High-peak-power structured beams by an Nd:YAG/Cr4+:YAG laser in a near-hemispherical cavity.

An Nd:YAG/Cr4+:YAG passively Q-switched (PQS) laser in a near-hemispherical cavity is exploited to generate high-order structured pulsed fields. Under tightly focused on-axis pumping, radial-order Laguerre-Gaussian (LG) modes with controllable mode orders by the input pump power are realized to exhibit quite stable temporal behavior. The pulse repetition rates of radial-LG modes can reach up to 78 kHz with an average output power of 0.57 W and peak power beyond 300 W under a 5-W pump level. Furthermore, by introducing 1D off-axis pumping into the PQS laser, various structured pulsed fields with transverse morphologies as high-order Ince-Gaussian (IG) modes are further created. With clean and well-defined beam structures, the IG pulsed fields can be nicely reconstructed by the resonant modes of the inhomogeneous Helmholtz equation for spherical cavities. More importantly, these high-order PQS IG modes reveal highly regular pulse trains with the maximum pulse repetition rate beyond 20 kHz and overall peak power higher than 1.5 kW.

Generating high-power Lissajous structured modes and trochoidal vortex beams by an off-axis end-pumped Nd:YVO4 laser with astigmatic transformation.

High-power structured beams with the transverse morphologies as the Lissajous figures are generated by an Nd:YVO4 laser under two-dimensional off-axis pumping. By fine-tuning the cavity length in the neighborhood around the condition of longitudinal-transverse coupling, different cases of accidental degeneracies from the intracavity astigmatism are achieved to lead the output emission to be various Lissajous modes with different transverse frequency ratios. The generated Lissajous modes reveals good power performance with slope efficiency up to 47% and optical-to-optical conversion efficiency to be higher than 37.5% at a pump power of 16 W. Moreover, by applying beam transformation via a single-lens astigmatic mode converter, the generated Lissajous modes are further converted into structured vortex beams with transverse patterns localized on the trochoidal curves. The transformed trochoidal vortex beams are confirmed to preserve well-defined mode structures even when the average output power has been scaled up to be higher than 4 W.

Corrigendum: A multiply-add engine with monolithically integrated 3D memristor crossbar/CMOS hybrid circuit.

This corrects the article DOI: 10.1038/srep42429.

A multiply-add engine with monolithically integrated 3D memristor crossbar/CMOS hybrid circuit.

Silicon (Si) based complementary metal-oxide semiconductor (CMOS) technology has been the driving force of the information-technology revolution. However, scaling of CMOS technology as per Moore's law has reached a serious bottleneck. Among the emerging technologies memristive devices can be promising for both memory as well as computing applications. Hybrid CMOS/memristor circuits with CMOL (CMOS + "Molecular") architecture have been proposed to combine the extremely high density of the memristive devices with the robustness of CMOS technology, leading to terabit-scale memory and extremely efficient computing paradigm. In this work, we demonstrate a hybrid 3D CMOL circuit with 2 layers of memristive crossbars monolithically integrated on a pre-fabricated CMOS substrate. The integrated crossbars can be fully operated through the underlying CMOS circuitry. The memristive devices in both layers exhibit analog switching behavior with controlled tunability and stable multi-level operation. We perform dot-product operations with the 2D and 3D memristive crossbars to demonstrate the applicability of such 3D CMOL hybrid circuits as a multiply-add engine. To the best of our knowledge this is the first demonstration of a functional 3D CMOL hybrid circuit.

Coding for stable transmission of W-band radio-over-fiber system using direct-beating of two independent lasers.

