A novel berberine derivative targeting adipocyte differentiation to alleviate TNF-α-induced inflammatory effects and insulin resistance in OP9 cells

Inflammation and insulin resistance play important roles in the development and progression of type 2 diabetes mellitus. The enhancement of adipocyte differentiation can improve insulin sensitivity by increasing glucose uptake, improving insulin signaling, and reducing inflammation. However, only a few adipogenic agents have shown clinical success in patients with type 2 diabetes mellitus. The therapeutic potential of berberine in type 2 diabetes mellitus was confirmed in terms of the target gene-disease relationship using a network pharmacology database prior to synthesizing the derivatives. Novel berberine derivatives were synthesized, and compound 3b promoted adipocyte differentiation and improvement of insulin resistance in OP9 cells. Compound 3b significantly increased the expression of key adipogenic markers including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein β (C/EBPβ) and promoted lipid accumulation without cytotoxicity. Furthermore, tumor necrosis factor α (TNF-α)-induced inhibition of adipocyte differentiation and the elevation of inflammatory responses were reversed by compound 3b. Subsequently glucose uptake level through insulin sensitivity improvement was enhanced by compound 3b. Mechanistically, TNF-α activated mitogen-activated protein kinases (MAPKs): ERK, JNK, and p38, whereas compound 3b attenuated phosphorylation of three MAPKs. Finally, in silico molecular docking suggested the possible binding sites of compound 3b on PPARγ. Collectively, the adipogenic and glucose uptake effects of compound 3b were associated with its anti-inflammatory effects and reduced phosphorylation of MAPKs. These findings suggest that the berberine derivative compound 3b may be a potent antidiabetic agent.

A superconducting nanowire single-photon camera with 400,000 pixels

For the past 50 years, superconducting detectors have offered exceptional sensitivity and speed for detecting faint electromagnetic signals in a wide range of applications. These detectors operate at very low temperatures and generate a minimum of excess noise, making them ideal for testing the non-local nature of reality1,2, investigating dark matter3,4, mapping the early universe5-7 and performing quantum computation8-10 and communication11-14. Despite their appealing properties, however, there are at present no large-scale superconducting cameras-even the largest demonstrations have never exceeded 20,000 pixels15. This is especially true for superconducting nanowire single-photon detectors (SNSPDs)16-18. These detectors have been demonstrated with system detection efficiencies of 98.0% (ref. 19), sub-3-ps timing jitter20, sensitivity from the ultraviolet21 to the mid-infrared22 and microhertz dark-count rates3, but have never achieved an array size larger than a kilopixel23,24. Here we report on the development of a 400,000-pixel SNSPD camera, a factor of 400 improvement over the state of the art. The array spanned an area of 4 × 2.5 mm with 5 × 5-μm resolution, reached unity quantum efficiency at wavelengths of 370 nm and 635 nm, counted at a rate of 1.1 × 105 counts per second (cps) and had a dark-count rate of 1.0 × 10-4 cps per detector (corresponding to 0.13 cps over the whole array). The imaging area contains no ancillary circuitry and the architecture is scalable well beyond the present demonstration, paving the way for large-format superconducting cameras with near-unity detection efficiencies across a wide range of the electromagnetic spectrum.

WJCPR11 reverses the TNF-α-induced inhibition of adipocyte differentiation and glucose uptake

Berberine is a natural isoquinoline alkaloid present in various herbs and is effective against metabolic syndrome in the pre-diabetic stage and high insulin resistance. The present study aimed to determine the effectiveness of WJCPR11, a berberine derivative that is commonly used for diabetes treatment, in ameliorating insulin resistance and diabetes treatment. WJCPR11 promoted adipocyte differentiation to a higher extent than other berberine derivatives and showed no noticeable toxicity in its effective concentration range. It increased the mRNA expression levels and protein abundance of adipogenic markers, including peroxisome proliferator-activated receptor γ (PPARγ), glucose transporter type 4 (GluT4), and fatty acid synthase (FAS), and markedly enhanced the level of adiponectin, a distinct marker of insulin sensitivity. Meanwhile, the mRNA levels of inflammatory markers such as plasminogen activator inhibitor-1 (PAI-1), monocyte chemoattractant protein-1 (MCP-1), and interleukin 6 (IL-6) were reduced after WJCPR11 treatment. Furthermore, the tumor necrosis factor-α (TNF-α)-induced inhibition of adipocyte differentiation and downregulation of glucose uptake were markedly reversed by WJCPR11 treatment. Collectively, the findings of this study indicate that WJCPR11 has great potential for diabetes treatment.

Quantum circuits with many photons on a programmable nanophotonic chip

Growing interest in quantum computing for practical applications has led to a surge in the availability of programmable machines for executing quantum algorithms1,2. Present-day photonic quantum computers3-7 have been limited either to non-deterministic operation, low photon numbers and rates, or fixed random gate sequences. Here we introduce a full-stack hardware-software system for executing many-photon quantum circuit operations using integrated nanophotonics: a programmable chip, operating at room temperature and interfaced with a fully automated control system. The system enables remote users to execute quantum algorithms that require up to eight modes of strongly squeezed vacuum initialized as two-mode squeezed states in single temporal modes, a fully general and programmable four-mode interferometer, and photon number-resolving readout on all outputs. Detection of multi-photon events with photon numbers and rates exceeding any previous programmable quantum optical demonstration is made possible by strong squeezing and high sampling rates. We verify the non-classicality of the device output, and use the platform to carry out proof-of-principle demonstrations of three quantum algorithms: Gaussian boson sampling, molecular vibronic spectra and graph similarity8. These demonstrations validate the platform as a launchpad for scaling photonic technologies for quantum information processing.

