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The aim of this research is to examine the dimensions of junior high school teachers? readiness for implementing a flipped classroom approach and to construct and validate an instrument?the Flipped-Classroom Teacher Scale (FCTS). Two sets of samples (170 and 495 junior high school teachers) served to explore and confirm the constructs of the FCTS model proposed by this study. The model has been empirically validated via exploratory factor analysis (EFA) and confirmatory factor analysis. The research participants were from different geographical locations in Taiwan. The FCTS consists of four factors: institutional support, technology self-efficacy (TSE), teacher beliefs and teaching strategies (TS). The results show that the FCTS model is a valid and reliable scale. Teachers may use the FCTS to gain a greater understanding of their instructional design and strategies in relation to flipped classrooms.

We are experiencing heavy COVID-19 outbroke globally since January 2020. In Taiwan, because its low infection rate (< 0.01%), there was not enough evidence for diagnosis through medical imaging. At present, chest X-ray is widely used in lung infection diagnoses. This study uses deep learning methods to assist doctors in classifying COVID-19 disease from chest X-ray images. After pre-processing, the images were put into the VGG16 model to automatically classify into three categories to assist the radiologist in the treatment of the disease. The results show that the classification accuracy was 78%. Detail analyses disclosed that this accuracy can be improved by rectifying the unbalanced images problem. In addition, choosing proper image pre-processing algorithms has a high tendency to generate better results.

Porcine circovirus type 3 (PCV3) is a newly emerging porcine circovirus that infects pig populations worldwide. In this study, we investigated the prevalence of PCV3 in Taiwan and analyzed the phylogenetic relationships between the Taiwanese PCV3 strains and those from other countries. A total of 463 clinical specimens from sick pigs were collected in 2016-2019 and analyzed for PCV3 by PCR. The positivity rate for PCV3 was 10.6% in 2016, increasing markedly to 34.78% in 2019. A phylogenetic analysis based on full-length genomic sequences of PCV3 divided the PCV3 strains into three clades, with the Taiwanese strains in clade 1.

Avian influenza virus (AIV) can cause severe diseases in poultry worldwide. H6N1 AIV was the dominant enzootic subtype in 1985 in the chicken farms of Taiwan until the initial outbreak of a low pathogenic avian influenza (LPAI) H5N2 virus in 2003; thereafter, this and other LPAIs have been sporadically detected. In 2015, the outbreak of three novel H5Nx viruses of highly pathogenic avian influenza (HPAI) emerged and devastated Taiwanese chicken and waterfowl industries. The mechanism of variation in pathogenicity among these viruses is unclear; but, in light of the many biological functions of viral non-structural protein 1 (NS1), including interferon (IFN) antagonist and host range determinant, we hypothesized that NS genetic diversity contributes to AIV pathogenesis. To determine the impact of NS1 variants on viral infection dynamics, we established a reverse genetics system with the genetic backbone of the enzootic Taiwanese H6N1 for generation of reassortant AIVs carrying exogenous NS segments of three different Taiwanese H5N2 strains. We observed distinct cellular distributions of NS1 among the reassortant viruses. Moreover, exchange of the NS segment significantly influenced growth kinetics and induction of cytokines [IFN-α, IFN-β, and tumor necrosis factor alpha (TNF-α)] in an NS1- and host-specific manner. The impact of NS1 variants on viral replication appears related to their synergic effects on viral RNA-dependent RNA polymerase activity and IFN response. With these approaches, we revealed that NS1 is a key factor responsible for the diverse characteristics of AIVs in Taiwan.

A high-power GaN-based light-emitting diode (LED) with an inductively coupled plasma (ICP)-transferred nanohemispherical hybrid backside reflector is studied. A self-assembled 100 ± 5 nm SiO2 nanosphere monolayer is drop-coated on the backside of a sapphire substrate as a mask to transfer nanohemispherical patterns onto the backside of the sapphire substrate by ICP. Nanohemispherical patterns could be transferred to the deposited backside reflector. Thus, reflected photons could be redirected and scattered into arbitrary directions for light extraction. As compared with a conventional LED without a backside reflector, at 350 mA, the studied device exhibits a 118.2% enhancement in light output power without the degradation of electrical properties. Note that the adhesion between an ICP-transferred sapphire substrate and the hybrid backside reflector is better than when directly inserting an SiO2 nanosphere monolayer in the device. Thus, the process yield could be enhanced for applying in the solid-state lighting.

