The ELFIN Mission.

The Electron Loss and Fields Investigation with a Spatio-Temporal Ambiguity-Resolving option (ELFIN-STAR, or heretoforth simply: ELFIN) mission comprises two identical 3-Unit (3U) CubeSats on a polar (∼93∘ inclination), nearly circular, low-Earth (∼450 km altitude) orbit. Launched on September 15, 2018, ELFIN is expected to have a >2.5 year lifetime. Its primary science objective is to resolve the mechanism of storm-time relativistic electron precipitation, for which electromagnetic ion cyclotron (EMIC) waves are a prime candidate. From its ionospheric vantage point, ELFIN uses its unique pitch-angle-resolving capability to determine whether measured relativistic electron pitch-angle and energy spectra within the loss cone bear the characteristic signatures of scattering by EMIC waves or whether such scattering may be due to other processes. Pairing identical ELFIN satellites with slowly-variable along-track separation allows disambiguation of spatial and temporal evolution of the precipitation over minutes-to-tens-of-minutes timescales, faster than the orbit period of a single low-altitude satellite (Torbit ∼ 90 min). Each satellite carries an energetic particle detector for electrons (EPDE) that measures 50 keV to 5 MeV electrons with Δ E/E < 40% and a fluxgate magnetometer (FGM) on a ∼72 cm boom that measures magnetic field waves (e.g., EMIC waves) in the range from DC to 5 Hz Nyquist (nominally) with <0.3 nT/sqrt(Hz) noise at 1 Hz. The spinning satellites (Tspin ∼ 3 s) are equipped with magnetorquers (air coils) that permit spin-up or -down and reorientation maneuvers. Using those, the spin axis is placed normal to the orbit plane (nominally), allowing full pitch-angle resolution twice per spin. An energetic particle detector for ions (EPDI) measures 250 keV - 5 MeV ions, addressing secondary science. Funded initially by CalSpace and the University Nanosat Program, ELFIN was selected for flight with joint support from NSF and NASA between 2014 and 2018 and launched by the ELaNa XVIII program on a Delta II rocket (with IceSatII as the primary). Mission operations are currently funded by NASA. Working under experienced UCLA mentors, with advice from The Aerospace Corporation and NASA personnel, more than 250 undergraduates have matured the ELFIN implementation strategy; developed the instruments, satellite, and ground systems and operate the two satellites. ELFIN's already high potential for cutting-edge science return is compounded by concurrent equatorial Heliophysics missions (THEMIS, Arase, Van Allen Probes, MMS) and ground stations. ELFIN's integrated data analysis approach, rapid dissemination strategies via the SPace Environment Data Analysis System (SPEDAS), and data coordination with the Heliophysics/Geospace System Observatory (H/GSO) optimize science yield, enabling the widest community benefits. Several storm-time events have already been captured and are presented herein to demonstrate ELFIN's data analysis methods and potential. These form the basis of on-going studies to resolve the primary mission science objective. Broad energy precipitation events, precipitation bands, and microbursts, clearly seen both at dawn and dusk, extend from tens of keV to >1 MeV. This broad energy range of precipitation indicates that multiple waves are providing scattering concurrently. Many observed events show significant backscattered fluxes, which in the past were hard to resolve by equatorial spacecraft or non-pitch-angle-resolving ionospheric missions. These observations suggest that the ionosphere plays a significant role in modifying magnetospheric electron fluxes and wave-particle interactions. Routine data captures starting in February 2020 and lasting for at least another year, approximately the remainder of the mission lifetime, are expected to provide a very rich dataset to address questions even beyond the primary mission science objective.

The Early Impact of COVID-19 on Urological Service Provision.

