500 research outputs found
Prophylactic Use of Liposomal Amphotericin B in Preventing Fungal Infections Early After Liver Transplantation: a Retrospective, Single-Center Study
In this study the authors evaluated the efficacy of prophylaxis with liposomal amphotericin B (L-AmB) in the incidence of fungal infections (FI) during the first 3 months after liver transplant (LT). The study was retrospective and accessed a 4-year period from 2008 to 2011. All patients who died in the first 48 hours after LT were excluded. Patients were divided by the risk groups for FI: Group 1, high-risk (at least 1 of the following conditions: urgent LT; serum creatinine >2 mg/dL; early acute kidney injury [AKI] after LT; retransplantation; surgical exploration early post-LT; transfused cellular blood components [>40 U]); and Group 2, low-risk patients. Group 1 patients were further separated into those who received antifungal prophylaxis with L-AmB and those who did not. Prophylaxis with L-AmB consisted of intravenous administration of L-AmB, 100 mg daily for 14 days. Four hundred ninety-two patients underwent LT; 31 died in the first 48 hours after LT. From the remaining 461 patients, 104 presented with high-risk factors for FI (Group 1); of these, 66 patients received antifungal prophylaxis and 38 did not. In this group 8 FI were observed, 5 in patients without antifungal prophylaxis (P = .011). Three more FI were identified in Group 2. By logistic regression analysis, the categorical variable high-risk group was independently related to the occurrence of invasive FI (P = .006). We conclude that prophylaxis with L-AmB after LT was effective in reducing the incidence of FI. No influence on mortality was detected
A Comparative Study of Cardiovascular Tolerability with Slow Extended Dialysis Versus Continuous Haemodiafiltration in the Critical Patient
Background: In the haemodynamically unstable patient the method of treatment of acute renal failure is still largely controversial. The purpose of our study was to compare slow extended dialysis with continuous
haemodiafiltration in the critical patient with indication for renal replacement therapy and haemodynamic
instability. Patients and Methods: This is a cohort study comparing in 63 ventilated critical patients a 12 month
period when only continuous haemodiafiltration was used (n=25) with an equal period of slow extended
dialysis (n=38). Our primary objective was to evaluate the impact of the dialytic procedure on cardiovascular
stability in those patients. As secondary aims we considered system coagulation/thrombosis and predictors
of mortality. In the two groups we analysed the first session performed, the second session performed and
the average of all the sessions performed in each patient. Results: In these patients, mortality in the
intensive care unit was high (68% in the continuous haemodiafiltration group and 63% in the slow extended
dialysis group). We did not find any association between the dialytic technique used and death; only
the APACHE score was a predictor of death. Slow extended dialysis was a predictor of haemodynamic
stability, a negative predictor of sessions that had to be interrupted for haemodynamic instability, and a
predictor of achieving the volume removal initially sought. Slow extended dialysis was also associated
with less coagulation of the system. Conclusions: Our data suggested that slow extended dialysis use was
not inferior to continuous haemodiafiltration use in terms of cardiovascular tolerability
Tentative Detection of the Nitrosylium Ion in Space
We report the tentative detection in space of the nitrosylium ion, NO.
The observations were performed towards the cold dense core Barnard 1-b. The
identification of the NO =2--1 line is supported by new laboratory
measurements of NO rotational lines up to the =8--7 transition
(953207.189\,MHz), which leads to an improved set of molecular constants: \,MHz, \,kHz, and \,MHz. The profile of the feature assigned to NO exhibits two
velocity components at 6.5 and 7.5 km s, with column densities of and cm, respectively. New
observations of NO and HNO, also reported here, allow to estimate the following
abundance ratios: (NO)/(NO), and
(HNO)/(NO). This latter value provides important constraints
on the formation and destruction processes of HNO. The chemistry of NO and
other related nitrogen-bearing species is investigated by the means of a
time-dependent gas phase model which includes an updated chemical network
according to recent experimental studies. The predicted abundance for NO
and NO is found to be consistent with the observations. However, that of HNO
relative to NO is too high. No satisfactory chemical paths have been found to
explain the observed low abundance of HNO. HSCN and HNCS are also reported here
with an abundance ratio of . Finally, we have searched for NNO,
NO, HNNO, and NNOH, but only upper limits have been obtained for
their column density, except for the latter for which we report a tentative
3- detection.Comment: To appear in the Astrophysical Journal October 20, 201
Reactive Magnetron Sputter Deposition of Bismuth Tungstate Coatings for Water Treatment Applications under Natural Sunlight
Bismuth complex oxides, in particular, bismuth tungstate, have recently attracted attention as promising photocatalytic materials for water treatment processes. In the present work, photocatalytic bismuth tungstate films were prepared by pulsed direct current (DC) reactive magnetron sputtering of Bi and W targets in an Ar/O2 atmosphere onto spherically-shaped glass beads. The uniform coverage of the substrate was enabled by the use of oscillating bowl placed underneath the magnetrons. The atomic ratio of Bi/W was varied through the variation of the power applied to the magnetrons. The deposited coatings were analyzed by the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy and atomic force microscopy. The photocatalytic properties of the films were studied via the methylene blue (MB) degradation process under artificial (fluorescent light) and natural (sunlight) irradiation, and compared to the photocatalytic performance of titanium dioxide coatings deposited onto identical substrates. The results showed that the photocatalytic performance of bismuth tungstate and bismuth oxide-coated beads was superior to that exhibited by TiO2-coated beads. Overall, reactive magnetron co-sputtering has been shown to be a promising technique for deposition of narrow band gap bismuth-based semiconducting oxides onto irregularly-shaped substrates for potential use in water treatment applications
Liver Depurative Techniques: A Single Liver Transplantation Center Experience
In a liver transplant (LT) center, treatments with Prometheus were evaluated. The main outcome considered was 1 and 6 months survival.
