Structural assignments of distinct FRET states.

<p>(A) CD spectra of Tel23 thermally annealed in 100 mM KCl (open circles), Tel23 in 100 mM NaCl (asterisks), and Hybrid Mutant in 100 mM KCl (closed circles). (B) The smFRET distribution of Tel23 thermally annealed in 100 mM NaCl fit with Gaussian functions. Gaussian fits to the data are shown in black. (C) The smFRET distribution of Hybrid Mutant thermally annealed in 100 mM KCl fit with Gaussian functions. Gaussian fits to the data are shown in black.</p

A qualitative energy landscape model for kinetic partitioning during telomere DNA GQ folding.

<p>A lower energy barrier between the low-FRET (unfolded) and the high-FRET (folded) state creates a kinetic trap during the early stages of folding. To escape the kinetic trap, the molecule must unfold and then re-fold into one of the more energetically stable mid-FRET (folded) states. This process is facilitated during thermal annealing at higher temperatures, or during <i>in </i><i>situ</i> folding by low ionic strength or prolonged incubation times. </p

Experimental setup for telomere DNA GQ single molecule FRET measurements.

<p>(A) Planar telomere DNA G-quartet structure with coordinated monovalent cation. (B) Grey rectangles represent planar G-quartets and backbone polarity (5’à3’) is indicated by black arrowheads. Molecules are immobilized on a microscope slide and FRET is measured as the energy transfer between the donor (Cy3) and acceptor (Cy5) dye. (C) Human telomere G-quadruplex structures formed by Tel23 sequence.</p

Diagnostic Accuracy of Computed Tomography for Chronic Thromboembolic Pulmonary Hypertension: A Systematic Review and Meta-Analysis

<div><p>This study aimed to determine the diagnostic accuracy of computed tomography imaging for the diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH). Additionally, the effect of test and study characteristics was explored. Studies published between 1990 and 2015 identified by PubMed, OVID search and citation tracking were examined. Of the 613 citations, 11 articles (n=712) met the inclusion criteria. The patient-based analysis demonstrated a pooled sensitivity of 76% (95% confidence interval [CI]: 69% to 82%), and a pooled specificity of 96% (95%CI: 93% to 98%). This resulted in a pooled diagnostic odds ratio (DOR) of 191 (95%CI: 75 to 486). The vessel-based analyses were divided into 3 levels: total arteries、main+ lobar arteries and segmental arteries. The pooled sensitivity were 88% (95%CI: 87% to 90%)、95% (95%CI: 92% to 97%) and 88% (95%CI: 87% to 90%), respectively, with a pooled specificity of 90% (95%CI: 88% to 91%)、96% (95%CI: 94% to 97%) and 89% (95% CI: 87% to 91%). This resulted in a pooled diagnostic odds ratio of 76 (95%CI: 23 to 254),751 (95%CI: 57 to 9905) and 189 (95%CI: 21 to 1072), respectively. In conclusion, CT is a favorable method to rule in CTEPH and to rule out pulmonary endarterectomy (PEA) patients for proximal branches. Furthermore, dual-energy and 320-slices CT can increase the sensitivity for subsegmental arterials, which are promising imaging techniques for balloon pulmonary angioplasty (BPA) approach. In the near future, CT could position itself as the key for screening consideration and for surgical and interventional operability.</p></div

Characteristics of included studies¹.

<p>¹mPAP: mean PAP; sPAP: standard PAP.</p><p>Characteristics of included studies<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126985#t001fn001" target="_blank">¹</a>.</p

Removal of Ca²⁺ from the Oxygen-Evolving Complex in Photosystem II Has Minimal Effect on the Mn₄O₅ Core Structure: A Polarized Mn X‑ray Absorption Spectroscopy Study

Ca²⁺-depleted and Ca²⁺-reconstituted spinach photosystem II was studied using polarized X-ray absorption spectroscopy of oriented PS II preparations to investigate the structural and functional role of the Ca²⁺ ion in the Mn₄O₅Ca cluster of the oxygen-evolving complex (OEC). Samples were prepared by low pH/citrate treatment as one-dimensionally ordered membrane layers and poised in the Ca²⁺-depleted S₁ (S₁′) and S₂ (S₂′) states, the S₂′Y_Z^• state, at which point the catalytic cycle of water oxidation is inhibited, and the Ca²⁺-reconstituted S₁ state. Polarized Mn K-edge XANES and EXAFS spectra exhibit pronounced dichroism. Polarized EXAFS data of all states of Ca²⁺-depleted PS II investigated show only minor changes in distances and orientations of the Mn–Mn vectors compared to the Ca²⁺-containing OEC, which may be attributed to some loss of rigidity of the core structure. Thus, removal of the Ca²⁺ ion does not lead to fundamental distortion or rearrangement of the tetranuclear Mn cluster, which indicates that the Ca²⁺ ion in the OEC is not critical for structural maintenance of the cluster, at least in the S₁ and S₂ states, but fulfills a crucial catalytic function in the mechanism of the water oxidation reaction. On the basis of this structural information, reasons for the inhibitory effect of Ca²⁺ removal are discussed, attributing to the Ca²⁺ ion a fundamental role in organizing the surrounding (substrate) water framework and in proton-coupled electron transfer to Y_Z^• (D1-Tyr161)

Flow Diagram of Literature Search.

<div><p>Of 613 potentially relevant citations, 11 articles met our inclusion criteria and were included in the meta-analysis.</p> <p><i>From</i>: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). <i>P</i>referred <i>R</i>eporting <i>I</i>tems for <i>S</i>ystematic Reviews and <i>M</i>eta-<i>A</i>nalyses: The PRISMA Statement. PLoS Med 6(6): e1000097. doi:<a href="http://dx.doi.org/10.1371/journal.pmed1000097" target="_blank">10.1371/journal.pmed1000097</a></p> <p>For more information, visit <a href="http://www.prisma-statement.org" target="_blank">www.prisma-statement.org</a>.</p></div

Pooled Quality Assessment of Primary Studies.

<p>Pooled Quality Assessment of Primary Studies.</p

Forest plots of sensitivity.

<p>Sensitivity in (A) patient basis; (B) total arteries; (C) main + lobar arteries; (D) segmental arteries.</p

Forest plots of specificity.

<p>Specificity in (A) patient basis; (B) total arteries; (C) main + lobar arteries; (D) segmental arteries.</p