During translation, the ribosome and several of its constituent proteins undergo structural transitions between different functional states. Protein L12, present in four copies in prokaryotic ribosomes, forms a flexible "stalk" with key functions in factor-dependent GTP hydrolysis during translocation. Here we have used heteronuclear NMR spectroscopy to characterize L12 conformation and dynamics i

The effects of enzyme structure and activity on the degradation of model cellulose substrates were investigated by ellipsometry for the cellulase Humicola insolens GH45. The inactive variant D10N was found to adsorb at the cellulose surface but also to be incorporated into the cellulose films to an extent that depended on pH. For the native protein, the initial adsorption monitored for the inactiv

Telomerase activity has been suggested to be critically involved in hematopoietic stem cell (HSC) self-renewal. However, it has been unclear whether human HSCs have telomerase activity and how telomerase activity is regulated within the HSC and progenitor pool. Here, we isolated living cord-blood (CB) CD34+ cells with up-regulated human telomerase reverse transcriptase (hTERT) expression by using

The function of six porcine left lung allografts was studied after pulmonary (140 mL/kg) and bronchial (50 mL/kg) artery perfusion with Perfadex (Kabi Pharmacia, Uppsala, Sweden) at room temperature, followed by 24-hour storage of the lungs in an atelectatic state in 6 degrees to 8 degrees C Perfadex, which is a low-potassium-dextran solution. Left lung transplantation was done followed by right p

Time-resolved transmittance was used to extract in vivo optical properties of leaves of green plants experimentally. In time-resolved transmittance measurements an ultrashort light pulse is directed onto the surface of the object and the transmitted light is measured with a time resolution in the range of picoseconds. A table-top terawatt laser was used to generate 200 fs light pulses at 790 nm wi

BACKGROUND: The aim of this study was to transplant lungs that had been topically cooled in the non-heart-beating donor for 6 hours, using the most challenging evaluation method possible, namely single-lung transplantation followed by immediate contralateral pneumonectomy. METHODS: Domestic pigs were used (6 donors and 6 recipients) with a mean body weight of 59 +/- 3 kg. Ventricular fibrillation

Treatment of [(COD)PtCl2] with LiN(SiMe3)(2) gives [COD]PtClN(SiMe3)(2) in high yield. This product was fully characterized, including an X-ray structure. From a number of examples it is shown to be a very convenient starting material for the preparation of PXP platinum pincer complexes, giving excellent yields of the cyclometalated product under mild conditions.

Direct and mediated electron transfer (DET and MET) between the enzyme and electrodes were compared for cellobiose dehydrogenase (CDH) from the basidiomycete Phanerochaete sordida (PsCDH). For DET, PsCDH was adsorbed at pyrolytic graphite (PG) electrodes while for MET the enzyme was covalently linked to a low potential Os redox polymer. Both types of electrodes were prepared in the presence of sin

Arsenic enrichment of groundwater in the Red River (Song Hong) delta in Vietnam was discovered in 1998. Several studies performed in this area found concentrations of As exceeding the WHO-guideline of 10 lg/L. This study focuses on an area south of Hanoi city, Nam Du, where a new well field came into operation in 2004. The new well field is situated on the bank along the Red River in order to faci

Background: The aim of the present study was to evaluate the future cumulative risk of prostate cancer in relation to levels of prostate-specific antigen (PSA) in blood and to determine whether this information could be used to individualize the PSA testing interval. Methods: The study included 5855 of 9972 men (aged 50-66 years) who accepted an invitation to participate in a prospective, randomiz

Selective supercritical fluid extraction (SFE) at 40 degrees C, 400 bar and 60 min was used to selectively remove bioavailable PCBs from a naturally contaminated limnic sediment. The extraction decreased the sediment concentrations of the nine studied PCBs by 54% (on average). Chironomid larvae were thereafter cultured in pre-extracted sediment as well as in untreated sediment to study the differe

Sixteen open-top chambers (diameter, 3.66 m) were established in a scrub oak habitat in central Florida where vegetation was removed in a planned burn prior to chamber installation. Eight control chambers have been continuously exposed to ambient air and eight have been continuously exposed to elevated CO2 at twice-ambient concentration (similar to700 ppm) for 5 years. Soil cores were collected fr

Impactor sampling and PIXE analysis constitute a good combination in detecting the influence of fugitive emission and ventilation air on ambient air quality. In total filter samples heavier natural particles mask the increase in mass due to the smaller industrial particles. Multielemental analysis of many samples is important in finding unknown sources and in evaluating the effect of all the sourc

In this population-based study, we assessed the relation between socioeconomic and psychosocial conditions in 1,094 pregnant women and subsequent infantile colic by means of self-administered questionnaires measuring exposures in the 17th pregnancy week and telephone interviews at infant age 5 weeks. There was a higher risk of colic in infants born to younger mothers, mothers with low instrumental

CD4(+) T-cell entry to the intestinal mucosa is central to the generation of mucosal immunity as well as chronic intestinal inflammation, yet the mechanisms regulating this process remain poorly defined. Here we show that murine small intestinal CD4+ lamina propria lymphocytes express a heterogeneous but restricted array of chemokine receptors including CCR5, CCR6, CCR9, CXCR3, and CXCR6. CD4+ T-c

A desymmetrization route to fused Troger's base analogues was developed. In this way, the synthesis of the first example of an anti-anti diastereomer of a fused tris-Troger's base analogue was accomplished. The resulting compound 5b is a nonlinear symmetric regioisomer obtained from p-bromoaniline in 7% yield. The corresponding syn-anti diastereomer 5a was obtained in 4% yield.

The amounts of sixty elements in developing, maturing, senescent and wilting leaves, and in the wintering dead leaves attached to the branches, are reported for a beech (Fagus sylvatica) forest on mor Podzol in south Sweden, a site with no local sources of pollution or geological anomalies. The amounts (contents per leaf) of K (potassium), Rb (rubidium), Cs (caesium), Cu (copper) and P (phosphorus

The use of molecular mechanics calculations to supplement experimental data in standard X-ray crystallography and NMR refinements is discussed and it is shown that structures can be locally improved by the use of quantum chemical calculations. Such calculations can also be used to interpret the structures, e. g. to decide the protonation state of metal-bound ligands. They have shown that metal sit

Three separate proteins, BchD, BchH, and BchI, together with ATP, insert magnesium into protoporphyrin IX. An analysis of ATP utilization by the subunits revealed the following: BchH catalyzed ATP hydrolysis at the rate of 0.9 nmol per min per mg of protein. BchI and BchD, tested individually, had no ATPase activity but, when combined, hydrolyzed ATP at the rate of 117.9 nmol/min per mg of protein