487 research outputs found
Convulsions and Shigellosis
The records of 97 children with culture-proven Shigellosis were reviewed in order to assess the frequency and risk factors of convulsions associated with this infection. Thirteen (13.4%) had convulsions, three of whom had additional features suggestive of encephalopathy. Clinical and laboratory data were compared between patients with and without convulsions to define the risk factors for the development of seizures. A high peak temperature and high band forms in excess of 10% of the differential white cell count were significant risk factors. Age, sex, family history of febrile seizure or epilepsy, and the Shigella strain were not significant risk factors.published_or_final_versio
Generation of induced pluripotent stem cell lines from 3 distinct laminopathies bearing heterogeneous mutations in lamin A/C
The term laminopathies defines a group of genetic disorders caused by defects in the nuclear envelope, mostly the lamins. Lamins are the main constituents of the nuclear lamina, a filamentous meshwork associated with the inner nuclear membrane that provides mechanical stability and plays important roles in processes such as transcription, DNA replication and chromatin organization. More than 300 mutations in lamin A/C have been associated with diverse clinical phenotypes, understanding the molecular basis of these diseases may provide a rationale for treating them. Here we describe the generation of induced pluripotent stem cells (iPSCs) from a patient with inherited dilated cardiomiopathy and 2 patients with distinct accelerated forms of aging, atypical Werner syndrome and Hutchinson Gilford progeria, all of which are caused by mutations in lamin A/C. These cell lines were pluripotent and displayed normal nuclear membrane morphology compared to donor fibroblasts. Their differentiated progeny reproduced the disease phenotype, reinforcing the idea that they represent excellent tools for understanding the role of lamin A/C in normal physiology and the clinical diversity associated with these diseases
The GALAH survey: Properties of the Galactic disc(s) in the solar neighbourhood
Using data from the GALAH pilot survey, we determine properties of the Galactic thin and thick discs near the solar neighbourhood. The data cover a small range of Galactocentric radius (7.9 RGC 9.5 kpc), but extend up to 4 kpc in height from the Galactic plane, and several kpc in the direction of Galactic anti-rotation (at longitude 260◦ ≤ ≤ 280◦). This allows us to reliably measure the vertical density and abundance profiles of the chemically and
kinematically defined ‘thick’ and ‘thin’ discs of the Galaxy. The thin disc (low-α population) exhibits a steep negative vertical metallicity gradient, at d[M/H]/dz = −0.18 ± 0.01 dex kpc−1, which is broadly consistent with previous studies. In contrast, its vertical α-abundance profile is almost flat, with a gradient of d[α/M]/dz = 0.008 ± 0.002 dex kpc−1. The steep vertical metallicity gradient of the low-α population is in agreement with models where radial
migration has a major role in the evolution of the thin disc. The thick disc (high-α population) has a weaker vertical metallicity gradient d[M/H]/dz = −0.058 ± 0.003 dex kpc−1. The αabundance of the thick disc is nearly constant with height, d[α/M]/dz = 0.007 ± 0.002 dex kpc−1. The negative gradient in metallicity and the small gradient in [α/M] indicate that the high-α population experienced a settling phase, but also formed prior to the onset of major
Type Ia supernova enrichment. We explore the implications of the distinct α-enrichments and narrow [α/M] range of the sub-populations in the context of thick disc formation.LD and MA acknowledge funding from the Australian Government through ARC Laureate Fellowship FL110100012. LD, KCF, and RFGW acknowledge
support from ARC grant DP160103747. LC gratefully acknowledges support from the Australian Research Council (grants
DP150100250, FT160100402). DMN was supported by the Allan C. and Dorothy H. Davis Fellowship. DS is the recipient of
an Australian Research Council Future Fellowship (project number
FT1400147). TZ acknowledges financial support from the Slovenian Research Agency (research core funding No. P1-0188). Part of