It is usually believed that wall slip contributes small effects to macroscopic flow characteristics. Here we demonstrate that this is not the case for the thermocapillary migration of a long bubble in a slippery tube. We show that a fraction of the wall slip, with the slip length $\lambda $ much smaller than the tube radius $R$, can make the bubble migrate much faster than without wall slip. This speedup effect occurs in the strong-slip regime where the film thickness $b$ is smaller than $\lambda $ when the Marangoni number $S= \tau _{T} R/\sigma _{0}~ (\ll 1)$ is below the critical value $S^* \sim (\lambda /R)^{1/2}$, where $\tau _{T}$ is the driving thermal stress and $\sigma _{0}$ is the surface tension. The resulting bubble migration speed is found to be $U_{b} \sim (\sigma _{0}/\mu )S^{3}(\lambda /R)$, which can be more than a hundred times faster than the no-slip result $U_{b} \sim (\sigma _{0}/\mu )S^{5}$ (Wilson, J. Eng. Math., vol. 29, 1995, pp. 205–217; Mazouchi & Homsy, Phys. Fluids, vol. 12, 2000, pp. 542–549), with $\mu $ being the fluid viscosity. The change from the fifth power law to the cubic one also indicates a transition from the no-slip state to the strong-slip state, albeit the film thickness always scales as $b\sim RS^{2}$. The formal lubrication analysis and numerical results confirm the above findings. Our results in different slip regimes are shown to be equivalent to those for the Bretherton problem (Liao, Li & Wei, Phys. Rev. Lett., vol. 111, 2013, 136001). Extension to polygonal tubes and connection to experiments are also made. It is found that the slight discrepancy between experiment (Lajeunesse & Homsy, Phys. Fluids, vol. 15, 2003, pp. 308–314) and theory (Mazouchi & Homsy, Phys. Fluids, vol. 13, 2001, pp. 1594–1600) can be interpreted by including wall slip effects.

Enhanced light extraction efficiency (LEE) of high-power GaN-based light-emitting diodes (LEDs) is achieved by inserting a self-assembled SiO2 nanosphere monolayer between the substrate and backside reflectors. Due to the presence of concave surfaces and photonic crystal-like air voids, downward photons emitted from multiple quantum well toward 3-D backside reflectors, could be reflected, scattered, and redirected into arbitrary directions for light extraction. These textured 3-D backside reflectors with an SiO2 nanosphere monolayer could also extract the lateral light inside device into the normal direction and improve LEE. As compared with a conventional LED without a backside reflector and an LED with a planar hybrid backside reflector, at 350 mA, the studied device with a 3-D hybrid backside reflector exhibits 136.4% (165%) and 23.6% (27.4%) enhancements in light output power (luminous flux) without the degradation of electrical properties. Higher light intensities in light emission mapping image and far-field pattern are also obtained. These results show that a textured 3-D backside reflector could be easily formed by inserting an SiO2 nanosphere monolayer to significantly enhance the performance of high-power GaN-based LEDs.

A series of cobalt(III) complexes of the potent DNA minor groove alkylator (1-(chloromethyl)-5-hydroxy-1H-pyrrolo[3,2-f]quinolin-3(2H)-yl)(5,6,7-trimethoxy-1H-indol-2-yl)methanone (3; seco-CPyI-TMI), with cyclam or cyclen auxiliary ligands (L3 and L5) containing a cross-bridging ethylene (CH2CH2) group or the N,N'-dimethyl derivatives of these (L4 and L6), was prepared. Two 8-quinolinato (2) model complexes of these, [Co(L3)(2)](ClO4)2 and [Co(L6)(2)](ClO4)2, and the aquated derivative [Co(L6)(H2O)2](OTf)3 were characterized by X-ray crystallography. Electrochemistry of the 8-quinolinato model complexes showed that the Co(III)/(II) reduction potential was lowered relative to the unsubstituted cyclen ligand. Evaluation of the cytotoxicity of the racemic seco-CPyI cobalt complexes in vitro showed considerable attenuation of their cytotoxicity relative to the free alkylator and marked hypoxic selectivity, especially [Co(L3)(3)](2+) (9), which was 81-212-fold more potent under hypoxia than 20% oxygen in a panel of 10 human tumor cell lines. However, 9 did not elicit significant killing of hypoxic cells in HT29 tumor xenografts, suggesting possible pharmacological limitations in vivo.

