Writing Electronic Devices on Paper with Carbon Nanotube Ink

The normal paper used in any printer is among the cheapest flexible organic materials that exist. We demonstrate that we can print on paper high-frequency circuits tunable with an applied dc voltage. This is possible with the help of an ink containing functionalized carbon nanotubes and water. After the water is evaporated from the paper, the nanotubes remain steadily imprinted on paper, showing a semiconducting behaviour and tunable electrical properties

Export diversification and economic growth in Kuwait: evidence from time series and field survey analyses

This study examines whether export diversification can foster sustained economic growth in Kuwait, using time series analysis for the period 1980–2019 and a field survey of one hundred Kuwait business leaders engaged in import and export of goods and services. The time series analysis reveals that there is no causality between export diversification and economic growth in the short-run. However, an indirect causality runs from export diversification to economic growth, and vice versa, via imports. In the long-run, no causality runs from export diversification to economic growth, but economic growth does cause export diversification. The field survey results indicate that there is a consensus among Kuwaiti CEOs that there are positive spillover effects from exports and imports to producers of local goods and services, and that imports are conductive to economic diversification

Inequalities of harmonic univalent functions with connections of hypergeometric functions

Let SH be the class of functions f = h + (g) over bar that are harmonic univalent and sense-preserving in the open unit disk U = {z : vertical bar z vertical bar < 1} for which f(0) = f'(0) - 1 = 0. In this paper, we introduce and study a subclass H(alpha, beta)of the class SH and the subclass NH(alpha, beta) with negative coefficients. We obtain basic results involving sufficient coefficient conditions for a function in the subclass H(alpha, beta) and we show that these conditions are also necessary for negative coefficients, distortion bounds, extreme points, convolution and convex combinations. In this paper an attempt has also been made to discuss some results that uncover some of the connections of hypergeometric functions with a subclass of harmonic univalent functions

Enhanced flatness of 20 Ghz channel spacing multiwavelength Brillouin-Raman fiber laser with sub-millimeter air gap

We discover the technique of controlling the flatness in signal amplitude of a multiwavelength Brillouin-Raman fiber laser by employing an air-gap outside of the cavity. The structure that is adjustable within sub-millimeter length behaves as flexible optical feedback that provides modifiable portions of multiple Fresnel reflectivities. This is the main benchmark that allows the efficient management of gain competition between self-lasing modes and Brillouin Stokes waves that is vital for self-flattening initiation. When setting the Brillouin pump wavelength at 1529 nm and the air-gap distance to 0.4 mm, 296 Stokes lines are produced with a channel spacing of 0.158 nm. The lasing bandwidth is 46.60 nm that covers from 1529.16 to 1575.76 nm wavelength. In this case at Raman power of 950 mW, the intense Brillouin pump power of 2 dBm saturates the cascaded higher-orders lasing lines. As a result, the overall peak power discrepancy is maintained at just 1.8 dB where an average optical-signal-to-noise ratio of 20 dB is realized. To date, this is the widest bandwidth with the flattest spectrum attained in multiwavelength fiber lasers that incorporate a single Raman pump unit

The Release of Nitric Oxide from S-Nitrosothiols Promotes Angiogenesis

BACKGROUND: Free nitric oxide (NO) reacts with sulphydryl residues to form S-nitrosothiols, which act as NO reservoirs. We sought to determine whether thiol-preserving agents and antioxidants, such as dithiothreitol (DTT) and vitamin C, induce NO release from S-nitrosylated proteins in endothelial cell cultures to promote angiogenesis. METHODOLOGY/PRINCIPAL FINDINGS: NO release was measured directly in cell supernatants using a Sievers NO Analyser, and in vitro angiogenesis was assessed by quantifying capillary-like tube network formation of porcine aortic endothelial cells (PAEC) on growth factor-reduced Matrigel. Incubation of PAEC with DTT or vitamin C significantly increased NO release in a concentration-dependent manner. However, the nitric oxide synthase (NOS) inhibitors, L-NNA and L-NIO, had no effect on DTT- or vitamin C-induced NO release, and there was no concomitant increase in the phosphorylation of endothelial NOS at serine-1177 following DTT or vitamin C treatment. DTT and vitamin C increased capillary-like tube network formation by nine- and two-fold, respectively, and the addition of copper ions doubled the effect of vitamin C. Surprisingly, DTT maintained endothelial tube networks for up to one month under serum-free conditions, and selective inhibitors of guanylyl cyclase (ODQ) and PKG (KT-5823) blocked this, demonstrating the requirement of cyclic GMP and PKG in this process. CONCLUSIONS/SIGNIFICANCE: Both DTT and vitamin C are capable of releasing sufficient NO from S-nitrosothiols to induce capillary morphogenesis. This study provides the first evidence that increased denitrosylation leads to increased bioavailability of NO, independent of NOS activity, to promote sustained angiogenesis

A comparison of characteristics of periodic surface micro/nano structures generated via single laser beam direct writing and particle lens array parallel beam processing

