ABSTRACT
Type II supernovae (SNe II) show strong hydrogen features in their spectra throughout their whole evolution, while type IIb supernovae (SNe IIb) spectra evolve from dominant hydrogen lines ...at early times to increasingly strong helium features later on. However, it is currently unclear whether the progenitors of these SN types form a continuum in pre-SN hydrogen mass or whether they are physically distinct. SN light-curve morphology directly relates to progenitor and explosion properties such as the amount of hydrogen in the envelope, the pre-SN radius, the explosion energy, and the synthesized mass of radioactive material. In this work, we study the morphology of the optical-wavelength light curves of hydrogen-rich SNe II and hydrogen-poor SNe IIb to test whether an observational continuum exists between the two. Using a sample of 95 SNe (73 SNe II and 22 SNe IIb), we define a range of key observational parameters and present a comparative analysis between both types. We find a lack of events that bridge the observed properties of SNe II and IIb. Light-curve parameters such as rise times and post-maximum decline rates and curvatures clearly separate both SN types and we therefore conclude that there is no continuum, with the two SN types forming two observationally distinct families. In the V band a rise time of 17 d (SNe II lower and SNe IIb higher), and a magnitude difference between 30 and 40 d post-explosion of 0.4 mag (SNe II lower and SNe IIb higher) serve as approximate thresholds to differentiate both types.
Obstructive jaundice is frequently complicated by infections and has been associated with increased bacterial translocation and gut mucosal hyperpermeability in animal models. Proper expression of ...the tight junction (TJ) proteins ZO-1 and occludin is important for normal gut barrier function. We tested whether bile modulates intestinal epithelial ZO-1 and occludin expression.
(a) Male C57BL/6 mice; (b) male Sprague-Dawley rats.
(a) Mice were subjected to common bile duct ligation (CBDL) or a sham procedure, and 96 h later all surviving animals were killed for measurement of ileal mucosal permeability to FITC-labeled dextran (everted gut sac technique), bacterial translocation to mesenteric lymph nodes, and ileal epithelial ZO-1 and occludin expression (western blots). (b) Rat IEC-6 enterocytic monolayers were incubated in the presence or absence of graded concentrations of rat bile and/or U0126, an inhibitor of extracellular signal related kinase (ERK) 1/2 activation.
(a) Compared to sham-treated controls, CBDL significantly increased gut mucosal permeability and bacterial translocation and markedly decreased ileal epithelial expression of ZO-1 and occludin. In a follow-up in vivo experiment, gavaging mice with fresh rat bile twice daily significantly ameliorated the deleterious effects of CBDL on gut barrier function. (b) Addition of 1% (v/v) bile to media enhanced phosphorylation of ERK1/2, increased the expression of ZO-1 and occludin and decreased permeability to FITC-dextran. All of these bile-mediated effects were blocked by 10 microM U0126.
These data support the view that the presence of bile in the intestinal lumen is essential for normal gut barrier function, possibly because compounds present in bile initiate ERK1/2-dependent signaling that is essential for normal expression of key TJ proteins.
Abstract
We present a study of the optical and near-infrared (NIR) spectra of SN 2013ai along with its light curves. These data range from discovery until 380 days after explosion. SN 2013ai is a ...fast declining Type II supernova (SN II) with an unusually long rise time, 18.9 ± 2.7 days in the
V
-band, and a bright
V
-band peak absolute magnitude of −18.7 ± 0.06 mag. The spectra are dominated by hydrogen features in the optical and NIR. The spectral features of SN 2013ai are unique in their expansion velocities, which, when compared to large samples of SNe II, are more than 1,000 km s
−1
faster at 50 days past explosion. In addition, the long rise time of the light curve more closely resembles SNe IIb rather than SNe II. If SN 2013ai is coeval with a nearby compact cluster, we infer a progenitor zero-age main-sequence mass of ∼17
M
⊙
. After performing light-curve modeling, we find that SN 2013ai could be the result of the explosion of a star with little hydrogen mass, a large amount of synthesized
56
Ni, 0.3–0.4
M
⊙
, and an explosion energy of 2.5–3.0 × 10
51
erg. The density structure and expansion velocities of SN 2013ai are similar to those of the prototypical SN IIb, SN 1993J. However, SN 2013ai shows no strong helium features in the optical, likely due to the presence of a dense core that prevents the majority of
γ
-rays from escaping to excite helium. Our analysis suggests that SN 2013ai could be a link between SNe II and stripped-envelope SNe.
