2,274 research outputs found
The Impact of the Belt and Road Initiative Investment in Digital Connectivity and Information and Communication Technologies on Achieving the SDGs
The lion’s share of the “Belt and Road Initiative (BRI)” investment in infrastructure from the Chinese investors has gone to the energy and transportation sectors, and only a very small share to the information and communication technologies (ICT) sector. However, the ICT sector has attracted growing investment not only from the public sector but also from the private enterprises in China, and stronger interests from the stakeholders in the BRI-related countries. The existing Chinese literature shows that the current investment in ICTs as well as digital connectivity and digital economy has had some positive influence on the implementation of the Sustainable Development Goals in those recipient countries. It has helped to facilitate economic growth of the least developed countries and rural areas of middle-income countries, to promote development of small and medium-sized enterprises, to encourage digital transformation of traditional industries and green growth, to narrow down the digital gap, and to enhance digital inclusion
First-principles study on the effective masses of zinc-blend-derived Cu_2Zn-IV-VI_4 (IV = Sn, Ge, Si and VI = S, Se)
The electron and hole effective masses of kesterite (KS) and stannite (ST)
structured Cu_2Zn-IV-VI_4 (IV = Sn, Ge, Si and VI = S, Se) semiconductors are
systematically studied using first-principles calculations. We find that the
electron effective masses are almost isotropic, while strong anisotropy is
observed for the hole effective mass. The electron effective masses are
typically much smaller than the hole effective masses for all studied
compounds. The ordering of the topmost three valence bands and the
corresponding hole effective masses of the KS and ST structures are different
due to the different sign of the crystal-field splitting. The electron and hole
effective masses of Se-based compounds are significantly smaller compared to
the corresponding S-based compounds. They also decrease as the atomic number of
the group IV elements (Si, Ge, Sn) increases, but the decrease is less notable
than that caused by the substitution of S by Se.Comment: 14 pages, 6 figures, 2 table
Gentiana macrophylla Pall (Gentianaceae) extract exerts protective effects against osteoporosis in mice
Purpose: To evaluate the anti-osteoporotic effect of G. macrophylla extract in a mice model.Methods: Antioxidant activity was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) for radical scavenging, nitro-blue tetrazolium (NBT) reducing, and ferric reducing antioxidant power (FRAP) assays using standard biochemical procedures. The expression of some bone-related genes was measured by quantitative real-time polymerase chain reaction (qTR-PCR). Phytochemical analysis was carried out by liquid chromatography-mass spectrometry (LC/MS).Results: The extract exhibited strong antioxidant activity as evident from DPPH, NBT and FRAP data, with half-maximal inhibitory concentration (IC50) values of 275, 262 and 180 μg/ml, respectively. The antioxidant activity was concentration-dependent. The results showed that the extract restored bone characteristics by suppressing bone resorption through induction of expressions of several boneassociated genes. The results from phytochemical analyses showed the presence of loganic acid, swertiamarin, sweroside, gentiopicroside, gentesin and isogentesin.Conclusion: These results indicate that the extract may be beneficial in the treatment of osteoporosis.Keywords: Gentiana macrophylla, Osteoporosis, Bone mass, Loganic acid, Swertiamarin, Sweroside, Gentiopicroside, Gentesi
Active inductor shunt peaking in high-speed VCSEL driver design
An all transistor active inductor shunt peaking structure has been used in a
prototype of 8-Gbps high-speed VCSEL driver which is designed for the optical
link in ATLAS liquid Argon calorimeter upgrade. The VCSEL driver is fabricated
in a commercial 0.25-um Silicon-on-Sapphire (SoS) CMOS process for radiation
tolerant purpose. The all transistor active inductor shunt peaking is used to
overcome the bandwidth limitation from the CMOS process. The peaking structure
has the same peaking effect as the passive one, but takes a small area, does
not need linear resistors and can overcome the process variation by adjust the
peaking strength via an external control. The design has been tapped out, and
the prototype has been proofed by the preliminary electrical test results and
bit error ratio test results. The driver achieves 8-Gbps data rate as simulated
with the peaking. We present the all transistor active inductor shunt peaking
structure, simulation and test results in this paper.Comment: 4 pages, 6 figures and 1 table, Submitted to 'Chinese Physics C
Tickets to the global market: first US patent awards and Chinese firm exports
We investigate how international patent activity enables firms from emerging economies to thrive in the global marketplace. We match Chinese customs data to US patent records and leverage the quasi-random assignment of USPTO patent examiners to identify the causal effect of a US patent grant on the subsequent export performance of Chinese firms. Successful first-time patent applicants achieve significantly higher export growth, compared to otherwise similar first-time applicants that failed. This effect operates only in small part through market protection for technologically patent-related products in the US and is largely driven by expansion in other markets. The response across destinations and products reveals that a US patent award signals the Chinese firm's capacity to produce high-quality products and credibility to honor contracts, mitigating information frictions in international trade. There is little evidence for the relaxation of financial constraints or the promotion of follow-on innovation
