Correction: Band gap modification and photoluminescence enhancement of graphene nanoribbon filled single-walled carbon nanotubes.

Correction for 'Band gap modification and photoluminescence enhancement of graphene nanoribbon filled single-walled carbon nanotubes' by A. I. Chernov et al., Nanoscale, 2018, DOI: 10.1039/c7nr07054c.

Band gap modification and photoluminescence enhancement of graphene nanoribbon filled single-walled carbon nanotubes.

Molecule encapsulation inside the single-walled carbon nanotube (SWCNT) core has been demonstrated to be a successful route for the modification of nanotube properties. SWCNT diameter-dependent filling results in band gap modification together with the enhancement of photoluminescence quantum yield. However, the interaction between the inner structure and the outer shell is complex. It depends on the orientation of the molecules inside, the geometry of the host nanotube and on several other mechanisms determining the resulting properties of the hybrid nanosystem. In this work we study the influence of encapsulated graphene nanoribbons on the optical properties of the host single-walled carbon nanotubes. The interplay of strain and dielectric screening caused by the internal environment of the nanotube affects its band gap. The photoluminescence of the filled nanotubes becomes enhanced when the graphene nanoribbons are polymerized inside the SWCNTs at low temperatures. We show a gradual photoluminescence quenching together with a selective signal enhancement for exact nanotube geometries, specifically (14,6) and (13,8) species. A precise adjustment of the optical properties and an enhancement of the photoluminescence quantum yield upon filling for nanotubes with specific diameters were assigned to optimal organization of the inner structures.

Atomic-Resolution STEM Imaging of Graphene at Low Voltage of 30 kV with Resolution Enhancement by Using Large Convergence Angle.

Atomic resolution at a low accelerating voltage with aberration correction is required to reduce the electron irradiation damage in scanning transmission electron microscopy imaging. However, the reduction in resolution caused by the diffraction limit becomes severe with increasing electron wavelength at low accelerating voltages. The developed aberration corrector can compensate for higher-order aberration in scanning transmission electron microscopy to expand the uniform phase angle. The resolution for imaging graphene at 30 kV is evaluated by changing the convergence angle for a probe-forming system with a higher-order aberration corrector. A single-carbon atom on graphene is successfully imaged at atomic resolution with a cold-field emission gun by dark-field imaging at an accelerating voltage of 30 kV.

Capturing the signature of single atoms with the tiny probe of a STEM.

With their first scanning transmission electron microscope (STEM), Albert Crewe and his collaborators have succeeded 40 years ago in bringing to reality a dream for all electron microscopists, to see individual atoms. In the derivation of Crewe's pioneering work, the present review describes various historical and present steps, involving continuous instrumental and methodological developments as well as the preparation of suitable specimens. They have lead to the identification of individual atoms by electron energy-loss spectroscopy (EELS) and to the demonstration of atom-by-atom spectroscopy. Beyond these spectacular successes which open wide fields of use, most recent technical achievements, such as the introduction of monochromators on the incident electron beam or of optical spectrometers for recording spectra (in the visible as well as in the X-ray domain), will undoubtedly lead to refine the accessible signature of single atoms and molecules.

Large intrinsic energy bandgaps in annealed nanotube-derived graphene nanoribbons.

The usefulness of graphene for electronics has been limited because it does not have an energy bandgap. Although graphene nanoribbons have non-zero bandgaps, lithographic fabrication methods introduce defects that decouple the bandgap from electronic properties, compromising performance. Here we report direct measurements of a large intrinsic energy bandgap of approximately 50 meV in nanoribbons (width, approximately 100 nm) fabricated by high-temperature hydrogen-annealing of unzipped carbon nanotubes. The thermal energy required to promote a charge to the conduction band (the activation energy) is measured to be seven times greater than in lithographically defined nanoribbons, and is close to the width of the voltage range over which differential conductance is zero (the transport gap). This similarity suggests that the activation energy is in fact the intrinsic energy bandgap. High-resolution transmission electron and Raman microscopy, in combination with an absence of hopping conductance and stochastic charging effects, suggest a low defect density.

Long-term outcome of transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head in patients with systemic lupus erythematosus.

