Efficient and bright green InP quantum dot light-emitting diodes enabled by a self-assembled dipole interface monolayer.

The interfacial state between the hole transport layer (HTL) and quantum dots (QDs) plays a crucial role in the optoelectronic performance of light-emitting diodes. Herein, we reported an efficient and bright green indium phosphide (InP) QD-based light-emitting diode (LED) by introducing a self-assembled monolayer of 4-bromo-2-fluorothiophenol (SAM-BFTP) molecule to improve interfacial charge transport in LED devices. The molecular dipole layer at the interface of the QD layer and HTL not only reduces the energy barrier of holes injected into QDs through vacuum energy level shift but also inhibits the fluorescence quenching of QDs caused by the HTL. Moreover, copper ions doped into phosphomolybdic acid (Cu:PMA) is selected as the hole injection layer (HIL) into the device system based on the SAM-BFTP molecule, and as a result, a green InP QD LED (QLED) with a maximum external quantum efficiency (EQE) of 8.46% and a luminance of 18 356 cd m-2 was realized. This work can inform and underpin the future development of InP-based QLEDs with concurrent high efficiency and brightness.

Validation of copy number variation sequencing for detecting chromosome imbalances in human preimplantation embryos.

Chromosome aneuploidies commonly arise in embryos produced by assisted reproductive technologies and represent a major cause of implantation failure and miscarriage. Currently, preimplantation genetic diagnosis (PGD) is performed by array-based methods to identify euploid embryos for transfer to the patient. We speculated that a combination of next-generation sequencing technologies and sophisticated bioinformatics would deliver a more comprehensive and accurate methodology to improve the overall efficacy of embryo testing. To meet this challenge, we developed a high-resolution copy number variation (CNV) sequencing pipeline suitable for single-cell analysis. In validation studies, we showed that CNV-Seq was highly sensitive and specific for detection of euploidy, aneuploidy, and segmental imbalances in 24 whole genome amplification samples from PGD embryos that were originally diagnosed by gold standard array comparative genomic hybridization. In addition, CNV-Seq was capable of detecting, mapping, and accurately quantifying terminal chromosome imbalances down to 1 Mb in size originating from abnormal segregation of translocation chromosomes. These validation studies indicate that CNV-Seq displays the hallmarks of an accurate and reliable embryo test with the potential to further improve the overall efficacy of PGD.

[Effects of electromagnetic pulses on apoptosis and TGF-ß3 expression of mouse testis tissue].

OBJECTIVE: To investigate the effects of electromagnetic pulses (EMP) on the apoptosis and transforming growth factor beta 3 (TGF-ß3) expression of mouse testis tissue. METHODS: Thirty-two male BALB/c mice were randomly and equally divided into one control group and three EMP treated groups, which were whole-body exposed to EMP at 200 kV/m with 100, 200, and 400 pulses, respectively. The control group received no treatment. The pathological changes and cell apoptosis in testis tissue were analyzed by TUNEL assay. The mRNA expression of TGF-ß3 in testis tissue was determined by RT-PCR, and the protein expression of TGF-ß3 was determined by immunohistochemistry and Western blot. RESULTS: No obvious pathological changes were found in testis tissue after EMP exposure at 200 kV/m with 100 and 200 pulses. However, after EMP exposure with 400 pulses, degeneration and shedding of testis tissue, accompanied by significant increase in apoptosis rate (P < 0.05), was observed. The RT-PCR, immunohistochemistry, and Western blot showed that the expression of TGF-ß3 mRNA and protein increased significantly after EMP exposure with 400 pulses as compared with that of the control group (P < 0.05). CONCLUSION: EMP exposure at 200 kV/m with 400 pulses increases the incidence of apoptosis and expression of TGF-ß3 in mouse testis tissue, which is potentially one of the mechanisms by which EMP increases blood-testis barrier permeability in mice.

Detection of chromosomal aneuploidy in human preimplantation embryos by next-generation sequencing.

