Endoplasmic reticulum stress (ER stress) has been implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF), a disease of progressive fibrosis and respiratory failure. ER stress activates a signaling pathway called the unfolded protein response (UPR) that either restores homeostasis or promotes apoptosis. The bifunctional kinase/RNase IRE1α is a UPR sensor/effector that promotes apoptosis if ER stress remains high and irremediable (i.
View Article and Find Full Text PDFAnnu Rev Biochem
June 2019
X-ray free-electron lasers provide femtosecond-duration pulses of hard X-rays with a peak brightness approximately one billion times greater than is available at synchrotron radiation facilities. One motivation for the development of such X-ray sources was the proposal to obtain structures of macromolecules, macromolecular complexes, and virus particles, without the need for crystallization, through diffraction measurements of single noncrystalline objects. Initial explorations of this idea and of outrunning radiation damage with femtosecond pulses led to the development of serial crystallography and the ability to obtain high-resolution structures of small crystals without the need for cryogenic cooling.
View Article and Find Full Text PDFActa Crystallogr A Found Adv
January 2019
To date X-ray protein crystallography is the most successful technique available for the determination of high-resolution 3D structures of biological molecules and their complexes. In X-ray protein crystallography the structure of a protein is refined against the set of observed Bragg reflections from a protein crystal. The resolution of the refined protein structure is limited by the highest angle at which Bragg reflections can be observed.
View Article and Find Full Text PDFX-ray free electron lasers (XFELs) provide ultrashort intense X-ray pulses suitable to probe electron dynamics but can also induce a multitude of nonlinear excitation processes. These affect spectroscopic measurements and interpretation, particularly for upcoming brighter XFELs. Here we identify and discuss the limits to observing classical spectroscopy, where only one photon is absorbed per atom for a Mn in a light element (O, C, H) environment.
View Article and Find Full Text PDFThe analysis of a single-particle imaging (SPI) experiment performed at the AMO beamline at LCLS as part of the SPI initiative is presented here. A workflow for the three-dimensional virus reconstruction of the PR772 bacteriophage from measured single-particle data is developed. It consists of several well defined steps including single-hit diffraction data classification, refined filtering of the classified data, reconstruction of three-dimensional scattered intensity from the experimental diffraction patterns by orientation determination and a final three-dimensional reconstruction of the virus electron density without symmetry constraints.
View Article and Find Full Text PDFPrim Health Care Res Dev
January 2019
AimsTo assess the 'Okay to Stay' plan to investigate if this reduces visits to emergency departments, unplanned admissions and elective admission to hospital in elderly patients with long-term health conditions. BACKGROUND: The incidence of long-term conditions is rising as the elderly population increases, resulting in more people from this group attending emergency departments and being admitted to hospital. Okay to Stay is a simple plan for people with long-term conditions to help them remain in their own home if they suffer an acute exacerbation in their health.
View Article and Find Full Text PDFIndividuals with gambling disorder (GD) report much higher rates of post-traumatic stress symptoms and post-traumatic stress disorder (PTSS/D) than the general population, and individuals with both PTSS/D and GD often report much greater distress and impairment in daily life in comparison to individuals with GD alone (Grubbs, Chapman, Milner, Gutierrez, & Bradley, 2018). Despite these associations, little is known about the specific ways in which PTSS/D and GD might influence each other. To address this gap in research, the present work sought to examine how PTSD might be related to the expression and experience of gambling related cognitions.
View Article and Find Full Text PDFProblem gambling and gambling disorder (GD) are associated with a range of mental health concerns that extend beyond gambling behaviors alone. Prior works have consistently linked gambling disorder with symptoms of posttraumatic stress disorder (PTSD), both cross-sectionally and over time. However, very little work has examined the specific relationships between these 2 disorders.
View Article and Find Full Text PDFLiquid microjets are a common means of delivering protein crystals to the focus of X-ray free-electron lasers (FELs) for serial femtosecond crystallography measurements. The high X-ray intensity in the focus initiates an explosion of the microjet and sample. With the advent of X-ray FELs with megahertz rates, the typical velocities of these jets must be increased significantly in order to replenish the damaged material in time for the subsequent measurement with the next X-ray pulse.
View Article and Find Full Text PDFDiffraction before destruction using X-ray free-electron lasers (XFELs) has the potential to determine radiation-damage-free structures without the need for crystallization. This article presents the three-dimensional reconstruction of the Melbournevirus from single-particle X-ray diffraction patterns collected at the LINAC Coherent Light Source (LCLS) as well as reconstructions from simulated data exploring the consequences of different kinds of experimental sources of noise. The reconstruction from experimental data suffers from a strong artifact in the center of the particle.