State Readout of a Trapped Ion Qubit Using a Trap-Integrated Superconducting Photon Detector

We report high-fidelity state readout of a trapped ion qubit using a trap-integrated photon detector. We determine the hyperfine qubit state of a single ^{9}Be^{+} ion held in a surface-electrode rf ion trap by counting state-dependent ion fluorescence photons with a superconducting nanowire single-photon detector fabricated into the trap structure. The average readout fidelity is 0.9991(1), with a mean readout duration of 46  μs, and is limited by the polarization impurity of the readout laser beam and by off-resonant optical pumping. Because there are no intervening optical elements between the ion and the detector, we can use the ion fluorescence as a self-calibrated photon source to determine the detector quantum efficiency and its dependence on photon incidence angle and polarization.

Broadband quadrature-squeezed vacuum and nonclassical photon number correlations from a nanophotonic device

We report demonstrations of both quadrature-squeezed vacuum and photon number difference squeezing generated in an integrated nanophotonic device. Squeezed light is generated via strongly driven spontaneous four-wave mixing below threshold in silicon nitride microring resonators. The generated light is characterized with both homodyne detection and direct measurements of photon statistics using photon number-resolving transition-edge sensors. We measure 1.0(1) decibels of broadband quadrature squeezing (~4 decibels inferred on-chip) and 1.5(3) decibels of photon number difference squeezing (~7 decibels inferred on-chip). Nearly single temporal mode operation is achieved, with measured raw unheralded second-order correlations g ⁽²⁾ as high as 1.95(1). Multiphoton events of over 10 photons are directly detected with rates exceeding any previous quantum optical demonstration using integrated nanophotonics. These results will have an enabling impact on scaling continuous variable quantum technology.

Discovery and development of berberine derivatives as stimulants of osteoblast differentiation

Berberine is an essential phytochemical for the treatment of various diseases; however, when used to treat osteoporosis, it has minor effect as compared with that of the currently available drugs. This study aimed to find a new compound that would have a better anti-osteoporotic effect than that of berberine. Based on structure and activity relationship study, we identified compound 2c, a berberine derivative, to be the most potent compound to affect osteoblast differentiation. Compound 2c was more effective than berberine and exhibited no toxicity within its effective concentration. Compound 2c increased, in a dose-dependent manner, ALP activity during osteoblast differentiation and enhanced the mRNA expression of osteogenic factors including ALP, Runx2, and Osterix. Furthermore, compound 2c increased the transcriptional activity induced by BMP4 on the ALP and BSP promoter. Taken together, compound 2c shows promise as a therapeutic agent for osteoporosis by promoting osteoblast differentiation.

Detector-Agnostic Phase-Space Distributions

The representation of quantum states via phase-space functions constitutes an intuitive technique to characterize light. However, the reconstruction of such distributions is challenging as it demands specific types of detectors and detailed models thereof to account for their particular properties and imperfections. To overcome these obstacles, we derive and implement a measurement scheme that enables a reconstruction of phase-space distributions for arbitrary states whose functionality does not depend on the knowledge of the detectors, thus defining the notion of detector-agnostic phase-space distributions. Our theory presents a generalization of well-known phase-space quasiprobability distributions, such as the Wigner function. We implement our measurement protocol, using state-of-the-art transition-edge sensors without performing a detector characterization. Based on our approach, we reveal the characteristic features of heralded single- and two-photon states in phase space and certify their nonclassicality with high statistical significance.

A high-density customizable microwave vacuum feedthrough for cryogenic applications

We have designed, constructed, and tested an electrical vacuum feedthrough that can carry a large number of microwave signal lines, has high vacuum compatibility, and is highly customizable. We found that it had a leak rate of approximately 10^-7 Pa L/s (7.5 × 10^-9 torr L/s), making it suitable for high-vacuum systems such as cryostats. The feedthrough is low-cost, and the printed circuit board-based design allows the choice of any surface-mountable microwave connector. We additionally verified operation through consistent use on a real cryogenic system and verified the mechanical robustness of the feedthrough.

Quantum-enhanced interferometry with large heralded photon-number states

Quantum phenomena such as entanglement can improve fundamental limits on the sensitivity of a measurement probe. In optical interferometry, a probe consisting of N entangled photons provides up to aN enhancement in phase sensitivity compared to a classical probe of the same energy. Here, we employ high-gain parametric down-conversion sources and photon-number-resolving detectors to perform interferometry with heralded quantum probes of sizes up to N = 8 (i.e. measuring up to 16-photon coincidences). Our probes are created by injecting heralded photon-number states into an interferometer, and in principle provide quantum-enhanced phase sensitivity even in the presence of significant optical loss. Our work paves the way towards quantum-enhanced interferometry using large entangled photonic states.

A superconducting thermal switch with ultrahigh impedance for interfacing superconductors to semiconductors

A number of current approaches to quantum and neuromorphic computing use superconductors as the basis of their platform or as a measurement component, and will need to operate at cryogenic temperatures. Semiconductor systems are typically proposed as a top-level control in these architectures, with low-temperature passive components and intermediary superconducting electronics acting as the direct interface to the lowest-temperature stages. The architectures, therefore, require a low-power superconductor-semiconductor interface, which is not currently available. Here we report a superconducting switch that is capable of translating low-voltage superconducting inputs directly into semiconductor-compatible (above 1,000 mV) outputs at kelvin-scale temperatures (1K or 4 K). To illustrate the capabilities in interfacing superconductors and semiconductors, we use it to drive a light-emitting diode (LED) in a photonic integrated circuit, generating photons at 1K from a low-voltage input and detecting them with an on-chip superconducting single-photon detector. We also characterize our device's timing response (less than 300 ps turn-on, 15 ns turn-off), output impedance (greater than 1MΩ), and energy requirements (0.18fJ/μm2,3.24mV/nW).

Demonstration of Einstein-Podolsky-Rosen Steering Using Hybrid Continuous- and Discrete-Variable Entanglement of Light

Einstein-Podolsky-Rosen steering is known to be a key resource for one-sided device-independent quantum information protocols. Here we demonstrate steering using hybrid entanglement between continuous- and discrete-variable optical qubits. To this end, we report on suitable steering inequalities and detail the implementation and requirements for this demonstration. Steering is experimentally certified by observing a violation by more than 5 standard deviations. Our results illustrate the potential of optical hybrid entanglement for applications in heterogeneous quantum networks that would interconnect disparate physical platforms and encodings.

