Publications by authors named "Jennifer Esbenshade"

Group IV intermetallics electrochemically alloy with Li with stoichiometries as high as LiM (M = Si, Ge, Sn, or Pb). This provides the second highest known specific capacity (after pure lithium metal) for lithium-ion batteries, but the dramatic volume change during cycling greatly limits their use as anodes in Li-ion batteries. We describe an approach to overcome this limitation by constructing electrodes using a Ge/Ti multilayer architecture.

View Article and Find Full Text PDF

The solid electrolyte interface (SEI) formed via electrolyte decomposition on the anode of lithium ion batteries is largely responsible for the stable cycling of conventional lithium ion batteries. Similarly, there is a lesser-known analogous layer on the cathode side of a lithium ion battery, termed the cathode electrolyte interface (CEI), whose composition and role are debated. To confirm the existence and composition of the CEI, desorption electrospray ionization mass spectrometry (DESI-MS) is applied to study common lithium ion battery cathodes.

View Article and Find Full Text PDF

Solid-state (7)Li and (13)C MAS NMR spectra of cycled graphitic Li-ion anodes demonstrate SEI compound formation upon lithiation that is followed by changes in the SEI upon delithiation. Solid-state (13)C DPMAS NMR shows changes in peaks associated with organic solvent compounds (ethylene carbonate and dimethyl carbonate, EC/DMC) upon electrochemical cycling due to the formation of and subsequent changes in the SEI compounds. Solid-state (13)C NMR spin-lattice (T1) relaxation time measurements of lithiated Li-ion anodes and reference poly(ethylene oxide) (PEO) powders, along with MALDI-TOF mass spectrometry results, indicate that large-molecular-weight polymers are formed in the SEI layers of the discharged anodes.

View Article and Find Full Text PDF
Article Synopsis
  • In situ EQCM experiments revealed that a sulfur-carbon cathode in a Li-S battery gains mass during the first discharge due to the formation of long chain polysulfides.
  • As discharge continues below 2.4 V, the cathode's crystal resistance increases, indicating it becomes rougher.
  • During charging, the cathode's roughness decreases, but it shows an overall trend of increasing roughness with deeper discharges over repeated cycles.
View Article and Find Full Text PDF

Background: Pediatric oncology patients are at increased risk for blood stream infections (BSI). Risk in the absence of severe neutropenia (absolute neutrophil count [ANC] ≥500/µl) is not well defined.

Procedure: In a retrospective cohort of febrile (temperature ≥38.

View Article and Find Full Text PDF

Background: Healthcare-associated transmission of respiratory viruses is a concerning patient safety issue.

Design: Surveillance for influenza virus among a cohort of healthcare workers (HCWs) was conducted in a tertiary care children's hospital from November 2009 through April 2010 using biweekly nasal swab specimen collection. If a subject reported respiratory symptoms, an additional specimen was collected.

View Article and Find Full Text PDF

Objective: Pediatric infectious diseases (ID) fellows are required to receive training in hospital epidemiology and infection control and prevention. We sought to assess the current state of healthcare epidemiology training for fellows and to determine which topics are considered important by key stakeholders.

Participants: US pediatric ID fellowship program directors and hospital epidemiologists.

View Article and Find Full Text PDF

Although commonly asymptomatic, congenital CMV infection is the leading cause of nonhereditary SNHL. Other sequelae that may be evident only after the neonatal period can include chorioretinitis, neurodevelopmental delay with mental or motor impairment, and microcephaly. (13) • Congenital CMV infection is confirmed by detection of the virus in urine, blood, or saliva within the first 3 weeks of life by culture or polymerase chain reaction.

View Article and Find Full Text PDF

Ehrlichiosis, a tickborne illness transmitted by tick vectors Amblyomma americanum and Ixodes scapularis, can be acquired in endemic areas. Clinical manifestations range from asymptomatic to fulminant in nature. We report three cases of ehrlichiosis in pediatric oncology patients, one of whom was a stem cell transplant recipient.

View Article and Find Full Text PDF