Cassini revealed that Saturn's Moon Enceladus hosts a subsurface ocean that meets the accepted criteria for habitability with bio-essential elements and compounds, liquid water, and energy sources available in the environment. Whether these conditions are sufficiently abundant and collocated to support life remains unknown and cannot be determined from Cassini data. However, thanks to the plume of oceanic material emanating from Enceladus’ south pole, a new mission to Enceladus could search for evidence of life without having to descend through kilometers of ice. In this article, we outline the science motivations for such a successor to Cassini, choosing the primary science goal to be determining whether Enceladus is inhabited and assuming a resource level equivalent to NASA's Flagship-class missions. We selected a set of potential biosignature measurements that are complementary and orthogonal to build a robust case for any life detection result. This result would be further informed by quantifications of the habitability of the environment through geochemical and geophysical investigations into the ocean and ice shell crust. This study demonstrates that Enceladus’ plume offers an unparalleled opportunity for in situ exploration of an Ocean World and that the planetary science and astrobiology community is well equipped to take full advantage of it in the coming decades.

Purpose: We sought to identify clinical features associated with difficult subcutaneous port removals in children. Methods: Ports placed between April 2014 and September 2017 at our institution were prospectively tracked for difficult removals. A case-control analysis was performed. Patients with ports that were diffi-cult to remove (stuck; cases) were compared to biological sex and age-matched controls in a ratio of 1:3. Logistic regression determined the association between case/control status and clinical features adjusting for biological sex and age as covariates. A multivariable analysis was performed to identify independent associations. Results: 57 stuck ports (28 extreme [10 endovascular intervention] and 29 moderate) and 171 controls were analyzed. Stuck ports were associated with a diagnosis of acute lymphoblastic leukemia (86% cases versus 22.2% controls; p < 0.001) and a longer placement duration (median 2.6 years [interquartile range (IQR) 2.5-2.6] versus 0.8 years [IQR 0.5-1.4]; p < 0.001). On univariate analysis, procedural and de-vice features associated with stuck ports included subclavian access (71.9% cases versus 48.5% controls; p = 0.0126), a polyurethane versus silicone catheter (96.5% cases versus 79.9% controls; p = 0.001), and a rough catheter appearance at removal (92.6% cases versus 9.4% controls; p < 0.0 0 01). A diagnosis of ALL and duration of line placement were associated with having a stuck port on multivariate analysis. Conclusion: Polyurethane central venous catheters placed for the two-year treatment of acute lym-phoblastic leukemia may become difficult to remove. This constellation of factors warrants more exten-sive preoperative discussion of risk, endovascular backup availability, and scheduling for longer operating room time. (c) 2021 Elsevier Inc. All rights reserved.

Enceladus’s long-lived plume of ice grains and water vapor makes accessing oceanic material readily achievable from orbit (around Saturn or Enceladus) and from the moon’s surface. In preparation for the National Academies of Sciences, Engineering and Medicine 2023–2032 Planetary Science and Astrobiology Decadal Survey, we investigated four architectures capable of collecting and analyzing plume material from orbit and/or on the surface to address the most pressing questions at Enceladus: Is the subsurface ocean inhabited? Why, or why not? Trades specific to these four architectures were studied to allow an evaluation of the science return with respect to investment. The team found that Orbilander, a mission concept that would first orbit and then land on Enceladus, represented the best balance. Orbilander was thus studied at a higher fidelity, including a more detailed science operations plan during both orbital and landed phases, landing site characterization and selection analyses, and landing procedures. The Orbilander mission concept demonstrates that scientifically compelling but resource-conscious Flagship-class missions can be executed in the next decade to search for life at Enceladus.

