2,860 research outputs found
Supersymmetric Radion in the Randall-Sundrum Scenario
We derive the effective action for the radion supermultiplet in the
supersymmetric Randall-Sundrum model with two opposite tension branes.Comment: Latex, 15 pages. Published versio
Topological Properties of Spatial Coherence Function
Topology of the spatial coherence function is considered in details. The
phase singularity (coherence vortices) structures of coherence function are
classified by Hopf index and Brouwer degree in topology. The coherence flux
quantization and the linking of the closed coherence vortices are also studied
from the topological properties of the spatial coherence function.Comment: 9 page
Enhanced Photodetection in Graphene-Integrated Photonic Crystal Cavity
We demonstrate the controlled enhancement of photoresponsivity in a graphene
photodetector by coupling to slow light modes in a long photonic crystal linear
defect cavity. Near the Brillouin zone (BZ) boundary, spectral coupling of
multiple cavity modes results in broad-band photocurrent enhancement from 1530
nm to 1540 nm. Away from the BZ boundary, individual cavity resonances enhance
the photocurrent eight-fold in narrow resonant peaks. Optimization of the
photocurrent via critical coupling of the incident field with the
graphene-cavity system is discussed. The enhanced photocurrent demonstrates the
feasibility of a wavelength-scale graphene photodetector for efficient
photodetection with high spectral selectivity and broadband response
Lab studies of gas compositions on coal outburst
Coal and gas outburst remains one of the most severe dynamic hazards to many underground coal mining operations worldwide, posing great threats to mine safety and productivity. To understand the influence of gas composition on coal and gas outburst propensity, bulk coal samples were collected from underground coal mine sites in NSW and QLD, and subjected to experimental studies. Isotherm adsorption experiments were carried out using the gravimetric isotherm testing method to investigate the impact of coal seam gas composition on gas adsorption characteristics with a range of coal sample particle sizes, to a maximum gas pressure of 4 MPa, at 35°C. The seam gas composition employed in the tests included 100% CH4, a gas mixture of 50% CH4 and 50% CO2, and 100% CO2. For all test coal samples of different particle sizes, the adsorption capacity of CO2 was observed to be the highest, followed by the CO2/CH4 mixture and CH4. For a given gas content, the equilibrium gas pressure of a CH4 rich coal sample is significantly greater than the equivalent CO2 rich coal sample. Given that gas pressure provides energy to induce outbursts, it is reasonable to suggest that CH4 rich coal contains greater outburst initiating energy. Hysteresis occurs during the CH4 and CO2 sorption and is calculated by an improved hysteresis index (IHI) method. CO2 sorption hysteresis is more significant than CH4 sorption hysteresis, with the ratio of IHI_CO2/IHI_CH4 ranging between 1.50 and 2.25. At equivalent adsorption gas content, the amount of CO2 desorption is less than that of CH4, making it difficult to provide sufficient supply of desorption gas, resulting in low gas desorption energy, which is less conducive to the development of outburst. The research results can provide useful theoretical support for mine site gas management in underground coal mines, particularly those operating in areas with moderate to high composition of CO2 seam gas
Traditional Open-bay Versus Single-family Room Neonatal Intensive Care Unit: a Comparison of Selected nutrition Outcomes
Background: In contrast to the traditional open-bay–type design of the neonatal intensive care unit (tNICU), infants in developmentally appropriate NICU (dNICU) are housed in individual rooms with greater control of light and noise. Previous reports have documented positive influence of the dNICU in cardiorespiratory status, physiologic stability, and weight gain of the infants. The objective of this study was to explore selected nutrition outcomes of infants in the dNICU versus tNICU. Method: A prospective cohort study was conducted on infants with birth weight of 1500 g or less cared for in dNICU (n = 42) or tNICU (n = 31). Differences between days to reach full parenteral nutrition, full enteral nutrition, or full bottling were determined using analysis of covariance controlling for gestational age, birth weight, and clinical risk index for babies (CRIB) acuity score. Results: There were no differences between the two groups in days to reach full parenteral and bottle feeding. The infants in the dNICU took fewer days to reach full enteral nutrition (20.8 days, 95% confidence intervals [CI]: 17, 24.6 (dNICU) vs 23.3 days, 95% CI: 17.1, 29.6 (tNICU), P = 0.04) than those in the tNICU. Conclusions: Although the two groups of infants only differed in the days to reach full enteral feeding, it is important to remember that the lack of difference may be clinically significant. Clinically, the infants in the dNICU were younger (gestational age) and sicker (CRIB acuity score) than the infants in the tNICU. Consequently, the results of this study support the change to dNICU, as the private room model provides a supportive environment for growth as evidenced by similar nutritional outcome measures. More research is needed to determine the effect of the dNICU on nutrition outcomes
