12 research outputs found
Aromatic Heterocyclic Organic Spacer Cation-Assisted Growth of Large-Grain-Size 2DRP Perovskite Film for Enhanced Solar Cell Performance
No full textOrganic spacer cations play an important role in the aggregation of two-dimensional Ruddlesden-Popper (2DRP) L'2Ln-1BnX3n+1 perovskite precursors. There-fore, it is necessary to study how mixed A' spacer cations affect the aggregation behavior of precursors and the carrier transport properties of 2DRP films. Herein, a novel spacer cation 4-pyridinylmethylammonium (PyA) is introduced to prepare a new mixed spacer cation 2DRP (BA(1-x)PyA(x))(2)MA(3)Pb(4)I(13) perovskite. The incorporation of PyA suppresses the precursor aggregation and reduces the transformation energy of the sol-gel to the directional three-dimensional phase, leading to the formation of large-grain-size 2DRP perovskite films. The PyA-based 2DRP perovskite exhibits efficient carrier transport owing to fewer defects and suppressed nonradiative recombination. Thus, the champion efficiency of 13.01% is achieved for BA-and PyA-based devices. The unencapsulated PyA-based devices maintain 98% of their initial efficiency after storage under nitrogen atmosphere for 1200 h. This work paves the way for preparing a large-grain-size 2DRP perovskite by suppressing precursor aggregation
Aromatic Heterocyclic Organic Spacer Cation-Assisted Growth of Large-Grain-Size 2DRP Perovskite Film for Enhanced Solar Cell Performance
No full textOrganic spacer cations play an important role in the
aggregation
of two-dimensional Ruddlesden–Popper (2DRP) L′2Ln–1BnX3n+1 perovskite precursors. Therefore,
it is necessary to study how mixed A′ spacer cations affect
the aggregation behavior of precursors and the carrier transport properties
of 2DRP films. Herein, a novel spacer cation 4-pyridinylmethylammonium
(PyA) is introduced to prepare a new mixed spacer cation 2DRP (BA1–xPyAx)2MA3Pb4I13 perovskite.
The incorporation of PyA suppresses the precursor aggregation and
reduces the transformation energy of the sol–gel to the directional
three-dimensional phase, leading to the formation of large-grain-size
2DRP perovskite films. The PyA-based 2DRP perovskite exhibits efficient
carrier transport owing to fewer defects and suppressed nonradiative
recombination. Thus, the champion efficiency of 13.01% is achieved
for BA- and PyA-based devices. The unencapsulated PyA-based devices
maintain 98% of their initial efficiency after storage under nitrogen
atmosphere for 1200 h. This work paves the way for preparing a large-grain-size
2DRP perovskite by suppressing precursor aggregation
One-dimensional Europium(III) coordination polymer based on 3-pyridylacrylic acid
No full textUnder hydrothermal conditions, the reaction of racemic 3-pyridyl-3- aminopropionic acid (rac-HPAPA) with Eu(ClO4)3· 6H2O affords a 1-D chain complex, [Eu(3-PYA)3(H 2O)]n (1) (3-PYA=3-pyridylacrylate), which represents an example of neutral 1-D coordination polymeric material based on 3-HPYA (HPYA= pyridylacrylic acid) ligand with strong red fluorescent emission in the solid state.link_to_subscribed_fulltex
Characterization of two acetyltransferase genes in the pyripyropene biosynthetic gene cluster from Penicillium coprobium
No full textPyripyropenes potently and selectively inhibit acyl-CoA:cholesterol acyltransferase 2 (ACAT-2). Among multiple isomers of pyripyropene (A to R), pyripyropene A (PyA) has insecticidal properties in addition to its growth inhibition properties against human umbilical vein endothelial cells. Based on the predicted biosynthetic gene cluster of pyripyropene A, two genes (ppb8 and ppb9) encoding two acetyltransferases (ATs) were separately isolated and introduced into the model fungus Aspergillus oryzae, using the protoplast-polyethylene glycol method. The bioconversion of certain predicted intermediates in the transformants revealed the manner by which acetylation occurred in the biosynthetic pathway by the products expressed by these