We demonstrate experimentally Manchester (MC) coding based W-band (75 - 110 GHz) radio-over-fiber (ROF) system to reduce the low-frequency-components (LFCs) signal distortion generated by two independent low-cost lasers using spectral shaping. Hence, a low-cost and higher performance W-band ROF system is achieved. In this system, direct-beating of two independent low-cost CW lasers without frequency tracking circuit (FTC) is used to generate the millimeter-wave. Approaches, such as delayed self-heterodyne interferometer and heterodyne beating are performed to characterize the optical-beating-interference sub-terahertz signal (OBIS). Furthermore, W-band ROF systems using MC coding and NRZ-OOK are compared and discussed.

A scalable and continuous-upgradable optical wireless and wired convergent access network.

In this work, a scalable and continuous upgradable convergent optical access network is proposed. By using a multi-wavelength coherent comb source and a programmable waveshaper at the central office (CO), optical millimeter-wave (mm-wave) signals of different frequencies (from baseband to > 100 GHz) can be generated. Hence, it provides a scalable and continuous upgradable solution for end-user who needs 60 GHz wireless services now and > 100 GHz wireless services in the future. During the upgrade, user only needs to upgrade their optical networking unit (ONU). A programmable waveshaper is used to select the suitable optical tones with wavelength separation equals to the desired mm-wave frequency; while the CO remains intact. The centralized characteristics of the proposed system can easily add any new service and end-user. The centralized control of the wavelength makes the system more stable. Wired data rate of 17.45 Gb/s and w-band wireless data rate up to 3.36 Gb/s were demonstrated after transmission over 40 km of single-mode fiber (SMF).

Hyperfine splitting of the 2s1/2 and 2p1/2 levels in Li- and be-like ions of (59)(141) Pr.

High-resolution spectroscopy of the 2s(1/2)-2p(1/2) transition in the extreme ultraviolet region is shown to resolve the level splitting induced by the nuclear magnetic field of both the 2s(1/2) and the 2p(1/2) levels in lithiumlike (141)Pr(56+) and of the 2s(1/2)2p(1/2) (3)P(1) level in berylliumlike (141)Pr(55+). The (141)Pr ions are an ideal test of this measurement approach because their energy levels are known well from first principles and are unaffected by small energy contributions from QED and nuclear magnetization effects. The accuracy attained in the measured 196.5 ± 1.2 meV 2s(1/2) splitting is more than an order of magnitude better than that achieved before using crystal spectroscopy of the 2s(1/2)-2p(3/2) x-ray transition and at the level needed to implement a proposed scheme for disentangling the contributions from QED and nuclear magnetization effects in higher-Z ions, such as (209)Bi.

Thomson scattering in the average-atom approximation.

The average-atom model is applied to study Thomson scattering of x-rays from warm dense matter with emphasis on scattering by bound electrons. Parameters needed to evaluate the dynamic structure function (chemical potential, average ionic charge, free electron density, bound and continuum wave functions, and occupation numbers) are obtained from the average-atom model. The resulting analysis provides a relatively simple diagnostic for use in connection with x-ray scattering measurements. Applications are given to dense hydrogen, beryllium, aluminum, and titanium plasmas. In the case of titanium, bound states are predicted to modify the spectrum significantly.

TRPV4 mediates tumor-derived endothelial cell migration via arachidonic acid-activated actin remodeling.

