Sökresultat

Filtyp

Din sökning på "*" gav 533854 sökträffar

Evaluation of male fertility potential by Toluidine Blue test for sperm chromatin structure assessment

We have previously suggested that the Toluidine Blue (TB) test can be used for sperm chromatin structure assessment. In this study, we wished to evaluate the clinical applicability of the TB test in assessing male fertility potential using well-defined groups of fertile and infertile men. Sixty-three fertile and 79 infertile men were tested. Infertility thresholds for the proportion of sperm with

The online freeze-tag problem

We consider the following problem from swarm robotics: given one or more "awake" robots in some metric space M, wake up a set of "asleep" robots. A robot awakens a sleeping robot by moving to the sleeping robot's position. When a robot awakens, it is available to assist in awakening other slumbering robots. We investigate offline and online versions of this problem and give a 2-competitive strateg

A variant in the transcription factor 7-like 2 (TCF7L2) gene is associated with an increased risk of gestational diabetes mellitus.

Aims/hypothesis Genetic and epidemiological studies suggest an association between gestational diabetes mellitus and type 2 diabetes. Both are polygenic multifactorial disorders characterised by beta cell dysfunction and insulin resistance. Our aim was to investigate whether common genetic variants that have previously been associated with type 2 diabetes or related phenotypes would also confer ri

Applications of two-photon absorption for detection of CO in combustion gases

Laser-induced fluorescence has been used for detection of CO in different environments. The fluorescence light was obtained by using a two-photon transition between theX1?- and theB1?- electronical states around 230 nm. Cell measurements indicate a detection limit lower than 0.1 ppm. Measurements in a CH4/air flame and in a low pressure dc discharge were realized with a diode-array detector, which

International Biofuel Trade - A Study of the Swedish Import

Following the development of large-scale use of biomass energy in the EU, international biofuel trade is a plausible scenario and something that is already taking place in Northern Europe. This paper focuses on Swedish biofuel imports, both direct and indirect imports, the latter which derive from the fact that part of the imported pulpwood and timber end up as fuel. The objective is to describe t

Effect of matrix elasticity on affinity binding and release of bioparticles. Elution of bound cells by temperature-induced shrinkage of the smart macroporous hydrogel

The first step of bacterial or viral invasion is affinity and presumably multisite binding of bioparticles to an elastic matrix like a living tissue. We have demonstrated that model bioparticles such as inclusion bodies (spheres of about 1 mu m in size) Escherichia coli cells (rods 1 x 3 mu m), yeast cells (8 mu m spheres), and synthetic microgel particles (0.4 mu m spheres) are binding via differ

Evaluation of seven different enzyme-linked immunosorbent assays for serodiagnosis of Staphylococcus aureus bacteremia

Objective: Serologic assays for Staphylococcus aureus antibodies were evaluated regarding their ability to differentiate between uncomplicated and complicated S. aureus bacteremia, between S. aureus and non-S. aureus bacteremia, and between S. aureus and non-S. aureus endocarditis. Methods: Enzyme-linked immunosorbent assays (ELISAs) were performed to measure Ig G antibodies against seven S. altre

Antioxidants, low molecular weight carbohydrates, and total antioxidant capacity in strawberries (Fragaria x ananassa): Effects of cultivar, ripening, and storage

Four cultivars of strawberries (Senga Sengana, BFr77111, Elsanta, and Honeoye) were studied for their content of antioxidants, total antioxidant capacity, and low molecular weight carbohydrates in relation to harvest year, ripening stage, and cold storage. For ascorbic acid, chlorogenic acid, ellagic acid, and total antioxidative capacity, measured in both water-soluble and water-insoluble extract

Synthesis of a globotetraose trimer.

The synthesis is described of a globotetraose trimer in 74% yield by the reaction of tris(2-aminoethyl)amine with the hydrophobic squaric decyl ester glycoside of globotetraose. The synthesis was readily monitored and purified using reversed phase HPLC. Unreacted squaric decyl ester globotetraoside was recovered rendering the method highly economical.