two genes (AT-1 and AT-2). The acetylated products detected by high-performance liquid chromatography (HPLC) in the extracts from AT-1 and AT-2 transformant clones were not present in the extract from the transformant clone with an empty vector. The HLPC charts of each bioconversion study exhibited high peaks at 12, 10.5 and 9min, respectively. Further ultraviolet absorption and mass spectrometry analyses identified the products as PyE, PyO and PyA, respectively. AT-1 acetylated the C-1 of deacetyl-pyripyropene E (deAc-PyE), while AT-2 played an active role in acetylating the C-11 of 11-deAc-PyO and C-7 of deAc-PyA at two different steps of the biosynthetic pathway.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000348870100006&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Biotechnology & Applied MicrobiologySCI(E)[email protected]
The use of interdisciplinary seminars for the development of caring dispositions in nursing and social work students
No full textAuthor name used in this publication: Amy Ho Po-yingAuthor name used in this publication: Jenny Hui Man-chun2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishedPublisher permissio
The economic effects of minimum import prices : with an application to Uruguay
No full textBy increasing the costs of imports, minimum unit import reference prices not only generate the usual distortions one expects from tariff protection but add new ones that a pure tariff system would not generate. Reference prices substantially reduce the price gap between imports with prices above and below the reference price. By making cheap imports relatively more expensive than expensive imports, reference prices affect quality in three ways that appear not to have been analyzed before: 1) they can induce foreign firms to shift toward more expensive exports to the country with reference prices; 2) they can induce domestic producers in that country to shift production toward lower-quality, cheaper goods; and 3) because this decreases the relative price of the expensive varieties, domestic consumers may lean toward buying more expensive goods. Using the case of Uruguay, the authors estimate what protection the reference price procedures provide for Uruguayan industries and analyze how this protection affects Uruguay's economy. The authors show that the reference and minimum export price procedures impose floor prices on imports that cover more than a third of value added in Uruguayan manufacturing. These systems jeopardize trade liberalization efforts by creating the impression that tariff cuts are greater than they really are. These systems also create massive distortions between the relative domestic prices of imported goods above and below the floor prices.Environmental Economics&Policies,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Economic Theory&Research,Markets and Market Access,Access to Markets
Stable Porous Organic Polymers Used for Reversible Adsorption and Efficient Separation of Trace SO<sub>2</sub>
No full textThe development of porous solid adsorbents for selective
adsorption
and separation of SO2 has attracted much attention recently.
Herein, we design porous organic polymers (POPs) decorated with pyridine
ligands as building units (POP-Py) through a radical polymerization
of the 2,5-divinylpyridine (v-Py) monomer. Due to its high BET surface
area, nanoporosity, and excellent stability, the prepared POP-Py can
be used for reversible adsorption and efficient separation of SO2. The POP-Py possesses a SO2 capacity of 10.8 mmol
g–1 at 298 K and 1.0 bar, which can be well retained
after 6 recycles, showing an excellent reversible adsorption capacity.
The POP-Py also shows superior separation performance for SO2 from a ternary SO2/CO2/N2 mixture
(0.17/15/84.83v%), giving a breakthrough time and a saturated SO2 capacity at 178 min g–1 and 0.4 mmol g–1. The retention time was well maintained even under
high moisture conditions, confirming its superior water resistance.
