1,704 research outputs found
Fabrikasi dan Pencirian Pencerai 3×3 Berasaskan Gentian Optik Polimer (POF) dengan Teknik Pelakuran Berkos Rendah
Gentian optik polimer (POF) mempunyai banyak kelebihan dan banyak digunakan untuk komunikasi terutamanya dalam industri automotif. Komunikasi ini memerlukan maklumat yang banyak dihantar pada satu masa dengan kos yang rendah. Untuk itu pencerai 3×3 POF yang berkonsepkan pemultipleks bahagi jarak gelombang (WDM) yang berkos rendah dan berteknologi hijau difabrikasikan. Pencerai POF ini difabrikasikan dengan menggunakan alat yang murah dan mudah didapati, iaitu tiub besi dan lilin. Teknik fabrikasi yang digunakan adalah dengan memanaskan tiga lembar POF sehingga bahagian tengahnya mencair dan melakur sehingga mengecil dan memanjang berdiameter 1 mm. Pencerai 3x3 POF yang berjaya difabrikasi dicirikan dengan mengukur kehilangan POF sebelum dan selepas hujungnya diratakan dan digilap dengan dua jenis kertas pasir yang berlainan darjah kekasaran. Ini untuk melihat kesan gilapan pada kehilangan isyarat optik. Kehilangan pencerai POF juga diukur pada suhu yang berbeza bagi melihat kesannya pada prestasi pencerai POF. Berdasarkan keputusan yang diperoleh, dapat dilihat bahawa kebersihan dan kerataan hujung POF memberi kesan kepada kehilangan dengan penurunan antara 0.3 hingga 5.0 dB. Suhu juga memberi kesan kepada kehilangan isyarat POF, walaupun tidak begitu ketara, dengan purata peningkatan kehilangan sebanyak 0.3 dB. Walaupun secara keseluruhannya nilai kehilangan dalam pencerai POF yang difabrikasi ini masih tinggi, prestasi ini dapat diperbaiki dengan penambahbaikan pada teknik pelakuran dan penggunaan alat yang lebih berkualiti. Teknik pemfabrikasi berkos rendah ini dipercayai boleh menghasilkan pencerai POF yang murah secara komersil, tetapi dengan kajian yang lebih mendalam pada teknik pelakuran, punca kehilangan dan cara meminimumkan kehilangan boleh diperoleh dan meningkatkan isyarat optik keluaran
Dynamical Autler-Townes control of a phase qubit
Routers, switches, and repeaters are essential components of modern
information-processing systems. Similar devices will be needed in future
superconducting quantum computers. In this work we investigate experimentally
the time evolution of Autler-Townes splitting in a superconducting phase qubit
under the application of a control tone resonantly coupled to the second
transition. A three-level model that includes independently determined
parameters for relaxation and dephasing gives excellent agreement with the
experiment. The results demonstrate that the qubit can be used as a ON/OFF
switch with 100 ns operating time-scale for the reflection/transmission of
photons coming from an applied probe microwave tone. The ON state is realized
when the control tone is sufficiently strong to generate an Autler-Townes
doublet, suppressing the absorption of the probe tone photons and resulting in
a maximum of transmission.Comment: 8 pages, 8 figure
Public Debt, Current Account Balance, and Fiscal Balance : The Threshold Effects in Selected ASEAN Countries
Indebtedness is a huge global issue faced by all economies around the world since the older time until today. The high and increasing debt levels have become a concern, and public debt has become the core of the turmoil that began a few years ago. When the government's spending in a year exceeds its revenue, there will be a budget deficit for that fiscal year. Hence, it must use debt to fill the funding gap. This situation creates an annual deficit, which cannot end until the accumulated debt becomes unsustainable and the government's finances collapse. Hence, this study is aimed to assess the impact of the public debt threshold on
current account balance and fiscal balance in selected ASEAN countries (Indonesia, Malaysia, Philippines, Singapore , Thailand, and Vietnam) by adopting annual data from 1990 to 2021. In panel long run estimation by pooled mean group (PMG) estimator, public debt affects twin balances to have a positive relationship. In the empirical analysis, the single threshold sample splitting model is employed to assess the impact of the public debt threshold on the current account balance and fiscal balance either below or above the threshold level. The outcomes indicate that the public debt threshold level is at 63.36%. When the public debt threshold is below 63.36%, there is a negative relationship between the current account balance and fiscal balance; whereas when the public debt threshold is higher than 63.36%, there is positive nexus between the current account balance and fiscal balance. This result implies the situation of twin divergence situation when exceeding the public debt threshold level
Current Account Imbalances in Asia’s Countries : The Contributing Elements
