Diabetes mellitus negatively impacts survival of patients with colon cancer, particularly in stage II disease

PURPOSE

This retrospective study aimed to determine the effects of diabetes on overall survival (OS) and cancer-specific survival (CSS) in patients with newly diagnosed colon cancers, with particular focus on the impact of diabetes on survival at each stage of colon cancer.

METHODS

From January 1999 to January 2008, 2762 consecutive patients diagnosed with colon cancer in Taipei Veterans General Hospital were enrolled. The general characteristics as well as presence of diabetes prior to colon cancer diagnosis were identified. Cox proportional hazard analyses were used for prognostic factors determination; and survival was analyzed using the Kaplan-Meier method with log-rank test.

RESULTS

A total of 469 patients (17%) had diabetes at diagnosis of colon cancer. Patients with diabetes had baseline characteristics comparable to those without diabetes with the exception that the patients with diabetes were older (>65 years). Diabetes significantly and negatively impacted OS and CSS in multivariate analyses. After adjusting for possible confounding factors, the prognostic impact of diabetes on OS and CSS was particularly significant in patients with stage II colon cancer.

CONCLUSIONS

Diabetes is a poor prognostic factor in patients with newly diagnosed colon cancer, and it may directly impact the tumor behavior of stage II disease. Further study is required to elucidate the underlying pathophysiologic mechanisms.

Loop-mediated isothermal amplification method for rapid detection of Vibrio alginolyticus, the causative agent of vibriosis in mariculture fish

AIMS

The purpose of this study was to develop a loop-mediated isothermal amplification (LAMP) method for the rapid, sensitive and simple detection of Vibrio alginolyticus in mariculture fish.

METHODS AND RESULTS

LAMP primers were designed by targeting the gyrB gene. With Bst DNA polymerase, the target DNA can be clearly amplified for 60 min at 64 degrees C in a simple water bath. The detection sensitivity of the LAMP assay for the detection of V. alginolyticus is about 3.7 x 10(2) CFU ml(-1) (3.7 CFU per reaction). LAMP products could be judged with agar gel or naked eye after the addition of SYBR Green I. There were no cross-reactions with other bacterial strains indicating a high specificity of the LAMP. The LAMP method was applied to detect V. alginolyticus-infected fish tissues effectively.

CONCLUSIONS

The LAMP established in this study is a simple, sensitive, specific, inexpensive and rapid protocol for the detection of V. alginolyticus.

SIGNIFICANCE AND IMPACT OF THE STUDY

This LAMP method provides an important diagnostic tool for the detection of V. alginolyticus infection both in the laboratory and field.

Fiber-laser-pumped CW OPO for red, green, blue laser generation

We report a CW, watt-level, red, green, and blue (RGB) laser pumped by an economical multimode (1-nm linewidth) Yb-fiber laser at 1.064 mum. A singly resonant optical parametric oscillator at 1.56 mum has two intracavity sum-frequency generators for red and blue laser generation. An extracavity second harmonic generator converts the residual pump power into green laser radiation. At 25-W pump power, the laser generated 3.9, 0.456, and 0.49 W at 633, 532, and 450 nm, respectively. The multimode pump laser offers a large temperature bandwidth for operating the RGB OPO without the need of a precision crystal temperature stabilizer.

Thermal waveguide OPO

We report a mid-infrared, CW singly resonant optical parametric oscillator (OPO) with a thermally induced waveguide in its gain crystal. We measured a numerical aperture of 0.0062 for the waveguide at 80-W intracavity power at 3.2 microm. This thermal-guiding effect benefits to the stable operation of an OPO and improves the parametric conversion efficiency by more than a factor of two when compared with that without thermal guiding.

Observation of thermal-induced optical guiding and bistability in a mid-IR continuous-wave, singly resonant optical parametric oscillator

We report the observation of thermal-induced optical guiding and bistability in a mid-IR cw, singly resonant optical parametric oscillator (SRO) at approximately 3.2 microm. The SRO employs a MgO:PPLN crystal as the gain medium and a 1-nm-linewidth Yb-fiber laser at 1.064 microm as the pump source. As soon as the pump power reaches the thermal guiding threshold at 16.5 W, the SRO shows a step increase in the parametric efficiency by a factor of 2.5. At 25 W pump power, the SRO generated 5.3 and 1.2 W at 1.58 and 3.23 microm, respectively, with single-longitudinal-mode performance for the 3.23 microm radiation.

Low-threshold, narrow-line THz-wave parametric oscillator with an intra-cavity grazing-incidence grating

We report a low-threshold, narrow-line THz-wave parametric oscillator with an intra-cavity grazing-incidence grating and a 1-mm thick, 45-mm long lithium-niobate planar waveguide. When pumped by an actively Q-switched Nd:YAG laser, the threshold energy and intensity of the parametric oscillator were about 2.2 mJ and 70 MW/cm(2), respectively. The linewidths of the output THz wave were 12 and 134 GHz with and without the intra-cavity grating, respectively.

