Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs.

The magnetic order in antiferromagnetic materials is hard to control with external magnetic fields. Using x-ray magnetic linear dichroism microscopy, we show that staggered effective fields generated by electrical current can induce modification of the antiferromagnetic domain structure in microdevices fabricated from a tetragonal CuMnAs thin film. A clear correlation between the average domain orientation and the anisotropy of the electrical resistance is demonstrated, with both showing reproducible switching in response to orthogonally applied current pulses. However, the behavior is inhomogeneous at the submicron level, highlighting the complex nature of the switching process in multidomain antiferromagnetic films.

Synthesis, evaluation and molecular modelling of piceatannol analogues as arginase inhibitors.

Arginase is involved in a wide range of pathologies including cardiovascular diseases and infectious diseases whilst it is also a promising target to improve cancer immunotherapy. To date, only a limited number of inhibitors of arginase have been reported. Natural polyphenols, among them piceatannol, are moderate inhibitors of arginase. Herein, we report our efforts to investigate catechol binding by quantum chemistry and generate analogues of piceatannol. In this work, we synthesized a novel series of amino-polyphenols which were then evaluated as arginase inhibitors. Their structure-activity relationships were elucidated by deep quantum chemistry modelling. 4-((3,4-Dihydroxybenzyl)amino)benzene-1,2-diol 3t displays a mixed inhibition activity on bovine and human arginase I with IC50 (K i) values of 76 (82) µM and 89 µM, respectively.

The antecedents and correlates of necrotizing enterocolitis and spontaneous intestinal perforation among infants born before the 28th week of gestation.

OBJECTIVE: To identify antecedents of "medical" necrotizing enterocolitis (mNEC), "surgical" NEC (sNEC), and spontaneous intestinal perforation (SIP) in newborns delivered before 28 weeks gestation. STUDY DESIGN: Prospective multicenter cohort study. During study period, 2002- 2004, women delivering before 28 weeks gestation at one of 14 participating institutions were enrolled. Well defined antenatal and postnatal variables were collected. Bivariate analyses were performed to identify candidates for developing multinomial multivariable time-oriented logistic regression models. RESULTS: Of the 1320 infants, 5% had mNEC, 6% had sNEC, and 4% had SIP. Antecedents of mNEC included mother's identification as Black, consumption of aspirin during the pregnancy, and vaginal bleeding after the 12th week of gestation. For sNEC the antecedents were maternal self- support, obesity and anemia during the pregnancy, birth before the 24th week, birth weight ≤750gm, and receipt of fresh frozen plasma (FFP) during the first postnatal week. An infant was at increased risk of SIP if the placenta had increased syncytial knots, birth occurred before the 24th week, and received FFP during the first week. CONCLUSIONS: Maternal and neonatal characteristics might help identify at-risk ELGANs for NEC and SIP, who then may potentially benefit from targeted preventive strategies.

Maturational, comorbid, maternal and discharge domain impact on preterm rehospitalizations: a comparison of planned and unplanned rehospitalizations.

OBJECTIVE: To determine the predictive value of (1) maternal, (2) maturational, (3) comorbid and (4) discharge domains associated with preterm infant rehospitalization. STUDY DESIGN: Retrospective, cohort study of preterm infants discharged home from a level IV neonatal intensive care unit. Rates of unplanned and planned 6-month readmissions were assessed. The four domains were modeled incrementally and separately to predict relative and combined contributions to the readmission risk. RESULT: Out of 504 infants, 5% had 30-day readmissions (22 unplanned, three planned). By 6 months, 13% were rehospitalized (52 unplanned, 15 planned). Sixty-seven infants had 96 readmission events with 30% of readmission events elective. The four domains together predicted 78% of total 1-month, all 6-month and unplanned 6-month readmissions. Discharge complexity was as predictive as comorbidity in all models. CONCLUSION: These four-domain models were more predictive than single domains. Many total readmission events were planned, suggesting parsing planned and unplanned rehospitalizations may benefit quality-improvement efforts.

Electrical switching of an antiferromagnet.

Antiferromagnets are hard to control by external magnetic fields because of the alternating directions of magnetic moments on individual atoms and the resulting zero net magnetization. However, relativistic quantum mechanics allows for generating current-induced internal fields whose sign alternates with the periodicity of the antiferromagnetic lattice. Using these fields, which couple strongly to the antiferromagnetic order, we demonstrate room-temperature electrical switching between stable configurations in antiferromagnetic CuMnAs thin-film devices by applied current with magnitudes of order 10(6) ampere per square centimeter. Electrical writing is combined in our solid-state memory with electrical readout and the stored magnetic state is insensitive to and produces no external magnetic field perturbations, which illustrates the unique merits of antiferromagnets for spintronics.