The Wilms tumor suppressor WT1 encodes a zinc finger transcription factor that is expressed in glomerular podocytes during a narrow window in kidney development. By immunoprecipitation and protein ...microsequencing analysis, we have identified a major cellular protein associated with endogenous WT1 to be the inducible chaperone Hsp70. WT1 and Hsp70 are physically associated in embryonic rat kidney cells, in primary Wilms tumor specimens and in cultured cells with inducible expression of WT1. Colocalization of WT1 and Hsp70 is evident within podocytes of the developing kidney, and Hsp70 is recruited to the characteristic subnuclear clusters that contain WT1. The amino-terminal transactivation domain of WT1 is required for binding to Hsp70, and expression of that domain itself is sufficient to induce expression of Hsp70 through the heat shock element (HSE). Substitution of a heterologous Hsp70-binding domain derived from human DNAJ is sufficient to restore the functional properties of a WT1 protein with an amino-terminal deletion, an effect that is abrogated by a point mutation in DNAJ that reduces binding to Hsp70. These observations indicate that Hsp70 is an important cofactor for the function of WT1, and suggest a potential role for this chaperone during kidney differentiation.
Fungicides pose a risk for crustacean leaf shredders serving as key-stone species for leaf litter breakdown in detritus-based stream ecosystems. However, little is known about the impact of ...strobilurin fungicides on shredders, even though they are presumed to be the most hazardous fungicide class for aquafauna. Therefore, we assessed the impact of the strobilurin azoxystrobin (AZO) on the survival, energy processing (leaf consumption and feces production), somatic growth (growth rate and molting activity), and energy reserves (neutral lipid fatty and amino acids) of the amphipod crustacean Gammarus fossarum via waterborne exposure and food quality-mediated (through the impact of leaf colonizing aquatic microorganisms) and thus indirect effects using 2 × 2-factorial experiments over 24 days. In a first bioassay with 30 µg AZO/L, waterborne exposure substantially reduced survival, energy processing and affected molting activity of gammarids, while no effects were observed via the dietary pathway. Furthermore, a negative growth rate (indicating a body mass loss in gammarids) was induced by waterborne exposure, which cannot be explained by a loss in neutral lipid fatty and amino acids. These energy reserves were increased indicating a disruption of the energy metabolism in G. fossarum caused by AZO. Contrary to the first bioassay, no waterborne AZO effects were observed during a second experiment with 15 µg AZO/L. However, an altered energy processing was determined in gammarids fed with leaves microbially colonized in the presence of AZO, which was probably caused by fungicide-induced effects on the microbial decomposition efficiency ultimately resulting in a lower food quality. The results of the present study show that diet-related strobilurin effects can occur at concentrations below those inducing waterborne toxicity. However, the latter seems to be more relevant at higher fungicide concentrations.
•30 µg azoxystrobin/L induces 50% mortality via waterborne exposure.•Azoxystrobin acts as metabolic disruptor.•Diet-related effects in Gammarus were observed at low azoxystrobin levels.
Shapes and vorticities of superfluid helium nanodroplets Gomez, Luis F.; Ferguson, Ken R.; Cryan, James P. ...