Influence of Small Particles Inclusion on Selective Laser Melting of Ti-6al-4v Powder
The particle size distribution and powder morphology of metallic powders have an important effect on powder bed fusion based additive manufacturing processes, such as selective laser melting (SLM). The process development and parameter optimization require a fundamental understanding of the influence of powder on SLM. This study introduces a pre-alloyed titanium alloy Ti-6Al-4V powder, which has a certain amount of small particles, for SLM. The influence of small particle inclusion is investigated through microscopy of surface topography, elemental and microstructural analysis, and mechanical testing, compared to the Ti-6Al-4V powder provided by SLM machine vendor. It is found that the small particles inclusion in Ti-6Al-4V powder has a noticeable effect on extra laser energy absorption, which may develop imperfections and deteriorate the SLM fatigue performance
Effects of the endoparasitoid Cotesia chilonis (Hymenoptera: Braconidae) parasitism, venom, and calyx fluid on cellular and humoral immunity of its host Chilo suppressalis (Lepidoptera: Crambidae) larvae
AbstractThe larval endoparasitoid Cotesia chilonis injects venom and bracoviruses into its host Chilo suppressalis during oviposition. Here we study the effects of the polydnavirus (PDV)-carrying endoparasitoid C. chilonis (Hymenoptera: Braconidae) parasitism, venom and calyx fluid on host cellular and humoral immunity, specifically hemocyte composition, cellular spreading, encapsulation and melanization. Total hemocyte counts (THCs) were higher in parasitized larvae than in unparasitized larvae in the late stages following parasitization. While both plasmatocyte and granulocyte fractions and hemocyte mortality did not differ between parasitized and unparasitized hosts, in vitro spreading behavior of hemocytes was inhibited significantly by parasitism throughout the course of parasitoid development. C. chilonis parasitism suppressed the encapsulation response and melanization in the early stages. Venom alone did not alter cellular immune responses, including effects on THCs, mortality, hemocyte composition, cell spreading and encapsulation, but venom did inhibit humoral immunity by reducing melanization within 6h after injection. In contrast to venom, calyx fluid had a significant effect on cell spreading, encapsulation and melanization from 6h after injection. Dose–response injection studies indicated the effects of venom and calyx fluid synergized, showing a stronger and more persistent reduction in immune system responses than the effect of either injected alone
IGF-1/IGFBP-1 increases blastocyst formation and total blastocyst cell number in mouse embryo culture and facilitates the establishment of a stem-cell line
BACKGROUND: Apoptosis occurs frequently for blastocysts cultured in vitro, where conditions are suboptimal to those found in the natural environment. Insulin-like growth factor-1 (IGF-1) plays an important role in preventing apoptosis in the early development of the embryo, as well as in the progressive regulation of organ development. We hypothesize that IGF-1 and its dephosphorylated binding protein (IGFBP-1) may be able to improve embryo culture with an associated reduced cell death, and that the resultant increase in the total cell number of the embryo could increase the chances of establishing an embryonic stem-cell line. RESULTS: In vivo fertilized zygotes were cultured in medium containing supplementary IGF-1, or IGFBP-1/IGF-1. The stages of the resultant embryos were evaluated at noon on day five post-hCG injection. The extent of apoptosis and necrosis was evaluated using Annexin V and propidium iodine staining under fluorescent microscopy. The establishment of embryonic stem-cell lines was performed using the hatching blastocysts that were cultured in the presence of IGF-1 or IGFBP-1/IGF-1. The results show that the rate of blastocyst formation in a tissue-culture system in the presence of IGF-1 was 88.7% and IGFBP-1/IGF-1 it was 94.6%, respectively, and that it was significantly greater than the figure for the control group (81.9%). IGFBP-1/IGF-1 also resulted in a higher hatching rate than was the case for the control group (68.8% vs. 48.6% respectively). IGF-1 also increased the number of Annexin V-free and propidium iodine-free blastocysts in culture (86.8% vs. 75.9% respectively). Total cell number of blastocyst in culture was increased by 18.9% for those examples cultured with dephosphorylated IGFBP-1/IGF-1. For subsequent stem-cell culture, the chances of the successful establishment of a stem-cell line was increased for the IGF-1 and IGFBP-1/IGF-1 groups (IGF-1 vs. IGFBP-1/IGF-1 vs. control: 45.8% vs. 59.6% vs. 27.3% respectively). CONCLUSION: IGF-1 or dephosphorylated IGFBP-1/IGF-1 supplement does result in an anti-apoptotic effect for early embryo development in culture, with a subsequent increased total cell number resulting from cell culture. The effect is beneficial for the later establishment of a stem-cell line
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