Statistical methodology: III. Receiver operating characteristic (ROC) curves.

Measures including sensitivity, specificity, and positive and negative predictive values have been traditionally used to assess a diagnostic test's ability to detect the presence or absence of disease. Receiver operating characteristic (ROC) curve analysis allows visual evaluation of the trade-offs between sensitivity and specificity associated with different values of the test result, or different "cutpoints" for defining a positive result. The purpose of this article is to define, construct, and interpret a ROC curve using a hypothetical example applicable to emergency medicine practice.

Impact of technetium-99m sestamibi imaging on the emergency department management and costs in the evaluation of low-risk chest pain.

OBJECTIVES: To assess the impact of rest sestamibi scanning on emergency physicians' (EPs') diagnostic certainty and decision making (as assessed by the hypothetical disposition of patients) for 69 consenting stable patients with suspected acute cardiac ischemia and nondiagnostic electrocardiograms. The resultant impact on costs was examined as a secondary outcome. METHODS: Patients with suspected acute cardiac ischemia were injected with 25 mCi of sestamibi within two hours of active pain in one of three emergency department study sites. The probability of acute myocardial infarction (AMI) and unstable angina (UA), and hypothetical disposition decisions were recorded immediately before and after physicians were notified of scan results. Changes in disposition were classified as optimal or suboptimal. For the cost determinations, a cost-based decision support program was used. RESULTS: For the subgroup found to be free of acute cardiac events (ACEs) (n = 62), the EPs' post-sestamibi scan probabilities for AMI decreased by 11% and UA by 18% (p < 0.001 for both conditions). In seven patients with ACEs, the post-scan probabilities of AMI and UA increased, but neither was statistically significant. Scan results led to hypothetical disposition changes in 29 patients (42%), of which 27 (93%) were optimal (nine patients were reassigned to a lower level of care, two to a higher level, and 16 additional patients to "discharge-home" status). The strategy of scanning all patients who were low to moderate risk for acute cardiac ischemia would result in an increase of direct costs of care of $222 per patient evaluated, due to added cost of sestamibi scanning. CONCLUSIONS: Sestamibi scanning results appropriately affected the EPs' estimates of the probability of AMI and UA and improved disposition decisions. Scanning all low-risk patients would likely be associated with increased costs at this medical center.

Vasopressin can increase coronary perfusion pressure during human cardiopulmonary resuscitation.

OBJECTIVES: To determine the hemodynamic effect of vasopressin on coronary perfusion pressure (CPP) in prolonged human cardiac arrest. METHODS: A prospective, open-label clinical trial of vasopressin during cardiac resuscitation was performed. Ten patients presenting in cardiac arrest initially received resuscitative measures by emergency physicians according to Advanced Cardiac Life Support (ACLS) guidelines. A central venous catheter for fluid and drug administration and a femoral artery catheter for measurement of CPP (aortic minus right atrial relaxation phase pressures) were placed. When each patient was deemed nonsalvageable, 1.0 mg epinephrine was given and CPP was measured for 5 minutes, followed by a dose of vasopressin (1.0 U/kg). CPP measurements were continued for another 5 minutes. RESULTS: The mean duration of cardiac arrest (out-of-hospital interval plus duration of ED ACLS) was 39.6 +/- 16.5 min. There was no improvement in CPP after 1.0 mg of epinephrine. Vasopressin administration resulted in a significant increase of CPP in 4 of the 10 patients. Patients responding to vasopressin had a mean increase in CPP of 28.2 +/- 16.4 mm Hg (range: 10-51.5), with these peak increases occurring at 15 seconds to 4 minutes after administration. The increases in the vasopressin levels after administration did not differ between the responders and nonresponders. CONCLUSIONS: In this human model of prolonged cardiac arrest, 40% of the patients receiving vasopressin had a significant increase in CPP. This pilot study suggests that investigation of earlier use of vasopressin as a therapeutic alternative in the treatment of cardiac arrest is warranted.

The chest pain center in the emergency department.