A salt-inclusion mixed-valence uranium(V,VI) silicate, [Na9F2][(U(V)O2)(U(VI)O2)2(Si2O7)2], was synthesized under hydrothermal conditions at 585 °C and 160 MPa and structurally characterized by powder and single-crystal X-ray diffraction (XRD). The valence states of uranium were established by U 4f X-ray photoelectron spectroscopy (XPS). The structure contains two-dimensional (2D) sheets of uranyl disilicate with the composition [UO2Si2O7], which are connected by U(1)(V)O6 tetragonal bipyramids to form thick layers. The Na(+) cations are located at sites in the intralayer and interlayer regions. In addition to Na(+) cations, the interlayer region also contains F(-) anions such that infinite chains with the formula FNa1/1Na4/2 are formed. The same type of chain was observed in K2SnO3. The title compound is not only the first example of salt-inclusion metal silicate synthesized under high-temperature, high-pressure hydrothermal conditions, as well as the first salt-inclusion mixed-valence uranium silicate, but it is also the first mixed-valence uranium(V,VI) silicate in the literature. Crystal data: [Na9F2][(U(V)O2)(U(VI)O2)2(Si2O7)2], triclinic, P1 (No. 2), a = 5.789(1) A, b = 7.423(2) A, c = 12.092(2) A, α = 90.75(3)°, β = 96.09(3)°, γ = 90.90(3)°, V = 516.5(2) A(3), Z = 1, R1 = 0.0241, and wR2 = 0.0612.

Some physical factors including initial pH of medium, cultivation temperature and shaking speed as well as reuse affecting the production of cholesterol oxidase (CholOx) in reactors containing calcium alginate-immobilized cells of Rhodococcus equi No. 23 were investigated. Results revealed that the free cells showed the maximum CholOx in the culture with an initial pH of 5.0, while culture inoculated with immobilized cells exhibited a broad pH range, 6.0–9.0, for maximum CholOx production. The immobilized and free cells produced the maximum CholOx in the culture incubated at 30 and 25°C, respectively. The CholOx production decreased upon increasing the cultivation temperature. Increasing CholOx activity was also noted for both immobilized and free cells of R. equi No. 23 in the culture with increasing shaking speed. Under the optimal culture conditions, that were established, a higher maximum CholOx production of 0.94 unit/ml was found for immobilized R. equi No. 23 compared to that of 0.84 unit/ml for free cells after 48 h of cultivation. Furthermore, no gel leakage was noted after re-use of the calcium alginate-immobilized R. equi No. 23 for seven consecutive 48 h batch culture. The CholOx production in the seventh cycle was about 60.4% of that obtained in the first cycle.

An interesting approach to improving the light extraction efficiency of high-power GaN-based light-emitting diodes (LEDs) by the use of a 3-D-photonic crystal (3-D-PhC) backside reflector is studied. A 3-D-PhC backside reflector is formed by coating a self-assembled SiO2 nanosphere monolayer between the hybrid reflector and backside of a sapphire substrate. The 3-D-PhC structure is used to enhance light scattering. At 350 mA, as compared with a conventional LED (with a hybrid reflector while only without the 3-D-PhC structure), the studied device exhibits 23.6% enhancement in the light output power without the degradation of electrical properties. Therefore, the performance of high-power GaN-based LEDs could be further improved by using a 3-D-PhC backside reflector.

The isotypic compounds (III) and (V) are characterized by single crystal XRD, UV/VIS spectroscopy, and XPS.

A uranium(IV) phosphate, Na10U2P6O24, was synthesized under hydrothermal conditions at 570 °C and 160 MPa and structurally characterized by single-crystal X-ray diffraction. The valence state of uranium was established by UV-vis and U 4f X-ray photoelectron spectroscopy. The powder sample has a second-harmonic-generation signal, confirming the absence of a center of symmetry in the structure. The structure contains UO8 snub-disphenoidal polyhedra that are linked to monophosphate tetrahedra by vertex and edge sharing such that a three-dimensional framework with intersecting 12-sided circular and rectangular channels is formed. All 10 sodium sites are situated inside the channels and are fully occupied. This is the first uranium(IV) phosphate synthesized under high-temperature, high-pressure hydrothermal conditions. The isotypic cerium(IV) phosphate, Na10Ce2P6O24, was also synthesized under the same hydrothermal conditions. It is the first structurally characterized Ce(IV) phosphate with a P/Ce ratio of 3. Crystal data of Na10U2P6O24: orthorhombic, P212121 (No. 19), a = 6.9289(3) Å, b = 16.1850(7) Å, c = 18.7285(7) Å, V = 2100.3(2) Å(3), Z = 4, R1 = 0.0304, and wR2 = 0.0522. Crystal data of Na10Ce2P6O24: orthorhombic, P2(1)2(1)2(1) (No. 19), a = 6.9375(14) Å, b = 16.215(3) Å, c = 18.765(4) Å, V = 2111.0(7) Å(3), Z = 4, R1 = 0.0202, and wR2 = 0.0529.