Methods. During the study period, 74 patients underwent treatment with Prometheus; 64 were enrolled,with a mean age of 51 13 years; 47men underwent 212 treatments (mean, 3.02 per patient). The parameters evaluated were age, sex, laboratorial (liver enzymes, ammonia)
and clinical (model for end-stage liver disease and Child-Turcotte-Pugh score) data.
Results. Death was verified in 23 patients (35.9%) during the hospitalization period, 20 patients (31.3%) were submitted to liver transplantation, and 21 were discharged. LT was performed in 4 patients with acute liver failure (ALF, 23.7%), in 7 patients with acute on chronic liver failure (AoCLF, 43.7%), and in 6 patients with liver disease after LT (30%).
Seven patients who underwent LT died (35%). In the multivariate analysis, older age (P ¼ .015), higher international normalized ratio (INR) (P ¼ .019), and acute liver failure (P ¼ .039) were independently associated with an adverse 1-month clinical outcome. On the other hand, older age (P ¼ .011) and acute kidney injury (P ¼ .031) at presentation
were both related to worse 6-month outcome. For patients with ALF and AoCLF we did not observe the same differences.
Conclusions. In this cohort, older age was the most important parameter defining 1- and 6-month survival, although higher INR and presence of ALF were important for 1-month survival and AKI for 6-month survival. No difference was observed between patients who underwent LT or did not have LT
A new protonated molecule discovered in TMC-1: HCCNCH+
In recent years we have seen an important increase in the number of
protonated molecules detected in cold dense clouds. Here we report the
detection in TMC-1 of HCCNCH+, the protonated form of HCCNC, which is a
metastable isomer of HC3N. This is the first protonated form of a metastable
isomer detected in a cold dense cloud. The detection was based on observations
carried out with the Yebes 40m and IRAM 30m telescopes, which revealed four
harmonically related lines. We derive a rotational constant B = 4664.431891 +/-
0.000692 MHz and a centrifugal distortion constant D = 519.14 +/- 4.14 Hz. From
a high-level ab initio screening of potential carriers we confidently assign
the series of lines to the ion HCCNCH+. We derive a column density of (3.0 +/-
0.5)e10 cm-2 for HCCNCH+, which results in a HCCNCH+/HCCNC abundance ratio of
0.010 +/- 0.002. This value is well reproduced by a state-of-the-art chemical
model, which however is subject to important uncertainties regarding the
chemistry of HCCNCH+. The observational and theoretical status of protonated
molecules in cold dense clouds indicate that there exists a global trend in
which protonated-to-neutral abundance ratios MH+/M increase with increasing
proton affinity of the neutral M, although if one restricts to species M with
high proton affinities (>700 kJ/mol), MH+/M ratios fall in the range 0.001-0.1,
with no apparent correlation with proton affinity. We suggest various
protonated molecules that are good candidates for detection in cold dense
clouds in the near future.Comment: Accepted for publication in A&A Letter
Discovery of two new interstellar molecules with QUIJOTE: HCCCHCCC and HCCCCS
We report on the discovery of two new molecules, HCCCHCCC and HCCCCS, towards
the starless core TMC-1 in the Taurus region from the QUIJOTE line survey in
the 31.1-50.2 GHz frequency range. We identify a total of twenty-nine lines of
HCCCHCCC and six rotational transitions of HCCCCS. The rotational quantum
numbers range from Ju=10 up to 15 and Ka <=2 for HCCCHCCC and Ju=21/2 up to
31/2 for HCCCCS. We derived a column density for HCCCHCCC of
N=(1.3+/-0.2)x10^11 cm-2 with a rotational temperature of 6+/-1 K, while for
HCCCCS we derived N=(9.5+/-0.8)x10^10 cm-2 and Trot =10+/-1 K. The abundance of
HCCCHCCC is higher than that of its recently discovered isomer, l-H2C6. If we
compare HCCCCS with its related molecules, HCS and HCCS, we obtain abundance
ratios HCS/HCCCCS=58 and HCCS/HCCCCS=7.2. We investigated the formation of