A key science priority for planetary exploration is to search for signs of life in our Solar System. Life-detection mission concepts aim to assess whether or not biomolecular signatures of life are present, which requires highly sensitive instrumentation. This introduces greater risk of false positives, and perhaps false negatives. Stringent science-derived contamination requirements for achieving science measurements on life-detection missions necessitate mitigation approaches that minimize, protect from, and prevent science-relevant contamination of critical surfaces of the science payload and provide high confidence to life-detection determinations. To this end, we report on technology advances that focus on understanding contamination transfer from pre-launch processing to end of mission using high-fidelity physics in the form of computational fluid dynamics and sorption physics for monolayer adsorption/desorption, and on developing a new full-spacecraft bio-molecular barrier design that restricts contamination of the spacecraft and instruments by the launch vehicle hardware. The bio-molecular barrier isolates the spacecraft from biological, molecular, and particulate contamination from the external environment. Models were used to evaluate contamination transport for a designs reference mission that utilizes the barrier. Results of the modeling verify the efficacy of the barrier and an in-cruise decontamination activity. Overall mission contamination tracking from launch to science operations demonstrated exceptionally low probability on contamination impacting science measurements, meeting the stringent contamination requirements of femtomolar levels of compounds. These advances will enable planetary missions that aim to detect and identify signatures of life in our Solar System.

Background: The risk of infection associated with subcutaneous port (SQP) placement in patients with neutropenia remains unclear. We reviewed the rate of early infectious complications (<30 days) following SQP placement in pediatric oncology patients with or without neutropenia [absolute neutrophil count (ANC) <500/mm(3)]. Methods: Baseline characteristics and infectious complications were compared between groups using univariate and multivariate analyses. Results: A total of 614 SQP were placed in 542 patients. Compared to nonneutropenic patients, those with neutropenia were more likely to have leukemia (n = 74, 94% vs n = 268, 50%), preoperative fever (n = 17, 22% vs n = 25, 5%), recent documented infection (n = 15, 19% vs n = 47, 9%), and were younger (81 vs 109 months) (p values <0.01). After adjusting for fever and underlying-disease, there was a nonsignificant association between neutropenia and early postoperative infection (OR 2.42, 95% CI 0.82-7.18, p = 0.11). Only preoperative fever was a predictor of infection (OR 6.09, 95% CI 2.08-17.81, p = 0.001). Conclusion: SQP placement appears safe in most neutropenic patients. Type of study: Retrospective comparative study. (C) 2018 Elsevier Inc. All rights reserved.

The four Magnetospheric Multiscale (MMS) spacecraft observed a ∼1 min burst of energetic ions (50–1000 keV) in the region upstream from the subsolar quasi‐perpendicular bow shock on 6 December 2015. The composition, flux levels, and spectral indices of these energetic protons, helium, and oxygen ions greatly resemble those seen in the outer magnetosphere earlier while MMS crossed the magnetopause and differ significantly from those simultaneously observed far upstream by Advanced Composition Explorer (ACE). However, the event cannot be explained solely in terms of leakage from the magnetosphere. The strongly southward orientation of the interplanetary magnetic field (IMF) lines at the time of the event precludes any connection to the magnetosphere. This point is confirmed by the presence of energetic electrons, known to occur on magnetic field lines that graze the bow shock rather than connect to the magnetosphere. We suggest that the ions gradient drifted out of the nearby quasi‐parallel foreshock and into the quasi‐perpendicular bow shock. Each of the ion species exhibited an inverse energy dispersion. As predicted by models for shock drift acceleration, the energies of the ions increased as θBn, the angle between the IMF and the shock normal, increased. Finally, we note that a similar event was observed a few minutes later in the subsolar magnetosheath, indicating that such events can be swept downstream of the bow shock.

The great success of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission was possible only through a series of technological advances and a number of innovative uses of existing technologies. A Mercury orbital mission had been studied for 30 years before MESSENGER and was believed to require a multi-billion-dollar effort. However, the innovations developed by the MESSENGER team enabled the mission to be accomplished within NASA's low-cost planetary program, known as Discovery. Not only were key enabling developments put into practice before launch, but also a number of innovations were implemented after launch, and in-depth planning for critical events greatly enhanced the scientific return from the mission. These postlaunch improvements also simplified mission operations and saved enough propellant to permit extending the mission beyond the originally planned 1 Earth year at Mercury. The communications practices were optimized to ensure that even more science data could be returned to Earth, and the orbital period was lowered to give 50% more low-altitude coverage. When part of the Gamma-Ray Spectrometer had exceeded its useful life, the rest of the instrument was repurposed to give new insight into the rapidly varying magnetosphere.

