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991.
Nano-aluminum: transport through sand columns and environmental effects on plants and soil communities 总被引:3,自引:0,他引:3
Nano-aluminum is being used in increasing quantities as energetic material. This research addresses the transport of two types of nanosized aluminum particles (with aluminum oxide, or carboxylate ligand coating, Alex and L-Alex, respectively) through sand columns along with associated environmental impacts on soil systems. Surface phenomena and pH are variables controlling the transport of nano-aluminum particles through porous media. pH environment controls solubility and electrostatic interactions between nano-aluminum particles and porous media. (i.e., changes in point of zero charge, agglomeration, etc.). Concentrations (up to 17 mg/L) far greater than the World Health Organization guideline for Al in drinking water (0.2 mg/L) were measured in columns' leachates. Plant uptake studies, mineralization of radiolabeled glucose test and Microtox test were used to investigate the environmental impacts of nano-aluminum on soil communities and plants. It appears that the presence of nano-aluminum particles did not have an adverse effect on the growth of California red kidney bean (Phaseolus vulgaris) and rye grass (Lolium perenne) plants in the concentration range tested. California red beans did not show uptake of aluminum, while the situation was different for rye grass where a 2.5-fold increase in Al concentration in the leaves was observed as compared with control tests. Nano-aluminum particles in suspension do not appear to have an impact on the metabolic activity of Vibrio fischeri. However, when the nano-aluminum particles were amended to the soil, Alex aluminum resulted in a 50% reduction of light output at concentrations below 5000 mg/L soil suspension concentration while L-Alex showed a similar effect at around 17,500 mg/L and the control soil at 37,500 mg/L. Soil respiration studies show that there are not statistical differences between the time and sizes of peaks in CO(2) production and the total mineralization of glucose. 相似文献
992.
993.
Karagiannis DA Karampelas MD Soumplis VM Amariotakis C Georgalas I Kandarakis A 《Canadian journal of ophthalmology. Journal canadien d'ophtalmologie》2011,46(6):486-490
Objective
To evaluate the recurrence of macular edema (ME) in a mixed group of patients with branch (BRVO) and central (CRVO) retinal vein occlusion after early onset treatment with intravitreal injections of ranibizumab.Design
Nonrandomized, uncontrolled prospective clinical trial.Participants
Forty patients were enrolled in our study. Twenty-two patients had BRVO and 18 patients had CRVO.Methods
All patients had a minimum follow-up of 12 months. All patients had fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) at presentation. The time period between RVO occurrences and initial examination and treatment was <1 month. Every patient was treated with 2 consecutive intravitreal injections of ranibizumab (0.5 mg) 1 month apart. Assessment was carried out on a monthly basis and injection was carried out if necessary, based on OCT findings.Results
Recurrence of ME occurred in 13 patients (13/22, 59%) in the BRVO group, whereas in the CRVO group occurred in all patients (18/18, 100%). Mean time interval of these recurrences from last injection was 2.4 months and 1.2 months for BRVO and CRVO groups, respectively. Mean period of ME reabsorption was 2.5 months for the BRVO group and 3.5 months for the CRVO group.Conclusions
Recurrent ME occurred in 77.5% of our patients. These recurrences occurred sooner, were more prominent and lasted longer in patients with CRVO. 相似文献994.
995.