this research was supported by the Munich Institute for Astro- and
Particle Physics (MIAPP) of the DFG cluster of excellence ‘Origin
and Structure of the Universe’
Proteomic Analysis of the Cell Cycle of Procylic FormTrypanosoma brucei
We describe a single-step centrifugal elutriation method to produce synchronous G1-phase procyclic trypanosomes at a scale amenable for proteomic analysis of the cell cycle. Using ten-plex tandem mass tag (TMT) labelling and mass spectrometry (MS)-based proteomics technology, the expression levels of 5,325 proteins were quantified across the cell cycle in this parasite. Of these, 384 proteins were classified as cell-cycle regulated and subdivided into nine clusters with distinct temporal regulation. These groups included many known cell cycle regulators in trypanosomes, which validates the approach. In addition, we identify 40 novel cell cycle regulated proteins that are essential for trypanosome survival and thus represent potential future drug targets for the prevention of trypanosomiasis. Through cross-comparison to the TrypTag endogenous tagging microscopy database, we were able to validate the cell-cycle regulated patterns of expression for many of the proteins of unknown function detected in our proteomic analysis. A convenient interface to access and interrogate these data is also presented, providing a useful resource for the scientific community. Data are available via ProteomeXchange with identifier PXD008741
The GALAH survey: velocity fluctuations in the Milky Way using red clump giants
If the Galaxy is axisymmetric and in dynamical equilibrium, we expect negligible fluctuations in the residual line-of-sight velocity field. However, non-axisymmetric structures like a bar, spiral arms and merger events can generate velocity fluctuations. Recent results using the APOGEE survey find significant fluctuations in velocity for stars in the midplane (|z|< 0.25 kpc) and out to 5 kpc, which suggests that the dynamical influence of the Milky Way's bar extends out to the Solar neighborhood. Their measured power spectrum has a characteristic amplitude of 11 km/s on a scale of ~ 2.5 kpc. The existence of large streaming motions on these scales has important implications for determining the Sun's motion about the Galactic Centre. Using red clump stars from the GALAH and APOGEE surveys, we map the line-of-sight velocity field around the Sun out to distances of 5 kpc and up to 1.25 kpc from the Galactic Plane. By subtracting a smooth axisymmetric model for the velocity field, we study the residual velocity fluctuations and compare our findings with mock survey generated by Galaxia based on an axisymmetric, steady state model. We find negligible large-scale fluctuations away from the plane. In the mid-plane, we reproduce the earlier APOGEE power spectrum results but with 20\% smaller amplitude (9.5 km/s) after taking a few systematic effects into account (e.g. volume completeness). The amplitude power is further reduced to 6.7 km/s if a flexible axisymmetric model is used. Additionally, our mock simulations show that, in the plane, the distances are underestimated for high mass red clump stars and this can lead to spurious power with amplitude of about 5.5 km/s. Taking this into account, we estimate the amplitude of real fluctuations to be less than 4.2 km/s, about a factor of three less than the previous result from APOGEE
Infection with hepatitis B virus carrying novel pre-S/S gene mutations in female siblings vaccinated at birth: two case reports
<p>Abstract</p> <p>Introduction</p> <p>After the initiation of a mass hepatitis B vaccination program in Taiwan, the prevalence of hepatitis B virus infection has declined progressively. However, about 1 percent of the young generation, who received hepatitis B vaccination at birth, remain carriers. Infection with vaccine-escape hepatitis B virus mutants always occurs shortly after birth. Here, we report two female siblings in whom the infection occurred in their adolescence. This report raises the question of whether a booster for hepatitis B vaccination is needed.