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Intermetallic Zintl phases whose structures consist of honeycomb layers of main group elements often serve as useful precursors for two-dimensional group 14 graphane derivatives. Here, we probe how the Raman spectra and band gaps evolve in these precursor intermetallic phases before they transform into their van der Waals counterparts. Through polarization-dependent Raman experiments on seven different group 14 and 15 Zintl phases with different stacking motifs, we show that the in-plane and out-of-plane Raman frequencies mostly depend on the reduced mass and the in-plane bond lengths of the elements constituting the honeycomb framework. From optical absorption measurements, we show that the honeycomb framework comprised of single elements is metallic, but when the framework is comprised of alternating elements in a BN-like fashion, such as in NaSnP, KSnAs and KSnSb, a band gap is opened up ranging from 0.54 eV for KSnSb to 0.95 eV for NaSnP. This study allows for the determination of the structure and stacking motifs for this emerging class of 2D layered metallic and semiconducting materials.

Despite the immense interest in magnetic, topological, and magnetoelectronic phenomena in isolated layers of 2D materials and their vertically stacked heterostructures, there remains a dearth of 2D magnetic materials that can be readily exfoliated into single layers. Here, we synthesize EuSn2As2, the first exfoliatable, layered magnetic Zintl–Klemm phase that features van der Waals bonding between neighboring layers. In these crystals, Eu2+ 4f7 spins magnetically order at 24 K and are coupled ferromagnetically within each layer and antiferromagnetically, with some potential canting, across adjacent layers. Magnetic ground state DFT calculations and temperature-dependent transport measurements on single crystals together establish that EuSn2As2 is semimetallic. Finally, we show that this material can be thinned down to a few layers having steps corresponding to SnAsEuAsSn layers via micromechanical exfoliation. This work opens up further explorations into the design, synthesis, and layer-dependent magnetic properties of exfoliatable, lanthanide-based magnetic van der Waals Zintl phases.

Leaf temperatures were lower when light entry at the leaf tip window was prevented through covering the window with reflective tape, relative to leaf temperatures of plants with leaf tip windows covered with transparent tape. This was true when leaf temperatures were measured with an infrared thermometer, but not with a fine-wire thermocouple. Leaf tip windows of Lithops growing in high-rainfall regions of southern Africa were larger than the windows of plants (numerous individuals of 17 species) growing in areas with less rainfall and, thus, more annual insolation. The results of this study indicate that leaf tip windows of desert plants with an underground growth habit can allow entry of supra-optimal levels of radiant energy, thus most likely inhibiting photosynthetic activity. Consequently, the size of the leaf tip windows correlates inversely with habitat solar irradiance, minimising the probability of photoinhibition, while maximising the absorption of irradiance in cloudy, high-rainfall regions.

The purpose of this study was to evaluate several psychosocial correlates of depressed mood during pregnancy. The psychosocial factors examined included background characteristics (socioeconomic status, planning of pregnancy), perceived social support, and coping styles.One hundred fifty pregnant lower income, minority women were recruited from an obstetrics clinic at an urban hospital. Patients completed a battery of psychosocial measures including measures of social support, coping style, and depressed mood.Perceived social support and an avoidant coping style were the most salient psychosocial correlates of depressed mood during pregnancy, accounting for 34% of the variance in the model. More specifically, women who reported less social support satisfaction experienced greater avoidant coping strategies, which was then associated with higher levels of depressed mood.This study suggests that women who perceive less social support satisfaction utilize more avoidant coping strategies and experience greater depression mood. Thus, although these associations are not indicative of a causal relationship, results raise the possibility that women at-risk for depressed mood during pregnancy can be identified by assessing perceived social support and coping styles. Future prospective studies are needed to test the causal relationships among these variables. Clinical interventions to target these psychosocial factors during pregnancy are discussed.

