Neuroprotective effects of lomerizine on retinal ganglion cells in the diet-induced obese C57BL/6J mice

AIM: To research the neuroprotective effects of lomerizine(LOM)on retinal ganglion cells(RGCs)in the diet-induced obese C57BL/6J mice. <p>METHODS: Fifty-four mice were randomly divided into two groups which were fed a high-fat diet for 19wk. One group mice were lavaged LOM by the dosage of 80mg/kg daily at the same time. The obese mice were selected and divided into diet-induced obesity(DIO)group, diet-induced obesity and lomerizine(DIO+LOM)group. The mice in the control(CON)group were fed a basal diet. The ultrastructural changes of RGCs were detected by transmission electron microscope. The cellular apoptosis was detected by TUNEL. The laser scanning confocal microscope was used to measure intracellular calcium ion concentration. <p>RESULTS: Compared with the CON group, the RGCs in DIO group showed smaller and condensation of nuclear chromatin and increased electron density of the cytoplasm, whereas the changes in DIO+LOM mice were obviously diminished. TUNEL staining showed that the number of apoptosis cells in the ganglion cell layer(GCL)increased in DIO group and the percentage of apoptotic cells was much higher than that in the CON groups(<i>P</i><0.01). The DIO+LOM group mice showed fewer apoptosis cells and the percentage of apoptotic cells in this group were significantly decreased than the DIO mice(<i>P</i><0.05). The Laser scanning confocal microscope detection showed Ca²⁺ staining intensity of RGCs in DIO group increased and its staining intensity ratio was significantly higher than in CON group(<i>P</i><0.01), the Ca²⁺ staining intensity and its staining intensity ratio in DIO+LOM group were significantly decreased than the DIO group(<i>P</i><0.01). <p>CONCLUSION: Lomerizine has neuroprotective effects on damage of retinal ganglion cells in diet-induced obesity mice, which may be related to the attenuation of intracellular Ca²⁺ overload

Effect of α-linolenic acid on endoplasmic reticulum stress-mediated apoptosis of palmitic acid lipotoxicity in primary rat hepatocytes

<p>Abstract</p> <p>Background</p> <p>Hepatic inflammation and degeneration induced by lipid depositions may be the major cause of nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the effects of saturated and unsaturated fatty acids (FA) on apoptosis in primary rat hepatocytes.</p> <p>Methods</p> <p>The primary rat hepatocytes were treated with palmitic acid and/or α-linolenic acid in vitro. The expression of proteins associated with endoplasmic reticulum (ER) stress, apoptosis, caspase-3 levels were detected after the treatment.</p> <p>Results</p> <p>The treatment with palmitic acid produced a significant increase in cell death. The unfolded protein response (UPR)-associated genes CHOP, GRP78, and GRP94 were induced to higher expression levels by palmitic acid. Co-treatment with α-linolenic acid reversed the apoptotic effect and levels of all three indicators of ER stress exerted by palmitic acid. Tunicamycin, which induces ER stress produced similar effects to those obtained using palmitic acid; its effects were also reversed by α-linolenic acid.</p> <p>Conclusions</p> <p>α-Linolenic acid may provide a useful strategy to avoid the lipotoxicity of dietary palmitic acid and nutrient overload accompanied with obesity and NAFLD.</p

Photoluminescence pressure coefficients of InAs/GaAs quantum dots

We have investigated the band-gap pressure coefficients of self-assembled InAs/GaAs quantum dots by calculating 17 systems with different quantum dot shape, size, and alloying profile using atomistic empirical pseudopotential method within the ``strained linear combination of bulk bands'' approach. Our results confirm the experimentally observed significant reductions of the band gap pressure coefficients from the bulk values. We show that the nonlinear pressure coefficients of the bulk InAs and GaAs are responsible for these reductions. We also find a rough universal pressure coefficient versus band gap relationship which agrees quantitatively with the experimental results. We find linear relationships between the percentage of electron wavefunction on the GaAs and the quantum dot band gaps and pressure coefficients. These linear relationships can be used to get the information of the electron wavefunctions.Comment: 8 pages, 2 tables, 4 figure

DOTA: A Large-scale Dataset for Object Detection in Aerial Images

Object detection is an important and challenging problem in computer vision. Although the past decade has witnessed major advances in object detection in natural scenes, such successes have been slow to aerial imagery, not only because of the huge variation in the scale, orientation and shape of the object instances on the earth's surface, but also due to the scarcity of well-annotated datasets of objects in aerial scenes. To advance object detection research in Earth Vision, also known as Earth Observation and Remote Sensing, we introduce a large-scale Dataset for Object deTection in Aerial images (DOTA). To this end, we collect $2806$ aerial images from different sensors and platforms. Each image is of the size about 4000-by-4000 pixels and contains objects exhibiting a wide variety of scales, orientations, and shapes. These DOTA images are then annotated by experts in aerial image interpretation using $15$ common object categories. The fully annotated DOTA images contains $188,282$ instances, each of which is labeled by an arbitrary (8 d.o.f.) quadrilateral To build a baseline for object detection in Earth Vision, we evaluate state-of-the-art object detection algorithms on DOTA. Experiments demonstrate that DOTA well represents real Earth Vision applications and are quite challenging.Comment: Accepted to CVPR 201

