Design, Modeling, and Characterization of Hot Electron Light Emission and Lasing in Semiconductor Heterostructure-VCSOA with Optical Gain up to 36 dB

Vertical-cavity semiconductor optical amplifiers (VCSOAs) are interesting devices for optical communication applications. In this work, we have studied the characteristics of gain spectra and amplifier bandwidth in reflection mode at 1300 nm GaInNAs/GaAs hot electron light emission and lasing in semiconductor heterostructure-VCSOA structure using MATLAB program. The device contains 16 Ga0.7In0.3N0.038As0.962 multiple quantum wells (QWs) in its intrinsic region; the active region is bounded between eight pairs of GaAs/AlAs top distributed Bragg reflectors (DBRs) mirror and 25 pairs of AlAs/GaAs bottom DBRs mirror. Simulation results suggest that the resonance cavity of QW of HILLISH-VCSOA is varied with temperature and number of DBRs periods. We compare the relation between the wavelength and gain at a different single-pass gain in both reflection and transmission modes. The highest gain at around 36 dB is observed in reflection mode. Moreover, we calculated the amplifier bandwidth at different periods of top mirror’s reflectivity, in which when the peak reflection gains increases, the amplifier bandwidth decreases

mTOR Controls Ovarian Follicle Growth by Regulating Granulosa Cell Proliferation

We have shown that inhibition of mTOR in granulosa cells and ovarian follicles results in compromised granulosa proliferation and reduced follicle growth. Further analysis here using spontaneously immortalized rat granulosa cells has revealed that mTOR pathway activity is enhanced during M-phase of the cell cycle. mTOR specific phosphorylation of p70S6 kinase and 4E-BP, and expression of Raptor are all enhanced during M-phase. The predominant effect of mTOR inhibition by the specific inhibitor Rapamycin (RAP) was a dose-responsive arrest in the G1 cell cycle stage. The fraction of granulosa cells that continued to divide in the presence of RAP exhibited a dose-dependent increase in aberrant mitotic figures known as anaphase bridges. Strikingly, estradiol consistently decreased the incidence of aberrant mitotic figures. In mice treated with RAP, the mitotic index was reduced compared to controls, and a similar increase in aberrant mitotic events was noted. RAP injected during a superovulation regime resulted in a dose-dependent reduction in the numbers of eggs ovulated. Implications for the real-time regulation of follicle growth and dominance, including the consequences of increased numbers of aneuploid granulosa cells, are discussed

Alternative splicing of the mouse embryonic poly(A) binding protein (Epab) mRNA is regulated by an exonic splicing enhancer: a model for post-transcriptional control of gene expression in the oocyte

Embryonic poly(A) binding protein (EPAB), expressed in oocytes and early embryos, binds and stabilizes maternal mRNAs, and mediates initiation of their translation. We identified an alternatively spliced form of Epab lacking exon 10 (c.Ex10del) and investigated the regulation of Epab mRNA alternative splicing as a model for alternative splicing in oocytes and early preimplantation embryos. Specifically, we evaluated the following mechanisms: imprinting; RNA editing and exonic splicing enhancers (ESEs). Sequence analysis led to the identification of two single nucleotide polymorphisms (SNPs): one was detected in exon 9 (rs55858A/G), and served as a marker for the parental origin of the alternatively spliced form, and the other was found in exon 10 (rs56574G/C), and co-segregated with the exon 9 SNP. We found that the presence of rs56574G in exon 10 led to the formation of an ESE, leading to efficient exclusion of exon 10. Real-time RT–PCR results revealed a 5-fold increase in the expression of the c.Ex10del alternative splicing variant in animals carrying rs56574G/G in exon 10 compared with rs56574C/C at the same locus. Our findings suggest that SNPs may alter the ratio between alternative splicing variants of oocyte-specific proteins. The role that these subtle differences play in determining individual reproductive outcome remains to be determined