Particle-induced osteolysis is caused by an imbalance in bone resorption and formation, often leading to loss of implant fixation. Bone remodeling biomarkers may be useful for identification of osteolysis and studying pathogenesis, but interpretation of biomarker data could be confounded if local osteolysis engenders systemic bone remodeling. Our goal was to determine if remote bone remodeling contributes to biomarker levels. Serum concentrations of eight biomarkers and bone remodeling rates at local (femur), contiguous (tibia), and remote (humerus and lumbar vertebra) sites were evaluated in a rat model of particle-induced osteolysis. Serum CTX-1, cathepsin K, PINP, and OPG were elevated and osteocalcin was suppressed in the osteolytic group, but RANKL, TRAP 5b, and sclerostin were not affected at the termination of the study at 12 weeks. The one marker tested longitudinally (CTX-1) was elevated by 3 weeks. We found increased bone resorption and decreased bone formation locally, subtle differences in contiguous sites, but no differences remotely at 12 weeks. Thus, the skeletal response to local particle challenge was not systemic, implying that the observed differences in serum biomarker levels reflect differences in local remodeling.

Aneurysm of the ductus arteriosus may be either spontaneous or acquired as a complication of surgical closure of a patent duct. Patients may be asymptomatic or present with a wide spectrum of symptoms, including hoarseness, respiratory symptoms, aortic or pulmonary thrombosis or embolism, or rupture of the aneurysm. We present the first report of prenatal ultrasonographic diagnosis of isolated ductus arteriosus aneurysm. The aneurysm presented at 39 weeks as an enlarged, dilated, vascular structure 15 mm in diameter, which began at the bifurcation of the main pulmonary artery and ended in the descending aorta. Doppler imaging demonstrated turbulent flow in this lesion. Following spontaneous delivery, a bidirectional shunt in the ductus arteriosus was found on the 1st day, but the caliber of the vessel was normal. An almost completely functionally closed ductus was found on the 2nd day. Spontaneous resolution of the lesion was confirmed by magnetic resonance imaging at 4 weeks of age.

The original Palmaz balloon expandable stent has been used extensively for the treatment of vascular stenoses in older children and young adults. Placement of the Palmaz stent in infants and small children, however, is limited by stent inflexibility, large delivery sheath size, and concerns about creating fixed obstructions after the placement of small diameter stents in growing patients. New Palmaz Corinthian stents were placed through 6 French sheaths in four high-risk patients with postoperative right ventricular outflow obstruction. Patients were not considered candidates for surgical repair. Median patient age and weight were 17 months (range 5-32 months) and 7.7 kg (range 4.6-11.1 kg), respectively. Median fluoroscopy time was 58.2 min (range 55.2-172 min). No complications were encountered. In each case, successful stent placement was achieved, and surgery with cardiopulmonary bypass was avoided. Palmaz Corinthian stents are more flexible, require a smaller delivery sheath, have equal or increased radial strength, and can be maximally expanded to a greater cross sectional area when compared to the original Palmaz stent. These characteristics make the Palmaz Corinthian stent a reasonable alternative for use in a select group of infants and small children who are not candidates for surgical repair of postoperative right ventricular outflow obstruction.

The previous literature describing choroidal vascular circulatory organization is highly controversial. In vivo indocyanine green (ICG) videoangiographic studies using dye subtraction algorithms confirm prior in vitro latex injection studies which demonstrated the choroidal vascular bed as one continuous, freely anastomotic system. In contrast, laser targeted fluorescein angiographic dye studies confirm previous conventional fluorescein angiographic studies which illustrated multiple choroidal vascular zones of watershed filling in the posterior pole. This latter type of choroidal watershed vascular physiology is consistent with clinical entities such as the triangular syndrome and Elschnig’s spots. Overall, these findings may represent a normal spectrum of choroidal vascular physioanatomical heterogeneity, thereby explaining the variability found in the literature.