Improved chemical analysis of cellulose ethers using dialkylamine derivatization and mass spectrometry

Oligosaccharides of hydroxypropylmethyl cellulose, hydroxypropyl cellulose, and methyl cellulose were investigated by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The cellulose ether oligosaccharides were produced either by enzymatic depolymerization utilizing the purified family 5 endoglucanase from Bacillus agaradhaerens or by partial acidic depolymerization. To lowe

Local seed rain and seed bank in a species-rich grassland: effects of plant abundance and seed size

In this study, we examined the relationship between seed size, seed rain, and seed bank in a species-rich perennial grassland in Sweden. The seed rain was monitored by 100 seed traps placed in a 10 m x 10 m area for 1 year. The seed bank was sampled by taking 100 soil samples, each in close vicinity to a seed trap. Abundance of reproductive ramets in the area was estimated, since this is likely to

Time dependence of the activity concentration ratio of red marrow to blood and implications for red marrow dosimetry.

BACKGROUND: The method for red marrow dosimetry in radioimmunotherapy, in the absence of specific activity uptake in red marrow, is based on the activity measured in the blood or plasma. The activity concentration ratio of red marrow to blood is then assumed to be constant. The aim of the current study was to determine whether this ratio varies with time after injection. METHODS: Measurements were

Time-resolved NIR/Vis spectroscopy for analysis of solids: Pharmaceutical tablets

Time-resolved spectroscopy in the visible and near-infrared (NIR) regions was used in a feasibility study for analysis of solid pharmaceuticals. The objective of the experiments was to study the interaction of light with pharmaceutical solids and to investigate the usefulness of the method as an analytical toot for spectroscopic analysis. In these experiments, a pulsed Ti:sapphire laser and white

Near-infrared spectroscopic imaging of stimulus-related hemodynamic responses on the neonatal auditory cortices.

We have used near-infrared spectroscopy (NIRS) to study hemodynamic auditory evoked responses on 7 full-term neonates. Measurements were done simultaneously above both auditory cortices to study the distribution of speech and music processing between hemispheres using a 16-channel frequency-domain instrument. The stimulation consisted of 5-second samples of music and speech with a 25-second silent

Nestling provisioning in polygynous great reed warblers (Acrocephalus arundinaceus): do males bring larger prey to compensate for fewer nest visits?

Most studies of social polygyny in birds have examined male provisioning on the basis of the number of feeding visits. This may be misleading if males compensate for infrequent visits by bringing larger prey at each visit. We investigated nestling provisioning in the socially polygynous great reed warbler, Acrocephalus arundinaceus, in south Central Sweden in 1996-1997. We collected data on rare o

Roxithromycin potentiates the effects of chloroquine and mefloquine on multidrug-resistant Plasmodium falciparum in vitro

Chloroquine (CQ) and mefloquine (MQ) are no longer potent antimalarial drugs due to the emergence of resistant Plasmodium falciparum. Combination therapy has become the standard for many regimes in overcoming drug resistance. Roxithromycin (ROM), a known p-glycoprotein inhibitor, is reported to have antimalarial activity and it is hoped it will potentiate the effects of both CQ/MQ and reverse CQ/M

Cytokines induce upregulation of vascular P2Y(2) receptors and increased mitogenic responses to UTP and ATP

P2Y(2) receptors, which mediate contractile and mitogenic effects of extracellular nucleotides in vascular smooth muscle cells (VSMCs), are upregulated in the synthetic phenotype of VSMCs and in the neointima after balloon angioplasty, suggesting a role in the development of atherosclerosis. Because released cytokines in atherosclerotic lesions mediate multiple effects on gene transcription in VSM

Controlled fed-batch fermentations of dilute-acid hydrolysate in pilot development unit scale

Inhibitors formed during wood hydrolysis constitute a major problem in fermenting dilute-acid hydrolysates. By applying a fed-batch technique, the levels of inhibitory compounds may be held low, enabling high ethanol productivity. In this study, a previously developed fed-batch strategy was modified and implemented for use in pilot development unit (PDU) scale. The rate of total gas formation, mea