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InP(111) surfaces are sulfurized using vaporized Sb2S3 and Bi2S3 as the providers of S. Temperatures higher than 340 °C are required to substitute the Sb atoms in Sb2S3 with the In atoms from the s...

Andreev reflection can be forbidden by means of quantum interference when superconductors are attached at the side edges of graphene nanoribbons (GNRs). The blocking is restricted to single-mode nanoribbons having symmetric zigzag edges and is destroyed by the application of a magnetic field. These characteristics are shown to be the effects of the wavefunction parity on the Andreev retro and specular reflections. Not only the mirror symmetry of the GNRs but also symmetric coupling of the superconductors is required for the quantum blocking. The quasi-flat-band states around the Dirac point energy induced for armchair nanoribbons by adding carbon atoms at the nanoribbon edges do not cause the quantum blocking due to the lack of the mirror symmetry. Furthermore, the phase modulation by the superconductors is shown to be able to convert the quasi-flat dispersion for the edge states of zigzag nanoribbons to a quasi-vertical dispersion.

Narrow conduction channels are fabricated from an In0.75Ga0.25As-InP heterostructure using electron-beam lithography and dry etching. The etched surface is realized to be smooth by employing a reactive ion etching. The etching-induced surface conduction is eliminated by removing the damaged surface layer using a diluted HCl solution. The negligible surface depletion for the In-rich quantum well enables to create conducting channels in arbitrary geometries such as in a circular shape. We evidence the presence of a ballistic contribution in the electron transport by demonstrating a rectification of rf excitations that is achieved by the magnetic-field-tuned transmission asymmetry in the circularly-shaped channels. The absence of the surface depletion is shown to cause, on the other hand, a surface scattering for the electrons confined in the channels. An increase of the resistance, including its anomalous enhancement at low temperatures, is induced by the gas molecules attached to the sidewalls of the channels. We also report a large persistent photoconduction, which occurs as a parallel conduction in the undoped InP barrier layer.

Made available in DSpace on 2021-06-25T12:21:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 University of Texas Lung Cancer Specialized Programs of Research Excellence Foundation for the Support of Research of the State of Sao Paulo Context.-Identification of gene mutations that are indicative of epithelial-mesenchymal transition and a noninflammatory immune phenotype may be important for predicting response to immune checkpoint inhibitors. Objective.-To evaluate the utility of multiplex immunofluorescence for immune profiling and to determine the relationships among tumor immune checkpoint and epithelial-mesenchymal transition genomic profiles and the clinical outcomes of patients with nonmetastatic non-small cell lung cancer. Design.-Tissue microarrays containing 164 primary tumor specimens from patients with stages I to IIIA non-small cell lung carcinoma were examined by multiplex immunofluorescence and image analysis to determine the expression of programmed death ligand-1 (PD-L1) on malignant cells, CD68; macrophages, and cells expressing the immune markers CD3, CD8, CD57, CD45RO, FOXP3, PD-1, and CD20. Immune phenotype data were tested for correlations with clinicopathologic characteristics, somatic and germline genetic variants, and outcome. Results.-A high percentage of PD-L1(+) malignant cells was associated with clinicopathologic characteristics, and high density of CD3+PD-1(+) T cells was associated with metastasis, suggesting that these phenotypes may be clinically useful to identify patients who will likely benefit from immunotherapy. We also found that ZEB2 mutations were a proxy for immunologic ignorance and immune tolerance microenvironments and may predict response to checkpoint inhibitors. A multivariate Cox regression model predicted a lower risk of death for patients with a high density of CD3(+)CD45RO(+) memory T cells, carriers of allele G of CTLA4 variant rs231775, and those whose tumors do not have ZEB2 mutations. Conclusions.-Genetic variants in epithelial mesenchymal transition and immune checkpoint genes are associated with immune cell profiles and may predict patient outcomes and response to immune checkpoint blockade. Univ Texas MD Anderson Canc Ctr, Dept Translat Mol Pathol, 1515 Holcombe Blvd,Unit 951, Houston, TX 77030 USA Univ Sao Paulo, Fac Med, Dept Pathol & Lab Genom & Histomorphometry, Sao Paulo, SP, Brazil Univ Sao Paulo, Fac Med, Div Pneumol, Heart Inst Incor, Sao Paulo, Brazil Sao Paulo State Univ, Clin Hosp, Fac Med, Dept Oncol, Sao Paulo, Brazil AC Camargo Canc Ctr, Med Oncol Dept, Sa Paulo, Brazil AC Camargo Canc Ctr, Translat Immune Oncol Grp, Sa Paulo, Brazil Inst Canc Sao Paulo, Dept Thorac Surg, Sao Paulo, Brazil Heart Inst Incor, Dept Thorac Surg, Sao Paulo, Brazil Univ Sao Paulo, Ribeirao Preto Sch Med, Dept Pathol & Legal Med, Ribeirao Preto, Brazil Sao Paulo State Univ, Clin Hosp, Fac Med, Dept Oncol, Sao Paulo, Brazil University of Texas Lung Cancer Specialized Programs of Research Excellence: P50CA70907 Foundation for the Support of Research of the State of Sao Paulo: FAPESP 2013/14277-4 Foundation for the Support of Research of the State of Sao Paulo: FAPESP 2018-20403-6