The X-Ray Spectrometer (XRS) on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft regularly detected fluorescent X-rays near Mercury induced by low-energy (1-10 keV) or suprathermal electrons. We devised an algorithm to select these events from XRS records between April 2011 and March 2015 on the basis of their duration, location, and spectral slope. We identified 3102 events during 3900 orbits around Mercury, sampling all Mercury longitudes multiple times over the 4 year period. These suprathermal electrons were present near the planet at all local times, but the majority were on the nightside of the planet, and a dawn-dusk asymmetry is seen in the data. When the event locations are plotted in a coordinate system based on a simplified magnetic field model, several distinct clusters of events are evident. We infer that all are signatures of accelerated electrons that were injected from Mercury's tail region to form a quasi-trapped electron population at Mercury.

The X-Ray Spectrometer (XRS) that flew on the MESSENGER spacecraft measured X-rays from the surface of Mercury in the energy range ~1–10keV. Detection of characteristic Kα-line emissions from Mg, Al, Si, S, Ca, Ti, and Fe yielded the surface abundances of these geologically important elements. Spatial resolution as fine as ~40km (across track) was possible at periapsis for those elements for which counting statistics were not a limiting factor. Four years of orbital observations have made it possible to generate from XRS spectra detailed elemental composition maps that cover a majority of Mercury׳s surface. Converting measurements to compositions requires a thorough understanding of the XRS instrument capabilities. The ground and flight calibration measurements presented here are necessary for the reduction and analysis of the X-ray data from the MESSENGER mission.

Background: Osteosarcoma (OS) and the Ewing sarcoma family of tumors (ESFT) are the most common primary pediatric bone malignancies. We sought to assess the diagnostic accuracy of initial tumor biopsies in patients with OS or ESFT at a pediatric cancer center.Methods: All biopsies performed at initial presentation of patients with OS or ESFT at our institution from 2003 to 2012 were retrospectively reviewed. Diagnostic accuracy and incidence of complications were correlated with study variables using logistic regression analysis.Results: One hundred forty-two biopsies were performed in 105 patients (median age 13.4 years, range: 1.8-23.0), 104 (73.2%) OS and 38 (27.8%) ESFT. Thirty-one (21.8%) were performed on metastatic sites. Eighty-five (76.6%) of 111 primary site biopsies were open procedures, and 26 were percutaneous (23.4%). Primary site biopsies were successful in 94.1% of open and 73.1% of percutaneous procedures. Odds of obtaining a successful diagnostic specimen were 7.8 times higher with open approach (CI: 1.6-36.8). Metastatic site biopsies were successful in 66.7% of percutaneous and 100% of open and thoracoscopic procedures.Conclusion: Biopsy of metastatic sites was equal to primary site in obtaining diagnostic material with the added benefit of accurate staging, with few adverse events and high diagnostic yield. (C) 2016 Elsevier Inc. All rights reserved.

OBJECTIVE The purpose of this study was to determine whether clinical and imaging features can distinguish osteomyelitis from Ewing sarcoma (EWS) and to assess the accuracy of percutaneous biopsy versus open biopsy in the diagnosis of these diseases. MATERIALS AND METHODS Three radiologists reviewed the radiographs and MRI examinations of 32 subjects with osteomyelitis and 31 subjects with EWS to determine the presence of 36 imaging parameters. Information on demographic characteristics, history, physical examination findings, laboratory findings, biopsy type, and biopsy results were recorded. Individual imaging and clinical parameters and combinations of these parameters were tested for correlation with findings from histologic analysis. The diagnostic accuracy of biopsy was also determined. RESULTS On radiography, the presence of joint or metaphyseal involvement, a wide transition zone, a Codman triangle, a periosteal reaction, or a soft-tissue mass, when tested individually, was more likely to be noted in subjects with EWS (p ≤ 0.05) than in subjects with osteomyelitis. On MRI, permeative cortical involvement and soft-tissue mass were more likely in subjects with EWS (p ≤ 0.02), whereas a serpiginous tract was more likely to be seen in subjects with osteomyelitis (p = 0.04). African Americans were more likely to have osteomyelitis than EWS (p = 0). According to the results of multiple regression analysis, only ethnicity and soft-tissue mass remained statistically significant (p ≤ 0.01). The findings from 100% of open biopsies (18/18) and 58% of percutaneous biopsies (7/12) resulted in the diagnosis of osteomyelitis, whereas the findings from 88% of open biopsies (22/25) and 50% of percutaneous biopsies (3/6) resulted in a diagnosis of EWS. CONCLUSION Several imaging features are significantly associated with either EWS or osteomyelitis, but many features are associated with both diseases. Other than ethnicity, no clinical feature improved diagnostic accuracy. Compared with percutaneous biopsy, open biopsy provides a higher diagnostic yield but may be inconclusive, especially for cases of EWS. Our findings underscore the need for better methods of diagnosing these disease processes.