Abstract Changing material surface micro/nanostructures using laser beam texturing is a valuable approach in wide applications such as control of cell/bacterial adhesion and proliferation, solar cells and optical metamaterials. Here, we report a comparison of the characteristics of surface micro/nanostructures produced using single beam laser direct writing and particle lens array parallel laser beam patterning. A Nd:YVO4 nanosecond pulsed laser at the wavelength of 532 nm was used in the laser direct writing method to texture the stainless steel surface submerged in water and in air with different scanning patterns. Changes in surface morphology, wettability, surface chemistry, and optical reflectivity were analyzed. In the particle lens array method, an excimer nanosecond laser at 248 nm wavelength was adopted to produce surface patterns on GeSbTe (GST) film coated on a polycarbonate substrate by splitting and focusing a single laser beam into millions of parallel breams. Single beam laser direct writing shows that the surface of high roughness and oxygen percentage content presented high wettability and low reflectivity characteristics. However, the controllability of the type of surface micro/nanopatterns is limited. The parallel laser beam processing using particle lens array allows rapid production of user designed periodic surface patterns at nanoscale overcoming the optical diffraction limit with a high degree of controllability. Controlling the uniformity of the particle lens array is a challenge

Autocrine activity of soluble Flt-1 controls endothelial cell function and angiogenesis

Background - The negative feedback system is an important physiological regulatory mechanism controlling angiogenesis. Soluble vascular endothelial growth factor (VEGF) receptor-1 (sFlt-1), acts as a potent endogenous soluble inhibitor of VEGF- and placenta growth factor (PlGF)-mediated biological function and can also form dominant-negative complexes with competent full-length VEGF receptors. Methods and results - Systemic overexpression of VEGF-A in mice resulted in significantly elevated circulating sFlt-1. In addition, stimulation of human umbilical vein endothelial cells (HUVEC) with VEGF-A, induced a five-fold increase in sFlt-1 mRNA, a time-dependent significant increase in the release of sFlt-1 into the culture medium and activation of the flt-1 gene promoter. This response was dependent on VEGF receptor-2 (VEGFR-2) and phosphoinositide-3'-kinase signalling. siRNA-mediated knockdown of sFlt-1 in HUVEC stimulated the activation of endothelial nitric oxide synthase, increased basal and VEGF-induced cell migration and enhanced endothelial tube formation on growth factor reduced Matrigel. In contrast, adenoviral overexpression of sFlt-1 suppressed phosphorylation of VEGFR-2 at tyrosine 951 and ERK-1/-2 MAPK and reduced HUVEC proliferation. Preeclampsia is associated with elevated placental and systemic sFlt-1. Phosphorylation of VEGFR-2 tyrosine 951 was greatly reduced in placenta from preeclamptic patients compared to gestationally-matched normal placenta. Conclusion - These results show that endothelial sFlt-1 expression is regulated by VEGF and acts as an autocrine regulator of endothelial cell function

Protein Content in Snake Fruit Cultivar Pondoh (Salacca Edulis Reinw.) with Aseptic Condition in Room Storage

Snake fruit is a type of tropical fruit with high market demand, however it is easily damaged and approximately ± 7 days at room temperature of shelf life. After 3 days of harvest, quality of snake fruit has decrease in chemical components, such as color, hardness, and proximate. The decline in the quality may also be caused by microbial contamination. This study aimed to determine the protein content of snake fruit during storage at room temperature under aseptic condition. This study was done in storage temperature of 25±5ºC and carried out at 3 times repetition. The protein content of snake fruit was observed for 3 days. The results showed that protein content of snake fruit at the beginning of storage were about 0.5%. Then, the protein content decreased until undetectable by the Kjeldahl method on the third day of storage. As conclusion, the three days of decrease in the protein content could be determined

The effect of 980 nm and 1480 nm pumping on the performance of newly Hafnium Bismuth Erbium-doped fiber amplifier

An experimental study on the comparison of optical amplifying performance between 980 nm and 1480 nm pumping for the newly Hafnium Bismuth Erbium co-doped fiber (HB-DF) has been presented. A short length of 1-meter HB-EDF was used as the gain medium of the optical amplifier. 1480 nm pumping is found to provide higher attainable gain and lower noise figure compared to 980 nm pumping. At 1480 nm pumping, the average small signal gain for HB-EDFA in the single pass configuration has improved by 13.4 dB in the C-band region range from 1525 nm to 1565 nm. In the double-pass configuration, a maximum small signal gain of 36.6 dB was achieved at the wavelength of 1560 nm, this is 11.6 dB higher compared to the HB-EDFA with 980 nm pumping. The double pass HB-EDFA with 1480 nm pumping has exhibited a reduction of average noise figure by 23.4% and 29.8% for-30 dBm and-10 dBm of input signal power respectively in the C- and L-band region

Preservation of Snake Fruit Cultivar Pondoh (Salacca Edulis Reinw.) at Cold Temperature Storage

This study was done to preserve snake fruit cultivar Pondoh cold temperature storage. Snake fruits was obtained from Turi, Sleman, Yogyakarta and transferred to the laboratory with the aseptic condition. The sortation based on the visual method was used to collect the proper snake fruit. The cleaning using aseptic cloth was done prior to storage. The snake fruit was collected individually in refrigeration containers at temperatures of 10±5˚C. The storage was done for 30 days and it was stopped until appearance of physical damage in snake fruit. The result indicates that the storage using this method might extend the shelf-life of snake fruit until 28 days. However, snake fruit was hardly to peeled and dry. It can be concluded that cold temperature might extend the shelf-life of snake fruit