568 research outputs found
Depth profiling analysis of solar wind helium collected in diamond-like carbon film from Genesis
The distribution of solar-wind ions in Genesis mission collectors, as determined by depth profiling analysis, constrains the physics of ion-solid interactions involving the solar wind. Thus, they provide an experimental basis for revealing ancient solar activities represented by solar-wind implants in natural samples. We measured the first depth profile of ^4He in a Genesis collector; the shallow implantation (peaking at <20 nm) required us to use sputtered neutral mass spectrometry with post-photoionization by a strong field. The solar wind He fluence calculated using depth profiling is ~8.5 × 10^(14) cm^(–2). The shape of the solar wind 4He depth profile is consistent with TRIM simulations using the observed ^4He velocity distribution during the Genesis mission. It is therefore likely that all solar-wind elements heavier than H are completely intact in this Genesis collector and, consequently, the solar particle energy distributions for each element can be calculated from their depth profiles. Ancient solar activities and space weathering of solar system objects could be quantitatively reproduced by solar particle implantation profiles
Comparison of hospital course of geriatric inpatients with or without active cancer: a bicentric case-control study
BACKGROUND: The hospital course of older patients with cancer hospitalized in geriatrics units remain poorly known. The aim of our study was to compare the clinical characteristics and hospital courses of geriatric inpatients with or without active cancer.
METHODS: A case-control study was conducted in 2013 in the geriatric acute care units of Angers University Hospital and Le Mans Hospital, France, to compare 204 consecutive cases with cancer (mean age, 85.4±5.5 years; 42.6% male) and 1,020 controls without active cancer (mean age, 85.5±5.8 years; 42.6% male) matched for age, gender, recruitment period and center. Hospital courses were evaluated by the length of hospital stay and the in-hospital mortality. The place of life, body mass index, cumulative illness rating scale-geriatrics (CIRS-G) score, history of falls, and reason for admission were used as covariates.
RESULTS: Cases with active cancer exhibited a higher (i.e., worse) CIRS-G score (p<0.001) and were hospitalized more often for an organic failure (p<0.001) than controls. The hospital stay of cases was longer (16.3±13.0 days versus 12.6±9.4 days, p<0.001), and their in-hospital mortality rate was higher than controls (23.5% versus 5.6%, p<0.001). After adjustment, having an active cancer was associated with increased length of hospital stay (β=3.3, p<0.001) and greater in-hospital mortality (OR=4.4, p<0.001).
CONCLUSION: The length of hospital stay and in-hospital mortality rate were greater in geriatric patients with active cancer compared to controls, which reflects more complicated hospital courses in this population
Combinatorial Roles of Heparan Sulfate Proteoglycans and Heparan Sulfates in Caenorhabditis elegans Neural Development
Heparan sulfate proteoglycans (HSPGs) play critical roles in the development and adult physiology of all metazoan organisms. Most of the known molecular interactions of HSPGs are attributed to the structurally highly complex heparan sulfate (HS) glycans. However, whether a specific HSPG (such as syndecan) contains HS modifications that differ from another HSPG (such as glypican) has remained largely unresolved. Here, a neural model in C. elegans is used to demonstrate for the first time the relationship between specific HSPGs and HS modifications in a defined biological process in vivo. HSPGs are critical for the migration of hermaphrodite specific neurons (HSNs) as genetic elimination of multiple HSPGs leads to 80% defect of HSN migration. The effects of genetic elimination of HSPGs are additive, suggesting that multiple HSPGs, present in the migrating neuron and in the matrix, act in parallel to support neuron migration. Genetic analyses suggest that syndecan/sdn-1 and HS 6-O-sulfotransferase, hst-6, function in a linear signaling pathway and glypican/lon-2 and HS 2-O-sulfotransferase, hst-2, function together in a pathway that is parallel to sdn-1 and hst-6. These results suggest core protein specific HS modifications that are critical for HSN migration. In C. elegans, the core protein specificity of distinct HS modifications may be in part regulated at the level of tissue specific expression of genes encoding for HSPGs and HS modifying enzymes. Genetic analysis reveals that there is a delicate balance of HS modifications and eliminating one HS modifying enzyme in a compromised genetic background leads to significant changes in the overall phenotype. These findings are of importance with the view of HS as a critical regulator of cell signaling in normal development and disease