Embryos produced by assisted reproductive technologies are commonly associated with a high level of aneuploidy. Currently, 24-chromosome profiling of embryo biopsy samples by array-based methods is available to identify euploid embryos for transfer that have a higher potential for implantation and development to term. From a laboratory and patient perspective, there is a need to explore the feasibility of developing an alternative method for routine aneuploidy assessment of embryos that would be more comprehensive, cost-effective, and efficient. We speculated that aneuploidy could be readily assessed in test single-cell biopsy samples by first performing whole genome amplification followed by library generation, massively parallel shot-gun sequencing, and finally bioinformatics analysis to quantitatively compare the ratio of uniquely mapped reads to reference cells. Using Down syndrome as an example, the copy number change for chromosome 21 was consistently 1.5-fold higher in multiple cell and single-cell samples with a 47,XX,+21 karyotype. Applying the validated sequencing strategy to 10 sister blastomeres from a single human embryo, we showed that the aneuploidy status called by sequencing was consistent with short tandem repeat allelic profiling. These validation studies indicate that aneuploidy detection using sequencing-based methodology is feasible for further improving the practice of preimplantation genetic diagnosis.

Effects of electromagnetic radiation on morphology and TGF-ß3 expression in mouse testicular tissue.

Exposure to electromagnetic pulses in certain doses may lead to increase in the permeability of the blood testes barrier (BTB) in mice, which in turn affects spermatogenesis, penetration and spermiation. TGF-ß3 is a key molecule involved in BTB permeability via regulation of tight junction proteins, and it participates in regulating spermatogenesis, synthesis of steroids and production of the extracellular matrix in testicular tissue. Therefore, it is hypothesized that TGF-ß3 plays important roles in electromagnetic pulse (EMP)-induced changes in BTB permeability. In the present study, we carried out whole-body irradiation on mice using EMP of different intensities. No obvious pathological changes or significant increase in apoptosis was detected in testicular tissues after exposure to 100 and 200 pulses of intensity 200kV/m; however, with 400 pulses we observed the degeneration and shrinkage of testicular tissues along with a significant increase in apoptotic rate. Moreover, in the 100- and 200-EMP groups, a non-significant increase in TGF-ß3 mRNA and protein expression was observed, whereas in the 400-EMP group a significant increase was observed (P<0.05). These results indicate that increase in the apoptotic rate of testicular tissues and increase in TGF-ß3 expression may be one of the mechanisms for EMP-induced increase in BTB permeability in mice.

Endogenous EGF maintains Sertoli germ cell anchoring junction integrity and is required for early recovery from acute testicular ischemia/reperfusion injury.

Administration of exogenous epidermal growth factor (EGF) improves testicular injury after acute ischemia-reperfusion (IR) stress, but the molecular basis is poorly understood. The role of endogenous EGF in testicular recovery and the underlying intracellular signaling pathways involved were herein investigated. In mice, testicular IR injury significantly enhanced the expression level of endogenous Egf at the very beginning of reperfusion. Expression of EGF receptor (Egfr (ErbB1)) was accordingly upregulated 3  h after reperfusion. Deprivation of majority of circulated EGF by sialoadenectomy aggravated testicular detriment (especially in pachytene spermatocytes), enhanced germ cell apoptosis, and thereafter resulted in impaired meiotic differentiation after IR insult. Mechanistically, endogenous EGF signaling appeared to be indispensable for the proper maintenance of Sertoli germ cells anchoring junction dynamics during the early testicular recovery. We also provided the in vitro evidences in a well-established rat Sertoli germ cell co-cultures model that the pro-survival effect of endogenous EGF on germ cells in response to testicular IR insult is mediated, at least in part, via the phosphatidylinositol 3-kinase/pAkt pathway. Collectively, our results suggest that the augment of endogenous EGF during the early testicular recovery may act on top of an endocrinous cascade orchestrating the intimate interactions between Sertoli cells and germ cells and may operate as indispensable defensive mechanism in response to testicular IR stress. Future studies in this field would shed light on this complicated pathogenesis.