OBJECTIVE. The purpose of this study was to determine whether clinical and imaging features can distinguish osteomyelitis from Ewing sarcoma (EWS) and to assess the accuracy of percutaneous biopsy versus open biopsy in the diagnosis of these diseases.MATERIALS AND METHODS. Three radiologists reviewed the radiographs and MRI examinations of 32 subjects with osteomyelitis and 31 subjects with EWS to determine the presence of 36 imaging parameters. Information on demographic characteristics, history, physical examination findings, laboratory findings, biopsy type, and biopsy results were recorded. Individual imaging and clinical parameters and combinations of these parameters were tested for correlation with findings from histologic analysis. The diagnostic accuracy of biopsy was also determined.RESULTS. On radiography, the presence of joint or metaphyseal involvement, a wide transition zone, a Codman triangle, a periosteal reaction, or a soft-tissue mass, when tested individually, was more likely to be noted in subjects with EWS (p <= 0.05) than in subjects with osteomyelitis. On MRI, permeative cortical involvement and soft-tissue mass were more likely in subjects with EWS (p <= 0.02), whereas a serpiginous tract was more likely to be seen in subjects with osteomyelitis (p = 0.04). African Americans were more likely to have osteomyelitis than EWS (p = 0). According to the results of multiple regression analysis, only ethnicity and soft-tissue mass remained statistically significant (p <= 0.01). The findings from 100% of open biopsies (18/18) and 58% of percutaneous biopsies (7/12) resulted in the diagnosis of osteomyelitis, whereas the findings from 88% of open biopsies (22/25) and 50% of percutaneous biopsies (3/6) resulted in a diagnosis of EWS.CONCLUSION. Several imaging features are significantly associated with either EWS or osteomyelitis, but many features are associated with both diseases. Other than ethnicity, no clinical feature improved diagnostic accuracy. Compared with percutaneous biopsy, open biopsy provides a higher diagnostic yield but may be inconclusive, especially for cases of EWS. Our findings underscore the need for better methods of diagnosing these disease processes.

This work presents the results of an experimental study of ice particle impacts on a moving wedge. The experiment was conducted in the Adverse Environment Rotor Test Stand (AERTS) facility located at Penn State University. The wedge was placed at the tip of a rotating blade. Ice particles shot from a pressure gun intercepted the moving wedge and impacted it at a location along its circular path. The upward velocity of the ice particles varied from 7 to 12 meters per second. Wedge velocities were varied from 0 to 120 meters per second. Wedge angles tested were 0 deg, 30 deg, 45 deg, and 60 deg. High speed imaging combined with backlighting captured the impact allowing observation of the effect of velocity and wedge angle on the impact and the post-impact fragment behavior. It was found that the pressure gun and the rotating wedge could be synchronized to consistently obtain ice particle impacts on the target wedge. It was observed that the number of fragments increase with the normal component of the impact velocity. Particle fragments ejected immediately after impact showed velocities higher than the impact velocity. The results followed the major qualitative features observed by other researchers for hailstone impacts, even though the reduced scale size of the particles used in the present experiment as compared to hailstones was 4:1.