Despite the improvement of medical treatment for acute coronary syndromes throughout the 20th century, the authors believe that many cases of life-threatening coronary events could be avoided through early detection of CAD and the use of preventive strategies. Establishing chest pain units that are linked to the ED is one excellent strategy to risk-stratify patients with symptoms who are at risk for sustaining an AMI or having lethal arrhythmias. There is a need for more research on chest pain units to determine the value for cost and to further optimize strategies for ACI detection and screening. In EDs with high volumes of chest pain patients, or high pressures to avoid hospital admissions, a planned, systematic, and rapid approach to the treatment of AMI and the diagnosis of chest pain is a rewarding necessity.

[Allergy to anesthetic agents: analysis of 96 recent cases]. / L'allergie aux agents anesthésiques: analyse de 96 observations récentes.

This retrospective study concerning 96 observations from 1984 to 1987 allows to estimate the incidence of anaphylactoid reactions, the risk factors and the drugs involved in these accidents. During these three years, 96 anaphylactoid reactions due to anaesthetic drugs were collected. These anaphylactoid reactions were investigated by intradermal skin tests and in vitro by leukocyte histamine release. The drugs most often involved were the muscle relaxants and over all suxamethonium. This muscle relaxant must be reserved to strict indications.

Perceptions and practices of registered nurses regarding pastoral care and the spiritual need of hospital patients.

Reports the findings of a questionnaire survey designed to examine the impact of pastoral care on patient care and job satisfaction of registered nurses (N-280) employed in a metropolitan hospital. Suggests that educational strategies be explored as a way of broadening the perspectives of nurses regarding reasons for consulting pastoral care departments.

ECG scores for a triage of patients with acute myocardial infarction transported by the emergency medical system.

Prehospital triage of cardiac patients for bypass from community hospitals to cardiac centers may improve survival. This article determines if electrocardiogram (ECG)-based scoring triage methods (Aldrich MI scoring, QRS distortion, and the TIMI classification) and location of infarct (via 12 lead ECG) are associated with mortality before and after adjusting for age, sex, and race. It is a retrospective study of 291 AMI adult patients transported by ambulance to community hospitals or cardiac centers. Patients with an ED chief complaint of chest pain or dyspnea, presence of MI as defined by ECG findings of 0.1 mV of ST segment elevation in two leads or positive CPK-MB were eligible for the study. The primary outcome variable was 2-year mortality as determined with a metropolitan Detroit tri-county death index. Logistic regression was used to calculate the unadjusted and adjusted odds ratios (with 95% CIs) of the predictor variables with mortality. Of the initial population selected for the study (n = 291), 229 patients were eligible for the analysis. The mean age was 66 years (SD of 14.4) with 63.8% being male and 54% being white. The overall mortality point estimate was 21.3% (95% CI of 15.2 to 27.3%). Aldrich scores and QRS distortion (yes/no) were not associated with mortality. Patients classified as a "high risk" for AMI per TIMI status were almost 3 times more likely to die than those at "low risk" and reached borderline statistical significance (P = .06) after adjusting for the covariates. Having an anterior infarct, as opposed to an inferior infarct, was significantly associated with death before and after adjusting for the covariates (Unadjusted OR = 2.6, Adjusted OR = 2.8). Properly training emergency medical system professionals in this area may prove useful for identifying higher risk AMI patients in the prehospital setting.

A prediction model for prehospital triage of patients with suspected cardiac ischemia.

The American College of Cardiology recommends that patients with high risk acute myocardial infarction (AMI) be triaged to hospitals with percutaneous transluminal coronary angioplasty capability. However, there are no prehospital triage criteria to select candidates for bypassing community hospitals and being taken directly to "cardiac centers." This article assesses which independent variables predict death within 7 days in patients with suspected AMI transported by EMS. This is a retrospective study of 291 AMI patients transported by ambulance to 3 hospitals during 1996-1997. Included were patients who were (n = 244) > or =18 years of age, had a ED chief complaint of chest pain or dyspnea for whom we had mortality data. Mortality at 7 days, our primary outcome measure, was obtained by using a metropolitan Detroit tricounty death index records. Differences between the survivors and nonsurvivors were assessed using the Student's t-test and chi-square tests. Multiple triage criteria were assessed for optimal identification of high risk patients by constructing a logistic multivariate model. Among the study population, 15% died within 7 days (95% confidence interval (CI) 10.3-19.2), and this group represented 63.2% of all deaths over a 2 year surveillance period. Survivors, compared to nonsurvivors, were 14.1 years younger (P < or = .001) and more often men (P < or = 0.001). The dispatch time to ED arrival was less among survivors than nonsurvivors (42.8 vs. 50.6 min, P < or = .01). EMS vital signs differed by survivor status. Among survivors, HR was lower (-11.9 bpm; P < or = 0.01), RR was lower (-6.7 rpm; P < or = .001), SBP was higher (+14.5 mmHg; P < or = 0.05) and DBP was higher (+13.2 mm Hg; P < or = .01). A multivariate model identified the following as independent predictors of early mortality: female gender (OR = 2.3; P < or = .05), age > or =65 (OR = 5.9; P < or = .01), RR > or = 20 (OR = 4.6; P < or = .001), SBP < 120 (OR = 2.4; P < or = .05). The overall model was 86% sensitive and 53% specific with an area under the receiving operating characteristic curve of 0.8 (P < or = .001). A triage rule based on a multivariate model can identify the group at high risk of early cardiac death. This decision rule needs to be prospectively validated.

