Photoassociative Production and Trapping of Ultracold KRb Molecules

We have produced ultracold heteronuclear KRb molecules by the process of photoassociation in a two-species magneto-optical trap. Following decay of the photoassociated KRb*, the molecules are detected using two-photon ionization and time-of-flight mass spectroscopy of KRb$^+$. A portion of the metastable triplet molecules thus formed are magnetically trapped. Photoassociative spectra down to 91 cm$^{-1}$ below the K(4$s$) + Rb (5$p_{1/2}$) asymptote have been obtained. We have made assignments to all eight of the attractive Hund's case (c) KRb* potential curves in this spectral region.Comment: 4 pages, 4 figure

Beam spin asymmetry measurements of deeply virtual π0 production with CLAS12

The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive pi0 production in a wide kinematic region with the photon virtualities Q2 up to 6.6 GeV2 and the Bjorken scaling variable xB in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions. The interpretation of these measurements in terms of the Generalized Parton Distributions (GPDs) demonstrates their sensitivity to the chiral-odd GPD ET, which contains information on quark transverse spin densities in unpolarized and polarized nucleons and provides access to the nucleon's transverse anomalous magnetic moment. Additionally, the data were compared to a theoretical model based on a Regge formalism that was extended to the high photon virtualities

Implementation and use of cloud-based electronic lab notebook in a bioprocess engineering teaching laboratory

Abstract Background Electronic lab notebooks (ELNs) are better equipped than paper lab notebooks (PLNs) to handle present-day life science and engineering experiments that generate large data sets and require high levels of data integrity. But limited training and a lack of workforce with ELN knowledge have restricted the use of ELN in academic and industry research laboratories which still rely on cumbersome PLNs for recordkeeping. We used LabArchives, a cloud-based ELN in our bioprocess engineering lab course to train students in electronic record keeping, good documentation practices (GDPs), and data integrity. Results Implementation of ELN in the bioprocess engineering lab course, an analysis of user experiences, and our development actions to improve ELN training are presented here. ELN improved pedagogy and learning outcomes of the lab course through stream lined workflow, quick data recording and archiving, and enhanced data sharing and collaboration. It also enabled superior data integrity, simplified information exchange, and allowed real-time and remote monitoring of experiments. Several attributes related to positive user experiences of ELN improved between the two subsequent years in which ELN was offered. Student responses also indicate that ELN is better than PLN for compliance. Conclusions We demonstrated that ELN can be successfully implemented in a lab course with significant benefits to pedagogy, GDP training, and data integrity. The methods and processes presented here for ELN implementation can be adapted to many types of laboratory experiments

Batch correction methods for nontarget chemical analysis data: application to a municipal wastewater collection system

Nontarget chemical analysis using high-resolution mass spectrometry has increasingly been used to discern spatial patterns and temporal trends in anthropogenic chemical abundance in natural and engineered systems. A critical experimental design consideration in such applications, especially those monitoring complex matrices over long time periods, is a choice between analyzing samples in multiple batches as they are collected, or in one batch after all samples have been processed. While datasets acquired in multiple analytical batches can include the effects of instrumental variability over time, datasets acquired in a single batch risk compound degradation during sample storage. To assess the influence of batch effects on the analysis and interpretation of nontarget data, this study examined a set of 56 samples collected from a municipal wastewater system over 7 months. Each month's samples included 6 from sites within the collection system, one combined influent, and one treated effluent sample. Samples were analyzed using liquid chromatography high-resolution mass spectrometry in positive electrospray ionization mode in multiple batches as the samples were collected and in a single batch at the conclusion of the study. Data were aligned and normalized using internal standard scaling and ComBat, an empirical Bayes method developed for estimating and removing batch effects in microarrays. As judged by multiple lines of evidence, including comparing principal variance component analysis between single and multi-batch datasets and through patterns in principal components and hierarchical clustering analyses, ComBat appeared to significantly reduce the influence of batch effects. For this reason, we recommend the use of more, small batches with an appropriate batch correction step rather than acquisition in one large batch

A Prospective Study of a Focused, Surgeon-Performed Ultrasound Examination for the Detection of Occult Common Femoral Vein Thrombosis in Critically Ill Patients

