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The origin and evolution of ribonucleotide reduction.

Ribonucleotide reduction is the only pathway for de novo synthesis of deoxyribonucleotides in extant organisms. This chemically demanding reaction, which proceeds via a carbon-centered free radical, is catalyzed by ribonucleotide reductase (RNR). The mechanism has been deemed unlikely to be catalyzed by a ribozyme, creating an enigma regarding how the building blocks for DNA were synthesized at th

CYP19A1 Genetic Variation in Relation to Prostate Cancer Risk and Circulating Sex Hormone Concentrations in Men from the Breast and Prostate Cancer Cohort Consortium

Sex hormones, particularly the androgens, are important for the growth of the prostate gland and have been implicated in prostate cancer carcinogenesis, yet the determinants of endogenous steroid hormone levels remain poorly understood. Twin studies suggest a heritable component for circulating concentrations of sex hormones, although epidemiologic evidence linking steroid hormone gene variants to

TCF7L2 Polymorphism, Weight Loss and Proinsulin: Insulin Ratio in the Diabetes Prevention Program

Aims: TCF7L2 variants have been associated with type 2 diabetes, body mass index (BMI), and deficits in proinsulin processing and insulin secretion. Here we sought to test whether these effects were apparent in high-risk individuals and modify treatment responses. Methods: We examined the potential role of the TCF7L2 rs7903146 variant in predicting resistance to weight loss or a lack of improvemen

Exploring critical factors for fermentative hydrogen production from various types of lignocellulosic biomass

Four dilute-acid pretreated and hydrolysed lignocellulosic raw materials were evaluated as substrates for fermentative hydrogen production by Caldicellulosiruptor saccharolyticus. Their fermentability was ranked in the order: barley straw > wheat straw > corn stalk > corn cob. The content of 5-hydroxymethylfurfural (HMF) in medium with hydrolysates prepared from corn cob (1.0 g/L) and corn stalk (

Treating tumoural diseases (cancer) with a

The aim is to review a patented method and apparatus for treating tumor diseases (cancer) with a combination of ionizing radiation and pulsed electric fields that might open a new regime of radiation therapy fractionation with a short intensive treatment with high radiation dose fractions combined with pulsed electric fields. Sub-optimal radiation treatment was administered separately or in combin

Physiological recovery from night-call duty - a field study of physicians

Popular Abstract in Swedish Läkares nattjour innebär långa arbetspass, höga krav, stress och sömnbrist. I dagens läge liknar nattjouren ofta ett nattskift med begränsade möjligheter till vila under arbetspasset. Skiftarbete med nattskift har i många undersökningar visats ge ökad risk för bland annat hjärtinfarkt och diabetes, samt även ha en negativ inverkan på välbefinnande och sömn. Samtliga desAbstract Physicians’ work on night-call entails long and stressful working hours with high demands and disrupted sleep. Incomplete recovery is considered to be the most important link between acute physiological stress reactions, shift work and chronic health effects. Mental and physiological activation naturally accompanies night-call duty, but the crucial issue, from a health perspective, is wh

The structure of superantigen complexed with TCR and MHC reveals novel insights into superantigenic T cell activation

Superantigens (SAgs) are bacterial toxins that interact with immunoreceptors, T cell receptor (TCR) and major histocompatibility complex (MHC) class II, conventionally through the variable beta-domain of TCR (TCRV beta). They induce a massive release of cytokines, which can lead to diseases such as food poisoning and toxic shock syndrome. In this study, we report the X-ray structure of the ternary

Tumor Suppressor function of the deubiquitinating enzyme BAP1 and its substrate gamma-tubulin In regulation of cell cycle and genome stability

In normal cells, the cell cycle is controlled by a complex series of signalling pathways by which a cell grows, replicates its DNA and divides. The critical task of the cell cycle is to ensure that DNA is faithfully replicated and that identical chromosomal copies are distributed equally to two daughter cells during mitosis with the help of the mitotic spindle. Thus, mitotic spindle formation is v

Boktryckarna i Åbo 1750-1828. En bokhistorisk studie genom ett yrke

When the immigrant printer from Germany, Johan Christopher Frenckell (1719-1779), became co-owner and principal of the academic printing house in Åbo in 1765, the old competition with the Royal Finnish Printing Office in Stockholm became obvious. The privileges to print catechisms and hymnbooks in Finnish now belonged again to the university of Åbo, but the Carlbohms continued to print these best-

Hygroscopic properties of submicrometer atmospheric aerosol particles measured with H-TDMA instruments in various environments - a review

The hygroscopic properties play a vital role for the direct and indirect effects of aerosols on climate, as well as the health effects of particulate matter (PM) by modifying the deposition pattern of inhaled particles in the humid human respiratory tract. Hygroscopic Tandem Differential Mobility Analyzer (H-TDMA) instruments have been used in field campaigns in various environments globally over

Observing solute transport in the capillary fringe using image analysis and electrical resistivity tomography in laboratory experiments

Five laboratory experiments were conducted to study solute transport in the capillary fringe in a sand filled glass tank containing an artificial groundwater zone, an unsaturated zone, and a capillary fringe in between. Dye stained water, applied at the soil surface, moved downwards through the unsaturated zone and then horizontally in the capillary fringe. The horizontal velocity of the dye plume

Snail herbivory decreases cyanobacterial abundance and lichen diversity along cracks of limestone pavements

Herbivores are known to decrease plant species diversity in ecosystems with low productivity. Limestone pavements are low-productive habitats harboring specialized communities of cyanobacteria, and endo- and epilithic lichens exposed to extreme temperature and humidity fluctuations. Pavements of the Great Alvar (O¨ land, Sweden) are covered by free-living cyanobacteria giving the rock surface a da

Growth of asteroids, planetary embryos, and Kuiper belt objects by chondrule accretion.

Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but the mechanism is not understood. We show that the main growth of asteroids can result from gas drag-assisted accretion of chondrules. The largest planetesimals of a pop

The Earthshine Telescope Project

The Earthshine telescope project is a collaborative effort between Lund Observatory (LO) in Sweden and the Danish Meteorological Institute (DMI) with the purpose of constructing one or more robotic telescopes to record the albedo of the Earth over a long time. The objective is to measure long-term development of the global cloud cover and reflectivity for climate modeling. A 1% change in the Earth