Flexible hybrid graphene/a-Si:H multispectral photodetectors

We report on the integration of large area CVD grown single- and bilayer graphene transparent conductive electrodes (TCEs) on amorphous silicon multispectral photodetectors. The broadband transmission of graphene results in 440% enhancement of the detectors' spectral response in the ultraviolet (UV) region at λ = 320 nm compared to reference devices with conventional aluminum doped zinc oxide (ZnO:Al) electrodes. The maximum responsivity of the multispectral photodetectors can be tuned in their wavelength from 320 nm to 510 nm by an external bias voltage, allowing single pixel detection of UV to visible light. Graphene electrodes further enable fully flexible diodes on polyimide substrates. Here, an upgrade from single to bilayer graphene boosts the maximum photoresponsivity from 134 mA W^-1 to 239 mA W^-1. Interference patterns that are present in conventional TCE devices are suppressed as a result of the atomically thin graphene electrodes. The proposed detectors may be of interest in fields of UV/VIS spectroscopy or for biomedical and life science applications, where the extension to the UV range can be essential.

Intravenous nicardipine for treatment of postcoarctectomy hypertension in children

Our objective was to evaluate the efficacy of intravenous (IV) nicardipine for the treatment of postcoarctectomy hypertension in children with coarctation of the aorta. We carried out a retrospective review in a pediatric intensive care unit at a tertiary care children's hospital. The patients were children with coarctation of the aorta treated for postcoarctectomy hypertension. Children with postcoarctectomy hypertension defined as a systolic blood pressure >95th percentile for age measured by indwelling arterial catheter were treated with IV nicardipine. We measured change in mean arterial blood pressure (MAP), mean systolic and diastolic blood pressure, and mean heart rate (HR) from baseline after initiating treatment with IV nicardipine. The outcome measure was a reduction in MAP and mean systolic and diastolic blood pressure after treatment with IV nicardipine. During a 4-year period, 10 children met the study criteria. Median age was 3.25 months (range, 0.25 to 180 months). Initial median treatment dose of IV nicardipine was 1.0 micro g/kg/min (range, 0.5 to 6 micro g/kg/min); median dose used to control hypertension was 1.5 micro g/kg/min (range, 0.25 to 6 micro g/kg/min). Median duration of therapy was 26.3 h (range, 13 to 49 h). Treatment with IV nicardipine resulted in a 26.5% decrease in MAP from baseline during the first hour of treatment ( p = 0.0006). Mean systolic blood pressure decreased from 133 to 105 mmHg ( p = 0.005), and mean diastolic blood pressure decreased from 75 to 52.5 mmHg ( p = 0.001) during the first hour of therapy with nicardipine. There was a significant reduction ( p = 0.0005) in MAP during continued treatment with IV nicardipine. The mean HR of 150 remained unchanged during the first hour of therapy with nicardipine, and no significant change in mean HR or adverse effects was noted during continued therapy. Two children receiving other antihypertensive therapy demonstrated further reduction in their blood pressure when IV nicardipine was initiated. Tachycardia and hypotension were not observed in any child treated with IV nicardipine. We concluded that IV nicardipine reduced MAP with no significant change in mean HR and no adverse effects in patients with postcoarctectomy hypertension. Nicardipine produced a further reduction in MAP in children receiving other antihypertensive agents. Nicardipine is an effective agent for treatment of postcoarctectomy hypertension in children with coarctation of the aorta.

Unique family with Townes-Brocks syndrome, SALL1 mutation, and cardiac defects

Townes-Brocks syndrome (TBS) is a condition with imperforate anus, hand anomalies, and ear malformations with sensorineural hearing loss. Many cases are sporadic. Within and between families, the phenotype displays striking variability. Recently, the disease-causing gene for TBS was identified as SALL1, a zinc finger transcription factor. Here, we report a three-generation family with seven affected individuals who have a novel SALL1 mutation. Unique cardiac anomalies seen in this family include lethal truncus arteriosus in one patient and a lethal complicated defect, including pulmonary valve atresia, in a second patient. These severe cardiac anomalies have not previously been reported in a familial case of TBS. This family and a review of the literature indicate that cardiac evaluation is warranted in all individuals with this disorder. In addition, hypoplastic thumbs were seen in two individuals in this family and should, therefore, be considered a true feature of TBS.

