Following decades of detailed kinetic and spectroscopic evidence, two new, independent X-ray structures for the cytochrome b(6)f complex of photosynthesis now reveal the arrangement of its key electron carriers relative to each other, and to their protein ligands. But these are not predictable additions to the structural collection. The complex is dimeric, and encloses a central chamber in which p

Joining chain (J-chain) is well known as an integrated component of dimeric immunoglobulin A (IgA) and pentameric IgM. We show here that the J-chain protein is also expressed in a subset of CD11c+ dendritic cells (DC) in C57BL/6 mice. J-chain knockout mice (J−/− mice) had a reduced fraction of CD4−/CD8α+ and mPDCA-1+ DC in the spleen. J−/− mice also had reduced levels of RNA for the immunoregulato

Timely regulation of phosphatidylinositol-3,4-bisphosphate [PI(3,4)P2] and phosphatidylinositol-3,4,5-trisphosphate [PI(3,4,5)P3] abundance in cells is essential for the control of cellular homeostasis. The concentrations of these lipids are low in quiescent cells but rapidly and transiently increase following growth factor receptor (GFR) stimulation, which triggers cellular metabolic changes, pro

Based on a nanometer-scale semiconductor channel with an intentionally broken geometric symmetry, we have realized a type of memory device that consists of only two terminals, rather than the minimum of three terminals in conventional semiconductor memories. The charge retention time is at least 10 h at cryogenic temperatures and a few minutes at room temperature. Furthermore, the simplicity of th

The development of metal tolerance in soil bacterial communities exposed to different heavy metals was examined under laboratory conditions. An agricultural soil amended with different Zn concentrations was studied most intensively, and measurements were made over a 28-month incubation period by means of the thymidine incorporation technique. Tolerance levels were not affected by metal concentrati

Low-lying resonance states in 7He(6He+n), formed after fragmentation reactions of a 227 MeV/nucleon 8He beam on a carbon target, have been studied. Coincidences between 6He nuclei and neutrons, corresponding to the one-neutron knockout channel in 8He, were selected. The relative energy spectrum in the 6He+n system shows a structure, which is interpreted as the 7He ( Ipi = 3/2(-)) ground state, unb

Leaf and bark volatiles from nonhost angiosperm trees were tested on lps duplicatus by gas chromatographic-electroantennographic detection (GC-EAD) and by pheromone-baited traps in Sweden and Inner Mongolia, China, respectively. GC-EAD analysis of the headspace volatiles from fresh bark chips of Betula pubescens revealed trans-conophthorin, two green leaf Volatiles (GLVs): 1-hexanol and (Z)-3-hexe

1. The ability to resist infection is an important component of survival and lifetime reproductive success. Mounting and maintaining an immunological defence is assumed to be energetically costly and nutritional resources expended on immune function may induce trade-offs with other energetically expensive functions, including reproduction. Resource limitation may even have transgenerational effect

A result is given, relating the leading principal minors of a direct product of matrices to the leading principal minors of the matrices.

The majority of studies on molecularly imprinted polymers has until now been carried out on irregularly shaped particles prepared by grinding of polymer monoliths. The preparation procedures are time- and labor-consuming and produce particles of wide size distributions. To answer the need for fast and straightforward routes to spherical molecularly imprinted polymer beads, we have developed a meth

The phase behavior (temperature vs composition) and microstructure for the two binary systems Pluronic 25R4 [(PO)(19)(EO)33(PO)(19)]-water and Pluronic 25R2 [PO)(21)(EO)(14)(PO)(21)]-water have been studied by a combined experimental approach in the whole concentration range and from 5 to 80 degreesC. The general phase behavior has been identified by inspection under polarized light. Precise phase

A generally implementable method for predicting salvageability on the presenting electrocardiogram (ECG) in patients with acute myocardial infarction (AMI) would be of great clinical importance. ECG-derived Grades of Ischemia (1) have been proven useful in predicting the extent and severity of left ventricular dysfunction after anterior MI, estimating short and long-term prognosis, final infarct s

While the enormous clinical and psychosocial importance of pruritus in many areas of medicine and the detrimental effects of chronic 'itch' on the quality of life of an affected individual are widely appreciated, the complexity of this sensation is still often grossly underestimated. The current Controversies feature highlights this complexity by portraying pruritus as a truly interdisciplinary pr

Endometriotic tissue sometimes shows an invasive pattern. but the growth regulation of the tissue is insufficiently characterized. In a research programme on factors regulating endometriotic growth, the DNA ploidy status and S-phase fraction (SPF) were studied. Fresh-frozen endometriotic tissue from 14 women and endometrium from 11 of them were studied using flow cytometry. A clear diploid pattern

In this work, a k-space segmentation technique for quantitative studies of pulsatile cerebrospinal fluid (CSF) flow is suggested. Three k-space lines are sampled for each of two interleaved gradient-echo sequences (velocity-compensated and velocity-encoded) within each repetition interval. Nine cardiac phases are obtained at a heart rate of 60 bpm with maintained nominal resolution and a factor of

Endotoxin exposure is associated with wheeze and asthma morbidity, while early life exposure may reduce risk of allergy and asthma. Unfortunately, it is difficult to compare endotoxin results from different laboratories and environments. We undertook this study to determine if lipopolysaccharide ( LPS) extraction efficiency could account for differences among laboratories. We generated and collect