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Gemini surfactants: New synthetic vectors for gene transfection

The superior surfactant properties of cationic gemini surfactants are applied to the complex problem of introducing genes into cells. Of almost 250 new compounds tested, of some 20 different structural types, a majority showed very good transfection activity in vitro. The surfactant is shown to bind and compact DNA efficiently, and structural studies and calculations provide a working picture of t

Ternary phase diagrams in surfactant science

Phase equilibria in ternary systems ionic surfactant-long chain alcohol-water are discussed in relation to Per Ekwall's pioneering contributions to the field. It is described how modeling of the thermodynamic behavior leads to a better understanding of what molecular interactions cause the rich phase behavior of these systems.

Optimization of PIXE-sensitivity for detection of Ti in thin human skin sections

Modern sunscreens contain particles like TiO2 having sizes of 25-70 nm and acting as a reflecting substance. For cosmetic reasons the particle size is minimized. Questions have been raised to what degree these nano particles penetrate the skin barrier, and how they do affect the human. The EU funded project "Quality of skin as a barrier to ultra-fine particles" - NANODERM has started with the purp

Hög känsla av sammanhang kan ha hälsofrämjande effekter

Sense of coherence (SOC), e.g. meaningfulness of life, is according to the sociologist A. Antonovsky a health-promoting construct, which has been used in a number of descriptive studies in various populations. The aim of this population-based cross-sectional study was to investigate if middle-aged women with a self-reported low level of SOC also differed in biological variables, e.g. related to gl

Finite element models for use in mechanics including geological engineering

A number of finite element (FE) models have been developed, starting with a purely magnetic one. The magnetic model was verified against analytical solutions and the commercial FE-programme ANSYS. The magnetic model was then coupled to the wave-equation, resulting in a model governing linear magnetostriction. In the magnetostrictive model a property of two degrees of freedom, that is, displacement

High resolution banding analysis of the reciprocal translocation t(6;9) in acute nonlymphocytic leukemia

The cytogenetic, hematologic, and clinical characteristics of a 13-year-old girl with acquired t(6;9)(p23;q34) and dysmyelopoietic syndrome developing into acute myelomonocytic leukemia are described, bringing the total number of patients with t(6;9) and hematologic disease described in the literature up to 19. The diagnosis has been acute myeloid leukemia in the great majority of these patients;

Effects on the structure of arctic ecosystems in the short- and long-term perspectives

Species individualistic responses to warming and increased UV-B radiation are moderated by the responses of neighbors within communities, and trophic interactions within ecosystems. All of these responses lead to changes in ecosystem structure. Experimental manipulation of environmental factors expected to change at high latitudes showed that summer warming of tundra vegetation has generally led t

Factor V Leiden in pregnancies complicated by placental abruption

Objective Recent studies suggest an increased prevalence of obstetric complications in female carriers of hereditary or acquired thrombophilias. The aim of the study was to determine if carriership of the factor V (FV) Leiden mutation (activated protein C [APC] resistance) is higher in women who have had of placental abruption during pregnancy. Design A retrospective case-control study. Setting Un

Metabolic correlates to pacemaker activity in the smooth muscle of guinea-pig mesotubarium

Oxygen consumption (FO2) and lactate production (Flac) were measured during spontaneous activity in the guinea-pig mesotubarium. During spontaneous contractions FO2 increased to maximally 0.270 +/- 0.025 mumol min-1g-1 (n = 23), followed by a rapid fall immediately upon relaxation. In the relaxed period (5-15 min) between spontaneous contractions FO2 continued to slowly decrease by about 25% towar

Secondary limonene endo-ozonide: A major product from gas-phase ozonolysis of R-(+)-limonene at ambient temperature

A 16 s old gas-phase ambient temperature and 1% relative humidity reaction mixture of ozone and R-limonene (ca. 1:10) was sampled on XAD-2 resin followed by pressurized liquid extraction with dichloromethane at ambient temperature. Low temperature on-column injection and gas chromatography (GC) revealed equal amounts of diastereomeric secondary endo-limonene ozonides, in addition to 4-acetyl-l-met