125 research outputs found
Neonatal Tumors
Neonatal tumors encompass a group of heterogeneous neoplasms that demonstrate anatomic locations, behavior patterns, histologic features, and treatment responses that are distinct from neoplasms found in older children. The majority of neonatal tumors are benign, with malignant lesions accounting for only 2% of childhood cancers. However, histologically benign tumors can lead to detrimental effects on the fetus and newborn due to their size and location in relation to vital structures. An understanding of the incidence, appearance, and typical locations of neonatal tumors can provide important diagnostic information and guide treatment decisions. Although surgical intervention is the mainstay of therapy for many neonatal tumors, it is important to recognize that some lesions will regress spontaneously, whereas others may respond to noninvasive treatment modalities. In this chapter, we explore the epidemiology of neonatal tumors and provide a location-based classification schema to aid in diagnosis. A summary of the presentation, diagnosis, and management of the most common neonatal tumors is provided as well
A reconsideration of electrostatically accelerated and confined nuclear fusion for space applications.
Most present-day research into Nuclear Fusion concentrates on high-temperature plasmas combined with Inertial or Magnetic Confinement. However, there exists another body of less well-known work based on Electrostatic Acceleration and Confinement. The most thoroughly researched of these devices is known as the Farnsworth Fusor. This paper reviews the technique and then argues that, with development, similar technologies would be particularly suited to space-borne applications, due to their safety, simplicity and light weight. The paper then goes on to suggest several possible directions for new research into such devices which might result in a working machine
A dial-reading translator for digital machine inputs
At the Southern California Co-operative Wind Tunnel, part of the need for rapid and accurate recording of instrument readings on tabular data sheets has been met by the development of a new automatic-translating device. This device has unusually low torque and is especially suitable for use with self-balancing potentiometers. The device picks up the reading as a whole number and electrically transfers it to standard printing and punched-card machines, without lag and without restricting the normal operation of the potentiometer
Physical and structural characteristics of Weddell Sea pack ice
Journal ArticleRecent studies by CRREL researchers of the dynamics and thermodynamics of sea ice in the Antarctic have included investigations of the physical and structural properties of pack ice in the Weddell Sea. The formation of pack ice and its subsequent movement from source areas in the Weddell Sea is particularly important in modifying ocean-atmosphere and water mass development both in and beyond the Weddell Sea embayment. The pack ice area affected by Weddell Sea processes is 8-10 million square kilometers (Ackley 1979a), thus representing about one - third of the total area os sea ice encircling Antarctica at its maximum extent
Fuel encapsulation for inertial electrostatic confinement nuclear fusion reactors.
Inertial Electrostatic Confinement (IEC) is an approach to nuclear fusion which utilises the properties of electrostatically accelerated ion-beams instead of hot plasmas. The best known device which uses the principle is the Farnsworth-Hirsch fusor. It has been argued that such devices have some potential advantages in spaceflight and in-particular as power-supplies for trans-atmospheric propulsion. This paper builds on previous work in the field and focuses on how the fixing of the fuel for such reactors in a solid, liquid or encapsulated form may provide a high enough energy-density to make such devices practical power sources. Several methods of fixing the fuel are discussed; theoretical calculations are presented and applicable literature is reviewed. Finally, there is a discussion of practical issues and feasibility, together with suggestions for further work
Overcoming fuel-air mixing issues with pulsed scramjets and pelletized fuel.