The title compound is hydrothermally synthesized from an aqueous mixture of UO3, NaOH, NaF, Na2HPO4, and Na2SiO3 in a molar ratio of Na:F:U:P:Si = 39:5:1:2:10 (autoclave, 160 MPa, 585 °C, 2 d, 71% yield).

A salt-inclusion mixed-valence uranium(V,VI) silicate, [Na9F2][(U(V)O2)(U(VI)O2)2(Si2O7)2], was synthesized under hydrothermal conditions at 585 °C and 160 MPa and structurally characterized by powder and single-crystal X-ray diffraction (XRD). The valence states of uranium were established by U 4f X-ray photoelectron spectroscopy (XPS). The structure contains two-dimensional (2D) sheets of uranyl disilicate with the composition [UO2Si2O7], which are connected by U(1)(V)O6 tetragonal bipyramids to form thick layers. The Na(+) cations are located at sites in the intralayer and interlayer regions. In addition to Na(+) cations, the interlayer region also contains F(-) anions such that infinite chains with the formula FNa1/1Na4/2 are formed. The same type of chain was observed in K2SnO3. The title compound is not only the first example of salt-inclusion metal silicate synthesized under high-temperature, high-pressure hydrothermal conditions, as well as the first salt-inclusion mixed-valence uranium silicate, but it is also the first mixed-valence uranium(V,VI) silicate in the literature. Crystal data: [Na9F2][(U(V)O2)(U(VI)O2)2(Si2O7)2], triclinic, P1 (No. 2), a = 5.789(1) Å, b = 7.423(2) Å, c = 12.092(2) Å, α = 90.75(3)°, β = 96.09(3)°, γ = 90.90(3)°, V = 516.5(2) Å(3), Z = 1, R1 = 0.0241, and wR2 = 0.0612.

Knowing the critical velocity (ucrit) of a chromatography column is an important part of process development as it allows the optimization of chromatographic flow conditions. The conventional flow step method for determining ucrit is prone to error as it depends heavily on human judgment. In this study, two automated methods for determining ucrit have been developed: the automatic flow step (AFS) method and the automatic pressure step (APS) method. In the AFS method, the column pressure drop is monitored upon application of automated incremental increases in flow velocity, whereas in the APS method the flow velocity is monitored upon application of automated incremental increases in pressure drop. The APS method emerged as the one with the higher levels of accuracy, efficiency and ease of application having the greater potential to assist defining the best operational parameters of a chromatography column. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012

A series of cobalt complexes of the potent DNA minor groove alkylator 1-(chloromethyl)-3-(5,6,7-trimethoxyindol-2-ylcarbonyl)-2,3-dihydro-1H-pyrrolo[3,2-f]quinolin-5-ol (seco-6-azaCBI-TMI) were prepared from a series of N-substituted cyclen ligands. The final N-substituted complexes carried formal overall charges ranging from +2 to −2 and showed limited improvements in solubility. They showed similar stabilities to that of the complex with the unsubstituted cyclen ligand, and large but variable attenuation of the cytotoxicity of the free alkylator (2–30-fold), compared to 150-fold for the unsubstituted ligand. However, they had oxic/hypoxic ratios (2–22-fold) comparable to that of the unsubstituted cyclen complex (5).