Hypothesis A focused, surgeon-performed ultrasound examination of the common femoral veins is an accurate screening tool for the detection of common femoral vein thrombosis in high-risk, critically ill patients. Design A prospective study using a focused ultrasound examination for findings consistent with deep vein thrombosis of the common femoral veins. The results of these examinations were compared with those of duplex imaging or computed tomographic venography studies. Setting Surgical intensive care unit. Patients All critically ill patients who were admitted to the surgical intensive care unit and considered to be at high risk for the development of deep vein thrombosis. Main Outcome Measure Presence of deep vein thrombosis in the common femoral veins. Results During a 16-month period, surgeons performed 306 ultrasound examinations on 220 critically ill surgical patients. The results included 295 true negative, 9 true positive, 1 false negative, and 1 false positive, yielding a 90.0% sensitivity, 99.6% specificity, and 99.3% accuracy. Conclusion A focused, surgeon-performed ultrasound examination is a rapid and accurate screening method to detect common femoral vein thrombosis in critically ill patients as well as to examine those patients in whom pulmonary embolism is strongly suspected. The development of deep vein thrombosis (DVT) with its potential complications significantly increases morbidity and mortality for critically ill surgical patients. Although prophylactic agents and regimens have been shown to prevent DVT in most patients, they are not completely effective.1- 5 Therefore, additional measures such as sequential compression devices for prevention and serial duplex imaging of the lower extremities for early detection are used in select patients. Although sequential compression devices are widely available, serial duplex imaging, especially in a busy surgical intensive care unit (SICU), may be difficult to do routinely because of limited resources. Furthermore, the frequency with which such a study should be done to detect occult DVT is unknown. Considering the successful use of surgeon-performed, focused ultrasound examinations in patients with multiple acute conditions, it seems reasonable to use this technology as a screening tool for the detection of occult DVT in critically ill patients.6- 9 We hypothesized that serial focused ultrasound examinations performed by surgeons could accurately detect common femoral vein (CFV) thrombosis in critically ill surgical patients. The purpose of this study was to evaluate the efficacy of a limited ultrasound examination for the detection of occult CFV thrombosis

A Prospective Study of a Focused, Surgeon-Performed Ultrasound Examination for the Detection of Occult Common Femoral Vein Thrombosis in Critically Ill Patients

Hypothesis A focused, surgeon-performed ultrasound examination of the common femoral veins is an accurate screening tool for the detection of common femoral vein thrombosis in high-risk, critically ill patients. Design A prospective study using a focused ultrasound examination for findings consistent with deep vein thrombosis of the common femoral veins. The results of these examinations were compared with those of duplex imaging or computed tomographic venography studies. Setting Surgical intensive care unit. Patients All critically ill patients who were admitted to the surgical intensive care unit and considered to be at high risk for the development of deep vein thrombosis. Main Outcome Measure Presence of deep vein thrombosis in the common femoral veins. Results During a 16-month period, surgeons performed 306 ultrasound examinations on 220 critically ill surgical patients. The results included 295 true negative, 9 true positive, 1 false negative, and 1 false positive, yielding a 90.0% sensitivity, 99.6% specificity, and 99.3% accuracy. Conclusion A focused, surgeon-performed ultrasound examination is a rapid and accurate screening method to detect common femoral vein thrombosis in critically ill patients as well as to examine those patients in whom pulmonary embolism is strongly suspected. The development of deep vein thrombosis (DVT) with its potential complications significantly increases morbidity and mortality for critically ill surgical patients. Although prophylactic agents and regimens have been shown to prevent DVT in most patients, they are not completely effective.1- 5 Therefore, additional measures such as sequential compression devices for prevention and serial duplex imaging of the lower extremities for early detection are used in select patients. Although sequential compression devices are widely available, serial duplex imaging, especially in a busy surgical intensive care unit (SICU), may be difficult to do routinely because of limited resources. Furthermore, the frequency with which such a study should be done to detect occult DVT is unknown. Considering the successful use of surgeon-performed, focused ultrasound examinations in patients with multiple acute conditions, it seems reasonable to use this technology as a screening tool for the detection of occult DVT in critically ill patients.6- 9 We hypothesized that serial focused ultrasound examinations performed by surgeons could accurately detect common femoral vein (CFV) thrombosis in critically ill surgical patients. The purpose of this study was to evaluate the efficacy of a limited ultrasound examination for the detection of occult CFV thrombosis