Changes in intracellular calcium [Ca(2+)](i) levels control critical cytosolic and nuclear events that are involved in the initiation and progression of tumor angiogenesis in endothelial cells (ECs). Therefore, the mechanism(s) involved in agonist-induced Ca(2+)(i) signaling is a potentially important molecular target for controlling angiogenesis and tumor growth. Several studies have shown that blood vessels in tumors differ from normal vessels in their morphology, blood flow and permeability. We had previously reported a key role for arachidonic acid (AA)-mediated Ca(2+) entry in the initial stages of tumor angiogenesis in vitro. In this study we assessed the mechanism involved in AA-induced EC migration. We report that TRPV4, an AA-activated channel, is differentially expressed in EC derived from human breast carcinomas (BTEC) as compared with 'normal' EC (HMVEC). BTEC display a significant increase in TRPV4 expression, which was correlated with greater Ca(2+) entry, induced by AA or 4αPDD (a selective TRPV4 agonist) in the tumor-derived ECs. Wound-healing assays revealed a key role of TRPV4 in regulating cell migration of BTEC but not HMVEC. Knockdown of TRPV4 expression completely abolished AA-induced BTEC migration, suggesting that TRPV4 mediates the pro-angiogenic effects promoted by AA. Furthermore, pre-incubation of BTEC with AA induced actin remodeling and a subsequent increase in the surface expression of TRPV4. This was consistent with the increased plasma membrane localization of TRPV4 and higher AA-stimulated Ca(2+) entry in the migrating cells. Together, the data presented herein demonstrate that: (1) TRPV4 is differentially expressed in tumor-derived versus 'normal' EC; (2) TRPV4 has a critical role in the migration of tumor-derived but not 'normal' EC migration; and (3) AA induces actin remodeling in BTEC, resulting in a corresponding increase of TRPV4 expression in the plasma membrane. We suggest that the latter is critical for migration of EC and thus in promoting angiogenesis and tumor growth.

Antitumor and immunostimulating effects of Anoectochilus formosanus Hayata.

The water extract of Anoectochilus formosanus Hayata showed a potent tumor inhibitory activity in BALB/c mice after subcutaneous transplantation of CT-26 murine colon cancer cells. The tumor-inhibition ratios of mice pre-administered with A. formosanus for 2 days before tumor transplantation, and treated further for 12 consecutive days, were 55.4% and 58.9% at the oral dose of 50 and 10 mg/mouse per day, respectively. Even for the tumor-bearing mice, after oral administration of the water extract of A. formosanus for 12 consecutive days, the tumor inhibition ratios were still 23.8% and 40.5% at doses of 50 and 10 mg/mouse, respectively. Because the low-concentration water extract of A. formosanus does not show direct cytotoxicity in CT-26 tumor cells, we observed further that oral administration of the water extract of A. formosanus may activate murine immune responses, such as stimulating the proliferation of lymphoid tissues and activating the phagocytosis of peritoneal macrophages against Staphylococcus aureus. This study suggests that the antitumor activity of A. formosanus may be associated with its potent immunostimulating effect. It is worth further analyzing the immunomodulating component purified from A. formosanus, and evaluating its potential value for the treatment of human cancers.

Effects of Anoectochilus formosanus Hayata extract and glucocorticoid on lung maturation in preterm rats.

We investigated the effects of maternal administration of Anoectochilus formosanus extract and dexamethasone on lung maturation in preterm rats. A. formosanus group mothers were tube-fed A. formosanus extract (300 mg/kg body wt./day) for 7 days from days 12-18 of gestation. Dexamethasone group mothers were injected intraperitoneally with dexamethasone (0.2 mg/kg body wt.) in saline on day 18 of gestation. Control group mothers were similarly injected with saline alone. On day 19 of gestation, fetuses were delivered by cesarean section. A. formosanus treatment significantly increased the fetal lung/body weight ratio, as compared to dexamethasone treatment. Saturated phosphatidylcholine levels in fetal lung tissue and growth hormone levels in maternal serum were significantly increased in the A. formosanus- and dexamethasone-treated groups as compared to controls. The histological appearance of preterm rat lungs revealed extensive branching of intermediate airways, denser mesenchyme, and more epithelial tubules in the dexamethasone and A. formosanus groups as compared with the control group. These results suggest that antenatal A. formosanus treatment may play a role in accelerating fetal rat lung maturation.

Nondipole effects in the photoionization of xe 4d5/2 and 4d3/2: evidence for quadrupole satellites.

Measurements of nondipole parameters in spin-orbit-resolved Xe 4d photoionization demonstrate dynamical differences arising from relativistic effects. The experimental data do not agree with relativistic random-phase approximation calculations of single ionization dipole and quadrupole channels. It is suggested that the discrepancy is due to the omission of multiple-excitation quadrupole channels, i.e., quadrupole satellite transitions.

