328 research outputs found
Highly Conductive Graphene/Ag Hybrid Fibers for Flexible Fiber-Type Transistors
Mechanically robust, flexible, and electrically conductive textiles are highly suitable for use in wearable electronic applications. In this study, highly conductive and flexible graphene/Ag hybrid fibers were prepared and used as electrodes for planar and fiber-type transistors. The graphene/Ag hybrid fibers were fabricated by the wet-spinning/drawing of giant graphene oxide and subsequent functionalization with Ag nanoparticles. The graphene/Ag hybrid fibers exhibited record-high electrical conductivity of up to 15,800 S cm(-1). As the graphene/Ag hybrid fibers can be easily cut and placed onto flexible substrates by simply gluing or stitching, ion gel-gated planar transistors were fabricated by using the hybrid fibers as source, drain, and gate electrodes. Finally, fibertype transistors were constructed by embedding the graphene/Ag hybrid fiber electrodes onto conventional polyurethane monofilaments, which exhibited excellent flexibility (highly bendable and rollable properties), high electrical performance (mu(h) = 15.6 cm(2) V-1 s(-1), I-on/I-off > 10(4)), and outstanding device performance stability (stable after 1,000 cycles of bending tests and being exposed for 30 days to ambient conditions). We believe that our simple methods for the fabrication of graphene/Ag hybrid fiber electrodes for use in fiber-type transistors can potentially be applied to the development all-organic wearable devices.111912Ysciescopu
Is lymphovascular invasion a powerful predictor for biochemical recurrence in pT3 N0 prostate cancer?: Results from the K-CaP database
To assess the impact of lymphovascular invasion (LVI) on the risk of biochemical recurrence (BCR) in pT3 N0 prostate cancer, clinical data were extracted from 1,622 patients with pT3 N0 prostate cancer from the K-CaP database. Patients with neoadjuvant androgen deprivation therapy (n = 325) or insufficient pathologic or follow-up data (n = 87) were excluded. The primary endpoint was the oncologic importance of LVI, and the secondary endpoint was the hierarchical relationships for estimating BCR between the evaluated variables. LVI was noted in 260 patients (21.5%) and was significantly associated with other adverse clinicopathologic features. In the multivariate Cox regression analysis, LVI was significantly associated with an increased risk of BCR after adjusting for known prognostic factors. In the Bayesian belief network analysis, LVI and pathologic Gleason score were found to be first-degree associates of BCR, whereas prostate-specific antigen (PSA) level, seminal vesicle invasion, perineural invasion, and high-grade prostatic intraepithelial neoplasia were considered second-degree associates. In the random survival forest, pathologic Gleason score, LVI, and PSA level were three most important variables in determining BCR of patients with pT3 N0 prostate cancer. In conclusion, LVI is one of the most powerful adverse prognostic factors for BCR in patients with pT3 N0 prostate cancer.1132Ysciescopu
A HIF-independent, CD133-mediated mechanism of cisplatin resistance in glioblastoma cells
Purpose
Glioblastoma Multiforme (GBM) is the commonest brain tumour in adults. A population of cells, known as cancer stem cells (CSCs), is thought to mediate chemo/radiotherapy resistance. CD133 is a cell surface marker to identify and isolate CSCs. However, its functional significance and the relevant microenvironment in which to study CD133 remain unknown. We examined the influence of hypoxia on CD133 expression and the potential functional significance of CD133 in glioblastoma chemoresistance.
Methods
Gene expression was analysed by qRT-PCR. siRNA technique was used to downregulate genes and confirmed by flow cytometry. IC50 values was evaluated with the Alamar blue assay.
Results
CD133 expression was upregulated in hypoxia in 2D and 3D models. There was increased resistance to chemotherapeutics, cisplatin, temozolomide and etoposide, in cells cultured in hypoxia compared to normoxia. siRNA knockdown of either HIF1a or HIF2a resulted in reduced CD133 mRNA expression with HIF2a having a more prolonged effect on CD133 expression. HIF2a downregulation sensitized GBM cells to cisplatin to a greater extent than HIF1a but CD133 knockdown had a much more marked effect on cisplatin sensitisation than knockdown of either of the HIFs suggesting a HIF-independent mechanism of cisplatin resistance mediated via CD133. The same mechanism was not involved in temozolomide resistance since downregulation of HIF1a but not HIF2a or CD133 sensitized GBM cells to temozolomide.
