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We report directly grown strongly adherent graphene on Co3O4(111) by carbon molecular beam epitaxy (C MBE) at 850 K and density functional theory (DFT) findings that the first graphene layer is reconstructed to fit the Co3O4 surface, while subsequent layers retain normal graphene structure. This adherence to the Co3O4 structure results from partial bonding of half the carbons to top oxygens of the substrate. This structure is validated by X-ray photoelectron spectroscopy and low-energy electron diffraction studies, showing layer-by-layer graphene growth with ∼0.08 electrons/carbon atom transferred to the oxide from the first graphene layer, in agreement with DFT. In contrast, for Cr2O3 DFT finds no strong bonding to the surface and C MBE on Cr2O3(0001) yields only graphite formation at 700 K, with C desorption above 800 K. Thus strong graphene-to-oxide charge transfer aids nucleation of graphene on incommensurate oxide substrates and may have implications for spintronics.

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The direct growth of hexagonal boron nitride (h-BN) by industrially scalable methods is of broad interest for spintronic and nanoelectronic device applications. Such applications often require atomically precise control of film thickness and azimuthal registry between layers and substrate. We report the formation, by atomic layer epitaxy (ALE), of multilayer h-BN(0001) films (up to 7 monolayers) on Co(0001). The ALE process employs BCl3/NH3 cycles at 600 K substrate temperature. X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED) data show that this process yields an increase in h-BN average film thickness linearly proportional to the number of BCl3/NH3 cycles, with BN layers in azimuthal registry with each other and with the Co(0001) substrate. LEED diffraction spot profile data indicate an average BN domain size of at least 1900 Å. Optical microscopy data indicate the presence of some domains as large as ∼20 µm. Transmission electron microscopy (TEM) and ambient exposure studies demonstrate macroscopic and microscopic continuity of the h-BN film, with the h-BN film highly conformal to the Co substrate. Photoemission data show that the h-BN(0001) film is p-type, with band bending near the Co/h-BN interface. Growth of graphene by molecular beam epitaxy (MBE) is observed on the surface of multilayer h-BN(0001) at temperatures of 800 K. LEED data indicate azimuthal graphene alignment with the h-BN and Co(0001) lattices, with domain size similar to BN. The evidence of multilayer BN and graphene azimuthal alignment with the lattice of the Co(0001) substrate demonstrates that this procedure is suitable for scalable production of heterojunctions for spintronic applications.

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Autism spectrum disorder (ASD) is a neurodevelopmental disorder that impacts communicative interactions, with patterns of repetitive and restricted behaviors, interests, and cognitive rigidity. Recent incidence rate estimates for ASD are 1 in 68, and primarily male (4:1). A major epidemiological issue in ASD is transitioning to independence in adulthood, particularly navigating the healthcare system. This commentary will focus on approaches healthcare providers can use to not overlook and support individuals with ASD.

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OBJECTIVE: The purpose of this study was to reveal the effectiveness of non-thermal atmospheric plasma brush in surface wettability and modification of four dental substrates. METHODS: Specimens of dental substrates including dentin, enamel, and two composites Filtek Z250, Filtek LS Silorane were prepared (∼2mm thick, ∼10mm diameter). The prepared surfaces were treated for 5-45s with a non-thermal atmospheric plasma brush working at temperatures from 36 to 38°C. The plasma-treatment effects on these surfaces were studied with contact-angle measurement, X-ray photoemission spectroscopy (XPS) and scanning electron microscopy (SEM). RESULTS: The non-thermal atmospheric argon plasma brush was very efficient in improving the surface hydrophilicity of four substrates studied. The results indicated that water contact angle values decreased considerably after only 5s plasma treatment of all these substrates. After 30s treatment, the values were further reduced to <5°, which was close to a value for super hydrophilic surfaces. XPS analysis indicated that the percent of elements associated with mineral in dentin/enamel or fillers in the composites increased. In addition, the percent of carbon (%C) decreased while %O increased for all four substrates. As a result, the O/C ratio increased dramatically, suggesting that new oxygen-containing polar moieties were formed on the surfaces after plasma treatment. SEM surface images indicated that no significant morphology change was induced on these dental substrates after exposure to plasmas. SIGNIFICANCE: Without affecting the bulk properties, a super-hydrophilic surface could be easily achieved by the plasma brush treatment regardless of original hydrophilicity/hydrophobicity of dental substrates tested.