Magnetotransport properties of zigzag and armchair graphene nanoribbons that are in contact with superconductors are investigated using a tight-binding model. The cyclotron orbital motion together with the quantum interference under the coexistence of Andreev and normal reflections gives rise to a number of oscillations in characteristic magnetic-field regimes when the superconducting coupling is weak. The oscillations become irregular and/or suppressed as the coupling is made strong. The period of the oscillations differs from that when a nonrelativistic two-dimensional electron gas is employed rather than the graphene sheet. The modifications of the oscillations are attributed to the phase shift associated with the reflection from the graphene–superconductor interface. The presence of a magnetic field suppresses the quantum blocking of Andreev transmission, which occurs for the edge mode of zigzag nanoribbons, in the same way regardless of it being induced by the Andreev retro- or specular reflection.

Bi2Te3 is deposited by hot wall epitaxy in an attempt to form nanosheets on epitaxially-grown ferromagnetic layers of Fe, Fe3Si and Co2FeSi. Bi2Te3 reacts strongly with pure Fe, producing FeTe2. The reaction is suppressed for silicides Fe3Si and Co2FeSi. For the latter, partial incorporation of Co into the Bi2Te3 islands occurs at high temperatures, causing magnetic doping of the topological insulator. Although (0001) remains to be the favored growth orientation on Fe3Si and Co2FeSi, non-(0001)-oriented three-dimensional islands dominantly coexist on these surfaces further strengthening the growth characteristic on GaAs and contrary to the overwhelming formation of the nanosheets on Si and SiO2. Deterioration of the magnetic properties of the ferromagnetic layers by heat treatment in the overgrowth is confirmed to be not significant. In addition, we show the surface plasmon emission in the visible energy range from the nanoislands. Finding the material combinations for which the overlayer-substrate reaction is circumvented opens the way to epitaxially create topological-insulator–ferromagnet multiple layer structures.

Fiber-like textures resulting from axiotaxy in BiTe films grown on InP(111) at high temperatures are investigated. Pole-figure measurements of X-ray diffraction reveal the axiotaxy being driven by the (10.4) plane of BiTe, whose d-spacing is nearly matched to that of the InP(11) plane. Coexistence of additional minor axiotaxy textures generated by other planes is also indicated. We provide transmission-electron-microscopy evidence of an epitaxy where the d-spacing is adjusted between the BiTe(10.8) and InP(11) planes by altering the local lattice periodicity. The alignment of the axiotaxy axis associated with the (10.4) plane is about 5° shifted from the InP〈11〉 direction towards the InP(111) plane, suggesting significant lattice distortions at the vicinity of the hetero-interface.

We report a case of axiotaxy that takes place in growing films of the thermoelectric and topological-insulator material Bi2Te3 on InP(111)B by hot wall epitaxy. The films become poly-crystalline with a Te deficiency when the substrate temperature is barely below the limit for film deposition. In addition to the usual epitaxial component, for which the (0001) plane of Bi2Te3 is parallel to the (111) plane of InP, fiber textures led by the Bi2Te3(1120) plane emerge. The fiber axes are aligned to the ⟨111⟩- and ⟨772⟩-type directions of InP. Although the d-spacing is matched at the heterointerface, it is accomplished by means of coincidence site lattices for the ⟨111⟩ alignment.