Early development of de novo hepatocellular carcinoma after direct-acting agent therapy: Comparison with pegylated interferon-based therapy in chronic hepatitis C patients

Patients with chronic hepatitis C who achieve a sustained viral response after pegylated interferon therapy have a reduced risk of hepatocellular carcinoma, but the risk after treatment with direct-acting antivirals is unclear. We compared the rates of early development of hepatocellular carcinoma after direct-acting antivirals and after pegylated interferon therapy. We retrospectively analysed 785 patients with chronic hepatitis C who had no history of hepatocellular carcinoma (211 treated with pegylated interferon, 574 with direct-acting antivirals) and were followed up for at least 24 weeks after antiviral treatment. De novo hepatocellular carcinoma developed in 6 of 574 patients receiving direct-acting antivirals and in 1 of 211 patients receiving pegylated interferon. The cumulative incidence of early hepatocellular carcinoma development did not differ between the treatment groups either for the whole cohort (1.05% vs 0.47%, P = .298) or for those patients with Child-Pugh Class A cirrhosis (3.73% vs 2.94%, P = .827). Multivariate analysis indicated that alpha-fetoprotein level >9.5 ng/mL at the time of end-of-treatment response was the only independent risk factor for early development of hepatocellular carcinoma in all patients (P < .0001, hazard ratio 176.174, 95% confidence interval 10.768-2882.473) and in patients treated with direct-acting agents (P < .0001, hazard ratio 128.402, 95% confidence interval 8.417-1958.680). In conclusion, the rate of early development of hepatocellular carcinoma did not differ between patients treated with pegylated interferon and those treated with direct-acting antivirals and was associated with the serum alpha-fetoprotein level at the time of end-of-treatment response.

UV superconducting nanowire single-photon detectors with high efficiency, low noise, and 4 K operating temperature

For photon-counting applications at ultraviolet wavelengths, there are currently no detectors that combine high efficiency (> 50%), sub-nanosecond timing resolution, and sub-Hz dark count rates. Superconducting nanowire single-photon detectors (SNSPDs) have seen success over the past decade for photon-counting applications in the near-infrared, but little work has been done to optimize SNSPDs for wavelengths below 400 nm. Here, we describe the design, fabrication, and characterization of UV SNSPDs operating at wavelengths between 250 and 370 nm. The detectors have active areas up to 56 μm in diameter, 70 - 80% efficiency at temperatures up to 4.2 K, timing resolution down to 60 ps FWHM, blindness to visible and infrared photons, and dark count rates of ∼ 0.25 counts/hr for a 56 μm diameter pixel. These performance metrics make UV SNSPDs ideal for applications in trapped-ion quantum information processing, lidar studies of the upper atmosphere, UV fluorescent-lifetime imaging microscopy, and photon-starved UV astronomy.

Verification of calibration methods for determining photon-counting detection efficiency using superconducting nano-wire single photon detectors

In recent years several ways to radiometrically calibrate optical fiber-coupled detectors have been developed. However, fiber-coupled calibration methods for single photon detectors have not been compared by national metrology institutes in order to validate their equivalence or traceability to the international systems of units yet.. Here, we present the comparison of radiometric calibration methods traceable to a NIST cryogenic radiometer at the 'few-photon' level. The calibration methods are based on metrology grade optical power meters. The expanded (k = 2) relative standard uncertainties of the calibration methods for the detection efficiency are of the order of 0.5%. However, the results changed relatively by 10% with a different set of optical fibers and mating connectors. These results stress the importance of fiber-core dimensions and fiber-connector repeatability.

Heralded Single Photons Based on Spectral Multiplexing and Feed-Forward Control

We propose and experimentally demonstrate a novel approach to a heralded single-photon source based on spectral multiplexing (SMUX) and feed-forward-based spectral manipulation of photons created by means of spontaneous parametric down-conversion in a periodically poled LiNbO_{3} crystal. As a proof of principle, we show that our three-mode SMUX increases the heralded single-photon rate compared to that of the individual modes without compromising the quality of the emitted single photons. We project that by adding further modes, our approach can lead to a deterministic single-photon source.

Detector-Independent Verification of Quantum Light

We introduce a method for the verification of nonclassical light which is independent of the complex interaction between the generated light and the material of the detectors. This is accomplished by means of a multiplexing arrangement. Its theoretical description yields that the coincidence statistics of this measurement layout is a mixture of multinomial distributions for any classical light field and any type of detector. This allows us to formulate bounds on the statistical properties of classical states. We apply our directly accessible method to heralded multiphoton states which are detected with a single multiplexing step only and two detectors, which are in our work superconducting transition-edge sensors. The nonclassicality of the generated light is verified and characterized through the violation of the classical bounds without the need for characterizing the used detectors.

UV-sensitive superconducting nanowire single photon detectors for integration in an ion trap

We demonstrate superconducting nanowire single photon detectors with 76 ± 4% system detection efficiency at a wavelength of 315 nm and an operating temperature of 3.2 K, with a background count rate below 1 count per second at saturated detection efficiency. We propose integrating these detectors into planar surface electrode radio-frequency Paul traps for use in trapped ion quantum information processing. We operate detectors integrated into test ion trap structures at 3.8 K both with and without typical radio-frequency trapping electric fields. The trapping fields reduce system detection efficiency by 9%, but do not increase background count rates.

Demonstration of Einstein-Podolsky-Rosen Steering Using Single-Photon Path Entanglement and Displacement-Based Detection

We demonstrate the violation of an Einstein-Podolsky-Rosen steering inequality developed for single-photon path entanglement with displacement-based detection. We use a high-rate source of heralded single-photon path-entangled states, combined with high-efficiency superconducting-based detectors, in a scheme that is free of any postselection and thus immune to the detection loophole. This result conclusively demonstrates single-photon entanglement in a one-sided device-independent scenario, and opens the way towards implementations of device-independent quantum technologies within the paradigm of path entanglement.