Science (American Association for the Advancement of Science),
08/2014, Letnik:
345, Številka:
6199
Journal Article
Recenzirano
Odprti dostop
Helium nanodroplets are considered ideal model systems to explore quantum hydrodynamics in self-contained, isolated superfluids. However, exploring the dynamic properties of individual droplets is ...experimentally challenging. In this work, we used single-shot femtosecond x-ray coherent diffractive imaging to investigate the rotation of single, isolated superfluid helium-4 droplets containing ~10⁸ to 1011 atoms. The formation of quantum vortex lattices inside the droplets is confirmed by observing characteristic Bragg patterns from xenon clusters trapped in the vortex cores. The vortex densities are up to five orders of magnitude larger than those observed in bulk liquid helium. The droplets exhibit large centrifugal deformations but retain axially symmetric shapes at angular velocities well beyond the stability range of viscous classical droplets.
Ethyl pyruvate (EP) is a simple aliphatic ester derived from the endogenous metabolite, pyruvic acid. EP has been shown to decrease the expression of various pro-inflammatory mediators, including ...nitric oxide (NO
), tumor necrosis factor (TNF), cyclooxygenase-2, and interleukin (IL)-6, in a variety of in vitro and in vivo model systems. In an effort to better understand the chemical features that might explain the anti-inflammatory properties of EP, we screened 15 commercially available compounds for cytoprotective or anti-inflammatory effects using two in vitro assay systems: TNF and NO
production by lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage-like cells and changes in the permeability of Caco-2 human enterocyte-like monolayers stimulated with a cocktail of pro-inflammatory cytokines called cytomix (1000
U/ml IFN-γ plus 10
ng/ml TNF-α plus 1
ng/ml IL-1β). Two compounds, namely diethyl oxaloproprionate (DEOP) and 2-acetamidoacrylate (2AA), demonstrated consistent anti-inflammatory or cytoprotective pharmacological properties in this screening process. Treatment of mice with either of these compounds ameliorated LPS-induced ileal mucosal hyperpermeability to the fluorescent probe, fluorescein isothiocyanate-labeled dextran (average molecular mass 4
kDa), and bacterial translocation to mesenteric lymph nodes. Treatment with either of these compounds also improved survival in mice challenged with a lethal dose of LPS. Finally, in a study that compared 2AA to its methyl ester, we showed that methyl-2-acetamidoacrylate is at least 100-fold more potent than the parent carboxylate as an inhibitor of LPS-induced NO
production by RAW 264.7 cells. Collectively, these data are consistent with the view that anti-inflammatory activity is demonstrable for a number of compounds that either incorporate an olefinic linkage conjugated to a carbonyl moiety or are capable of undergoing tautomeric rearrangement to form such a structure. Moreover, our findings suggest that esters with these general characteristics, perhaps because of their greater lipophilicity or electrophilicity, are more potent anti-inflammatory agents than are the parent carboxylates.
STUDY QUESTION
Do the benefits of ovarian tissue cryopreservation outweigh the risks for patients seeking to preserve fertility before gonadotoxic treatment in various indications?
SUMMARY ANSWER
In ...>90% of the patients undergoing cryopreservation of ovarian tissue, oncological treatment was associated with a reduced ovarian reserve and in 30% of patients, premature ovarian failure (POF) occurred within 5 years.
WHAT IS KNOWN ALREADY
Ovarian tissue cryopreservation is an effective fertility preservation option, especially for pre-pubertal patients and patients who have a short time between diagnosis of a disease and gonadotoxic treatment.
STUDY DESIGN, SETTING, DURATION
This study retrospectively analysed ovarian function and fertility recovery rates, as well as ovarian tissue characteristics, of patients who underwent ovarian tissue cryopreservation at Erasme Hospital between 1999 and 2011.