This study sought to examine the long-term outcomes of transtrochanteric anterior rotational osteotomy (ARO) as treatment for osteonecrosis of the femoral head (ONFH) in patients with systemic lupus erythematosus (SLE). Twenty-one patients (33 hips), aged 20-40 years, underwent ARO between 1980 and 1988. We examined 16 patients (25 hips), a 76% follow-up rate. A Kaplan-Meier curve was used for survivorship analysis. Patients with surviving hips were evaluated by the modified Oxford hip score and Short Form 36 (SF-36). Twelve hips in eight patients had survived at the final follow-up. The average length of hip survival was 24.6 years (range: 20.1-27.2 years). Three patients (six hips) had died of unrelated causes without any subsequent operation. Based on Kaplan-Meier analysis with the endpoint defined as the need for a subsequent operation, the hip survival rate at 25 years was 73.7% (95% confidence interval, +/-19.8%). Based on classification by the modified Oxford hip score, five hips were classified as excellent, two hips were good, and the remaining five hips were fair. The average SF-36 summary score for the physical and mental components was 38.7 and 47.2 points, respectively. The physical component summary scores for three patients exceeded the normal level of the Japanese population. Lupus (2010) 19, 860-865.

In-situ formation of sandwiched structures of nanotube/CuxOy/Cu composites for lithium battery applications.

Development of materials and structures leading to lithium ion batteries with high energy and power density is a major requirement for catering to the power needs of present day electronic industry. Here, we report an in situ formation of a sandwiched structure involving single-walled carbon nanotube film, copper oxide, and copper during the direct synthesis of nanotube macrofilms over copper foils and their electrochemical performance in lithium ion batteries. The sandwiched structure showed a remarkably high reversible capacity of 220 mAh/g at a high cycling current of 18.6 A/g (50 C), leading to a significantly improved electrochemical performance which is extremely high compared to pure carbon nanotube and any other carbon based materials.

Screening the missing electron: nanochemistry in action.

The excitement of nano-test-tube chemistry in a single-walled carbon nanotube is exemplified in our study on electron doping in carbon nanotubes. Electron doping through the 1D van Hove singularity of single-walled carbon nanotubes is realized via a chemical reaction of an encapsulated organocerium compound, CeCp3. The decomposition of CeCp3 inside the carbon nanotubes increases the doping level and greatly enhances the density of conduction electrons. The transition of the cerium encapsulating semiconducting tubes to metallic results in enhanced screening of the photoexcited core hole potential. This fact illustrates the importance of many body effects in understanding core-level excitation process in carbon nanotubes.

Pressure-induced enhancement of giant magnetoresistance due to crossover of interlayer exchange coupling in Fe/Cr multilayers.

We report the first observation of a large pressure-induced enhancement of giant magnetoresistance (GMR) in magnetic multilayers (MML). In Fe/Cr MMLs with the Cr layer thickness of approximately 30 A, a crossover from biquadratic to bilinear interlayer exchange coupling (IEC) was observed by applying pressure, and simultaneously the GMR under high pressure (>2 GPa) was enhanced to be twice as large as that at ambient pressure. The enhanced GMR is attributed to the suppression of the biquadratic IEC by applying pressure, and the electrical resistivity in parallel alignment of magnetization also showed a crossover behavior, suggesting an electronic origin for the observed pressure effects.

Prospective evaluation of contrast-enhanced ultrasonography with advanced dynamic flow for the diagnosis of intestinal ischaemia.

This study aims to prospectively evaluate the importance of contrast-enhanced ultrasonography with advanced dynamic flow in the diagnosis of intestinal ischaemia in bowel obstruction. 50 patients admitted for bowel obstruction were included in this study. Of these, 17 patients had intestinal ischaemia (bowel strangulation, nine; superior mesenteric artery thromboembolism, four; non-occlusive mesenteric ischaemia, four), whereas 33 patients had simple obstructions. The definitive diagnosis of intestinal ischaemia was established by surgery. After administration of SHU 508A, the least peristaltic and/or the most dilated segments were imaged by this method. Colour signals depicted in the bowel wall were classified as normal, diminished or absent. The ultrasonographic findings were later correlated with the clinical outcomes and surgical findings. The colour signals were absent in 12 patients (bowel strangulation, six; superior mesenteric artery thromboembolism, four; non-occlusive mesenteric ischaemia, two), were diminished in four patients (bowel strangulation, two; non-occlusive mesenteric ischaemia, two) and were normal in 34 patients (simple obstruction, 33; bowel strangulation, one). Assuming that the diminished and absent colour signals indicate the presence of intestinal ischaemia, the sensitivity, specificity, positive predictive value and negative predictive value of the method were 94.1%, 100%, 100% and 97.1%, respectively. Our preliminary experience suggests that contrast-enhanced ultrasonography with advanced dynamic flow is a highly sensitive method for the diagnosis of intestinal ischaemia in patients with bowel obstruction.

Characterization of genetic loci conferring adult plant resistance to leaf rust and stripe rust in spring wheat.

