3,142 research outputs found
How good are we at managing acute kidney injury in hospital?
Introduction. Acute kidney injury (AKI) is a common clinical problem associated with adverse outcomes.
This study identifies the incidence of AKI in two UK district general hospitals’ without
on-site renal services and assesses AKI management and level of nephrologist input.
Methods. The AKIN classification was used to identify 1020 AKI patients over 6 months. Data were
collated on patient demographics, AKI management and referral to nephrology and intensive care
services. Short/long-term renal outcomes were investigated. Patients were followed up for 14
months post-discharge.
Results. Incidence of hospital-based AKI was 6.4%. Mean patient age was 73 years. There was
28.1% acute in-hospital mortality with a further 21.6% 14-month mortality. Only 8.3% of patients
were referred to nephrology services for in-hospital review, and only 8.1% had outpatient nephrology
follow-up. Compliance with the AKI National Confidential Enquiry into Patient Outcomes and
Deaths (NCEPOD) recommendations was poor with 32.8% of patients having renal imaging and
15% of patients having acid–base status assessed. NCEPOD compliance improved with nephrology
input. Patients referred to nephrology were likely to be younger with pre-existing CKD and severe
AKI. 10.5% of AKI episodes were unrecognized. Forty percent of those with unrecognized AKI,
(compared with 15% of recognized AKI) developed de novo or progression of pre-existing CKD.
Conclusion. AKI in DGHs is mostly managed without nephrology input. There are significant shortcomings
in AKI recognition and management in this setting. This is associated with poor mortality
and long-term CKD. This study supports a need to improve the teaching and training of front-line
medical staff in identifying AKI. Additionally, implementation of AKI e-alert systems may encourage
early recognition and provide a prompt for renal referral
A framework to evaluate whether to pool or separate behaviors in a multilayer network
A multilayer network approach combines different network layers, which are
connected by interlayer edges, to create a single mathematical object. These
networks can contain a variety of information types and represent different
aspects of a system. However, the process for selecting which information to
include is not always straightforward. Using data on two agonistic behaviors in
a captive population of monk parakeets (Myiopsitta monachus), we developed a
framework for investigating how pooling or splitting behaviors at the scale of
dyadic relationships (between two individuals) affects individual- and
group-level social properties. We designed two reference models to test whether
randomizing the number of interactions across behavior types results in similar
structural patterns as the observed data. Although the behaviors were
correlated, the first reference model suggests that the two behaviors convey
different information about some social properties and should therefore not be
pooled. However, once we controlled for data sparsity, we found that the
observed measures corresponded with those from the second reference model.
Hence, our initial result may have been due to the unequal frequencies of each
behavior. Overall, our findings support pooling the two behaviors. Awareness of
how selected measurements can be affected by data properties is warranted, but
nonetheless our framework disentangles these efforts and as a result can be
used for myriad types of behaviors and questions. This framework will help
researchers make informed and data-driven decisions about which behaviors to
pool or separate, prior to using the data in subsequent multilayer network
analyses.Comment: accepted for Current Zoolog
More about the comparison of local and non-local NN interaction models
The effect of non-locality in the NN interaction with an off-energy shell
character has been studied in the past in relation with the possibility that
some models could be approximately phase-shifts equivalent. This work is
extended to a non-locality implying terms that involve an anticommutator with
the operator p^2. It includes both scalar and tensor components. The most
recent ``high accuracy'' models are considered in the analysis. After studying
the deuteron wave functions, electromagnetic properties of various models are
compared with the idea that these ones differ by their non-locality but are
equivalent up to a unitary transformation. It is found that the extra non-local
tensor interaction considered in this work tends to re-enforce the role of the
term considered in previous works, allowing one to explain almost completely
the difference in the deuteron D-state probabilities evidenced by the
comparison of the Bonn-QB and Paris models for instance. Conclusions for the
effect of the non-local scalar interaction are not so clear. In many cases, it
was found that these terms could explain part of the differences that the
comparison of predictions for various models evidences but cases where they
could not were also found. Some of these last ones have been analyzed in order
to pointing out the origin of the failure.Comment: 32 pages, 24 figure
Three Dimensional Quantification of Angiotensin II-Induced Murine Abdominal Aortic Aneurysms Using High Frequency Ultrasound
Abdominal aortic aneurysms (AAAs), a localized dilation of the vessel wall of 50% or more above normal, claims approximately 14,000 U.S. lives yearly due to aortic rupture. This commonly asymptomatic disease can only be treated by endovascular stent grafts or invasive surgery, usually after the AAA diameter reaches 5 cm. Because these treatment methods carry serious risk, stem cell therapy is being explored in order to provide a low risk option for managing smaller AAAs. To determine if stem cell therapy, once administered, could stabilize or reduce AAA growth, baseline 3D ultrasound measurements in a control group were first needed. High frequency ultrasound was used on apolipoprotein E-deficient (apoE-/-) mice given angiotensin II (AngII) from subcutaneously implanted osmotic mini pumps. This mouse model developed dissecting AAAs, containing a false and true lumen, which were clearly visualized and quantified using 3D ultrasound imaging. With this ultrasound technique, we found that aneurysm diameter, total volume, and false lumen volume all increased steadily over a period of 28 days once AAAs formed. These data suggest our noninvasive, 3D ultrasound technique can be used to monitor the progression of aneurysms that may be delayed once stem cell therapy is administered
Nonlinear Optical Microscopy of Murine Abdominal Aortic Aneurysm