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The electronic and chemical structure of the metal-to-semiconductor interface was studied by photoemission spectroscopy for evaporated Cr, Ti, Al and Cu overlayers on sputter-cleaned as-deposited and thermally treated thin films of amorphous hydrogenated boron carbide (a-B(x)C:H(y)) grown by plasma-enhanced chemical vapor deposition. The films were found to contain ~10% oxygen in the bulk and to have approximate bulk stoichiometries of a-B(3)CO(0.5):H(y). Measured work functions of 4.7/4.5 eV and valence band maxima to Fermi level energy gaps of 0.80/0.66 eV for the films (as-deposited/thermally treated) led to predicted Schottky barrier heights of 1.0/0.7 eV for Cr, 1.2/0.9 eV for Ti, 1.2/0.9 eV for Al, and 0.9/0.6 eV for Cu. The Cr interface was found to contain a thick partial metal oxide layer, dominated by the wide-bandgap semiconductor Cr(2)O(3), expected to lead to an increased Schottky barrier at the junction and the formation of a space-charge region in the a-B(3)CO(0.5):H (y) layer. Analysis of the Ti interface revealed a thick layer of metal oxide, comprising metallic TiO and Ti (2)O (3), expected to decrease the barrier height. A thinner, insulating Al(2)O(3) layer was observed at the Al-to-a-B(3)CO(0.5):H(y) interface, expected to lead to tunnel junction behavior. Finally, no metal oxides or other new chemical species were evident at the Cu-to-a-B(3)CO(0.5):H(y) interface in either the core level or valence band photoemission spectra, wherein characteristic metallic Cu features were observed at very thin overlayer coverages. These results highlight the importance of thin-film bulk oxygen content on the metal-to-semiconductor junction character as well as the use of Cu as a potential Ohmic contact material for amorphous hydrogenated boron carbide semiconductor devices such as high-efficiency direct-conversion solid-state neutron detectors.

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Magic angle spinning solid-state nuclear magnetic resonance spectroscopy techniques are applied to the elucidation of the local physical structure of an intermediate product in the plasma-enhanced chemical vapour deposition of thin-film amorphous hydrogenated boron carbide (B(x)C:H(y)) from an orthocarborane precursor. Experimental chemical shifts are compared with theoretical shift predictions from ab initio calculations of model molecular compounds to assign atomic chemical environments, while Lee-Goldburg cross-polarization and heteronuclear recoupling experiments are used to confirm atomic connectivities. A model for the B(x)C:H(y) intermediate is proposed wherein the solid is dominated by predominantly hydrogenated carborane icosahedra that are lightly cross-linked via nonhydrogenated intraicosahedral B atoms, either directly through B-B bonds or through extraicosahedral hydrocarbon chains. While there is no clear evidence for extraicosahedral B aside from boron oxides, ∼40% of the C is found to exist as extraicosahedral hydrocarbon species that are intimately bound within the icosahedral network rather than in segregated phases.

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AIM: This study investigates differences in bacterial growth response in broth amended with compost-substrate extracts periodically bypassed during broiler litter composting. METHODS AND RESULTS: Compost samples, suspended in diluent were mixed with double strength broth into which ampicillin selective (0.3 g l(-1)) Escherichia coli and E. faecalis were separately seeded. Growth was measured by viable cell count. The Levenberg-Marquardt algorithm was applied to obtain a four-parameter sigmoidal function that best described the diminishing height transitions of the curves for extracts of increasing composting age. The time course of the growth rate followed a unimodal bell-shaped curve. The Microfit application was run to generate information of direct microbiological interest: increasing lambda and decreasing mu(max) for both bacteria with time. CONCLUSION: More than the curve-fitting process, the Unified model option of the Microfit application has confirmed the significant differences (P < 0.05) in the growth curve behaviour with more stabilized substrate extracts. The study demonstrates further scopes for characterization of the sanitization potential and indirectly, the impact of indigenous microbial competitive exclusion effects on enteric bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: A different outlook to understanding faecal bacterial growth dynamics in compost has been presented, using predictive microbiology concepts. Further structured studies are needed to fine-tune the generality of the findings for model development.