The c-Abl expression in uterine epithelium during the mouse estrus cycle

WOS: 000299376400013PubMed ID: 22143492The epithelial cells of the mouse endometrium comprises the recurring physiologic changes such as proliferation and apoptosis induced by the reproductive hormones throughout the estrus cycle. The c-Abl is a protein tyrosine kinase, localized in the different cellular compartments such as nucleus, cytoplasm, mitochondria, and endoplasmic reticulum, interacts with different cellular proteins, including signaling adaptors, kinases, phosphatases, cell-cycle regulators, transcription factors and cytoskeletal proteins. Our hypothesis is that the c-Abl expression in the mouse uterine epithelium shows cyclic changes during the estrus cycle that is involved in regulation of the endometrial epithelial cells. The regulation of c-Abl gene and protein expression in the uterus of intact animals in the different cycle phases was investigated using immunohistochemistry, western blot and semi-quantitative RT-PCR. The immunohistochemistry results revealed that the luminal and the glandular epithelium (LE) and (GE), respectively, showed gradually increase in the expression of c-Abl from the proestrus (P) to the metestrus and followed by a decrease in the diestrus (D). c-Abl immunoreactivity was detected in the both LE and GE cells, especially the LE showed diminished the c-Abl protein expression on the D phase and the minimal value was detected on the P day. The c-Abl protein level in the LE was increased during the M, presenting a high correlation with the hormonal level of this cell type. The result of c-Abl RT-PCR analysis was compatible with pattern of c-Abl protein expression. In conclusion, the stage-specific protein pattern of the mammalian c-Abl tyrosine kinase presented a good correlation with the mouse estrus cycle and may have a regulative function during the uterine remodeling.Akdeniz University-Antalya/Turkey [2004.02.0122.006]This study was supported by the Research Fund of Akdeniz University-Antalya/Turkey (project #2004.02.0122.006)

p38 MAPK signal activity is critical for GLUT1 and GLUT4 expressions, maintaining pluripotency and survival of early mouse embryos

29th Annual Meeting of the European-Society-of-Human-Reproduction-and-Embryology (ESHRE) -- JUL 07-10, 2013 -- London, ENGLANDWOS: 000320467700398…European Soc Human Reprod & Embryol (ESHRE

Superovulation influences epab and pabpc1 gene expressions in mouse oocytes and early preimplantation embryos

29th Annual Meeting of the European-Society-of-Human-Reproduction-and-Embryology (ESHRE) -- JUL 07-10, 2013 -- London, ENGLANDWOS: 000320467700824…European Soc Human Reprod & Embryol (ESHRE

Ultrastructural and immunohistochemical similarities of two distinct entities; multiple sclerosis and hereditary motor sensory neuropathy

In the present study, we present the ultrastructural. and immunohistochemical. properties of the sural nerves of two patients, one of whom was diagnosed as having multiple sclerosis with involvement of the peripheral nervous system (PNS), and the other as having hereditary motor sensory neuropathy type-I with involvement of the central nervous system (CNS). Expression of several extracellutar matrix (ECM) proteins (fibronectin, laminin, and collagen type-IV), intermediate filaments (vimentin) and S-100 protein (marker for the axon-Schwann cell interface) was investigated by means of immunohistochemical. methods. In addition, the tissue samples were evaluated ultrastructurally. Immunohistochemical staining revealed increased expression of the ECM molecules mentioned above in relation with the sural. nerves of the patients. We hypothesize that this enhanced expression is due to Schwann cell-axon interactions. Vimentin expression was different in Schwann cells and S-100 immunostaining was decreased near the Schwann cell-axon interface. Myelin fragmentation, axon vacuolization, onion bulbs, tomoculous formation, axonal. degeneration were found to occur. These results suggest that there is active ECM reorganization in the sural nerve of these patients, and some ultrastructural changes are similar in the damaged axonal organization and in Schwann cells although the changes are not completely the same in the two patients. In conclusion, our study demonstrates that there is an association between the demyelinization process in the CNS and the PNS even though they are affected by different mechanisms. (C) 2004 Elsevier GmbH. All rights reserved

Detection of Ebola virus in oral fluid specimens during outbreaks of Ebola virus hemorrhagic fever in the republic of Congo

Background. Patients who have refused to provide blood samples has meant that there have been significant delays in confirming outbreaks of Ebola virus hemorrhagic fever (EVHF). During the 2 EVHF outbreaks in the Republic of Congo in 2003, we assessed the use of oral fluid specimens versus serum samples for laboratory confirmation of cases of EVHF. Methods. Serum and oral fluid specimens were obtained from 24 patients with suspected Ebola and 10 healthy control subjects. Specimens were analyzed for immunoglobulin G antibodies by enzyme-linked immunosorbent assay (ELISA) and for Ebola virus by antigen detection ELISA and reverse-transcriptase polymerase chain reaction (RT-PCR). Oral fluid specimens were collected with a commercially available collection device. Results. We failed to detect antibodies against Ebola in the oral fluid specimens obtained from patients whose serum samples were seropositive. All patients with positive serum RT-PCR results also had positive results for their oral fluid specimens. Conclusions. This study demonstrates the usefulness of oral fluid samples for the investigation of Ebola outbreaks, but further development in antibodies and antigen detection in oral fluid specimens is needed before these samples are used for filovirus surveillance activities in Africa