Abdominal aortic aneurysm (AAA) is a cardiovascular disease characterized by dilation and weakening of the vessel wall. AAA rupture is responsible for approximately 14,000 deaths annually in the United States [1]. Nonlinear optical (NLO) microscopy presents new possibilities for analyzing AAA tissue samples from murine models. Common NLO techniques are two-photon excitation fluorescence (TPEF), which detects the intrinsic autofluorescent properties of elastin, and second-harmonic generation (SHG), which is specific for collagen fibrils. Elastin and collagen, two major extracellular matrix components, help the aortic wall withstand internal pressure. Murine AAAs were created through 1) subcutaneous continuous systemic infusion of angiotensin II (AngII) in hyperlipidemic apolipoprotein E-deficient mice and 2) by intraluminal infusion of elastase (low 0.5 U/ml and high 25 U/ml concentrations) into the infrarenal aorta of rats [2]. We imaged aneurysmal and control tissue using TPEF and SHG and compared the resulting images to sections stained with standard elastin and collagen markers. TPEF images revealed disorganized elastin sheets and SHG images indicated collagen turnover after aneurysm formation. We quantified the relative degree of elastin degradation and collagen content in the aortic media within a user-defined area on sections stained with Verhoeff-van Gieson (VVG) or Masson’s trichrome (MTC), as well as on TPEF and SHG images. Our analysis with VVG-stained sections shows that elastin content in AAA tissue is significantly decreased by 64% in AngII models (P=0.02), by 34% in low concentration elastase models (P=0.07), and by 99% in high concentration elastase models (P=0.03), relative to control aortic tissue
Poincare' Covariant Current Operator and Elastic Electron-Deuteron Scattering in the Front-form Hamiltonian Dynamics
The deuteron electromagnetic form factors, and , and the
tensor polarization , are unambiguously calculated within the
front-form relativistic Hamiltonian dynamics, by using a novel current, built
up from one-body terms, which fulfills Poincar\'e, parity and time reversal
covariance, together with Hermiticity and the continuity equation. A
simultaneous description of the experimental data for the three deuteron form
factors is achieved up to . At higher momentum transfer,
different nucleon-nucleon interactions strongly affect , , and
and the effects of the interactions can be related to -state
kinetic energy in the deuteron. Different nucleon form factor models have huge
effects on , smaller effects on and essentially none on
.Comment: 31 pages + 16 figures. Submitted to Phys. Rev.
Maternal and neonatal outcomes in patients with hepatitis C and intrahepatic cholestasis of pregnancy: The sum of the parts.
ObjectiveHepatitis C virus and intrahepatic cholestasis of pregnancy (ICP) are well-known independent risk factors for adverse outcomes in pregnancy. In addition, it is well-established that there is an association between Hepatitis C and ICP. This study's objective was to describe the impact of having both Hepatitis C and ICP on maternal and obstetric outcomes compared to patients having either Hepatitis C or ICP.MethodsWe conducted a retrospective cohort study of the Nationwide Readmissions Database, an all-payor sample of discharges from approximately 60% of US hospitalizations. Deliveries at 24-42+ weeks between 10/2015 and 12/2020 were included. Diagnosis of Hepatitis C and ICP, and outcomes related to severe maternal morbidity were identified using International Classification of Disease-10 codes. Patients were categorized based on Hepatitis C and ICP status. Weighted logistic and negative binomial regression analyses were used to evaluate the association between Hepatitis C and ICP status and outcomes, adjusting for patient and hospital characteristics. The primary outcome was any severe maternal morbidity; secondary outcomes included acute respiratory distress syndrome, acute kidney injury, sepsis, gestational diabetes, cesarean delivery, preterm birth, and hospital length of stay. We modeled interaction terms between ICP and Hepatitis C to assess whether there was a greater or lesser effect from having both conditions on outcomes than we would expect from additive combination of the individual components (i.e., synergy or antagonism).ResultsA total of 10,040,850 deliveries between 24-42+ weeks were identified. Of these, 45,368 had Hepatitis C only; 84,582 had ICP only; and 1,967 had both Hepatitis C and ICP. Patients with both Hepatitis C and ICP had 1.5-fold higher odds of developing severe maternal morbidity compared to having neither. There was an also an increased odds of severe maternal morbidity in patients with both Hepatitis C and ICP compared to patients with only Hepatitis C or ICP. Having both was also associated with higher odds of preterm birth and length of stay compared to having only Hepatitis C, only ICP, or neither (preterm birth: aOR 5.09, 95% CI 4.87-5.33 vs. neither; length of stay: 46% mean increase, 95% CI 35-58% vs. neither). Associations were additive-no significant interactions between hepatitis C and cholestasis were found on rates of severe maternal morbidity, acute respiratory distress syndrome, acute kidney injury, sepsis, cesarean section, or preterm birth (all p>0.05), and was minimal for gestational diabetes and length of stay.ConclusionHepatitis C and ICP are independent, additive risk factors for adverse maternal and obstetric outcomes. Despite physiologic plausibility, no evidence of a synergistic effect of these two diagnoses on outcomes was noted. These data may be useful in counseling patients regarding their increased risk of adverse outcomes when ICP presents in association with Hepatitis C versus ICP alone
The deuteron: structure and form factors
A brief review of the history of the discovery of the deuteron in provided.
The current status of both experiment and theory for the elastic electron
scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic
Large Momentum Transfer Measurements of the Deuteron Elastic Structure Function A(Q^2) at Jefferson Laboratory
The deuteron elastic structure function A(Q^2) has been extracted in the Q^2
range 0.7 to 6.0 (GeV/c)^2 from cross section measurements of elastic
electron-deuteron scattering in coincidence using the Hall A Facility of
Jefferson Laboratory. The data are compared to theoretical models based on the
impulse approximation with inclusion of meson-exchange currents, and to
predictions of quark dimensional scaling and perturbative quantum
chromodynamicsComment: Submitted to Physical Review Letter
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
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