Unique family with Townes-Brocks syndrome, SALL1 mutation, and cardiac defects

Townes-Brocks syndrome (TBS) is a condition with imperforate anus, hand anomalies, and ear malformations with sensorineural hearing loss. Many cases are sporadic. Within and between families, the phenotype displays striking variability. Recently, the disease-causing gene for TBS was identified as SALL1, a zinc finger transcription factor. Here, we report a three-generation family with seven affected individuals who have a novel SALL1 mutation. Unique cardiac anomalies seen in this family include lethal truncus arteriosus in one patient and a lethal complicated defect, including pulmonary valve atresia, in a second patient. These severe cardiac anomalies have not previously been reported in a familial case of TBS. This family and a review of the literature indicate that cardiac evaluation is warranted in all individuals with this disorder. In addition, hypoplastic thumbs were seen in two individuals in this family and should, therefore, be considered a true feature of TBS.

Congenital heart block: development of late-onset cardiomyopathy, a previously underappreciated sequela

OBJECTIVE

We report 16 infants with complete congenital heart block (CHB) who developed late-onset dilated cardiomyopathy despite early institution of cardiac pacing.

BACKGROUND

Isolated CHB has an excellent prognosis following pacemaker implantation. Most early deaths result from delayed initiation of pacing therapy or hemodynamic abnormalities associated with congenital heart defects.

METHODS

A multi-institutional study was performed to identify common clinical features and possible risk factors associated with late-onset dilated cardiomyopathy in patients born with congenital CHB.

RESULTS

Congenital heart block was diagnosed in utero in 12 patients and at birth in four patients. Ten of 16 patients had serologic findings consistent with neonatal lupus syndrome (NLS). A pericardial effusion was evident on fetal ultrasound in six patients. In utero determination of left ventricular (LV) function was normal in all. Following birth, one infant exhibited a rash consistent with NLS and two had elevated hepatic transaminases and transient thrombocytopenia. In the early postnatal period, LV function was normal in 15 patients (shortening fraction [SF] = 34 +/- 7%) and was decreased in one (SF = 20%). A cardiac pacemaker was implanted during the first two weeks of life in 15 patients and at seven months in one patient. Left ventricular function significantly decreased during follow-up (14 days to 9.3 years, SF = 9% +/- 5%). Twelve of 16 patients developed congestive heart failure before age 24 months. Myocardial biopsy revealed hypertrophy in 11 patients, interstitial fibrosis in 11 patients, and myocyte degeneration in two patients. Clinical status during follow-up was guarded: four patients died from congestive heart failure; seven required cardiac transplantation; one was awaiting cardiac transplantation; and four exhibited recovery of SF (31 +/- 2%).

CONCLUSIONS

Despite early institution of cardiac pacing, some infants with CHB develop LV cardiomyopathy. Patients with CHB require close follow-up not only of their cardiac rate and rhythm, but also ventricular function.

Residual mesenchyme persisting into adulthood

PURPOSE

(1) To detect the presence of residual mesenchyme in temporal bones of adults and children above 5 years of age; (2) to evaluate its regression with increasing age, and; (3) to detect pathologic conditions associated with the presence of unresolved mesenchyme.

MATERIALS AND METHODS

We examined 1,404 human temporal bones of donors from 5 to 94 years of age for histopathologic evidence of mesenchyme. The presence of stellate (star-shaped) cells with interdigitating processes and large nuclei embedded in a structureless ground substance was labeled as "pure mesenchyme." Temporal bones showing these features and focal areas of fibrosis, fibroblasts, and capillaries were classified as showing "transitional mesenchyme." Selected sections were stained with Gomori's trichrome. Pathological features indicating otitis media and congenital anomalies of the ear were also documented. Case histories were reviewed, and any otologic complaints were noted. Statistical analysis was performed with the Chi-square test, analysis of variance, regression analysis, and confidence interval.

RESULTS

Mesenchyme was found in 2.07% of temporal bones of patients from 5 to 81 years of age. Of these, 92.1% had transitional mesenchyme, whereas 7.9% had pure mesenchyme. Seventy-six percent of the bones showed mesenchyme in the mastoid air cells. In all 3 bones with pure mesenchyme, it was present in the round window niche. Otitis media was associated with residual mesenchyme in 84.2% of the temporal bones. No pattern of regression of mesenchyme with increasing age was observed in temporal bones from patients over the age of 5 years.

CONCLUSIONS

Residual mesenchyme can be present in patients older than 5 years of age and can persist into adulthood, especially in the mastoid air cells. Persistence of mesenchyme is closely associated with evidence of otitis media.

Anatomic and technical considerations in needle electromyography of the lumbar spine

Interpretation of the paraspinal needle electromyographic examination requires knowledge of complex and specialized anatomy and pathophysiological processes. The purpose of this article is to elucidate the anatomy and physiology of the lumbar paraspinal needle examination and apply this knowledge to accurate needle technique and rational clinical interpretation of the paraspinal examination.