The Anti-Sigma Factor MucA of Pseudomonas aeruginosa: Dramatic Differences of a mucA22 vs. a ΔmucA Mutant in Anaerobic Acidified Nitrite Sensitivity of Planktonic and Biofilm Bacteria in vitro and During Chronic Murine Lung Infection
Mucoid mucA22 Pseudomonas aeruginosa (PA) is an opportunistic lung pathogen of cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) patients that is highly sensitive to acidified nitrite (A-NO2-). In this study, we first screened PA mutant strains for sensitivity or resistance to 20 mM A-NO2- under anaerobic conditions that represent the chronic stages of the aforementioned diseases. Mutants found to be sensitive to A-NO2- included PA0964 (pmpR, PQS biosynthesis), PA4455 (probable ABC transporter permease), katA (major catalase, KatA) and rhlR (quorum sensing regulator). In contrast, mutants lacking PA0450 (a putative phosphate transporter) and PA1505 (moaA2) were A-NO2- resistant. However, we were puzzled when we discovered that mucA22 mutant bacteria, a frequently isolated mucA allele in CF and to a lesser extent COPD, were more sensitive to A-NO2- than a truncated ΔmucA deletion (Δ157–194) mutant in planktonic and biofilm culture, as well as during a chronic murine lung infection. Subsequent transcriptional profiling of anaerobic, A-NO2--treated bacteria revealed restoration of near wild-type transcript levels of protective NO2- and nitric oxide (NO) reductase (nirS and norCB, respectively) in the ΔmucA mutant in contrast to extremely low levels in the A-NO2--sensitive mucA22 mutant. Proteins that were S-nitrosylated by NO derived from A-NO2- reduction in the sensitive mucA22 strain were those involved in anaerobic respiration (NirQ, NirS), pyruvate fermentation (UspK), global gene regulation (Vfr), the TCA cycle (succinate dehydrogenase, SdhB) and several double mutants were even more sensitive to A-NO2-. Bioinformatic-based data point to future studies designed to elucidate potential cellular binding partners for MucA and MucA22. Given that A-NO2- is a potentially viable treatment strategy to combat PA and other infections, this study offers novel developments as to how clinicians might better treat problematic PA infections in COPD and CF airway diseases
Topology of Knotted Optical Vortices
Optical vortices as topological objects exist ubiquitously in nature. In this
paper, by making use of the -mapping topological current theory, we
investigate the topology in the closed and knotted optical vortices. The
topological inner structure of the optical vortices are obtained, and the
linking of the knotted optical vortices is also given.Comment: 11 pages, no figures, accepted by Commun. Theor. Phys. (Beijing, P.
R. China
Jiedu Tongluo granules ameliorates post-stroke depression rat model via regulating NMDAR/BDNF signaling pathway
Post-stroke depression (PSD) is one of the most common stroke complications, which seriously affects stroke’s therapeutic effect and brings great pain for patients. The pathological mechanism of PSD has not been revealed. Jiedu Tongluo granules (JDTLG) is an effective traditional Chinese medicine for PSD treatment which is widely used in clinical treatment. JDTLG has a significant therapeutic effect against PSD, but the mechanism is still unclear. The PSD rat model was established by carotid artery embolization combined with chronic sleep deprivation followed by treating with JDTLG. Neurobehavioral and neurofunctional experiments were engaged in studying the neural function of rats. Histomorphology, proteomics, and western blotting researches were performed to investigate the potential molecular mechanisms related to JDTLG therapy. Oral treatment of JDTLG could significantly improve the symptoms of neurological deficit and depression symptoms of PSD rats. Proteomic analysis identified several processes that may involve the regulation of JDTLG on the PSD animal model, including energy metabolism, nervous system, and N-methyl-D-aspartate receptor (NMDAR)/brain-derived neurotrophic factor (BDNF) signal pathway. Our results showed that JDTLG could reduce glutamate (Glu) level and increase gamma-aminobutyric acid (GABA) level via regulating the NMDAR/BDNF pathway, which may play a vital role in the occurrence and development of PSD
Knotted Topological Phase Singularities of Electromagnetic Field
In this paper, knotted objects (RS vortices) in the theory of topological
phase singularity in electromagnetic field have been investigated in details.
By using the -mapping topological current theory proposed by Prof. Duan,
we rewrite the topological current form of RS vortices and use this topological
current we reveal that the Hopf invariant of RS vortices is just the sum of the
linking and self-linking numbers of the knotted RS vortices. Furthermore, the
conservation of the Hopf invariant in the splitting, the mergence and the
intersection processes of knotted RS vortices is also discussed.Comment: 6 pages, no figures, author's name have been correcte
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