Forward and backward terahertz-wave difference-frequency generations from periodically poled lithium niobate

We report terahertz-wave generation in the wavelength range of 190 - 210 and 457 - 507 microm from forward and backward difference frequency generations, respectively, in a 3.2-cm long multi-grating periodically poled lithium niobate (PPLN) crystal. The grating period of the PPLN crystal varies form 63 to 70 microm in 1-microm increments. The extraordinary refractive index of lithium niobate in the THz-wave range was precisely deduced from the quasi-phase-matching condition of the difference frequency generations.

Magnetic and quantum confinement effects on electronic and optical properties of graphene ribbons

Through the tight-binding calculation, we demonstrate that magnetic and quantum confinements have a great influence on the low-energy band structures of one-dimensional (1D) armchair graphene ribbons. The magnetic field first changes 1D parabolic bands into the Hall-edge states which originate in the Landau wavefunctions deformed by one or two ribbon edges. The quantum confinement dominates the characteristics of the Hall-edge states only when the Landau wavefunctions touch two ribbon edges. Then, some of the Hall-edge states evolve as the Landau states when the field strength grows. The partial flat bands (Landau levels), related to the Landau states, appear. The magnetic field dramatically modifies the energy dispersions and it changes the size of the bandgap, shifts the band-edge states, destroys the degeneracy of the energy bands, induces the semiconductor-metal transition and generates the partial flat bands. The above-mentioned magneto-electronic properties are completely reflected in the low-frequency absorption spectra--the shift of peak position, the change of peak symmetry, the alteration of peak height, the generation of new peaks and the change of absorption edges. As a result, there are magnetic-field-dependent absorption frequencies. The findings show that the magnetic field could be used to modulate the electronic properties and the absorption spectra.

Monolithically integrated laser Bragg Q-switch and wavelength converter in a PPLN crystal

We report a periodically poled lithium niobate (PPLN) crystal for both temperature-insensitive laser Q-switching and temperature-tuned wavelength conversion. The PPLN crystal consists of two sections, a 20.3-mum period section functioning as an electro-optic Bragg grating for Qswitching a diode-pumped Nd:YVO4 laser at 1064 nm and a 31-mum-period section functioning as an optical parametric generator for down converting the generated 1064-nm laser. When driving the PPLN Bragg grating with 170-V voltage pulses, we measured 181 muJ pulse energy at 1064 nm from the Nd:YVO4 laser pumped by 20.4 W diode power. The 181-muJ pulsed laser was further converted into mid-infrared radiation in the monolithic PPLN crystal with 35% parametric efficiency. The wavelengths were broadly tunable in the range of 1.75-1.88 mum (signal) and 2.7-2.44 mum (idler) via temperature without affecting the performance of the PPLN Bragg Qswitch.

Average-power mediated ultrafast laser osteotomy using a mode-locked Nd:YVO4 laser oscillator

By using a novel temporal characterization technique, we determined that a threshold average laser power of 160 mW is required to drill through a 0.75-mm-thick cortical bone for a Nd:YVO(4) mode-locked laser oscillator with a peak intensity of 1.3 GWcm(2). The ablation mechanism is identified as average-power induced carbonization followed by peak-power induced avalanche ionization in the carbonized osseous tissue.

Development of a novel bioreactor for the mechanical loading of tissue-engineered heart muscle

OBJECTIVE

In this study, we describe a novel bioreactor system to deliver controlled stretch protocols to bioengineered heart muscle (BEHM) constructs. Our primary objective was to evaluate the effect of mechanical stretch on the contractile properties of three-dimensional cardiac constructs in vitro.

METHODS

BEHMs were formed by culturing primary neonatal cardiac myocytes in a fibrin gel using a method previously developed in our laboratory. A custom bioreactor system was designed using SolidWorks (Concord, MA) and structural components were manufactured using fusion deposition modeling. We utilized the bioreactor to evaluate the effect of 2-, 6-, and 24-hour stretch protocols on the stretch-induced changes in contractile function of BEHMs.

RESULTS

We were able to demonstrate compatibility of the bioreactor system with BEHMs and were able to stretch all the constructs with zero incidence of failure. We found that loading the constructs for 2, 6, and 24 hours during a 24-hour period using a stretch protocol of 1 Hz, 10% stretch did not result in any significant change in the active force, specific force, pacing characteristics, and morphological features.

CONCLUSIONS

In this study, we demonstrate compatibility of a novel bioreactor system with BEHMs and the stability of the BEHMs in response to stretch protocols.

