178 research outputs found
Ladder operators for subtle hidden shape invariant potentials
Ladder operators can be constructed for all potentials that present the
integrability condition known as shape invariance, satisfied by most of the
exactly solvable potentials. Using the superalgebra of supersymmetric quantum
mechanics we construct the ladder operators for two exactly solvable potentials
that present a subtle hidden shape invariance.Comment: 9 pages, based on the talk given at International Conference Progress
in Supersymmetric Quantum Mechanics (PSQM03), Valladolid, Spain, 15-19 July,
2003, to appear in a Special Issue of J. Phys. A: Math. Ge
Cost-effectiveness of In-Home Cognitive Behavioral Therapy for low-income depressed mothers participating in early childhood prevention programs
To determine the cost-effectiveness of In-Home Cognitive Behavioral Therapy (IH-CBT) for low-income mothers enrolled in a home visiting program
Exactly solvable models of supersymmetric quantum mechanics and connection to spectrum generating algebra
For nonrelativistic Hamiltonians which are shape invariant, analytic
expressions for the eigenvalues and eigenvectors can be derived using the well
known method of supersymmetric quantum mechanics. Most of these Hamiltonians
also possess spectrum generating algebras and are hence solvable by an
independent group theoretic method. In this paper, we demonstrate the
equivalence of the two methods of solution by developing an algebraic framework
for shape invariant Hamiltonians with a general change of parameters, which
involves nonlinear extensions of Lie algebras.Comment: 12 pages, 2 figure
TCT-99 Short- and Long-Term Outcomes of Patients With Chronic Kidney Disease Undergoing Protected High-Risk Percutaneous Coronary Intervention
Background: Patients with chronic kidney disease (CKD) and concomitant multivessel coronary artery disease (CAD) with or without left ventricular dysfunction often have high surgical risk and are declined for coronary artery bypass grafting. There is little data regarding clinical outcomes in these patients undergoing high-risk PCI (HRPCI) using Impella.
Methods: We analyzed patients from the PROTECT III Study who underwent Impella-supported HRPCI and stratified them into 3 groups by kidney function status based on history: 1) normal kidney function, 2) CKD without dialysis, and 3) CKD with dialysis. We compared the composite incidence of major adverse cardiac and cerebrovascular events (MACCE) rate, defined as all-cause death, myocardial infarction (MI), stroke/transient ischemic attack (TIA), and repeat revascularization at 30 and 90 days.
Results: We included 1,223 patients, aged 71 ± 11 years; 73% (893) were men, 68% (834) had normal kidney function (serum creatinine [Cr] 1.1 mg/dL, IQR 0.9-1.2), 23% (278) had CKD without dialysis (Cr 1.7 mg/dL, IQR 1.3-1.9), and 9% (111) were on dialysis. Patients on dialysis were younger with more comorbidities such as diabetes, heart failure, anemia, PVD and prior stroke. HRPCI status (urgent or elective), proportion of acute MI, and mean SYNTAX scores were similar. No significant differences in MACCE were shown between groups at 30 days or 90 days (Table). Patients with normal kidney function had comparable risks of 30-day and 90-day MACCE compared with CKD patients without dialysis with Cox proportional hazards analysis, and lower risk of 90-day MACCE compared to CKD patients with dialysis. Notably, CKD patients with or without dialysis also had similar 90-day MACCE risk (Table).
Conclusion: Patients with CKD and dialysis undergoing HRPCI exhibit higher risk for 90-day MACCE compared to patients with normal kidney function. CKD patients without dialysis also had higher risk of MI at 90 days. Further research is needed.
Categories: CORONARY: Complex and Higher Risk Procedures for Indicated Patients (CHIP
TCT-545 Angiographic Features, Lesion, and Procedural Characteristics in Patients With Chronic Kidney Disease Undergoing Protected High-Risk Percutaneous Coronary Intervention
Background: Patients with chronic kidney disease (CKD) are at risk for accelerated atherosclerosis. There is a paucity of data regarding coronary lesion characteristics and procedural details of CKD patients, especially those on dialysis, undergoing high-risk percutaneous coronary intervention (HRPCI) with left ventricular support.
Methods: We analyzed patients from the PROTECT III study who underwent Impella-supported HRPCI, stratified into 3 groups according to kidney function status based on history: 1) normal kidney function; 2) CKD not on dialysis; and 3) CKD on dialysis. Baseline characteristics, angiographic features, and procedural details were assessed.
Results: The study population included 3,702 treated lesions in 1,223 patients with a mean age of 71 ± 11 years; 73% (893) were male, 68% (834) had normal kidney function (serum creatinine = 1 mg/dL [IQR: 0.9-1.2]), 23% (278) had CKD not on dialysis (serum creatinine = 1.6 mg/dL [IQR: 1.3-1.9]), and 9% (111) were on dialysis. Patients on dialysis were significantly younger and had more comorbidities, as well as a greater incidence of acute myocardial infarction as an indication for HRPCI compared with the other 2 groups (45.0 [dialysis] vs 30.1 [CKD not on dialysis] vs 36.0 [normal kidney function]; P = 0.03). There was no difference between groups in prevalence of 3-vessel disease (P = 0.63). Patients on dialysis had greater prevalence of severely calcified lesions and higher use of rotational and orbital atherectomy with greater number of passes (Table 1). Despite this, no significant differences were observed in post-PCI Thrombolysis In Myocardial Infarction flow, incidence of no-reflow, or dissection/perforation.