High-efficiency superconducting nanowire single-photon detectors fabricated from MoSi thin-films

We report on MoSi SNSPDs which achieved high system detection efficiency (87.1 ± 0.5% at 1542 nm) at 0.7 K and we demonstrate that these detectors can also be operated with saturated internal efficiency at a temperature of 2.3 K in a Gifford-McMahon cryocooler. We measured a minimum system jitter of 76 ps, maximum count rate approaching 10 MHz, and polarization dependence as low as 3.3 ± 0.1%. The performance of MoSi SNSPDs at 2.3 K is similar to the performance of WSi SNSPDs at < 1 K. The higher operating temperature of MoSi SNSPDs makes these devices promising for widespread use due to the simpler and less expensive cryogenics required for their operation.

Downregulation of microRNA-362-3p and microRNA-329 promotes tumor progression in human breast cancer

p130Cas regulates cancer progression by driving tyrosine receptor kinase signaling. Tight regulation of p130Cas expression is necessary for survival, apoptosis, and maintenance of cell motility in various cell types. Several studies revealed that transcriptional and post-translational control of p130Cas are important for maintenance of its expression and activity. To explore novel regulatory mechanisms of p130Cas expression, we studied the effect of microRNAs (miRs) on p130Cas expression in human breast cancer MCF7 cells. Here, we provide experimental evidence that miR-362-3p and miR-329 perform a tumor-suppressive function and their expression is downregulated in human breast cancer. miR-362-3p and miR-329 inhibited cellular proliferation, migration, and invasion, thereby suppressing tumor growth, by downregulating p130Cas. Ectopic expression of p130Cas attenuated the inhibitory effects of the two miRs on tumor progression. Relative expression levels of miR-362-3p/329 and p130Cas between normal and breast cancer correlated inversely; miR-362-3p/329 expression was decreased, whereas that of p130Cas increased in breast cancers. Furthermore, we showed that downregulation of miR-362-3p and miR-329 was caused by differential DNA methylation of miR genes. Enhanced DNA methylation (according to methylation-specific PCR) was responsible for downregulation of miR-362-3p and miR-329 in breast cancer. Taken together, these findings point to a novel role for miR-362-3p and miR-329 as tumor suppressors; the miR-362-3p/miR-329-p130Cas axis seemingly has a crucial role in breast cancer progression. Thus, modulation of miR-362-3p/miR-329 may be a novel therapeutic strategy against breast cancer.

The influence of geometrical characteristics on the photocatalytic activity of TiO2 nanotube arrays for degradation of refractory organic pollutants in wastewater

The effects of geometrical characteristics such as surface area (SA) and porosity of TiO2 nanotube arrays (TNAs) on its photocatalytic activity were investigated by applying variable voltages and reaction times for the anodization of Ti substrates. While larger SA of nanotubes was observed under higher applied potential, the porosity of TNAs decreased by increasing anodizing voltage. Under applied potential of 80 V, the SA of TNAs increased from 0.164 to 0.471 m2/g as anodization time increased from 1 to 5 hours, respectively. However, no significant effect on the porosity of TNAs was observed. On the other hand, both SA and porosity of TNAs, synthesized at 60 V, increased by augmenting the anodization time from 1 to 3 hours. But further increasing of anodization time to 5 hours resulted in a decreased SA of TNAs with no effect on their porosity. Accordingly, the TNAs with SA of 0.368 m2/g and porosity of 47% showed the highest photocatalytic activity for degradation of 4-chlorobenzoic acid (4CBA). Finally, the degradation of refractory model compounds such as carbamazepine and bisphenol-A was tested and more than 50% of both compounds could be degraded under UV-A irradiation (λmax=365 nm).

Efficient Bell state analyzer for time-bin qubits with fast-recovery WSi superconducting single photon detectors

We experimentally demonstrate a high-efficiency Bell state measurement for time-bin qubits that employs two superconducting nanowire single-photon detectors with short dead-times, allowing projections onto two Bell states, |ψ⁻〉 and |ψ⁺〉. Compared to previous implementations for time-bin qubits, this yields an increase in the efficiency of Bell state analysis by a factor of thirty.

Mid-long term effect of non-ablative high radiofrequency therapy on the rabbit dermal extracellular matrix

This study quantitatively investigated the postoperative effects of radiofrequency (RF) application on the normal dermal extracellular matrix (ECM) of in vivo rabbits. Postoperative effects were evaluated by histology and atomic force microscopy analysis of dermal tissues treated using three RF energy levels (10 ~ 30 W) and either a single- or multiple-pass procedure. Progressive changes in the morphology of rabbit dermal ECMs were investigated over a 30-day postoperartive period. All RF-treated groups, except for the low energy group (10 W), displayed more prominent inflammatory responses compared to the control. This inflammatory reaction was more prominent a day after application. Dermal tissues 30 days after RF application exhibited prominent myofibroblast activity associated with ECM contractile activity during wound healing in addition to chronic inflammation. A decrease in the morphology of dermal ECMs after RF application continued until seven days postoperatively. The ECM diameter increased to near baseline at 30 days postoperatively. Low energy and multi-pass applications resulted in greater collagen fibril contraction and recovery at the ultra-structural level at 30 days postoperatively than did a single high energy application.

Detection-loophole-free test of quantum nonlocality, and applications

We present a source of entangled photons that violates a Bell inequality free of the "fair-sampling" assumption, by over 7 standard deviations. This violation is the first reported experiment with photons to close the detection loophole, and we demonstrate enough "efficiency" overhead to eventually perform a fully loophole-free test of local realism. The entanglement quality is verified by maximally violating additional Bell tests, testing the upper limit of quantum correlations. Finally, we use the source to generate "device-independent" private quantum random numbers at rates over 4 orders of magnitude beyond previous experiments.