PARTICIPANTS/MATERIALS, SETTINGS, METHODS
A total of 225 patients referred from 15 Belgian oncological units underwent cryopreservation of ovarian tissue before gonadotoxic therapy for malignant or benign diseases. There were 28 patients (12.4%) who died during follow-up due to recurrence of disease. One severe adverse event occurred during anaesthesia for ovarian tissue collection, leading to the death of the patient. Ovarian function and fertility outcomes were available for 114 patients including 13 girls who were pre-pubertal at the time of the procedure. Eight patients had undergone ovarian tissue transplantation in order to restore their fertility after remission of the disease.
MAIN RESULTS AND THE ROLE OF CHANCE
Breast cancer and haematological disease were the most frequent indications for ovarian tissue cryopreservation. Overall, 90% of post-pubertal patients were diagnosed with poor ovarian reserve (AMH < 0.5 ng/ml) after a mean of 50 months of follow-up (11–125 months), including 30% with POF (FSH > 40 IU/ml). Breast cancer patients had a lower rate of POF than did post-pubertal patients with haematological diseases (11 versus 34.5%, respectively), despite the older age (mean 31 versus 23.5 years old, respectively) of the breast cancer patients. Ovarian function returned in 71 post-pubertal patients without the need for grafts of cryopreserved tissue. Spontaneous pregnancies were reported for 33 of them, leading to 34 live births. Among the 13 pre-pubertal patients who reached pubertal age during the follow-up, 10 had POF. Eight patients received cryopreserved ovarian grafts to reverse POF and three of them have already become pregnant.
LIMITATIONS, REASONS FOR CAUTION
This study is a retrospective analysis. The cohort was not compared with a control group of patients who did not undergo the procedure.
WIDER IMPLICATIONS OF THE FINDINGS
After careful evaluation of the surgical risks, ovarian tissue cryopreservation can be proposed as an efficient option to preserve the fertility of children and young adults facing gonadotoxic therapies. However, alternative procedures such as oocyte or embryo cryopreservation should be considered as first options especially for older patients or if there is high risk of neoplastic cells within the ovaries.
STUDY FUNDING/COMPETING INTEREST
This study was supported by the Télévie, FNRS-FRSM and Fondation Belge contre le cancer. There are no competing interests to report.
Purpose
Defining the benefits of resection of isolated non-colorectal, non-neuroendocrine (NCRNNE) liver metastases is difficult. To better understand the survival benefit in this group of patients, ...we conducted a systematic review of the previous literature.
Methods
Medline, Web of Knowledge, and manual searches were performed using search terms, such as “liver resection” and “primary tumor.” Inclusion criteria were year > 1990, >five patients, and median survival reported or derived. An expected median survival was calculated from weighted averages of median survivals, and differences were assessed using a permutation test.
Results
A total of 7,857 references were identified. Overall 4,735 abstracts were reviewed; 120 manuscripts evaluated and of these, 73 met the study inclusion criteria. The final population consisted of 3,596 patients with renal (
n
= 234), ovarian (
n
= 119), testicular (
n
= 153), adrenal (
n
= 90), small bowel (
n
= 28), gallbladder (
n
= 21), duodenum (
n
= 38), gastric (
n
= 481), pancreatic (
n
= 55), esophageal (
n
= 23), head and neck (
n
= 15), and lung (
n
= 36) cancers, gastrointestinal stromal tumors (GISTs) (
n
= 106), cholangiocarcinoma (
n
= 13), sarcoma (
n
= 189), and melanoma (
n
= 643). The greatest expected median was 63 months for genitourinary (GU) primaries (
n
= 549; range 5.4–142 months) followed by 44.4 months for breast cancer (
n
= 1,013; range 8–74 months), 22.3 months for gastrointestinal cancer (
n
= 549; range 5–58 months), and 23.7 months for other tumor types (
n
= 1,082; range 10–72 months). Using a permutation test, we observed that survival was best for patients with GU primaries followed by that for breast cancer patients. Additionally, we also observed that survival was similar for those with cancer of the GI tract and other primary sites.
Conclusions
There appears to be a benefit to resection for patients with NCRNNE liver metastases. The degree of survival advantage is predicated by primary site.
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