine the effect of dietary dosages ranging from 0 to 6000 mcg/g AIN-93G diet on plasma genistein concentration. Plasma genistein concentration increased in a dose-dependent manner up to 7 mcmol/L at 6000 mcg/g AIN-93G diet. These data suggest that although genistein inhibits cancer cell growth in vitro, it is unlikely that the plasma concentration required to inhibit cancer cell growth in vivo can be achieved from a dietary dosage of genistein.

Serum fatty acids, lipoprotein(a) and apolipoprotein composition of rural, suburban and urban populations in North Vietnam.

This study was conducted to investigate the concentrations of serum fatty acids, lipoprotein(a) and apolipoprotein of three populations in North Vietnam: rural area with low income (n = 101), suburban with average income (n = 97), and urban with high income (n = 95). The results showed the suburban and urban populations had higher fat intake than the rural. The fat intake in quality was different in these three populations. The suburban had the highest consumption of fatty foods rich in n-6 polyunsaturated fatty acid (PUFA). The rural consumed more fatty foods rich in monounsaturated fatty acid (MUFA), but less fatty foods rich in n-3 PUFA than the two other populations. The high index of thrombogenicity (IT) of the Vietnamese diet may result from their low intake of fish and vegetable oils. Risk factors for premature cardiovascular disease (CVD) assessed by serum lipoprotein(a) and apolipoprotein levels were not observed in all three populations. However, coronary heart disease (CHD) and stroke are problems that should be monitored because the increase of CVD morbidity has been reported in Vietnamese people. From a nutritional point of view, the increase of fish and vegetable oils consumption is necessary for the prevention of CVD and CHD in these Vietnamese populations.