Conclusion
Knowledge of the mechanisms involved in the novel hypoxia-induced CD133-mediated resistance to cisplatin observed might lead to identification of new strategies that enable more effective use of current therapeutic agents
The Bulge/Disk Connection in Late-type Spirals
Recent ground-based photometric investigations suggest that central regions of late-type spirals are closely coupled to the inner disk and probably formed via secular evolution. Evidence presented in support of this model includes the predominance of exponential bulges, the correlation of bulge and disk scale lengths, blueness of the bulge and small differences between bulge and central disk colors, detection of spiral structure into the core, and rapid rotation. Recent HST observations show that our own bulge and that of M31, M32, and M33 probably harbor both an old and intermediate-age populations in agreement with models of early collapse of the spheroid plus gas transfer from the disk. Secular evolution provides a mechanism to build-up central regions in late-type spirals; mergers or accretion of small satellites could explain the brighter, kinematically distinct bulges of Sa's and SO's
Radical Prostatectomy in Korean Men Aged 75-Years or Older: Safety and Efficacy in Comparison with Patients Aged 65-69 Years
Prostate cancer is the most common type of male cancer worldwide. Although radical prostatectomy (RP) is advised for prostate cancer in patients with a life expectancy of more than 10 years by various guidelines, most elderly men still do not undergo the procedure regardless of increasing life expectancy. This study aimed to determine whether RP is suitable for patients with prostate cancer aged 75 years or older. A retrospective study of patients who underwent RP at 6 institutions between 2005 and 2012 was conducted. Patients were divided into 2 groups at the time of surgery: 65-69 years (younger group) and 75 years or older (older group). We compared clinical characteristics, pathological results, complication rates, and recurrence-free survival between the two groups. Compared with the younger group, the older group had significantly higher preoperative serum prostate-specific antigen level, pre- and postoperative Eastern Cooperative Oncology Group (ECOG) performance status grade, hypertension prevalence, and Gleason score at biopsy and RP. However, except urinary incontinence, there were no statistically significant differences in the peri- and post-operative complications. After median follow-up periods of 36 months (younger group) and 40 months (older group), the biochemical recurrence-free survival rates were not significantly different (P = 0.581). Although the urinary incontinence rate was higher in the older group, RP was a suitable option for selected Korean men aged 75 years or older with limited complication rates and excellent outcomes similar to those for patients aged 65-69 years
Epigenetic re-wiring of breast cancer by pharmacological targeting of C-terminal binding protein
The C-terminal binding protein (CtBP) is an NADH-dependent dimeric family of nuclear proteins that scaffold interactions between transcriptional regulators and chromatin-modifying complexes. Its association with poor survival in several cancers implicates CtBP as a promising target for pharmacological intervention. We employed computer-assisted drug design to search for CtBP inhibitors, using quantitative structure-activity relationship (QSAR) modeling and docking. Functional screening of these drugs identified 4 compounds with low toxicity and high water solubility. Micro molar concentrations of these CtBP inhibitors produces significant de-repression of epigenetically silenced pro-epithelial genes, preferentially in the triple-negative breast cancer cell line MDA-MB-231. This epigenetic reprogramming occurs through eviction of CtBP from gene promoters; disrupted recruitment of chromatin-modifying protein complexes containing LSD1, and HDAC1; and re-wiring of activating histone marks at targeted genes. In functional assays, CtBP inhibition disrupts CtBP dimerization, decreases cell migration, abolishes cellular invasion, and improves DNA repair. Combinatorial use of CtBP inhibitors with the LSD1 inhibitor pargyline has synergistic influence. Finally, integrated correlation of gene expression in breast cancer patients with nuclear levels of CtBP1 and LSD1, reveals new potential therapeutic vulnerabilities. These findings implicate a broad role for this class of compounds in strategies for epigenetically targeted therapeutic intervention
Biofunctionalization of zinc oxide nanowires for DNA sensory applications