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AIMS: The objective of this study was to deduce and analyse equations that best describe the behaviour of faecal bacterial indicators and two decomposition parameters during broiler litter composting. Mathematical models were fitted and the order of rate equations were identified. METHODS AND RESULTS: The Levenburg-Marquardt algorithm was used to fit nonlinear mathematical models to total coliforms (TC), faecal coliforms (FC), Escherichia coli (EC), faecal enterococci (FE), organic-C and volatile solids reduction, VS Red, by the least squares procedure. The rate equations showed that TC, FC and EC reductions were expressed by second-order decay kinetics. FE reduction followed first-order decay. Temperature dependency of decomposition rate was effectively verified by applying empirically derived rate equations. CONCLUSIONS: The governing mathematical models critically compare the inactivation kinetics of faecal indicators. TC, FC and EC were rapidly destroyed while FE was more resistant. Temperature elevation, organic-C and VS Red dynamics provide an accurate understanding of composting-induced decomposition of the broiler litter. SIGNIFICANCE AND IMPACT OF THE STUDY: The conservative performance of FE with respect to the other indicators has been established. Hence, FE presents better opportunities to encompass the totality of the composting process in terms of attainment of hygiene efficacy compared with EC.

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A technique is described that allows the staining and subsequent visualization of polymers that contain the phosphorylcholine (PC) group. These materials are useful as bulk materials or coatings for the fabrication of medical devices. The staining method employs rhodamine 6G, which can be simply and rapidly applied to the polymer coating and imaged using fluorescence microscopy. The specificity of the staining for the PC polymers makes this technique suitable for the evaluation of a wide range of substrates and provides qualitative information on coating uniformity, coverage and morphology. It can be used to examine the durability of, and defects in, the coating. Statistical analysis of the fluorescent intensity by measuring the pixel value during imaging can allow for the method to be used as a quality control tool.

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Anti-biofouling polymers containing phosphorylcholine (PC)-substituted methacrylate units have been prepared by copolymerization with dodecyl methacrylate and used to coat luminescent oxygen sensors. Nanometer-sized coatings of such materials are shown to reduce significantly the adhesion of marine bacteria (more than 70%) and thrombocytes (more than 90%) to the surface of tris-(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)-doped silicone layers. A thorough analytical characterization of both the PC-coated and the uncoated dyed films has demonstrated that the anti-biofouling layers do not alter dramatically the performance of the fiber-optic oxygen sensors in aqueous media and are mechanically stable for more than one year of continuous immersion. The slope of the linear calibration plots in the 0-8 mg L(-1) oxygen concentration range (ca. 1.0 L mg(-1)) decreases 8-11% after applying the 50-nm protective layer with no change in the sensor precision (1.1-1.9% RSD, n = 6). The response time of the 200-microm O2-sensitive layers (1.5-6 min) increases up to 2-fold, depending on the nature of the PC polymer used, but the temperature effect on the sensor response (0.020 L mg(-1) degrees C(-1)) remains essentially unchanged. Oxygen detection limits as low as 0.04 mg L(-1) have been measured with the coated optodes. The novel biofouling-resistant optosensors have been successfully validated against a commercial oxygen electrode and are shown to respond faster than the electrochemical device for large oxygen concentration changes. The biomimetic coatings will be particularly useful for drift-free long-term operation of environmental optosensors and in vivo fiber-optic oxygen analyzers.

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Unwanted interactions of biomedical sensors with surrounding tissues, body fluids, and cells are one of the most crucial problems affecting their long-term stability. In vivo processes were simulated in a computer-controlled bioreactor connected to a flow chamber system. Optical sensor materials were inserted into a parallel-plate chamber and monitored by light microscopy in order to get information about the number of adhered cells. Tests with thrombocyte-enriched plasma show that novel phosphorylcholine (PC)-polymer-coated sensors appear to be more bioinert, and thus demonstrate better haemocopatibility in comparison with untreated glass sensors. The influence of different materials on the morphology of adhered cells was investigated by off-line methods such as scanning electron microscopy (SEM) and atomic-force microscopy (AFM). SEM showed a reduction in the number of adhered thrombocytes and the lack of any fibrin network on the PC-polymer-modified glass surface, in contrast to the pure glass surface. AFM gives topographical information, and the calculated contact areas and cell volumes indicate smaller interactions between cells and sensor material in the case of PC-polymer-coated sensors.

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PURPOSE: This study evaluated long-term results in patients who had ossicular reconstruction with a Goldenberg hydroxylapatite implant. METHODS: A total of 233 patients underwent implantation; of these, 77 had 5-year or longer follow-up and are the subjects of this study of long-term hearing results. All 233 patients were included for analysis of extrusion rate and postoperative otorrhea. RESULTS: The hearing success rate at long-term follow-up was 56.8%; the mean air-bone gap was 21.1 dB. Prosthesis extrusion occurred in 5.29% of the 233 patients, and visible slippage occurred in 7.7%. Overall, 50. 6% of patients met the criteria for successful hearing, which included no extrusion and a dry ear. Better hearing before surgery and presence of the malleus long process were factors associated with a successful hearing result, as was tympanoplasty alone and canal wall up tympanomastoidectomy. CONCLUSION: Hydroxylapatite hybrid prostheses provide stable hearing results over time with low extrusion and a dry ear overall.