Rapid and efficient reprogramming of human amnion-derived cells into pluripotency by three factors OCT4/SOX2/NANOG.

Reprogramming human somatic cells to pluripotency represents a valuable resource for research aiming at the development of in vitro models for human diseases and regenerative medicines to produce patient-specific induced pluripotent stem (iPS) cells. Seeking appropriate cell resources for higher efficiency and reducing the risk of viral transgene activation, especially oncogene activation, are of significance for iPS cell research. In this study, we tested whether human amnion-derived cells (hADCs) could be rapidly and efficiently reprogrammed into iPS cells by the defined factors: OCT4/SOX2/NANOG. hADCs from normal placenta were isolated and cultured. The 3rd passage cells were infected with the lentiviral vectors for the delivery of OCT4, SOX2, and NANOG. Afterwards, the generated iPSCs were identified by morphology, pluripotency markers, global gene expression profiles, and epigenetic status both in vitro and in vivo. The results showed that we were able to reprogram hADCs by the defined factors (OCT4/SOX2/NANOG). The efficiency was significantly high (about 0.1%), and the typical colonies appeared on the 9th day after infection. They were similar to human embryonic stem (ES) cells in morphology, proliferation, surface markers, gene expression, and the epigenetic status of pluripotent cell-specific genes. Furthermore, these cells were able to differentiate into various cell types of all three germ layers both in vitro and in vivo. These results demonstrate that hADCs were an ideal somatic cell resource for the rapid and efficient generation of iPS cells by OCT4/SOX2/NANOG.

Overexpression of miR-152 leads to reduced expression of human leukocyte antigen-G and increased natural killer cell mediated cytolysis in JEG-3 cells.

OBJECTIVE: The purpose of this study was to gain a further understanding of the relationship between miR-152 and human leukocyte antigen (HLA)-G in human trophoblast cell line (JEG-3). STUDY DESIGN: The JEG-3 cells were transfected with pre-miR-152. The effect of the overexpressed miR-152 on HLA-G expression, trophoblast invasion, and natural killer (NK) cell-mediated cytolysis were assessed by reverse-transcription polymerase chain reaction (RT-PCR) and Western blot analysis, transwell invasion assay, and NK cell cytotoxicity assay, respectively. RESULTS: The miR-152 repressed HLA-G expression but exerted no effect on JEG-3 cell invasion, and overexpression of miR-152 led to increased NK cell-mediated cytolysis in JEG-3 cells. CONCLUSION: The data indicate that miR-152 may function as an immune system enhancer through up-regulating NK cell-mediated cytolysis of host cells.

[Changes of dentin, dental pulp and periodontium tissue in tail-suspended rats].

OBJECTIVE: To investigate the metabolic changes of calcium and phosphorus in dentin, dental pulp and periodontium in tail-suspended rats, and the functions of TGF-beta 1, c-fos, collagen-I and collagen IV in dentin, dental pulp and periodontium. METHOD: Relative percentage contents of Ca, P in dentin, dental pulp and periodontium were measured with scanning electron microscope and energy spectrum analytical system in 3 groups of rats. The expression of TGF-beta 1, c-fos, collagen-I and collagen IV were also observed. RESULT: In the suspension group, the relative percentage content of Ca declined significantly, while P increased slightly. There were no significant differences of Ca, P in alveolar bone. The expressions of TGF-beta 1, c-fos and collagen-I declined, but the expression of collagen-IV in pulp vessel increased. There were no significant changes of expressions of TGF-beta 1, c-fos, collagen-I and collagen-IV in the vicinity of PDL. After adopting artificial countermeasures, the above expressions restored partly. CONCLUSION: Weightlessness might cause abnormal mineralization in dentin, and 1.5 G artificial countermeasures could eliminate the above changes of mineral metabolism. The poor mineralization of dentin might be associated with the reduced secretion of TGF-beta 1, c-fos and collagen-I in tail-suspended rats.