Electro-optic narrowband multi-wavelength filter in aperiodically poled lithium niobate

We report on an iterative design scheme for and the first experimental demonstration of active narrowband multi-wavelength filters based on aperiodically poled lithium niobate crystals. A simultaneous transmission of 8 wavelengths, each with a ~0.45-nm linewidth and nearly 100% peak transmittance, was achieved in such a device. The transmission spectrum of this device can be tuned by temperature at a rate of ~0.65 nm/ degrees C.

Electro-optic Ti:PPLN waveguide as efficient optical wavelength filter and polarization mode converter

We report the first experimental demonstration of electrically controlled Solc-type optical wavelength filters and TE-TM mode converters based on Ti-diffused periodically poled lithium niobate (Ti:PPLN) waveguides. A maximum mode conversion efficiency or a peak spectral transmittance of ~99% in the telecom C-L bands was obtained from a 9-mm long, 21.5-21.8-mum multiple-grating Ti:PPLN waveguide device with a switching voltage of as low as 22 V or 0.99 Vxd(mum)/L(cm), where d is the electrode separation and L is the electrode length. The spectral range of this device can be tuned by temperature at a rate of ~0.758 nm/ degrees C.

Electro-optic periodically poled lithium niobate Bragg modulator as a laser Q-switch

We report an electro-optic Bragg modulator using a periodically poled lithium niobate (PPLN) crystal. We measured a half-wave voltage of 160 V when transmitting a 1064 nm laser through a 14.2 mm long, 780 microm thick, 20.13 microm period PPLN crystal at the Bragg angle. We also demonstrated a Q-switched Nd:YVO(4) laser using such a PPLN Bragg modulator as its Q-switch, producing 7.8 ns, 201 microJ pulses at a 10 kHz repetition rate when pumped by a 19.35 W diode laser at 808 nm.

Juxtacrine function of interleukin-15/interleukin-15 receptor system in tumour derived human B-cell lines

Interleukin-15 (IL-15) is a cytokine that induces proliferation and promotes cell survival of human T, B and NK cells. IL-15 and interleukin-2 (IL-2) exhibit a similar spectrum of immune effects and share the IL-2 receptor (IL-2R) subunits IL-2Rbeta and IL-2Rgamma(c) for signalling in haematopoietic cells. Furthermore, each cytokine has a private alpha receptor, namely IL-2Ralpha for IL-2 and IL-15Ralpha for IL-15, that functions in ligand binding. Using reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) methods, the expression and secretion of IL-15 and IL-15Ralpha in tumour-derived B-cell lines were studied. The results as presented in this study identify that IL-15 mRNA is predominantly expressed in EBV positive (EBV(+)) B-cell lines, although IL-15Ralpha is ubiquitously and constitutively expressed in all these B-cell lines. Although no detectable levels of IL-15 protein secretion were observed in any of these cell lines, we were able to detect membrane-bound expression of IL-15 protein by FACS analysis in some cell lines. These data imply that the IL-15/IL-15R system requires complex regulatory mechanisms for protein secretion. Taken together, we speculate that these results suggest a juxtacrine, intracrine function for IL-15/IL-15R.

Light-enhanced electro-optic spectral tuning in annealed proton-exchanged periodically poled lithium niobate channel waveguides

We report the observation of light-enhanced electro-optic spectral tuning in annealed proton-exchanged, asymmetric domain-duty-cycle periodically poled lithium niobate (PPLN) channel waveguides for second-harmonic generation. The spectral tuning rate was increased rapidly from 0.07 nm/(kV/mm) to a saturated value of 0.32 nm/(kV/mm) in a 30%/70% domain-duty-cycle PPLN waveguide when the fundamental pump power near 1534 nm was increased from 0.6 to 46 mW. The second-harmonic laser power at 767 nm was identified to be the source enhancing the spectral tuning.

A comparison of sexual satisfaction and post-natal depression in the UK and Taiwan

AIM

To compare the sexual expression and sexual satisfaction of women in the UK and Taiwan before and after childbirth, to determine if there is an association between self reported sexual satisfaction and postnatal depression (PND) and the main sources of sexual information for women during this period.

METHOD

A comparative survey of postnatal women in the UK and Taiwan using a selfadministered questionnaire, a semi structured interview and the Edinburgh Postnatal Depression Scale (EPDS) to investigate sexual satisfaction, sexual expression and main sources of information as well the prevalence of postnatal depression.

RESULTS

Seventy per cent of the UK women and 89% of the Taiwanese women were generally satisfied with their sex life during the postnatal period although in both countries women thought that sexual expression was not as important to themselves as to their partner. There were differences in ranking criteria for physical and emotional sexual satisfaction in the two countries. Eighty-three per cent of UK women had sufficient information about sex during the postnatal period compared to 60% of Taiwanese women. There was no significant difference in the prevalence of PND (18% UK, 19% Taiwan p < 0.01 ANOVA) but significant negative associations (correlation coefficient) between 'sexual self-confidence' and PND in the UK (p < 0.01) and Taiwan (p < 0.05). UK Women with an unsatisfactory sex life (p < 0.05), insufficient sexual information (p < 0.05) and sexual worries after birth (p < 0.05) were more likely to have symptoms of PND. There was a strong association between a poor relationship with her partner and PND (p < 0.001).