Furthermore, when other vinyl-functionalized organic ligand monomers
(bipyridine, pyrimidine, and pyrazine) were employed for radical polymerization,
all of the resultant porous organic ligand polymers (POP-BPy, POP-PyI,
and POP-PyA) exhibited superior performance for reversible adsorption
and efficient separation of SO2. The combined features
of reversible adsorption, efficient separation, and water resistance
are important for the industrial applications of these materials as
SO2 adsorbents
[[alternative]]TNF-α/IFN-γ-induced iNOS expression increased by prostaglandin E2 in rat primary astrocytes via EP2-evoked cAMP/PKA and intracellular calcium signaling
No full text[[abstract]]Astrocytes, the most abundant glia in the central nervous system (CNS), produce a large amount of prostaglandin E-2 (PGE(2)) in response to proinflammatory mediators after CNS injury. However, it is unclear whether PGE2 has a regulatory role in astrocytic activity under the inflamed condition. In the present work, we showed that PGE2 increased inducible nitric oxide synthase (iNOS) production by tumor necrosis factor-et and interferon-gamma (T/I) in astrocytes. Pharmacological and RNA interference approaches further indicated the involvement of the receptor EP2 in PGE(2)-induced iNOS upregulation in T/I-treated astrocytes. Quantitative real-time polymerase chain reaction and gel mobility shift assays also demonstrated that PGE2 increased iNOS transcription through EP2-induced cAMP/protein kinase A (PYA)-dependent pathway. Consistently, the effect of EP2 was significantly attenuated by the PKA inhibitor KT-5720 and partially suppressed by the inhibitor (SB203580) of p38 mitogen-activated protein kinase (p38MAPK), which serves as one of the downstream components of the PKA-dependent pathway. Interestingly, EP2-mediated PKA signaling appeared to increase intracellular Ca2+ release through inositol triphosphate (IP3) receptor activation, which might in turn stimulate protein kinase C (PKC) activation to promote iNOS production in T/I-primed astrocytes. By analyzing the expression of astrocytic glial fibrillary acidic protein (GFAP), we found that PGE(2) alone only triggered the EP2-induced cAMP/PKA/p38MAPK signaling pathway in astrocytes. Collectively, PGE2 may enhance T/I-induced astrocytic activation by augmenting iNOS/NO production through EP2-mediated cross-talk between cAMP/PKA and IP3/Ca2+ signaling pathways
Research progress on sexual functioning and associated factors in childhood cancer survivors : a scoping review
No full text202504 bcrcVersion of RecordSelf-fundedPublishedC
An RT-PCR panel for rapid serotyping of dengue virus serotypes 1 to 4 in human serum and mosquito on a field-deployable PCR system
No full text[[abstract]]BACKGROUND: Dengue fever, a mosquito-borne disease, is caused by dengue virus (DENV) which includes four major serotypes (DENV-1, -2, -3, and -4). Some serotypes cause more severe diseases than the other; severe dengue is associated with secondary infections by a different serotype. Timely serotyping can provide early warning of dengue epidemics to improve management of patients and outbreaks. A mobile insulated isothermal PCR (iiPCR) system is available to allow molecular detection of pathogens near points of need. METHODOLOGY/PRINCIPLE FINDINGS: In this study, side-by-side comparison with the CDC DENV-1-4 Real Time RT-PCR (qRT-PCR) was performed to evaluate the performance of four singleplex DENV-1-4 serotyping reverse transcription-iiPCR (RT-iiPCR) reagents for DENV subtyping on the mobile PCR system. The four RT-iiPCRs did not react with Zika virus and chikungunya virus; tests with serial dilutions of the four DENV serotypes made in human serum showed they had detection endpoints comparable to those of the reference method, indicating great analytical sensitivity and specificity. Clinical performance of the RT-iiPCR reagents was evaluated by testing 40 serum samples each (around 20 target serotype-positive and 20 DENV-negative); all four reagents had high agreement (97.5-100%) with the reference qRT-PCR. Moreover, testing of mosquitoes separately infected experimentally with each serotype showed that the four reagents detected specifically their target DENV serotypes in mosquito. CONCLUSIONS/SIGNIFICANCE: With analytical and clinical performance comparable to the reference qRT-PCR assay, the four index RT-iiPCR reagents on the field-deployable PCR system can serve as a useful tool for DENV detection near points of needs