The phase transition near 40~$^{\circ }$C of both as-grown thin epitaxial MnAs films prepared by molecular beam epitaxy on GaAs(001) and nanometer-scale disks fabricated from the same films is studied. The disks are found to exhibit a pronounced hysteresis in the temperature curve of the phase composition. In contrast, supercooling and overheating take place far less in the samples of continuous layers. These phenomena are explained in terms of the necessary formation of nuclei of the other phase in each of the disks independent from each other. The influence of the elastic strains in the disks is reduced considerably.

We demonstrate that electrical charges are stored in the bilayer junctions of Al and Bi–Cu–S alloys. The junctions exhibit interfacial resistance switching, which is caused by a spontaneous production of high resistivity compounds at the interface and their electrochemical dissolution under a voltage bias. The charge storage results from the redox reactions that are responsible for the resistance switching. In contrast to conventional secondary batteries, the storing capability increases as the temperature is lowered from room temperature to 77 K, where the charges are released in a time scale nearly on the order of hours. The charging and discharging are thereby indicated not to rely on ionic transport. The battery effect is reversible in polarity. Storage characteristics are modified when Cu in the ternary alloy is replaced with Ag or Ni in a similar manner to the way the properties of the interfacial resistance switching are altered.

Insulating compounds are produced spontaneously for the chalcogenides containing certain elements in a reaction with Al. The generation of the electrical barrier at the Al-chalcogenide interface and its electrochemical annihilation give rise to interfacial resistance switching. We demonstrate the dependence of the barrier creation on the transition metal constituent using alloys based on S and Bi. While the resistance switching takes place generally when Cu is incorporated, the switching is not observed for the inclusion of Ni, apart from exceptional situations. A marginal behavior is found for the case with Ag. The Bi–Ag–S alloys develop a barrier layer also by a reaction with Ag. This barrier is dissolved at the opposite bias polarity in comparison to the case with the Al contact. We additionally show that the properties of the alloy films change widely with synthesis temperature. The sheet resistivity of the Cu-containing films can be orders of magnitude smaller than that of the Ag- and Ni-containing films. Large switching ratios of the resistance can thus be achieved using the Bi–Cu–S alloys, especially for the technologically advantageous low temperature synthesis.

The coupling of superconductivity in a two-dimensional electron gas (2DEG) generates a number of magnetotransport oscillations. For instance, an Aharonov–Bohm-type oscillation at intermediate magnetic fields and an Altshuler–Aronov–Spivak-like oscillation around zero magnetic field appear under the circumstance of the coexistence of Andreev and normal reflections from the interface between the normal-conductor and the superconductor. The presence and the characteristics of such magnetotransport oscillations are investigated in this work by carrying out fully quantum-mechanical simulations. The significant role of the quantum interference is thereby demonstrated. It is also shown how the oscillations are affected by the presence of a potential disorder and finite excitation biases. Shubnikow–de Haas oscillations of the 2DEG are not always suppressed by the disorder under the influence of superconductivity, making their distinction from the Aharonov–Bohm-type oscillation possibly ambiguous.

Conduction properties of the junctions of chalcogenide alloys Bi–Cu–Se, Bi–Ag–Se, and Sb–Cu–Te with metals are investigated to examine the capability for realizing the interfacial resistive switch. Electrically reversible spontaneous generation of insulating interfaces can take place with Al in all the cases. Controllable resistance switching is thereby demonstrated to occur for a range of alloys that consist of group V elements, transition metals, and chalcogens. The sheet resistivity of the chalcogenide films changes orders of magnitude when the material synthesis temperature is varied. Optimum conditions for the resistive switch devices are explored with emphasis on slowly progressing interfacial chemical reactions that cause aging effects. The dependence on the synthesis temperature is examined further in terms of the structural and optical properties. In addition, the spontaneous interface reaction is confirmed using transmission electron microscopy.