BACKGROUND Tumor biopsies are central to the diagnosis and management of cancer and are critical to efforts in personalized medicine and targeted therapeutics. In the current study, the authors sought to evaluate the safety and accuracy of biopsies in children with cancer. METHODS All biopsies performed in children at the study institution with a suspected or established diagnosis of cancer from 2003 through 2012 were reviewed retrospectively. Patient characteristics and disease‐related and procedure‐related factors were correlated with procedure‐related complications and diagnostic accuracy using logistic regression analysis. RESULTS A total of 1073 biopsies were performed in 808 patients. Of 1025 biopsies with adequate follow‐up, 79 (7.7%) were associated with an adverse event, 35 (3.4%) of which were minor (grade 1‐2) and 32 (3.1%) of which were major (grade 3‐4) (grading was performed according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). The most common major adverse events were blood transfusion (>10 mL/kg; 24 cases) and infection requiring intravenous antibiotics (6 cases). Eleven deaths (1.4%) occurred within 30 days after the procedure, but the procedure may have contributed to the outcome in only 2 cases. A total of 926 biopsies (90.3%) provided definitive histologic diagnoses. Using multivariable analysis, biopsy site, preprocedure hematocrit level, and body mass index were found to be associated with the risk of postprocedural complications ( P <.0001, P <.0001, and P = .0029, respectively). Excisional biopsy and biopsy site were found to be independently associated with obtaining a diagnostic result ( P = .0002 and P = .0008, respectively). CONCLUSIONS Tumor biopsies in children with cancer are associated with a low incidence of complications and a high rate of diagnostic accuracy. The predictive factors identified for adverse outcomes may aid in risk assessment and preprocedural counseling. Cancer 2015;121:1098–1107 . © 2014 American Cancer Society .

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, launched in August 2004 under NASA's Discovery Program, was inserted into orbit about the planet Mercury in March 2011. MESSENGER's three flybys of Mercury in 2008–2009 marked the first spacecraft visits to the innermost planet since the Mariner 10 flybys in 1974–1975. The unprecedented orbital operations are yielding new insights into the nature and evolution of Mercury. The scientific questions that frame the MESSENGER mission led to the mission measurement objectives to be achieved by the seven payload instruments and the radio science experiment. Interweaving the full set of required orbital observations in a manner that maximizes the opportunity to satisfy all mission objectives and yet meet stringent spacecraft pointing and thermal constraints was a complex optimization problem that was solved with a software tool that simulates science observations and tracks progress toward meeting each objective. The final orbital observation plan, the outcome of that optimization process, meets all mission objectives. MESSENGER's Mercury Dual Imaging System is acquiring a global monochromatic image mosaic at better than 90% coverage and at least 250m average resolution, a global color image mosaic at better than 90% coverage and at least 1km average resolution, and global stereo imaging at better than 80% coverage and at least 250m average resolution. Higher-resolution images are also being acquired of targeted areas. The elemental remote sensing instruments, including the Gamma-Ray and Neutron Spectrometer and the X-Ray Spectrometer, are being operated nearly continuously and will establish the average surface abundances of most major elements. The Visible and Infrared Spectrograph channel of MESSENGER's Mercury Atmospheric and Surface Composition Spectrometer is acquiring a global map of spectral reflectance from 300 to 1450nm wavelength at a range of incidence and emission angles. Targeted areas have been selected for spectral coverage into the ultraviolet with the Ultraviolet and Visible Spectrometer (UVVS). MESSENGER's Mercury Laser Altimeter is acquiring topographic profiles when the slant range to Mercury's surface is less than 1800km, encompassing latitudes from 20°S to the north pole. Topography over the remainder of the southern hemisphere will be derived from stereo imaging, radio occultations, and limb profiles. MESSENGER's radio science experiment is determining Mercury's gravity field from Doppler signals acquired during frequent downlinks. MESSENGER's Magnetometer is measuring the vector magnetic field both within Mercury's magnetosphere and in Mercury's solar wind environment at an instrument sampling rate of up to 20 samples/s. The UVVS is determining the three-dimensional, time-dependent distribution of Mercury's exospheric neutral and ionic species via their emission lines. During each spacecraft orbit, the Energetic Particle Spectrometer measures energetic electrons and ions, and the Fast Imaging Plasma Spectrometer measures the energies and mass per charge of thermal plasma components, both within Mercury's magnetosphere and in Mercury's solar-wind environment. The primary mission observation sequence will continue for one Earth year, until March 2012. An extended mission, currently under discussion with NASA, would add a second year of orbital observations targeting a set of focused follow-on questions that build on observations to date and take advantage of the more active Sun expected during 2012–2013. MESSENGER's total primary mission cost, projected at $446M in real-year dollars, is comparable to that of Mariner 10 after adjustment for inflation.