The current account has emerged as one of the primary indicators of external imbalances in the global economy, and it may be used to assess the strength of a nation's economy. Since the 1990s, it has been a prevalent trend for Asia region to always demonstrate a current account surplus condition and continue to reinforce in the early 2000s. Although it experiences a huge drop of current account balance in 2009 during the mortgage crisis period, the region persists in its current account surplus. Hence, the aim of this study is to assess the determinants of current account imbalances in Asia region. This study is a panel regression model that covered a total of 48 Asia countries from 1990 to 2021 annually. The dependent variable is current account balance and the independent variables are fiscal balance, public debt, age dependency ratio for old, age dependency ratio for young, ICT, and real GDP. The empirical methods that employed are including of panel unit root tests, panel cointegration tests, and pooled mean group (PMG) estimation. The major finding demonstrates that the determinants of current account imbalances are fiscal balance, public debt, age dependency ratio for old, age dependency ratio for young, and real GDP
Prognostic significance of a systemic inflammatory response in patients receiving first-line palliative chemotherapy for recurred or metastatic gastric cancer
<p>Abstract</p> <p>Background</p> <p>There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor prognosis in patients with advanced cancers. We evaluated the relationships between clinical status, laboratory factors and progression free survival (PFS), and overall survival (OS) in patients with recurrent or metastatic gastric cancer receiving first-line palliative chemotherapy.</p> <p>Methods</p> <p>We reviewed 402 patients with advanced gastric adenocarcinoma who received first-line palliative chemotherapy from June 2004 and December 2009. Various chemotherapy regimens were used. Eastern Cooperative Oncology Group performance status (ECOG PS), C-reactive protein (CRP), albumin, Glasgow prognostic score (GPS), and clinical factors were recorded immediately prior to first-line chemotherapy. Patients with both an elevated CRP (>1.0 mg/dL) and hypoalbuminemia (<3.5 mg/dL) were assigned a GPS of 2. Patients in whom only one of these biochemical abnormalities was present were assigned a GPS of 1, and patients with a normal CRP and albumin were assigned a score of 0. To evaluate the factors that affected PFS and OS, univariate and multivariate analyses were performed.</p> <p>Results</p> <p>According to multivariate analysis, the factors independently associated with PFS were ECOG PS (HR 1.37, 95% CI 1.02-1.84, <it>P </it>= 0.035), bone metastasis (HR 1.74, 95% CI 1.14-2.65, <it>P </it>= 0.009), and CRP elevation (HR 1.64, 95% CI 1.28-2.09, <it>P </it>= 0.001). The factors independently associated with OS were ECOG PS (HR 1.33, 95% CI 1.01-1.76, <it>P </it>= 0.037), bone metastasis (HR 1.61, 95% CI 1.08-2.39, <it>P </it>= 0.017), and GPS ≥ 1 (HR 1.76, 95% CI 1.41-2.19, <it>P </it>= 0.001).</p> <p>Conclusions</p> <p>The results of this study showed that the presence of a systemic inflammatory response as evidenced by the CRP, GPS was significantly associated with shorter PFS and OS in patients with recurrent or metastatic gastric cancer receiving first-line palliative chemotherapy. Bone metastasis and GPS were very useful indicator for survival in patients with recurrent or metastatic gastric cancer receiving palliative chemotherapy.</p
Absolute quantitative total-body small-animal SPECT with focusing pinholes
Purpose: In pinhole SPECT, attenuation of the photon flux on trajectories between source and pinholes affects quantitative accuracy of reconstructed images. Previously we introduced iterative methods that compensate for image degrading effects of detector and pinhole blurring, pinhole sensitivity and scatter for multi-pinhole SPECT. The aim of this paper is (1) to investigate the accuracy of the Chang algorithm in rodents and (2) to present a practical Changbased method using body outline contours obtained with optical cameras. Methods: Here we develop and experimentally validate a practical method for attenuation correction based on a Chang first-order method. This approach has the advantage that it is employed after, and therefore independently from, iterative reconstruction. Therefore, no new system matrix has to be calculated for each specific animal. Experiments with phantoms and animals were performed with a highresolution focusing multi-pinhole SPECT system (USPECT-II, MILabs, The Netherlands). This SPECT system provides three additional optical camera images of the animal for each SPECT scan from which the animal contour can be