CONCLUSIONS

These associations may be either a consequence of or a contributing factor to PND. The observed differences between the two countries may be attributed to cross cultural factors and differences in health care systems although further investigation is required.

Low-energy electronic properties of the AB-stacked few-layer graphites

In the presence of a perpendicular electric field, the low-energy electronic properties of the AB-stacked N-layer graphites with layer number N = 2, 3, and 4, respectively, are examined through the tight-binding model. The interlayer interactions, the number of layers, and the field strength are closely related to them. The interlayer interactions can significantly change the energy dispersions and produce new band-edge states. Bi-layer and four-layer graphites are two-dimensional semimetals due to a tiny overlap between the valence and conduction bands, while tri-layer graphite is a narrow-gap semiconductor. The electric field affects the low-energy electronic properties: the production of oscillating bands, the cause of subband (anti)crossing, the change in subband spacing, and the increase in band-edge states. Most importantly, the aforementioned effects are revealed completely in the density of states, e.g. the generation of special structures, the shift in peak position, the change in peak height, and the alteration of the band gap.

Single-longitudinal-mode, tunable dual-wavelength,CW Nd:YVO(4) laser

We report a single-longitudinal-mode CW diode-pumped Nd:YVO(4) laser emitting at both 1064 and 1342 nm with 10% optical efficiency at 20-W pump power. The measured spectral widths at 1064 and 1342 nm were less than 450 MHz and 400 MHz, respectively. The two emission wavelengths can be independently tuned over the lasing bandwidths of the dual-wavelength laser.

Identification of differentially transcribed genes in human lymphoblastoid cells irradiated with 0.5 Gy of gamma-ray and the involvement of low dose radiation inducible CHD6 gene in cell proliferation and radiosensitivity

PURPOSE

To identify candidate genes specifically involved in response to low-dose irradiation in human lymphoblastoid cells; to better clarify the role of the human chromodomain helicase DNA binding protein 6 gene (CHD6), one of these genes, in cell proliferation and radiosensitivity.

MATERIALS AND METHODS

DNA microarray technology was used to analyse global transcriptional profile in human lymphoblastoid AHH-1 cells at 4 h after exposure to 0.5 Gy of gamma-ray. Gene expression changes were confirmed by semi-quantitative reverse transcription--polymerase chain reaction (RT-PCR) and Northern blot. RNA interfering technology was employed to knock-down the CHD6 gene in A549 cells. Colony-forming ability was used to analyse radiosensitivity.

RESULTS

The microarray assay revealed a set of 0.5 Gy-responsive genes, including 30 up-regulated genes and 45 down-regulated genes. The up-regulated genes include a number of genes involved in: signal transduction pathways, e.g., STAT3, CAMKK2, SIRT1, CREM, MAPK3K7IP2 and GPR56; transcription or DNA-binding, e.g., CHD6, CRSP3, SNURF, SH2 domain binding protein 1 and MIZF. Some of the down-regulated genes are involved in: cytoskeleton and cell movement (WASF2, LCP1, MSN, NIPSNAP1, KIF2C); DNA replication and repair (MCM2, MCM3, MCM7 and XRCC-4). Radiation-increased expression of CHD6 was also found in A549 cells and HeLa cells. The sustained CHD6 induction was restricted to relatively low doses (0.2 Gy or 0.5 Gy), no change occurring after 4 Gy irradiation. Silencing of CHD6 mediated by siRNA increased the growth rate of A549 cells by 40 approximately 60%. Most importantly, silencing CHD6 led to an increased radioresistance of A459 cells to radiation doses up to 2 Gy, but barely affected the sensitivity of cells at 4 and 8 Gy.

CONCLUSION

This study has identified a set of genes responsive to 0.5 Gy of gamma-rays. CDH6 gene can be specifically up-regulated by low dose irradiation, and its inducible expression could be involved in a low dose hypersensitive response.

Enhanced terahertz-wave parametric generation and oscillation in lithium niobate waveguides at terahertz frequencies

We observed parametric-generation efficiency of 1.61% from 1064 to 1071 nm and at 162 microm in a 0.5 mm thick, 45 mm long z-cut congruent lithium niobate waveguide with a pump energy of 2.2 mJ and a pump pulse width of 5.8 ns. We also measured an ultralow-threshold intensity of 70 MW/cm2 for a 1064 nm pumped parametric oscillator resonating at 1071 nm and emitting at 162 microm with a 1 mm thick, 45 mm long lithium niobate waveguide.