Dating and remarriage over the first two years of widowhood

In this study we examined the following: (1) frequencies of remarrying or becoming romantically involved for widows and widowers during the first 2 years of widowhood; (2) attitudes toward dating and remarriage among the recently widowed, and their evolution; (3) identifiable factors which predict the development of new romances, such as sex, age, income, and level of education; and (4) the psychological well-being of those widows and widowers involved in romances compared to those who were not. The San Diego Widowhood Project was a prospective study in which 249 widows and 101 widowers who were identified through San Diego County death certificates completed detailed questionnaires 2, 7, 13, 19, and 25 months after their spouses' deaths. The main outcome measures for this study were marital and romance status, attitudes toward romance at several time points, demographic predictors of romance status, and self-reported measures of psychological well-being. By 25 months after the spouse's death 61% of men and 19% of women were either remarried or involved in a new romance. Women expressed more negative feelings about forming new romantic relationships. Younger age was a predictor of becoming involved in a new romance for women, and higher monthly income and level of education were predictors for men. Greater psychological well-being was highly correlated with being remarried or in a new romance 25 months after the spouse's death. It may be helpful for family, friends, and therapists to know that dating and remarriage are common and appear to be highly adaptive behaviors among the recently bereaved.

A processed form of the Spatzle protein defines dorsal-ventral polarity in the Drosophila embryo

Stein et al. (1991) identified a soluble, extracellular factor that induces ventral structures at the site where it is injected in the extracellular space of the early Drosophila embryo. This factor, called polarizing activity, has the properties predicted for a ligand for the transmembrane receptor encoded by the Toll gene. Using a bioassay to follow activity, we purified a 24 × 10(3) M(r) protein that has polarizing activity. The purified protein is recognized by antibodies to the C-terminal half of the Spatzle protein, indicating that this polarizing activity is a product of the spatzle gene. The purified protein is smaller than the primary translation product of spatzle, suggesting that proteolytic processing of Spatzle on the ventral side of the embryo is required to generate the localized, active form of the protein.

Dominant and recessive mutations define functional domains of Toll, a transmembrane protein required for dorsal-ventral polarity in the Drosophila embryo

The asymmetry of the dorsal-ventral pattern of the Drosophila embryo appears to depend on the ventral activation of the transmembrane Toll protein. The Toll protein is found around the entire dorsal-ventral circumference of the embryo, and it appears to act as a receptor for a ventral, extracellular signal and to then relay that signal to the cytoplasm in ventral regions of the embryo. Three of five recessive loss-of-function alleles of Toll are caused by point mutations in the region of the cytoplasmic domain of Toll that is similar to the mammalian interleukin-1 receptor, supporting the hypothesis that Toll acts as a signal-transducing receptor. Nine dominant gain-of-function alleles that cause Toll to be active in dorsal, as well as ventral, regions of the embryo are caused by mutations in the extracellular domain. Three of the dominant alleles appear to cause the protein to be constitutively active and are caused by cysteine-to-tyrosine changes immediately outside the transmembrane domain. All six of the remaining dominant alleles require the presence of a wild-type transmembrane Toll protein for their ventralizing effect and all encode truncated proteins that lack the transmembrane and cytoplasmic domains.

Cardiac malformations in relatives of infants with hypoplastic left-heart syndrome

In a pilot study of relatives of infants with hypoplastic left-heart syndrome (HLHS), we obtained a medical history, cardiovascular examination, and echocardiogram in 48 first-degree relatives of 11 probands with isolated HLHS and 3 with HLHS and noncardiac malformations. Echocardiography confirmed heart defects in 5 of 41 relatives of patients with isolated HLHS. In four instances, the cardiac abnormality was unrecognized. Among 7 relatives of infants with HLHS and extracardiac anomalies, no heart defects were detected. Cardiac defects occurred in first-degree relatives of probands at a frequency higher than previously predicted by an additive multifactorial model of inheritance. These findings suggest that first-degree relatives of HLHS probands may have an increased risk for subclinical cardiac defects and that genetic factors likely contribute to the cause of left-heart blood-flow lesions.