Highly efficient secretion of heterologous proteins from Saccharomyces cerevisiae using inulinase signal peptides

The INU genes of Kluyveromyces marxianus encode inulinases which are readily secreted from Saccharomyces cerevisiae into the culture medium. To evaluate the utility of the INU signal peptides for the secretion of heterologous proteins from S. cerevisiae, a variety of expression and secretion vectors were constructed with GAL10 promoter and GAL7 terminator. The coding sequence for human lipocortin-1 (LC1) was inserted in-frame with the INU signal sequences, and then the secretion efficiency and localization of LC1 were investigated in more detail and compared with those when being expressed by the vector with the MFalpha1 leader peptide. The vector systems with INU signal peptides secreted ca. 95% of the total LC1 expressed into the extracellular medium, while the MFalpha1 leader peptide-containing vector resulted in very low secretion efficiency below 10%. In addition, recombinant human interleukin-2 (IL-2) was expressed and secreted with the vector systems with INU signal peptide, and a majority fraction of the human IL-2 expressed was found to be secreted into the extracellular medium as observed in LC1 expression. (c) 1995 John Wiley & Sons, Inc.

Alteration of reducing powers in an isogenic phosphoglucose isomerase (pgi)-disrupted Escherichia coli expressing NAD(P)-dependent malic enzymes and NADP-dependent glyceraldehyde 3-phosphate dehydrogenase

AIMS

To understand the intracellular reducing power metabolism, growth and intracellular NAD(P)H concentrations of a phosphoglucose isomerase (pgi)-disrupted Escherichia coli (KS002) were investigated with the expressions of redox enzymes.

METHODS AND RESULTS

The isogenic pgi-mutation enabled E. coli to harbour two times both the intracellular NADPH and NADH at half the growth rate. The wild-type expressing NAD-dependent malic enzyme (maeA) was incapable of sufficient growth (<0·02 h(-1)), and the growth retardations were distinctively recovered when NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (gapB) from Bacillus subtilis was coexpressed. The KS002 expressing maeA harboured the highest intracellular reducing powers (NADPH of 3·9 and NADH of 5·2 μmol g DCW(-1) ) by three times each of those in wild type. The expression of NADP-dependent malic enzyme (maeB) enabled wild-type and KS002 strains to grow without significant alteration.

CONCLUSIONS

The alterations of reducing powers and the growth were analysed in the genetic engineered E. coli strains. The potential application of the cells with the high intracellular NAD(P)H level is discussed based on the results.

SIGNIFICANCE AND IMPACT OF THE STUDY

Metabolic engineering strategy for higher reducing power regeneration is provided.

Thermoelectric properties of nanocrystalline Ca(3-x)Cu(x)Co4O9 (0 < or = x < or = 0.32) for power generation

We successfully synthesized nano-sized Ca(3-x)Cu(x)Co4O9 (0 < or = x < or = 0.32) powders by solution combustion process. Plate-like grains and porous structure were observed in the sintered Ca(3-x)Cu(x)Co4O9 ceramics. The sintered Ca(3-x)Cu(x)Co4O9 showed a monoclinic symmetry. The electrical conductivity of the Ca(3-x)Cu(x)Co4O9 increased with increasing temperature, indicative of a semiconducting behavior. The added Cu led to a significant increase in the electrical conductivity. The Seebeck coefficient of the Cu-added Ca(3-x)Cu(x)Co4O9 was much higher than that of the Cu-free Ca3Co4O9. The highest power factor (9.99 x 10(-4) Wm(-1)K-2) was obtained for Ca2.76Cu0.24Co4O9 at 800 degrees C.

Improvement in high-temperature thermoelectric properties by adding Mn for Co in Ca3Co4O9

Nano-sized Ca3Co(4-x)Mn(x)O9 (0 < or = x < or = 0.6) thermoelectric powders were synthesized by solution combustion method, using aspartic acid as fuel. The microstructure and high-temperature (500-800 degrees C) thermoelectric properties of the Ca3Co(4-x)Mn(x)O9 were investigated. The addition of Mn for Co in Ca3Co(4-x)Mn(x)O9 resulted in a decrease of the electrical conductivity and a significant increase of the Seebeck coefficient. Consequently, the power factor was remarkably enhanced by the addition of Mn. Ca3Co(3.7)Mn(0.3)O9 sample showed the highest value of the power factor (1.24 x 10(-4) Wm(-1) K(-2)) at 800 degrees C. We believe that the Ca3Co(4-x)Mn(x)O9 is strongly desirable as a novel high-temperature thermoelectric material for power generation.

Electrical properties of nanocrystalline Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta) (0.1 < or = x < or = 0.3) ceramics for IT-SOFC

Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta) (0.1 < or = x < or = 0.3) nano-sized powders were successfully synthesized by the solution combustion synthesis process. The calcined nanopowders showed a ceria-based single phase with a cubic fluorite structure. In this study, we discussed the structural and electrical characteristics of the sintered Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta). We obtained high-quality Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta) ceramics with a high density, ultra-fine grain size, and high electrical conductivity even at low sintering temperature using the nanosized powders. The electrical conductivities at 800 degrees C for the Ce(0.8)Sm(0.2)O(2-delta) sintered at 1400 degrees C and the Ce(0.8)Gd(0.2)O(2-delta) sintered at 1350 degrees C were 0.110 and 0.104 Scm(-1), respectively.

The Glu346Lys polymorphism and frameshift mutations of the Methyl-CpG Binding Domain 4 gene in gastrointestinal cancer

MBD4 (Methyl-CpG Binding Domain 4) is a human DNA repair protein that may be involved in DNA mismatch repair. The polymorphisms and frameshift mutations in MBD4 may influence cancer susceptibility and the development of cancer. The specific aim of this study was to investigate whether frameshift mutations of the MBD4 gene and the codon 346 polymorphism were associated with microsatellite instability (MSI) and the risk for gastrointestinal cancer. We examined the MSI, frameshift mutations and polymorphisms of the MBD4 gene in 84 patients with gastric cancers, 82 colorectal cancers and 299 healthy controls. MSI was found in 19 (22.6%) and 26 (31.7%) of the gastric and colorectal cancer samples, respectively. The mutation analysis revealed no frameshift mutations in the MBD4 gene among the gastrointestinal cancers. The frequencies of genotypes: Glu/Glu, Glu/Lys and Lys/Lys were 41.7% (35/84), 41.7% (35/84) and 16.6% (14/84), respectively, in the gastric cancer cases, and 42.7% (35/82), 36.6% (30/82) and 20.7% (17/82), respectively, in the colorectal cancers. MSI was not associated with the MBD4 codon 346 polymorphism and there was no significant difference in the frequency of the genotypes between healthy controls and gastric cancer patients (P=0.2748). However, the MBD4 codon 346 polymorphism was significantly associated with the risk of colorectal cancer (P=0.0315). Our findings suggest that microsatellite instability may not be associated with frameshift mutations in the MBD4 gene, and that the MBD4 codon 346 polymorphism may play arole in colorectal cancer susceptibility in the Korean population.