Cofilin-1 (CFL1), a small protein of 18 kDa, has been studied as a biomarker due to its involvement in tumor cell migration and invasion. Our aim was to evaluate CFL1 as an indicator of malignancy and aggressiveness in sputum samples. CFL1 was analyzed by ELISA immunoassay in the sputum of 73 lung cancer patients, 13 cancer-free patients, and 6 healthy volunteers. Statistical analyses included ANOVA, ROC curves, Spearman correlation, and logistic regression. Sputum CFL1 levels were increased in cancer patients compared to cancer-free patients and volunteers (P1.475 pg/mL showed augmented chance of death, suggesting lung cancer aggressiveness. CFL1 presented diagnostic value in detecting lung cancer and was associated to tumor aggressiveness., São Paulo Research Foundation (FAPESP No. 2010/11005-5) and the National Council for Scientific and Technological Development (CNPq No. 471939/2010-2 and No. 483005/2012, info:eu-repo/semantics/publishedVersion

We collected a series of 136 lung/bronchial and 56 matched lung parenchyma tissue samples from patients who underwent lung/bronchial biopsies and presented invasive carcinoma after lung surgery. The lung/bronchial samples included basal cell hyperplasia, squamous metaplasia, moderate dysplasia, adenomatous hyperplasia, severe dysplasia, squamous cell carcinoma and adenocarcinoma. Matched lung parenchyma tissue samples included 25 squamous cell carcinomas and 31 adenocarcinomas. Immunohistochemistry was performed to analyze for the distribution of hyaluronidase (Hyal)-1 and −3, and hyaluronan synthases (HAS)-1, −2, and −3. Hyal-1 showed significantly higher expression in basal cell hyperplasia than in moderate dysplasia (P=0.01), atypical adenomatous hyperplasia (P=0.0001), or severe dysplasia (P=0.03). Lower expression of Hyal-3 was found in atypical adenomatous hyperplasia than in basal cell hyperplasia (P=0.01) or moderate dysplasia (P=0.02). HAS-2 was significantly higher in severe dysplasia (P=0.002) and in squamous metaplasia (P=0.04) compared with basal cell hyperplasia. HAS-3 was significantly expressed in basal cell hyperplasia compared with atypical adenomatous hyperplasia (P=0.05) and severe dysplasia (P=0.02). Lower expression of HAS-3 was found in severe dysplasia compared with squamous metaplasia (P=0.01) and moderate dysplasia (P=0.01). Epithelial Hyal-1 and −3 and HAS-1, −2, and −3 expressions were significantly higher in pre-neoplastic lesions than in neoplastic lesions. Comparative Cox multivariate analysis controlled by N stage and histologic tumor type showed that patients with high HAS-3 expression in pre-neoplastic cells obtained by lung/bronchial biopsy presented a significantly higher risk of death (HR=1.19; P=0.04). We concluded that localization of Hyal and HAS in lung/bronchial pre-neoplastic and neoplastic lesions was inversely related to malignancy, which implied that visualizing these factors could be a useful diagnostic procedure for suspected lung cancer. Finalizing this conclusion will require a wider study in a randomized and prospective trial.

Aim: To show additional prognostic information about the mutational profile and new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification of adenocarcinoma (ADC) in patients without epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor treatments. Methods: In human lung ADC patients (n = 125), including 24 lepidic, 67 acinar, 23 papillary, and 11 solid predominant subtypes, EGFR and KRAS were sequenced, and anaplastic lymphoma kinase (ALK) rearrangements were screened using fluorescence in situ hybridization (FISH). Results:EGFR was mutated in 21.6% of patients with 19.57% showing a mean expression. The most frequent EGFR mutation was a deletion in exon 19, followed by an L858R amino acid substitution in exon 21. KRAS was mutated in 26.4% of patients with 50% displaying mean expression. ALK rearrangement was detected in 6 patients (4.8%). Predominant acinar ADC was strongly associated with EGFR and KRAS mutation. Clinical stage, lymph node metastases, and EGFR mutation in exon 18 showed a significant difference in disease-free and overall survival, but only a trend significance for EGFR and KRAS mutations. Multivariate analysis revealed that men aged >71 years, with a history of smoking (72 packs/year), and having a predominant solid ADC and EGFR mutation in exon 18. Conclusions: These results indicate that the mutational profile and new IASLC/ATS/ERS classification provide additional prognostic information about lung ADC.

Magnetic-field dependence of the transport properties of ballistic two-dimensional electrons in a planar superconductor–normal-conductor–superconductor structure is numerically investigated. In the circumstance where the Andreev reflection from the normal-conductor–superconductor interfaces is almost perfect, two oscillatory behaviors occur for magnetic fields higher and lower than that for the coincidence of the cyclotron diameter with the separation between the superconductors. The oscillation period for the former and latter cases is proportional to the magnetic field and inverse of the magnetic field, respectively. The low-field oscillation originates from commensurability-driven guiding of Andreev-reflected trajectories along the interfaces between the normal conductor and the superconductors. If the Andreev reflection probability is considerably less than unity, the commensurability oscillation is suppressed in amplitude and is dwarfed by additionally emerged oscillations originating from the quantum interference between the Andreev- and normal-reflected components.

