To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Intrauterine growth restriction (IUGR) and fetal growth restriction (FGR) are pregnancy complications associated with morbidity in later life. Despite a growing body of evidence from current research on developmental origins of health and disease (DOHaD), little information is currently provided to parents on long-term metabolic, cardiovascular and neurologic consequences. As parents strongly rely on internet-based health-related information, we examined the quality of information on IUGR/FGR sequelae and DOHaD in webpages used by laypersons. Simulating non-clinicians experience, we entered the terms ‘IUGR consequences’ and ‘FGR consequences’ into Google and Yahoo search engines. The quality of the top search-hits was analyzed with regard to the certification through the Health On the Net Foundation (HON), currentness of cited references, while reliability of information and DOHaD-related consequences were assessed via the DISCERN Plus score (DPS). Overall the citation status was not up-to-date and only a few websites were HON-certified. The results of our analysis showed a dichotomy between the growing body of evidence regarding IUGR/FGR-related sequelae and lack of current guidelines, leaving parents without clear directions. Furthermore, detailed information on the concept of DOHaD is not provided. These findings emphasize the responsibility of the individual physician for providing advice on IUGR/FGR-related sequelae, monitoring and follow-up.
Idiopathic intrauterine growth restriction (IUGR) is a result of impaired placental nutrient supply. Newborns with IUGR exhibiting postnatal catch-up growth are of higher risk for cardiovascular and metabolic co-morbidities in adult life. Mammalian target of rapamycin (mTOR) was recently shown to function as a placental nutrient sensor. Thus, we determined possible correlations of members of the placental mTOR signaling cascade with auxologic parameters of postnatal growth. The protein expression and activity of mTOR-pathway signaling components, Akt, AMP-activated protein kinase α, mTOR, p70S6kinase1 and insulin receptor substrate-1 were analysed via western blotting in IUGR v. matched appropriate-for-gestational age (AGA) placentas. Moreover, mTOR was immunohistochemically stained in placental sections. Data from western blot analyses were correlated with retrospective auxological follow-up data at 1 year of age. We found significant catch-up growth in the 1st year of life in the IUGR group. MTOR and its activated form are immunohistochemically detected in multiple placental compartments. We identified correlations of placental mTOR-pathway signaling components to auxological data at birth and at 1 year of life in IUGR. Analysis of the protein expression and phosphorylation level of mTOR-pathway components in IUGR and AGA placentas postpartum, however, did not reveal pathognomonic changes. Our findings suggest that the level of activated mTOR correlates with early catch-up growth following IUGR. However, the complexity of signals converging at the mTOR nexus and its cellular distribution pattern seem to limit its potential as biomarker in this setting.
Embedded wafer-level ball grid array (eWLB) is investigated as a low-cost plastic package for automotive radar applications in the 76–81 GHz range. Low transmission losses from chip to package and board are achieved by appropriate circuit and package design. Special measures are taken to effectively remove the heat from the package and to optimize the package process to achieve automotive quality targets. A 77 GHz radar chip set in eWLB package is developed, which can be applied on the system board using standard solder reflow assembly. These radar MMICs provide excellent radio frequency (RF) performance for the next generation automotive radar sensors. The potential for even higher system integration is shown by a radar transceiver with antennas integrated in the eWLB package. These results demonstrate that eWLB technology is an attractive candidate to realize low-cost radar systems and to enable radar safety affordable for everyone in the near future.
The crystallization process of SrxBiyTa2O5+x+3y/2 thin films grown by metalorganic chemical vapor deposition was investigated. Phase formation and crystal growth is greatly affected by the film composition and crystallization temperature. Phase diagrams for varying Sr or Bi contents were determined as a function of the crystallization temperature. The higher the Sr or Bi content in the film, the lower the phase transition temperature from the amorphous to the fluorite-type phase and from the fluorite-type to the Bi-layered Aurivillius phase. Low Sr and Bi contents support pyrochlore-type phase formation as a second phase. During annealing, excess Bi is not lost due to evaporation, but due to migration to the bottom electrode. Contrary to the fluorite-type phase, the Aurivillius phase is not able to incorporate the excess of Bi atoms. Decreasing grain size and pyrochlore-type phase formation entail decreasing remanent polarization.
Thin films of high-k dielectric/ferroelectric materials such as BaxSr1−xTiO3 (BST), PbZrxTi1−xO3 (PZT) and SrBi2Ta2O9 (SBT) are currently investigated for integration into high-density CMOS technology. Characterization of these materials by SPM techniques combines imaging of the morphology and microstructure of these films and recording of various electrical parameters at the same local area. Using commercial equipment we have investigated electrical properties such as polarization and leakage current behavior of MOD/MOCVD SBT by applying electrostatic force microscopy (EFM) and conducting atomic force microscopy (CAFM). After applying bias voltages of a few volts across the SBT films between the scanning tip and the lower electrode completely polarized/reverse polarized SBT layers could be observed by EFM. Even single crystallite polarization was imaged. However, unexpectedly some films showed incomplete polarization, which may be caused by local electrical field effects. Images taken by C-AFM displayed enhancement of leakage currents in grain boundary regions, in particular at depressions between adjacent crystallites. The results achieved demonstrate that SPM techniques operated in a variety of imaging and measuring modes, provide a tremendous potential in the elucidation of the microscopic properties of high-k materials.
The imprint behavior of CSD processed SrBi2Ta2O9 (SBT) thin films has been investigated as a function of time, applied bias, illumination with band gap light and post anneal under different oxygen partial pressures. Applying a bias in the direction of the polarization enhances the tendency of the capacitor to exhibit a voltage shift as well as illuminating the poled capacitor with band gap light. Post anneal after top electrode deposition and patterning under slightly reducing atmospheres does not affect the imprint rate. From these experimental results, a model is presented which explains the imprint behavior of SBT films by transport of electronic charges from the electrodes into the film and subsequent trapping of these charges near the interface.
In order to ensure the quality of the source catalogue derived from the SASS processing an automatic as well as a visual screening procedure was applied to 1378 survey fields. Most (94%) of the 18,811 sources were confirmed by this screening process. The rest is flagged for various reasons. Broad band images are available for a subset of the flagged sources. Details of the screening process can be found at www.rosat.mpe-garching.mpg.de/survey/rass-bsc/doc.html.
This work presents a survey of the mechanisms of the polarization in ferroelectric thin films which are relevant for application in non-volatile ferroelectric memories (FeRAM). Since the integration of these materials in new memory generations requires small structures and therefore a maximum utilization of the switchable polarization, the distinction between the several polarization mechanisms is of specific interest. Standard characterization methods, such as hysteresis loops, C-V measurements and fast pulse switching tests are evaluated and used to distinguish between the reversible and irreversible contributions to the total polarization. The respective contributions are described qualitatively and demonstrated at spin-coated SrBiTa2O9 thin films and compared with Pb(Zr,Ti)O3 films. Additionally, a method is described to obtain the static hysteresis curve, a precise characterization of the polarization which does not depend on the measuring frequency. These data are compared with C-V measurements. It is shown that the standard dynamic hysteresis curve reveals misleading statements about the remanent polarization and the coercive voltage.