Effect of an external/internal magnetic field on the photocurrent in Py-topological insulator heterojunction NiFe/TI (BiTe/BiSe/BiTeSe)/p-Si devices.

This study demonstrates the fabrication and study of a permalloy (Py)/topological insulator heterojunction, , the NiFe/TI(BiTe/BiSe/BiTeSe)/p-Si heterojunction, for spintronic device applications at room temperature. In this work, the forward current values, under the absence of a magnetic field, for NiFe/BiTeSe/p-Si, NiFe/BiSe/p-Si, and NiFe/BiTe/p-Si heterojunctions were 12.7 μA, 8.

Proximity induced band gap opening in topological-magnetic heterostructure (NiFe/p-TlBiSe/p-Si) under ambient condition.

The broken time reversal symmetry states may result in the opening of a band gap in TlBiSe leading to several interesting phenomena which are potentially relevant for spintronic applications. In this work, the quantum interference and magnetic proximity effects have been studied in NiFe/p-TlBiSe/p-Si (Magnetic/TI) heterostructure using physical vapor deposition technique. Raman analysis shows the symmetry breaking with the appearance of A mode.

Aberrant photoelectric effect in the topological insulator/n-GaN heterojunction (BiTe/n-GaN) under unpolarized illumination.

A topological insulator has a unique graphene-like Dirac cone conducting surface state, which is excellent for broadband absorption and photodetector applications. Experimental investigations on the BiTe/n-GaN heterojunction exhibited an aberrant photoelectric effect under the influence of unpolarized light. Transport measurements of the BiTe/n-GaN heterojunction revealed a negative photoconductance, with a sudden increase in resistance.

Covalently linked benzothiadiazole-fullerene adducts for organic optoelectronic devices: synthesis and characterization.

Fullerene adducts have attracted attention in a variety of applications including organic optoelectronic devices. In this regard, we have designed a covalently linked donor-acceptor dyad comprising a fluorobenzothiadiazole-thiophene (BTF-Th) unit with the electron acceptor fullerene in an Acceptor-Donor-Acceptor (A-D-A) molecular arrangement. We synthesized and characterized two new covalently bonded benzothiadiazole-based fullerene molecules, mono-adduct, 7 (benzothiadiazole : PCBM = 1 : 1, anchored terminally esterification reaction) and multi-adduct, 10-I (benzothiadiazole : PCBM =  : 1, where ≥ 1, attached directly to the fullerene core the Prato reaction) using different synthetic strategies.

Flexible perylenediimide/GaN organic-inorganic hybrid system with exciting optical and interfacial properties.

We report the band gap tuning and facilitated charge transport at perylenediimide (PDI)/GaN interface in organic-inorganic hybrid nanostructure system over flexible titanium (Ti) foil. Energy levels of the materials perfectly align and facilitate high efficiency charge transfer from electron rich n-GaN to electron deficient PDI molecules. Proper interface formation resulted in band gap tuning as well as facilitated electron transport as evident in I-V characteristics.

Facile Synthesis and Evaluation of Electron Transport and Photophysical Properties of Photoluminescent PDI Derivatives.

Perylenediimides (PDIs) have emerged as potential materials for optoelectronic applications. In the current work, four PDI derivatives, substituted at imide nitrogen with 2,6-diisopropyl phenyl, 2-nitrophenyl, diphenylmethylene, and pentafluorophenyl groups, have been synthesized from perylene 3,4,9,10-tetracarboxylic dianhydride using a facile imidization synthesis process. PDI derivatives have been spectroscopically characterized for their structure and optical properties.

Comparative Charge Transfer Studies of Porphyrin-Fullerene Dyads: Substituents Effect.

The present study deals with the study of charge transfer and photophysical properties of synthesized non-metallated fullerene-porphyrin dyad-III (H2P3-C60) via Prato reaction. The porphyrin has been substituted with electron donating groups (3,5-di--butylbenzene) at meso positions facilitating the effective charge transfer for the formation of long lived charge-separated states in dyad molecule. The photophysical and thermal activated conducting properties of dyad was comprehensively studied to establish the effect of substituents and also by comparing with our reported dyad II having only meso-phenyl groups.

Molecular integrity of chloroplast DNA and mitochondrial DNA in mesophyll and bundle sheath cells of maize.

When compared to maize mesophyll cells, the plastid and mitochondrial DNAs in bundle sheath cells are less fragmented, less damaged, and contain fewer DNA polymerase-blocking impediments. Plants that conduct C4 photosynthesis differ from those that employ C3 photosynthesis with respect to leaf anatomy, biochemical pathways, and the proteins and RNA transcripts present in the leaf mesophyll (M) and bundle sheath (BS) cells. Here, we investigate the organellar DNA (orgDNA) from plastids and mitochondria in these two cell types.

Changes in DNA damage, molecular integrity, and copy number for plastid DNA and mitochondrial DNA during maize development.

The amount and structural integrity of organellar DNAs change during plant development, although the mechanisms of change are poorly understood. Using PCR-based methods, we quantified DNA damage, molecular integrity, and genome copy number for plastid and mitochondrial DNAs of maize seedlings. A DNA repair assay was also used to assess DNA impediments.

The amount and integrity of mtDNA in maize decline with development.

In maize and other grasses there is a developmental gradient from the meristematic cells at the base of the stalk to the differentiated cells at the leaf tip. This gradient presents an opportunity to investigate changes in mitochondrial DNA (mtDNA) that accompany growth under light and dark conditions, as done previously for plastid DNA. Maize mtDNA was analyzed by DAPI-DNA staining of individual mitochondria, gel electrophoresis/blot hybridization, and real-time qPCR.

Distinguishing authentic mitochondrial and plastid DNAs from similar DNA sequences in the nucleus using the polymerase chain reaction.

DNA sequences similar to those in the organellar genomes are also found in the nucleus. These non-coding sequences may be co-amplified by PCR with the authentic organellar DNA sequences, leading to erroneous conclusions. To avoid this problem, we describe an experimental procedure to prevent amplification of this "promiscuous" DNA when total tissue DNA is used with PCR.

Evidence-based genomic diagnosis characterized chromosomal and cryptic imbalances in 30 elderly patients with myelodysplastic syndrome and acute myeloid leukemia.

Background: To evaluate the clinical validity of genome-wide oligonucleotide array comparative genomic hybridization (aCGH) for detecting somatic abnormalities, we have applied this genomic analysis to 30 cases (13 MDS and 17 AML) with clonal chromosomal abnormalities detected in more than 50% of analyzed metaphase cells.

Results: The aCGH detected all numerical chromosomal gains and losses from the mainline clones and 113 copy number alterations (CNAs) ranging from 0.257 to 102.

Virus-induced gene silencing as a tool for comparative functional studies in Thalictrum.

Perennial woodland herbs in the genus Thalictrum exhibit high diversity of floral morphology, including four breeding and two pollination systems. Their phylogenetic position, in the early-diverging eudicots, makes them especially suitable for exploring the evolution of floral traits and the fate of gene paralogs that may have shaped the radiation of the eudicots. A current limitation in evolution of plant development studies is the lack of genetic tools for conducting functional assays in key taxa spanning the angiosperm phylogeny.