Surface-assisted photoalignment in dye-doped liquid-crystal films.

This study examines the surface-assisted photoalignment effect of dye-doped liquid-crystal films having a homogeneous alignment. Observations made using a polarizing optical microscope, a scanning electronic microscope, and an atomic force microscope confirm that the morphology of laser-induced surface-adsorbed dyes at the command surface strongly affects the orientation of liquid crystals (LC's) in a manner that depends significantly on the intensity and duration of the pumping. In weak-intensity regime, a homogeneous and fine layer of adsorbed dyes competes with a layer of ripple structure in reorienting LC's. These two effects dominantly cause LC's to reorient perpendicular and parallel to the polarization direction of the pump beam in the early and late stages, respectively. In the high-intensity regime, rough and inhomogeneous ribbonlike adsorbents produced by rapid and random aggregation and adsorption form on the top of the preformed microgrooves, reorienting LC's irregularly. This surface morphology does not enable photoalignment.

Dramatic nondipole effects in low-energy photoionization: experimental and theoretical study of Xe 5s.

The Xe 5s nondipole photoelectron parameter gamma is obtained experimentally and theoretically from threshold to approximately 200 eV photon energy. Significant nondipole effects are seen even in the threshold region of this valence shell photoionization. In addition, contrary to previous understanding, clear evidence of interchannel coupling among quadrupole photoionization channels is found.

Free radical-scavenging activity of Taiwanese native plants.

The 70% aqueous acetone extracts of ten Taiwanese native plants were evaluated by various antioxidant assays, including 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (.OH) radicals, and reducing power assay. In the present study, extracts of Acer buerferianum var. formosanum, Cleyera japonica var. morii, Cyclobalanopsis stenophylla var. stenophylloides, and Machilus zuihoensis exhibited stronger activity against DPPH radicals, and their IC50 values ranged from 5.4 to 8.3 microg/ml. The ten selected extracts effectively inhibited the formation of .OH generated in the Fenton reaction system. Among the extracts whose reducing power activities were determined, A. buerferianum var. formosanum, C. japonica var. morii, C. stenophylla var. stenophylloides, Eriobotrya deflex, and M. zuihoensis showed high activity. The results indicate the 70% aqueous acetone extracts of A. buerferianum var. formosanum, C. japonica var. morii, C. stenophylla var. stenophylloides, and M. zuihoensis with great potency in these assay systems and may be candidates for the development of natural antioxidants.

RAPD analysis of Astragalus medicines marketed in Taiwan.

The genetic variability of Astragalus medicine materials sold by twenty randomly selected stores in Taiwan was investigated using RAPD analysis in order to obtain available primers which could clearly differentiate among them. Total DNA isolated from the rhizomes of the samples were used as templates, and sixty 10 mer arbitrary primers were used in the analysis. The aim of the present study is to construct an identification model of molecular biotechniques applicable to Chinese herbal medicines in RAPD analysis. Three of the primers, OPT-03, OPT-13, and OPT-17, revealed polymorphic RAPD fingerprints among the samples of Astragalus membranaceus, and between Astragalus membranaceus and Hedysarum polybotrys samples. SSCP analysis was also conducted on PCR products from the ITS-1 region of ribosomal DNA in order to differentiate the two species.

Determination of the components in a Chinese prescription, yu-ping-feng san, by RAPD analysis.