Electronic structures of GaAs/AlxGa1-xAs quantum double rings

In the framework of effective mass envelope function theory, the electronic structures of GaAs/AlxGa1-xAs quantum double rings (QDRs) are studied. Our model can be used to calculate the electronic structures of quantum wells, wires, dots, and the single ring. In calculations, the effects due to the different effective masses of electrons and holes in GaAs and AlxGa1-xAs and the valence band mixing are considered. The energy levels of electrons and holes are calculated for different shapes of QDRs. The calculated results are useful in designing and fabricating the interrelated photoelectric devices. The single electron states presented here are useful for the study of the electron correlations and the effects of magnetic fields in QDRs

Relationship and prognostic significance of SPARC and VEGF protein expression in colon cancer

<p>Abstract</p> <p>Background</p> <p>SPARC (secreted protein, acidic and rich in cysteine) is closely related with the progress, invasion and metastasis of malignant tumor and angiogenesis.</p> <p>Methods</p> <p>Using human colon adenocarcinoma tissues (hereinafter referred to as colon cancer) and their corresponding non-diseased colon from 114 patients' biopsies, the expression of SPARC and vascular endothelial growth factor (VEGF) were investigated by immunohistochemistry staining to assessment the relationship between SPARC and VEGF, as well as their prognostic significance in patients. Evaluation of VEGF expression level with the same tissues was used to establish the antigenic profiles, and the marker of CD34 staining was used as an indicator of microvessel density (MVD).</p> <p>Results</p> <p>SPARC expression was mainly in the stromal cells surrounding the colon cancer, and was significant difference in those tissues with the lymph node metastasis and differentiation degree of tumor. Expression of SPARC was significantly correlated with the expression of VEGF and MVD in colon cancer tissues. Patients with low or absence expressing SPARC had significantly worse overall survival and disease-free survival in a Single Factor Analysis; Cox Regression Analysis, SPARC emerged as an overall survival and disease-free survival independent prognostic factor for colon cancer.</p> <p>Conclusion</p> <p>The low expression or absence of stromal SPARC was an independent prognostic factor for poor prognosis of colon cancer. SPARC maybe involved in the regulation of anti-angiogenesis by which it may serve as a novel target for colon cancer treatment as well as a novel distinctive marker.</p

Ultraviolet emission of silicon quantum tips

Silicon tips used as field emitters have dimensions that are within the quantum confinement regime. Therefore they can be considered as freestanding silicon tips. In this letter, a photoluminescence spectrum of a 100×100100×100 array of silicon tips was taken at 10 K. Narrow ultraviolet luminescence peaks were observed. Using the empirical pseudopotential homojunction model, it is demonstrated that these luminescence peaks come from energy levels arising from quantum confinement. By fitting the theoretical result to the experimental result, we conclude that the luminescence peaks come from Si quantum tips of about 20 Å in width and that they are covered by silicon dioxide. © 1999 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71101/2/APPLAB-74-3-386-1.pd

Calcium interactions in amelogenin-derived peptide assembly

Phosphorylation of serine residues has been recognized as a pivotal event in the evolution of mineralized tissues in many biological systems. During enamel development, the extracellular matrix protein amelogenin is most abundant and appears to be critical to the extreme high aspect ratios (length:width) of apatite mineral fibers reaching several millimeters in larger mammalian teeth. A 14-residue peptide (14P2, residues Gly8 to Thr21) was previously identified as a key sequence mediating amelogenin assembly formation, the domain also contains the native single phosphoserine residue (Ser16) of the full-length amelogenin. In this research, 14P2 and its phosphorylated form (p14P2) were investigated at pH 6.0 with various calcium and phosphate ion concentrations, indicating that both peptides could self-assemble into amyloid-like conformation but with differences in structural details. With calcium, the distance between 31P within the p14P2 self-assemblies is averaged to be 4.4 ± 0.2Å, determined by solid-state NMR 31P PITHIRDS-CT experiments. Combining with other experimental results, solid-state Nuclear Magnetic Resonance (SSNMR) suggests that the p14P2 self-assemblies are in parallel in-register β-sheet conformation and divalent calcium ions most likely connect two adjacent peptide chains by binding to the phosphate group of Ser16 and the carboxylate of Glu18 side-chain. This study on the interactions between calcium ions and amelogenin-derived peptides provides insights on how amelogenin may self-assemble in the presence of calcium ions in early enamel development

Electronic Structure of a Hydrogenic Acceptor Impurity in Semiconductor Nano-structures

The electronic structure and binding energy of a hydrogenic acceptor impurity in 2, 1, and 0-dimensional semiconductor nano-structures (i.e. quantum well (QW), quantum well wire (QWW), and quantum dot (QD)) are studied in the framework of effective-mass envelope-function theory. The results show that (1) the energy levels monotonically decrease as the quantum confinement sizes increase; (2) the impurity energy levels decrease more slowly for QWWs and QDs as their sizes increase than for QWs; (3) the changes of the acceptor binding energies are very complex as the quantum confinement size increases; (4) the binding energies monotonically decrease as the acceptor moves away from the nano-structures’ center; (5) as the symmetry decreases, the degeneracy is lifted, and the first binding energy level in the QD splits into two branches. Our calculated results are useful for the application of semiconductor nano-structures in electronic and photoelectric devices