Low frequency mutation of the Ephrin receptor A3 gene in hepatocellular carcinoma

EphA3 is a component of the Eph/ephrin tyrosine kinase system, which participates in vasculature development. This receptor/ligand system is associated with various signaling pathways related to cell growth and viability, cytoskeletal organization, cell migration, and anti-apoptosis. Accumulated evidence suggests that aberrant regulation of EphA3 and its genetic alterations are implicated in the development and progression of various cancers. However, despite a high incidence of EphA3 over-expression, no such investigation has been performed in hepatocellular carcinoma. Thus, we investigated genetic alterations of the EphA3 gene in 73 cases of hepatocellular carcinoma by single-strand conformational polymorphism and sequencing. One novel D219V missense mutation was found in the extracellular domain of EphA3, and two genetic alterations in the intracellular sterile-alpha-motif (SAM) domain of EphA3 appeared to be polymorphisms. Although the functional assessments of this mutant are incomplete, it is believed that this novel EphA3 mutation may contribute to the development of hepatocellular carcinoma.

The p53 codon 72 polymorphism and susceptibility to colorectal cancer in Korean patients

TP53 is a major gene involved in the determination of proliferation or growth arrest at the cellular level. The polymorphism of p53 at codon 72 has been widely studied; this variation has been associated with cancer susceptibility and disease outcome. The specific aim of this study was to investigate whether the p53 codon 72 polymorphism is associated with individual susceptibility to colorectal cancer in Korean patients. The frequency of the polymorphism was examined in 156 patients with colorectal cancer and in 293 healthy controls. The polymorphism analysis was performed by amplifying exon 4 of p53 and digesting the products with restriction enzyme. The frequencies of genotypes: Arg/Arg, Arg/Pro and Pro/Pro were 34.6% (54/156), 43.0% (67/156) and 22.4% (35/156), respectively, in the cases with colorectal cancer, and 28.9% (114/293), 47.8% (140/293) and 13.3% (39/293), respectively, in the healthy controls. Statistically, there was a significant difference in the frequency of the genotypes when the healthy controls were compared to the patients with colorectal cancer (<em>p</em>=0.0459). The specific allele frequencies showed borderline significance (<em>p</em>=0.0502). Our findings suggest that the p53 Pro72 variant is associated with an increased risk for colorectal cancer in the Korean population.

KEYWORDS

p53, colorectal cancer, polymorphism, susceptibility, metastasis.

Overexpression of Wnt-2 in colorectal cancers

The binding of the Wnt ligand to its receptor Frizzled, activates the Wnt canonical signaling pathway in carcinogenesis as well as many cellular processes, including cellular proliferation and differentiation. Wnt-2, one of 19 members of the <em>Wnt</em> gene family, is frequently overexpressed in malignant tissues. Here, in order to investigate the role of Wnt-2 in colorectal carcinogenesis, we examined the expression of the Wnt-2 protein in 120 colorectal cancers by immunohistochemistry. Wnt-2 protein was expressed in the cell membrane and cytoplasm and up-regulated in 74 (61.7%) of 120 colorectal cancers. Statistically, overexpression of Wnt-2 protein was not associated with the clinical and pathological parameters studied, including tumor location, tumor size, clinical stage, lymph node metastasis, and 5-year survival (<em>P > </em>0.05). These results indicate that up-regulation of the Wnt-2 protein might play a role in the development of colorectal cancers, as an early event of carcinogenesis.

KEYWORDS

Wnt-2 protein, expression, immunohistochemistry, tissue microarray, colon cancer.

Mutational analysis of JAK1 gene in human hepatocellular carcinoma

The <em>Janus kinase 1</em> (JAK1) gene encodes a cytoplasmic tyrosine kinase that is noncovalently associated with a variety of cytokine receptors and plays a nonredundant role in cell proliferation, survival, and differentiation. The mutated forms of JAK1 often altered the activation of JAK1 and then changed the activation of JAK1/STAT pathways, and this may contribute to cancer development and progression. Thus, to investigate whether genetic mutations of JAK1 gene are associated in hepatocellular carcinoma (HCC) progression, we analyzed genetic alterations of JAK1 gene in 84 human HCCs by single-strand conformational polymorphism (SSCP) and direct sequencing. Of 24 exons of JAK1 gene, 12 exons were previously reported to have mutations, we searched genetic alteration of JAK1 in these exons. Overall, one missense mutation (1.2%) was found. In addition, 12 cases (14%) were found to have single nucleotide polymorphism (14%) in exon 14. Taken together, we found one novel missense mutation of JAK1 gene in hepatocellular carcinomas with some polymorphisms. Although the functional assessment of this novel mutant remains to be completed, JAK1 mutation may contribute to the tumor development in liver cancer.

KEYWORDS

JAK1 gene, hepatocellular carcinoma, mutation.

Long-distance entanglement-based quantum key distribution over optical fiber

We report the first entanglement-based quantum key distribution (QKD) experiment over a 100-km optical fiber. We used superconducting single photon detectors based on NbN nanowires that provide high-speed single photon detection for the 1.5-mum telecom band, an efficient entangled photon pair source that consists of a fiber coupled periodically poled lithium niobate waveguide and ultra low loss filters, and planar lightwave circuit Mach-Zehnder interferometers (MZIs) with ultra stable operation. These characteristics enabled us to perform an entanglement-based QKD experiment over a 100-km optical fiber. In the experiment, which lasted approximately 8 hours, we successfully generated a 16 kbit sifted key with a quantum bit error rate of 6.9 % at a rate of 0.59 bits per second, from which we were able to distill a 3.9 kbit secure key.