A recent experiment [Hortelano et al., Semicond. Sci. Technol. 32, 125005 (2017)] reported a rectification effect that appeared in curved narrow ballistic channels of a two-dimensional electron gas when the strength of a magnetic field applied to the channels was tuned. The phenomenon was reproduced by classical billiard simulations as resulting from a transmission asymmetry caused by diffuse boundary scattering. However, this manifests breakdown of a commonly used simple model for diffuse boundary since the magnetic-field dependence of the transmission in two-terminal geometries has to be symmetric in equilibrium. We demonstrate here that this tendency of the system predicted by the billiard simulations is a real transmission asymmetry effect that emerges in the nonequilibrium transport. We perform nonequilibrium quantum-mechanical simulations with taking into account Coulomb repulsion. Experimental observations are presented to demonstrate consistencies with the numerical results.

da Costa Souza P, Parra E R, Atanazio M J, da Silva O B, Noleto G S, Ab’Saber A M, de Morais Fernezlian S, Takagaki T & Capelozzi V L (2012) Histopathology 61, 587–596 Different morphology, stage and treatment affect immune cell infiltration and long-term outcome in patients with non-small-cell lung carcinoma Aims: Development of effective immune-based therapies for patients with non-small-cell lung carcinoma (NSCLC) depends on an accurate characterization of complex interactions that occur between immune cells and the tumour environment. Methods and results: Innate and adaptive immune responses were evaluated in relation to prognosis in 65 patients with surgically excised NSCLC. Immunohistochemistry and morphometry were used to determine the abundance and distribution of immune cells. We found low numbers of immune cells and levels of cytokines in the tumour environment when compared with surrounding parenchyma. Smoking was associated inversely with the adaptive immune response and directly with innate immunity. We observed a prominent adaptive immune response in squamous cell carcinomas (SCC) but greater innate immune responses in adenocarcinomas and large cell carcinomas. Cox model analysis showed a low risk of death for smoking 16.81% and macrophages/monocytes >4.5%. Collectively, the data indicate that in NSCLC there is not a substantive local immune cell infiltrate within the tumour. Conclusion: Although immune cell infiltration is limited in NSCLC it appears to have an impact on prognosis and this may be of relevance for new immunotherapeutic approaches.

The quantum transmission of helical edge states across a square potential barrier is numerically investigated in narrow channels of a two-dimensional topological insulator. Although the transmission probability in general decreases when a potential offset is introduced in the middle of the channels, the transmission remains almost perfect regardless of the amplitude and length of the potential offset when the hybridization energy gap is closed by tuning the off-diagonal spin-orbit terms in the effective four-band Hamiltonian. The approximate absence of scattering resembling the Klein tunneling, where the transmission is unimpeded as an electron propagates relativistically as a hole in the barrier without decay, improves further when an interference condition is satisfied within the barrier. The dependence of the residual reflection on the Fermi level reveals anomalous characteristics in the Klein tunneling regime.

Nanometer-sized channels are fabricated in (In,Ga)As-InP heterostructures using Ar ion milling. The ion milling causes spontaneous creation of nanowires, and moreover, electrical conduction of the surface as carriers is generated by sputtering-induced defects. We demonstrate a method to restore electrical isolation in the etched area that is compatible with the presence of the nanochannels. We remove the heavily damaged surface layer using a diluted HCl solution and subsequently recover the crystalline order in the moderately damaged part by annealing. We optimize the HCl concentration to make the removal stop on its own before reaching the conduction channel part. The lateral depletion in the channels is shown to be almost absent.