Leaf (brown) and stripe (yellow) rusts, caused by Puccinia triticina and Puccinia striiformis, respectively, are fungal diseases of wheat (Triticum aestivum) that cause significant yield losses annually in many wheat-growing regions of the world. The objectives of our study were to characterize genetic loci associated with resistance to leaf and stripe rusts using molecular markers in a population derived from a cross between the rust-susceptible cultivar 'Avocet S' and the resistant cultivar 'Pavon76'. Using bulked segregant analysis and partial linkage mapping with AFLPs, SSRs and RFLPs, we identified 6 independent loci that contributed to slow rusting or adult plant resistance (APR) to the 2 rust diseases. Using marker information available from existing linkage maps, we have identified additional markers associated with resistance to these 2 diseases and established several linkage groups in the 'Avocet S' x 'Pavon76' population. The putative loci identified on chromosomes 1BL, 4BL, and 6AL influenced resistance to both stripe and leaf rust. The loci on chromosomes 3BS and 6BL had significant effects only on stripe rust, whereas another locus, characterized by AFLP markers, had minor effects on leaf rust only. Data derived from Interval mapping indicated that the loci identified explained 53% of the total phenotypic variation (R2) for stripe rust and 57% for leaf rust averaged across 3 sets of field data. A single chromosome recombinant line population segregating for chromosome 1B was used to map Lr46/Yr29 as a single Mendelian locus. Characterization of slow-rusting genes for leaf and stripe rust in improved wheat germplasm would enable wheat breeders to combine these additional loci with known slow-rusting loci to generate wheat cultivars with higher levels of slow-rusting resistance.

Quantitative trait Loci mapping for adult-plant resistance to powdery mildew in bread wheat.

ABSTRACT Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a major disease to wheat (Triticum aestivum) worldwide. Use of adult-plant resistance (APR) is an effective method to develop wheat cultivars with durable resistance to powdery mildew. In the present study, 432 molecular markers were used to map quantitative trait loci (QTL) for APR to powdery mildew in a doubled haploid (DH) population with 107 lines derived from the cross Fukuho-komugi x Oligoculm. Field trials were conducted in Beijing and Anyang, China during 2003-2004 and 2004-2005 cropping seasons, respectively. The DH lines were planted in a randomized complete block design with three replicates. Artificial inoculation was carried out in Beijing with highly virulent isolate E20 of B. graminis f. sp. tritici and the powdery mildew severity on penultimate leaf was evaluated four times, and the maximum disease severity (MDS) on penultimate leaf was investigated in Anyang under natural inoculation in May 2004 and 2005. The heritability of resistance to powdery mildew for MDS in 2 years and two locations ranged from 0.82 to 0.93, while the heritability for area under the disease progress curve was between 0.84 and 0.91. With the method of composite interval mapping, four QTL for APR to powdery mildew were detected on chromosomes 1AS, 2BL, 4BL, and 7DS, explaining 5.7 to 26.6% of the phenotypic variance. Three QTL on chromosomes 1AS, 2BL, and 7DS were derived from the female, Fukuho-komugi, while the one on chromosome 4BL was from the male, Oligoculm. The QTL on chromosome 1AS showed high genetic effect on powdery mildew resistance, accounting for 19.5 to 26.6% of phenotypic variance across two environments. The QTL on 7DS associated with the locus Lr34/Yr18, flanked by microsatellite Xgwm295.1 and Ltn (leaf tip necrosis). These results will benefit for improving powdery mildew resistance in wheat breeding programs.

A trial for histopathological subclassification of papillary cystadenoma lymphomatosum by 99Tcm-pertechnetate in a patient with multiple bilateral lesions of the parotid glands.

OBJECTIVES: The purpose of this report was to evaluate the possibility of subclassification of papillary cystadenoma lymphomatosum (PCL) with 99Tc(m)-pertechnetate. METHODS: A patient with multiple bilateral PCLs in the parotid glands was examined by using 99Tc(m)-pertechnetate. RESULTS: All PCLs of the present case, which were diagnosed as the subtype-II histopathologically, showed similar radioactive indexes in scintigraphy (the mean radioactive index = 3.62), although tumours were different in size. The mean radioactive index corresponded well with that from four cases of subtype-II of our previous report (the mean radioactive index = 3.84). CONCLUSIONS: The results of the present report suggest a possibility of histopathological subclassification of PCLs into subtypes by 99Tc(m)-pertechnetate scintigraphy.

Direct imaging of Sc2@C84 molecules encapsulated inside single-wall carbon nanotubes by high resolution electron microscopy with atomic sensitivity.