Down-regulation of ATBF1 is a major inactivating mechanism in hepatocellular carcinoma

AIMS

alpha-Fetoprotein (AFP) is frequently detected in hepatocellular carcinomas (HCCs) and AT motif binding factor 1 (ATBF1) down-regulates AFP gene expression in hepatic cells. The ATBF1 gene also inhibits cell growth and differentiation, and altered gene expression is associated with malignant transformation. The aim was to investigate the potential role of the ATBF1 gene in HCCs.

METHODS AND RESULTS

Somatic mutations, allelic loss and hypermethylation of the ATBF1 gene were analysed in 76 sporadic HCCs. The level of ATBF-1 mRNA expression was analysed using quantitative real-time reverse transcriptase-polymerase chain reaction. Genetic studies of the ATBF1 gene revealed absence of somatic mutation in the hotspot region and 15 (25%) of 60 informative cases showed allelic loss at the ATBF1 locus. Hypermethylation in the intron 1 region of the ATBF1 gene was detected in only one case. Interestingly, ATBF1 mRNA expression in HCCs was significantly reduced in 55 (72.4%) samples compared with the corresponding surrounding liver tissues. Reduced expression was not statistically associated with clinicopathological parameters including stage, histological grade, infective virus type, and serum alpha-fetoprotein level.

CONCLUSIONS

The ATBF1 gene may contribute to the development of HCCs via transcriptional down-regulation of mRNA expression, but not by genetic or epigenetic alterations.

No association of MDM2 T309G polymorphism with susceptibility to Korean gastric cancer patients

Mouse double minute 2 (Mdm2) acts as a negative regulator of p53 by binding to the amino-terminus of p53. The common T309G polymorphism of Mdm2 has been the most frequently investigated, which can influence in cancer susceptibility and disease outcome. The specific aim of this study is to investigate whether the T309G polymorphism of Mdm2 was associated with individual susceptibility to gastric cancer in Korea. The frequency of the polymorphism was examined in 239 gastric cancer patients and 299 healthy controls. Polymorphism analysis was performed by amplifying the first intron of the Mdm2 and digesting with restriction enzyme and sequencing the products. The frequencies of genotypes: T/T, T/G and G/G were 26.8% (64/239), 46.0% (110/239) and 27.2% (65/239), respectively, in gastric cancer cases and 20.4% (61/299), 50.8% (152/ 299) and 28.8% (86/299), respectively, in healthy controls. Statistically, there was no significant difference in the frequency of genotype and allele between healthy control and gastric cancer patients. Finally, the polymorphism was not associated with increased risk of gastric cancer in this population. When stratified by histological subtype of gastric cancer, the risk was also not statistically significant. Our findings suggested that the T309G polymorphism of Mdm2 was not associated with an increased risk for gastric cancer in Korean population.

KLF6 IVS1 -27G/A polymorphism with susceptibility to gastric cancers in Korean

KLF6 is a key cell cycle regulator that is downregulated in several kinds of human cancers, including gastric cancer. The IVS1 -27G/A polymorphism of KLF6 has been investigated, which can influence susceptibility to gastric cancer and disease outcome. In order to investigate whether the IVS1 -27G/A polymorphism of KLF6 is associated with individual susceptibility to gastric cancer in Korea, the frequency of the polymorphism was examined in 264 gastric cancer patients and 299 healthy controls. Single nucleotide polymorphism (SNP) analysis was performed by amplifying intron 1 of KLF6 and sequencing the products. The frequencies of genotypes: G/G, G/A and A/A were 91.7% (242/264), 5.7% (15/264) and 2.6%, respectively, in gastric cancer cases and 91.9%, 7.0% and 1.1%, respectively, in healthy controls. Genotype frequencies in Korean population were very similar to those of Caucasian population. Interestingly, the male gastric cancer patients showed a significantly higher proportion of the G allele (Chi-Square test, P=0.005) compared to female gastric cancer patients. However, the polymorphism was statistically not associated with increased risk of gastric cancer in Korea. When stratified by histological subtype of gastric cancer, the risk was also not statistically significant. Thus, our results suggested that the IVS1 -27G/A polymorphism of KLF6 is not associated with an increased risk for gastric cancer in Korean population.

Chk1 frameshift mutation in sporadic and hereditary non-polyposis colorectal cancers with microsatellite instability

AIM

Protein kinase Chk1 (hChk1) is essential in human cells for cell cycle arrest in response to DNA damage, and has been shown to play an important role in the G2/M checkpoint. The BRAF mutations have been suggested to be linked with defective mismatch repair in colorectal cancers. The aim of this study was to investigate whether a frameshift mutation within the Chk1 gene contribute to the development or progression of eastern sporadic and hereditary non-polyposis colorectal cancer (HNPCC) with microsatellite instability (MSI).

METHODS

We analyzed MSI using the 6 microsatellite markers and a frameshift mutation in the BRAF gene and in poly(A)9 within the Chk1 gene in 51 sporadic colorectal cancer and 14 HNPCC specimens.

RESULTS

Eleven of the 51 sporadic colorectal cancers and all of the 14 HNPCCs were MSI-positive. Chk1 frameshift mutations were observed in 2 and 3 sporadic colon cancers and HNPCC, respectively, whereas no BRAF mutations were detected in these samples. Interestingly, all cases with the Chk1 frameshift mutation had high-frequency MSI.

CONCLUSION

These results suggest that the Chk1 gene is a target of genomic instability in MSI-positive colorectal cancers and that the Chk1 framshift mutations might be involved in colorectal tumourigenesis through a defect in response to DNA damage in a subset of sporadic colorectal cancers and HNPCCs.