Patterns of cardiac care in infants with Down syndrome

To determine if the pattern of cardiac care is affected by the presence of Down syndrome (DS) we analyzed the records of infants enrolled in the Baltimore-Washington Infant Study, a regional case-control study of congenital cardiovascular malformations. The age at cardiac diagnosis, the timing of cardiac surgery, and the one-year outcome were compared in 160 infants with DS and 540 infants with the same cardiac diagnoses but without chromosomal or other extracardiac anomalies (Isolated cardiovascular malformation [ICM] group). Cardiac referral and diagnosis were accomplished by 13 weeks of age in 78% of infants with DS and 67% of those with ICMs. However, by 26 weeks of age, the proportion of infants in both groups was comparable. Cardiac surgery was performed before 1 year of age in 99 of 160 infants with DS and in 141 of 540 infants with ICMs. The surgical outcome was similar in the two groups. We conclude that for defects of comparable severity, the pattern of cardiac care in the Baltimore-Washington, DC, area for infants with DS is timely and comparable to care for infants with ICMs.

Effect of amiodarone on rat heart myosin isoenzymes

The effects of amiodarone on heart weight, production of 14C-CO2 from labelled glucose, myosin ATPase activity, and myosin isoenzyme patterns were determined by comparing control and amiodarone-treated male Wistar rats. Since it has been suggested that amiodarone may interfere with thyroid hormone action on the heart, similar experiments were also carried out in hypothyroid and amiodarone-plus-triiodothyronine(T3)-treated rats, and the data were compared to those obtained in amiodarone-treated rats. Amiodarone treatment for 6 weeks resulted in lower heart weight, decreased atrial production of 14C-CO2 from labelled glucose, decreased myosin Ca-ATPase activity, and preferential synthesis of V3 isomyosin. These effects were similar to those observed in hypothyroid rats but were lesser in magnitude. T3 treatment of amiodarone-treated rats reversed all the changes induced by amiodarone. Serum thyroxine (T4) was higher in amiodarone-treated than in control rats, while serum T3 was similar. Serum T3 was higher in the amiodarone-plus-T3 than in the amiodarone-treated group. These results show that 1) amiodarone-induced changes resemble hypothyroidism with respect to cardiac myosin expression and atrial CO2 production, 2) amiodarone causes hypothyroid-like changes despite normal serum T3 and increased serum T4, and 3) T3 reverses the effects of amiodarone. These data support the hypothesis that amiodarone inhibits the action of thyroid hormone on the heart.

Neighbouring group participation by the carboxy group in the solvolysis of the dipeptides in acetic acid

The acid-catalysed solvolysis of the dipeptides in acetic acid solution occurs readily both in the presence and absence of water. The rates increase with increasing methylation, which is consistent with a mechanism involving a ring-closure pathway by the terminal carboxy group. The experimentally determined rate law is: f × rate × [H2O]/[dipeptidium(1+) ClO4-][ΣH+] = k1 + k2[H2O]2 where f is the salt effect factor and ΣH+ is the acetic acidium perchlorate concentration after correcting for the presence of oxonium perchlorate. The k1 values increase with increasing methylation, as required for a ring-closure mechanism, and the inverse water term in this component of the rate is ascribed to a medium effect. The ratecontrolling step is defined as being the acid-catalysed ring fission of a rapidly formed intermediate, oxazalone acetic acid solvate. The k2 component of the rate is first order with respect to water and would appear to refer to the normal mode of solvolysis. But the much higher values of k2 for the heavily methylated compounds as compared with Gly-Gly are incompatible with the much lower activities shown by these compounds when reacting by the normal mode of solvolysis. Since k2 passes through a minimum with increasing methylation, it is suggested that it is a composite of the normal and ring-closure modes of solvolysis. The rate-controlling step for this latter reaction is the acid-catalysed reaction of water with the oxazolone acetic acid solvate. The increasing rates arising from increasing methylation are due to increasing stabilities of the oxazolone solvate ring systems resulting in a kinetically favourable displacement of this equilibrium towards the ring system. Infrared analysis shows that the oxazolone of Aibu-Aibu readily undergoes a fast reaction with acidified acetic acid to form a stable acetic acid solvate with the complete disappearance of all oxazolone absorption frequencies. Aibu-Aibu on heating in acidified acetic acid solution rapidly forms the same oxazolone acetic acid solvate with no evidence of any oxazolone absorption frequencies. The solvolysis of optically active Gly-Val demonstrates that the oxazolone is not formed as an intermediate because the Val produced retains its optical activity with no evidence of any racemization.

Photorearrangement of trans-1,1′:3,4-Diepoxy-1-methyl-2-tetralone, an α,β:α′,β′- diepoxyketone

Irradiation of trans-l,l':3,4-diepoxy-1-methyl-2-tetralone (1) with a medium-pressure mercury lamp yielded 2,3-dihydroxy-1-naphthaldehyde (2), 2,4-dihydroxy-1-naphthaldehyde (3), and 3-(2'-hydroxyphenyl)-4H-pyran-4-one(4).