estimated. Results: Phantom experiments demonstrated that an average quantification error of –18.7% was reduced to –1.7% when both window-based scatter correction and Chang correction based on the body outline from optical images were applied. Without scatter and attenuation correction, quantification errors in a sacrificed rat containing sources with known activity ranged from –23.6 to –9.3%. These errors were reduced to values between –6.3 and +4.3% (with an average magnitude of 2.1%) after applying scatter and Chang attenuation correction. Conclusion: We conclude that the modified Chang correction based on body contour combined with window-based scatter correction is a practical method for obtaining small-animal SPECT images with high quantitative accuracy.Radiation, Radionuclides and ReactorsApplied Science
Graphene plasmonics
Two rich and vibrant fields of investigation, graphene physics and
plasmonics, strongly overlap. Not only does graphene possess intrinsic plasmons
that are tunable and adjustable, but a combination of graphene with noble-metal
nanostructures promises a variety of exciting applications for conventional
plasmonics. The versatility of graphene means that graphene-based plasmonics
may enable the manufacture of novel optical devices working in different
frequency ranges, from terahertz to the visible, with extremely high speed, low
driving voltage, low power consumption and compact sizes. Here we review the
field emerging at the intersection of graphene physics and plasmonics.Comment: Review article; 12 pages, 6 figures, 99 references (final version
available only at publisher's web site
Diabetes and pancreatic cancer survival: A prospective cohort-based study
BACKGROUND: Diabetes is a risk factor for pancreatic cancer but its association with survival from pancreatic cancer is poorly understood. Our objective was to investigate the association of diabetes with survival among pancreatic cancer patients in a prospective cohort-based study where diabetes history was ascertained before pancreatic cancer diagnosis. METHODS: We evaluated survival by baseline (1993–2001) self-reported diabetes history (n=62) among 504 participants that developed exocrine pancreatic cancer within the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were estimated using Cox proportional hazards model, adjusted for age, sex, body mass index, race, smoking, and tumour stage (local, locally advanced, and metastatic). RESULTS: The multivariable-adjusted HR for mortality comparing participants with diabetes to those without was 1.52 (95% CI=1.14–2.04, P-value <0.01). After excluding those diagnosed with pancreatic cancer within 3 years of study enrolment, HR for mortality among those with diabetes was 1.45 (95% CI=1.06–2.00, P-value=0.02). CONCLUSIONS: Using prospectively collected data, our findings indicate that diabetes is associated with worse survival among patients with pancreatic cancer
Cloning and characterization of XiR1, a locus responsible for dagger nematode resistance in grape
The dagger nematode, Xiphinemaindex, feeds aggressively on grape roots and in the process, vectors grapevine fanleaf virus (GFLV) leading to the severe viral disease known as fanleaf degeneration. Resistance to X. index and GFLV has been the key objective of grape rootstock breeding programs. A previous study found that resistance to X. index derived from Vitis arizonica was largely controlled by a major quantitative trait locus, XiR1 (X. index Resistance 1), located on chromosome 19. The study presented here develops high-resolution genetic and physical maps in an effort to identify the XiR1 gene(s). The mapping was carried out with 1,375 genotypes in three populations derived from D8909-15, a resistant selection from a cross of V. rupestris A. de Serres (susceptible) × V. arizonica b42-26 (resistant). Resistance to X. index was evaluated on 99 informative recombinants that were identified by screening the three populations with two markers flanking the XiR1 locus. The high-resolution genetic map of XiR1 was primarily constructed with seven DNA markers developed in this study. Physical mapping of XiR1 was accomplished by screening three bacterial artificial chromosome (BAC) libraries constructed from D8909-15, V. vinifera Cabernet Sauvignon and V. arizonica b42-26. A total of 32 BAC clones were identified and the XiR1 locus was delineated within a 115 kb region. Sequence analysis of three BAC clones identified putative nucleotide binding/leucine-rich repeat (NB-LRR) genes. This is the first report of a closely linked major gene locus responsible for ectoparasitic nematode resistance. The markers developed from this study are being used to expedite the breeding of resistant grape rootstocks
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