View Article and Find Full Text PDFDuring the past few years, serial crystallography methods have undergone continuous development and serial data collection has become well established at high-intensity synchrotron-radiation beamlines and XFEL radiation sources. However, the application of experimental phasing to serial crystallography data has remained a challenging task owing to the inherent inaccuracy of the diffraction data. Here, a particularly gentle method for incorporating heavy atoms into micrometre-sized crystals utilizing lipidic cubic phase (LCP) as a carrier medium is reported.
View Article and Find Full Text PDFPreeclampsia is a common obstetrical complication, hallmarked by new-onset hypertension. Believed to result from placental insufficiency and chronic placental ischemia, the symptoms of preeclampsia are caused by release of pathogenic factors from the placenta itself, although the mechanisms of their regulation are in many cases unknown. One potential mechanism is through changes in placental epigenetic chromatin modifications, particularly histone acetylation and DNA methylation.
View Article and Find Full Text PDFThe non-monochromatic beamline BL1 at the FLASH free-electron laser facility at DESY was upgraded with new transport and focusing optics, and a new permanent end-station, CAMP, was installed. This multi-purpose instrument is optimized for electron- and ion-spectroscopy, imaging and pump-probe experiments at free-electron lasers. It can be equipped with various electron- and ion-spectrometers, along with large-area single-photon-counting pnCCD X-ray detectors, thus enabling a wide range of experiments from atomic, molecular, and cluster physics to material and energy science, chemistry and biology.
View Article and Find Full Text PDFIn both NOD mice and humans, the development of type 1 diabetes (T1D) is dependent in part on autoreactive CD8 T cells recognizing pancreatic β cell peptides presented by often quite common MHC class I variants. Studies in NOD mice previously revealed that the common H2-K and/or H2-D class I molecules expressed by this strain aberrantly lose the ability to mediate the thymic deletion of pathogenic CD8 T cell responses through interactions with T1D susceptibility genes outside the MHC. A gene(s) mapping to proximal chromosome 7 was previously shown to be an important contributor to the failure of the common class I molecules expressed by NOD mice to mediate the normal thymic negative selection of diabetogenic CD8 T cells.
View Article and Find Full Text PDFAmphibians are the vertebrate group with the highest number of species threatened with extinction, and habitat loss and fragmentation are considered to be among the leading causes of their declines and extinctions. Little is known of the population biology of amphibian species inhabiting montane forests in Central and West Africa, where anthropogenic activities such as farming and cattle raising are major threats to native biodiversity. We used Amplified Fragment Length Polymorphisms (AFLPs) to assess the population genetic structure of two poorly known species, Cardioglossa schioetzi and Leptodactylodon bicolor (both in the Arthroleptidae), in and around Ngel Nyaki Forest Reserve on the Mambilla Plateau in eastern Nigeria.
View Article and Find Full Text PDFPast research has found that individuals who are more sensitive to physically disgusting stimuli also condemn moral transgressions more harshly. However, there is debate about whether this condemnation includes transgressions that do not involve impure behaviors. We present a meta-analysis of 6 studies ( = 1082) which suggests that trait disgust is associated with condemnation of nonpurity transgressions.
View Article and Find Full Text PDFGWAS have repeatedly mapped susceptibility loci for emphysema to genes that modify hedgehog signaling, but the functional relevance of hedgehog signaling to this morbid disease remains unclear. In the current study, we identified a broad population of mesenchymal cells in the adult murine lung receptive to hedgehog signaling, characterized by higher activation of hedgehog surrounding the proximal airway relative to the distal alveoli. Single-cell RNA-sequencing showed that the hedgehog-receptive mesenchyme is composed of mostly fibroblasts with distinct proximal and distal subsets with discrete identities.
View Article and Find Full Text PDFThe homeobox gene Gsx2 has previously been shown to inhibit oligodendroglial specification in dorsal lateral ganglionic eminence (dLGE) progenitors of the ventral telencephalon. The precocious specification of oligodendrocyte progenitor cells (OPCs) observed in Gsx2 mutants, however, is transient and begins to normalize by late stages of embryogenesis. Interestingly, this normalization correlates with the expansion of Gsx1, a close homolog of Gsx2, in a subset of progenitors in the Gsx2 mutant LGE.
View Article and Find Full Text PDFBackground: Ever since the first atomic structure of an enzyme was solved, the discovery of the mechanism and dynamics of reactions catalyzed by biomolecules has been the key goal for the understanding of the molecular processes that drive life on earth. Despite a large number of successful methods for trapping reaction intermediates, the direct observation of an ongoing reaction has been possible only in rare and exceptional cases.
Results: Here, we demonstrate a general method for capturing enzyme catalysis "in action" by mix-and-inject serial crystallography (MISC).
Global efforts to eliminate tuberculosis by 2050 continue to challenge health systems. In countries with low reported tuberculosis incidence, such as the USA (3.1/100,000 population) and Cuba (6.
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