The prevalence of anti-latex IgE antibodies among registered nurses.

BACKGROUND: Recent studies have reported that the prevalence of latex allergy among volunteer populations of health care workers ranges from 2% to 25%. To date, no epidemiologic study has investigated the prevalence of latex allergy and its relationship to possible risk factors among nurses. METHODS: Registered nurses (n = 741) in a large metropolitan hospital participated in a latex allergy prevalence study. Latex exposure data were obtained through self-administered questionnaires. Blood samples were classified as positive or negative for anti-latex IgE antibodies. Associations between potential risk factors for latex allergy and anti-latex antibodies were assessed. RESULTS: The participation rate was 90.6% among eligible nurses. Sixty-five samples were positive for a prevalence of 8.9% (95% confidence interval, 6.7 to 10.8). No differences in latex positivity among five nursing specialties were noted. Logistic regression indicated that after adjusting for age and sex, the following factors were significantly associated with latex seropositivity: nonwhite race (odds ratio [OR] = 4.2), reported histories of penicillin allergy (OR = 2.2), pruritic skin (OR = 2.2), conjunctivitis (OR = 3.0), localized urticaria (OR = 1.8), hay fever (OR = 2.1), avocado allergy (OR = 9.9), and ragweed allergy (OR = 3.4). CONCLUSIONS: The prevalence of latex sensitization appeared to be substantial (8.9%) among the nurses studied, and the prevalence did not vary by nursing specialty. The factors associated with latex positivity in the logistic regression model correctly classified 81.3% of the nurses with a sensitivity and specificity of 66.7% and 82.7%, respectively.

Prognostic value of a normal or nonspecific initial electrocardiogram in acute myocardial infarction.

CONTEXT: Although previous studies have suggested that normal and nonspecific initial electrocardiograms (ECGs) are associated with a favorable prognosis for patients with acute myocardial infarction (AMI), their independent predictive value for mortality has not been examined. OBJECTIVE: To compare in-hospital mortality among patients with AMI who have normal or nonspecific initial ECGs with that of patients who have diagnostic ECGs. DESIGN, SETTING, AND PATIENTS: Multihospital observational study in which 391 208 patients with AMI met the study criteria between June 1994 and June 2000 and had ECGs that were normal (n = 30 759), nonspecific (n = 137 574), or diagnostic (n = 222 875; defined as ST-segment elevation or depression and/or left bundle-branch block). A logistic regression model was constructed using a propensity score for ECG findings and data on demographics, medical history, diagnostic procedures, and therapy to determine the independent prognostic value of a normal or nonspecific initial ECG. MAIN OUTCOME MEASURES: In-hospital mortality; composite outcome of in-hospital death and life-threatening adverse events. RESULTS: In-hospital mortality rates were 5.7%, 8.7%, and 11.5% while the rates of the composite of mortality and life-threatening adverse events were 19.2%, 27.5%, and 34.9% for the normal, nonspecific, and diagnostic ECG groups, respectively. After adjusting for other predictor variables, the odds of mortality for the normal ECG group was 0.59 (95% confidence interval [CI], 0.56-0.63; P<.001) and for the nonspecific group was 0.70 (95% CI, 0.68-0.72; P<.001), compared with the diagnostic ECG group. CONCLUSION: In this large cohort of patients with AMI, patients presenting with normal or nonspecific ECGs did have lower in-hospital mortality rates than those of patients with diagnostic ECGs, yet the absolute rates were still unexpectedly high.