Conclusion: In contrast to patients with normal kidney function, patients with CKD with or without dialysis treated with Impella had more comorbidities, higher prevalence of severely calcified lesions, and greater use of atherectomy with more passes. Despite the complexity of PCI, no significant differences in complications were observed.
Categories: CORONARY: Complex and Higher Risk Procedures for Indicated Patients (CHIP
Antimicrobial Peptides and Skin: A Paradigm of Translational Medicine
Antimicrobial peptides (AMPs) are small, cationic, amphiphilic peptides with broad-spectrum microbicidal activity against both bacteria and fungi. In mammals, AMPs form the first line of host defense against infections and generally play an important role as effector agents of the innate immune system. The AMP era was born more than 6 decades ago when the first cationic cyclic peptide antibiotics, namely polymyxins and tyrothricin, found their way into clinical use. Due to the good clinical experience in the treatment of, for example, infections of mucus membranes as well as the subsequent understanding of mode of action, AMPs are now considered for treatment of inflammatory skin diseases and for improving healing of infected wounds. Based on the preclinical findings, including pathobiochemistry and molecular medicine, targeted therapy strategies are developed and first results indicate that AMPs influence processes of diseased skin. Importantly, in contrast to other antibiotics, AMPs do not seem to propagate the development of antibiotic-resistant micro-organisms. Therefore, AMPs should be tested in clinical trials for their efficacy and tolerability in inflammatory skin diseases and chronic wounds. Apart from possible fields of application, these peptides appear suited as an example of the paradigm of translational medicine for skin diseases which is today seen as a `two-way road' - from bench to bedside and backwards from bedside to bench. Copyright (c) 2012 S. Karger AG, Base
Matrilineal behavioral and physiological changes following the death of a non-alpha matriarch in rhesus macaque
In many species, the loss of alpha matriarchs is associated with a number of negative outcomes such as troop fission, eviction, wounding, and reduced vitality. However, whether
the dramatic consequences of their loss are due to their role as an old experienced figure or
to their alpha status remains unclear. In a retrospective study, we tested that in a semi-free
ranging colony of rhesus macaques (Macaca mulatta), the removal of a non-alpha matriarch, who had a large set of kin, led to changes in behavior and physiological stress within
her matriline. Following her removal, her matriline increased in aggression, vigilance, and
social grooming. Additionally, hierarchical stability, measured by levels of rank changes,
decreased within her matriline, and levels of intense aggression by high-ranking animals
were more frequent, as well as matrilineal wounding. Although ordinal rank was positively
associated with higher chronic hair cortisol concentrations (HCCs) in the months before the
matriarch’s removal, following her removal, only those who experienced large increases in
rank within her matriline displayed higher HCCs. Changes in matrilineal stability, aggression, behavior, and HCCs within the other two matrilines in the troop were not evident,
although caution is needed due to the small sample sizes. We conclude that the removal of
the non-alpha matriarch led to matrilineal instability, characterized by higher levels of
aggression and subsequent vigilance, rank changes, physiological stress, and grooming.
We suggest that non-alpha matriarchs with a large number of kin and social support can be
integral to the stability of matrilines.Division of Intramural Research, National Institute of Child Health and Human Development, 1ZIAHD001107- 3
The Impact of COVID-19 Pandemic on Spine Surgeons Worldwide : A One Year Prospective Comparative Study
Study Design: Survey Objective: In March of 2020, an original study by Louie et al investigated the impact of COVID-19 on 902 spine surgeons internationally. Since then, due to varying government responses and public health initiatives to the pandemic, individual countries and regions of the world have been affected differently. Therefore, this follow-up study aimed to assess how the COVID-19 impact on spine surgeons has changed 1 year later. Methods: A repeat, multi-dimensional, 90-item survey written in English was distributed to spine surgeons worldwide via email to the AO Spine membership who agreed to receive surveys. Questions were categorized into the following domains: demographics, COVID-19 observations, preparedness, personal impact, patient care, and future perceptions. Results: Basic respondent demographics, such as gender, age, home demographics, medical comorbidities, practice type, and years since training completion, were similar to those of the original 2020 survey. Significant differences between groups included reasons for COVID testing, opinions of media coverage, hospital unemployment, likelihood to be performing elective surgery, percentage of cases cancelled, percentage of personal income, sick leave, personal time allocation, stress coping mechanisms, and the belief that future guidelines were needed (P<.05). Conclusion: Compared to baseline results collected at the beginning of the COVID-19 pandemic in 2020, significant differences in various domains related to COVID-19 perceptions, hospital preparedness, practice impact, personal impact, and future perceptions have developed. Follow-up assessment of spine surgeons has further indicated that telemedicine and virtual education are mainstays. Such findings may help to inform and manage expectations and responses to any future outbreaks.publishedVersionPeer reviewe
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