Collagen V shows promise as an inducer of the death response via caspases. Remodeling of the microenvironment by collagen V, tumoral/vascular apoptosis, and the immune response were evaluated, based on the prognosis of 65 patients with surgically excised non-small cell lung cancer. Immunofluorescence, immunohistochemistry, morphometry, tridimensional reconstruction, and a real-time polymerase chain reaction were used to evaluate the amount, structure, and molecular chains of collagen V, tumoral and vascular apoptosis, immune cells, and microvessel density. The impact of these markers was tested on follow-up until death from recurrent lung cancer occurred. A decreased and abnormal synthesis of collagen V was found to lead to increased angiogenesis due to a low endothelial death rate and a low immune response. A Cox model analysis, controlled for the lymph node stage, demonstrated that only collagen V and vascular apoptosis variables were significantly associated with survival time. A point at the median for collagen V and vascular apoptosis divided patients into 2 groups, each with a distinctive prognosis. Those with a collagen V higher than 9.40% and vascular apoptosis higher than 1.09% had a low risk of death (0.27 and 0.41, respectively) compared to those with a collagen V lower than 9.40% and vascular apoptosis lower than 1.09%. Collagen V and vascular apoptosis in resected non-small cell lung cancer was strongly related to the prognosis, suggesting that strategies aimed at preventing low collagen V synthesis, or local responses to low vascular apoptosis may have a greater impact in lung cancer treatment.

The first order phase transition between ferromagnetic α-MnAs and paramagnetic β-MnAs in nanoscale disks etched out of an epitaxial MnAs film on GaAs(001) is studied by means of X-ray diffraction and magnetic force microscopy. The temperature hysteresis loop is observed to be expanded with decreasing disk size. The hysteresis is absent in the original continuous epitaxial film from which the disks are fabricated. The hysteresis is explained as a competition between the energy gain due to the phase transition and the energy loss due to the elastic strain.

Malignancy of pulmonary large cell carcinomas (LCC) increases from classic LCC through LCC with neuroendocrine morphology (LCCNM) to large cell neuroendocrine carcinomas (LCNEC). However, the histological classification has sometimes proved to be difficult. Because the malignancy of LCC is highly dependent on proteins with functions in the cell cycle, DNA repair, and apoptosis, p53 has been targeted as a potentially useful biological marker. p53 mutations in lung cancers have been shown to result in expression and protein expression also occurs in the absence of mutations. To validate the importance of both p53 protein expression (by immunostaining) and p53 gene mutations in lung LCC (by PCR-single strand conformational polymorphism analysis of exons 5, 6, 7, and 8) and to study their relationships with clinical factors and sub-classification we investigated the correlation of p53 abnormalities in 15 patients with LCC (5 classic LCC, 5 LCNEC, and 5 LCCNM) who had undergone resection with curative intent. Of these patients, 5/15 expressed p53 and none had mutant p53 sequences. There was a negative survival correlation with positive p53 immunostaining (P = 0.05). After adjustment for stage, age, gender, chemotherapy, radiotherapy, and histological subtypes by multivariate analysis, p53 expression had an independent impact on survival. The present study indicates that p53 assessment may provide an objective marker for the prognosis of LCC irrespective of morphological variants and suggests that p53 expression is important for outcome prediction in patients with the early stages of LCC. The results reported here should be considered to be initial results because tumors from only 15 patients were studied: 5 each from LCC, LCNEC and LCCNM. This was due to the rarity of these specific diseases.

Hyaluronan (HA) shows promise for detecting cancerous change in pleural effusion and urine. However, there is uncertainty about the localization of HA in tumor tissue and its relationship with different histological types and other components of the extracellular matrix, such as angiogenesis. We evaluated the association between HA and degree of malignancy through expression in lung tumor tissue and sputum. Tumoral tissue had significantly increased HA compared to normal tissue. Strong HA staining intensity associated with cancer cells was significant in squamous cell carcinoma compared to adenocarcinoma and large cell carcinoma. A significant direct association was found between tumors with a high percentage of HA and MVD (microvessel density) in tumoral stroma. Similarly significant was the direct association between N1 tumors and high levels of HA in cancer cells. Cox multivariate analysis showed significant association between better survival and low HA. HA increased in sputum from lung cancer patients compared to cancer-free and healthy volunteers and a significant correlation was found between HA in sputum and HA in cancer tissue. Localization of HA in tumor tissue was related to malignancy and reflected in sputum, making this an emerging factor for an important diagnostic procedure in patients suspected to have lung cancer. Further study in additional patients in a randomized prospective trial is required to finalize these results and to validate our quantitative assessment of HA, as well as to couple it to gold standard sputum cytology., Research supported by FAPESP (2010/11005-5 and 2010/04462) and CNPq (#471939/2010-2 and 483005/2012-6)

We numerically calculate the conductance of a one-dimensional Aharonov-Bohm loop containing a weakly coupled dot. The Coulomb repulsion is taken into account in the dot within the slave-boson mean-field approximation. We avoid the so-called phase locking by attaching an additional lead to the loop. The phase of the electron wavefunction deduced from the Aharonov-Bohm oscillation changes gradually by π when the Fermi energy sweeps across a transmission resonance in the dot. The asymmetric lineshape of Fano-type resonances is also examined.