</p> <p>Case presentation</p> <p>Two 19 and 14-year-old Taiwanese female siblings were born to a mother infected with hepatitis B virus and received a complete course of hepatitis B vaccination at birth. They remained negative for serum hepatitis B surface antigen and positive for serum anti-hepatitis B surface antibody throughout their childhood. However, both were infected with the hepatitis B virus in their adolescence. Hepatitis B virus DNA was extracted from serum samples from the mother and two siblings. Hepatitis B virus pre-S/S sequence was amplified by polymerase chain reaction followed by nucleotide sequencing. When compared with the sequence obtained from the mother, multiple amino acid substitutions located near or in the major hydrophilic region of the surface antigen were identified in the elder sister. Four of these mutations (sL97S, sL98S, sG102R, and sA159P) were novel. A novel in-frame deletion (14 amino acids deleted, pre-S 127-140) was found in the hepatitis B virus pre-S2 region in the younger sister.</p> <p>Conclusions</p> <p>Despite having received hepatitis B vaccination at birth, hepatitis B virus infection can still occur in adolescence with the emergence of novel mutations in the pre-S/S gene. This is a rare event and, to the best of our knowledge, has not been previously reported.</p
Anodic Aluminum Oxide Membrane-Assisted Fabrication of β-In2S3Nanowires
In this study, β-In2S3nanowires were first synthesized by sulfurizing the pure Indium (In) nanowires in an AAO membrane. As FE-SEM results, β-In2S3nanowires are highly ordered, arranged tightly corresponding to the high porosity of the AAO membrane used. The diameter of the β-In2S3nanowires is about 60 nm with the length of about 6–8 μm. Moreover, the aspect ratio of β-In2S3nanowires is up to 117. An EDS analysis revealed the β-In2S3nanowires with an atomic ratio of nearly S/In = 1.5. X-ray diffraction and corresponding selected area electron diffraction patterns demonstrated that the β-In2S3nanowire is tetragonal polycrystalline. The direct band gap energy (Eg) is 2.40 eV from the optical measurement, and it is reasonable with literature
The GALAH survey: Co-orbiting stars and chemical tagging
We present a study using the second data release of the GALAH survey of
stellar parameters and elemental abundances of 15 pairs of stars identified by
Oh et al 2017. They identified these pairs as potentially co-moving pairs using
proper motions and parallaxes from Gaia DR1. We find that 11 very wide (>1.7
pc) pairs of stars do in fact have similar Galactic orbits, while a further
four claimed co-moving pairs are not truly co-orbiting. Eight of the 11
co-orbiting pairs have reliable stellar parameters and abundances, and we find
that three of those are quite similar in their abundance patterns, while five
have significant [Fe/H] differences. For the latter, this indicates that they
could be co-orbiting because of the general dynamical coldness of the thin
disc, or perhaps resonances induced by the Galaxy, rather than a shared
formation site. Stars such as these, wide binaries, debris of past star
formation episodes, and coincidental co-orbiters, are crucial for exploring the
limits of chemical tagging in the Milky Way.Comment: 14 pages, 9 figures, submitted to MNRAS. Updated for Gaia DR2 value
The GALAH survey: Co-orbiting stars and chemical tagging
We present a study using the second data release of the GALAH survey of
stellar parameters and elemental abundances of 15 pairs of stars identified by
Oh et al 2017. They identified these pairs as potentially co-moving pairs using
proper motions and parallaxes from Gaia DR1. We find that 11 very wide (>1.7
pc) pairs of stars do in fact have similar Galactic orbits, while a further
four claimed co-moving pairs are not truly co-orbiting. Eight of the 11
co-orbiting pairs have reliable stellar parameters and abundances, and we find
that three of those are quite similar in their abundance patterns, while five
have significant [Fe/H] differences. For the latter, this indicates that they
could be co-orbiting because of the general dynamical coldness of the thin
disc, or perhaps resonances induced by the Galaxy, rather than a shared
formation site. Stars such as these, wide binaries, debris of past star
formation episodes, and coincidental co-orbiters, are crucial for exploring the
limits of chemical tagging in the Milky Way.Comment: 14 pages, 9 figures, submitted to MNRAS. Updated for Gaia DR2 value
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