Correction to: Accuracy of surface strain measurements from transmission electron microscopy images of nanoparticles

Abstract Unfortunately, after publication of this article [1], it was noticed that the name of the fifth author was incorrectly displayed as Jakob Schiøz. The correct name is Jakob Schiøtz and can be seen in the corrected author list above. The original article has also been updated to correct this error

Accuracy of surface strain measurements from transmission electron microscopy images of nanoparticles

Additional file 1. Section S1. Measuring the center of mass. Figure S1. Definition of integration regions for center of mass calculations. Figure S2. Comparison of center of mass positions with peak positions. Figure S3. Magnitudes of thermal vibrations. Figure S4. Comparison of our method with GPA. Figure S5. Negative defocus measurements. Figure S6. Planar strain errors for increasing tilt. Figure S7. Surface strain errors for increasing tilt

Why growth equals power - and why it shouldn't : constructing visions of China

When discussing the success of China's transition from socialism, there is a tendency to focus on growth figures as an indication of performance. Whilst these figures are indeed impressive, we should not confuse growth with development and assume that the former necessarily automatically generates the latter. Much has been done to reduce poverty in China, but the task is not as complete as some observers would suggest; particularly in terms of access to health, education and welfare, and also in dealing with relative (rather than absolute) depravation and poverty. Visions of China have been constructed that exaggerate Chinese development and power in the global system partly to serve political interests, but partly due to the failure to consider the relationship between growth and development, partly due to the failure to disaggregate who gets what in China, and partly due to the persistence of inter-national conceptions of globalised production, trade, and financial flows

Mechanism of the Quorum-Quenching Lactonase (AiiA) from Bacillus thuringiensis. 1. Product-Bound Structures†‡

ABSTRACT: The N-acyl-L-homoserine lactone hydrolases (AHL lactonases) have attracted considerable attention because of their ability to quench AHL-mediated quorum-sensing pathways in Gram-negative bacteria and because of their relation to other enzymes in the metallo--lactamase superfamily. To elucidate the detailed catalytic mechanism of AHL lactonase, mutations are made on residues that presumably contribute to substrate binding and catalysis. Steady-state kinetic studies are carried out on both the wild-type and mutant enzymes using a spectrum of substrates. Two mutations, Y194F and D108N, present significant effects on the overall catalysis. On the basis of a high-resolution structural model of the enzyme-product complex, a hybrid quantum mechanical/molecular mechanical method is used to model the substrate binding orientation and to probe the effect of the Y194F mutation. Combining all experimental and computational results, we propose a detailed mechanism for the ring-opening hydrolysis of AHL substrates as catalyzed by the AHL lactonase from Bacillus thuringiensis. Several features of the mechanism that are also found in related enzymes are discussed and may help to define an evolutionary thread that connects the hydrolytic enzymes of this mechanistically diverse superfamily. Proteins in the metallo--lactamase superfamily span all three domains of life and are quite diverse, encompassin

Structural and Biochemical Characterization of AidC, a Quorum-Quenching Lactonase With Atypical Selectivity

Quorum-quenching catalysts are of interest for potential application as biochemical tools for interrogating interbacterial communication pathways, as antibiofouling agents, and as anti-infective agents in plants and animals. Herein, the structure and function of AidC, an N-acyl-l-homoserine lactone (AHL) lactonase from Chryseobacterium, is characterized. Steady-state kinetics show that zinc-supplemented AidC is the most efficient wild-type quorum-quenching enzymes characterized to date, with a kcat/KM value of approximately 2 × 106 M–1 s–1 for N-heptanoyl-l-homoserine lactone. The enzyme has stricter substrate selectivity and significantly lower KM values (ca. 50 μM for preferred substrates) compared to those of typical AHL lactonases (ca. >1 mM). X-ray crystal structures of AidC alone and with the product N-hexanoyl-l-homoserine were determined at resolutions of 1.09 and 1.67 Å, respectively. Each structure displays as a dimer, and dimeric oligiomerization was also observed in solution by size-exclusion chromatography coupled with multiangle light scattering. The structures reveal two atypical features as compared to previously characterized AHL lactonases: a “kinked” α-helix that forms part of a closed binding pocket that provides affinity and enforces selectivity for AHL substrates and an active-site His substitution that is usually found in a homologous family of phosphodiesterases. Implications for the catalytic mechanism of AHL lactonases are discussed

Interferon-β 1a and SARS Coronavirus Replication

A global outbreak of severe acute respiratory syndrome (SARS) caused by a novel coronavirus began in March 2003. The rapid emergence of SARS and the substantial illness and death it caused have made it a critical public health issue. Because no effective treatments are available, an intensive effort is under way to identify and test promising antiviral drugs. Here, we report that recombinant human interferon (IFN)-β 1a potently inhibits SARS coronavirus replication in vitro

S100A8 and S100A9 Are Associated with Doxorubicin-Induced Cardiotoxicity in the Heart of Diabetic Mice

© 2016 Pei, Tam, Sin, Wang, Yung, Chan, Wong, Ying, Lai and Siu. Cardiomyopathy is a clinical problem that occurs in the hearts of type 2 diabetic patients as well as cancer patients undergoing doxorubicin chemotherapy. The number of diabetic cancer patients is increasing but surprisingly the cardiac damaging effects of doxorubicin, a commonly used chemotherapeutic drug, on diabetic hearts have not been well-examined. As the signaling mechanisms of the doxorubicin-induced cardiomyopathy in type 2 diabetic heart are largely unknown, this study examined the molecular signaling pathways that are responsible for the doxorubicin-induced cardiotoxicity in type 2 diabetic hearts. Male 14- to 18-week-old db/db mice were used as the type 2 diabetic model, and age-matched non-diabetic db/+ mice served as controls. The db/+ non-diabetic and db/db diabetic mice were randomly assigned to the following groups: db/+CON, db/+DOX-5d, db/+DOX-7d, db/dbCON, db/dbDOX-5d, and db/dbDOX-7d. Mice assigned to doxorubicin (DOX) group were exposed to an intraperitoneal (i.p.) injection of DOX at a dose of 15 mg/kg to induce cardiomyopathy. Mice in control (CON) groups were i.p. injected with the same volume of saline instead of DOX. Mice were euthanized by overdose of ketamine and xylazine 5 or 7 days after the DOX injection. Microarray analysis was adopted to examine the changes of the whole transcriptional profile in response to doxorubicin exposure in diabetic hearts. Ventricular fractional shortening was examined as an indicator of cardiac function by transthoracic echocardiography. The presence of diabetic cardiomyopathy in db/db mice was evident by the reduction of fractional shortening. There was a further impairment of cardiac contractile function 7 days after the DOX administration in db/db diabetic mice. According to our microarray analysis, we identified a panel of regulatory genes associated with cardiac remodeling, inflammatory response, oxidative stress, and metabolism in the DOX-induced cardiac injury in diabetic heart. The microarray results of selected genes were confirmed by real time PCR. Notably, S100A8 and S100A9 were found to have a unique specific expression pattern that was coincident with the DOX-induced cardiomyopathy in diabetic hearts. Correspondingly, NF-κB expression in diabetic hearts was increased together with the elevation of S100A8/9 and activation of p38 MAPK signaling after DOX administration, which induced cardiac inflammation as demonstrated by the elevation of cardiac IL-6 level. These findings provide novel pre-clinical information for revealing the S100A8/A9-associated molecular signaling pathways that mediate the doxorubicin-induced cardiotoxicity in diabetic hearts.Link_to_subscribed_fulltex