these two molecules using chemical modelling calculations. The observed
abundances can be accounted for by assuming standard gas-phase formation routes
involving neutral-neutral reactions and ion-neutral reactions.Comment: arXiv admin note: text overlap with arXiv:2206.0899
Doença Hepática Crónica Agudizada: Revisão da Experiência de um Centro Português de Referenciação
Acute-on-chronic liver failure (ACLF) is a syndrome characterized by an acute deterioration of a patient with cirrhosis, frequently associated with multi-organ failure and a high short-term mortality rate. We present a retrospective study that aims to characterize the presentation, evolution, and outcome of patients diagnosed with ACLF at our center over the last 3 years, with a comparative analysis between the group of patients that had ACLF precipitated by infectious insults of bacterial origin and the group of those with ACLF triggered by a nonbacterial infectious insult; the incidence of acute kidney injury and its impact on the prognosis of ACLF was also analyzed. Twenty-nine patients were enrolled, the majority of them being male (89.6%), and the mean age was 53 years. Fourteen patients (48.3%) developed ACLF due to a bacterial infectious event, and 9 of them died (64.2%, overall mortality rate 31%); however, no statistical significance was found (p < 0.7). Of the remaining 15 patients (51.7%) with noninfectious triggers, 11 died (73.3%, overall mortality rate 37.9%); again there was no statistical significance (p < 0.7). Twenty-four patients (83%) developed acute kidney injury (overall mortality rate 65.5%; p < 0.022) at the 28-day and 90-day follow-up. Twelve patients had acute kidney injury requiring renal replacement therapy (41.37%; overall mortality rate 37.9%; p < 0.043). Hepatic transplant was performed in 3 patients, with a 100% survival at the 28-day and 90-day follow-up (p < 0.023). Higher grades of ACLF were associated with increased mortality (p < 0.02; overall mortality 69%).
CONCLUSIONS:
ACLF is a heterogeneous syndrome with a variety of precipitant factors and different grades of extrahepatic involvement. Most cases will have some degree of renal dysfunction, with an increased risk of mortality. Hepatic transplant is an efficient form of therapy for this syndrome.info:eu-repo/semantics/publishedVersio
Discovery of the C7N- anion in TMC-1 and IRC+10216
We report on the discovery of the C7N- anion towards the starless core TMC-1
and towards the carbon-rich evolved star IRC+10216. We used the data of the
QUIJOTE line survey towards TMC-1 and found six lines in perfect harmonic
frequency relation from J=27-26 up to J=32-31. The frequency of the lines can
be reproduced with a rotational constant and a distortion constant of
B=582.68490+/-0.00024 MHz and D=4.01+/-0.13 Hz, respectively. The standard
deviation of the fit is 4 kHz. Towards IRC+10216, we identify 17 lines from
J=27-26 up to J=43-42; their frequencies are also in harmonic relation,
providing B=582.6827+/-0.00085 MHz and D=3.31+/-0.31 Hz. The nearly exact
coincidence of the rotational and distortion constants in both sources points
unambiguously to a common molecular carrier. Taking into account the chemical
peculiarities of both sources, the carrier could be a radical or an anion. The
radical can be discarded, as the observed lines belong to a singlet species.
Hence, the most plausible carrier is an anion. High-level ab initio
calculations indicate that C7N-, for which we compute a rotational constant of
B=582.0 MHz and a dipole moment of 7.5 D, is the carrier of the lines in both
sources. We predict the neutral C7N to have a ground electronic state 2Pi and a
dipole moment around 1 D. Because of this low dipole moment value and to its
much larger rotational partition function, its lines are expected to be well
below the sensitivity of our data for both sources.Comment: Accepted as a Letter to the Editor in Astronomy & Astrophysics.
Submitted on 29/12/2022 and accepted on 30/1/202
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