A numerical investigation on the transition of surface acoustic waves (SAWs) in AlxGa1−xN/GaN/SiC heterostructures to Lamb-like modes localized in the GaN layers is presented. The significantly large sound velocity in AlN in comparison to that in GaN leads to an expulsion of the SAWs from the surface AlxGa1−xN layer into the buried GaN layer when the SAW wavelength is roughly less than the thicknesses of the AlxGa1−xN and/or GaN layers. The confinement effect is examined as a function of Al composition in the top layer, and is found to be present even when the composition is as low as x ~ 0.3.

We report immunohistochemical staining results for cyclooxygenase (COX)-2 and matrix metalloproteinase (MMP)-9 in primary tumors of 117 patients with resected adenocarcinoma of the lung (median follow-up, 20 months). For COX-2, we graded the degree of tumor staining according to the sum of staining intensity and the proportion of cells staining. For MMP-9, we used morphometry to quantify cytoplasmic staining. We used the Cox proportional hazards model to analyze overall survival. With only 29 patients censored at last follow-up, after controlling for the effect of pathologic stage, staining for COX-2 and MMP-9 and subtype of tumor were related significantly to survival ( P < 6 × 10−5). The effects of COX-2 and MMP-9 were opposite. Whereas any staining for COX-2 decreased the hazard and increased survival time, increased staining for MMP-9 increased the hazard and decreased survival time. The results also suggested that staining for COX-2 decreases with dedifferentiation. Our results suggest that staining for the combination of COX-2 and MMP-9 and categorizing tumors into papillary and nonpapillary types may provide important prognostic information for patients with resected adenocarcinoma of the lung; it is possible that these 3 variables could aid decisions about postoperative adjuvant treatment.

The opening of the energy gap at the Dirac point when the helical edge states of two-dimensional topological insulators are hybridized in narrow channels is investigated. While the energy gap widens exponentially as the width is reduced within the block-diagonal effective four-band model, the dependence is no longer monotonic when off-diagonal terms representing spin-orbit coupling are taken into account. The energy gap vanishes periodically as the width is varied with the period being almost inversely proportional to the strength of the spin-orbit coupling. Both the bulk inversion asymmetry and Rashba terms cause the cancellation of the confinement effect. The disappearance of the hybridization takes place when the overlap integral becomes zero in the presence of the spin-orbit coupling due to the oscillatory decay of the transverse wave function.

Interfacial phase change memory (iPCM), that has a structure of a superlattice made of alternating atomically thin GeTe and Sb2Te3 layers, has recently attracted attention not only due to its superior performance compared to the alloy of the same average composition in terms of energy consumption but also due to its strong response to an external magnetic field (giant magnetoresistance) that has been speculated to arise from switching between topological insulator (RESET) and normal insulator (SET) phases. Here we report magneto-optical Kerr rotation loops in the visible range, that have mirror symmetric resonances with respect to the magnetic field polarity at temperatures above 380 K when the material is in the SET phase that has Kramers-pairs in spin-split bands. We further found that this threshold temperature may be controlled if the sample was cooled in a magnetic field. The observed results open new possibilities for use of iPCM beyond phase-change memory applications.

We present a mechanism that gives rise to a strong magnetic field dependence of the optical properties in quantum dots even when the dots are too small to have the orbital wavefunction significantly influenced by the field. For large indium contents x 1, top valence band levels in InxGa1 xAs quantum dots exhibit strong entanglement of the states of which the envelope wavefunction is characterized by sand p-type symmetries. Although the optical anisotropy associated with each hole level is nearly independent of the magnetic field, the total anisotropy is enhanced when a level crossing is induced by the field.

