906 research outputs found
Use of quantitative micro-complement fixation for detection of small differences in protein structure
Quantitative micro-complement fixation for detection of small differences in protein structur
The Impact of COVID-19 on Noncitizens and Across the U.S. Immigration System
The COVID-19 (the novel coronavirus) pandemic, and the related federal response, disrupted virtually every aspect of the U.S. immigration system. Visa processing overseas by the Department of State, as well as the processing of some immigration benefits within the country by U.S. Citizenship and Immigration Services (USCIS), have come to a near standstill. Entry into the United States along the Mexican and Canadian borders—including by asylum seekers and unaccompanied children—has been severely restricted. Immigration enforcement actions in the interior of the country have been curtailed, although they have not stopped entirely. Tens of thousands of people remain in immigration detention despite the high risk of COVID-19 transmission in crowded jails, prisons, and detention centers that U.S. Immigration and Customs Enforcement (ICE) uses to hold noncitizens. The pandemic led to the suspension of many immigration court hearings and limited the functioning of the few courts which remain open or were reopened. Meanwhile, Congress left millions of immigrants and their families out of legislative relief, leaving many people struggling to stay afloat in a time of economic uncertainty.This report seeks to provide a comprehensive overview of the impact of COVID-19 across the immigration system in the United States. Given that the landscape of immigration policy is changing rapidly in the face of the pandemic, this report will be updated as needed
Prediction of the haemodynamic response to tracheal intubation: comparison of laser-Doppler skin vasomotor reflex and pulse wave reflex
Background. The laser-Doppler skin vasomotor reflex (SVmR) caused by tetanic stimulation of the ulnar nerve may be a test that can predict the haemodynamic response to tracheal intubation. A decrease in pulse wave amplitude (pulse wave reflex, PWR) may be an alternative index of this response. We compared the abilities of PWR and SVmR to predict the haemodynamic response to tracheal intubation and studied how alfentanil, muscle relaxation, stimulation site and stimulation pattern affected the two reflexes. Methods. Anaesthesia was induced and maintained with 2% sevoflurane and 50% nitrous oxide in two groups of 10 ASA status I patients. Tetanic stimuli were applied to the flexor muscles of the forearm and the ulnar nerve before and after administration of vecuronium. The change in skin blood flow (laser-Doppler) and pulse wave amplitude (pulse oximetry) after a 5 and 10 s stimulation was measured on the opposite hand. If skin blood flow (laser-Doppler) decreased by more than 10%, a computer-controlled infusion of alfentanil was started and the target plasma concentration was increased in steps until this response was suppressed (<10%). The trachea was intubated and arterial pressure and heart rate responses were recorded. Plasma alfentanil concentration was measured. Results. When PWR and SVmR were suppressed, the haemodynamic response to tracheal intubation was reduced in 100 and 53% of patients respectively. PWR and SVmR responses decreased with increasing plasma alfentanil concentration. The SVmR response to muscle stimulation was reduced by muscle relaxants. The pulse wave response to both muscle and neural stimulation was reduced by relaxants. The responses to 5 and 10 s stimulations were similar. Conclusion. An absent SVmR does not predict a blunted arterial pressure or heart rate response to tracheal intubation. The PWR may be a better predicto
Predictors for early mortality and arrhythmic events in patients with cardiac resynchronization therapy with defibrillator: A two center cohort study
Background: Guidelines of heart failure therapy include cardiac resynchronization as standard ofcare in patients with severely depressed left ventricular function and wide QRS complex. It has beenshown that patients benefit regarding mortality and morbidity. However, early mortality precludes longtermbenefits from the device. The aim of the study was to identify predictors for early occurrence ofboth death and first-ever implantable cardioverter-defibrillator (ICD) therapy using a large combineddatabase of patients with cardiac resynchronization therapy with defibrillator (CRT-D).Methods: From two registries (tertiary care centers) 904 patients were identified, no single patient wasexcluded. Early death was defined as death occurring within the 3 years after implantation whereasearly ICD therapy as such occurring within the first year. 33 baseline parameters were compared usinguni- and multivariate analysis with the Cox model and binary logistic regression.Results: The population was predominantly male (77%), with mean age of 63 ± 11 years and primaryprevention indication in 80%. Mean follow-up was 55 ± 38 months. 256 (28%) patients hadICD therapies whereof the first-ever event occurred early in 52%. 270 (30%) patients died after 41 ±± 31 months, mostly from advancing heart failure (41%), 141 (52%) patients of them early. Independentpredictors for early ICD therapy were secondary prevention and renal failure. Independent predictors forearly mortality were a history of percutaneous coronary intervention and of peripheral vascular disease.Conclusions: Predictors for early mortality after CRT-D implantation were a history of percutaneouscoronary intervention and peripheral vascular disease, present in only a minority of patients, thus limitingtheir use in clinical practice
TRAF2 Is Essential for JNK but Not NF-ÎşB Activation and Regulates Lymphocyte Proliferation and Survival
AbstractTRAF2 is believed to mediate the activation of NF-κB and JNK induced by the tumor necrosis factor receptor (TNFR) superfamily, which elicits pleiotropic responses in lymphocytes. We have investigated the physiological roles of TRAF2 in these processes by expressing a lymphocyte-specific dominant negative form of TRAF2, thereby blocking this protein's effector function. We find that the TNFR superfamily signals require TRAF2 for activation of JNK but not NF-κB. In addition, we show that TRAF2 induces NF-κB–independent antiapoptotic pathways during TNF-induced apoptosis. Inhibition of TRAF2 leads to splenomegaly, lymphadenopathy, and an increased number of B cells. These findings indicate that TRAF2 is involved in the regulation of lymphocyte function and growth in vivo
Contact force sensing in ablation of ventricular arrhythmias using a 56-hole open-irrigation catheter: a propensity-matched analysis.