Intramolecular structure of the scandium dimetallofullerene (Sc(2)@C(84)) has been clearly revealed by high resolution transmission electron microscopy with the single-atom sensitivity. Direct observation of two Sc atoms inside each fullerene molecule has led to a successful determination of the molecular symmetry among the three possible structural isomers for the Sc(2)@C(84). The present work introduces a new electron microscopic approach to investigate individual molecular structures and demonstrates the possibility for determining the molecular isomer on a single-molecular basis.

Microsatellite markers for genes lr34/yr18 and other quantitative trait Loci for leaf rust and stripe rust resistance in bread wheat.

ABSTRACT Leaf rust and stripe rust, caused by Puccinia triticina and P. striiformis, respectively, are important diseases of wheat in many countries. In this study we sought to identify molecular markers for adult plant resistance genes that could aid in incorporating such durable resistance into wheat. We used a doubled haploid population from a Japanese cv. Fukuho-komugi x Israeli wheat Oligoculm cross that had segregated for resistance to leaf rust and stripe rust in field trials. Joint and/or single-year analyses by composite interval mapping identified two quantitative trait loci (QTL) that reduced leaf rust severity and up to 11 and 7 QTLs that might have influenced stripe rust severity and infection type, respectively. Four common QTLs reduced stripe rust severity and infection type. Except for a QTL on chromosome 7DS, no common QTL for leaf rust and stripe rust was detected. QTL-7DS derived from 'Fukuho-komugi' had the largest effect on both leaf rust and stripe rust severities, possibly due to linked resistance genes Lr34/Yr18. The microsatellite locus Xgwm295.1, located almost at the peak of the likelihood ratio contours for both leaf and stripe rust severity, was closest to Lr34/Yr18. QTLs located on 1BL for leaf rust severity and 3BS for stripe rust infection type were derived from 'Oligoculm' and considered to be due to genes Lr46 and Yr30, respectively. Most of the remaining QTLs for stripe rust severity or infection type had smaller effects. Our results indicate there is significant diversity for genes that have minor effects on stripe rust resistance, and that successful detection of these QTLs by molecular markers should be helpful both for characterizing wheat genotypes effectively and combining such resistance genes.

Linking chiral indices and transport properties of double-walled carbon nanotubes.

We performed in situ transport measurements in a transmission-electron microscope (TEM) on individual double-walled carbon nanotubes (DWNT). Using selected-area electron diffraction, the chiral indices of the two tubes constituting the DWNTs were determined through careful comparison with theory. We discuss the case of a DWNT whose two tubes have a gap at half filling and show a finite density of delocalized state at the Fermi level. The exact determination of chiral indices should be reachable in any transport-measurement experiment with samples that allow TEM characterization.

Cross-linked nano-onions of carbon nitride in the solid phase: existence of a novel C(48)N(12) aza-fullerene.

We report a new fullerenelike material consisting of cross-linked nano-onions of C and N. Growth of the onion shells takes place atom by atom on a substrate surface and yields thin solid films during magnetron sputter deposition. Electron microscopy and energy loss spectroscopy show that the core shell contains up to 20 at. % N corresponding to C(48)N(12) aza-fullerene composition. Nanoindentation of this nanostructured material gives high resilience with hardness 7 GPa, Young's modulus 37 GPa, and complete elastic recovery after loading with 0.5 mN to a depth of 75 nm. Total energy calculations show the stability of C(60-2n)N(2n) aza-fullerenes and suggest the existence of a novel C(48)N(12) molecule.

Long-term low-dose acyclovir against varicella-zoster virus reactivation after allogeneic hematopoietic stem cell transplantation.

To evaluate the efficacy of long-term administration of acyclovir as prophylaxis against varicella-zoster virus (VZV) reactivation, we analyzed the medical records of 86 consecutive adult patients who obtained engraftment after allogeneic hematopoietic stem cell transplantation from January 1996 to March 2000. We started long-term low-dose (400 mg/day) oral administration of acyclovir in June 1999, and this was continued until the end of immunosuppressive therapy after transplantation. There was no breakthrough reactivation of VZV in patients receiving acyclovir. Five patients who were receiving cyclosporine or prednisolone developed VZV reactivation after discontinuing acyclovir. With this prophylaxis, the cumulative incidence of VZV reactivation at 1 year after transplantation decreased from 33% to 10% (P = 0.025). On multivariate analysis, the use of long-term acyclovir was identified as a significant independent parameter for the development of VZV reactivation. These findings suggest the efficacy of long-term prophylaxis with low-dose acyclovir. Resumption of acyclovir upon restarting immunosuppressive therapy might be important for the further prevention of VZV reactivation. The benefit of long-term low-dose acyclovir should be confirmed prospectively.