New ligands H(2)L2-H(2)L6 comprise the cyclen macrocycle which is N,N'-dialkylated at the 1,7-nitrogen atoms by three- and four-carbon alkyl chains bearing terminal sulfonic (C(3) H(2)L2), phosphonic (C(3) H(2)L3, C(4) H(2)L4) or carboxylic acid (C(3) H(2)L5, C(4) H(2)L6) groups, and HL7 is N-monoalkylated by a four-carbon sulfonic acid group. The ligands were prepared by alkylation of a bridged bisaminal intermediate. The syntheses of cobalt(III) complexes containing a tetradentate cyclen, N,N'-1,7-Me(2)cyclen, cyclam or L2-L7 ligand together with the bidentate 8-quinolinato (8QO(-)) ligand, of interest as it is a model for a more potent cytotoxic analogue, were investigated. Coordination of ligands (L) cyclen, N,N'-1,7-Me(2)cyclen or cyclam to cobalt(III) was achieved using Na(3)[Co(NO(6))] to form [Co(L)(NO(2))(2)](+). HOTf (trifluoromethansulfonic acid) was used to prepare the triflato complexes [Co(L)(OTf)(2)](+), followed by substitution of the labile triflato ligands to yield [Co(L)(8QO)](ClO(4))(2) isolated as the perchlorate salts. One further example containing cyclam and the 5-hydroxymethyl-8-quinolinato ligand was also prepared by this method. Complexes containing the pendant arm ligands L2-L6 were prepared from the cobalt precursor trans-[Co(py)(4)Cl(2)](+). Reaction of this complex with H(2)L2·4HCl and 8QOH produced [Co(L2)(8QO)] in one step and contains two deprotonated sulfonato pendant arms. The reaction of H(2)L3·4HBr with [Co(py)(4)Cl(2)](+) gave [Co(L3)]Cl in which L3 acts as a hexadenate ligand with the three-carbon phosphonato side chains coordinated to cobalt. H(2)L5·4HCl bearing three-carbon carboxylic acid pendant arms gave a similar result. The four-carbon ligands were coordinated to cobalt by reaction of [Co(py)(4)Cl(2)](+) with H(2)L4·4HBr or H(2)L6·4HCl to give [Co(HL4)Cl(2)] or [Co(H(2)L6)Cl(2)]Cl, which in turn with 8QOH gave the 8QO(-) complexes [Co(L4)(8QO)] bearing anionic phosphate pendant arms or [Co(H(2)L6)(8QO)]Cl(2) containing neutral carboxylic acid side chains. The reaction of Na(3)[Co(CO(3))(3)] with the mono-N-alkylated ligand HL7·4HCl and then HOTf gave [Co(L7)(CO(3))] and then in turn [Co(L7)(OTf)(2)]. The carbonato complex [Co(L7)(CO(3))] with [8QO](2)[SO(4)] produced [Co(L7)(CO(3))]. All complexes containing L7 bear an anionic sulfonato group on the side chain. The synthesis and characterisation of the six new ligands based on N-alkylated cylen ligand and the cobalt complexes outlined above are described, along with cyclic voltammograms of the 8QO(-) complexes and the molecular structures determined by X-ray crystallography of [Co(cyclen)(H(2)O)(2)](OTf)(3) (formed by aquation of the triflato complex), [Co(cyclen)(8QO)](ClO(4))(2), Co(L2)(8QO)·2H(2)O, Co(L4)(8QO)·6H(2)O and [Co(H(2)L6)Cl(2)]Cl·H(2)O. These demonstrate the coordination of the cyclen ligand in the folded anti-O,syn-N configuration with the N-alkylated nitrogens occupying apical positions.

A series of metal complexes were prepared as potential prodrugs of the extremely toxic DNA minor groove alkylator 1-(chloromethyl)-5-hydroxy-3-[(5,6,7-trimethoxyindol-2-yl)carbonyl]-2,3-dihydro-1H-pyrrolo[3,2-f]quinoline (seco-6-azaCBI-TMI) and close analogues. The pyrrolo[3,2-f]quinoline cytotoxins were prepared from 2-methoxy-4-nitroaniline in a nine-step synthesis involving a Skraup construction of a quinoline intermediate, its appropriate functionalization, and a final radical cyclization. The metal complexes were prepared from these and the labile metal complex synthons [Co(cyclen)(OTf)(2)](+), [Cr(acac)(2)(H(2)O)(2)](+), and [Co(2)(Me(2)dtc)(5)](+). The cobalt complexes were considerably more stable than the free effectors and showed significant attenuation of the cytotoxicity of the latter, with IC(50) ratios (complex/effector) of 50- to 150-fold, and substantial hypoxic cell selectivity, with IC(50) ratios (oxic/hypoxic cells) of 20- to 40-fold. The cobalt complexes were also efficiently activated by ionizing radiation, with G values for loss of the compound close to the theoretical value for one-electron reduction of 0.68 micromol/J. This work extends earlier observations that cobalt cyclen complexes are suitable for both the bioreductive and radiolytic release of potent pyrrolo[3,2-f]quinoline effectors.

Rhodococcus equi No. 23 was immobilized in calcium alginate. No detrimental effect on the viability of the test organism was observed during the immobilization procedure. Approx. 98% of the cell population originally present in the alginate solution were immobilized in the gel beads. When the cells of an equal volume of the culture, obtained respectively at exponential phase (12 h preculture), late-exponential phase (20 h preculture) or stationary phase (36 h preculture) were immobilized, the gel beads prepared with the stationary-phase culture were found to contain the highest cell population [about 10(8) colony-forming units (CFU)/g of beads]. In addition, gel beads, prepared with late-exponential-phase culture, exhibited the highest production of cholesterol oxidase (CholOx) after 48 h of incubation. Increasing the bead mass from 3.5 to 14.0 g/100 ml of medium increased CholOx production. However, further increasing the bead mass resulted in a reduction of CholOx production. Furthermore, on the basis of a similar initial cell population, the alginate-immobilized cells of R. equi No. 23 produced a significantly higher amount of CholOx (P