PURPOSE: The effect of adding contact force (CF) sensing to 56-hole tip irrigation in ventricular arrhythmia (VA) ablation has not been previously studied. We aimed to compare outcomes with and without CF sensing in VA ablation using a 56-hole radiofrequency (RF) catheter. METHODS: A total of 164 patients who underwent first-time VA ablation using Thermocool SmartTouch Surround Flow (TC-STSF) catheter (Biosense-Webster, Diamond Bar, CA, USA) were propensity-matched in a 1:1 fashion to 164 patients who had first-time ablation using Thermocool Surround Flow (TC-SF) catheter. Patients were matched for age, gender, cardiac aetiology, ejection fraction and approach. Acute success, complications and long-term follow-up were compared. RESULTS: There was no difference between procedures utilising either TC-SF or TC-STSF in acute success (TC-SF: 134/164 (82%), TC-STSF: 141/164 (86%), p = 0.3), complications (TC-SF: 11/164 (6.7%), TC-STSF: 11/164 (6.7%), p = 1.0) or VA-free survival (TC-SF: mean arrhythmia-free survival time = 5.9 years, 95% CI = 5.4-6.4, TC-STSF: mean = 3.2 years, 95% CI = 3-3.5, log-rank p = 0.74). Fluoroscopy time was longer in normal hearts with TC-SF (19 min, IQR: 14-30) than TC-STSF (14 min, IQR: 8-25; p = 0.04). CONCLUSION: Both TC-SF and TC-STSF catheters are safe and effective in treating VAs. The use of CF sensing catheters did not improve safety or acute and long-term outcomes, but reduced fluoroscopy time in normal heart VA
High Pressure Insulator-Metal Transition in Molecular Fluid Oxygen
We report the first experimental evidence for a metallic phase in fluid
molecular oxygen. Our electrical conductivity measurements of fluid oxygen
under dynamic quasi-isentropic compression show that a non-metal/metal
transition occurs at 3.4 fold compression, 4500 K and 1.2 Mbar. We discuss the
main features of the electrical conductivity dependence on density and
temperature and give an interpretation of the nature of the electrical
transport mechanisms in fluid oxygen at these extreme conditions.Comment: RevTeX, 4 figure
The national segmentation of euro area bank balance sheets during the financial crisis
This paper analyses bank balance sheet data in conjunction with macroeconomic and other financial variables. Our aim is to understand the nature of the instability in financial intermediation in the euro area during the recent financial crises. We define “large changes” as significant departures in the actual evolution of balance sheet variables during the crisis from their historical association with the business and financial cycles. In the course of the global 2008–2009 financial crisis, such “large changes” were features of the behaviour of cross-border inter-bank flows, both within the euro area and between the euro area and the rest of the world. By contrast, retail assets and liabilities, as well as inter-bank flows among banks of the same country, did not significantly deviate from historical regularities. Since the euro area sovereign crisis of 2011–2012, “large changes” have been more pervasive. In particular, a significant home bias in the sovereign bond market has emerged
High-Pressure Amorphous Nitrogen
The phase diagram and stability limits of diatomic solid nitrogen have been
explored in a wide pressure--temperature range by several optical spectroscopic
techniques. A newly characterized narrow-gap semiconducting phase has
been found to exist in a range of 80--270 GPa and 10--510 K. The vibrational
and optical properties of the phase produced under these conditions
indicate that it is largely amorphous and back transforms to a new molecular
phase. The band gap of the phase is found to decrease with pressure
indicating possible metallization by band overlap above 280 GPa.Comment: 5 pages, 4 figure
Activation of the B cell receptor leads to increased membrane proximity of the Igα cytoplasmic domain.
Binding of antigen to the B cell receptor (BCR) induces conformational changes in BCR's cytoplasmic domains that are concomitant with phosphorylation of the immunoreceptor tyrosine-based activation motifs (ITAMs). Recently, reversible folding of the CD3ε and ξ chain ITAMs into the plasma membrane has been suggested to regulate T cell receptor signaling. Here we show that the Igα and Igβ cytoplasmic domains of the BCR do not associate with plasma membrane in resting B cells. However, antigen binding and ITAM phosphorylation specifically increased membrane proximity of Igα, but not Igβ. Thus, BCR activation is accompanied by asymmetric conformational changes, possibly promoting the binding of Igα and Igβ to differently localized signaling complexes
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