We report on the biofunctionalization of zinc oxide nanowires for the attachment of DNA target molecules on the nanowire surface. With the organosilane glycidyloxypropyltrimethoxysilane acting as a bifunctional linker, amino-modified capture molecule oligonucleotides have been immobilized on the nanowire surface. The dye-marked DNA molecules were detected via fluorescence microscopy, and our results reveal a successful attachment of DNA capture molecules onto the nanowire surface. The electrical field effect induced by the negatively charged attached DNA molecules should be able to control the electrical properties of the nanowires and gives way to a ZnO nanowire-based biosensing device
cExternal beam radiation results in minimal changes in post void residual urine volumes during the treatment of clinically localized prostate cancer
<p>Abstract</p> <p>Background</p> <p>To evaluate the impact of external beam radiation therapy (XRT) on weekly ultrasound determined post-void residual (PVR) urine volumes in patients with prostate cancer.</p> <p>Methods</p> <p>125 patients received XRT for clinically localized prostate cancer. XRT was delivered to the prostate only (n = 66) or if the risk of lymph node involvement was greater than 10% to the whole pelvis followed by a prostate boost (n = 59). All patients were irradiated in the prone position in a custom hip-fix mobilization device with an empty bladder and rectum. PVR was obtained at baseline and weekly. Multiple clinical and treatment parameters were evaluated as predictors for weekly PVR changes.</p> <p>Results</p> <p>The mean patient age was 73.9 years with a mean pre-treatment prostate volume of 53.3 cc, a mean IPSS of 11.3 and a mean baseline PVR of 57.6 cc. During treatment, PVR decreased from baseline in both cohorts with the absolute difference within the limits of accuracy of the bladder scanner. Alpha-blockers did not predict for a lower PVR during treatment. There was no significant difference in mean PVR urine volumes or differences from baseline in either the prostate only or pelvic radiation groups (p = 0.664 and p = 0.458, respectively). Patients with a larger baseline PVR (>40 cc) had a greater reduction in PVR, although the greatest reduction was seen between weeks one and three. Patients with a small PVR (<40 cc) had no demonstrable change throughout treatment.</p> <p>Conclusion</p> <p>Prostate XRT results in clinically insignificant changes in weekly PVR volumes, suggesting that radiation induced bladder irritation does not substantially influence bladder residual urine volumes.</p
Optimizing Preparative Regimen for Umbilical Cord Blood Transplantation in Adult Acute Leukemia Patients: Acute Lymphoblastic Leukemia Requires Myeloablative Conditioning but Not Acute Myeloid Leukemia
Cord blood transplantation (CBT) is a valuable alternative to bone marrow transplantation in adults without readily available donors. We conducted this study to investigate the feasibility of CBT for adult patients with acute leukemia with regards to impact of different conditioning and graft-versus-host disease (GVHD) prophylaxis regimens on clinical outcomes. From 16 centers in Korea, 41 acute myeloid leukemia (AML) and 29 ALL (acute lymphoblastic leukemia) patients undergoing CBT were enrolled. For AML patients, the neutrophil engraftment was observed in 87.5% of reduced intensity conditioning (RIC) and 72.0% of myeloablative conditioning (MAC) (p = 0.242). The median RFS was 5 months and OS 7 months. Conditioning regimen did not affect relapse free survival (RFS) or overall survival (OS). GVHD prophylaxis using calcineurin inhibitors (CNI) plus methotrexate was associated with better RFS compared to CNI plus ATG (p = 0.032). For ALL patients, neutrophil engraftment was observed in 55.6% of RIC and 90.0% of MAC (p = 0.034). The median RFS was 5 months and OS 19 months. MAC regimens, especially total body irradiation (TBI)-based regimen, were associated with both longer RFS and OS compared to other conditioning regimens. In conclusion, individualized conditioning regimens will add value in terms of enhancing safety and efficacy of CBT
Integrative DNA Methylation and Gene Expression Analyses Identify DNA Packaging and Epigenetic Regulatory Genes Associated with Low Motility Sperm
In previous studies using candidate gene approaches, low sperm count (oligospermia) has been associated with altered sperm mRNA content and DNA methylation in both imprinted and non-imprinted genes. We performed a genome-wide analysis of sperm DNA methylation and mRNA content to test for associations with sperm function. (NCBI 1788). There was a trend among altered expression of these epigenetic regulatory genes and RPMM DNA methylation class.Using integrative genome-wide approaches we identified CpG methylation profiles and mRNA alterations associated with low sperm motility
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