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Delavirdine is a nonnucleoside reverse transcriptase inhibitor with in vitro activity against human immunodeficiency virus type 1 (HIV-1) that is currently being evaluated in combination regimens with various nucleoside analogs, including didanosine. Due to the pH-dependent solubility of delavirdine, the buffering agents in didanosine formulations may reduce delavirdine absorption. To evaluate the potential interaction between these agents, 12 HIV-infected patients (mean [+/- standard deviation] CD4+ cell count, 304 +/- 213/mm3) were enrolled in a three-way crossover single-dose study. Didanosine (125 to 200 mg given as buffered tablets) and delavirdine mesylate (400 mg) pharmacokinetics were evaluated when each drug was given alone (treatments A and B, respectively), when the two drugs were given concurrently (treatment C), and when didanosine was given 1 h after delavirdine (treatment D). Delavirdine exposure was reduced by concurrent administration of didanosine. The maximum drug concentration in serum (Cmax) was reduced from 7.22 +/- 4.0 to 3.51 +/- 1.9 microM, and the area under the concentration-time curve from 0 h to infinity (AUC0-->infinity) was reduced from 22.5 +/- 14 to 14 +/- 5.7 microM.h. The extent of N-dealkylation, as indicated by the ratio of the N-dealkylated delavirdine AUC0-->infinity to the delavirdine AUC0-->infinity, was unchanged across study treatments (P = 0.708). Reductions in didanosine exposure were observed during concurrent administration with delavirdine with a Cmax reduction from 4.65 +/- 2.0 to 3.22 +/- 0.59 microM and an AUC0-->infinity reduction from 7.93 +/- 3.9 to 6.54 +/- 2.3 microM.h. Thus, concurrent administration of delavirdine and didanosine may reduce the AUC0-->infinity of both drugs, although the clinical significance of this reduction is unknown. Administration of delavirdine 1 h before didanosine avoided the interaction. Due to the single-dose nature of this study, these findings require further evaluation at steady state.

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Atevirdine is a nonnucleoside reverse transcriptase inhibitor with in vitro activity against human immunodeficiency virus type 1 and is currently in phase II clinical trials. Atevirdine is most soluble at a pH of < 2, and therefore, normal gastric acidity is most likely necessary for optimal bioavailability. Because of the rapid development of resistance in vitro, atevirdine is being evaluated in combination with didanosine and/or zidovudine in both two- and three-drug combination regimens. To examine the influence of concurrent didanosine (buffered tablet formulation) on the disposition of atevirdine, 12 human immunodeficiency virus type 1-infected subjects (mean CD4+ cell count, 199 cells per mm3; range, 13 to 447 cells/mm3) participated in a three-way, partially randomized, crossover, single-dose study to evaluate the pharmacokinetics of didanosine and atevirdine when each drug was given alone (treatments A and B, respectively) versus concurrently (treatment C). Concurrent administration of didanosine and atevirdine significantly reduced the maximum concentration of atevirdine in serum from 3.45 +/- 2.8 to 0.854 +/- 0.33 microM (P = 0.004). Likewise, the mean atevirdine area under the concentration-time curve from 0 to 24 h after administration of the combination was reduced to 6.47 +/- 2.2 microM.h (P = 0.004) relative to a value of 11.3 +/- 4.8 microM.h for atevirdine alone. Atevirdine had no statistically significant effect on the pharmacokinetic parameters of didanosine. Concurrent administration of single doses of atevirdine and didanosine resulted in a markedly lower maximum concentration of atevirdine in serum and area under the concentration-time curve, with a minimal effect on the disposition of didanosine. It is unknown whether an interaction of similar magnitude would occur under steady-state conditions; thus, combination regimens which include both atevirdine and didanosine should be designed so that their administration times are separated. Since the duration of the buffering effect of didanosine formulations is unknown, atevirdine should be given prior to didanosine.