Aim COVID-19 has posed an unprecedented challenge to healthcare systems. We aimed to observe the impact on urological care delivery in an Irish university hospital. Methods Data on urological activity was prospectively collected for 3 months from March 2020. A retrospective review of the same period in 2019 was performed for control data. Results Over the 2020 study period, 356 urological admissions were recorded; a 23.1% decrease from the 2019 corresponding period(n=463). A 21.7% decrease in flexible cystoscopies was seen (162 versus 207). 125 theatre cases (36 off-site) were performed in the 2020 period, versus 151 in 2019. Emergency case load remained stable, with 69 cases in the 2020 period. The percentage of trainee-performed cases was preserved. COVID-era outpatient activity increased, to involve 559 clinic consultations compared to 439 the preceding year; a reflection of annual growth in service demand and facilitated by virtual clinic application (n=403). There were 490 instances of patients cancelling/failing to attend outpatient appointments, compared to 335 in 2019. Conclusion The Irish COVID-19 outbreak has created obstacles for urological care. Nonetheless, urgent/emergent urological cases persist. Our unit has managed this to-date with flexible adaptation of service delivery. The global challenge posed by COVID-19 will demand ongoing resourcefulness to minimise impact on patients with time-sensitive urological conditions.

Thoracoscopic mediastinal lymph node sampling: useful for mediastinal lymph node stations inaccessible by cervical mediastinoscopy.

Cervical mediastinoscopy is useful for the diagnosis of paratracheal lymph node metastasis from bronchogenic carcinoma. Access to adenopathy in the aorticopulmonary window, anterior mediastinal, periazygos, and subcarinal lymph nodes is difficult with this technique. Operative visibility in these locations through anterior mediastinotomy, the Chamberlain procedure, is limited. We have used thoracoscopic mediastinal exploration in 40 patients with computed tomographic scan evidence of enlarged aorticopulmonary window (n = 30) or enlarged right periazygos or subcarinal lymph nodes (n = 10). This procedure was used primarily as an adjunct to cervical mediastinoscopy in the staging of bronchogenic carcinoma. Adjunctive thoracoscopic nodal sampling was 100% sensitive and 100% specific in diagnosing the mediastinal adenopathy. It did not significantly delay thoracotomy in cases of benign adenopathy. Visibility of the ipsilateral pleural space and mediastinum was excellent. Thoracoscopic exploration with mediastinal nodal sampling is a valuable diagnostic adjunct for assessment of adenopathy inaccessible to cervical mediastinoscopy and can overcome many of the limitations of anterior mediastinotomy.

Fate of intravenously administered rat lymphokine-activated killer cells labeled with different markers.

Rat lymphokine-activated killer (LAK) cells, generated by adhering rat splenocytes isolated from the 52% Percoll density fraction to plastic flasks, demonstrate restricted in vivo tissue distribution, localizing in the lungs and liver after 2 h, but redistributing into the liver and spleen 24 h after i.v. administration. However, a different pattern of distribution was observed when this population of LAK cells was labeled with one of four commonly used radioisotopes. For example, LAK cells showed a high distribution into the lungs 30 min after administration when labeled with 51Cr, 125I-dUrd or 111In-oxine, whereas 111InCl-labeled LAK cells showed an equal distribution into the blood, lungs and liver at this time. Two hours after administration, cells labeled with 111In-oxine showed an equivalent distribution into the lungs and liver, those labeled with 125I-dUrd or 51Cr showed a high accumulation in the lungs, whereas those labeled with 111In-Cl entered more into the liver and blood. The pattern of distribution of 111In-Cl- or 111In-oxine-labeled cells was confirmed using gamma camera imaging analysis. By 24 h, LAK cells labeled with 111InCl, 111In-oxine or 51Cr distributed in the liver and spleen in variable concentrations. In contrast, cells labeled with 125I-dUrd were not detected in any organ tested. This study was paralleled by monitoring the distribution of LAK cells labeled with Hoechst 33342 (H33342) and analyzed for the presence of fluoresceinated cells in different organs either by flow cytometry analysis, or in frozen section. The data indicate that the distribution pattern of LAK cells labeled with 111In-oxine is the closest to the distribution of H33342-labeled cells. Of all the radioisotopes used, 125I-dUrd has the most disadvantages and is not recommended for monitoring the in vivo distribution of leukocytes.