974 resultados para 368.28
Resumo:
The growing commercial applications had brought aluminium oxide nanoparticles under,toxicologists' purview. In the present study, the cytotoxicity of two different sized aluminium oxide nanoparticles (ANP(1), mean hydrodynamic diameter 82.6 +/- 22 nm and ANP(2), mean hydrodynamic diameter 246.9 +/- 39 nm) towards freshwater algal isolate Chlorella ellipsoids at low exposure levels (<= 1 mu g/mL) using sterile lake water as the test medium was assessed. The dissolution of alumina nanoparticles and consequent contribution towards toxicity remained largely unexplored owing to its presumed insoluble nature. Herein, the leached Al3+ ion mediated toxicity has been studied along with direct particulate toxicity to bring out the dynamics of toxicity through colloidal stability, biochemical, spectroscopic and microscopic analyses. The mean hydrodynamic diameter increased with time both for ANP(1) 82.6 +/- 22 nm (0 h) to 246.3 +/- 59 nm (24h), to 1204 +/- 140 nm (72 h)] and ANP(2) 246.9 +/- 39 nm (Oh) to 368.28 +/- 48 nm (24 h), to 1225.96 +/- 186 nm (72 h)] signifying decreased relative abundance of submicron sized particles (<1000 nm). The detailed cytotoxicity assays showed a significant reduction in the viability dependent on dose and exposure. A significant increase in ROS and LDH levels were noted for both ANPs at 1 mu g/mL concentration. The zeta potential and FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (SEM, TEM, and CLSM). At 72 h, significant Al3+ ion release in the test medium 0.092 mu g/mL for ANP(1), and 0.19 mu g/mL for ANP(2)] was noted, and the resulting suspension containing leached ions caused significant cytotoxicity, revealing a substantial ionic contribution. This study indicates that both the nano-size and ionic dissolution play a significant role in the cytotoxicity of ANPs towards freshwater algae, and the exposure period largely determines the prevalent mode of nano-toxicity.
[書評] James M. Freeman and Nguyễn Đình Hữu, Voices from the Camps: Vietnamese Children Seeking Asylum
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The purpose of this paper is to shed light on the historical relation between conflict and land tenure in Rwanda, a country that experienced a harsh civil war and genocide in the mid-1990s. The victory of the Tutsi-led rebel, Rwandan Patriotic Front (RPF) at that time triggered a massive return of refugees and a drastic change in land tenure policy. These were refugees who had fled the country at around the time of independence, in 1962, due to the political turmoil and persecution (the "social revolution") and who shared the background of the core RPF members. The social revolution had dismantled the existent Tutsi-led political order, compelling many Tutsi families to seek refuge outside their homeland. Under the post-independence rule of a Hutu-led government, the Tutsi refugees were not allowed to return and the lands they left behind were often arbitrarily distributed by local authorities among Hutu peasants. After victory in the mid-1990s civil war, the newly established RPF-led government ordered the current inhabitants of the lands to divide the properties in order to allocate portions to the Tutsi returnees. Different patterns of land holding and land division will be explained in the paper from data gathered through the authors' fieldworks in the southern and eastern parts of Rwanda. Although overt resistance to land division has not been observed to date, the land rights of the Tutsi returnees must be considered unstable because their legitimacy depends primarily on the strength and political stability of the RPF-led government. If the authority of RPF were to weaken, the land rights will be jeopardized. Throughout Rwandan history, in which political exclusion has often led to serious conflict, macro-level politics have repeatedly influenced land holding. Promotion of an inclusive democracy, therefore, is indispensable to escape the vicious circle between political instability and land rights.
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95 Briefe und Beilagen zwischen Siegfried Kracauer und Max Horkheimer, 1936-1949; 2 Briefe zwischen Else Staudinger vom American Committee for Refugee Scholars, Writers and Artists New York und Max Horkheimer, 10.07.1945, 24.07.1945; 2 Briefe zwischen Meyer Schapiro und Siegfried Kracauer 19.11.1937, 03.12.1937; 2 Briefe von Leo Löwenthal an Schapiro Meyer, 1940, 1941; 1 Brief und 1 Beilage von Max Horkheimer an A. Schütz, 02.08.1940; 1 Brief von Max Horkheimer an Trude Krautheimer, 30.07.1940; 1 Brief von Max Horkheimer an das Hebrew Sheltering and Immigrant Aid New York, 10.06.1940; 2 Briefe ziwschen dem Department of State Washington und Max Horkheimer, 05.04.1939, 1939; 2 Briefe zwischen Betty Drury Max Horkheimer, 05.11.1938, 07.11.1938; 2 Briefe zwischen Margaret Krafft und Max Horkheimer, 1938, 1939; 1 Brief von Gertrud Kurth-Kieslinger an Max Horkheimer, 02.10.1939; 2 Briefe zwischen Werner Kraft und Max Horkheimer, 19.01.1940, 01.03.1940; 1 Brief und 1 Beilage von Friedrich Krause an Max Horkheimer, 05.01.1939; 2 Briefe zwischen Karl Krayl und Max Horkheimer, 201.10.1937, 25.11.1937; 11 Briefe zwischen Ernst Krenek und Max Horkheimer, 1937-1941; 1 Brief von S. Krezel an Max Horkheimer, 12.02.1936; 1 Brief von Charles I. Krieger an Max Horkheimer, 01.08.1940; 1 Brief von H. Kronstein an Max Horkheimer, 20.05.1935; 3 Briefe zwischen Germaine Krull und Max Horkheimer, 1934, 06.09.1937, 1937; 3 Briefe zwischen Lawrence S. Kubie Sekretär der American Psychoanalytic Association, New York und Max Horkheimer, 11.05.1938, 1938; 5 Briefe und Beilagen zwsichen Julius Kühl und Max Horkheimer, 18.10.1939-1940; 1 Brief von Max Horkheimer an Herr Guggenheim, 20.02.1940; 1 Brief von Julius Kühl an die ESKA, 31.03.1945; 4 Briefe zwischen B. Kugelmann und Max Horkheimer, 1934, 1938, 1939; 1 Brief von Georg Kunzel an Max Horkheimer, 01.08.1930;
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Overcrowding of hospital Emergency Departments (EDs) in Australia is a complex issue of high public and professional prominence, resulted from a combination of increasing demands, increased complexity of care and Access Block. The aim of this study is to describe the distribution of the acuity and severity of current Queensland ED patients to better understand ED users...