Feller L Anagnostopoulos C Wood NH Bouckaert M Raubenheimer EJ Lemmer J 《Journal of periodontology》2008,79(2):362-368
BACKGROUND: Kaposi sarcoma (KS) is the most common human immunodeficiency virus (HIV)-associated neoplasm (HIV-KS). Highly active antiretroviral therapy (HAART) results in a decrease in the incidence and prevalence of HIV-KS as well as in clinical improvement. However, in a subset of subjects who are HIV seropositive, KS may recrudesce early following the introduction of HAART as an immune reconstitution inflammatory syndrome (IRIS). METHODS: The management of a patient who is HIV seropositive with rapid clinical worsening of oral KS lesions shortly after the initiation of HAART was documented. Repeated serologic testing for CD4(+) T-cell count and microscopic examination of two biopsy specimens of the oral lesion, one taken before and the other taken after cytotoxic chemotherapy, followed by surgical excision was the treatment modality used. RESULTS: Microscopic examination of the incisional biopsy specimen taken from the oral lesion at the time of the initial consultation confirmed the clinical diagnosis of KS. The sequential serological tests showed a progressive increase in CD4(+) T-cell counts that paralleled the rapid clinical worsening of the KS disease. This was consistent with the diagnosis of IRIS-associated HIV-KS. Subsequent cytotoxic chemotherapy brought about resolution of the IRIS and regression of the HIV-KS lesions. Microscopic examination of a biopsy specimen obtained after cytotoxic chemotherapy did not show any of the original KS. The residual palatal exophytic mass was excised. CONCLUSIONS: IRIS-associated HIV-KS is not a disease, but rather a temporary paradoxical immunoinflammatory reaction brought about by improvement in immune status following HAART. IRIS-associated HIV-KS can be controlled effectively by limited systemic cytotoxic chemotherapy in the setting of HAART. 相似文献
996.
Gogos C Theodorou V Economides N Beltes P Kolokouris I 《Journal of endodontics》2008,34(11):1385-1387
The aim of this study was to evaluate the relative bond strengths of AH-26 and Epiphany sealers to both Resilon and composite resin. Four groups of substrate/bonded sealer combinations were tested: group A, composite resin substrate + Epiphany sealer; group B, composite resin substrate + AH-26 sealer; group C, Resilon substrate + Epiphany sealer; and group D, Resilon substrate + AH-26 sealer. Bond strength was evaluated in shear mode by using a universal testing machine at a crosshead speed of 0.5 mm/min. Statistical analysis (Kruskall-Wallis and Dunn tests) showed that the bond strength of AH-26 to both substrates was significantly greater than the bond strength of Epiphany. Therefore, the monoblock in the root canal might be more effectively achieved by combining Resilon core material with the epoxy resin-based sealer (AH-26) rather than Epiphany sealer. 相似文献
997.
PURPOSE: To evaluate the phase separation, extent of dentin demineralization, and curing efficiency of one-step self-etching adhesives placed on dentin and on inert substrate. MATERIALS AND METHODS: The adhesives tested were G-Bond (GB), iBond (IB) and Clearfil S3 Bond (SB). Two groups (2 x 3) of dentin and inert (gold) specimens were prepared for each product. The films formed on inert surfaces were subjected to mild (1st group) or strong air drying (2nd group) and examined with near- and mid-FTIR microspectroscopy. On dentin (1st group), the extent of demineralization (% DM) was evaluated before and after adhesive treatment plus rinsing with water and acetone by mid-FTIR microspectroscopy. The films formed after strong air drying (2nd group) and 20 s of light curing were rinsed with acetone, and the degree of cure (% DC) was measured by micro-multiple internal reflection FTIR spectroscopy. ANOVA was used to assess the statistically significant differences in % DM and % DC (alpha = 0.05). RESULTS: In GB and IB, mild air drying produced more water droplets and monomer separation than strong air drying. SB demonstrated the least separation. IB induced the highest % DM. All the adhesives demonstrated the greatest % DC on dentin. On both substrates SB showed the highest % DC values. CONCLUSION: Phase separation including water and/or monomers was found in all the adhesives. The extent of dentin demineralization and degree of cure varied among the products tested. The degree of cure was higher on dentin than on the inert substrate. 相似文献
998.
999.
1000.
George Rachiotis Varvara A Mouchtouri Clara Schlaich Tobias Riemer Carmen Varela Martinez Gordon Nichols Christopher LR Bartlett Jenny Kremastinou Christos Hadjichristodoulou the SHIPSAN partnership 《Journal of occupational medicine and toxicology (London, England)》2010,5(1):1