There have been very few reports of the effect of pesticides on immediate allergy. In the previous report, the effect of pyrethroid pesticides and organophosphorus pesticides on immediate allergic reaction was investigated. Subsequently, 12 organonitrogen pesticides, 14 carbamate pesticides and 4 other pesticides were investigated for their effects on the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from rat basophilic leukemia cells (RBL-2H3). Two organonitrogen pesticides, bitertanol and pyridaben, and two organotin pesticides, cyhexatin and fenbutatin oxide, were found to promote beta-hexosaminidase release. Bitertanol non-specifically caused the promotion of chemical mediator release, while the release-promotive action of pyridaben was related to IgE antibody and those of cyhexatin and fenbutatin oxide to cell injury. On the other hand, two organonitrogen pesticides, propiconazole and triadimenol, and imazalil showed release-inhibitory action. These data suggested that some pesticides can affect immediate allergy.

Although soft confinement of electrons in ballistic cavities gives rise to a power law of classical probability distributions, the behavior is limited to a narrow range of the variable if the potential is not substantially smooth. The presence of a magnetic field normal to the cavity extends the power-law regime by generating a hierarchical phase space structure. The change in dynamics induced by the magnetic field is confirmed experimentally through analysis of conductance fluctuations in quantum cavities defined by electrostatic gates on a high-mobility heterojunction. Nonfractal conductance fluctuations as a function of the gate bias at zero magnetic field are transformed to be fractal when the cyclotron radius is comparable to the cavity size.

The tunnel coupling between the edges of two-dimensional electron gases is investigated in the quantum Hall regime. At the overlaps of the edge dispersion curves originating from the two lateral quantum Hall systems, anticrossing takes place in the energy spectrum. The gaps give rise to peaks in the conductance that are periodic with the inverse magnetic field. With increasing bias voltage applied across the weak link, the gaps move along the dispersion curves higher or lower in energy for carrier injection from the anode or the cathode, respectively. The shift can hence be used to map the dispersion curves. In addition, the peaks split because of a nonuniform variation of the gap energies arising from different Landau levels.

The transport properties in a normal-conductor–superconductor (NS) junction are investigated when a magnetic impurity is present in the normal region. As the spin of quasiparticles is reversed when they are Andreev-reflected from the NS interface, spin-flip scattering takes place regardless the spin alignment of an incident quasiparticle with respect to the magnetic impurity. The magnetic coupling between the quasiparticle and the impurity gives rise to subgap conductance peaks. The resonance state responsible for the subgap structures is found to be a hybrid of singlet and triplet states.

Magnetoconductance fluctuations in quantum cavities are numerically calculated for soft-wall confinement potentials. Employing a tight-binding lattice consisting of $200\ifmmode\times\else\texttimes\fi{}200$ sites, the conductance fluctuations are confirmed to be fractal for one order of magnitude in magnetic-field scale. We find no emergence of self-affine conductance fluctuations with fine scales in a Sinai billiard, suggesting that the hierarchical phase space structure in the underlying classical dynamics alone cannot explain recent experimental observations.

The tunneling conductance when quasiparticles are injected from a quantum point contact into a superconductor is calculated. The zero-bias conductance peak due to midgap states in d-wave superconductors is removed because of the quantum-mechanical diffraction of the electron wave by the narrow opening. Moreover, the zero-bias conductance vanishes even when the interface barrier between the normal metal and the superconductor is absent, except when the point contact is aligned along the (100) axis of the superconductor. These observations indicate that the tip condition of a scanning tunneling microscope significantly influences the tunneling spectrum.

We investigate the quantum interference effects in quantum dots of a two-dimensional electron gas attached to a superconductor. When the dot size is comparable to the Fermi wavelength of an electron, transmission resonance shows up in the conductance as distinct peaks and dips. The coupling of electron-like and hole-like excitations by the Andreev reflection leads to a rich variety of behavior of the resonance, in particular, against the bias voltage. Enlarging the dot size, the transmission resonance evolves into conductance fluctuations. The low-magnetic-field conductance fluctuations are shown to be remarkably geometry-specific in comparison to those in the normal counterparts.

Quantum interference effects in semiconductor microcavities terminated by a superconductor are investigated in terms of the quasiparticle injection into the resonator. The resonance structure varies strongly with the lead position if merely a part of the cavity boundary is replaced by the superconductor. When the incident flux of quasiparticles is not directed toward the semiconductor–superconductor interface, the resonance originating from partial normal reflection from the interface is enhanced in amplitude. This indicates that the influence of the normal reflection can be of significant importance in some device geometries.