OBJECTIVE To analyze outcomes and complications of percutaneous (PRC) and laparoscopic renal cryoablation (LRC) using the radius, endophytic, nearness to collecting system, anterior/posterior, and location (RENAL) nephrometry system.METHODS Retrospective multicenter analysis of 154 consecutive patients who underwent either ultrasound-guided LRC (n = 88) or computed tomography (CT)-guided PRC (n = 66) from March 2003 to December 2011. RENAL score and demographics were compared to postoperative complications (Clavien). Multivariable analysis was carried out for factors associated with development of postprocedure complications.RESULTS Mean age was 68 years (94 men/60 women). Median follow-up was 34 months (range 23.6-45.6 months). Mean tumor size was 2.6 +/- 1 cm. Mean RENAL score was 5.2 +/- 1.4. Differences in (A) nterior/posterior component and (H)ilar domain of the RENAL scores were noted, with PRC favoring posterior tumors and hilar lesions compared to LRC (P < .001 and P = .044, respectively). There were 14.9% complications, all of which were low-grade (Clavien 1,2). There were no differences in complications between LRC and PRC (15.9% vs 13.6%, P = .82). Most common complication type was hemorrhagic in 9 of 154 patients (5.8%); significant increase in the hemorrhagic complication rate was noted for patients with "N" ("nearness") component score of 2 or 3 (5/36, or 13.9%), compared to patients with "N" score of 1 (4/115 or 3.5%, P = .033). multivariable analysis demonstrated that increasing RENAL score was associated with postprocedure complications (odds ratio [OR] = 1.37, P = .025). When separated into individual domains, multivariable analysis revealed that "N" score 3 was significantly associated with postoperative complications (OR 16.15, P = .027).CONCLUSION Increasing RENAL score was associated development of postprocedure complications after renal cryotherapy. Further investigation is requisite to elucidate the role of RENAL nephrometry score in risk stratification prior to renal cryotherapy. UROLOGY 81: 775-780, 2013. (C) 2013 Elsevier Inc.

The Neutron, Gamma ray, and X-ray Spectrometer (NGXS) is a compact instrument designed to detect neutrons, gamma-rays, and hard X-rays. The original goal of NGXS was to detect and characterize neutrons, gamma-rays, and X-rays from the Sun as part of the Solar Probe Plus mission in order to provide direct insight into particle acceleration, magnetic reconnection, and cross-field transport processes that take place near the Sun. Based on high-energy neutron detections from prompt solar flares, it is estimated that the NGXS would detect neutrons from 15 to 24 impulsive flares. The NGXS sensitivity to 2.2MeV gamma rays would enable a detection of ∼50–60 impulsive flares. The NGXS is estimated to measure ∼120counts/s for a GOES C1-type flare at 0.1AU, which allows for a large dynamic range to detect both small and large flares.

The Energetic Particle Spectrometer (EPS) on the MESSENGER spacecraft, in orbit about Mercury since March 2011, has detected bursts of low‐ and moderate‐energy (tens to hundreds of keV) electrons during portions of most orbits. There have been periods when such bursts were observed regularly on every orbit over a span of several weeks, and other periods when electrons were not observed for several days at a time. We have systematically characterized these energetic events on the basis of particle intensity over the 12‐month period since MESSENGER began orbital operations. Now that MESSENGER has sampled most Mercury longitudes and local times, it is evident that the largest burst events were either at high northern latitudes or near local midnight. Lower‐energy events were also seen near the equator but were mostly absent in both the dawn and dusk local time sectors. The high‐latitude and nightside events are similar in particle intensity, spectra, and pitch angle and are interpreted to be the result of acceleration by the same mechanism. Another group of events occurred upstream of Mercury's bow shock. For two examples of this group of upstream events with good pitch angle coverage, the particles were field‐aligned and traveling away from the bow shock. This group of events is interpreted to be similar to upstream events found at Earth during which particles are accelerated at the bow shock and subsequently travel upstream into the solar wind.