Severe progressive scoliosis due to huge subcutaneous cavernous hemangioma: A case report
Cavernous hemangioma consists mainly of congenital vascular malformations present before birth and gradually increasing in size with skeletal growth. A small number of patients with cavernous hemangioma develop scoliosis, and surgical treatment for the scoliosis in such cases has not been reported to date. Here we report a 12-year-old male patient with severe progressive scoliosis due to a huge subcutaneous cavernous hemangioma, who underwent posterior correction and fusion surgery. Upon referral to our department, radiographs revealed a scoliosis of 85° at T6-L1 and a kyphosis of 58° at T4-T10. CT and MR images revealed a huge hemangioma extending from the subcutaneous region to the paraspinal muscles and the retroperitoneal space and invading the spinal canal. Posterior correction and fusion surgery using pedicle screws between T2 and L3 were performed. Massive hemorrhage from the hemangioma occurred during the surgery, with intraoperative blood loss reaching 2800 ml. The scoliosis was corrected to 59°, and the kyphosis to 45° after surgery. Seven hours after surgery, the patient suffered from hypovolemic shock and disseminated intravascular coagulation due to postoperative hemorrhage from the hemangioma. The patient developed sensory and conduction aphasia caused by cerebral hypoxia during the shock on the day of the surgery. At present, two years after the surgery, although the patient has completely recovered from the aphasia. This case illustrates that, in correction surgery for scoliosis due to huge subcutaneous cavernous hemangioma, intraoperative and postoperative intensive care for hemodynamics should be performed, since massive hemorrhage can occur during the postoperative period as well as the intraoperative period
Syntheses, characterization, density functional theory calculations, and activity of tridentate SNS zinc pincer complexes
A series of tridentate SNS ligand precursors were metallated with ZnCl2 to give new tridentate SNS pincer zinc complexes. The zinc complexes serve as models for the zinc active site in liver alcohol dehydrogenase (LADH) and were characterized with single crystal X-ray diffraction, 1H, 13C, and HSQC NMR spectroscopies and electrospray mass spectrometry. The bond lengths and bond angles of the zinc complexes correlate well to those in horse LADH. The zinc complexes feature SNS donor atoms and pseudotetrahedral geometry about the zinc center, as is seen for liver alcohol dehydrogenase. The SNS ligand precursors were characterized with 1H, 13C, and HSQC NMR spectroscopies and cyclic voltammetry, and were found to be redox active. Gaussian calculations were performed and agree quite well with the experimentally observed oxidation potential for the pincer ligand. The zinc complexes were screened for the reduction of electron poor aldehydes in the presence of a hydrogen donor, 1-benzyl-1,4-dihydronicotinamide (BNAH). The zinc complexes enhance the reduction of electron poor aldehydes. Density functional theory calculations were performed to better understand why the geometry about the zinc center is pseudo-tetrahedral rather than pseudo-square planar, which is seen for most pincer complexes. For the SNS tridentate pincer complexes, the data indicate that the pseudo-tetrahedral geometry was 43.8 kcal/mol more stable than the pseudo-square planar geometry. Density functional theory calculations were also performed on zinc complexes with monodentate ligands and the data indicate that the pseudo-tetrahedral geometry was 30.6 kcal/mol more stable than pseudo-square planar geometry. Overall, the relative stabilities of the pseudo-tetrahedral and pseudo-square planar systems are the same for this coordination environment whether the ligand set is a single tridentate SNS system or is broken into three separate units. The preference of a d10 Zn center to attain a tetrahedral local environment trumps any stabilization gained by removal of constraints within the ligand set
End-processing during non-homologous end-joining: a role for exonuclease 1