In this study, the RAPD (random amplified polymorphic DNA) technique was employed for the first time to determine the components in a Chinese herbal prescription. Forty decamer oligonucleotide primers were screened in the RAPD analysis to identify three Chinese medicines, the dried root of Astragalus membranaceus (Fisch.) Bge., the dried root of Ledebouriella seseloides Wolff, and the dried rhizome of Atractylodes macrocephala Koidz, in a Chinese prescription. Only primer OPP-10 simultaneously generated three distinct markers were each specific to one component. The marker with 200 bp is specific to Astragalus membranaceus; the 440 bp marker is specific to Atractylodes macrocephala; and the remaining marker with 500 bp was present in Ledebouriella seseloides. The presence of the three herbal medicines in the mixed sample, the Chinese prescription, was determined when the primer OPP-10 RAPD reaction was performed. The technique was proved to contribute to the identification of components in the Chinese medicinal preparations.

Identification of Anoectochilus formosanus and Anoectochilus koshunensis species with RAPD markers.

RAPD (random amplified polymorphic DNA) markers were developed to distinguish Anoectochilus formosanus from Anoectochilus koshunensis and their putative hybrids. Morphological differentiation of these two species beyond the flowering period is difficult. RAPD markers provide a rapid and easy tool for identification of the two Anoectochilus species. In the study, forty arbitrary decamer primers were screened, and nineteen species-specific RAPD markers generated from polymerase chain reactions (PCR) with eight random primers were obtained. Nine were specific to A. formosanus and ten to A. koshunensis. Two primers, OPC-08 and OPL-07, produced two markers, one specific to A. formosanus and the other specific to A. koshunensis, which simultaneously appeared in the hybrids pattern. The RAPD markers can be applied both to identification of A. formosanus and A. koshunensis species and to assessment of the extent fo hybridization in hybrids between them. This information facilitates the breeding program process.

Differentiation of genuines and counterfeits of Cordyceps species using random amplified polymorphic DNA.

For identification of genuine and counterfeit samples of Cordyceps sinensis, an RAPD (random amplified polymorphic DNA) analysis was performed. In the study, twelve samples were collected, of which six were genuine and six were counterfeit samples. Genuine samples of Cordyceps sinensis contain two parasitic larvae produced from each of the three provinces, Sichuan (SC), Chinghai (CH), and Tibet (TB). The counterfeits contain two products of each of the three species, Cordyceps hawkesii, Stachys geobombycis, and Stachys sieboldii. In the RAPD analysis, twenty arbitrary decamer primers were screened to obtain primers appropriate for differentiating the genuine and counterfeit samples. The result of twelve RAPD markers generated from four primers, OPT-08, OPT-12, OPT-13, and OPT-17, were selected. The primers can easily distinguish between genuine and counterfeit samples of Cordyceps sinensis.

Ultratag RBC kit for combined cardiac first-pass and multigated acquisition studies.

UNLABELLED: The authors developed a procedure to use the in vitro Ultratag (Mallinckrodt, St. Louis, MO) red blood cell (RBC) labeling kit for both first-pass (FP) and multigated acquisition (MUGA) studies with a high specific activity in a reduced volume (50 mCi/0.5 ml) and a high labeling efficiency that can be used with a single-crystal camera to yield a quality study. METHODS: A packed red blood cell (PRBC) bolus was created by two methods: (a) reducing the volume of the components of the Ultratag kit and (b) centrifuging the final dose volume. The labeling efficiency of each bolus was evaluated, each PRBC bolus was visually inspected for clots and percent hemolysis was assessed using a hemocytometer at 30 min, 1 hr and 2 hr postcentrifugation. RESULTS: Use of the first method, the 50% kit, provided the best results. However, the resulting volume from this kit only approached 1 ml, which is not clinically adequate for a first-pass study. In the second method, the total volume was centrifuged to form a PRBC bolus, which appeared to be stable in the syringe for at least 2 hr. A combined FP/MUGA study from a centrifuged 50% reduced kit was performed in one normal subject as a preliminary assessment of the clinical utility of this procedure. The image quality of the scan is diagnostically adequate. CONCLUSION: By using the in vitro Ultratag kit, a compact PRBC bolus was created that was stable in the syringe and could be reinjected safely into the patient for combined cardiac FP/MUGA studies.