Aneurysm of the ductus arteriosus may be either spontaneous or acquired as a complication of surgical closure of a patent duct. Patients may be asymptomatic or present with a wide spectrum of symptoms, including hoarseness, respiratory symptoms, aortic or pulmonary thrombosis or embolism, or rupture of the aneurysm. We present the first report of prenatal ultrasonographic diagnosis of isolated ductus arteriosus aneurysm. The aneurysm presented at 39 weeks as an enlarged, dilated, vascular structure 15 mm in diameter, which began at the bifurcation of the main pulmonary artery and ended in the descending aorta. Doppler imaging demonstrated turbulent flow in this lesion. Following spontaneous delivery, a bidirectional shunt in the ductus arteriosus was found on the 1st day, but the caliber of the vessel was normal. An almost completely functionally closed ductus was found on the 2nd day. Spontaneous resolution of the lesion was confirmed by magnetic resonance imaging at 4 weeks of age.

A prospective investigation on the short-term effects of various sedation regimens on 549 nonhospitalized magnetic resonance (MR) patients was performed. The drugs evaluated were chloral hydrate, pentobarbital, midazolam, and diazepam (fentanyl was used for enhancement after any of these drugs). The overall safety and efficacy were quite good with all the regimens. Overall, 84% of children slept less than 8 h after the examination, 90% were drowsy and/or unsteady for less than 8 h after they awoke, and 97% resumed their usual activities by 24 h. Significant hyperactivity was seen only with pentobarbital and occurred in 8.4% of children over 8 years of age. The multiple-dose regimen of pentobarbital and fentanyl had a significant short-term effect on the children less than 8 years of age, with 35% sleeping longer than 8 h after the MR. Ten children who had needed the multiple-dose pentobarbital regimen or who had failed prior pentobarbital sedation presented for repeat sedation. Midazolam was effective in 9 of these 10 children.

The clinical course of ocular toxocariasis and the chronological development of peripheral retinal and macular granulomas are reported. Removing the epiretinal as well as subretinal component of the granuloma via pars plana vitrectomy and retinotomy techniques yielded an excellent clinical result. Clinicopathologic correlation of the specimen confirmed the diagnosis with histological evidence of degenerated larval structures in granulomatous inflammation.

Microcephaly (small head) is clinically important only if there is concomitant micrencephaly (small brain). Extensive studies on patients in mental institutions have shown that there is close correlation among microcephaly, micrencephaly, and mental retardation when the head is more than three standard deviations below the norm. If the small head is less than two standard deviations below the norm, no strong correlation exists with eigher small brain or mental retardation. High-resolution ultrasound permits imaging of the fetal head in utero, allowing accurate evaluation of head size and detection of intracranial anomalies. The microcephalics detected in utero over a 2-year period form the basis of this series, showing close correlation with the known clinical data on children with microcephaly. An approach to ultrasound detection and evaluation of fetal microcephaly is proposed.

Captan, folpet, and Difolatan® are structurally related fungicides. Major metabolites derived from these compounds are the imides: tetrahydrophthalimide and phthalimide. The epoxides of captan and Difolatan are possible alteration products which may form under conditions of weathering or degradative metabolism. A TLC method has been developed which differentiates between captan, folpet, Difolatan, tetrahydrophthalimide, phthalimide, captan epoxide, Difolatan epoxide, and tetrahydrophthalimide epoxide. The method is based upon chromatography on silica gel with 1% methanol in chloroform as solvent for development, followed by sequential color development of the resulting spots. N,NDimethyl - p - phenylenediamine, potassium permanganate, and chromic acid were the chromogenic sprays used. Lower limits of detection for these compounds were determined in the named TLC system. The GLC behavior of this group of compounds was also studied, utilizing both a 10% DC-200 on Gas Chrom Q (80—100 mesh) column and a mixed column of 10% DC-200:15% QF-1 (1:1) each on 100-120 mesh Gas Chrom Q. GLC retention times and response data were determined with an electron capture detector

A new structure is proposed for ethylene thiuram monosulfide based primarily on mass, Raman, and nuclear magnetic resonance spectral data. Data in the older literature, for the most part, are consistent with both the old and new structures; however, new data are consistent only with the new structure.