Non-homologous end-joining (NHEJ) is a critical error-prone pathway of double strand break repair. We recently showed that tyrosyl DNA phosphodiesterase 1 (Tdp1) regulates the accuracy of NHEJ repair junction formation in yeast. We assessed the role of other enzymes in the accuracy of junction formation using a plasmid repair assay. We found that exonuclease 1 (Exo1) is important in assuring accurate junction formation during NHEJ. Like tdp1Δ mutants, exo1Δ yeast cells repairing plasmids with 5′-extensions can produce repair junctions with templated insertions. We also found that exo1Δ mutants have a reduced median size of deletions when joining DNA with blunt ends. Surprisingly, exo1Δ pol4Δ mutants repair blunt ends with a very low frequency of deletions. This result suggests that there are multiple pathways that process blunt ends prior to end-joining. We propose that Exo1 acts at a late stage in end-processing during NHEJ. Exo1 can reverse nucleotide additions occurring due to polymerization, and may also be important for processing ends to expose microhomologies needed for NHEJ. We propose that accurate joining is controlled at two steps, a first step that blocks modification of DNA ends, which requires Tdp1, and a second step that occurs after synapsis that requires Exo1
10-kJ PW Laser for the FIREX-I Program
A 10-kJ PW laser (LFEX) is under construction for the
FIREX-I program. This paper reports a design overview of LFEX, the
technological development of a large-aperture arrayed amplifier with
modified four-pass architecture, wavefront correction, a large-aperture
Faraday rotator with a superconducting magnet, a new pulse compressor
arrangement, and focus control
Possibility of a White Dwarf as the Accreting Compact Star in CI Cam (= XTE J0421+560)
We present results from ASCA observations of the binary CI Cam both in
quiescence and in outburst in order to identify its central accreting object.
The quiescence spectrum of CI Cam consists of soft and hard components which
are separated clearly at aound 2-3keV. A large equivalent width of an iron Ka
emission line prefers an optically thin thermal plasma emission model to a
non-thermal power-law model for the hard component, which favors a white dwarf
as the accreting object, since the optically thin thermal hard X-ray emission
is a common characteristic among cataclysmic variables (binaries including an
accreting white dwarf).
The outburst spectrum, on the other hand, is composed of a hard component
represented by a multi-temperature optically thin thermal plasma emission and
of an independent soft X-ray component that appears below 1 keV intermittently
on a decaying light curve of the hard component. The spectrum of the soft
component is represented well by a blackbody with the temperature of
0.07-0.12keV overlaid with several K-edges associated with highly ionized
oxygen. This, together with the luminosity as high as ~1E38 erg/s is similar to
a super-soft source (SSS). The outburst in the hard X-ray band followed by the
appearance of the soft blackbody component reminds us of recent observations of
novae in outburst. We thus assume the outburst of CI Cam is that of a nova, and
obtain the distance to CI Cam to be 5-17kpc by means of the relation between
the optical decay time and the absolute magnitude. This agrees well with a
recent estimate of the distance of 5-9kpc in the optical band. All of these
results from the outburst data prefer a white dwarf for the central object of
CI Cam.Comment: 20 pages, 5 figures, to appear in the Astrophysical Journal v601, n2,
February 1, 2004 issu
International Union of Immunological Societies: 2017 Primary Immunodeficiency Diseases Committee Report on Inborn Errors of Immunity
Beginning in 1970, a committee was constituted under the auspices of the World Health Organization (WHO) to catalog primary immunodeficiencies. Twenty years later, the International Union of Immunological Societies (IUIS) took the remit of this committee. The current report details the categorization and listing of 354 (as of February 2017) inborn errors of immunity. The growth and increasing complexity of the field have been impressive, encompassing an increasing variety of conditions, and the classification described here will serve as a critical reference for immunologists and researchers worldwide
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The Ever-Increasing Array of Novel Inborn Errors of Immunity : an Interim Update by the IUIS Committee
The most recent updated classification of inborn errors of immunity/primary immunodeficiencies, compiled by the International Union of Immunological Societies Expert Committee, was published in January 2020. Within days of completing this report, it was already out of date, evidenced by the frequent publication of genetic variants proposed to cause novel inborn errors of immunity. As the next formal report from the IUIS Expert Committee will not be published until 2022, we felt it important to provide the community with a brief update of recent contributions to the field of inborn errors of immunity. Herein, we highlight studies that have identified 26 additional monogenic gene defects that reach the threshold to represent novel causes of immune defects.Peer reviewe
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