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The effect of a high-fat meal and the timing of this meal on the absorption of a 400-mg oral dose of cefpodoxime proxetil was evaluated in 20 healthy, adult, male volunteers in a four-way crossover study. The area under the plasma concentration-time curve, peak plasma concentration, and urinary recovery were significantly greater (P = .0001) after administration of cefpodoxime proxetil tablets with and 2 hours after a meal relative to dosing under fasted conditions or 1 hour before a meal. The time to peak concentration did not differ significantly among treatments, which suggests that food did not affect the rate of drug absorption. These results indicate that absorption of cefpodoxime proxetil is enhanced when tablets are taken with food or shortly after a meal.

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Resected extrahepatic remnants taken at the time of portoenterostomy were examined in a single-center review of 205 cases of biliary atresia. The morphological features of the size and number of residual ducts at the porta hepatis and the degree of inflammation at the porta hepatis were analyzed using a semiquantitative scoring system. The morphology of the common hepatic and common bile duct was classified into seven types. These features were then related to age at time of initial surgery and to survival. This showed that few or absent ductal remnants at the porta hepatis and absence of portal inflammation were predictors of poor prognosis. These histological features may represent the "burnt out" end result of the disease process. There was no correlation between age at time of portoenterostomy and either portal duct patency or portal inflammation. The common hepatic and common bile duct were variably involved in the sclerosing process, but the patterns of obliteration were not indicative of prognosis. The severity of intrahepatic biliary cholangiopathy and the extent of liver damage may ultimately be more important to survival in the long term.

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Biliary atresia is an obliterative disorder of the bile ducts, causing obstructive jaundice in neonates. In this study, the developing biliary system of normal human embryos and fetuses was examined and compared with the resected extrahepatic biliary remnants from 205 cases of biliary atresia. At the porta hepatis level, it was found that the primary biliary ductal plate undergoes a specific sequence of remodelling, resulting in the formation of large tubular bile ducts surrounded by thick mesenchyme, between 11 and 13 weeks postfertilisation. These developing ducts are in luminal continuity with the extrahepatic biliary tree throughout gestation. Contrary to long-held belief, no "solid phase" was observed in the development of the extrahepatic bile duct. Examination of the biliary remnants in biliary atresia showed that the porta hepatis is encased in fibrous tissue, and a variable pattern of obliteration of the common hepatic and common bile ducts was observed. Anticytokeratin immunostaining showed similarities between the abnormal ductules within the porta hepatis in biliary atresia, and the developing bile ducts in the first trimester. Biliary atresia may be caused by failure of the remodelling process at the hepatic hilum, with persistence of fetal bile ducts poorly supported by mesenchyme. As bile flow increases perinatally, bile leakage from these abnormal ducts may trigger an intense inflammatory reaction, with subsequent obliteration of the biliary tree.

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A 14 year old girl with multiseptate gall bladder and cystic dilatation of the biliary tree is presented. This is the 20th published case report of patients with multiseptate gall bladder and only the second to be associated with a choledochal cyst. The cystic spaces of the gall bladder did not communicate with the neck of the gall bladder or the rest of the biliary tree, and this unusual feature has not been previously described. A multiseptate gall bladder with a normal biliary tree commonly causes symptoms suggestive of cholecystitis, although gall stones are seldom present. Diagnosis is confirmed by an oral cholecystogram or ultrasound scan that may show the fine intraluminal septae, and these features should be looked for in patients with biliary symptoms without biliary calculi. Cholecystectomy is curative for the isolated gall bladder anomaly but hepaticojejunostomy may be necessary for an associated choledochal cyst.

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Histological features in liver biopsy specimens taken from 71 infants at the time of surgery for biliary atresia (portoenterostomy) were analyzed using a scoring system and compared with an endoscopic grading of esophageal varices performed at a mean age of 3.4 years. The analysis showed no correlation between a "global" score, which represented the severity of all histological changes in the original biopsy specimen, and the severity of esophageal varices. Further analysis also showed no correlation with any individual histological feature (eg, fibrosis). These findings failed to confirm a previous study, which suggested a relationship between liver changes at surgery and the later development of esophageal varices in children with biliary atresia.

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Normal development of the human lower urinary tract was studied between the 14th and 20th week of gestation using 3 modes of fixation. Fixation by direct distension provides a high degree of reproducibility of parameters used to study the growth of the fetal bladder. Using this method, fetuses ranging from 12 to 21 weeks gestation were studied. Results obtained demonstrate that the length of the bladder, the inter-ureteric distance, and the distance between the apex of the trigone and the distal tip of the urethra occur in a linear mode. Furthermore, the rate of growth of the male urethra was evidently higher when compared to that of the female from the 12th week of gestation. Data from this work can be used for a more accurate assessment of cases with abnormal lower urinary tract development.

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