We present an integrated 2:1 multiplexer and a companion 1:2 demultiplexer in CMOS. Both integrated circuits (ICs) operate up to a bit rate of 40 Gb/s. The 2:1 multiplexer features two in-phase data ...inputs which are achieved by a master-slave flip-flop and a master-slave-master flip-flop. Current-mode logic is used because of the higher speed compared to static CMOS and the robustness against common-mode disturbances. The multiplexer uses no output buffer and directly drives the 50-/spl Omega/ environment. An inductance connected in series to the output in combination with shunt peaking is used to enhance the bandwidth of the multiplexer. Fully symmetric on-chip inductors are used for peaking. The inductors are mutually coupled to save chip area. Lumped equivalent models of both peaking inductors allow optimization of the circuit. The ICs are fabricated in a 120-nm standard CMOS technology and use 1.5-V supply voltage. Measured eye diagrams of both ICs demonstrate their performance.
The k(e)(0) value is the first order rate constant determining the equilibration of drugs between plasma or end-tidal concentration and effect-site (e.g., brain) concentration. Parametric and ...semiparametric approaches have been used for estimating individual k(e)(0) values and describing the drug-response curve. In this study, we introduce a new semiparametric approach calculating k(e)(0) values for isoflurane, sevoflurane, and desflurane by maximizing the prediction probability P(K).
Data from 45 patients scheduled for a radical prostatectomy were analyzed. After lumbar epidural catheterization, patients received remifentanil and propofol solely for induction of anesthesia. Thereafter, epidural analgesia was initiated, and isoflurane, sevoflurane, or desflurane (15 patients each) was added to maintain unconsciousness. At least 45 min later, end-tidal concentrations were varied between 0.5 and 2 minimum alveolar anesthetic concentration. We estimated an individual k(e)(0) value for each patient by optimizing the prediction probability P(K) (P(K)-based k(e)(0)) or by minimizing the area within the hysteresis loop (area-based k(e)(0)). Data are mean +/- sd.
Both semiparametric approaches led to comparable k(e)(0) values with 0.18 +/- 0.06 min(-1) (P(K) based) and 0.15 +/- 0.04 min(-1) (area based) for isoflurane and 0.17 +/- 0.08 min(-1) (P(K) based) and 0.16 +/- 0.11 min(-1) (area based) for sevoflurane. k(e)(0) values for desflurane (P(K) based: 0.30 +/- 0.17min(-1); area based: 0.32 +/- 0.25 min(-1)) were significantly higher than for isoflurane and sevoflurane.
Maximizing the prediction probability P(K) for estimating k(e)(0) seems to be a promising method that researchers could use on an exploratory basis.
Changes in cerebral blood flow are important in the pathogenesis of ischaemic brain damage, but standard methods cannot measure volume of cerebral blood flow quantitatively in neonates. We used ...colour duplex sonography of the extracranial cerebral arteries to measure volume of global cerebral blood flow in 67 healthy preterm and term neonates. Volume of cerebral blood flow increased between the postmenstrual ages of 34 weeks (median 33 mL/min range 23–43) and 42 weeks (85 mL/min 57–104). However, intersession and interobserver variability was quite large. This non-invasive method will allow quantitative bedside monitoring of global brain perfusion in preterm and term neonates with pathological disorders, and could also be used to monitor effects of neuroprotective measures.
Perceptual learning is defined as a long-lasting improvement of perception as a result of experience. Here we examined the role of task on fast perceptual learning for shape localisation either in ...simple
detection or based on form
discrimination in different visual submodalities, using identical stimulus position and stimulus types for both tasks. Thresholds for each submodality were identified by four-alternative-forced-choice tasks. Fast perceptual learning occurred for shape detection-based on luminance, motion and color differences but not for texture differences. In contradistinction, fast perceptual learning was not evident in shape localisation based on discrimination. Thresholds of all submodalities were stable across days. Fast perceptual learning seems to differ not only between different visual submodalities, but also across different tasks within the same visual submodality.
Large deletions of the NF1 gene and its flanking regions are frequently associated with a severe clinical manifestation. Different types of gross NF1 deletion have been identified that are ...distinguishable both by their size and the number of genes included within the deleted regions. Type-1 NF1 deletions encompass 1.4 Mb and include 14 genes, whereas the much less common type-2 NF1 deletions span 1.2 Mb and contain 13 genes. Genotype-phenotype correlations in patients with large NF1 deletions are likely to be influenced by the nature and number of the genes deleted in addition to the NF1 gene. Whereas the clinical phenotype associated with type-1 NF1 deletions has been well documented, the detailed clinical characterization of patients with non-mosaic type-2 NF1 deletions has not so far been reported.
In the present report we characterized two Caucasian European patients with non-mosaic (germline) type-2 NF1 deletions. Our first patient was a 13-year-old girl with dysmorphic facial features, mild developmental delay, large hands and feet, hyperflexibility of the joints, macrocephaly and T2 hyperintensities in the brain. A whole-body magnetic resonance imaging scan indicated two internal plexiform neurofibromas. Our second patient was an 18-year-old man who exhibited dysmorphic facial features, developmental delay, learning disability, large hands and feet, hyperflexibility of the joints, macrocephaly and a very high subcutaneous and internal tumor load as measured volumetrically on whole-body magnetic resonance imaging scans. At the age of 18 years, he developed a malignant peripheral nerve sheath tumor and died from secondary complications. Both our patients exhibited cardiovascular malformations.
Our two patients with non-mosaic type-2 NF1 deletions exhibited clinical features that have been reported in individuals with germline type-1 NF1 deletions. Therefore, a severe disease manifestation is not confined to only patients with type-1 NF1 deletions but may also occur in individuals with type-2 NF1 deletions. Our findings support the concept of an NF1 microdeletion syndrome with severe clinical manifestation that is caused by type-1 as well as type-2 NF1 deletions.
Patients with long-segment cervical spinal fusion resulting from spinal ankylosing disorders (SADs) are at high risk for highly unstable cervical spine fractures necessitating surgery as the ...treatment of choice; however, without an existing gold standard. Specifically, patients without concomitant myelo- pathy, representing a rare entity, may benefit from a minimized surgical approach of a single-stage posterior stabilization without bone grafting for posterolateral fusion. This retrospective monocenter study in a Level I trauma center included all patients treated with navigated posterior stabilization without posterolateral bone grafting between January 2013 and January 2019 for cervical spine fractures in preexisting SADs without myelopathy. The outcomes were analyzed based on complication rates, revision frequency, neurologic deficits, and fusion times and rates. Fusion was evaluated by X-ray and computed tomography. 14 patients (11 male, 3 female) with a mean age of 72.7 ± 17.6 years were included. Five fractures were at the upper and nine at the subaxial cervical spine (predominantly C5-7). There was one surgery-specific complication of postoperative paresthesia. There was no infection, implant loosening, or dislocation, and no revision surgery necessary. All fractures healed after a median time of 4 months and 12 months being the latest time of fusion in one patient. Single-stage posterior stabilization without posterolateral fusion is an alternative for patients with SADs and cervical spine fractures without myelopathy. They can benefit from a minimization of surgical trauma while having equal times of fusion and no increased rate of complications.
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