In this paper the concept of a pulsed Scramjet using pelletized fuel is examined. The aim is to overcome the main technical problem inherent in more traditional designs - poor air-fuel mixing. In this new paradigm, airflow is diverted away from the main engine duct and fuel pellets are injected at timing intervals which ensure that they are evenly distributed throughout the mixing volume. The main airflow is then permitted to enter the duct and the inertia of the pellets allows the air to envelop and then vaporise them - and so their fuel load is evenly spread through the duct volume. The paper outlines the basic concept and calculations and simulations are used to demonstrate its feasibility
Measurements of Ice Shelf Water beneath the front of the Ross Ice Shelf using gliders
Measurements made by an underwater glider deployed near the Ross Ice Shelf were used to identify the presence of Ice Shelf Water (ISW), which is defined as seawater with its potential temperature lower than its surface freezing point temperature. Properties logged by the glider included in situ temperature, electrical conductivity, pressure, GPS location at surfacings and time. For most of the first 30 recorded dives of its deployment, evidence suggests the glider was prevented from surfacing due to being under the ice shelf. For dives under the ice shelf, farthest from the ice shelf front, ISW layers of varying thicknesses and depth locations were observed; between 2 m thick (centred at 231 m depth) to >93 m thick (centred at >360 m). For dives under the ice shelf, close to the ice shelf front, either no ISW was observed or ISW layers were centred at shallower depths (116–127 m). Thicker ISW layers (e.g. up to 250 m thickness centred at 421 m) were observed for some glider dives in open water in front of the Ross Ice Shelf. No in situ supercooling (water colder than the pressure-dependent freezing point temperature) was observed
Prospective, Single-Arm, Longitudinal Study of Biomarkers in Real-World Patients with Severe Asthma
n/
Surgical protocol violations in children with renal tumors provides an opportunity to improve pediatric cancer care: a report from the Children’s Oncology Group
BackgroundThe purpose of this study was to evaluate the frequency and characteristics of surgical protocol violations (SPVs) among children undergoing surgery for renal tumors who were enrolled on the Children’s Oncology Group (COG) renal tumor biology and classification study AREN03B2.MethodsAREN03B2 was opened in February 2006, and as on March 31, 2013, there were 3,664 eligible patients. The surgical review forms for 3,536 patients with unilateral disease were centrally reviewed for SPVs. The frequency, type, number of violations, institutional prevalence, and quartiles for SPVs were assessed.ResultsOf the 3,536 patients, there were a total of 505 with at least one SPV (564 total SPVs reported), for an overall incidence of 14.28%. The types of SPVs included a lack of lymph node sampling in 365 (64.7%), avoidable spill in 61 (10.8%), biopsy immediately before nephrectomy in 89 (15.8%), an incorrect abdominal incision in 32 (5.7%), and unnecessary resection of organs in 17 (3.0%). The SPVs occurred in 163 of 215 participating institutions (75.8%). For centers with at least one SPV, the mean number of SPVs reported was 3.10 ± 2.39 (mean ± standard deviation). The incidence of protocol violation per institution ranged from 0 to 67%. Centers with an average of ≤1 case/year had an incidence of SPVs of 12.2 ± 3.8%, those with an average of >1 to 0.05).ConclusionsSPVs that potentially result in additional exposure to chemotherapy and radiation therapy are not uncommon in children undergoing resection of renal malignancies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134088/1/pbc26083.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134088/2/pbc26083_am.pd
Electromagnetic and physical properties of sea ice formed in the presence of wave action
Estimating the magnitude of brine flux to the upper ocean requires an ability to assess the dynamics of the formation of sea ice in a region. Brine storage and rate of expulsion is determined by the environmental conditions under which the sea ice forms. In this paper, the physical and electromagnetic properties of sea ice, formed under wave-agitated conditions, are studied and compared with results obtained from ice formed under quiescent conditions. Wave agitation is known to have a profound effect on the air-ice interface and internal ice structure. A variety of sensors, both active and passive, optical and microwave, were used to perform this characterization. Measured electromagnetic parameters included radar backscatter, microwave emission, and spectral albedo in the visible and infrared. Measured physical properties included ice structure, brine and temperature distribution, profiles of the vertical height of the air-ice interface, and ice formation processes. Results showed that emission, backscatter, and albedo all take different signature paths during the transformation from saline water to young sea ice and that the paths depend on sea surface state during ice formation
- …