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Objective To examine the extent to which the odds of birth, pregnancy, or adverse birth outcomes are higher among women aged 28 to 36 years who use fertility treatment compared with untreated women. Design Prospective, population-based. Setting Not applicable. Patient(s) Participants in the ALSWH born in 1973 to 1978 who reported on their infertility and use of in vitro fertilization (IVF) or ovulation induction (OI). Intervention(s) Postal survey questionnaires administered as part of ALSWH. Main Outcome Measure(s) Among women treated with IVF or OI and untreated women, the odds of birth outcomes estimated by use of adjusted logistic regression modeling. Result(s) Among 7,280 women, 18.6% (n = 1,376) reported infertility. Half (53.0%) of the treated women gave birth compared with 43.8% of untreated women. Women with prior parity were less likely to use IVF compared with nulliparous women. Women using IVF or OI, respectively, were more likely to have given birth after treatment or be pregnant compared with untreated women. Women using IVF or OI were as likely to have ectopic pregnancies, stillbirths, or premature or low birthweight babies as untreated women. Conclusion(s) More than 40% of women aged 28–36 years reporting a history of infertility can achieve births without using treatment, indicating they are subfertile rather than infertile.
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In a previous study we found evidence for an X-linked genetic component for familial typical migraine in two large Australian white pedigrees, designated MF7 and MF14. Significant excess allele sharing was indicated by nonparametric linkage (NPL) analysis using GENEHUNTER (P=0.031 and P=0.012, respectively), with a combined analysis of the two pedigrees showing further increased evidence for linkage, producing a maximum NPL score of 2.87 (P=0.011 ) at DXS 1123 on Xq27. The present study was aimed at refining the localization of the migraine X-chromosomal component by typing additional markers, performing haplotype analysis and applying a more powerful technique in the analysis of linkage data from these two pedigrees. Results from the haplotype analyses, coupled with linkage analyses that produced a peak GENEHUNTER-PLUS LOD* score of 2.388 (P=0.0005), provide compelling evidence for the presence of a migraine susceptibility locus on chromosome Xq24-28.
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Vibrational spectroscopy enables subtle details of the molecular structure of whiteite to be determined. Single crystals of a pure phase from a Brazilian pegmatite were used. The infrared and Raman spectroscopy were applied to compare the molecular structure of whiteite with that of other phosphate minerals. The Raman spectrum of whiteite shows an intense band at 972 cm-1 assigned to the m1 PO3- 4 symmetric stretching vibrations. The low intensity Raman bands at 1076 and 1173 cm-1 are assigned to the m3 PO3- 4 antisymmetric stretching modes. The Raman bands at 1266, 1334 and 1368 cm-1 are assigned to AlOH deformation modes. The infrared band at 967 cm-1 is ascribed to the PO3- 4 m1 symmetric stretching vibrational mode. The infrared bands at 1024, 1072, 1089 and 1126 cm-1 are attributed to the PO3-4 m3 antisymmetric stretching vibrations. Raman bands at 553, 571 and 586 cm-1 are assigned to the m4 out of plane bending modes of the PO3- 4 unit. Raman bands at 432, 457, 479 and 500 cm-1 are attributed to the m2 PO4 and H2PO4 bending modes. In the 2600 to 3800 cm-1 spectral range, Raman bands for whiteite are found 3426, 3496 and 3552 cm-1 are assigned to AlOH stretching vibrations. Broad infrared bands are also found at 3186 cm-1. Raman bands at 2939 and 3220 cm-1 are assigned to water stretching vibrations. Raman spectroscopy complimented with infrared spectroscopy has enabled aspects of the structure of whiteite to be ascertained and compared with that of other phosphate minerals.