To improve the gas chromatographic properties of 3-chloropropanediol, a phenylboronic acid derivative was prepared. This method appears to be suitable for trace analysis of the title compound. Epichlorohydrin, 1,2-propanediol, and 1,2-dichloropropanol were among the structurally related compounds shown not to interfere. The structure of the derivative was confirmed by gas chromatography-Fourier transform infrared spectroscopy utilizing a matrix isolation interface and gas chromatography-mass spectrometry.

Two prospective, controlled studies were conducted to determine if psychological and social functioning could be enhanced in patients with Hodgkin's disease by either education or participation in a peer support therapy group. Eighty-one patients were evaluated with the Cancer Patient Behavior Scale prior to and following intervention. Following education, patients experienced significant improvement in the frequency of Anxiety, Treatment Problems, Depression, and Life Disruption (p less than or equal to 0.1) compared to a control group. Following participation in peer support groups, patients showed no improvement in any of 10 areas of life functioning. Thus education represents an effective, efficient, and inexpensive means of improving psychological and social behavior in patients with Hodgkin's disease. Participation in this peer support therapy group did not result in significant behavior change.

The first comprehensive analytical procedures for the quantitative analysis of N-nitroso compounds are described. The scheme divides N-nitroso compounds into four major, overlapping categories: volatile (Class I), non-volatile, low polarity (Class II), non-volatile, non-ionic, high polarity (Class III) and non-volatile, ionic, high polarity (Class IV). Existing analytical techniques for each class of compound are integrated into an organized and logical sequence of analysis to allow all classes of compounds to be determined. TEA-GC is used for the volatile compounds and TEA-HPLC for the non-volatile. It is emphasized that the coincidence of retention time in either TEA-GC alone or TEA-HPLC alone cannot be taken as sufficient evidence for the identification of N-nitroso compounds, especially for samples from complex matrices. Independent techniques are required to confirm these results. The confirmatory techniques used frequently in our laboratory are: (1) spectroscopic analysis (IR, NMR, UV and MS), (2) formation and identification of derivatives, and (3) parallel TEA-GC/TEA-HPLC techniques. These procedures are now used at Thermo Electron for the comprehensive screening of environmental samples.

The ability to make a prenatal diagnosis of Meckel syndrome (encephalocele, polydactyly, and polycystic kidney) by ultrasound is described. Three cases are detailed; in 2 of these the diagnosis was made at 18 and 36 weeks' gestation, respectively. In case 1 Meckel syndrome was identified by the presence of oligohydramnios, microcephaly, and enlarged cerebral ventricles. In case 2 oligohydramnios was associated with an encephalocele, bilateral renal enlargement, and a polydactyly. In case 3 the diagnosis was excluded in a fetus at risk. The usefulness of ultrasound in making this diagnosis is discussed for cases in which the amniotic fluid alpha-fetoprotein value is normal, inconclusive, or unobtainable.

Five experiments were conducted to determine the biological availability of the Ca in high-Ca (calcitic) limestone, dolomitic limestone, oyster shell flour, gypsum, marble dust and aragonite for the growing pig, and to determine the influence of particle size of the Ca source on the bioavailability of Ca. A low-Ca, fortified, corn soybean meal basal diet calculated to contain .2% Ca and .6% P was used. This diet was supplemented with 0 or .3% Ca from either CaCO3 precipitate (the standard) or the test source of Ca. Diets were fed on an ad libitum basis to three to eight replicate pens of pigs (one or two/pen) for 35 to 42 d. Average initial weight of the pigs was 15 kg. At the end of each experiment the pigs were killed, the third and fourth metacarpals and metatarsals and the femurs were removed, and breaking strength and ash were determined. The increase in bone strength from feeding the test source of Ca relative to the increase in bone strength from feeding the CaCO3 standard was used to calculate the relative availability of Ca in the supplements. The bioavailability of Ca in calcitic limestone (two sources), oyster shell flour, gypsum, marble dust and aragonite was similar, ranging from 93 to 102%. However, the Ca in two sources of dolomitic limestone was less available (51 and 78%) than in the other sources. Particle size of the Ca sources (geometric mean diameter of .10 to .54 mm) did not influence the availability of Ca.