Association of cyclin D1 G870A polymorphism with susceptibility to gastric cancers in Korean male patients

Cyclin D1 is a key cell cycle regulator that is upregulated in gastric cancer. The common G870A polymorphism of cyclin D1 which can influence cancer susceptibility and disease outcome has been the most frequently investigated. The specific aim of this study is to investigate whether the G870A polymorphism of cyclin D1 was associated with individual susceptibility to gastric cancer in Korea. The frequency of the polymorphism was examined in 253 gastric cancer patients and 442 healthy controls. Polymorphism analysis was performed by amplifying exon 4 of cyclin D1 and sequencing the products. The frequencies of genotypes: G/G, G/A and A/A were 28.1% (71/253), 49.4% (125/253) and 22.5% (57/253), respectively, in gastric cancer cases, and 23.1%, 51.1% and 25.8%, respectively, in healthy controls. Statistically, the polymorphism was not associated with increased risk of gastric cancer. When stratified by histological subtype of gastric cancer, the risk was also not statistically significant. However, the male gastric cancer patients showed a significantly higher proportion of the homozygous G/G genotype and the G allele (Chi-Square test, P = 0.0242 & P = 0.0307) compared to males in the control group. Thus, our findings suggested that the G870A polymorphism of cyclin D1 was not associated with an increased risk for gastric cancer in this population, however, it may contribute to susceptibility to gastric cancer in men.

Mutational analysis of the hCDC4 gene in gastric carcinomas

hCDC4, a ubiquitin ligase, plays a role in the control of cell cycle and chromosome stability. The hCDC4 gene is considered a tumour suppressor gene and is mutated in several human neoplasias, including colorectal and endometrial tumours. Data on the hCDC4 mutation in gastric cancer is, however, lacking. This study explored the possibility that hCDC4 mutation is involved in the development of gastric cancer. The hCDC4 gene in 162 gastric adenocarcinoma tissues was analysed for somatic mutations using a polymerase chain reaction-single strand conformation polymorphism assay. Overall, six hCDC4 mutations were found (3.7%), comprising four missense, one frameshift deletion and one nonsense mutation(s). It is notable that the hCDC4 mutations were found in early as well as in advanced gastric carcinomas. These data indicate that hCDC4 mutation occasionally occurs in gastric carcinomas and suggest that it might play a role in the development of some gastric carcinomas.

Expressional analysis of anti-apoptotic phospho-BAD protein and mutational analysis of pro-apoptotic BAD gene in hepatocellular carcinomas

BACKGROUND

It has become clear that, together with proliferation, deregulation of apoptosis plays a pivotal role in tumourigenesis. BAD is a pro-apoptotic Bcl-2 family protein and regulates the intrinsic apoptosis pathway. Phosphorylation of BAD inhibits the apoptosis function of BAD.

AIMS

To investigate whether alteration of the phospho-BAD protein and somatic mutation of BAD gene are characteristics of human hepatocellular carcinoma.

PATIENTS AND METHODS

We analysed the expression of phospho-BAD in 20 hepatocellular carcinomas by immunohistochemistry. Also, we analysed the BAD gene for the detection of somatic mutations by a single-strand conformation polymorphism assay in 69 hepatocellular carcinomas.

RESULTS

Phospho-BAD expression in the non-tumour hepatocytes was seen in all of the hepatocellular carcinomas, while the expression in the cancer cells was observed in 15% (3 of the 20) of the hepatocellular carcinomas. There was no somatic mutation of BAD Bcl-2 homology 3 (BH3) domain in the 69 hepatocellular carcinomas.

CONCLUSIONS

The data showed that loss of phospho-BAD expression, but not BAD gene mutation, is a feature of hepatocellular carcinomas. The decreased expression of phospho-BAD in the hepatocellular carcinoma cells compared to the non-tumour hepatocytes suggests that loss of phospho-BAD expression may play a role in hepatocellular tumourigenesis.

The JAK2 V617F mutation in de novo acute myelogenous leukemias

A missense somatic mutation in JAK2 gene (JAK2 V617F) has recently been reported in chronic myeloproliferative disorders, including polycythemia vera, essential thrombocythemia and myelofibrosis with myeloid metaplasia, strongly suggesting its role in the pathogenesis of myeloid disorders. As activation of JAK2 signaling is occurred in other malignancies as well, we have analysed 558 tissues from common human cancers, including colon, breast and lung carcinomas, and 143 acute adulthood leukemias by polymerase chain reaction -- single strand conformation polymorphism analysis. We found three JAK2 mutations in the 113 acute myelogenous leukemias (AMLs) (2.7%), but none in other cancers. The mutations consisted of two V617F mutations and one K607N mutation. None of the AML patients with the JAK2 V617F mutation had a history of previous hematologic disorders. This is the first report on the JAK2 gene mutation in AML, and the data indicated that the JAK2 gene mutation may not only contribute to the development of chronic myeloid disorders, but also to some AMLs.

Genetic analysis of the LKB1/STK11 gene in hepatocellular carcinomas

The tumour suppressor gene, LKB1/STK11, has been mapped to chromosome 19p13, a region showing frequent allelic loss in various human cancers, including hepatocellular carcinoma (HCC). Additionally, LKB1 physically associates with p53 and regulates p53-dependent apoptotic pathways. To investigate whether genetic alterations of LKB1 could be involved in the tumorigenesis of HCC, we analysed the genetic alterations of the LKB1 and p53 genes in seven dysplastic nodules and 80 HCCs. We found one LKB1 missense mutation, CCG-->CTG (Pro-->Leu) at codon 281 within the kinase domain. We also found allelic loss in six of 27 (22%) informative HCC cases and all of them were HBV-positive cases. In addition, we detected seven missense, one nonsense and one silent mutations (nine of 80, 11%) of p53 in HCCs only. These results suggest that genetic alterations of the LKB1 or p53 genes may play an important role in tumour development or progression of a sub-set of HCCs, and may also provide alternative mechanisms to protect the HCC cell from p53-dependent apoptosis.